drivers/net/caif/caif_hsi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) ST-Ericsson AB 2010
   4  * Author:  Daniel Martensson
   5  *          Dmitry.Tarnyagin  / dmitry.tarnyagin@lockless.no
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME fmt
   9
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/device.h>
  13 #include <linux/netdevice.h>
  14 #include <linux/string.h>
  15 #include <linux/list.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/delay.h>
  18 #include <linux/sched.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/timer.h>
  21 #include <net/rtnetlink.h>
  22 #include <linux/pkt_sched.h>
  23 #include <net/caif/caif_layer.h>
  24 #include <net/caif/caif_hsi.h>
  25
  26 MODULE_LICENSE("GPL");
  27 MODULE_AUTHOR("Daniel Martensson");
  28 MODULE_DESCRIPTION("CAIF HSI driver");
  29
  30 /* Returns the number of padding bytes for alignment. */
  31 #define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
  32                                 (((pow)-((x)&((pow)-1)))))
  33
  34 static const struct cfhsi_config  hsi_default_config = {
  35
  36         /* Inactivity timeout on HSI, ms */
  37         .inactivity_timeout = HZ,
  38
  39         /* Aggregation timeout (ms) of zero means no aggregation is done*/
  40         .aggregation_timeout = 1,
  41
  42         /*
  43          * HSI link layer flow-control thresholds.
  44          * Threshold values for the HSI packet queue. Flow-control will be
  45          * asserted when the number of packets exceeds q_high_mark. It will
  46          * not be de-asserted before the number of packets drops below
  47          * q_low_mark.
  48          * Warning: A high threshold value might increase throughput but it
  49          * will at the same time prevent channel prioritization and increase
  50          * the risk of flooding the modem. The high threshold should be above
  51          * the low.
  52          */
  53         .q_high_mark = 100,
  54         .q_low_mark = 50,
  55
  56         /*
  57          * HSI padding options.
  58          * Warning: must be a base of 2 (& operation used) and can not be zero !
  59          */
  60         .head_align = 4,
  61         .tail_align = 4,
  62 };
  63
  64 #define ON 1
  65 #define OFF 0
  66
  67 static LIST_HEAD(cfhsi_list);
  68
  69 static void cfhsi_inactivity_tout(struct timer_list *t)
  70 {
  71         struct cfhsi *cfhsi = from_timer(cfhsi, t, inactivity_timer);
  72
  73         netdev_dbg(cfhsi->ndev, "%s.\n",
  74                 __func__);
  75
  76         /* Schedule power down work queue. */
  77         if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
  78                 queue_work(cfhsi->wq, &cfhsi->wake_down_work);
  79 }
  80
  81 static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
  82                                            const struct sk_buff *skb,
  83                                            int direction)
  84 {
  85         struct caif_payload_info *info;
  86         int hpad, tpad, len;
  87
  88         info = (struct caif_payload_info *)&skb->cb;
  89         hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
  90         tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
  91         len = skb->len + hpad + tpad;
  92
  93         if (direction > 0)
  94                 cfhsi->aggregation_len += len;
  95         else if (direction < 0)
  96                 cfhsi->aggregation_len -= len;
  97 }
  98
  99 static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
 100 {
 101         int i;
 102
 103         if (cfhsi->cfg.aggregation_timeout == 0)
 104                 return true;
 105
 106         for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
 107                 if (cfhsi->qhead[i].qlen)
 108                         return true;
 109         }
 110
 111         /* TODO: Use aggregation_len instead */
 112         if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
 113                 return true;
 114
 115         return false;
 116 }
 117
 118 static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
 119 {
 120         struct sk_buff *skb;
 121         int i;
 122
 123         for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
 124                 skb = skb_dequeue(&cfhsi->qhead[i]);
 125                 if (skb)
 126                         break;
 127         }
 128
 129         return skb;
 130 }
 131
 132 static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
 133 {
 134         int i, len = 0;
 135         for (i = 0; i < CFHSI_PRIO_LAST; ++i)
 136                 len += skb_queue_len(&cfhsi->qhead[i]);
 137         return len;
 138 }
 139
 140 static void cfhsi_abort_tx(struct cfhsi *cfhsi)
 141 {
 142         struct sk_buff *skb;
 143
 144         for (;;) {
 145                 spin_lock_bh(&cfhsi->lock);
 146                 skb = cfhsi_dequeue(cfhsi);
 147                 if (!skb)
 148                         break;
 149
 150                 cfhsi->ndev->stats.tx_errors++;
 151                 cfhsi->ndev->stats.tx_dropped++;
 152                 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 153                 spin_unlock_bh(&cfhsi->lock);
 154                 kfree_skb(skb);
 155         }
 156         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
 157         if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 158                 mod_timer(&cfhsi->inactivity_timer,
 159                         jiffies + cfhsi->cfg.inactivity_timeout);
 160         spin_unlock_bh(&cfhsi->lock);
 161 }
 162
 163 static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
 164 {
 165         char buffer[32]; /* Any reasonable value */
 166         size_t fifo_occupancy;
 167         int ret;
 168
 169         netdev_dbg(cfhsi->ndev, "%s.\n",
 170                 __func__);
 171
 172         do {
 173                 ret = cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
 174                                 &fifo_occupancy);
 175                 if (ret) {
 176                         netdev_warn(cfhsi->ndev,
 177                                 "%s: can't get FIFO occupancy: %d.\n",
 178                                 __func__, ret);
 179                         break;
 180                 } else if (!fifo_occupancy)
 181                         /* No more data, exitting normally */
 182                         break;
 183
 184                 fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
 185                 set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
 186                 ret = cfhsi->ops->cfhsi_rx(buffer, fifo_occupancy,
 187                                 cfhsi->ops);
 188                 if (ret) {
 189                         clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
 190                         netdev_warn(cfhsi->ndev,
 191                                 "%s: can't read data: %d.\n",
 192                                 __func__, ret);
 193                         break;
 194                 }
 195
 196                 ret = 5 * HZ;
 197                 ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
