drivers/net/mlx4/en_tx.c

   1 /*
   2  * Copyright (c) 2007 Mellanox Technologies. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  */
  33
  34 #include <asm/page.h>
  35 #include <linux/mlx4/cq.h>
  36 #include <linux/mlx4/qp.h>
  37 #include <linux/skbuff.h>
  38 #include <linux/if_vlan.h>
  39 #include <linux/vmalloc.h>
  40
  41 #include "mlx4_en.h"
  42
  43 enum {
  44         MAX_INLINE = 104, /* 128 - 16 - 4 - 4 */
  45 };
  46
  47 static int inline_thold __read_mostly = MAX_INLINE;
  48
  49 module_param_named(inline_thold, inline_thold, int, 0444);
  50 MODULE_PARM_DESC(inline_thold, "treshold for using inline data");
  51
  52 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
  53                            struct mlx4_en_tx_ring *ring, u32 size,
  54                            u16 stride)
  55 {
  56         struct mlx4_en_dev *mdev = priv->mdev;
  57         int tmp;
  58         int err;
  59
  60         ring->size = size;
  61         ring->size_mask = size - 1;
  62         ring->stride = stride;
  63
  64         inline_thold = min(inline_thold, MAX_INLINE);
  65
  66         spin_lock_init(&ring->comp_lock);
  67
  68         tmp = size * sizeof(struct mlx4_en_tx_info);
  69         ring->tx_info = vmalloc(tmp);
  70         if (!ring->tx_info) {
  71                 mlx4_err(mdev, "Failed allocating tx_info ring\n");
  72                 return -ENOMEM;
  73         }
  74         mlx4_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
  75                  ring->tx_info, tmp);
  76
  77         ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
  78         if (!ring->bounce_buf) {
  79                 mlx4_err(mdev, "Failed allocating bounce buffer\n");
  80                 err = -ENOMEM;
  81                 goto err_tx;
  82         }
  83         ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
  84
  85         err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size,
  86                                  2 * PAGE_SIZE);
  87         if (err) {
  88                 mlx4_err(mdev, "Failed allocating hwq resources\n");
  89                 goto err_bounce;
  90         }
  91
  92         err = mlx4_en_map_buffer(&ring->wqres.buf);
  93         if (err) {
  94                 mlx4_err(mdev, "Failed to map TX buffer\n");
  95                 goto err_hwq_res;
  96         }
  97
  98         ring->buf = ring->wqres.buf.direct.buf;
  99
 100         mlx4_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d "
 101                  "buf_size:%d dma:%llx\n", ring, ring->buf, ring->size,
 102                  ring->buf_size, (unsigned long long) ring->wqres.buf.direct.map);
 103
 104         err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn);
 105         if (err) {
 106                 mlx4_err(mdev, "Failed reserving qp for tx ring.\n");
 107                 goto err_map;
 108         }
 109
 110         err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp);
 111         if (err) {
 112                 mlx4_err(mdev, "Failed allocating qp %d\n", ring->qpn);
 113                 goto err_reserve;
 114         }
 115         ring->qp.event = mlx4_en_sqp_event;
 116
 117         return 0;
 118
 119 err_reserve:
 120         mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
 121 err_map:
 122         mlx4_en_unmap_buffer(&ring->wqres.buf);
 123 err_hwq_res:
 124         mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
 125 err_bounce:
 126         kfree(ring->bounce_buf);
 127         ring->bounce_buf = NULL;
 128 err_tx:
 129         vfree(ring->tx_info);
 130         ring->tx_info = NULL;
 131         return err;
 132 }
 133
 134 void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
 135                              struct mlx4_en_tx_ring *ring)
 136 {
 137         struct mlx4_en_dev *mdev = priv->mdev;
 138         mlx4_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
 139
 140         mlx4_qp_remove(mdev->dev, &ring->qp);
 141         mlx4_qp_free(mdev->dev, &ring->qp);
 142         mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
 143         mlx4_en_unmap_buffer(&ring->wqres.buf);
 144         mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
 145         kfree(ring->bounce_buf);
 146         ring->bounce_buf = NULL;
 147         vfree(ring->tx_info);
 148         ring->tx_info = NULL;
