Hi
Am 16.09.26 um 05:33 schrieb Chen-Yu Tsai:
Currently drm_fb_dma_get_gem_addr() calculates the offset into the
framebuffer memory for the framebuffer's unclipped source coordinates,
adds that to the framebuffer's backing storage, and returns the result.
We are about to add a variant that uses the clipped source coordinates,
so there is already some reuse of code. However, calculating the data
offset for a given pixel is not specific to the DMA FB helpers. The
offset is only related to the framebuffer.
Split out the offset calculation into a new framebuffer helper so that
non-DMA users can also reuse the same code.
Suggested-by: Thomas Zimmermann <[email protected]>
Cc: <[email protected]> # dependency for next patch
Signed-off-by: Chen-Yu Tsai <[email protected]>
---
Changes since v1:
- New patch
---
drivers/gpu/drm/drm_fb_dma_helper.c | 28 ++----------------
drivers/gpu/drm/drm_framebuffer.c | 45 +++++++++++++++++++++++++++++
include/drm/drm_framebuffer.h | 3 ++
3 files changed, 51 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_dma_helper.c
b/drivers/gpu/drm/drm_fb_dma_helper.c
index fd71969d2fb1..ab0f37d8a5ff 100644
--- a/drivers/gpu/drm/drm_fb_dma_helper.c
+++ b/drivers/gpu/drm/drm_fb_dma_helper.c
@@ -75,36 +75,14 @@ dma_addr_t drm_fb_dma_get_gem_addr(struct drm_framebuffer
*fb,
unsigned int plane)
{
struct drm_gem_dma_object *obj;
- dma_addr_t dma_addr;
- u8 h_div = 1, v_div = 1;
- u32 block_w = drm_format_info_block_width(fb->format, plane);
- u32 block_h = drm_format_info_block_height(fb->format, plane);
- u32 block_size = fb->format->char_per_block[plane];
- u32 sample_x;
- u32 sample_y;
- u32 block_start_y;
- u32 num_hblocks;
obj = drm_fb_dma_get_gem_obj(fb, plane);
if (!obj)
return 0;
- dma_addr = obj->dma_addr + fb->offsets[plane];
-
- if (plane > 0) {
- h_div = fb->format->hsub;
- v_div = fb->format->vsub;
- }
-
- sample_x = (state->src_x >> 16) / h_div;
- sample_y = (state->src_y >> 16) / v_div;
- block_start_y = (sample_y / block_h) * block_h;
- num_hblocks = sample_x / block_w;
-
- dma_addr += fb->pitches[plane] * block_start_y;
- dma_addr += block_size * num_hblocks;
-
- return dma_addr;
+ return obj->dma_addr + drm_framebuffer_get_block_offset(fb, plane,
+ state->src_x >>
16,
+ state->src_y >>
16);
}
EXPORT_SYMBOL_GPL(drm_fb_dma_get_gem_addr);
diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index d32aceb6ca9b..9e1231162047 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -1208,6 +1208,51 @@ void drm_framebuffer_print_info(struct drm_printer *p,
unsigned int indent,
}
}
+/**
+ * drm_framebuffer_get_block_offset() - Get offset to start of pixel block for
+ * the given framebuffer and coordinates.
+ * @fb: The framebuffer
+ * @plane: Which plane
+ * @x: x coordinate for pixel
+ * @y: y coordinate for pixel
+ *
+ * This function will usually be called from the PLANE callback functions,
+ * or from one of the helpers that calculates the framebuffer's DMA address.
+ *
+ * Return: offset from start of framebuffer to start of pixel block
+ */
+u32 drm_framebuffer_get_block_offset(struct drm_framebuffer *fb, unsigned int
plane,
+ unsigned int x, unsigned int y)
Better use u64 as return type.
+{
+ u8 h_div = 1, v_div = 1;
+ u32 block_w = drm_format_info_block_width(fb->format, plane);
+ u32 block_h = drm_format_info_block_height(fb->format, plane);
+ u32 block_size = fb->format->char_per_block[plane];
+ u32 sample_x;
+ u32 sample_y;
+ u32 block_start_y;
+ u32 num_hblocks;
+ u32 offset;
+
+ offset = fb->offsets[plane];
+
+ if (plane > 0) {
+ h_div = fb->format->hsub;
+ v_div = fb->format->vsub;
+ }
+
+ sample_x = x / h_div;
+ sample_y = y / v_div;
+ block_start_y = (sample_y / block_h) * block_h;
+ num_hblocks = sample_x / block_w;
+
+ offset += fb->pitches[plane] * block_start_y;
+ offset += block_size * num_hblocks;
User space controls the values in fb->offsets and fb->pitches. I'm not
sure how well they have been validated already at this point. Did you
investigate this?
Best regards
Thomas
+
+ return offset;
+}
+EXPORT_SYMBOL(drm_framebuffer_get_block_offset);
+
#ifdef CONFIG_DEBUG_FS
static int drm_framebuffer_info(struct seq_file *m, void *data)
{
diff --git a/include/drm/drm_framebuffer.h b/include/drm/drm_framebuffer.h
index 38b24fc8978d..c07aea1cc59f 100644
--- a/include/drm/drm_framebuffer.h
+++ b/include/drm/drm_framebuffer.h
@@ -220,6 +220,9 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb);
void drm_framebuffer_cleanup(struct drm_framebuffer *fb);
void drm_framebuffer_unregister_private(struct drm_framebuffer *fb);
+u32 drm_framebuffer_get_block_offset(struct drm_framebuffer *fb, unsigned int plane,
+ unsigned int x, unsigned int y);
+
/**
* drm_framebuffer_get - acquire a framebuffer reference
* @fb: DRM framebuffer
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)
