drm/format-helper: Rework XRGB8888-to-XRGB2101010 conversion

Update XRGB8888-to-XRGB2101010 conversion to support struct iosys_map
and convert all users. Although these are single-plane color formats,
the new interface supports multi-plane formats for consistency with
drm_fb_blit().

v2:
	* update documentation (Sam)
	* add TODO on vaddr location (Sam)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220808125406.20752-11-tzimmermann@suse.de

drivers/gpu/drm/drm_format_helper.c

@@ -554,26 +554,45 @@ static void drm_fb_xrgb8888_to_xrgb2101010_line(void *dbuf, const void *sbuf, un
 }
 
 /**
- * drm_fb_xrgb8888_to_xrgb2101010_toio - Convert XRGB8888 to XRGB2101010 clip
- * buffer
- * @dst: XRGB2101010 destination buffer (iomem)
- * @dst_pitch: Number of bytes between two consecutive scanlines within dst
- * @vaddr: XRGB8888 source buffer
+ * drm_fb_xrgb8888_to_xrgb2101010 - Convert XRGB8888 to XRGB2101010 clip buffer
+ * @dst: Array of XRGB2101010 destination buffers
+ * @dst_pitch: Array of numbers of bytes between the start of two consecutive scanlines
+ *             within @dst; can be NULL if scanlines are stored next to each other.
+ * @vmap: Array of XRGB8888 source buffers
  * @fb: DRM framebuffer
  * @clip: Clip rectangle area to copy
  *
- * Drivers can use this function for XRGB2101010 devices that don't natively
- * support XRGB8888.
+ * This function copies parts of a framebuffer to display memory and converts the
+ * color format during the process. Destination and framebuffer formats must match. The
+ * parameters @dst, @dst_pitch and @vmap refer to arrays. Each array must have at
+ * least as many entries as there are planes in @fb's format. Each entry stores the
+ * value for the format's respective color plane at the same index.
+ *
+ * This function does not apply clipping on @dst (i.e. the destination is at the
+ * top-left corner).
+ *
+ * Drivers can use this function for XRGB2101010 devices that don't support XRGB8888
+ * natively.
  */
-void drm_fb_xrgb8888_to_xrgb2101010_toio(void __iomem *dst,
-					 unsigned int dst_pitch, const void *vaddr,
-					 const struct drm_framebuffer *fb,
-					 const struct drm_rect *clip)
+void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
+				    const struct iosys_map *vmap, const struct drm_framebuffer *fb,
+				    const struct drm_rect *clip)
 {
-	drm_fb_xfrm_toio(dst, dst_pitch, 4, vaddr, fb, clip, false,
-			 drm_fb_xrgb8888_to_xrgb2101010_line);
+	static const unsigned int default_dst_pitch[DRM_FORMAT_MAX_PLANES] = {
+		0, 0, 0, 0
+	};
+
+	if (!dst_pitch)
+		dst_pitch = default_dst_pitch;
+
+	/* TODO: handle vmap in I/O memory here */
+	if (dst[0].is_iomem)
+		drm_fb_xfrm_toio(dst[0].vaddr_iomem, dst_pitch[0], 4, vmap[0].vaddr, fb,
+				 clip, false, drm_fb_xrgb8888_to_xrgb2101010_line);
+	else
+		drm_fb_xfrm(dst[0].vaddr, dst_pitch[0], 4, vmap[0].vaddr, fb,
+			    clip, false, drm_fb_xrgb8888_to_xrgb2101010_line);
 }
-EXPORT_SYMBOL(drm_fb_xrgb8888_to_xrgb2101010_toio);
 
 static void drm_fb_xrgb8888_to_gray8_line(void *dbuf, const void *sbuf, unsigned int pixels)
 {
@@ -681,8 +700,7 @@ int drm_fb_blit(struct iosys_map *dst, const unsigned int *dst_pitch, uint32_t d
 		}
 	} else if (dst_format == DRM_FORMAT_XRGB2101010) {
 		if (fb_format == DRM_FORMAT_XRGB8888) {
-			drm_fb_xrgb8888_to_xrgb2101010_toio(dst[0].vaddr_iomem, dst_pitch[0],
-							    vmap[0].vaddr, fb, clip);
+			drm_fb_xrgb8888_to_xrgb2101010(dst, dst_pitch, vmap, fb, clip);
 			return 0;
 		}
 	}

include/drm/drm_format_helper.h

@@ -29,9 +29,9 @@ void drm_fb_xrgb8888_to_rgb565(struct iosys_map *dst, const unsigned int *dst_pi
 void drm_fb_xrgb8888_to_rgb888(struct iosys_map *dst, const unsigned int *dst_pitch,
 			       const struct iosys_map *vmap, const struct drm_framebuffer *fb,
 			       const struct drm_rect *clip);
-void drm_fb_xrgb8888_to_xrgb2101010_toio(void __iomem *dst, unsigned int dst_pitch,
-					 const void *vaddr, const struct drm_framebuffer *fb,
-					 const struct drm_rect *clip);
+void drm_fb_xrgb8888_to_xrgb2101010(struct iosys_map *dst, const unsigned int *dst_pitch,
+				    const struct iosys_map *vmap, const struct drm_framebuffer *fb,
+				    const struct drm_rect *clip);
 void drm_fb_xrgb8888_to_gray8(void *dst, unsigned int dst_pitch, const void *vaddr,
 			      const struct drm_framebuffer *fb, const struct drm_rect *clip);