[Intel-gfx] [PATCH v5 1/7] drm/i915/pmu: Change bitmask of enabled events to u32

Umesh Nerlige Ramappa
2023-05-16T23:35:45Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Having it as u64 was a confusing (but harmless) mistake.

Also add some asserts to make sure the internal field does not overflow
in the future.

v2: Fix WARN_ON firing for INTERRUPT event (Umesh)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
---
drivers/gpu/drm/i915/i915_pmu.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index 7ece883a7d95..96543dce2db1 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -50,7 +50,7 @@ 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)
+static bool is_engine_config(const u64 config)
{
return config < __I915_PMU_OTHER(0);
}
@@ -88,9 +88,20 @@ static unsigned int config_bit(const u64 config)
return other_bit(config);
}

-static u64 config_mask(u64 config)
+static u32 config_mask(const u64 config)
{
- return BIT_ULL(config_bit(config));
+ unsigned int bit = config_bit(config);
+
+ if (__builtin_constant_p(config))
+ BUILD_BUG_ON(bit >
+ BITS_PER_TYPE(typeof_member(struct i915_pmu,
+ enable)) - 1);
+ else
+ WARN_ON_ONCE(bit >
+ BITS_PER_TYPE(typeof_member(struct i915_pmu,
+ enable)) - 1);
+
+ return BIT(config_bit(config));
}

static bool is_engine_event(struct perf_event *event)
@@ -633,11 +644,10 @@ static void i915_pmu_enable(struct perf_event *event)
{
struct drm_i915_private *i915 =
container_of(event->pmu, typeof(*i915), pmu.base);
+ const unsigned int bit = event_bit(event);
struct i915_pmu *pmu = &i915->pmu;
unsigned long flags;
- unsigned int bit;

- bit = event_bit(event);
if (bit == -1)
goto update;

@@ -651,7 +661,7 @@ static void i915_pmu_enable(struct perf_event *event)
GEM_BUG_ON(bit >= ARRAY_SIZE(pmu->enable_count));
GEM_BUG_ON(pmu->enable_count[bit] == ~0);

- pmu->enable |= BIT_ULL(bit);
+ pmu->enable |= BIT(bit);
pmu->enable_count[bit]++;

/*
@@ -698,7 +708,7 @@ 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_bit(event);
+ const unsigned int bit = event_bit(event);
struct i915_pmu *pmu = &i915->pmu;
unsigned long flags;

@@ -734,7 +744,7 @@ static void i915_pmu_disable(struct perf_event *event)
* bitmask when the last listener on an event goes away.
*/
if (--pmu->enable_count[bit] == 0) {
- pmu->enable &= ~BIT_ULL(bit);
+ pmu->enable &= ~BIT(bit);
pmu->timer_enabled &= pmu_needs_timer(pmu, true);
}

--
2.36.1