From: Christoph Muellner <cmuellner@linux.com>
Zicbom is the Cache-Block Management extension defined in the already
ratified RISC-V Base Cache Management Operation (CBO) ISA extension [1].
The extension contains three instructions: cbo.clean, cbo.flush and
cbo.inval. All of them must be implemented in the same group as LQ and
cbo.zero due to overlapping patterns.
All these instructions can throw a Illegal Instruction/Virtual
Instruction exception, similar to the existing cbo.zero. The same
check_zicbo_envcfg() is used to handle these exceptions.
Aside from that, these instructions also need to handle page faults and
guest page faults. This is done in a new check_zicbom_access() helper.
As with Zicboz, the cache block size for Zicbom is also configurable.
Note that the spec determines that Zicbo[mp] and Zicboz can have
different cache sizes (Section 2.7 of [1]), so we also include a
'cbom_blocksize' to go along with the existing 'cboz_blocksize'. They
are set to the same size, so unless users want to play around with the
settings both sizes will be the same.
[1]
https://github.com/riscv/riscv-CMOs/blob/master/specifications/cmobase-v1.0.1.pdf
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Christoph Muellner <cmuellner@linux.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
target/riscv/cpu.c | 3 +
target/riscv/cpu.h | 2 +
target/riscv/helper.h | 2 +
target/riscv/insn32.decode | 5 +
target/riscv/insn_trans/trans_rvzicbo.c.inc | 27 +++++
target/riscv/op_helper.c | 107 ++++++++++++++++++++
6 files changed, 146 insertions(+)
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index 7dd37de7f9..4b779b1775 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -74,6 +74,7 @@ struct isa_ext_data {
static const struct isa_ext_data isa_edata_arr[] = {
ISA_EXT_DATA_ENTRY(h, false, PRIV_VERSION_1_12_0, ext_h),
ISA_EXT_DATA_ENTRY(v, false, PRIV_VERSION_1_10_0, ext_v),
+ ISA_EXT_DATA_ENTRY(zicbom, true, PRIV_VERSION_1_12_0, ext_icbom),
ISA_EXT_DATA_ENTRY(zicboz, true, PRIV_VERSION_1_12_0, ext_icboz),
ISA_EXT_DATA_ENTRY(zicsr, true, PRIV_VERSION_1_10_0, ext_icsr),
ISA_EXT_DATA_ENTRY(zifencei, true, PRIV_VERSION_1_10_0, ext_ifencei),
@@ -1127,6 +1128,8 @@ static Property riscv_cpu_extensions[] = {
DEFINE_PROP_BOOL("zhinx", RISCVCPU, cfg.ext_zhinx, false),
DEFINE_PROP_BOOL("zhinxmin", RISCVCPU, cfg.ext_zhinxmin, false),
+ DEFINE_PROP_BOOL("zicbom", RISCVCPU, cfg.ext_icbom, true),
+ DEFINE_PROP_UINT16("cbom_blocksize", RISCVCPU, cfg.cbom_blocksize, 64),
DEFINE_PROP_BOOL("zicboz", RISCVCPU, cfg.ext_icboz, true),
DEFINE_PROP_UINT16("cboz_blocksize", RISCVCPU, cfg.cboz_blocksize, 64),
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index 6b4c714d3a..a0673b4604 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -447,6 +447,7 @@ struct RISCVCPUConfig {
bool ext_zkt;
bool ext_ifencei;
bool ext_icsr;
+ bool ext_icbom;
bool ext_icboz;
bool ext_zihintpause;
bool ext_smstateen;
@@ -495,6 +496,7 @@ struct RISCVCPUConfig {
char *vext_spec;
uint16_t vlen;
uint16_t elen;
+ uint16_t cbom_blocksize;
uint16_t cboz_blocksize;
bool mmu;
bool pmp;
diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index ce165821b8..37b54e0991 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -98,6 +98,8 @@ DEF_HELPER_FLAGS_2(fcvt_h_lu, TCG_CALL_NO_RWG, i64, env, tl)
DEF_HELPER_FLAGS_2(fclass_h, TCG_CALL_NO_RWG_SE, tl, env, i64)
/* Cache-block operations */
+DEF_HELPER_2(cbo_clean_flush, void, env, tl)
+DEF_HELPER_2(cbo_inval, void, env, tl)
DEF_HELPER_2(cbo_zero, void, env, tl)
