Commit 6a797bdf authored by Adrián Larumbe's avatar Adrián Larumbe Committed by Boris Brezillon
Browse files

drm/panthor: add sysfs knob for enabling job profiling 



This commit introduces a DRM device sysfs attribute that lets UM control
the job accounting status in the device. The knob variable had been brought
in as part of a previous commit, but now we're able to fix it manually.

As sysfs files are part of a driver's uAPI, describe its legitimate input
values and output format in a documentation file.

Signed-off-by: default avatarAdrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240923230912.2207320-6-adrian.larumbe@collabora.com
parent 064bb574

Documentation/ABI/testing/sysfs-driver-panthor-profiling

0 → 100644
+10 −0
Original line number Diff line number Diff line 
What:		/sys/bus/platform/drivers/panthor/.../profiling

Date:		September 2024

KernelVersion:	6.11.0

Contact:	Adrian Larumbe <adrian.larumbe@collabora.com>

Description:

		Bitmask to enable drm fdinfo's job profiling measurements.

		Valid values are:

		0: Don't enable fdinfo job profiling sources.

		1: Enable GPU cycle measurements for running jobs.

		2: Enable GPU timestamp sampling for running jobs.

Documentation/gpu/panthor.rst

0 → 100644
+46 −0
Original line number Diff line number Diff line 
.. SPDX-License-Identifier: GPL-2.0+



=========================

 drm/Panthor CSF driver

=========================



.. _panfrost-usage-stats:



Panthor DRM client usage stats implementation

==============================================



The drm/Panthor driver implements the DRM client usage stats specification as

documented in :ref:`drm-client-usage-stats`.



Example of the output showing the implemented key value pairs and entirety of

the currently possible format options:



::

     pos:    0

     flags:  02400002

     mnt_id: 29

     ino:    491

     drm-driver:     panthor

     drm-client-id:  10

     drm-engine-panthor:     111110952750 ns

     drm-cycles-panthor:     94439687187

     drm-maxfreq-panthor:    1000000000 Hz

     drm-curfreq-panthor:    1000000000 Hz

     drm-total-memory:       16480 KiB

     drm-shared-memory:      0

     drm-active-memory:      16200 KiB

     drm-resident-memory:    16480 KiB

     drm-purgeable-memory:   0



Possible `drm-engine-` key names are: `panthor`.

`drm-curfreq-` values convey the current operating frequency for that engine.



Users must bear in mind that engine and cycle sampling are disabled by default,

because of power saving concerns. `fdinfo` users and benchmark applications which

query the fdinfo file must make sure to toggle the job profiling status of the

driver by writing into the appropriate sysfs node::



    echo <N> > /sys/bus/platform/drivers/panthor/[a-f0-9]*.gpu/profiling



Where `N` is a bit mask where cycle and timestamp sampling are respectively

enabled by the first and second bits.

drivers/gpu/drm/panthor/panthor_drv.c

+39 −0
Original line number Diff line number Diff line
@@ -1536,6 +1536,44 @@ static void panthor_remove(struct platform_device *pdev) 
	panthor_device_unplug(ptdev);

}



static ssize_t profiling_show(struct device *dev,

			      struct device_attribute *attr,

			      char *buf)

{

	struct panthor_device *ptdev = dev_get_drvdata(dev);



	return sysfs_emit(buf, "%d\n", ptdev->profile_mask);

}



static ssize_t profiling_store(struct device *dev,

			       struct device_attribute *attr,

			       const char *buf, size_t len)

{

	struct panthor_device *ptdev = dev_get_drvdata(dev);

	u32 value;

	int err;



	err = kstrtou32(buf, 0, &value);

	if (err)

		return err;



	if ((value & ~PANTHOR_DEVICE_PROFILING_ALL) != 0)

		return -EINVAL;



	ptdev->profile_mask = value;



	return len;

}



static DEVICE_ATTR_RW(profiling);



static struct attribute *panthor_attrs[] = {

	&dev_attr_profiling.attr,

	NULL,

};



ATTRIBUTE_GROUPS(panthor);



static const struct of_device_id dt_match[] = {

	{ .compatible = "rockchip,rk3588-mali" },

	{ .compatible = "arm,mali-valhall-csf" },
@@ -1555,6 +1593,7 @@ static struct platform_driver panthor_driver = { 
		.name = "panthor",

		.pm = pm_ptr(&panthor_pm_ops),

		.of_match_table = dt_match,

		.dev_groups = panthor_groups,

	},

};