From: Rob Clark robdclark@chromium.org
Re-work the boost and idle clamping to use PM QoS requests instead, so they get aggreggated with other requests (such as cooling device).
This does have the minor side-effect that devfreq sysfs min_freq/ max_freq files now reflect the boost and idle clamping, as they show (despite what they are documented to show) the aggregated min/max freq. Fixing that in devfreq does not look straightforward after considering that OPPs can be dynamically added/removed. However writes to the sysfs files still behave as expected.
v2: Use 64b math to avoid potential 32b overflow
Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/msm_gpu.h | 33 +++++++--- drivers/gpu/drm/msm/msm_gpu_devfreq.c | 87 +++++++++++++++------------ 2 files changed, 71 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h index 59cdd00b69d0..96d8d37dd5b7 100644 --- a/drivers/gpu/drm/msm/msm_gpu.h +++ b/drivers/gpu/drm/msm/msm_gpu.h @@ -87,6 +87,21 @@ struct msm_gpu_devfreq { /** devfreq: devfreq instance */ struct devfreq *devfreq;
+ /** + * idle_constraint: + * + * A PM QoS constraint to limit max freq while the GPU is idle. + */ + struct dev_pm_qos_request idle_freq; + + /** + * boost_constraint: + * + * A PM QoS constraint to boost min freq for a period of time + * until the boost expires. + */ + struct dev_pm_qos_request boost_freq; + /** * busy_cycles: * @@ -103,22 +118,19 @@ struct msm_gpu_devfreq { ktime_t idle_time;
/** - * idle_freq: + * idle_work: * - * Shadow frequency used while the GPU is idle. From the PoV of - * the devfreq governor, we are continuing to sample busyness and - * adjust frequency while the GPU is idle, but we use this shadow - * value as the GPU is actually clamped to minimum frequency while - * it is inactive. + * Used to delay clamping to idle freq on active->idle transition. */ - unsigned long idle_freq; + struct msm_hrtimer_work idle_work;
/** - * idle_work: + * boost_work: * - * Used to delay clamping to idle freq on active->idle transition. + * Used to reset the boost_constraint after the boost period has + * elapsed */ - struct msm_hrtimer_work idle_work; + struct msm_hrtimer_work boost_work; };
struct msm_gpu { @@ -498,6 +510,7 @@ void msm_devfreq_init(struct msm_gpu *gpu); void msm_devfreq_cleanup(struct msm_gpu *gpu); void msm_devfreq_resume(struct msm_gpu *gpu); void msm_devfreq_suspend(struct msm_gpu *gpu); +void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor); void msm_devfreq_active(struct msm_gpu *gpu); void msm_devfreq_idle(struct msm_gpu *gpu);
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index 1f55242bb6a1..11be623de2ab 100644 --- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -9,6 +9,7 @@
#include <linux/devfreq.h> #include <linux/devfreq_cooling.h> +#include <linux/units.h>
/* * Power Management: @@ -22,15 +23,6 @@ static int msm_devfreq_target(struct device *dev, unsigned long *freq,
opp = devfreq_recommended_opp(dev, freq, flags);
- /* - * If the GPU is idle, devfreq is not aware, so just ignore - * it's requests - */ - if (gpu->devfreq.idle_freq) { - gpu->devfreq.idle_freq = *freq; - return 0; - } - if (IS_ERR(opp)) return PTR_ERR(opp);
@@ -48,9 +40,6 @@ static int msm_devfreq_target(struct device *dev, unsigned long *freq,
static unsigned long get_freq(struct msm_gpu *gpu) { - if (gpu->devfreq.idle_freq) - return gpu->devfreq.idle_freq; - if (gpu->funcs->gpu_get_freq) return gpu->funcs->gpu_get_freq(gpu);
@@ -88,6 +77,7 @@ static struct devfreq_dev_profile msm_devfreq_profile = { .get_cur_freq = msm_devfreq_get_cur_freq, };
+static void msm_devfreq_boost_work(struct kthread_work *work); static void msm_devfreq_idle_work(struct kthread_work *work);
