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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-12-10 22:25:50 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-12-15 18:19:32 +0300 |
| commit | 9c6508b9d2091d14a8fde5d478e19e053bf46552 (patch) | |
| tree | 3064a13b9b1f04077fa7c6bf0b6ed6b7f1c30a88 /drivers/gpu/drm/i915/i915_pmu.c | |
| parent | 3afba095158269c281c49518f49da5a702878919 (diff) | |
| download | linux-9c6508b9d2091d14a8fde5d478e19e053bf46552.tar.xz | |
drm/i915/pmu: Replace open coded kstat_irqs() copy
Driver code has no business with the internals of the irq descriptor.
Aside of that the count is per interrupt line and therefore takes
interrupts from other devices into account which share the interrupt line
and are not handled by the graphics driver.
Replace it with a pmu private count which only counts interrupts which
originate from the graphics card.
To avoid atomics or heuristics of some sort make the counter field
'unsigned long'. That limits the count to 4e9 on 32bit which is a lot and
postprocessing can easily deal with the occasional wraparound.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Link: https://lore.kernel.org/r/20201210194043.957046529@linutronix.de
Diffstat (limited to 'drivers/gpu/drm/i915/i915_pmu.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_pmu.c | 19 |
1 files changed, 1 insertions, 18 deletions
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 69c0fa20eba1..3b88cb01b4da 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -4,7 +4,6 @@ * Copyright © 2017-2018 Intel Corporation */ -#include <linux/irq.h> #include <linux/pm_runtime.h> #include "gt/intel_engine.h" @@ -423,22 +422,6 @@ static enum hrtimer_restart i915_sample(struct hrtimer *hrtimer) 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) { struct drm_i915_private *i915 = @@ -581,7 +564,7 @@ static u64 __i915_pmu_event_read(struct perf_event *event) USEC_PER_SEC /* to MHz */); break; case I915_PMU_INTERRUPTS: - val = count_interrupts(i915); + val = READ_ONCE(pmu->irq_count); break; case I915_PMU_RC6_RESIDENCY: val = get_rc6(&i915->gt); |