diff options
Diffstat (limited to 'drivers/gpu/drm/msm/msm_gpu_devfreq.c')
| -rw-r--r-- | drivers/gpu/drm/msm/msm_gpu_devfreq.c | 128 |
1 files changed, 111 insertions, 17 deletions
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c index 12641616acd3..d1f70426f554 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/math64.h> #include <linux/units.h> /* @@ -19,6 +20,7 @@ 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; /* @@ -31,10 +33,13 @@ static int msm_devfreq_target(struct device *dev, unsigned long *freq, trace_msm_gpu_freq_change(dev_pm_opp_get_freq(opp)); - if (gpu->funcs->gpu_set_freq) - gpu->funcs->gpu_set_freq(gpu, opp); - else + if (gpu->funcs->gpu_set_freq) { + mutex_lock(&df->lock); + gpu->funcs->gpu_set_freq(gpu, opp, df->suspended); + mutex_unlock(&df->lock); + } else { clk_set_rate(gpu->core_clk, *freq); + } dev_pm_opp_put(opp); @@ -49,18 +54,104 @@ static unsigned long get_freq(struct msm_gpu *gpu) return clk_get_rate(gpu->core_clk); } -static int msm_devfreq_get_dev_status(struct device *dev, +static void get_raw_dev_status(struct msm_gpu *gpu, 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; - status->current_frequency = get_freq(gpu); - status->busy_time = gpu->funcs->gpu_busy(gpu); + mutex_lock(&df->lock); + status->current_frequency = get_freq(gpu); time = ktime_get(); - status->total_time = ktime_us_delta(time, gpu->devfreq.time); - gpu->devfreq.time = time; + status->total_time = ktime_us_delta(time, df->time); + df->time = time; + + if (df->suspended) { + mutex_unlock(&df->lock); + status->busy_time = 0; + return; + } + + 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; +} + +static void update_average_dev_status(struct msm_gpu *gpu, + const struct devfreq_dev_status *raw) +{ + struct msm_gpu_devfreq *df = &gpu->devfreq; + const u32 polling_ms = df->devfreq->profile->polling_ms; + const u32 max_history_ms = polling_ms * 11 / 10; + struct devfreq_dev_status *avg = &df->average_status; + u64 avg_freq; + + /* simple_ondemand governor interacts poorly with gpu->clamp_to_idle. + * When we enforce the constraint on idle, it calls get_dev_status + * which would normally reset the stats. When we remove the + * constraint on active, it calls get_dev_status again where busy_time + * would be 0. + * + * To remedy this, we always return the average load over the past + * polling_ms. + */ + + /* raw is longer than polling_ms or avg has no history */ + if (div_u64(raw->total_time, USEC_PER_MSEC) >= polling_ms || + !avg->total_time) { + *avg = *raw; + return; + } + + /* Truncate the oldest history first. + * + * Because we keep the history with a single devfreq_dev_status, + * rather than a list of devfreq_dev_status, we have to assume freq + * and load are the same over avg->total_time. We can scale down + * avg->busy_time and avg->total_time by the same factor to drop + * history. + */ + if (div_u64(avg->total_time + raw->total_time, USEC_PER_MSEC) >= + max_history_ms) { + const u32 new_total_time = polling_ms * USEC_PER_MSEC - + raw->total_time; + avg->busy_time = div_u64( + mul_u32_u32(avg->busy_time, new_total_time), + avg->total_time); + avg->total_time = new_total_time; + } + + /* compute the average freq over avg->total_time + raw->total_time */ + avg_freq = mul_u32_u32(avg->current_frequency, avg->total_time); + avg_freq += mul_u32_u32(raw->current_frequency, raw->total_time); + do_div(avg_freq, avg->total_time + raw->total_time); + + avg->current_frequency = avg_freq; + avg->busy_time += raw->busy_time; + avg->total_time += raw->total_time; +} + +static int msm_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct msm_gpu *gpu = dev_to_gpu(dev); + struct devfreq_dev_status raw; + + get_raw_dev_status(gpu, &raw); + update_average_dev_status(gpu, &raw); + *status = gpu->devfreq.average_status; return 0; } @@ -97,6 +188,8 @@ void msm_devfreq_init(struct msm_gpu *gpu) if (!gpu->funcs->gpu_busy) return; + mutex_init(&df->lock); + dev_pm_qos_add_request(&gpu->pdev->dev, &df->idle_freq, DEV_PM_QOS_MAX_FREQUENCY, PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); @@ -166,12 +259,16 @@ void msm_devfreq_cleanup(struct msm_gpu *gpu) void msm_devfreq_resume(struct msm_gpu *gpu) { struct msm_gpu_devfreq *df = &gpu->devfreq; + unsigned long sample_rate; if (!has_devfreq(gpu)) return; - df->busy_cycles = 0; + 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); } @@ -183,6 +280,10 @@ void msm_devfreq_suspend(struct msm_gpu *gpu) 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); @@ -224,7 +325,6 @@ void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor) void msm_devfreq_active(struct msm_gpu *gpu) { struct msm_gpu_devfreq *df = &gpu->devfreq; - struct devfreq_dev_status status; unsigned int idle_time; if (!has_devfreq(gpu)) @@ -248,12 +348,6 @@ void msm_devfreq_active(struct msm_gpu *gpu) 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); } |