This reverts commit 5fc586a0.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-4-tzimmermann@suse.de
(cherry picked from commit e3ddd2d2)

This reverts commit 7f5cc4a3.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-3-tzimmermann@suse.de
(cherry picked from commit 8b83e1a4)

This reverts commit 27c3e945.

Needed to restore the fbdev damage worker. There have been bug reports
about locking order [1] and incorrectly takens branches. [2] Restore
the damage worker until these problems have been resovled.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://intel-gfx-ci.01.org/tree/drm-tip/fi-kbl-8809g.html # 1
Link: https://lore.kernel.org/dri-devel/20221115115819.23088-6-tzimmermann@suse.de/T/#m06eedc0a468940e4cbbd14ca026733b639bc445a # 2
Link: https://patchwork.freedesktop.org/patch/msgid/20221118133535.9739-2-tzimmermann@suse.de
(cherry picked from commit 7aa3d63e)

The fbdev damage worker is unused, so remove it.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-7-tzimmermann@suse.de

Schedule the deferred-I/O worker instead of the damage worker after
writing to the fbdev framebuffer. The deferred-I/O worker then performs
the dirty-fb update. The fbdev emulation will initialize deferred I/O
for all drivers that require damage updates. It is therefore a valid
assumption that the deferred-I/O worker is present.

It would be possible to perform the damage handling directly from within
the write operation. But doing this could increase the overhead of the
write or interfere with a concurrently scheduled deferred-I/O worker.
Instead, scheduling the deferred-I/O worker with its regular delay of
50 ms removes load off the write operation and allows the deferred-I/O
worker to handle multiple write operations that arrived during the delay
time window.

v3:
	* remove unused variable (lkp)
v2:
	* keep drm_fb_helper_damage() (Daniel)
	* use fb_deferred_io_schedule_flush() (Daniel)
	* clarify comments (Daniel)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-6-tzimmermann@suse.de

Call fb_dirty directly from drm_fb_helper_deferred_io() to avoid the
latency of running the damage worker.

The deferred-I/O helper drm_fb_helper_deferred_io() runs in a worker
thread at regular intervals as part of writing to mmaped framebuffer
memory. It used to schedule the fbdev damage worker to flush the
framebuffer. Changing this to flushing the framebuffer directly avoids
the latency introduced by the damage worker.

v2:
	* remove fb_dirty from defio in separate patch (Daniel)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-5-tzimmermann@suse.de

The helper for processing deferred I/O on pages has no dependency on
the fb_dirty damge-handling callback; so remove the test. In practice,
deferred I/O is only used with damage handling and the damage worker
already guarantees the presence of the fb_dirty callback.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-4-tzimmermann@suse.de

Move the dirty-fb update from the damage-worker callback into the
new helper drm_fb_helper_fb_dirty(), so that it can run outside the
damage worker. This change will help to remove the damage worker
entirely. No functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-3-tzimmermann@suse.de

Set the damage area in the new helper drm_fb_helper_add_damage_clip().
It can now be updated without scheduling the damage worker. This change
will help to remove the damage worker entirely. No functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20221115115819.23088-2-tzimmermann@suse.de

Clarify documentation in the use of struct drm_driver.last_close and
struct drm_mode_config_funcs.output_poll_changed. Those callbacks should
not be said for fbdev implementations on top of struct drm_client_funcs.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-24-tzimmermann@suse.de

Move the generic fbdev implementation into its own source and header
file. Adapt drivers. No functional changes, but some of the internal
helpers have been renamed to fit into the drm_fbdev_ naming scheme.

v3:
	* rename drm_fbdev.{c,h} to drm_fbdev_generic.{c,h}
	* rebase onto vmwgfx changes
	* rebase onto xlnx changes
	* fix include statements in amdgpu
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-22-tzimmermann@suse.de

Uncouple the parameter drm_leak_fbdev_smem from the implementation by
setting a flag in struct drm_fb_helper. This will help to move the
generic fbdev emulation into its own source file, while keeping the
parameter in drm_fb_helper.c. No functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-21-tzimmermann@suse.de

Initialize the generic fbdev emulation even if it has been disabled
on the kernel command line. The hotplug and mode initialization will
fail accordingly.

The kernel parameter can still be changed at runtime and the emulation
will initialize after hotplugging the connector.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-20-tzimmermann@suse.de

Pull the test for fb_dirty into the caller to avoid extra work
if no callback has been set. In this case no damage handling is
required and no damage area needs to be computed. Print a warning
if the damage worker runs without getting an fb_dirty callback.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-19-tzimmermann@suse.de

Implement the fbdev's read/write helpers with the same functions. Use
the generic fbdev's code as template. Convert all drivers.

