#undef DEBUG
/*
* ARM performance counter support.
*
* Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
*
* This code is based on the sparc64 perf event code, which is in turn based
* on the x86 code. Callchain code is based on the ARM OProfile backtrace
* code.
*/
#define pr_fmt(fmt) "hw perfevents: " fmt
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/perf_event.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <asm/cputype.h>
#include <asm/irq.h>
#include <asm/irq_regs.h>
#include <asm/pmu.h>
#include <asm/stacktrace.h>
static const struct pmu_irqs *pmu_irqs;
/*
* Hardware lock to serialize accesses to PMU registers. Needed for the
* read/modify/write sequences.
*/
DEFINE_SPINLOCK(pmu_lock);
/*
* ARMv6 supports a maximum of 3 events, starting from index 1. If we add
* another platform that supports more, we need to increase this to be the
* largest of all platforms.
*/
#define ARMPMU_MAX_HWEVENTS 4
/* The events for a given CPU. */
struct cpu_hw_events {
/*
* The events that are active on the CPU for the given index. Index 0
* is reserved.
*/
struct perf_event *events[ARMPMU_MAX_HWEVENTS];
/*
* A 1 bit for an index indicates that the counter is being used for
* an event. A 0 means that the counter can be used.
*/
unsigned long used_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
/*
* A 1 bit for an index indicates that the counter is actively being
* used.
*/
unsigned long active_mask[BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)];
};
DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
struct arm_pmu {
const char *name;
irqreturn_t (*handle_irq)(int irq_num, void *dev);
void (*enable)(struct hw_perf_event *evt, int idx);
void (*disable)(struct hw_perf_event *evt, int idx);
int (*event_map)(int evt);
u64 (*raw_event)(u64);
int (*get_event_idx)(struct cpu_hw_events *cpuc,
struct hw_perf_event *hwc);
u32 (*read_counter)(int idx);
void (*write_counter)(int idx, u32 val);
void (*start)(void);
void (*stop)(void);
int num_events;
u64 max_period;
};
/* Set at runtime when we know what CPU type we are. */
static const struct arm_pmu *armpmu;
#define HW_OP_UNSUPPORTED 0xFFFF
#define C(_x) \
PERF_COUNT_HW_CACHE_##_x
#define CACHE_OP_UNSUPPORTED 0xFFFF
static unsigned armpmu_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX];
static int
armpmu_map_cache_event(u64 config)
{
unsigned int cache_type, cache_op, cache_result, ret;
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;
ret = (int)armpmu_perf_cache_map[cache_type][cache_op][cache_result];
if (ret == CACHE_OP_UNSUPPORTED)
return -ENOENT;
return ret;
}
static int
armpmu_event_set_period(struct perf_event *event,
struct hw_perf_event *hwc,
int idx)
{
s64 left = atomic64_read(&hwc->period_left);
s64 period = hwc->sample_period;
int ret = 0;
if (unlikely(left <= -period)) {
left = period;
atomic64_set(&hwc->period_left, left);
hwc->last_period = period;
ret = 1;
}
if (unlikely(left <= 0)) {
left += period;
atomic64_set(&hwc->period_left, left);
hwc->last_period = period;
ret = 1;
}
if (left > (s64)armpmu->max_period)
left = armpmu->max_period;
atomic64_set(&hwc->prev_count, (u64)-left);
armpmu->write_counter(idx, (u64)(-left) & 0xffffffff);
perf_event_update_userpage(event);
return ret;
}
static u64
armpmu_event_update(struct perf_event *event,
struct hw_perf_event *hwc,
int idx)
{
int shift = 64 - 32;
s64 prev_raw_count, new_raw_count;
s64 delta;
again:
prev_raw_count = atomic64_read(&hwc->prev_count);
new_raw_count = armpmu->read_counter(idx);
if (atomic64_cmpxchg(&hwc->prev_count, prev_raw_count,
new_raw_count) != prev_raw_count)
goto again;
delta = (new_raw_count << shift) - (prev_raw_count << shift);
delta >>= shift;
atomic64_add(delta, &event->count);
atomic64_sub(delta, &hwc->period_left);
return new_raw_count;
}
static void
armpmu_disable(struct perf_event *event)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
int idx = hwc->idx;
WARN_ON(idx < 0);
clear_bit(idx, cpuc->active_mask);
armpmu->disable(hwc, idx);
barrier();
armpmu_event_update(event, hwc, idx);
cpuc->events[idx] = NULL;
clear_bit(idx, cpuc->used_mask);
perf_event_update_userpage(event);
}
static void
armpmu_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
/* Don't read disabled counters! */
if (hwc->idx < 0)
return;
armpmu_event_update(event, hwc, hwc->idx);
}
static void
armpmu_unthrottle(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
/*
* Set the period again. Some counters can't be stopped, so when we
* were throttled we simply disabled the IRQ source and the counter
* may have been left counting. If we don't do this step then we may
* get an interrupt too soon or *way* too late if the overflow has
* happened since disabling.
