[PATCH] dmaengine: milbeaut-hdmac: use kzalloc_flex

From: Rosen Penev

Date: Sun Mar 08 2026 - 18:22:09 EST


Reduces allocation to a single one for simplicity.

Added __counted_by for extra runtime analysis.

Replace loop with memcpy. The loop adds no value here.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
drivers/dma/milbeaut-hdmac.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/dma/milbeaut-hdmac.c b/drivers/dma/milbeaut-hdmac.c
index b4ebc09e80d0..2e15a2256b55 100644
--- a/drivers/dma/milbeaut-hdmac.c
+++ b/drivers/dma/milbeaut-hdmac.c
@@ -58,10 +58,10 @@

struct milbeaut_hdmac_desc {
struct virt_dma_desc vd;
- struct scatterlist *sgl;
unsigned int sg_len;
unsigned int sg_cur;
enum dma_transfer_direction dir;
+ struct scatterlist sgl[] __counted_by(sg_len);
};

struct milbeaut_hdmac_chan {
@@ -260,25 +260,16 @@ milbeaut_hdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
{
struct virt_dma_chan *vc = to_virt_chan(chan);
struct milbeaut_hdmac_desc *md;
- int i;

if (!is_slave_direction(direction))
return NULL;

- md = kzalloc_obj(*md, GFP_NOWAIT);
+ md = kzalloc_flex(*md, sgl, sg_len, GFP_NOWAIT);
if (!md)
return NULL;

- md->sgl = kzalloc_objs(*sgl, sg_len, GFP_NOWAIT);
- if (!md->sgl) {
- kfree(md);
- return NULL;
- }
-
- for (i = 0; i < sg_len; i++)
- md->sgl[i] = sgl[i];
-
md->sg_len = sg_len;
+ memcpy(md->sgl, sgl, sg_len * sizeof(*sgl));
md->dir = direction;

return vchan_tx_prep(vc, &md->vd, flags);
@@ -395,7 +386,6 @@ static void milbeaut_hdmac_desc_free(struct virt_dma_desc *vd)
{
struct milbeaut_hdmac_desc *md = to_milbeaut_hdmac_desc(vd);

- kfree(md->sgl);
kfree(md);
}

--
2.53.0