drm: Add library for shmem backed GEM objects

This adds a library for shmem backed GEM objects.

v8:
- export drm_gem_shmem_create_with_handle
- call mapping_set_gfp_mask to set default zone to GFP_HIGHUSER
- Add helper drm_gem_shmem_get_pages_sgt()

v7:
- Use write-combine for mmap instead. This is the more common
  case. (robher)

v6:
- Fix uninitialized variable issue in an error path (anholt).
- Add a drm_gem_shmem_vm_open() to the fops to get proper refcounting
  of the pages (anholt).

v5:
- Drop drm_gem_shmem_prime_mmap() (Daniel Vetter)
- drm_gem_shmem_mmap(): Subtract drm_vma_node_start() to get the real
  vma->vm_pgoff
- drm_gem_shmem_fault(): Use vmf->pgoff now that vma->vm_pgoff is correct

v4:
- Drop cache modes (Thomas Hellstrom)
- Add a GEM attached vtable

v3:
- Grammar (Sam Ravnborg)
- s/drm_gem_shmem_put_pages_unlocked/drm_gem_shmem_put_pages_locked/
  (Sam Ravnborg)
- Add debug output in error path (Sam Ravnborg)

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190313004344.24169-1-robh@kernel.org

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 073a947b282d..e630eccb951c 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -25,6 +25,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
 drm-$(CONFIG_DRM_VM) += drm_vm.o
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
 drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
+drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o
 drm-$(CONFIG_PCI) += ati_pcigart.o
 drm-$(CONFIG_DRM_PANEL) += drm_panel.o
 drm-$(CONFIG_OF) += drm_of.o