linux/drivers/gpu/drm/i915/i915_pmu.c
Arnd Bergmann 54a9adc460 drm/i915/pmu: avoid an maybe-uninitialized warning
Conditional spinlocks make it hard for gcc and for lockdep to
follow the code flow. This one causes a warning with at least
gcc-9 and higher:

In file included from include/linux/irq.h:14,
                 from drivers/gpu/drm/i915/i915_pmu.c:7:
drivers/gpu/drm/i915/i915_pmu.c: In function 'i915_sample':
include/linux/spinlock.h:289:3: error: 'flags' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  289 |   _raw_spin_unlock_irqrestore(lock, flags); \
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/i915_pmu.c:288:17: note: 'flags' was declared here
  288 |   unsigned long flags;
      |                 ^~~~~

Split out the part between the locks into a separate function
for readability and to let the compiler figure out what the
logic actually is.

Fixes: d79e1bd676 ("drm/i915/pmu: Only use exclusive mmio access for gen7")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200527140526.1458215-1-arnd@arndb.de
(cherry picked from commit 6ec81b8273)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
2020-06-15 12:36:02 +03:00

1177 lines
28 KiB
C

/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2017-2018 Intel Corporation
*/
#include <linux/irq.h>
#include <linux/pm_runtime.h>
#include "gt/intel_engine.h"
#include "gt/intel_engine_pm.h"
#include "gt/intel_engine_user.h"
#include "gt/intel_gt_pm.h"
#include "gt/intel_rc6.h"
#include "gt/intel_rps.h"
#include "i915_drv.h"
#include "i915_pmu.h"
#include "intel_pm.h"
/* Frequency for the sampling timer for events which need it. */
#define FREQUENCY 200
#define PERIOD max_t(u64, 10000, NSEC_PER_SEC / FREQUENCY)
#define ENGINE_SAMPLE_MASK \
(BIT(I915_SAMPLE_BUSY) | \
BIT(I915_SAMPLE_WAIT) | \
BIT(I915_SAMPLE_SEMA))
#define ENGINE_SAMPLE_BITS (1 << I915_PMU_SAMPLE_BITS)
static cpumask_t i915_pmu_cpumask;
static u8 engine_config_sample(u64 config)
{
return config & I915_PMU_SAMPLE_MASK;
}
static u8 engine_event_sample(struct perf_event *event)
{
return engine_config_sample(event->attr.config);
}
static u8 engine_event_class(struct perf_event *event)
{
return (event->attr.config >> I915_PMU_CLASS_SHIFT) & 0xff;
}
static u8 engine_event_instance(struct perf_event *event)
{
return (event->attr.config >> I915_PMU_SAMPLE_BITS) & 0xff;
}
static bool is_engine_config(u64 config)
{
return config < __I915_PMU_OTHER(0);
}
static unsigned int config_enabled_bit(u64 config)
{
if (is_engine_config(config))
return engine_config_sample(config);
else
return ENGINE_SAMPLE_BITS + (config - __I915_PMU_OTHER(0));
}
static u64 config_enabled_mask(u64 config)
{
return BIT_ULL(config_enabled_bit(config));
}
static bool is_engine_event(struct perf_event *event)
{
return is_engine_config(event->attr.config);
}
static unsigned int event_enabled_bit(struct perf_event *event)
{
return config_enabled_bit(event->attr.config);
}
static bool pmu_needs_timer(struct i915_pmu *pmu, bool gpu_active)
{
struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
u64 enable;
/*
* Only some counters need the sampling timer.
*
* We start with a bitmask of all currently enabled events.
*/
enable = pmu->enable;
/*
* Mask out all the ones which do not need the timer, or in
* other words keep all the ones that could need the timer.
*/
enable &= config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) |
config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY) |
ENGINE_SAMPLE_MASK;
/*
* When the GPU is idle per-engine counters do not need to be
* running so clear those bits out.
*/
if (!gpu_active)
enable &= ~ENGINE_SAMPLE_MASK;
/*
* Also there is software busyness tracking available we do not
* need the timer for I915_SAMPLE_BUSY counter.
*/
else if (i915->caps.scheduler & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
enable &= ~BIT(I915_SAMPLE_BUSY);
/*
* If some bits remain it means we need the sampling timer running.
