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         } else if (work->word2.snoip.err_code == 5 ||
  94                    work->word2.snoip.err_code == 7) {
  95                 /*
  96                  * We received a packet with either an alignment error
  97                  * or a FCS error. This may be signalling that we are
  98                  * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
  99                  * off. If this is the case we need to parse the
 100                  * packet to determine if we can remove a non spec
 101                  * preamble and generate a correct packet.
 102                  */
 103                 int interface = cvmx_helper_get_interface_num(port);
 104                 int index = cvmx_helper_get_interface_index_num(port);
 105                 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
 106
 107                 gmxx_rxx_frm_ctl.u64 =
 108                     cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
 109                 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
 110                         u8 *ptr =
 111                             cvmx_phys_to_ptr(work->packet_ptr.s.addr);
 112                         int i = 0;
 113
 114                         while (i < work->word1.len - 1) {
 115                                 if (*ptr != 0x55)
 116                                         break;
 117                                 ptr++;
 118                                 i++;
 119                         }
 120
 121                         if (*ptr == 0xd5) {
 122                                 /* Port received 0xd5 preamble */
 123                                 work->packet_ptr.s.addr += i + 1;
 124                                 work->word1.len -= i + 5;
 125                         } else if ((*ptr & 0xf) == 0xd) {
 126                                 /* Port received 0xd preamble */
 127                                 work->packet_ptr.s.addr += i;
 128                                 work->word1.len -= i + 4;
 129                                 for (i = 0; i < work->word1.len; i++) {
 130                                         *ptr =
 131                                             ((*ptr & 0xf0) >> 4) |
 132                                             ((*(ptr + 1) & 0xf) << 4);
 133                                         ptr++;
 134                                 }
 135                         } else {
 136                                 printk_ratelimited("Port %d unknown preamble, packet dropped\n",
 137                                                    port);
 138                                 cvm_oct_free_work(work);
 139                                 return 1;
 140                         }
 141                 }
 142         } else {
 143                 printk_ratelimited("Port %d receive error code %d, packet dropped\n",
 144                                    port, work->word2.snoip.err_code);
 145                 cvm_oct_free_work(work);
 146                 return 1;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
 153 {
 154         const int       coreid = cvmx_get_core_num();
 155         u64     old_group_mask;
 156         u64     old_scratch;
 157         int             rx_count = 0;
 158         int             did_work_request = 0;
 159         int             packet_not_copied;
 160
 161         /* Prefetch cvm_oct_device since we know we need it soon */
 162         prefetch(cvm_oct_device);
 163
 164         if (USE_ASYNC_IOBDMA) {
 165                 /* Save scratch in case userspace is using it */
 166                 CVMX_SYNCIOBDMA;
 167                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 168         }
 169
 170         /* Only allow work for our group (and preserve priorities) */
 171         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 172                 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
 173                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
 174                                BIT(rx_group->group));
 175                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 176         } else {
 177                 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 178                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 179                                (old_group_mask & ~0xFFFFull) |
 180                                BIT(rx_group->group));
 181         }
 182
 183         if (USE_ASYNC_IOBDMA) {
 184                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 185                 did_work_request = 1;
 186         }
 187
 188         while (rx_count < budget) {
 189                 struct sk_buff *skb = NULL;
 190                 struct sk_buff **pskb = NULL;
 191                 int skb_in_hw;
 192                 cvmx_wqe_t *work;
 193                 int port;
 194
 195                 if (USE_ASYNC_IOBDMA && did_work_request)
 196                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 197                 else
 198                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 199
 200                 prefetch(work);
 201                 did_work_request = 0;
 202                 if (!work) {
 203                         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 204                                 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
 205                                                BIT(rx_group->group));
 206                                 cvmx_write_csr(CVMX_SSO_WQ_INT,
 207                                                BIT(rx_group->group));
 208                         } else {
 209                                 union cvmx_pow_wq_int wq_int;
 210
 211                                 wq_int.u64 = 0;
 212                                 wq_int.s.iq_dis = BIT(rx_group->group);
 213                                 wq_int.s.wq_int = BIT(rx_group->group);
 214                                 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 215                         }
 216                         break;
 217                 }
 218                 pskb = (struct sk_buff **)
 219                         (cvm_oct_get_buffer_ptr(work->packet_ptr) -
 220                         sizeof(void *));
 221                 prefetch(pskb);
 222
 223                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 224                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 225                                                             CVMX_POW_NO_WAIT);
 226                         did_work_request = 1;
 227                 }
 228                 rx_count++;
 229
 230                 skb_in_hw = work->word2.s.bufs == 1;
 231                 if (likely(skb_in_hw)) {
 232                         skb = *pskb;
 233                         prefetch(&skb->head);
 234                         prefetch(&skb->len);
 235                 }
 236
 237                 if (octeon_has_feature(OCTEON_FEATURE_PKND))
 238                         port = work->word0.pip.cn68xx.pknd;