 149 }
 150
 151 int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
 152                              struct mlx4_en_tx_ring *ring,
 153                              int cq, int srqn)
 154 {
 155         struct mlx4_en_dev *mdev = priv->mdev;
 156         int err;
 157
 158         ring->cqn = cq;
 159         ring->prod = 0;
 160         ring->cons = 0xffffffff;
 161         ring->last_nr_txbb = 1;
 162         ring->poll_cnt = 0;
 163         ring->blocked = 0;
 164         memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info));
 165         memset(ring->buf, 0, ring->buf_size);
 166
 167         ring->qp_state = MLX4_QP_STATE_RST;
 168         ring->doorbell_qpn = swab32(ring->qp.qpn << 8);
 169
 170         mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn,
 171                                 ring->cqn, srqn, &ring->context);
 172
 173         err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
 174                                &ring->qp, &ring->qp_state);
 175
 176         return err;
 177 }
 178
 179 void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
 180                                 struct mlx4_en_tx_ring *ring)
 181 {
 182         struct mlx4_en_dev *mdev = priv->mdev;
 183
 184         mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
 185                        MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
 186 }
 187
 188
 189 static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv,
 190                                 struct mlx4_en_tx_ring *ring,
 191                                 int index, u8 owner)
 192 {
 193         struct mlx4_en_dev *mdev = priv->mdev;
 194         struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
 195         struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
 196         struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset;
 197         struct sk_buff *skb = tx_info->skb;
 198         struct skb_frag_struct *frag;
 199         void *end = ring->buf + ring->buf_size;
 200         int frags = skb_shinfo(skb)->nr_frags;
 201         int i;
 202         __be32 *ptr = (__be32 *)tx_desc;
 203         __be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
 204
 205         /* Optimize the common case when there are no wraparounds */
 206         if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
 207                 if (!tx_info->inl) {
 208                         if (tx_info->linear) {
 209                                 pci_unmap_single(mdev->pdev,
 210                                         (dma_addr_t) be64_to_cpu(data->addr),
 211                                          be32_to_cpu(data->byte_count),
 212                                          PCI_DMA_TODEVICE);
 213                                 ++data;
 214                         }
 215
 216                         for (i = 0; i < frags; i++) {
 217                                 frag = &skb_shinfo(skb)->frags[i];
 218                                 pci_unmap_page(mdev->pdev,
 219                                         (dma_addr_t) be64_to_cpu(data[i].addr),
 220                                         frag->size, PCI_DMA_TODEVICE);
 221                         }
 222                 }
 223                 /* Stamp the freed descriptor */
 224                 for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE; i += STAMP_STRIDE) {
 225                         *ptr = stamp;
 226                         ptr += STAMP_DWORDS;
 227                 }
 228
 229         } else {
 230                 if (!tx_info->inl) {
 231                         if ((void *) data >= end) {
 232                                 data = (struct mlx4_wqe_data_seg *)
 233                                                 (ring->buf + ((void *) data - end));
 234                         }
 235
 236                         if (tx_info->linear) {
 237                                 pci_unmap_single(mdev->pdev,
 238                                         (dma_addr_t) be64_to_cpu(data->addr),
 239                                          be32_to_cpu(data->byte_count),
 240                                          PCI_DMA_TODEVICE);
 241                                 ++data;
 242                         }
 243
 244                         for (i = 0; i < frags; i++) {
 245                                 /* Check for wraparound before unmapping */
