drivers/staging/octeon/ethernet-rx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This file is based on code from OCTEON SDK by Cavium Networks.
   4  *
   5  * Copyright (c) 2003-2010 Cavium Networks
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/cache.h>
  11 #include <linux/cpumask.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/ip.h>
  15 #include <linux/string.h>
  16 #include <linux/prefetch.h>
  17 #include <linux/ratelimit.h>
  18 #include <linux/smp.h>
  19 #include <linux/interrupt.h>
  20 #include <net/dst.h>
  21 #ifdef CONFIG_XFRM
  22 #include <linux/xfrm.h>
  23 #include <net/xfrm.h>
  24 #endif /* CONFIG_XFRM */
  25
  26 #include <asm/octeon/octeon.h>
  27
  28 #include "ethernet-defines.h"
  29 #include "ethernet-mem.h"
  30 #include "ethernet-rx.h"
  31 #include "octeon-ethernet.h"
  32 #include "ethernet-util.h"
  33
  34 #include <asm/octeon/cvmx-helper.h>
  35 #include <asm/octeon/cvmx-wqe.h>
  36 #include <asm/octeon/cvmx-fau.h>
  37 #include <asm/octeon/cvmx-pow.h>
  38 #include <asm/octeon/cvmx-pip.h>
  39 #include <asm/octeon/cvmx-scratch.h>
  40
  41 #include <asm/octeon/cvmx-gmxx-defs.h>
  42
  43 static atomic_t oct_rx_ready = ATOMIC_INIT(0);
  44
  45 static struct oct_rx_group {
  46         int irq;
  47         int group;
  48         struct napi_struct napi;
  49 } oct_rx_group[16];
  50
  51 /**
  52  * cvm_oct_do_interrupt - interrupt handler.
  53  * @irq: Interrupt number.
  54  * @napi_id: Cookie to identify the NAPI instance.
  55  *
  56  * The interrupt occurs whenever the POW has packets in our group.
  57  *
  58  */
  59 static irqreturn_t cvm_oct_do_interrupt(int irq, void *napi_id)
  60 {
  61         /* Disable the IRQ and start napi_poll. */
  62         disable_irq_nosync(irq);
  63         napi_schedule(napi_id);
  64
  65         return IRQ_HANDLED;
  66 }
  67
  68 /**
  69  * cvm_oct_check_rcv_error - process receive errors
  70  * @work: Work queue entry pointing to the packet.
  71  *
  72  * Returns Non-zero if the packet can be dropped, zero otherwise.
  73  */
  74 static inline int cvm_oct_check_rcv_error(cvmx_wqe_t *work)
  75 {
  76         int port;
  77
  78         if (octeon_has_feature(OCTEON_FEATURE_PKND))
  79                 port = work->word0.pip.cn68xx.pknd;
  80         else
  81                 port = work->word1.cn38xx.ipprt;
  82
  83         if ((work->word2.snoip.err_code == 10) && (work->word1.len <= 64))
  84                 /*
  85                  * Ignore length errors on min size packets. Some
  86                  * equipment incorrectly pads packets to 64+4FCS
  87                  * instead of 60+4FCS.  Note these packets still get
  88                  * counted as frame errors.
  89                  */
  90                 return 0;
  91
  92         if (work->word2.snoip.err_code == 5 ||
  93             work->word2.snoip.err_code == 7) {
  94                 /*
  95                  * We received a packet with either an alignment error
  96                  * or a FCS error. This may be signalling that we are
  97                  * running 10Mbps with GMXX_RXX_FRM_CTL[PRE_CHK]
  98                  * off. If this is the case we need to parse the
  99                  * packet to determine if we can remove a non spec
 100                  * preamble and generate a correct packet.
