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[Qemu-arm] [PATCH v5 1/1] target/arm/helper: Move M profile routines to
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From: |
Philippe Mathieu-Daudé |
|
Subject: |
[Qemu-arm] [PATCH v5 1/1] target/arm/helper: Move M profile routines to m_helper.c |
|
Date: |
Tue, 2 Jul 2019 16:43:35 +0200 |
In preparation for supporting TCG disablement on ARM, we move most
of TCG related v7m/v8m helpers and APIs into their own file.
Note: It is easier to review this commit using the 'histogram'
diff algorithm:
$ git diff --diff-algorithm=histogram ...
or
$ git diff --histogram ...
Suggested-by: Samuel Ortiz <address@hidden>
Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
patch generated with git diff --histogram.
v4: rebased
v5:
- compile m_helper.o inconditionally (Kconfig change missing)
- keep arm_cpu_get_phys_page_attrs_debug (incorrectly rebased)
---
target/arm/Makefile.objs | 1 +
target/arm/helper.c | 2638 +------------------------------------
target/arm/m_helper.c | 2676 ++++++++++++++++++++++++++++++++++++++
3 files changed, 2681 insertions(+), 2634 deletions(-)
create mode 100644 target/arm/m_helper.c
diff --git a/target/arm/Makefile.objs b/target/arm/Makefile.objs
index 82bedefc3d..5cafc1eb6c 100644
--- a/target/arm/Makefile.objs
+++ b/target/arm/Makefile.objs
@@ -36,6 +36,7 @@ obj-y += tlb_helper.o debug_helper.o
obj-y += translate.o op_helper.o
obj-y += crypto_helper.o
obj-y += iwmmxt_helper.o vec_helper.o neon_helper.o
+obj-y += m_helper.o
obj-$(CONFIG_SOFTMMU) += psci.o
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6d91e0a1f9..c4349b5d56 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -19,7 +19,6 @@
#include "qemu/crc32c.h"
#include "qemu/qemu-print.h"
#include "exec/exec-all.h"
-#include "exec/cpu_ldst.h"
#include <zlib.h> /* For crc32 */
#include "hw/semihosting/semihost.h"
#include "sysemu/cpus.h"
@@ -30,6 +29,7 @@
#include "qemu/guest-random.h"
#ifdef CONFIG_TCG
#include "arm_ldst.h"
+#include "exec/cpu_ldst.h"
#endif
#define ARM_CPU_FREQ 1000000000 /* FIXME: 1 GHz, should be configurable */
@@ -7457,75 +7457,6 @@ uint32_t HELPER(rbit)(uint32_t x)
#ifdef CONFIG_USER_ONLY
-/* These should probably raise undefined insn exceptions. */
-void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val)
-{
- ARMCPU *cpu = env_archcpu(env);
-
- cpu_abort(CPU(cpu), "v7m_msr %d\n", reg);
-}
-
-uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
-{
- ARMCPU *cpu = env_archcpu(env);
-
- cpu_abort(CPU(cpu), "v7m_mrs %d\n", reg);
- return 0;
-}
-
-void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest)
-{
- /* translate.c should never generate calls here in user-only mode */
- g_assert_not_reached();
-}
-
-void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest)
-{
- /* translate.c should never generate calls here in user-only mode */
- g_assert_not_reached();
-}
-
-void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
-{
- /* translate.c should never generate calls here in user-only mode */
- g_assert_not_reached();
-}
-
-void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
-{
- /* translate.c should never generate calls here in user-only mode */
- g_assert_not_reached();
-}
-
-void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr)
-{
- /* translate.c should never generate calls here in user-only mode */
- g_assert_not_reached();
-}
-
-uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
-{
- /*
- * The TT instructions can be used by unprivileged code, but in
- * user-only emulation we don't have the MPU.
- * Luckily since we know we are NonSecure unprivileged (and that in
- * turn means that the A flag wasn't specified), all the bits in the
- * register must be zero:
- * IREGION: 0 because IRVALID is 0
- * IRVALID: 0 because NS
- * S: 0 because NS
- * NSRW: 0 because NS
- * NSR: 0 because NS
- * RW: 0 because unpriv and A flag not set
- * R: 0 because unpriv and A flag not set
- * SRVALID: 0 because NS
- * MRVALID: 0 because unpriv and A flag not set
- * SREGION: 0 becaus SRVALID is 0
- * MREGION: 0 because MRVALID is 0
- */
- return 0;
-}
-
static void switch_mode(CPUARMState *env, int mode)
{
ARMCPU *cpu = env_archcpu(env);
@@ -7720,2078 +7651,6 @@ void arm_log_exception(int idx)
}
}
-/*
- * What kind of stack write are we doing? This affects how exceptions
- * generated during the stacking are treated.
- */
-typedef enum StackingMode {
- STACK_NORMAL,
- STACK_IGNFAULTS,
- STACK_LAZYFP,
-} StackingMode;
-
-static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value,
- ARMMMUIdx mmu_idx, StackingMode mode)
-{
- CPUState *cs = CPU(cpu);
- CPUARMState *env = &cpu->env;
- MemTxAttrs attrs = {};
- MemTxResult txres;
- target_ulong page_size;
- hwaddr physaddr;
- int prot;
- ARMMMUFaultInfo fi = {};
- bool secure = mmu_idx & ARM_MMU_IDX_M_S;
- int exc;
- bool exc_secure;
-
- if (get_phys_addr(env, addr, MMU_DATA_STORE, mmu_idx, &physaddr,
- &attrs, &prot, &page_size, &fi, NULL)) {
- /* MPU/SAU lookup failed */
- if (fi.type == ARMFault_QEMU_SFault) {
- if (mode == STACK_LAZYFP) {
- qemu_log_mask(CPU_LOG_INT,
- "...SecureFault with SFSR.LSPERR "
- "during lazy stacking\n");
- env->v7m.sfsr |= R_V7M_SFSR_LSPERR_MASK;
- } else {
- qemu_log_mask(CPU_LOG_INT,
- "...SecureFault with SFSR.AUVIOL "
- "during stacking\n");
- env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK;
- }
- env->v7m.sfsr |= R_V7M_SFSR_SFARVALID_MASK;
- env->v7m.sfar = addr;
- exc = ARMV7M_EXCP_SECURE;
- exc_secure = false;
- } else {
- if (mode == STACK_LAZYFP) {
- qemu_log_mask(CPU_LOG_INT,
- "...MemManageFault with CFSR.MLSPERR\n");
- env->v7m.cfsr[secure] |= R_V7M_CFSR_MLSPERR_MASK;
- } else {
- qemu_log_mask(CPU_LOG_INT,
- "...MemManageFault with CFSR.MSTKERR\n");
- env->v7m.cfsr[secure] |= R_V7M_CFSR_MSTKERR_MASK;
- }
- exc = ARMV7M_EXCP_MEM;
- exc_secure = secure;
- }
- goto pend_fault;
- }
- address_space_stl_le(arm_addressspace(cs, attrs), physaddr, value,
- attrs, &txres);
- if (txres != MEMTX_OK) {
- /* BusFault trying to write the data */
- if (mode == STACK_LAZYFP) {
- qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.LSPERR\n");
- env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_LSPERR_MASK;
- } else {
- qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.STKERR\n");
- env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_STKERR_MASK;
- }
- exc = ARMV7M_EXCP_BUS;
- exc_secure = false;
- goto pend_fault;
- }
- return true;
-
-pend_fault:
- /*
- * By pending the exception at this point we are making
- * the IMPDEF choice "overridden exceptions pended" (see the
- * MergeExcInfo() pseudocode). The other choice would be to not
- * pend them now and then make a choice about which to throw away
- * later if we have two derived exceptions.
- * The only case when we must not pend the exception but instead
- * throw it away is if we are doing the push of the callee registers
- * and we've already generated a derived exception (this is indicated
- * by the caller passing STACK_IGNFAULTS). Even in this case we will
- * still update the fault status registers.
- */
- switch (mode) {
- case STACK_NORMAL:
- armv7m_nvic_set_pending_derived(env->nvic, exc, exc_secure);
- break;
- case STACK_LAZYFP:
- armv7m_nvic_set_pending_lazyfp(env->nvic, exc, exc_secure);
- break;
- case STACK_IGNFAULTS:
- break;
- }
- return false;
-}
-
-static bool v7m_stack_read(ARMCPU *cpu, uint32_t *dest, uint32_t addr,
- ARMMMUIdx mmu_idx)
-{
- CPUState *cs = CPU(cpu);
- CPUARMState *env = &cpu->env;
- MemTxAttrs attrs = {};
- MemTxResult txres;
- target_ulong page_size;
- hwaddr physaddr;
- int prot;
- ARMMMUFaultInfo fi = {};
- bool secure = mmu_idx & ARM_MMU_IDX_M_S;
- int exc;
- bool exc_secure;
- uint32_t value;
-
- if (get_phys_addr(env, addr, MMU_DATA_LOAD, mmu_idx, &physaddr,
- &attrs, &prot, &page_size, &fi, NULL)) {
- /* MPU/SAU lookup failed */
- if (fi.type == ARMFault_QEMU_SFault) {
- qemu_log_mask(CPU_LOG_INT,
- "...SecureFault with SFSR.AUVIOL during unstack\n");
- env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK |
R_V7M_SFSR_SFARVALID_MASK;
- env->v7m.sfar = addr;
- exc = ARMV7M_EXCP_SECURE;
- exc_secure = false;
- } else {
- qemu_log_mask(CPU_LOG_INT,
- "...MemManageFault with CFSR.MUNSTKERR\n");
- env->v7m.cfsr[secure] |= R_V7M_CFSR_MUNSTKERR_MASK;
- exc = ARMV7M_EXCP_MEM;
- exc_secure = secure;
- }
- goto pend_fault;
- }
-
- value = address_space_ldl(arm_addressspace(cs, attrs), physaddr,
- attrs, &txres);
- if (txres != MEMTX_OK) {
- /* BusFault trying to read the data */
- qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.UNSTKERR\n");
- env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_UNSTKERR_MASK;
- exc = ARMV7M_EXCP_BUS;
- exc_secure = false;
- goto pend_fault;
- }
-
- *dest = value;
- return true;
-
-pend_fault:
- /*
- * By pending the exception at this point we are making
- * the IMPDEF choice "overridden exceptions pended" (see the
- * MergeExcInfo() pseudocode). The other choice would be to not
- * pend them now and then make a choice about which to throw away
- * later if we have two derived exceptions.
- */
- armv7m_nvic_set_pending(env->nvic, exc, exc_secure);
- return false;
-}
-
-void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
-{
- /*
- * Preserve FP state (because LSPACT was set and we are about
- * to execute an FP instruction). This corresponds to the
- * PreserveFPState() pseudocode.
- * We may throw an exception if the stacking fails.
- */
- ARMCPU *cpu = env_archcpu(env);
- bool is_secure = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
- bool negpri = !(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_HFRDY_MASK);
- bool is_priv = !(env->v7m.fpccr[is_secure] & R_V7M_FPCCR_USER_MASK);
- bool splimviol = env->v7m.fpccr[is_secure] & R_V7M_FPCCR_SPLIMVIOL_MASK;
- uint32_t fpcar = env->v7m.fpcar[is_secure];
- bool stacked_ok = true;
- bool ts = is_secure && (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK);
- bool take_exception;
-
- /* Take the iothread lock as we are going to touch the NVIC */
- qemu_mutex_lock_iothread();
-
- /* Check the background context had access to the FPU */
- if (!v7m_cpacr_pass(env, is_secure, is_priv)) {
- armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE,
is_secure);
- env->v7m.cfsr[is_secure] |= R_V7M_CFSR_NOCP_MASK;
- stacked_ok = false;
- } else if (!is_secure && !extract32(env->v7m.nsacr, 10, 1)) {
- armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S);
- env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK;
- stacked_ok = false;
- }
-
- if (!splimviol && stacked_ok) {
- /* We only stack if the stack limit wasn't violated */
- int i;
- ARMMMUIdx mmu_idx;
-
- mmu_idx = arm_v7m_mmu_idx_all(env, is_secure, is_priv, negpri);
- for (i = 0; i < (ts ? 32 : 16); i += 2) {
- uint64_t dn = *aa32_vfp_dreg(env, i / 2);
- uint32_t faddr = fpcar + 4 * i;
- uint32_t slo = extract64(dn, 0, 32);
- uint32_t shi = extract64(dn, 32, 32);
-
- if (i >= 16) {
- faddr += 8; /* skip the slot for the FPSCR */
- }
- stacked_ok = stacked_ok &&
- v7m_stack_write(cpu, faddr, slo, mmu_idx, STACK_LAZYFP) &&
- v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, STACK_LAZYFP);
- }
-
- stacked_ok = stacked_ok &&
- v7m_stack_write(cpu, fpcar + 0x40,
- vfp_get_fpscr(env), mmu_idx, STACK_LAZYFP);
- }
-
- /*
- * We definitely pended an exception, but it's possible that it
- * might not be able to be taken now. If its priority permits us
- * to take it now, then we must not update the LSPACT or FP regs,
- * but instead jump out to take the exception immediately.
- * If it's just pending and won't be taken until the current
- * handler exits, then we do update LSPACT and the FP regs.
- */
- take_exception = !stacked_ok &&
- armv7m_nvic_can_take_pending_exception(env->nvic);
-
- qemu_mutex_unlock_iothread();
-
- if (take_exception) {
- raise_exception_ra(env, EXCP_LAZYFP, 0, 1, GETPC());
- }
-
- env->v7m.fpccr[is_secure] &= ~R_V7M_FPCCR_LSPACT_MASK;
-
- if (ts) {
- /* Clear s0 to s31 and the FPSCR */
- int i;
-
- for (i = 0; i < 32; i += 2) {
- *aa32_vfp_dreg(env, i / 2) = 0;
- }
- vfp_set_fpscr(env, 0);
- }
- /*
- * Otherwise s0 to s15 and FPSCR are UNKNOWN; we choose to leave them
- * unchanged.
- */
-}
-
-/*
- * Write to v7M CONTROL.SPSEL bit for the specified security bank.
- * This may change the current stack pointer between Main and Process
- * stack pointers if it is done for the CONTROL register for the current
- * security state.
- */
-static void write_v7m_control_spsel_for_secstate(CPUARMState *env,
- bool new_spsel,
- bool secstate)
-{
- bool old_is_psp = v7m_using_psp(env);
-
- env->v7m.control[secstate] =
- deposit32(env->v7m.control[secstate],
- R_V7M_CONTROL_SPSEL_SHIFT,
- R_V7M_CONTROL_SPSEL_LENGTH, new_spsel);
-
- if (secstate == env->v7m.secure) {
- bool new_is_psp = v7m_using_psp(env);
- uint32_t tmp;
-
- if (old_is_psp != new_is_psp) {
- tmp = env->v7m.other_sp;
- env->v7m.other_sp = env->regs[13];
- env->regs[13] = tmp;
- }
- }
-}
-
-/*
- * Write to v7M CONTROL.SPSEL bit. This may change the current
- * stack pointer between Main and Process stack pointers.
- */
-static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel)
-{
- write_v7m_control_spsel_for_secstate(env, new_spsel, env->v7m.secure);
-}
-
-void write_v7m_exception(CPUARMState *env, uint32_t new_exc)
-{
- /*
- * Write a new value to v7m.exception, thus transitioning into or out
- * of Handler mode; this may result in a change of active stack pointer.
- */
- bool new_is_psp, old_is_psp = v7m_using_psp(env);
- uint32_t tmp;
-
- env->v7m.exception = new_exc;
-
- new_is_psp = v7m_using_psp(env);
-
- if (old_is_psp != new_is_psp) {
- tmp = env->v7m.other_sp;
- env->v7m.other_sp = env->regs[13];
- env->regs[13] = tmp;
- }
-}
-
-/* Switch M profile security state between NS and S */
-static void switch_v7m_security_state(CPUARMState *env, bool new_secstate)
-{
- uint32_t new_ss_msp, new_ss_psp;
-
- if (env->v7m.secure == new_secstate) {
- return;
- }
-
- /*
- * All the banked state is accessed by looking at env->v7m.secure
- * except for the stack pointer; rearrange the SP appropriately.
- */
- new_ss_msp = env->v7m.other_ss_msp;
- new_ss_psp = env->v7m.other_ss_psp;
-
- if (v7m_using_psp(env)) {
- env->v7m.other_ss_psp = env->regs[13];
- env->v7m.other_ss_msp = env->v7m.other_sp;
- } else {
- env->v7m.other_ss_msp = env->regs[13];
- env->v7m.other_ss_psp = env->v7m.other_sp;
- }
-
- env->v7m.secure = new_secstate;
-
- if (v7m_using_psp(env)) {
- env->regs[13] = new_ss_psp;
- env->v7m.other_sp = new_ss_msp;
- } else {
- env->regs[13] = new_ss_msp;
- env->v7m.other_sp = new_ss_psp;
- }
-}
-
-void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest)
-{
- /*
- * Handle v7M BXNS:
- * - if the return value is a magic value, do exception return (like BX)
- * - otherwise bit 0 of the return value is the target security state
- */
- uint32_t min_magic;
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- /* Covers FNC_RETURN and EXC_RETURN magic */
- min_magic = FNC_RETURN_MIN_MAGIC;
- } else {
- /* EXC_RETURN magic only */
- min_magic = EXC_RETURN_MIN_MAGIC;
- }
-
- if (dest >= min_magic) {
- /*
- * This is an exception return magic value; put it where
- * do_v7m_exception_exit() expects and raise EXCEPTION_EXIT.
- * Note that if we ever add gen_ss_advance() singlestep support to
- * M profile this should count as an "instruction execution complete"
- * event (compare gen_bx_excret_final_code()).
- */
- env->regs[15] = dest & ~1;
- env->thumb = dest & 1;
- HELPER(exception_internal)(env, EXCP_EXCEPTION_EXIT);
- /* notreached */
- }
-
- /* translate.c should have made BXNS UNDEF unless we're secure */
- assert(env->v7m.secure);
-
- if (!(dest & 1)) {
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
- }
- switch_v7m_security_state(env, dest & 1);
- env->thumb = 1;
- env->regs[15] = dest & ~1;
-}
-
-void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest)
-{
- /*
- * Handle v7M BLXNS:
- * - bit 0 of the destination address is the target security state
- */
-
- /* At this point regs[15] is the address just after the BLXNS */
- uint32_t nextinst = env->regs[15] | 1;
- uint32_t sp = env->regs[13] - 8;
- uint32_t saved_psr;
-
- /* translate.c will have made BLXNS UNDEF unless we're secure */
- assert(env->v7m.secure);
-
- if (dest & 1) {
- /*
- * Target is Secure, so this is just a normal BLX,
- * except that the low bit doesn't indicate Thumb/not.
- */
- env->regs[14] = nextinst;
- env->thumb = 1;
- env->regs[15] = dest & ~1;
- return;
- }
-
- /* Target is non-secure: first push a stack frame */
- if (!QEMU_IS_ALIGNED(sp, 8)) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "BLXNS with misaligned SP is UNPREDICTABLE\n");
- }
-
- if (sp < v7m_sp_limit(env)) {
- raise_exception(env, EXCP_STKOF, 0, 1);
- }
-
- saved_psr = env->v7m.exception;
- if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK) {
- saved_psr |= XPSR_SFPA;
- }
-
- /* Note that these stores can throw exceptions on MPU faults */
- cpu_stl_data(env, sp, nextinst);
- cpu_stl_data(env, sp + 4, saved_psr);
-
- env->regs[13] = sp;
- env->regs[14] = 0xfeffffff;
- if (arm_v7m_is_handler_mode(env)) {
- /*
- * Write a dummy value to IPSR, to avoid leaking the current secure
- * exception number to non-secure code. This is guaranteed not
- * to cause write_v7m_exception() to actually change stacks.
- */
- write_v7m_exception(env, 1);
- }
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
- switch_v7m_security_state(env, 0);
- env->thumb = 1;
- env->regs[15] = dest;
-}
-
-static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode,
- bool spsel)
-{
- /*
- * Return a pointer to the location where we currently store the
- * stack pointer for the requested security state and thread mode.
- * This pointer will become invalid if the CPU state is updated
- * such that the stack pointers are switched around (eg changing
- * the SPSEL control bit).
- * Compare the v8M ARM ARM pseudocode LookUpSP_with_security_mode().
- * Unlike that pseudocode, we require the caller to pass us in the
- * SPSEL control bit value; this is because we also use this
- * function in handling of pushing of the callee-saves registers
- * part of the v8M stack frame (pseudocode PushCalleeStack()),
- * and in the tailchain codepath the SPSEL bit comes from the exception
- * return magic LR value from the previous exception. The pseudocode
- * opencodes the stack-selection in PushCalleeStack(), but we prefer
- * to make this utility function generic enough to do the job.
- */
- bool want_psp = threadmode && spsel;
-
- if (secure == env->v7m.secure) {
- if (want_psp == v7m_using_psp(env)) {
- return &env->regs[13];
- } else {
- return &env->v7m.other_sp;
- }
- } else {
- if (want_psp) {
- return &env->v7m.other_ss_psp;
- } else {
- return &env->v7m.other_ss_msp;
- }
- }
-}
-
-static bool arm_v7m_load_vector(ARMCPU *cpu, int exc, bool targets_secure,
- uint32_t *pvec)
-{
- CPUState *cs = CPU(cpu);
- CPUARMState *env = &cpu->env;
- MemTxResult result;
- uint32_t addr = env->v7m.vecbase[targets_secure] + exc * 4;
- uint32_t vector_entry;
- MemTxAttrs attrs = {};
- ARMMMUIdx mmu_idx;
- bool exc_secure;
-
- mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targets_secure, true);
-
- /*
- * We don't do a get_phys_addr() here because the rules for vector
- * loads are special: they always use the default memory map, and
- * the default memory map permits reads from all addresses.
- * Since there's no easy way to pass through to pmsav8_mpu_lookup()
- * that we want this special case which would always say "yes",
- * we just do the SAU lookup here followed by a direct physical load.
- */
- attrs.secure = targets_secure;
- attrs.user = false;
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- V8M_SAttributes sattrs = {};
-
- v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs);
- if (sattrs.ns) {
- attrs.secure = false;
- } else if (!targets_secure) {
- /* NS access to S memory */
- goto load_fail;
- }
- }
-
- vector_entry = address_space_ldl(arm_addressspace(cs, attrs), addr,
- attrs, &result);
- if (result != MEMTX_OK) {
- goto load_fail;
- }
- *pvec = vector_entry;
- return true;
-
-load_fail:
- /*
- * All vector table fetch fails are reported as HardFault, with
- * HFSR.VECTTBL and .FORCED set. (FORCED is set because
- * technically the underlying exception is a MemManage or BusFault
- * that is escalated to HardFault.) This is a terminal exception,
- * so we will either take the HardFault immediately or else enter
- * lockup (the latter case is handled in
armv7m_nvic_set_pending_derived()).
