[Qemu-devel] [PATCH v3 19/22] target/arm: Finish implementation of PM[X]EVCNTR and PM[X]EVTYPER

[Aaron Lindsay <alindsay@codeaurora.org>]

Add arrays to hold the registers, the definitions themselves, access
functions, and add logic to reset counters when PMCR.P is set.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
---
 target/arm/cpu.h    |   7 +-
 target/arm/helper.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 207 insertions(+), 19 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 19f005d..7a74966 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -454,8 +454,9 @@ typedef struct CPUARMState {
         uint64_t oslsr_el1; /* OS Lock Status */
         uint64_t mdcr_el2;
         uint64_t mdcr_el3;
-        /* If the counter is enabled, this stores the last time the counter
-         * was reset. Otherwise it stores the counter value
+        /* If the pmccntr and pmevcntr counters are enabled, they store the
+         * offset the last time the counter was reset. Otherwise they store the
+         * counter value.
          */
         uint64_t c15_ccnt;
         /* ccnt_cached_cycles is used to hold the last cycle count when
@@ -463,6 +464,8 @@ typedef struct CPUARMState {
          * PMU operations which require this.
          */
         uint64_t ccnt_cached_cycles;
+        uint64_t c14_pmevcntr[31];
+        uint64_t c14_pmevtyper[31];
         uint64_t pmccfiltr_el0; /* Performance Monitor Filter Register */
         uint64_t vpidr_el2; /* Virtualization Processor ID Register */
         uint64_t vmpidr_el2; /* Virtualization Multiprocessor ID Register */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 6a4f900..2fa8308 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -906,6 +906,7 @@ static const ARMCPRegInfo v6_cp_reginfo[] = {
 #define PMCRN_SHIFT 11
 #define PMCRD   0x8
 #define PMCRC   0x4
+#define PMCRP   0x2
 #define PMCRE   0x1
 
 #define PMXEVTYPER_P          0x80000000
@@ -931,7 +932,7 @@ typedef struct pm_event {
     bool (*supported)(CPUARMState *);
     /* Retrieve the current count of the underlying event. The programmed
      * counters hold a difference from the return value from this function */
-    uint64_t (*get_count)(CPUARMState *);
+    uint64_t (*get_count)(CPUARMState *, uint64_t cycles);
 } pm_event;
 
 #define SUPPORTED_EVENT_SENTINEL UINT16_MAX
@@ -1054,6 +1055,21 @@ static inline bool pmu_counter_enabled(CPUARMState *env, uint8_t counter)
         return false;
     }
 
+    if (counter != 31) {
+        /* If not checking PMCCNTR, ensure the counter is setup to an event we
+         * support */
+        uint16_t event = env->cp15.c14_pmevtyper[counter] & PMXEVTYPER_EVTCOUNT;
+        if (event > 0x3f) {
+            return false; /* We only support common architectural and
+                             microarchitectural events */
+        }
+
+        uint16_t event_idx = supported_event_map[event];
+        if (event_idx == SUPPORTED_EVENT_SENTINEL) {
+            return false;
+        }
+    }
+
     return true;
 }
 
@@ -1149,14 +1165,37 @@ void pmccntr_op_finish(CPUARMState *env, uint64_t prev_cycles)
     }
 }
 
+static void pmu_sync_counter(CPUARMState *env, uint8_t counter, uint64_t cycles)
+{
+    if (pmu_counter_enabled(env, counter) &&
+        !pmu_counter_filtered(env, env->cp15.c14_pmevtyper[counter])) {
+
+        uint16_t event = env->cp15.c14_pmevtyper[counter] & PMXEVTYPER_EVTCOUNT;
+        uint16_t event_idx = supported_event_map[event];
+
+        uint64_t count = pm_events[event_idx].get_count(env, cycles);
+        env->cp15.c14_pmevcntr[counter] =
+            count - env->cp15.c14_pmevcntr[counter];
+    }
+}
+
 uint64_t pmu_op_start(CPUARMState *env)
 {
-    return pmccntr_op_start(env);
+    uint64_t saved_cycles = pmccntr_op_start(env);
+    unsigned int i;
+    for (i = 0; i < PMU_NUM_COUNTERS(env); i++) {
+        pmu_sync_counter(env, i, saved_cycles);
+    }
+    return saved_cycles;
 }
 
