drivers/staging/octeon/ethernet-tx.c

   1 /*********************************************************************
   2  * Author: Cavium Networks
   3  *
   4  * Contact: support@caviumnetworks.com
   5  * This file is part of the OCTEON SDK
   6  *
   7  * Copyright (c) 2003-2010 Cavium Networks
   8  *
   9  * This file is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, Version 2, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This file is distributed in the hope that it will be useful, but
  14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  16  * NONINFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this file; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  22  * or visit http://www.gnu.org/licenses/.
  23  *
  24  * This file may also be available under a different license from Cavium.
  25  * Contact Cavium Networks for more information
  26 *********************************************************************/
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/init.h>
  31 #include <linux/etherdevice.h>
  32 #include <linux/ip.h>
  33 #include <linux/ratelimit.h>
  34 #include <linux/string.h>
  35 #include <linux/interrupt.h>
  36 #include <net/dst.h>
  37 #ifdef CONFIG_XFRM
  38 #include <linux/xfrm.h>
  39 #include <net/xfrm.h>
  40 #endif /* CONFIG_XFRM */
  41
  42 #include <linux/atomic.h>
  43
  44 #include <asm/octeon/octeon.h>
  45
  46 #include "ethernet-defines.h"
  47 #include "octeon-ethernet.h"
  48 #include "ethernet-tx.h"
  49 #include "ethernet-util.h"
  50
  51 #include <asm/octeon/cvmx-wqe.h>
  52 #include <asm/octeon/cvmx-fau.h>
  53 #include <asm/octeon/cvmx-pip.h>
  54 #include <asm/octeon/cvmx-pko.h>
  55 #include <asm/octeon/cvmx-helper.h>
  56
  57 #include <asm/octeon/cvmx-gmxx-defs.h>
  58
  59 #define CVM_OCT_SKB_CB(skb)     ((u64 *)((skb)->cb))
  60
  61 /*
  62  * You can define GET_SKBUFF_QOS() to override how the skbuff output
  63  * function determines which output queue is used. The default
  64  * implementation always uses the base queue for the port. If, for
  65  * example, you wanted to use the skb->priority field, define
  66  * GET_SKBUFF_QOS as: #define GET_SKBUFF_QOS(skb) ((skb)->priority)
  67  */
  68 #ifndef GET_SKBUFF_QOS
  69 #define GET_SKBUFF_QOS(skb) 0
  70 #endif
  71
  72 static void cvm_oct_tx_do_cleanup(unsigned long arg);
  73 static DECLARE_TASKLET(cvm_oct_tx_cleanup_tasklet, cvm_oct_tx_do_cleanup, 0);
  74
  75 /* Maximum number of SKBs to try to free per xmit packet. */
  76 #define MAX_SKB_TO_FREE (MAX_OUT_QUEUE_DEPTH * 2)
  77
  78 static inline int32_t cvm_oct_adjust_skb_to_free(int32_t skb_to_free, int fau)
  79 {
  80         int32_t undo;
  81         undo = skb_to_free > 0 ? MAX_SKB_TO_FREE : skb_to_free + MAX_SKB_TO_FREE;
  82         if (undo > 0)
  83                 cvmx_fau_atomic_add32(fau, -undo);
  84         skb_to_free = -skb_to_free > MAX_SKB_TO_FREE ? MAX_SKB_TO_FREE : -skb_to_free;
  85         return skb_to_free;
  86 }
  87
  88 static void cvm_oct_kick_tx_poll_watchdog(void)
  89 {
  90         union cvmx_ciu_timx ciu_timx;
  91         ciu_timx.u64 = 0;
  92         ciu_timx.s.one_shot = 1;
  93         ciu_timx.s.len = cvm_oct_tx_poll_interval;
  94         cvmx_write_csr(CVMX_CIU_TIMX(1), ciu_timx.u64);
  95 }
  96
  97 void cvm_oct_free_tx_skbs(struct net_device *dev)
  98 {
  99         int32_t skb_to_free;
 100         int qos, queues_per_port;
 101         int total_freed = 0;
 102         int total_remaining = 0;
 103         unsigned long flags;
 104         struct octeon_ethernet *priv = netdev_priv(dev);
 105
 106         queues_per_port = cvmx_pko_get_num_queues(priv->port);
 107         /* Drain any pending packets in the free list */
 108         for (qos = 0; qos < queues_per_port; qos++) {