- */
- exc_secure = targets_secure ||
- !(cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK);
- env->v7m.hfsr |= R_V7M_HFSR_VECTTBL_MASK | R_V7M_HFSR_FORCED_MASK;
- armv7m_nvic_set_pending_derived(env->nvic, ARMV7M_EXCP_HARD, exc_secure);
- return false;
-}
-
-static uint32_t v7m_integrity_sig(CPUARMState *env, uint32_t lr)
-{
- /*
- * Return the integrity signature value for the callee-saves
- * stack frame section. @lr is the exception return payload/LR value
- * whose FType bit forms bit 0 of the signature if FP is present.
- */
- uint32_t sig = 0xfefa125a;
-
- if (!arm_feature(env, ARM_FEATURE_VFP) || (lr & R_V7M_EXCRET_FTYPE_MASK)) {
- sig |= 1;
- }
- return sig;
-}
-
-static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain,
- bool ignore_faults)
-{
- /*
- * For v8M, push the callee-saves register part of the stack frame.
- * Compare the v8M pseudocode PushCalleeStack().
- * In the tailchaining case this may not be the current stack.
- */
- CPUARMState *env = &cpu->env;
- uint32_t *frame_sp_p;
- uint32_t frameptr;
- ARMMMUIdx mmu_idx;
- bool stacked_ok;
- uint32_t limit;
- bool want_psp;
- uint32_t sig;
- StackingMode smode = ignore_faults ? STACK_IGNFAULTS : STACK_NORMAL;
-
- if (dotailchain) {
- bool mode = lr & R_V7M_EXCRET_MODE_MASK;
- bool priv = !(env->v7m.control[M_REG_S] & R_V7M_CONTROL_NPRIV_MASK) ||
- !mode;
-
- mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, M_REG_S, priv);
- frame_sp_p = get_v7m_sp_ptr(env, M_REG_S, mode,
- lr & R_V7M_EXCRET_SPSEL_MASK);
- want_psp = mode && (lr & R_V7M_EXCRET_SPSEL_MASK);
- if (want_psp) {
- limit = env->v7m.psplim[M_REG_S];
- } else {
- limit = env->v7m.msplim[M_REG_S];
- }
- } else {
- mmu_idx = arm_mmu_idx(env);
- frame_sp_p = &env->regs[13];
- limit = v7m_sp_limit(env);
- }
-
- frameptr = *frame_sp_p - 0x28;
- if (frameptr < limit) {
- /*
- * Stack limit failure: set SP to the limit value, and generate
- * STKOF UsageFault. Stack pushes below the limit must not be
- * performed. It is IMPDEF whether pushes above the limit are
- * performed; we choose not to.
- */
- qemu_log_mask(CPU_LOG_INT,
- "...STKOF during callee-saves register stacking\n");
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- env->v7m.secure);
- *frame_sp_p = limit;
- return true;
- }
-
- /*
- * Write as much of the stack frame as we can. A write failure may
- * cause us to pend a derived exception.
- */
- sig = v7m_integrity_sig(env, lr);
- stacked_ok =
- v7m_stack_write(cpu, frameptr, sig, mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x10, env->regs[6], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x14, env->regs[7], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x18, env->regs[8], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x1c, env->regs[9], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x20, env->regs[10], mmu_idx, smode) &&
- v7m_stack_write(cpu, frameptr + 0x24, env->regs[11], mmu_idx, smode);
-
- /* Update SP regardless of whether any of the stack accesses failed. */
- *frame_sp_p = frameptr;
-
- return !stacked_ok;
-}
-
-static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain,
- bool ignore_stackfaults)
-{
- /*
- * Do the "take the exception" parts of exception entry,
- * but not the pushing of state to the stack. This is
- * similar to the pseudocode ExceptionTaken() function.
- */
- CPUARMState *env = &cpu->env;
- uint32_t addr;
- bool targets_secure;
- int exc;
- bool push_failed = false;
-
- armv7m_nvic_get_pending_irq_info(env->nvic, &exc, &targets_secure);
- qemu_log_mask(CPU_LOG_INT, "...taking pending %s exception %d\n",
- targets_secure ? "secure" : "nonsecure", exc);
-
- if (dotailchain) {
- /* Sanitize LR FType and PREFIX bits */
- if (!arm_feature(env, ARM_FEATURE_VFP)) {
- lr |= R_V7M_EXCRET_FTYPE_MASK;
- }
- lr = deposit32(lr, 24, 8, 0xff);
- }
-
- if (arm_feature(env, ARM_FEATURE_V8)) {
- if (arm_feature(env, ARM_FEATURE_M_SECURITY) &&
- (lr & R_V7M_EXCRET_S_MASK)) {
- /*
- * The background code (the owner of the registers in the
- * exception frame) is Secure. This means it may either already
- * have or now needs to push callee-saves registers.
- */
- if (targets_secure) {
- if (dotailchain && !(lr & R_V7M_EXCRET_ES_MASK)) {
- /*
- * We took an exception from Secure to NonSecure
- * (which means the callee-saved registers got stacked)
- * and are now tailchaining to a Secure exception.
- * Clear DCRS so eventual return from this Secure
- * exception unstacks the callee-saved registers.
- */
- lr &= ~R_V7M_EXCRET_DCRS_MASK;
- }
- } else {
- /*
- * We're going to a non-secure exception; push the
- * callee-saves registers to the stack now, if they're
- * not already saved.
- */
- if (lr & R_V7M_EXCRET_DCRS_MASK &&
- !(dotailchain && !(lr & R_V7M_EXCRET_ES_MASK))) {
- push_failed = v7m_push_callee_stack(cpu, lr, dotailchain,
- ignore_stackfaults);
- }
- lr |= R_V7M_EXCRET_DCRS_MASK;
- }
- }
-
- lr &= ~R_V7M_EXCRET_ES_MASK;
- if (targets_secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- lr |= R_V7M_EXCRET_ES_MASK;
- }
- lr &= ~R_V7M_EXCRET_SPSEL_MASK;
- if (env->v7m.control[targets_secure] & R_V7M_CONTROL_SPSEL_MASK) {
- lr |= R_V7M_EXCRET_SPSEL_MASK;
- }
-
- /*
- * Clear registers if necessary to prevent non-secure exception
- * code being able to see register values from secure code.
- * Where register values become architecturally UNKNOWN we leave
- * them with their previous values.
- */
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- if (!targets_secure) {
- /*
- * Always clear the caller-saved registers (they have been
- * pushed to the stack earlier in v7m_push_stack()).
- * Clear callee-saved registers if the background code is
- * Secure (in which case these regs were saved in
- * v7m_push_callee_stack()).
- */
- int i;
-
- for (i = 0; i < 13; i++) {
- /* r4..r11 are callee-saves, zero only if EXCRET.S == 1 */
- if (i < 4 || i > 11 || (lr & R_V7M_EXCRET_S_MASK)) {
- env->regs[i] = 0;
- }
- }
- /* Clear EAPSR */
- xpsr_write(env, 0, XPSR_NZCV | XPSR_Q | XPSR_GE | XPSR_IT);
- }
- }
- }
-
- if (push_failed && !ignore_stackfaults) {
- /*
- * Derived exception on callee-saves register stacking:
- * we might now want to take a different exception which
- * targets a different security state, so try again from the top.
- */
- qemu_log_mask(CPU_LOG_INT,
- "...derived exception on callee-saves register
stacking");
- v7m_exception_taken(cpu, lr, true, true);
- return;
- }
-
- if (!arm_v7m_load_vector(cpu, exc, targets_secure, &addr)) {
- /* Vector load failed: derived exception */
- qemu_log_mask(CPU_LOG_INT, "...derived exception on vector table
load");
- v7m_exception_taken(cpu, lr, true, true);
- return;
- }
-
- /*
- * Now we've done everything that might cause a derived exception
- * we can go ahead and activate whichever exception we're going to
- * take (which might now be the derived exception).
- */
- armv7m_nvic_acknowledge_irq(env->nvic);
-
- /* Switch to target security state -- must do this before writing SPSEL */
- switch_v7m_security_state(env, targets_secure);
- write_v7m_control_spsel(env, 0);
- arm_clear_exclusive(env);
- /* Clear SFPA and FPCA (has no effect if no FPU) */
- env->v7m.control[M_REG_S] &=
- ~(R_V7M_CONTROL_FPCA_MASK | R_V7M_CONTROL_SFPA_MASK);
- /* Clear IT bits */
- env->condexec_bits = 0;
- env->regs[14] = lr;
- env->regs[15] = addr & 0xfffffffe;
- env->thumb = addr & 1;
-}
-
-static void v7m_update_fpccr(CPUARMState *env, uint32_t frameptr,
- bool apply_splim)
-{
- /*
- * Like the pseudocode UpdateFPCCR: save state in FPCAR and FPCCR
- * that we will need later in order to do lazy FP reg stacking.
- */
- bool is_secure = env->v7m.secure;
- void *nvic = env->nvic;
- /*
- * Some bits are unbanked and live always in fpccr[M_REG_S]; some bits
- * are banked and we want to update the bit in the bank for the
- * current security state; and in one case we want to specifically
- * update the NS banked version of a bit even if we are secure.
- */
- uint32_t *fpccr_s = &env->v7m.fpccr[M_REG_S];
- uint32_t *fpccr_ns = &env->v7m.fpccr[M_REG_NS];
- uint32_t *fpccr = &env->v7m.fpccr[is_secure];
- bool hfrdy, bfrdy, mmrdy, ns_ufrdy, s_ufrdy, sfrdy, monrdy;
-
- env->v7m.fpcar[is_secure] = frameptr & ~0x7;
-
- if (apply_splim && arm_feature(env, ARM_FEATURE_V8)) {
- bool splimviol;
- uint32_t splim = v7m_sp_limit(env);
- bool ign = armv7m_nvic_neg_prio_requested(nvic, is_secure) &&
- (env->v7m.ccr[is_secure] & R_V7M_CCR_STKOFHFNMIGN_MASK);
-
- splimviol = !ign && frameptr < splim;
- *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, SPLIMVIOL, splimviol);
- }
-
- *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, LSPACT, 1);
-
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, S, is_secure);
-
- *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, USER, arm_current_el(env) == 0);
-
- *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, THREAD,
- !arm_v7m_is_handler_mode(env));
-
- hfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_HARD, false);
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, HFRDY, hfrdy);
-
- bfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_BUS, false);
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, BFRDY, bfrdy);
-
- mmrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_MEM, is_secure);
- *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, MMRDY, mmrdy);
-
- ns_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, false);
- *fpccr_ns = FIELD_DP32(*fpccr_ns, V7M_FPCCR, UFRDY, ns_ufrdy);
-
- monrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_DEBUG, false);
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, MONRDY, monrdy);
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- s_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, true);
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, UFRDY, s_ufrdy);
-
- sfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_SECURE, false);
- *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, SFRDY, sfrdy);
- }
-}
-
-void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
-{
- /* fptr is the value of Rn, the frame pointer we store the FP regs to */
- bool s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
- bool lspact = env->v7m.fpccr[s] & R_V7M_FPCCR_LSPACT_MASK;
-
- assert(env->v7m.secure);
-
- if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
- return;
- }
-
- /* Check access to the coprocessor is permitted */
- if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) {
- raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC());
- }
-
- if (lspact) {
- /* LSPACT should not be active when there is active FP state */
- raise_exception_ra(env, EXCP_LSERR, 0, 1, GETPC());
- }
-
- if (fptr & 7) {
- raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC());
- }
-
- /*
- * Note that we do not use v7m_stack_write() here, because the
- * accesses should not set the FSR bits for stacking errors if they
- * fail. (In pseudocode terms, they are AccType_NORMAL, not AccType_STACK
- * or AccType_LAZYFP). Faults in cpu_stl_data() will throw exceptions
- * and longjmp out.
- */
- if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) {
- bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK;
- int i;
-
- for (i = 0; i < (ts ? 32 : 16); i += 2) {
- uint64_t dn = *aa32_vfp_dreg(env, i / 2);
- uint32_t faddr = fptr + 4 * i;
- uint32_t slo = extract64(dn, 0, 32);
- uint32_t shi = extract64(dn, 32, 32);
-
- if (i >= 16) {
- faddr += 8; /* skip the slot for the FPSCR */
- }
- cpu_stl_data(env, faddr, slo);
- cpu_stl_data(env, faddr + 4, shi);
- }
- cpu_stl_data(env, fptr + 0x40, vfp_get_fpscr(env));
-
- /*
- * If TS is 0 then s0 to s15 and FPSCR are UNKNOWN; we choose to
- * leave them unchanged, matching our choice in v7m_preserve_fp_state.
- */
- if (ts) {
- for (i = 0; i < 32; i += 2) {
- *aa32_vfp_dreg(env, i / 2) = 0;
- }
- vfp_set_fpscr(env, 0);
- }
- } else {
- v7m_update_fpccr(env, fptr, false);
- }
-
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
-}
-
-void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr)
-{
- /* fptr is the value of Rn, the frame pointer we load the FP regs from */
- assert(env->v7m.secure);
-
- if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
- return;
- }
-
- /* Check access to the coprocessor is permitted */
- if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) {
- raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC());
- }
-
- if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) {
- /* State in FP is still valid */
- env->v7m.fpccr[M_REG_S] &= ~R_V7M_FPCCR_LSPACT_MASK;
- } else {
- bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK;
- int i;
- uint32_t fpscr;
-
- if (fptr & 7) {
- raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC());
- }
-
- for (i = 0; i < (ts ? 32 : 16); i += 2) {
- uint32_t slo, shi;
- uint64_t dn;
- uint32_t faddr = fptr + 4 * i;
-
- if (i >= 16) {
- faddr += 8; /* skip the slot for the FPSCR */
- }
-
- slo = cpu_ldl_data(env, faddr);
- shi = cpu_ldl_data(env, faddr + 4);
-
- dn = (uint64_t) shi << 32 | slo;
- *aa32_vfp_dreg(env, i / 2) = dn;
- }
- fpscr = cpu_ldl_data(env, fptr + 0x40);
- vfp_set_fpscr(env, fpscr);
- }
-
- env->v7m.control[M_REG_S] |= R_V7M_CONTROL_FPCA_MASK;
-}
-
-static bool v7m_push_stack(ARMCPU *cpu)
-{
- /*
- * Do the "set up stack frame" part of exception entry,
- * similar to pseudocode PushStack().
- * Return true if we generate a derived exception (and so
- * should ignore further stack faults trying to process
- * that derived exception.)
- */
- bool stacked_ok = true, limitviol = false;
- CPUARMState *env = &cpu->env;
- uint32_t xpsr = xpsr_read(env);
- uint32_t frameptr = env->regs[13];
- ARMMMUIdx mmu_idx = arm_mmu_idx(env);
- uint32_t framesize;
- bool nsacr_cp10 = extract32(env->v7m.nsacr, 10, 1);
-
- if ((env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) &&
- (env->v7m.secure || nsacr_cp10)) {
- if (env->v7m.secure &&
- env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK) {
- framesize = 0xa8;
- } else {
- framesize = 0x68;
- }
- } else {
- framesize = 0x20;
- }
-
- /* Align stack pointer if the guest wants that */
- if ((frameptr & 4) &&
- (env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_STKALIGN_MASK)) {
- frameptr -= 4;
- xpsr |= XPSR_SPREALIGN;
- }
-
- xpsr &= ~XPSR_SFPA;
- if (env->v7m.secure &&
- (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
- xpsr |= XPSR_SFPA;
- }
-
- frameptr -= framesize;
-
- if (arm_feature(env, ARM_FEATURE_V8)) {
- uint32_t limit = v7m_sp_limit(env);
-
- if (frameptr < limit) {
- /*
- * Stack limit failure: set SP to the limit value, and generate
- * STKOF UsageFault. Stack pushes below the limit must not be
- * performed. It is IMPDEF whether pushes above the limit are
- * performed; we choose not to.
- */
- qemu_log_mask(CPU_LOG_INT,
- "...STKOF during stacking\n");
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- env->v7m.secure);
- env->regs[13] = limit;
- /*
- * We won't try to perform any further memory accesses but
- * we must continue through the following code to check for
- * permission faults during FPU state preservation, and we
- * must update FPCCR if lazy stacking is enabled.
- */
- limitviol = true;
- stacked_ok = false;
- }
- }
-
- /*
- * Write as much of the stack frame as we can. If we fail a stack
- * write this will result in a derived exception being pended
- * (which may be taken in preference to the one we started with
- * if it has higher priority).
- */
- stacked_ok = stacked_ok &&
- v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 4, env->regs[1],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 8, env->regs[2],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 12, env->regs[3],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 16, env->regs[12],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 20, env->regs[14],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 24, env->regs[15],
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, STACK_NORMAL);
-
- if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) {
- /* FPU is active, try to save its registers */
- bool fpccr_s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
- bool lspact = env->v7m.fpccr[fpccr_s] & R_V7M_FPCCR_LSPACT_MASK;
-
- if (lspact && arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- qemu_log_mask(CPU_LOG_INT,
- "...SecureFault because LSPACT and FPCA both set\n");
- env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- } else if (!env->v7m.secure && !nsacr_cp10) {
- qemu_log_mask(CPU_LOG_INT,
- "...Secure UsageFault with CFSR.NOCP because "
- "NSACR.CP10 prevents stacking FP regs\n");
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S);
- env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK;
- } else {
- if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) {
- /* Lazy stacking disabled, save registers now */
- int i;
- bool cpacr_pass = v7m_cpacr_pass(env, env->v7m.secure,
- arm_current_el(env) != 0);
-
- if (stacked_ok && !cpacr_pass) {
- /*
- * Take UsageFault if CPACR forbids access. The pseudocode
- * here does a full CheckCPEnabled() but we know the NSACR
- * check can never fail as we have already handled that.
- */
- qemu_log_mask(CPU_LOG_INT,
- "...UsageFault with CFSR.NOCP because "
- "CPACR.CP10 prevents stacking FP regs\n");
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_NOCP_MASK;
- stacked_ok = false;
- }
-
- for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) {
- uint64_t dn = *aa32_vfp_dreg(env, i / 2);
- uint32_t faddr = frameptr + 0x20 + 4 * i;
- uint32_t slo = extract64(dn, 0, 32);
- uint32_t shi = extract64(dn, 32, 32);
-
- if (i >= 16) {
- faddr += 8; /* skip the slot for the FPSCR */
- }
- stacked_ok = stacked_ok &&
- v7m_stack_write(cpu, faddr, slo,
- mmu_idx, STACK_NORMAL) &&
- v7m_stack_write(cpu, faddr + 4, shi,
- mmu_idx, STACK_NORMAL);
- }
- stacked_ok = stacked_ok &&
- v7m_stack_write(cpu, frameptr + 0x60,
- vfp_get_fpscr(env), mmu_idx, STACK_NORMAL);
- if (cpacr_pass) {
- for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) {
- *aa32_vfp_dreg(env, i / 2) = 0;
- }
- vfp_set_fpscr(env, 0);
- }
- } else {
- /* Lazy stacking enabled, save necessary info to stack later */
- v7m_update_fpccr(env, frameptr + 0x20, true);
- }
- }
- }
-
- /*
- * If we broke a stack limit then SP was already updated earlier;
- * otherwise we update SP regardless of whether any of the stack
- * accesses failed or we took some other kind of fault.
- */
- if (!limitviol) {
- env->regs[13] = frameptr;
- }
-
- return !stacked_ok;
-}
-
-static void do_v7m_exception_exit(ARMCPU *cpu)
-{
- CPUARMState *env = &cpu->env;
- uint32_t excret;
- uint32_t xpsr, xpsr_mask;
- bool ufault = false;
- bool sfault = false;
- bool return_to_sp_process;
- bool return_to_handler;
- bool rettobase = false;
- bool exc_secure = false;
- bool return_to_secure;
- bool ftype;
- bool restore_s16_s31;
-
- /*
- * If we're not in Handler mode then jumps to magic exception-exit
- * addresses don't have magic behaviour. However for the v8M
- * security extensions the magic secure-function-return has to
- * work in thread mode too, so to avoid doing an extra check in
- * the generated code we allow exception-exit magic to also cause the
- * internal exception and bring us here in thread mode. Correct code
- * will never try to do this (the following insn fetch will always
- * fault) so we the overhead of having taken an unnecessary exception
- * doesn't matter.
- */
- if (!arm_v7m_is_handler_mode(env)) {
- return;
- }
-
- /*
- * In the spec pseudocode ExceptionReturn() is called directly
- * from BXWritePC() and gets the full target PC value including
- * bit zero. In QEMU's implementation we treat it as a normal
- * jump-to-register (which is then caught later on), and so split
- * the target value up between env->regs[15] and env->thumb in
- * gen_bx(). Reconstitute it.
- */
- excret = env->regs[15];
- if (env->thumb) {
- excret |= 1;
- }
-
- qemu_log_mask(CPU_LOG_INT, "Exception return: magic PC %" PRIx32
- " previous exception %d\n",
- excret, env->v7m.exception);
-
- if ((excret & R_V7M_EXCRET_RES1_MASK) != R_V7M_EXCRET_RES1_MASK) {
- qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero high bits in exception
"
- "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n",
- excret);
- }
-
- ftype = excret & R_V7M_EXCRET_FTYPE_MASK;
-
- if (!arm_feature(env, ARM_FEATURE_VFP) && !ftype) {
- qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero FTYPE in exception "
- "exit PC value 0x%" PRIx32 " is UNPREDICTABLE "
- "if FPU not present\n",
- excret);
- ftype = true;
- }
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- /*
- * EXC_RETURN.ES validation check (R_SMFL). We must do this before
- * we pick which FAULTMASK to clear.
- */
- if (!env->v7m.secure &&
- ((excret & R_V7M_EXCRET_ES_MASK) ||
- !(excret & R_V7M_EXCRET_DCRS_MASK))) {
- sfault = 1;
- /* For all other purposes, treat ES as 0 (R_HXSR) */
- excret &= ~R_V7M_EXCRET_ES_MASK;
- }
- exc_secure = excret & R_V7M_EXCRET_ES_MASK;
- }
-
- if (env->v7m.exception != ARMV7M_EXCP_NMI) {
- /*
- * Auto-clear FAULTMASK on return from other than NMI.
