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authorIngo Molnar <mingo@kernel.org>2012-05-09 15:22:23 +0200
committerIngo Molnar <mingo@kernel.org>2012-05-09 15:22:23 +0200
commitad8537cda68a8fe81776cceca6c22d54dd652ea5 (patch)
treebbef398c784fb884ca77fc2b7bee74c4ac5e1853
parent149936a068d83370c9dcd68894c276d4ba0f8560 (diff)
parentfab06992de6433af097c4a1d2d1b119812753ca7 (diff)
Merge branch 'perf/x86-ibs' into perf/core
-rw-r--r--arch/x86/include/asm/msr-index.h5
-rw-r--r--arch/x86/include/asm/perf_event.h2
-rw-r--r--arch/x86/kernel/cpu/perf_event_amd_ibs.c438
3 files changed, 438 insertions, 7 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index ccb805966f6..957ec87385a 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -134,6 +134,8 @@
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
#define MSR_AMD64_IBSFETCHLINAD 0xc0011031
#define MSR_AMD64_IBSFETCHPHYSAD 0xc0011032
+#define MSR_AMD64_IBSFETCH_REG_COUNT 3
+#define MSR_AMD64_IBSFETCH_REG_MASK ((1UL<<MSR_AMD64_IBSFETCH_REG_COUNT)-1)
#define MSR_AMD64_IBSOPCTL 0xc0011033
#define MSR_AMD64_IBSOPRIP 0xc0011034
#define MSR_AMD64_IBSOPDATA 0xc0011035
@@ -141,8 +143,11 @@
#define MSR_AMD64_IBSOPDATA3 0xc0011037
#define MSR_AMD64_IBSDCLINAD 0xc0011038
#define MSR_AMD64_IBSDCPHYSAD 0xc0011039
+#define MSR_AMD64_IBSOP_REG_COUNT 7
+#define MSR_AMD64_IBSOP_REG_MASK ((1UL<<MSR_AMD64_IBSOP_REG_COUNT)-1)
#define MSR_AMD64_IBSCTL 0xc001103a
#define MSR_AMD64_IBSBRTARGET 0xc001103b
+#define MSR_AMD64_IBS_REG_COUNT_MAX 8 /* includes MSR_AMD64_IBSBRTARGET */
/* Fam 15h MSRs */
#define MSR_F15H_PERF_CTL 0xc0010200
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 2291895b183..8a3c75d824b 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -178,6 +178,8 @@ struct x86_pmu_capability {
#define IBS_FETCH_MAX_CNT 0x0000FFFFULL
/* IbsOpCtl bits */
+/* lower 4 bits of the current count are ignored: */
+#define IBS_OP_CUR_CNT (0xFFFF0ULL<<32)
#define IBS_OP_CNT_CTL (1ULL<<19)
#define IBS_OP_VAL (1ULL<<18)
#define IBS_OP_ENABLE (1ULL<<17)
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index 3b8a2d30d14..8ff74d43904 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -16,36 +16,460 @@ static u32 ibs_caps;
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
-static struct pmu perf_ibs;
+#include <linux/kprobes.h>
+#include <linux/hardirq.h>
+
+#include <asm/nmi.h>
+
+#define IBS_FETCH_CONFIG_MASK (IBS_FETCH_RAND_EN | IBS_FETCH_MAX_CNT)
+#define IBS_OP_CONFIG_MASK IBS_OP_MAX_CNT
+
+enum ibs_states {
+ IBS_ENABLED = 0,
+ IBS_STARTED = 1,
+ IBS_STOPPING = 2,
+
+ IBS_MAX_STATES,
+};
+
+struct cpu_perf_ibs {
+ struct perf_event *event;
+ unsigned long state[BITS_TO_LONGS(IBS_MAX_STATES)];
+};
+
+struct perf_ibs {
+ struct pmu pmu;
+ unsigned int msr;
+ u64 config_mask;
+ u64 cnt_mask;
+ u64 enable_mask;
+ u64 valid_mask;
+ u64 max_period;
+ unsigned long offset_mask[1];
+ int offset_max;
+ struct cpu_perf_ibs __percpu *pcpu;
+ u64 (*get_count)(u64 config);
+};
+
+struct perf_ibs_data {
+ u32 size;
+ union {
+ u32 data[0]; /* data buffer starts here */
+ u32 caps;
+ };
+ u64 regs[MSR_AMD64_IBS_REG_COUNT_MAX];
+};
+
+static int
+perf_event_set_period(struct hw_perf_event *hwc, u64 min, u64 max, u64 *count)
+{
+ s64 left = local64_read(&hwc->period_left);
+ s64 period = hwc->sample_period;
+ int overflow = 0;
+
+ /*
+ * If we are way outside a reasonable range then just skip forward:
+ */
+ if (unlikely(left <= -period)) {
+ left = period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ overflow = 1;
+ }
+
+ if (unlikely(left <= 0)) {
+ left += period;
+ local64_set(&hwc->period_left, left);
+ hwc->last_period = period;
+ overflow = 1;
+ }
+
+ if (unlikely(left < min))
+ left = min;
+
+ if (left > max)
+ left = max;
+
+ *count = (u64)left;
+
+ return overflow;
+}
+
+static int
+perf_event_try_update(struct perf_event *event, u64 new_raw_count, int width)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int shift = 64 - width;
+ u64 prev_raw_count;
+ u64 delta;
+
+ /*
+ * Careful: an NMI might modify the previous event value.
