drivers/staging/octeon/ethernet-rx.c

   1 /*
   2  * This file is based on code from OCTEON SDK by Cavium Networks.
   3  *
   4  * Copyright (c) 2003-2010 Cavium Networks
   5  *
   6  * This file is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, Version 2, as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/cache.h>
  14 #include <linux/cpumask.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/ip.h>
  18 #include <linux/string.h>
  19 #include <linux/prefetch.h>
  20 #include <linux/ratelimit.h>
  21 #include <linux/smp.h>
  22 #include <linux/interrupt.h>
  23 #include <net/dst.h>
  24 #ifdef CONFIG_XFRM
  25 #include <linux/xfrm.h>
  26 #include <net/xfrm.h>
  27 #endif /* CONFIG_XFRM */
  28
  29 #include <asm/octeon/octeon.h>
  30
  31 #include "ethernet-defines.h"
  32 #include "ethernet-mem.h"
  33 #include "ethernet-rx.h"
  34 #include "octeon-ethernet.h"
  35 #include "ethernet-util.h"
  36
  37 #include <asm/octeon/cvmx-helper.h>
  38 #include <asm/octeon/cvmx-wqe.h>
  39 #include <asm/octeon/cvmx-fau.h>
  40 #include <asm/octeon/cvmx-pow.h>
  41 #include <asm/octeon/cvmx-pip.h>
  42 #include <asm/octeon/cvmx-scratch.h>
  43
  44 #include <asm/octeon/cvmx-gmxx-defs.h>
  45
  46 static atomic_t oct_rx_ready = ATOMIC_INIT(0);
  47
  48 static struct oct_rx_group {
  49         int irq;
  50         int group;
  51         struct napi_struct napi;
  52 } oct_rx_group[16];
  53
  54 /**
  55  * cvm_oct_do_interrupt - interrupt handler.
  56  * @irq: Interrupt number.
  57  * @napi_id: Cookie to identify the NAPI instance.
  58  *
  59  * The interrupt occurs whenever the POW has packets in our group.
  60  *
  61  */
  62 static irqreturn_t cvm_oct_do_interrupt(int irq, void *napi_id)
  63 {
  64         /* Disable the IRQ and start napi_poll. */
  65         disable_irq_nosync(irq);
  66         napi_schedule(napi_id);
  67
  68         return IRQ_HANDLED;
  69 }
  70
  71 /**
  72  * cvm_oct_check_rcv_error - process receive errors
  73  * @work: Work queue entry pointing to the packet.
  74  *
  75  * Returns Non-zero if the packet can be dropped, zero otherwise.
  76  */
  77 static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
  78 {
  79         int port;
  80
  81         if (octeon_has_feature(OCTEON_FEATURE_PKND))
  82                 port = work->word0.pip.cn68xx.pknd;
  83         else
  84                 port = work->word1.cn38xx.ipprt;
  85
  86         if ((work->word2.snoip.err_code == 10) && (work->word1.len <= 64))
  87                 /*
  88                  * Ignore length errors on min size packets. Some
  89                  * equipment incorrectly pads packets to 64+4FCS
  90                  * instead of 60+4FCS.  Note these packets still get
  91                  * counted as frame errors.
  92                  */
  93                 return 0;
  94
  95         if (work->word2.snoip.err_code == 5 ||
  96             work->word2.snoip.err_code == 7) {
  97                 /*
  98                  * We received a packet with either an alignment error
  99                  * or a FCS error. This may be signalling that we are
 100                  * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
 101                  * off. If this is the case we need to parse the
 102                  * packet to determine if we can remove a non spec
 103                  * preamble and generate a correct packet.