 198                          !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
 199
 200                 if (ret < 0) {
 201                         netdev_warn(cfhsi->ndev,
 202                                 "%s: can't wait for flush complete: %d.\n",
 203                                 __func__, ret);
 204                         break;
 205                 } else if (!ret) {
 206                         ret = -ETIMEDOUT;
 207                         netdev_warn(cfhsi->ndev,
 208                                 "%s: timeout waiting for flush complete.\n",
 209                                 __func__);
 210                         break;
 211                 }
 212         } while (1);
 213
 214         return ret;
 215 }
 216
 217 static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 218 {
 219         int nfrms = 0;
 220         int pld_len = 0;
 221         struct sk_buff *skb;
 222         u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
 223
 224         skb = cfhsi_dequeue(cfhsi);
 225         if (!skb)
 226                 return 0;
 227
 228         /* Clear offset. */
 229         desc->offset = 0;
 230
 231         /* Check if we can embed a CAIF frame. */
 232         if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
 233                 struct caif_payload_info *info;
 234                 int hpad;
 235                 int tpad;
 236
 237                 /* Calculate needed head alignment and tail alignment. */
 238                 info = (struct caif_payload_info *)&skb->cb;
 239
 240                 hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
 241                 tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
 242
 243                 /* Check if frame still fits with added alignment. */
 244                 if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
 245                         u8 *pemb = desc->emb_frm;
 246                         desc->offset = CFHSI_DESC_SHORT_SZ;
 247                         *pemb = (u8)(hpad - 1);
 248                         pemb += hpad;
 249
 250                         /* Update network statistics. */
 251                         spin_lock_bh(&cfhsi->lock);
 252                         cfhsi->ndev->stats.tx_packets++;
 253                         cfhsi->ndev->stats.tx_bytes += skb->len;
 254                         cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 255                         spin_unlock_bh(&cfhsi->lock);
 256
 257                         /* Copy in embedded CAIF frame. */
 258                         skb_copy_bits(skb, 0, pemb, skb->len);
 259
 260                         /* Consume the SKB */
 261                         consume_skb(skb);
 262                         skb = NULL;
 263                 }
 264         }
 265
 266         /* Create payload CAIF frames. */
 267         while (nfrms < CFHSI_MAX_PKTS) {
 268                 struct caif_payload_info *info;
 269                 int hpad;
 270                 int tpad;
 271
 272                 if (!skb)
 273                         skb = cfhsi_dequeue(cfhsi);
 274
 275                 if (!skb)
 276                         break;
 277
 278                 /* Calculate needed head alignment and tail alignment. */
 279                 info = (struct caif_payload_info *)&skb->cb;
 280
 281                 hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
 282                 tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
 283
 284                 /* Fill in CAIF frame length in descriptor. */
 285                 desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
 286
 287                 /* Fill head padding information. */
 288                 *pfrm = (u8)(hpad - 1);
 289                 pfrm += hpad;
 290
 291                 /* Update network statistics. */
 292                 spin_lock_bh(&cfhsi->lock);
 293                 cfhsi->ndev->stats.tx_packets++;
 294                 cfhsi->ndev->stats.tx_bytes += skb->len;
 295                 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
 296                 spin_unlock_bh(&cfhsi->lock);
 297
 298                 /* Copy in CAIF frame. */
 299                 skb_copy_bits(skb, 0, pfrm, skb->len);
 300
 301                 /* Update payload length. */
 302                 pld_len += desc->cffrm_len[nfrms];
 303
 304                 /* Update frame pointer. */
 305                 pfrm += skb->len + tpad;
 306
 307                 /* Consume the SKB */
 308                 consume_skb(skb);
 309                 skb = NULL;
 310
 311                 /* Update number of frames. */
 312                 nfrms++;
 313         }
 314
 315         /* Unused length fields should be zero-filled (according to SPEC). */
 316         while (nfrms < CFHSI_MAX_PKTS) {
 317                 desc->cffrm_len[nfrms] = 0x0000;
 318                 nfrms++;
 319         }
 320
 321         /* Check if we can piggy-back another descriptor. */
 322         if (cfhsi_can_send_aggregate(cfhsi))
 323                 desc->header |= CFHSI_PIGGY_DESC;
 324         else
 325                 desc->header &= ~CFHSI_PIGGY_DESC;
 326
 327         return CFHSI_DESC_SZ + pld_len;
 328 }
 329
 330 static void cfhsi_start_tx(struct cfhsi *cfhsi)
 331 {
 332         struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
 333         int len, res;
 334
 335         netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
 336
 337         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 338                 return;
 339
 340         do {
 341                 /* Create HSI frame. */
 342                 len = cfhsi_tx_frm(desc, cfhsi);
 343                 if (!len) {
 344                         spin_lock_bh(&cfhsi->lock);
 345                         if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
 346                                 spin_unlock_bh(&cfhsi->lock);
 347                                 res = -EAGAIN;
 348                                 continue;
 349                         }
 350                         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
 351                         /* Start inactivity timer. */
 352                         mod_timer(&cfhsi->inactivity_timer,
 353                                 jiffies + cfhsi->cfg.inactivity_timeout);
 354                         spin_unlock_bh(&cfhsi->lock);
 355                         break;
 356                 }
 357
 358                 /* Set up new transfer. */
 359                 res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
 360                 if (WARN_ON(res < 0))
 361                         netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
 362                                 __func__, res);
 363         } while (res < 0);
 364 }
 365
 366 static void cfhsi_tx_done(struct cfhsi *cfhsi)
 367 {
 368         netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
 369
 370         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 371                 return;
 372
 373         /*
 374          * Send flow on if flow off has been previously signalled
 375          * and number of packets is below low water mark.
