Most platforms with a Mali-400 or Mali-450 GPU also have support for changing the GPU clock frequency. Add devfreq support so the GPU clock rate is updated based on the actual GPU usage when the "operating-points-v2" property is present in the board.dts.
The actual devfreq code is taken from panfrost_devfreq.c and modified so it matches what the lima hardware needs: - a call to dev_pm_opp_set_clkname() during initialization because there are two clocks on Mali-4x0 IPs. "core" is the one that actually clocks the GPU so we need to control it using devfreq. - locking when reading or writing the devfreq statistics because (unlike than panfrost) we have multiple PP and GP IRQs which may finish jobs concurrently.
Signed-off-by: Martin Blumenstingl martin.blumenstingl@googlemail.com --- drivers/gpu/drm/lima/Kconfig | 1 + drivers/gpu/drm/lima/Makefile | 3 +- drivers/gpu/drm/lima/lima_devfreq.c | 183 ++++++++++++++++++++++++++++ drivers/gpu/drm/lima/lima_devfreq.h | 15 +++ drivers/gpu/drm/lima/lima_device.c | 4 + drivers/gpu/drm/lima/lima_device.h | 17 +++ drivers/gpu/drm/lima/lima_drv.c | 14 ++- drivers/gpu/drm/lima/lima_sched.c | 7 ++ drivers/gpu/drm/lima/lima_sched.h | 3 + 9 files changed, 244 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/drm/lima/lima_devfreq.c create mode 100644 drivers/gpu/drm/lima/lima_devfreq.h
diff --git a/drivers/gpu/drm/lima/Kconfig b/drivers/gpu/drm/lima/Kconfig index 571dc369a7e9..cdd24b68b5d4 100644 --- a/drivers/gpu/drm/lima/Kconfig +++ b/drivers/gpu/drm/lima/Kconfig @@ -10,5 +10,6 @@ config DRM_LIMA depends on OF select DRM_SCHED select DRM_GEM_SHMEM_HELPER + select PM_DEVFREQ help DRM driver for ARM Mali 400/450 GPUs. diff --git a/drivers/gpu/drm/lima/Makefile b/drivers/gpu/drm/lima/Makefile index a85444b0a1d4..5e5c29875e9c 100644 --- a/drivers/gpu/drm/lima/Makefile +++ b/drivers/gpu/drm/lima/Makefile @@ -14,6 +14,7 @@ lima-y := \ lima_sched.o \ lima_ctx.o \ lima_dlbu.o \ - lima_bcast.o + lima_bcast.o \ + lima_devfreq.o
obj-$(CONFIG_DRM_LIMA) += lima.o diff --git a/drivers/gpu/drm/lima/lima_devfreq.c b/drivers/gpu/drm/lima/lima_devfreq.c new file mode 100644 index 000000000000..a5fd6b8faa77 --- /dev/null +++ b/drivers/gpu/drm/lima/lima_devfreq.c @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 Martin Blumenstingl martin.blumenstingl@googlemail.com + * + * Based on panfrost_devfreq.c: + * Copyright 2019 Collabora ltd. + */ +#include <linux/clk.h> +#include <linux/devfreq.h> +#include <linux/devfreq_cooling.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> + +#include "lima_device.h" +#include "lima_devfreq.h" + +static void lima_devfreq_update_utilization(struct lima_device *ldev) +{ + unsigned long irqflags; + ktime_t now, last; + + if (!ldev->devfreq.devfreq) + return; + + spin_lock_irqsave(&ldev->devfreq.lock, irqflags); + + now = ktime_get(); + last = ldev->devfreq.time_last_update; + + if (atomic_read(&ldev->devfreq.busy_count) > 0) + ldev->devfreq.busy_time += ktime_sub(now, last); + else + ldev->devfreq.idle_time += ktime_sub(now, last); + + ldev->devfreq.time_last_update = now; + + spin_unlock_irqrestore(&ldev->devfreq.lock, irqflags); +} + +static int lima_devfreq_target(struct device *dev, unsigned long *freq, + u32 flags) +{ + struct dev_pm_opp *opp; + int err; + + opp = devfreq_recommended_opp(dev, freq, flags); + if (IS_ERR(opp)) + return PTR_ERR(opp); + dev_pm_opp_put(opp); + + err = dev_pm_opp_set_rate(dev, *freq); + if (err) + return err; + + return 0; +} + +static void lima_devfreq_reset(struct lima_device *ldev) +{ + unsigned long irqflags; + + spin_lock_irqsave(&ldev->devfreq.lock, irqflags); + + ldev->devfreq.busy_time = 0; + ldev->devfreq.idle_time = 0; + ldev->devfreq.time_last_update = ktime_get(); + + spin_unlock_irqrestore(&ldev->devfreq.lock, irqflags); +} + +static int lima_devfreq_get_dev_status(struct device *dev, + struct