 109                 if (skb_queue_len(&priv->tx_free_list[qos]) == 0)
 110                         continue;
 111                 skb_to_free = cvmx_fau_fetch_and_add32(priv->fau+qos*4, MAX_SKB_TO_FREE);
 112                 skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);
 113
 114
 115                 total_freed += skb_to_free;
 116                 if (skb_to_free > 0) {
 117                         struct sk_buff *to_free_list = NULL;
 118                         spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
 119                         while (skb_to_free > 0) {
 120                                 struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
 121                                 t->next = to_free_list;
 122                                 to_free_list = t;
 123                                 skb_to_free--;
 124                         }
 125                         spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
 126                         /* Do the actual freeing outside of the lock. */
 127                         while (to_free_list) {
 128                                 struct sk_buff *t = to_free_list;
 129                                 to_free_list = to_free_list->next;
 130                                 dev_kfree_skb_any(t);
 131                         }
 132                 }
 133                 total_remaining += skb_queue_len(&priv->tx_free_list[qos]);
 134         }
 135         if (total_freed >= 0 && netif_queue_stopped(dev))
 136                 netif_wake_queue(dev);
 137         if (total_remaining)
 138                 cvm_oct_kick_tx_poll_watchdog();
 139 }
 140
 141 /**
 142  * cvm_oct_xmit - transmit a packet
 143  * @skb:    Packet to send
 144  * @dev:    Device info structure
 145  *
 146  * Returns Always returns NETDEV_TX_OK
 147  */
 148 int cvm_oct_xmit(struct sk_buff *skb, struct net_device *dev)
 149 {
 150         cvmx_pko_command_word0_t pko_command;
 151         union cvmx_buf_ptr hw_buffer;
 152         uint64_t old_scratch;
 153         uint64_t old_scratch2;
 154         int qos;
 155         int i;
 156         enum {QUEUE_CORE, QUEUE_HW, QUEUE_DROP} queue_type;
 157         struct octeon_ethernet *priv = netdev_priv(dev);
 158         struct sk_buff *to_free_list;
 159         int32_t skb_to_free;
 160         int32_t buffers_to_free;
 161         u32 total_to_clean;
 162         unsigned long flags;
 163 #if REUSE_SKBUFFS_WITHOUT_FREE
 164         unsigned char *fpa_head;
 165 #endif
 166
 167         /*
 168          * Prefetch the private data structure.  It is larger than the
 169          * one cache line.
 170          */
 171         prefetch(priv);
 172
 173         /*
 174          * The check on CVMX_PKO_QUEUES_PER_PORT_* is designed to
 175          * completely remove "qos" in the event neither interface
 176          * supports multiple queues per port.
 177          */
 178         if ((CVMX_PKO_QUEUES_PER_PORT_INTERFACE0 > 1) ||
 179             (CVMX_PKO_QUEUES_PER_PORT_INTERFACE1 > 1)) {
 180                 qos = GET_SKBUFF_QOS(skb);
 181                 if (qos <= 0)
 182                         qos = 0;
 183                 else if (qos >= cvmx_pko_get_num_queues(priv->port))
 184                         qos = 0;
 185         } else
 186                 qos = 0;
 187
 188         if (USE_ASYNC_IOBDMA) {
 189                 /* Save scratch in case userspace is using it */
 190                 CVMX_SYNCIOBDMA;
 191                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 192                 old_scratch2 = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);
 193
 194                 /*
 195                  * Fetch and increment the number of packets to be
 196                  * freed.