 246                                 if ((void *) data >= end)
 247                                         data = (struct mlx4_wqe_data_seg *) ring->buf;
 248                                 frag = &skb_shinfo(skb)->frags[i];
 249                                 pci_unmap_page(mdev->pdev,
 250                                         (dma_addr_t) be64_to_cpu(data->addr),
 251                                          frag->size, PCI_DMA_TODEVICE);
 252                         }
 253                 }
 254                 /* Stamp the freed descriptor */
 255                 for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE; i += STAMP_STRIDE) {
 256                         *ptr = stamp;
 257                         ptr += STAMP_DWORDS;
 258                         if ((void *) ptr >= end) {
 259                                 ptr = ring->buf;
 260                                 stamp ^= cpu_to_be32(0x80000000);
 261                         }
 262                 }
 263
 264         }
 265         dev_kfree_skb_any(skb);
 266         return tx_info->nr_txbb;
 267 }
 268
 269
 270 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
 271 {
 272         struct mlx4_en_priv *priv = netdev_priv(dev);
 273         int cnt = 0;
 274
 275         /* Skip last polled descriptor */
 276         ring->cons += ring->last_nr_txbb;
 277         mlx4_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
 278                  ring->cons, ring->prod);
 279
 280         if ((u32) (ring->prod - ring->cons) > ring->size) {
 281                 if (netif_msg_tx_err(priv))
 282                         mlx4_warn(priv->mdev, "Tx consumer passed producer!\n");
 283                 return 0;
 284         }
 285
 286         while (ring->cons != ring->prod) {
 287                 ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
 288                                                 ring->cons & ring->size_mask,
 289                                                 !!(ring->cons & ring->size));
 290                 ring->cons += ring->last_nr_txbb;
 291                 cnt++;
 292         }
 293
 294         if (cnt)
 295                 mlx4_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
 296
 297         return cnt;
 298 }
 299
 300 void mlx4_en_set_prio_map(struct mlx4_en_priv *priv, u16 *prio_map, u32 ring_num)
 301 {
 302         int block = 8 / ring_num;
 303         int extra = 8 - (block * ring_num);
 304         int num = 0;
 305         u16 ring = 1;
 306         int prio;
 307
 308         if (ring_num == 1) {
 309                 for (prio = 0; prio < 8; prio++)
 310                         prio_map[prio] = 0;
 311                 return;
 312         }
 313
 314         for (prio = 0; prio < 8; prio++) {
 315                 if (extra && (num == block + 1)) {
 316                         ring++;
 317                         num = 0;
 318                         extra--;
 319                 } else if (!extra && (num == block)) {
 320                         ring++;
 321                         num = 0;
 322                 }
 323                 prio_map[prio] = ring;
 324                 mlx4_dbg(DRV, priv, " prio:%d --> ring:%d\n", prio, ring);
 325                 num++;
 326         }
 327 }
 328
 329 static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq)
 330 {
 331         struct mlx4_en_priv *priv = netdev_priv(dev);
 332         struct mlx4_cq *mcq = &cq->mcq;
 333         struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring];
 334         struct mlx4_cqe *cqe = cq->buf;
 335         u16 index;
 336         u16 new_index;
 337         u32 txbbs_skipped = 0;
 338         u32 cq_last_sav;
 339
 340         /* index always points to the first TXBB of the last polled descriptor */
 341         index = ring->cons & ring->size_mask;
 342         new_index = be16_to_cpu(cqe->wqe_index) & ring->size_mask;
 343         if (index == new_index)
 344                 return;
 345
 346         if (!priv->port_up)
 347                 return;
 348
 349         /*
 350          * We use a two-stage loop:
 351          * - the first samples the HW-updated CQE
 352          * - the second frees TXBBs until the last sample
 353          * This lets us amortize CQE cache misses, while still polling the CQ
 354          * until is quiescent.
