cc'ing TTM maintainers for comments. We might want to use the I/O pointer structure with TTM at some point.
Am 06.08.20 um 10:52 schrieb Thomas Zimmermann:
DRM's fbdev console uses regular load and store operations to update framebuffer memory. The bochs driver on sparc64 requires the use of I/O-specific load and store operations. We have a workaround, but need a long-term solution to the problem. Previous attempts to resolve the issue returned an extra is_iomem flag from vmap(), or added a separate vmap_iomem() callback to GEM objects.
This patchset is yet another iteration with a different idea. Instead of a raw pointer, vmap() interfaces now return a structure that contains the buffer address in system or I/O memory, plus a flag that signals which location the address is in.
Patch #1 updates the vboxvideo driver to match the latest VRAM helpers. This simplifies the other patches and should be merged in any case.
Patch #2 adds struct drm_gem_membuf, which contains the pointer and flag, and converts the generic GEM interfaces to use it.
Patch #3 converts vmap/vunmap in GEM object functions and updates most GEM backends. A few drivers are still missing, but the patch should be acceptable for an RFC.
Patch #4 changes fbdev helpers to access framebuffer memory either with system or I/O memcpy functions.
Thomas Zimmermann (4): drm/vboxvideo: Use drm_gem_vram_vmap() interfaces drm/gem: Update client API to use struct drm_gem_membuf drm/gem: Use struct drm_gem_membuf in vmap op and convert GEM backends drm/fb_helper: Access framebuffer as I/O memory, if required
drivers/gpu/drm/ast/ast_cursor.c | 29 ++- drivers/gpu/drm/ast/ast_drv.h | 2 +- drivers/gpu/drm/bochs/bochs_kms.c | 1 - drivers/gpu/drm/drm_client.c | 25 ++- drivers/gpu/drm/drm_fb_helper.c | 246 ++++++++++++++++++++++--- drivers/gpu/drm/drm_gem.c | 28 +-- drivers/gpu/drm/drm_gem_cma_helper.c | 15 +- drivers/gpu/drm/drm_gem_shmem_helper.c | 31 ++-- drivers/gpu/drm/drm_gem_vram_helper.c | 142 +++++--------- drivers/gpu/drm/drm_internal.h | 5 +- drivers/gpu/drm/drm_prime.c | 16 +- drivers/gpu/drm/mgag200/mgag200_mode.c | 11 +- drivers/gpu/drm/qxl/qxl_display.c | 12 +- drivers/gpu/drm/qxl/qxl_draw.c | 14 +- drivers/gpu/drm/qxl/qxl_drv.h | 6 +- drivers/gpu/drm/qxl/qxl_object.c | 19 +- drivers/gpu/drm/qxl/qxl_object.h | 2 +- drivers/gpu/drm/qxl/qxl_prime.c | 12 +- drivers/gpu/drm/tiny/cirrus.c | 15 +- drivers/gpu/drm/tiny/gm12u320.c | 12 +- drivers/gpu/drm/udl/udl_modeset.c | 10 +- drivers/gpu/drm/vboxvideo/vbox_mode.c | 17 +- include/drm/drm_client.h | 7 +- include/drm/drm_device.h | 26 +++ include/drm/drm_gem.h | 5 +- include/drm/drm_gem_cma_helper.h | 4 +- include/drm/drm_gem_shmem_helper.h | 4 +- include/drm/drm_gem_vram_helper.h | 9 +- include/drm/drm_mode_config.h | 12 -- 29 files changed, 464 insertions(+), 273 deletions(-)
-- 2.28.0