 197                  */
 198                 cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH + 8,
 199                                                FAU_NUM_PACKET_BUFFERS_TO_FREE,
 200                                                0);
 201                 cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH,
 202                                                priv->fau + qos * 4,
 203                                                MAX_SKB_TO_FREE);
 204         }
 205
 206         /*
 207          * We have space for 6 segment pointers, If there will be more
 208          * than that, we must linearize.
 209          */
 210         if (unlikely(skb_shinfo(skb)->nr_frags > 5)) {
 211                 if (unlikely(__skb_linearize(skb))) {
 212                         queue_type = QUEUE_DROP;
 213                         if (USE_ASYNC_IOBDMA) {
 214                                 /* Get the number of skbuffs in use by the hardware */
 215                                 CVMX_SYNCIOBDMA;
 216                                 skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 217                         } else {
 218                                 /* Get the number of skbuffs in use by the hardware */
 219                                 skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
 220                                                                        MAX_SKB_TO_FREE);
 221                         }
 222                         skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau + qos * 4);
 223                         spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
 224                         goto skip_xmit;
 225                 }
 226         }
 227
 228         /*
 229          * The CN3XXX series of parts has an errata (GMX-401) which
 230          * causes the GMX block to hang if a collision occurs towards
 231          * the end of a <68 byte packet. As a workaround for this, we
 232          * pad packets to be 68 bytes whenever we are in half duplex
 233          * mode. We don't handle the case of having a small packet but
 234          * no room to add the padding.  The kernel should always give
 235          * us at least a cache line
 236          */
 237         if ((skb->len < 64) && OCTEON_IS_MODEL(OCTEON_CN3XXX)) {
 238                 union cvmx_gmxx_prtx_cfg gmx_prt_cfg;
 239                 int interface = INTERFACE(priv->port);
 240                 int index = INDEX(priv->port);
 241
 242                 if (interface < 2) {
 243                         /* We only need to pad packet in half duplex mode */
 244                         gmx_prt_cfg.u64 =
 245                             cvmx_read_csr(CVMX_GMXX_PRTX_CFG(index, interface));
 246                         if (gmx_prt_cfg.s.duplex == 0) {
 247                                 int add_bytes = 64 - skb->len;
 248                                 if ((skb_tail_pointer(skb) + add_bytes) <=
 249                                     skb_end_pointer(skb))
 250                                         memset(__skb_put(skb, add_bytes), 0,
 251                                                add_bytes);
 252                         }
 253                 }
 254         }
 255
 256         /* Build the PKO command */
 257         pko_command.u64 = 0;
 258         pko_command.s.n2 = 1;   /* Don't pollute L2 with the outgoing packet */
 259         pko_command.s.segs = 1;
 260         pko_command.s.total_bytes = skb->len;
 261         pko_command.s.size0 = CVMX_FAU_OP_SIZE_32;
 262         pko_command.s.subone0 = 1;
 263
 264         pko_command.s.dontfree = 1;
 265
 266         /* Build the PKO buffer pointer */
 267         hw_buffer.u64 = 0;
 268         if (skb_shinfo(skb)->nr_frags == 0) {
 269                 hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
 270                 hw_buffer.s.pool = 0;
 271                 hw_buffer.s.size = skb->len;
 272         } else {
 273                 hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)skb->data);
 274                 hw_buffer.s.pool = 0;
 275                 hw_buffer.s.size = skb_headlen(skb);
 276                 CVM_OCT_SKB_CB(skb)[0] = hw_buffer.u64;
 277                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 278                         struct skb_frag_struct *fs = skb_shinfo(skb)->frags + i;
 279                         hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)(page_address(fs->page.p) + fs->page_offset));
 280                         hw_buffer.s.size = fs->size;
 281                         CVM_OCT_SKB_CB(skb)[i + 1] = hw_buffer.u64;
 282                 }
 283                 hw_buffer.s.addr = XKPHYS_TO_PHYS((u64)CVM_OCT_SKB_CB(skb));
 284                 hw_buffer.s.size = skb_shinfo(skb)->nr_frags + 1;
 285                 pko_command.s.segs = skb_shinfo(skb)->nr_frags + 1;
 286                 pko_command.s.gather = 1;
 287                 goto dont_put_skbuff_in_hw;
 288         }
 289
 290         /*
 291          * See if we can put this skb in the FPA pool. Any strange
 292          * behavior from the Linux networking stack will most likely
 293          * be caused by a bug in the following code. If some field is
 294          * in use by the network stack and gets carried over when a
 295          * buffer is reused, bad things may happen.  If in doubt and
 296          * you dont need the absolute best performance, disable the
 297          * define REUSE_SKBUFFS_WITHOUT_FREE. The reuse of buffers has
 298          * shown a 25% increase in performance under some loads.
