[PATCH v5 2/6] dma-buf: udmabuf: Implement .{begin,end}_access

Paul Cercueil
2024-01-19T14:14:30Z

Implement .begin_access() and .end_access() callbacks.

For now these functions will simply sync/flush the CPU cache when
needed.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>

---
v5: New patch
---
drivers/dma-buf/udmabuf.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c40645999648..a87d89b58816 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -179,6 +179,31 @@ static int end_cpu_udmabuf(struct dma_buf *buf,
return 0;
}

+static int begin_udmabuf(struct dma_buf_attachment *attach,
+ struct sg_table *sgt,
+ enum dma_data_direction dir)
+{
+ struct dma_buf *buf = attach->dmabuf;
+ struct udmabuf *ubuf = buf->priv;
+ struct device *dev = ubuf->device->this_device;
+
+ dma_sync_sg_for_device(dev, sgt->sgl, sg_nents(sgt->sgl), dir);
+ return 0;
+}
+
+static int end_udmabuf(struct dma_buf_attachment *attach,
+ struct sg_table *sgt,
+ enum dma_data_direction dir)
+{
+ struct dma_buf *buf = attach->dmabuf;
+ struct udmabuf *ubuf = buf->priv;
+ struct device *dev = ubuf->device->this_device;
+
+ if (dir != DMA_TO_DEVICE)
+ dma_sync_sg_for_cpu(dev, sgt->sgl, sg_nents(sgt->sgl), dir);
+ return 0;
+}
+
static const struct dma_buf_ops udmabuf_ops = {
.cache_sgt_mapping = true,
.map_dma_buf = map_udmabuf,
@@ -189,6 +214,8 @@ static const struct dma_buf_ops udmabuf_ops = {
.vunmap = vunmap_udmabuf,
.begin_cpu_access = begin_cpu_udmabuf,
.end_cpu_access = end_cpu_udmabuf,
+ .begin_access = begin_udmabuf,
+ .end_access = end_udmabuf,
};

#define SEALS_WANTED (F_SEAL_SHRINK)
--
2.43.0