*/
return enable;
}
static u64 __get_rc6(struct intel_gt *gt)
{
struct drm_i915_private *i915 = gt->i915;
u64 val;
val = intel_rc6_residency_ns(&gt->rc6,
IS_VALLEYVIEW(i915) ?
VLV_GT_RENDER_RC6 :
GEN6_GT_GFX_RC6);
if (HAS_RC6p(i915))
val += intel_rc6_residency_ns(&gt->rc6, GEN6_GT_GFX_RC6p);
if (HAS_RC6pp(i915))
val += intel_rc6_residency_ns(&gt->rc6, GEN6_GT_GFX_RC6pp);
return val;
}
#if IS_ENABLED(CONFIG_PM)
static inline s64 ktime_since(const ktime_t kt)
{
return ktime_to_ns(ktime_sub(ktime_get(), kt));
}
static u64 get_rc6(struct intel_gt *gt)
{
struct drm_i915_private *i915 = gt->i915;
struct i915_pmu *pmu = &i915->pmu;
unsigned long flags;
bool awake = false;
u64 val;
if (intel_gt_pm_get_if_awake(gt)) {
val = __get_rc6(gt);
intel_gt_pm_put_async(gt);
awake = true;
}
spin_lock_irqsave(&pmu->lock, flags);
if (awake) {
pmu->sample[__I915_SAMPLE_RC6].cur = val;
} else {
/*
* We think we are runtime suspended.
*
* Report the delta from when the device was suspended to now,
* on top of the last known real value, as the approximated RC6
* counter value.
*/
val = ktime_since(pmu->sleep_last);
val += pmu->sample[__I915_SAMPLE_RC6].cur;
}
if (val < pmu->sample[__I915_SAMPLE_RC6_LAST_REPORTED].cur)
val = pmu->sample[__I915_SAMPLE_RC6_LAST_REPORTED].cur;
else
pmu->sample[__I915_SAMPLE_RC6_LAST_REPORTED].cur = val;
spin_unlock_irqrestore(&pmu->lock, flags);
return val;
}
static void park_rc6(struct drm_i915_private *i915)
{
struct i915_pmu *pmu = &i915->pmu;
if (pmu->enable & config_enabled_mask(I915_PMU_RC6_RESIDENCY))
pmu->sample[__I915_SAMPLE_RC6].cur = __get_rc6(&i915->gt);
pmu->sleep_last = ktime_get();
}
#else
static u64 get_rc6(struct intel_gt *gt)
{
return __get_rc6(gt);
}
static void park_rc6(struct drm_i915_private *i915) {}
#endif
static void __i915_pmu_maybe_start_timer(struct i915_pmu *pmu)
{
if (!pmu->timer_enabled && pmu_needs_timer(pmu, true)) {
pmu->timer_enabled = true;
pmu->timer_last = ktime_get();
hrtimer_start_range_ns(&pmu->timer,
ns_to_ktime(PERIOD), 0,
HRTIMER_MODE_REL_PINNED);
}
}
void i915_pmu_gt_parked(struct drm_i915_private *i915)
{
struct i915_pmu *pmu = &i915->pmu;
if (!pmu->base.event_init)
return;
spin_lock_irq(&pmu->lock);
park_rc6(i915);
/*
* Signal sampling timer to stop if only engine events are enabled and
* GPU went idle.
*/
pmu->timer_enabled = pmu_needs_timer(pmu, false);
spin_unlock_irq(&pmu->lock);
}
void i915_pmu_gt_unparked(struct drm_i915_private *i915)
{
struct i915_pmu *pmu = &i915->pmu;
if (!pmu->base.event_init)
return;
spin_lock_irq(&pmu->lock);
/*
* Re-enable sampling timer when GPU goes active.
*/
__i915_pmu_maybe_start_timer(pmu);
spin_unlock_irq(&pmu->lock);
}
static void
add_sample(struct i915_pmu_sample *sample, u32 val)
{
sample->cur += val;
}
static bool exclusive_mmio_access(const struct drm_i915_private *i915)
{
/*
* We have to avoid concurrent mmio cache line access on gen7 or
* risk a machine hang. For a fun history lesson dig out the old
* userspace intel_gpu_top and run it on Ivybridge or Haswell!