 299          */
 300 #if REUSE_SKBUFFS_WITHOUT_FREE
 301         fpa_head = skb->head + 256 - ((unsigned long)skb->head & 0x7f);
 302         if (unlikely(skb->data < fpa_head)) {
 303                 /*
 304                  * printk("TX buffer beginning can't meet FPA
 305                  * alignment constraints\n");
 306                  */
 307                 goto dont_put_skbuff_in_hw;
 308         }
 309         if (unlikely
 310             ((skb_end_pointer(skb) - fpa_head) < CVMX_FPA_PACKET_POOL_SIZE)) {
 311                 /*
 312                    printk("TX buffer isn't large enough for the FPA\n");
 313                  */
 314                 goto dont_put_skbuff_in_hw;
 315         }
 316         if (unlikely(skb_shared(skb))) {
 317                 /*
 318                    printk("TX buffer sharing data with someone else\n");
 319                  */
 320                 goto dont_put_skbuff_in_hw;
 321         }
 322         if (unlikely(skb_cloned(skb))) {
 323                 /*
 324                    printk("TX buffer has been cloned\n");
 325                  */
 326                 goto dont_put_skbuff_in_hw;
 327         }
 328         if (unlikely(skb_header_cloned(skb))) {
 329                 /*
 330                    printk("TX buffer header has been cloned\n");
 331                  */
 332                 goto dont_put_skbuff_in_hw;
 333         }
 334         if (unlikely(skb->destructor)) {
 335                 /*
 336                    printk("TX buffer has a destructor\n");
 337                  */
 338                 goto dont_put_skbuff_in_hw;
 339         }
 340         if (unlikely(skb_shinfo(skb)->nr_frags)) {
 341                 /*
 342                    printk("TX buffer has fragments\n");
 343                  */
 344                 goto dont_put_skbuff_in_hw;
 345         }
 346         if (unlikely
 347             (skb->truesize !=
 348              sizeof(*skb) + skb_end_offset(skb))) {
 349                 /*
 350                    printk("TX buffer truesize has been changed\n");
 351                  */
 352                 goto dont_put_skbuff_in_hw;
 353         }
 354
 355         /*
 356          * We can use this buffer in the FPA.  We don't need the FAU
 357          * update anymore
 358          */
 359         pko_command.s.dontfree = 0;
 360
 361         hw_buffer.s.back = ((unsigned long)skb->data >> 7) - ((unsigned long)fpa_head >> 7);
 362         *(struct sk_buff **)(fpa_head - sizeof(void *)) = skb;
 363
 364         /*
 365          * The skbuff will be reused without ever being freed. We must
 366          * cleanup a bunch of core things.
