Am 26.01.22 um 21:36 schrieb Lucas De Marchi:
Just like memcpy_toio(), there is also need to write a direct value to a
memory block. Add dma_buf_map_memset() to abstract memset() vs memset_io()
Cc: Matt Roper <matthew.d.roper@xxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linaro-mm-sig@xxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
---
include/linux/dma-buf-map.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
index 3514a859f628..c9fb04264cd0 100644
--- a/include/linux/dma-buf-map.h
+++ b/include/linux/dma-buf-map.h
@@ -317,6 +317,23 @@ static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const void *sr
memcpy(dst->vaddr, src, len);
}
+/**
+ * dma_buf_map_memset - Memset into dma-buf mapping
+ * @dst: The dma-buf mapping structure
+ * @value: The value to set
+ * @len: The number of bytes to set in dst
+ *
+ * Set value in dma-buf mapping. Depending on the buffer's location, the helper
+ * picks the correct method of accessing the memory.
+ */
+static inline void dma_buf_map_memset(struct dma_buf_map *dst, int value, size_t len)
+{
+ if (dst->is_iomem)
+ memset_io(dst->vaddr_iomem, value, len);
+ else
+ memset(dst->vaddr, value, len);
+}
+
Yeah, that's certainly a valid use case. But maybe directly add a
dma_buf_map_memset_with_offset() variant as well when that helps to
avoid patch #2.
Regards,
Christian.
/**
* dma_buf_map_incr - Increments the address stored in a dma-buf mapping
* @map: The dma-buf mapping structure
