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 (file)
--- 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);
 

diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
index 9f4f5f0..3473e9e 100644 (file)
--- a/drivers/gpu/drm/mgag200/mgag200_drv.c
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -121,7 +121,7 @@ int mgag200_driver_dumb_create(struct drm_file *file,
                pg_align = PFN_UP(mdev->mc.vram_size);
 
        return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev,
-                                            pg_align, false, args);
+                                            pg_align, 0, false, args);
 }
 
 static struct drm_driver driver = {

diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index 08adaf3..b86d038 100644 (file)
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -112,6 +112,7 @@ 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);