diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_pmu.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_pmu.c | 74 |
1 files changed, 61 insertions, 13 deletions
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c index 6f09aa0be80a..28a82c849bac 100644 --- a/drivers/gpu/drm/i915/i915_pmu.c +++ b/drivers/gpu/drm/i915/i915_pmu.c @@ -259,6 +259,16 @@ 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 engines_sample(struct intel_gt *gt, unsigned int period_ns) { @@ -269,8 +279,12 @@ engines_sample(struct intel_gt *gt, unsigned int period_ns) if ((i915->pmu.enable & ENGINE_SAMPLE_MASK) == 0) return; + if (!intel_gt_pm_is_awake(gt)) + return; + for_each_engine(engine, gt, id) { struct intel_engine_pmu *pmu = &engine->pmu; + spinlock_t *mmio_lock; unsigned long flags; bool busy; u32 val; @@ -278,7 +292,12 @@ engines_sample(struct intel_gt *gt, unsigned int period_ns) if (!intel_engine_pm_get_if_awake(engine)) continue; - spin_lock_irqsave(&engine->uncore->lock, flags); + mmio_lock = NULL; + if (exclusive_mmio_access(i915)) + mmio_lock = &engine->uncore->lock; + + if (unlikely(mmio_lock)) + spin_lock_irqsave(mmio_lock, flags); val = ENGINE_READ_FW(engine, RING_CTL); if (val == 0) /* powerwell off => engine idle */ @@ -309,7 +328,8 @@ engines_sample(struct intel_gt *gt, unsigned int period_ns) add_sample(&pmu->sample[I915_SAMPLE_BUSY], period_ns); skip: - spin_unlock_irqrestore(&engine->uncore->lock, flags); + if (unlikely(mmio_lock)) + spin_unlock_irqrestore(mmio_lock, flags); intel_engine_pm_put_async(engine); } } @@ -320,6 +340,13 @@ 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) { @@ -328,19 +355,33 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns) struct i915_pmu *pmu = &i915->pmu; struct intel_rps *rps = >->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; - val = rps->cur_freq; - if (intel_gt_pm_get_if_awake(gt)) { - val = intel_uncore_read_notrace(uncore, GEN6_RPSTAT1); - val = intel_get_cagf(rps, val); - intel_gt_pm_put_async(gt); - } + /* + * 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); + intel_gpu_freq(rps, val), period_ns / 1000); } if (pmu->enable & config_enabled_mask(I915_PMU_REQUESTED_FREQUENCY)) { @@ -348,6 +389,8 @@ frequency_sample(struct intel_gt *gt, unsigned int period_ns) 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) @@ -1074,12 +1117,17 @@ void i915_pmu_register(struct drm_i915_private *i915) hrtimer_init(&pmu->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); pmu->timer.function = i915_sample; - if (!is_igp(i915)) + if (!is_igp(i915)) { pmu->name = kasprintf(GFP_KERNEL, - "i915-%s", + "i915_%s", dev_name(i915->drm.dev)); - else + if (pmu->name) { + /* tools/perf reserves colons as special. */ + strreplace((char *)pmu->name, ':', '_'); + } + } else { pmu->name = "i915"; + } if (!pmu->name) goto err; |