drm/ttm: replace busy placement with flags v6

Instead of a list of separate busy placement add flags which indicate
that a placement should only be used when there is room or if we need to
evict.

v2: add missing TTM_PL_FLAG_IDLE for i915
v3: fix auto build test ERROR on drm-tip/drm-tip
v4: fix some typos pointed out by checkpatch
v5: cleanup some rebase problems with VMWGFX
v6: implement some missing VMWGFX functionality pointed out by Zack,
rename the flags as suggested by Michel, rebase on drm-tip and
adjust XE as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Reviewed-by: Zack Rusin <zack.rusin@broadcom.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240112125158.2748-4-christian.koenig@amd.com

drm/vram-helper: Fix 'multi-line' kernel-doc comments

Reformat lines in kernel-doc comments, which make use of the backslash at
the end to suggest it is a multi-line comment. kernel-doc is able to
process e.g. the short description of a function properly, even if it is
across two lines.

No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240122093152.22536-2-anna-maria@linutronix.de

drm/vram-helper: fix function names in vram helper doc

Refer to drmm_vram_helper_init() instead of the non-existent
drmm_vram_helper_alloc_mm().

Fixes: a5f23a72355d ("drm/vram-helper: Managed vram helpers")
Signed-off-by: Luc Ma <luc@sietium.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/64583db2.630a0220.eb75d.8f51@mx.google.com

drm/gem-vram: handle NULL bo->resource in move callback

The ttm BO now initially has NULL bo->resource, and leaves the driver
the handle that. However it looks like we forgot to handle that for
ttm_bo_move_memcpy() users, like with vram-gem, since it just silently
returns zero. This seems to then trigger warnings like:

WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/drm_gem_vram_helper.c:255 drm_gem_vram_offset (??:?)

Fix this by calling move_null() if the new resource is TTM_PL_SYSTEM,
otherwise do the multi-hop sequence to ensure can safely call into
ttm_bo_move_memcpy(), since it might also need to clear the memory.
This should give the same behaviour as before.

While we are here let's also treat calling ttm_bo_move_memcpy() with
NULL bo->resource as programmer error, where expectation is that upper
layers should now handle it.

Fixes: 180253782038 ("drm/ttm: stop allocating dummy resources during BO creation")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230208145319.397235-1-matthew.auld@intel.com
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>

drm: use new debugfs device-centered functions on DRM core files

Replace the use of drm_debugfs_create_files() with the new
drm_debugfs_add_files() function in all DRM core files, centering the
debugfs files management on the drm_device instead of drm_minor.

Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-3-mcanal@igalia.com

drm/ttm: merge ttm_bo_api.h and ttm_bo_driver.h v2

Merge and cleanup the two headers into a single description of the
object API. Also move all the documentation to the implementation and
drop unnecessary includes from the header.

No functional change.

v2: minimal checkpatch.pl cleanup

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221125102137.1801-4-christian.koenig@amd.com

drm/gem-vram: Fix deadlock in drm_gem_vram_vmap()

Recently DRM framebuffer core and all drivers were moved to unlocked
vmapping functions that take the reservation lock. The drm_gem_vram_vmap()
was missed out by accident and now deadlocks drivers that use drm_gem_vram
helpers when framebuffer is updated, like Bochs driver. Remove the locking
from drm_gem_vram_v[un]map() functions to fix the deadlock.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: 79e2cf2e7a19 ("drm/gem: Take reservation lock for vmap/vunmap operations")
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221113233850.427704-1-dmitry.osipenko@collabora.com

drm/ttm: rename and cleanup ttm_bo_init

Rename ttm_bo_init to ttm_bo_init_validate since that better matches
what the function is actually doing.

Remove the unused size parameter, move the function's kerneldoc to the
implementation and cleanup the whole error handling.

Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220707102453.3633-2-christian.koenig@amd.com
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>

drm/gem-vram: Ignore planes that are unused by framebuffer format

Only handle color planes that exist in a framebuffer's color format.
Ignore non-existing planes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220517113327.26919-5-tzimmermann@suse.de

drm/gem-vram: Share code between GEM VRAM's _{prepare, cleanup}_fb()

The error-recovery code in drm_gem_vram_plane_helper_prepare_fb() is of
the same pattern as drm_gem_vram_plane_helper_cleanup_fb(). Implement
both of them using an internal helper. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220517113327.26919-4-tzimmermann@suse.de

drm/ttm: Add a parameter to add extra pages into ttm_tt

Add a parameter called "extra_pages" for ttm_tt_init, to indicate that
driver needs extra pages in ttm_tt.

v2:
Used imperative wording [Thomas and Christian]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
cc: Christian Koenig <christian.koenig@amd.com>
cc: Hellstrom Thomas <thomas.hellstrom@intel.com>
Reviewed-by: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian Konig <christian.koenig@amd.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220401123751.27771-8-ramalingam.c@intel.com

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: Return error codes from struct drm_driver.gem_create_object

GEM helper libraries use struct drm_driver.gem_create_object to let
drivers override GEM object allocation. On failure, the call returns
NULL.

Change the semantics to make the calls return a pointer-encoded error.
This aligns the callback with its callers. Fixes the ingenic driver,
which already returns an error pointer.

Also update the callers to handle the involved types more strictly.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211130095255.26710-1-tzimmermann@suse.de

drm/ttm: remove ttm_tt_destroy_common v2

Move the functionality into ttm_tt_fini and ttm_bo_tt_destroy instead.