 101                  */
 102                 int interface = cvmx_helper_get_interface_num(port);
 103                 int index = cvmx_helper_get_interface_index_num(port);
 104                 union cvmx_gmxx_rxx_frm_ctl gmxx_rxx_frm_ctl;
 105
 106                 gmxx_rxx_frm_ctl.u64 =
 107                     cvmx_read_csr(CVMX_GMXX_RXX_FRM_CTL(index, interface));
 108                 if (gmxx_rxx_frm_ctl.s.pre_chk == 0) {
 109                         u8 *ptr =
 110                             cvmx_phys_to_ptr(work->packet_ptr.s.addr);
 111                         int i = 0;
 112
 113                         while (i < work->word1.len - 1) {
 114                                 if (*ptr != 0x55)
 115                                         break;
 116                                 ptr++;
 117                                 i++;
 118                         }
 119
 120                         if (*ptr == 0xd5) {
 121                                 /* Port received 0xd5 preamble */
 122                                 work->packet_ptr.s.addr += i + 1;
 123                                 work->word1.len -= i + 5;
 124                                 return 0;
 125                         }
 126
 127                         if ((*ptr & 0xf) == 0xd) {
 128                                 /* Port received 0xd preamble */
 129                                 work->packet_ptr.s.addr += i;
 130                                 work->word1.len -= i + 4;
 131                                 for (i = 0; i < work->word1.len; i++) {
 132                                         *ptr =
 133                                             ((*ptr & 0xf0) >> 4) |
 134                                             ((*(ptr + 1) & 0xf) << 4);
 135                                         ptr++;
 136                                 }
 137                                 return 0;
 138                         }
 139
 140                         printk_ratelimited("Port %d unknown preamble, packet dropped\n",
 141                                            port);
 142                         cvm_oct_free_work(work);
 143                         return 1;
 144                 }
 145         }
 146
 147         printk_ratelimited("Port %d receive error code %d, packet dropped\n",
 148                            port, work->word2.snoip.err_code);
 149         cvm_oct_free_work(work);
 150         return 1;
 151 }
 152
 153 static void copy_segments_to_skb(cvmx_wqe_t *work, struct sk_buff *skb)
 154 {
 155         int segments = work->word2.s.bufs;
 156         union cvmx_buf_ptr segment_ptr = work->packet_ptr;
 157         int len = work->word1.len;
 158         int segment_size;
 159
 160         while (segments--) {
 161                 union cvmx_buf_ptr next_ptr;
 162
 163                 next_ptr = *(union cvmx_buf_ptr *)
 164                         cvmx_phys_to_ptr(segment_ptr.s.addr - 8);
 165
 166                 /*
 167                  * Octeon Errata PKI-100: The segment size is wrong.
 168                  *
 169                  * Until it is fixed, calculate the segment size based on
 170                  * the packet pool buffer size.
 171                  * When it is fixed, the following line should be replaced
 172                  * with this one:
 173                  * int segment_size = segment_ptr.s.size;
 174                  */
 175                 segment_size =
 176                         CVMX_FPA_PACKET_POOL_SIZE -
 177                         (segment_ptr.s.addr -
 178                          (((segment_ptr.s.addr >> 7) -
 179                            segment_ptr.s.back) << 7));
 180
 181                 /* Don't copy more than what is left in the packet */
 182                 if (segment_size > len)
 183                         segment_size = len;
 184
 185                 /* Copy the data into the packet */
 186                 skb_put_data(skb, cvmx_phys_to_ptr(segment_ptr.s.addr),
 187                              segment_size);
 188                 len -= segment_size;
 189                 segment_ptr = next_ptr;
 190         }
 191 }
 192
 193 static int cvm_oct_poll(struct oct_rx_group *rx_group, int budget)
 194 {
 195         const int       coreid = cvmx_get_core_num();
 196         u64     old_group_mask;
 197         u64     old_scratch;
 198         int             rx_count = 0;
 199         int             did_work_request = 0;
 200         int             packet_not_copied;
 201
 202         /* Prefetch cvm_oct_device since we know we need it soon */
 203         prefetch(cvm_oct_device);
 204
 205         if (USE_ASYNC_IOBDMA) {
 206                 /* Save scratch in case userspace is using it */
 207                 CVMX_SYNCIOBDMA;
 208                 old_scratch = cvmx_scratch_read64(CVMX_SCR_SCRATCH);
 209         }
 210
 211         /* Only allow work for our group (and preserve priorities) */
 212         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 213                 old_group_mask = cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid));
 214                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid),
 215                                BIT(rx_group->group));