 355          */
 356         cq_last_sav = mcq->cons_index;
 357         do {
 358                 do {
 359                         /* Skip over last polled CQE */
 360                         index = (index + ring->last_nr_txbb) & ring->size_mask;
 361                         txbbs_skipped += ring->last_nr_txbb;
 362
 363                         /* Poll next CQE */
 364                         ring->last_nr_txbb = mlx4_en_free_tx_desc(
 365                                                 priv, ring, index,
 366                                                 !!((ring->cons + txbbs_skipped) &
 367                                                    ring->size));
 368                         ++mcq->cons_index;
 369
 370                 } while (index != new_index);
 371
 372                 new_index = be16_to_cpu(cqe->wqe_index) & ring->size_mask;
 373         } while (index != new_index);
 374         AVG_PERF_COUNTER(priv->pstats.tx_coal_avg,
 375                          (u32) (mcq->cons_index - cq_last_sav));
 376
 377         /*
 378          * To prevent CQ overflow we first update CQ consumer and only then
 379          * the ring consumer.
 380          */
 381         mlx4_cq_set_ci(mcq);
 382         wmb();
 383         ring->cons += txbbs_skipped;
 384
 385         /* Wakeup Tx queue if this ring stopped it */
 386         if (unlikely(ring->blocked)) {
 387                 if ((u32) (ring->prod - ring->cons) <=
 388                      ring->size - HEADROOM - MAX_DESC_TXBBS) {
 389
 390                         /* TODO: support multiqueue netdevs. Currently, we block
 391                          * when *any* ring is full. Note that:
 392                          * - 2 Tx rings can unblock at the same time and call
 393                          *   netif_wake_queue(), which is OK since this
 394                          *   operation is idempotent.
 395                          * - We might wake the queue just after another ring
 396                          *   stopped it. This is no big deal because the next
 397                          *   transmission on that ring would stop the queue.
 398                          */
 399                         ring->blocked = 0;
 400                         netif_wake_queue(dev);
 401                         priv->port_stats.wake_queue++;
 402                 }
 403         }
 404 }
 405
 406 void mlx4_en_tx_irq(struct mlx4_cq *mcq)
 407 {
 408         struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
 409         struct mlx4_en_priv *priv = netdev_priv(cq->dev);
 410         struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring];
 411
 412         if (!spin_trylock(&ring->comp_lock))
 413                 return;
 414         mlx4_en_process_tx_cq(cq->dev, cq);
 415         mod_timer(&cq->timer, jiffies + 1);
 416         spin_unlock(&ring->comp_lock);
 417 }
 418
 419
 420 void mlx4_en_poll_tx_cq(unsigned long data)
 421 {
 422         struct mlx4_en_cq *cq = (struct mlx4_en_cq *) data;
 423         struct mlx4_en_priv *priv = netdev_priv(cq->dev);
 424         struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring];
 425         u32 inflight;
 426
 427         INC_PERF_COUNTER(priv->pstats.tx_poll);
 428
 429         if (!spin_trylock_irq(&ring->comp_lock)) {
 430                 mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
 431                 return;
 432         }
 433         mlx4_en_process_tx_cq(cq->dev, cq);
 434         inflight = (u32) (ring->prod - ring->cons - ring->last_nr_txbb);
 435
 436         /* If there are still packets in flight and the timer has not already
 437          * been scheduled by the Tx routine then schedule it here to guarantee
 438          * completion processing of these packets */
 439         if (inflight && priv->port_up)
 440                 mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
 441
 442         spin_unlock_irq(&ring->comp_lock);
 443 }
 444
 445 static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
 446                                                       struct mlx4_en_tx_ring *ring,
 447                                                       u32 index,
 448                                                       unsigned int desc_size)
