[tip:perfcounters/core] perfcounters: IRQ and NMI support on AMD CPUs
From: Peter Zijlstra
Date: Thu Mar 05 2009 - 12:28:24 EST
Commit-ID: b0f3f28e0f14eb335f67bfaae33ce8b8d74fd58b
Gitweb: http://git.kernel.org/tip/b0f3f28e0f14eb335f67bfaae33ce8b8d74fd58b
Author: "Peter Zijlstra" <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Thu, 5 Mar 2009 18:08:27 +0100
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 5 Mar 2009 18:25:16 +0100
perfcounters: IRQ and NMI support on AMD CPUs
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@xxxxxxxxx>
Cc: Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
LKML-Reference: <1236273633.5187.286.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/perf_counter.c | 272 ++++++++++++++++++++++++++++++------
1 files changed, 228 insertions(+), 44 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 3b65f19..6ebe9ab 100644
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -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");
--
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