target/linux/bcm4908/patches-5.10/074-v5.13-0003-net-broadcom-bcm4908_enet-support-TX-interrupt.patch

   1 From 12bb508bfe5a564c36864b12253db23cac83bfa1 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   3 Date: Thu, 11 Mar 2021 13:35:21 +0100
   4 Subject: [PATCH] net: broadcom: bcm4908_enet: support TX interrupt
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 It appears that each DMA channel has its own interrupt and both rings
  10 can be configured (the same way) to handle interrupts.
  11
  12 1. Make ring interrupts code generic (make it operate on given ring)
  13 2. Move napi to ring (so each has its own)
  14 3. Make IRQ handler generic (match ring against received IRQ number)
  15 4. Add (optional) support for TX interrupt
  16
  17 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  18 Signed-off-by: David S. Miller <davem@davemloft.net>
  19 ---
  20  drivers/net/ethernet/broadcom/bcm4908_enet.c | 138 ++++++++++++++-----
  21  1 file changed, 103 insertions(+), 35 deletions(-)
  22
  23 --- a/drivers/net/ethernet/broadcom/bcm4908_enet.c
  24 +++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c
  25 @@ -54,6 +54,7 @@ struct bcm4908_enet_dma_ring {
  26         int length;
  27         u16 cfg_block;
  28         u16 st_ram_block;
  29 +       struct napi_struct napi;
  30
  31         union {
  32                 void *cpu_addr;
  33 @@ -67,8 +68,8 @@ struct bcm4908_enet_dma_ring {
  34  struct bcm4908_enet {
  35         struct device *dev;
  36         struct net_device *netdev;
  37 -       struct napi_struct napi;
  38         void __iomem *base;
  39 +       int irq_tx;
  40
  41         struct bcm4908_enet_dma_ring tx_ring;
  42         struct bcm4908_enet_dma_ring rx_ring;
  43 @@ -123,24 +124,31 @@ static void enet_umac_set(struct bcm4908
  44   * Helpers
  45   */
  46
  47 -static void bcm4908_enet_intrs_on(struct bcm4908_enet *enet)
  48 +static void bcm4908_enet_set_mtu(struct bcm4908_enet *enet, int mtu)
  49  {
  50 -       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, ENET_DMA_INT_DEFAULTS);
  51 +       enet_umac_write(enet, UMAC_MAX_FRAME_LEN, mtu + ENET_MAX_ETH_OVERHEAD);
  52  }
  53
  54 -static void bcm4908_enet_intrs_off(struct bcm4908_enet *enet)
  55 +/***
  56 + * DMA ring ops
  57 + */
  58 +
  59 +static void bcm4908_enet_dma_ring_intrs_on(struct bcm4908_enet *enet,
  60 +                                          struct bcm4908_enet_dma_ring *ring)
  61  {
  62 -       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_MASK, 0);
  63 +       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_MASK, ENET_DMA_INT_DEFAULTS);
  64  }
  65
  66 -static void bcm4908_enet_intrs_ack(struct bcm4908_enet *enet)
  67 +static void bcm4908_enet_dma_ring_intrs_off(struct bcm4908_enet *enet,
  68 +                                           struct bcm4908_enet_dma_ring *ring)
  69  {
  70 -       enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS);
  71 +       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_MASK, 0);
  72  }
  73
  74 -static void bcm4908_enet_set_mtu(struct bcm4908_enet *enet, int mtu)
  75 +static void bcm4908_enet_dma_ring_intrs_ack(struct bcm4908_enet *enet,
  76 +                                           struct bcm4908_enet_dma_ring *ring)
  77  {
  78 -       enet_umac_write(enet, UMAC_MAX_FRAME_LEN, mtu + ENET_MAX_ETH_OVERHEAD);
  79 +       enet_write(enet, ring->cfg_block + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS);
  80  }
  81
  82  /***
  83 @@ -414,11 +422,14 @@ static void bcm4908_enet_gmac_init(struc
  84  static irqreturn_t bcm4908_enet_irq_handler(int irq, void *dev_id)
  85  {
  86         struct bcm4908_enet *enet = dev_id;
  87 +       struct bcm4908_enet_dma_ring *ring;
  88
  89 -       bcm4908_enet_intrs_off(enet);
  90 -       bcm4908_enet_intrs_ack(enet);
  91 +       ring = (irq == enet->irq_tx) ? &enet->tx_ring : &enet->rx_ring;
  92
  93 -       napi_schedule(&enet->napi);
  94 +       bcm4908_enet_dma_ring_intrs_off(enet, ring);
  95 +       bcm4908_enet_dma_ring_intrs_ack(enet, ring);
  96 +
  97 +       napi_schedule(&ring->napi);
  98
  99         return IRQ_HANDLED;
 100  }
 101 @@ -426,6 +437,8 @@ static irqreturn_t bcm4908_enet_irq_hand
