drivers/net/wireless/b43/pio.c

   1 /*
   2
   3   Broadcom B43 wireless driver
   4
   5   PIO data transfer
   6
   7   Copyright (c) 2005-2008 Michael Buesch <mb@bu3sch.de>
   8
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; either version 2 of the License, or
  12   (at your option) any later version.
  13
  14   This program is distributed in the hope that it will be useful,
  15   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17   GNU General Public License for more details.
  18
  19   You should have received a copy of the GNU General Public License
  20   along with this program; see the file COPYING.  If not, write to
  21   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  22   Boston, MA 02110-1301, USA.
  23
  24 */
  25
  26 #include "b43.h"
  27 #include "pio.h"
  28 #include "dma.h"
  29 #include "main.h"
  30 #include "xmit.h"
  31
  32 #include <linux/delay.h>
  33
  34
  35 static void b43_pio_rx_work(struct work_struct *work);
  36
  37
  38 static u16 generate_cookie(struct b43_pio_txqueue *q,
  39                            struct b43_pio_txpacket *pack)
  40 {
  41         u16 cookie;
  42
  43         /* Use the upper 4 bits of the cookie as
  44          * PIO controller ID and store the packet index number
  45          * in the lower 12 bits.
  46          * Note that the cookie must never be 0, as this
  47          * is a special value used in RX path.
  48          * It can also not be 0xFFFF because that is special
  49          * for multicast frames.
  50          */
  51         cookie = (((u16)q->index + 1) << 12);
  52         cookie |= pack->index;
  53
  54         return cookie;
  55 }
  56
  57 static
  58 struct b43_pio_txqueue * parse_cookie(struct b43_wldev *dev,
  59                                       u16 cookie,
  60                                       struct b43_pio_txpacket **pack)
  61 {
  62         struct b43_pio *pio = &dev->pio;
  63         struct b43_pio_txqueue *q = NULL;
  64         unsigned int pack_index;
  65
  66         switch (cookie & 0xF000) {
  67         case 0x1000:
  68                 q = pio->tx_queue_AC_BK;
  69                 break;
  70         case 0x2000:
  71                 q = pio->tx_queue_AC_BE;
  72                 break;
  73         case 0x3000:
  74                 q = pio->tx_queue_AC_VI;
  75                 break;
  76         case 0x4000:
  77                 q = pio->tx_queue_AC_VO;
  78                 break;
  79         case 0x5000:
  80                 q = pio->tx_queue_mcast;
  81                 break;
  82         }
  83         if (B43_WARN_ON(!q))
  84                 return NULL;
  85         pack_index = (cookie & 0x0FFF);
  86         if (B43_WARN_ON(pack_index >= ARRAY_SIZE(q->packets)))
  87                 return NULL;
  88         *pack = &q->packets[pack_index];
  89
  90         return q;
  91 }
  92
  93 static u16 index_to_pioqueue_base(struct b43_wldev *dev,
  94                                   unsigned int index)
  95 {
  96         static const u16 bases[] = {
  97                 B43_MMIO_PIO_BASE0,
  98                 B43_MMIO_PIO_BASE1,
  99                 B43_MMIO_PIO_BASE2,
 100                 B43_MMIO_PIO_BASE3,
 101                 B43_MMIO_PIO_BASE4,
 102                 B43_MMIO_PIO_BASE5,
 103                 B43_MMIO_PIO_BASE6,
 104                 B43_MMIO_PIO_BASE7,
 105         };
 106         static const u16 bases_rev11[] = {
 107                 B43_MMIO_PIO11_BASE0,
