drm/vram: Support scanline alignment for dumb buffers
Adding the pitch alignment as an argument to
drm_gem_vram_fill_create_dumb() allows to align scanlines to certain
offsets. A value of 0 disables scanline pitches.
v3:
* only do power-of-2 test if pitch_align given; fails otherwise
* mgag200: call drm_gem_vram_fill_create_dumb() with pitch_align
v2:
* split of patch from related hibmc changes
* test if scanline pitch is power of 2
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203083819.6643-4-tzimmermann@suse.de
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c
index 666cb4c..51ee1f7 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -485,6 +485,7 @@ EXPORT_SYMBOL(drm_gem_vram_vunmap);
* @dev: the DRM device
* @bdev: the TTM BO device managing the buffer object
* @pg_align: the buffer's alignment in multiples of the page size
+ * @pitch_align: the scanline's alignment in powers of 2
* @interruptible: sleep interruptible if waiting for memory
* @args: the arguments as provided to \
&struct drm_driver.dumb_create
@@ -502,6 +503,7 @@ int drm_gem_vram_fill_create_dumb(struct drm_file *file,
struct drm_device *dev,
struct ttm_bo_device *bdev,
unsigned long pg_align,
+ unsigned long pitch_align,
bool interruptible,
struct drm_mode_create_dumb *args)
{
@@ -510,7 +512,12 @@ int drm_gem_vram_fill_create_dumb(struct drm_file *file,
int ret;
u32 handle;
- pitch = args->width * ((args->bpp + 7) / 8);
+ pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
+ if (pitch_align) {
+ if (WARN_ON_ONCE(!is_power_of_2(pitch_align)))
+ return -EINVAL;
+ pitch = ALIGN(pitch, pitch_align);
+ }
size = pitch * args->height;
size = roundup(size, PAGE_SIZE);
@@ -612,8 +619,8 @@ int drm_gem_vram_driver_dumb_create(struct drm_file *file,
if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
return -EINVAL;
- return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0,
- false, args);
+ return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev,
+ 0, 0, false, args);
}
EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