 367          */
 368         dst_release(skb_dst(skb));
 369         skb_dst_set(skb, NULL);
 370 #ifdef CONFIG_XFRM
 371         secpath_put(skb->sp);
 372         skb->sp = NULL;
 373 #endif
 374         nf_reset(skb);
 375
 376 #ifdef CONFIG_NET_SCHED
 377         skb->tc_index = 0;
 378 #ifdef CONFIG_NET_CLS_ACT
 379         skb->tc_verd = 0;
 380 #endif /* CONFIG_NET_CLS_ACT */
 381 #endif /* CONFIG_NET_SCHED */
 382 #endif /* REUSE_SKBUFFS_WITHOUT_FREE */
 383
 384 dont_put_skbuff_in_hw:
 385
 386         /* Check if we can use the hardware checksumming */
 387         if (USE_HW_TCPUDP_CHECKSUM && (skb->protocol == htons(ETH_P_IP)) &&
 388             (ip_hdr(skb)->version == 4) && (ip_hdr(skb)->ihl == 5) &&
 389             ((ip_hdr(skb)->frag_off == 0) || (ip_hdr(skb)->frag_off == 1 << 14))
 390             && ((ip_hdr(skb)->protocol == IPPROTO_TCP)
 391                 || (ip_hdr(skb)->protocol == IPPROTO_UDP))) {
 392                 /* Use hardware checksum calc */
 393                 pko_command.s.ipoffp1 = sizeof(struct ethhdr) + 1;
 394         }
 395
 396         if (USE_ASYNC_IOBDMA) {
 397                 /* Get the number of skbuffs in use by the hardware */
 398                 CVMX_SYNCIOBDMA;
 399                 skb_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 400                 buffers_to_free = cvmx_scratch_read64(CVMX_SCR_SCRATCH + 8);
 401         } else {
 402                 /* Get the number of skbuffs in use by the hardware */
 403                 skb_to_free = cvmx_fau_fetch_and_add32(priv->fau + qos * 4,
 404                                                        MAX_SKB_TO_FREE);
 405                 buffers_to_free =
 406                     cvmx_fau_fetch_and_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, 0);
 407         }
 408
 409         skb_to_free = cvm_oct_adjust_skb_to_free(skb_to_free, priv->fau+qos*4);
 410
 411         /*
 412          * If we're sending faster than the receive can free them then
 413          * don't do the HW free.
 414          */
 415         if ((buffers_to_free < -100) && !pko_command.s.dontfree)
 416                 pko_command.s.dontfree = 1;
 417
 418         if (pko_command.s.dontfree) {
 419                 queue_type = QUEUE_CORE;
 420                 pko_command.s.reg0 = priv->fau+qos*4;
 421         } else {
 422                 queue_type = QUEUE_HW;
 423         }
 424         if (USE_ASYNC_IOBDMA)
 425                 cvmx_fau_async_fetch_and_add32(CVMX_SCR_SCRATCH, FAU_TOTAL_TX_TO_CLEAN, 1);
 426
 427         spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
 428
 429         /* Drop this packet if we have too many already queued to the HW */
 430         if (unlikely(skb_queue_len(&priv->tx_free_list[qos]) >= MAX_OUT_QUEUE_DEPTH)) {
 431                 if (dev->tx_queue_len != 0) {
 432                         /* Drop the lock when notifying the core.  */
 433                         spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
 434                         netif_stop_queue(dev);
 435                         spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
 436                 } else {
 437                         /* If not using normal queueing.  */
 438                         queue_type = QUEUE_DROP;
 439                         goto skip_xmit;
 440                 }
 441         }
 442
 443         cvmx_pko_send_packet_prepare(priv->port, priv->queue + qos,
 444                                      CVMX_PKO_LOCK_NONE);
 445
 446         /* Send the packet to the output queue */
 447         if (unlikely(cvmx_pko_send_packet_finish(priv->port,
 448                                                  priv->queue + qos,
 449                                                  pko_command, hw_buffer,
 450                                                  CVMX_PKO_LOCK_NONE))) {
 451                 printk_ratelimited("%s: Failed to send the packet\n", dev->name);
 452                 queue_type = QUEUE_DROP;
 453         }
 454 skip_xmit:
