From 3affa310de523d63e52ea8e2efb3c476df29e414 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Tue, 29 Oct 2024 13:17:09 +0100 Subject: [PATCH 1/2] net: airoha: Read completion queue data in airoha_qdma_tx_napi_poll() In order to avoid any possible race, read completion queue head and pending entry in airoha_qdma_tx_napi_poll routine instead of doing it in airoha_irq_handler. Remove unused airoha_tx_irq_queue unused fields. This is a preliminary patch to add Qdisc offload for airoha_eth driver. Signed-off-by: Lorenzo Bianconi Link: https://patch.msgid.link/20241029-airoha-en7581-tx-napi-work-v1-1-96ad1686b946@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mediatek/airoha_eth.c | 31 +++++++++------------- 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/drivers/net/ethernet/mediatek/airoha_eth.c b/drivers/net/ethernet/mediatek/airoha_eth.c index f463a505f5ba..6cd8901ed38f 100644 --- a/drivers/net/ethernet/mediatek/airoha_eth.c +++ b/drivers/net/ethernet/mediatek/airoha_eth.c @@ -752,11 +752,9 @@ struct airoha_tx_irq_queue { struct airoha_qdma *qdma; struct napi_struct napi; - u32 *q; int size; - int queued; - u16 head; + u32 *q; }; struct airoha_hw_stats { @@ -1656,25 +1654,31 @@ static int airoha_qdma_init_rx(struct airoha_qdma *qdma) static int airoha_qdma_tx_napi_poll(struct napi_struct *napi, int budget) { struct airoha_tx_irq_queue *irq_q; + int id, done = 0, irq_queued; struct airoha_qdma *qdma; struct airoha_eth *eth; - int id, done = 0; + u32 status, head; irq_q = container_of(napi, struct airoha_tx_irq_queue, napi); qdma = irq_q->qdma; id = irq_q - &qdma->q_tx_irq[0]; eth = qdma->eth; - while (irq_q->queued > 0 && done < budget) { - u32 qid, last, val = irq_q->q[irq_q->head]; + status = airoha_qdma_rr(qdma, REG_IRQ_STATUS(id)); + head = FIELD_GET(IRQ_HEAD_IDX_MASK, status); + head = head % irq_q->size; + irq_queued = FIELD_GET(IRQ_ENTRY_LEN_MASK, status); + + while (irq_queued > 0 && done < budget) { + u32 qid, last, val = irq_q->q[head]; struct airoha_queue *q; if (val == 0xff) break; - irq_q->q[irq_q->head] = 0xff; /* mark as done */ - irq_q->head = (irq_q->head + 1) % irq_q->size; - irq_q->queued--; + irq_q->q[head] = 0xff; /* mark as done */ + head = (head + 1) % irq_q->size; + irq_queued--; done++; last = FIELD_GET(IRQ_DESC_IDX_MASK, val); @@ -2026,20 +2030,11 @@ static irqreturn_t airoha_irq_handler(int irq, void *dev_instance) if (intr[0] & INT_TX_MASK) { for (i = 0; i < ARRAY_SIZE(qdma->q_tx_irq); i++) { - struct airoha_tx_irq_queue *irq_q = &qdma->q_tx_irq[i]; - u32 status, head; - if (!(intr[0] & TX_DONE_INT_MASK(i))) continue; airoha_qdma_irq_disable(qdma, QDMA_INT_REG_IDX0, TX_DONE_INT_MASK(i)); - - status = airoha_qdma_rr(qdma, REG_IRQ_STATUS(i)); - head = FIELD_GET(IRQ_HEAD_IDX_MASK, status); - irq_q->head = head % irq_q->size; - irq_q->queued = FIELD_GET(IRQ_ENTRY_LEN_MASK, status); - napi_schedule(&qdma->q_tx_irq[i].napi); } } From 0c729f53b8c33b9e5eadc2d5e673759e3510501e Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Tue, 29 Oct 2024 13:17:10 +0100 Subject: [PATCH 2/2] net: airoha: Simplify Tx napi logic Simplify Tx napi logic relying just on the packet index provided by completion queue indicating the completed packet that can be removed from the Tx DMA ring. This is a preliminary patch to add Qdisc offload for airoha_eth