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 void copy_segments_to_skb(cvmx_wqe_t *work, struct sk_buff *skb)
 153 {
 154         int segments = work->word2.s.bufs;
 155         union cvmx_buf_ptr segment_ptr = work->packet_ptr;
 156         int len = work->word1.len;
 157         int segment_size;
 158
 159         while (segments--) {
 160                 union cvmx_buf_ptr next_ptr;
 161
 162                 next_ptr = *(union cvmx_buf_ptr *)
 163                         cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
 164
 165                 /*
 166                  * Octeon Errata PKI-100: The segment size is wrong.
 167                  *
 168                  * Until it is fixed, calculate the segment size based on
 169                  * the packet pool buffer size.
 170                  * When it is fixed, the following line should be replaced
 171                  * with this one:
 172                  * int segment_size = segment_ptr.s.size;
 173                  */
 174                 segment_size =
 175                         CVMX_FPA_PACKET_POOL_SIZE -
 176                         (segment_ptr.s.addr -
 177                          (((segment_ptr.s.addr >> 7) -
 178                            segment_ptr.s.back) << 7));
 179
 180                 /* Don't copy more than what is left in the packet */
 181                 if (segment_size > len)
 182                         segment_size = len;
 183
 184                 /* Copy the data into the packet */
 185                 skb_put_data(skb, cvmx_phys_to_ptr(segment_ptr.s.addr),
 186                              segment_size);
 187                 len -= segment_size;
 188                 segment_ptr = next_ptr;
 189         }
 190 }
 191
 192 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
 193 {
 194         const int       coreid = cvmx_get_core_num();
 195         u64     old_group_mask;
 196         u64     old_scratch;
 197         int             rx_count = 0;
 198         int             did_work_request = 0;
 199         int             packet_not_copied;
 200
 201         /* Prefetch cvm_oct_device since we know we need it soon */
 202         prefetch(cvm_oct_device);
 203
 204         if (USE_ASYNC_IOBDMA) {
 205                 /* Save scratch in case userspace is using it */
 206                 CVMX_SYNCIOBDMA;
 207                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 208         }
 209
 210         /* Only allow work for our group (and preserve priorities) */
 211         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 212                 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
 213                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
 214                                BIT(rx_group->group));
 215                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 216         } else {
 217                 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 218                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 219                                (old_group_mask & ~0xFFFFull) |
 220                                BIT(rx_group->group));
 221         }
 222
 223         if (USE_ASYNC_IOBDMA) {
 224                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 225                 did_work_request = 1;
 226         }
 227
 228         while (rx_count < budget) {
 229                 struct sk_buff *skb = NULL;
 230                 struct sk_buff **pskb = NULL;
 231                 int skb_in_hw;
 232                 cvmx_wqe_t *work;
 233                 int port;
 234
 235                 if (USE_ASYNC_IOBDMA && did_work_request)
 236                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 237                 else
 238                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 239
 240                 prefetch(work);
 241                 did_work_request = 0;
 242                 if (!work) {
 243                         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 244                                 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
 245                                                BIT(rx_group->group));
 246                                 cvmx_write_csr(CVMX_SSO_WQ_INT,
 247                                                BIT(rx_group->group));
 248                         } else {
 249                                 union cvmx_pow_wq_int wq_int;
 250
 251                                 wq_int.u64 = 0;
 252                                 wq_int.s.iq_dis = BIT(rx_group->group);
 253                                 wq_int.s.wq_int = BIT(rx_group->group);
 254                                 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 255                         }
 256                         break;
 257                 }
 258                 pskb = (struct sk_buff **)
 259                         (cvm_oct_get_buffer_ptr(work->packet_ptr) -
 260                         sizeof(void *));
 261                 prefetch(pskb);
 262
 263                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 264                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 265                                                             CVMX_POW_NO_WAIT);
 266                         did_work_request = 1;
 267                 }
 268                 rx_count++;
 269
 270                 skb_in_hw = work->word2.s.bufs == 1;
 271                 if (likely(skb_in_hw)) {
 272                         skb = *pskb;
 273                         prefetch(&skb->head);
 274                         prefetch(&skb->len);
 275                 }
 276
 277                 if (octeon_has_feature(OCTEON_FEATURE_PKND))
 278                         port = work->word0.pip.cn68xx.pknd;
 279                 else
 280                         port = work->word1.cn38xx.ipprt;
 281
 282                 prefetch(cvm_oct_device[port]);
 283
 284                 /* Immediately throw away all packets with receive errors */
 285                 if (unlikely(work->word2.snoip.rcv_error)) {
 286                         if (cvm_oct_check_rcv_error(work))
 287                                 continue;
 288                 }
 289
 290                 /*
 291                  * We can only use the zero copy path if skbuffs are
 292                  * in the FPA pool and the packet fits in a single
 293                  * buffer.
