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