*/
armpmu_event_set_period(event, hwc, hwc->idx);
armpmu->enable(hwc, hwc->idx);
}
static int
armpmu_enable(struct perf_event *event)
{
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
struct hw_perf_event *hwc = &event->hw;
int idx;
int err = 0;
/* If we don't have a space for the counter then finish early. */
idx = armpmu->get_event_idx(cpuc, hwc);
if (idx < 0) {
err = idx;
goto out;
}
/*
* If there is an event in the counter we are going to use then make
* sure it is disabled.
*/
event->hw.idx = idx;
armpmu->disable(hwc, idx);
cpuc->events[idx] = event;
set_bit(idx, cpuc->active_mask);
/* Set the period for the event. */
armpmu_event_set_period(event, hwc, idx);
/* Enable the event. */
armpmu->enable(hwc, idx);
/* Propagate our changes to the userspace mapping. */
perf_event_update_userpage(event);
out:
return err;
}
static struct pmu pmu = {
.enable = armpmu_enable,
.disable = armpmu_disable,
.unthrottle = armpmu_unthrottle,
.read = armpmu_read,
};
static int
validate_event(struct cpu_hw_events *cpuc,
struct perf_event *event)
{
struct hw_perf_event fake_event = event->hw;
if (event->pmu && event->pmu != &pmu)
return 0;
return armpmu->get_event_idx(cpuc, &fake_event) >= 0;
}
static int
validate_group(struct perf_event *event)
{
struct perf_event *sibling, *leader = event->group_leader;
struct cpu_hw_events fake_pmu;
memset(&fake_pmu, 0, sizeof(fake_pmu));
if (!validate_event(&fake_pmu, leader))
return -ENOSPC;
list_for_each_entry(sibling, &leader->sibling_list, group_entry) {
if (!validate_event(&fake_pmu, sibling))
return -ENOSPC;
}
if (!validate_event(&fake_pmu, event))
return -ENOSPC;
return 0;
}
static int
armpmu_reserve_hardware(void)
{
int i;
int err;
pmu_irqs = reserve_pmu();
if (IS_ERR(pmu_irqs)) {
pr_warning("unable to reserve pmu\n");
return PTR_ERR(pmu_irqs);
}
init_pmu();
if (pmu_irqs->num_irqs < 1) {
pr_err("no irqs for PMUs defined\n");
return -ENODEV;
}
for (i = 0; i < pmu_irqs->num_irqs; ++i) {
err = request_irq(pmu_irqs->irqs[i], armpmu->handle_irq,
IRQF_DISABLED, "armpmu", NULL);
if (err) {
pr_warning("unable to request IRQ%d for ARM "
"perf counters\n", pmu_irqs->irqs[i]);
break;
}
}
if (err) {
for (i = i - 1; i >= 0; --i)
free_irq(pmu_irqs->irqs[i], NULL);
release_pmu(pmu_irqs);
pmu_irqs = NULL;
}
return err;
}
static void
armpmu_release_hardware(void)
{
int i;
for (i = pmu_irqs->num_irqs - 1; i >= 0; --i)
free_irq(pmu_irqs->irqs[i], NULL);
armpmu->stop();
release_pmu(pmu_irqs);
pmu_irqs = NULL;
}
static atomic_t active_events = ATOMIC_INIT(0);
static DEFINE_MUTEX(pmu_reserve_mutex);
static void
hw_perf_event_destroy(struct perf_event *event)
{
if (atomic_dec_and_mutex_lock(&active_events, &pmu_reserve_mutex)) {
armpmu_release_hardware();
mutex_unlock(&pmu_reserve_mutex);
}
}
static int
__hw_perf_event_init(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
int mapping, err;
/* Decode the generic type into an ARM event identifier. */
if (PERF_TYPE_HARDWARE == event->attr.type) {
mapping = armpmu->event_map(event->attr.config);
} else if (PERF_TYPE_HW_CACHE == event->attr.type) {
mapping = armpmu_map_cache_event(event->attr.config);
} else if (PERF_TYPE_RAW == event->attr.type) {
mapping = armpmu->raw_event(event->attr.config);
} else {
pr_debug("event type %x not supported\n", event->attr.type);
return -EOPNOTSUPP;
}
if (mapping < 0) {
pr_debug("event %x:%llx not supported\n", event->attr.type,
event->attr.config);
return mapping;
}
/*
* Check whether we need to exclude the counter from certain modes.
