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[Qemu-devel] [PATCH v4 1/6] target-arm: Add CNTVOFF_EL2
From: |
Edgar E. Iglesias |
Subject: |
[Qemu-devel] [PATCH v4 1/6] target-arm: Add CNTVOFF_EL2 |
Date: |
Fri, 5 Jun 2015 20:33:36 +1000 |
From: "Edgar E. Iglesias" <address@hidden>
Adds support for the virtual timer offset controlled by EL2.
Signed-off-by: Edgar E. Iglesias <address@hidden>
---
target-arm/cpu.h | 1 +
target-arm/helper.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++-------
2 files changed, 52 insertions(+), 7 deletions(-)
diff --git a/target-arm/cpu.h b/target-arm/cpu.h
index 21b5b8e..1a66aa4 100644
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -355,6 +355,7 @@ typedef struct CPUARMState {
};
uint64_t c14_cntfrq; /* Counter Frequency register */
uint64_t c14_cntkctl; /* Timer Control register */
+ uint64_t cntvoff_el2; /* Counter Virtual Offset register */
ARMGenericTimer c14_timer[NUM_GTIMERS];
uint32_t c15_cpar; /* XScale Coprocessor Access Register */
uint32_t c15_ticonfig; /* TI925T configuration byte. */
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 3da0c05..7901da1 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -1208,9 +1208,20 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
/* Timer enabled: calculate and set current ISTATUS, irq, and
* reset timer to when ISTATUS next has to change
*/
+ uint64_t offset = timeridx == GTIMER_VIRT ?
+ cpu->env.cp15.cntvoff_el2 : 0;
uint64_t count = gt_get_countervalue(&cpu->env);
- /* Note that this must be unsigned 64 bit arithmetic: */
- int istatus = count >= gt->cval;
+ /* The ARM spec says that count, offset and gt->cval are all
+ * unsigned 64bit values.
+ * The event trig is described as:
+ * (Counter[63:0] - Offset[63:0])[63:0] - CompareValue[63:0]) >= 0
+ *
+ * We do the subtractions as unsigned values to avoid under/overflowing
+ * signed integers (undefined behaviour in C).
+ * To be able to do the compare >= 0 we cast the result into a
+ * signed int64_t.
+ */
+ int istatus = (int64_t) (count - offset - gt->cval) >= 0;
uint64_t nexttick;
gt->ctl = deposit32(gt->ctl, 2, 1, istatus);
@@ -1221,7 +1232,7 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx)
nexttick = UINT64_MAX;
} else {
/* Next transition is when we hit cval */
- nexttick = gt->cval;
+ nexttick = gt->cval + offset;
}
/* Note that the desired next expiry time might be beyond the
* signed-64-bit range of a QEMUTimer -- in this case we just
@@ -1253,6 +1264,11 @@ static uint64_t gt_cnt_read(CPUARMState *env, const
ARMCPRegInfo *ri)
return gt_get_countervalue(env);
}
+static uint64_t gt_virt_cnt_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+ return gt_get_countervalue(env) - env->cp15.cntvoff_el2;
+}
+
static void gt_cval_write(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value)
{
@@ -1265,17 +1281,19 @@ static void gt_cval_write(CPUARMState *env, const
ARMCPRegInfo *ri,
static uint64_t gt_tval_read(CPUARMState *env, const ARMCPRegInfo *ri)
{
int timeridx = ri->crm & 1;
+ uint64_t offset = timeridx == GTIMER_VIRT ? env->cp15.cntvoff_el2 : 0;
