- 根目录:
- arch
- metag
- kernel
- perf
- perf_event.c
/*
* Meta performance counter support.
* Copyright (C) 2012 Imagination Technologies Ltd
*
* This code is based on the sh pmu code:
* Copyright (C) 2009 Paul Mundt
*
* and on the arm pmu code:
* Copyright (C) 2009 picoChip Designs, Ltd., James Iles
* Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/atomic.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/irqchip/metag.h>
#include <linux/perf_event.h>
#include <linux/slab.h>
#include <asm/core_reg.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/processor.h>
#include "perf_event.h"
static int _hw_perf_event_init(struct perf_event *);
static void _hw_perf_event_destroy(struct perf_event *);
/* Determines which core type we are */
static struct metag_pmu *metag_pmu __read_mostly;
/* Processor specific data */
static DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events);
/* PMU admin */
const char *perf_pmu_name(void)
{
if (!metag_pmu)
return NULL;
return metag_pmu->name;
}
EXPORT_SYMBOL_GPL(perf_pmu_name);
int perf_num_counters(void)
{
if (metag_pmu)
return metag_pmu->max_events;
return 0;
}
EXPORT_SYMBOL_GPL(perf_num_counters);
static inline int metag_pmu_initialised(void)
{
return !!metag_pmu;
}
static void release_pmu_hardware(void)
{
int irq;
unsigned int version = (metag_pmu->version &
(METAC_ID_MINOR_BITS | METAC_ID_REV_BITS)) >>
METAC_ID_REV_S;
/* Early cores don't have overflow interrupts */
if (version < 0x0104)
return;
irq = internal_irq_map(17);
if (irq >= 0)
free_irq(irq, (void *)1);
irq = internal_irq_map(16);
if (irq >= 0)
free_irq(irq, (void *)0);
}
static int reserve_pmu_hardware(void)
{
int err = 0, irq[2];
unsigned int version = (metag_pmu->version &
(METAC_ID_MINOR_BITS | METAC_ID_REV_BITS)) >>
METAC_ID_REV_S;
/* Early cores don't have overflow interrupts */
if (version < 0x0104)
goto out;
/*
* Bit 16 on HWSTATMETA is the interrupt for performance counter 0;
* similarly, 17 is the interrupt for performance counter 1.
* We can't (yet) interrupt on the cycle counter, because it's a
* register, however it holds a 32-bit value as opposed to 24-bit.
*/
irq[0] = internal_irq_map(16);
if (irq[0] < 0) {
pr_err("unable to map internal IRQ %d\n", 16);
goto out;
}
err = request_irq(irq[0], metag_pmu->handle_irq, IRQF_NOBALANCING,
"metagpmu0", (void *)0);
if (err) {
pr_err("unable to request IRQ%d for metag PMU counters\n",
irq[0]);
goto out;
}
irq[1] = internal_irq_map(17);
if (irq[1] < 0) {
pr_err("unable to map internal IRQ %d\n", 17);
goto out_irq1;
}
err = request_irq(irq[1], metag_pmu->handle_irq, IRQF_NOBALANCING,
"metagpmu1", (void *)1);
if (err) {
pr_err("unable to request IRQ%d for metag PMU counters\n",
irq[1]);
goto out_irq1;
}
return 0;
out_irq1:
free_irq(irq[0], (void *)0);
out:
return err;
}
/* PMU operations */
static void metag_pmu_enable(struct pmu *pmu)
{
}
static void metag_pmu_disable(struct pmu *pmu)
{
}
static int metag_pmu_event_init(struct perf_event *event)
{
int err = 0;
atomic_t *active_events = &metag_pmu->active_events;
if (!metag_pmu_initialised()) {
err = -ENODEV;
goto out;
}
if (has_branch_stack(event))
return -EOPNOTSUPP;
event->destroy = _hw_perf_event_destroy;
if (!atomic_inc_not_zero(active_events)) {
mutex_lock(&metag_pmu->reserve_mutex);
if (atomic_read(active_events) == 0)
err = reserve_pmu_hardware();
if (!err)
atomic_inc(active_events);
mutex_unlock(&metag_pmu->reserve_mutex);
}
/* Hardware and caches counters */
switch (event->attr.type) {
case PERF_TYPE_HARDWARE:
case PERF_TYPE_HW_CACHE:
case PERF_TYPE_RAW:
err = _hw_perf_event_init(event);
break;
default:
return -ENOENT;
}
if (err)
event->destroy(event);
out:
return err;
}
void metag_pmu_event_update(struct perf_event *event,
struct hw_perf_event *hwc, int idx)
{
u64 prev_raw_count, new_raw_count;
s64 delta;
/*
* If this counter is chained, it may be that the previous counter
* value has been changed beneath us.
