perfcounters: IRQ and NMI support on AMD CPUs
authorPeter Zijlstra <a.p.zijlstra@chello.nl>
Thu, 5 Mar 2009 17:08:27 +0000 (18:08 +0100)
committerIngo Molnar <mingo@elte.hu>
Thu, 5 Mar 2009 17:25:16 +0000 (18:25 +0100)
The below completes the K7+ performance counter support:

 - IRQ support
 - NMI support

KernelTop output works now as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1236273633.5187.286.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/cpu/perf_counter.c

index 3b65f19a6681a33f31559f3b7db7ac70ec7a5923..6ebe9abf6aefb512ed77e65c850cf66e992b92bc 100644 (file)
@@ -28,6 +28,7 @@ static bool perf_counters_initialized __read_mostly;
 static int nr_counters_generic __read_mostly;
 static u64 perf_counter_mask __read_mostly;
 static u64 counter_value_mask __read_mostly;
+static int counter_value_bits __read_mostly;
 
 static int nr_counters_fixed __read_mostly;
 
@@ -35,7 +36,9 @@ struct cpu_hw_counters {
        struct perf_counter     *counters[X86_PMC_IDX_MAX];
        unsigned long           used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
        unsigned long           interrupts;
-       u64                     global_enable;
+       u64                     throttle_ctrl;
+       u64                     active_mask;
+       int                     enabled;
 };
 
 /*
@@ -43,21 +46,28 @@ struct cpu_hw_counters {
  */
 struct pmc_x86_ops {
        u64             (*save_disable_all)(void);
-       void            (*restore_all)(u64 ctrl);
+       void            (*restore_all)(u64);
+       u64             (*get_status)(u64);
+       void            (*ack_status)(u64);
+       void            (*enable)(int, u64);
+       void            (*disable)(int, u64);
        unsigned        eventsel;
        unsigned        perfctr;
-       int             (*event_map)(int event);
+       u64             (*event_map)(int);
+       u64             (*raw_event)(u64);
        int             max_events;
 };
 
 static struct pmc_x86_ops *pmc_ops;
 
-static DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters);
+static DEFINE_PER_CPU(struct cpu_hw_counters, cpu_hw_counters) = {
+       .enabled = 1,
+};
 
 /*
  * Intel PerfMon v3. Used on Core2 and later.
  */
-static const int intel_perfmon_event_map[] =
+static const u64 intel_perfmon_event_map[] =
 {
   [PERF_COUNT_CPU_CYCLES]              = 0x003c,
   [PERF_COUNT_INSTRUCTIONS]            = 0x00c0,
@@ -68,15 +78,29 @@ static const int intel_perfmon_event_map[] =
   [PERF_COUNT_BUS_CYCLES]              = 0x013c,
 };
 
-static int pmc_intel_event_map(int event)
+static u64 pmc_intel_event_map(int event)
 {
        return intel_perfmon_event_map[event];
 }
 
+static u64 pmc_intel_raw_event(u64 event)
+{
+#define CORE_EVNTSEL_EVENT_MASK                0x000000FF
+#define CORE_EVNTSEL_UNIT_MASK         0x0000FF00
+#define CORE_EVNTSEL_COUNTER_MASK      0xFF000000
+
+#define CORE_EVNTSEL_MASK              \
+       (CORE_EVNTSEL_EVENT_MASK |      \
+        CORE_EVNTSEL_UNIT_MASK  |      \
+        CORE_EVNTSEL_COUNTER_MASK)
+
+       return event & CORE_EVNTSEL_MASK;
+}
+
 /*
  * AMD Performance Monitor K7 and later.
  */
-static const int amd_perfmon_event_map[] =
+static const u64 amd_perfmon_event_map[] =
 {
   [PERF_COUNT_CPU_CYCLES]              = 0x0076,
   [PERF_COUNT_INSTRUCTIONS]            = 0x00c0,
@@ -86,11 +110,25 @@ static const int amd_perfmon_event_map[] =
   [PERF_COUNT_BRANCH_MISSES]           = 0x00c5,
 };
 
-static int pmc_amd_event_map(int event)
+static u64 pmc_amd_event_map(int event)
 {
        return amd_perfmon_event_map[event];
 }
 
