linux.git/drivers/gpu/drm/drm_internal.h, branch v5.8

drm: Manage drm_vblank_cleanup with drmm_

2020-03-26T14:38:17+00:00

Nothing special here, except that this is the first time that we
automatically clean up something that's initialized with an explicit
driver call. But the cleanup was done at the very end of the release
sequence for all drivers, and that's still the case. At least without
more uses of drmm_ through explicit driver calls.

Also for this one we need drmm_kcalloc, so lets add those.

The motivation here is to allow us to remove the explicit calls to
drm_dev_fini() from all drivers.

v2: Sort includes (Laurent)

v3: Motivate the change in the commit message better (Sam)

Acked-by: Sam Ravnborg 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-25-daniel.vetter@ffwll.ch

drm: Manage drm_gem_init with drmm_

2020-03-26T14:38:09+00:00

We might want to look into pushing this down into drm_mm_init, but
that would mean rolling out return codes to a pile of functions
unfortunately. So let's leave that for now.

Acked-by: Sam Ravnborg 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-24-daniel.vetter@ffwll.ch

drm: add managed resources tied to drm_device

2020-03-26T13:49:13+00:00

We have lots of these. And the cleanup code tends to be of dubious
quality. The biggest wrong pattern is that developers use devm_, which
ties the release action to the underlying struct device, whereas
all the userspace visible stuff attached to a drm_device can long
outlive that one (e.g. after a hotunplug while userspace has open
files and mmap'ed buffers). Give people what they want, but with more
correctness.

Mostly copied from devres.c, with types adjusted to fit drm_device and
a few simplifications - I didn't (yet) copy over everything. Since
the types don't match code sharing looked like a hopeless endeavour.

For now it's only super simplified, no groups, you can't remove
actions (but kfree exists, we'll need that soon). Plus all specific to
drm_device ofc, including the logging. Which I didn't bother to make
compile-time optional, since none of the other drm logging is compile
time optional either.

One tricky bit here is the chicken&egg between allocating your
drm_device structure and initiliazing it with drm_dev_init. For
perfect onion unwinding we'd need to have the action to kfree the
allocation registered before drm_dev_init registers any of its own
release handlers. But drm_dev_init doesn't know where exactly the
drm_device is emebedded into the overall structure, and by the time it
returns it'll all be too late. And forcing drivers to be able clean up
everything except the one kzalloc is silly.

Work around this by having a very special final_kfree pointer. This
also avoids troubles with the list head possibly disappearing from
underneath us when we release all resources attached to the
drm_device.

v2: Do all the kerneldoc at the end, to avoid lots of fairly pointless
shuffling while getting everything into shape.

v3: Add static to add/del_dr (Neil)
Move typo fix to the right patch (Neil)

v4: Enforce contract for drmm_add_final_kfree:

Use ksize() to check that the drm_device is indeed contained somewhere
in the final kfree(). Because we need that or the entire managed
release logic blows up in a pile of use-after-frees. Motivated by a
discussion with Laurent.

v5: Review from Laurent:
- %zu instead of casting size_t
- header guards
- sorting of includes
- guarding of data assignment if we didn't allocate it for a NULL
  pointer
- delete spurious newline
- cast void* data parameter correctly in ->release call, no idea how
  this even worked before

v6: Review from Sam
- Add the kerneldoc for the managed sub-struct back in, even if it
  doesn't show up in the generated html somehow.
- Explain why __always_inline.
- Fix bisectability around the final kfree() in drm_dev_relase(). This
  is just interim code which will disappear again.
- Some whitespace polish.
- Add debug output when drmm_add_action or drmm_kmalloc fail.

v7: My bisectability fix wasn't up to par as noticed by smatch.

v8: Remove unecessary {} around if else

v9: Use kstrdup_const, which requires kfree_const and introducing a free_dr()
helper (Thomas).

v10: kfree_const goes boom on the plain "kmalloc" assignment, somehow
we need to wrap that in kstrdup_const() too!! Also renumber revision
log, I somehow reset it midway thruh.