 104                  */
 105                 int interface = cvmx_helper_get_interface_num(port);
 106                 int index = cvmx_helper_get_interface_index_num(port);
 107                 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
 108
 109                 gmxx_rxx_frm_ctl.u64 =
 110                     cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
 111                 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
 112                         u8 *ptr =
 113                             cvmx_phys_to_ptr(work->packet_ptr.s.addr);
 114                         int i = 0;
 115
 116                         while (i < work->word1.len - 1) {
 117                                 if (*ptr != 0x55)
 118                                         break;
 119                                 ptr++;
 120                                 i++;
 121                         }
 122
 123                         if (*ptr == 0xd5) {
 124                                 /* Port received 0xd5 preamble */
 125                                 work->packet_ptr.s.addr += i + 1;
 126                                 work->word1.len -= i + 5;
 127                                 return 0;
 128                         }
 129
 130                         if ((*ptr & 0xf) == 0xd) {
 131                                 /* Port received 0xd preamble */
 132                                 work->packet_ptr.s.addr += i;
 133                                 work->word1.len -= i + 4;
 134                                 for (i = 0; i < work->word1.len; i++) {
 135                                         *ptr =
 136                                             ((*ptr & 0xf0) >> 4) |
 137                                             ((*(ptr + 1) & 0xf) << 4);
 138                                         ptr++;
 139                                 }
 140                                 return 0;
 141                         }
 142
 143                         printk_ratelimited("Port %d unknown preamble, packet dropped\n",
 144                                            port);
 145                         cvm_oct_free_work(work);
 146                         return 1;
 147                 }
 148         }
 149
 150         printk_ratelimited("Port %d receive error code %d, packet dropped\n",
 151                            port, work->word2.snoip.err_code);
 152         cvm_oct_free_work(work);
 153         return 1;
 154 }
 155
 156 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
 157 {
 158         const int       coreid = cvmx_get_core_num();
 159         u64     old_group_mask;
 160         u64     old_scratch;
 161         int             rx_count = 0;
 162         int             did_work_request = 0;
 163         int             packet_not_copied;
 164
 165         /* Prefetch cvm_oct_device since we know we need it soon */
 166         prefetch(cvm_oct_device);
 167
 168         if (USE_ASYNC_IOBDMA) {
 169                 /* Save scratch in case userspace is using it */
 170                 CVMX_SYNCIOBDMA;
 171                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 172         }
 173
 174         /* Only allow work for our group (and preserve priorities) */
 175         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 176                 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
 177                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
 178                                BIT(rx_group->group));
 179                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 180         } else {
 181                 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 182                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 183                                (old_group_mask & ~0xFFFFull) |
 184                                BIT(rx_group->group));
 185         }
 186
 187         if (USE_ASYNC_IOBDMA) {
 188                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 189                 did_work_request = 1;
 190         }
 191
 192         while (rx_count < budget) {
 193                 struct sk_buff *skb = NULL;
 194                 struct sk_buff **pskb = NULL;
 195                 int skb_in_hw;
 196                 cvmx_wqe_t *work;
 197                 int port;
 198
 199                 if (USE_ASYNC_IOBDMA && did_work_request)
 200                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 201                 else
 202                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 203
 204                 prefetch(work);
 205                 did_work_request = 0;
 206                 if (!work) {
 207                         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 208                                 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
 209                                                BIT(rx_group->group));
 210                                 cvmx_write_csr(CVMX_SSO_WQ_INT,
 211                                                BIT(rx_group->group));
 212                         } else {
 213                                 union cvmx_pow_wq_int wq_int;
 214
 215                                 wq_int.u64 = 0;
 216                                 wq_int.s.iq_dis = BIT(rx_group->group);
 217                                 wq_int.s.wq_int = BIT(rx_group->group);
 218                                 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 219                         }
 220                         break;
 221                 }
 222                 pskb = (struct sk_buff **)
 223                         (cvm_oct_get_buffer_ptr(work->packet_ptr) -
 224                         sizeof(void *));
 225                 prefetch(pskb);
 226
 227                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 228                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 229                                                             CVMX_POW_NO_WAIT);
 230                         did_work_request = 1;
 231                 }
 232                 rx_count++;
 233
 234                 skb_in_hw = work->word2.s.bufs == 1;
 235                 if (likely(skb_in_hw)) {
 236                         skb = *pskb;
 237                         prefetch(&skb->head);
 238                         prefetch(&skb->len);
 239                 }
 240
 241                 if (octeon_has_feature(OCTEON_FEATURE_PKND))
 242                         port = work->word0.pip.cn68xx.pknd;
 243                 else
 244                         port = work->word1.cn38xx.ipprt;
 245
 246                 prefetch(cvm_oct_device[port]);
 247
 248                 /* Immediately throw away all packets with receive errors */
 249                 if (unlikely(work->word2.snoip.rcv_error)) {
 250                         if (cvm_oct_check_rcv_error(work))
 251                                 continue;
 252                 }
 253
 254                 /*
 255                  * We can only use the zero copy path if skbuffs are
 256                  * in the FPA pool and the packet fits in a single
 257                  * buffer.
 258                  */
 259                 if (likely(skb_in_hw)) {
 260                         skb->data = skb->head + work->packet_ptr.s.addr -
 261                                 cvmx_ptr_to_phys(skb->head);
 262                         prefetch(skb->data);
 263                         skb->len = work->word1.len;
 264                         skb_set_tail_pointer(skb, skb->len);
 265                         packet_not_copied = 1;
 266                 } else {
 267                         /*
 268                          * We have to copy the packet. First allocate
 269                          * an skbuff for it.