/* Special functions */
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 3985bc703f..3788f86528 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -181,6 +181,11 @@ sraw 0100000 ..... ..... 101 ..... 0111011 @r
ldu ............ ..... 111 ..... 0000011 @i
{
[
+ # *** RV32 Zicbom Standard Extension ***
+ cbo_clean 0000000 00001 ..... 010 00000 0001111 @sfence_vm
+ cbo_flush 0000000 00010 ..... 010 00000 0001111 @sfence_vm
+ cbo_inval 0000000 00000 ..... 010 00000 0001111 @sfence_vm
+
# *** RV32 Zicboz Standard Extension ***
cbo_zero 0000000 00100 ..... 010 00000 0001111 @sfence_vm
]
diff --git a/target/riscv/insn_trans/trans_rvzicbo.c.inc
b/target/riscv/insn_trans/trans_rvzicbo.c.inc
index feabc28342..7df9c30b58 100644
--- a/target/riscv/insn_trans/trans_rvzicbo.c.inc
+++ b/target/riscv/insn_trans/trans_rvzicbo.c.inc
@@ -16,12 +16,39 @@
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#define REQUIRE_ZICBOM(ctx) do { \
+ if (!ctx->cfg_ptr->ext_icbom) { \
+ return false; \
+ } \
+} while (0)
+
#define REQUIRE_ZICBOZ(ctx) do { \
if (!ctx->cfg_ptr->ext_icboz) { \
return false; \
} \
} while (0)
+static bool trans_cbo_clean(DisasContext *ctx, arg_cbo_clean *a)
+{
+ REQUIRE_ZICBOM(ctx);
+ gen_helper_cbo_clean_flush(cpu_env, cpu_gpr[a->rs1]);
+ return true;
+}
+
+static bool trans_cbo_flush(DisasContext *ctx, arg_cbo_flush *a)
+{
+ REQUIRE_ZICBOM(ctx);
+ gen_helper_cbo_clean_flush(cpu_env, cpu_gpr[a->rs1]);
+ return true;
+}
+
+static bool trans_cbo_inval(DisasContext *ctx, arg_cbo_inval *a)
+{
+ REQUIRE_ZICBOM(ctx);
+ gen_helper_cbo_inval(cpu_env, cpu_gpr[a->rs1]);
+ return true;
+}
+
static bool trans_cbo_zero(DisasContext *ctx, arg_cbo_zero *a)
{
REQUIRE_ZICBOZ(ctx);
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index 154007af80..573cca4cd3 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -176,6 +176,113 @@ void helper_cbo_zero(CPURISCVState *env, target_ulong
address)
memset(mem, 0, cbozlen);
}
+/*
+ * check_zicbom_access
+ *
+ * Check access permissions (LOAD, STORE or FETCH as specified in
+ * section 2.5.2 of the CMO specification) for Zicbom, raising
+ * either store page-fault (non-virtualized) or store guest-page
+ * fault (virtualized).
+ */
+static void check_zicbom_access(CPURISCVState *env,
+ target_ulong address,
+ uintptr_t ra)
+{
+ RISCVCPU *cpu = env_archcpu(env);
+ int mmu_idx = cpu_mmu_index(env, false);
+ uint16_t cbomlen = cpu->cfg.cbom_blocksize;
+ void *phost;
+ int ret;
+
+ /* Mask off low-bits to align-down to the cache-block. */
+ address &= ~(cbomlen - 1);
+
+ /*
+ * Section 2.5.2 of cmobase v1.0.1:
+ *
+ * "A cache-block management instruction is permitted to
+ * access the specified cache block whenever a load instruction
+ * or store instruction is permitted to access the corresponding
+ * physical addresses. If neither a load instruction nor store
+ * instruction is permitted to access the physical addresses,
+ * but an instruction fetch is permitted to access the physical
+ * addresses, whether a cache-block management instruction is
+ * permitted to access the cache block is UNSPECIFIED.
+ *
+ * This means we have to make a choice of whether checking
+ * MMU_INST_FETCH is worth it or not. We'll go the easier
+ * route and check MMU_DATA_LOAD and MMU_DATA_STORE only.
+ */
+ ret = probe_access_range_flags(env, address, cbomlen,
+ MMU_DATA_LOAD,
+ mmu_idx, true, &phost, ra);
+
+ if (ret == TLB_INVALID_MASK) {
+ probe_access_range_flags(env, address, cbomlen,
+ MMU_DATA_STORE,
+ mmu_idx, true, &phost, ra);