1f708c5 --- Cc: Nicolas Ferre Cc: Claudiu Beznea Cc: Andrew Lunn Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Russell King --- drivers/net/ethernet/cadence/macb_main.c | 98 +++++++++++++++++++++++++++++++- 1 file changed, 95 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 3dcae4d5f74c9709a86fae837d25501da4484bf7..952aaf84757c20e94f3bbc98162a18330aa4cf73 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include "macb.h" @@ -786,6 +787,97 @@ static void macb_mac_link_down(struct phylink_config *config, unsigned int mode, netif_tx_stop_all_queues(ndev); } +/* Use juggling algorithm to left rotate tx ring and tx skb array */ +static void gem_shuffle_tx_one_ring(struct macb_queue *queue) +{ + unsigned int head, tail, count, ring_size, desc_size; + struct macb_tx_skb tx_skb, *skb_curr, *skb_next; + struct macb_dma_desc *desc_curr, *desc_next; + unsigned int i, cycles, shift, curr, next; + struct macb *bp = queue->bp; + unsigned char desc[24]; + unsigned long flags; + + desc_size = macb_dma_desc_get_size(bp); + + if (WARN_ON_ONCE(desc_size > ARRAY_SIZE(desc))) + return; + + spin_lock_irqsave(&queue->tx_ptr_lock, flags); + head = queue->tx_head; + tail = queue->tx_tail; + ring_size = bp->tx_ring_size; + count = CIRC_CNT(head, tail, ring_size); + + if (!(tail % ring_size)) + goto unlock; + + if (!count) { + queue->tx_head = 0; + queue->tx_tail = 0; + goto unlock; + } + + shift = tail % ring_size; + cycles = gcd(ring_size, shift); + + for (i = 0; i < cycles; i++) { + memcpy(&desc, macb_tx_desc(queue, i), desc_size); + memcpy(&tx_skb, macb_tx_skb(queue, i), + sizeof(struct macb_tx_skb)); + + curr = i; + next = (curr + shift) % ring_size; + + while (next != i) { + desc_curr = macb_tx_desc(queue, curr); + desc_next = macb_tx_desc(queue, next); + + memcpy(desc_curr, desc_next, desc_size); + + if (next == ring_size - 1) + desc_curr->ctrl &= ~MACB_BIT(TX_WRAP); + if (curr == ring_size - 1) + desc_curr->ctrl |= MACB_BIT(TX_WRAP); + + skb_curr = macb_tx_skb(queue, curr); + skb_next = macb_tx_skb(queue, next); + memcpy(skb_curr, skb_next, sizeof(struct macb_tx_skb)); + + curr = next; + next = (curr + shift) % ring_size; + } + + desc_curr = macb_tx_desc(queue, curr); + memcpy(desc_curr, &desc, desc_size); + if (i == ring_size - 1) + desc_curr->ctrl &= ~MACB_BIT(TX_WRAP); + if (curr == ring_size - 1) + desc_curr->ctrl |= MACB_BIT(TX_WRAP); + memcpy(macb_tx_skb(queue, curr), &tx_skb, + sizeof(struct macb_tx_skb)); + } + + queue->tx_head = count; + queue->tx_tail = 0; + + /* Make descriptor updates visible to hardware */ + wmb(); + +unlock: + spin_unlock_irqrestore(&queue->tx_ptr_lock, flags); +} + +/* Rotate the queue so that the tail is at index 0 */ +static void gem_shuffle_tx_rings(struct macb *bp) +{ + struct macb_queue *queue; + int q; + + for (q = 0, queue = bp->queues; q < bp->num_queues; q++, queue++) + gem_shuffle_tx_one_ring(queue); +} + static void macb_mac_link_up(struct phylink_config *config, struct phy_device *phy, unsigned int mode, phy_interface_t interface, @@ -824,8 +916,6 @@ static void macb_mac_link_up(struct phylink_config *config, ctrl |= MACB_BIT(PAE); for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) { - queue->tx_head = 0; - queue->tx_tail = 0; queue_writel(queue, IER, bp->rx_intr_mask | MACB_TX_INT_FLAGS | MACB_BIT(HRESP)); } @@ -839,8 +929,10 @@ static void macb_mac_link_up(struct phylink_config *config, spin_unlock_irqrestore(&bp->lock, flags); - if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC)) + if (!(bp->caps & MACB_CAPS_MACB_IS_EMAC)) { macb_set_tx_clk(bp, speed); + gem_shuffle_tx_rings(bp); + } /* Enable Rx and Tx; Enable PTP unicast */ ctrl = macb_readl(bp, NCR); --- base-commit: a0ae2a256046c0c5d3778d1a194ff2e171f16e5f change-id: 20260214-zynqmp-74d35f3862f8 Best regards, -- Kevin Hao [PATCH net v2] net: macb: Shuffle the tx ring before enabling txKevin Hao undefinednetdev@vger.kernel.org undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefinedŸO†Å: