Quelle  knc.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Driver for Intel Xeon Phi "Knights Corner" PMU */

#include <linux/perf_event.h>
#include <linux/types.h>

#include <asm/hardirq.h>
#include <asm/msr.h>

#include "../perf_event.h"

static const u64 knc_perfmon_event_map[] =
{
  [PERF_COUNT_HW_CPU_CYCLES]  = 0x002a,
  [PERF_COUNT_HW_INSTRUCTIONS]  = 0x0016,
  [PERF_COUNT_HW_CACHE_REFERENCES] = 0x0028,
  [PERF_COUNT_HW_CACHE_MISSES]  = 0x0029,
  [PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x0012,
  [PERF_COUNT_HW_BRANCH_MISSES]  = 0x002b,
};

static const u64 __initconst knc_hw_cache_event_ids
    [PERF_COUNT_HW_CACHE_MAX]
    [PERF_COUNT_HW_CACHE_OP_MAX]
    [PERF_COUNT_HW_CACHE_RESULT_MAX] =
{
 [ C(L1D) ] = {
 [ C(OP_READ) ] = {
  /* On Xeon Phi event "0" is a valid DATA_READ          */
  /*   (L1 Data Cache Reads) Instruction.                */
  /* We code this as ARCH_PERFMON_EVENTSEL_INT as this   */
  /* bit will always be set in x86_pmu_hw_config().      */
  [ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
      /* DATA_READ           */
  [ C(RESULT_MISS)   ] = 0x0003, /* DATA_READ_MISS      */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = 0x0001, /* DATA_WRITE          */
  [ C(RESULT_MISS)   ] = 0x0004, /* DATA_WRITE_MISS     */
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = 0x0011, /* L1_DATA_PF1         */
  [ C(RESULT_MISS)   ] = 0x001c, /* L1_DATA_PF1_MISS    */
 },
 },
 [ C(L1I ) ] = {
 [ C(OP_READ) ] = {
  [ C(RESULT_ACCESS) ] = 0x000c, /* CODE_READ          */
  [ C(RESULT_MISS)   ] = 0x000e, /* CODE_CACHE_MISS    */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = -1,
  [ C(RESULT_MISS)   ] = -1,
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = 0x0,
  [ C(RESULT_MISS)   ] = 0x0,
 },
 },
 [ C(LL  ) ] = {
 [ C(OP_READ) ] = {
  [ C(RESULT_ACCESS) ] = 0,
  [ C(RESULT_MISS)   ] = 0x10cb, /* L2_READ_MISS */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = 0x10cc, /* L2_WRITE_HIT */
  [ C(RESULT_MISS)   ] = 0,
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = 0x10fc, /* L2_DATA_PF2      */
  [ C(RESULT_MISS)   ] = 0x10fe, /* L2_DATA_PF2_MISS */
 },
 },
 [ C(DTLB) ] = {
 [ C(OP_READ) ] = {
  [ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
      /* DATA_READ */
      /* see note on L1 OP_READ */
  [ C(RESULT_MISS)   ] = 0x0002, /* DATA_PAGE_WALK */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = 0x0001, /* DATA_WRITE */
  [ C(RESULT_MISS)   ] = 0x0002, /* DATA_PAGE_WALK */
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = 0x0,
  [ C(RESULT_MISS)   ] = 0x0,
 },
 },
 [ C(ITLB) ] = {
 [ C(OP_READ) ] = {
  [ C(RESULT_ACCESS) ] = 0x000c, /* CODE_READ */
  [ C(RESULT_MISS)   ] = 0x000d, /* CODE_PAGE_WALK */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = -1,
  [ C(RESULT_MISS)   ] = -1,
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = -1,
  [ C(RESULT_MISS)   ] = -1,
 },
 },
 [ C(BPU ) ] = {
 [ C(OP_READ) ] = {
  [ C(RESULT_ACCESS) ] = 0x0012, /* BRANCHES */
  [ C(RESULT_MISS)   ] = 0x002b, /* BRANCHES_MISPREDICTED */
 },
 [ C(OP_WRITE) ] = {
  [ C(RESULT_ACCESS) ] = -1,
  [ C(RESULT_MISS)   ] = -1,
 },
 [ C(OP_PREFETCH) ] = {
  [ C(RESULT_ACCESS) ] = -1,
  [ C(RESULT_MISS)   ] = -1,
 },
 },
};