*
* To get around this, we read and exchange the new raw count, then
* add the delta (new - prev) to the generic counter atomically.
*
* Without interrupts, this is the simplest approach.
*/
again:
prev_raw_count = local64_read(&hwc->prev_count);
new_raw_count = metag_pmu->read(idx);
if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
new_raw_count) != prev_raw_count)
goto again;
/*
* Calculate the delta and add it to the counter.
*/
delta = (new_raw_count - prev_raw_count) & MAX_PERIOD;
local64_add(delta, &event->count);
local64_sub(delta, &hwc->period_left);
}
int metag_pmu_event_set_period(struct perf_event *event,
struct hw_perf_event *hwc, int idx)
{
s64 left = local64_read(&hwc->period_left);
s64 period = hwc->sample_period;
int ret = 0;
/* The period may have been changed */
if (unlikely(period != hwc->last_period))
left += period - hwc->last_period;
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 > (s64)metag_pmu->max_period)
left = metag_pmu->max_period;
if (metag_pmu->write) {
local64_set(&hwc->prev_count, -(s32)left);
metag_pmu->write(idx, -left & MAX_PERIOD);
}
perf_event_update_userpage(event);
return ret;
}
static void metag_pmu_start(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 (WARN_ON_ONCE(idx == -1))
return;
/*
* We always have to reprogram the period, so ignore PERF_EF_RELOAD.
*/
if (flags & PERF_EF_RELOAD)
WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
hwc->state = 0;
/*
* Reset the period.
* Some counters can't be stopped (i.e. are core global), so when the
* counter was 'stopped' we merely disabled the IRQ. If we don't reset
* the period, then we'll either: a) get an overflow too soon;
* or b) too late if the overflow happened since disabling.
* Obviously, this has little bearing on cores without the overflow
* interrupt, as the performance counter resets to zero on write
* anyway.
*/
if (metag_pmu->max_period)
metag_pmu_event_set_period(event, hwc, hwc->idx);
cpuc->events[idx] = event;
metag_pmu->enable(hwc, idx);
}
static void metag_pmu_stop(struct perf_event *event, int flags)
{
struct hw_perf_event *hwc = &event->hw;
/*
* We should always update the counter on stop; see comment above
* why.
*/
if (!(hwc->state & PERF_HES_STOPPED)) {
metag_pmu_event_update(event, hwc, hwc->idx);
metag_pmu->disable(hwc, hwc->idx);
hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
}
}
static int metag_pmu_add(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 = 0, ret = 0;
perf_pmu_disable(event->pmu);
/* check whether we're counting instructions */
if (hwc->config == 0x100) {
if (__test_and_set_bit(METAG_INST_COUNTER,
cpuc->used_mask)) {
ret = -EAGAIN;
goto out;
}
idx = METAG_INST_COUNTER;
} else {
/* Check whether we have a spare counter */
idx = find_first_zero_bit(cpuc->used_mask,
atomic_read(&metag_pmu->active_events));
if (idx >= METAG_INST_COUNTER) {
ret = -EAGAIN;
goto out;
}
__set_bit(idx, cpuc->used_mask);
}
hwc->idx = idx;
/* Make sure the counter is disabled */
metag_pmu->disable(hwc, idx);
hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
if (flags & PERF_EF_START)
metag_pmu_start(event, PERF_EF_RELOAD);
perf_event_update_userpage(event);
out:
perf_pmu_enable(event->pmu);
return ret;
}
static void metag_pmu_del(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;
WARN_ON(idx < 0);
metag_pmu_stop(event, PERF_EF_UPDATE);
cpuc->events[idx] = NULL;
__clear_bit(idx, cpuc->used_mask);
perf_event_update_userpage(event);
}
static void metag_pmu_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
/* Don't read disabled counters! */
if (hwc->idx < 0)
return;
