drm/format-helper: Pass format-conversion state to helpers

Pass an instance of struct drm_format_conv_state to DRM's format
conversion helpers. Update all callers.

Most drivers can use the format-conversion state from their shadow-
plane state. The shadow plane's destroy function releases the
allocated buffer. Drivers will later be able to allocate a buffer
of appropriate size in their plane's atomic_check code.

The gud driver uses a separate thread for committing updates. For
now, the update worker contains its own format-conversion state.

Images in the format-helper tests are small. The tests preallocate
a static page for the temporary buffer. Unloading the module releases
the memory.

v6:
* update patch for ssd132x support
v5:
* avoid using unusupported shadow-plane state in repaper (Noralf)
* fix documentation (Noralf, kernel test robot)
v3:
* store buffer in shadow-plane state (Javier, Maxime)
* replace ARRAY_SIZE() with sizeof() (Jani)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com> # ssd130x
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Lechner <david@lechnology.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231009141018.11291-4-tzimmermann@suse.de

drm/gud: Use size_add() in call to struct_size()

If, for any reason, the open-coded arithmetic causes a wraparound, the
protection that `struct_size()` adds against potential integer overflows
is defeated. Fix this by hardening call to `struct_size()` with `size_add()`.

Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
Signed-off-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/ZQSlyHKPdw/zsy4c@work
Signed-off-by: Kees Cook <keescook@chromium.org>

drm/gud: use vmalloc_array and vcalloc

Use vmalloc_array and vcalloc to protect against
multiplication overflows.

The changes were done using the following Coccinelle
semantic patch:

// <smpl>
@initialize:ocaml@
@@

let rename alloc =
match alloc with
"vmalloc" -> "vmalloc_array"
| "vzalloc" -> "vcalloc"
| _ -> failwith "unknown"

@@
size_t e1,e2;
constant C1, C2;
expression E1, E2, COUNT, x1, x2, x3;
typedef u8;
typedef __u8;
type t = {u8,__u8,char,unsigned char};
identifier alloc = {vmalloc,vzalloc};
fresh identifier realloc = script:ocaml(alloc) { rename alloc };
@@

(
alloc(x1*x2*x3)
|
alloc(C1 * C2)
|
alloc((sizeof(t)) * (COUNT), ...)
|
- alloc((e1) * (e2))
+ realloc(e1, e2)
|
- alloc((e1) * (COUNT))
+ realloc(COUNT, e1)
|
- alloc((E1) * (E2))
+ realloc(E1, E2)
)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230627144339.144478-4-Julia.Lawall@inria.fr

drm/gud: Fix missing include

Add missing vmalloc.h include.

Fixes: c17d048609bf ("drm/gud: Use the shadow plane helper")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221207-gud-missing-include-v1-0-c5b32c9c59da@tronnes.org

drm/gud: Enable synchronous flushing by default

gud has a module parameter that controls whether framebuffer flushing
happens synchronously during the commit or asynchronously in a worker.

GNOME before version 3.38 handled all displays in the same rendering loop.
This lead to gud slowing down the refresh rate for a faster monitor. This
has now been fixed so lets change the default.

The plan is to remove async flushing in the future. The code is now
structured in a way that makes it easy to do this.

Link: https://blogs.gnome.org/shell-dev/2020/07/02/splitting-up-the-frame-clock/
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-6-435037990a83@tronnes.org

drm/gud: Use the shadow plane helper

Use the shadow plane helper to take care of mapping the framebuffer for
CPU access. The synchronous flushing is now done inline without the use of
a worker. The async path now uses a shadow buffer to hold framebuffer
changes and it doesn't read the framebuffer behind userspace's back
anymore.

v2:
- Use src as variable name for iosys_map (Thomas)
- Prepare imported buffer for CPU access in the driver (Thomas)

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-5-435037990a83@tronnes.org

drm/gud: Prepare buffer for CPU access in gud_flush_work()

In preparation for moving to the shadow plane helper prepare the
framebuffer for CPU access as early as possible.

v2:
- Use src as variable name for iosys_map (Thomas)

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-4-435037990a83@tronnes.org

drm/gud: Split up gud_flush_work()

In preparation for inlining synchronous flushing split out the part of
gud_flush_work() that can be shared by the sync and async code paths.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-3-435037990a83@tronnes.org

drm/gud: Don't retry a failed framebuffer flush

If a framebuffer flush fails the driver will do one retry by requeing the
worker. Currently the worker is used even for synchronous flushing, but a
later patch will inline it, so this needs to change. Thinking about how to
solve this I came to the conclusion that this retry mechanism was a fix
for a problem that was only in the mind of the developer (me) and not
something that solved a real problem.