We don't need this any more since we removed the unbind from the destroy
code paths in the drivers.

Also add a warning to ttm_tt_fini() if we try to fini a still populated TT
object.

v2: instead of reverting the patch move the functionality to different
places.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210728130552.2074-5-christian.koenig@amd.com

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

drm/vram-helper: Unexport drm_vram_helper_{alloc,release}_mm()

All GEM-VRAM-based drivers use auto-cleanup via drmm_vram_helper_init().
Unexport the manual APIs and make them internal implementation.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702075434.27677-4-tzimmermann@suse.de

drm/ttm: flip the switch for driver allocated resources v2

Instead of both driver and TTM allocating memory finalize embedding the
ttm_resource object as base into the driver backends.

v2: fix typo in vmwgfx grid mgr and double init in amdgpu_vram_mgr.c

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602100914.46246-10-christian.koenig@amd.com

drm/ttm: flip over the range manager to self allocated nodes

Start with the range manager to make the resource object the base
class for the allocated nodes.

While at it cleanup a lot of the code around that.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602100914.46246-2-christian.koenig@amd.com

drm/ttm: rename bo->mem and make it a pointer

When we want to decouble resource management from buffer management we need to
be able to handle resources separately.

Add a resource pointer and rename bo->mem so that all code needs to
change to access the pointer instead.

No functional change.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210430092508.60710-4-christian.koenig@amd.com

drm/vram-helper: Use drm_gem_ttm_dumb_map_offset()

VRAM helpers now use drm_gem_ttm_dumb_map_offset() to implement
struct drm_driver.dumb_map_offset.

v2:
* update hibmc as well (kernel test robot)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210408140139.27731-3-tzimmermann@suse.de

drm/gem: Move drm_gem_fb_prepare_fb() to GEM atomic helpers

The function drm_gem_fb_prepare_fb() is a helper for atomic modesetting,
but currently located next to framebuffer helpers. Move it to GEM atomic
helpers, rename it slightly and adopt the drivers. Same for the rsp
simple-pipe helper.

Compile-tested with x86-64, aarch64 and arm. The patch is fairly large,
but there are no functional changes.

v3:
* remove out-comented line in drm_gem_framebuffer_helper.h
(Maxime)
v2:
* rename to drm_gem_plane_helper_prepare_fb() (Daniel)
* add tutorial-style documentation

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210222141756.7864-1-tzimmermann@suse.de

drm/vram-helper: cleanup drm_gem_vram_bo_driver_move_notify

Swapping bo->mem was completely unecessary. Cleanup the function which
is just a leftover from a TTM cleanup.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210211131659.276275-1-christian.koenig@amd.com

drm/ttm: move memory accounting into vmwgfx v4

This is just another feature which is only used by VMWGFX, so move
it into the driver instead.

I've tried to add the accounting sysfs file to the kobject of the drm
minor, but I'm not 100% sure if this works as expected.

v2: fix typo in KFD and avoid 64bit divide
v3: fix init order in VMWGFX
v4: use pdev sysfs reference instead of drm

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Zack Rusin <zackr@vmware.com> (v3)
Tested-by: Nirmoy Das <nirmoy.das@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210208133226.36955-2-christian.koenig@amd.com

drm/ttm: device naming cleanup

Rename ttm_bo_device to ttm_device.
Rename ttm_bo_driver to ttm_device_funcs.
Rename ttm_bo_global to ttm_global.

Move global and device related functions to ttm_device.[ch].

No functional change.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/415222/

drm/vram-helper: Reuse existing page mappings in vmap

For performance, BO page mappings can stay in place even if the
map counter has returned to 0. In these cases, the existing page
mapping has to be reused by the next vmap operation. Otherwise
a new mapping would be installed and the old mapping's pages leak.

Fix the issue by reusing existing page mappings for vmap operations.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 1086db71a1db ("drm/vram-helper: Remove invariant parameters from internal kmap function")
Acked-by: Christian König <christian.koenig@amd.com>
Tested-by: Eli Cohen <elic@nvidia.com>
Reported-by: Eli Cohen <elic@nvidia.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Christian König <christian.koenig@amd.com>
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/20210118144639.27307-1-tzimmermann@suse.de

drm/vram-helper: Fix use of top-down placement

Commit 7053e0eab473 ("drm/vram-helper: stop using TTM placement flags")
cleared the BO placement flags if top-down placement had been selected.
Hence, BOs that were supposed to go into VRAM are now placed in a default
location in system memory.

Trying to scanout the incorrectly pinned BO results in displayed garbage
and an error message.

[ 146.108127] ------------[ cut here ]------------
[ 146.1V08180] WARNING: CPU: 0 PID: 152 at drivers/gpu/drm/drm_gem_vram_helper.c:284 drm_gem_vram_offset+0x59/0x60 [drm_vram_helper]
...
[ 146.108591] ast_cursor_page_flip+0x3e/0x150 [ast]
[ 146.108622] ast_cursor_plane_helper_atomic_update+0x8a/0xc0 [ast]
[ 146.108654] drm_atomic_helper_commit_planes+0x197/0x4c0
[ 146.108699] drm_atomic_helper_commit_tail_rpm+0x59/0xa0
[ 146.108718] commit_tail+0x103/0x1c0
...
[ 146.109302] ---[ end trace d901a1ba1d949036 ]---

Fix the bug by keeping the placement flags. The top-down placement flag
is stored in a separate variable.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Fixes: 7053e0eab473 ("drm/vram-helper: stop using TTM placement flags")
Reported-by: Pu Wen <puwen@hygon.cn> [for 5.10-rc1]
Tested-by: Pu Wen <puwen@hygon.cn>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
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/20200921142536.4392-1-tzimmermann@suse.de
(cherry picked from commit b8f8dbf6495850b0babc551377bde754b7bc0eea)
[pulled into fixes from drm-next]
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: fix some kernel-doc markups

Some identifiers have different names between their prototypes
and the kernel-doc markup.