 455         to_free_list = NULL;
 456
 457         switch (queue_type) {
 458         case QUEUE_DROP:
 459                 skb->next = to_free_list;
 460                 to_free_list = skb;
 461                 priv->stats.tx_dropped++;
 462                 break;
 463         case QUEUE_HW:
 464                 cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE, -1);
 465                 break;
 466         case QUEUE_CORE:
 467                 __skb_queue_tail(&priv->tx_free_list[qos], skb);
 468                 break;
 469         default:
 470                 BUG();
 471         }
 472
 473         while (skb_to_free > 0) {
 474                 struct sk_buff *t = __skb_dequeue(&priv->tx_free_list[qos]);
 475                 t->next = to_free_list;
 476                 to_free_list = t;
 477                 skb_to_free--;
 478         }
 479
 480         spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
 481
 482         /* Do the actual freeing outside of the lock. */
 483         while (to_free_list) {
 484                 struct sk_buff *t = to_free_list;
 485                 to_free_list = to_free_list->next;
 486                 dev_kfree_skb_any(t);
 487         }
 488
 489         if (USE_ASYNC_IOBDMA) {
 490                 CVMX_SYNCIOBDMA;
 491                 total_to_clean = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 492                 /* Restore the scratch area */
 493                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 494                 cvmx_scratch_write64(CVMX_SCR_SCRATCH + 8, old_scratch2);
 495         } else {
 496                 total_to_clean = cvmx_fau_fetch_and_add32(FAU_TOTAL_TX_TO_CLEAN, 1);
 497         }
 498
 499         if (total_to_clean & 0x3ff) {
 500                 /*
 501                  * Schedule the cleanup tasklet every 1024 packets for
 502                  * the pathological case of high traffic on one port
 503                  * delaying clean up of packets on a different port
 504                  * that is blocked waiting for the cleanup.
 505                  */
 506                 tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
 507         }
 508
 509         cvm_oct_kick_tx_poll_watchdog();
 510
 511         return NETDEV_TX_OK;
 512 }
 513
 514 /**
 515  * cvm_oct_xmit_pow - transmit a packet to the POW
 516  * @skb:    Packet to send
 517  * @dev:    Device info structure
 518
 519  * Returns Always returns zero
 520  */
 521 int cvm_oct_xmit_pow(struct sk_buff *skb, struct net_device *dev)
 522 {
 523         struct octeon_ethernet *priv = netdev_priv(dev);
 524         void *packet_buffer;
 525         void *copy_location;
 526
 527         /* Get a work queue entry */
 528         cvmx_wqe_t *work = cvmx_fpa_alloc(CVMX_FPA_WQE_POOL);
 529         if (unlikely(work == NULL)) {
 530                 printk_ratelimited("%s: Failed to allocate a work "
 531                                    "queue entry\n", dev->name);
 532                 priv->stats.tx_dropped++;
 533                 dev_kfree_skb(skb);
 534                 return 0;
 535         }
 536
 537         /* Get a packet buffer */
 538         packet_buffer = cvmx_fpa_alloc(CVMX_FPA_PACKET_POOL);
 539         if (unlikely(packet_buffer == NULL)) {
 540                 printk_ratelimited("%s: Failed to allocate a packet buffer\n",
 541                                    dev->name);
 542                 cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, DONT_WRITEBACK(1));
 543                 priv->stats.tx_dropped++;
 544                 dev_kfree_skb(skb);
 545                 return 0;
 546         }
 547
 548         /*
 549          * Calculate where we need to copy the data to. We need to
 550          * leave 8 bytes for a next pointer (unused). We also need to
 551          * include any configure skip. Then we need to align the IP
 552          * packet src and dest into the same 64bit word. The below
 553          * calculation may add a little extra, but that doesn't
 554          * hurt.