 216                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 217         } else {
 218                 old_group_mask = cvmx_read_csr(CVMX_POW_PP_GRP_MSKX(coreid));
 219                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid),
 220                                (old_group_mask & ~0xFFFFull) |
 221                                BIT(rx_group->group));
 222         }
 223
 224         if (USE_ASYNC_IOBDMA) {
 225                 cvmx_pow_work_request_async(CVMX_SCR_SCRATCH, CVMX_POW_NO_WAIT);
 226                 did_work_request = 1;
 227         }
 228
 229         while (rx_count < budget) {
 230                 struct sk_buff *skb = NULL;
 231                 struct sk_buff **pskb = NULL;
 232                 int skb_in_hw;
 233                 cvmx_wqe_t *work;
 234                 int port;
 235
 236                 if (USE_ASYNC_IOBDMA && did_work_request)
 237                         work = cvmx_pow_work_response_async(CVMX_SCR_SCRATCH);
 238                 else
 239                         work = cvmx_pow_work_request_sync(CVMX_POW_NO_WAIT);
 240
 241                 prefetch(work);
 242                 did_work_request = 0;
 243                 if (!work) {
 244                         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 245                                 cvmx_write_csr(CVMX_SSO_WQ_IQ_DIS,
 246                                                BIT(rx_group->group));
 247                                 cvmx_write_csr(CVMX_SSO_WQ_INT,
 248                                                BIT(rx_group->group));
 249                         } else {
 250                                 union cvmx_pow_wq_int wq_int;
 251
 252                                 wq_int.u64 = 0;
 253                                 wq_int.s.iq_dis = BIT(rx_group->group);
 254                                 wq_int.s.wq_int = BIT(rx_group->group);
 255                                 cvmx_write_csr(CVMX_POW_WQ_INT, wq_int.u64);
 256                         }
 257                         break;
 258                 }
 259                 pskb = (struct sk_buff **)
 260                         (cvm_oct_get_buffer_ptr(work->packet_ptr) -
 261                         sizeof(void *));
 262                 prefetch(pskb);
 263
 264                 if (USE_ASYNC_IOBDMA && rx_count < (budget - 1)) {
 265                         cvmx_pow_work_request_async_nocheck(CVMX_SCR_SCRATCH,
 266                                                             CVMX_POW_NO_WAIT);
 267                         did_work_request = 1;
 268                 }
 269                 rx_count++;
 270
 271                 skb_in_hw = work->word2.s.bufs == 1;
 272                 if (likely(skb_in_hw)) {
 273                         skb = *pskb;
 274                         prefetch(&skb->head);
 275                         prefetch(&skb->len);
 276                 }
 277
 278                 if (octeon_has_feature(OCTEON_FEATURE_PKND))
 279                         port = work->word0.pip.cn68xx.pknd;
 280                 else
 281                         port = work->word1.cn38xx.ipprt;
 282
 283                 prefetch(cvm_oct_device[port]);
 284
 285                 /* Immediately throw away all packets with receive errors */
 286                 if (unlikely(work->word2.snoip.rcv_error)) {
 287                         if (cvm_oct_check_rcv_error(work))
 288                                 continue;
 289                 }
 290
 291                 /*
 292                  * We can only use the zero copy path if skbuffs are
 293                  * in the FPA pool and the packet fits in a single
 294                  * buffer.
 295                  */
 296                 if (likely(skb_in_hw)) {
 297                         skb->data = skb->head + work->packet_ptr.s.addr -
 298                                 cvmx_ptr_to_phys(skb->head);
 299                         prefetch(skb->data);
 300                         skb->len = work->word1.len;
 301                         skb_set_tail_pointer(skb, skb->len);
 302                         packet_not_copied = 1;
 303                 } else {
 304                         /*
 305                          * We have to copy the packet. First allocate
 306                          * an skbuff for it.
 307                          */
 308                         skb = dev_alloc_skb(work->word1.len);
 309                         if (!skb) {
 310                                 cvm_oct_free_work(work);
 311                                 continue;
 312                         }
 313
 314                         /*
 315                          * Check if we've received a packet that was
 316                          * entirely stored in the work entry.
 317                          */
 318                         if (unlikely(work->word2.s.bufs == 0)) {
 319                                 u8 *ptr = work->packet_data;
 320
 321                                 if (likely(!work->word2.s.not_IP)) {
 322                                         /*
 323                                          * The beginning of the packet
 324                                          * moves for IP packets.