 449 {
 450         u32 copy = (ring->size - index) * TXBB_SIZE;
 451         int i;
 452
 453         for (i = desc_size - copy - 4; i >= 0; i -= 4) {
 454                 if ((i & (TXBB_SIZE - 1)) == 0)
 455                         wmb();
 456
 457                 *((u32 *) (ring->buf + i)) =
 458                         *((u32 *) (ring->bounce_buf + copy + i));
 459         }
 460
 461         for (i = copy - 4; i >= 4 ; i -= 4) {
 462                 if ((i & (TXBB_SIZE - 1)) == 0)
 463                         wmb();
 464
 465                 *((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
 466                         *((u32 *) (ring->bounce_buf + i));
 467         }
 468
 469         /* Return real descriptor location */
 470         return ring->buf + index * TXBB_SIZE;
 471 }
 472
 473 static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind)
 474 {
 475         struct mlx4_en_cq *cq = &priv->tx_cq[tx_ind];
 476         struct mlx4_en_tx_ring *ring = &priv->tx_ring[tx_ind];
 477
 478         /* If we don't have a pending timer, set one up to catch our recent
 479            post in case the interface becomes idle */
 480         if (!timer_pending(&cq->timer))
 481                 mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
 482
 483         /* Poll the CQ every mlx4_en_TX_MODER_POLL packets */
 484         if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)
 485                 if (spin_trylock_irq(&ring->comp_lock)) {
 486                         mlx4_en_process_tx_cq(priv->dev, cq);
 487                         spin_unlock_irq(&ring->comp_lock);
 488                 }
 489 }
 490
 491 static void *get_frag_ptr(struct sk_buff *skb)
 492 {
 493         struct skb_frag_struct *frag =  &skb_shinfo(skb)->frags[0];
 494         struct page *page = frag->page;
 495         void *ptr;
 496
 497         ptr = page_address(page);
 498         if (unlikely(!ptr))
 499                 return NULL;
 500
 501         return ptr + frag->page_offset;
 502 }
 503
 504 static int is_inline(struct sk_buff *skb, void **pfrag)
 505 {
 506         void *ptr;
 507
 508         if (inline_thold && !skb_is_gso(skb) && skb->len <= inline_thold) {
 509                 if (skb_shinfo(skb)->nr_frags == 1) {
 510                         ptr = get_frag_ptr(skb);
 511                         if (unlikely(!ptr))
 512                                 return 0;
 513
 514                         if (pfrag)
 515                                 *pfrag = ptr;
 516
 517                         return 1;
 518                 } else if (unlikely(skb_shinfo(skb)->nr_frags))
 519                         return 0;
 520                 else
 521                         return 1;
 522         }
 523
 524         return 0;
 525 }
 526
 527 static int inline_size(struct sk_buff *skb)
 528 {
 529         if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
 530             <= MLX4_INLINE_ALIGN)
 531                 return ALIGN(skb->len + CTRL_SIZE +
 532                              sizeof(struct mlx4_wqe_inline_seg), 16);
 533         else
 534                 return ALIGN(skb->len + CTRL_SIZE + 2 *
 535                              sizeof(struct mlx4_wqe_inline_seg), 16);
 536 }
 537
 538 static int get_real_size(struct sk_buff *skb, struct net_device *dev,
 539                          int *lso_header_size)
 540 {
 541         struct mlx4_en_priv *priv = netdev_priv(dev);
 542         struct mlx4_en_dev *mdev = priv->mdev;
 543         int real_size;
 544
 545         if (skb_is_gso(skb)) {
 546                 *lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
 547                 real_size = CTRL_SIZE + skb_shinfo(skb)->nr_frags * DS_SIZE +
 548                         ALIGN(*lso_header_size + 4, DS_SIZE);
 549                 if (unlikely(*lso_header_size != skb_headlen(skb))) {
 550                         /* We add a segment for the skb linear buffer only if
 551                          * it contains data */
 552                         if (*lso_header_size < skb_headlen(skb))
 553                                 real_size += DS_SIZE;
 554                         else {
 555                                 if (netif_msg_tx_err(priv))
