Commit 3f09a0cd authored by Rob Clark's avatar Rob Clark Committed by Neil Armstrong
Browse files

drm: Add common fdinfo helper 



Handle a bit of the boiler-plate in a single case, and make it easier to
add some core tracked stats.  This also ensures consistent behavior
across drivers for standardised fields.

v2: Update drm-usage-stats.rst, 64b client-id, rename drm_show_fdinfo
v3: Rebase on drm-misc-next

Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Acked-by: default avatarDave Airlie <airlied@redhat.com>
Signed-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-3-robdclark@gmail.com
parent 0020582a

Documentation/gpu/drm-usage-stats.rst

+9 −1
Original line number Diff line number Diff line
@@ -126,7 +126,15 @@ percentage utilization of the engine, whereas drm-engine-<str> only reflects 
time active without considering what frequency the engine is operating as a

percentage of it's maximum frequency.



Implementation Details

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



Drivers should use drm_show_fdinfo() in their `struct file_operations`, and

implement &drm_driver.show_fdinfo if they wish to provide any stats which

are not provided by drm_show_fdinfo().  But even driver specific stats should

be documented above and where possible, aligned with other drivers.



Driver specific implementations

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

-------------------------------



:ref:`i915-usage-stats`

drivers/gpu/drm/drm_file.c

+35 −0
Original line number Diff line number Diff line
@@ -148,6 +148,7 @@ bool drm_dev_needs_global_mutex(struct drm_device *dev) 
 */

struct drm_file *drm_file_alloc(struct drm_minor *minor)

{

	static atomic64_t ident = ATOMIC_INIT(0);

	struct drm_device *dev = minor->dev;

	struct drm_file *file;

	int ret;
@@ -156,6 +157,8 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor) 
	if (!file)

		return ERR_PTR(-ENOMEM);



	/* Get a unique identifier for fdinfo: */

	file->client_id = atomic64_inc_return(&ident);

	file->pid = get_pid(task_tgid(current));

	file->minor = minor;
@@ -868,6 +871,38 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e) 
}

EXPORT_SYMBOL(drm_send_event);



/**

 * drm_show_fdinfo - helper for drm file fops

 * @seq_file: output stream

 * @f: the device file instance

 *

 * Helper to implement fdinfo, for userspace to query usage stats, etc, of a

 * process using the GPU.  See also &drm_driver.show_fdinfo.

 *

 * For text output format description please see Documentation/gpu/drm-usage-stats.rst

 */

void drm_show_fdinfo(struct seq_file *m, struct file *f)

{

	struct drm_file *file = f->private_data;

	struct drm_device *dev = file->minor->dev;

	struct drm_printer p = drm_seq_file_printer(m);



	drm_printf(&p, "drm-driver:\t%s\n", dev->driver->name);

	drm_printf(&p, "drm-client-id:\t%llu\n", file->client_id);



	if (dev_is_pci(dev->dev)) {

		struct pci_dev *pdev = to_pci_dev(dev->dev);



		drm_printf(&p, "drm-pdev:\t%04x:%02x:%02x.%d\n",

			   pci_domain_nr(pdev->bus), pdev->bus->number,

			   PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));

	}



	if (dev->driver->show_fdinfo)

		dev->driver->show_fdinfo(&p, file);

}

EXPORT_SYMBOL(drm_show_fdinfo);



/**

 * mock_drm_getfile - Create a new struct file for the drm device

 * @minor: drm minor to wrap (e.g. #drm_device.primary)

include/drm/drm_drv.h

+7 −0
Original line number Diff line number Diff line
@@ -401,6 +401,13 @@ struct drm_driver { 
			       struct drm_device *dev, uint32_t handle,

			       uint64_t *offset);



	/**

	 * @show_fdinfo:

	 *

	 * Print device specific fdinfo.  See Documentation/gpu/drm-usage-stats.rst.

	 */

	void (*show_fdinfo)(struct drm_printer *p, struct drm_file *f);



	/** @major: driver major number */

	int major;

	/** @minor: driver minor number */

include/drm/drm_file.h

+4 −0
Original line number Diff line number Diff line
@@ -258,6 +258,9 @@ struct drm_file { 
	/** @pid: Process that opened this file. */

	struct pid *pid;



	/** @client_id: A unique id for fdinfo */

	u64 client_id;



	/** @magic: Authentication magic, see @authenticated. */

	drm_magic_t magic;
@@ -438,6 +441,7 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e); 
void drm_send_event_timestamp_locked(struct drm_device *dev,

				     struct drm_pending_event *e,

				     ktime_t timestamp);

void drm_show_fdinfo(struct seq_file *m, struct file *f);



struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);