 void pmu_op_finish(CPUARMState *env, uint64_t prev_cycles)
 {
     pmccntr_op_finish(env, prev_cycles);
+    unsigned int i;
+    for (i = 0; i < PMU_NUM_COUNTERS(env); i++) {
+        pmu_sync_counter(env, i, prev_cycles);
+    }
 }
 
 void pmu_pre_el_change(ARMCPU *cpu, void *ignored)
@@ -1179,6 +1218,13 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
         env->cp15.c15_ccnt = 0;
     }
 
+    if (value & PMCRP) {
+        unsigned int i;
+        for (i = 0; i < PMU_NUM_COUNTERS(env); i++) {
+            env->cp15.c14_pmevcntr[i] = 0;
+        }
+    }
+
     /* only the DP, X, D and E bits are writable */
     env->cp15.c9_pmcr &= ~0x39;
     env->cp15.c9_pmcr |= (value & 0x39);
@@ -1294,30 +1340,127 @@ static void pmovsset_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->cp15.c9_pmovsr |= value;
 }
 
-static void pmxevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
-                             uint64_t value)
+static void pmevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value, const uint8_t counter)
 {
+    if (counter == 0x1f) {
+        pmccfiltr_write(env, ri, value);
+    } else if (counter < PMU_NUM_COUNTERS(env)) {
+        uint64_t cycles = 0;
+#ifndef CONFIG_USER_ONLY
+        cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+                          ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
+#endif
+        pmu_sync_counter(env, counter, cycles);
+        env->cp15.c14_pmevtyper[counter] = value & 0xfe0003ff;
+        pmu_sync_counter(env, counter, cycles);
+    }
     /* Attempts to access PMXEVTYPER are CONSTRAINED UNPREDICTABLE when
      * PMSELR value is equal to or greater than the number of implemented
      * counters, but not equal to 0x1f. We opt to behave as a RAZ/WI.
      */
-    if (env->cp15.c9_pmselr == 0x1f) {
-        pmccfiltr_write(env, ri, value);
+}
+
+static uint64_t pmevtyper_read(CPUARMState *env, const ARMCPRegInfo *ri,
+                               const uint8_t counter)
+{
+    if (counter == 0x1f) {
+        return env->cp15.pmccfiltr_el0;
+    } else if (counter < PMU_NUM_COUNTERS(env)) {
+        return env->cp15.c14_pmevtyper[counter];
+    } else {
+      /* We opt to behave as a RAZ/WI when attempts to access PMXEVTYPER
+       * are CONSTRAINED UNPREDICTABLE. See comments in pmevtyper_write().
+       */
+        return 0;
     }
 }
 