return (uint32_t)(env->cp15.c14_timer[timeridx].cval -
- gt_get_countervalue(env));
+ gt_get_countervalue(env) - offset);
}
static void gt_tval_write(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value)
{
int timeridx = ri->crm & 1;
+ uint64_t offset = timeridx == GTIMER_VIRT ? env->cp15.cntvoff_el2 : 0;
- env->cp15.c14_timer[timeridx].cval = gt_get_countervalue(env) +
+ env->cp15.c14_timer[timeridx].cval = gt_get_countervalue(env) - offset +
sextract64(value, 0, 32);
gt_recalc_timer(arm_env_get_cpu(env), timeridx);
}
@@ -1300,6 +1318,15 @@ static void gt_ctl_write(CPUARMState *env, const
ARMCPRegInfo *ri,
}
}
+static void gt_cntvoff_write(CPUARMState *env, const ARMCPRegInfo *ri,
+ uint64_t value)
+{
+ ARMCPU *cpu = arm_env_get_cpu(env);
+
+ raw_write(env, ri, value);
+ gt_recalc_timer(cpu, GTIMER_VIRT);
+}
+
void arm_gt_ptimer_cb(void *opaque)
{
ARMCPU *cpu = opaque;
@@ -1409,13 +1436,13 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[] = {
{ .name = "CNTVCT", .cp = 15, .crm = 14, .opc1 = 1,
.access = PL0_R, .type = ARM_CP_64BIT | ARM_CP_NO_RAW | ARM_CP_IO,
.accessfn = gt_vct_access,
- .readfn = gt_cnt_read, .resetfn = arm_cp_reset_ignore,
+ .readfn = gt_virt_cnt_read, .resetfn = arm_cp_reset_ignore,
},
{ .name = "CNTVCT_EL0", .state = ARM_CP_STATE_AA64,
.opc0 = 3, .opc1 = 3, .crn = 14, .crm = 0, .opc2 = 2,
.access = PL0_R, .type = ARM_CP_NO_RAW | ARM_CP_IO,
.accessfn = gt_vct_access,
- .readfn = gt_cnt_read, .resetfn = gt_cnt_reset,
+ .readfn = gt_virt_cnt_read, .resetfn = gt_cnt_reset,
},
/* Comparison value, indicating when the timer goes off */
{ .name = "CNTP_CVAL", .cp = 15, .crm = 14, .opc1 = 2,
@@ -2539,6 +2566,12 @@ static const ARMCPRegInfo el3_no_el2_cp_reginfo[] = {
{ .name = "HTTBR", .cp = 15, .opc1 = 4, .crm = 2,
.access = PL2_RW, .type = ARM_CP_64BIT | ARM_CP_CONST,
.resetvalue = 0 },
+ { .name = "CNTVOFF_EL2", .state = ARM_CP_STATE_AA64,
+ .opc0 = 3, .opc1 = 4, .crn = 14, .crm = 0, .opc2 = 3,
+ .access = PL2_RW, .type = ARM_CP_CONST, .resetvalue = 0 },
+ { .name = "CNTVOFF", .cp = 15, .opc1 = 4, .crm = 14,
+ .access = PL2_RW, .type = ARM_CP_64BIT | ARM_CP_CONST,
+ .resetvalue = 0 },
REGINFO_SENTINEL
};
@@ -2651,6 +2684,17 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
.opc0 = 1, .opc1 = 4, .crn = 8, .crm = 3, .opc2 = 1,
.type = ARM_CP_NO_RAW, .access = PL2_W,
.writefn = tlbi_aa64_vaa_write },
+#ifndef CONFIG_USER_ONLY
+ { .name = "CNTVOFF_EL2", .state = ARM_CP_STATE_AA64,
+ .opc0 = 3, .opc1 = 4, .crn = 14, .crm = 0, .opc2 = 3,
+ .access = PL2_RW, .type = ARM_CP_IO, .resetvalue = 0,
+ .writefn = gt_cntvoff_write,
+ .fieldoffset = offsetof(CPUARMState, cp15.cntvoff_el2) },
+ { .name = "CNTVOFF", .cp = 15, .opc1 = 4, .crm = 14,
+ .access = PL2_RW, .type = ARM_CP_64BIT | ARM_CP_ALIAS | ARM_CP_IO,
+ .writefn = gt_cntvoff_write,
+ .fieldoffset = offsetof(CPUARMState, cp15.cntvoff_el2) },
+#endif
REGINFO_SENTINEL
};
--
1.9.1
[Qemu-devel] [PATCH v4 3/6] target-arm: Pass timeridx as argument to various timer functions, Edgar E. Iglesias, 2015/06/05
[Qemu-devel] [PATCH v4 4/6] target-arm: Add the Hypervisor timer, Edgar E. Iglesias, 2015/06/05