*/
return IS_GEN(i915, 7);
}
static void engine_sample(struct intel_engine_cs *engine, unsigned int period_ns)
{
struct intel_engine_pmu *pmu = &engine->pmu;
bool busy;
u32 val;
val = ENGINE_READ_FW(engine, RING_CTL);
if (val == 0) /* powerwell off => engine idle */
return;
if (val & RING_WAIT)
add_sample(&pmu->sample[I915_SAMPLE_WAIT], period_ns);
if (val & RING_WAIT_SEMAPHORE)
add_sample(&pmu->sample[I915_SAMPLE_SEMA], period_ns);
/* No need to sample when busy stats are supported. */
if (intel_engine_supports_stats(engine))
return;
/*
* While waiting on a semaphore or event, MI_MODE reports the
* ring as idle. However, previously using the seqno, and with
* execlists sampling, we account for the ring waiting as the
* engine being busy. Therefore, we record the sample as being
* busy if either waiting or !idle.
*/
busy = val & (RING_WAIT_SEMAPHORE | RING_WAIT);
if (!busy) {
val = ENGINE_READ_FW(engine, RING_MI_MODE);
busy = !(val & MODE_IDLE);
}
if (busy)
add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns);
}
static void
engines_sample(struct intel_gt *gt, unsigned int period_ns)
{
struct drm_i915_private *i915 = gt->i915;
struct intel_engine_cs *engine;
enum intel_engine_id id;
unsigned long flags;
if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0)
return;
if (!intel_gt_pm_is_awake(gt))
return;
for_each_engine(engine, gt, id) {
if (!intel_engine_pm_get_if_awake(engine))
continue;
if (exclusive_mmio_access(i915)) {
spin_lock_irqsave(&engine->uncore->lock, flags);
engine_sample(engine, period_ns);
spin_unlock_irqrestore(&engine->uncore->lock, flags);
} else {
engine_sample(engine, period_ns);
}
intel_engine_pm_put_async(engine);
}
}
static void
add_sample_mult(struct i915_pmu_sample *sample, u32 val, u32 mul)
{
sample->cur += mul_u32_u32(val, mul);
}
static bool frequency_sampling_enabled(struct i915_pmu *pmu)
{
return pmu->enable &
(config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY) |
config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY));
}
static void
frequency_sample(struct intel_gt *gt, unsigned int period_ns)
{
struct drm_i915_private *i915 = gt->i915;
struct intel_uncore *uncore = gt->uncore;
struct i915_pmu *pmu = &i915->pmu;
struct intel_rps *rps = &gt->rps;
if (!frequency_sampling_enabled(pmu))
return;
/* Report 0/0 (actual/requested) frequency while parked. */
if (!intel_gt_pm_get_if_awake(gt))
return;
if (pmu->enable & config_enabled_mask(I915_PMU_ACTUAL_FREQUENCY)) {
u32 val;
/*
* We take a quick peek here without using forcewake
* so that we don't perturb the system under observation
* (forcewake => !rc6 => increased power use). We expect
* that if the read fails because it is outside of the
* mmio power well, then it will return 0 -- in which
* case we assume the system is running at the intended
* frequency. Fortunately, the read should rarely fail!
*/
val = intel_uncore_read_fw(uncore, GEN6_RPSTAT1);
if (val)
val = intel_rps_get_cagf(rps, val);
else
val = rps->cur_freq;
add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_ACT],
intel_gpu_freq(rps, val), period_ns / 1000);
}
if (pmu->enable & config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY)) {
add_sample_mult(&pmu->sample[__I915_SAMPLE_FREQ_REQ],
intel_gpu_freq(rps, rps->cur_freq),
period_ns / 1000);
}
intel_gt_pm_put_async(gt);
}
static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer)
{
struct drm_i915_private *i915 =
container_of(hrtimer, struct drm_i915_private, pmu.timer);
struct i915_pmu *pmu = &i915->pmu;
struct intel_gt *gt = &i915->gt;
unsigned int period_ns;
ktime_t now;
if (!READ_ONCE(pmu->timer_enabled))
return HRTIMER_NORESTART;
now = ktime_get();
period_ns = ktime_to_ns(ktime_sub(now, pmu->timer_last));
pmu->timer_last = now;
/*
* Strictly speaking the passed in period may not be 100% accurate for
* all internal calculation, since some amount of time can be spent on
* grabbing the forcewake. However the potential error from timer call-
* back delay greatly dominates this so we keep it simple.