Reviewed-by: Sam Ravnborg 
Cc: Thomas Zimmermann 
Cc: Dan Carpenter 
Cc: Sam Ravnborg 
Cc: Laurent Pinchart 
Cc: Neil Armstrong 
Cc: "Rafael J. Wysocki" 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20200324124540.3227396-1-daniel.vetter@ffwll.ch

drm: convert .debugfs_init() hook to return void.

2020-03-18T16:53:28+00:00

As a result of commit 987d65d01356 (drm: debugfs: make
drm_debugfs_create_files() never fail) and changes to various debugfs
functions in drm/core and across various drivers, there is no need for
the drm_driver.debugfs_init() hook to have a return value. Therefore,
declare it as void.

This also includes refactoring all users of the .debugfs_init() hook to
return void across the subsystem.

v2: include changes to the hook and drivers that use it in one patch to
prevent driver breakage and enable individual successful compilation of
this change.

References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html
Signed-off-by: Wambui Karuga 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-18-wambui.karugax@gmail.com

drm/hdcp: optimizing the srm handling

2020-03-04T01:03:00+00:00

As we are not using the sysfs infrastructure anymore, link to it is
removed. And global srm data and mutex to protect it are removed,
with required handling at revocation check function.

v2:
  srm_data is dropped and few more comments are addressed.
v3:
  ptr passing around is fixed with functional testing.
v4:
  fix htmldoc [lkp]

Signed-off-by: Ramalingam C 
Suggested-by: Sean Paul 
Reviewed-by: Sean Paul 
Link: https://patchwork.freedesktop.org/patch/msgid/20200212102942.26568-2-ramalingam.c@intel.com

drm: Nerf drm_global_mutex BKL for good drivers

2020-02-11T14:03:09+00:00

This catches the majority of drivers (unfortunately not if we take
users into account, because all the big drivers have at least a
lastclose hook).

With the prep patches out of the way all drm state is fully protected
and either prevents or can deal with the races from dropping the BKL
around open/close. The only thing left to audit are the various driver
hooks - by keeping the BKL around if any of them are set we have a
very simple cop-out!

Note that one of the biggest prep pieces to get here was making
dev->open_count atomic, which was done in

commit 7e13ad896484a0165a68197a2e64091ea28c9602
Author: Chris Wilson 
Date:   Fri Jan 24 13:01:07 2020 +0000

    drm: Avoid drm_global_mutex for simple inc/dec of dev->open_count

v2:
- Rebase and fix locking in drm_open() (Chris)
- Indentation fix in drm_release
- Typo fix in the commit message (Sam)

Cc: Chris Wilson 
Cc: Sam Ravnborg 
Reviewed-by: Chris Wilson 
Tested-by: Thomas Zimmermann 
Acked-by: Thomas Zimmermann 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20200204150146.2006481-6-daniel.vetter@ffwll.ch

drm/pci: Only build drm_pci.c if CONFIG_PCI is set

2019-12-05T07:43:14+00:00

Non-PCI systems should not build PCI helpers. Set up source code, header
file and Makefile accordingly.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Emil Velikov 
Reviewed-by: Alex Deucher 
Link: https://patchwork.freedesktop.org/patch/msgid/20191203100406.9674-2-tzimmermann@suse.de

drm/gem: Unexport drm_gem_(un)pin/v(un)map

2019-06-17T15:37:01+00:00

They're purely for internal use, not for drivers.

Cc: Noralf Trønnes 
Cc: Christian König 
Reviewed-by: Eric Anholt 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20190614203615.12639-3-daniel.vetter@ffwll.ch

drm: no need to check return value of debugfs_create functions

2019-06-13T14:39:16+00:00

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Because there is no need to check these functions, a number of local
functions can be made to return void to simplify things as nothing can
fail.

Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Sean Paul 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20190613133439.GA6715@kroah.com

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

2019-05-28T07:39:08+00:00

This picks up rc2 for us as well.

Signed-off-by: Maarten Lankhorst