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linux/arch/tile/kernel/perf_event.c

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/*
* Copyright 2014 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
*
* Perf_events support for Tile processor.
*
* This code is based upon the x86 perf event
* code, which is:
*
* Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
* Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
* Copyright (C) 2009 Jaswinder Singh Rajput
* Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
* Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra
* Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
* Copyright (C) 2009 Google, Inc., Stephane Eranian
*/
#include <linux/kprobes.h>
#include <linux/kernel.h>
#include <linux/kdebug.h>
#include <linux/mutex.h>
#include <linux/bitmap.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/perf_event.h>
#include <linux/atomic.h>
#include <asm/traps.h>
#include <asm/stack.h>
#include <asm/pmc.h>
#include <hv/hypervisor.h>
#define TILE_MAX_COUNTERS 4
#define PERF_COUNT_0_IDX 0
#define PERF_COUNT_1_IDX 1
#define AUX_PERF_COUNT_0_IDX 2
#define AUX_PERF_COUNT_1_IDX 3
struct cpu_hw_events {
int n_events;
struct perf_event *events[TILE_MAX_COUNTERS]; /* counter order */
struct perf_event *event_list[TILE_MAX_COUNTERS]; /* enabled
order */
int assign[TILE_MAX_COUNTERS];
unsigned long active_mask[BITS_TO_LONGS(TILE_MAX_COUNTERS)];
unsigned long used_mask;
};
/* TILE arch specific performance monitor unit */
struct tile_pmu {
const char *name;
int version;
const int *hw_events; /* generic hw events table */
/* generic hw cache events table */
const int (*cache_events)[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX];
int (*map_hw_event)(u64); /*method used to map
hw events */
int (*map_cache_event)(u64); /*method used to map
cache events */
u64 max_period; /* max sampling period */
u64 cntval_mask; /* counter width mask */
int cntval_bits; /* counter width */
int max_events; /* max generic hw events
in map */
int num_counters; /* number base + aux counters */
int num_base_counters; /* number base counters */
};
DEFINE_PER_CPU(u64, perf_irqs);
static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
#define TILE_OP_UNSUPP (-1)
#ifndef __tilegx__
/* TILEPro hardware events map */
static const int tile_hw_event_map[] = {
[PERF_COUNT_HW_CPU_CYCLES] = 0x01, /* ONE */
[PERF_COUNT_HW_INSTRUCTIONS] = 0x06, /* MP_BUNDLE_RETIRED */
[PERF_COUNT_HW_CACHE_REFERENCES] = TILE_OP_UNSUPP,
[PERF_COUNT_HW_CACHE_MISSES] = TILE_OP_UNSUPP,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0x16, /*
MP_CONDITIONAL_BRANCH_ISSUED */
[PERF_COUNT_HW_BRANCH_MISSES] = 0x14, /*
MP_CONDITIONAL_BRANCH_MISSPREDICT */
[PERF_COUNT_HW_BUS_CYCLES] = TILE_OP_UNSUPP,
};
#else
/* TILEGx hardware events map */
static const int tile_hw_event_map[] = {
[PERF_COUNT_HW_CPU_CYCLES] = 0x181, /* ONE */
[PERF_COUNT_HW_INSTRUCTIONS] = 0xdb, /* INSTRUCTION_BUNDLE */
[PERF_COUNT_HW_CACHE_REFERENCES] = TILE_OP_UNSUPP,
[PERF_COUNT_HW_CACHE_MISSES] = TILE_OP_UNSUPP,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = 0xd9, /*
COND_BRANCH_PRED_CORRECT */
[PERF_COUNT_HW_BRANCH_MISSES] = 0xda, /*
COND_BRANCH_PRED_INCORRECT */
[PERF_COUNT_HW_BUS_CYCLES] = TILE_OP_UNSUPP,
};
#endif
#define C(x) PERF_COUNT_HW_CACHE_##x
/*
* Generalized hw caching related hw_event table, filled
* in on a per model basis. A value of -1 means
* 'not supported', any other value means the
* raw hw_event ID.