- * If the security extension is implemented then this only
- * happens if the raw execution priority is >= 0; the
- * value of the ES bit in the exception return value indicates
- * which security state's faultmask to clear. (v8M ARM ARM R_KBNF.)
- */
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- if (armv7m_nvic_raw_execution_priority(env->nvic) >= 0) {
- env->v7m.faultmask[exc_secure] = 0;
- }
- } else {
- env->v7m.faultmask[M_REG_NS] = 0;
- }
- }
-
- switch (armv7m_nvic_complete_irq(env->nvic, env->v7m.exception,
- exc_secure)) {
- case -1:
- /* attempt to exit an exception that isn't active */
- ufault = true;
- break;
- case 0:
- /* still an irq active now */
- break;
- case 1:
- /*
- * We returned to base exception level, no nesting.
- * (In the pseudocode this is written using "NestedActivation != 1"
- * where we have 'rettobase == false'.)
- */
- rettobase = true;
- break;
- default:
- g_assert_not_reached();
- }
-
- return_to_handler = !(excret & R_V7M_EXCRET_MODE_MASK);
- return_to_sp_process = excret & R_V7M_EXCRET_SPSEL_MASK;
- return_to_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) &&
- (excret & R_V7M_EXCRET_S_MASK);
-
- if (arm_feature(env, ARM_FEATURE_V8)) {
- if (!arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- /*
- * UNPREDICTABLE if S == 1 or DCRS == 0 or ES == 1 (R_XLCP);
- * we choose to take the UsageFault.
- */
- if ((excret & R_V7M_EXCRET_S_MASK) ||
- (excret & R_V7M_EXCRET_ES_MASK) ||
- !(excret & R_V7M_EXCRET_DCRS_MASK)) {
- ufault = true;
- }
- }
- if (excret & R_V7M_EXCRET_RES0_MASK) {
- ufault = true;
- }
- } else {
- /* For v7M we only recognize certain combinations of the low bits */
- switch (excret & 0xf) {
- case 1: /* Return to Handler */
- break;
- case 13: /* Return to Thread using Process stack */
- case 9: /* Return to Thread using Main stack */
- /*
- * We only need to check NONBASETHRDENA for v7M, because in
- * v8M this bit does not exist (it is RES1).
- */
- if (!rettobase &&
- !(env->v7m.ccr[env->v7m.secure] &
- R_V7M_CCR_NONBASETHRDENA_MASK)) {
- ufault = true;
- }
- break;
- default:
- ufault = true;
- }
- }
-
- /*
- * Set CONTROL.SPSEL from excret.SPSEL. Since we're still in
- * Handler mode (and will be until we write the new XPSR.Interrupt
- * field) this does not switch around the current stack pointer.
- * We must do this before we do any kind of tailchaining, including
- * for the derived exceptions on integrity check failures, or we will
- * give the guest an incorrect EXCRET.SPSEL value on exception entry.
- */
- write_v7m_control_spsel_for_secstate(env, return_to_sp_process,
exc_secure);
-
- /*
- * Clear scratch FP values left in caller saved registers; this
- * must happen before any kind of tail chaining.
- */
- if ((env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_CLRONRET_MASK) &&
- (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) {
- if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) {
- env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
- "stackframe: error during lazy state
deactivation\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- } else {
- /* Clear s0..s15 and FPSCR */
- int i;
-
- for (i = 0; i < 16; i += 2) {
- *aa32_vfp_dreg(env, i / 2) = 0;
- }
- vfp_set_fpscr(env, 0);
- }
- }
-
- if (sfault) {
- env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
- "stackframe: failed EXC_RETURN.ES validity check\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- if (ufault) {
- /*
- * Bad exception return: instead of popping the exception
- * stack, directly take a usage fault on the current stack.
- */
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
- qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "
- "stackframe: failed exception return integrity check\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- /*
- * Tailchaining: if there is currently a pending exception that
- * is high enough priority to preempt execution at the level we're
- * about to return to, then just directly take that exception now,
- * avoiding an unstack-and-then-stack. Note that now we have
- * deactivated the previous exception by calling armv7m_nvic_complete_irq()
- * our current execution priority is already the execution priority we are
- * returning to -- none of the state we would unstack or set based on
- * the EXCRET value affects it.
- */
- if (armv7m_nvic_can_take_pending_exception(env->nvic)) {
- qemu_log_mask(CPU_LOG_INT, "...tailchaining to pending exception\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- switch_v7m_security_state(env, return_to_secure);
-
- {
- /*
- * The stack pointer we should be reading the exception frame from
- * depends on bits in the magic exception return type value (and
- * for v8M isn't necessarily the stack pointer we will eventually
- * end up resuming execution with). Get a pointer to the location
- * in the CPU state struct where the SP we need is currently being
- * stored; we will use and modify it in place.
- * We use this limited C variable scope so we don't accidentally
- * use 'frame_sp_p' after we do something that makes it invalid.
- */
- uint32_t *frame_sp_p = get_v7m_sp_ptr(env,
- return_to_secure,
- !return_to_handler,
- return_to_sp_process);
- uint32_t frameptr = *frame_sp_p;
- bool pop_ok = true;
- ARMMMUIdx mmu_idx;
- bool return_to_priv = return_to_handler ||
- !(env->v7m.control[return_to_secure] & R_V7M_CONTROL_NPRIV_MASK);
-
- mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, return_to_secure,
- return_to_priv);
-
- if (!QEMU_IS_ALIGNED(frameptr, 8) &&
- arm_feature(env, ARM_FEATURE_V8)) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "M profile exception return with non-8-aligned SP "
- "for destination state is UNPREDICTABLE\n");
- }
-
- /* Do we need to pop callee-saved registers? */
- if (return_to_secure &&
- ((excret & R_V7M_EXCRET_ES_MASK) == 0 ||
- (excret & R_V7M_EXCRET_DCRS_MASK) == 0)) {
- uint32_t actual_sig;
-
- pop_ok = v7m_stack_read(cpu, &actual_sig, frameptr, mmu_idx);
-
- if (pop_ok && v7m_integrity_sig(env, excret) != actual_sig) {
- /* Take a SecureFault on the current stack */
- env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
- "stackframe: failed exception return integrity "
- "signature check\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- pop_ok = pop_ok &&
- v7m_stack_read(cpu, &env->regs[4], frameptr + 0x8, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[5], frameptr + 0xc, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[6], frameptr + 0x10, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[7], frameptr + 0x14, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[8], frameptr + 0x18, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[9], frameptr + 0x1c, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[10], frameptr + 0x20, mmu_idx)
&&
- v7m_stack_read(cpu, &env->regs[11], frameptr + 0x24, mmu_idx);
-
- frameptr += 0x28;
- }
-
- /* Pop registers */
- pop_ok = pop_ok &&
- v7m_stack_read(cpu, &env->regs[0], frameptr, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[1], frameptr + 0x4, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[2], frameptr + 0x8, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[3], frameptr + 0xc, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[12], frameptr + 0x10, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[14], frameptr + 0x14, mmu_idx) &&
- v7m_stack_read(cpu, &env->regs[15], frameptr + 0x18, mmu_idx) &&
- v7m_stack_read(cpu, &xpsr, frameptr + 0x1c, mmu_idx);
-
- if (!pop_ok) {
- /*
- * v7m_stack_read() pended a fault, so take it (as a tail
- * chained exception on the same stack frame)
- */
- qemu_log_mask(CPU_LOG_INT, "...derived exception on unstacking\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- /*
- * Returning from an exception with a PC with bit 0 set is defined
- * behaviour on v8M (bit 0 is ignored), but for v7M it was specified
- * to be UNPREDICTABLE. In practice actual v7M hardware seems to ignore
- * the lsbit, and there are several RTOSes out there which incorrectly
- * assume the r15 in the stack frame should be a Thumb-style "lsbit
- * indicates ARM/Thumb" value, so ignore the bit on v7M as well, but
- * complain about the badly behaved guest.
- */
- if (env->regs[15] & 1) {
- env->regs[15] &= ~1U;
- if (!arm_feature(env, ARM_FEATURE_V8)) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "M profile return from interrupt with misaligned
"
- "PC is UNPREDICTABLE on v7M\n");
- }
- }
-
- if (arm_feature(env, ARM_FEATURE_V8)) {
- /*
- * For v8M we have to check whether the xPSR exception field
- * matches the EXCRET value for return to handler/thread
- * before we commit to changing the SP and xPSR.
- */
- bool will_be_handler = (xpsr & XPSR_EXCP) != 0;
- if (return_to_handler != will_be_handler) {
- /*
- * Take an INVPC UsageFault on the current stack.
- * By this point we will have switched to the security state
- * for the background state, so this UsageFault will target
- * that state.
- */
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
- qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "
- "stackframe: failed exception return integrity "
- "check\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
- }
-
- if (!ftype) {
- /* FP present and we need to handle it */
- if (!return_to_secure &&
- (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK)) {
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...taking SecureFault on existing stackframe: "
- "Secure LSPACT set but exception return is "
- "not to secure state\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- restore_s16_s31 = return_to_secure &&
- (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK);
-
- if (env->v7m.fpccr[return_to_secure] & R_V7M_FPCCR_LSPACT_MASK) {
- /* State in FPU is still valid, just clear LSPACT */
- env->v7m.fpccr[return_to_secure] &= ~R_V7M_FPCCR_LSPACT_MASK;
- } else {
- int i;
- uint32_t fpscr;
- bool cpacr_pass, nsacr_pass;
-
- cpacr_pass = v7m_cpacr_pass(env, return_to_secure,
- return_to_priv);
- nsacr_pass = return_to_secure ||
- extract32(env->v7m.nsacr, 10, 1);
-
- if (!cpacr_pass) {
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- return_to_secure);
- env->v7m.cfsr[return_to_secure] |= R_V7M_CFSR_NOCP_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...taking UsageFault on existing "
- "stackframe: CPACR.CP10 prevents unstacking "
- "FP regs\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- } else if (!nsacr_pass) {
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
true);
- env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_INVPC_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...taking Secure UsageFault on existing "
- "stackframe: NSACR.CP10 prevents unstacking "
- "FP regs\n");
- v7m_exception_taken(cpu, excret, true, false);
- return;
- }
-
- for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) {
- uint32_t slo, shi;
- uint64_t dn;
- uint32_t faddr = frameptr + 0x20 + 4 * i;
-
- if (i >= 16) {
- faddr += 8; /* Skip the slot for the FPSCR */
- }
-
- pop_ok = pop_ok &&
- v7m_stack_read(cpu, &slo, faddr, mmu_idx) &&
- v7m_stack_read(cpu, &shi, faddr + 4, mmu_idx);
-
- if (!pop_ok) {
- break;
- }
-
- dn = (uint64_t)shi << 32 | slo;
- *aa32_vfp_dreg(env, i / 2) = dn;
- }
- pop_ok = pop_ok &&
- v7m_stack_read(cpu, &fpscr, frameptr + 0x60, mmu_idx);
- if (pop_ok) {
- vfp_set_fpscr(env, fpscr);
- }
- if (!pop_ok) {
- /*
- * These regs are 0 if security extension present;
- * otherwise merely UNKNOWN. We zero always.
- */
- for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) {
- *aa32_vfp_dreg(env, i / 2) = 0;
- }
- vfp_set_fpscr(env, 0);
- }
- }
- }
- env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S],
- V7M_CONTROL, FPCA, !ftype);
-
- /* Commit to consuming the stack frame */
- frameptr += 0x20;
- if (!ftype) {
- frameptr += 0x48;
- if (restore_s16_s31) {
- frameptr += 0x40;
- }
- }
- /*
- * Undo stack alignment (the SPREALIGN bit indicates that the original
- * pre-exception SP was not 8-aligned and we added a padding word to
- * align it, so we undo this by ORing in the bit that increases it
- * from the current 8-aligned value to the 8-unaligned value. (Adding 4
- * would work too but a logical OR is how the pseudocode specifies it.)
- */
- if (xpsr & XPSR_SPREALIGN) {
- frameptr |= 4;
- }
- *frame_sp_p = frameptr;
- }
-
- xpsr_mask = ~(XPSR_SPREALIGN | XPSR_SFPA);
- if (!arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
- xpsr_mask &= ~XPSR_GE;
- }
- /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */
- xpsr_write(env, xpsr, xpsr_mask);
-
- if (env->v7m.secure) {
- bool sfpa = xpsr & XPSR_SFPA;
-
- env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S],
- V7M_CONTROL, SFPA, sfpa);
- }
-
- /*
- * The restored xPSR exception field will be zero if we're
- * resuming in Thread mode. If that doesn't match what the
- * exception return excret specified then this is a UsageFault.
- * v7M requires we make this check here; v8M did it earlier.
- */
- if (return_to_handler != arm_v7m_is_handler_mode(env)) {
- /*
- * Take an INVPC UsageFault by pushing the stack again;
- * we know we're v7M so this is never a Secure UsageFault.
- */
- bool ignore_stackfaults;
-
- assert(!arm_feature(env, ARM_FEATURE_V8));
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
- ignore_stackfaults = v7m_push_stack(cpu);
- qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: "
- "failed exception return integrity check\n");
- v7m_exception_taken(cpu, excret, false, ignore_stackfaults);
- return;
- }
-
- /* Otherwise, we have a successful exception exit. */
- arm_clear_exclusive(env);
- qemu_log_mask(CPU_LOG_INT, "...successful exception return\n");
-}
-
-static bool do_v7m_function_return(ARMCPU *cpu)
-{
- /*
- * v8M security extensions magic function return.
- * We may either:
- * (1) throw an exception (longjump)
- * (2) return true if we successfully handled the function return
- * (3) return false if we failed a consistency check and have
- * pended a UsageFault that needs to be taken now
- *
- * At this point the magic return value is split between env->regs[15]
- * and env->thumb. We don't bother to reconstitute it because we don't
- * need it (all values are handled the same way).
- */
- CPUARMState *env = &cpu->env;
- uint32_t newpc, newpsr, newpsr_exc;
-
- qemu_log_mask(CPU_LOG_INT, "...really v7M secure function return\n");
-
- {
- bool threadmode, spsel;
- TCGMemOpIdx oi;
- ARMMMUIdx mmu_idx;
- uint32_t *frame_sp_p;
- uint32_t frameptr;
-
- /* Pull the return address and IPSR from the Secure stack */
- threadmode = !arm_v7m_is_handler_mode(env);
- spsel = env->v7m.control[M_REG_S] & R_V7M_CONTROL_SPSEL_MASK;
-
- frame_sp_p = get_v7m_sp_ptr(env, true, threadmode, spsel);
- frameptr = *frame_sp_p;
-
- /*
- * These loads may throw an exception (for MPU faults). We want to
- * do them as secure, so work out what MMU index that is.
- */
- mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true);
- oi = make_memop_idx(MO_LE, arm_to_core_mmu_idx(mmu_idx));
- newpc = helper_le_ldul_mmu(env, frameptr, oi, 0);
- newpsr = helper_le_ldul_mmu(env, frameptr + 4, oi, 0);
-
- /* Consistency checks on new IPSR */
- newpsr_exc = newpsr & XPSR_EXCP;
- if (!((env->v7m.exception == 0 && newpsr_exc == 0) ||
- (env->v7m.exception == 1 && newpsr_exc != 0))) {
- /* Pend the fault and tell our caller to take it */
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
- env->v7m.secure);
- qemu_log_mask(CPU_LOG_INT,
- "...taking INVPC UsageFault: "
- "IPSR consistency check failed\n");
- return false;
- }
-
- *frame_sp_p = frameptr + 8;
- }
-
- /* This invalidates frame_sp_p */
- switch_v7m_security_state(env, true);
- env->v7m.exception = newpsr_exc;
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
- if (newpsr & XPSR_SFPA) {
- env->v7m.control[M_REG_S] |= R_V7M_CONTROL_SFPA_MASK;
- }
- xpsr_write(env, 0, XPSR_IT);
- env->thumb = newpc & 1;
- env->regs[15] = newpc & ~1;
-
- qemu_log_mask(CPU_LOG_INT, "...function return successful\n");
- return true;
-}
-
-static bool v7m_read_half_insn(ARMCPU *cpu, ARMMMUIdx mmu_idx,
- uint32_t addr, uint16_t *insn)
-{
- /*
- * Load a 16-bit portion of a v7M instruction, returning true on success,
- * or false on failure (in which case we will have pended the appropriate
- * exception).
- * We need to do the instruction fetch's MPU and SAU checks
- * like this because there is no MMU index that would allow
- * doing the load with a single function call. Instead we must
- * first check that the security attributes permit the load
- * and that they don't mismatch on the two halves of the instruction,
- * and then we do the load as a secure load (ie using the security
- * attributes of the address, not the CPU, as architecturally required).
- */
- CPUState *cs = CPU(cpu);
- CPUARMState *env = &cpu->env;
- V8M_SAttributes sattrs = {};
- MemTxAttrs attrs = {};
- ARMMMUFaultInfo fi = {};
- MemTxResult txres;
- target_ulong page_size;
- hwaddr physaddr;
- int prot;
-
- v8m_security_lookup(env, addr, MMU_INST_FETCH, mmu_idx, &sattrs);
- if (!sattrs.nsc || sattrs.ns) {
- /*
- * This must be the second half of the insn, and it straddles a
- * region boundary with the second half not being S&NSC.
- */
- env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- qemu_log_mask(CPU_LOG_INT,
- "...really SecureFault with SFSR.INVEP\n");
- return false;
- }
- if (get_phys_addr(env, addr, MMU_INST_FETCH, mmu_idx,
- &physaddr, &attrs, &prot, &page_size, &fi, NULL)) {
- /* the MPU lookup failed */
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM, env->v7m.secure);
- qemu_log_mask(CPU_LOG_INT, "...really MemManage with CFSR.IACCVIOL\n");
- return false;
- }
- *insn = address_space_lduw_le(arm_addressspace(cs, attrs), physaddr,
- attrs, &txres);
- if (txres != MEMTX_OK) {
- env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false);
- qemu_log_mask(CPU_LOG_INT, "...really BusFault with CFSR.IBUSERR\n");
- return false;
- }
- return true;
-}
-
-static bool v7m_handle_execute_nsc(ARMCPU *cpu)
-{
- /*
- * Check whether this attempt to execute code in a Secure & NS-Callable
- * memory region is for an SG instruction; if so, then emulate the
- * effect of the SG instruction and return true. Otherwise pend
- * the correct kind of exception and return false.
- */
- CPUARMState *env = &cpu->env;
- ARMMMUIdx mmu_idx;
- uint16_t insn;
-
- /*
- * We should never get here unless get_phys_addr_pmsav8() caused
- * an exception for NS executing in S&NSC memory.
- */
- assert(!env->v7m.secure);
- assert(arm_feature(env, ARM_FEATURE_M_SECURITY));
-
- /* We want to do the MPU lookup as secure; work out what mmu_idx that is */
- mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true);
-
- if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15], &insn)) {
- return false;
- }
-
- if (!env->thumb) {
- goto gen_invep;
- }
-
- if (insn != 0xe97f) {
- /*
- * Not an SG instruction first half (we choose the IMPDEF
- * early-SG-check option).
- */
- goto gen_invep;
- }
-
- if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15] + 2, &insn)) {
- return false;
- }
-
- if (insn != 0xe97f) {
- /*
- * Not an SG instruction second half (yes, both halves of the SG
- * insn have the same hex value)
- */
- goto gen_invep;
- }
-
- /*
- * OK, we have confirmed that we really have an SG instruction.
- * We know we're NS in S memory so don't need to repeat those checks.
- */
- qemu_log_mask(CPU_LOG_INT, "...really an SG instruction at 0x%08" PRIx32
- ", executing it\n", env->regs[15]);
- env->regs[14] &= ~1;
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
- switch_v7m_security_state(env, true);
- xpsr_write(env, 0, XPSR_IT);
- env->regs[15] += 4;
- return true;
-
-gen_invep:
- env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- qemu_log_mask(CPU_LOG_INT,
- "...really SecureFault with SFSR.INVEP\n");
- return false;
-}
-
-void arm_v7m_cpu_do_interrupt(CPUState *cs)
-{
- ARMCPU *cpu = ARM_CPU(cs);
- CPUARMState *env = &cpu->env;
- uint32_t lr;
- bool ignore_stackfaults;
-
- arm_log_exception(cs->exception_index);
-
- /*
- * For exceptions we just mark as pending on the NVIC, and let that
- * handle it.
- */
- switch (cs->exception_index) {
- case EXCP_UDEF:
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNDEFINSTR_MASK;
- break;
- case EXCP_NOCP:
- {
- /*
- * NOCP might be directed to something other than the current
- * security state if this fault is because of NSACR; we indicate
- * the target security state using exception.target_el.
- */
- int target_secstate;
-
- if (env->exception.target_el == 3) {
- target_secstate = M_REG_S;
- } else {
- target_secstate = env->v7m.secure;
- }
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, target_secstate);
- env->v7m.cfsr[target_secstate] |= R_V7M_CFSR_NOCP_MASK;
- break;
- }
- case EXCP_INVSTATE:
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVSTATE_MASK;
- break;
- case EXCP_STKOF:
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
- break;
- case EXCP_LSERR:
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
- break;
- case EXCP_UNALIGNED:
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNALIGNED_MASK;
- break;
- case EXCP_SWI:
- /* The PC already points to the next instruction. */
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SVC, env->v7m.secure);
- break;
- case EXCP_PREFETCH_ABORT:
- case EXCP_DATA_ABORT:
- /*
- * Note that for M profile we don't have a guest facing FSR, but
- * the env->exception.fsr will be populated by the code that
- * raises the fault, in the A profile short-descriptor format.
- */
- switch (env->exception.fsr & 0xf) {
- case M_FAKE_FSR_NSC_EXEC:
- /*
- * Exception generated when we try to execute code at an address
- * which is marked as Secure & Non-Secure Callable and the CPU
- * is in the Non-Secure state. The only instruction which can
- * be executed like this is SG (and that only if both halves of
- * the SG instruction have the same security attributes.)
- * Everything else must generate an INVEP SecureFault, so we
- * emulate the SG instruction here.
- */
- if (v7m_handle_execute_nsc(cpu)) {
- return;
- }
- break;
- case M_FAKE_FSR_SFAULT:
- /*
- * Various flavours of SecureFault for attempts to execute or
- * access data in the wrong security state.
