From 82b761126dfb04581b18eaf8c54ba5e22897d2a0 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 5 Dec 2017 14:17:24 +0100 Subject: [PATCH] ar71xx: allocate rx/tx descriptor/buffers in one chunk Reduces false sharing due to cache aliases Signed-off-by: Felix Fietkau --- .../net/ethernet/atheros/ag71xx/ag71xx_main.c | 85 +++++++++---------- 1 file changed, 38 insertions(+), 47 deletions(-) diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c index 566e9513d8..eea54132f9 100644 --- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c +++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c @@ -97,41 +97,6 @@ static inline void ag71xx_dump_intr(struct ag71xx *ag, char *label, u32 intr) (intr & AG71XX_INT_RX_BE) ? "RXBE " : ""); } -static void ag71xx_ring_free(struct ag71xx_ring *ring) -{ - int ring_size = BIT(ring->order); - kfree(ring->buf); - - if (ring->descs_cpu) - dma_free_coherent(NULL, ring_size * AG71XX_DESC_SIZE, - ring->descs_cpu, ring->descs_dma); -} - -static int ag71xx_ring_alloc(struct ag71xx_ring *ring) -{ - int ring_size = BIT(ring->order); - int err; - - ring->descs_cpu = dma_alloc_coherent(NULL, ring_size * AG71XX_DESC_SIZE, - &ring->descs_dma, GFP_ATOMIC); - if (!ring->descs_cpu) { - err = -ENOMEM; - goto err; - } - - - ring->buf = kzalloc(ring_size * sizeof(*ring->buf), GFP_KERNEL); - if (!ring->buf) { - err = -ENOMEM; - goto err; - } - - return 0; - -err: - return err; -} - static void ag71xx_ring_tx_clean(struct ag71xx *ag) { struct ag71xx_ring *ring = &ag->tx_ring; @@ -322,30 +287,56 @@ static int ag71xx_ring_rx_refill(struct ag71xx *ag) static int ag71xx_rings_init(struct ag71xx *ag) { - int ret; + struct ag71xx_ring *tx = &ag->tx_ring; + struct ag71xx_ring *rx = &ag->rx_ring; + int ring_size = BIT(tx->order) + BIT(rx->order); + int tx_size = BIT(tx->order); + + tx->buf = kzalloc(ring_size * sizeof(*tx->buf), GFP_KERNEL); + if (!tx->buf) + return -ENOMEM; + + tx->descs_cpu = dma_alloc_coherent(NULL, ring_size * AG71XX_DESC_SIZE, + &tx->descs_dma, GFP_ATOMIC); + if (!tx->descs_cpu) { + kfree(tx->buf); + tx->buf = NULL; + return -ENOMEM; + } - ret = ag71xx_ring_alloc(&ag->tx_ring); - if (ret) - return ret; + rx->buf = &tx->buf[BIT(tx->order)]; + rx->descs_cpu = ((void *)tx->descs_cpu) + tx_size * AG71XX_DESC_SIZE; + rx->descs_dma = tx->descs_dma + tx_size * AG71XX_DESC_SIZE; ag71xx_ring_tx_init(ag); + return ag71xx_ring_rx_init(ag); +} - ret = ag71xx_ring_alloc(&ag->rx_ring); - if (ret) - return ret; +static void ag71xx_rings_free(struct ag71xx *ag) +{ + struct ag71xx_ring *tx = &ag->tx_ring; + struct ag71xx_ring *rx = &ag->rx_ring; + int ring_size = BIT(tx->order) + BIT(rx->order); - ret = ag71xx_ring_rx_init(ag); - return ret; + if (tx->descs_cpu) + dma_free_coherent(NULL, ring_size * AG71XX_DESC_SIZE, + tx->descs_cpu, tx->descs_dma); + + kfree(tx->buf); + + tx->descs_cpu = NULL; + rx->descs_cpu = NULL; + tx->buf = NULL; + rx->buf = NULL; } static void ag71xx_rings_cleanup(struct ag71xx *ag) { ag71xx_ring_rx_clean(ag); - ag71xx_ring_free(&ag->rx_ring); - ag71xx_ring_tx_clean(ag); + ag71xx_rings_free(ag); + netdev_reset_queue(ag->dev); - ag71xx_ring_free(&ag->tx_ring); } static unsigned char *ag71xx_speed_str(struct ag71xx *ag) -- 2.30.2