 376          */
 377         spin_lock_bh(&cfhsi->lock);
 378         if (cfhsi->flow_off_sent &&
 379                         cfhsi_tx_queue_len(cfhsi) <= cfhsi->cfg.q_low_mark &&
 380                         cfhsi->cfdev.flowctrl) {
 381
 382                 cfhsi->flow_off_sent = 0;
 383                 cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
 384         }
 385
 386         if (cfhsi_can_send_aggregate(cfhsi)) {
 387                 spin_unlock_bh(&cfhsi->lock);
 388                 cfhsi_start_tx(cfhsi);
 389         } else {
 390                 mod_timer(&cfhsi->aggregation_timer,
 391                         jiffies + cfhsi->cfg.aggregation_timeout);
 392                 spin_unlock_bh(&cfhsi->lock);
 393         }
 394
 395         return;
 396 }
 397
 398 static void cfhsi_tx_done_cb(struct cfhsi_cb_ops *cb_ops)
 399 {
 400         struct cfhsi *cfhsi;
 401
 402         cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
 403         netdev_dbg(cfhsi->ndev, "%s.\n",
 404                 __func__);
 405
 406         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 407                 return;
 408         cfhsi_tx_done(cfhsi);
 409 }
 410
 411 static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 412 {
 413         int xfer_sz = 0;
 414         int nfrms = 0;
 415         u16 *plen = NULL;
 416         u8 *pfrm = NULL;
 417
 418         if ((desc->header & ~CFHSI_PIGGY_DESC) ||
 419                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
 420                 netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
 421                         __func__);
 422                 return -EPROTO;
 423         }
 424
 425         /* Check for embedded CAIF frame. */
 426         if (desc->offset) {
 427                 struct sk_buff *skb;
 428                 int len = 0;
 429                 pfrm = ((u8 *)desc) + desc->offset;
 430
 431                 /* Remove offset padding. */
 432                 pfrm += *pfrm + 1;
 433
 434                 /* Read length of CAIF frame (little endian). */
 435                 len = *pfrm;
 436                 len |= ((*(pfrm+1)) << 8) & 0xFF00;
 437                 len += 2;       /* Add FCS fields. */
 438
 439                 /* Sanity check length of CAIF frame. */
 440                 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
 441                         netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
 442                                 __func__);
 443                         return -EPROTO;
 444                 }
 445
 446                 /* Allocate SKB (OK even in IRQ context). */
 447                 skb = alloc_skb(len + 1, GFP_ATOMIC);
 448                 if (!skb) {
 449                         netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
 450                                 __func__);
 451                         return -ENOMEM;
 452                 }
 453                 caif_assert(skb != NULL);
 454
 455                 skb_put_data(skb, pfrm, len);
 456
 457                 skb->protocol = htons(ETH_P_CAIF);
 458                 skb_reset_mac_header(skb);
 459                 skb->dev = cfhsi->ndev;
 460
 461                 /*
 462                  * We are in a callback handler and
 463                  * unfortunately we don't know what context we're
 464                  * running in.
 465                  */
 466                 if (in_interrupt())
 467                         netif_rx(skb);
 468                 else
 469                         netif_rx_ni(skb);
 470
 471                 /* Update network statistics. */
 472                 cfhsi->ndev->stats.rx_packets++;
 473                 cfhsi->ndev->stats.rx_bytes += len;
 474         }
 475
 476         /* Calculate transfer length. */
 477         plen = desc->cffrm_len;
 478         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 479                 xfer_sz += *plen;
 480                 plen++;
 481                 nfrms++;
 482         }
 483
 484         /* Check for piggy-backed descriptor. */
 485         if (desc->header & CFHSI_PIGGY_DESC)
 486                 xfer_sz += CFHSI_DESC_SZ;
 487
 488         if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
 489                 netdev_err(cfhsi->ndev,
 490                                 "%s: Invalid payload len: %d, ignored.\n",
 491                         __func__, xfer_sz);
 492                 return -EPROTO;
 493         }
 494         return xfer_sz;
 495 }
 496
 497 static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
 498 {
 499         int xfer_sz = 0;
 500         int nfrms = 0;
 501         u16 *plen;
 502
 503         if ((desc->header & ~CFHSI_PIGGY_DESC) ||
 504                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
 505
 506                 pr_err("Invalid descriptor. %x %x\n", desc->header,
 507                                 desc->offset);
 508                 return -EPROTO;
 509         }
 510
 511         /* Calculate transfer length. */
 512         plen = desc->cffrm_len;
 513         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 514                 xfer_sz += *plen;
 515                 plen++;
 516                 nfrms++;
 517         }
 518
 519         if (xfer_sz % 4) {
 520                 pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
 521                 return -EPROTO;
 522         }
 523         return xfer_sz;
 524 }
 525
 526 static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
 527 {
 528         int rx_sz = 0;
 529         int nfrms = 0;
 530         u16 *plen = NULL;
 531         u8 *pfrm = NULL;
 532
 533         /* Sanity check header and offset. */
 534         if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
 535                         (desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
 536                 netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
 537                         __func__);
 538                 return -EPROTO;
 539         }
 540
 541         /* Set frame pointer to start of payload. */
 542         pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
 543         plen = desc->cffrm_len;
 544
 545         /* Skip already processed frames. */
 546         while (nfrms < cfhsi->rx_state.nfrms) {
 547                 pfrm += *plen;
 548                 rx_sz += *plen;
 549                 plen++;
 550                 nfrms++;
 551         }
 552
 553         /* Parse payload. */
 554         while (nfrms < CFHSI_MAX_PKTS && *plen) {
 555                 struct sk_buff *skb;
 556                 u8 *pcffrm = NULL;
 557                 int len;
 558
 559                 /* CAIF frame starts after head padding. */
 560                 pcffrm = pfrm + *pfrm + 1;
 561
 562                 /* Read length of CAIF frame (little endian). */
 563                 len = *pcffrm;
 564                 len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
 565                 len += 2;       /* Add FCS fields. */
 566
 567                 /* Sanity check length of CAIF frames. */
 568                 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
 569                         netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
 570                                 __func__);
 571                         return -EPROTO;
 572                 }
 573
 574                 /* Allocate SKB (OK even in IRQ context). */
 575                 skb = alloc_skb(len + 1, GFP_ATOMIC);
 576                 if (!skb) {
 577                         netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
 578                                 __func__);
 579                         cfhsi->rx_state.nfrms = nfrms;
 580                         return -ENOMEM;
 581                 }
 582                 caif_assert(skb != NULL);
 583
 584                 skb_put_data(skb, pcffrm, len);
 585
 586                 skb->protocol = htons(ETH_P_CAIF);
 587                 skb_reset_mac_header(skb);
 588                 skb->dev = cfhsi->ndev;
 589
 590                 /*
 591                  * We're called in callback from HSI
 592                  * and don't know the context we're running in.