 294                  */
 295                 if (likely(skb_in_hw)) {
 296                         skb->data = skb->head + work->packet_ptr.s.addr -
 297                                 cvmx_ptr_to_phys(skb->head);
 298                         prefetch(skb->data);
 299                         skb->len = work->word1.len;
 300                         skb_set_tail_pointer(skb, skb->len);
 301                         packet_not_copied = 1;
 302                 } else {
 303                         /*
 304                          * We have to copy the packet. First allocate
 305                          * an skbuff for it.
 306                          */
 307                         skb = dev_alloc_skb(work->word1.len);
 308                         if (!skb) {
 309                                 cvm_oct_free_work(work);
 310                                 continue;
 311                         }
 312
 313                         /*
 314                          * Check if we've received a packet that was
 315                          * entirely stored in the work entry.
 316                          */
 317                         if (unlikely(work->word2.s.bufs == 0)) {
 318                                 u8 *ptr = work->packet_data;
 319
 320                                 if (likely(!work->word2.s.not_IP)) {
 321                                         /*
 322                                          * The beginning of the packet
 323                                          * moves for IP packets.
 324                                          */
 325                                         if (work->word2.s.is_v6)
 326                                                 ptr += 2;
 327                                         else
 328                                                 ptr += 6;
 329                                 }
 330                                 skb_put_data(skb, ptr, work->word1.len);
 331                                 /* No packet buffers to free */
 332                         } else {
 333                                 copy_segments_to_skb(work, skb);
 334                         }
 335                         packet_not_copied = 0;
 336                 }
 337                 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
 338                            cvm_oct_device[port])) {
 339                         struct net_device *dev = cvm_oct_device[port];
 340
 341                         /*
 342                          * Only accept packets for devices that are
 343                          * currently up.
 344                          */
 345                         if (likely(dev->flags & IFF_UP)) {
 346                                 skb->protocol = eth_type_trans(skb, dev);
 347                                 skb->dev = dev;
 348
 349                                 if (unlikely(work->word2.s.not_IP ||
 350                                              work->word2.s.IP_exc ||
 351                                              work->word2.s.L4_error ||
 352                                              !work->word2.s.tcp_or_udp))
 353                                         skb->ip_summed = CHECKSUM_NONE;
 354                                 else
 355                                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 356
 357                                 /* Increment RX stats for virtual ports */
 358                                 if (port >= CVMX_PIP_NUM_INPUT_PORTS) {
 359                                         dev->stats.rx_packets++;
 360                                         dev->stats.rx_bytes += skb->len;
 361                                 }
 362                                 netif_receive_skb(skb);
 363                         } else {
 364                                 /*
 365                                  * Drop any packet received for a device that
 366                                  * isn't up.
 367                                  */
 368                                 dev->stats.rx_dropped++;
 369                                 dev_kfree_skb_irq(skb);
 370                         }
 371                 } else {
 372                         /*
 373                          * Drop any packet received for a device that
 374                          * doesn't exist.
 375                          */
 376                         printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
 377                                            port);
 378                         dev_kfree_skb_irq(skb);
 379                 }
 380                 /*
 381                  * Check to see if the skbuff and work share the same
 382                  * packet buffer.
 383                  */
 384                 if (likely(packet_not_copied)) {
 385                         /*
 386                          * This buffer needs to be replaced, increment
 387                          * the number of buffers we need to free by
 388                          * one.
 389                          */
 390                         cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
 391                                               1);
 392
 393                         cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, 1);
 394                 } else {
 395                         cvm_oct_free_work(work);
 396                 }
 397         }
 398         /* Restore the original POW group mask */
 399         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 400                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask);
 401                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 402         } else {
 403                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
 404         }
 405
 406         if (USE_ASYNC_IOBDMA) {
 407                 /* Restore the scratch area */
 408                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 409         }
 410         cvm_oct_rx_refill_pool(0);
 411
 412         return rx_count;
 413 }
 414
 415 /**
 416  * cvm_oct_napi_poll - the NAPI poll function.