 325                                          */
 326                                         if (work->word2.s.is_v6)
 327                                                 ptr += 2;
 328                                         else
 329                                                 ptr += 6;
 330                                 }
 331                                 skb_put_data(skb, ptr, work->word1.len);
 332                                 /* No packet buffers to free */
 333                         } else {
 334                                 copy_segments_to_skb(work, skb);
 335                         }
 336                         packet_not_copied = 0;
 337                 }
 338                 if (likely((port < TOTAL_NUMBER_OF_PORTS) &&
 339                            cvm_oct_device[port])) {
 340                         struct net_device *dev = cvm_oct_device[port];
 341
 342                         /*
 343                          * Only accept packets for devices that are
 344                          * currently up.
 345                          */
 346                         if (likely(dev->flags & IFF_UP)) {
 347                                 skb->protocol = eth_type_trans(skb, dev);
 348                                 skb->dev = dev;
 349
 350                                 if (unlikely(work->word2.s.not_IP ||
 351                                              work->word2.s.IP_exc ||
 352                                              work->word2.s.L4_error ||
 353                                              !work->word2.s.tcp_or_udp))
 354                                         skb->ip_summed = CHECKSUM_NONE;
 355                                 else
 356                                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 357
 358                                 /* Increment RX stats for virtual ports */
 359                                 if (port >= CVMX_PIP_NUM_INPUT_PORTS) {
 360                                         dev->stats.rx_packets++;
 361                                         dev->stats.rx_bytes += skb->len;
 362                                 }
 363                                 netif_receive_skb(skb);
 364                         } else {
 365                                 /*
 366                                  * Drop any packet received for a device that
 367                                  * isn't up.
 368                                  */
 369                                 dev->stats.rx_dropped++;
 370                                 dev_kfree_skb_irq(skb);
 371                         }
 372                 } else {
 373                         /*
 374                          * Drop any packet received for a device that
 375                          * doesn't exist.
 376                          */
 377                         printk_ratelimited("Port %d not controlled by Linux, packet dropped\n",
 378                                            port);
 379                         dev_kfree_skb_irq(skb);
 380                 }
 381                 /*
 382                  * Check to see if the skbuff and work share the same
 383                  * packet buffer.
 384                  */
 385                 if (likely(packet_not_copied)) {
 386                         /*
 387                          * This buffer needs to be replaced, increment
 388                          * the number of buffers we need to free by
 389                          * one.
 390                          */
 391                         cvmx_fau_atomic_add32(FAU_NUM_PACKET_BUFFERS_TO_FREE,
 392                                               1);
 393
 394                         cvmx_fpa_free(work, CVMX_FPA_WQE_POOL, 1);
 395                 } else {
 396                         cvm_oct_free_work(work);
 397                 }
 398         }
 399         /* Restore the original POW group mask */
 400         if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 401                 cvmx_write_csr(CVMX_SSO_PPX_GRP_MSK(coreid), old_group_mask);
 402                 cvmx_read_csr(CVMX_SSO_PPX_GRP_MSK(coreid)); /* Flush */
 403         } else {
 404                 cvmx_write_csr(CVMX_POW_PP_GRP_MSKX(coreid), old_group_mask);
 405         }
 406
 407         if (USE_ASYNC_IOBDMA) {
 408                 /* Restore the scratch area */
 409                 cvmx_scratch_write64(CVMX_SCR_SCRATCH, old_scratch);
 410         }
 411         cvm_oct_rx_refill_pool(0);
 412
 413         return rx_count;
 414 }
 415
 416 /**
 417  * cvm_oct_napi_poll - the NAPI poll function.
 418  * @napi: The NAPI instance.
 419  * @budget: Maximum number of packets to receive.
 420  *
 421  * Returns the number of packets processed.
 422  */
 423 static int cvm_oct_napi_poll(struct napi_struct *napi, int budget)
 424 {
 425         struct oct_rx_group *rx_group = container_of(napi, struct oct_rx_group,
 426                                                      napi);
 427         int rx_count;
 428
 429         rx_count = cvm_oct_poll(rx_group, budget);
 430
 431         if (rx_count < budget) {
 432                 /* No more work */
 433                 napi_complete_done(napi, rx_count);
 434                 enable_irq(rx_group->irq);
 435         }
 436         return rx_count;
 437 }
 438
 439 #ifdef CONFIG_NET_POLL_CONTROLLER
 440 /**
 441  * cvm_oct_poll_controller - poll for receive packets
 442  * device.