Others need to be fixed, as kernel-doc markups should use this format:
identifier - description

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/12d4ca26f6843618200529ce5445063734d38c04.1605521731.git.mchehab+huawei@kernel.org

drm/ttm: add multihop infrastrucutre (v3)

Currently drivers get called to move a buffer, but if they have to
move it temporarily through another space (SYSTEM->VRAM via TT)
then they can end up with a lot of ttm->driver->ttm call stacks,
if the temprorary space moves requires eviction.

Instead of letting the driver do all the placement/space for the
temporary, allow it to report back (-EMULTIHOP) and a placement (hop)
to the move code, which will then do the temporary move, and the
correct placement move afterwards.

This removes a lot of code from drivers, at the expense of
adding some midlayering. I've some further ideas on how to turn
it inside out, but I think this is a good solution to the call
stack problems.

v2: separate out the driver patches, add WARN for getting
MULTHOP in paths we shouldn't (Daniel)
v3: use memset (Christian)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: hristian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201109005432.861936-2-airlied@gmail.com

drm/gem: Use struct dma_buf_map in GEM vmap ops and convert GEM backends

This patch replaces the vmap/vunmap's use of raw pointers in GEM object
functions with instances of struct dma_buf_map. GEM backends are
converted as well. For most of them, this simply changes the returned type.

TTM-based drivers now return information about the location of the memory,
either system or I/O memory. GEM VRAM helpers and qxl now use ttm_bo_vmap()
et al. Amdgpu, nouveau and radeon use drm_gem_ttm_vmap() et al instead of
implementing their own vmap callbacks.

v7:
* init QXL cursor to mapped BO buffer (kernel test robot)
v5:
* update vkms after switch to shmem
v4:
* use ttm_bo_vmap(), drm_gem_ttm_vmap(), et al. (Daniel, Christian)
* fix a trailing { in drm_gem_vmap()
* remove several empty functions instead of converting them (Daniel)
* comment uses of raw pointers with a TODO (Daniel)
* TODO list: convert more helpers to use struct dma_buf_map

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-7-tzimmermann@suse.de

drm/vram-helper: Remove invariant parameters from internal kmap function

The parameters map and is_iomem are always of the same value. Removed them
to prepares the function for conversion to struct dma_buf_map.

v4:
* don't check for !kmap->virtual; will always be false

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-2-tzimmermann@suse.de

drm/vram_helpers: drop ttm_page_alloc.h include

Not needed as far as I can see.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Madhav Chauhan <madhav.chauhan@amd.com>
Tested-by: Huang Rui <ray.huang@amd.com>
Link: https://patchwork.freedesktop.org/patch/397085/?series=83051&rev=1

drm/ttm: wire up the new pool as default one v2

Provide the necessary parameters by all drivers and use the new pool alloc
when no driver specific function is provided.

v2: fix the GEM VRAM helpers

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Madhav Chauhan <madhav.chauhan@amd.com>
Tested-by: Huang Rui <ray.huang@amd.com>
Link: https://patchwork.freedesktop.org/patch/397081/?series=83051&rev=1

drm/ttm: replace last move_notify with delete_mem_notify

The move notify callback is only used in one place, this should
be removed in the future, but for now just rename it to the use
case which is to notify the driver that the GPU memory is to be
deleted.

Drivers can be cleaned up after this separately.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201021044031.1752624-2-airlied@gmail.com

drm/ttm: drop move notify around move.

The drivers now do this in the move callback.

move_notify is still needed in the destroy path.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201020010319.1692445-7-airlied@gmail.com

drm/ttm: nuke caching placement flags

Changing the caching on the fly never really worked
flawlessly.

So stop this completely and just let drivers specific the
desired caching in the tt or bus object.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/394256/

drm/ttm: add caching state to ttm_bus_placement

And implement setting it up correctly in the drivers.

This allows getting rid of the placement flags for this.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/394254/

drm/ttm: set the tt caching state at creation time

All drivers can determine the tt caching state at creation time,
no need to do this on the fly during every validation.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Link: https://patchwork.freedesktop.org/patch/394253/

drm/vram_helper: implement a ttm move callback.