 108                 B43_MMIO_PIO11_BASE1,
 109                 B43_MMIO_PIO11_BASE2,
 110                 B43_MMIO_PIO11_BASE3,
 111                 B43_MMIO_PIO11_BASE4,
 112                 B43_MMIO_PIO11_BASE5,
 113         };
 114
 115         if (dev->dev->id.revision >= 11) {
 116                 B43_WARN_ON(index >= ARRAY_SIZE(bases_rev11));
 117                 return bases_rev11[index];
 118         }
 119         B43_WARN_ON(index >= ARRAY_SIZE(bases));
 120         return bases[index];
 121 }
 122
 123 static u16 pio_txqueue_offset(struct b43_wldev *dev)
 124 {
 125         if (dev->dev->id.revision >= 11)
 126                 return 0x18;
 127         return 0;
 128 }
 129
 130 static u16 pio_rxqueue_offset(struct b43_wldev *dev)
 131 {
 132         if (dev->dev->id.revision >= 11)
 133                 return 0x38;
 134         return 8;
 135 }
 136
 137 static struct b43_pio_txqueue * b43_setup_pioqueue_tx(struct b43_wldev *dev,
 138                                                       unsigned int index)
 139 {
 140         struct b43_pio_txqueue *q;
 141         struct b43_pio_txpacket *p;
 142         unsigned int i;
 143
 144         q = kzalloc(sizeof(*q), GFP_KERNEL);
 145         if (!q)
 146                 return NULL;
 147         spin_lock_init(&q->lock);
 148         q->dev = dev;
 149         q->rev = dev->dev->id.revision;
 150         q->mmio_base = index_to_pioqueue_base(dev, index) +
 151                        pio_txqueue_offset(dev);
 152         q->index = index;
 153
 154         q->free_packet_slots = B43_PIO_MAX_NR_TXPACKETS;
 155         if (q->rev >= 8) {
 156                 q->buffer_size = 1920; //FIXME this constant is wrong.
 157         } else {
 158                 q->buffer_size = b43_piotx_read16(q, B43_PIO_TXQBUFSIZE);
 159                 q->buffer_size -= 80;
 160         }
 161
 162         INIT_LIST_HEAD(&q->packets_list);
 163         for (i = 0; i < ARRAY_SIZE(q->packets); i++) {
 164                 p = &(q->packets[i]);
 165                 INIT_LIST_HEAD(&p->list);
 166                 p->index = i;
 167                 p->queue = q;
 168                 list_add(&p->list, &q->packets_list);
 169         }
 170
 171         return q;
 172 }
 173
 174 static struct b43_pio_rxqueue * b43_setup_pioqueue_rx(struct b43_wldev *dev,
 175                                                       unsigned int index)
 176 {
 177         struct b43_pio_rxqueue *q;
 178
 179         q = kzalloc(sizeof(*q), GFP_KERNEL);
 180         if (!q)
 181                 return NULL;
 182         spin_lock_init(&q->lock);
 183         q->dev = dev;
 184         q->rev = dev->dev->id.revision;
 185         q->mmio_base = index_to_pioqueue_base(dev, index) +
 186                        pio_rxqueue_offset(dev);
 187         INIT_WORK(&q->rx_work, b43_pio_rx_work);
 188
 189         /* Enable Direct FIFO RX (PIO) on the engine. */
 190         b43_dma_direct_fifo_rx(dev, index, 1);
 191
 192         return q;
 193 }
 194
 195 static void b43_pio_cancel_tx_packets(struct b43_pio_txqueue *q)
 196 {
 197         struct b43_pio_txpacket *pack;
 198         unsigned int i;
 199
 200         for (i = 0; i < ARRAY_SIZE(q->packets); i++) {
 201                 pack = &(q->packets[i]);
 202                 if (pack->skb) {
 203                         dev_kfree_skb_any(pack->skb);
 204                         pack->skb = NULL;
 205                 }
 206         }
 207 }
 208
 209 static void b43_destroy_pioqueue_tx(struct b43_pio_txqueue *q,