+ *
+ * Our tactic to handle this is to first atomically read and
+ * exchange a new raw count - then add that new-prev delta
+ * count to the generic event atomically:
+ */
+ prev_raw_count = local64_read(&hwc->prev_count);
+ if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+ new_raw_count) != prev_raw_count)
+ return 0;
+
+ /*
+ * Now we have the new raw value and have updated the prev
+ * timestamp already. We can now calculate the elapsed delta
+ * (event-)time and add that to the generic event.
+ *
+ * Careful, not all hw sign-extends above the physical width
+ * of the count.
+ */
+ delta = (new_raw_count << shift) - (prev_raw_count << shift);
+ delta >>= shift;
+
+ local64_add(delta, &event->count);
+ local64_sub(delta, &hwc->period_left);
+
+ return 1;
+}
+
+static struct perf_ibs perf_ibs_fetch;
+static struct perf_ibs perf_ibs_op;
+
+static struct perf_ibs *get_ibs_pmu(int type)
+{
+ if (perf_ibs_fetch.pmu.type == type)
+ return &perf_ibs_fetch;
+ if (perf_ibs_op.pmu.type == type)
+ return &perf_ibs_op;
+ return NULL;
+}
static int perf_ibs_init(struct perf_event *event)
{
- if (perf_ibs.type != event->attr.type)
+ struct hw_perf_event *hwc = &event->hw;
+ struct perf_ibs *perf_ibs;
+ u64 max_cnt, config;
+
+ perf_ibs = get_ibs_pmu(event->attr.type);
+ if (!perf_ibs)
return -ENOENT;
+
+ config = event->attr.config;
+ if (config & ~perf_ibs->config_mask)
+ return -EINVAL;
+
+ if (hwc->sample_period) {
+ if (config & perf_ibs->cnt_mask)
+ /* raw max_cnt may not be set */
+ return -EINVAL;
+ if (hwc->sample_period & 0x0f)
+ /* lower 4 bits can not be set in ibs max cnt */
+ return -EINVAL;
+ } else {
+ max_cnt = config & perf_ibs->cnt_mask;
+ config &= ~perf_ibs->cnt_mask;
+ event->attr.sample_period = max_cnt << 4;
+ hwc->sample_period = event->attr.sample_period;
+ }
+
+ if (!hwc->sample_period)
+ return -EINVAL;
+
+ hwc->config_base = perf_ibs->msr;
+ hwc->config = config;
+
return 0;
}
+static int perf_ibs_set_period(struct perf_ibs *perf_ibs,
+ struct hw_perf_event *hwc, u64 *period)
+{
+ int ret;
+
+ /* ignore lower 4 bits in min count: */
+ ret = perf_event_set_period(hwc, 1<<4, perf_ibs->max_period, period);
+ local64_set(&hwc->prev_count, 0);
+
+ return ret;
+}
+
+static u64 get_ibs_fetch_count(u64 config)
+{
+ return (config & IBS_FETCH_CNT) >> 12;
+}
+
+static u64 get_ibs_op_count(u64 config)
+{
+ return (config & IBS_OP_CUR_CNT) >> 32;
+}
+
+static void
+perf_ibs_event_update(struct perf_ibs *perf_ibs, struct perf_event *event,
+ u64 config)
+{
+ u64 count = perf_ibs->get_count(config);
+
+ while (!perf_event_try_update(event, count, 20)) {
+ rdmsrl(event->hw.config_base, config);
+ count = perf_ibs->get_count(config);
+ }
+}
+
+/* Note: The enable mask must be encoded in the config argument. */
+static inline void perf_ibs_enable_event(struct hw_perf_event *hwc, u64 config)
+{
+ wrmsrl(hwc->config_base, hwc->config | config);
+}
+
+/*
+ * We cannot restore the ibs pmu state, so we always needs to update
+ * the event while stopping it and then reset the state when starting
+ * again. Thus, ignoring PERF_EF_RELOAD and PERF_EF_UPDATE flags in
+ * perf_ibs_start()/perf_ibs_stop() and instead always do it.