 593                  */
 594                 if (in_interrupt())
 595                         netif_rx(skb);
 596                 else
 597                         netif_rx_ni(skb);
 598
 599                 /* Update network statistics. */
 600                 cfhsi->ndev->stats.rx_packets++;
 601                 cfhsi->ndev->stats.rx_bytes += len;
 602
 603                 pfrm += *plen;
 604                 rx_sz += *plen;
 605                 plen++;
 606                 nfrms++;
 607         }
 608
 609         return rx_sz;
 610 }
 611
 612 static void cfhsi_rx_done(struct cfhsi *cfhsi)
 613 {
 614         int res;
 615         int desc_pld_len = 0, rx_len, rx_state;
 616         struct cfhsi_desc *desc = NULL;
 617         u8 *rx_ptr, *rx_buf;
 618         struct cfhsi_desc *piggy_desc = NULL;
 619
 620         desc = (struct cfhsi_desc *)cfhsi->rx_buf;
 621
 622         netdev_dbg(cfhsi->ndev, "%s\n", __func__);
 623
 624         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 625                 return;
 626
 627         /* Update inactivity timer if pending. */
 628         spin_lock_bh(&cfhsi->lock);
 629         mod_timer_pending(&cfhsi->inactivity_timer,
 630                         jiffies + cfhsi->cfg.inactivity_timeout);
 631         spin_unlock_bh(&cfhsi->lock);
 632
 633         if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
 634                 desc_pld_len = cfhsi_rx_desc_len(desc);
 635
 636                 if (desc_pld_len < 0)
 637                         goto out_of_sync;
 638
 639                 rx_buf = cfhsi->rx_buf;
 640                 rx_len = desc_pld_len;
 641                 if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
 642                         rx_len += CFHSI_DESC_SZ;
 643                 if (desc_pld_len == 0)
 644                         rx_buf = cfhsi->rx_flip_buf;
 645         } else {
 646                 rx_buf = cfhsi->rx_flip_buf;
 647
 648                 rx_len = CFHSI_DESC_SZ;
 649                 if (cfhsi->rx_state.pld_len > 0 &&
 650                                 (desc->header & CFHSI_PIGGY_DESC)) {
 651
 652                         piggy_desc = (struct cfhsi_desc *)
 653                                 (desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
 654                                                 cfhsi->rx_state.pld_len);
 655
 656                         cfhsi->rx_state.piggy_desc = true;
 657
 658                         /* Extract payload len from piggy-backed descriptor. */
 659                         desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
 660                         if (desc_pld_len < 0)
 661                                 goto out_of_sync;
 662
 663                         if (desc_pld_len > 0) {
 664                                 rx_len = desc_pld_len;
 665                                 if (piggy_desc->header & CFHSI_PIGGY_DESC)
 666                                         rx_len += CFHSI_DESC_SZ;
 667                         }
 668
 669                         /*
 670                          * Copy needed information from the piggy-backed
 671                          * descriptor to the descriptor in the start.
 672                          */
 673                         memcpy(rx_buf, (u8 *)piggy_desc,
 674                                         CFHSI_DESC_SHORT_SZ);
 675                 }
 676         }
 677
 678         if (desc_pld_len) {
 679                 rx_state = CFHSI_RX_STATE_PAYLOAD;
 680                 rx_ptr = rx_buf + CFHSI_DESC_SZ;
 681         } else {
 682                 rx_state = CFHSI_RX_STATE_DESC;
 683                 rx_ptr = rx_buf;
 684                 rx_len = CFHSI_DESC_SZ;
 685         }
 686
 687         /* Initiate next read */
 688         if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
 689                 /* Set up new transfer. */
 690                 netdev_dbg(cfhsi->ndev, "%s: Start RX.\n",
 691                                 __func__);
 692
 693                 res = cfhsi->ops->cfhsi_rx(rx_ptr, rx_len,
 694                                 cfhsi->ops);
 695                 if (WARN_ON(res < 0)) {
 696                         netdev_err(cfhsi->ndev, "%s: RX error %d.\n",
 697                                 __func__, res);
 698                         cfhsi->ndev->stats.rx_errors++;
 699                         cfhsi->ndev->stats.rx_dropped++;
 700                 }
 701         }
 702
 703         if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
 704                 /* Extract payload from descriptor */
 705                 if (cfhsi_rx_desc(desc, cfhsi) < 0)
 706                         goto out_of_sync;
 707         } else {
 708                 /* Extract payload */
 709                 if (cfhsi_rx_pld(desc, cfhsi) < 0)
 710                         goto out_of_sync;
 711                 if (piggy_desc) {
 712                         /* Extract any payload in piggyback descriptor. */
 713                         if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
 714                                 goto out_of_sync;
 715                         /* Mark no embedded frame after extracting it */
 716                         piggy_desc->offset = 0;
 717                 }
 718         }
 719
 720         /* Update state info */
 721         memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
 722         cfhsi->rx_state.state = rx_state;
 723         cfhsi->rx_ptr = rx_ptr;
 724         cfhsi->rx_len = rx_len;
 725         cfhsi->rx_state.pld_len = desc_pld_len;
 726         cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
 727
 728         if (rx_buf != cfhsi->rx_buf)
 729                 swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
 730         return;
 731
 732 out_of_sync:
 733         netdev_err(cfhsi->ndev, "%s: Out of sync.\n", __func__);
 734         print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
 735                         cfhsi->rx_buf, CFHSI_DESC_SZ);
 736         schedule_work(&cfhsi->out_of_sync_work);
 737 }
 738
 739 static void cfhsi_rx_slowpath(struct timer_list *t)
 740 {
 741         struct cfhsi *cfhsi = from_timer(cfhsi, t, rx_slowpath_timer);
 742
 743         netdev_dbg(cfhsi->ndev, "%s.\n",
 744                 __func__);
 745
 746         cfhsi_rx_done(cfhsi);
 747 }
 748
 749 static void cfhsi_rx_done_cb(struct cfhsi_cb_ops *cb_ops)
 750 {
 751         struct cfhsi *cfhsi;
 752
 753         cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
 754         netdev_dbg(cfhsi->ndev, "%s.\n",
 755                 __func__);
 756
 757         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 758                 return;
 759
 760         if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
 761                 wake_up_interruptible(&cfhsi->flush_fifo_wait);
 762         else
 763                 cfhsi_rx_done(cfhsi);
 764 }
 765
 766 static void cfhsi_wake_up(struct work_struct *work)
 767 {
 768         struct cfhsi *cfhsi = NULL;
 769         int res;
 770         int len;
 771         long ret;
 772
 773         cfhsi = container_of(work, struct cfhsi, wake_up_work);
 774
 775         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 776                 return;
 777
 778         if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
 779                 /* It happenes when wakeup is requested by