devfreq_dev_status *status) +{ + struct lima_device *ldev = dev_get_drvdata(dev); + unsigned long irqflags; + + lima_devfreq_update_utilization(ldev); + + status->current_frequency = clk_get_rate(ldev->clk_gpu); + + spin_lock_irqsave(&ldev->devfreq.lock, irqflags); + + status->total_time = ktime_to_ns(ktime_add(ldev->devfreq.busy_time, + ldev->devfreq.idle_time)); + status->busy_time = ktime_to_ns(ldev->devfreq.busy_time); + + spin_unlock_irqrestore(&ldev->devfreq.lock, irqflags); + + lima_devfreq_reset(ldev); + + dev_dbg(ldev->dev, "busy %lu total %lu %lu %% freq %lu MHz\n", + status->busy_time, status->total_time, + status->busy_time / (status->total_time / 100), + status->current_frequency / 1000 / 1000); + + return 0; +} + +static struct devfreq_dev_profile lima_devfreq_profile = { + .polling_ms = 50, /* ~3 frames */ + .target = lima_devfreq_target, + .get_dev_status = lima_devfreq_get_dev_status, +}; + +int lima_devfreq_init(struct lima_device *ldev) +{ + struct thermal_cooling_device *cooling; + struct device *dev = &ldev->pdev->dev; + struct devfreq *devfreq; + struct dev_pm_opp *opp; + unsigned long cur_freq; + int ret; + + spin_lock_init(&ldev->devfreq.lock); + + ldev->devfreq.opp_table = dev_pm_opp_set_clkname(dev, "core"); + if (IS_ERR(ldev->devfreq.opp_table)) + return PTR_ERR(ldev->devfreq.opp_table); + + ret = dev_pm_opp_of_add_table(dev); + if (ret == -ENODEV) /* Optional, continue without devfreq */ + return 0; + else if (ret) + return ret; + + lima_devfreq_reset(ldev); + + cur_freq = clk_get_rate(ldev->clk_gpu); + + opp = devfreq_recommended_opp(dev, &cur_freq, 0); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + lima_devfreq_profile.initial_freq = cur_freq; + dev_pm_opp_put(opp); + + devfreq = devm_devfreq_add_device(dev, &lima_devfreq_profile, + DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL); + if (IS_ERR(devfreq)) { + dev_err(dev, "Couldn't initialize GPU devfreq\n"); + dev_pm_opp_of_remove_table(dev); + return PTR_ERR(devfreq); + } + + ldev->devfreq.devfreq = devfreq; + + cooling = of_devfreq_cooling_register(dev->of_node, devfreq); + if (IS_ERR(cooling)) + dev_info(dev, "Failed to register cooling device\n"); + else + ldev->devfreq.cooling = cooling; + + return 0; +} + +void lima_devfreq_fini(struct lima_device *ldev) +{ + if (ldev->devfreq.cooling) + devfreq_cooling_unregister(ldev->devfreq.cooling); + + if (ldev->devfreq.opp_table) { + dev_pm_opp_put_clkname(ldev->devfreq.opp_table); + ldev->devfreq.opp_table = NULL; + } + + dev_pm_opp_of_remove_table(&ldev->pdev->dev); +} + +void lima_devfreq_record_busy(struct lima_device *ldev) +{ + lima_devfreq_update_utilization(ldev); + atomic_inc(&ldev->devfreq.busy_count); +} + +void lima_devfreq_record_idle(struct lima_device *ldev) +{ + int count; + + lima_devfreq_update_utilization(ldev); + count = atomic_dec_if_positive(&ldev->devfreq.busy_count); + WARN_ON(count < 0); +} diff --git a/drivers/gpu/drm/lima/lima_devfreq.h b/drivers/gpu/drm/lima/lima_devfreq.h new file mode 100644 index 000000000000..fe4f8a437033 --- /dev/null +++ b/drivers/gpu/drm/lima/lima_devfreq.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright 2019 Martin Blumenstingl martin.blumenstingl@googlemail.com */ + +#ifndef __LIMA_DEVFREQ_H__ +#define __LIMA_DEVFREQ_H__ + +struct lima_device; + +int lima_devfreq_init(struct lima_device *ldev); +void lima_devfreq_fini(struct lima_device *ldev); + +void lima_devfreq_record_busy(struct lima_device *ldev); +void lima_devfreq_record_idle(struct lima_device *ldev); + +#endif diff --git a/drivers/gpu/drm/lima/lima_device.c b/drivers/gpu/drm/lima/lima_device.c index 19829b543024..7f1f7a1c03e5 100644 --- a/drivers/gpu/drm/lima/lima_device.c +++ b/drivers/gpu/drm/lima/lima_device.c @@ -214,6 +214,8 @@ static int lima_init_gp_pipe(struct lima_device *dev) struct lima_sched_pipe *pipe = dev->pipe + lima_pipe_gp; int err;