 556                                         mlx4_warn(mdev, "Non-linear headers\n");
 557                                 dev_kfree_skb_any(skb);
 558                                 return 0;
 559                         }
 560                 }
 561                 if (unlikely(*lso_header_size > MAX_LSO_HDR_SIZE)) {
 562                         if (netif_msg_tx_err(priv))
 563                                 mlx4_warn(mdev, "LSO header size too big\n");
 564                         dev_kfree_skb_any(skb);
 565                         return 0;
 566                 }
 567         } else {
 568                 *lso_header_size = 0;
 569                 if (!is_inline(skb, NULL))
 570                         real_size = CTRL_SIZE + (skb_shinfo(skb)->nr_frags + 1) * DS_SIZE;
 571                 else
 572                         real_size = inline_size(skb);
 573         }
 574
 575         return real_size;
 576 }
 577
 578 static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, struct sk_buff *skb,
 579                              int real_size, u16 *vlan_tag, int tx_ind, void *fragptr)
 580 {
 581         struct mlx4_wqe_inline_seg *inl = &tx_desc->inl;
 582         int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl;
 583
 584         if (skb->len <= spc) {
 585                 inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
 586                 skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb));
 587                 if (skb_shinfo(skb)->nr_frags)
 588                         memcpy(((void *)(inl + 1)) + skb_headlen(skb), fragptr,
 589                                skb_shinfo(skb)->frags[0].size);
 590
 591         } else {
 592                 inl->byte_count = cpu_to_be32(1 << 31 | spc);
 593                 if (skb_headlen(skb) <= spc) {
 594                         skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb));
 595                         if (skb_headlen(skb) < spc) {
 596                                 memcpy(((void *)(inl + 1)) + skb_headlen(skb),
 597                                         fragptr, spc - skb_headlen(skb));
 598                                 fragptr +=  spc - skb_headlen(skb);
 599                         }
 600                         inl = (void *) (inl + 1) + spc;
 601                         memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
 602                 } else {
 603                         skb_copy_from_linear_data(skb, inl + 1, spc);
 604                         inl = (void *) (inl + 1) + spc;
 605                         skb_copy_from_linear_data_offset(skb, spc, inl + 1,
 606                                         skb_headlen(skb) - spc);
 607                         if (skb_shinfo(skb)->nr_frags)
 608                                 memcpy(((void *)(inl + 1)) + skb_headlen(skb) - spc,
 609                                         fragptr, skb_shinfo(skb)->frags[0].size);
 610                 }
 611
 612                 wmb();
 613                 inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
 614         }
 615         tx_desc->ctrl.vlan_tag = cpu_to_be16(*vlan_tag);
 616         tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN * !!(*vlan_tag);
 617         tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f;
 618 }
 619
 620 static int get_vlan_info(struct mlx4_en_priv *priv, struct sk_buff *skb,
 621                          u16 *vlan_tag)
 622 {
 623         int tx_ind;
 624
 625         /* Obtain VLAN information if present */
 626         if (priv->vlgrp && vlan_tx_tag_present(skb)) {
 627                 *vlan_tag = vlan_tx_tag_get(skb);
 628                 /* Set the Tx ring to use according to vlan priority */
 629                 tx_ind = priv->tx_prio_map[*vlan_tag >> 13];
 630         } else {
 631                 *vlan_tag = 0;
 632                 tx_ind = 0;
 633         }
 634         return tx_ind;
 635 }
 636
 637 int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 638 {
 639         struct mlx4_en_priv *priv = netdev_priv(dev);
 640         struct mlx4_en_dev *mdev = priv->mdev;
 641         struct mlx4_en_tx_ring *ring;
 642         struct mlx4_en_cq *cq;
 643         struct mlx4_en_tx_desc *tx_desc;
 644         struct mlx4_wqe_data_seg *data;