 270                          */
 271                         skb = dev_alloc_skb(work->word1.len);
 272                         if (!skb) {
 273                                 cvm_oct_free_work(work);
 274                                 continue;
 275                         }
 276
 277                         /*
 278                          * Check if we've received a packet that was
 279                          * entirely stored in the work entry.
 280                          */
 281                         if (unlikely(work->word2.s.bufs == 0)) {
 282                                 u8 *ptr = work->packet_data;
 283
 284                                 if (likely(!work->word2.s.not_IP)) {
 285                                         /*
 286                                          * The beginning of the packet
 287                                          * moves for IP packets.
 288                                          */
 289                                         if (work->word2.s.is_v6)
 290                                                 ptr += 2;
 291                                         else
 292                                                 ptr += 6;
 293                                 }
 294                                 memcpy(skb_put(skb, work->word1.len), ptr,
 295                                        work->word1.len);
 296                                 /* No packet buffers to free */
 297                         } else {
 298                                 int segments = work->word2.s.bufs;
 299                                 union cvmx_buf_ptr segment_ptr =
 300                                     work->packet_ptr;
 301                                 int len = work->word1.len;
 302
 303                                 while (segments--) {
 304                                         union cvmx_buf_ptr next_ptr =
 305                                             *(union cvmx_buf_ptr *)
 306                                               cvmx_phys_to_ptr(
 307                                               segment_ptr.s.addr - 8);
 308
 309                         /*
 310                          * Octeon Errata PKI-100: The segment size is
 311                          * wrong. Until it is fixed, calculate the
 312                          * segment size based on the packet pool
 313                          * buffer size. When it is fixed, the
 314                          * following line should be replaced with this
 315                          * one: int segment_size =
 316                          * segment_ptr.s.size;
 317                          */
 318                                         int segment_size =
 319                                             CVMX_FPA_PACKET_POOL_SIZE -
 320                                             (segment_ptr.s.addr -
 321                                              (((segment_ptr.s.addr >> 7) -
 322                                                segment_ptr.s.back) << 7));
 323                                         /*
 324                                          * Don't copy more than what
 325                                          * is left in the packet.
 326                                          */
 327                                         if (segment_size > len)
 328                                                 segment_size = len;
 329                                         /* Copy the data into the packet */
 330                                         memcpy(skb_put(skb, segment_size),
 331                                                cvmx_phys_to_ptr(
 332                                                segment_ptr.s.addr),
 333                                                segment_size);
 334                                         len -= segment_size;
 335                                         segment_ptr = next_ptr;
 336                                 }
 337                         }
 338                         packet_not_copied = 0;
 339                 }
 340                 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
 341                            cvm_oct_device[port])) {
 342                         struct net_device *dev = cvm_oct_device[port];
 343                         struct octeon_ethernet *priv = netdev_priv(dev);
 344
 345                         /*
 346                          * Only accept packets for devices that are
 347                          * currently up.
 348                          */
 349                         if (likely(dev->flags & IFF_UP)) {
 350                                 skb->protocol = eth_type_trans(skb, dev);
 351                                 skb->dev = dev;
 352
 353                                 if (unlikely(work->word2.s.not_IP ||
 354                                              work->word2.s.IP_exc ||
 355                                              work->word2.s.L4_error ||
 356                                              !work->word2.s.tcp_or_udp))
 357                                         skb->ip_summed = CHECKSUM_NONE;
 358                                 else
 359                                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 360
 361                                 /* Increment RX stats for virtual ports */
 362                                 if (port >= CVMX_PIP_NUM_INPUT_PORTS) {
 363                                         priv->stats.rx_packets++;
 364                                         priv->stats.rx_bytes += skb->len;
 365                                 }
 366                                 netif_receive_skb(skb);
 367                         } else {
 368                                 /*
 369                                  * Drop any packet received for a device that
 370                                  * isn't up.
 371                                  */
 372                                 priv->stats.rx_dropped++;
 373                                 dev_kfree_skb_irq(skb);
 374                         }
 375                 } else {
 376                         /*
 377                          * Drop any packet received for a device that
 378                          * doesn't exist.
 379                          */
 380                         printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
 381                                            port);
 382                         dev_kfree_skb_irq(skb);
 383                 }
 384                 /*
 385                  * Check to see if the skbuff and work share the same
 386                  * packet buffer.
 387                  */
 388                 if (likely(packet_not_copied)) {
 389                         /*
 390                          * This buffer needs to be replaced, increment
 391                          * the number of buffers we need to free by
 392                          * one.