 780                  * both ends at the same time. */
 781                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 782                 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 783                 return;
 784         }
 785
 786         /* Activate wake line. */
 787         cfhsi->ops->cfhsi_wake_up(cfhsi->ops);
 788
 789         netdev_dbg(cfhsi->ndev, "%s: Start waiting.\n",
 790                 __func__);
 791
 792         /* Wait for acknowledge. */
 793         ret = CFHSI_WAKE_TOUT;
 794         ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
 795                                         test_and_clear_bit(CFHSI_WAKE_UP_ACK,
 796                                                         &cfhsi->bits), ret);
 797         if (unlikely(ret < 0)) {
 798                 /* Interrupted by signal. */
 799                 netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
 800                         __func__, ret);
 801
 802                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 803                 cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
 804                 return;
 805         } else if (!ret) {
 806                 bool ca_wake = false;
 807                 size_t fifo_occupancy = 0;
 808
 809                 /* Wakeup timeout */
 810                 netdev_dbg(cfhsi->ndev, "%s: Timeout.\n",
 811                         __func__);
 812
 813                 /* Check FIFO to check if modem has sent something. */
 814                 WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
 815                                         &fifo_occupancy));
 816
 817                 netdev_dbg(cfhsi->ndev, "%s: Bytes in FIFO: %u.\n",
 818                                 __func__, (unsigned) fifo_occupancy);
 819
 820                 /* Check if we misssed the interrupt. */
 821                 WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
 822                                                         &ca_wake));
 823
 824                 if (ca_wake) {
 825                         netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
 826                                 __func__);
 827
 828                         /* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
 829                         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 830
 831                         /* Continue execution. */
 832                         goto wake_ack;
 833                 }
 834
 835                 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 836                 cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
 837                 return;
 838         }
 839 wake_ack:
 840         netdev_dbg(cfhsi->ndev, "%s: Woken.\n",
 841                 __func__);
 842
 843         /* Clear power up bit. */
 844         set_bit(CFHSI_AWAKE, &cfhsi->bits);
 845         clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
 846
 847         /* Resume read operation. */
 848         netdev_dbg(cfhsi->ndev, "%s: Start RX.\n", __func__);
 849         res = cfhsi->ops->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->ops);
 850
 851         if (WARN_ON(res < 0))
 852                 netdev_err(cfhsi->ndev, "%s: RX err %d.\n", __func__, res);
 853
 854         /* Clear power up acknowledment. */
 855         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 856
 857         spin_lock_bh(&cfhsi->lock);
 858
 859         /* Resume transmit if queues are not empty. */
 860         if (!cfhsi_tx_queue_len(cfhsi)) {
 861                 netdev_dbg(cfhsi->ndev, "%s: Peer wake, start timer.\n",
 862                         __func__);
 863                 /* Start inactivity timer. */
 864                 mod_timer(&cfhsi->inactivity_timer,
 865                                 jiffies + cfhsi->cfg.inactivity_timeout);
 866                 spin_unlock_bh(&cfhsi->lock);
 867                 return;
 868         }
 869
 870         netdev_dbg(cfhsi->ndev, "%s: Host wake.\n",
 871                 __func__);
 872
 873         spin_unlock_bh(&cfhsi->lock);
 874
 875         /* Create HSI frame. */
 876         len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
 877
 878         if (likely(len > 0)) {
 879                 /* Set up new transfer. */
 880                 res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
 881                 if (WARN_ON(res < 0)) {
 882                         netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
 883                                 __func__, res);
 884                         cfhsi_abort_tx(cfhsi);
 885                 }
 886         } else {
 887                 netdev_err(cfhsi->ndev,
 888                                 "%s: Failed to create HSI frame: %d.\n",
 889                                 __func__, len);
 890         }
 891 }
 892
 893 static void cfhsi_wake_down(struct work_struct *work)
 894 {
 895         long ret;
 896         struct cfhsi *cfhsi = NULL;
 897         size_t fifo_occupancy = 0;
 898         int retry = CFHSI_WAKE_TOUT;
 899
 900         cfhsi = container_of(work, struct cfhsi, wake_down_work);
 901         netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
 902
 903         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 904                 return;
 905
 906         /* Deactivate wake line. */
 907         cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
 908
 909         /* Wait for acknowledge. */
 910         ret = CFHSI_WAKE_TOUT;
 911         ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
 912                                         test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
 913                                                         &cfhsi->bits), ret);
 914         if (ret < 0) {
 915                 /* Interrupted by signal. */
 916                 netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
 917                         __func__, ret);
 918                 return;
 919         } else if (!ret) {
 920                 bool ca_wake = true;
 921
 922                 /* Timeout */
 923                 netdev_err(cfhsi->ndev, "%s: Timeout.\n", __func__);
 924
 925                 /* Check if we misssed the interrupt. */
 926                 WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
 927                                                         &ca_wake));
 928                 if (!ca_wake)
 929                         netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
 930                                 __func__);
 931         }
 932
 933         /* Check FIFO occupancy. */
 934         while (retry) {
 935                 WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
 936                                                         &fifo_occupancy));
 937
 938                 if (!fifo_occupancy)
 939                         break;
 940
 941                 set_current_state(TASK_INTERRUPTIBLE);
 942                 schedule_timeout(1);
 943                 retry--;
 944         }
 945
 946         if (!retry)
 947                 netdev_err(cfhsi->ndev, "%s: FIFO Timeout.\n", __func__);
 948
 949         /* Clear AWAKE condition. */
 950         clear_bit(CFHSI_AWAKE, &cfhsi->bits);
 951
 952         /* Cancel pending RX requests. */
 953         cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
 954 }
 955