 417  * @napi: The NAPI instance.
 418  * @budget: Maximum number of packets to receive.
 419  *
 420  * Returns the number of packets processed.
 421  */
 422 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
 423 {
 424         struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group,
 425                                                      napi);
 426         int rx_count;
 427
 428         rx_count = cvm_oct_poll(rx_group, budget);
 429
 430         if (rx_count < budget) {
 431                 /* No more work */
 432                 napi_complete_done(napi, rx_count);
 433                 enable_irq(rx_group->irq);
 434         }
 435         return rx_count;
 436 }
 437
 438 #ifdef CONFIG_NET_POLL_CONTROLLER
 439 /**
 440  * cvm_oct_poll_controller - poll for receive packets
 441  * device.
 442  *
 443  * @dev:    Device to poll. Unused
 444  */
 445 void cvm_oct_poll_controller(struct net_device *dev)
 446 {
 447         int i;
 448
 449         if (!atomic_read(&oct_rx_ready))
 450                 return;
 451
 452         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 453                 if (!(pow_receive_groups & BIT(i)))
 454                         continue;
 455
 456                 cvm_oct_poll(&oct_rx_group[i], 16);
 457         }
 458 }
 459 #endif
 460
 461 void cvm_oct_rx_initialize(void)
 462 {
 463         int i;
 464         struct net_device *dev_for_napi = NULL;
 465
 466         for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
 467                 if (cvm_oct_device[i]) {
 468                         dev_for_napi = cvm_oct_device[i];
 469                         break;
 470                 }
 471         }
 472
 473         if (!dev_for_napi)
 474                 panic("No net_devices were allocated.");
 475
 476         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 477                 int ret;
 478
 479                 if (!(pow_receive_groups & BIT(i)))
 480                         continue;
 481
 482                 netif_napi_add(dev_for_napi, &oct_rx_group[i].napi,
 483                                cvm_oct_napi_poll, rx_napi_weight);
 484                 napi_enable(&oct_rx_group[i].napi);
 485
 486                 oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i;
 487                 oct_rx_group[i].group = i;
 488
 489                 /* Register an IRQ handler to receive POW interrupts */
 490                 ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0,
 491                                   "Ethernet", &oct_rx_group[i].napi);
 492                 if (ret)
 493                         panic("Could not acquire Ethernet IRQ %d\n",
 494                               oct_rx_group[i].irq);
 495
 496                 disable_irq_nosync(oct_rx_group[i].irq);
 497
 498                 /* Enable POW interrupt when our port has at least one packet */
 499                 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 500                         union cvmx_sso_wq_int_thrx int_thr;
 501                         union cvmx_pow_wq_int_pc int_pc;
 502
 503                         int_thr.u64 = 0;
 504                         int_thr.s.tc_en = 1;
 505                         int_thr.s.tc_thr = 1;
 506                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64);
 507
 508                         int_pc.u64 = 0;
 509                         int_pc.s.pc_thr = 5;
 510                         cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64);
 511                 } else {
 512                         union cvmx_pow_wq_int_thrx int_thr;
 513                         union cvmx_pow_wq_int_pc int_pc;
 514
 515                         int_thr.u64 = 0;
 516                         int_thr.s.tc_en = 1;
 517                         int_thr.s.tc_thr = 1;
 518                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64);
 519
 520                         int_pc.u64 = 0;
 521                         int_pc.s.pc_thr = 5;
 522                         cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
 523                 }
 524
 525                 /* Schedule NAPI now. This will indirectly enable the
 526                  * interrupt.
 527                  */
 528                 napi_schedule(&oct_rx_group[i].napi);
 529         }
 530         atomic_inc(&oct_rx_ready);
 531 }
 532
 533 void cvm_oct_rx_shutdown(void)
 534 {
 535         int i;
 536
 537         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 538                 if (!(pow_receive_groups & BIT(i)))
 539                         continue;
 540
 541                 /* Disable POW interrupt */
 542                 if (OCTEON_IS_MODEL(OCTEON_CN68XX))
 543                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0);
 544                 else
 545                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
 546
 547                 /* Free the interrupt handler */
 548                 free_irq(oct_rx_group[i].irq, cvm_oct_device);
 549
 550                 netif_napi_del(&oct_rx_group[i].napi);
 551         }
 552 }