diff mbox series

[v6,09/14] target/arm: Add array for supported PMU events, generate PMCEID[01]

Message ID 20181010203735.27918-10-aclindsa@gmail.com
State New
Headers show
Series More fully implement ARM PMUv3 | expand

Commit Message

Aaron Lindsay Oct. 10, 2018, 8:37 p.m. UTC 
This commit doesn't add any supported events, but provides the framework
for adding them. We store the pm_event structs in a simple array, and
provide the mapping from the event numbers to array indexes in the
supported_event_map array. Because the value of PMCEID[01] depends upon
which events are supported at runtime, generate it dynamically.

Signed-off-by: Aaron Lindsay <alindsay@codeaurora.org>
---
 target/arm/cpu.c    | 20 +++++++++++++-------
 target/arm/cpu.h    | 10 ++++++++++
 target/arm/cpu64.c  |  2 --
 target/arm/helper.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 65 insertions(+), 9 deletions(-)

Comments

Richard Henderson Oct. 15, 2018, 9:35 p.m. UTC | #1 
On 10/10/18 1:37 PM, Aaron Lindsay wrote:
> +        cpu->pmceid0 = pmceid & 0xffffffff;
> +        cpu->pmceid1 = (pmceid >> 32) & 0xffffffff;

extract64(pmceid, 0, 32) and extract64(pmceid, 32, 32).

> +static const pm_event pm_events[] = {
> +};
> +#define MAX_EVENT_ID 0x0

Is this going to be ARRAY_SIZE(pm_events) - 1 in the end?

> +static uint16_t supported_event_map[MAX_EVENT_ID + 1];

Better as ARRAY_SIZE(pm_events)?

> +    for (i = 0; i <= MAX_EVENT_ID; i++) {
> +        supported_event_map[i] = UNSUPPORTED_EVENT;
> +    }

I think maybe

  for (i = 0; i < ARRAY_SIZE(supported_map_event); ++i) {

would be better.


r~
Aaron Lindsay Oct. 16, 2018, 9:55 a.m. UTC | #2 
On Oct 15 14:35, Richard Henderson wrote:
> On 10/10/18 1:37 PM, Aaron Lindsay wrote:
> > +static const pm_event pm_events[] = {
> > +};
> > +#define MAX_EVENT_ID 0x0
> 
> Is this going to be ARRAY_SIZE(pm_events) - 1 in the end?

No, this ends up being a 'sparse' array. It maps the ARM architected PMU
event numbers to their implementations. So, MAX_EVENT_ID ends up being
the maximum architected event number we implement when my later patches
add those.

-Aaron
diff mbox series

Patch

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index f69addb961..7f39f25f51 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -948,9 +948,19 @@  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
     if (!cpu->has_pmu) {
         unset_feature(env, ARM_FEATURE_PMU);
         cpu->id_aa64dfr0 &= ~0xf00;
-    } else if (!kvm_enabled()) {
-        arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
-        arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
+    }
+    if (arm_feature(env, ARM_FEATURE_PMU)) {
+        uint64_t pmceid = get_pmceid(&cpu->env);
+        cpu->pmceid0 = pmceid & 0xffffffff;
+        cpu->pmceid1 = (pmceid >> 32) & 0xffffffff;
+
+        if (!kvm_enabled()) {
+            arm_register_pre_el_change_hook(cpu, &pmu_pre_el_change, 0);
+            arm_register_el_change_hook(cpu, &pmu_post_el_change, 0);
+        }
+    } else {
+        cpu->pmceid0 = 0x00000000;
+        cpu->pmceid1 = 0x00000000;
     }
 
     if (!arm_feature(env, ARM_FEATURE_EL2)) {
@@ -1583,8 +1593,6 @@  static void cortex_a7_initfn(Object *obj)
     cpu->id_pfr0 = 0x00001131;
     cpu->id_pfr1 = 0x00011011;
     cpu->id_dfr0 = 0x02010555;
-    cpu->pmceid0 = 0x00000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->id_afr0 = 0x00000000;
     cpu->id_mmfr0 = 0x10101105;
     cpu->id_mmfr1 = 0x40000000;
@@ -1626,8 +1634,6 @@  static void cortex_a15_initfn(Object *obj)
     cpu->id_pfr0 = 0x00001131;
     cpu->id_pfr1 = 0x00011011;
     cpu->id_dfr0 = 0x02010555;
-    cpu->pmceid0 = 0x0000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->id_afr0 = 0x00000000;
     cpu->id_mmfr0 = 0x10201105;
     cpu->id_mmfr1 = 0x20000000;
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index d9cd8dd92c..cc026f0b75 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -975,6 +975,16 @@  void pmu_op_finish(CPUARMState *env);
 void pmu_pre_el_change(ARMCPU *cpu, void *ignored);
 void pmu_post_el_change(ARMCPU *cpu, void *ignored);
 
+/*
+ * get_pmceid
+ * @env: CPUARMState
+ *
+ * Return the PMCEID[01] register values corresponding to the counters which
+ * are supported given the current configuration (0 is low 32, 1 is high 32
+ * bits)
+ */
+uint64_t get_pmceid(CPUARMState *env);
+
 /* SCTLR bit meanings. Several bits have been reused in newer
  * versions of the architecture; in that case we define constants
  * for both old and new bit meanings. Code which tests against those
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index db71504cb5..440d874c17 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -143,8 +143,6 @@  static void aarch64_a57_initfn(Object *obj)
     cpu->id_isar6 = 0;
     cpu->id_aa64pfr0 = 0x00002222;
     cpu->id_aa64dfr0 = 0x10305106;
-    cpu->pmceid0 = 0x00000000;
-    cpu->pmceid1 = 0x00000000;
     cpu->id_aa64isar0 = 0x00011120;
     cpu->id_aa64mmfr0 = 0x00001124;
     cpu->dbgdidr = 0x3516d000;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index f3c00c3db0..375b6dcda5 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -976,6 +976,48 @@  static inline uint64_t pmu_counter_mask(CPUARMState *env)
   return (1 << 31) | ((1 << pmu_num_counters(env)) - 1);
 }
 
+typedef struct pm_event {
+    uint16_t number; /* PMEVTYPER.evtCount is 16 bits wide */
+    /* If the event is supported on this CPU (used to generate PMCEID[01]) */
+    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 *);
+} pm_event;
+
+static const pm_event pm_events[] = {
+};
+#define MAX_EVENT_ID 0x0
+#define UNSUPPORTED_EVENT UINT16_MAX
+static uint16_t supported_event_map[MAX_EVENT_ID + 1];
+
+/*
+ * Called upon initialization to build PMCEID0 (low 32 bits) and PMCEID1 (high
+ * 32). We also use it to build a map of ARM event numbers to indices in
+ * our pm_events array.
+ */
+uint64_t get_pmceid(CPUARMState *env)
+{
+    uint64_t pmceid = 0;
+    unsigned int i;
+
+    for (i = 0; i <= MAX_EVENT_ID; i++) {
+        supported_event_map[i] = UNSUPPORTED_EVENT;
+    }
+
+    for (i = 0; i < ARRAY_SIZE(pm_events); i++) {
+        const pm_event *cnt = &pm_events[i];
+        assert(cnt->number <= MAX_EVENT_ID);
+        if (cnt->supported(env)) {
+            pmceid |= (1 << cnt->number);
+            supported_event_map[cnt->number] = i;
+        }
+    }
+    return pmceid;
+}
+
 static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
                                    bool isread)
 {