 555          */
 556         copy_location = packet_buffer + sizeof(uint64_t);
 557         copy_location += ((CVMX_HELPER_FIRST_MBUFF_SKIP + 7) & 0xfff8) + 6;
 558
 559         /*
 560          * We have to copy the packet since whoever processes this
 561          * packet will free it to a hardware pool. We can't use the
 562          * trick of counting outstanding packets like in
 563          * cvm_oct_xmit.
 564          */
 565         memcpy(copy_location, skb->data, skb->len);
 566
 567         /*
 568          * Fill in some of the work queue fields. We may need to add
 569          * more if the software at the other end needs them.
 570          */
 571         work->hw_chksum = skb->csum;
 572         work->len = skb->len;
 573         work->ipprt = priv->port;
 574         work->qos = priv->port & 0x7;
 575         work->grp = pow_send_group;
 576         work->tag_type = CVMX_HELPER_INPUT_TAG_TYPE;
 577         work->tag = pow_send_group;     /* FIXME */
 578         /* Default to zero. Sets of zero later are commented out */
 579         work->word2.u64 = 0;
 580         work->word2.s.bufs = 1;
 581         work->packet_ptr.u64 = 0;
 582         work->packet_ptr.s.addr = cvmx_ptr_to_phys(copy_location);
 583         work->packet_ptr.s.pool = CVMX_FPA_PACKET_POOL;
 584         work->packet_ptr.s.size = CVMX_FPA_PACKET_POOL_SIZE;
 585         work->packet_ptr.s.back = (copy_location - packet_buffer) >> 7;
 586
 587         if (skb->protocol == htons(ETH_P_IP)) {
 588                 work->word2.s.ip_offset = 14;
 589 #if 0
 590                 work->word2.s.vlan_valid = 0;   /* FIXME */
 591                 work->word2.s.vlan_cfi = 0;     /* FIXME */
 592                 work->word2.s.vlan_id = 0;      /* FIXME */
 593                 work->word2.s.dec_ipcomp = 0;   /* FIXME */
 594 #endif
 595                 work->word2.s.tcp_or_udp =
 596                     (ip_hdr(skb)->protocol == IPPROTO_TCP)
 597                     || (ip_hdr(skb)->protocol == IPPROTO_UDP);
 598 #if 0
 599                 /* FIXME */
 600                 work->word2.s.dec_ipsec = 0;
 601                 /* We only support IPv4 right now */
 602                 work->word2.s.is_v6 = 0;
 603                 /* Hardware would set to zero */
 604                 work->word2.s.software = 0;
 605                 /* No error, packet is internal */
 606                 work->word2.s.L4_error = 0;
 607 #endif
 608                 work->word2.s.is_frag = !((ip_hdr(skb)->frag_off == 0)
 609                                           || (ip_hdr(skb)->frag_off ==
 610                                               1 << 14));
 611 #if 0
 612                 /* Assume Linux is sending a good packet */
 613                 work->word2.s.IP_exc = 0;
 614 #endif
 615                 work->word2.s.is_bcast = (skb->pkt_type == PACKET_BROADCAST);
 616                 work->word2.s.is_mcast = (skb->pkt_type == PACKET_MULTICAST);
 617 #if 0
 618                 /* This is an IP packet */
 619                 work->word2.s.not_IP = 0;
 620                 /* No error, packet is internal */
 621                 work->word2.s.rcv_error = 0;
 622                 /* No error, packet is internal */
 623                 work->word2.s.err_code = 0;
 624 #endif
 625
 626                 /*
 627                  * When copying the data, include 4 bytes of the
 628                  * ethernet header to align the same way hardware
 629                  * does.