This will always do memcpy moves.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201006000644.1005758-5-airlied@gmail.com

drm/vram-helper: Don't put new BOs into VRAM

Most drivers that use VRAM helpers have only a few MiB of framebuffer
memory available. To reduce fragmentation, new BOs are now put into
system memory by default. Only pin operations are allowed to move BOs
into VRAM.

v2:
* rebased onto latest drm-tip

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200922145700.25413-4-tzimmermann@suse.de

drm/vram-helper: Set object function iff they are not provided by driver

Don't override the GEM object functions unconditionally. If the driver
sets the GEM functions, VRAM helpers will not set them. The idea has been
taken from SHMEM helpers.

v2:
* updated the commit message (Sam)
* document the new feature for drm_gem_vram_create()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200922145700.25413-3-tzimmermann@suse.de

drm/vram-helper: Integrate drm_gem_vram_init() into drm_gem_vram_create()

The drm_gem_vram_create() function is the only caller of the internal
helper drm_gem_vram_init(). Streamline the code by putting all code into
the create function.

v2:
* rebased onto latest drm-tip
* fixed typo in commit message (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200922145700.25413-2-tzimmermann@suse.de

drm/vram-helper: switch over to the new pin interface

Stop using TTM_PL_FLAG_NO_EVICT.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Link: https://patchwork.freedesktop.org/patch/391603/?series=81973&rev=1

drm/vram-helper: Fix use of top-down placement

Commit 7053e0eab473 ("drm/vram-helper: stop using TTM placement flags")
cleared the BO placement flags if top-down placement had been selected.
Hence, BOs that were supposed to go into VRAM are now placed in a default
location in system memory.

Trying to scanout the incorrectly pinned BO results in displayed garbage
and an error message.

[ 146.108127] ------------[ cut here ]------------
[ 146.1V08180] WARNING: CPU: 0 PID: 152 at drivers/gpu/drm/drm_gem_vram_helper.c:284 drm_gem_vram_offset+0x59/0x60 [drm_vram_helper]
...
[ 146.108591] ast_cursor_page_flip+0x3e/0x150 [ast]
[ 146.108622] ast_cursor_plane_helper_atomic_update+0x8a/0xc0 [ast]
[ 146.108654] drm_atomic_helper_commit_planes+0x197/0x4c0
[ 146.108699] drm_atomic_helper_commit_tail_rpm+0x59/0xa0
[ 146.108718] commit_tail+0x103/0x1c0
...
[ 146.109302] ---[ end trace d901a1ba1d949036 ]---

Fix the bug by keeping the placement flags. The top-down placement flag
is stored in a separate variable.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Fixes: 7053e0eab473 ("drm/vram-helper: stop using TTM placement flags")
Cc: Christian König <christian.koenig@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
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/20200921142536.4392-1-tzimmermann@suse.de

drm/ttm: flip tt destroy ordering.

Call the driver first and have it call the common code cleanup.

This is useful later to fix unbind.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200917043040.146575-3-airlied@gmail.com

drm/ttm: remove available_caching

Instead of letting TTM make an educated guess based on
some mask all drivers should just specify what caching
they want for their CPU mappings.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390207/

drm/ttm: remove default caching

As far as I can tell this was never used either and we just
always fallback to the order cached > wc > uncached anyway.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/390142/

drm: fix double free for gbo in drm_gem_vram_init and drm_gem_vram_create

I got a use-after-free report when doing some fuzz test:

If ttm_bo_init() fails, the "gbo" and "gbo->bo.base" will be
freed by ttm_buffer_object_destroy() in ttm_bo_init(). But
then drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" and "gbo->bo.base" again.

BUG: KMSAN: use-after-free in drm_vma_offset_remove+0xb3/0x150
CPU: 0 PID: 24282 Comm: syz-executor.1 Tainted: G B W 5.7.0-rc4-msan #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Call Trace:
__dump_stack
dump_stack+0x1c9/0x220
kmsan_report+0xf7/0x1e0
__msan_warning+0x58/0xa0
drm_vma_offset_remove+0xb3/0x150
drm_gem_free_mmap_offset
drm_gem_object_release+0x159/0x180
drm_gem_vram_init
drm_gem_vram_create+0x7c5/0x990
drm_gem_vram_fill_create_dumb
drm_gem_vram_driver_dumb_create+0x238/0x590
drm_mode_create_dumb
drm_mode_create_dumb_ioctl+0x41d/0x450
drm_ioctl_kernel+0x5a4/0x710
drm_ioctl+0xc6f/0x1240
vfs_ioctl
ksys_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x2e9/0x410
__x64_sys_ioctl+0x4a/0x70
do_syscall_64+0xb8/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4689b9
Code: fd e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb e0 fa ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f368fa4dc98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000076bf00 RCX: 00000000004689b9
RDX: 0000000020000240 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004d17e0 R14: 00007f368fa4e6d4 R15: 000000000076bf0c

Uninit was created at:
kmsan_save_stack_with_flags
kmsan_internal_poison_shadow+0x66/0xd0
kmsan_slab_free+0x6e/0xb0
slab_free_freelist_hook
slab_free
kfree+0x571/0x30a0
drm_gem_vram_destroy
ttm_buffer_object_destroy+0xc8/0x130
ttm_bo_release
kref_put
ttm_bo_put+0x117d/0x23e0
ttm_bo_init_reserved+0x11c0/0x11d0
ttm_bo_init+0x289/0x3f0
drm_gem_vram_init
drm_gem_vram_create+0x775/0x990
drm_gem_vram_fill_create_dumb
drm_gem_vram_driver_dumb_create+0x238/0x590
drm_mode_create_dumb
drm_mode_create_dumb_ioctl+0x41d/0x450
drm_ioctl_kernel+0x5a4/0x710
drm_ioctl+0xc6f/0x1240
vfs_ioctl
ksys_ioctl
__do_sys_ioctl
__se_sys_ioctl+0x2e9/0x410
__x64_sys_ioctl+0x4a/0x70
do_syscall_64+0xb8/0x160
entry_SYSCALL_64_after_hwframe+0x44/0xa9

If ttm_bo_init() fails, the "gbo" will be freed by
ttm_buffer_object_destroy() in ttm_bo_init(). But then
drm_gem_vram_create() and drm_gem_vram_init() will free
"gbo" again.