 210                                     const char *name)
 211 {
 212         if (!q)
 213                 return;
 214         b43_pio_cancel_tx_packets(q);
 215         kfree(q);
 216 }
 217
 218 static void b43_destroy_pioqueue_rx(struct b43_pio_rxqueue *q,
 219                                     const char *name)
 220 {
 221         if (!q)
 222                 return;
 223         kfree(q);
 224 }
 225
 226 #define destroy_queue_tx(pio, queue) do {                               \
 227         b43_destroy_pioqueue_tx((pio)->queue, __stringify(queue));      \
 228         (pio)->queue = NULL;                                            \
 229   } while (0)
 230
 231 #define destroy_queue_rx(pio, queue) do {                               \
 232         b43_destroy_pioqueue_rx((pio)->queue, __stringify(queue));      \
 233         (pio)->queue = NULL;                                            \
 234   } while (0)
 235
 236 void b43_pio_free(struct b43_wldev *dev)
 237 {
 238         struct b43_pio *pio;
 239
 240         if (!b43_using_pio_transfers(dev))
 241                 return;
 242         pio = &dev->pio;
 243
 244         destroy_queue_rx(pio, rx_queue);
 245         destroy_queue_tx(pio, tx_queue_mcast);
 246         destroy_queue_tx(pio, tx_queue_AC_VO);
 247         destroy_queue_tx(pio, tx_queue_AC_VI);
 248         destroy_queue_tx(pio, tx_queue_AC_BE);
 249         destroy_queue_tx(pio, tx_queue_AC_BK);
 250 }
 251
 252 void b43_pio_stop(struct b43_wldev *dev)
 253 {
 254         if (!b43_using_pio_transfers(dev))
 255                 return;
 256         cancel_work_sync(&dev->pio.rx_queue->rx_work);
 257 }
 258
 259 int b43_pio_init(struct b43_wldev *dev)
 260 {
 261         struct b43_pio *pio = &dev->pio;
 262         int err = -ENOMEM;
 263
 264         b43_write32(dev, B43_MMIO_MACCTL, b43_read32(dev, B43_MMIO_MACCTL)
 265                     & ~B43_MACCTL_BE);
 266         b43_shm_write16(dev, B43_SHM_SHARED, B43_SHM_SH_RXPADOFF, 0);
 267
 268         pio->tx_queue_AC_BK = b43_setup_pioqueue_tx(dev, 0);
 269         if (!pio->tx_queue_AC_BK)
 270                 goto out;
 271
 272         pio->tx_queue_AC_BE = b43_setup_pioqueue_tx(dev, 1);
 273         if (!pio->tx_queue_AC_BE)
 274                 goto err_destroy_bk;
 275
 276         pio->tx_queue_AC_VI = b43_setup_pioqueue_tx(dev, 2);
 277         if (!pio->tx_queue_AC_VI)
 278                 goto err_destroy_be;
 279
 280         pio->tx_queue_AC_VO = b43_setup_pioqueue_tx(dev, 3);
 281         if (!pio->tx_queue_AC_VO)
 282                 goto err_destroy_vi;
 283
 284         pio->tx_queue_mcast = b43_setup_pioqueue_tx(dev, 4);
 285         if (!pio->tx_queue_mcast)
 286                 goto err_destroy_vo;
 287
 288         pio->rx_queue = b43_setup_pioqueue_rx(dev, 0);
 289         if (!pio->rx_queue)
 290                 goto err_destroy_mcast;
 291
 292         b43dbg(dev->wl, "PIO initialized\n");
 293         err = 0;
 294 out:
 295         return err;
 296
 297 err_destroy_mcast:
 298         destroy_queue_tx(pio, tx_queue_mcast);
 299 err_destroy_vo:
 300         destroy_queue_tx(pio, tx_queue_AC_VO);
 301 err_destroy_vi:
 302         destroy_queue_tx(pio, tx_queue_AC_VI);
 303 err_destroy_be:
 304         destroy_queue_tx(pio, tx_queue_AC_BE);
 305 err_destroy_bk:
 306         destroy_queue_tx(pio, tx_queue_AC_BK);
 307         return err;
 308 }
 309
 310 /* Static mapping of mac80211's queues (priorities) to b43 PIO queues. */
 311 static struct b43_pio_txqueue * select_queue_by_priority(struct b43_wldev *dev,
 312                                                          u8 queue_prio)
 313 {
 314         struct b43_pio_txqueue *q;
 315
 316         if (b43_modparam_qos) {
 317                 /* 0 = highest priority */
 318                 switch (queue_prio) {
 319                 default:
 320                         B43_WARN_ON(1);
 321                         /* fallthrough */
 322                 case 0:
 323                         q = dev->pio.tx_queue_AC_VO;
 324                         break;
 325                 case 1:
 326                         q = dev->pio.tx_queue_AC_VI;
 327                         break;
 328                 case 2:
 329                         q = dev->pio.tx_queue_AC_BE;
 330                         break;
 331                 case 3:
 332                         q = dev->pio.tx_queue_AC_BK;
 333                         break;
 334                 }
 335         } else
 336                 q = dev->pio.tx_queue_AC_BE;
 337
 338         return q;
 339 }
 340
 341 static u16 tx_write_2byte_queue(struct b43_pio_txqueue *q,
 342                                 u16 ctl,
 343                                 const void *_data,
 344                                 unsigned int data_len)
 345 {
 346         struct b43_wldev *dev = q->dev;
 347         const u8 *data = _data;
 348
 349         ctl |= B43_PIO_TXCTL_WRITELO | B43_PIO_TXCTL_WRITEHI;
 350         b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
 351
 352         ssb_block_write(dev->dev, data, (data_len & ~1),
 353                         q->mmio_base + B43_PIO_TXDATA,
 354                         sizeof(u16));
 355         if (data_len & 1) {
 356                 /* Write the last byte. */
 357                 ctl &= ~B43_PIO_TXCTL_WRITEHI;
 358                 b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
 359                 b43_piotx_write16(q, B43_PIO_TXDATA, data[data_len - 1]);
 360         }
 361
 362         return ctl;
 363 }
 364
 365 static void pio_tx_frame_2byte_queue(struct b43_pio_txpacket *pack,
 366                                      const u8 *hdr, unsigned int hdrlen)
 367 {
 368         struct b43_pio_txqueue *q = pack->queue;
 369         const char *frame = pack->skb->data;
 370         unsigned int frame_len = pack->skb->len;
 371         u16 ctl;
 372
 373         ctl = b43_piotx_read16(q, B43_PIO_TXCTL);
 374         ctl |= B43_PIO_TXCTL_FREADY;
 375         ctl &= ~B43_PIO_TXCTL_EOF;
 376
 377         /* Transfer the header data. */
 378         ctl = tx_write_2byte_queue(q, ctl, hdr, hdrlen);
 379         /* Transfer the frame data. */
 380         ctl = tx_write_2byte_queue(q, ctl, frame, frame_len);
 381
 382         ctl |= B43_PIO_TXCTL_EOF;
 383         b43_piotx_write16(q, B43_PIO_TXCTL, ctl);
 384 }
 385
 386 static u32 tx_write_4byte_queue(struct b43_pio_txqueue *q,
 387                                 u32 ctl,
 388                                 const void *_data,
 389                                 unsigned int data_len)
 390 {
 391         struct b43_wldev *dev = q->dev;
 392         const u8 *data = _data;
 393
 394         ctl |= B43_PIO8_TXCTL_0_7 | B43_PIO8_TXCTL_8_15 |
 395                B43_PIO8_TXCTL_16_23 | B43_PIO8_TXCTL_24_31;
 396         b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
 397
 398         ssb_block_write(dev->dev, data, (data_len & ~3),
 399                         q->mmio_base + B43_PIO8_TXDATA,