+static u64 pmc_amd_raw_event(u64 event)
+{
+#define K7_EVNTSEL_EVENT_MASK  0x7000000FF
+#define K7_EVNTSEL_UNIT_MASK   0x00000FF00
+#define K7_EVNTSEL_COUNTER_MASK        0x0FF000000
+
+#define K7_EVNTSEL_MASK                        \
+       (K7_EVNTSEL_EVENT_MASK |        \
+        K7_EVNTSEL_UNIT_MASK  |        \
+        K7_EVNTSEL_COUNTER_MASK)
+
+       return event & K7_EVNTSEL_MASK;
+}
+
 /*
  * Propagate counter elapsed time into the generic counter.
  * Can only be executed on the CPU where the counter is active.
@@ -179,7 +217,7 @@ static int __hw_perf_counter_init(struct perf_counter *counter)
         * Raw event type provide the config in the event structure
         */
        if (hw_event->raw) {
-               hwc->config |= hw_event->type;
+               hwc->config |= pmc_ops->raw_event(hw_event->type);
        } else {
                if (hw_event->type >= pmc_ops->max_events)
                        return -EINVAL;
@@ -205,18 +243,24 @@ static u64 pmc_intel_save_disable_all(void)
 
 static u64 pmc_amd_save_disable_all(void)
 {
-       int idx;
-       u64 val, ctrl = 0;
+       struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+       int enabled, idx;
+
+       enabled = cpuc->enabled;
+       cpuc->enabled = 0;
+       barrier();
 
        for (idx = 0; idx < nr_counters_generic; idx++) {
+               u64 val;
+
                rdmsrl(MSR_K7_EVNTSEL0 + idx, val);
-               if (val & ARCH_PERFMON_EVENTSEL0_ENABLE)
-                       ctrl |= (1 << idx);
-               val &= ~ARCH_PERFMON_EVENTSEL0_ENABLE;
-               wrmsrl(MSR_K7_EVNTSEL0 + idx, val);
+               if (val & ARCH_PERFMON_EVENTSEL0_ENABLE) {
+                       val &= ~ARCH_PERFMON_EVENTSEL0_ENABLE;
+                       wrmsrl(MSR_K7_EVNTSEL0 + idx, val);
+               }
        }
 
-       return ctrl;
+       return enabled;
 }
 
 u64 hw_perf_save_disable(void)
@@ -226,6 +270,9 @@ u64 hw_perf_save_disable(void)
 
        return pmc_ops->save_disable_all();
 }
+/*
+ * Exported because of ACPI idle
+ */
 EXPORT_SYMBOL_GPL(hw_perf_save_disable);
 
 static void pmc_intel_restore_all(u64 ctrl)
@@ -235,11 +282,18 @@ static void pmc_intel_restore_all(u64 ctrl)
 
 static void pmc_amd_restore_all(u64 ctrl)
 {
-       u64 val;
+       struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
        int idx;
 
+       cpuc->enabled = ctrl;
+       barrier();
+       if (!ctrl)
+               return;
+
        for (idx = 0; idx < nr_counters_generic; idx++) {
-               if (ctrl & (1 << idx)) {
+               if (test_bit(idx, (unsigned long *)&cpuc->active_mask)) {
+                       u64 val;
+
                        rdmsrl(MSR_K7_EVNTSEL0 + idx, val);
                        val |= ARCH_PERFMON_EVENTSEL0_ENABLE;
                        wrmsrl(MSR_K7_EVNTSEL0 + idx, val);
@@ -254,8 +308,112 @@ void hw_perf_restore(u64 ctrl)
 
        pmc_ops->restore_all(ctrl);
 }
+/*
+ * Exported because of ACPI idle
+ */
 EXPORT_SYMBOL_GPL(hw_perf_restore);
 