 393                          */
 394                         cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
 395                                               1);
 396
 397                         cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, 1);
 398                 } else {
 399                         cvm_oct_free_work(work);
 400                 }
 401         }
 402         /* Restore the original POW group mask */
 403         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 404                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask);
 405                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 406         } else {
 407                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
 408         }
 409
 410         if (USE_ASYNC_IOBDMA) {
 411                 /* Restore the scratch area */
 412                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 413         }
 414         cvm_oct_rx_refill_pool(0);
 415
 416         return rx_count;
 417 }
 418
 419 /**
 420  * cvm_oct_napi_poll - the NAPI poll function.
 421  * @napi: The NAPI instance.
 422  * @budget: Maximum number of packets to receive.
 423  *
 424  * Returns the number of packets processed.
 425  */
 426 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
 427 {
 428         struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group,
 429                                                      napi);
 430         int rx_count;
 431
 432         rx_count = cvm_oct_poll(rx_group, budget);
 433
 434         if (rx_count < budget) {
 435                 /* No more work */
 436                 napi_complete(napi);
 437                 enable_irq(rx_group->irq);
 438         }
 439         return rx_count;
 440 }
 441
 442 #ifdef CONFIG_NET_POLL_CONTROLLER
 443 /**
 444  * cvm_oct_poll_controller - poll for receive packets
 445  * device.
 446  *
 447  * @dev:    Device to poll. Unused
 448  */
 449 void cvm_oct_poll_controller(struct net_device *dev)
 450 {
 451         int i;
 452
 453         if (!atomic_read(&oct_rx_ready))
 454                 return;
 455
 456         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 457                 if (!(pow_receive_groups & BIT(i)))
 458                         continue;
 459
 460                 cvm_oct_poll(&oct_rx_group[i], 16);
 461         }
 462 }
 463 #endif
 464
 465 void cvm_oct_rx_initialize(void)
 466 {
 467         int i;
 468         struct net_device *dev_for_napi = NULL;
 469
 470         for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
 471                 if (cvm_oct_device[i]) {
 472                         dev_for_napi = cvm_oct_device[i];
 473                         break;
 474                 }
 475         }
 476
 477         if (!dev_for_napi)
 478                 panic("No net_devices were allocated.");
 479
 480         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 481                 int ret;
 482
 483                 if (!(pow_receive_groups & BIT(i)))
 484                         continue;
 485
 486                 netif_napi_add(dev_for_napi, &oct_rx_group[i].napi,
 487                                cvm_oct_napi_poll, rx_napi_weight);
 488                 napi_enable(&oct_rx_group[i].napi);
 489
 490                 oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i;
 491                 oct_rx_group[i].group = i;
 492
 493                 /* Register an IRQ handler to receive POW interrupts */
 494                 ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0,
 495                                   "Ethernet", &oct_rx_group[i].napi);
 496                 if (ret)
 497                         panic("Could not acquire Ethernet IRQ %d\n",
 498                               oct_rx_group[i].irq);
 499
 500                 disable_irq_nosync(oct_rx_group[i].irq);
 501
 502                 /* Enable POW interrupt when our port has at least one packet */
 503                 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 504                         union cvmx_sso_wq_int_thrx int_thr;
 505                         union cvmx_pow_wq_int_pc int_pc;
 506
 507                         int_thr.u64 = 0;
 508                         int_thr.s.tc_en = 1;
 509                         int_thr.s.tc_thr = 1;
 510                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64);
 511
 512                         int_pc.u64 = 0;
 513                         int_pc.s.pc_thr = 5;
 514                         cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64);
 515                 } else {
 516                         union cvmx_pow_wq_int_thrx int_thr;
 517                         union cvmx_pow_wq_int_pc int_pc;
 518
 519                         int_thr.u64 = 0;
 520                         int_thr.s.tc_en = 1;
 521                         int_thr.s.tc_thr = 1;
 522                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64);
 523
 524                         int_pc.u64 = 0;
 525                         int_pc.s.pc_thr = 5;
 526                         cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
 527                 }
 528
 529                 /* Schedule NAPI now. This will indirectly enable the
 530                  * interrupt.
 531                  */
 532                 napi_schedule(&oct_rx_group[i].napi);
 533         }
 534         atomic_inc(&oct_rx_ready);
 535 }
 536
 537 void cvm_oct_rx_shutdown(void)
 538 {
 539         int i;
 540
 541         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 542                 if (!(pow_receive_groups & BIT(i)))
 543                         continue;
 544
 545                 /* Disable POW interrupt */
 546                 if (OCTEON_IS_MODEL(OCTEON_CN68XX))
 547                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0);
 548                 else
 549                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
 550
 551                 /* Free the interrupt handler */
 552                 free_irq(oct_rx_group[i].irq, cvm_oct_device);
 553
 554                 netif_napi_del(&oct_rx_group[i].napi);
 555         }
 556 }