 956 static void cfhsi_out_of_sync(struct work_struct *work)
 957 {
 958         struct cfhsi *cfhsi = NULL;
 959
 960         cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
 961
 962         rtnl_lock();
 963         dev_close(cfhsi->ndev);
 964         rtnl_unlock();
 965 }
 966
 967 static void cfhsi_wake_up_cb(struct cfhsi_cb_ops *cb_ops)
 968 {
 969         struct cfhsi *cfhsi = NULL;
 970
 971         cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
 972         netdev_dbg(cfhsi->ndev, "%s.\n",
 973                 __func__);
 974
 975         set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
 976         wake_up_interruptible(&cfhsi->wake_up_wait);
 977
 978         if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
 979                 return;
 980
 981         /* Schedule wake up work queue if the peer initiates. */
 982         if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
 983                 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
 984 }
 985
 986 static void cfhsi_wake_down_cb(struct cfhsi_cb_ops *cb_ops)
 987 {
 988         struct cfhsi *cfhsi = NULL;
 989
 990         cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
 991         netdev_dbg(cfhsi->ndev, "%s.\n",
 992                 __func__);
 993
 994         /* Initiating low power is only permitted by the host (us). */
 995         set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
 996         wake_up_interruptible(&cfhsi->wake_down_wait);
 997 }
 998
 999 static void cfhsi_aggregation_tout(struct timer_list *t)
1000 {
1001         struct cfhsi *cfhsi = from_timer(cfhsi, t, aggregation_timer);
1002
1003         netdev_dbg(cfhsi->ndev, "%s.\n",
1004                 __func__);
1005
1006         cfhsi_start_tx(cfhsi);
1007 }
1008
1009 static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
1010 {
1011         struct cfhsi *cfhsi = NULL;
1012         int start_xfer = 0;
1013         int timer_active;
1014         int prio;
1015
1016         if (!dev)
1017                 return -EINVAL;
1018
1019         cfhsi = netdev_priv(dev);
1020
1021         switch (skb->priority) {
1022         case TC_PRIO_BESTEFFORT:
1023         case TC_PRIO_FILLER:
1024         case TC_PRIO_BULK:
1025                 prio = CFHSI_PRIO_BEBK;
1026                 break;
1027         case TC_PRIO_INTERACTIVE_BULK:
1028                 prio = CFHSI_PRIO_VI;
1029                 break;
1030         case TC_PRIO_INTERACTIVE:
1031                 prio = CFHSI_PRIO_VO;
1032                 break;
1033         case TC_PRIO_CONTROL:
1034         default:
1035                 prio = CFHSI_PRIO_CTL;
1036                 break;
1037         }
1038
1039         spin_lock_bh(&cfhsi->lock);
1040
1041         /* Update aggregation statistics  */
1042         cfhsi_update_aggregation_stats(cfhsi, skb, 1);
1043
1044         /* Queue the SKB */
1045         skb_queue_tail(&cfhsi->qhead[prio], skb);
1046
1047         /* Sanity check; xmit should not be called after unregister_netdev */
1048         if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
1049                 spin_unlock_bh(&cfhsi->lock);
1050                 cfhsi_abort_tx(cfhsi);
1051                 return -EINVAL;
1052         }
1053
1054         /* Send flow off if number of packets is above high water mark. */
1055         if (!cfhsi->flow_off_sent &&
1056                 cfhsi_tx_queue_len(cfhsi) > cfhsi->cfg.q_high_mark &&
1057                 cfhsi->cfdev.flowctrl) {
1058                 cfhsi->flow_off_sent = 1;
1059                 cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
1060         }
1061
1062         if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
1063                 cfhsi->tx_state = CFHSI_TX_STATE_XFER;
1064                 start_xfer = 1;
1065         }
1066
1067         if (!start_xfer) {
1068                 /* Send aggregate if it is possible */
1069                 bool aggregate_ready =
1070                         cfhsi_can_send_aggregate(cfhsi) &&
1071                         del_timer(&cfhsi->aggregation_timer) > 0;
1072                 spin_unlock_bh(&cfhsi->lock);
1073                 if (aggregate_ready)
1074                         cfhsi_start_tx(cfhsi);
1075                 return 0;
1076         }
1077
1078         /* Delete inactivity timer if started. */
1079         timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1080
1081         spin_unlock_bh(&cfhsi->lock);
1082
1083         if (timer_active) {
1084                 struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
1085                 int len;
1086                 int res;
1087
1088                 /* Create HSI frame. */
1089                 len = cfhsi_tx_frm(desc, cfhsi);
1090                 WARN_ON(!len);
1091
1092                 /* Set up new transfer. */
1093                 res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
1094                 if (WARN_ON(res < 0)) {
1095                         netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
1096                                 __func__, res);
1097                         cfhsi_abort_tx(cfhsi);
1098                 }
1099         } else {
1100                 /* Schedule wake up work queue if the we initiate. */
1101                 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1102                         queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1103         }
1104
1105         return 0;
1106 }
1107
1108 static const struct net_device_ops cfhsi_netdevops;
1109
1110 static void cfhsi_setup(struct net_device *dev)
1111 {
1112         int i;
1113         struct cfhsi *cfhsi = netdev_priv(dev);
1114         dev->features = 0;
1115         dev->type = ARPHRD_CAIF;
1116         dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1117         dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1118         dev->priv_flags |= IFF_NO_QUEUE;
1119         dev->needs_free_netdev = true;
1120         dev->netdev_ops = &cfhsi_netdevops;
1121         for (i = 0; i < CFHSI_PRIO_LAST; ++i)
1122                 skb_queue_head_init(&cfhsi->qhead[i]);
1123         cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
1124         cfhsi->cfdev.use_frag = false;
1125         cfhsi->cfdev.use_stx = false;
1126         cfhsi->cfdev.use_fcs = false;
1127         cfhsi->ndev = dev;
1128         cfhsi->cfg = hsi_default_config;
1129 }
1130
1131 static int cfhsi_open(struct net_device *ndev)
1132 {
1133         struct cfhsi *cfhsi = netdev_priv(ndev);
1134         int res;
1135
1136         clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1137
1138         /* Initialize state vaiables. */
1139         cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1140         cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
1141
1142         /* Set flow info */
1143         cfhsi->flow_off_sent = 0;
1144
1145         /*
1146          * Allocate a TX buffer with the size of a HSI packet descriptors
1147          * and the necessary room for CAIF payload frames.
1148          */
1149         cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
1150         if (!cfhsi->tx_buf) {
1151                 res = -ENODEV;
1152                 goto err_alloc_tx;
1153         }
1154
1155         /*
1156          * Allocate a RX buffer with the size of two HSI packet descriptors and
1157          * the necessary room for CAIF payload frames.