- */
- switch (cs->exception_index) {
- case EXCP_PREFETCH_ABORT:
- if (env->v7m.secure) {
- env->v7m.sfsr |= R_V7M_SFSR_INVTRAN_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...really SecureFault with SFSR.INVTRAN\n");
- } else {
- env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...really SecureFault with SFSR.INVEP\n");
- }
- break;
- case EXCP_DATA_ABORT:
- /* This must be an NS access to S memory */
- env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK;
- qemu_log_mask(CPU_LOG_INT,
- "...really SecureFault with SFSR.AUVIOL\n");
- break;
- }
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
- break;
- case 0x8: /* External Abort */
- switch (cs->exception_index) {
- case EXCP_PREFETCH_ABORT:
- env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK;
- qemu_log_mask(CPU_LOG_INT, "...with CFSR.IBUSERR\n");
- break;
- case EXCP_DATA_ABORT:
- env->v7m.cfsr[M_REG_NS] |=
- (R_V7M_CFSR_PRECISERR_MASK | R_V7M_CFSR_BFARVALID_MASK);
- env->v7m.bfar = env->exception.vaddress;
- qemu_log_mask(CPU_LOG_INT,
- "...with CFSR.PRECISERR and BFAR 0x%x\n",
- env->v7m.bfar);
- break;
- }
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false);
- break;
- default:
- /*
- * All other FSR values are either MPU faults or "can't happen
- * for M profile" cases.
- */
- switch (cs->exception_index) {
- case EXCP_PREFETCH_ABORT:
- env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK;
- qemu_log_mask(CPU_LOG_INT, "...with CFSR.IACCVIOL\n");
- break;
- case EXCP_DATA_ABORT:
- env->v7m.cfsr[env->v7m.secure] |=
- (R_V7M_CFSR_DACCVIOL_MASK | R_V7M_CFSR_MMARVALID_MASK);
- env->v7m.mmfar[env->v7m.secure] = env->exception.vaddress;
- qemu_log_mask(CPU_LOG_INT,
- "...with CFSR.DACCVIOL and MMFAR 0x%x\n",
- env->v7m.mmfar[env->v7m.secure]);
- break;
- }
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM,
- env->v7m.secure);
- break;
- }
- break;
- case EXCP_BKPT:
- if (semihosting_enabled()) {
- int nr;
- nr = arm_lduw_code(env, env->regs[15], arm_sctlr_b(env)) & 0xff;
- if (nr == 0xab) {
- env->regs[15] += 2;
- qemu_log_mask(CPU_LOG_INT,
- "...handling as semihosting call 0x%x\n",
- env->regs[0]);
- env->regs[0] = do_arm_semihosting(env);
- return;
- }
- }
- armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG, false);
- break;
- case EXCP_IRQ:
- break;
- case EXCP_EXCEPTION_EXIT:
- if (env->regs[15] < EXC_RETURN_MIN_MAGIC) {
- /* Must be v8M security extension function return */
- assert(env->regs[15] >= FNC_RETURN_MIN_MAGIC);
- assert(arm_feature(env, ARM_FEATURE_M_SECURITY));
- if (do_v7m_function_return(cpu)) {
- return;
- }
- } else {
- do_v7m_exception_exit(cpu);
- return;
- }
- break;
- case EXCP_LAZYFP:
- /*
- * We already pended the specific exception in the NVIC in the
- * v7m_preserve_fp_state() helper function.
- */
- break;
- default:
- cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
- return; /* Never happens. Keep compiler happy. */
- }
-
- if (arm_feature(env, ARM_FEATURE_V8)) {
- lr = R_V7M_EXCRET_RES1_MASK |
- R_V7M_EXCRET_DCRS_MASK;
- /*
- * The S bit indicates whether we should return to Secure
- * or NonSecure (ie our current state).
- * The ES bit indicates whether we're taking this exception
- * to Secure or NonSecure (ie our target state). We set it
- * later, in v7m_exception_taken().
- * The SPSEL bit is also set in v7m_exception_taken() for v8M.
- * This corresponds to the ARM ARM pseudocode for v8M setting
- * some LR bits in PushStack() and some in ExceptionTaken();
- * the distinction matters for the tailchain cases where we
- * can take an exception without pushing the stack.
- */
- if (env->v7m.secure) {
- lr |= R_V7M_EXCRET_S_MASK;
- }
- if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) {
- lr |= R_V7M_EXCRET_FTYPE_MASK;
- }
- } else {
- lr = R_V7M_EXCRET_RES1_MASK |
- R_V7M_EXCRET_S_MASK |
- R_V7M_EXCRET_DCRS_MASK |
- R_V7M_EXCRET_FTYPE_MASK |
- R_V7M_EXCRET_ES_MASK;
- if (env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK) {
- lr |= R_V7M_EXCRET_SPSEL_MASK;
- }
- }
- if (!arm_v7m_is_handler_mode(env)) {
- lr |= R_V7M_EXCRET_MODE_MASK;
- }
-
- ignore_stackfaults = v7m_push_stack(cpu);
- v7m_exception_taken(cpu, lr, false, ignore_stackfaults);
-}
-
/*
* Function used to synchronize QEMU's AArch64 register set with AArch32
* register set. This is necessary when switching between AArch32 and AArch64
@@ -12754,466 +10613,6 @@ hwaddr arm_cpu_get_phys_page_attrs_debug(CPUState
*cs, vaddr addr,
return phys_addr;
}
-uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
-{
- uint32_t mask;
- unsigned el = arm_current_el(env);
-
- /* First handle registers which unprivileged can read */
-
- switch (reg) {
- case 0 ... 7: /* xPSR sub-fields */
- mask = 0;
- if ((reg & 1) && el) {
- mask |= XPSR_EXCP; /* IPSR (unpriv. reads as zero) */
- }
- if (!(reg & 4)) {
- mask |= XPSR_NZCV | XPSR_Q; /* APSR */
- if (arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
- mask |= XPSR_GE;
- }
- }
- /* EPSR reads as zero */
- return xpsr_read(env) & mask;
- break;
- case 20: /* CONTROL */
- {
- uint32_t value = env->v7m.control[env->v7m.secure];
- if (!env->v7m.secure) {
- /* SFPA is RAZ/WI from NS; FPCA is stored in the M_REG_S bank */
- value |= env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK;
- }
- return value;
- }
- case 0x94: /* CONTROL_NS */
- /*
- * We have to handle this here because unprivileged Secure code
- * can read the NS CONTROL register.
- */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.control[M_REG_NS] |
- (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK);
- }
-
- if (el == 0) {
- return 0; /* unprivileged reads others as zero */
- }
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- switch (reg) {
- case 0x88: /* MSP_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.other_ss_msp;
- case 0x89: /* PSP_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.other_ss_psp;
- case 0x8a: /* MSPLIM_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.msplim[M_REG_NS];
- case 0x8b: /* PSPLIM_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.psplim[M_REG_NS];
- case 0x90: /* PRIMASK_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.primask[M_REG_NS];
- case 0x91: /* BASEPRI_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.basepri[M_REG_NS];
- case 0x93: /* FAULTMASK_NS */
- if (!env->v7m.secure) {
- return 0;
- }
- return env->v7m.faultmask[M_REG_NS];
- case 0x98: /* SP_NS */
- {
- /*
- * This gives the non-secure SP selected based on whether we're
- * currently in handler mode or not, using the NS CONTROL.SPSEL.
- */
- bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK;
-
- if (!env->v7m.secure) {
- return 0;
- }
- if (!arm_v7m_is_handler_mode(env) && spsel) {
- return env->v7m.other_ss_psp;
- } else {
- return env->v7m.other_ss_msp;
- }
- }
- default:
- break;
- }
- }
-
- switch (reg) {
- case 8: /* MSP */
- return v7m_using_psp(env) ? env->v7m.other_sp : env->regs[13];
- case 9: /* PSP */
- return v7m_using_psp(env) ? env->regs[13] : env->v7m.other_sp;
- case 10: /* MSPLIM */
- if (!arm_feature(env, ARM_FEATURE_V8)) {
- goto bad_reg;
- }
- return env->v7m.msplim[env->v7m.secure];
- case 11: /* PSPLIM */
- if (!arm_feature(env, ARM_FEATURE_V8)) {
- goto bad_reg;
- }
- return env->v7m.psplim[env->v7m.secure];
- case 16: /* PRIMASK */
- return env->v7m.primask[env->v7m.secure];
- case 17: /* BASEPRI */
- case 18: /* BASEPRI_MAX */
- return env->v7m.basepri[env->v7m.secure];
- case 19: /* FAULTMASK */
- return env->v7m.faultmask[env->v7m.secure];
- default:
- bad_reg:
- qemu_log_mask(LOG_GUEST_ERROR, "Attempt to read unknown special"
- " register %d\n", reg);
- return 0;
- }
-}
-
-void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val)
-{
- /*
- * We're passed bits [11..0] of the instruction; extract
- * SYSm and the mask bits.
- * Invalid combinations of SYSm and mask are UNPREDICTABLE;
- * we choose to treat them as if the mask bits were valid.
- * NB that the pseudocode 'mask' variable is bits [11..10],
- * whereas ours is [11..8].
- */
- uint32_t mask = extract32(maskreg, 8, 4);
- uint32_t reg = extract32(maskreg, 0, 8);
- int cur_el = arm_current_el(env);
-
- if (cur_el == 0 && reg > 7 && reg != 20) {
- /*
- * only xPSR sub-fields and CONTROL.SFPA may be written by
- * unprivileged code
- */
- return;
- }
-
- if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
- switch (reg) {
- case 0x88: /* MSP_NS */
- if (!env->v7m.secure) {
- return;
- }
- env->v7m.other_ss_msp = val;
- return;
- case 0x89: /* PSP_NS */
- if (!env->v7m.secure) {
- return;
- }
- env->v7m.other_ss_psp = val;
- return;
- case 0x8a: /* MSPLIM_NS */
- if (!env->v7m.secure) {
- return;
- }
- env->v7m.msplim[M_REG_NS] = val & ~7;
- return;
- case 0x8b: /* PSPLIM_NS */
- if (!env->v7m.secure) {
- return;
- }
- env->v7m.psplim[M_REG_NS] = val & ~7;
- return;
- case 0x90: /* PRIMASK_NS */
- if (!env->v7m.secure) {
- return;
- }
- env->v7m.primask[M_REG_NS] = val & 1;
- return;
- case 0x91: /* BASEPRI_NS */
- if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
- return;
- }
- env->v7m.basepri[M_REG_NS] = val & 0xff;
- return;
- case 0x93: /* FAULTMASK_NS */
- if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
- return;
- }
- env->v7m.faultmask[M_REG_NS] = val & 1;
- return;
- case 0x94: /* CONTROL_NS */
- if (!env->v7m.secure) {
- return;
- }
- write_v7m_control_spsel_for_secstate(env,
- val &
R_V7M_CONTROL_SPSEL_MASK,
- M_REG_NS);
- if (arm_feature(env, ARM_FEATURE_M_MAIN)) {
- env->v7m.control[M_REG_NS] &= ~R_V7M_CONTROL_NPRIV_MASK;
- env->v7m.control[M_REG_NS] |= val & R_V7M_CONTROL_NPRIV_MASK;
- }
- /*
- * SFPA is RAZ/WI from NS. FPCA is RO if NSACR.CP10 == 0,
- * RES0 if the FPU is not present, and is stored in the S bank
- */
- if (arm_feature(env, ARM_FEATURE_VFP) &&
- extract32(env->v7m.nsacr, 10, 1)) {
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
- env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK;
- }
- return;
- case 0x98: /* SP_NS */
- {
- /*
- * This gives the non-secure SP selected based on whether we're
- * currently in handler mode or not, using the NS CONTROL.SPSEL.
- */
- bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK;
- bool is_psp = !arm_v7m_is_handler_mode(env) && spsel;
- uint32_t limit;
-
- if (!env->v7m.secure) {
- return;
- }
-
- limit = is_psp ? env->v7m.psplim[false] : env->v7m.msplim[false];
-
- if (val < limit) {
- CPUState *cs = env_cpu(env);
-
- cpu_restore_state(cs, GETPC(), true);
- raise_exception(env, EXCP_STKOF, 0, 1);
- }
-
- if (is_psp) {
- env->v7m.other_ss_psp = val;
- } else {
- env->v7m.other_ss_msp = val;
- }
- return;
- }
- default:
- break;
- }
- }
-
- switch (reg) {
- case 0 ... 7: /* xPSR sub-fields */
- /* only APSR is actually writable */
- if (!(reg & 4)) {
- uint32_t apsrmask = 0;
-
- if (mask & 8) {
- apsrmask |= XPSR_NZCV | XPSR_Q;
- }
- if ((mask & 4) && arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
- apsrmask |= XPSR_GE;
- }
- xpsr_write(env, val, apsrmask);
- }
- break;
- case 8: /* MSP */
- if (v7m_using_psp(env)) {
- env->v7m.other_sp = val;
- } else {
- env->regs[13] = val;
- }
- break;
- case 9: /* PSP */
- if (v7m_using_psp(env)) {
- env->regs[13] = val;
- } else {
- env->v7m.other_sp = val;
- }
- break;
- case 10: /* MSPLIM */
- if (!arm_feature(env, ARM_FEATURE_V8)) {
- goto bad_reg;
- }
- env->v7m.msplim[env->v7m.secure] = val & ~7;
- break;
- case 11: /* PSPLIM */
- if (!arm_feature(env, ARM_FEATURE_V8)) {
- goto bad_reg;
- }
- env->v7m.psplim[env->v7m.secure] = val & ~7;
- break;
- case 16: /* PRIMASK */
- env->v7m.primask[env->v7m.secure] = val & 1;
- break;
- case 17: /* BASEPRI */
- if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
- goto bad_reg;
- }
- env->v7m.basepri[env->v7m.secure] = val & 0xff;
- break;
- case 18: /* BASEPRI_MAX */
- if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
- goto bad_reg;
- }
- val &= 0xff;
- if (val != 0 && (val < env->v7m.basepri[env->v7m.secure]
- || env->v7m.basepri[env->v7m.secure] == 0)) {
- env->v7m.basepri[env->v7m.secure] = val;
- }
- break;
- case 19: /* FAULTMASK */
- if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
- goto bad_reg;
- }
- env->v7m.faultmask[env->v7m.secure] = val & 1;
- break;
- case 20: /* CONTROL */
- /*
- * Writing to the SPSEL bit only has an effect if we are in
- * thread mode; other bits can be updated by any privileged code.
- * write_v7m_control_spsel() deals with updating the SPSEL bit in
- * env->v7m.control, so we only need update the others.
- * For v7M, we must just ignore explicit writes to SPSEL in handler
- * mode; for v8M the write is permitted but will have no effect.
- * All these bits are writes-ignored from non-privileged code,
- * except for SFPA.
- */
- if (cur_el > 0 && (arm_feature(env, ARM_FEATURE_V8) ||
- !arm_v7m_is_handler_mode(env))) {
- write_v7m_control_spsel(env, (val & R_V7M_CONTROL_SPSEL_MASK) !=
0);
- }
- if (cur_el > 0 && arm_feature(env, ARM_FEATURE_M_MAIN)) {
- env->v7m.control[env->v7m.secure] &= ~R_V7M_CONTROL_NPRIV_MASK;
- env->v7m.control[env->v7m.secure] |= val &
R_V7M_CONTROL_NPRIV_MASK;
- }
- if (arm_feature(env, ARM_FEATURE_VFP)) {
- /*
- * SFPA is RAZ/WI from NS or if no FPU.
- * FPCA is RO if NSACR.CP10 == 0, RES0 if the FPU is not present.
- * Both are stored in the S bank.
- */
- if (env->v7m.secure) {
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
- env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_SFPA_MASK;
- }
- if (cur_el > 0 &&
- (env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)
||
- extract32(env->v7m.nsacr, 10, 1))) {
- env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
- env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK;
- }
- }
- break;
- default:
- bad_reg:
- qemu_log_mask(LOG_GUEST_ERROR, "Attempt to write unknown special"
- " register %d\n", reg);
- return;
- }
-}
-
-uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
-{
- /* Implement the TT instruction. op is bits [7:6] of the insn. */
- bool forceunpriv = op & 1;
- bool alt = op & 2;
- V8M_SAttributes sattrs = {};
- uint32_t tt_resp;
- bool r, rw, nsr, nsrw, mrvalid;
- int prot;
- ARMMMUFaultInfo fi = {};
- MemTxAttrs attrs = {};
- hwaddr phys_addr;
- ARMMMUIdx mmu_idx;
- uint32_t mregion;
- bool targetpriv;
- bool targetsec = env->v7m.secure;
- bool is_subpage;
-
- /*
- * Work out what the security state and privilege level we're
- * interested in is...
- */
- if (alt) {
- targetsec = !targetsec;
- }
-
- if (forceunpriv) {
- targetpriv = false;
- } else {
- targetpriv = arm_v7m_is_handler_mode(env) ||
- !(env->v7m.control[targetsec] & R_V7M_CONTROL_NPRIV_MASK);
- }
-
- /* ...and then figure out which MMU index this is */
- mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targetsec,
targetpriv);
-
- /*
- * We know that the MPU and SAU don't care about the access type
- * for our purposes beyond that we don't want to claim to be
- * an insn fetch, so we arbitrarily call this a read.
- */
-
- /*
- * MPU region info only available for privileged or if
- * inspecting the other MPU state.
- */
- if (arm_current_el(env) != 0 || alt) {
- /* We can ignore the return value as prot is always set */
- pmsav8_mpu_lookup(env, addr, MMU_DATA_LOAD, mmu_idx,
- &phys_addr, &attrs, &prot, &is_subpage,
- &fi, &mregion);
- if (mregion == -1) {
- mrvalid = false;
- mregion = 0;
- } else {
- mrvalid = true;
- }
- r = prot & PAGE_READ;
- rw = prot & PAGE_WRITE;
- } else {
- r = false;
- rw = false;
- mrvalid = false;
- mregion = 0;
- }
-
- if (env->v7m.secure) {
- v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs);
- nsr = sattrs.ns && r;
- nsrw = sattrs.ns && rw;
- } else {
- sattrs.ns = true;
- nsr = false;
- nsrw = false;
- }
-
- tt_resp = (sattrs.iregion << 24) |
- (sattrs.irvalid << 23) |
- ((!sattrs.ns) << 22) |
- (nsrw << 21) |
- (nsr << 20) |
- (rw << 19) |
- (r << 18) |
- (sattrs.srvalid << 17) |
- (mrvalid << 16) |
- (sattrs.sregion << 8) |
- mregion;
-
- return tt_resp;
-}
-
#endif
/* Note that signed overflow is undefined in C. The following routines are
@@ -13578,41 +10977,12 @@ int fp_exception_el(CPUARMState *env, int cur_el)
return 0;
}
-ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env,
- bool secstate, bool priv, bool negpri)
-{
- ARMMMUIdx mmu_idx = ARM_MMU_IDX_M;
-
- if (priv) {
- mmu_idx |= ARM_MMU_IDX_M_PRIV;
- }
-
- if (negpri) {
- mmu_idx |= ARM_MMU_IDX_M_NEGPRI;
- }
-
- if (secstate) {
- mmu_idx |= ARM_MMU_IDX_M_S;
- }
-
- return mmu_idx;
-}
-
-ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env,
- bool secstate, bool priv)
-{
- bool negpri = armv7m_nvic_neg_prio_requested(env->nvic, secstate);
-
- return arm_v7m_mmu_idx_all(env, secstate, priv, negpri);
-}
-
-/* Return the MMU index for a v7M CPU in the specified security state */
+#ifndef CONFIG_TCG
ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate)
{
- bool priv = arm_current_el(env) != 0;
-
- return arm_v7m_mmu_idx_for_secstate_and_priv(env, secstate, priv);
+ g_assert_not_reached();
}
+#endif
ARMMMUIdx arm_mmu_idx(CPUARMState *env)
{
diff --git a/target/arm/m_helper.c b/target/arm/m_helper.c
new file mode 100644
index 0000000000..1b0ad95a05
--- /dev/null
+++ b/target/arm/m_helper.c
@@ -0,0 +1,2676 @@
+/*
+ * ARM generic helpers.
+ *
+ * This code is licensed under the GNU GPL v2 or later.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include "qemu/osdep.h"
+#include "qemu/units.h"
+#include "target/arm/idau.h"
+#include "trace.h"
+#include "cpu.h"
+#include "internals.h"
+#include "exec/gdbstub.h"
+#include "exec/helper-proto.h"
+#include "qemu/host-utils.h"
+#include "sysemu/sysemu.h"
+#include "qemu/bitops.h"
+#include "qemu/crc32c.h"
+#include "qemu/qemu-print.h"
+#include "exec/exec-all.h"
+#include <zlib.h> /* For crc32 */
+#include "hw/semihosting/semihost.h"
+#include "sysemu/cpus.h"
+#include "sysemu/kvm.h"
+#include "qemu/range.h"
+#include "qapi/qapi-commands-target.h"
+#include "qapi/error.h"
+#include "qemu/guest-random.h"
+#ifdef CONFIG_TCG
+#include "arm_ldst.h"
+#include "exec/cpu_ldst.h"
+#endif
+
+#ifdef CONFIG_USER_ONLY
+
+/* These should probably raise undefined insn exceptions. */
+void HELPER(v7m_msr)(CPUARMState *env, uint32_t reg, uint32_t val)
+{
+ ARMCPU *cpu = env_archcpu(env);
+
+ cpu_abort(CPU(cpu), "v7m_msr %d\n", reg);
+}
+
+uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
+{
+ ARMCPU *cpu = env_archcpu(env);
+
+ cpu_abort(CPU(cpu), "v7m_mrs %d\n", reg);
+ return 0;
+}
+
+void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
+void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
+void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
+void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
+void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr)
+{
+ /* translate.c should never generate calls here in user-only mode */
+ g_assert_not_reached();
+}
+
+uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
+{
+ /*
+ * The TT instructions can be used by unprivileged code, but in
+ * user-only emulation we don't have the MPU.
+ * Luckily since we know we are NonSecure unprivileged (and that in
+ * turn means that the A flag wasn't specified), all the bits in the
+ * register must be zero:
+ * IREGION: 0 because IRVALID is 0
+ * IRVALID: 0 because NS
+ * S: 0 because NS
+ * NSRW: 0 because NS
+ * NSR: 0 because NS
+ * RW: 0 because unpriv and A flag not set
+ * R: 0 because unpriv and A flag not set
+ * SRVALID: 0 because NS
+ * MRVALID: 0 because unpriv and A flag not set
+ * SREGION: 0 becaus SRVALID is 0
+ * MREGION: 0 because MRVALID is 0
+ */
+ return 0;
+}
+
+#else
+
+/*
+ * What kind of stack write are we doing? This affects how exceptions
+ * generated during the stacking are treated.