*/
#ifndef __tilegx__
/* TILEPro hardware cache event map */
static const int tile_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0x21, /* RD_MISS */
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0x22, /* WR_MISS */
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x12, /* MP_ICACHE_HIT_ISSUED */
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(DTLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x1d, /* TLB_CNT */
[C(RESULT_MISS)] = 0x20, /* TLB_EXCEPTION */
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x13, /* MP_ITLB_HIT_ISSUED */
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
};
#else
/* TILEGx hardware events map */
static const int tile_cache_event_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
/*
* Like some other architectures (e.g. ARM), the performance
* counters don't differentiate between read and write
* accesses/misses, so this isn't strictly correct, but it's the
* best we can do. Writes and reads get combined.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0x44, /* RD_MISS */
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0x45, /* WR_MISS */
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(DTLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x40, /* TLB_CNT */
[C(RESULT_MISS)] = 0x43, /* TLB_EXCEPTION */
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = 0x40, /* TLB_CNT */
[C(RESULT_MISS)] = 0x43, /* TLB_EXCEPTION */
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0xd4, /* ITLB_MISS_INT */
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = 0xd4, /* ITLB_MISS_INT */
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = TILE_OP_UNSUPP,
[C(RESULT_MISS)] = TILE_OP_UNSUPP,
},
},
};
#endif
static atomic_t tile_active_events;
static DEFINE_MUTEX(perf_intr_reserve_mutex);
static int tile_map_hw_event(u64 config);
static int tile_map_cache_event(u64 config);
static int tile_pmu_handle_irq(struct pt_regs *regs, int fault);
/*
* To avoid new_raw_count getting larger then pre_raw_count
* in tile_perf_event_update(), we limit the value of max_period to 2^31 - 1.
*/
static const struct tile_pmu tilepmu = {
#ifndef __tilegx__
.name = "tilepro",
#else
.name = "tilegx",
#endif
.max_events = ARRAY_SIZE(tile_hw_event_map),
.map_hw_event = tile_map_hw_event,
.hw_events = tile_hw_event_map,
.map_cache_event = tile_map_cache_event,
.cache_events = &tile_cache_event_map,
.cntval_bits = 32,
.cntval_mask = (1ULL << 32) - 1,
.max_period = (1ULL << 31) - 1,
.num_counters = TILE_MAX_COUNTERS,
.num_base_counters = TILE_BASE_COUNTERS,
};
static const struct tile_pmu *tile_pmu __read_mostly;
/*
* Check whether perf event is enabled.
*/
int tile_perf_enabled(void)
{
return atomic_read(&tile_active_events) != 0;
}
/*
* Read Performance Counters.
*/
static inline u64 read_counter(int idx)
{
u64 val = 0;
/* __insn_mfspr() only takes an immediate argument */
switch (idx) {
case PERF_COUNT_0_IDX:
val = __insn_mfspr(SPR_PERF_COUNT_0);
break;
case PERF_COUNT_1_IDX:
val = __insn_mfspr(SPR_PERF_COUNT_1);
break;
case AUX_PERF_COUNT_0_IDX:
val = __insn_mfspr(SPR_AUX_PERF_COUNT_0);
break;
case AUX_PERF_COUNT_1_IDX:
val = __insn_mfspr(SPR_AUX_PERF_COUNT_1);
break;
default:
WARN_ON_ONCE(idx > AUX_PERF_COUNT_1_IDX ||
idx < PERF_COUNT_0_IDX);
}
return val;
}
/*
* Write Performance Counters.
*/
static inline void write_counter(int idx, u64 value)
{
/* __insn_mtspr() only takes an immediate argument */
switch (idx) {
case PERF_COUNT_0_IDX:
__insn_mtspr(SPR_PERF_COUNT_0, value);
break;
case PERF_COUNT_1_IDX:
__insn_mtspr(SPR_PERF_COUNT_1, value);
break;
case AUX_PERF_COUNT_0_IDX:
__insn_mtspr(SPR_AUX_PERF_COUNT_0, value);
break;
case AUX_PERF_COUNT_1_IDX:
__insn_mtspr(SPR_AUX_PERF_COUNT_1, value);
break;
default:
WARN_ON_ONCE(idx > AUX_PERF_COUNT_1_IDX ||
idx < PERF_COUNT_0_IDX);
}
}
/*
* Enable performance event by setting
* Performance Counter Control registers.