 645         struct skb_frag_struct *frag;
 646         struct mlx4_en_tx_info *tx_info;
 647         int tx_ind = 0;
 648         int nr_txbb;
 649         int desc_size;
 650         int real_size;
 651         dma_addr_t dma;
 652         u32 index;
 653         __be32 op_own;
 654         u16 vlan_tag;
 655         int i;
 656         int lso_header_size;
 657         void *fragptr;
 658
 659         if (unlikely(!skb->len)) {
 660                 dev_kfree_skb_any(skb);
 661                 return NETDEV_TX_OK;
 662         }
 663         real_size = get_real_size(skb, dev, &lso_header_size);
 664         if (unlikely(!real_size))
 665                 return NETDEV_TX_OK;
 666
 667         /* Allign descriptor to TXBB size */
 668         desc_size = ALIGN(real_size, TXBB_SIZE);
 669         nr_txbb = desc_size / TXBB_SIZE;
 670         if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
 671                 if (netif_msg_tx_err(priv))
 672                         mlx4_warn(mdev, "Oversized header or SG list\n");
 673                 dev_kfree_skb_any(skb);
 674                 return NETDEV_TX_OK;
 675         }
 676
 677         tx_ind = get_vlan_info(priv, skb, &vlan_tag);
 678         ring = &priv->tx_ring[tx_ind];
 679
 680         /* Check available TXBBs And 2K spare for prefetch */
 681         if (unlikely(((int)(ring->prod - ring->cons)) >
 682                      ring->size - HEADROOM - MAX_DESC_TXBBS)) {
 683                 /* every full Tx ring stops queue.
 684                  * TODO: implement multi-queue support (per-queue stop) */
 685                 netif_stop_queue(dev);
 686                 ring->blocked = 1;
 687                 priv->port_stats.queue_stopped++;
 688
 689                 /* Use interrupts to find out when queue opened */
 690                 cq = &priv->tx_cq[tx_ind];
 691                 mlx4_en_arm_cq(priv, cq);
 692                 return NETDEV_TX_BUSY;
 693         }
 694
 695         /* Now that we know what Tx ring to use */
 696         if (unlikely(!priv->port_up)) {
 697                 if (netif_msg_tx_err(priv))
 698                         mlx4_warn(mdev, "xmit: port down!\n");
 699                 dev_kfree_skb_any(skb);
 700                 return NETDEV_TX_OK;
 701         }
 702
 703         /* Track current inflight packets for performance analysis */
 704         AVG_PERF_COUNTER(priv->pstats.inflight_avg,
 705                          (u32) (ring->prod - ring->cons - 1));
 706
 707         /* Packet is good - grab an index and transmit it */
 708         index = ring->prod & ring->size_mask;
 709
 710         /* See if we have enough space for whole descriptor TXBB for setting
 711          * SW ownership on next descriptor; if not, use a bounce buffer. */
 712         if (likely(index + nr_txbb <= ring->size))
 713                 tx_desc = ring->buf + index * TXBB_SIZE;
 714         else
 715                 tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
 716
 717         /* Save skb in tx_info ring */
 718         tx_info = &ring->tx_info[index];
 719         tx_info->skb = skb;
 720         tx_info->nr_txbb = nr_txbb;
 721
 722         /* Prepare ctrl segement apart opcode+ownership, which depends on
 723          * whether LSO is used */
 724         tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag);
 725         tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN * !!vlan_tag;
 726         tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f;
 727         tx_desc->ctrl.srcrb_flags = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE |
 728                                                 MLX4_WQE_CTRL_SOLICITED);
 729         if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
 730                 tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
 731                                                          MLX4_WQE_CTRL_TCP_UDP_CSUM);
 732                 priv->port_stats.tx_chksum_offload++;
 733         }
 734
 735         /* Handle LSO (TSO) packets */
 736         if (lso_header_size) {
 737                 /* Mark opcode as LSO */
 738                 op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) |
 739                         ((ring->prod & ring->size) ?