* The ARM performance counters are on all of the time so if someone
* has asked us for some excludes then we have to fail.
*/
if (event->attr.exclude_kernel || event->attr.exclude_user ||
event->attr.exclude_hv || event->attr.exclude_idle) {
pr_debug("ARM performance counters do not support "
"mode exclusion\n");
return -EPERM;
}
/*
* We don't assign an index until we actually place the event onto
* hardware. Use -1 to signify that we haven't decided where to put it
* yet. For SMP systems, each core has it's own PMU so we can't do any
* clever allocation or constraints checking at this point.
*/
hwc->idx = -1;
/*
* Store the event encoding into the config_base field. config and
* event_base are unused as the only 2 things we need to know are
* the event mapping and the counter to use. The counter to use is
* also the indx and the config_base is the event type.
*/
hwc->config_base = (unsigned long)mapping;
hwc->config = 0;
hwc->event_base = 0;
if (!hwc->sample_period) {
hwc->sample_period = armpmu->max_period;
hwc->last_period = hwc->sample_period;
atomic64_set(&hwc->period_left, hwc->sample_period);
}
err = 0;
if (event->group_leader != event) {
err = validate_group(event);
if (err)
return -EINVAL;
}
return err;
}
const struct pmu *
hw_perf_event_init(struct perf_event *event)
{
int err = 0;
if (!armpmu)
return ERR_PTR(-ENODEV);
event->destroy = hw_perf_event_destroy;
if (!atomic_inc_not_zero(&active_events)) {
if (atomic_read(&active_events) > perf_max_events) {
atomic_dec(&active_events);
return ERR_PTR(-ENOSPC);
}
mutex_lock(&pmu_reserve_mutex);
if (atomic_read(&active_events) == 0) {
err = armpmu_reserve_hardware();
}
if (!err)
atomic_inc(&active_events);
mutex_unlock(&pmu_reserve_mutex);
}
if (err)
return ERR_PTR(err);
err = __hw_perf_event_init(event);
if (err)
hw_perf_event_destroy(event);
return err ? ERR_PTR(err) : &pmu;
}
void
hw_perf_enable(void)
{
/* Enable all of the perf events on hardware. */
int idx;
struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
if (!armpmu)
return;
for (idx = 0; idx <= armpmu->num_events; ++idx) {
struct perf_event *event = cpuc->events[idx];
if (!event)
continue;
armpmu->enable(&event->hw, idx);
}
armpmu->start();
}
void
hw_perf_disable(void)
{
if (armpmu)
armpmu->stop();
}
/*
* ARMv6 Performance counter handling code.
*
* ARMv6 has 2 configurable performance counters and a single cycle counter.
* They all share a single reset bit but can be written to zero so we can use
* that for a reset.
*
* The counters can't be individually enabled or disabled so when we remove
* one event and replace it with another we could get spurious counts from the
* wrong event. However, we can take advantage of the fact that the
* performance counters can export events to the event bus, and the event bus
* itself can be monitored. This requires that we *don't* export the events to
* the event bus. The procedure for disabling a configurable counter is:
* - change the counter to count the ETMEXTOUT[0] signal (0x20). This
* effectively stops the counter from counting.
* - disable the counter's interrupt generation (each counter has it's
* own interrupt enable bit).
* Once stopped, the counter value can be written as 0 to reset.
*
* To enable a counter:
* - enable the counter's interrupt generation.
* - set the new event type.