DRM's fb helpers must implement regular I/O functionality in struct
fb_ops and possibly perform a damage update. Handle all this in the
same functions and convert drivers. The functionality has been used
as part of the generic fbdev code for some time. The drivers don't
set struct drm_fb_helper.fb_dirty, so they will not be affected by
damage handling.

For I/O memory, fb helpers now provide drm_fb_helper_cfb_read() and
drm_fb_helper_cfb_write(). Several drivers require these. Until now
tegra used I/O read and write, although the memory buffer appears to
be in system memory. So use _sys_ helpers now.

v3:
	* fix docs (Javier)
v2:
	* rebase onto vmwgfx changes
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-18-tzimmermann@suse.de

Call struct fb_ops.fb_sync in drm_fbdev_{read,write}() to mimic the
behavior of fbdev. Fbdev implementations of fb_read and fb_write in
struct fb_ops invoke fb_sync to synchronize with outstanding operations
before I/O. Doing the same in DRM implementations will allow us to use
them throughout DRM drivers.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-17-tzimmermann@suse.de

The fbdev helpers implement a damage worker that forwards fbdev
updates to the DRM driver. The worker's update logic depends on
the generic fbdev emulation. Separate the two via function pointer.

The generic fbdev emulation sets struct drm_fb_helper_funcs.fb_dirty,
a new callback that hides the update logic from the damage worker.
It's not possible to use the generic logic with other fbdev emulation,
because it contains additional code for the shadow buffering that
the generic emulation employs.

DRM drivers with internal fbdev emulation can set fb_dirty to their
own implementation if they require damage handling; although no such
drivers currently exist.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-16-tzimmermann@suse.de

Rename drm_fb_helper_unregister_fbi() to drm_fb_helper_unregister_info()
as part of unifying the naming within fbdev helpers. Adapt drivers. No
functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-15-tzimmermann@suse.de

Rename drm_fb_helper_alloc_fbi() to drm_fb_helper_alloc_info() as
part of unifying the naming within fbdev helpers. Adapt drivers. No
functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-14-tzimmermann@suse.de

Rename struct drm_fb_helper.fbdev to info. The current name is
misleading as it overlaps with generic fbdev naming conventions.
Adapt to the usual naming in fbdev drivers by calling the field
'info'. No functional changes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-13-tzimmermann@suse.de

Add support for color-indexed frame buffer formats with two, four, and
sixteen colors to the DRM framebuffer helper functions:
  1. Add support for 1, 2, and 4 bits per pixel to the damage helper,
  2. For color-indexed modes, the length of the color bitfields must be
     set to the color depth, else the logo code may pick a logo with too
     many colors.  Drop the incorrect DAC width comment, which
     originates from the i915 driver.
  3. Accept C[124] modes when validating or filling in struct
     fb_var_screeninfo, and use the correct number of bits per pixel.
  4. Set the visual to FB_VISUAL_PSEUDOCOLOR for all color-indexed
     modes.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/db3e80b445df661ff0cd7e698507a8d24a4c867e.1657294931.git.geert@linux-m68k.org

Clip memory range to screen-buffer size to avoid out-of-bounds access
in fbdev deferred I/O's damage handling.

Fbdev's deferred I/O can only track pages. From the range of pages, the
damage handler computes the clipping rectangle for the display update.
If the fbdev screen buffer ends near the beginning of a page, that page
could contain more scanlines. The damage handler would then track these
non-existing scanlines as dirty and provoke an out-of-bounds access
during the screen update. Hence, clip the maximum memory range to the
size of the screen buffer.

While at it, rename the variables min/max to min_off/max_off in
drm_fb_helper_deferred_io(). This avoids confusion with the macros of
the same name.
Reported-by: NNuno Gonçalves <nunojpg@gmail.com>
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Tested-by: NNuno Gonçalves <nunojpg@gmail.com>
Fixes: 67b723f5 ("drm/fb-helper: Calculate damaged area in separate helper")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: <stable@vger.kernel.org> # v5.18+
Link: https://patchwork.freedesktop.org/patch/msgid/20220621104617.8817-1-tzimmermann@suse.de

drm_crtc.h has no need for drm_frambuffer.h, so don't include it.
Avoids useless rebuilds of the entire universe when
touching drm_framebuffer.h.

Quite a few placs do currently depend on drm_framebuffer.h without
actually including it directly. All of those need to be fixed
up.

v2: Fix up msm some more
v2: Deal with ingenic and shmobile as well
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220614095449.29311-1-ville.syrjala@linux.intel.comAcked-by: NSam Ravnborg <sam@ravnborg.org>
Acked-by: NJani Nikula <jani.nikula@intel.com>

Rename various instances of pagelist to pagereflist. The list now
stores pageref structures, so the new name is more appropriate.