static u64 knc_pmu_event_map(int hw_event)
{
 return knc_perfmon_event_map[hw_event];
}

static struct event_constraint knc_event_constraints[] =
{
 INTEL_EVENT_CONSTRAINT(0xc3, 0x1), /* HWP_L2HIT */
 INTEL_EVENT_CONSTRAINT(0xc4, 0x1), /* HWP_L2MISS */
 INTEL_EVENT_CONSTRAINT(0xc8, 0x1), /* L2_READ_HIT_E */
 INTEL_EVENT_CONSTRAINT(0xc9, 0x1), /* L2_READ_HIT_M */
 INTEL_EVENT_CONSTRAINT(0xca, 0x1), /* L2_READ_HIT_S */
 INTEL_EVENT_CONSTRAINT(0xcb, 0x1), /* L2_READ_MISS */
 INTEL_EVENT_CONSTRAINT(0xcc, 0x1), /* L2_WRITE_HIT */
 INTEL_EVENT_CONSTRAINT(0xce, 0x1), /* L2_STRONGLY_ORDERED_STREAMING_VSTORES_MISS */
 INTEL_EVENT_CONSTRAINT(0xcf, 0x1), /* L2_WEAKLY_ORDERED_STREAMING_VSTORE_MISS */
 INTEL_EVENT_CONSTRAINT(0xd7, 0x1), /* L2_VICTIM_REQ_WITH_DATA */
 INTEL_EVENT_CONSTRAINT(0xe3, 0x1), /* SNP_HITM_BUNIT */
 INTEL_EVENT_CONSTRAINT(0xe6, 0x1), /* SNP_HIT_L2 */
 INTEL_EVENT_CONSTRAINT(0xe7, 0x1), /* SNP_HITM_L2 */
 INTEL_EVENT_CONSTRAINT(0xf1, 0x1), /* L2_DATA_READ_MISS_CACHE_FILL */
 INTEL_EVENT_CONSTRAINT(0xf2, 0x1), /* L2_DATA_WRITE_MISS_CACHE_FILL */
 INTEL_EVENT_CONSTRAINT(0xf6, 0x1), /* L2_DATA_READ_MISS_MEM_FILL */
 INTEL_EVENT_CONSTRAINT(0xf7, 0x1), /* L2_DATA_WRITE_MISS_MEM_FILL */
 INTEL_EVENT_CONSTRAINT(0xfc, 0x1), /* L2_DATA_PF2 */
 INTEL_EVENT_CONSTRAINT(0xfd, 0x1), /* L2_DATA_PF2_DROP */
 INTEL_EVENT_CONSTRAINT(0xfe, 0x1), /* L2_DATA_PF2_MISS */
 INTEL_EVENT_CONSTRAINT(0xff, 0x1), /* L2_DATA_HIT_INFLIGHT_PF2 */
 EVENT_CONSTRAINT_END
};

#define MSR_KNC_IA32_PERF_GLOBAL_STATUS  0x0000002d
#define MSR_KNC_IA32_PERF_GLOBAL_OVF_CONTROL 0x0000002e
#define MSR_KNC_IA32_PERF_GLOBAL_CTRL  0x0000002f

#define KNC_ENABLE_COUNTER0   0x00000001
#define KNC_ENABLE_COUNTER1   0x00000002

static void knc_pmu_disable_all(void)
{
 u64 val;

 rdmsrq(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
 val &= ~(KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
 wrmsrq(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
}

static void knc_pmu_enable_all(int added)
{
 u64 val;

 rdmsrq(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
 val |= (KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
 wrmsrq(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
}

static inline void
knc_pmu_disable_event(struct perf_event *event)
{
 struct hw_perf_event *hwc = &event->hw;
 u64 val;

 val = hwc->config;
 val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;