 740                                 cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
 741
 742                 /* Fill in the LSO prefix */
 743                 tx_desc->lso.mss_hdr_size = cpu_to_be32(
 744                         skb_shinfo(skb)->gso_size << 16 | lso_header_size);
 745
 746                 /* Copy headers;
 747                  * note that we already verified that it is linear */
 748                 memcpy(tx_desc->lso.header, skb->data, lso_header_size);
 749                 data = ((void *) &tx_desc->lso +
 750                         ALIGN(lso_header_size + 4, DS_SIZE));
 751
 752                 priv->port_stats.tso_packets++;
 753                 i = ((skb->len - lso_header_size) / skb_shinfo(skb)->gso_size) +
 754                         !!((skb->len - lso_header_size) % skb_shinfo(skb)->gso_size);
 755                 ring->bytes += skb->len + (i - 1) * lso_header_size;
 756                 ring->packets += i;
 757         } else {
 758                 /* Normal (Non LSO) packet */
 759                 op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
 760                         ((ring->prod & ring->size) ?
 761                          cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
 762                 data = &tx_desc->data;
 763                 ring->bytes += max(skb->len, (unsigned int) ETH_ZLEN);
 764                 ring->packets++;
 765
 766         }
 767         AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len);
 768
 769
 770         /* valid only for none inline segments */
 771         tx_info->data_offset = (void *) data - (void *) tx_desc;
 772
 773         tx_info->linear = (lso_header_size < skb_headlen(skb) && !is_inline(skb, NULL)) ? 1 : 0;
 774         data += skb_shinfo(skb)->nr_frags + tx_info->linear - 1;
 775
 776         if (!is_inline(skb, &fragptr)) {
 777                 /* Map fragments */
 778                 for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) {
 779                         frag = &skb_shinfo(skb)->frags[i];
 780                         dma = pci_map_page(mdev->dev->pdev, frag->page, frag->page_offset,
 781                                            frag->size, PCI_DMA_TODEVICE);
 782                         data->addr = cpu_to_be64(dma);
 783                         data->lkey = cpu_to_be32(mdev->mr.key);
 784                         wmb();
 785                         data->byte_count = cpu_to_be32(frag->size);
 786                         --data;
 787                 }
 788
 789                 /* Map linear part */
 790                 if (tx_info->linear) {
 791                         dma = pci_map_single(mdev->dev->pdev, skb->data + lso_header_size,
 792                                              skb_headlen(skb) - lso_header_size, PCI_DMA_TODEVICE);
 793                         data->addr = cpu_to_be64(dma);
 794                         data->lkey = cpu_to_be32(mdev->mr.key);
 795                         wmb();
 796                         data->byte_count = cpu_to_be32(skb_headlen(skb) - lso_header_size);
 797                 }
 798                 tx_info->inl = 0;
 799         } else {
 800                 build_inline_wqe(tx_desc, skb, real_size, &vlan_tag, tx_ind, fragptr);
 801                 tx_info->inl = 1;
 802         }
 803
 804         ring->prod += nr_txbb;
 805
 806         /* If we used a bounce buffer then copy descriptor back into place */
 807         if (tx_desc == (struct mlx4_en_tx_desc *) ring->bounce_buf)
 808                 tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
 809
 810         /* Run destructor before passing skb to HW */
 811         if (likely(!skb_shared(skb)))
 812                 skb_orphan(skb);
 813
 814         /* Ensure new descirptor hits memory
 815          * before setting ownership of this descriptor to HW */
 816         wmb();
 817         tx_desc->ctrl.owner_opcode = op_own;
 818
 819         /* Ring doorbell! */
 820         wmb();
 821         writel(ring->doorbell_qpn, mdev->uar_map + MLX4_SEND_DOORBELL);
 822         dev->trans_start = jiffies;
 823
 824         /* Poll CQ here */
 825         mlx4_en_xmit_poll(priv, tx_ind);
 826
 827         return 0;
 828 }
 829