+ pipe->ldev = dev; + err = lima_sched_pipe_init(pipe, "gp"); if (err) return err; @@ -244,6 +246,8 @@ static int lima_init_pp_pipe(struct lima_device *dev) struct lima_sched_pipe *pipe = dev->pipe + lima_pipe_pp; int err, i;
+ pipe->ldev = dev; + err = lima_sched_pipe_init(pipe, "pp"); if (err) return err; diff --git a/drivers/gpu/drm/lima/lima_device.h b/drivers/gpu/drm/lima/lima_device.h index 31158d86271c..26f0efdd17f1 100644 --- a/drivers/gpu/drm/lima/lima_device.h +++ b/drivers/gpu/drm/lima/lima_device.h @@ -5,6 +5,7 @@ #define __LIMA_DEVICE_H__
#include <drm/drm_device.h> +#include <linux/atomic.h> #include <linux/delay.h>
#include "lima_sched.h" @@ -94,6 +95,22 @@ struct lima_device {
u32 *dlbu_cpu; dma_addr_t dlbu_dma; + + struct { + struct devfreq *devfreq; + struct opp_table *opp_table; + struct thermal_cooling_device *cooling; + ktime_t busy_time; + ktime_t idle_time; + ktime_t time_last_update; + atomic_t busy_count; + /* + * Protect busy_time, idle_time and time_last_update because + * these can be updated concurrently - for example by the GP + * and PP interrupts. + */ + spinlock_t lock; + } devfreq; };
static inline struct lima_device * diff --git a/drivers/gpu/drm/lima/lima_drv.c b/drivers/gpu/drm/lima/lima_drv.c index 124efe4fa97b..b64b1777f220 100644 --- a/drivers/gpu/drm/lima/lima_drv.c +++ b/drivers/gpu/drm/lima/lima_drv.c @@ -10,6 +10,7 @@ #include <drm/drm_prime.h> #include <drm/lima_drm.h>
+#include "lima_devfreq.h" #include "lima_drv.h" #include "lima_gem.h" #include "lima_vm.h" @@ -296,18 +297,26 @@ static int lima_pdev_probe(struct platform_device *pdev) if (err) goto err_out1;
+ err = lima_devfreq_init(ldev); + if (err) { + dev_err(&pdev->dev, "Fatal error during devfreq init\n"); + goto err_out2; + } + /* * Register the DRM device with the core and the connectors with * sysfs. */ err = drm_dev_register(ddev, 0); if (err < 0) - goto err_out2; + goto err_out3;
return 0;
-err_out2: +err_out3: lima_device_fini(ldev); +err_out2: + lima_devfreq_fini(ldev); err_out1: drm_dev_put(ddev); err_out0: @@ -321,6 +330,7 @@ static int lima_pdev_remove(struct platform_device *pdev) struct drm_device *ddev = ldev->ddev;
drm_dev_unregister(ddev); + lima_devfreq_fini(ldev); lima_device_fini(ldev); drm_dev_put(ddev); lima_sched_slab_fini(); diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c index f522c5f99729..851c496a168b 100644 --- a/drivers/gpu/drm/lima/lima_sched.c +++ b/drivers/gpu/drm/lima/lima_sched.c @@ -5,6 +5,7 @@ #include <linux/slab.h> #include <linux/xarray.h>
+#include "lima_devfreq.h" #include "lima_drv.h" #include "lima_sched.h" #include "lima_vm.h" @@ -213,6 +214,8 @@ static struct dma_fence *lima_sched_run_job(struct drm_sched_job *job) */ ret = dma_fence_get(task->fence);
+ lima_devfreq_record_busy(pipe->ldev); + pipe->current_task = task;
/* this is needed for MMU to work correctly, otherwise GP/PP @@ -280,6 +283,8 @@ static void lima_sched_handle_error_task(struct lima_sched_pipe *pipe, pipe->current_vm = NULL; pipe->current_task = NULL;
+ lima_devfreq_record_idle(pipe->ldev); + drm_sched_resubmit_jobs(&pipe->base); drm_sched_start(&pipe->base, true); } @@ -348,6 +353,8 @@ void lima_sched_pipe_fini(struct lima_sched_pipe *pipe)
void lima_sched_pipe_task_done(struct lima_sched_pipe *pipe) { + lima_devfreq_record_idle(pipe->ldev); + if (pipe->error) schedule_work(&pipe->error_work); else { diff --git a/drivers/gpu/drm/lima/lima_sched.h b/drivers/gpu/drm/lima/lima_sched.h index 928af91c1118..9ae7df7d7fbb 100644 --- a/drivers/gpu/drm/lima/lima_sched.h +++ b/drivers/gpu/drm/lima/lima_sched.h @@ -6,6 +6,7 @@
#include <drm/gpu_scheduler.h>
+struct lima_device; struct lima_vm;
struct lima_sched_task { @@ -41,6 +42,8 @@ struct lima_sched_pipe { u32 fence_seqno; spinlock_t fence_lock;
+ struct lima_device *ldev; + struct lima_sched_task *current_task; struct lima_vm *current_vm;