linux-stable.git/include/drm/drm_file.h, branch v6.7

drm: Update file owner during use

2023-09-20T13:27:44+00:00

With the typical model where the display server opens the file descriptor
and then hands it over to the client(*), we were showing stale data in
debugfs.

Fix it by updating the drm_file->pid on ioctl access from a different
process.

The field is also made RCU protected to allow for lockless readers. Update
side is protected with dev->filelist_mutex.

Before:

$ cat /sys/kernel/debug/dri/0/clients
             command   pid dev master a   uid      magic
                Xorg  2344   0   y    y     0          0
                Xorg  2344   0   n    y     0          2
                Xorg  2344   0   n    y     0          3
                Xorg  2344   0   n    y     0          4

After:

$ cat /sys/kernel/debug/dri/0/clients
             command  tgid dev master a   uid      magic
                Xorg   830   0   y    y     0          0
       xfce4-session   880   0   n    y     0          1
               xfwm4   943   0   n    y     0          2
           neverball  1095   0   n    y     0          3

*)
More detailed and historically accurate description of various handover
implementation kindly provided by Emil Velikov:

"""
The traditional model, the server was the orchestrator managing the
primary device node. From the fd, to the master status and
authentication. But looking at the fd alone, this has varied across
the years.

IIRC in the DRI1 days, Xorg (libdrm really) would have a list of open
fd(s) and reuse those whenever needed, DRI2 the client was responsible
for open() themselves and with DRI3 the fd was passed to the client.

Around the inception of DRI3 and systemd-logind, the latter became
another possible orchestrator. Whereby Xorg and Wayland compositors
could ask it for the fd. For various reasons (hysterical and genuine
ones) Xorg has a fallback path going the open(), whereas Wayland
compositors are moving to solely relying on logind... some never had
fallback even.

Over the past few years, more projects have emerged which provide
functionality similar (be that on API level, Dbus, or otherwise) to
systemd-logind.
"""

v2:
 * Fixed typo in commit text and added a fine historical explanation
   from Emil.

Signed-off-by: Tvrtko Ursulin 
Cc: "Christian König" 
Cc: Daniel Vetter 
Acked-by: Christian König 
Reviewed-by: Emil Velikov 
Reviewed-by: Rob Clark 
Tested-by: Rob Clark 
Link: https://patchwork.freedesktop.org/patch/msgid/20230621094824.2348732-1-tvrtko.ursulin@linux.intel.com
Signed-off-by: Christian König

drm/debugfs: rework drm_debugfs_create_files implementation v2

2023-09-01T06:54:12+00:00

Use managed memory allocation for this. That allows us to not keep
track of all the files any more.

v2: keep drm_debugfs_cleanup(), but rename to drm_debugfs_unregister(),
    we still need to cleanup the symlink

Signed-off-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20230829110115.3442-6-christian.koenig@amd.com
Reviewed-by: Andi Shyti

drm/debugfs: rework debugfs directory creation v5

2023-09-01T06:51:18+00:00

Instead of the per minor directories only create a single debugfs
directory for the whole device directly when the device is initialized.

For DRM devices each minor gets a symlink to the per device directory
for now until we can be sure that this isn't useful any more in any way.

Accel devices create only the per device directory and also drops the mid
layer callback to create driver specific files.

v2: cleanup accel component as well
v3: fix typo when debugfs is disabled
v4: call drm_debugfs_dev_fini() during release as well,
    some kerneldoc typos fixed
v5: rebased and one more kerneldoc fix

Signed-off-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20230829110115.3442-4-christian.koenig@amd.com
Reviewed-by: Andi Shyti

drm/file: use explicit values for enum drm_minor_type

2023-07-17T08:40:41+00:00

This makes it clearer that the values cannot be changed because
they are ABI.