So let's remove this for now and revisit later should it become necessary.
gud_add_damage() has now only one caller so it can be inlined.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-2-435037990a83@tronnes.org

drm/gud: Fix UBSAN warning

UBSAN complains about invalid value for bool:

[ 101.165172] [drm] Initialized gud 1.0.0 20200422 for 2-3.2:1.0 on minor 1
[ 101.213360] gud 2-3.2:1.0: [drm] fb1: guddrmfb frame buffer device
[ 101.213426] usbcore: registered new interface driver gud
[ 101.989431] ================================================================================
[ 101.989441] UBSAN: invalid-load in linux/include/linux/iosys-map.h:253:9
[ 101.989447] load of value 121 is not a valid value for type '_Bool'
[ 101.989451] CPU: 1 PID: 455 Comm: kworker/1:6 Not tainted 5.18.0-rc5-gud-5.18-rc5 #3
[ 101.989456] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991, BIOS L71 Ver. 01.44 04/12/2018
[ 101.989459] Workqueue: events_long gud_flush_work [gud]
[ 101.989471] Call Trace:
[ 101.989474] <TASK>
[ 101.989479] dump_stack_lvl+0x49/0x5f
[ 101.989488] dump_stack+0x10/0x12
[ 101.989493] ubsan_epilogue+0x9/0x3b
[ 101.989498] __ubsan_handle_load_invalid_value.cold+0x44/0x49
[ 101.989504] dma_buf_vmap.cold+0x38/0x3d
[ 101.989511] ? find_busiest_group+0x48/0x300
[ 101.989520] drm_gem_shmem_vmap+0x76/0x1b0 [drm_shmem_helper]
[ 101.989528] drm_gem_shmem_object_vmap+0x9/0xb [drm_shmem_helper]
[ 101.989535] drm_gem_vmap+0x26/0x60 [drm]
[ 101.989594] drm_gem_fb_vmap+0x47/0x150 [drm_kms_helper]
[ 101.989630] gud_prep_flush+0xc1/0x710 [gud]
[ 101.989639] ? _raw_spin_lock+0x17/0x40
[ 101.989648] gud_flush_work+0x1e0/0x430 [gud]
[ 101.989653] ? __switch_to+0x11d/0x470
[ 101.989664] process_one_work+0x21f/0x3f0
[ 101.989673] worker_thread+0x200/0x3e0
[ 101.989679] ? rescuer_thread+0x390/0x390
[ 101.989684] kthread+0xfd/0x130
[ 101.989690] ? kthread_complete_and_exit+0x20/0x20
[ 101.989696] ret_from_fork+0x22/0x30
[ 101.989706] </TASK>
[ 101.989708] ================================================================================

The source of this warning is in iosys_map_clear() called from
dma_buf_vmap(). It conditionally sets values based on map->is_iomem. The
iosys_map variables are allocated uninitialized on the stack leading to
->is_iomem having all kinds of values and not only 0/1.

Fix this by zeroing the iosys_map variables.

Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
Cc: <stable@vger.kernel.org> # v5.18+
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-1-435037990a83@tronnes.org

drm/format-helper: Rework XRGB8888-to-GRAY8 conversion

Update XRGB8888-to-GRAY8 conversion to support struct iosys_map
and convert all users. Although these are single-plane color formats,
the new interface supports multi-plane formats for consistency with
drm_fb_blit().

v2:
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-12-tzimmermann@suse.de

drm/format-helper: Rework XRGB8888-to-RGB888 conversion

Update XRGB8888-to-RGB888 conversion to support struct iosys_map
and convert all users. Although these are single-plane color formats,
the new interface supports multi-plane formats for consistency with
drm_fb_blit().