1158          */
1159         cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1160         if (!cfhsi->rx_buf) {
1161                 res = -ENODEV;
1162                 goto err_alloc_rx;
1163         }
1164
1165         cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1166         if (!cfhsi->rx_flip_buf) {
1167                 res = -ENODEV;
1168                 goto err_alloc_rx_flip;
1169         }
1170
1171         /* Initialize aggregation timeout */
1172         cfhsi->cfg.aggregation_timeout = hsi_default_config.aggregation_timeout;
1173
1174         /* Initialize recieve vaiables. */
1175         cfhsi->rx_ptr = cfhsi->rx_buf;
1176         cfhsi->rx_len = CFHSI_DESC_SZ;
1177
1178         /* Initialize spin locks. */
1179         spin_lock_init(&cfhsi->lock);
1180
1181         /* Set up the driver. */
1182         cfhsi->cb_ops.tx_done_cb = cfhsi_tx_done_cb;
1183         cfhsi->cb_ops.rx_done_cb = cfhsi_rx_done_cb;
1184         cfhsi->cb_ops.wake_up_cb = cfhsi_wake_up_cb;
1185         cfhsi->cb_ops.wake_down_cb = cfhsi_wake_down_cb;
1186
1187         /* Initialize the work queues. */
1188         INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1189         INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1190         INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1191
1192         /* Clear all bit fields. */
1193         clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1194         clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1195         clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1196         clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1197
1198         /* Create work thread. */
1199         cfhsi->wq = alloc_ordered_workqueue(cfhsi->ndev->name, WQ_MEM_RECLAIM);
1200         if (!cfhsi->wq) {
1201                 netdev_err(cfhsi->ndev, "%s: Failed to create work queue.\n",
1202                         __func__);
1203                 res = -ENODEV;
1204                 goto err_create_wq;
1205         }
1206
1207         /* Initialize wait queues. */
1208         init_waitqueue_head(&cfhsi->wake_up_wait);
1209         init_waitqueue_head(&cfhsi->wake_down_wait);
1210         init_waitqueue_head(&cfhsi->flush_fifo_wait);
1211
1212         /* Setup the inactivity timer. */
1213         timer_setup(&cfhsi->inactivity_timer, cfhsi_inactivity_tout, 0);
1214         /* Setup the slowpath RX timer. */
1215         timer_setup(&cfhsi->rx_slowpath_timer, cfhsi_rx_slowpath, 0);
1216         /* Setup the aggregation timer. */
1217         timer_setup(&cfhsi->aggregation_timer, cfhsi_aggregation_tout, 0);
1218
1219         /* Activate HSI interface. */
1220         res = cfhsi->ops->cfhsi_up(cfhsi->ops);
1221         if (res) {
1222                 netdev_err(cfhsi->ndev,
1223                         "%s: can't activate HSI interface: %d.\n",
1224                         __func__, res);
1225                 goto err_activate;
1226         }
1227
1228         /* Flush FIFO */
1229         res = cfhsi_flush_fifo(cfhsi);
1230         if (res) {
1231                 netdev_err(cfhsi->ndev, "%s: Can't flush FIFO: %d.\n",
1232                         __func__, res);
1233                 goto err_net_reg;
1234         }
1235         return res;
1236
1237  err_net_reg:
1238         cfhsi->ops->cfhsi_down(cfhsi->ops);
1239  err_activate:
1240         destroy_workqueue(cfhsi->wq);
1241  err_create_wq:
1242         kfree(cfhsi->rx_flip_buf);
1243  err_alloc_rx_flip:
1244         kfree(cfhsi->rx_buf);
1245  err_alloc_rx:
1246         kfree(cfhsi->tx_buf);
1247  err_alloc_tx:
1248         return res;
1249 }
1250
1251 static int cfhsi_close(struct net_device *ndev)
1252 {
1253         struct cfhsi *cfhsi = netdev_priv(ndev);
1254         u8 *tx_buf, *rx_buf, *flip_buf;
1255
1256         /* going to shutdown driver */
1257         set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1258
1259         /* Delete timers if pending */
1260         del_timer_sync(&cfhsi->inactivity_timer);
1261         del_timer_sync(&cfhsi->rx_slowpath_timer);
1262         del_timer_sync(&cfhsi->aggregation_timer);
1263
1264         /* Cancel pending RX request (if any) */
1265         cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
1266
1267         /* Destroy workqueue */
1268         destroy_workqueue(cfhsi->wq);
1269
1270         /* Store bufferes: will be freed later. */
1271         tx_buf = cfhsi->tx_buf;
1272         rx_buf = cfhsi->rx_buf;
1273         flip_buf = cfhsi->rx_flip_buf;
1274         /* Flush transmit queues. */
1275         cfhsi_abort_tx(cfhsi);
1276
1277         /* Deactivate interface */
1278         cfhsi->ops->cfhsi_down(cfhsi->ops);
1279
1280         /* Free buffers. */
1281         kfree(tx_buf);
1282         kfree(rx_buf);
1283         kfree(flip_buf);
1284         return 0;
1285 }
1286
1287 static void cfhsi_uninit(struct net_device *dev)
1288 {
1289         struct cfhsi *cfhsi = netdev_priv(dev);
1290         ASSERT_RTNL();
1291         symbol_put(cfhsi_get_device);
1292         list_del(&cfhsi->list);
1293 }
1294
1295 static const struct net_device_ops cfhsi_netdevops = {
1296         .ndo_uninit = cfhsi_uninit,
1297         .ndo_open = cfhsi_open,
1298         .ndo_stop = cfhsi_close,
1299         .ndo_start_xmit = cfhsi_xmit
1300 };
1301
1302 static void cfhsi_netlink_parms(struct nlattr *data[], struct cfhsi *cfhsi)
1303 {
1304         int i;
1305
1306         if (!data) {
1307                 pr_debug("no params data found\n");
1308                 return;
1309         }
1310
1311         i = __IFLA_CAIF_HSI_INACTIVITY_TOUT;
1312         /*
1313          * Inactivity timeout in millisecs. Lowest possible value is 1,
1314          * and highest possible is NEXT_TIMER_MAX_DELTA.
