1 files changed, 377 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 000000000..85c443a37
--- /dev/null
+++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c
@@ -0,0 +1,377 @@
+// 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 (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);
+
+	return 0;
+}
+
+static unsigned long get_freq(struct msm_gpu *gpu)
+{
+	if (gpu->funcs->gpu_get_freq)
+		return gpu->funcs->gpu_get_freq(gpu);
+
+	return clk_get_rate(gpu->core_clk);
+}
+
+static void get_raw_dev_status(struct msm_gpu *gpu,
+		struct devfreq_dev_status *status)
+{
+	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;
+	}
+
+	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;
+}
+
+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;
+
+	/* We need target support to do devfreq */
+	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);
+	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,
+			NULL);
+
+	if (IS_ERR(df->devfreq)) {
+		DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize GPU devfreq\n");
+		dev_pm_qos_remove_request(&df->idle_freq);
+		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);
+	dev_pm_qos_remove_request(&df->idle_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;
+
+	if (!has_devfreq(gpu))
+		return;
+
+	/*
+	 * Cancel any pending transition to idle frequency:
+	 */
+	cancel_idle_work(df);
+
+	idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time));
+
+	/*
+	 * 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);
+	}
+
+	dev_pm_qos_update_request(&df->idle_freq,
+				  PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
+}
+
+
+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);
+
+	df->idle_time = ktime_get();
+
+	if (gpu->clamp_to_idle)
+		dev_pm_qos_update_request(&df->idle_freq, 0);
+}
+
+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);
+}