+static void pmevtyper_writefn(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    pmevtyper_write(env, ri, value, counter);
+}
+
+static uint64_t pmevtyper_readfn(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    return pmevtyper_read(env, ri, counter);
+}
+
+static void pmxevtyper_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    pmevtyper_write(env, ri, value, env->cp15.c9_pmselr & 31);
+}
+
 static uint64_t pmxevtyper_read(CPUARMState *env, const ARMCPRegInfo *ri)
 {
-    /* We opt to behave as a RAZ/WI when attempts to access PMXEVTYPER
-     * are CONSTRAINED UNPREDICTABLE. See comments in pmxevtyper_write().
-     */
-    if (env->cp15.c9_pmselr == 0x1f) {
-        return env->cp15.pmccfiltr_el0;
+    return pmevtyper_read(env, ri, env->cp15.c9_pmselr & 31);
+}
+
+static void pmevcntr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value, uint8_t counter)
+{
+    if (counter < PMU_NUM_COUNTERS(env)) {
+        uint64_t cycles = 0;
+#ifndef CONFIG_USER_ONLY
+        cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+                          ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
+#endif
+        env->cp15.c14_pmevcntr[counter] = value;
+        pmu_sync_counter(env, counter, cycles);
+    }
+    /* We opt to behave as a RAZ/WI when attempts to access PM[X]EVCNTR
+     * are CONSTRAINED UNPREDICTABLE. */
+}
+
+static uint64_t pmevcntr_read(CPUARMState *env, const ARMCPRegInfo *ri,
+                              uint8_t counter)
+{
+    if (counter < PMU_NUM_COUNTERS(env)) {
+        uint64_t ret;
+        uint64_t cycles = 0;
+#ifndef CONFIG_USER_ONLY
+        cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+                          ARM_CPU_FREQ, NANOSECONDS_PER_SECOND);
+#endif
+        pmu_sync_counter(env, counter, cycles);
+        ret = env->cp15.c14_pmevcntr[counter];
+        pmu_sync_counter(env, counter, cycles);
+        return ret;
     } else {
+      /* We opt to behave as a RAZ/WI when attempts to access PM[X]EVCNTR
+       * are CONSTRAINED UNPREDICTABLE. */
         return 0;
     }
 }
 