*
* Note: the dedicated cycle counter only counts cycles and can't be
* enabled/disabled independently of the others. When we want to disable the
* cycle counter, we have to just disable the interrupt reporting and start
* ignoring that counter. When re-enabling, we have to reset the value and
* enable the interrupt.
*/
enum armv6_perf_types {
ARMV6_PERFCTR_ICACHE_MISS = 0x0,
ARMV6_PERFCTR_IBUF_STALL = 0x1,
ARMV6_PERFCTR_DDEP_STALL = 0x2,
ARMV6_PERFCTR_ITLB_MISS = 0x3,
ARMV6_PERFCTR_DTLB_MISS = 0x4,
ARMV6_PERFCTR_BR_EXEC = 0x5,
ARMV6_PERFCTR_BR_MISPREDICT = 0x6,
ARMV6_PERFCTR_INSTR_EXEC = 0x7,
ARMV6_PERFCTR_DCACHE_HIT = 0x9,
ARMV6_PERFCTR_DCACHE_ACCESS = 0xA,
ARMV6_PERFCTR_DCACHE_MISS = 0xB,
ARMV6_PERFCTR_DCACHE_WBACK = 0xC,
ARMV6_PERFCTR_SW_PC_CHANGE = 0xD,
ARMV6_PERFCTR_MAIN_TLB_MISS = 0xF,
ARMV6_PERFCTR_EXPL_D_ACCESS = 0x10,
ARMV6_PERFCTR_LSU_FULL_STALL = 0x11,
ARMV6_PERFCTR_WBUF_DRAINED = 0x12,
ARMV6_PERFCTR_CPU_CYCLES = 0xFF,
ARMV6_PERFCTR_NOP = 0x20,
};
enum armv6_counters {
ARMV6_CYCLE_COUNTER = 1,
ARMV6_COUNTER0,
ARMV6_COUNTER1,
};
/*
* The hardware events that we support. We do support cache operations but
* we have harvard caches and no way to combine instruction and data
* accesses/misses in hardware.
*/
static const unsigned armv6_perf_map[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = ARMV6_PERFCTR_CPU_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV6_PERFCTR_INSTR_EXEC,
[PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6_PERFCTR_BR_EXEC,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV6_PERFCTR_BR_MISPREDICT,
[PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
};
static const unsigned armv6_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
/*
* 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)] = ARMV6_PERFCTR_DCACHE_ACCESS,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = ARMV6_PERFCTR_DCACHE_ACCESS,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DCACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ICACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(DTLB)] = {
/*
* The ARM performance counters can count micro DTLB misses,
* micro ITLB misses and main TLB misses. There isn't an event
* for TLB misses, so use the micro misses here and if users
* want the main TLB misses they can use a raw counter.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_DTLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6_PERFCTR_ITLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
};
enum armv6mpcore_perf_types {
ARMV6MPCORE_PERFCTR_ICACHE_MISS = 0x0,
ARMV6MPCORE_PERFCTR_IBUF_STALL = 0x1,
ARMV6MPCORE_PERFCTR_DDEP_STALL = 0x2,
ARMV6MPCORE_PERFCTR_ITLB_MISS = 0x3,
ARMV6MPCORE_PERFCTR_DTLB_MISS = 0x4,
ARMV6MPCORE_PERFCTR_BR_EXEC = 0x5,
ARMV6MPCORE_PERFCTR_BR_NOTPREDICT = 0x6,
ARMV6MPCORE_PERFCTR_BR_MISPREDICT = 0x7,
ARMV6MPCORE_PERFCTR_INSTR_EXEC = 0x8,
ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS = 0xA,
ARMV6MPCORE_PERFCTR_DCACHE_RDMISS = 0xB,
ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS = 0xC,
ARMV6MPCORE_PERFCTR_DCACHE_WRMISS = 0xD,
ARMV6MPCORE_PERFCTR_DCACHE_EVICTION = 0xE,
ARMV6MPCORE_PERFCTR_SW_PC_CHANGE = 0xF,
ARMV6MPCORE_PERFCTR_MAIN_TLB_MISS = 0x10,
ARMV6MPCORE_PERFCTR_EXPL_MEM_ACCESS = 0x11,
ARMV6MPCORE_PERFCTR_LSU_FULL_STALL = 0x12,
ARMV6MPCORE_PERFCTR_WBUF_DRAINED = 0x13,
ARMV6MPCORE_PERFCTR_CPU_CYCLES = 0xFF,
};
/*
* The hardware events that we support. We do support cache operations but
* we have harvard caches and no way to combine instruction and data
* accesses/misses in hardware.