 400                         sizeof(u32));
 401         if (data_len & 3) {
 402                 u32 value = 0;
 403
 404                 /* Write the last few bytes. */
 405                 ctl &= ~(B43_PIO8_TXCTL_8_15 | B43_PIO8_TXCTL_16_23 |
 406                          B43_PIO8_TXCTL_24_31);
 407                 data = &(data[data_len - 1]);
 408                 switch (data_len & 3) {
 409                 case 3:
 410                         ctl |= B43_PIO8_TXCTL_16_23;
 411                         value |= (u32)(*data) << 16;
 412                         data--;
 413                 case 2:
 414                         ctl |= B43_PIO8_TXCTL_8_15;
 415                         value |= (u32)(*data) << 8;
 416                         data--;
 417                 case 1:
 418                         value |= (u32)(*data);
 419                 }
 420                 b43_piotx_write32(q, B43_PIO8_TXCTL, ctl);
 421                 b43_piotx_write32(q, B43_PIO8_TXDATA, value);
 422         }
 423
 424         return ctl;
 425 }
 426
 427 static void pio_tx_frame_4byte_queue(struct b43_pio_txpacket *pack,
 428                                      const u8 *hdr, unsigned int hdrlen)
 429 {
 430         struct b43_pio_txqueue *q = pack->queue;
 431         const char *frame = pack->skb->data;
 432         unsigned int frame_len = pack->skb->len;
 433         u32 ctl;
 434
 435         ctl = b43_piotx_read32(q, B43_PIO8_TXCTL);
 436         ctl |= B43_PIO8_TXCTL_FREADY;
 437         ctl &= ~B43_PIO8_TXCTL_EOF;
 438
 439         /* Transfer the header data. */
 440         ctl = tx_write_4byte_queue(q, ctl, hdr, hdrlen);
 441         /* Transfer the frame data. */
 442         ctl = tx_write_4byte_queue(q, ctl, frame, frame_len);
 443
 444         ctl |= B43_PIO8_TXCTL_EOF;
 445         b43_piotx_write32(q, B43_PIO_TXCTL, ctl);
 446 }
 447
 448 static int pio_tx_frame(struct b43_pio_txqueue *q,
 449                         struct sk_buff *skb,
 450                         struct ieee80211_tx_control *ctl)
 451 {
 452         struct b43_pio_txpacket *pack;
 453         struct b43_txhdr txhdr;
 454         u16 cookie;
 455         int err;
 456         unsigned int hdrlen;
 457
 458         B43_WARN_ON(list_empty(&q->packets_list));
 459         pack = list_entry(q->packets_list.next,
 460                           struct b43_pio_txpacket, list);
 461         memset(&pack->txstat, 0, sizeof(pack->txstat));
 462         memcpy(&pack->txstat.control, ctl, sizeof(*ctl));
 463
 464         cookie = generate_cookie(q, pack);
 465         hdrlen = b43_txhdr_size(q->dev);
 466         err = b43_generate_txhdr(q->dev, (u8 *)&txhdr, skb->data,
 467                                  skb->len, ctl, cookie);
 468         if (err)
 469                 return err;
 470
 471         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
 472                 /* Tell the firmware about the cookie of the last
 473                  * mcast frame, so it can clear the more-data bit in it. */
 474                 b43_shm_write16(q->dev, B43_SHM_SHARED,
 475                                 B43_SHM_SH_MCASTCOOKIE, cookie);
 476         }
 477
 478         pack->skb = skb;
 479         if (q->rev >= 8)
 480                 pio_tx_frame_4byte_queue(pack, (const u8 *)&txhdr, hdrlen);
 481         else
 482                 pio_tx_frame_2byte_queue(pack, (const u8 *)&txhdr, hdrlen);
 483
 484         /* Remove it from the list of available packet slots.