metag_pmu_event_update(event, hwc, hwc->idx);
}
static struct pmu pmu = {
.pmu_enable = metag_pmu_enable,
.pmu_disable = metag_pmu_disable,
.event_init = metag_pmu_event_init,
.add = metag_pmu_add,
.del = metag_pmu_del,
.start = metag_pmu_start,
.stop = metag_pmu_stop,
.read = metag_pmu_read,
};
/* Core counter specific functions */
static const int metag_general_events[] = {
[PERF_COUNT_HW_CPU_CYCLES] = 0x03,
[PERF_COUNT_HW_INSTRUCTIONS] = 0x100,
[PERF_COUNT_HW_CACHE_REFERENCES] = -1,
[PERF_COUNT_HW_CACHE_MISSES] = -1,
[PERF_COUNT_HW_BRANCH_INSTRUCTIONS] = -1,
[PERF_COUNT_HW_BRANCH_MISSES] = -1,
[PERF_COUNT_HW_BUS_CYCLES] = -1,
[PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = -1,
[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = -1,
[PERF_COUNT_HW_REF_CPU_CYCLES] = -1,
};
static const int metag_pmu_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
[C(L1D)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x08,
[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(L1I)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0x09,
[C(RESULT_MISS)] = 0x0a,
},
[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(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)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0xd0,
[C(RESULT_MISS)] = 0xd2,
},
[C(OP_WRITE)] = {
[C(RESULT_ACCESS)] = 0xd4,
[C(RESULT_MISS)] = 0xd5,
},
[C(OP_PREFETCH)] = {
[C(RESULT_ACCESS)] = CACHE_OP_UNSUPPORTED,
[C(RESULT_MISS)] = CACHE_OP_UNSUPPORTED,
},
},
[C(ITLB)] = {
[C(OP_READ)] = {
[C(RESULT_ACCESS)] = 0xd1,
[C(RESULT_MISS)] = 0xd3,
},
[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(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,
},
},
[C(NODE)] = {
[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 void _hw_perf_event_destroy(struct perf_event *event)
{
atomic_t *active_events = &metag_pmu->active_events;
struct mutex *pmu_mutex = &metag_pmu->reserve_mutex;
if (atomic_dec_and_mutex_lock(active_events, pmu_mutex)) {
release_pmu_hardware();
mutex_unlock(pmu_mutex);
}
}
static int _hw_perf_cache_event(int config, int *evp)
{
unsigned long type, op, result;
int ev;
if (!metag_pmu->cache_events)
return -EINVAL;
/* Unpack config */
type = config & 0xff;
op = (config >> 8) & 0xff;
result = (config >> 16) & 0xff;
if (type >= PERF_COUNT_HW_CACHE_MAX ||
op >= PERF_COUNT_HW_CACHE_OP_MAX ||
result >= PERF_COUNT_HW_CACHE_RESULT_MAX)
return -EINVAL;
ev = (*metag_pmu->cache_events)[type][op][result];
if (ev == 0)
return -EOPNOTSUPP;
if (ev == -1)
return -EINVAL;
*evp = ev;
return 0;
}
static int _hw_perf_event_init(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
struct hw_perf_event *hwc = &event->hw;
int mapping = 0, err;
switch (attr->type) {
case PERF_TYPE_HARDWARE:
if (attr->config >= PERF_COUNT_HW_MAX)
return -EINVAL;
mapping = metag_pmu->event_map(attr->config);
break;
case PERF_TYPE_HW_CACHE:
err = _hw_perf_cache_event(attr->config, &mapping);
if (err)
return err;
break;
case PERF_TYPE_RAW:
mapping = attr->config;
break;
}
/* Return early if the event is unsupported */
if (mapping == -1)
return -EINVAL;
/*
* Don't assign an index until the event is placed into the hardware.
* -1 signifies that we're still deciding where to put it. On SMP
* systems each core has its own set of counters, so we can't do any
* constraint checking yet.
*/
hwc->idx = -1;
/* Store the event encoding */
hwc->config |= (unsigned long)mapping;
/*
* For non-sampling runs, limit the sample_period to half of the
* counter width. This way, the new counter value should be less
* likely to overtake the previous one (unless there are IRQ latency
* issues...)
