Commit Graph

9 Commits

Author SHA1 Message Date
Thierry Reding f2912237eb drm/aperture: Fix some kerneldoc comments
Reword some kerneldoc comments for the DRM aperture handling code.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220905162241.391226-1-thierry.reding@gmail.com
2022-09-12 09:34:07 +02:00
Thomas Zimmermann 7283f862bd drm: Implement DRM aperture helpers under video/
Implement DRM's aperture helpers under video/ for sharing with other
sub-systems. Remove DRM-isms from the interface. The helpers track
the ownership of framebuffer apertures and provide hand-over from
firmware, such as EFI and VESA, to native graphics drivers.

Other subsystems, such as fbdev and vfio, also have to maintain ownership
of framebuffer apertures. Moving DRM's aperture helpers to a more public
location allows all subsystems to interact with each other and share a
common implementation.

The aperture helpers are selected by the various firmware drivers within
DRM and fbdev, and the VGA text-console driver.

The original DRM interface is kept in place for use by DRM drivers.

v3:
	* prefix all interfaces with aperture_ (Javier)
	* rework and simplify documentation (Javier)
	* rename struct dev_aperture to struct aperture_range
	* rebase onto latest DRM
	* update MAINTAINERS entry

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220622140134.12763-3-tzimmermann@suse.de
2022-06-27 11:07:55 +02:00
Thomas Zimmermann fb84efa28a drm/aperture: Run fbdev removal before internal helpers
Always run fbdev removal first to remove simpledrm via
sysfb_disable(). This clears the internal state. The later call
to drm_aperture_detach_drivers() then does nothing. Otherwise,
with drm_aperture_detach_drivers() running first, the call to
sysfb_disable() uses inconsistent state.

Example backtrace show below:

[   11.663422] ==================================================================
[   11.663426] BUG: KASAN: use-after-free in device_del+0x79/0x5f0
[   11.663435] Read of size 8 at addr ffff888108185050 by task systemd-udevd/311
[   11.663440] CPU: 0 PID: 311 Comm: systemd-udevd Tainted: G            E     5
	.19.0-rc2-1-default+ #1689
[   11.663445] Hardware name: HP ProLiant DL120 G7, BIOS J01 04/21/2011
[   11.663447] Call Trace:
[   11.663449]  <TASK>
[   11.663451]  ? device_del+0x79/0x5f0
[   11.663456]  dump_stack_lvl+0x5b/0x73
[   11.663462]  print_address_description.constprop.0+0x1f/0x1b0
[   11.663468]  ? device_del+0x79/0x5f0
[   11.663471]  ? device_del+0x79/0x5f0
[   11.663475]  print_report.cold+0x3c/0x21c
[   11.663481]  ? lock_acquired+0x87/0x1e0
[   11.663484]  ? lock_acquired+0x87/0x1e0
[   11.663489]  ? device_del+0x79/0x5f0
[   11.663492]  kasan_report+0xbf/0xf0
[   11.663498]  ? device_del+0x79/0x5f0
[   11.663503]  device_del+0x79/0x5f0
[   11.663509]  ? device_remove_attrs+0x170/0x170
[   11.663514]  ? lock_is_held_type+0xe8/0x140
[   11.663523]  platform_device_del.part.0+0x19/0xe0
[   11.663530]  platform_device_unregister+0x1c/0x30
[   11.663535]  sysfb_disable+0x2d/0x70
[   11.663540]  remove_conflicting_framebuffers+0x1c/0xf0
[   11.663546]  remove_conflicting_pci_framebuffers+0x130/0x1a0
[   11.663554]  drm_aperture_remove_conflicting_pci_framebuffers+0x86/0xb0
[   11.663561]  ? mgag200_pci_remove+0x30/0x30 [mgag200]
[   11.663578]  mgag200_pci_probe+0x2d/0x140 [mgag200]

Reported-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Fixes: 873eb3b118 ("fbdev: Disable sysfb device registration when removing conflicting FBs")
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Changcheng Deng <deng.changcheng@zte.com.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20220617121027.30273-1-tzimmermann@suse.de
2022-06-21 12:54:34 +02:00
Cai Huoqing 0ae865ef92 drm: Fix typo in comments
fix typo for drm

v1->v2:
respin with the change "iff ==> implies that"

