Commit 4ae0604a authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Jakub Kicinski
Browse files

net: airoha: Add dma_rmb() and READ_ONCE() in airoha_qdma_rx_process() 



Add missing dma_rmb() in airoha_qdma_rx_process routine to make sure the
DMA read operations are completed when the NIC reports the processing on
the current descriptor is done. Moreover, add missing READ_ONCE() in
airoha_qdma_rx_process() for DMA descriptor control fields in order to
avoid any compiler reordering.

Fixes: 23020f04 ("net: airoha: Introduce ethernet support for EN7581 SoC")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260407-airoha_qdma_rx_process-fix-reordering-v3-1-91c36e9da31f@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent e159f05e

drivers/net/ethernet/airoha/airoha_eth.c

+10 −6
Original line number Diff line number Diff line
@@ -584,7 +584,7 @@ static int airoha_qdma_fill_rx_queue(struct airoha_queue *q) 
static int airoha_qdma_get_gdm_port(struct airoha_eth *eth,

				    struct airoha_qdma_desc *desc)

{

	u32 port, sport, msg1 = le32_to_cpu(desc->msg1);

	u32 port, sport, msg1 = le32_to_cpu(READ_ONCE(desc->msg1));



	sport = FIELD_GET(QDMA_ETH_RXMSG_SPORT_MASK, msg1);

	switch (sport) {
@@ -612,21 +612,24 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) 
	while (done < budget) {

		struct airoha_queue_entry *e = &q->entry[q->tail];

		struct airoha_qdma_desc *desc = &q->desc[q->tail];

		u32 hash, reason, msg1 = le32_to_cpu(desc->msg1);

		struct page *page = virt_to_head_page(e->buf);

		u32 desc_ctrl = le32_to_cpu(desc->ctrl);

		u32 hash, reason, msg1, desc_ctrl;

		struct airoha_gdm_port *port;

		int data_len, len, p;

		struct page *page;



		desc_ctrl = le32_to_cpu(READ_ONCE(desc->ctrl));

		if (!(desc_ctrl & QDMA_DESC_DONE_MASK))

			break;



		dma_rmb();



		q->tail = (q->tail + 1) % q->ndesc;

		q->queued--;



		dma_sync_single_for_cpu(eth->dev, e->dma_addr,

					SKB_WITH_OVERHEAD(q->buf_size), dir);



		page = virt_to_head_page(e->buf);

		len = FIELD_GET(QDMA_DESC_LEN_MASK, desc_ctrl);

		data_len = q->skb ? q->buf_size

				  : SKB_WITH_OVERHEAD(q->buf_size);
@@ -670,8 +673,8 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) 
			 * DMA descriptor. Report DSA tag to the DSA stack

			 * via skb dst info.

			 */

			u32 sptag = FIELD_GET(QDMA_ETH_RXMSG_SPTAG,

					      le32_to_cpu(desc->msg0));

			u32 msg0 = le32_to_cpu(READ_ONCE(desc->msg0));

			u32 sptag = FIELD_GET(QDMA_ETH_RXMSG_SPTAG, msg0);



			if (sptag < ARRAY_SIZE(port->dsa_meta) &&

			    port->dsa_meta[sptag])
@@ -679,6 +682,7 @@ static int airoha_qdma_rx_process(struct airoha_queue *q, int budget) 
						  &port->dsa_meta[sptag]->dst);

		}



		msg1 = le32_to_cpu(READ_ONCE(desc->msg1));

		hash = FIELD_GET(AIROHA_RXD4_FOE_ENTRY, msg1);

		if (hash != AIROHA_RXD4_FOE_ENTRY)

			skb_set_hash(q->skb, jhash_1word(hash, 0),