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 <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 1470fc1..b2b1803 100644 (file)
--- 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 fb2a112..f7c92d4 100644 (file)
--- 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 @@ unmap:
                         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;