In their write-back helpers, several fbdev drivers refer to the
pageref list in struct fb_deferred_io instead of using the one
supplied as argument to the function. Convert them over to the
supplied one. It's the same instance, so no change of behavior
occurs.

v4:
	* fix commit message (Javier)
Suggested-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-5-tzimmermann@suse.de

Store the per-page state for fbdev's deferred I/O in struct
fb_deferred_io_pageref. Maintain a list of pagerefs for the pages
that have to be written back to video memory. Update all affected
drivers.

As with pages before, fbdev acquires a pageref when an mmaped page
of the framebuffer is being written to. It holds the pageref in a
list of all currently written pagerefs until it flushes the written
pages to video memory. Writeback occurs periodically. After writeback
fbdev releases all pagerefs and builds up a new dirty list until the
next writeback occurs.

Using pagerefs has a number of benefits.

For pages of the framebuffer, the deferred I/O code used struct
page.lru as an entry into the list of dirty pages. The lru field is
owned by the page cache, which makes deferred I/O incompatible with
some memory pages (e.g., most notably DRM's GEM SHMEM allocator).
struct fb_deferred_io_pageref now provides an entry into a list of
dirty framebuffer pages, freeing lru for use with the page cache.

Drivers also assumed that struct page.index is the page offset into
the framebuffer. This is not true for DRM buffers, which are located
at various offset within a mapped area. struct fb_deferred_io_pageref
explicitly stores an offset into the framebuffer. struct page.index
is now only the page offset into the mapped area.

These changes will allow DRM to use fbdev deferred I/O without an
intermediate shadow buffer.

v3:
	* use pageref->offset for sorting
	* fix grammar in comment
v2:
	* minor fixes in commit message
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-3-tzimmermann@suse.de

The fbdev mmap function fb_mmap() unconditionally overrides the
driver's implementation if deferred I/O has been activated. This
makes it hard to implement mmap with anything but a vmalloc()'ed
software buffer. That is specifically a problem for DRM, where
video memory is maintained by a memory manager.

Leave the mmap handling to drivers and expect them to call the
helper for deferred I/O by thmeselves.

v4:
	* unlock mm_lock in fb_mmap() error path (Dan)
v3:
	* fix warning if fb_mmap is missing (kernel test robot)
v2:
	* print a helpful error message if the defio setup is
	  incorrect (Javier)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220429100834.18898-2-tzimmermann@suse.de

In certain situations it's useful to be able to write to an
offset of the mapping. Add a dst_offset to iosys_map_memcpy_to().

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-2-lucas.demarchi@intel.com

Clip the damage area horizontally if only a single scanline has been
changed. This is helpful to reduce the memcpy overhead for small writes.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-6-tzimmermann@suse.de

Write helpers used to mark the complete screen as dirty. This is
wasteful for writes that only change a small portion of the screen.
Fix the problem by computing the damaged area from the written
memory range and perform damage handling accordingly.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-5-tzimmermann@suse.de

Add drm_fb_helper_memory_range_to_clip(), a helper function that
accepts an linear range of video memory and converts it into a
rectangle. The computed rectangle describes the damaged area in
terms of scanlines and pixels per scanline.

While at it, make the code more readable by using struct drm_rect
and related helpers.

The code was previously part of the deferred I/O helpers, but is
also useful for damage handling of regular write operations. Update
the deferred I/O code to use the new function.

v2:
	* rename helper (Javier)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-4-tzimmermann@suse.de

Don't clip the damage rectangle against the viewport. This only
works if the viewport is located at the beginning of the video
memory and the video memory doesn't extend the screen (i.e., if
there's no overallocation).

Fbdev emulation transfers data from write operations into a
possible shadow buffer, then into a GEM buffer object, and finally
via graphics driver onto the screen.

If callers write outside the currently visible area, clipping the
damage rectangle against the viewport will loose these updates in
the shadow buffer and the fbdev's buffer object will contain stale
data. Panning the viewport to the stale area of the buffer will
display obsolete data.

Instead, mark all written areas as damaged, so that the damage
handler updates the buffer object from the shadow buffer for all
such areas. The graphics driver's later has the option of clipping
the damaged area against the viewport when updating the screen
from the buffer object.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-3-tzimmermann@suse.de

Computing the clip rectangle is prone to off-by-one errors when writes
happen near the end of a memory page. Point the end of the memory area
to the first trailing byte, so that (end - start) returns the area's
length.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209161617.3553-2-tzimmermann@suse.de

Rename struct dma_buf_map to struct iosys_map and corresponding APIs.
Over time dma-buf-map grew up to more functionality than the one used by
dma-buf: in fact it's just a shim layer to abstract system memory, that
can be accessed via regular load and store, from IO memory that needs to
be acessed via arch helpers.

The idea is to extend this API so it can fulfill other needs, internal
to a single driver. Example: in the i915 driver it's desired to share
the implementation for integrated graphics, which uses mostly system
memory, with discrete graphics, which may need to access IO memory.