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730132729.376-1-caihuoqing@baidu.com
2021-08-02 10:19:43 +02:00
Thomas Zimmermann 97c9bfe3f6 drm/aperture: Pass DRM driver structure instead of driver name
Print the name of the DRM driver when taking over fbdev devices. Makes
the output to dmesg more consistent. Note that the driver name is only
used for printing a string to the kernel log. No UAPI is affected by this
change.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Nirmoy Das <nirmoy.das@amd.com>
Acked-by: Chen-Yu Tsai <wens@csie.org> # sun4i
Acked-by: Neil Armstrong <narmstrong@baylibre.com> # meson
Link: https://patchwork.freedesktop.org/patch/msgid/20210629135833.22679-1-tzimmermann@suse.de
2021-07-01 11:11:55 +02:00
Zou Wei 858aa5a4be drm/aperture: Fix missing unlock on error in devm_aperture_acquire()
Add the missing unlock before return from function devm_aperture_acquire()
in the error handling case.

Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 730e7992dc ("drm/aperture: Add infrastructure for aperture ownership")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/1620895564-52367-1-git-send-email-zou_wei@huawei.com
2021-05-13 15:06:32 +02:00
Thomas Zimmermann 730e7992dc drm/aperture: Add infrastructure for aperture ownership
Platform devices might operate on firmware framebuffers, such as VESA or
EFI. Before a native driver for the graphics hardware can take over the
device, it has to remove any platform driver that operates on the firmware
framebuffer. Aperture helpers provide the infrastructure for platform
drivers to acquire firmware framebuffers, and for native drivers to remove
them later on.

It works similar to the related fbdev mechanism. During initialization, the
platform driver acquires the firmware framebuffer's I/O memory and provides
a callback to be removed. The native driver later uses this information to
remove any platform driver for it's framebuffer I/O memory.

The aperture removal code is integrated into the existing code for removing
conflicting framebuffers, so native drivers use it automatically.

v5:
	* fix build error introduced by rebasing v4
	* fix typo in documentation
v4:
	* hide detach callback in implementation (Daniel)
	* documentation fixes
v3:
	* rebase onto existing aperture infrastructure
	* release aperture from list during detach; fix dangling apertures
	* don't export struct drm_aperture
	* document struct drm_aperture_funcs
v2:
	* rename plaform helpers to aperture helpers
	* tie to device lifetime with devm_ functions
	* removed unsued remove() callback
	* rename kickout to detach
	* make struct drm_aperture private
	* rebase onto existing drm_aperture.h header file
	* use MIT license only for simplicity
	* documentation

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: nerdopolis <bluescreen_avenger@verizon.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210430105840.30515-4-tzimmermann@suse.de
2021-05-01 12:45:03 +02:00
Thomas Zimmermann 603dc7ed91 drm/aperture: Inline fbdev conflict helpers into aperture helpers
Fbdev's helpers for handling conflicting framebuffer drivers are
related to framebuffer apertures, not console emulation. Therefore
remove them from drm_fb_helper.h and inline them into the aperture
helpers. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412131043.5787-4-tzimmermann@suse.de
2021-04-14 09:00:04 +02:00
Thomas Zimmermann 2916059147 drm/aperture: Add infrastructure for aperture ownership
Platform devices might operate on firmware framebuffers, such as VESA
or EFI. Before a native driver for the graphics hardware can take over
the device, it has to remove any platform driver that operates on the
firmware framebuffer. Aperture helpers provide the infrastructure for
native drivers to remove the generic ones.

For now, this only concerns generic fbdev drivers. Code for removing
these is provided by drm_fb_helper_remove_conflicting_framebuffers() et
al. Simply wrap these functions for now. At a later point, code can be
added for generic DRM drivers to acquire firmware framebuffers.

v2:
	* fix docs for drm_aperture_remove_framebuffers()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210412131043.5787-2-tzimmermann@suse.de
2021-04-14 09:00:04 +02:00