Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
drm/panfrost: Replace fdinfo's profiling debugfs knob with sysfs
Debugfs isn't always available in production builds that try to squeeze
every single byte out of the kernel image, but we still need a way to
toggle the timestamp and cycle counter registers so that jobs can be
profiled for fdinfo's drm engine and cycle calculations.
Drop the debugfs knob and replace it with a sysfs file that accomplishes
the same functionality, and document its ABI in a separate file.
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240306015819.822128-2-adrian.larumbe@collabora.com
authored by
Adrián Larumbe
and committed by
Boris Brezillon
b12f3ea7
57a4e3a9
+56
-44
+10
Documentation/ABI/testing/sysfs-driver-panfrost-profiling
+10
Documentation/ABI/testing/sysfs-driver-panfrost-profiling
···
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What: /sys/bus/platform/drivers/panfrost/.../profiling
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Date: February 2024
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KernelVersion: 6.8.0
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Contact: Adrian Larumbe <adrian.larumbe@collabora.com>
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Description:
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Get/set drm fdinfo's engine and cycles profiling status.
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Valid values are:
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0: Don't enable fdinfo job profiling sources.
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1: Enable fdinfo job profiling sources, this enables both the GPU's
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timestamp and cycle counter registers.
+9
Documentation/gpu/panfrost.rst
+9
Documentation/gpu/panfrost.rst
···
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Possible `drm-engine-` key names are: `fragment`, and `vertex-tiler`.
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`drm-curfreq-` values convey the current operating frequency for that engine.
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Users must bear in mind that engine and cycle sampling are disabled by default,
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because of power saving concerns. `fdinfo` users and benchmark applications which
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query the fdinfo file must make sure to toggle the job profiling status of the
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driver by writing into the appropriate sysfs node::
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echo <N> > /sys/bus/platform/drivers/panfrost/[a-f0-9]*.gpu/profiling
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Where `N` is either `0` or `1`, depending on the desired enablement status.
-2
drivers/gpu/drm/panfrost/Makefile
-2
drivers/gpu/drm/panfrost/Makefile
-21
drivers/gpu/drm/panfrost/panfrost_debugfs.c
-21
drivers/gpu/drm/panfrost/panfrost_debugfs.c
···
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright 2023 Collabora ltd. */
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/* Copyright 2023 Amazon.com, Inc. or its affiliates. */
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#include <linux/debugfs.h>
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#include <linux/platform_device.h>
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#include <drm/drm_debugfs.h>
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#include <drm/drm_file.h>
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#include <drm/panfrost_drm.h>
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#include "panfrost_device.h"
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#include "panfrost_gpu.h"
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#include "panfrost_debugfs.h"
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void panfrost_debugfs_init(struct drm_minor *minor)
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{
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struct drm_device *dev = minor->dev;
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struct panfrost_device *pfdev = platform_get_drvdata(to_platform_device(dev->dev));
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debugfs_create_atomic_t("profile", 0600, minor->debugfs_root, &pfdev->profile_mode);
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}
-14
drivers/gpu/drm/panfrost/panfrost_debugfs.h
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drivers/gpu/drm/panfrost/panfrost_debugfs.h
···
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright 2023 Collabora ltd.
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* Copyright 2023 Amazon.com, Inc. or its affiliates.
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*/
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#ifndef PANFROST_DEBUGFS_H
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#define PANFROST_DEBUGFS_H
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#ifdef CONFIG_DEBUG_FS
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void panfrost_debugfs_init(struct drm_minor *minor);
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#endif
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#endif /* PANFROST_DEBUGFS_H */
+1
-1
drivers/gpu/drm/panfrost/panfrost_device.h
+1
-1
drivers/gpu/drm/panfrost/panfrost_device.h
+35
-5
drivers/gpu/drm/panfrost/panfrost_drv.c
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-5
drivers/gpu/drm/panfrost/panfrost_drv.c
···
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#include "panfrost_job.h"
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#include "panfrost_gpu.h"
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#include "panfrost_perfcnt.h"
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#include "panfrost_debugfs.h"
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static bool unstable_ioctls;
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module_param_unsafe(unstable_ioctls, bool, 0600);
···
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.gem_create_object = panfrost_gem_create_object,
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.gem_prime_import_sg_table = panfrost_gem_prime_import_sg_table,
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#ifdef CONFIG_DEBUG_FS
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.debugfs_init = panfrost_debugfs_init,
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#endif
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};
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static int panfrost_probe(struct platform_device *pdev)
···
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drm_dev_put(ddev);
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}
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static ssize_t profiling_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct panfrost_device *pfdev = dev_get_drvdata(dev);
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return sysfs_emit(buf, "%d\n", pfdev->profile_mode);
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}
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static ssize_t profiling_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t len)
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{
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struct panfrost_device *pfdev = dev_get_drvdata(dev);
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bool value;
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int err;
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err = kstrtobool(buf, &value);
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if (err)
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return err;
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pfdev->profile_mode = value;
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return len;
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}
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static DEVICE_ATTR_RW(profiling);
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static struct attribute *panfrost_attrs[] = {
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&dev_attr_profiling.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(panfrost);
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/*
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* The OPP core wants the supply names to be NULL terminated, but we need the
···
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.name = "panfrost",
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.pm = pm_ptr(&panfrost_pm_ops),
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.of_match_table = dt_match,
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.dev_groups = panfrost_groups,
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},
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};
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module_platform_driver(panfrost_driver);
+1
-1
drivers/gpu/drm/panfrost/panfrost_job.c
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-1
drivers/gpu/drm/panfrost/panfrost_job.c
···
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subslot = panfrost_enqueue_job(pfdev, js, job);
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/* Don't queue the job if a reset is in progress */
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if (!atomic_read(&pfdev->reset.pending)) {
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if (atomic_read(&pfdev->profile_mode)) {
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if (pfdev->profile_mode) {
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panfrost_cycle_counter_get(pfdev);
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job->is_profiled = true;
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job->start_time = ktime_get();