+static u64 pmc_intel_get_status(u64 mask)
+{
+       u64 status;
+
+       rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+
+       return status;
+}
+
+static u64 pmc_amd_get_status(u64 mask)
+{
+       u64 status = 0;
+       int idx;
+
+       for (idx = 0; idx < nr_counters_generic; idx++) {
+               s64 val;
+
+               if (!(mask & (1 << idx)))
+                       continue;
+
+               rdmsrl(MSR_K7_PERFCTR0 + idx, val);
+               val <<= (64 - counter_value_bits);
+               if (val >= 0)
+                       status |= (1 << idx);
+       }
+
+       return status;
+}
+
+static u64 hw_perf_get_status(u64 mask)
+{
+       if (unlikely(!perf_counters_initialized))
+               return 0;
+
+       return pmc_ops->get_status(mask);
+}
+
+static void pmc_intel_ack_status(u64 ack)
+{
+       wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
+}
+
+static void pmc_amd_ack_status(u64 ack)
+{
+}
+
+static void hw_perf_ack_status(u64 ack)
+{
+       if (unlikely(!perf_counters_initialized))
+               return;
+
+       pmc_ops->ack_status(ack);
+}
+
+static void pmc_intel_enable(int idx, u64 config)
+{
+       wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + idx,
+                       config | ARCH_PERFMON_EVENTSEL0_ENABLE);
+}
+
+static void pmc_amd_enable(int idx, u64 config)
+{
+       struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+
+       set_bit(idx, (unsigned long *)&cpuc->active_mask);
+       if (cpuc->enabled)
+               config |= ARCH_PERFMON_EVENTSEL0_ENABLE;
+
+       wrmsrl(MSR_K7_EVNTSEL0 + idx, config);
+}
+
+static void hw_perf_enable(int idx, u64 config)
+{
+       if (unlikely(!perf_counters_initialized))
+               return;
+
+       pmc_ops->enable(idx, config);
+}
+
+static void pmc_intel_disable(int idx, u64 config)
+{
+       wrmsrl(MSR_ARCH_PERFMON_EVENTSEL0 + idx, config);
+}
+
+static void pmc_amd_disable(int idx, u64 config)
+{
+       struct cpu_hw_counters *cpuc = &__get_cpu_var(cpu_hw_counters);
+
+       clear_bit(idx, (unsigned long *)&cpuc->active_mask);
+       wrmsrl(MSR_K7_EVNTSEL0 + idx, config);
+
+}
+
+static void hw_perf_disable(int idx, u64 config)
+{
+       if (unlikely(!perf_counters_initialized))
+               return;
+
+       pmc_ops->disable(idx, config);
+}
+
 static inline void
 __pmc_fixed_disable(struct perf_counter *counter,
                    struct hw_perf_counter *hwc, unsigned int __idx)
@@ -278,7 +436,7 @@ __pmc_generic_disable(struct perf_counter *counter,
        if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
                __pmc_fixed_disable(counter, hwc, idx);
        else
-               wrmsr_safe(hwc->config_base + idx, hwc->config, 0);
+               hw_perf_disable(idx, hwc->config);
 }
 
 static DEFINE_PER_CPU(u64, prev_left[X86_PMC_IDX_MAX]);
@@ -354,8 +512,7 @@ __pmc_generic_enable(struct perf_counter *counter,
        if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL))
                __pmc_fixed_enable(counter, hwc, idx);
        else
-               wrmsr(hwc->config_base + idx,
-                     hwc->config | ARCH_PERFMON_EVENTSEL0_ENABLE, 0);
+               hw_perf_enable(idx, hwc->config);
 }
 
 static int
@@ -567,22 +724,20 @@ perf_handle_group(struct perf_counter *sibling, u64 *status, u64 *overflown)
  * This handler is triggered by the local APIC, so the APIC IRQ handling
  * rules apply:
  */
-static void __smp_perf_counter_interrupt(struct pt_regs *regs, int nmi)
+static int __smp_perf_counter_interrupt(struct pt_regs *regs, int nmi)
 {
        int bit, cpu = smp_processor_id();
        u64 ack, status;
        struct cpu_hw_counters *cpuc = &per_cpu(cpu_hw_counters, cpu);
+       int ret = 0;
 
-       rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, cpuc->global_enable);
-
-       /* Disable counters globally */
-       wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
-       ack_APIC_irq();
+       cpuc->throttle_ctrl = hw_perf_save_disable();
 
-       rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+       status = hw_perf_get_status(cpuc->throttle_ctrl);
        if (!status)
                goto out;
 
+       ret = 1;
 again:
        inc_irq_stat(apic_perf_irqs);
        ack = status;
@@ -618,12 +773,12 @@ again:
                }
        }
 
-       wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, ack);
+       hw_perf_ack_status(ack);
 
        /*
         * Repeat if there is more work to be done:
         */
-       rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, status);
+       status = hw_perf_get_status(cpuc->throttle_ctrl);
        if (status)
                goto again;
 out:
@@ -631,32 +786,27 @@ out:
         * Restore - do not reenable when global enable is off or throttled:
         */
        if (++cpuc->interrupts < PERFMON_MAX_INTERRUPTS)
-               wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, cpuc->global_enable);
+               hw_perf_restore(cpuc->throttle_ctrl);
+
+       return ret;
 }
 
 void perf_counter_unthrottle(void)
 {
        struct cpu_hw_counters *cpuc;
-       u64 global_enable;
 
        if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON))
                return;
 
