iosys-map: Add offset to iosys_map_memcpy_to()

In certain situations it's useful to be able to write to an
offset of the mapping. Add a dst_offset to iosys_map_memcpy_to().

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220216174147.3073235-2-lucas.demarchi@intel.com

1 files changed, 9 insertions, 8 deletions

diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h
index f4186f91caa6..edd730b1e899 100644
--- a/include/linux/iosys-map.h
+++ b/include/linux/iosys-map.h
@@ -220,22 +220,23 @@ static inline void iosys_map_clear(struct iosys_map *map)
 }
 
 /**
- * iosys_map_memcpy_to - Memcpy into iosys mapping
+ * iosys_map_memcpy_to - Memcpy into offset of iosys_map
  * @dst:	The iosys_map structure
+ * @dst_offset:	The offset from which to copy
  * @src:	The source buffer
  * @len:	The number of byte in src
  *
- * Copies data into a iosys mapping. The source buffer is in system
- * memory. Depending on the buffer's location, the helper picks the correct
- * method of accessing the memory.
+ * Copies data into a iosys_map with an offset. The source buffer is in
+ * system memory. Depending on the buffer's location, the helper picks the
+ * correct method of accessing the memory.
  */
-static inline void iosys_map_memcpy_to(struct iosys_map *dst, const void *src,
-				       size_t len)
+static inline void iosys_map_memcpy_to(struct iosys_map *dst, size_t dst_offset,
+				       const void *src, size_t len)
 {
 	if (dst->is_iomem)
-		memcpy_toio(dst->vaddr_iomem, src, len);
+		memcpy_toio(dst->vaddr_iomem + dst_offset, src, len);
 	else
-		memcpy(dst->vaddr, src, len);
+		memcpy(dst->vaddr + dst_offset, src, len);
 }
 
 /**