kernel/drivers/staging/octeon/ethernet-rx.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/cache.h>
  30 #include <linux/cpumask.h>
  31 #include <linux/netdevice.h>
  32 #include <linux/etherdevice.h>
  33 #include <linux/ip.h>
  34 #include <linux/string.h>
  35 #include <linux/prefetch.h>
  36 #include <linux/ratelimit.h>
  37 #include <linux/smp.h>
  38 #include <linux/interrupt.h>
  39 #include <net/dst.h>
  40 #ifdef CONFIG_XFRM
  41 #include <linux/xfrm.h>
  42 #include <net/xfrm.h>
  43 #endif /* CONFIG_XFRM */
  44
  45 #include <linux/atomic.h>
  46
  47 #include <asm/octeon/octeon.h>
  48
  49 #include "ethernet-defines.h"
  50 #include "ethernet-mem.h"
  51 #include "ethernet-rx.h"
  52 #include "octeon-ethernet.h"
  53 #include "ethernet-util.h"
  54
  55 #include <asm/octeon/cvmx-helper.h>
  56 #include <asm/octeon/cvmx-wqe.h>
  57 #include <asm/octeon/cvmx-fau.h>
  58 #include <asm/octeon/cvmx-pow.h>
  59 #include <asm/octeon/cvmx-pip.h>
  60 #include <asm/octeon/cvmx-scratch.h>
  61
  62 #include <asm/octeon/cvmx-gmxx-defs.h>
  63
  64 static struct napi_struct cvm_oct_napi;
  65
  66 /**
  67  * cvm_oct_do_interrupt - interrupt handler.
  68  *
  69  * The interrupt occurs whenever the POW has packets in our group.
  70  *
  71  */
  72 static irqreturn_t cvm_oct_do_interrupt(int cpl, void *dev_id)
  73 {
  74         /* Disable the IRQ and start napi_poll. */
  75         disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
  76         napi_schedule(&cvm_oct_napi);
  77
  78         return IRQ_HANDLED;
  79 }
  80
  81 /**
  82  * cvm_oct_check_rcv_error - process receive errors
  83  * @work: Work queue entry pointing to the packet.
  84  *
  85  * Returns Non-zero if the packet can be dropped, zero otherwise.
  86  */
  87 static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
  88 {
  89         if ((work->word2.snoip.err_code == 10) && (work->len <= 64)) {
  90                 /*
  91                  * Ignore length errors on min size packets. Some
  92                  * equipment incorrectly pads packets to 64+4FCS
  93                  * instead of 60+4FCS.  Note these packets still get
  94                  * counted as frame errors.
  95                  */
  96         } else
  97             if (USE_10MBPS_PREAMBLE_WORKAROUND
  98                 && ((work->word2.snoip.err_code == 5)
  99                     || (work->word2.snoip.err_code == 7))) {
 100
 101                 /*
 102                  * We received a packet with either an alignment error
 103                  * or a FCS error. This may be signalling that we are
 104                  * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
 105                  * off. If this is the case we need to parse the
 106                  * packet to determine if we can remove a non spec
 107                  * preamble and generate a correct packet.
 108                  */
 109                 int interface = cvmx_helper_get_interface_num(work->ipprt);
 110                 int index = cvmx_helper_get_interface_index_num(work->ipprt);
 111                 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
 112
 113                 gmxx_rxx_frm_ctl.u64 =
 114                     cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
 115                 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
 116
 117                         uint8_t *ptr =
 118                             cvmx_phys_to_ptr(work->packet_ptr.s.addr);
 119                         int i = 0;
 120
 121                         while (i < work->len - 1) {
 122                                 if (*ptr != 0x55)
 123                                         break;
 124                                 ptr++;
 125                                 i++;
 126                         }
 127
 128                         if (*ptr == 0xd5) {
 129                                 /*
 130                                   printk_ratelimited("Port %d received 0xd5 preamble\n",
 131                                           work->ipprt);
 132                                  */
 133                                 work->packet_ptr.s.addr += i + 1;
 134                                 work->len -= i + 5;
 135                         } else if ((*ptr & 0xf) == 0xd) {
 136                                 /*
 137                                   printk_ratelimited("Port %d received 0x?d preamble\n",
 138                                           work->ipprt);
 139                                  */
 140                                 work->packet_ptr.s.addr += i;
 141                                 work->len -= i + 4;
 142                                 for (i = 0; i < work->len; i++) {
 143                                         *ptr =
 144                                             ((*ptr & 0xf0) >> 4) |
 145                                             ((*(ptr + 1) & 0xf) << 4);
 146                                         ptr++;
 147                                 }
 148                         } else {
 149                                 printk_ratelimited("Port %d unknown preamble, packet dropped\n",
 150                                                    work->ipprt);
 151                                 /*
 152                                    cvmx_helper_dump_packet(work);
 153                                  */
 154                                 cvm_oct_free_work(work);
 155                                 return 1;
 156                         }
 157                 }
 158         } else {
 159                 printk_ratelimited("Port %d receive error code %d, packet dropped\n",
 160                                    work->ipprt, work->word2.snoip.err_code);
 161                 cvm_oct_free_work(work);
 162                 return 1;
 163         }
 164
 165         return 0;
 166 }
 167
 168 /**
 169  * cvm_oct_napi_poll - the NAPI poll function.