-       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
-               return;
-
        if (unlikely(!perf_counters_initialized))
                return;
 
-       cpuc = &per_cpu(cpu_hw_counters, smp_processor_id());
+       cpuc = &__get_cpu_var(cpu_hw_counters);
        if (cpuc->interrupts >= PERFMON_MAX_INTERRUPTS) {
                if (printk_ratelimit())
                        printk(KERN_WARNING "PERFMON: max interrupts exceeded!\n");
-               wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, cpuc->global_enable);
+               hw_perf_restore(cpuc->throttle_ctrl);
        }
-       rdmsrl(MSR_CORE_PERF_GLOBAL_CTRL, global_enable);
-       if (unlikely(cpuc->global_enable && !global_enable))
-               wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, cpuc->global_enable);
        cpuc->interrupts = 0;
 }
 
@@ -664,8 +814,8 @@ void smp_perf_counter_interrupt(struct pt_regs *regs)
 {
        irq_enter();
        apic_write(APIC_LVTPC, LOCAL_PERF_VECTOR);
+       ack_APIC_irq();
        __smp_perf_counter_interrupt(regs, 0);
-
        irq_exit();
 }
 
@@ -722,16 +872,23 @@ perf_counter_nmi_handler(struct notifier_block *self,
 {
        struct die_args *args = __args;
        struct pt_regs *regs;
+       int ret;
+
+       switch (cmd) {
+       case DIE_NMI:
+       case DIE_NMI_IPI:
+               break;
 
-       if (likely(cmd != DIE_NMI_IPI))
+       default:
                return NOTIFY_DONE;
+       }
 
        regs = args->regs;
 
        apic_write(APIC_LVTPC, APIC_DM_NMI);
-       __smp_perf_counter_interrupt(regs, 1);
+       ret = __smp_perf_counter_interrupt(regs, 1);
 
-       return NOTIFY_STOP;
+       return ret ? NOTIFY_STOP : NOTIFY_OK;
 }
 
 static __read_mostly struct notifier_block perf_counter_nmi_notifier = {
@@ -743,18 +900,28 @@ static __read_mostly struct notifier_block perf_counter_nmi_notifier = {
 static struct pmc_x86_ops pmc_intel_ops = {
        .save_disable_all       = pmc_intel_save_disable_all,
        .restore_all            = pmc_intel_restore_all,
+       .get_status             = pmc_intel_get_status,
+       .ack_status             = pmc_intel_ack_status,
+       .enable                 = pmc_intel_enable,
+       .disable                = pmc_intel_disable,
        .eventsel               = MSR_ARCH_PERFMON_EVENTSEL0,
        .perfctr                = MSR_ARCH_PERFMON_PERFCTR0,
        .event_map              = pmc_intel_event_map,
+       .raw_event              = pmc_intel_raw_event,
        .max_events             = ARRAY_SIZE(intel_perfmon_event_map),
 };
 
 static struct pmc_x86_ops pmc_amd_ops = {
        .save_disable_all       = pmc_amd_save_disable_all,
        .restore_all            = pmc_amd_restore_all,
+       .get_status             = pmc_amd_get_status,
+       .ack_status             = pmc_amd_ack_status,
+       .enable                 = pmc_amd_enable,
+       .disable                = pmc_amd_disable,
        .eventsel               = MSR_K7_EVNTSEL0,
        .perfctr                = MSR_K7_PERFCTR0,
        .event_map              = pmc_amd_event_map,
+       .raw_event              = pmc_amd_raw_event,
        .max_events             = ARRAY_SIZE(amd_perfmon_event_map),
 };
 
@@ -787,8 +954,25 @@ static struct pmc_x86_ops *pmc_intel_init(void)
 
 static struct pmc_x86_ops *pmc_amd_init(void)
 {
+       u64 old;
+       int bits;
+
        nr_counters_generic = 4;
        nr_counters_fixed = 0;
+       counter_value_mask = ~0ULL;
+
+       rdmsrl(MSR_K7_PERFCTR0, old);
+       wrmsrl(MSR_K7_PERFCTR0, counter_value_mask);
+       /*
+        * read the truncated mask
+        */
+       rdmsrl(MSR_K7_PERFCTR0, counter_value_mask);
+       wrmsrl(MSR_K7_PERFCTR0, old);
+
+       bits = 32 + fls(counter_value_mask >> 32);
+       if (bits == 32)
+               bits = fls((u32)counter_value_mask);
+       counter_value_bits = bits;
 
        pr_info("AMD Performance Monitoring support detected.\n");