*/
engines_sample(gt, period_ns);
frequency_sample(gt, period_ns);
hrtimer_forward(hrtimer, now, ns_to_ktime(PERIOD));
return HRTIMER_RESTART;
}
static u64 count_interrupts(struct drm_i915_private *i915)
{
/* open-coded kstat_irqs() */
struct irq_desc *desc = irq_to_desc(i915->drm.pdev->irq);
u64 sum = 0;
int cpu;
if (!desc || !desc->kstat_irqs)
return 0;
for_each_possible_cpu(cpu)
sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
return sum;
}
static void i915_pmu_event_destroy(struct perf_event *event)
{
WARN_ON(event->parent);
module_put(THIS_MODULE);
}
static int
engine_event_status(struct intel_engine_cs *engine,
enum drm_i915_pmu_engine_sample sample)
{
switch (sample) {
case I915_SAMPLE_BUSY:
case I915_SAMPLE_WAIT:
break;
case I915_SAMPLE_SEMA:
if (INTEL_GEN(engine->i915) < 6)
return -ENODEV;
break;
default:
return -ENOENT;
}
return 0;
}
static int
config_status(struct drm_i915_private *i915, u64 config)
{
switch (config) {
case I915_PMU_ACTUAL_FREQUENCY:
if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
/* Requires a mutex for sampling! */
return -ENODEV;
/* Fall-through. */
case I915_PMU_REQUESTED_FREQUENCY:
if (INTEL_GEN(i915) < 6)
return -ENODEV;
break;
case I915_PMU_INTERRUPTS:
break;
case I915_PMU_RC6_RESIDENCY:
if (!HAS_RC6(i915))
return -ENODEV;
break;
default:
return -ENOENT;
}
return 0;
}
static int engine_event_init(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
struct intel_engine_cs *engine;
engine = intel_engine_lookup_user(i915, engine_event_class(event),
engine_event_instance(event));
if (!engine)
return -ENODEV;
return engine_event_status(engine, engine_event_sample(event));
}
static int i915_pmu_event_init(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
int ret;
if (event->attr.type != event->pmu->type)
return -ENOENT;
/* unsupported modes and filters */
if (event->attr.sample_period) /* no sampling */
return -EINVAL;
if (has_branch_stack(event))
return -EOPNOTSUPP;
if (event->cpu < 0)
return -EINVAL;
/* only allow running on one cpu at a time */
if (!cpumask_test_cpu(event->cpu, &i915_pmu_cpumask))
return -EINVAL;
if (is_engine_event(event))
ret = engine_event_init(event);
else
ret = config_status(i915, event->attr.config);
if (ret)
return ret;
if (!event->parent) {
__module_get(THIS_MODULE);
event->destroy = i915_pmu_event_destroy;
}
return 0;
}
static u64 __i915_pmu_event_read(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
struct i915_pmu *pmu = &i915->pmu;
u64 val = 0;
if (is_engine_event(event)) {
u8 sample = engine_event_sample(event);
struct intel_engine_cs *engine;
engine = intel_engine_lookup_user(i915,
engine_event_class(event),
engine_event_instance(event));
if (drm_WARN_ON_ONCE(&i915->drm, !engine)) {
/* Do nothing */
} else if (sample == I915_SAMPLE_BUSY &&
intel_engine_supports_stats(engine)) {
val = ktime_to_ns(intel_engine_get_busy_time(engine));
} else {
val = engine->pmu.sample[sample].cur;
}
} else {
switch (event->attr.config) {
case I915_PMU_ACTUAL_FREQUENCY:
val =
div_u64(pmu->sample[__I915_SAMPLE_FREQ_ACT].cur,
USEC_PER_SEC /* to MHz */);
break;
case I915_PMU_REQUESTED_FREQUENCY:
val =
div_u64(pmu->sample[__I915_SAMPLE_FREQ_REQ].cur,
USEC_PER_SEC /* to MHz */);
break;
case I915_PMU_INTERRUPTS:
val = count_interrupts(i915);
break;
case I915_PMU_RC6_RESIDENCY:
val = get_rc6(&i915->gt);
break;
}
}
return val;
}
static void i915_pmu_event_read(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
u64 prev, new;
again:
prev = local64_read(&hwc->prev_count);
new = __i915_pmu_event_read(event);
if (local64_cmpxchg(&hwc->prev_count, prev, new) != prev)
goto again;
local64_add(new - prev, &event->count);
}
static void i915_pmu_enable(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
unsigned int bit = event_enabled_bit(event);
struct i915_pmu *pmu = &i915->pmu;
intel_wakeref_t wakeref;
unsigned long flags;
wakeref = intel_runtime_pm_get(&i915->runtime_pm);
spin_lock_irqsave(&pmu->lock, flags);
/*
* Update the bitmask of enabled events and increment
* the event reference counter.