void msm_devfreq_init(struct msm_gpu *gpu) @@ -98,6 +88,12 @@ void msm_devfreq_init(struct msm_gpu *gpu) if (!gpu->funcs->gpu_busy) return;
+ dev_pm_qos_add_request(&gpu->pdev->dev, &df->idle_freq, + DEV_PM_QOS_MAX_FREQUENCY, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); + dev_pm_qos_add_request(&gpu->pdev->dev, &df->boost_freq, + DEV_PM_QOS_MIN_FREQUENCY, 0); + msm_devfreq_profile.initial_freq = gpu->fast_rate;
/* @@ -128,13 +124,19 @@ void msm_devfreq_init(struct msm_gpu *gpu) gpu->cooling = NULL; }
+ msm_hrtimer_work_init(&df->boost_work, gpu->worker, msm_devfreq_boost_work, + CLOCK_MONOTONIC, HRTIMER_MODE_REL); msm_hrtimer_work_init(&df->idle_work, gpu->worker, msm_devfreq_idle_work, CLOCK_MONOTONIC, HRTIMER_MODE_REL); }
void msm_devfreq_cleanup(struct msm_gpu *gpu) { + struct msm_gpu_devfreq *df = &gpu->devfreq; + devfreq_cooling_unregister(gpu->cooling); + dev_pm_qos_remove_request(&df->boost_freq); + dev_pm_qos_remove_request(&df->idle_freq); }
void msm_devfreq_resume(struct msm_gpu *gpu) @@ -150,12 +152,40 @@ void msm_devfreq_suspend(struct msm_gpu *gpu) devfreq_suspend_device(gpu->devfreq.devfreq); }
+static void msm_devfreq_boost_work(struct kthread_work *work) +{ + struct msm_gpu_devfreq *df = container_of(work, + struct msm_gpu_devfreq, boost_work.work); + + dev_pm_qos_update_request(&df->boost_freq, 0); +} + +void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + uint64_t freq; + + freq = get_freq(gpu); + freq *= factor; + + /* + * A nice little trap is that PM QoS operates in terms of KHz, + * while devfreq operates in terms of Hz: + */ + do_div(freq, HZ_PER_KHZ); + + dev_pm_qos_update_request(&df->boost_freq, freq); + + msm_hrtimer_queue_work(&df->boost_work, + ms_to_ktime(msm_devfreq_profile.polling_ms), + HRTIMER_MODE_REL); +} + void msm_devfreq_active(struct msm_gpu *gpu) { struct msm_gpu_devfreq *df = &gpu->devfreq; struct devfreq_dev_status status; unsigned int idle_time; - unsigned long target_freq = df->idle_freq;
if (!df->devfreq) return; @@ -165,12 +195,6 @@ void msm_devfreq_active(struct msm_gpu *gpu) */ hrtimer_cancel(&df->idle_work.timer);
- /* - * Hold devfreq lock to synchronize with get_dev_status()/ - * target() callbacks - */ - mutex_lock(&df->devfreq->lock); - idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time));
/* @@ -179,20 +203,17 @@ void msm_devfreq_active(struct msm_gpu *gpu) * the governor to ramp up the freq.. so give some boost */ if (idle_time > msm_devfreq_profile.polling_ms) { - target_freq *= 2; + msm_devfreq_boost(gpu, 2); }
- df->idle_freq = 0; - - msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); + dev_pm_qos_update_request(&df->idle_freq, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
/* * Reset the polling interval so we aren't inconsistent * about freq vs busy/total cycles */ msm_devfreq_get_dev_status(&gpu->pdev->dev, &status); - - mutex_unlock(&df->devfreq->lock); }
@@ -201,23 +222,11 @@ static void msm_devfreq_idle_work(struct kthread_work *work) struct msm_gpu_devfreq *df = container_of(work, struct msm_gpu_devfreq, idle_work.work); struct msm_gpu *gpu = container_of(df, struct msm_gpu, devfreq); - unsigned long idle_freq, target_freq = 0; - - /* - * Hold devfreq lock to synchronize with get_dev_status()/ - * target() callbacks - */ - mutex_lock(&df->devfreq->lock); - - idle_freq = get_freq(gpu); - - if (gpu->clamp_to_idle) - msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0);
df->idle_time = ktime_get(); - df->idle_freq = idle_freq;
- mutex_unlock(&df->devfreq->lock); + if (gpu->clamp_to_idle) + dev_pm_qos_update_request(&df->idle_freq, 0); }
void msm_devfreq_idle(struct msm_gpu *gpu)