drm: remove pgprot_decrypted() before calls to io_remap_pfn_range()

commit f8f6ae5 ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") moves the pgprot_decrypted() into
io_remap_pfn_range(). Delete any, now confusing, open coded calls that
directly precede io_remap_pfn_range():

- drm_io_prot() is only in drm_mmap_locked() to call io_remap_pfn_range()

- fb_mmap() immediately calls vm_iomap_memory() which is a convenience
  wrapper for io_remap_pfn_range()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/0-v1-2e6a0db57868+166-drm_sme_clean_jgg@nvidia.com

drivers/gpu/drm/drm_vm.c

@@ -70,9 +70,6 @@ static pgprot_t drm_io_prot(struct drm_local_map *map,
 {
 	pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 
-	/* We don't want graphics memory to be mapped encrypted */
-	tmp = pgprot_decrypted(tmp);
-
 #if defined(__i386__) || defined(__x86_64__) || defined(__powerpc__) || \
     defined(__mips__)
 	if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING))

drivers/video/fbdev/core/fbmem.c

@@ -1380,11 +1380,6 @@ fb_mmap(struct file *file, struct vm_area_struct * vma)
 	mutex_unlock(&info->mm_lock);
 
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	/*
-	 * The framebuffer needs to be accessed decrypted, be sure
-	 * SME protection is removed
-	 */
-	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
 	fb_pgprotect(file, vma, start);
 
 	return vm_iomap_memory(vma, start, len);