From: Gerd Hoffmann <kraxel@xxxxxxxxxx> commit 1cad629257e76025bcbf490c58de550fb67d4d0e upstream. Add map_cached bool to drm_gem_shmem_object, to request cached mappings on a per-object base. Check the flag before adding writecombine to pgprot bits. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx> Reviewed-by: Gurchetan Singh <gurchetansingh@xxxxxxxxxxxx> Tested-by: Guillaume Gardet <Guillaume.Gardet@xxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/20200226154752.24328-2-kraxel@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_gem_shmem_helper.c | 15 +++++++++++---- include/drm/drm_gem_shmem_helper.h | 5 +++++ 2 files changed, 16 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -254,11 +254,16 @@ static void *drm_gem_shmem_vmap_locked(s if (ret) goto err_zero_use; - if (obj->import_attach) + if (obj->import_attach) { shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); - else + } else { + pgprot_t prot = PAGE_KERNEL; + + if (!shmem->map_cached) + prot = pgprot_writecombine(prot); shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, - VM_MAP, pgprot_writecombine(PAGE_KERNEL)); + VM_MAP, prot); + } if (!shmem->vaddr) { DRM_DEBUG_KMS("Failed to vmap pages\n"); @@ -537,7 +542,9 @@ int drm_gem_shmem_mmap(struct drm_gem_ob } vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND; - vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); + if (!shmem->map_cached) + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); vma->vm_ops = &drm_gem_shmem_vm_ops; --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -96,6 +96,11 @@ struct drm_gem_shmem_object { * The address are un-mapped when the count reaches zero. */ unsigned int vmap_use_count; + + /** + * @map_cached: map object cached (instead of using writecombine). + */ + bool map_cached; }; #define to_drm_gem_shmem_obj(obj) \