Reported-by: Hulk Robot <hulkci@huawei.com>
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Signed-off-by: Jia Yang <jiayang5@huawei.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200714083238.28479-2-tzimmermann@suse.de

drm/vboxvideo: Use drm_gem_vram_vmap() interfaces

VRAM helpers support ref counting for pin and vmap operations, no need
to avoid these operations by employing the internal kmap interface. Just
use drm_gem_vram_vmap() and let it handle the details.

Also unexport the kmap interfaces from VRAM helpers. Vboxvideo was the
last user of these internal functions.

v2:
* fixed a comma in commit description

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200911075922.19317-1-tzimmermann@suse.de

drm/ttm: nuke memory type flags

It's not supported to specify more than one of those flags.
So it never made sense to make this a flag in the first place.

Nuke the flags and specify directly which memory type to use.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389826/?series=81551&rev=1

drm/vram-helper: stop using TTM placement flags

Those are going to be removed, stop using them here.

Instead define separate flags for the helper.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389823/?series=81551&rev=1

drm/gem_vram/ttm: move to driver backend destroy function.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200907204630.1406528-10-airlied@gmail.com

drm/ttm: merge offset and base in ttm_bus_placement

This is used by TTM to communicate the physical address
which should be used with ioremap(), ioremap_wc(). We don't
need to separate the base and offset in any way here.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/389457/

drm/ttm: remove bdev from ttm_tt

I want to split this structure up and use it differently,
step one remove bdev pointer from it and pass it explicitly.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200826014428.828392-4-airlied@gmail.com

drm/ttm: init mem->bus in common code.

The drivers all do the same thing here.

Reviewed-by: Christian König <christian.koenig@amd.com> for both.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200811074658.58309-1-airlied@gmail.com

drm/ttm: rename ttm_mem_reg to ttm_resource.

This name better reflects what the object does. I didn't rename
all the pointers it seemed too messy.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-60-airlied@gmail.com

drm/ttm: rename ttm_mem_type_manager -> ttm_resource_manager.

This name makes a lot more sense, since these are about managing
driver resources rather than just memory ranges.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-59-airlied@gmail.com

drm/ttm: make ttm_range_man_init/takedown take type + args

This makes it easier to move these to a driver allocated system

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-47-airlied@gmail.com

drm/vram-helper: use wrapper to access memory managers

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-39-airlied@gmail.com

drm/vram_helper: call explicit mm takedown

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-30-airlied@gmail.com

drm/vram_helper: use new ttm manager init function

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-19-airlied@gmail.com

drm/vram-helper: call the ttm manager debug function

This code was assuming there was a drm_mm here, don't do
that call the correct API.

v2: use the new exported interface.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-13-airlied@gmail.com

drm/vram-helper: remove populate/unpopulate

The default path for populate/unpopulate is already this.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-8-airlied@gmail.com

drm/ttm: remove the init_mem_type callback

It is a very strange concept to call a function which just
calls back the caller for the functions parameters.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/382085/

drm/vram-helper: stop implementing init_mem_type

Instead just initialize the memory type parameters
before calling ttm_bo_init_mm.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/382086/

drm/ttm: remove TTM_MEMTYPE_FLAG_FIXED v2

Instead use a boolean field in the memory manager structure.

Also invert the meaning of the field since the use of a TT
structure is the special case here.

v2: cleanup zero init.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/382079/

drm/ttm: initialize the system domain with defaults v2

Instead of repeating that in each driver.

v2: keep the caching limitation for VMWGFX for now.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/382078/

drm: remove optional dummy function from drivers using TTM

Implementing those is completely unnecessary.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Madhav Chauhan <madhav.chauhan@amd.com>
Link: https://patchwork.freedesktop.org/patch/378236/

drm/vram-helper: stop using TTM_MEMTYPE_FLAG_MAPPABLE

The helper doesn't expose any not-mapable memory resources.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/377649/

drm/vram-helper: Managed vram helpers

Calling drmm_vram_helper_init() sets up a managed instance of
VRAM MM. Releasing the DRM device also frees the memory manager.

The patch also updates the DRM documentation for VRAM helpers. The
tutorial now describes the new managed interface. The old interfaces
are deprecated and should not be used in new code.

v2:
* rename init function to drmm_vram_helper_init()
* return errno code from init function; caller does not
need vram_mm anyway
* update documentation and remove docs for deprecated
un-managed functions

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716125353.31512-2-tzimmermann@suse.de

drm/vram-helper: don't use ttm bo->offset v4

Calculate GEM VRAM bo's offset within vram-helper without depending on
bo->offset.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/372938/

drm: remove _unlocked suffix in drm_gem_object_put_unlocked

Spelling out _unlocked for each and every driver is a annoying.
Especially if we consider how many drivers, do not know (or need to)
about the horror stories involving struct_mutex.

Just drop the suffix. It makes the API cleaner.