v2:
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-8-tzimmermann@suse.de

drm/format-helper: Rework XRGB8888-to-RGBG565 conversion

Update XRGB8888-to-RGB565 conversion to support struct iosys_map
and convert all users. Although these are single-plane color formats,
the new interface supports multi-plane formats for consistency with
drm_fb_blit().

v2:
* update new Kunit tests
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-7-tzimmermann@suse.de

drm/format-helper: Rework XRGB8888-to-RGBG332 conversion

Update XRGB8888-to-RGB332 conversion to support struct iosys_map
and convert all users. Although these are single-plane color formats,
the new interface supports multi-plane formats for consistency with
drm_fb_blit().

v2:
* rebase onto refactored Kunit tests
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-6-tzimmermann@suse.de

drm/format-helper: Convert drm_fb_swab() to struct iosys_map

Convert drm_fb_swab() to use struct iosys_map() and convert users. The
new interface supports multi-plane color formats, but implementation
only supports a single plane for now.

v2:
* use drm_format_info_bpp() (Sam)
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-5-tzimmermann@suse.de

drm/format-helper: Merge drm_fb_memcpy() and drm_fb_memcpy_toio()

Merge drm_fb_memcpy() and drm_fb_memcpy_toio() into a drm_fb_memcpy()
that uses struct iosys_map for buffers. The new function also supports
multi-plane color formats. Convert all users of the original helpers.

v2:
* rebase onto refactored mgag200
* use drm_formap_info_bpp() (Sam)
* do static init in hyperv and mgag200 (Sam)
* update documentation (Sam)
* add TODO on vaddr location (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-4-tzimmermann@suse.de

drm/gud: Fix endianness in gud_xrgb8888_to_color() helper

DRM formats are defined to be little-endian, unless the
DRM_FORMAT_BIG_ENDIAN flag is set. Hence when converting from one
format to another, multi-byte pixel values loaded from memory must be
converted from little-endian to host-endian. Conversely, multi-byte
pixel values written to memory must be converted from host-endian to
little-endian. Currently only drm_fb_xrgb8888_to_rgb332_line() includes
endianness handling.

Fix gud_xrgb8888_to_color() on big-endian platforms by adding the
missing endianness handling.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/b47589ed5d8ca44e0956684412e3f16f3227f887.1657300532.git.geert@linux-m68k.org

dma-buf-map: Rename to iosys-map

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: Lucas De Marchi <lucas.demarchi@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204170541.829227-1-lucas.demarchi@intel.com

drm/format-helper: Rework format-helper conversion functions

Move destination-buffer clipping from all format-helper conversion
functions into callers. Support destination-buffer pitch. Only
distinguish between system and I/O memory, but use same logic
everywhere.

Simply harmonize the interface and semantics of the existing code.
Not all conversion helpers support all combinations of parameters.
We have to add additional features when we need them.

v2:
* fix default destination pitch in drm_fb_xrgb8888_to_gray8()
(Noralf)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211110103702.374-5-tzimmermann@suse.de

drm/format-helper: Add destination-buffer pitch to drm_fb_swab()

Add destination-buffer pitch as argument to drm_fb_swab(). Done for
consistency with the rest of the interface.

v2:
* update documentation (Noralf)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211110103702.374-4-tzimmermann@suse.de

drm/format-helper: Rework format-helper memcpy functions

Move destination-buffer clipping from all format-helper memcpy
function into callers. Support destination-buffer pitch. Only
distinguish between system and I/O memory, but use same logic
everywhere.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211110103702.374-3-tzimmermann@suse.de

drm/gud: Add GUD_PIXEL_FORMAT_RGB888

Add support for the RGB888 pixel format.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929191201.34456-7-noralf@tronnes.org

drm/gud: Add GUD_PIXEL_FORMAT_RGB332

Add support for the RGB332 pixel format.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929191201.34456-6-noralf@tronnes.org

drm/gud: Add GUD_PIXEL_FORMAT_R8

Add support for 8-bit greyscale format.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929191201.34456-5-noralf@tronnes.org

drm/gud: Get offset-adjusted mapping from drm_gem_fb_vmap()

Pass the data parameter to drm_gem_fb_vmap() to retrieve pointers
to the data. This address is different from the mapping addresses
for framebuffers with non-zero offsets. Replaces gud's internal
computation.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210803125928.27780-4-tzimmermann@suse.de

drm/gem: Provide offset-adjusted framebuffer BO mappings

Add an additional argument to drm_gem_fb_vmap() to return each BO's
mapping adjusted by the respective offset. Update all callers.