The conversion was mostly done with the following semantic patch:

	@r1@
	@@
	- struct dma_buf_map
	+ struct iosys_map

	@r2@
	@@
	(
	- DMA_BUF_MAP_INIT_VADDR
	+ IOSYS_MAP_INIT_VADDR
	|
	- dma_buf_map_set_vaddr
	+ iosys_map_set_vaddr
	|
	- dma_buf_map_set_vaddr_iomem
	+ iosys_map_set_vaddr_iomem
	|
	- dma_buf_map_is_equal
	+ iosys_map_is_equal
	|
	- dma_buf_map_is_null
	+ iosys_map_is_null
	|
	- dma_buf_map_is_set
	+ iosys_map_is_set
	|
	- dma_buf_map_clear
	+ iosys_map_clear
	|
	- dma_buf_map_memcpy_to
	+ iosys_map_memcpy_to
	|
	- dma_buf_map_incr
	+ iosys_map_incr
	)

	@@
	@@
	- #include <linux/dma-buf-map.h>
	+ #include <linux/iosys-map.h>

Then some files had their includes adjusted and some comments were
update to remove mentions to dma-buf-map.

Since this is not specific to dma-buf anymore, move the documentation to
the "Bus-Independent Device Accesses" section.

v2:
  - Squash patches

v3:
  - Fix wrong removal of dma-buf.h from MAINTAINERS
  - Move documentation from dma-buf.rst to device-io.rst

v4:
  - Change documentation title and level
Signed-off-by: NLucas De Marchi <lucas.demarchi@intel.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NSumit Semwal <sumit.semwal@linaro.org>
Acked-by: NThomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

Mark screen buffers in system memory with FBINFO_VIRTFB. Otherwise, fbdev
deferred I/O marks mmap'ed areas of system memory with VM_IO. (There's an
inverse relationship between the two flags.)

For shadow buffers, also set the FBINFO_READS_FAST hint.

v3:
	* change FB_ to FBINFO_ in commit description
v2:
	* updated commit description (Daniel)
	* added Fixes tag
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Fixes: d536540f ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.19+
Link: https://patchwork.freedesktop.org/patch/msgid/20220201115305.9333-1-tzimmermann@suse.de

This reverts commit b3484d2b.

That change attempted to improve the DRM drivers fbdev emulation device
names to avoid having confusing names like "simpledrmdrmfb" in /proc/fb.

But unfortunately, there are user-space programs such as pm-utils that
match against the fbdev names and so broke after the mentioned commit.

Since the names in /proc/fb are used by tools that consider it an uAPI,
let's restore the old names even when this lead to silly names like the
one mentioned above.

Fixes: b3484d2b ("drm/fb-helper: improve DRM fbdev emulation device names")
Reported-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211020165740.3011927-1-javierm@redhat.com

Allocating a shadow buffer of the height of the buffer object does
not support fbdev overallocation. Use surface height instead.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: NNoralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211110103702.374-7-tzimmermann@suse.de

Clamp the fbdev surface size of the available maximumi height to avoid
failing to init console emulation. An example error is shown below.

  bad framebuffer height 2304, should be >= 768 && <= 768
  [drm] Initialized simpledrm 1.0.0 20200625 for simple-framebuffer.0 on minor 0
  simple-framebuffer simple-framebuffer.0: [drm] *ERROR* fbdev: Failed to setup generic emulation (ret=-22)

This is especially a problem with drivers that have very small screen
sizes and cannot over-allocate at all.

v2:
	* reduce warning level (Ville)
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Fixes: 11e8f5fd ("drm: Add simpledrm driver")
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reported-by: NAmanoel Dawod <kernel@amanoeldawod.com>
Reported-by: NZoltán Kővágó <dirty.ice.hu@gmail.com>
Reported-by: NMichael Stapelberg <michael+lkml@stapelberg.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20211005070355.7680-1-tzimmermann@suse.deSigned-off-by: NDave Airlie <airlied@redhat.com>

This reverts commit 7c5f2eec.

This patchset breaks on intel platforms and was previously NACK'd by
Ville.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fernando Ramos <greenfoo@u92.eu>
Acked-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211002154542.15800-13-sean@poorly.run

As requested in Documentation/gpu/todo.rst, replace driver calls to
drm_modeset_lock_all() with DRM_MODESET_LOCK_ALL_BEGIN() and
DRM_MODESET_LOCK_ALL_END()
Signed-off-by: NFernando Ramos <greenfoo@u92.eu>
Reviewed-by: NSean Paul <sean@poorly.run>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924064324.229457-5-greenfoo@u92.eu

fix typo for drm

v1->v2:
respin with the change "iff ==> implies that"
Signed-off-by: NCai Huoqing <caihuoqing@baidu.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730132729.376-1-caihuoqing@baidu.com