*/
BUILD_BUG_ON(ARRAY_SIZE(pmu->enable_count) != I915_PMU_MASK_BITS);
GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
GEM_BUG_ON(pmu->enable_count[bit] == ~0);
if (pmu->enable_count[bit] == 0 &&
config_enabled_mask(I915_PMU_RC6_RESIDENCY) & BIT_ULL(bit)) {
pmu->sample[__I915_SAMPLE_RC6_LAST_REPORTED].cur = 0;
pmu->sample[__I915_SAMPLE_RC6].cur = __get_rc6(&i915->gt);
pmu->sleep_last = ktime_get();
}
pmu->enable |= BIT_ULL(bit);
pmu->enable_count[bit]++;
/*
* Start the sampling timer if needed and not already enabled.
*/
__i915_pmu_maybe_start_timer(pmu);
/*
* For per-engine events the bitmask and reference counting
* is stored per engine.
*/
if (is_engine_event(event)) {
u8 sample = engine_event_sample(event);
struct intel_engine_cs *engine;
engine = intel_engine_lookup_user(i915,
engine_event_class(event),
engine_event_instance(event));
BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.enable_count) !=
I915_ENGINE_SAMPLE_COUNT);
BUILD_BUG_ON(ARRAY_SIZE(engine->pmu.sample) !=
I915_ENGINE_SAMPLE_COUNT);
GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
GEM_BUG_ON(engine->pmu.enable_count[sample] == ~0);
engine->pmu.enable |= BIT(sample);
engine->pmu.enable_count[sample]++;
}
spin_unlock_irqrestore(&pmu->lock, flags);
/*
* Store the current counter value so we can report the correct delta
* for all listeners. Even when the event was already enabled and has
* an existing non-zero value.
*/
local64_set(&event->hw.prev_count, __i915_pmu_event_read(event));
intel_runtime_pm_put(&i915->runtime_pm, wakeref);
}
static void i915_pmu_disable(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
unsigned int bit = event_enabled_bit(event);
struct i915_pmu *pmu = &i915->pmu;
unsigned long flags;
spin_lock_irqsave(&pmu->lock, flags);
if (is_engine_event(event)) {
u8 sample = engine_event_sample(event);
struct intel_engine_cs *engine;
engine = intel_engine_lookup_user(i915,
engine_event_class(event),
engine_event_instance(event));
GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.enable_count));
GEM_BUG_ON(sample >= ARRAY_SIZE(engine->pmu.sample));
GEM_BUG_ON(engine->pmu.enable_count[sample] == 0);
/*
* Decrement the reference count and clear the enabled
* bitmask when the last listener on an event goes away.
*/
if (--engine->pmu.enable_count[sample] == 0)
engine->pmu.enable &= ~BIT(sample);
}
GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
GEM_BUG_ON(pmu->enable_count[bit] == 0);
/*
* Decrement the reference count and clear the enabled
* bitmask when the last listener on an event goes away.