*/
static inline void tile_pmu_enable_event(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
unsigned long cfg, mask;
int shift, idx = hwc->idx;
/*
* prevent early activation from tile_pmu_start() in hw_perf_enable
*/
if (WARN_ON_ONCE(idx == -1))
return;
if (idx < tile_pmu->num_base_counters)
cfg = __insn_mfspr(SPR_PERF_COUNT_CTL);
else
cfg = __insn_mfspr(SPR_AUX_PERF_COUNT_CTL);
switch (idx) {
case PERF_COUNT_0_IDX:
case AUX_PERF_COUNT_0_IDX:
mask = TILE_EVENT_MASK;
shift = 0;
break;
case PERF_COUNT_1_IDX:
case AUX_PERF_COUNT_1_IDX:
mask = TILE_EVENT_MASK << 16;
shift = 16;
break;
default:
WARN_ON_ONCE(idx < PERF_COUNT_0_IDX ||
idx > AUX_PERF_COUNT_1_IDX);
return;
}
/* Clear mask bits to enable the event. */
cfg &= ~mask;
cfg |= hwc->config << shift;
if (idx < tile_pmu->num_base_counters)
__insn_mtspr(SPR_PERF_COUNT_CTL, cfg);
else
__insn_mtspr(SPR_AUX_PERF_COUNT_CTL, cfg);
}
/*
* Disable performance event by clearing
* Performance Counter Control registers.
*/
static inline void tile_pmu_disable_event(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
unsigned long cfg, mask;
int idx = hwc->idx;
if (idx == -1)
return;
if (idx < tile_pmu->num_base_counters)
cfg = __insn_mfspr(SPR_PERF_COUNT_CTL);
else
cfg = __insn_mfspr(SPR_AUX_PERF_COUNT_CTL);
switch (idx) {
case PERF_COUNT_0_IDX:
case AUX_PERF_COUNT_0_IDX:
mask = TILE_PLM_MASK;
break;
case PERF_COUNT_1_IDX:
case AUX_PERF_COUNT_1_IDX:
mask = TILE_PLM_MASK << 16;
break;
default:
WARN_ON_ONCE(idx < PERF_COUNT_0_IDX ||
idx > AUX_PERF_COUNT_1_IDX);
return;
}
/* Set mask bits to disable the event. */
cfg |= mask;
if (idx < tile_pmu->num_base_counters)
__insn_mtspr(SPR_PERF_COUNT_CTL, cfg);
else
__insn_mtspr(SPR_AUX_PERF_COUNT_CTL, cfg);
}
/*
* Propagate event elapsed time into the generic event.
* Can only be executed on the CPU where the event is active.
* Returns the delta events processed.
*/
static u64 tile_perf_event_update(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int shift = 64 - tile_pmu->cntval_bits;
u64 prev_raw_count, new_raw_count;
u64 oldval;
int idx = hwc->idx;
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:
*/
again:
prev_raw_count = local64_read(&hwc->prev_count);
new_raw_count = read_counter(idx);
oldval = local64_cmpxchg(&hwc->prev_count, prev_raw_count,
new_raw_count);
if (oldval != prev_raw_count)
goto again;
/*
* 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 new_raw_count;
}
/*
* Set the next IRQ period, based on the hwc->period_left value.
* To be called with the event disabled in hw:
*/
static int tile_event_set_period(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
s64 left = local64_read(&hwc->period_left);
s64 period = hwc->sample_period;
int ret = 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;
ret = 1;
}
if (unlikely(left <= 0)) {
left += period;
local64_set(&hwc->period_left, left);
hwc->last_period = period;
ret = 1;
}
if (left > tile_pmu->max_period)
left = tile_pmu->max_period;
/*
* The hw event starts counting from this event offset,
* mark it to be able to extra future deltas:
*/
local64_set(&hwc->prev_count, (u64)-left);
write_counter(idx, (u64)(-left) & tile_pmu->cntval_mask);
perf_event_update_userpage(event);
return ret;
}
/*
* Stop the event but do not release the PMU counter
*/
static void tile_pmu_stop(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
if (__test_and_clear_bit(idx, cpuc->active_mask)) {
tile_pmu_disable_event(event);
cpuc->events[hwc->idx] = NULL;
WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
hwc->state |= PERF_HES_STOPPED;
}
if ((flags & PERF_EF_UPDATE) && !(hwc->state & PERF_HES_UPTODATE)) {
/*
* Drain the remaining delta count out of a event
* that we are disabling:
*/
tile_perf_event_update(event);
hwc->state |= PERF_HES_UPTODATE;
}
}
/*
* Start an event (without re-assigning counter)
*/
static void tile_pmu_start(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
int idx = event->hw.idx;
if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
return;
if (WARN_ON_ONCE(idx == -1))
return;
if (flags & PERF_EF_RELOAD) {
WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
tile_event_set_period(event);
}
event->hw.state = 0;
cpuc->events[idx] = event;
__set_bit(idx, cpuc->active_mask);
unmask_pmc_interrupts();
tile_pmu_enable_event(event);
perf_event_update_userpage(event);
}
/*
* Add a single event to the PMU.