 102  static int bcm4908_enet_open(struct net_device *netdev)
 103  {
 104         struct bcm4908_enet *enet = netdev_priv(netdev);
 105 +       struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring;
 106 +       struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring;
 107         struct device *dev = enet->dev;
 108         int err;
 109
 110 @@ -435,6 +448,17 @@ static int bcm4908_enet_open(struct net_
 111                 return err;
 112         }
 113
 114 +       if (enet->irq_tx > 0) {
 115 +               err = request_irq(enet->irq_tx, bcm4908_enet_irq_handler, 0,
 116 +                                 "tx", enet);
 117 +               if (err) {
 118 +                       dev_err(dev, "Failed to request IRQ %d: %d\n",
 119 +                               enet->irq_tx, err);
 120 +                       free_irq(netdev->irq, enet);
 121 +                       return err;
 122 +               }
 123 +       }
 124 +
 125         bcm4908_enet_gmac_init(enet);
 126         bcm4908_enet_dma_reset(enet);
 127         bcm4908_enet_dma_init(enet);
 128 @@ -443,14 +467,19 @@ static int bcm4908_enet_open(struct net_
 129
 130         enet_set(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_MASTER_EN);
 131         enet_maskset(enet, ENET_DMA_CONTROLLER_CFG, ENET_DMA_CTRL_CFG_FLOWC_CH1_EN, 0);
 132 -       bcm4908_enet_dma_rx_ring_enable(enet, &enet->rx_ring);
 133
 134 -       napi_enable(&enet->napi);
 135 +       if (enet->irq_tx > 0) {
 136 +               napi_enable(&tx_ring->napi);
 137 +               bcm4908_enet_dma_ring_intrs_ack(enet, tx_ring);
 138 +               bcm4908_enet_dma_ring_intrs_on(enet, tx_ring);
 139 +       }
 140 +
 141 +       bcm4908_enet_dma_rx_ring_enable(enet, rx_ring);
 142 +       napi_enable(&rx_ring->napi);
 143         netif_carrier_on(netdev);
 144         netif_start_queue(netdev);
 145 -
 146 -       bcm4908_enet_intrs_ack(enet);
 147 -       bcm4908_enet_intrs_on(enet);
 148 +       bcm4908_enet_dma_ring_intrs_ack(enet, rx_ring);
 149 +       bcm4908_enet_dma_ring_intrs_on(enet, rx_ring);
 150
 151         return 0;
 152  }
 153 @@ -458,16 +487,20 @@ static int bcm4908_enet_open(struct net_
 154  static int bcm4908_enet_stop(struct net_device *netdev)
 155  {
 156         struct bcm4908_enet *enet = netdev_priv(netdev);
 157 +       struct bcm4908_enet_dma_ring *tx_ring = &enet->tx_ring;
 158 +       struct bcm4908_enet_dma_ring *rx_ring = &enet->rx_ring;
 159
 160         netif_stop_queue(netdev);
 161         netif_carrier_off(netdev);
 162 -       napi_disable(&enet->napi);
 163 +       napi_disable(&rx_ring->napi);
 164 +       napi_disable(&tx_ring->napi);
 165
 166         bcm4908_enet_dma_rx_ring_disable(enet, &enet->rx_ring);
 167         bcm4908_enet_dma_tx_ring_disable(enet, &enet->tx_ring);
 168
 169         bcm4908_enet_dma_uninit(enet);
 170
 171 +       free_irq(enet->irq_tx, enet);
 172         free_irq(enet->netdev->irq, enet);
 173
 174         return 0;
 175 @@ -484,25 +517,19 @@ static int bcm4908_enet_start_xmit(struc
 176         u32 tmp;
 177
 178         /* Free transmitted skbs */
 179 -       while (ring->read_idx != ring->write_idx) {
 180 -               buf_desc = &ring->buf_desc[ring->read_idx];
 181 -               if (le32_to_cpu(buf_desc->ctl) & DMA_CTL_STATUS_OWN)
 182 -                       break;
 183 -               slot = &ring->slots[ring->read_idx];
 184 -
 185 -               dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_TO_DEVICE);
 186 -               dev_kfree_skb(slot->skb);
 187 -               if (++ring->read_idx == ring->length)
 188 -                       ring->read_idx = 0;
 189 -       }
 190 +       if (enet->irq_tx < 0 &&
 191 +           !(le32_to_cpu(ring->buf_desc[ring->read_idx].ctl) & DMA_CTL_STATUS_OWN))
 192 +               napi_schedule(&enet->tx_ring.napi);
 193
 194         /* Don't use the last empty buf descriptor */
 195         if (ring->read_idx <= ring->write_idx)
 196                 free_buf_descs = ring->read_idx - ring->write_idx + ring->length;
 197         else
 198                 free_buf_descs = ring->read_idx - ring->write_idx;
 199 -       if (free_buf_descs < 2)
 200 +       if (free_buf_descs < 2) {
 201 +               netif_stop_queue(netdev);