 630                  */
 631                 memcpy(work->packet_data, skb->data + 10,
 632                        sizeof(work->packet_data));
 633         } else {
 634 #if 0
 635                 work->word2.snoip.vlan_valid = 0;       /* FIXME */
 636                 work->word2.snoip.vlan_cfi = 0; /* FIXME */
 637                 work->word2.snoip.vlan_id = 0;  /* FIXME */
 638                 work->word2.snoip.software = 0; /* Hardware would set to zero */
 639 #endif
 640                 work->word2.snoip.is_rarp = skb->protocol == htons(ETH_P_RARP);
 641                 work->word2.snoip.is_arp = skb->protocol == htons(ETH_P_ARP);
 642                 work->word2.snoip.is_bcast =
 643                     (skb->pkt_type == PACKET_BROADCAST);
 644                 work->word2.snoip.is_mcast =
 645                     (skb->pkt_type == PACKET_MULTICAST);
 646                 work->word2.snoip.not_IP = 1;   /* IP was done up above */
 647 #if 0
 648                 /* No error, packet is internal */
 649                 work->word2.snoip.rcv_error = 0;
 650                 /* No error, packet is internal */
 651                 work->word2.snoip.err_code = 0;
 652 #endif
 653                 memcpy(work->packet_data, skb->data, sizeof(work->packet_data));
 654         }
 655
 656         /* Submit the packet to the POW */
 657         cvmx_pow_work_submit(work, work->tag, work->tag_type, work->qos,
 658                              work->grp);
 659         priv->stats.tx_packets++;
 660         priv->stats.tx_bytes += skb->len;
 661         dev_kfree_skb(skb);
 662         return 0;
 663 }
 664
 665 /**
 666  * cvm_oct_tx_shutdown_dev - free all skb that are currently queued for TX.
 667  * @dev:    Device being shutdown
 668  *
 669  */
 670 void cvm_oct_tx_shutdown_dev(struct net_device *dev)
 671 {
 672         struct octeon_ethernet *priv = netdev_priv(dev);
 673         unsigned long flags;
 674         int qos;
 675
 676         for (qos = 0; qos < 16; qos++) {
 677                 spin_lock_irqsave(&priv->tx_free_list[qos].lock, flags);
 678                 while (skb_queue_len(&priv->tx_free_list[qos]))
 679                         dev_kfree_skb_any(__skb_dequeue
 680                                           (&priv->tx_free_list[qos]));
 681                 spin_unlock_irqrestore(&priv->tx_free_list[qos].lock, flags);
 682         }
 683 }
 684
 685 static void cvm_oct_tx_do_cleanup(unsigned long arg)
 686 {
 687         int port;
 688
 689         for (port = 0; port < TOTAL_NUMBER_OF_PORTS; port++) {
 690                 if (cvm_oct_device[port]) {
 691                         struct net_device *dev = cvm_oct_device[port];
 692                         cvm_oct_free_tx_skbs(dev);
 693                 }
 694         }
 695 }
 696
 697 static irqreturn_t cvm_oct_tx_cleanup_watchdog(int cpl, void *dev_id)
 698 {
 699         /* Disable the interrupt.  */
 700         cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
 701         /* Do the work in the tasklet.  */
 702         tasklet_schedule(&cvm_oct_tx_cleanup_tasklet);
 703         return IRQ_HANDLED;
 704 }
 705
 706 void cvm_oct_tx_initialize(void)
 707 {
 708         int i;
 709
 710         /* Disable the interrupt.  */
 711         cvmx_write_csr(CVMX_CIU_TIMX(1), 0);
 712         /* Register an IRQ hander for to receive CIU_TIMX(1) interrupts */
 713         i = request_irq(OCTEON_IRQ_TIMER1,
 714                         cvm_oct_tx_cleanup_watchdog, 0,
 715                         "Ethernet", cvm_oct_device);
 716
 717         if (i)
 718                 panic("Could not acquire Ethernet IRQ %d\n", OCTEON_IRQ_TIMER1);
 719 }
 720
 721 void cvm_oct_tx_shutdown(void)
 722 {
 723         /* Free the interrupt handler */
 724         free_irq(OCTEON_IRQ_TIMER1, cvm_oct_device);
 725 }