Done via the following script:

__from=drm_gem_object_put_unlocked
__to=drm_gem_object_put
for __file in $(git grep --name-only $__from); do
sed -i "s/$__from/$__to/g" $__file;
done

Pay special attention to the compat #define

v2: keep sed and #define removal separate

Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org> (v1)
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200515095118.2743122-14-emil.l.velikov@gmail.com

drm/vram-helpers: Merge code into a single file

Most of the documentation was in an otherwise empty file, which was
probably just left from a previous clean-up effort. So move code and
documentation into a single file.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331081238.24749-1-tzimmermann@suse.de

drm/vram-helpers: Set plane fence for display update

Calling the VRAM helper's prepare_fb() helper now sets the plane's
fence object. This will be useful for PRIME support. VRAM helpers
don't support buffer sharing ATM, so for now there are no drivers
requiring this change.

v2:
* removed a TODO comment about buffer synchronization

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200331092740.29282-1-tzimmermann@suse.de

drm/vram-helper: remove unneeded #if defined/endif guards.

Remove unneeded #if/#endif guards for checking whether the
CONFIG_DEBUG_FS option is set or not. If the option is not set, the
compiler optimizes the functions making the guards
unnecessary.

Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323112802.228214-1-wambui.karugax@gmail.com

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

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 <wambui.karugax@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-18-wambui.karugax@gmail.com

drm/vram-helper: make drm_vram_mm_debugfs_init() return 0

Since 987d65d01356 (drm: debugfs: make
drm_debugfs_create_files() never fail), drm_debugfs_create_files() never
fails and should return void. Therefore, remove its use as the
return value of drm_vram_mm_debugfs_init(), and have the function
return 0 directly.

v2: have drm_vram_mm_debugfs_init() return 0 instead of void to avoid
introducing build issues and build breakage.

References: https://lists.freedesktop.org/archives/dri-devel/2020-February/257183.html
Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200310133121.27913-11-wambui.karugax@gmail.com

drm/vram: Add helpers to validate a display mode's memory requirements

Devices with low amount of dedicated video memory may not be able
to use all possible display modes, as the framebuffers may not fit
into VRAM. The new helper function drm_vram_helper_mode_valid()
implements a simple test to sort out all display modes that can
not be used in any case. Drivers should call this function from
struct drm_mode_config_funcs.mode_valid.

The functionality was originally implemented by the ast driver, which
is being converted as well.

v2:
* WARN_ON if VRAM memory manager has not been initialized
* documentation fixes
* unexported drm_vram_helper_mode_valid_internal()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200203155258.9346-2-tzimmermann@suse.de

drm/vram-helper: Support struct drm_driver.gem_create_object

Drivers that what to allocate VRAM GEM objects with additional fields
can now do this by implementing struct drm_driver.gem_create_object.

v3:
* separately check allocation failure in if/else branches
before upcast to gbo
v2:
* only cast to gbo within if branch; set gbo directly
in else branch

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200106125745.13797-9-tzimmermann@suse.de

drm/vram-helper: Remove BO device from public interface

TTM is an implementation detail of the VRAM helpers and therefore
shouldn't be exposed to the callers. There's only one correct value
for the BO device anyway, which is the one stored in the DRM device.

So remove struct ttm_bo_device from the VRAM-helper interface and
use the device's VRAM manager unconditionally. The GEM initializer
function fails if the VRAM manager has not been initialized.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200106125745.13797-8-tzimmermann@suse.de

drm/vram-helper: Remove interruptible flag from public interface

The flag 'interruptible', which is passed to various functions,
is always set to be false. Remove it and hard-code the value.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200106125745.13797-7-tzimmermann@suse.de

drm/vram: Support scanline alignment for dumb buffers

Adding the pitch alignment as an argument to
drm_gem_vram_fill_create_dumb() allows to align scanlines to certain
offsets. A value of 0 disables scanline pitches.

v3:
* only do power-of-2 test if pitch_align given; fails otherwise
* mgag200: call drm_gem_vram_fill_create_dumb() with pitch_align
v2:
* split of patch from related hibmc changes
* test if scanline pitch is power of 2

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203083819.6643-4-tzimmermann@suse.de

drm/ttm: remove pointers to globals

As the name says global memory and bo accounting is global. So it doesn't
make to much sense having pointers to global structures all around the code.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thellstrom@vmware.com>
Link: https://patchwork.freedesktop.org/patch/332879/

drm/vram-helpers: Add helpers for prepare_fb() and cleanup_fb()

The new helpers pin and unpin a framebuffer's GEM VRAM objects during
plane updates. This should be sufficient for most drivers' implementation
of prepare_fb() and cleanup_fb().

v2:
* provide helpers for struct drm_simple_display_pipe_funcs
* rename plane-helper funcs

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191024081404.6978-2-tzimmermann@suse.de

drm/vram: drop verify_access

Not needed any more.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20191016115203.20095-11-kraxel@redhat.com

drm/vram: switch vram helper to &drm_gem_object_funcs.mmap()

Wire up the new drm_gem_ttm_mmap() helper function,
use generic drm_gem_mmap for &fops.mmap and
delete dead drm_vram_mm_file_operations_mmap().

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20191016115203.20095-10-kraxel@redhat.com

drm/vram: Support top-down placement flag

Pinning lots of small buffer objects, such as cursors or sprites, to video
memory can lead to fragmentation, which is a problem for devices with only
a small amount of memory. As a result, framebuffer images might not get
pinned, even though there's enough space available overall.