*/
static const unsigned armv6mpcore_perf_map[PERF_COUNT_HW_MAX] = {
[PERF_COUNT_HW_CPU_CYCLES] = ARMV6MPCORE_PERFCTR_CPU_CYCLES,
[PERF_COUNT_HW_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_INSTR_EXEC,
[PERF_COUNT_HW_CACHE_REFERENCES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_CACHE_MISSES] = HW_OP_UNSUPPORTED,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = ARMV6MPCORE_PERFCTR_BR_EXEC,
[PERF_COUNT_HW_BRANCH_MISSES] = ARMV6MPCORE_PERFCTR_BR_MISPREDICT,
[PERF_COUNT_HW_BUS_CYCLES] = HW_OP_UNSUPPORTED,
};
static const unsigned armv6mpcore_perf_cache_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)] =
ARMV6MPCORE_PERFCTR_DCACHE_RDACCESS,
[C(RESULT_MISS)] =
ARMV6MPCORE_PERFCTR_DCACHE_RDMISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] =
ARMV6MPCORE_PERFCTR_DCACHE_WRACCESS,
[C(RESULT_MISS)] =
ARMV6MPCORE_PERFCTR_DCACHE_WRMISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ICACHE_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(LL)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(DTLB)] = {
/*
* The ARM performance counters can count micro DTLB misses,
* micro ITLB misses and main TLB misses. There isn't an event
* for TLB misses, so use the micro misses here and if users
* want the main TLB misses they can use a raw counter.
*/
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_DTLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = ARMV6MPCORE_PERFCTR_ITLB_MISS,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(BPU)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
};
static inline unsigned long
armv6_pmcr_read(void)
{
u32 val;
asm volatile("mrc p15, 0, %0, c15, c12, 0" : "=r"(val));
return val;
}
static inline void
armv6_pmcr_write(unsigned long val)
{
asm volatile("mcr p15, 0, %0, c15, c12, 0" : : "r"(val));
}
#define ARMV6_PMCR_ENABLE (1 << 0)
#define ARMV6_PMCR_CTR01_RESET (1 << 1)
#define ARMV6_PMCR_CCOUNT_RESET (1 << 2)
#define ARMV6_PMCR_CCOUNT_DIV (1 << 3)
#define ARMV6_PMCR_COUNT0_IEN (1 << 4)
#define ARMV6_PMCR_COUNT1_IEN (1 << 5)
#define ARMV6_PMCR_CCOUNT_IEN (1 << 6)
#define ARMV6_PMCR_COUNT0_OVERFLOW (1 << 8)
#define ARMV6_PMCR_COUNT1_OVERFLOW (1 << 9)
#define ARMV6_PMCR_CCOUNT_OVERFLOW (1 << 10)
#define ARMV6_PMCR_EVT_COUNT0_SHIFT 20
#define ARMV6_PMCR_EVT_COUNT0_MASK (0xFF << ARMV6_PMCR_EVT_COUNT0_SHIFT)
#define ARMV6_PMCR_EVT_COUNT1_SHIFT 12
#define ARMV6_PMCR_EVT_COUNT1_MASK (0xFF << ARMV6_PMCR_EVT_COUNT1_SHIFT)
#define ARMV6_PMCR_OVERFLOWED_MASK \
(ARMV6_PMCR_COUNT0_OVERFLOW | ARMV6_PMCR_COUNT1_OVERFLOW | \
ARMV6_PMCR_CCOUNT_OVERFLOW)
static inline int
armv6_pmcr_has_overflowed(unsigned long pmcr)
{
return (pmcr & ARMV6_PMCR_OVERFLOWED_MASK);
}
static inline int
armv6_pmcr_counter_has_overflowed(unsigned long pmcr,
enum armv6_counters counter)
{
int ret = 0;
if (ARMV6_CYCLE_COUNTER == counter)
ret = pmcr & ARMV6_PMCR_CCOUNT_OVERFLOW;
else if (ARMV6_COUNTER0 == counter)
ret = pmcr & ARMV6_PMCR_COUNT0_OVERFLOW;
else if (ARMV6_COUNTER1 == counter)
ret = pmcr & ARMV6_PMCR_COUNT1_OVERFLOW;
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
return ret;
}
static inline u32
armv6pmu_read_counter(int counter)
{
unsigned long value = 0;
if (ARMV6_CYCLE_COUNTER == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 1" : "=r"(value));
else if (ARMV6_COUNTER0 == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 2" : "=r"(value));
else if (ARMV6_COUNTER1 == counter)
asm volatile("mrc p15, 0, %0, c15, c12, 3" : "=r"(value));
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
return value;
}
static inline void
armv6pmu_write_counter(int counter,
u32 value)
{