 170  * @napi: The NAPI instance, or null if called from cvm_oct_poll_controller
 171  * @budget: Maximum number of packets to receive.
 172  *
 173  * Returns the number of packets processed.
 174  */
 175 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
 176 {
 177         const int       coreid = cvmx_get_core_num();
 178         uint64_t        old_group_mask;
 179         uint64_t        old_scratch;
 180         int             rx_count = 0;
 181         int             did_work_request = 0;
 182         int             packet_not_copied;
 183
 184         /* Prefetch cvm_oct_device since we know we need it soon */
 185         prefetch(cvm_oct_device);
 186
 187         if (USE_ASYNC_IOBDMA) {
 188                 /* Save scratch in case userspace is using it */
 189                 CVMX_SYNCIOBDMA;
 190                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 191         }
 192
 193         /* Only allow work for our group (and preserve priorities) */
 194         old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 195         cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 196                        (old_group_mask & ~0xFFFFull) | 1 << pow_receive_group);
 197
 198         if (USE_ASYNC_IOBDMA) {
 199                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 200                 did_work_request = 1;
 201         }
 202
 203         while (rx_count < budget) {
 204                 struct sk_buff *skb = NULL;
 205                 struct sk_buff **pskb = NULL;
 206                 int skb_in_hw;
 207                 cvmx_wqe_t *work;
 208
 209                 if (USE_ASYNC_IOBDMA && did_work_request)
 210                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 211                 else
 212                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 213
 214                 prefetch(work);
 215                 did_work_request = 0;
 216                 if (work == NULL) {
 217                         union cvmx_pow_wq_int wq_int;
 218
 219                         wq_int.u64 = 0;
 220                         wq_int.s.iq_dis = 1 << pow_receive_group;
 221                         wq_int.s.wq_int = 1 << pow_receive_group;
 222                         cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 223                         break;
 224                 }
 225                 pskb = (struct sk_buff **)(cvm_oct_get_buffer_ptr(work->packet_ptr) -
 226                         sizeof(void *));
 227                 prefetch(pskb);
 228
 229                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 230                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 231                                                             CVMX_POW_NO_WAIT);
 232                         did_work_request = 1;
 233                 }
 234                 rx_count++;
 235
 236                 skb_in_hw = USE_SKBUFFS_IN_HW && work->word2.s.bufs == 1;
 237                 if (likely(skb_in_hw)) {
 238                         skb = *pskb;
 239                         prefetch(&skb->head);
 240                         prefetch(&skb->len);
 241                 }
 242                 prefetch(cvm_oct_device[work->ipprt]);
 243
 244                 /* Immediately throw away all packets with receive errors */
 245                 if (unlikely(work->word2.snoip.rcv_error)) {
 246                         if (cvm_oct_check_rcv_error(work))
 247                                 continue;
 248                 }
 249
 250                 /*
 251                  * We can only use the zero copy path if skbuffs are
 252                  * in the FPA pool and the packet fits in a single
 253                  * buffer.
 254                  */
 255                 if (likely(skb_in_hw)) {
 256                         skb->data = skb->head + work->packet_ptr.s.addr -
 257                                 cvmx_ptr_to_phys(skb->head);
 258                         prefetch(skb->data);
 259                         skb->len = work->len;
 260                         skb_set_tail_pointer(skb, skb->len);
 261                         packet_not_copied = 1;
 262                 } else {
 263                         /*
 264                          * We have to copy the packet. First allocate
 265                          * an skbuff for it.
