[PATCH v6-S1 4/6] dma/dpaa2: release SG FLE on completion ring overflow

[Prashant Gupta]

From: Jun Yang <jun.yang at nxp.com>

In the DPAA2_QDMA_FD_SG branch of dpaa2_qdma_dq_fd(), the FLE was
recorded in qdma_vq->fle_elem[] before qdma_cntx_idx_ring_eq() was
called. On overflow the function returned -ENOSPC with the entry
already accounted for, leaving the release to the bulk
rte_mempool_put_bulk() that dpaa2_qdma_dequeue() performs after the
loop.

This is not a leak and not a double put, the object is returned exactly
once either way. However the ownership is easier to follow if the error
path releases the FLE itself, so return it with rte_mempool_put() and
only record it in fle_elem[] once the indices are in the ring. This
matches how the caller treats a failed dq_fd() as having consumed
nothing.

No functional change.

Signed-off-by: Jun Yang <jun.yang at nxp.com>
Signed-off-by: Prashant Gupta <prashant.gupta_3 at nxp.com>
---
 drivers/dma/dpaa2/dpaa2_qdma.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dpaa2/dpaa2_qdma.c b/drivers/dma/dpaa2/dpaa2_qdma.c
index 7d3f3d2003..3b272f6593 100644
--- a/drivers/dma/dpaa2/dpaa2_qdma.c
+++ b/drivers/dma/dpaa2/dpaa2_qdma.c
@@ -965,15 +965,17 @@ dpaa2_qdma_dq_fd(const struct qbman_fd *fd,
 	}
 	if (type == DPAA2_QDMA_FD_SG) {
 		fle_sdd = (void *)(uintptr_t)DPAA2_GET_FD_FLC(fd);
-		qdma_vq->fle_elem[*fle_elem_nb] = fle_sdd;
-		(*fle_elem_nb)++;
 		cntx_sg = container_of(fle_sdd,
 				struct qdma_cntx_sg, fle_sdd);
 		ret = qdma_cntx_idx_ring_eq(qdma_vq->ring_cntx_idx,
 				cntx_sg->cntx_idx,
 				cntx_sg->job_nb, free_space);
-		if (unlikely(ret < cntx_sg->job_nb))
+		if (unlikely(ret < cntx_sg->job_nb)) {
+			rte_mempool_put(qdma_vq->fle_pool, fle_sdd);
 			return -ENOSPC;
+		}
+		qdma_vq->fle_elem[*fle_elem_nb] = fle_sdd;
+		(*fle_elem_nb)++;
 
 		return 0;
 	}
-- 
2.43.0