| Message ID | 20201130120433.7205-1-tzimmermann@suse.de (mailing list archive) |
|---|---|
| Headers | show |
| Series | drm/vram-helper: Lock GEM BOs while they are mapped | expand |
Am 30.11.20 um 13:04 schrieb Thomas Zimmermann: > GEM VRAM helpers used to pin the BO in their implementation of vmap, so > that they could not be relocated. In a recent discussion, [1] it became > clear that this is incorrect and that vmap should rather repend on the > reservation lock to prevent relocation. This patchset addresses the issue. > Besides the vram helpers, this affects ast, vboxvideo and the generic > fbdev emulation. > > Patch 1 adds a few more rules to vmap internfaces. With VRAM, it is > necessary to keep the BO evictable, which requires soem care when mapping > the memory. Patch 2 changes ast's cursor code accordingly. > > Patch 3 adds vram helpers that acquires the reservation lock and vmap the > memory buffer. Same for vunmap in reverse. Patches 4 and 5 convert ast > and vboxvideo to the new helper. > > Patch 6 removes pinning and locking from VRAM helper's vmap and vunmap. > The affected users in ast and fbdev emulation acquire the reservation > locks of the GEM objects before vmapping BOs. VRAM helpers don't support > to export the buffer, so there are no other users of these functions. > > The the pinning and locking removed, vmap can be simplified as done in > patches 7 and 8. > > Tested on ast with GEM VRAM and also on mgag200 to verify that the fbdev > change does not interfere with GEM SHMEM. Acked-by: Christian König <christian.koenig@amd.com> for the series. > > Thomas Zimmermann (8): > drm/gem: Write down some rules for vmap usage > drm/ast: Only map cursor BOs during updates > drm/vram-helper: Provide drm_gem_vram_vmap_unlocked() > drm/ast: Use drm_gem_vram_vmap_unlocked() in ast_cursor_show() > drm/vboxvideo: Use drm_gem_vram_vmap_unlocked() in cursor update > drm/vram-helper: Remove pinning and locking from drm_gem_vram_vmap() > drm/vram-helper: Remove vmap reference counting > drm/vram-helper: Simplify vmap implementation > > drivers/gpu/drm/ast/ast_cursor.c | 63 +++++++++------- > drivers/gpu/drm/ast/ast_drv.h | 2 - > drivers/gpu/drm/drm_client.c | 31 ++++++++ > drivers/gpu/drm/drm_fb_helper.c | 10 ++- > drivers/gpu/drm/drm_gem_vram_helper.c | 101 +++++++++++++------------- > drivers/gpu/drm/drm_prime.c | 6 ++ > drivers/gpu/drm/vboxvideo/vbox_mode.c | 7 +- > include/drm/drm_client.h | 2 + > include/drm/drm_gem.h | 16 ++++ > include/drm/drm_gem_vram_helper.h | 21 ++---- > 10 files changed, 159 insertions(+), 100 deletions(-) > > -- > 2.29.2 >
Hi Am 30.11.20 um 13:04 schrieb Thomas Zimmermann: > GEM VRAM helpers used to pin the BO in their implementation of vmap, so > that they could not be relocated. In a recent discussion, [1] it became [1] was supposed to point to the discussion at https://patchwork.freedesktop.org/patch/400054/?series=83765&rev=1 > clear that this is incorrect and that vmap should rather repend on the > reservation lock to prevent relocation. This patchset addresses the issue. > Besides the vram helpers, this affects ast, vboxvideo and the generic > fbdev emulation. > > Patch 1 adds a few more rules to vmap internfaces. With VRAM, it is > necessary to keep the BO evictable, which requires soem care when mapping > the memory. Patch 2 changes ast's cursor code accordingly. > > Patch 3 adds vram helpers that acquires the reservation lock and vmap the > memory buffer. Same for vunmap in reverse. Patches 4 and 5 convert ast > and vboxvideo to the new helper. > > Patch 6 removes pinning and locking from VRAM helper's vmap and vunmap. > The affected users in ast and fbdev emulation acquire the reservation > locks of the GEM objects before vmapping BOs. VRAM helpers don't support > to export the buffer, so there are no other users of these functions. > > The the pinning and locking removed, vmap can be simplified as done in > patches 7 and 8. > > Tested on ast with GEM VRAM and also on mgag200 to verify that the fbdev > change does not interfere with GEM SHMEM. > > Thomas Zimmermann (8): > drm/gem: Write down some rules for vmap usage > drm/ast: Only map cursor BOs during updates > drm/vram-helper: Provide drm_gem_vram_vmap_unlocked() > drm/ast: Use drm_gem_vram_vmap_unlocked() in ast_cursor_show() > drm/vboxvideo: Use drm_gem_vram_vmap_unlocked() in cursor update > drm/vram-helper: Remove pinning and locking from drm_gem_vram_vmap() > drm/vram-helper: Remove vmap reference counting > drm/vram-helper: Simplify vmap implementation > > drivers/gpu/drm/ast/ast_cursor.c | 63 +++++++++------- > drivers/gpu/drm/ast/ast_drv.h | 2 - > drivers/gpu/drm/drm_client.c | 31 ++++++++ > drivers/gpu/drm/drm_fb_helper.c | 10 ++- > drivers/gpu/drm/drm_gem_vram_helper.c | 101 +++++++++++++------------- > drivers/gpu/drm/drm_prime.c | 6 ++ > drivers/gpu/drm/vboxvideo/vbox_mode.c | 7 +- > include/drm/drm_client.h | 2 + > include/drm/drm_gem.h | 16 ++++ > include/drm/drm_gem_vram_helper.h | 21 ++---- > 10 files changed, 159 insertions(+), 100 deletions(-) > > -- > 2.29.2 >