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 void copy_segments_to_skb(cvmx_wqe_t *work, struct sk_buff *skb)
 157 {
 158         int segments = work->word2.s.bufs;
 159         union cvmx_buf_ptr segment_ptr = work->packet_ptr;
 160         int len = work->word1.len;
 161         int segment_size;
 162
 163         while (segments--) {
 164                 union cvmx_buf_ptr next_ptr;
 165
 166                 next_ptr = *(union cvmx_buf_ptr *)
 167                         cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
 168
 169                 /*
 170                  * Octeon Errata PKI-100: The segment size is wrong.
 171                  *
 172                  * Until it is fixed, calculate the segment size based on
 173                  * the packet pool buffer size.
 174                  * When it is fixed, the following line should be replaced
 175                  * with this one:
 176                  * int segment_size = segment_ptr.s.size;
 177                  */
 178                 segment_size =
 179                         CVMX_FPA_PACKET_POOL_SIZE -
 180                         (segment_ptr.s.addr -
 181                          (((segment_ptr.s.addr >> 7) -
 182                            segment_ptr.s.back) << 7));
 183
 184                 /* Don't copy more than what is left in the packet */
 185                 if (segment_size > len)
 186                         segment_size = len;
 187
 188                 /* Copy the data into the packet */
 189                 skb_put_data(skb, cvmx_phys_to_ptr(segment_ptr.s.addr),
 190                              segment_size);
 191                 len -= segment_size;
 192                 segment_ptr = next_ptr;
 193         }
 194 }
 195
 196 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
 197 {
 198         const int       coreid = cvmx_get_core_num();
 199         u64     old_group_mask;
 200         u64     old_scratch;
 201         int             rx_count = 0;
 202         int             did_work_request = 0;
 203         int             packet_not_copied;
 204
 205         /* Prefetch cvm_oct_device since we know we need it soon */
 206         prefetch(cvm_oct_device);
 207
 208         if (USE_ASYNC_IOBDMA) {
 209                 /* Save scratch in case userspace is using it */
 210                 CVMX_SYNCIOBDMA;
 211                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 212         }
 213
 214         /* Only allow work for our group (and preserve priorities) */
 215         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 216                 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
 217                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
 218                                BIT(rx_group->group));
 219                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 220         } else {
 221                 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 222                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 223                                (old_group_mask & ~0xFFFFull) |
 224                                BIT(rx_group->group));
 225         }
 226
 227         if (USE_ASYNC_IOBDMA) {
 228                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 229                 did_work_request = 1;
 230         }
 231
 232         while (rx_count < budget) {
 233                 struct sk_buff *skb = NULL;
 234                 struct sk_buff **pskb = NULL;
 235                 int skb_in_hw;
 236                 cvmx_wqe_t *work;
 237                 int port;
 238
 239                 if (USE_ASYNC_IOBDMA && did_work_request)
 240                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 241                 else
 242                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 243
 244                 prefetch(work);
 245                 did_work_request = 0;
 246                 if (!work) {
 247                         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 248                                 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
 249                                                BIT(rx_group->group));
 250                                 cvmx_write_csr(CVMX_SSO_WQ_INT,
 251                                                BIT(rx_group->group));
 252                         } else {
 253                                 union cvmx_pow_wq_int wq_int;
 254
 255                                 wq_int.u64 = 0;
 256                                 wq_int.s.iq_dis = BIT(rx_group->group);
 257                                 wq_int.s.wq_int = BIT(rx_group->group);
 258                                 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 259                         }
 260                         break;
 261                 }
 262                 pskb = (struct sk_buff **)
 263                         (cvm_oct_get_buffer_ptr(work->packet_ptr) -
 264                         sizeof(void *));
 265                 prefetch(pskb);
 266
 267                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 268                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 269                                                             CVMX_POW_NO_WAIT);
 270                         did_work_request = 1;
 271                 }
 272                 rx_count++;
 273
 274                 skb_in_hw = work->word2.s.bufs == 1;
 275                 if (likely(skb_in_hw)) {
 276                         skb = *pskb;
 277                         prefetch(&skb->head);
 278                         prefetch(&skb->len);
 279                 }
 280
 281                 if (octeon_has_feature(OCTEON_FEATURE_PKND))
 282                         port = work->word0.pip.cn68xx.pknd;
 283                 else
 284                         port = work->word1.cn38xx.ipprt;
 285
 286                 prefetch(cvm_oct_device[port]);
 287
 288                 /* Immediately throw away all packets with receive errors */
 289                 if (unlikely(work->word2.snoip.rcv_error)) {
 290                         if (cvm_oct_check_rcv_error(work))
 291                                 continue;
 292                 }
 293
 294                 /*
 295                  * We can only use the zero copy path if skbuffs are
 296                  * in the FPA pool and the packet fits in a single
 297                  * buffer.
 298                  */
 299                 if (likely(skb_in_hw)) {
 300                         skb->data = skb->head + work->packet_ptr.s.addr -
 301                                 cvmx_ptr_to_phys(skb->head);
 302                         prefetch(skb->data);
 303                         skb->len = work->word1.len;
 304                         skb_set_tail_pointer(skb, skb->len);
 305                         packet_not_copied = 1;
 306                 } else {
 307                         /*
 308                          * We have to copy the packet. First allocate
 309                          * an skbuff for it.
 310                          */
 311                         skb = dev_alloc_skb(work->word1.len);
 312                         if (!skb) {
 313                                 cvm_oct_free_work(work);
 314                                 continue;
 315                         }
 316
 317                         /*
 318                          * Check if we've received a packet that was
 319                          * entirely stored in the work entry.
 320                          */
 321                         if (unlikely(work->word2.s.bufs == 0)) {
 322                                 u8 *ptr = work->packet_data;
 323
 324                                 if (likely(!work->word2.s.not_IP)) {
 325                                         /*
 326                                          * The beginning of the packet
 327                                          * moves for IP packets.
 328                                          */
 329                                         if (work->word2.s.is_v6)
 330                                                 ptr += 2;
 331                                         else
 332                                                 ptr += 6;
 333                                 }
 334                                 skb_put_data(skb, ptr, work->word1.len);
 335                                 /* No packet buffers to free */
 336                         } else {
 337                                 copy_segments_to_skb(work, skb);
 338                         }
 339                         packet_not_copied = 0;
 340                 }
 341                 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
 342                            cvm_oct_device[port])) {
 343                         struct net_device *dev = cvm_oct_device[port];
 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                                         dev->stats.rx_packets++;
 364                                         dev->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                                 dev->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_done(napi, rx_count);
 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 }