The flag DRM_GEM_VRAM_PL_FLAG_TOPDOWN marks buffer objects to be pinned at
the high end of video memory. This leaves contiguous space available at
the memory's low end.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190923172753.26593-2-tzimmermann@suse.de
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>

drm/vram: Provide vmap and vunmap operations for GEM VRAM objects

The implementation of vmap and vunmap for GEM VRAM helpers is
already in PRIME helpers. The patch moves the operations to separate
functions and exports them for general use.

v3:
* remove v2's obsolete note on ref-counting
v2:
* fix documentation
* add cross references to function documentation
* document (the lack of) ref-counting for GEM VRAM BO mappings

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190911120352.20084-2-tzimmermann@suse.de

drm/vram: Unconditonally set BO call-back functions

The statement's condition is always true.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190911110910.30698-5-tzimmermann@suse.de

drm/vram: Unexport internal functions of VRAM MM

The init, cleanup and mmap functions of VRAM MM are only used internally.
Remove them from the public interface.

v2:
* update for debugfs support

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190911110910.30698-4-tzimmermann@suse.de

drm/vram: Have VRAM MM call GEM VRAM functions directly

VRAM MM and GEM VRAM buffer objects are only used with each other;
connected via 3 function pointers. Simplify this code by making the
memory manager call the rsp. functions of the BOs directly; and
remove the functions from the BO's public interface.

v2:
* typos in commit message

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190911110910.30698-3-tzimmermann@suse.de

drm/vram: Move VRAM memory manager to GEM VRAM implementation

The separation between GEM VRAM objects and the memory manager is
artificial, as they are only used with each other. Copying both
implementations into the same file is a first step to simplifying
the code.

This patch only moves code without functional changes.

v3:
* update to use dev->vma_offset_manager
v2:
* update for debugfs support
* typos in commit message

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190911110910.30698-2-tzimmermann@suse.de

drm/vram: use drm_gem_ttm_print_info

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20190904054740.20817-4-kraxel@redhat.com

drm/vram: Implement lazy unmapping for GEM VRAM buffers

Frequent mapping and unmapping a buffer object adds overhead for
modifying the page table and creates debug output. Unmapping a buffer
is only required when the memory manager evicts the buffer from its
current location.

v4:
* WARN_ON if buffer is still mapped during BO cleanup

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reported-and-tested-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190906122056.32018-5-tzimmermann@suse.de

drm/vram: Acquire lock only once per call to vmap()/vunmap()

The implementation of vmap() is a combined pin() and kmap(). As both
functions share the same lock, we can make vmap() slightly faster by
acquiring the lock only once for both operations. Same for the inverse,
vunmap().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reported-and-tested-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190906122056.32018-3-tzimmermann@suse.de

drm/vram: Add kmap ref-counting to GEM VRAM objects

The kmap and kunmap operations of GEM VRAM buffers can now be called
in interleaving pairs. The first call to drm_gem_vram_kmap() maps the
buffer's memory to kernel address space and the final call to
drm_gem_vram_kunmap() unmaps the memory. Intermediate calls to these
functions increment or decrement a reference counter.

This change allows for keeping buffer memory mapped for longer and
minimizes the amount of changes to TLB, page tables, etc.

v4:
* lock in kmap()/kunmap() with ttm_bo_reserve()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reported-and-tested-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190906122056.32018-2-tzimmermann@suse.de

drm/ttm: use gem vma_node

Drop vma_node from ttm_buffer_object, use the gem struct
(base.vma_node) instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190805140119.7337-9-kraxel@redhat.com

drm/vram: use embedded gem object

Drop drm_gem_object from drm_gem_vram_object, use the
ttm_buffer_object.base instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190805140119.7337-3-kraxel@redhat.com

drm/vram: Don't export driver callback functions for PRIME

PRIME functionality is now provided by GEM object functions. The driver
callback functions are obsolete. So this patch renames them and turns
them into static internal functions of the VRAM helper library. The
implementation of gem_prime_mmap is now unused and the patch removes it.

v3:
* kept each renamed function at its original location within file
* kept documentation

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702115012.4418-6-tzimmermann@suse.de

drm/vram: Set GEM object functions for PRIME

PRIME functionality is now provided via the callback functions in
struct drm_gem_object_funcs. The driver-structure functions are obsolete.
As a side effect of this patch, VRAM-based drivers get basic PRIME
support automatically without having to set any flags or additional
fields.

v2:
- use existing PRIME functions for object's table
v3:
- move object table to EOF so it can refer to internal interfaces

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190702115012.4418-2-tzimmermann@suse.de

drm: Remove functions with kmap-object argument from GEM VRAM helpers

The GEM VRAM functions with kmap-object argument are not required any
longer. Remove them.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613073041.29350-10-tzimmermann@suse.de

drm: Remove lock interfaces from GEM VRAM helpers

The lock functions and the locked-pin/unpin functions of GEM VRAM are not
required any longer. Remove them.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613073041.29350-9-tzimmermann@suse.de

drm/gem-vram: Support pinning buffers to current location

Pinning a buffer prevents it from being moved to a different memory
location. For some operations, such as buffer updates, it is not
important where the buffer is located. Setting the pin function's
pl_flag argument to 0 will pin the buffer to whereever it is stored.