+ */
+typedef enum StackingMode {
+ STACK_NORMAL,
+ STACK_IGNFAULTS,
+ STACK_LAZYFP,
+} StackingMode;
+
+static bool v7m_stack_write(ARMCPU *cpu, uint32_t addr, uint32_t value,
+ ARMMMUIdx mmu_idx, StackingMode mode)
+{
+ CPUState *cs = CPU(cpu);
+ CPUARMState *env = &cpu->env;
+ MemTxAttrs attrs = {};
+ MemTxResult txres;
+ target_ulong page_size;
+ hwaddr physaddr;
+ int prot;
+ ARMMMUFaultInfo fi = {};
+ bool secure = mmu_idx & ARM_MMU_IDX_M_S;
+ int exc;
+ bool exc_secure;
+
+ if (get_phys_addr(env, addr, MMU_DATA_STORE, mmu_idx, &physaddr,
+ &attrs, &prot, &page_size, &fi, NULL)) {
+ /* MPU/SAU lookup failed */
+ if (fi.type == ARMFault_QEMU_SFault) {
+ if (mode == STACK_LAZYFP) {
+ qemu_log_mask(CPU_LOG_INT,
+ "...SecureFault with SFSR.LSPERR "
+ "during lazy stacking\n");
+ env->v7m.sfsr |= R_V7M_SFSR_LSPERR_MASK;
+ } else {
+ qemu_log_mask(CPU_LOG_INT,
+ "...SecureFault with SFSR.AUVIOL "
+ "during stacking\n");
+ env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK;
+ }
+ env->v7m.sfsr |= R_V7M_SFSR_SFARVALID_MASK;
+ env->v7m.sfar = addr;
+ exc = ARMV7M_EXCP_SECURE;
+ exc_secure = false;
+ } else {
+ if (mode == STACK_LAZYFP) {
+ qemu_log_mask(CPU_LOG_INT,
+ "...MemManageFault with CFSR.MLSPERR\n");
+ env->v7m.cfsr[secure] |= R_V7M_CFSR_MLSPERR_MASK;
+ } else {
+ qemu_log_mask(CPU_LOG_INT,
+ "...MemManageFault with CFSR.MSTKERR\n");
+ env->v7m.cfsr[secure] |= R_V7M_CFSR_MSTKERR_MASK;
+ }
+ exc = ARMV7M_EXCP_MEM;
+ exc_secure = secure;
+ }
+ goto pend_fault;
+ }
+ address_space_stl_le(arm_addressspace(cs, attrs), physaddr, value,
+ attrs, &txres);
+ if (txres != MEMTX_OK) {
+ /* BusFault trying to write the data */
+ if (mode == STACK_LAZYFP) {
+ qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.LSPERR\n");
+ env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_LSPERR_MASK;
+ } else {
+ qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.STKERR\n");
+ env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_STKERR_MASK;
+ }
+ exc = ARMV7M_EXCP_BUS;
+ exc_secure = false;
+ goto pend_fault;
+ }
+ return true;
+
+pend_fault:
+ /*
+ * By pending the exception at this point we are making
+ * the IMPDEF choice "overridden exceptions pended" (see the
+ * MergeExcInfo() pseudocode). The other choice would be to not
+ * pend them now and then make a choice about which to throw away
+ * later if we have two derived exceptions.
+ * The only case when we must not pend the exception but instead
+ * throw it away is if we are doing the push of the callee registers
+ * and we've already generated a derived exception (this is indicated
+ * by the caller passing STACK_IGNFAULTS). Even in this case we will
+ * still update the fault status registers.
+ */
+ switch (mode) {
+ case STACK_NORMAL:
+ armv7m_nvic_set_pending_derived(env->nvic, exc, exc_secure);
+ break;
+ case STACK_LAZYFP:
+ armv7m_nvic_set_pending_lazyfp(env->nvic, exc, exc_secure);
+ break;
+ case STACK_IGNFAULTS:
+ break;
+ }
+ return false;
+}
+
+static bool v7m_stack_read(ARMCPU *cpu, uint32_t *dest, uint32_t addr,
+ ARMMMUIdx mmu_idx)
+{
+ CPUState *cs = CPU(cpu);
+ CPUARMState *env = &cpu->env;
+ MemTxAttrs attrs = {};
+ MemTxResult txres;
+ target_ulong page_size;
+ hwaddr physaddr;
+ int prot;
+ ARMMMUFaultInfo fi = {};
+ bool secure = mmu_idx & ARM_MMU_IDX_M_S;
+ int exc;
+ bool exc_secure;
+ uint32_t value;
+
+ if (get_phys_addr(env, addr, MMU_DATA_LOAD, mmu_idx, &physaddr,
+ &attrs, &prot, &page_size, &fi, NULL)) {
+ /* MPU/SAU lookup failed */
+ if (fi.type == ARMFault_QEMU_SFault) {
+ qemu_log_mask(CPU_LOG_INT,
+ "...SecureFault with SFSR.AUVIOL during unstack\n");
+ env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK |
R_V7M_SFSR_SFARVALID_MASK;
+ env->v7m.sfar = addr;
+ exc = ARMV7M_EXCP_SECURE;
+ exc_secure = false;
+ } else {
+ qemu_log_mask(CPU_LOG_INT,
+ "...MemManageFault with CFSR.MUNSTKERR\n");
+ env->v7m.cfsr[secure] |= R_V7M_CFSR_MUNSTKERR_MASK;
+ exc = ARMV7M_EXCP_MEM;
+ exc_secure = secure;
+ }
+ goto pend_fault;
+ }
+
+ value = address_space_ldl(arm_addressspace(cs, attrs), physaddr,
+ attrs, &txres);
+ if (txres != MEMTX_OK) {
+ /* BusFault trying to read the data */
+ qemu_log_mask(CPU_LOG_INT, "...BusFault with BFSR.UNSTKERR\n");
+ env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_UNSTKERR_MASK;
+ exc = ARMV7M_EXCP_BUS;
+ exc_secure = false;
+ goto pend_fault;
+ }
+
+ *dest = value;
+ return true;
+
+pend_fault:
+ /*
+ * By pending the exception at this point we are making
+ * the IMPDEF choice "overridden exceptions pended" (see the
+ * MergeExcInfo() pseudocode). The other choice would be to not
+ * pend them now and then make a choice about which to throw away
+ * later if we have two derived exceptions.
+ */
+ armv7m_nvic_set_pending(env->nvic, exc, exc_secure);
+ return false;
+}
+
+void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
+{
+ /*
+ * Preserve FP state (because LSPACT was set and we are about
+ * to execute an FP instruction). This corresponds to the
+ * PreserveFPState() pseudocode.
+ * We may throw an exception if the stacking fails.
+ */
+ ARMCPU *cpu = env_archcpu(env);
+ bool is_secure = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
+ bool negpri = !(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_HFRDY_MASK);
+ bool is_priv = !(env->v7m.fpccr[is_secure] & R_V7M_FPCCR_USER_MASK);
+ bool splimviol = env->v7m.fpccr[is_secure] & R_V7M_FPCCR_SPLIMVIOL_MASK;
+ uint32_t fpcar = env->v7m.fpcar[is_secure];
+ bool stacked_ok = true;
+ bool ts = is_secure && (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK);
+ bool take_exception;
+
+ /* Take the iothread lock as we are going to touch the NVIC */
+ qemu_mutex_lock_iothread();
+
+ /* Check the background context had access to the FPU */
+ if (!v7m_cpacr_pass(env, is_secure, is_priv)) {
+ armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE,
is_secure);
+ env->v7m.cfsr[is_secure] |= R_V7M_CFSR_NOCP_MASK;
+ stacked_ok = false;
+ } else if (!is_secure && !extract32(env->v7m.nsacr, 10, 1)) {
+ armv7m_nvic_set_pending_lazyfp(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S);
+ env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK;
+ stacked_ok = false;
+ }
+
+ if (!splimviol && stacked_ok) {
+ /* We only stack if the stack limit wasn't violated */
+ int i;
+ ARMMMUIdx mmu_idx;
+
+ mmu_idx = arm_v7m_mmu_idx_all(env, is_secure, is_priv, negpri);
+ for (i = 0; i < (ts ? 32 : 16); i += 2) {
+ uint64_t dn = *aa32_vfp_dreg(env, i / 2);
+ uint32_t faddr = fpcar + 4 * i;
+ uint32_t slo = extract64(dn, 0, 32);
+ uint32_t shi = extract64(dn, 32, 32);
+
+ if (i >= 16) {
+ faddr += 8; /* skip the slot for the FPSCR */
+ }
+ stacked_ok = stacked_ok &&
+ v7m_stack_write(cpu, faddr, slo, mmu_idx, STACK_LAZYFP) &&
+ v7m_stack_write(cpu, faddr + 4, shi, mmu_idx, STACK_LAZYFP);
+ }
+
+ stacked_ok = stacked_ok &&
+ v7m_stack_write(cpu, fpcar + 0x40,
+ vfp_get_fpscr(env), mmu_idx, STACK_LAZYFP);
+ }
+
+ /*
+ * We definitely pended an exception, but it's possible that it
+ * might not be able to be taken now. If its priority permits us
+ * to take it now, then we must not update the LSPACT or FP regs,
+ * but instead jump out to take the exception immediately.
+ * If it's just pending and won't be taken until the current
+ * handler exits, then we do update LSPACT and the FP regs.
+ */
+ take_exception = !stacked_ok &&
+ armv7m_nvic_can_take_pending_exception(env->nvic);
+
+ qemu_mutex_unlock_iothread();
+
+ if (take_exception) {
+ raise_exception_ra(env, EXCP_LAZYFP, 0, 1, GETPC());
+ }
+
+ env->v7m.fpccr[is_secure] &= ~R_V7M_FPCCR_LSPACT_MASK;
+
+ if (ts) {
+ /* Clear s0 to s31 and the FPSCR */
+ int i;
+
+ for (i = 0; i < 32; i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ /*
+ * Otherwise s0 to s15 and FPSCR are UNKNOWN; we choose to leave them
+ * unchanged.
+ */
+}
+
+/*
+ * Write to v7M CONTROL.SPSEL bit for the specified security bank.
+ * This may change the current stack pointer between Main and Process
+ * stack pointers if it is done for the CONTROL register for the current
+ * security state.
+ */
+static void write_v7m_control_spsel_for_secstate(CPUARMState *env,
+ bool new_spsel,
+ bool secstate)
+{
+ bool old_is_psp = v7m_using_psp(env);
+
+ env->v7m.control[secstate] =
+ deposit32(env->v7m.control[secstate],
+ R_V7M_CONTROL_SPSEL_SHIFT,
+ R_V7M_CONTROL_SPSEL_LENGTH, new_spsel);
+
+ if (secstate == env->v7m.secure) {
+ bool new_is_psp = v7m_using_psp(env);
+ uint32_t tmp;
+
+ if (old_is_psp != new_is_psp) {
+ tmp = env->v7m.other_sp;
+ env->v7m.other_sp = env->regs[13];
+ env->regs[13] = tmp;
+ }
+ }
+}
+
+/*
+ * Write to v7M CONTROL.SPSEL bit. This may change the current
+ * stack pointer between Main and Process stack pointers.
+ */
+static void write_v7m_control_spsel(CPUARMState *env, bool new_spsel)
+{
+ write_v7m_control_spsel_for_secstate(env, new_spsel, env->v7m.secure);
+}
+
+void write_v7m_exception(CPUARMState *env, uint32_t new_exc)
+{
+ /*
+ * Write a new value to v7m.exception, thus transitioning into or out
+ * of Handler mode; this may result in a change of active stack pointer.
+ */
+ bool new_is_psp, old_is_psp = v7m_using_psp(env);
+ uint32_t tmp;
+
+ env->v7m.exception = new_exc;
+
+ new_is_psp = v7m_using_psp(env);
+
+ if (old_is_psp != new_is_psp) {
+ tmp = env->v7m.other_sp;
+ env->v7m.other_sp = env->regs[13];
+ env->regs[13] = tmp;
+ }
+}
+
+/* Switch M profile security state between NS and S */
+static void switch_v7m_security_state(CPUARMState *env, bool new_secstate)
+{
+ uint32_t new_ss_msp, new_ss_psp;
+
+ if (env->v7m.secure == new_secstate) {
+ return;
+ }
+
+ /*
+ * All the banked state is accessed by looking at env->v7m.secure
+ * except for the stack pointer; rearrange the SP appropriately.
+ */
+ new_ss_msp = env->v7m.other_ss_msp;
+ new_ss_psp = env->v7m.other_ss_psp;
+
+ if (v7m_using_psp(env)) {
+ env->v7m.other_ss_psp = env->regs[13];
+ env->v7m.other_ss_msp = env->v7m.other_sp;
+ } else {
+ env->v7m.other_ss_msp = env->regs[13];
+ env->v7m.other_ss_psp = env->v7m.other_sp;
+ }
+
+ env->v7m.secure = new_secstate;
+
+ if (v7m_using_psp(env)) {
+ env->regs[13] = new_ss_psp;
+ env->v7m.other_sp = new_ss_msp;
+ } else {
+ env->regs[13] = new_ss_msp;
+ env->v7m.other_sp = new_ss_psp;
+ }
+}
+
+void HELPER(v7m_bxns)(CPUARMState *env, uint32_t dest)
+{
+ /*
+ * Handle v7M BXNS:
+ * - if the return value is a magic value, do exception return (like BX)
+ * - otherwise bit 0 of the return value is the target security state
+ */
+ uint32_t min_magic;
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ /* Covers FNC_RETURN and EXC_RETURN magic */
+ min_magic = FNC_RETURN_MIN_MAGIC;
+ } else {
+ /* EXC_RETURN magic only */
+ min_magic = EXC_RETURN_MIN_MAGIC;
+ }
+
+ if (dest >= min_magic) {
+ /*
+ * This is an exception return magic value; put it where
+ * do_v7m_exception_exit() expects and raise EXCEPTION_EXIT.
+ * Note that if we ever add gen_ss_advance() singlestep support to
+ * M profile this should count as an "instruction execution complete"
+ * event (compare gen_bx_excret_final_code()).
+ */
+ env->regs[15] = dest & ~1;
+ env->thumb = dest & 1;
+ HELPER(exception_internal)(env, EXCP_EXCEPTION_EXIT);
+ /* notreached */
+ }
+
+ /* translate.c should have made BXNS UNDEF unless we're secure */
+ assert(env->v7m.secure);
+
+ if (!(dest & 1)) {
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
+ }
+ switch_v7m_security_state(env, dest & 1);
+ env->thumb = 1;
+ env->regs[15] = dest & ~1;
+}
+
+void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest)
+{
+ /*
+ * Handle v7M BLXNS:
+ * - bit 0 of the destination address is the target security state
+ */
+
+ /* At this point regs[15] is the address just after the BLXNS */
+ uint32_t nextinst = env->regs[15] | 1;
+ uint32_t sp = env->regs[13] - 8;
+ uint32_t saved_psr;
+
+ /* translate.c will have made BLXNS UNDEF unless we're secure */
+ assert(env->v7m.secure);
+
+ if (dest & 1) {
+ /*
+ * Target is Secure, so this is just a normal BLX,
+ * except that the low bit doesn't indicate Thumb/not.
+ */
+ env->regs[14] = nextinst;
+ env->thumb = 1;
+ env->regs[15] = dest & ~1;
+ return;
+ }
+
+ /* Target is non-secure: first push a stack frame */
+ if (!QEMU_IS_ALIGNED(sp, 8)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "BLXNS with misaligned SP is UNPREDICTABLE\n");
+ }
+
+ if (sp < v7m_sp_limit(env)) {
+ raise_exception(env, EXCP_STKOF, 0, 1);
+ }
+
+ saved_psr = env->v7m.exception;
+ if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK) {
+ saved_psr |= XPSR_SFPA;
+ }
+
+ /* Note that these stores can throw exceptions on MPU faults */
+ cpu_stl_data(env, sp, nextinst);
+ cpu_stl_data(env, sp + 4, saved_psr);
+
+ env->regs[13] = sp;
+ env->regs[14] = 0xfeffffff;
+ if (arm_v7m_is_handler_mode(env)) {
+ /*
+ * Write a dummy value to IPSR, to avoid leaking the current secure
+ * exception number to non-secure code. This is guaranteed not
+ * to cause write_v7m_exception() to actually change stacks.
+ */
+ write_v7m_exception(env, 1);
+ }
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
+ switch_v7m_security_state(env, 0);
+ env->thumb = 1;
+ env->regs[15] = dest;
+}
+
+static uint32_t *get_v7m_sp_ptr(CPUARMState *env, bool secure, bool threadmode,
+ bool spsel)
+{
+ /*
+ * Return a pointer to the location where we currently store the
+ * stack pointer for the requested security state and thread mode.
+ * This pointer will become invalid if the CPU state is updated
+ * such that the stack pointers are switched around (eg changing
+ * the SPSEL control bit).
+ * Compare the v8M ARM ARM pseudocode LookUpSP_with_security_mode().
+ * Unlike that pseudocode, we require the caller to pass us in the
+ * SPSEL control bit value; this is because we also use this
+ * function in handling of pushing of the callee-saves registers
+ * part of the v8M stack frame (pseudocode PushCalleeStack()),
+ * and in the tailchain codepath the SPSEL bit comes from the exception
+ * return magic LR value from the previous exception. The pseudocode
+ * opencodes the stack-selection in PushCalleeStack(), but we prefer
+ * to make this utility function generic enough to do the job.
+ */
+ bool want_psp = threadmode && spsel;
+
+ if (secure == env->v7m.secure) {
+ if (want_psp == v7m_using_psp(env)) {
+ return &env->regs[13];
+ } else {
+ return &env->v7m.other_sp;
+ }
+ } else {
+ if (want_psp) {
+ return &env->v7m.other_ss_psp;
+ } else {
+ return &env->v7m.other_ss_msp;
+ }
+ }
+}
+
+static bool arm_v7m_load_vector(ARMCPU *cpu, int exc, bool targets_secure,
+ uint32_t *pvec)
+{
+ CPUState *cs = CPU(cpu);
+ CPUARMState *env = &cpu->env;
+ MemTxResult result;
+ uint32_t addr = env->v7m.vecbase[targets_secure] + exc * 4;
+ uint32_t vector_entry;
+ MemTxAttrs attrs = {};
+ ARMMMUIdx mmu_idx;
+ bool exc_secure;
+
+ mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targets_secure, true);
+
+ /*
+ * We don't do a get_phys_addr() here because the rules for vector
+ * loads are special: they always use the default memory map, and
+ * the default memory map permits reads from all addresses.
+ * Since there's no easy way to pass through to pmsav8_mpu_lookup()
+ * that we want this special case which would always say "yes",
+ * we just do the SAU lookup here followed by a direct physical load.
+ */
+ attrs.secure = targets_secure;
+ attrs.user = false;
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ V8M_SAttributes sattrs = {};
+
+ v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs);
+ if (sattrs.ns) {
+ attrs.secure = false;
+ } else if (!targets_secure) {
+ /* NS access to S memory */
+ goto load_fail;
+ }
+ }
+
+ vector_entry = address_space_ldl(arm_addressspace(cs, attrs), addr,
+ attrs, &result);
+ if (result != MEMTX_OK) {
+ goto load_fail;
+ }
+ *pvec = vector_entry;
+ return true;
+
+load_fail:
+ /*
+ * All vector table fetch fails are reported as HardFault, with
+ * HFSR.VECTTBL and .FORCED set. (FORCED is set because
+ * technically the underlying exception is a MemManage or BusFault
+ * that is escalated to HardFault.) This is a terminal exception,
+ * so we will either take the HardFault immediately or else enter
+ * lockup (the latter case is handled in
armv7m_nvic_set_pending_derived()).
+ */
+ exc_secure = targets_secure ||
+ !(cpu->env.v7m.aircr & R_V7M_AIRCR_BFHFNMINS_MASK);
+ env->v7m.hfsr |= R_V7M_HFSR_VECTTBL_MASK | R_V7M_HFSR_FORCED_MASK;
+ armv7m_nvic_set_pending_derived(env->nvic, ARMV7M_EXCP_HARD, exc_secure);
+ return false;
+}
+
+static uint32_t v7m_integrity_sig(CPUARMState *env, uint32_t lr)
+{
+ /*
+ * Return the integrity signature value for the callee-saves
+ * stack frame section. @lr is the exception return payload/LR value
+ * whose FType bit forms bit 0 of the signature if FP is present.
+ */
+ uint32_t sig = 0xfefa125a;
+
+ if (!arm_feature(env, ARM_FEATURE_VFP) || (lr & R_V7M_EXCRET_FTYPE_MASK)) {
+ sig |= 1;
+ }
+ return sig;
+}
+
+static bool v7m_push_callee_stack(ARMCPU *cpu, uint32_t lr, bool dotailchain,
+ bool ignore_faults)
+{
+ /*
+ * For v8M, push the callee-saves register part of the stack frame.
+ * Compare the v8M pseudocode PushCalleeStack().
+ * In the tailchaining case this may not be the current stack.
+ */
+ CPUARMState *env = &cpu->env;
+ uint32_t *frame_sp_p;
+ uint32_t frameptr;
+ ARMMMUIdx mmu_idx;
+ bool stacked_ok;
+ uint32_t limit;
+ bool want_psp;
+ uint32_t sig;
+ StackingMode smode = ignore_faults ? STACK_IGNFAULTS : STACK_NORMAL;
+
+ if (dotailchain) {
+ bool mode = lr & R_V7M_EXCRET_MODE_MASK;
+ bool priv = !(env->v7m.control[M_REG_S] & R_V7M_CONTROL_NPRIV_MASK) ||
+ !mode;
+
+ mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, M_REG_S, priv);
+ frame_sp_p = get_v7m_sp_ptr(env, M_REG_S, mode,
+ lr & R_V7M_EXCRET_SPSEL_MASK);
+ want_psp = mode && (lr & R_V7M_EXCRET_SPSEL_MASK);
+ if (want_psp) {
+ limit = env->v7m.psplim[M_REG_S];
+ } else {
+ limit = env->v7m.msplim[M_REG_S];
+ }
+ } else {
+ mmu_idx = arm_mmu_idx(env);
+ frame_sp_p = &env->regs[13];
+ limit = v7m_sp_limit(env);
+ }
+
+ frameptr = *frame_sp_p - 0x28;
+ if (frameptr < limit) {
+ /*
+ * Stack limit failure: set SP to the limit value, and generate
+ * STKOF UsageFault. Stack pushes below the limit must not be
+ * performed. It is IMPDEF whether pushes above the limit are
+ * performed; we choose not to.