*/
if (--pmu->enable_count[bit] == 0) {
pmu->enable &= ~BIT_ULL(bit);
pmu->timer_enabled &= pmu_needs_timer(pmu, true);
}
spin_unlock_irqrestore(&pmu->lock, flags);
}
static void i915_pmu_event_start(struct perf_event *event, int flags)
{
i915_pmu_enable(event);
event->hw.state = 0;
}
static void i915_pmu_event_stop(struct perf_event *event, int flags)
{
if (flags & PERF_EF_UPDATE)
i915_pmu_event_read(event);
i915_pmu_disable(event);
event->hw.state = PERF_HES_STOPPED;
}
static int i915_pmu_event_add(struct perf_event *event, int flags)
{
if (flags & PERF_EF_START)
i915_pmu_event_start(event, flags);
return 0;
}
static void i915_pmu_event_del(struct perf_event *event, int flags)
{
i915_pmu_event_stop(event, PERF_EF_UPDATE);
}
static int i915_pmu_event_event_idx(struct perf_event *event)
{
return 0;
}
struct i915_str_attribute {
struct device_attribute attr;
const char *str;
};
static ssize_t i915_pmu_format_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i915_str_attribute *eattr;
eattr = container_of(attr, struct i915_str_attribute, attr);
return sprintf(buf, "%s\n", eattr->str);
}
#define I915_PMU_FORMAT_ATTR(_name, _config) \
(&((struct i915_str_attribute[]) { \
{ .attr = __ATTR(_name, 0444, i915_pmu_format_show, NULL), \
.str = _config, } \
})[0].attr.attr)
static struct attribute *i915_pmu_format_attrs[] = {
I915_PMU_FORMAT_ATTR(i915_eventid, "config:0-20"),
NULL,
};
static const struct attribute_group i915_pmu_format_attr_group = {
.name = "format",
.attrs = i915_pmu_format_attrs,
};
struct i915_ext_attribute {
struct device_attribute attr;
unsigned long val;
};
static ssize_t i915_pmu_event_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i915_ext_attribute *eattr;
eattr = container_of(attr, struct i915_ext_attribute, attr);
return sprintf(buf, "config=0x%lx\n", eattr->val);
}
static ssize_t
i915_pmu_get_attr_cpumask(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return cpumap_print_to_pagebuf(true, buf, &i915_pmu_cpumask);
}
static DEVICE_ATTR(cpumask, 0444, i915_pmu_get_attr_cpumask, NULL);
static struct attribute *i915_cpumask_attrs[] = {
&dev_attr_cpumask.attr,
NULL,
};
static const struct attribute_group i915_pmu_cpumask_attr_group = {
.attrs = i915_cpumask_attrs,
};
#define __event(__config, __name, __unit) \
{ \
.config = (__config), \
.name = (__name), \
.unit = (__unit), \
}
#define __engine_event(__sample, __name) \
{ \
.sample = (__sample), \
.name = (__name), \
}
static struct i915_ext_attribute *
add_i915_attr(struct i915_ext_attribute *attr, const char *name, u64 config)
{
sysfs_attr_init(&attr->attr.attr);
attr->attr.attr.name = name;
attr->attr.attr.mode = 0444;
attr->attr.show = i915_pmu_event_show;
attr->val = config;
return ++attr;
}
static struct perf_pmu_events_attr *
add_pmu_attr(struct perf_pmu_events_attr *attr, const char *name,
const char *str)
{
sysfs_attr_init(&attr->attr.attr);
attr->attr.attr.name = name;
attr->attr.attr.mode = 0444;
attr->attr.show = perf_event_sysfs_show;
attr->event_str = str;
return ++attr;
}
static struct attribute **
create_event_attributes(struct i915_pmu *pmu)
{
struct drm_i915_private *i915 = container_of(pmu, typeof(*i915), pmu);
static const struct {
u64 config;
const char *name;
const char *unit;
} events[] = {
__event(I915_PMU_ACTUAL_FREQUENCY, "actual-frequency", "M"),
__event(I915_PMU_REQUESTED_FREQUENCY, "requested-frequency", "M"),
__event(I915_PMU_INTERRUPTS, "interrupts", NULL),
__event(I915_PMU_RC6_RESIDENCY, "rc6-residency", "ns"),
};