*/
if (metag_pmu->max_period) {
if (!hwc->sample_period) {
hwc->sample_period = metag_pmu->max_period >> 1;
hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
}
}
return 0;
}
static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx)
{
struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
unsigned int config = event->config;
unsigned int tmp = config & 0xf0;
unsigned long flags;
raw_spin_lock_irqsave(&events->pmu_lock, flags);
/*
* Check if we're enabling the instruction counter (index of
* MAX_HWEVENTS - 1)
*/
if (METAG_INST_COUNTER == idx) {
WARN_ONCE((config != 0x100),
"invalid configuration (%d) for counter (%d)\n",
config, idx);
local64_set(&event->prev_count, __core_reg_get(TXTACTCYC));
goto unlock;
}
/* Check for a core internal or performance channel event. */
if (tmp) {
void *perf_addr;
/*
* Anything other than a cycle count will write the low-
* nibble to the correct counter register.
*/
switch (tmp) {
case 0xd0:
perf_addr = (void *)PERF_ICORE(idx);
break;
case 0xf0:
perf_addr = (void *)PERF_CHAN(idx);
break;
default:
perf_addr = NULL;
break;
}
if (perf_addr)
metag_out32((config & 0x0f), perf_addr);
/*
* Now we use the high nibble as the performance event to
* to count.
*/
config = tmp >> 4;
}
tmp = ((config & 0xf) << 28) |
((1 << 24) << hard_processor_id());
if (metag_pmu->max_period)
/*
* Cores supporting overflow interrupts may have had the counter
* set to a specific value that needs preserving.
*/
tmp |= metag_in32(PERF_COUNT(idx)) & 0x00ffffff;
else
/*
* Older cores reset the counter on write, so prev_count needs
* resetting too so we can calculate a correct delta.
*/
local64_set(&event->prev_count, 0);
metag_out32(tmp, PERF_COUNT(idx));
unlock:
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static void metag_pmu_disable_counter(struct hw_perf_event *event, int idx)
{
struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
unsigned int tmp = 0;
unsigned long flags;
/*
* The cycle counter can't be disabled per se, as it's a hardware
* thread register which is always counting. We merely return if this
* is the counter we're attempting to disable.
*/
if (METAG_INST_COUNTER == idx)
return;
/*
* The counter value _should_ have been read prior to disabling,
* as if we're running on an early core then the value gets reset to
* 0, and any read after that would be useless. On the newer cores,
* however, it's better to read-modify-update this for purposes of
* the overflow interrupt.
* Here we remove the thread id AND the event nibble (there are at
* least two events that count events that are core global and ignore
* the thread id mask). This only works because we don't mix thread
* performance counts, and event 0x00 requires a thread id mask!
*/
raw_spin_lock_irqsave(&events->pmu_lock, flags);
tmp = metag_in32(PERF_COUNT(idx));
tmp &= 0x00ffffff;
metag_out32(tmp, PERF_COUNT(idx));
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static u64 metag_pmu_read_counter(int idx)
{
u32 tmp = 0;
if (METAG_INST_COUNTER == idx) {
tmp = __core_reg_get(TXTACTCYC);
goto out;
}
tmp = metag_in32(PERF_COUNT(idx)) & 0x00ffffff;
out:
return tmp;
}
static void metag_pmu_write_counter(int idx, u32 val)
{
struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
u32 tmp = 0;
unsigned long flags;
/*
* This _shouldn't_ happen, but if it does, then we can just
* ignore the write, as the register is read-only and clear-on-write.
*/
if (METAG_INST_COUNTER == idx)
return;
/*
* We'll keep the thread mask and event id, and just update the
* counter itself. Also , we should bound the value to 24-bits.