+ */
+ qemu_log_mask(CPU_LOG_INT,
+ "...STKOF during callee-saves register stacking\n");
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ env->v7m.secure);
+ *frame_sp_p = limit;
+ return true;
+ }
+
+ /*
+ * Write as much of the stack frame as we can. A write failure may
+ * cause us to pend a derived exception.
+ */
+ sig = v7m_integrity_sig(env, lr);
+ stacked_ok =
+ v7m_stack_write(cpu, frameptr, sig, mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x8, env->regs[4], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0xc, env->regs[5], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x10, env->regs[6], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x14, env->regs[7], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x18, env->regs[8], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x1c, env->regs[9], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x20, env->regs[10], mmu_idx, smode) &&
+ v7m_stack_write(cpu, frameptr + 0x24, env->regs[11], mmu_idx, smode);
+
+ /* Update SP regardless of whether any of the stack accesses failed. */
+ *frame_sp_p = frameptr;
+
+ return !stacked_ok;
+}
+
+static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain,
+ bool ignore_stackfaults)
+{
+ /*
+ * Do the "take the exception" parts of exception entry,
+ * but not the pushing of state to the stack. This is
+ * similar to the pseudocode ExceptionTaken() function.
+ */
+ CPUARMState *env = &cpu->env;
+ uint32_t addr;
+ bool targets_secure;
+ int exc;
+ bool push_failed = false;
+
+ armv7m_nvic_get_pending_irq_info(env->nvic, &exc, &targets_secure);
+ qemu_log_mask(CPU_LOG_INT, "...taking pending %s exception %d\n",
+ targets_secure ? "secure" : "nonsecure", exc);
+
+ if (dotailchain) {
+ /* Sanitize LR FType and PREFIX bits */
+ if (!arm_feature(env, ARM_FEATURE_VFP)) {
+ lr |= R_V7M_EXCRET_FTYPE_MASK;
+ }
+ lr = deposit32(lr, 24, 8, 0xff);
+ }
+
+ if (arm_feature(env, ARM_FEATURE_V8)) {
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY) &&
+ (lr & R_V7M_EXCRET_S_MASK)) {
+ /*
+ * The background code (the owner of the registers in the
+ * exception frame) is Secure. This means it may either already
+ * have or now needs to push callee-saves registers.
+ */
+ if (targets_secure) {
+ if (dotailchain && !(lr & R_V7M_EXCRET_ES_MASK)) {
+ /*
+ * We took an exception from Secure to NonSecure
+ * (which means the callee-saved registers got stacked)
+ * and are now tailchaining to a Secure exception.
+ * Clear DCRS so eventual return from this Secure
+ * exception unstacks the callee-saved registers.
+ */
+ lr &= ~R_V7M_EXCRET_DCRS_MASK;
+ }
+ } else {
+ /*
+ * We're going to a non-secure exception; push the
+ * callee-saves registers to the stack now, if they're
+ * not already saved.
+ */
+ if (lr & R_V7M_EXCRET_DCRS_MASK &&
+ !(dotailchain && !(lr & R_V7M_EXCRET_ES_MASK))) {
+ push_failed = v7m_push_callee_stack(cpu, lr, dotailchain,
+ ignore_stackfaults);
+ }
+ lr |= R_V7M_EXCRET_DCRS_MASK;
+ }
+ }
+
+ lr &= ~R_V7M_EXCRET_ES_MASK;
+ if (targets_secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ lr |= R_V7M_EXCRET_ES_MASK;
+ }
+ lr &= ~R_V7M_EXCRET_SPSEL_MASK;
+ if (env->v7m.control[targets_secure] & R_V7M_CONTROL_SPSEL_MASK) {
+ lr |= R_V7M_EXCRET_SPSEL_MASK;
+ }
+
+ /*
+ * Clear registers if necessary to prevent non-secure exception
+ * code being able to see register values from secure code.
+ * Where register values become architecturally UNKNOWN we leave
+ * them with their previous values.
+ */
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ if (!targets_secure) {
+ /*
+ * Always clear the caller-saved registers (they have been
+ * pushed to the stack earlier in v7m_push_stack()).
+ * Clear callee-saved registers if the background code is
+ * Secure (in which case these regs were saved in
+ * v7m_push_callee_stack()).
+ */
+ int i;
+
+ for (i = 0; i < 13; i++) {
+ /* r4..r11 are callee-saves, zero only if EXCRET.S == 1 */
+ if (i < 4 || i > 11 || (lr & R_V7M_EXCRET_S_MASK)) {
+ env->regs[i] = 0;
+ }
+ }
+ /* Clear EAPSR */
+ xpsr_write(env, 0, XPSR_NZCV | XPSR_Q | XPSR_GE | XPSR_IT);
+ }
+ }
+ }
+
+ if (push_failed && !ignore_stackfaults) {
+ /*
+ * Derived exception on callee-saves register stacking:
+ * we might now want to take a different exception which
+ * targets a different security state, so try again from the top.
+ */
+ qemu_log_mask(CPU_LOG_INT,
+ "...derived exception on callee-saves register
stacking");
+ v7m_exception_taken(cpu, lr, true, true);
+ return;
+ }
+
+ if (!arm_v7m_load_vector(cpu, exc, targets_secure, &addr)) {
+ /* Vector load failed: derived exception */
+ qemu_log_mask(CPU_LOG_INT, "...derived exception on vector table
load");
+ v7m_exception_taken(cpu, lr, true, true);
+ return;
+ }
+
+ /*
+ * Now we've done everything that might cause a derived exception
+ * we can go ahead and activate whichever exception we're going to
+ * take (which might now be the derived exception).
+ */
+ armv7m_nvic_acknowledge_irq(env->nvic);
+
+ /* Switch to target security state -- must do this before writing SPSEL */
+ switch_v7m_security_state(env, targets_secure);
+ write_v7m_control_spsel(env, 0);
+ arm_clear_exclusive(env);
+ /* Clear SFPA and FPCA (has no effect if no FPU) */
+ env->v7m.control[M_REG_S] &=
+ ~(R_V7M_CONTROL_FPCA_MASK | R_V7M_CONTROL_SFPA_MASK);
+ /* Clear IT bits */
+ env->condexec_bits = 0;
+ env->regs[14] = lr;
+ env->regs[15] = addr & 0xfffffffe;
+ env->thumb = addr & 1;
+}
+
+static void v7m_update_fpccr(CPUARMState *env, uint32_t frameptr,
+ bool apply_splim)
+{
+ /*
+ * Like the pseudocode UpdateFPCCR: save state in FPCAR and FPCCR
+ * that we will need later in order to do lazy FP reg stacking.
+ */
+ bool is_secure = env->v7m.secure;
+ void *nvic = env->nvic;
+ /*
+ * Some bits are unbanked and live always in fpccr[M_REG_S]; some bits
+ * are banked and we want to update the bit in the bank for the
+ * current security state; and in one case we want to specifically
+ * update the NS banked version of a bit even if we are secure.
+ */
+ uint32_t *fpccr_s = &env->v7m.fpccr[M_REG_S];
+ uint32_t *fpccr_ns = &env->v7m.fpccr[M_REG_NS];
+ uint32_t *fpccr = &env->v7m.fpccr[is_secure];
+ bool hfrdy, bfrdy, mmrdy, ns_ufrdy, s_ufrdy, sfrdy, monrdy;
+
+ env->v7m.fpcar[is_secure] = frameptr & ~0x7;
+
+ if (apply_splim && arm_feature(env, ARM_FEATURE_V8)) {
+ bool splimviol;
+ uint32_t splim = v7m_sp_limit(env);
+ bool ign = armv7m_nvic_neg_prio_requested(nvic, is_secure) &&
+ (env->v7m.ccr[is_secure] & R_V7M_CCR_STKOFHFNMIGN_MASK);
+
+ splimviol = !ign && frameptr < splim;
+ *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, SPLIMVIOL, splimviol);
+ }
+
+ *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, LSPACT, 1);
+
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, S, is_secure);
+
+ *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, USER, arm_current_el(env) == 0);
+
+ *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, THREAD,
+ !arm_v7m_is_handler_mode(env));
+
+ hfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_HARD, false);
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, HFRDY, hfrdy);
+
+ bfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_BUS, false);
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, BFRDY, bfrdy);
+
+ mmrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_MEM, is_secure);
+ *fpccr = FIELD_DP32(*fpccr, V7M_FPCCR, MMRDY, mmrdy);
+
+ ns_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, false);
+ *fpccr_ns = FIELD_DP32(*fpccr_ns, V7M_FPCCR, UFRDY, ns_ufrdy);
+
+ monrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_DEBUG, false);
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, MONRDY, monrdy);
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ s_ufrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_USAGE, true);
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, UFRDY, s_ufrdy);
+
+ sfrdy = armv7m_nvic_get_ready_status(nvic, ARMV7M_EXCP_SECURE, false);
+ *fpccr_s = FIELD_DP32(*fpccr_s, V7M_FPCCR, SFRDY, sfrdy);
+ }
+}
+
+void HELPER(v7m_vlstm)(CPUARMState *env, uint32_t fptr)
+{
+ /* fptr is the value of Rn, the frame pointer we store the FP regs to */
+ bool s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
+ bool lspact = env->v7m.fpccr[s] & R_V7M_FPCCR_LSPACT_MASK;
+
+ assert(env->v7m.secure);
+
+ if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
+ return;
+ }
+
+ /* Check access to the coprocessor is permitted */
+ if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) {
+ raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC());
+ }
+
+ if (lspact) {
+ /* LSPACT should not be active when there is active FP state */
+ raise_exception_ra(env, EXCP_LSERR, 0, 1, GETPC());
+ }
+
+ if (fptr & 7) {
+ raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC());
+ }
+
+ /*
+ * Note that we do not use v7m_stack_write() here, because the
+ * accesses should not set the FSR bits for stacking errors if they
+ * fail. (In pseudocode terms, they are AccType_NORMAL, not AccType_STACK
+ * or AccType_LAZYFP). Faults in cpu_stl_data() will throw exceptions
+ * and longjmp out.
+ */
+ if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) {
+ bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK;
+ int i;
+
+ for (i = 0; i < (ts ? 32 : 16); i += 2) {
+ uint64_t dn = *aa32_vfp_dreg(env, i / 2);
+ uint32_t faddr = fptr + 4 * i;
+ uint32_t slo = extract64(dn, 0, 32);
+ uint32_t shi = extract64(dn, 32, 32);
+
+ if (i >= 16) {
+ faddr += 8; /* skip the slot for the FPSCR */
+ }
+ cpu_stl_data(env, faddr, slo);
+ cpu_stl_data(env, faddr + 4, shi);
+ }
+ cpu_stl_data(env, fptr + 0x40, vfp_get_fpscr(env));
+
+ /*
+ * If TS is 0 then s0 to s15 and FPSCR are UNKNOWN; we choose to
+ * leave them unchanged, matching our choice in v7m_preserve_fp_state.
+ */
+ if (ts) {
+ for (i = 0; i < 32; i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ } else {
+ v7m_update_fpccr(env, fptr, false);
+ }
+
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
+}
+
+void HELPER(v7m_vlldm)(CPUARMState *env, uint32_t fptr)
+{
+ /* fptr is the value of Rn, the frame pointer we load the FP regs from */
+ assert(env->v7m.secure);
+
+ if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
+ return;
+ }
+
+ /* Check access to the coprocessor is permitted */
+ if (!v7m_cpacr_pass(env, true, arm_current_el(env) != 0)) {
+ raise_exception_ra(env, EXCP_NOCP, 0, 1, GETPC());
+ }
+
+ if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) {
+ /* State in FP is still valid */
+ env->v7m.fpccr[M_REG_S] &= ~R_V7M_FPCCR_LSPACT_MASK;
+ } else {
+ bool ts = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK;
+ int i;
+ uint32_t fpscr;
+
+ if (fptr & 7) {
+ raise_exception_ra(env, EXCP_UNALIGNED, 0, 1, GETPC());
+ }
+
+ for (i = 0; i < (ts ? 32 : 16); i += 2) {
+ uint32_t slo, shi;
+ uint64_t dn;
+ uint32_t faddr = fptr + 4 * i;
+
+ if (i >= 16) {
+ faddr += 8; /* skip the slot for the FPSCR */
+ }
+
+ slo = cpu_ldl_data(env, faddr);
+ shi = cpu_ldl_data(env, faddr + 4);
+
+ dn = (uint64_t) shi << 32 | slo;
+ *aa32_vfp_dreg(env, i / 2) = dn;
+ }
+ fpscr = cpu_ldl_data(env, fptr + 0x40);
+ vfp_set_fpscr(env, fpscr);
+ }
+
+ env->v7m.control[M_REG_S] |= R_V7M_CONTROL_FPCA_MASK;
+}
+
+static bool v7m_push_stack(ARMCPU *cpu)
+{
+ /*
+ * Do the "set up stack frame" part of exception entry,
+ * similar to pseudocode PushStack().
+ * Return true if we generate a derived exception (and so
+ * should ignore further stack faults trying to process
+ * that derived exception.)
+ */
+ bool stacked_ok = true, limitviol = false;
+ CPUARMState *env = &cpu->env;
+ uint32_t xpsr = xpsr_read(env);
+ uint32_t frameptr = env->regs[13];
+ ARMMMUIdx mmu_idx = arm_mmu_idx(env);
+ uint32_t framesize;
+ bool nsacr_cp10 = extract32(env->v7m.nsacr, 10, 1);
+
+ if ((env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) &&
+ (env->v7m.secure || nsacr_cp10)) {
+ if (env->v7m.secure &&
+ env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK) {
+ framesize = 0xa8;
+ } else {
+ framesize = 0x68;
+ }
+ } else {
+ framesize = 0x20;
+ }
+
+ /* Align stack pointer if the guest wants that */
+ if ((frameptr & 4) &&
+ (env->v7m.ccr[env->v7m.secure] & R_V7M_CCR_STKALIGN_MASK)) {
+ frameptr -= 4;
+ xpsr |= XPSR_SPREALIGN;
+ }
+
+ xpsr &= ~XPSR_SFPA;
+ if (env->v7m.secure &&
+ (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK)) {
+ xpsr |= XPSR_SFPA;
+ }
+
+ frameptr -= framesize;
+
+ if (arm_feature(env, ARM_FEATURE_V8)) {
+ uint32_t limit = v7m_sp_limit(env);
+
+ if (frameptr < limit) {
+ /*
+ * Stack limit failure: set SP to the limit value, and generate
+ * STKOF UsageFault. Stack pushes below the limit must not be
+ * performed. It is IMPDEF whether pushes above the limit are
+ * performed; we choose not to.
+ */
+ qemu_log_mask(CPU_LOG_INT,
+ "...STKOF during stacking\n");
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ env->v7m.secure);
+ env->regs[13] = limit;
+ /*
+ * We won't try to perform any further memory accesses but
+ * we must continue through the following code to check for
+ * permission faults during FPU state preservation, and we
+ * must update FPCCR if lazy stacking is enabled.
+ */
+ limitviol = true;
+ stacked_ok = false;
+ }
+ }
+
+ /*
+ * Write as much of the stack frame as we can. If we fail a stack
+ * write this will result in a derived exception being pended
+ * (which may be taken in preference to the one we started with
+ * if it has higher priority).
+ */
+ stacked_ok = stacked_ok &&
+ v7m_stack_write(cpu, frameptr, env->regs[0], mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 4, env->regs[1],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 8, env->regs[2],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 12, env->regs[3],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 16, env->regs[12],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 20, env->regs[14],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 24, env->regs[15],
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, frameptr + 28, xpsr, mmu_idx, STACK_NORMAL);
+
+ if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK) {
+ /* FPU is active, try to save its registers */
+ bool fpccr_s = env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_S_MASK;
+ bool lspact = env->v7m.fpccr[fpccr_s] & R_V7M_FPCCR_LSPACT_MASK;
+
+ if (lspact && arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ qemu_log_mask(CPU_LOG_INT,
+ "...SecureFault because LSPACT and FPCA both set\n");
+ env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ } else if (!env->v7m.secure && !nsacr_cp10) {
+ qemu_log_mask(CPU_LOG_INT,
+ "...Secure UsageFault with CFSR.NOCP because "
+ "NSACR.CP10 prevents stacking FP regs\n");
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, M_REG_S);
+ env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_NOCP_MASK;
+ } else {
+ if (!(env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPEN_MASK)) {
+ /* Lazy stacking disabled, save registers now */
+ int i;
+ bool cpacr_pass = v7m_cpacr_pass(env, env->v7m.secure,
+ arm_current_el(env) != 0);
+
+ if (stacked_ok && !cpacr_pass) {
+ /*
+ * Take UsageFault if CPACR forbids access. The pseudocode
+ * here does a full CheckCPEnabled() but we know the NSACR
+ * check can never fail as we have already handled that.
+ */
+ qemu_log_mask(CPU_LOG_INT,
+ "...UsageFault with CFSR.NOCP because "
+ "CPACR.CP10 prevents stacking FP regs\n");
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_NOCP_MASK;
+ stacked_ok = false;
+ }
+
+ for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) {
+ uint64_t dn = *aa32_vfp_dreg(env, i / 2);
+ uint32_t faddr = frameptr + 0x20 + 4 * i;
+ uint32_t slo = extract64(dn, 0, 32);
+ uint32_t shi = extract64(dn, 32, 32);
+
+ if (i >= 16) {
+ faddr += 8; /* skip the slot for the FPSCR */
+ }
+ stacked_ok = stacked_ok &&
+ v7m_stack_write(cpu, faddr, slo,
+ mmu_idx, STACK_NORMAL) &&
+ v7m_stack_write(cpu, faddr + 4, shi,
+ mmu_idx, STACK_NORMAL);
+ }
+ stacked_ok = stacked_ok &&
+ v7m_stack_write(cpu, frameptr + 0x60,
+ vfp_get_fpscr(env), mmu_idx, STACK_NORMAL);
+ if (cpacr_pass) {
+ for (i = 0; i < ((framesize == 0xa8) ? 32 : 16); i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ } else {
+ /* Lazy stacking enabled, save necessary info to stack later */
+ v7m_update_fpccr(env, frameptr + 0x20, true);
+ }
+ }
+ }
+
+ /*
+ * If we broke a stack limit then SP was already updated earlier;
+ * otherwise we update SP regardless of whether any of the stack
+ * accesses failed or we took some other kind of fault.
+ */
+ if (!limitviol) {
+ env->regs[13] = frameptr;
+ }
+
+ return !stacked_ok;
+}
+
+static void do_v7m_exception_exit(ARMCPU *cpu)
+{
+ CPUARMState *env = &cpu->env;
+ uint32_t excret;
+ uint32_t xpsr, xpsr_mask;
+ bool ufault = false;
+ bool sfault = false;
+ bool return_to_sp_process;
+ bool return_to_handler;
+ bool rettobase = false;
+ bool exc_secure = false;
+ bool return_to_secure;
+ bool ftype;
+ bool restore_s16_s31;
+
+ /*
+ * If we're not in Handler mode then jumps to magic exception-exit
+ * addresses don't have magic behaviour. However for the v8M
+ * security extensions the magic secure-function-return has to
+ * work in thread mode too, so to avoid doing an extra check in
+ * the generated code we allow exception-exit magic to also cause the
+ * internal exception and bring us here in thread mode. Correct code
+ * will never try to do this (the following insn fetch will always
+ * fault) so we the overhead of having taken an unnecessary exception
+ * doesn't matter.
+ */
+ if (!arm_v7m_is_handler_mode(env)) {
+ return;
+ }
+
+ /*
+ * In the spec pseudocode ExceptionReturn() is called directly
+ * from BXWritePC() and gets the full target PC value including
+ * bit zero. In QEMU's implementation we treat it as a normal
+ * jump-to-register (which is then caught later on), and so split
+ * the target value up between env->regs[15] and env->thumb in
+ * gen_bx(). Reconstitute it.
+ */
+ excret = env->regs[15];
+ if (env->thumb) {
+ excret |= 1;
+ }
+
+ qemu_log_mask(CPU_LOG_INT, "Exception return: magic PC %" PRIx32
+ " previous exception %d\n",
+ excret, env->v7m.exception);
+
+ if ((excret & R_V7M_EXCRET_RES1_MASK) != R_V7M_EXCRET_RES1_MASK) {
+ qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero high bits in exception
"
+ "exit PC value 0x%" PRIx32 " are UNPREDICTABLE\n",
+ excret);
+ }
+
+ ftype = excret & R_V7M_EXCRET_FTYPE_MASK;
+
+ if (!arm_feature(env, ARM_FEATURE_VFP) && !ftype) {
+ qemu_log_mask(LOG_GUEST_ERROR, "M profile: zero FTYPE in exception "
+ "exit PC value 0x%" PRIx32 " is UNPREDICTABLE "
+ "if FPU not present\n",
+ excret);
+ ftype = true;
+ }
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ /*
+ * EXC_RETURN.ES validation check (R_SMFL). We must do this before
+ * we pick which FAULTMASK to clear.
+ */
+ if (!env->v7m.secure &&
+ ((excret & R_V7M_EXCRET_ES_MASK) ||
+ !(excret & R_V7M_EXCRET_DCRS_MASK))) {
+ sfault = 1;
+ /* For all other purposes, treat ES as 0 (R_HXSR) */
+ excret &= ~R_V7M_EXCRET_ES_MASK;
+ }
+ exc_secure = excret & R_V7M_EXCRET_ES_MASK;
+ }
+
+ if (env->v7m.exception != ARMV7M_EXCP_NMI) {
+ /*
+ * Auto-clear FAULTMASK on return from other than NMI.
+ * If the security extension is implemented then this only
+ * happens if the raw execution priority is >= 0; the
+ * value of the ES bit in the exception return value indicates
+ * which security state's faultmask to clear. (v8M ARM ARM R_KBNF.)