 239                 else
 240                         port = work->word1.cn38xx.ipprt;
 241
 242                 prefetch(cvm_oct_device[port]);
 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->word1.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->word1.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                                 u8 *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->word1.len), ptr,
 291                                        work->word1.len);
 292                                 /* No packet buffers to free */
 293                         } else {
 294                                 int segments = work->word2.s.bufs;
 295                                 union cvmx_buf_ptr segment_ptr =
 296                                     work->packet_ptr;
 297                                 int len = work->word1.len;
 298
 299                                 while (segments--) {
 300                                         union cvmx_buf_ptr next_ptr =
 301                                             *(union cvmx_buf_ptr *)
 302                                               cvmx_phys_to_ptr(
 303                                               segment_ptr.s.addr - 8);
 304
 305                         /*
 306                          * Octeon Errata PKI-100: The segment size is
 307                          * wrong. Until it is fixed, calculate the
 308                          * segment size based on the packet pool
 309                          * buffer size. When it is fixed, the
 310                          * following line should be replaced with this
 311                          * one: int segment_size =
 312                          * segment_ptr.s.size;
 313                          */
 314                                         int segment_size =
 315                                             CVMX_FPA_PACKET_POOL_SIZE -
 316                                             (segment_ptr.s.addr -
 317                                              (((segment_ptr.s.addr >> 7) -
 318                                                segment_ptr.s.back) << 7));
 319                                         /*
 320                                          * Don't copy more than what
 321                                          * is left in the packet.
 322                                          */
 323                                         if (segment_size > len)
 324                                                 segment_size = len;
 325                                         /* Copy the data into the packet */
 326                                         memcpy(skb_put(skb, segment_size),
 327                                                cvmx_phys_to_ptr(
 328                                                segment_ptr.s.addr),
 329                                                segment_size);
 330                                         len -= segment_size;
 331                                         segment_ptr = next_ptr;
 332                                 }
 333                         }
 334                         packet_not_copied = 0;
 335                 }
 336                 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
 337                            cvm_oct_device[port])) {
 338                         struct net_device *dev = cvm_oct_device[port];
 339
 340                         /*
 341                          * Only accept packets for devices that are
 342                          * currently up.
 343                          */
 344                         if (likely(dev->flags & IFF_UP)) {
 345                                 skb->protocol = eth_type_trans(skb, dev);
 346                                 skb->dev = dev;
 347
 348                                 if (unlikely(work->word2.s.not_IP ||
 349                                              work->word2.s.IP_exc ||
 350                                              work->word2.s.L4_error ||
 351                                              !work->word2.s.tcp_or_udp))
 352                                         skb->ip_summed = CHECKSUM_NONE;
 353                                 else
 354                                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 355
 356                                 /* Increment RX stats for virtual ports */
 357                                 if (port >= CVMX_PIP_NUM_INPUT_PORTS) {
 358                                         dev->stats.rx_packets++;
 359                                         dev->stats.rx_bytes += skb->len;
 360                                 }
 361                                 netif_receive_skb(skb);
 362                         } else {
 363                                 /*
 364                                  * Drop any packet received for a device that
 365                                  * isn't up.
 366                                  */
 367                                 dev->stats.rx_dropped++;
 368                                 dev_kfree_skb_irq(skb);
 369                         }
 370                 } else {
 371                         /*
 372                          * Drop any packet received for a device that
 373                          * doesn't exist.
 374                          */
 375                         printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
 376                                            port);
 377                         dev_kfree_skb_irq(skb);
 378                 }
 379                 /*
 380                  * Check to see if the skbuff and work share the same
 381                  * packet buffer.
 382                  */
 383                 if (likely(packet_not_copied)) {
 384                         /*
 385                          * This buffer needs to be replaced, increment
 386                          * the number of buffers we need to free by
 387                          * one.
 388                          */
 389                         cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
 390                                               1);
 391
 392                         cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, 1);
 393                 } else {
 394                         cvm_oct_free_work(work);
 395                 }
 396         }
 397         /* Restore the original POW group mask */
 398         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 399                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask);
 400                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 401         } else {
 402                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
 403         }
 404
 405         if (USE_ASYNC_IOBDMA) {
 406                 /* Restore the scratch area */
 407                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 408         }
 409         cvm_oct_rx_refill_pool(0);
 410
 411         return rx_count;
 412 }
 413
 414 /**
 415  * cvm_oct_napi_poll - the NAPI poll function.