*
* The event is added to the group of enabled events
* but only if it can be scehduled with existing events.
*/
static int tile_pmu_add(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct hw_perf_event *hwc;
unsigned long mask;
int b, max_cnt;
hwc = &event->hw;
/*
* We are full.
*/
if (cpuc->n_events == tile_pmu->num_counters)
return -ENOSPC;
cpuc->event_list[cpuc->n_events] = event;
cpuc->n_events++;
hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
if (!(flags & PERF_EF_START))
hwc->state |= PERF_HES_ARCH;
/*
* Find first empty counter.
*/
max_cnt = tile_pmu->num_counters;
mask = ~cpuc->used_mask;
/* Find next free counter. */
b = find_next_bit(&mask, max_cnt, 0);
/* Should not happen. */
if (WARN_ON_ONCE(b == max_cnt))
return -ENOSPC;
/*
* Assign counter to event.
*/
event->hw.idx = b;
__set_bit(b, &cpuc->used_mask);
/*
* Start if requested.
*/
if (flags & PERF_EF_START)
tile_pmu_start(event, PERF_EF_RELOAD);
return 0;
}
/*
* Delete a single event from the PMU.
*
* The event is deleted from the group of enabled events.
* If it is the last event, disable PMU interrupt.
*/
static void tile_pmu_del(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
int i;
/*
* Remove event from list, compact list if necessary.
*/
for (i = 0; i < cpuc->n_events; i++) {
if (cpuc->event_list[i] == event) {
while (++i < cpuc->n_events)
cpuc->event_list[i-1] = cpuc->event_list[i];
--cpuc->n_events;
cpuc->events[event->hw.idx] = NULL;
__clear_bit(event->hw.idx, &cpuc->used_mask);
tile_pmu_stop(event, PERF_EF_UPDATE);
break;
}
}
/*
* If there are no events left, then mask PMU interrupt.
*/
if (cpuc->n_events == 0)
mask_pmc_interrupts();
perf_event_update_userpage(event);
}
/*
* Propagate event elapsed time into the event.
*/
static inline void tile_pmu_read(struct perf_event *event)
{
tile_perf_event_update(event);
}
/*
* Map generic events to Tile PMU.
*/
static int tile_map_hw_event(u64 config)
{
if (config >= tile_pmu->max_events)
return -EINVAL;
return tile_pmu->hw_events[config];
}
/*
* Map generic hardware cache events to Tile PMU.
*/
static int tile_map_cache_event(u64 config)
{
unsigned int cache_type, cache_op, cache_result;
int code;
if (!tile_pmu->cache_events)
return -ENOENT;
cache_type = (config >> 0) & 0xff;
if (cache_type >= PERF_COUNT_HW_CACHE_MAX)
return -EINVAL;
cache_op = (config >> 8) & 0xff;
if (cache_op >= PERF_COUNT_HW_CACHE_OP_MAX)
return -EINVAL;
cache_result = (config >> 16) & 0xff;
if (cache_result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
return -EINVAL;
code = (*tile_pmu->cache_events)[cache_type][cache_op][cache_result];
if (code == TILE_OP_UNSUPP)
return -EINVAL;
return code;
}
static void tile_event_destroy(struct perf_event *event)
{
if (atomic_dec_return(&tile_active_events) == 0)
release_pmc_hardware();
}
static int __tile_event_init(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
struct hw_perf_event *hwc = &event->hw;
int code;
switch (attr->type) {
case PERF_TYPE_HARDWARE:
code = tile_pmu->map_hw_event(attr->config);
break;
case PERF_TYPE_HW_CACHE:
code = tile_pmu->map_cache_event(attr->config);
break;
case PERF_TYPE_RAW:
code = attr->config & TILE_EVENT_MASK;
break;
default:
/* Should not happen. */
return -EOPNOTSUPP;
}
if (code < 0)
return code;
hwc->config = code;
hwc->idx = -1;
if (attr->exclude_user)
hwc->config |= TILE_CTL_EXCL_USER;
if (attr->exclude_kernel)
hwc->config |= TILE_CTL_EXCL_KERNEL;
if (attr->exclude_hv)
hwc->config |= TILE_CTL_EXCL_HV;
if (!hwc->sample_period) {
hwc->sample_period = tile_pmu->max_period;
hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
}
event->destroy = tile_event_destroy;
return 0;
}
static int tile_event_init(struct perf_event *event)
{
int err = 0;
perf_irq_t old_irq_handler = NULL;
if (atomic_inc_return(&tile_active_events) == 1)
old_irq_handler = reserve_pmc_hardware(tile_pmu_handle_irq);
if (old_irq_handler) {
pr_warn("PMC hardware busy (reserved by oprofile)\n");
atomic_dec(&tile_active_events);
return -EBUSY;
}
switch (event->attr.type) {
case PERF_TYPE_RAW:
case PERF_TYPE_HARDWARE:
case PERF_TYPE_HW_CACHE:
break;
default:
return -ENOENT;
}
err = __tile_event_init(event);
if (err) {
if (event->destroy)
event->destroy(event);
}
return err;
}
static struct pmu tilera_pmu = {
.event_init = tile_event_init,
.add = tile_pmu_add,
.del = tile_pmu_del,
.start = tile_pmu_start,
.stop = tile_pmu_stop,
.read = tile_pmu_read,
};
/*
* PMU's IRQ handler, PMU has 2 interrupts, they share the same handler.
