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| author | Dave Airlie <airlied@redhat.com> | 2020-10-29 13:58:52 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2020-11-11 11:11:03 +1000 |
| commit | ebdf565169af006ee3be8c40eecbfc77d28a3b84 (patch) | |
| tree | ccc29cae7148ec2940d137a6492852dc1d6f1ff9 /include/drm | |
| parent | 2dcab875e7637f1d3f9b978566e61ed1cbbba054 (diff) | |
| download | lwn-ebdf565169af006ee3be8c40eecbfc77d28a3b84.tar.gz lwn-ebdf565169af006ee3be8c40eecbfc77d28a3b84.zip | |
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
Diffstat (limited to 'include/drm')
| -rw-r--r-- | include/drm/ttm/ttm_bo_driver.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h index da8208f43378..f02f7cf9ae90 100644 --- a/include/drm/ttm/ttm_bo_driver.h +++ b/include/drm/ttm/ttm_bo_driver.h @@ -121,6 +121,8 @@ struct ttm_bo_driver { * Return the bo flags for a buffer which is not mapped to the hardware. * These will be placed in proposed_flags so that when the move is * finished, they'll end up in bo->mem.flags + * This should not cause multihop evictions, and the core will warn + * if one is proposed. */ void (*evict_flags)(struct ttm_buffer_object *bo, @@ -134,12 +136,15 @@ struct ttm_bo_driver { * the graphics address space * @ctx: context for this move with parameters * @new_mem: the new memory region receiving the buffer + @ @hop: placement for driver directed intermediate hop * * Move a buffer between two memory regions. + * Returns errno -EMULTIHOP if driver requests a hop */ int (*move)(struct ttm_buffer_object *bo, bool evict, struct ttm_operation_ctx *ctx, - struct ttm_resource *new_mem); + struct ttm_resource *new_mem, + struct ttm_place *hop); /** * struct ttm_bo_driver_member verify_access |