1315          */
1316         if (data[i]) {
1317                 u32 inactivity_timeout = nla_get_u32(data[i]);
1318                 /* Pre-calculate inactivity timeout. */
1319                 cfhsi->cfg.inactivity_timeout = inactivity_timeout * HZ / 1000;
1320                 if (cfhsi->cfg.inactivity_timeout == 0)
1321                         cfhsi->cfg.inactivity_timeout = 1;
1322                 else if (cfhsi->cfg.inactivity_timeout > NEXT_TIMER_MAX_DELTA)
1323                         cfhsi->cfg.inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1324         }
1325
1326         i = __IFLA_CAIF_HSI_AGGREGATION_TOUT;
1327         if (data[i])
1328                 cfhsi->cfg.aggregation_timeout = nla_get_u32(data[i]);
1329
1330         i = __IFLA_CAIF_HSI_HEAD_ALIGN;
1331         if (data[i])
1332                 cfhsi->cfg.head_align = nla_get_u32(data[i]);
1333
1334         i = __IFLA_CAIF_HSI_TAIL_ALIGN;
1335         if (data[i])
1336                 cfhsi->cfg.tail_align = nla_get_u32(data[i]);
1337
1338         i = __IFLA_CAIF_HSI_QHIGH_WATERMARK;
1339         if (data[i])
1340                 cfhsi->cfg.q_high_mark = nla_get_u32(data[i]);
1341
1342         i = __IFLA_CAIF_HSI_QLOW_WATERMARK;
1343         if (data[i])
1344                 cfhsi->cfg.q_low_mark = nla_get_u32(data[i]);
1345 }
1346
1347 static int caif_hsi_changelink(struct net_device *dev, struct nlattr *tb[],
1348                                struct nlattr *data[],
1349                                struct netlink_ext_ack *extack)
1350 {
1351         cfhsi_netlink_parms(data, netdev_priv(dev));
1352         netdev_state_change(dev);
1353         return 0;
1354 }
1355
1356 static const struct nla_policy caif_hsi_policy[__IFLA_CAIF_HSI_MAX + 1] = {
1357         [__IFLA_CAIF_HSI_INACTIVITY_TOUT] = { .type = NLA_U32, .len = 4 },
1358         [__IFLA_CAIF_HSI_AGGREGATION_TOUT] = { .type = NLA_U32, .len = 4 },
1359         [__IFLA_CAIF_HSI_HEAD_ALIGN] = { .type = NLA_U32, .len = 4 },
1360         [__IFLA_CAIF_HSI_TAIL_ALIGN] = { .type = NLA_U32, .len = 4 },
1361         [__IFLA_CAIF_HSI_QHIGH_WATERMARK] = { .type = NLA_U32, .len = 4 },
1362         [__IFLA_CAIF_HSI_QLOW_WATERMARK] = { .type = NLA_U32, .len = 4 },
1363 };
1364
1365 static size_t caif_hsi_get_size(const struct net_device *dev)
1366 {
1367         int i;
1368         size_t s = 0;
1369         for (i = __IFLA_CAIF_HSI_UNSPEC + 1; i < __IFLA_CAIF_HSI_MAX; i++)
1370                 s += nla_total_size(caif_hsi_policy[i].len);
1371         return s;
1372 }
1373
1374 static int caif_hsi_fill_info(struct sk_buff *skb, const struct net_device *dev)
1375 {
1376         struct cfhsi *cfhsi = netdev_priv(dev);
1377
1378         if (nla_put_u32(skb, __IFLA_CAIF_HSI_INACTIVITY_TOUT,
1379                         cfhsi->cfg.inactivity_timeout) ||
1380             nla_put_u32(skb, __IFLA_CAIF_HSI_AGGREGATION_TOUT,
1381                         cfhsi->cfg.aggregation_timeout) ||
1382             nla_put_u32(skb, __IFLA_CAIF_HSI_HEAD_ALIGN,
1383                         cfhsi->cfg.head_align) ||
1384             nla_put_u32(skb, __IFLA_CAIF_HSI_TAIL_ALIGN,
1385                         cfhsi->cfg.tail_align) ||
1386             nla_put_u32(skb, __IFLA_CAIF_HSI_QHIGH_WATERMARK,
1387                         cfhsi->cfg.q_high_mark) ||
1388             nla_put_u32(skb, __IFLA_CAIF_HSI_QLOW_WATERMARK,
1389                         cfhsi->cfg.q_low_mark))
1390                 return -EMSGSIZE;
1391
1392         return 0;
1393 }
1394
1395 static int caif_hsi_newlink(struct net *src_net, struct net_device *dev,
1396                             struct nlattr *tb[], struct nlattr *data[],
1397                             struct netlink_ext_ack *extack)
1398 {
1399         struct cfhsi *cfhsi = NULL;
1400         struct cfhsi_ops *(*get_ops)(void);
1401
1402         ASSERT_RTNL();
1403
1404         cfhsi = netdev_priv(dev);
1405         cfhsi_netlink_parms(data, cfhsi);
1406
1407         get_ops = symbol_get(cfhsi_get_ops);
1408         if (!get_ops) {
1409                 pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1410                 return -ENODEV;
1411         }
1412
1413         /* Assign the HSI device. */
1414         cfhsi->ops = (*get_ops)();
1415         if (!cfhsi->ops) {
1416                 pr_err("%s: failed to get the cfhsi_ops\n", __func__);
1417                 goto err;
1418         }
1419
1420         /* Assign the driver to this HSI device. */
1421         cfhsi->ops->cb_ops = &cfhsi->cb_ops;
1422         if (register_netdevice(dev)) {
1423                 pr_warn("%s: caif_hsi device registration failed\n", __func__);
1424                 goto err;
1425         }
1426         /* Add CAIF HSI device to list. */
1427         list_add_tail(&cfhsi->list, &cfhsi_list);
1428
1429         return 0;
1430 err:
1431         symbol_put(cfhsi_get_ops);
1432         return -ENODEV;
1433 }
1434
1435 static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
1436         .kind           = "cfhsi",
1437         .priv_size      = sizeof(struct cfhsi),
1438         .setup          = cfhsi_setup,
1439         .maxtype        = __IFLA_CAIF_HSI_MAX,
1440         .policy = caif_hsi_policy,
1441         .newlink        = caif_hsi_newlink,
1442         .changelink     = caif_hsi_changelink,
1443         .get_size       = caif_hsi_get_size,
1444         .fill_info      = caif_hsi_fill_info,
1445 };
1446
1447 static void __exit cfhsi_exit_module(void)
1448 {
1449         struct list_head *list_node;
1450         struct list_head *n;
1451         struct cfhsi *cfhsi;
1452
1453         rtnl_link_unregister(&caif_hsi_link_ops);
1454
1455         rtnl_lock();
1456         list_for_each_safe(list_node, n, &cfhsi_list) {
1457                 cfhsi = list_entry(list_node, struct cfhsi, list);
1458                 unregister_netdevice(cfhsi->ndev);
1459         }
1460         rtnl_unlock();
1461 }
1462
1463 static int __init cfhsi_init_module(void)
1464 {
1465         return rtnl_link_register(&caif_hsi_link_ops);
1466 }
1467
1468 module_init(cfhsi_init_module);
1469 module_exit(cfhsi_exit_module);