+static void pmevcntr_writefn(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    pmevcntr_write(env, ri, value, counter);
+}
+
+static uint64_t pmevcntr_readfn(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    uint8_t counter = ((ri->crm & 3) << 3) | (ri->opc2 & 7);
+    return pmevcntr_read(env, ri, counter);
+}
+
+static void pmxevcntr_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                             uint64_t value)
+{
+    pmevcntr_write(env, ri, value, env->cp15.c9_pmselr & 31);
+}
+
+static uint64_t pmxevcntr_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    return pmevcntr_read(env, ri, env->cp15.c9_pmselr & 31);
+}
+
 static void pmuserenr_write(CPUARMState *env, const ARMCPRegInfo *ri,
                             uint64_t value)
 {
@@ -1504,16 +1647,23 @@ static const ARMCPRegInfo v7_cp_reginfo[] = {
       .fieldoffset = offsetof(CPUARMState, cp15.pmccfiltr_el0),
       .resetvalue = 0, },
     { .name = "PMXEVTYPER", .cp = 15, .crn = 9, .crm = 13, .opc1 = 0, .opc2 = 1,
-      .access = PL0_RW, .type = ARM_CP_NO_RAW, .accessfn = pmreg_access,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access,
       .writefn = pmxevtyper_write, .readfn = pmxevtyper_read },
     { .name = "PMXEVTYPER_EL0", .state = ARM_CP_STATE_AA64,
       .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 13, .opc2 = 1,
-      .access = PL0_RW, .type = ARM_CP_NO_RAW, .accessfn = pmreg_access,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access,
       .writefn = pmxevtyper_write, .readfn = pmxevtyper_read },
-    /* Unimplemented, RAZ/WI. */
     { .name = "PMXEVCNTR", .cp = 15, .crn = 9, .crm = 13, .opc1 = 0, .opc2 = 2,
-      .access = PL0_RW, .type = ARM_CP_CONST, .resetvalue = 0,
-      .accessfn = pmreg_access_xevcntr },
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access_xevcntr,
+      .writefn = pmxevcntr_write, .readfn = pmxevcntr_read },
+    { .name = "PMXEVCNTR_EL0", .state = ARM_CP_STATE_AA64,
+      .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 13, .opc2 = 2,
+      .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+      .accessfn = pmreg_access_xevcntr,
+      .writefn = pmxevcntr_write, .readfn = pmxevcntr_read },
     { .name = "PMUSERENR", .cp = 15, .crn = 9, .crm = 14, .opc1 = 0, .opc2 = 0,
       .access = PL0_R | PL1_RW, .accessfn = access_tpm,
       .fieldoffset = offsetof(CPUARMState, cp15.c9_pmuserenr),
@@ -4204,7 +4354,7 @@ static const ARMCPRegInfo el2_cp_reginfo[] = {
 #endif
     /* The only field of MDCR_EL2 that has a defined architectural reset value
      * is MDCR_EL2.HPMN which should reset to the value of PMCR_EL0.N; but we
-     * don't impelment any PMU event counters, so using zero as a reset
+     * don't implement any PMU event counters, so using zero as a reset
      * value for MDCR_EL2 is okay
      */
     { .name = "MDCR_EL2", .state = ARM_CP_STATE_BOTH,
@@ -5016,6 +5166,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         define_arm_cp_regs(cpu, v7ve_cp_reginfo);
     }
     if (arm_feature(env, ARM_FEATURE_V7)) {
+        unsigned int i;
         /* v7 performance monitor control register: same implementor
          * field as main ID register, and we implement only the cycle
          * count register.
@@ -5040,6 +5191,40 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         };
         define_one_arm_cp_reg(cpu, &pmcr);
         define_one_arm_cp_reg(cpu, &pmcr64);
+        for (i = 0; i < 31; i++) {
+            char *pmevcntr_name = g_strdup_printf("PMEVCNTR%d", i);
+            char *pmevcntr_el0_name = g_strdup_printf("PMEVCNTR%d_EL0", i);
+            char *pmevtyper_name = g_strdup_printf("PMEVTYPER%d", i);
+            char *pmevtyper_el0_name = g_strdup_printf("PMEVTYPER%d_EL0", i);
+            ARMCPRegInfo pmev_regs[] = {
+                { .name = pmevcntr_name, .cp = 15, .crn = 15,
+                  .crm = 8 | (3 & (i >> 3)), .opc1 = 0, .opc2 = i & 7,
+                  .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+                  .readfn = pmevcntr_readfn, .writefn = pmevcntr_writefn,
+                  .accessfn = pmreg_access },
+                { .name = pmevcntr_el0_name, .state = ARM_CP_STATE_AA64,
+                  .opc0 = 3, .opc1 = 3, .crn = 15, .crm = 8 | (3 & (i >> 3)),
+                  .opc2 = i & 7, .access = PL0_RW, .accessfn = pmreg_access,
+                  .type = ARM_CP_NO_RAW | ARM_CP_IO,
+                  .readfn = pmevcntr_readfn, .writefn = pmevcntr_writefn },
+                { .name = pmevtyper_name, .cp = 15, .crn = 15,
+                  .crm = 12 | (3 & (i >> 3)), .opc1 = 0, .opc2 = i & 7,
+                  .access = PL0_RW, .type = ARM_CP_NO_RAW | ARM_CP_IO,
+                  .readfn = pmevtyper_readfn, .writefn = pmevtyper_writefn,
+                  .accessfn = pmreg_access },
+                { .name = pmevtyper_el0_name, .state = ARM_CP_STATE_AA64,
+                  .opc0 = 3, .opc1 = 3, .crn = 15, .crm = 12 | (3 & (i >> 3)),
+                  .opc2 = i & 7, .access = PL0_RW, .accessfn = pmreg_access,
+                  .type = ARM_CP_NO_RAW | ARM_CP_IO,
+                  .readfn = pmevtyper_readfn, .writefn = pmevtyper_writefn },
+                REGINFO_SENTINEL
+            };
+            define_arm_cp_regs(cpu, pmev_regs);
+            g_free(pmevcntr_name);
+            g_free(pmevcntr_el0_name);
+            g_free(pmevtyper_name);
+            g_free(pmevtyper_el0_name);
+        }
 #endif
         ARMCPRegInfo clidr = {
             .name = "CLIDR", .state = ARM_CP_STATE_BOTH,
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