 443  *
 444  * @dev:    Device to poll. Unused
 445  */
 446 void cvm_oct_poll_controller(struct net_device *dev)
 447 {
 448         int i;
 449
 450         if (!atomic_read(&oct_rx_ready))
 451                 return;
 452
 453         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 454                 if (!(pow_receive_groups & BIT(i)))
 455                         continue;
 456
 457                 cvm_oct_poll(&oct_rx_group[i], 16);
 458         }
 459 }
 460 #endif
 461
 462 void cvm_oct_rx_initialize(void)
 463 {
 464         int i;
 465         struct net_device *dev_for_napi = NULL;
 466
 467         for (i = 0; i < TOTAL_NUMBER_OF_PORTS; i++) {
 468                 if (cvm_oct_device[i]) {
 469                         dev_for_napi = cvm_oct_device[i];
 470                         break;
 471                 }
 472         }
 473
 474         if (!dev_for_napi)
 475                 panic("No net_devices were allocated.");
 476
 477         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 478                 int ret;
 479
 480                 if (!(pow_receive_groups & BIT(i)))
 481                         continue;
 482
 483                 netif_napi_add(dev_for_napi, &oct_rx_group[i].napi,
 484                                cvm_oct_napi_poll, rx_napi_weight);
 485                 napi_enable(&oct_rx_group[i].napi);
 486
 487                 oct_rx_group[i].irq = OCTEON_IRQ_WORKQ0 + i;
 488                 oct_rx_group[i].group = i;
 489
 490                 /* Register an IRQ handler to receive POW interrupts */
 491                 ret = request_irq(oct_rx_group[i].irq, cvm_oct_do_interrupt, 0,
 492                                   "Ethernet", &oct_rx_group[i].napi);
 493                 if (ret)
 494                         panic("Could not acquire Ethernet IRQ %d\n",
 495                               oct_rx_group[i].irq);
 496
 497                 disable_irq_nosync(oct_rx_group[i].irq);
 498
 499                 /* Enable POW interrupt when our port has at least one packet */
 500                 if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
 501                         union cvmx_sso_wq_int_thrx int_thr;
 502                         union cvmx_pow_wq_int_pc int_pc;
 503
 504                         int_thr.u64 = 0;
 505                         int_thr.s.tc_en = 1;
 506                         int_thr.s.tc_thr = 1;
 507                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), int_thr.u64);
 508
 509                         int_pc.u64 = 0;
 510                         int_pc.s.pc_thr = 5;
 511                         cvmx_write_csr(CVMX_SSO_WQ_INT_PC, int_pc.u64);
 512                 } else {
 513                         union cvmx_pow_wq_int_thrx int_thr;
 514                         union cvmx_pow_wq_int_pc int_pc;
 515
 516                         int_thr.u64 = 0;
 517                         int_thr.s.tc_en = 1;
 518                         int_thr.s.tc_thr = 1;
 519                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), int_thr.u64);
 520
 521                         int_pc.u64 = 0;
 522                         int_pc.s.pc_thr = 5;
 523                         cvmx_write_csr(CVMX_POW_WQ_INT_PC, int_pc.u64);
 524                 }
 525
 526                 /* Schedule NAPI now. This will indirectly enable the
 527                  * interrupt.
 528                  */
 529                 napi_schedule(&oct_rx_group[i].napi);
 530         }
 531         atomic_inc(&oct_rx_ready);
 532 }
 533
 534 void cvm_oct_rx_shutdown(void)
 535 {
 536         int i;
 537
 538         for (i = 0; i < ARRAY_SIZE(oct_rx_group); i++) {
 539                 if (!(pow_receive_groups & BIT(i)))
 540                         continue;
 541
 542                 /* Disable POW interrupt */
 543                 if (OCTEON_IS_MODEL(OCTEON_CN68XX))
 544                         cvmx_write_csr(CVMX_SSO_WQ_INT_THRX(i), 0);
 545                 else
 546                         cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
 547
 548                 /* Free the interrupt handler */
 549                 free_irq(oct_rx_group[i].irq, cvm_oct_device);
 550
 551                 netif_napi_del(&oct_rx_group[i].napi);
 552         }
 553 }