static const struct {
enum drm_i915_pmu_engine_sample sample;
char *name;
} engine_events[] = {
__engine_event(I915_SAMPLE_BUSY, "busy"),
__engine_event(I915_SAMPLE_SEMA, "sema"),
__engine_event(I915_SAMPLE_WAIT, "wait"),
};
unsigned int count = 0;
struct perf_pmu_events_attr *pmu_attr = NULL, *pmu_iter;
struct i915_ext_attribute *i915_attr = NULL, *i915_iter;
struct attribute **attr = NULL, **attr_iter;
struct intel_engine_cs *engine;
unsigned int i;
/* Count how many counters we will be exposing. */
for (i = 0; i < ARRAY_SIZE(events); i++) {
if (!config_status(i915, events[i].config))
count++;
}
for_each_uabi_engine(engine, i915) {
for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
if (!engine_event_status(engine,
engine_events[i].sample))
count++;
}
}
/* Allocate attribute objects and table. */
i915_attr = kcalloc(count, sizeof(*i915_attr), GFP_KERNEL);
if (!i915_attr)
goto err_alloc;
pmu_attr = kcalloc(count, sizeof(*pmu_attr), GFP_KERNEL);
if (!pmu_attr)
goto err_alloc;
/* Max one pointer of each attribute type plus a termination entry. */
attr = kcalloc(count * 2 + 1, sizeof(*attr), GFP_KERNEL);
if (!attr)
goto err_alloc;
i915_iter = i915_attr;
pmu_iter = pmu_attr;
attr_iter = attr;
/* Initialize supported non-engine counters. */
for (i = 0; i < ARRAY_SIZE(events); i++) {
char *str;
if (config_status(i915, events[i].config))
continue;
str = kstrdup(events[i].name, GFP_KERNEL);
if (!str)
goto err;
*attr_iter++ = &i915_iter->attr.attr;
i915_iter = add_i915_attr(i915_iter, str, events[i].config);
if (events[i].unit) {
str = kasprintf(GFP_KERNEL, "%s.unit", events[i].name);
if (!str)
goto err;
*attr_iter++ = &pmu_iter->attr.attr;
pmu_iter = add_pmu_attr(pmu_iter, str, events[i].unit);
}
}
/* Initialize supported engine counters. */
for_each_uabi_engine(engine, i915) {
for (i = 0; i < ARRAY_SIZE(engine_events); i++) {
char *str;
if (engine_event_status(engine,
engine_events[i].sample))
continue;
str = kasprintf(GFP_KERNEL, "%s-%s",
engine->name, engine_events[i].name);
if (!str)
goto err;
*attr_iter++ = &i915_iter->attr.attr;
i915_iter =
add_i915_attr(i915_iter, str,
__I915_PMU_ENGINE(engine->uabi_class,
engine->uabi_instance,
engine_events[i].sample));
str = kasprintf(GFP_KERNEL, "%s-%s.unit",
engine->name, engine_events[i].name);
if (!str)
goto err;
*attr_iter++ = &pmu_iter->attr.attr;
pmu_iter = add_pmu_attr(pmu_iter, str, "ns");
}
}
pmu->i915_attr = i915_attr;
pmu->pmu_attr = pmu_attr;
return attr;
err:;
for (attr_iter = attr; *attr_iter; attr_iter++)
kfree((*attr_iter)->name);
err_alloc:
kfree(attr);
kfree(i915_attr);
kfree(pmu_attr);
return NULL;
}
static void free_event_attributes(struct i915_pmu *pmu)
{
struct attribute **attr_iter = pmu->events_attr_group.attrs;
for (; *attr_iter; attr_iter++)
kfree((*attr_iter)->name);
kfree(pmu->events_attr_group.attrs);
kfree(pmu->i915_attr);
kfree(pmu->pmu_attr);
pmu->events_attr_group.attrs = NULL;
pmu->i915_attr = NULL;
pmu->pmu_attr = NULL;
}
static int i915_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
{
struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
GEM_BUG_ON(!pmu->base.event_init);
/* Select the first online CPU as a designated reader. */
if (!cpumask_weight(&i915_pmu_cpumask))
cpumask_set_cpu(cpu, &i915_pmu_cpumask);
return 0;
}
static int i915_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
{
struct i915_pmu *pmu = hlist_entry_safe(node, typeof(*pmu), cpuhp.node);