 266                          */
 267                         skb = dev_alloc_skb(work->len);
 268                         if (!skb) {
 269                                 cvm_oct_free_work(work);
 270                                 continue;
 271                         }
 272
 273                         /*
 274                          * Check if we've received a packet that was
 275                          * entirely stored in the work entry.
 276                          */
 277                         if (unlikely(work->word2.s.bufs == 0)) {
 278                                 uint8_t *ptr = work->packet_data;
 279
 280                                 if (likely(!work->word2.s.not_IP)) {
 281                                         /*
 282                                          * The beginning of the packet
 283                                          * moves for IP packets.
 284                                          */
 285                                         if (work->word2.s.is_v6)
 286                                                 ptr += 2;
 287                                         else
 288                                                 ptr += 6;
 289                                 }
 290                                 memcpy(skb_put(skb, work->len), ptr, work->len);
 291                                 /* No packet buffers to free */
 292                         } else {
 293                                 int segments = work->word2.s.bufs;
 294                                 union cvmx_buf_ptr segment_ptr =
 295                                     work->packet_ptr;
 296                                 int len = work->len;
 297
 298                                 while (segments--) {
 299                                         union cvmx_buf_ptr next_ptr =
 300                                             *(union cvmx_buf_ptr *)cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
 301
 302                         /*
 303                          * Octeon Errata PKI-100: The segment size is
 304                          * wrong. Until it is fixed, calculate the
 305                          * segment size based on the packet pool
 306                          * buffer size. When it is fixed, the
 307                          * following line should be replaced with this
 308                          * one: int segment_size =
 309                          * segment_ptr.s.size;
 310                          */
 311                                         int segment_size =
 312                                             CVMX_FPA_PACKET_POOL_SIZE -
 313                                             (segment_ptr.s.addr -
 314                                              (((segment_ptr.s.addr >> 7) -
 315                                                segment_ptr.s.back) << 7));
 316                                         /*
 317                                          * Don't copy more than what
 318                                          * is left in the packet.
 319                                          */
 320                                         if (segment_size > len)
 321                                                 segment_size = len;
 322                                         /* Copy the data into the packet */
 323                                         memcpy(skb_put(skb, segment_size),
 324                                                cvmx_phys_to_ptr(segment_ptr.s.addr),
 325                                                segment_size);
 326                                         len -= segment_size;
 327                                         segment_ptr = next_ptr;
 328                                 }
 329                         }
 330                         packet_not_copied = 0;
 331                 }
 332
 333                 if (likely((work->ipprt < TOTAL_NUMBER_OF_PORTS) &&
 334                            cvm_oct_device[work->ipprt])) {
 335                         struct net_device *dev = cvm_oct_device[work->ipprt];
 336                         struct octeon_ethernet *priv = netdev_priv(dev);
 337
 338                         /*
 339                          * Only accept packets for devices that are
 340                          * currently up.
 341                          */
 342                         if (likely(dev->flags & IFF_UP)) {
 343                                 skb->protocol = eth_type_trans(skb, dev);
 344                                 skb->dev = dev;
 345
 346                                 if (unlikely(work->word2.s.not_IP ||
 347                                              work->word2.s.IP_exc ||
 348                                              work->word2.s.L4_error ||
 349                                              !work->word2.s.tcp_or_udp))
 350                                         skb->ip_summed = CHECKSUM_NONE;
 351                                 else
 352                                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 353
 354                                 /* Increment RX stats for virtual ports */
 355                                 if (work->ipprt >= CVMX_PIP_NUM_INPUT_PORTS) {
 356 #ifdef CONFIG_64BIT
 357                                         atomic64_add(1,
 358                                                      (atomic64_t *)&priv->stats.rx_packets);
 359                                         atomic64_add(skb->len,
 360                                                      (atomic64_t *)&priv->stats.rx_bytes);
 361 #else
 362                                         atomic_add(1,
 363                                                    (atomic_t *)&priv->stats.rx_packets);
 364                                         atomic_add(skb->len,
 365                                                    (atomic_t *)&priv->stats.rx_bytes);
 366 #endif
 367                                 }
 368                                 netif_receive_skb(skb);
 369                         } else {
 370                                 /* Drop any packet received for a device that isn't up */
 371                                 /*
 372                                   printk_ratelimited("%s: Device not up, packet dropped\n",
 373                                            dev->name);
 374                                 */
 375 #ifdef CONFIG_64BIT
 376                                 atomic64_add(1,
 377                                              (atomic64_t *)&priv->stats.rx_dropped);
 378 #else
 379                                 atomic_add(1,
 380                                            (atomic_t *)&priv->stats.rx_dropped);
 381 #endif
 382                                 dev_kfree_skb_irq(skb);
 383                         }
 384                 } else {
 385                         /*
 386                          * Drop any packet received for a device that
 387                          * doesn't exist.