if (ARMV6_CYCLE_COUNTER == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 1" : : "r"(value));
else if (ARMV6_COUNTER0 == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 2" : : "r"(value));
else if (ARMV6_COUNTER1 == counter)
asm volatile("mcr p15, 0, %0, c15, c12, 3" : : "r"(value));
else
WARN_ONCE(1, "invalid counter number (%d)\n", counter);
}
void
armv6pmu_enable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, evt, flags;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = 0;
evt = ARMV6_PMCR_CCOUNT_IEN;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_EVT_COUNT0_MASK;
evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT0_SHIFT) |
ARMV6_PMCR_COUNT0_IEN;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_EVT_COUNT1_MASK;
evt = (hwc->config_base << ARMV6_PMCR_EVT_COUNT1_SHIFT) |
ARMV6_PMCR_COUNT1_IEN;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Mask out the current event and set the counter to count the event
* that we're interested in.
*/
spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
spin_unlock_irqrestore(&pmu_lock, flags);
}
static irqreturn_t
armv6pmu_handle_irq(int irq_num,
void *dev)
{
unsigned long pmcr = armv6_pmcr_read();
struct perf_sample_data data;
struct cpu_hw_events *cpuc;
struct pt_regs *regs;
int idx;
if (!armv6_pmcr_has_overflowed(pmcr))
return IRQ_NONE;
regs = get_irq_regs();
/*
* The interrupts are cleared by writing the overflow flags back to
* the control register. All of the other bits don't have any effect
* if they are rewritten, so write the whole value back.
*/
armv6_pmcr_write(pmcr);
data.addr = 0;
cpuc = &__get_cpu_var(cpu_hw_events);
for (idx = 0; idx <= armpmu->num_events; ++idx) {
struct perf_event *event = cpuc->events[idx];
struct hw_perf_event *hwc;
if (!test_bit(idx, cpuc->active_mask))
continue;
/*
* We have a single interrupt for all counters. Check that
* each counter has overflowed before we process it.
*/
if (!armv6_pmcr_counter_has_overflowed(pmcr, idx))
continue;
hwc = &event->hw;
armpmu_event_update(event, hwc, idx);
data.period = event->hw.last_period;
if (!armpmu_event_set_period(event, hwc, idx))
continue;
if (perf_event_overflow(event, 0, &data, regs))
armpmu->disable(hwc, idx);
}
/*
* Handle the pending perf events.
*
* Note: this call *must* be run with interrupts enabled. For
* platforms that can have the PMU interrupts raised as a PMI, this
* will not work.
*/
perf_event_do_pending();
return IRQ_HANDLED;
}
static void
armv6pmu_start(void)
{
unsigned long flags, val;
spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val |= ARMV6_PMCR_ENABLE;
armv6_pmcr_write(val);
spin_unlock_irqrestore(&pmu_lock, flags);
}
void
armv6pmu_stop(void)
{
unsigned long flags, val;
spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~ARMV6_PMCR_ENABLE;
armv6_pmcr_write(val);
spin_unlock_irqrestore(&pmu_lock, flags);
}
static inline int
armv6pmu_event_map(int config)
{
int mapping = armv6_perf_map[config];
if (HW_OP_UNSUPPORTED == mapping)
mapping = -EOPNOTSUPP;
return mapping;
}
static inline int
armv6mpcore_pmu_event_map(int config)
{
int mapping = armv6mpcore_perf_map[config];
if (HW_OP_UNSUPPORTED == mapping)
mapping = -EOPNOTSUPP;
return mapping;
}
static u64
armv6pmu_raw_event(u64 config)
{
return config & 0xff;
}
static int
armv6pmu_get_event_idx(struct cpu_hw_events *cpuc,
struct hw_perf_event *event)
{
/* Always place a cycle counter into the cycle counter. */
if (ARMV6_PERFCTR_CPU_CYCLES == event->config_base) {
if (test_and_set_bit(ARMV6_CYCLE_COUNTER, cpuc->used_mask))
return -EAGAIN;
return ARMV6_CYCLE_COUNTER;
} else {
/*
* For anything other than a cycle counter, try and use
* counter0 and counter1.