Signed-off-by: Simon Ser 
Reviewed-by:James Zhu 
Reviewed-by: Thomas Zimmermann 
Cc: Christian König 
Cc: Marek Olšák 
Cc: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20230714104557.518457-2-contact@emersion.fr

drm: Add fdinfo memory stats

2023-05-24T16:03:30+00:00

Add support to dump GEM stats to fdinfo.

v2: Fix typos, change size units to match docs, use div_u64
v3: Do it in core
v4: more kerneldoc
v5: doc fixes
v6: Actually use u64, bit more comment docs

Signed-off-by: Rob Clark 
Reviewed-by: Emil Velikov 
Reviewed-by: Daniel Vetter 
Acked-by: Tvrtko Ursulin 
Acked-by: Dave Airlie 
Signed-off-by: Neil Armstrong 
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-6-robdclark@gmail.com

drm: Add common fdinfo helper

2023-05-24T16:03:26+00:00

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: Daniel Vetter 
Signed-off-by: Rob Clark 
Acked-by: Dave Airlie 
Signed-off-by: Neil Armstrong 
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-3-robdclark@gmail.com

accel: Link to compute accelerator subsystem intro

2023-03-20T15:35:33+00:00

Commit 2c204f3d53218d ("accel: add dedicated minor for accelerator
devices") adds link to accelerator nodes section of DRM internals doc
(Documentation/gpu/drm-internals.rst), but the target doesn't exist.
Instead, there is only an introduction doc for computer accelerator
subsytem.

Link to that doc until there is documentation of accelerator internals.

Fixes: 2c204f3d53218d ("accel: add dedicated minor for accelerator devices")
Signed-off-by: Bagas Sanjaya 
Reviewed-by: Jeffrey Hugo 
Signed-off-by: Oded Gabbay

accel: add dedicated minor for accelerator devices

2022-11-22T11:14:44+00:00

The accelerator devices are exposed to user-space using a dedicated
major. In addition, they are represented in /dev with new, dedicated
device char names: /dev/accel/accel*. This is done to make sure any
user-space software that tries to open a graphic card won't open
the accelerator device by mistake.

The above implies that the minor numbering should be separated from
the rest of the DRM devices. However, to avoid code duplication, we
want the drm_minor structure to be able to represent the accelerator
device.

To achieve this, we add a new drm_minor* to drm_device that represents
the accelerator device. This pointer is initialized for drivers that
declare they handle compute accelerator, using a new driver feature
flag called DRIVER_COMPUTE_ACCEL. It is important to note that this
driver feature is mutually exclusive with DRIVER_RENDER. Devices that
want to expose both graphics and compute device char files should be
handled by two drivers that are connected using the auxiliary bus
framework.

In addition, we define a different IDR to handle the accelerators
minors. This is done to make the minor's index be identical to the
device index in /dev/. Any access to the IDR is done solely
by functions in accel_drv.c, as the IDR is define as static. The
DRM core functions call those functions in case they detect the minor's
type is DRM_MINOR_ACCEL.

We define a separate accel_open function (from drm_open) that the
accel drivers should set as their open callback function. Both these
functions eventually call the same drm_open_helper(), which had to be
changed to be non-static so it can be called from accel_drv.c.
accel_open() only partially duplicates drm_open as I removed some code
from it that handles legacy devices.

To help new drivers, I defined DEFINE_DRM_ACCEL_FOPS macro to easily
set the required function operations pointers structure.

Signed-off-by: Oded Gabbay 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Jeffrey Hugo 
Reviewed-by: Dave Airlie 
Acked-by: Thomas Zimmermann 
Acked-by: Jacek Lawrynowicz 
Tested-by: Jacek Lawrynowicz 
Reviewed-by: Melissa Wen

drm: Remove the drm_get_unmapped_area() helper

2022-08-04T15:39:27+00:00

This has been only used by the vmwgfx driver and vmwgfx over the last
year removed support for transparent hugepages on vram leaving
drm_get_unmapped_area completely unused.

There's no point in keeping unused code in core drm.

Signed-off-by: Zack Rusin 
Reviewed-by: Thomas Hellström 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Thomas Zimmermann 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220425203152.1314211-2-zack@kde.org

drm: fix a kernel-doc typo

2022-04-04T16:00:19+00:00

Fix a build warning from 'make htmldocs' by correcting the lock name
in the kernel-doc comment.

include/drm/drm_file.h:369: warning: Function parameter or member 'master_lookup_lock' not described in 'drm_file'

Signed-off-by: Randy Dunlap 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Simon Ser 
Signed-off-by: Simon Ser 
Link: https://patchwork.freedesktop.org/patch/msgid/20220403231040.18540-1-rdunlap@infradead.org