On Tue, May 16, 2023 at 10:24:45AM +0100, Tvrtko Ursulin wrote:
From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
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.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
---
I am not entirely sure the __builtin_constant_p->BUILD_BUG_ON branch will
work with all compilers. Lets see...
Compile tested only.
---
drivers/gpu/drm/i915/i915_pmu.c | 32 ++++++++++++++++++++++----------
1 file changed, 22 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index 7ece883a7d95..8736b3418f88 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);
}
@@ -82,15 +82,28 @@ static unsigned int other_bit(const u64 config)
static unsigned int config_bit(const u64 config)
{
+ unsigned int bit;
+
if (is_engine_config(config))
- return engine_config_sample(config);
+ bit = engine_config_sample(config);
else
- return other_bit(config);
+ bit = other_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);
The else is firing for the INTERRUPT event because event_bit() also
calls config_bit(). It would be best to move this check to config_mask()
and leave this function as is.
Thanks,
Umesh
+
+ return bit;
}
-static u64 config_mask(u64 config)
+static u32 config_mask(const u64 config)
{
- return BIT_ULL(config_bit(config));
+ return BIT(config_bit(config));
}
static bool is_engine_event(struct perf_event *event)
@@ -633,11 +646,10 @@ 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 +663,7 @@ 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 +710,7 @@ 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 +746,7 @@ 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);
}
--
2.39.2