The newly returned values point to the first byite of the data stored
in the framebuffer BOs. Drivers that access the BO data should use it.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210803125928.27780-2-tzimmermann@suse.de

drm/gud: Map framebuffer BOs with drm_gem_fb_vmap()

Abstract the framebuffer details by mapping its BOs with a call
to drm_gem_fb_vmap(). Unmap with drm_gem_fb_vunmap().

The call to drm_gem_fb_vmap() ensures that all BOs are mapped
correctly. Gud still only supports single-plane formats.

No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210730183511.20080-5-tzimmermann@suse.de

drm/gud: Use framebuffer dma-buf helpers

Replace dma_buf_begin_cpu_access() with drm_gem_fb_begin_cpu_access();
same for _end_cpu_access(). Remove some boiler-plate code. No functional
changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-5-tzimmermann@suse.de

drm/gud: Add async_flush module parameter

Provide a way for userspace to choose synchronous flushing/pageflips.
This helps save CPU and power.

It is also useful for test scripts since userspace can know when a flush
has happended and wait before doing the next visual test.

Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Peter Stuge <peter@stuge.se>
Link: https://patchwork.freedesktop.org/patch/msgid/20210703141321.35494-2-noralf@tronnes.org

drm/gud: Use scatter-gather USB bulk transfer

There'a limit to how big a kmalloc buffer can be, and as memory gets
fragmented it becomes more difficult to get big buffers. The downside of
smaller buffers is that the driver has to split the transfer up which
hampers performance. Compression might also take a hit because of the
splitting.

Solve this by allocating the transfer buffer using vmalloc and create a
SG table to be passed on to the USB subsystem. vmalloc_32() is used to
avoid DMA bounce buffers on USB controllers that can only access 32-bit
addresses.

This also solves the problem that split transfers can give host side
tearing since flushing is decoupled from rendering.

usb_sg_wait() doesn't have timeout handling builtin, so it is wrapped in
a timer like 4 out of 6 users in the kernel have done.

v2:
- Use DIV_ROUND_UP (Linus)
- Add timeout note to the commit log (Linus)
- Expand note about upper buffer limit (Linus)
- Change var name s/timer/ctx/ in gud_usb_bulk_timeout()

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210701170748.58009-2-noralf@tronnes.org

drm/gud: Remove unneeded semicolon

drivers/gpu/drm/gud/gud_connector.c:658:2-3: Unneeded semicolon
drivers/gpu/drm/gud/gud_connector.c:186:2-3: Unneeded semicolon
drivers/gpu/drm/gud/gud_drv.c:511:3-4: Unneeded semicolon
drivers/gpu/drm/gud/gud_pipe.c:127:4-5: Unneeded semicolon

Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
[fix subject and squash 3 per file patches]
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210322174434.58849-2-noralf@tronnes.org

drm: Add GUD USB Display driver

This adds a USB display driver with the intention that it can be
used with future USB interfaced low end displays/adapters. The Linux
gadget device driver will serve as the canonical device implementation.

The following DRM properties are supported:
- Plane rotation
- Connector TV properties

There is also support for backlight brightness exposed as a backlight
device.

Display modes can be made available to the host driver either as DRM
display modes or through EDID. If both are present, EDID is just passed
on to userspace.

Performance is preferred over color depth, so if the device supports
RGB565, DRM_CAP_DUMB_PREFERRED_DEPTH will return 16.

If the device transfer buffer can't fit an uncompressed framebuffer
update, the update is split up into parts that do fit.

Optimal user experience is achieved by providing damage reports either by
setting FB_DAMAGE_CLIPS on pageflips or calling DRM_IOCTL_MODE_DIRTYFB.

LZ4 compression is used if the device supports it.

The driver supports a one bit monochrome transfer format: R1. This is not
implemented in the gadget driver. It is added in preparation for future
monochrome e-ink displays.

