Hi
Am 18.02.25 um 20:32 schrieb Geert Uytterhoeven:
[...]
+ args->bpp);
+ fallthrough;
+ case 12:
+ case 15:
+ case 30: /* see drm_gem_afbc_get_bpp() */
+ case 10:
Perhaps keep them sorted numerically?
The first block comes from the afbc helper; the second block from Mesa;
hence the odd order. I'll reorder and comment each case individually.
+ case 64: /* used by Mesa */
+ pitch = args->width * DIV_ROUND_UP(args->bpp, SZ_8);
+ break;
+ }
+ }
+
+ if (!pitch || pitch > U32_MAX)
+ return -EINVAL;
+
+ args->pitch = pitch;
+
+ return drm_mode_align_dumb(args, pitch_align, size_align);
+}
+EXPORT_SYMBOL(drm_mode_size_dumb);
+
int drm_mode_create_dumb(struct drm_device *dev,
struct drm_mode_create_dumb *args,
struct drm_file *file_priv)
diff --git a/include/drm/drm_dumb_buffers.h b/include/drm/drm_dumb_buffers.h
new file mode 100644
index 000000000000..6fe36004b19d
--- /dev/null
+++ b/include/drm/drm_dumb_buffers.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef __DRM_DUMB_BUFFERS_H__
+#define __DRM_DUMB_BUFFERS_H__
+
+struct drm_device;
+struct drm_mode_create_dumb;
+
+int drm_mode_size_dumb(struct drm_device *dev,
+ struct drm_mode_create_dumb *args,
+ unsigned long pitch_align,
+ unsigned long size_align);
+
+#endif
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index c082810c08a8..eea09103b1a6 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -1058,7 +1058,7 @@ struct drm_mode_crtc_page_flip_target {
* struct drm_mode_create_dumb - Create a KMS dumb buffer for scanout.
* @height: buffer height in pixels
* @width: buffer width in pixels
- * @bpp: bits per pixel
+ * @bpp: color mode
* @flags: must be zero
* @handle: buffer object handle
* @pitch: number of bytes between two consecutive lines
@@ -1066,6 +1066,50 @@ struct drm_mode_crtc_page_flip_target {
*
* User-space fills @height, @width, @bpp and @flags. If the IOCTL succeeds,
* the kernel fills @handle, @pitch and @size.
+ *
+ * The value of @bpp is a color-mode number describing a specific format
+ * or a variant thereof. The value often corresponds to the number of bits
+ * per pixel for most modes, although there are exceptions. Each color mode
+ * maps to a DRM format plus a number of modes with similar pixel layout.
+ * Framebuffer layout is always linear.
+ *
+ * Support for all modes and formats is optional. Even if dumb-buffer
+ * creation with a certain color mode succeeds, it is not guaranteed that
+ * the DRM driver supports any of the related formats. Most drivers support
+ * a color mode of 32 with a format of DRM_FORMAT_XRGB8888 on their primary
+ * plane.
+ *
+ * +------------+------------------------+------------------------+
+ * | Color mode | Framebuffer format | Compatibles |
+ * +============+========================+========================+
+ * | 32 | * DRM_FORMAT_XRGB8888 | * DRM_FORMAT_XBGR8888 |
+ * | | | * DRM_FORMAT_RGBX8888 |
+ * | | | * DRM_FORMAT_BGRX8888 |
+ * +------------+------------------------+------------------------+
+ * | 24 | * DRM_FORMAT_RGB888 | * DRM_FORMAT_BGR888 |
+ * +------------+------------------------+------------------------+
+ * | 16 | * DRM_FORMAT_RGB565 | * DRM_FORMAT_BGR565 |
+ * +------------+------------------------+------------------------+
+ * | 15 | * DRM_FORMAT_XRGB1555 | * DRM_FORMAT_XBGR1555 |
+ * | | | * DRM_FORMAT_RGBX1555 |
+ * | | | * DRM_FORMAT_BGRX1555 |
+ * +------------+------------------------+------------------------+
+ * | 8 | * DRM_FORMAT_C8 | * DRM_FORMAT_R8 |
+ DRM_FORMAT_D8? (and 4/2/1 below)
Right, missed that.
And DRM_FORMAT_Y8, if/when Tomi's series introducing that is accepted...
Sure, if it is compatible, it can also go into the third column.
Best regards
Thomas
+ * +------------+------------------------+------------------------+
+ * | 4 | * DRM_FORMAT_C4 | * DRM_FORMAT_R4 |
+ * +------------+------------------------+------------------------+
+ * | 2 | * DRM_FORMAT_C2 | * DRM_FORMAT_R2 |
+ * +------------+------------------------+------------------------+
+ * | 1 | * DRM_FORMAT_C1 | * DRM_FORMAT_R1 |
+ * +------------+------------------------+------------------------+
+ *
+ * Color modes of 10, 12, 15, 30 and 64 are only supported for use by
+ * legacy user space. Please don't use them in new code. Other modes
+ * are not support.
+ *
+ * Do not attempt to allocate anything but linear framebuffer memory
+ * with single-plane RGB data. Allocation of other framebuffer
+ * layouts requires dedicated ioctls in the respective DRM driver.
*/
struct drm_mode_create_dumb {
__u32 height;
Gr{oetje,eeting}s,
Geert
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