unsigned int target;
GEM_BUG_ON(!pmu->base.event_init);
if (cpumask_test_and_clear_cpu(cpu, &i915_pmu_cpumask)) {
target = cpumask_any_but(topology_sibling_cpumask(cpu), cpu);
/* Migrate events if there is a valid target */
if (target < nr_cpu_ids) {
cpumask_set_cpu(target, &i915_pmu_cpumask);
perf_pmu_migrate_context(&pmu->base, cpu, target);
}
}
return 0;
}
static int i915_pmu_register_cpuhp_state(struct i915_pmu *pmu)
{
enum cpuhp_state slot;
int ret;
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
"perf/x86/intel/i915:online",
i915_pmu_cpu_online,
i915_pmu_cpu_offline);
if (ret < 0)
return ret;
slot = ret;
ret = cpuhp_state_add_instance(slot, &pmu->cpuhp.node);
if (ret) {
cpuhp_remove_multi_state(slot);
return ret;
}
pmu->cpuhp.slot = slot;
return 0;
}
static void i915_pmu_unregister_cpuhp_state(struct i915_pmu *pmu)
{
WARN_ON(pmu->cpuhp.slot == CPUHP_INVALID);
WARN_ON(cpuhp_state_remove_instance(pmu->cpuhp.slot, &pmu->cpuhp.node));
cpuhp_remove_multi_state(pmu->cpuhp.slot);
pmu->cpuhp.slot = CPUHP_INVALID;
}
static bool is_igp(struct drm_i915_private *i915)
{
struct pci_dev *pdev = i915->drm.pdev;
/* IGP is 0000:00:02.0 */
return pci_domain_nr(pdev->bus) == 0 &&
pdev->bus->number == 0 &&
PCI_SLOT(pdev->devfn) == 2 &&
PCI_FUNC(pdev->devfn) == 0;
}
void i915_pmu_register(struct drm_i915_private *i915)
{
struct i915_pmu *pmu = &i915->pmu;
const struct attribute_group *attr_groups[] = {
&i915_pmu_format_attr_group,
&pmu->events_attr_group,
&i915_pmu_cpumask_attr_group,
NULL
};
int ret = -ENOMEM;
if (INTEL_GEN(i915) <= 2) {
drm_info(&i915->drm, "PMU not supported for this GPU.");
return;
}
spin_lock_init(&pmu->lock);
hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
pmu->timer.function = i915_sample;
pmu->cpuhp.slot = CPUHP_INVALID;
if (!is_igp(i915)) {
pmu->name = kasprintf(GFP_KERNEL,
"i915_%s",
dev_name(i915->drm.dev));
if (pmu->name) {
/* tools/perf reserves colons as special. */
strreplace((char *)pmu->name, ':', '_');
}
} else {
pmu->name = "i915";
}
if (!pmu->name)
goto err;
pmu->events_attr_group.name = "events";
pmu->events_attr_group.attrs = create_event_attributes(pmu);
if (!pmu->events_attr_group.attrs)
goto err_name;
pmu->base.attr_groups = kmemdup(attr_groups, sizeof(attr_groups),
GFP_KERNEL);
if (!pmu->base.attr_groups)
goto err_attr;
pmu->base.task_ctx_nr = perf_invalid_context;
pmu->base.event_init = i915_pmu_event_init;
pmu->base.add = i915_pmu_event_add;
pmu->base.del = i915_pmu_event_del;
pmu->base.start = i915_pmu_event_start;
pmu->base.stop = i915_pmu_event_stop;
pmu->base.read = i915_pmu_event_read;
pmu->base.event_idx = i915_pmu_event_event_idx;
ret = perf_pmu_register(&pmu->base, pmu->name, -1);
if (ret)
goto err_groups;
ret = i915_pmu_register_cpuhp_state(pmu);
if (ret)
goto err_unreg;
return;
err_unreg:
perf_pmu_unregister(&pmu->base);
err_groups:
kfree(pmu->base.attr_groups);
err_attr:
pmu->base.event_init = NULL;
free_event_attributes(pmu);
err_name:
if (!is_igp(i915))
kfree(pmu->name);
err:
drm_notice(&i915->drm, "Failed to register PMU!\n");
}
void i915_pmu_unregister(struct drm_i915_private *i915)
{
struct i915_pmu *pmu = &i915->pmu;
if (!pmu->base.event_init)
return;
drm_WARN_ON(&i915->drm, pmu->enable);
hrtimer_cancel(&pmu->timer);
i915_pmu_unregister_cpuhp_state(pmu);
perf_pmu_unregister(&pmu->base);
pmu->base.event_init = NULL;
kfree(pmu->base.attr_groups);
if (!is_igp(i915))
kfree(pmu->name);
free_event_attributes(pmu);
}