v2:
* document pin flags in PRIME pin helper

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613073041.29350-2-tzimmermann@suse.de

drm: Ignore drm_gem_vram_mm_funcs in generated documentation

The documentation tools interpret drm_gem_vram_mm_funcs as function and
there appears to be no way of inline-documenting constants. This results
in a warning by 'make htmldocs'. For now, removing drm_gem_vram_mm_funcs
from generated documentation works around the issue.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190604111330.25324-1-tzimmermann@suse.de
Fixes: 5c9dcacfe566 ("drm: Add default instance for VRAM MM callback functions")
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Assert that BO is locked in drm_gem_vram_{pin, unpin}_locked()

We may not call drm_gem_vram_{pin,unpin}_locked() with an unlocked
BO. Now test for this.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20190521110831.20200-4-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Rename reserve/unreserve to lock/unlock in GEM VRAM helpers

To align with the rest of DRM terminology, the GEM VRAM helpers now use
lock and unlock in places where reserve and unreserve where used before.
All callers have been adapted.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20190521110831.20200-3-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Replace drm_gem_vram_push_to_system() with kunmap + unpin

The push-to-system function forces a buffer out of video RAM. This decision
should rather be made by the memory manager. By replacing the function with
calls to the kunmap and unpin functions, the buffer's memory becomes available,
but the buffer remains in VRAM until it's evicted by a pin operation.

This patch replaces the remaining instances of drm_gem_vram_push_to_system()
in ast and mgag200, and removes the function from DRM.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20190521110831.20200-2-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Reserve/unreserve GEM VRAM BOs from within pin/unpin functions

The original bochs and vbox implementations of pin and unpin functions
automatically reserved BOs during validation. This functionality got lost
while converting the code to a generic implementation. This may result
in validating unlocked TTM BOs.

Adding the reserve and unreserve operations to GEM VRAM's pin and unpin
functions fixes the bochs and vbox drivers. Additionally the patch changes
the mgag200, ast and hibmc drivers to not reserve BOs by themselves.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reported-by: kernel test robot <lkp@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190516162746.11636-3-tzimmermann@suse.de
Fixes: a3232987fdbf ("drm/bochs: Convert bochs driver to |struct drm_gem_vram_object|")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add drm_gem_vram_{pin/unpin}_reserved() and convert mgag200

The new interfaces drm_gem_vram_{pin/unpin}_reserved() are variants of the
GEM VRAM pin/unpin functions that do not reserve the BO during validation.
The mgag200 driver requires this behavior for its cursor handling. The
patch also converts the driver to use the new interfaces.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190516162746.11636-2-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Integrate VRAM MM into struct drm_device

There's now a pointer to struct drm_vram_mm stored in struct drm_device.
DRM drivers that use VRAM MM should use this field to refer to their
instance of the data structure. Appropriate helpers are now provided as
well.

Adding struct drm_vram_mm to struct drm_device further avoids wrappers
and boilerplate code in drivers. This patch implements default functions
for callbacks in struct drm_driver and struct file_operations that use
the struct drm_vram_mm stored in struct drm_device. Drivers that need to
provide their own implementations can still do so.

The patch also adds documentation for the VRAM helper library in general.

v5:
* set .llseek to no_llseek() from DRM_VRAM_MM_FILE_OPERATIONS
v4:
* cleanups from checkpatch.pl
* document VRAM helper library

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-9-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add default instance for VRAM MM callback functions

VRAM MM is most likely be used with GEM VRAM. The latter now provides the
required instance of struct drm_vram_mm_funcs for drivers to use.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-8-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add simple PRIME helpers for GEM VRAM

These basic helper functions for GEM VRAM allow for pinning and mapping
GEM VRAM objects via the PRIME interfaces. It's not a full implementation,
but complete enough for generic fbcon.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-6-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add drm_gem_vram_fill_create_dumb() to create dumb buffers

The helper function drm_gem_vram_fill_create_dumb() implements most of
struct drm_driver.dumb_create() for GEM-VRAM buffer objects. It's not a
full implementation of the callback, as several driver-specific parameters
are still required.

v4:
* cleanups from checkpatch.pl
v2:
* documentation fixes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-5-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add |struct drm_gem_vram_object| callbacks for |struct drm_driver|

The provided helpers can be used for the respective callback functions
in |struct drm_driver|.

v4:
* cleanups from checkpatch.pl
v2:
* documentation fixes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-4-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add |struct drm_gem_vram_object| callbacks for |struct ttm_bo_driver|

The provided helpers can be used for the respective callback functions
in |struct ttm_bo_driver|.

v2:
* drm_is_gem_vram() is now a private function
* documentation fixes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-3-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

drm: Add |struct drm_gem_vram_object| and helpers

The type |struct drm_gem_vram_object| implements a GEM object for simple
framebuffer devices with dedicated video memory. The BO is either located
in VRAM or system memory.

The implementation has been created from the respective code in ast,
bochs and mgag200. These drivers copy their implementation from each
other; except for the names of several data types. The helpers are
currently build with TTM, but this is considered an implementation
detail and may change in future updates.

v5:
* do WARN_ON_ONCE for pin-count mismatches
* allocate only 2 entries in placements array
v4:
* cleanups from checkpatch.pl
* removed several fixed-size types from interfaces
* DRM_VRAM_HELPER now selects DRM_TTM
* remove separate config option for GEM VRAM
v2:
* rename to |struct drm_gem_vram_object|
* move drm_is_gem_ttm() to a later patch in the series
* add drm_gem_vram_kmap_at()
* return is_iomem from kmap functions
* redefine TTM placement flags for public interface
* documentation fixes

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-2-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>