driver. Signed-off-by: Lorenzo Bianconi Link: https://patch.msgid.link/20241029-airoha-en7581-tx-napi-work-v1-2-96ad1686b946@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mediatek/airoha_eth.c | 77 ++++++++++++---------- 1 file changed, 43 insertions(+), 34 deletions(-) diff --git a/drivers/net/ethernet/mediatek/airoha_eth.c b/drivers/net/ethernet/mediatek/airoha_eth.c index 6cd8901ed38f..6c683a12d5aa 100644 --- a/drivers/net/ethernet/mediatek/airoha_eth.c +++ b/drivers/net/ethernet/mediatek/airoha_eth.c @@ -1670,8 +1670,12 @@ static int airoha_qdma_tx_napi_poll(struct napi_struct *napi, int budget) irq_queued = FIELD_GET(IRQ_ENTRY_LEN_MASK, status); while (irq_queued > 0 && done < budget) { - u32 qid, last, val = irq_q->q[head]; + u32 qid, val = irq_q->q[head]; + struct airoha_qdma_desc *desc; + struct airoha_queue_entry *e; struct airoha_queue *q; + u32 index, desc_ctrl; + struct sk_buff *skb; if (val == 0xff) break; @@ -1681,9 +1685,7 @@ static int airoha_qdma_tx_napi_poll(struct napi_struct *napi, int budget) irq_queued--; done++; - last = FIELD_GET(IRQ_DESC_IDX_MASK, val); qid = FIELD_GET(IRQ_RING_IDX_MASK, val); - if (qid >= ARRAY_SIZE(qdma->q_tx)) continue; @@ -1691,46 +1693,53 @@ static int airoha_qdma_tx_napi_poll(struct napi_struct *napi, int budget) if (!q->ndesc) continue; + index = FIELD_GET(IRQ_DESC_IDX_MASK, val); + if (index >= q->ndesc) + continue; + spin_lock_bh(&q->lock); - while (q->queued > 0) { - struct airoha_qdma_desc *desc = &q->desc[q->tail]; - struct airoha_queue_entry *e = &q->entry[q->tail]; - u32 desc_ctrl = le32_to_cpu(desc->ctrl); - struct sk_buff *skb = e->skb; - u16 index = q->tail; + if (!q->queued) + goto unlock; - if (!(desc_ctrl & QDMA_DESC_DONE_MASK) && - !(desc_ctrl & QDMA_DESC_DROP_MASK)) - break; + desc = &q->desc[index]; + desc_ctrl = le32_to_cpu(desc->ctrl); + if (!(desc_ctrl & QDMA_DESC_DONE_MASK) && + !(desc_ctrl & QDMA_DESC_DROP_MASK)) + goto unlock; + + e = &q->entry[index]; + skb = e->skb; + + dma_unmap_single(eth->dev, e->dma_addr, e->dma_len, + DMA_TO_DEVICE); + memset(e, 0, sizeof(*e)); + WRITE_ONCE(desc->msg0, 0); + WRITE_ONCE(desc->msg1, 0); + q->queued--; + + /* completion ring can report out-of-order indexes if hw QoS + * is enabled and packets with different priority are queued + * to same DMA ring. Take into account possible out-of-order + * reports incrementing DMA ring tail pointer + */ + while (q->tail != q->head && !q->entry[q->tail].dma_addr) q->tail = (q->tail + 1) % q->ndesc; - q->queued--; - dma_unmap_single(eth->dev, e->dma_addr, e->dma_len, - DMA_TO_DEVICE); + if (skb) { + u16 queue = skb_get_queue_mapping(skb); + struct netdev_queue *txq; - WRITE_ONCE(desc->msg0, 0); - WRITE_ONCE(desc->msg1, 0); + txq = netdev_get_tx_queue(skb->dev, queue); + netdev_tx_completed_queue(txq, 1, skb->len); + if (netif_tx_queue_stopped(txq) && + q->ndesc - q->queued >= q->free_thr) + netif_tx_wake_queue(txq); - if (skb) { - u16 queue = skb_get_queue_mapping(skb); - struct netdev_queue *txq; - - txq = netdev_get_tx_queue(skb->dev, queue); - netdev_tx_completed_queue(txq, 1, skb->len); - if (netif_tx_queue_stopped(txq) && - q->ndesc - q->queued >= q->free_thr) - netif_tx_wake_queue(txq); - - dev_kfree_skb_any(skb); - e->skb = NULL; - } - - if (index == last) - break; + dev_kfree_skb_any(skb); } - +unlock: spin_unlock_bh(&q->lock); }