 416  * @napi: The NAPI instance.
 417  * @budget: Maximum number of packets to receive.
 418  *
 419  * Returns the number of packets processed.
 420  */
 421 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
 422 {
 423         struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group,
 424                                                      napi);
 425         int rx_count;
 426
 427         rx_count = cvm_oct_poll(rx_group, budget);
 428
 429         if (rx_count < budget) {
 430                 /* No more work */
 431                 napi_complete_done(napi, rx_count);
 432                 enable_irq(rx_group->irq);
 433         }
 434         return rx_count;
 435 }
 436
 437 #ifdef CONFIG_NET_POLL_CONTROLLER
 438 /**
 439  * cvm_oct_poll_controller - poll for receive packets
 440  * device.
 441  *
 442  * @dev:    Device to poll. Unused
 443  */
 444 void cvm_oct_poll_controller(struct net_device *dev)
 445 {
 446         int i;
 447
 448         if (!atomic_read(&oct_rx_ready))
 449                 return;
 450
 451         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 452                 if (!(pow_receive_groups & BIT(i)))
 453                         continue;
 454
 455                 cvm_oct_poll(&oct_rx_group[i], 16);
 456         }
 457 }
 458 #endif
 459
 460 void cvm_oct_rx_initialize(void)
 461 {
 462         int i;
 463         struct net_device *dev_for_napi = NULL;
 464
 465         for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
 466                 if (cvm_oct_device[i]) {
 467                         dev_for_napi = cvm_oct_device[i];
 468                         break;
 469                 }
 470         }
 471
 472         if (!dev_for_napi)
 473                 panic("No net_devices were allocated.");
 474
 475         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 476                 int ret;
 477
 478                 if (!(pow_receive_groups & BIT(i)))
 479                         continue;
 480
 481                 netif_napi_add(dev_for_napi, &oct_rx_group[i].napi,
 482                                cvm_oct_napi_poll, rx_napi_weight);
 483                 napi_enable(&oct_rx_group[i].napi);
 484
 485                 oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i;
 486                 oct_rx_group[i].group = i;
 487
 488                 /* Register an IRQ handler to receive POW interrupts */
 489                 ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0,
 490                                   "Ethernet", &oct_rx_group[i].napi);
 491                 if (ret)
 492                         panic("Could not acquire Ethernet IRQ %d\n",
 493                               oct_rx_group[i].irq);
 494
 495                 disable_irq_nosync(oct_rx_group[i].irq);
 496
 497                 /* Enable POW interrupt when our port has at least one packet */
 498                 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 499                         union cvmx_sso_wq_int_thrx int_thr;
 500                         union cvmx_pow_wq_int_pc int_pc;
 501
 502                         int_thr.u64 = 0;
 503                         int_thr.s.tc_en = 1;
 504                         int_thr.s.tc_thr = 1;
 505                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64);
 506
 507                         int_pc.u64 = 0;
 508                         int_pc.s.pc_thr = 5;
 509                         cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64);
 510                 } else {
 511                         union cvmx_pow_wq_int_thrx int_thr;
 512                         union cvmx_pow_wq_int_pc int_pc;
 513
 514                         int_thr.u64 = 0;
 515                         int_thr.s.tc_en = 1;
 516                         int_thr.s.tc_thr = 1;
 517                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64);
 518
 519                         int_pc.u64 = 0;
 520                         int_pc.s.pc_thr = 5;
 521                         cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
 522                 }
 523
 524                 /* Schedule NAPI now. This will indirectly enable the
 525                  * interrupt.
 526                  */
 527                 napi_schedule(&oct_rx_group[i].napi);
 528         }
 529         atomic_inc(&oct_rx_ready);
 530 }
 531
 532 void cvm_oct_rx_shutdown(void)
 533 {
 534         int i;
 535
 536         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 537                 if (!(pow_receive_groups & BIT(i)))
 538                         continue;
 539
 540                 /* Disable POW interrupt */
 541                 if (OCTEON_IS_MODEL(OCTEON_CN68XX))
 542                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0);
 543                 else
 544                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
 545
 546                 /* Free the interrupt handler */
 547                 free_irq(oct_rx_group[i].irq, cvm_oct_device);
 548
 549                 netif_napi_del(&oct_rx_group[i].napi);
 550         }
 551 }