The driver is MIT licensed to smooth the path for any BSD port of the
driver.

v2:
- Use devm_drm_dev_alloc() and drmm_mode_config_init()
- drm_fbdev_generic_setup: Use preferred_bpp=0, 16 was a copy paste error
- The drm_backlight_helper is dropped, copy in the code
- Support protocol version backwards compatibility for device

v3:
- Use donated Openmoko USB pid
- Use direct compression from framebuffer when pitch matches, not only on
full frames, so split updates can benefit
- Use __le16 in struct gud_drm_req_get_connector_status
- Set edid property when the device only provides edid
- Clear compression fields in struct gud_drm_req_set_buffer
- Fix protocol version negotiation
- Remove mode->vrefresh, it's calculated

v4:
- Drop the status req polling which was a workaround for something that
turned out to be a dwc2 udc driver problem
- Add a flag for the Linux gadget to require a status request on
SET operations. Other devices will only get status req on STALL errors
- Use protocol specific error codes (Peter)
- Add a flag for devices that want to receive the entire framebuffer on
each flush (Lubomir)
- Retry a failed framebuffer flush
- If mode has changed wait for worker and clear pending damage before
queuing up new damage, fb width/height might have changed
- Increase error counter on bulk transfer failures
- Use DRM_MODE_CONNECTOR_USB
- Handle R1 kmalloc error (Peter)
- Don't try and replicate the USB get descriptor request standard for the
display descriptor (Peter)
- Make max_buffer_size optional (Peter), drop the pow2 requirement since
it's not necessary anymore.
- Don't pre-alloc a control request buffer, it was only 4k
- Let gud.h describe the whole protocol explicitly and don't let DRM
leak into it (Peter)
- Drop display mode .hskew and .vscan from the protocol
- Shorten names: s/GUD_DRM_/GUD_/ s/gud_drm_/gud_/ (Peter)
- Fix gud_pipe_check() connector picking when switching connector
- Drop gud_drm_driver_gem_create_object() cached is default now
- Retrieve USB device from struct drm_device.dev instead of keeping a
pointer
- Honour fb->offsets[0]
- Fix mode fetching when connector status is forced
- Check EDID length reported by the device
- Use drm_do_get_edid() so userspace can overrride EDID
- Set epoch counter to signal connector status change
- gud_drm_driver can be const now

v5:
- GUD_DRM_FORMAT_R1: Use non-human ascii values (Daniel)
- Change name to: GUD USB Display (Thomas, Simon)
- Change one __u32 -> __le32 in protocol header
- Always log fb flush errors, unless the previous one failed
- Run backlight update in a worker to avoid upsetting lockdep (Daniel)
- Drop backlight_ops.get_brightness, there's no readback from the device
so it doesn't really add anything.
- Set dma mask, needed by dma-buf importers

v6:
- Use obj-y in Makefile (Peter)
- Fix missing le32_to_cpu() when using GUD_DISPLAY_MAGIC (Peter)
- Set initial brightness on backlight device

v7:
- LZ4_compress_default() can return zero, check for that
- Fix memory leak in gud_pipe_check() error path (Peter)
- Improve debug and error messages (Peter)
- Don't pass length in protocol structs (Peter)
- Pass USB interface to gud_usb_control_msg() et al. (Peter)
- Improve gud_connector_fill_properties() (Peter)
- Add GUD_PIXEL_FORMAT_RGB111 (Peter)
- Remove GUD_REQ_SET_VERSION (Peter)
- Fix DRM_IOCTL_MODE_OBJ_SETPROPERTY and the rotation property
- Fix dma-buf import (Thomas)

v8:
- Forgot to filter RGB111 from reaching userspace
- Handle a device that only returns unknown device properties (Peter)
- s/GUD_PIXEL_FORMAT_RGB111/GUD_PIXEL_FORMAT_XRGB1111/ (Peter)
- Fix R1 and XRGB1111 format conversion
- Add FIXME about Big Endian being broken (Peter, Ilia)

Cc: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Peter Stuge <peter@stuge.se>
Tested-by: Peter Stuge <peter@stuge.se>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210313112545.37527-4-noralf@tronnes.org