*/
raw_spin_lock_irqsave(&events->pmu_lock, flags);
val &= 0x00ffffff;
tmp = metag_in32(PERF_COUNT(idx)) & 0xff000000;
val |= tmp;
metag_out32(val, PERF_COUNT(idx));
raw_spin_unlock_irqrestore(&events->pmu_lock, flags);
}
static int metag_pmu_event_map(int idx)
{
return metag_general_events[idx];
}
static irqreturn_t metag_pmu_counter_overflow(int irq, void *dev)
{
int idx = (int)dev;
struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
struct perf_event *event = cpuhw->events[idx];
struct hw_perf_event *hwc = &event->hw;
struct pt_regs *regs = get_irq_regs();
struct perf_sample_data sampledata;
unsigned long flags;
u32 counter = 0;
/*
* We need to stop the core temporarily from generating another
* interrupt while we disable this counter. However, we don't want
* to flag the counter as free
*/
__global_lock2(flags);
counter = metag_in32(PERF_COUNT(idx));
metag_out32((counter & 0x00ffffff), PERF_COUNT(idx));
__global_unlock2(flags);
/* Update the counts and reset the sample period */
metag_pmu_event_update(event, hwc, idx);
perf_sample_data_init(&sampledata, 0, hwc->last_period);
metag_pmu_event_set_period(event, hwc, idx);
/*
* Enable the counter again once core overflow processing has
* completed. Note the counter value may have been modified while it was
* inactive to set it up ready for the next interrupt.
*/
if (!perf_event_overflow(event, &sampledata, regs)) {
__global_lock2(flags);
counter = (counter & 0xff000000) |
(metag_in32(PERF_COUNT(idx)) & 0x00ffffff);
metag_out32(counter, PERF_COUNT(idx));
__global_unlock2(flags);
}
return IRQ_HANDLED;
}
static struct metag_pmu _metag_pmu = {
.handle_irq = metag_pmu_counter_overflow,
.enable = metag_pmu_enable_counter,
.disable = metag_pmu_disable_counter,
.read = metag_pmu_read_counter,
.write = metag_pmu_write_counter,
.event_map = metag_pmu_event_map,
.cache_events = &metag_pmu_cache_events,
.max_period = MAX_PERIOD,
.max_events = MAX_HWEVENTS,
};
/* PMU CPU hotplug notifier */
static int metag_pmu_cpu_notify(struct notifier_block *b, unsigned long action,
void *hcpu)
{
unsigned int cpu = (unsigned int)hcpu;
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
return NOTIFY_DONE;
memset(cpuc, 0, sizeof(struct cpu_hw_events));
raw_spin_lock_init(&cpuc->pmu_lock);
return NOTIFY_OK;
}
static struct notifier_block metag_pmu_notifier = {
.notifier_call = metag_pmu_cpu_notify,
};
/* PMU Initialisation */
static int __init init_hw_perf_events(void)
{
int ret = 0, cpu;
u32 version = *(u32 *)METAC_ID;
int major = (version & METAC_ID_MAJOR_BITS) >> METAC_ID_MAJOR_S;
int min_rev = (version & (METAC_ID_MINOR_BITS | METAC_ID_REV_BITS))
>> METAC_ID_REV_S;
/* Not a Meta 2 core, then not supported */
if (0x02 > major) {
pr_info("no hardware counter support available\n");
goto out;
} else if (0x02 == major) {
metag_pmu = &_metag_pmu;
if (min_rev < 0x0104) {
/*
* A core without overflow interrupts, and clear-on-
* write counters.
*/
metag_pmu->handle_irq = NULL;
metag_pmu->write = NULL;
metag_pmu->max_period = 0;
}
metag_pmu->name = "meta2";
metag_pmu->version = version;
metag_pmu->pmu = pmu;
}
pr_info("enabled with %s PMU driver, %d counters available\n",
metag_pmu->name, metag_pmu->max_events);
/*
* Early cores have "limited" counters - they have no overflow
* interrupts - and so are unable to do sampling without extra work
* and timer assistance.
*/
if (metag_pmu->max_period == 0) {
metag_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
}
/* Initialise the active events and reservation mutex */
atomic_set(&metag_pmu->active_events, 0);
mutex_init(&metag_pmu->reserve_mutex);
/* Clear the counters */
metag_out32(0, PERF_COUNT(0));
metag_out32(0, PERF_COUNT(1));
for_each_possible_cpu(cpu) {
struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
memset(cpuc, 0, sizeof(struct cpu_hw_events));
raw_spin_lock_init(&cpuc->pmu_lock);
}
register_cpu_notifier(&metag_pmu_notifier);
ret = perf_pmu_register(&pmu, metag_pmu->name, PERF_TYPE_RAW);
out:
return ret;
}
early_initcall(init_hw_perf_events);