+ */
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ if (armv7m_nvic_raw_execution_priority(env->nvic) >= 0) {
+ env->v7m.faultmask[exc_secure] = 0;
+ }
+ } else {
+ env->v7m.faultmask[M_REG_NS] = 0;
+ }
+ }
+
+ switch (armv7m_nvic_complete_irq(env->nvic, env->v7m.exception,
+ exc_secure)) {
+ case -1:
+ /* attempt to exit an exception that isn't active */
+ ufault = true;
+ break;
+ case 0:
+ /* still an irq active now */
+ break;
+ case 1:
+ /*
+ * We returned to base exception level, no nesting.
+ * (In the pseudocode this is written using "NestedActivation != 1"
+ * where we have 'rettobase == false'.)
+ */
+ rettobase = true;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
+ return_to_handler = !(excret & R_V7M_EXCRET_MODE_MASK);
+ return_to_sp_process = excret & R_V7M_EXCRET_SPSEL_MASK;
+ return_to_secure = arm_feature(env, ARM_FEATURE_M_SECURITY) &&
+ (excret & R_V7M_EXCRET_S_MASK);
+
+ if (arm_feature(env, ARM_FEATURE_V8)) {
+ if (!arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ /*
+ * UNPREDICTABLE if S == 1 or DCRS == 0 or ES == 1 (R_XLCP);
+ * we choose to take the UsageFault.
+ */
+ if ((excret & R_V7M_EXCRET_S_MASK) ||
+ (excret & R_V7M_EXCRET_ES_MASK) ||
+ !(excret & R_V7M_EXCRET_DCRS_MASK)) {
+ ufault = true;
+ }
+ }
+ if (excret & R_V7M_EXCRET_RES0_MASK) {
+ ufault = true;
+ }
+ } else {
+ /* For v7M we only recognize certain combinations of the low bits */
+ switch (excret & 0xf) {
+ case 1: /* Return to Handler */
+ break;
+ case 13: /* Return to Thread using Process stack */
+ case 9: /* Return to Thread using Main stack */
+ /*
+ * We only need to check NONBASETHRDENA for v7M, because in
+ * v8M this bit does not exist (it is RES1).
+ */
+ if (!rettobase &&
+ !(env->v7m.ccr[env->v7m.secure] &
+ R_V7M_CCR_NONBASETHRDENA_MASK)) {
+ ufault = true;
+ }
+ break;
+ default:
+ ufault = true;
+ }
+ }
+
+ /*
+ * Set CONTROL.SPSEL from excret.SPSEL. Since we're still in
+ * Handler mode (and will be until we write the new XPSR.Interrupt
+ * field) this does not switch around the current stack pointer.
+ * We must do this before we do any kind of tailchaining, including
+ * for the derived exceptions on integrity check failures, or we will
+ * give the guest an incorrect EXCRET.SPSEL value on exception entry.
+ */
+ write_v7m_control_spsel_for_secstate(env, return_to_sp_process,
exc_secure);
+
+ /*
+ * Clear scratch FP values left in caller saved registers; this
+ * must happen before any kind of tail chaining.
+ */
+ if ((env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_CLRONRET_MASK) &&
+ (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) {
+ if (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK) {
+ env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
+ "stackframe: error during lazy state
deactivation\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ } else {
+ /* Clear s0..s15 and FPSCR */
+ int i;
+
+ for (i = 0; i < 16; i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ }
+
+ if (sfault) {
+ env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
+ "stackframe: failed EXC_RETURN.ES validity check\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ if (ufault) {
+ /*
+ * Bad exception return: instead of popping the exception
+ * stack, directly take a usage fault on the current stack.
+ */
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "
+ "stackframe: failed exception return integrity check\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ /*
+ * Tailchaining: if there is currently a pending exception that
+ * is high enough priority to preempt execution at the level we're
+ * about to return to, then just directly take that exception now,
+ * avoiding an unstack-and-then-stack. Note that now we have
+ * deactivated the previous exception by calling armv7m_nvic_complete_irq()
+ * our current execution priority is already the execution priority we are
+ * returning to -- none of the state we would unstack or set based on
+ * the EXCRET value affects it.
+ */
+ if (armv7m_nvic_can_take_pending_exception(env->nvic)) {
+ qemu_log_mask(CPU_LOG_INT, "...tailchaining to pending exception\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ switch_v7m_security_state(env, return_to_secure);
+
+ {
+ /*
+ * The stack pointer we should be reading the exception frame from
+ * depends on bits in the magic exception return type value (and
+ * for v8M isn't necessarily the stack pointer we will eventually
+ * end up resuming execution with). Get a pointer to the location
+ * in the CPU state struct where the SP we need is currently being
+ * stored; we will use and modify it in place.
+ * We use this limited C variable scope so we don't accidentally
+ * use 'frame_sp_p' after we do something that makes it invalid.
+ */
+ uint32_t *frame_sp_p = get_v7m_sp_ptr(env,
+ return_to_secure,
+ !return_to_handler,
+ return_to_sp_process);
+ uint32_t frameptr = *frame_sp_p;
+ bool pop_ok = true;
+ ARMMMUIdx mmu_idx;
+ bool return_to_priv = return_to_handler ||
+ !(env->v7m.control[return_to_secure] & R_V7M_CONTROL_NPRIV_MASK);
+
+ mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, return_to_secure,
+ return_to_priv);
+
+ if (!QEMU_IS_ALIGNED(frameptr, 8) &&
+ arm_feature(env, ARM_FEATURE_V8)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "M profile exception return with non-8-aligned SP "
+ "for destination state is UNPREDICTABLE\n");
+ }
+
+ /* Do we need to pop callee-saved registers? */
+ if (return_to_secure &&
+ ((excret & R_V7M_EXCRET_ES_MASK) == 0 ||
+ (excret & R_V7M_EXCRET_DCRS_MASK) == 0)) {
+ uint32_t actual_sig;
+
+ pop_ok = v7m_stack_read(cpu, &actual_sig, frameptr, mmu_idx);
+
+ if (pop_ok && v7m_integrity_sig(env, excret) != actual_sig) {
+ /* Take a SecureFault on the current stack */
+ env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "
+ "stackframe: failed exception return integrity "
+ "signature check\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ pop_ok = pop_ok &&
+ v7m_stack_read(cpu, &env->regs[4], frameptr + 0x8, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[5], frameptr + 0xc, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[6], frameptr + 0x10, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[7], frameptr + 0x14, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[8], frameptr + 0x18, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[9], frameptr + 0x1c, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[10], frameptr + 0x20, mmu_idx)
&&
+ v7m_stack_read(cpu, &env->regs[11], frameptr + 0x24, mmu_idx);
+
+ frameptr += 0x28;
+ }
+
+ /* Pop registers */
+ pop_ok = pop_ok &&
+ v7m_stack_read(cpu, &env->regs[0], frameptr, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[1], frameptr + 0x4, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[2], frameptr + 0x8, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[3], frameptr + 0xc, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[12], frameptr + 0x10, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[14], frameptr + 0x14, mmu_idx) &&
+ v7m_stack_read(cpu, &env->regs[15], frameptr + 0x18, mmu_idx) &&
+ v7m_stack_read(cpu, &xpsr, frameptr + 0x1c, mmu_idx);
+
+ if (!pop_ok) {
+ /*
+ * v7m_stack_read() pended a fault, so take it (as a tail
+ * chained exception on the same stack frame)
+ */
+ qemu_log_mask(CPU_LOG_INT, "...derived exception on unstacking\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ /*
+ * Returning from an exception with a PC with bit 0 set is defined
+ * behaviour on v8M (bit 0 is ignored), but for v7M it was specified
+ * to be UNPREDICTABLE. In practice actual v7M hardware seems to ignore
+ * the lsbit, and there are several RTOSes out there which incorrectly
+ * assume the r15 in the stack frame should be a Thumb-style "lsbit
+ * indicates ARM/Thumb" value, so ignore the bit on v7M as well, but
+ * complain about the badly behaved guest.
+ */
+ if (env->regs[15] & 1) {
+ env->regs[15] &= ~1U;
+ if (!arm_feature(env, ARM_FEATURE_V8)) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "M profile return from interrupt with misaligned
"
+ "PC is UNPREDICTABLE on v7M\n");
+ }
+ }
+
+ if (arm_feature(env, ARM_FEATURE_V8)) {
+ /*
+ * For v8M we have to check whether the xPSR exception field
+ * matches the EXCRET value for return to handler/thread
+ * before we commit to changing the SP and xPSR.
+ */
+ bool will_be_handler = (xpsr & XPSR_EXCP) != 0;
+ if (return_to_handler != will_be_handler) {
+ /*
+ * Take an INVPC UsageFault on the current stack.
+ * By this point we will have switched to the security state
+ * for the background state, so this UsageFault will target
+ * that state.
+ */
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
+ qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "
+ "stackframe: failed exception return integrity "
+ "check\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+ }
+
+ if (!ftype) {
+ /* FP present and we need to handle it */
+ if (!return_to_secure &&
+ (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_LSPACT_MASK)) {
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...taking SecureFault on existing stackframe: "
+ "Secure LSPACT set but exception return is "
+ "not to secure state\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ restore_s16_s31 = return_to_secure &&
+ (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK);
+
+ if (env->v7m.fpccr[return_to_secure] & R_V7M_FPCCR_LSPACT_MASK) {
+ /* State in FPU is still valid, just clear LSPACT */
+ env->v7m.fpccr[return_to_secure] &= ~R_V7M_FPCCR_LSPACT_MASK;
+ } else {
+ int i;
+ uint32_t fpscr;
+ bool cpacr_pass, nsacr_pass;
+
+ cpacr_pass = v7m_cpacr_pass(env, return_to_secure,
+ return_to_priv);
+ nsacr_pass = return_to_secure ||
+ extract32(env->v7m.nsacr, 10, 1);
+
+ if (!cpacr_pass) {
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ return_to_secure);
+ env->v7m.cfsr[return_to_secure] |= R_V7M_CFSR_NOCP_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...taking UsageFault on existing "
+ "stackframe: CPACR.CP10 prevents unstacking "
+ "FP regs\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ } else if (!nsacr_pass) {
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
true);
+ env->v7m.cfsr[M_REG_S] |= R_V7M_CFSR_INVPC_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...taking Secure UsageFault on existing "
+ "stackframe: NSACR.CP10 prevents unstacking "
+ "FP regs\n");
+ v7m_exception_taken(cpu, excret, true, false);
+ return;
+ }
+
+ for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) {
+ uint32_t slo, shi;
+ uint64_t dn;
+ uint32_t faddr = frameptr + 0x20 + 4 * i;
+
+ if (i >= 16) {
+ faddr += 8; /* Skip the slot for the FPSCR */
+ }
+
+ pop_ok = pop_ok &&
+ v7m_stack_read(cpu, &slo, faddr, mmu_idx) &&
+ v7m_stack_read(cpu, &shi, faddr + 4, mmu_idx);
+
+ if (!pop_ok) {
+ break;
+ }
+
+ dn = (uint64_t)shi << 32 | slo;
+ *aa32_vfp_dreg(env, i / 2) = dn;
+ }
+ pop_ok = pop_ok &&
+ v7m_stack_read(cpu, &fpscr, frameptr + 0x60, mmu_idx);
+ if (pop_ok) {
+ vfp_set_fpscr(env, fpscr);
+ }
+ if (!pop_ok) {
+ /*
+ * These regs are 0 if security extension present;
+ * otherwise merely UNKNOWN. We zero always.
+ */
+ for (i = 0; i < (restore_s16_s31 ? 32 : 16); i += 2) {
+ *aa32_vfp_dreg(env, i / 2) = 0;
+ }
+ vfp_set_fpscr(env, 0);
+ }
+ }
+ }
+ env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S],
+ V7M_CONTROL, FPCA, !ftype);
+
+ /* Commit to consuming the stack frame */
+ frameptr += 0x20;
+ if (!ftype) {
+ frameptr += 0x48;
+ if (restore_s16_s31) {
+ frameptr += 0x40;
+ }
+ }
+ /*
+ * Undo stack alignment (the SPREALIGN bit indicates that the original
+ * pre-exception SP was not 8-aligned and we added a padding word to
+ * align it, so we undo this by ORing in the bit that increases it
+ * from the current 8-aligned value to the 8-unaligned value. (Adding 4
+ * would work too but a logical OR is how the pseudocode specifies it.)
+ */
+ if (xpsr & XPSR_SPREALIGN) {
+ frameptr |= 4;
+ }
+ *frame_sp_p = frameptr;
+ }
+
+ xpsr_mask = ~(XPSR_SPREALIGN | XPSR_SFPA);
+ if (!arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
+ xpsr_mask &= ~XPSR_GE;
+ }
+ /* This xpsr_write() will invalidate frame_sp_p as it may switch stack */
+ xpsr_write(env, xpsr, xpsr_mask);
+
+ if (env->v7m.secure) {
+ bool sfpa = xpsr & XPSR_SFPA;
+
+ env->v7m.control[M_REG_S] = FIELD_DP32(env->v7m.control[M_REG_S],
+ V7M_CONTROL, SFPA, sfpa);
+ }
+
+ /*
+ * The restored xPSR exception field will be zero if we're
+ * resuming in Thread mode. If that doesn't match what the
+ * exception return excret specified then this is a UsageFault.
+ * v7M requires we make this check here; v8M did it earlier.
+ */
+ if (return_to_handler != arm_v7m_is_handler_mode(env)) {
+ /*
+ * Take an INVPC UsageFault by pushing the stack again;
+ * we know we're v7M so this is never a Secure UsageFault.
+ */
+ bool ignore_stackfaults;
+
+ assert(!arm_feature(env, ARM_FEATURE_V8));
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
+ ignore_stackfaults = v7m_push_stack(cpu);
+ qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: "
+ "failed exception return integrity check\n");
+ v7m_exception_taken(cpu, excret, false, ignore_stackfaults);
+ return;
+ }
+
+ /* Otherwise, we have a successful exception exit. */
+ arm_clear_exclusive(env);
+ qemu_log_mask(CPU_LOG_INT, "...successful exception return\n");
+}
+
+static bool do_v7m_function_return(ARMCPU *cpu)
+{
+ /*
+ * v8M security extensions magic function return.
+ * We may either:
+ * (1) throw an exception (longjump)
+ * (2) return true if we successfully handled the function return
+ * (3) return false if we failed a consistency check and have
+ * pended a UsageFault that needs to be taken now
+ *
+ * At this point the magic return value is split between env->regs[15]
+ * and env->thumb. We don't bother to reconstitute it because we don't
+ * need it (all values are handled the same way).
+ */
+ CPUARMState *env = &cpu->env;
+ uint32_t newpc, newpsr, newpsr_exc;
+
+ qemu_log_mask(CPU_LOG_INT, "...really v7M secure function return\n");
+
+ {
+ bool threadmode, spsel;
+ TCGMemOpIdx oi;
+ ARMMMUIdx mmu_idx;
+ uint32_t *frame_sp_p;
+ uint32_t frameptr;
+
+ /* Pull the return address and IPSR from the Secure stack */
+ threadmode = !arm_v7m_is_handler_mode(env);
+ spsel = env->v7m.control[M_REG_S] & R_V7M_CONTROL_SPSEL_MASK;
+
+ frame_sp_p = get_v7m_sp_ptr(env, true, threadmode, spsel);
+ frameptr = *frame_sp_p;
+
+ /*
+ * These loads may throw an exception (for MPU faults). We want to
+ * do them as secure, so work out what MMU index that is.
+ */
+ mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true);
+ oi = make_memop_idx(MO_LE, arm_to_core_mmu_idx(mmu_idx));
+ newpc = helper_le_ldul_mmu(env, frameptr, oi, 0);
+ newpsr = helper_le_ldul_mmu(env, frameptr + 4, oi, 0);
+
+ /* Consistency checks on new IPSR */
+ newpsr_exc = newpsr & XPSR_EXCP;
+ if (!((env->v7m.exception == 0 && newpsr_exc == 0) ||
+ (env->v7m.exception == 1 && newpsr_exc != 0))) {
+ /* Pend the fault and tell our caller to take it */
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,
+ env->v7m.secure);
+ qemu_log_mask(CPU_LOG_INT,
+ "...taking INVPC UsageFault: "
+ "IPSR consistency check failed\n");
+ return false;
+ }
+
+ *frame_sp_p = frameptr + 8;
+ }
+
+ /* This invalidates frame_sp_p */
+ switch_v7m_security_state(env, true);
+ env->v7m.exception = newpsr_exc;
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
+ if (newpsr & XPSR_SFPA) {
+ env->v7m.control[M_REG_S] |= R_V7M_CONTROL_SFPA_MASK;
+ }
+ xpsr_write(env, 0, XPSR_IT);
+ env->thumb = newpc & 1;
+ env->regs[15] = newpc & ~1;
+
+ qemu_log_mask(CPU_LOG_INT, "...function return successful\n");
+ return true;
+}
+
+static bool v7m_read_half_insn(ARMCPU *cpu, ARMMMUIdx mmu_idx,
+ uint32_t addr, uint16_t *insn)
+{
+ /*
+ * Load a 16-bit portion of a v7M instruction, returning true on success,
+ * or false on failure (in which case we will have pended the appropriate
+ * exception).
+ * We need to do the instruction fetch's MPU and SAU checks
+ * like this because there is no MMU index that would allow
+ * doing the load with a single function call. Instead we must
+ * first check that the security attributes permit the load
+ * and that they don't mismatch on the two halves of the instruction,
+ * and then we do the load as a secure load (ie using the security
+ * attributes of the address, not the CPU, as architecturally required).
+ */
+ CPUState *cs = CPU(cpu);
+ CPUARMState *env = &cpu->env;
+ V8M_SAttributes sattrs = {};
+ MemTxAttrs attrs = {};
+ ARMMMUFaultInfo fi = {};
+ MemTxResult txres;
+ target_ulong page_size;
+ hwaddr physaddr;
+ int prot;
+
+ v8m_security_lookup(env, addr, MMU_INST_FETCH, mmu_idx, &sattrs);
+ if (!sattrs.nsc || sattrs.ns) {
+ /*
+ * This must be the second half of the insn, and it straddles a
+ * region boundary with the second half not being S&NSC.
+ */
+ env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ qemu_log_mask(CPU_LOG_INT,
+ "...really SecureFault with SFSR.INVEP\n");
+ return false;
+ }
+ if (get_phys_addr(env, addr, MMU_INST_FETCH, mmu_idx,
+ &physaddr, &attrs, &prot, &page_size, &fi, NULL)) {
+ /* the MPU lookup failed */
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM, env->v7m.secure);
+ qemu_log_mask(CPU_LOG_INT, "...really MemManage with CFSR.IACCVIOL\n");
+ return false;
+ }
+ *insn = address_space_lduw_le(arm_addressspace(cs, attrs), physaddr,
+ attrs, &txres);
+ if (txres != MEMTX_OK) {
+ env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false);
+ qemu_log_mask(CPU_LOG_INT, "...really BusFault with CFSR.IBUSERR\n");
+ return false;
+ }
+ return true;
+}
+
+static bool v7m_handle_execute_nsc(ARMCPU *cpu)
+{
+ /*
+ * Check whether this attempt to execute code in a Secure & NS-Callable
+ * memory region is for an SG instruction; if so, then emulate the
+ * effect of the SG instruction and return true. Otherwise pend
+ * the correct kind of exception and return false.
+ */
+ CPUARMState *env = &cpu->env;
+ ARMMMUIdx mmu_idx;
+ uint16_t insn;
+
+ /*
+ * We should never get here unless get_phys_addr_pmsav8() caused
+ * an exception for NS executing in S&NSC memory.
+ */
+ assert(!env->v7m.secure);
+ assert(arm_feature(env, ARM_FEATURE_M_SECURITY));
+
+ /* We want to do the MPU lookup as secure; work out what mmu_idx that is */
+ mmu_idx = arm_v7m_mmu_idx_for_secstate(env, true);
+
+ if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15], &insn)) {
+ return false;
+ }
+
+ if (!env->thumb) {
+ goto gen_invep;
+ }
+
+ if (insn != 0xe97f) {
+ /*
+ * Not an SG instruction first half (we choose the IMPDEF
+ * early-SG-check option).
+ */
+ goto gen_invep;
+ }
+
+ if (!v7m_read_half_insn(cpu, mmu_idx, env->regs[15] + 2, &insn)) {
+ return false;
+ }
+
+ if (insn != 0xe97f) {
+ /*
+ * Not an SG instruction second half (yes, both halves of the SG
+ * insn have the same hex value)
+ */
+ goto gen_invep;
+ }
+
+ /*
+ * OK, we have confirmed that we really have an SG instruction.
+ * We know we're NS in S memory so don't need to repeat those checks.
+ */
+ qemu_log_mask(CPU_LOG_INT, "...really an SG instruction at 0x%08" PRIx32
+ ", executing it\n", env->regs[15]);
+ env->regs[14] &= ~1;
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
+ switch_v7m_security_state(env, true);
+ xpsr_write(env, 0, XPSR_IT);
+ env->regs[15] += 4;
+ return true;
+
+gen_invep:
+ env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ qemu_log_mask(CPU_LOG_INT,
+ "...really SecureFault with SFSR.INVEP\n");
+ return false;
+}
+
+void arm_v7m_cpu_do_interrupt(CPUState *cs)
+{
+ ARMCPU *cpu = ARM_CPU(cs);
+ CPUARMState *env = &cpu->env;
+ uint32_t lr;
+ bool ignore_stackfaults;
+
+ arm_log_exception(cs->exception_index);
+
+ /*
+ * For exceptions we just mark as pending on the NVIC, and let that
+ * handle it.
+ */
+ switch (cs->exception_index) {
+ case EXCP_UDEF:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNDEFINSTR_MASK;
+ break;
+ case EXCP_NOCP:
+ {
+ /*
+ * NOCP might be directed to something other than the current
+ * security state if this fault is because of NSACR; we indicate
+ * the target security state using exception.target_el.
+ */
+ int target_secstate;
+
+ if (env->exception.target_el == 3) {
+ target_secstate = M_REG_S;
+ } else {
+ target_secstate = env->v7m.secure;
+ }
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, target_secstate);
+ env->v7m.cfsr[target_secstate] |= R_V7M_CFSR_NOCP_MASK;
+ break;
+ }
+ case EXCP_INVSTATE:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVSTATE_MASK;
+ break;
+ case EXCP_STKOF:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_STKOF_MASK;
+ break;
+ case EXCP_LSERR:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ env->v7m.sfsr |= R_V7M_SFSR_LSERR_MASK;
+ break;
+ case EXCP_UNALIGNED:
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_UNALIGNED_MASK;
+ break;
+ case EXCP_SWI:
+ /* The PC already points to the next instruction. */
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SVC, env->v7m.secure);
+ break;
+ case EXCP_PREFETCH_ABORT:
+ case EXCP_DATA_ABORT:
+ /*
+ * Note that for M profile we don't have a guest facing FSR, but
+ * the env->exception.fsr will be populated by the code that
+ * raises the fault, in the A profile short-descriptor format.