*/
if (!test_and_set_bit(ARMV6_COUNTER1, cpuc->used_mask)) {
return ARMV6_COUNTER1;
}
if (!test_and_set_bit(ARMV6_COUNTER0, cpuc->used_mask)) {
return ARMV6_COUNTER0;
}
/* The counters are all in use. */
return -EAGAIN;
}
}
static void
armv6pmu_disable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, evt, flags;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = ARMV6_PMCR_CCOUNT_IEN;
evt = 0;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_COUNT0_IEN | ARMV6_PMCR_EVT_COUNT0_MASK;
evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT0_SHIFT;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_COUNT1_IEN | ARMV6_PMCR_EVT_COUNT1_MASK;
evt = ARMV6_PERFCTR_NOP << ARMV6_PMCR_EVT_COUNT1_SHIFT;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Mask out the current event and set the counter to count the number
* of ETM bus signal assertion cycles. The external reporting should
* be disabled and so this should never increment.
*/
spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
spin_unlock_irqrestore(&pmu_lock, flags);
}
static void
armv6mpcore_pmu_disable_event(struct hw_perf_event *hwc,
int idx)
{
unsigned long val, mask, flags, evt = 0;
if (ARMV6_CYCLE_COUNTER == idx) {
mask = ARMV6_PMCR_CCOUNT_IEN;
} else if (ARMV6_COUNTER0 == idx) {
mask = ARMV6_PMCR_COUNT0_IEN;
} else if (ARMV6_COUNTER1 == idx) {
mask = ARMV6_PMCR_COUNT1_IEN;
} else {
WARN_ONCE(1, "invalid counter number (%d)\n", idx);
return;
}
/*
* Unlike UP ARMv6, we don't have a way of stopping the counters. We
* simply disable the interrupt reporting.
*/
spin_lock_irqsave(&pmu_lock, flags);
val = armv6_pmcr_read();
val &= ~mask;
val |= evt;
armv6_pmcr_write(val);
spin_unlock_irqrestore(&pmu_lock, flags);
}
static const struct arm_pmu armv6pmu = {
.name = "v6",
.handle_irq = armv6pmu_handle_irq,
.enable = armv6pmu_enable_event,
.disable = armv6pmu_disable_event,
.event_map = armv6pmu_event_map,
.raw_event = armv6pmu_raw_event,
.read_counter = armv6pmu_read_counter,
.write_counter = armv6pmu_write_counter,
.get_event_idx = armv6pmu_get_event_idx,
.start = armv6pmu_start,
.stop = armv6pmu_stop,
.num_events = 3,
.max_period = (1LLU << 32) - 1,
};
/*
* ARMv6mpcore is almost identical to single core ARMv6 with the exception
* that some of the events have different enumerations and that there is no
* *hack* to stop the programmable counters. To stop the counters we simply
* disable the interrupt reporting and update the event. When unthrottling we
* reset the period and enable the interrupt reporting.