*/
int tile_pmu_handle_irq(struct pt_regs *regs, int fault)
{
struct perf_sample_data data;
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct perf_event *event;
struct hw_perf_event *hwc;
u64 val;
unsigned long status;
int bit;
__this_cpu_inc(perf_irqs);
if (!atomic_read(&tile_active_events))
return 0;
status = pmc_get_overflow();
pmc_ack_overflow(status);
for_each_set_bit(bit, &status, tile_pmu->num_counters) {
event = cpuc->events[bit];
if (!event)
continue;
if (!test_bit(bit, cpuc->active_mask))
continue;
hwc = &event->hw;
val = tile_perf_event_update(event);
if (val & (1ULL << (tile_pmu->cntval_bits - 1)))
continue;
perf_sample_data_init(&data, 0, event->hw.last_period);
if (!tile_event_set_period(event))
continue;
if (perf_event_overflow(event, &data, regs))
tile_pmu_stop(event, 0);
}
return 0;
}
static bool __init supported_pmu(void)
{
tile_pmu = &tilepmu;
return true;
}
int __init init_hw_perf_events(void)
{
supported_pmu();
perf_pmu_register(&tilera_pmu, "cpu", PERF_TYPE_RAW);
return 0;
}
arch_initcall(init_hw_perf_events);
/* Callchain handling code. */
/*
* Tile specific backtracing code for perf_events.
*/
static inline void perf_callchain(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
struct KBacktraceIterator kbt;
unsigned int i;
/*
* Get the address just after the "jalr" instruction that
* jumps to the handler for a syscall. When we find this
* address in a backtrace, we silently ignore it, which gives
* us a one-step backtrace connection from the sys_xxx()
* function in the kernel to the xxx() function in libc.
* Otherwise, we lose the ability to properly attribute time
* from the libc calls to the kernel implementations, since
* oprofile only considers PCs from backtraces a pair at a time.
*/
unsigned long handle_syscall_pc = handle_syscall_link_address();
KBacktraceIterator_init(&kbt, NULL, regs);
kbt.profile = 1;
/*
* The sample for the pc is already recorded. Now we are adding the
* address of the callsites on the stack. Our iterator starts
* with the frame of the (already sampled) call site. If our
* iterator contained a "return address" field, we could have just
* used it and wouldn't have needed to skip the first
* frame. That's in effect what the arm and x86 versions do.
* Instead we peel off the first iteration to get the equivalent
* behavior.
*/
if (KBacktraceIterator_end(&kbt))
return;
KBacktraceIterator_next(&kbt);
/*
* Set stack depth to 16 for user and kernel space respectively, that
* is, total 32 stack frames.
*/
for (i = 0; i < 16; ++i) {
unsigned long pc;
if (KBacktraceIterator_end(&kbt))
break;
pc = kbt.it.pc;
if (pc != handle_syscall_pc)
perf_callchain_store(entry, pc);
KBacktraceIterator_next(&kbt);
}
}
void perf_callchain_user(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
perf_callchain(entry, regs);
}
void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
struct pt_regs *regs)
{
perf_callchain(entry, regs);
}
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