 (void)wrmsrq_safe(hwc->config_base + hwc->idx, val);
}

static void knc_pmu_enable_event(struct perf_event *event)
{
 struct hw_perf_event *hwc = &event->hw;
 u64 val;

 val = hwc->config;
 val |= ARCH_PERFMON_EVENTSEL_ENABLE;

 (void)wrmsrq_safe(hwc->config_base + hwc->idx, val);
}

static inline u64 knc_pmu_get_status(void)
{
 u64 status;

 rdmsrq(MSR_KNC_IA32_PERF_GLOBAL_STATUS, status);

 return status;
}

static inline void knc_pmu_ack_status(u64 ack)
{
 wrmsrq(MSR_KNC_IA32_PERF_GLOBAL_OVF_CONTROL, ack);
}

static int knc_pmu_handle_irq(struct pt_regs *regs)
{
 struct perf_sample_data data;
 struct cpu_hw_events *cpuc;
 int handled = 0;
 int bit, loops;
 u64 status;

 cpuc = this_cpu_ptr(&cpu_hw_events);

 knc_pmu_disable_all();

 status = knc_pmu_get_status();
 if (!status) {
  knc_pmu_enable_all(0);
  return handled;
 }

 loops = 0;
again:
 knc_pmu_ack_status(status);
 if (++loops > 100) {
  WARN_ONCE(1, "perf: irq loop stuck!\n");
  perf_event_print_debug();
  goto done;
 }

 inc_irq_stat(apic_perf_irqs);

 for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
  struct perf_event *event = cpuc->events[bit];
  u64 last_period;

  handled++;

  if (!test_bit(bit, cpuc->active_mask))
   continue;

  last_period = event->hw.last_period;
  if (!intel_pmu_save_and_restart(event))
   continue;

  perf_sample_data_init(&data, 0, last_period);

  perf_event_overflow(event, &data, regs);
 }

 /*
 * Repeat if there is more work to be done:
 */
 status = knc_pmu_get_status();
 if (status)
  goto again;

done:
 /* Only restore PMU state when it's active. See x86_pmu_disable(). */
 if (cpuc->enabled)
  knc_pmu_enable_all(0);

 return handled;
}


PMU_FORMAT_ATTR(event, "config:0-7" );
PMU_FORMAT_ATTR(umask, "config:8-15" );
PMU_FORMAT_ATTR(edge, "config:18" );
PMU_FORMAT_ATTR(inv, "config:23" );
PMU_FORMAT_ATTR(cmask, "config:24-31" );

static struct attribute *intel_knc_formats_attr[] = {
 &format_attr_event.attr,
 &format_attr_umask.attr,
 &format_attr_edge.attr,
 &format_attr_inv.attr,
 &format_attr_cmask.attr,
 NULL,
};

static const struct x86_pmu knc_pmu __initconst = {
 .name   = "knc",
 .handle_irq  = knc_pmu_handle_irq,
 .disable_all  = knc_pmu_disable_all,
 .enable_all  = knc_pmu_enable_all,
 .enable   = knc_pmu_enable_event,
 .disable  = knc_pmu_disable_event,
 .hw_config  = x86_pmu_hw_config,
 .schedule_events = x86_schedule_events,
 .eventsel  = MSR_KNC_EVNTSEL0,
 .perfctr  = MSR_KNC_PERFCTR0,
 .event_map  = knc_pmu_event_map,
 .max_events             = ARRAY_SIZE(knc_perfmon_event_map),
 .apic   = 1,
 .max_period  = (1ULL << 39) - 1,
 .version  = 0,
 .cntr_mask64  = 0x3,
 .cntval_bits  = 40,
 .cntval_mask  = (1ULL << 40) - 1,
 .get_event_constraints = x86_get_event_constraints,
 .event_constraints = knc_event_constraints,
 .format_attrs  = intel_knc_formats_attr,
};

__init int knc_pmu_init(void)
{
 x86_pmu = knc_pmu;

 memcpy(hw_cache_event_ids, knc_hw_cache_event_ids, 
  sizeof(hw_cache_event_ids));

 return 0;
}