+ */
+ switch (env->exception.fsr & 0xf) {
+ case M_FAKE_FSR_NSC_EXEC:
+ /*
+ * Exception generated when we try to execute code at an address
+ * which is marked as Secure & Non-Secure Callable and the CPU
+ * is in the Non-Secure state. The only instruction which can
+ * be executed like this is SG (and that only if both halves of
+ * the SG instruction have the same security attributes.)
+ * Everything else must generate an INVEP SecureFault, so we
+ * emulate the SG instruction here.
+ */
+ if (v7m_handle_execute_nsc(cpu)) {
+ return;
+ }
+ break;
+ case M_FAKE_FSR_SFAULT:
+ /*
+ * Various flavours of SecureFault for attempts to execute or
+ * access data in the wrong security state.
+ */
+ switch (cs->exception_index) {
+ case EXCP_PREFETCH_ABORT:
+ if (env->v7m.secure) {
+ env->v7m.sfsr |= R_V7M_SFSR_INVTRAN_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...really SecureFault with SFSR.INVTRAN\n");
+ } else {
+ env->v7m.sfsr |= R_V7M_SFSR_INVEP_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...really SecureFault with SFSR.INVEP\n");
+ }
+ break;
+ case EXCP_DATA_ABORT:
+ /* This must be an NS access to S memory */
+ env->v7m.sfsr |= R_V7M_SFSR_AUVIOL_MASK;
+ qemu_log_mask(CPU_LOG_INT,
+ "...really SecureFault with SFSR.AUVIOL\n");
+ break;
+ }
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);
+ break;
+ case 0x8: /* External Abort */
+ switch (cs->exception_index) {
+ case EXCP_PREFETCH_ABORT:
+ env->v7m.cfsr[M_REG_NS] |= R_V7M_CFSR_IBUSERR_MASK;
+ qemu_log_mask(CPU_LOG_INT, "...with CFSR.IBUSERR\n");
+ break;
+ case EXCP_DATA_ABORT:
+ env->v7m.cfsr[M_REG_NS] |=
+ (R_V7M_CFSR_PRECISERR_MASK | R_V7M_CFSR_BFARVALID_MASK);
+ env->v7m.bfar = env->exception.vaddress;
+ qemu_log_mask(CPU_LOG_INT,
+ "...with CFSR.PRECISERR and BFAR 0x%x\n",
+ env->v7m.bfar);
+ break;
+ }
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_BUS, false);
+ break;
+ default:
+ /*
+ * All other FSR values are either MPU faults or "can't happen
+ * for M profile" cases.
+ */
+ switch (cs->exception_index) {
+ case EXCP_PREFETCH_ABORT:
+ env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_IACCVIOL_MASK;
+ qemu_log_mask(CPU_LOG_INT, "...with CFSR.IACCVIOL\n");
+ break;
+ case EXCP_DATA_ABORT:
+ env->v7m.cfsr[env->v7m.secure] |=
+ (R_V7M_CFSR_DACCVIOL_MASK | R_V7M_CFSR_MMARVALID_MASK);
+ env->v7m.mmfar[env->v7m.secure] = env->exception.vaddress;
+ qemu_log_mask(CPU_LOG_INT,
+ "...with CFSR.DACCVIOL and MMFAR 0x%x\n",
+ env->v7m.mmfar[env->v7m.secure]);
+ break;
+ }
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_MEM,
+ env->v7m.secure);
+ break;
+ }
+ break;
+ case EXCP_BKPT:
+ if (semihosting_enabled()) {
+ int nr;
+ nr = arm_lduw_code(env, env->regs[15], arm_sctlr_b(env)) & 0xff;
+ if (nr == 0xab) {
+ env->regs[15] += 2;
+ qemu_log_mask(CPU_LOG_INT,
+ "...handling as semihosting call 0x%x\n",
+ env->regs[0]);
+ env->regs[0] = do_arm_semihosting(env);
+ return;
+ }
+ }
+ armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG, false);
+ break;
+ case EXCP_IRQ:
+ break;
+ case EXCP_EXCEPTION_EXIT:
+ if (env->regs[15] < EXC_RETURN_MIN_MAGIC) {
+ /* Must be v8M security extension function return */
+ assert(env->regs[15] >= FNC_RETURN_MIN_MAGIC);
+ assert(arm_feature(env, ARM_FEATURE_M_SECURITY));
+ if (do_v7m_function_return(cpu)) {
+ return;
+ }
+ } else {
+ do_v7m_exception_exit(cpu);
+ return;
+ }
+ break;
+ case EXCP_LAZYFP:
+ /*
+ * We already pended the specific exception in the NVIC in the
+ * v7m_preserve_fp_state() helper function.
+ */
+ break;
+ default:
+ cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
+ return; /* Never happens. Keep compiler happy. */
+ }
+
+ if (arm_feature(env, ARM_FEATURE_V8)) {
+ lr = R_V7M_EXCRET_RES1_MASK |
+ R_V7M_EXCRET_DCRS_MASK;
+ /*
+ * The S bit indicates whether we should return to Secure
+ * or NonSecure (ie our current state).
+ * The ES bit indicates whether we're taking this exception
+ * to Secure or NonSecure (ie our target state). We set it
+ * later, in v7m_exception_taken().
+ * The SPSEL bit is also set in v7m_exception_taken() for v8M.
+ * This corresponds to the ARM ARM pseudocode for v8M setting
+ * some LR bits in PushStack() and some in ExceptionTaken();
+ * the distinction matters for the tailchain cases where we
+ * can take an exception without pushing the stack.
+ */
+ if (env->v7m.secure) {
+ lr |= R_V7M_EXCRET_S_MASK;
+ }
+ if (!(env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK)) {
+ lr |= R_V7M_EXCRET_FTYPE_MASK;
+ }
+ } else {
+ lr = R_V7M_EXCRET_RES1_MASK |
+ R_V7M_EXCRET_S_MASK |
+ R_V7M_EXCRET_DCRS_MASK |
+ R_V7M_EXCRET_FTYPE_MASK |
+ R_V7M_EXCRET_ES_MASK;
+ if (env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK) {
+ lr |= R_V7M_EXCRET_SPSEL_MASK;
+ }
+ }
+ if (!arm_v7m_is_handler_mode(env)) {
+ lr |= R_V7M_EXCRET_MODE_MASK;
+ }
+
+ ignore_stackfaults = v7m_push_stack(cpu);
+ v7m_exception_taken(cpu, lr, false, ignore_stackfaults);
+}
+
+uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)
+{
+ uint32_t mask;
+ unsigned el = arm_current_el(env);
+
+ /* First handle registers which unprivileged can read */
+
+ switch (reg) {
+ case 0 ... 7: /* xPSR sub-fields */
+ mask = 0;
+ if ((reg & 1) && el) {
+ mask |= XPSR_EXCP; /* IPSR (unpriv. reads as zero) */
+ }
+ if (!(reg & 4)) {
+ mask |= XPSR_NZCV | XPSR_Q; /* APSR */
+ if (arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
+ mask |= XPSR_GE;
+ }
+ }
+ /* EPSR reads as zero */
+ return xpsr_read(env) & mask;
+ break;
+ case 20: /* CONTROL */
+ {
+ uint32_t value = env->v7m.control[env->v7m.secure];
+ if (!env->v7m.secure) {
+ /* SFPA is RAZ/WI from NS; FPCA is stored in the M_REG_S bank */
+ value |= env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK;
+ }
+ return value;
+ }
+ case 0x94: /* CONTROL_NS */
+ /*
+ * We have to handle this here because unprivileged Secure code
+ * can read the NS CONTROL register.
+ */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.control[M_REG_NS] |
+ (env->v7m.control[M_REG_S] & R_V7M_CONTROL_FPCA_MASK);
+ }
+
+ if (el == 0) {
+ return 0; /* unprivileged reads others as zero */
+ }
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ switch (reg) {
+ case 0x88: /* MSP_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.other_ss_msp;
+ case 0x89: /* PSP_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.other_ss_psp;
+ case 0x8a: /* MSPLIM_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.msplim[M_REG_NS];
+ case 0x8b: /* PSPLIM_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.psplim[M_REG_NS];
+ case 0x90: /* PRIMASK_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.primask[M_REG_NS];
+ case 0x91: /* BASEPRI_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.basepri[M_REG_NS];
+ case 0x93: /* FAULTMASK_NS */
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ return env->v7m.faultmask[M_REG_NS];
+ case 0x98: /* SP_NS */
+ {
+ /*
+ * This gives the non-secure SP selected based on whether we're
+ * currently in handler mode or not, using the NS CONTROL.SPSEL.
+ */
+ bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK;
+
+ if (!env->v7m.secure) {
+ return 0;
+ }
+ if (!arm_v7m_is_handler_mode(env) && spsel) {
+ return env->v7m.other_ss_psp;
+ } else {
+ return env->v7m.other_ss_msp;
+ }
+ }
+ default:
+ break;
+ }
+ }
+
+ switch (reg) {
+ case 8: /* MSP */
+ return v7m_using_psp(env) ? env->v7m.other_sp : env->regs[13];
+ case 9: /* PSP */
+ return v7m_using_psp(env) ? env->regs[13] : env->v7m.other_sp;
+ case 10: /* MSPLIM */
+ if (!arm_feature(env, ARM_FEATURE_V8)) {
+ goto bad_reg;
+ }
+ return env->v7m.msplim[env->v7m.secure];
+ case 11: /* PSPLIM */
+ if (!arm_feature(env, ARM_FEATURE_V8)) {
+ goto bad_reg;
+ }
+ return env->v7m.psplim[env->v7m.secure];
+ case 16: /* PRIMASK */
+ return env->v7m.primask[env->v7m.secure];
+ case 17: /* BASEPRI */
+ case 18: /* BASEPRI_MAX */
+ return env->v7m.basepri[env->v7m.secure];
+ case 19: /* FAULTMASK */
+ return env->v7m.faultmask[env->v7m.secure];
+ default:
+ bad_reg:
+ qemu_log_mask(LOG_GUEST_ERROR, "Attempt to read unknown special"
+ " register %d\n", reg);
+ return 0;
+ }
+}
+
+void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val)
+{
+ /*
+ * We're passed bits [11..0] of the instruction; extract
+ * SYSm and the mask bits.
+ * Invalid combinations of SYSm and mask are UNPREDICTABLE;
+ * we choose to treat them as if the mask bits were valid.
+ * NB that the pseudocode 'mask' variable is bits [11..10],
+ * whereas ours is [11..8].
+ */
+ uint32_t mask = extract32(maskreg, 8, 4);
+ uint32_t reg = extract32(maskreg, 0, 8);
+ int cur_el = arm_current_el(env);
+
+ if (cur_el == 0 && reg > 7 && reg != 20) {
+ /*
+ * only xPSR sub-fields and CONTROL.SFPA may be written by
+ * unprivileged code
+ */
+ return;
+ }
+
+ if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
+ switch (reg) {
+ case 0x88: /* MSP_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ env->v7m.other_ss_msp = val;
+ return;
+ case 0x89: /* PSP_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ env->v7m.other_ss_psp = val;
+ return;
+ case 0x8a: /* MSPLIM_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ env->v7m.msplim[M_REG_NS] = val & ~7;
+ return;
+ case 0x8b: /* PSPLIM_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ env->v7m.psplim[M_REG_NS] = val & ~7;
+ return;
+ case 0x90: /* PRIMASK_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ env->v7m.primask[M_REG_NS] = val & 1;
+ return;
+ case 0x91: /* BASEPRI_NS */
+ if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ return;
+ }
+ env->v7m.basepri[M_REG_NS] = val & 0xff;
+ return;
+ case 0x93: /* FAULTMASK_NS */
+ if (!env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ return;
+ }
+ env->v7m.faultmask[M_REG_NS] = val & 1;
+ return;
+ case 0x94: /* CONTROL_NS */
+ if (!env->v7m.secure) {
+ return;
+ }
+ write_v7m_control_spsel_for_secstate(env,
+ val &
R_V7M_CONTROL_SPSEL_MASK,
+ M_REG_NS);
+ if (arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ env->v7m.control[M_REG_NS] &= ~R_V7M_CONTROL_NPRIV_MASK;
+ env->v7m.control[M_REG_NS] |= val & R_V7M_CONTROL_NPRIV_MASK;
+ }
+ /*
+ * SFPA is RAZ/WI from NS. FPCA is RO if NSACR.CP10 == 0,
+ * RES0 if the FPU is not present, and is stored in the S bank
+ */
+ if (arm_feature(env, ARM_FEATURE_VFP) &&
+ extract32(env->v7m.nsacr, 10, 1)) {
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
+ env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK;
+ }
+ return;
+ case 0x98: /* SP_NS */
+ {
+ /*
+ * This gives the non-secure SP selected based on whether we're
+ * currently in handler mode or not, using the NS CONTROL.SPSEL.
+ */
+ bool spsel = env->v7m.control[M_REG_NS] & R_V7M_CONTROL_SPSEL_MASK;
+ bool is_psp = !arm_v7m_is_handler_mode(env) && spsel;
+ uint32_t limit;
+
+ if (!env->v7m.secure) {
+ return;
+ }
+
+ limit = is_psp ? env->v7m.psplim[false] : env->v7m.msplim[false];
+
+ if (val < limit) {
+ CPUState *cs = env_cpu(env);
+
+ cpu_restore_state(cs, GETPC(), true);
+ raise_exception(env, EXCP_STKOF, 0, 1);
+ }
+
+ if (is_psp) {
+ env->v7m.other_ss_psp = val;
+ } else {
+ env->v7m.other_ss_msp = val;
+ }
+ return;
+ }
+ default:
+ break;
+ }
+ }
+
+ switch (reg) {
+ case 0 ... 7: /* xPSR sub-fields */
+ /* only APSR is actually writable */
+ if (!(reg & 4)) {
+ uint32_t apsrmask = 0;
+
+ if (mask & 8) {
+ apsrmask |= XPSR_NZCV | XPSR_Q;
+ }
+ if ((mask & 4) && arm_feature(env, ARM_FEATURE_THUMB_DSP)) {
+ apsrmask |= XPSR_GE;
+ }
+ xpsr_write(env, val, apsrmask);
+ }
+ break;
+ case 8: /* MSP */
+ if (v7m_using_psp(env)) {
+ env->v7m.other_sp = val;
+ } else {
+ env->regs[13] = val;
+ }
+ break;
+ case 9: /* PSP */
+ if (v7m_using_psp(env)) {
+ env->regs[13] = val;
+ } else {
+ env->v7m.other_sp = val;
+ }
+ break;
+ case 10: /* MSPLIM */
+ if (!arm_feature(env, ARM_FEATURE_V8)) {
+ goto bad_reg;
+ }
+ env->v7m.msplim[env->v7m.secure] = val & ~7;
+ break;
+ case 11: /* PSPLIM */
+ if (!arm_feature(env, ARM_FEATURE_V8)) {
+ goto bad_reg;
+ }
+ env->v7m.psplim[env->v7m.secure] = val & ~7;
+ break;
+ case 16: /* PRIMASK */
+ env->v7m.primask[env->v7m.secure] = val & 1;
+ break;
+ case 17: /* BASEPRI */
+ if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ goto bad_reg;
+ }
+ env->v7m.basepri[env->v7m.secure] = val & 0xff;
+ break;
+ case 18: /* BASEPRI_MAX */
+ if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ goto bad_reg;
+ }
+ val &= 0xff;
+ if (val != 0 && (val < env->v7m.basepri[env->v7m.secure]
+ || env->v7m.basepri[env->v7m.secure] == 0)) {
+ env->v7m.basepri[env->v7m.secure] = val;
+ }
+ break;
+ case 19: /* FAULTMASK */
+ if (!arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ goto bad_reg;
+ }
+ env->v7m.faultmask[env->v7m.secure] = val & 1;
+ break;
+ case 20: /* CONTROL */
+ /*
+ * Writing to the SPSEL bit only has an effect if we are in
+ * thread mode; other bits can be updated by any privileged code.
+ * write_v7m_control_spsel() deals with updating the SPSEL bit in
+ * env->v7m.control, so we only need update the others.
+ * For v7M, we must just ignore explicit writes to SPSEL in handler
+ * mode; for v8M the write is permitted but will have no effect.
+ * All these bits are writes-ignored from non-privileged code,
+ * except for SFPA.
+ */
+ if (cur_el > 0 && (arm_feature(env, ARM_FEATURE_V8) ||
+ !arm_v7m_is_handler_mode(env))) {
+ write_v7m_control_spsel(env, (val & R_V7M_CONTROL_SPSEL_MASK) !=
0);
+ }
+ if (cur_el > 0 && arm_feature(env, ARM_FEATURE_M_MAIN)) {
+ env->v7m.control[env->v7m.secure] &= ~R_V7M_CONTROL_NPRIV_MASK;
+ env->v7m.control[env->v7m.secure] |= val &
R_V7M_CONTROL_NPRIV_MASK;
+ }
+ if (arm_feature(env, ARM_FEATURE_VFP)) {
+ /*
+ * SFPA is RAZ/WI from NS or if no FPU.
+ * FPCA is RO if NSACR.CP10 == 0, RES0 if the FPU is not present.
+ * Both are stored in the S bank.
+ */
+ if (env->v7m.secure) {
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_SFPA_MASK;
+ env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_SFPA_MASK;
+ }
+ if (cur_el > 0 &&
+ (env->v7m.secure || !arm_feature(env, ARM_FEATURE_M_SECURITY)
||
+ extract32(env->v7m.nsacr, 10, 1))) {
+ env->v7m.control[M_REG_S] &= ~R_V7M_CONTROL_FPCA_MASK;
+ env->v7m.control[M_REG_S] |= val & R_V7M_CONTROL_FPCA_MASK;
+ }
+ }
+ break;
+ default:
+ bad_reg:
+ qemu_log_mask(LOG_GUEST_ERROR, "Attempt to write unknown special"
+ " register %d\n", reg);
+ return;
+ }
+}
+
+uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
+{
+ /* Implement the TT instruction. op is bits [7:6] of the insn. */
+ bool forceunpriv = op & 1;
+ bool alt = op & 2;
+ V8M_SAttributes sattrs = {};
+ uint32_t tt_resp;
+ bool r, rw, nsr, nsrw, mrvalid;
+ int prot;
+ ARMMMUFaultInfo fi = {};
+ MemTxAttrs attrs = {};
+ hwaddr phys_addr;
+ ARMMMUIdx mmu_idx;
+ uint32_t mregion;
+ bool targetpriv;
+ bool targetsec = env->v7m.secure;
+ bool is_subpage;
+
+ /*
+ * Work out what the security state and privilege level we're
+ * interested in is...
+ */
+ if (alt) {
+ targetsec = !targetsec;
+ }
+
+ if (forceunpriv) {
+ targetpriv = false;
+ } else {
+ targetpriv = arm_v7m_is_handler_mode(env) ||
+ !(env->v7m.control[targetsec] & R_V7M_CONTROL_NPRIV_MASK);
+ }
+
+ /* ...and then figure out which MMU index this is */
+ mmu_idx = arm_v7m_mmu_idx_for_secstate_and_priv(env, targetsec,
targetpriv);
+
+ /*
+ * We know that the MPU and SAU don't care about the access type
+ * for our purposes beyond that we don't want to claim to be
+ * an insn fetch, so we arbitrarily call this a read.
+ */
+
+ /*
+ * MPU region info only available for privileged or if
+ * inspecting the other MPU state.
+ */
+ if (arm_current_el(env) != 0 || alt) {
+ /* We can ignore the return value as prot is always set */
+ pmsav8_mpu_lookup(env, addr, MMU_DATA_LOAD, mmu_idx,
+ &phys_addr, &attrs, &prot, &is_subpage,
+ &fi, &mregion);
+ if (mregion == -1) {
+ mrvalid = false;
+ mregion = 0;
+ } else {
+ mrvalid = true;
+ }
+ r = prot & PAGE_READ;
+ rw = prot & PAGE_WRITE;
+ } else {
+ r = false;
+ rw = false;
+ mrvalid = false;
+ mregion = 0;
+ }
+
+ if (env->v7m.secure) {
+ v8m_security_lookup(env, addr, MMU_DATA_LOAD, mmu_idx, &sattrs);
+ nsr = sattrs.ns && r;
+ nsrw = sattrs.ns && rw;
+ } else {
+ sattrs.ns = true;
+ nsr = false;
+ nsrw = false;
+ }
+
+ tt_resp = (sattrs.iregion << 24) |
+ (sattrs.irvalid << 23) |
+ ((!sattrs.ns) << 22) |
+ (nsrw << 21) |
+ (nsr << 20) |
+ (rw << 19) |
+ (r << 18) |
+ (sattrs.srvalid << 17) |
+ (mrvalid << 16) |
+ (sattrs.sregion << 8) |
+ mregion;
+
+ return tt_resp;
+}
+
+#endif /* !CONFIG_USER_ONLY */
+
+ARMMMUIdx arm_v7m_mmu_idx_all(CPUARMState *env,
+ bool secstate, bool priv, bool negpri)
+{
+ ARMMMUIdx mmu_idx = ARM_MMU_IDX_M;
+
+ if (priv) {
+ mmu_idx |= ARM_MMU_IDX_M_PRIV;
+ }
+
+ if (negpri) {
+ mmu_idx |= ARM_MMU_IDX_M_NEGPRI;
+ }
+
+ if (secstate) {
+ mmu_idx |= ARM_MMU_IDX_M_S;
+ }
+
+ return mmu_idx;
+}
+
+ARMMMUIdx arm_v7m_mmu_idx_for_secstate_and_priv(CPUARMState *env,
+ bool secstate, bool priv)
+{
+ bool negpri = armv7m_nvic_neg_prio_requested(env->nvic, secstate);
+
+ return arm_v7m_mmu_idx_all(env, secstate, priv, negpri);
+}
+
+/* Return the MMU index for a v7M CPU in the specified security state */
+ARMMMUIdx arm_v7m_mmu_idx_for_secstate(CPUARMState *env, bool secstate)
+{
+ bool priv = arm_current_el(env) != 0;
+
+ return arm_v7m_mmu_idx_for_secstate_and_priv(env, secstate, priv);
+}
--
2.20.1