From f543305da9b5a5efaf6fa61606e8bbc8977f406d Mon Sep 17 00:00:00 2001 From: Kazuya Mizuguchi Date: Wed, 19 Sep 2018 10:06:21 +0200 Subject: [PATCH] ravb: remove tx buffer addr 4byte alilgnment restriction for R-Car Gen3 This patch sets from two descriptor to one descriptor because R-Car Gen3 does not have the 4 bytes alignment restriction of the transmission buffer. Signed-off-by: Kazuya Mizuguchi Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/renesas/ravb.h | 6 +- drivers/net/ethernet/renesas/ravb_main.c | 143 ++++++++++++++--------- 2 files changed, 92 insertions(+), 57 deletions(-) diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h index 1470fc12282b..b2b18036380e 100644 --- a/drivers/net/ethernet/renesas/ravb.h +++ b/drivers/net/ethernet/renesas/ravb.h @@ -954,7 +954,10 @@ enum RAVB_QUEUE { #define RX_QUEUE_OFFSET 4 #define NUM_RX_QUEUE 2 #define NUM_TX_QUEUE 2 -#define NUM_TX_DESC 2 /* TX descriptors per packet */ + +/* TX descriptors per packet */ +#define NUM_TX_DESC_GEN2 2 +#define NUM_TX_DESC_GEN3 1 struct ravb_tstamp_skb { struct list_head list; @@ -1033,6 +1036,7 @@ struct ravb_private { unsigned no_avb_link:1; unsigned avb_link_active_low:1; unsigned wol_enabled:1; + int num_tx_desc; /* TX descriptors per packet */ }; static inline u32 ravb_read(struct net_device *ndev, enum ravb_reg reg) diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index fb2a1125780d..f7c92d48d0dd 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -182,6 +182,7 @@ static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only) { struct ravb_private *priv = netdev_priv(ndev); struct net_device_stats *stats = &priv->stats[q]; + int num_tx_desc = priv->num_tx_desc; struct ravb_tx_desc *desc; int free_num = 0; int entry; @@ -191,7 +192,7 @@ static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only) bool txed; entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] * - NUM_TX_DESC); + num_tx_desc); desc = &priv->tx_ring[q][entry]; txed = desc->die_dt == DT_FEMPTY; if (free_txed_only && !txed) @@ -200,12 +201,12 @@ static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only) dma_rmb(); size = le16_to_cpu(desc->ds_tagl) & TX_DS; /* Free the original skb. */ - if (priv->tx_skb[q][entry / NUM_TX_DESC]) { + if (priv->tx_skb[q][entry / num_tx_desc]) { dma_unmap_single(ndev->dev.parent, le32_to_cpu(desc->dptr), size, DMA_TO_DEVICE); /* Last packet descriptor? */ - if (entry % NUM_TX_DESC == NUM_TX_DESC - 1) { - entry /= NUM_TX_DESC; + if (entry % num_tx_desc == num_tx_desc - 1) { + entry /= num_tx_desc; dev_kfree_skb_any(priv->tx_skb[q][entry]); priv->tx_skb[q][entry] = NULL; if (txed) @@ -224,6 +225,7 @@ static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only) static void ravb_ring_free(struct net_device *ndev, int q) { struct ravb_private *priv = netdev_priv(ndev); + int num_tx_desc = priv->num_tx_desc; int ring_size; int i; @@ -249,7 +251,7 @@ static void ravb_ring_free(struct net_device *ndev, int q) ravb_tx_free(ndev, q, false); ring_size = sizeof(struct ravb_tx_desc) * - (priv->num_tx_ring[q] * NUM_TX_DESC + 1); + (priv->num_tx_ring[q] * num_tx_desc + 1); dma_free_coherent(ndev->dev.parent, ring_size, priv->tx_ring[q], priv->tx_desc_dma[q]); priv->tx_ring[q] = NULL; @@ -278,12 +280,13 @@ static void ravb_ring_free(struct net_device *ndev, int q) static void ravb_ring_format(struct net_device *ndev, int q) { struct ravb_private *priv = netdev_priv(ndev); + int num_tx_desc = priv->num_tx_desc; struct ravb_ex_rx_desc *rx_desc; struct ravb_tx_desc *tx_desc; struct ravb_desc *desc; int rx_ring_size = sizeof(*rx_desc) * priv->num_rx_ring[q]; int tx_ring_size = sizeof(*tx_desc) * priv->num_tx_ring[q] * - NUM_TX_DESC; + num_tx_desc; dma_addr_t dma_addr; int i; @@ -318,8 +321,10 @@ static void ravb_ring_format(struct net_device *ndev, int q) for (i = 0, tx_desc = priv->tx_ring[q]; i < priv->num_tx_ring[q]; i++, tx_desc++) { tx_desc->die_dt = DT_EEMPTY; - tx_desc++; - tx_desc->die_dt = DT_EEMPTY; + if (num_tx_desc > 1) { + tx_desc++; + tx_desc->die_dt = DT_EEMPTY; + } } tx_desc->dptr = cpu_to_le32((u32)priv->tx_desc_dma[q]); tx_desc->die_dt = DT_LINKFIX; /* type */ @@ -339,6 +344,7 @@ static void ravb_ring_format(struct net_device *ndev, int q) static int ravb_ring_init(struct net_device *ndev, int q) { struct ravb_private *priv = netdev_priv(ndev); + int num_tx_desc = priv->num_tx_desc; struct sk_buff *skb; int ring_size; int i; @@ -362,11 +368,13 @@ static int ravb_ring_init(struct net_device *ndev, int q) priv->rx_skb[q][i] = skb; } - /* Allocate rings for the aligned buffers */ - priv->tx_align[q] = kmalloc(DPTR_ALIGN * priv->num_tx_ring[q] + - DPTR_ALIGN - 1, GFP_KERNEL); - if (!priv->tx_align[q]) - goto error; + if (num_tx_desc > 1) { + /* Allocate rings for the aligned buffers */ + priv->tx_align[q] = kmalloc(DPTR_ALIGN * priv->num_tx_ring[q] + + DPTR_ALIGN - 1, GFP_KERNEL); + if (!priv->tx_align[q]) + goto error; + } /* Allocate all RX descriptors. */ ring_size = sizeof(struct ravb_ex_rx_desc) * (priv->num_rx_ring[q] + 1); @@ -380,7 +388,7 @@ static int ravb_ring_init(struct net_device *ndev, int q) /* Allocate all TX descriptors. */ ring_size = sizeof(struct ravb_tx_desc) * - (priv->num_tx_ring[q] * NUM_TX_DESC + 1); + (priv->num_tx_ring[q] * num_tx_desc + 1); priv->tx_ring[q] = dma_alloc_coherent(ndev->dev.parent, ring_size, &priv->tx_desc_dma[q], GFP_KERNEL); @@ -1485,6 +1493,7 @@ static void ravb_tx_timeout_work(struct work_struct *work) static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct ravb_private *priv = netdev_priv(ndev); + int num_tx_desc = priv->num_tx_desc; u16 q = skb_get_queue_mapping(skb); struct ravb_tstamp_skb *ts_skb; struct ravb_tx_desc *desc; @@ -1496,7 +1505,7 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) spin_lock_irqsave(&priv->lock, flags); if (priv->cur_tx[q] - priv->dirty_tx[q] > (priv->num_tx_ring[q] - 1) * - NUM_TX_DESC) { + num_tx_desc) { netif_err(priv, tx_queued, ndev, "still transmitting with the full ring!\n"); netif_stop_subqueue(ndev, q); @@ -1507,41 +1516,55 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) if (skb_put_padto(skb, ETH_ZLEN)) goto exit; - entry = priv->cur_tx[q] % (priv->num_tx_ring[q] * NUM_TX_DESC); - priv->tx_skb[q][entry / NUM_TX_DESC] = skb; - - buffer = PTR_ALIGN(priv->tx_align[q], DPTR_ALIGN) + - entry / NUM_TX_DESC * DPTR_ALIGN; - len = PTR_ALIGN(skb->data, DPTR_ALIGN) - skb->data; - /* Zero length DMA descriptors are problematic as they seem to - * terminate DMA transfers. Avoid them by simply using a length of - * DPTR_ALIGN (4) when skb data is aligned to DPTR_ALIGN. - * - * As skb is guaranteed to have at least ETH_ZLEN (60) bytes of - * data by the call to skb_put_padto() above this is safe with - * respect to both the length of the first DMA descriptor (len) - * overflowing the available data and the length of the second DMA - * descriptor (skb->len - len) being negative. - */ - if (len == 0) - len = DPTR_ALIGN; + entry = priv->cur_tx[q] % (priv->num_tx_ring[q] * num_tx_desc); + priv->tx_skb[q][entry / num_tx_desc] = skb; + + if (num_tx_desc > 1) { + buffer = PTR_ALIGN(priv->tx_align[q], DPTR_ALIGN) + + entry / num_tx_desc * DPTR_ALIGN; + len = PTR_ALIGN(skb->data, DPTR_ALIGN) - skb->data; + + /* Zero length DMA descriptors are problematic as they seem + * to terminate DMA transfers. Avoid them by simply using a + * length of DPTR_ALIGN (4) when skb data is aligned to + * DPTR_ALIGN. + * + * As skb is guaranteed to have at least ETH_ZLEN (60) + * bytes of data by the call to skb_put_padto() above this + * is safe with respect to both the length of the first DMA + * descriptor (len) overflowing the available data and the + * length of the second DMA descriptor (skb->len - len) + * being negative. + */ + if (len == 0) + len = DPTR_ALIGN; - memcpy(buffer, skb->data, len); - dma_addr = dma_map_single(ndev->dev.parent, buffer, len, DMA_TO_DEVICE); - if (dma_mapping_error(ndev->dev.parent, dma_addr)) - goto drop; + memcpy(buffer, skb->data, len); + dma_addr = dma_map_single(ndev->dev.parent, buffer, len, + DMA_TO_DEVICE); + if (dma_mapping_error(ndev->dev.parent, dma_addr)) + goto drop; - desc = &priv->tx_ring[q][entry]; - desc->ds_tagl = cpu_to_le16(len); - desc->dptr = cpu_to_le32(dma_addr); + desc = &priv->tx_ring[q][entry]; + desc->ds_tagl = cpu_to_le16(len); + desc->dptr = cpu_to_le32(dma_addr); - buffer = skb->data + len; - len = skb->len - len; - dma_addr = dma_map_single(ndev->dev.parent, buffer, len, DMA_TO_DEVICE); - if (dma_mapping_error(ndev->dev.parent, dma_addr)) - goto unmap; + buffer = skb->data + len; + len = skb->len - len; + dma_addr = dma_map_single(ndev->dev.parent, buffer, len, + DMA_TO_DEVICE); + if (dma_mapping_error(ndev->dev.parent, dma_addr)) + goto unmap; - desc++; + desc++; + } else { + desc = &priv->tx_ring[q][entry]; + len = skb->len; + dma_addr = dma_map_single(ndev->dev.parent, skb->data, skb->len, + DMA_TO_DEVICE); + if (dma_mapping_error(ndev->dev.parent, dma_addr)) + goto drop; + } desc->ds_tagl = cpu_to_le16(len); desc->dptr = cpu_to_le32(dma_addr); @@ -1549,9 +1572,11 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) if (q == RAVB_NC) { ts_skb = kmalloc(sizeof(*ts_skb), GFP_ATOMIC); if (!ts_skb) { - desc--; - dma_unmap_single(ndev->dev.parent, dma_addr, len, - DMA_TO_DEVICE); + if (num_tx_desc > 1) { + desc--; + dma_unmap_single(ndev->dev.parent, dma_addr, + len, DMA_TO_DEVICE); + } goto unmap; } ts_skb->skb = skb; @@ -1568,15 +1593,18 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) skb_tx_timestamp(skb); /* Descriptor type must be set after all the above writes */ dma_wmb(); - desc->die_dt = DT_FEND; - desc--; - desc->die_dt = DT_FSTART; - + if (num_tx_desc > 1) { + desc->die_dt = DT_FEND; + desc--; + desc->die_dt = DT_FSTART; + } else { + desc->die_dt = DT_FSINGLE; + } ravb_modify(ndev, TCCR, TCCR_TSRQ0 << q, TCCR_TSRQ0 << q); - priv->cur_tx[q] += NUM_TX_DESC; + priv->cur_tx[q] += num_tx_desc; if (priv->cur_tx[q] - priv->dirty_tx[q] > - (priv->num_tx_ring[q] - 1) * NUM_TX_DESC && + (priv->num_tx_ring[q] - 1) * num_tx_desc && !ravb_tx_free(ndev, q, true)) netif_stop_subqueue(ndev, q); @@ -1590,7 +1618,7 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) le16_to_cpu(desc->ds_tagl), DMA_TO_DEVICE); drop: dev_kfree_skb_any(skb); - priv->tx_skb[q][entry / NUM_TX_DESC] = NULL; + priv->tx_skb[q][entry / num_tx_desc] = NULL; goto exit; } @@ -2076,6 +2104,9 @@ static int ravb_probe(struct platform_device *pdev) ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN); ndev->min_mtu = ETH_MIN_MTU; + priv->num_tx_desc = chip_id == RCAR_GEN2 ? + NUM_TX_DESC_GEN2 : NUM_TX_DESC_GEN3; + /* Set function */ ndev->netdev_ops = &ravb_netdev_ops; ndev->ethtool_ops = &ravb_ethtool_ops; -- 2.45.2