*/
static const struct arm_pmu armv6mpcore_pmu = {
.name = "v6mpcore",
.handle_irq = armv6pmu_handle_irq,
.enable = armv6pmu_enable_event,
.disable = armv6mpcore_pmu_disable_event,
.event_map = armv6mpcore_pmu_event_map,
.raw_event = armv6pmu_raw_event,
.read_counter = armv6pmu_read_counter,
.write_counter = armv6pmu_write_counter,
.get_event_idx = armv6pmu_get_event_idx,
.start = armv6pmu_start,
.stop = armv6pmu_stop,
.num_events = 3,
.max_period = (1LLU << 32) - 1,
};
static int __init
init_hw_perf_events(void)
{
unsigned long cpuid = read_cpuid_id();
unsigned long implementor = (cpuid & 0xFF000000) >> 24;
unsigned long part_number = (cpuid & 0xFFF0);
/* We only support ARM CPUs implemented by ARM at the moment. */
if (0x41 == implementor) {
switch (part_number) {
case 0xB360: /* ARM1136 */
case 0xB560: /* ARM1156 */
case 0xB760: /* ARM1176 */
armpmu = &armv6pmu;
memcpy(armpmu_perf_cache_map, armv6_perf_cache_map,
sizeof(armv6_perf_cache_map));
perf_max_events = armv6pmu.num_events;
break;
case 0xB020: /* ARM11mpcore */
armpmu = &armv6mpcore_pmu;
memcpy(armpmu_perf_cache_map,
armv6mpcore_perf_cache_map,
sizeof(armv6mpcore_perf_cache_map));
perf_max_events = armv6mpcore_pmu.num_events;
break;
default:
pr_info("no hardware support available\n");
perf_max_events = -1;
}
}
if (armpmu)
pr_info("enabled with %s PMU driver\n",
armpmu->name);
return 0;
}
arch_initcall(init_hw_perf_events);
/*
* Callchain handling code.
*/
static inline void
callchain_store(struct perf_callchain_entry *entry,
u64 ip)
{
if (entry->nr < PERF_MAX_STACK_DEPTH)
entry->ip[entry->nr++] = ip;
}
/*
* The registers we're interested in are at the end of the variable
* length saved register structure. The fp points at the end of this
* structure so the address of this struct is:
* (struct frame_tail *)(xxx->fp)-1
*
* This code has been adapted from the ARM OProfile support.
*/
struct frame_tail {
struct frame_tail *fp;
unsigned long sp;
unsigned long lr;
} __attribute__((packed));
/*
* Get the return address for a single stackframe and return a pointer to the
* next frame tail.
*/
static struct frame_tail *
user_backtrace(struct frame_tail *tail,
struct perf_callchain_entry *entry)
{
struct frame_tail buftail;
/* Also check accessibility of one struct frame_tail beyond */
if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
return NULL;
if (__copy_from_user_inatomic(&buftail, tail, sizeof(buftail)))
return NULL;
callchain_store(entry, buftail.lr);
/*
* Frame pointers should strictly progress back up the stack
* (towards higher addresses).
*/
if (tail >= buftail.fp)
return NULL;
return buftail.fp - 1;
}
static void
perf_callchain_user(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
struct frame_tail *tail;
callchain_store(entry, PERF_CONTEXT_USER);
if (!user_mode(regs))
regs = task_pt_regs(current);
tail = (struct frame_tail *)regs->ARM_fp - 1;
while (tail && !((unsigned long)tail & 0x3))
tail = user_backtrace(tail, entry);
}
/*
* Gets called by walk_stackframe() for every stackframe. This will be called
* whist unwinding the stackframe and is like a subroutine return so we use
* the PC.
*/
static int
callchain_trace(struct stackframe *fr,
void *data)
{
struct perf_callchain_entry *entry = data;
callchain_store(entry, fr->pc);
return 0;
}
static void
perf_callchain_kernel(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
struct stackframe fr;
callchain_store(entry, PERF_CONTEXT_KERNEL);
fr.fp = regs->ARM_fp;
fr.sp = regs->ARM_sp;
fr.lr = regs->ARM_lr;
fr.pc = regs->ARM_pc;
walk_stackframe(&fr, callchain_trace, entry);
}
static void
perf_do_callchain(struct pt_regs *regs,
struct perf_callchain_entry *entry)
{
int is_user;
if (!regs)
return;
is_user = user_mode(regs);
if (!current || !current->pid)
return;
if (is_user && current->state != TASK_RUNNING)
return;
if (!is_user)
perf_callchain_kernel(regs, entry);
if (current->mm)
perf_callchain_user(regs, entry);
}
static DEFINE_PER_CPU(struct perf_callchain_entry, pmc_irq_entry);
struct perf_callchain_entry *
perf_callchain(struct pt_regs *regs)
{
struct perf_callchain_entry *entry = &__get_cpu_var(pmc_irq_entry);
entry->nr = 0;
perf_do_callchain(regs, entry);
return entry;
}