 388                          */
 389                         printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
 390                                    work->ipprt);
 391                         dev_kfree_skb_irq(skb);
 392                 }
 393                 /*
 394                  * Check to see if the skbuff and work share the same
 395                  * packet buffer.
 396                  */
 397                 if (USE_SKBUFFS_IN_HW && likely(packet_not_copied)) {
 398                         /*
 399                          * This buffer needs to be replaced, increment
 400                          * the number of buffers we need to free by
 401                          * one.
 402                          */
 403                         cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
 404                                               1);
 405
 406                         cvmx_fpa_free(work, CVMX_FPA_WQE_POOL,
 407                                       DONT_WRITEBACK(1));
 408                 } else {
 409                         cvm_oct_free_work(work);
 410                 }
 411         }
 412         /* Restore the original POW group mask */
 413         cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
 414         if (USE_ASYNC_IOBDMA) {
 415                 /* Restore the scratch area */
 416                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 417         }
 418         cvm_oct_rx_refill_pool(0);
 419
 420         if (rx_count < budget && napi != NULL) {
 421                 /* No more work */
 422                 napi_complete(napi);
 423                 enable_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group);
 424         }
 425         return rx_count;
 426 }
 427
 428 #ifdef CONFIG_NET_POLL_CONTROLLER
 429 /**
 430  * cvm_oct_poll_controller - poll for receive packets
 431  * device.
 432  *
 433  * @dev:    Device to poll. Unused
 434  */
 435 void cvm_oct_poll_controller(struct net_device *dev)
 436 {
 437         cvm_oct_napi_poll(NULL, 16);
 438 }
 439 #endif
 440
 441 void cvm_oct_rx_initialize(void)
 442 {
 443         int i;
 444         struct net_device *dev_for_napi = NULL;
 445         union cvmx_pow_wq_int_thrx int_thr;
 446         union cvmx_pow_wq_int_pc int_pc;
 447
 448         for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
 449                 if (cvm_oct_device[i]) {
 450                         dev_for_napi = cvm_oct_device[i];
 451                         break;
 452                 }
 453         }
 454
 455         if (NULL == dev_for_napi)
 456                 panic("No net_devices were allocated.");
 457
 458         netif_napi_add(dev_for_napi, &cvm_oct_napi, cvm_oct_napi_poll,
 459                        rx_napi_weight);
 460         napi_enable(&cvm_oct_napi);
 461
 462         /* Register an IRQ handler to receive POW interrupts */
 463         i = request_irq(OCTEON_IRQ_WORKQ0 + pow_receive_group,
 464                         cvm_oct_do_interrupt, 0, "Ethernet", cvm_oct_device);
 465
 466         if (i)
 467                 panic("Could not acquire Ethernet IRQ %d\n",
 468                       OCTEON_IRQ_WORKQ0 + pow_receive_group);
 469
 470         disable_irq_nosync(OCTEON_IRQ_WORKQ0 + pow_receive_group);
 471
 472         int_thr.u64 = 0;
 473         int_thr.s.tc_en = 1;
 474         int_thr.s.tc_thr = 1;
 475         /* Enable POW interrupt when our port has at least one packet */
 476         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(pow_receive_group), int_thr.u64);
 477
 478         int_pc.u64 = 0;
 479         int_pc.s.pc_thr = 5;
 480         cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
 481
 482         /* Schedule NAPI now. This will indirectly enable the interrupt. */
 483         napi_schedule(&cvm_oct_napi);
 484 }
 485
 486 void cvm_oct_rx_shutdown(void)
 487 {
 488         netif_napi_del(&cvm_oct_napi);
 489 }