+ */
+static void perf_ibs_start(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
+ struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
+ u64 config;
+
+ if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+ return;
+
+ WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
+ hwc->state = 0;
+
+ perf_ibs_set_period(perf_ibs, hwc, &config);
+ config = (config >> 4) | perf_ibs->enable_mask;
+ set_bit(IBS_STARTED, pcpu->state);
+ perf_ibs_enable_event(hwc, config);
+
+ perf_event_update_userpage(event);
+}
+
+static void perf_ibs_stop(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
+ struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
+ u64 val;
+ int stopping;
+
+ stopping = test_and_clear_bit(IBS_STARTED, pcpu->state);
+
+ if (!stopping && (hwc->state & PERF_HES_UPTODATE))
+ return;
+
+ rdmsrl(hwc->config_base, val);
+
+ if (stopping) {
+ set_bit(IBS_STOPPING, pcpu->state);
+ val &= ~perf_ibs->enable_mask;
+ wrmsrl(hwc->config_base, val);
+ WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
+ hwc->state |= PERF_HES_STOPPED;
+ }
+
+ if (hwc->state & PERF_HES_UPTODATE)
+ return;
+
+ perf_ibs_event_update(perf_ibs, event, val);
+ hwc->state |= PERF_HES_UPTODATE;
+}
+
static int perf_ibs_add(struct perf_event *event, int flags)
{
+ struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
+ struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
+
+ if (test_and_set_bit(IBS_ENABLED, pcpu->state))
+ return -ENOSPC;
+
+ event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+ pcpu->event = event;
+
+ if (flags & PERF_EF_START)
+ perf_ibs_start(event, PERF_EF_RELOAD);
+
return 0;
}
static void perf_ibs_del(struct perf_event *event, int flags)
{
+ struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
+ struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
+
+ if (!test_and_clear_bit(IBS_ENABLED, pcpu->state))
+ return;
+
+ perf_ibs_stop(event, PERF_EF_UPDATE);
+
+ pcpu->event = NULL;
+
+ perf_event_update_userpage(event);
}
-static struct pmu perf_ibs = {
- .event_init= perf_ibs_init,
- .add= perf_ibs_add,
- .del= perf_ibs_del,
+static void perf_ibs_read(struct perf_event *event) { }
+
+static struct perf_ibs perf_ibs_fetch = {
+ .pmu = {
+ .task_ctx_nr = perf_invalid_context,
+
+ .event_init = perf_ibs_init,
+ .add = perf_ibs_add,
+ .del = perf_ibs_del,
+ .start = perf_ibs_start,
+ .stop = perf_ibs_stop,
+ .read = perf_ibs_read,
+ },
+ .msr = MSR_AMD64_IBSFETCHCTL,
+ .config_mask = IBS_FETCH_CONFIG_MASK,
+ .cnt_mask = IBS_FETCH_MAX_CNT,
+ .enable_mask = IBS_FETCH_ENABLE,
+ .valid_mask = IBS_FETCH_VAL,
+ .max_period = IBS_FETCH_MAX_CNT << 4,
+ .offset_mask = { MSR_AMD64_IBSFETCH_REG_MASK },
+ .offset_max = MSR_AMD64_IBSFETCH_REG_COUNT,
+
+ .get_count = get_ibs_fetch_count,
};
+static struct perf_ibs perf_ibs_op = {
+ .pmu = {
+ .task_ctx_nr = perf_invalid_context,
+
+ .event_init = perf_ibs_init,
+ .add = perf_ibs_add,
+ .del = perf_ibs_del,
+ .start = perf_ibs_start,
+ .stop = perf_ibs_stop,
+ .read = perf_ibs_read,
+ },
+ .msr = MSR_AMD64_IBSOPCTL,
+ .config_mask = IBS_OP_CONFIG_MASK,
+ .cnt_mask = IBS_OP_MAX_CNT,
+ .enable_mask = IBS_OP_ENABLE,
+ .valid_mask = IBS_OP_VAL,
