blob: d1f70426f554ed552011d111f5595ce842c06acb [file] [log] [blame]
// 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");
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);
}