 202                 return NETDEV_TX_BUSY;
 203 +       }
 204
 205         /* Hardware removes OWN bit after sending data */
 206         buf_desc = &ring->buf_desc[ring->write_idx];
 207 @@ -539,9 +566,10 @@ static int bcm4908_enet_start_xmit(struc
 208         return NETDEV_TX_OK;
 209  }
 210
 211 -static int bcm4908_enet_poll(struct napi_struct *napi, int weight)
 212 +static int bcm4908_enet_poll_rx(struct napi_struct *napi, int weight)
 213  {
 214 -       struct bcm4908_enet *enet = container_of(napi, struct bcm4908_enet, napi);
 215 +       struct bcm4908_enet_dma_ring *rx_ring = container_of(napi, struct bcm4908_enet_dma_ring, napi);
 216 +       struct bcm4908_enet *enet = container_of(rx_ring, struct bcm4908_enet, rx_ring);
 217         struct device *dev = enet->dev;
 218         int handled = 0;
 219
 220 @@ -590,7 +618,7 @@ static int bcm4908_enet_poll(struct napi
 221
 222         if (handled < weight) {
 223                 napi_complete_done(napi, handled);
 224 -               bcm4908_enet_intrs_on(enet);
 225 +               bcm4908_enet_dma_ring_intrs_on(enet, rx_ring);
 226         }
 227
 228         /* Hardware could disable ring if it run out of descriptors */
 229 @@ -599,6 +627,42 @@ static int bcm4908_enet_poll(struct napi
 230         return handled;
 231  }
 232
 233 +static int bcm4908_enet_poll_tx(struct napi_struct *napi, int weight)
 234 +{
 235 +       struct bcm4908_enet_dma_ring *tx_ring = container_of(napi, struct bcm4908_enet_dma_ring, napi);
 236 +       struct bcm4908_enet *enet = container_of(tx_ring, struct bcm4908_enet, tx_ring);
 237 +       struct bcm4908_enet_dma_ring_bd *buf_desc;
 238 +       struct bcm4908_enet_dma_ring_slot *slot;
 239 +       struct device *dev = enet->dev;
 240 +       unsigned int bytes = 0;
 241 +       int handled = 0;
 242 +
 243 +       while (handled < weight && tx_ring->read_idx != tx_ring->write_idx) {
 244 +               buf_desc = &tx_ring->buf_desc[tx_ring->read_idx];
 245 +               if (le32_to_cpu(buf_desc->ctl) & DMA_CTL_STATUS_OWN)
 246 +                       break;
 247 +               slot = &tx_ring->slots[tx_ring->read_idx];
 248 +
 249 +               dma_unmap_single(dev, slot->dma_addr, slot->len, DMA_TO_DEVICE);
 250 +               dev_kfree_skb(slot->skb);
 251 +               bytes += slot->len;
 252 +               if (++tx_ring->read_idx == tx_ring->length)
 253 +                       tx_ring->read_idx = 0;
 254 +
 255 +               handled++;
 256 +       }
 257 +
 258 +       if (handled < weight) {
 259 +               napi_complete_done(napi, handled);
 260 +               bcm4908_enet_dma_ring_intrs_on(enet, tx_ring);
 261 +       }
 262 +
 263 +       if (netif_queue_stopped(enet->netdev))
 264 +               netif_wake_queue(enet->netdev);
 265 +
 266 +       return handled;
 267 +}
 268 +
 269  static int bcm4908_enet_change_mtu(struct net_device *netdev, int new_mtu)
 270  {
 271         struct bcm4908_enet *enet = netdev_priv(netdev);
 272 @@ -641,6 +705,8 @@ static int bcm4908_enet_probe(struct pla
 273         if (netdev->irq < 0)
 274                 return netdev->irq;
 275
 276 +       enet->irq_tx = platform_get_irq_byname(pdev, "tx");
 277 +
 278         dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
 279
 280         err = bcm4908_enet_dma_alloc(enet);
 281 @@ -655,7 +721,8 @@ static int bcm4908_enet_probe(struct pla
 282         netdev->min_mtu = ETH_ZLEN;
 283         netdev->mtu = ETH_DATA_LEN;
 284         netdev->max_mtu = ENET_MTU_MAX;
 285 -       netif_napi_add(netdev, &enet->napi, bcm4908_enet_poll, 64);
 286 +       netif_tx_napi_add(netdev, &enet->tx_ring.napi, bcm4908_enet_poll_tx, NAPI_POLL_WEIGHT);
 287 +       netif_napi_add(netdev, &enet->rx_ring.napi, bcm4908_enet_poll_rx, NAPI_POLL_WEIGHT);
 288
 289         err = register_netdev(netdev);
 290         if (err) {
 291 @@ -673,7 +740,8 @@ static int bcm4908_enet_remove(struct pl
 292         struct bcm4908_enet *enet = platform_get_drvdata(pdev);
 293
 294         unregister_netdev(enet->netdev);
 295 -       netif_napi_del(&enet->napi);
 296 +       netif_napi_del(&enet->rx_ring.napi);
 297 +       netif_napi_del(&enet->tx_ring.napi);
 298         bcm4908_enet_dma_free(enet);
 299
 300         return 0;