diff options
Diffstat (limited to 'drivers/gpu/drm/msm/msm_gpu_devfreq.c')
-rw-r--r-- | drivers/gpu/drm/msm/msm_gpu_devfreq.c | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c new file mode 100644 index 0000000000..ea70c1c32d --- /dev/null +++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c @@ -0,0 +1,369 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 Red Hat + * Author: Rob Clark <robdclark@gmail.com> + */ + +#include "msm_gpu.h" +#include "msm_gpu_trace.h" + +#include <linux/devfreq.h> +#include <linux/devfreq_cooling.h> +#include <linux/math64.h> +#include <linux/units.h> + +/* + * Power Management: + */ + +static int msm_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct msm_gpu *gpu = dev_to_gpu(dev); + struct msm_gpu_devfreq *df = &gpu->devfreq; + struct dev_pm_opp *opp; + + /* + * Note that devfreq_recommended_opp() can modify the freq + * to something that actually is in the opp table: + */ + opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + trace_msm_gpu_freq_change(dev_pm_opp_get_freq(opp)); + + /* + * If the GPU is idle, devfreq is not aware, so just stash + * the new target freq (to use when we return to active) + */ + if (df->idle_freq) { + df->idle_freq = *freq; + dev_pm_opp_put(opp); + return 0; + } + + if (gpu->funcs->gpu_set_freq) { + mutex_lock(&df->lock); + gpu->funcs->gpu_set_freq(gpu, opp, df->suspended); + mutex_unlock(&df->lock); + } else { + dev_pm_opp_set_rate(dev, *freq); + } + + dev_pm_opp_put(opp); + + return 0; +} + +static unsigned long get_freq(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + + /* + * If the GPU is idle, use the shadow/saved freq to avoid + * confusing devfreq (which is unaware that we are switching + * to lowest freq until the device is active again) + */ + if (df->idle_freq) + return df->idle_freq; + + if (gpu->funcs->gpu_get_freq) + return gpu->funcs->gpu_get_freq(gpu); + + return clk_get_rate(gpu->core_clk); +} + +static int msm_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct msm_gpu *gpu = dev_to_gpu(dev); + struct msm_gpu_devfreq *df = &gpu->devfreq; + u64 busy_cycles, busy_time; + unsigned long sample_rate; + ktime_t time; + + mutex_lock(&df->lock); + + status->current_frequency = get_freq(gpu); + time = ktime_get(); + status->total_time = ktime_us_delta(time, df->time); + df->time = time; + + if (df->suspended) { + mutex_unlock(&df->lock); + status->busy_time = 0; + return 0; + } + + busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); + busy_time = busy_cycles - df->busy_cycles; + df->busy_cycles = busy_cycles; + + mutex_unlock(&df->lock); + + busy_time *= USEC_PER_SEC; + busy_time = div64_ul(busy_time, sample_rate); + if (WARN_ON(busy_time > ~0LU)) + busy_time = ~0LU; + + status->busy_time = busy_time; + + return 0; +} + +static int msm_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) +{ + *freq = get_freq(dev_to_gpu(dev)); + + return 0; +} + +static struct devfreq_dev_profile msm_devfreq_profile = { + .timer = DEVFREQ_TIMER_DELAYED, + .polling_ms = 50, + .target = msm_devfreq_target, + .get_dev_status = msm_devfreq_get_dev_status, + .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); + +static bool has_devfreq(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + return !!df->devfreq; +} + +void msm_devfreq_init(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + struct msm_drm_private *priv = gpu->dev->dev_private; + + /* We need target support to do devfreq */ + if (!gpu->funcs->gpu_busy) + return; + + /* + * Setup default values for simple_ondemand governor tuning. We + * want to throttle up at 50% load for the double-buffer case, + * where due to stalling waiting for vblank we could get stuck + * at (for ex) 30fps at 50% utilization. + */ + priv->gpu_devfreq_config.upthreshold = 50; + priv->gpu_devfreq_config.downdifferential = 10; + + mutex_init(&df->lock); + + 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; + + /* + * Don't set the freq_table or max_state and let devfreq build the table + * from OPP + * After a deferred probe, these may have be left to non-zero values, + * so set them back to zero before creating the devfreq device + */ + msm_devfreq_profile.freq_table = NULL; + msm_devfreq_profile.max_state = 0; + + df->devfreq = devm_devfreq_add_device(&gpu->pdev->dev, + &msm_devfreq_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, + &priv->gpu_devfreq_config); + + if (IS_ERR(df->devfreq)) { + DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize GPU devfreq\n"); + dev_pm_qos_remove_request(&df->boost_freq); + df->devfreq = NULL; + return; + } + + devfreq_suspend_device(df->devfreq); + + gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node, df->devfreq); + if (IS_ERR(gpu->cooling)) { + DRM_DEV_ERROR(&gpu->pdev->dev, + "Couldn't register GPU cooling device\n"); + 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); +} + +static void cancel_idle_work(struct msm_gpu_devfreq *df) +{ + hrtimer_cancel(&df->idle_work.timer); + kthread_cancel_work_sync(&df->idle_work.work); +} + +static void cancel_boost_work(struct msm_gpu_devfreq *df) +{ + hrtimer_cancel(&df->boost_work.timer); + kthread_cancel_work_sync(&df->boost_work.work); +} + +void msm_devfreq_cleanup(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + + if (!has_devfreq(gpu)) + return; + + devfreq_cooling_unregister(gpu->cooling); + dev_pm_qos_remove_request(&df->boost_freq); +} + +void msm_devfreq_resume(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + unsigned long sample_rate; + + if (!has_devfreq(gpu)) + return; + + mutex_lock(&df->lock); + df->busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); + df->time = ktime_get(); + df->suspended = false; + mutex_unlock(&df->lock); + + devfreq_resume_device(df->devfreq); +} + +void msm_devfreq_suspend(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + + if (!has_devfreq(gpu)) + return; + + mutex_lock(&df->lock); + df->suspended = true; + mutex_unlock(&df->lock); + + devfreq_suspend_device(df->devfreq); + + cancel_idle_work(df); + cancel_boost_work(df); +} + +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; + + if (!has_devfreq(gpu)) + return; + + 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; + unsigned int idle_time; + unsigned long target_freq; + + if (!has_devfreq(gpu)) + return; + + /* + * Cancel any pending transition to idle frequency: + */ + cancel_idle_work(df); + + /* + * Hold devfreq lock to synchronize with get_dev_status()/ + * target() callbacks + */ + mutex_lock(&df->devfreq->lock); + + target_freq = df->idle_freq; + + idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time)); + + df->idle_freq = 0; + + /* + * We could have become active again before the idle work had a + * chance to run, in which case the df->idle_freq would have + * still been zero. In this case, no need to change freq. + */ + if (target_freq) + msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); + + mutex_unlock(&df->devfreq->lock); + + /* + * If we've been idle for a significant fraction of a polling + * interval, then we won't meet the threshold of busyness for + * the governor to ramp up the freq.. so give some boost + */ + if (idle_time > msm_devfreq_profile.polling_ms) { + msm_devfreq_boost(gpu, 2); + } +} + + +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); + struct msm_drm_private *priv = gpu->dev->dev_private; + 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 (priv->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); +} + +void msm_devfreq_idle(struct msm_gpu *gpu) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + + if (!has_devfreq(gpu)) + return; + + msm_hrtimer_queue_work(&df->idle_work, ms_to_ktime(1), + HRTIMER_MODE_REL); +} |