+ .max_period = IBS_OP_MAX_CNT << 4,
+ .offset_mask = { MSR_AMD64_IBSOP_REG_MASK },
+ .offset_max = MSR_AMD64_IBSOP_REG_COUNT,
+
+ .get_count = get_ibs_op_count,
+};
+
+static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
+{
+ struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
+ struct perf_event *event = pcpu->event;
+ struct hw_perf_event *hwc = &event->hw;
+ struct perf_sample_data data;
+ struct perf_raw_record raw;
+ struct pt_regs regs;
+ struct perf_ibs_data ibs_data;
+ int offset, size, overflow, reenable;
+ unsigned int msr;
+ u64 *buf, config;
+
+ if (!test_bit(IBS_STARTED, pcpu->state)) {
+ /* Catch spurious interrupts after stopping IBS: */
+ if (!test_and_clear_bit(IBS_STOPPING, pcpu->state))
+ return 0;
+ rdmsrl(perf_ibs->msr, *ibs_data.regs);
+ return (*ibs_data.regs & perf_ibs->valid_mask) ? 1 : 0;
+ }
+
+ msr = hwc->config_base;
+ buf = ibs_data.regs;
+ rdmsrl(msr, *buf);
+ if (!(*buf++ & perf_ibs->valid_mask))
+ return 0;
+
+ perf_sample_data_init(&data, 0);
+ if (event->attr.sample_type & PERF_SAMPLE_RAW) {
+ ibs_data.caps = ibs_caps;
+ size = 1;
+ offset = 1;
+ do {
+ rdmsrl(msr + offset, *buf++);
+ size++;
+ offset = find_next_bit(perf_ibs->offset_mask,
+ perf_ibs->offset_max,
+ offset + 1);
+ } while (offset < perf_ibs->offset_max);
+ raw.size = sizeof(u32) + sizeof(u64) * size;
+ raw.data = ibs_data.data;
+ data.raw = &raw;
+ }
+
+ regs = *iregs; /* XXX: update ip from ibs sample */
+
+ /*
+ * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not
+ * supported in all cpus. As this triggered an interrupt, we
+ * set the current count to the max count.
+ */
+ config = ibs_data.regs[0];
+ if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {
+ config &= ~IBS_OP_CUR_CNT;
+ config |= (config & IBS_OP_MAX_CNT) << 36;
+ }
+
+ perf_ibs_event_update(perf_ibs, event, config);
+
+ overflow = perf_ibs_set_period(perf_ibs, hwc, &config);
+ reenable = !(overflow && perf_event_overflow(event, &data, &regs));
+ config = (config >> 4) | (reenable ? perf_ibs->enable_mask : 0);
+ perf_ibs_enable_event(hwc, config);
+
+ perf_event_update_userpage(event);
+
+ return 1;
+}
+
+static int __kprobes
+perf_ibs_nmi_handler(unsigned int cmd, struct pt_regs *regs)
+{
+ int handled = 0;
+
+ handled += perf_ibs_handle_irq(&perf_ibs_fetch, regs);
+ handled += perf_ibs_handle_irq(&perf_ibs_op, regs);
+
+ if (handled)
+ inc_irq_stat(apic_perf_irqs);
+
+ return handled;
+}
+
+static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
+{
+ struct cpu_perf_ibs __percpu *pcpu;
+ int ret;
+
+ pcpu = alloc_percpu(struct cpu_perf_ibs);
+ if (!pcpu)
+ return -ENOMEM;
+
+ perf_ibs->pcpu = pcpu;
+
+ ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
+ if (ret) {
+ perf_ibs->pcpu = NULL;
+ free_percpu(pcpu);
+ }
+
+ return ret;
+}
+
static __init int perf_event_ibs_init(void)
{
if (!ibs_caps)
return -ENODEV; /* ibs not supported by the cpu */
- perf_pmu_register(&perf_ibs, "ibs", -1);
+ perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
+ perf_ibs_pmu_init(&perf_ibs_op, "ibs_op");
+ register_nmi_handler(NMI_LOCAL, perf_ibs_nmi_handler, 0, "perf_ibs");
printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);
return 0;