 485          * It will be put back when we receive the status report. */
 486         list_del(&pack->list);
 487
 488         /* Update the queue statistics. */
 489         q->buffer_used += roundup(skb->len + hdrlen, 4);
 490         q->free_packet_slots -= 1;
 491
 492         return 0;
 493 }
 494
 495 int b43_pio_tx(struct b43_wldev *dev,
 496                struct sk_buff *skb, struct ieee80211_tx_control *ctl)
 497 {
 498         struct b43_pio_txqueue *q;
 499         struct ieee80211_hdr *hdr;
 500         unsigned long flags;
 501         unsigned int hdrlen, total_len;
 502         int err = 0;
 503
 504         hdr = (struct ieee80211_hdr *)skb->data;
 505         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
 506                 /* The multicast queue will be sent after the DTIM. */
 507                 q = dev->pio.tx_queue_mcast;
 508                 /* Set the frame More-Data bit. Ucode will clear it
 509                  * for us on the last frame. */
 510                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 511         } else {
 512                 /* Decide by priority where to put this frame. */
 513                 q = select_queue_by_priority(dev, ctl->queue);
 514         }
 515
 516         spin_lock_irqsave(&q->lock, flags);
 517
 518         hdrlen = b43_txhdr_size(dev);
 519         total_len = roundup(skb->len + hdrlen, 4);
 520
 521         if (unlikely(total_len > q->buffer_size)) {
 522                 err = -ENOBUFS;
 523                 b43dbg(dev->wl, "PIO: TX packet longer than queue.\n");
 524                 goto out_unlock;
 525         }
 526         if (unlikely(q->free_packet_slots == 0)) {
 527                 err = -ENOBUFS;
 528                 b43warn(dev->wl, "PIO: TX packet overflow.\n");
 529                 goto out_unlock;
 530         }
 531         B43_WARN_ON(q->buffer_used > q->buffer_size);
 532
 533         if (total_len > (q->buffer_size - q->buffer_used)) {
 534                 /* Not enough memory on the queue. */
 535                 err = -EBUSY;
 536                 ieee80211_stop_queue(dev->wl->hw, ctl->queue);
 537                 q->stopped = 1;
 538                 goto out_unlock;
 539         }
 540
 541         /* Assign the queue number to the ring (if not already done before)
 542          * so TX status handling can use it. The mac80211-queue to b43-queue
 543          * mapping is static, so we don't need to store it per frame. */
 544         q->queue_prio = ctl->queue;
 545
 546         err = pio_tx_frame(q, skb, ctl);
 547         if (unlikely(err == -ENOKEY)) {
 548                 /* Drop this packet, as we don't have the encryption key
 549                  * anymore and must not transmit it unencrypted. */
 550                 dev_kfree_skb_any(skb);
 551                 err = 0;
 552                 goto out_unlock;
 553         }
 554         if (unlikely(err)) {
 555                 b43err(dev->wl, "PIO transmission failure\n");
 556                 goto out_unlock;
 557         }
 558         q->nr_tx_packets++;
 559
 560         B43_WARN_ON(q->buffer_used > q->buffer_size);
 561         if (((q->buffer_size - q->buffer_used) < roundup(2 + 2 + 6, 4)) ||
 562             (q->free_packet_slots == 0)) {
 563                 /* The queue is full. */
 564                 ieee80211_stop_queue(dev->wl->hw, ctl->queue);
 565                 q->stopped = 1;
 566         }
 567
 568 out_unlock:
 569         spin_unlock_irqrestore(&q->lock, flags);
 570
 571         return err;
 572 }
 573
 574 /* Called with IRQs disabled. */
 575 void b43_pio_handle_txstatus(struct b43_wldev *dev,
 576                              const struct b43_txstatus *status)
 577 {
 578         struct b43_pio_txqueue *q;
 579         struct b43_pio_txpacket *pack = NULL;
 580         unsigned int total_len;
 581
 582         q = parse_cookie(dev, status->cookie, &pack);
 583         if (unlikely(!q))
 584                 return;
 585         B43_WARN_ON(!pack);
 586
 587         spin_lock(&q->lock); /* IRQs are already disabled. */
 588
 589         b43_fill_txstatus_report(&(pack->txstat), status);
 590
 591         total_len = pack->skb->len + b43_txhdr_size(dev);
 592         total_len = roundup(total_len, 4);
 593         q->buffer_used -= total_len;
 594         q->free_packet_slots += 1;
 595
 596         ieee80211_tx_status_irqsafe(dev->wl->hw, pack->skb,
 597                                     &(pack->txstat));
 598         pack->skb = NULL;
 599         list_add(&pack->list, &q->packets_list);
 600
 601         if (q->stopped) {
 602                 ieee80211_wake_queue(dev->wl->hw, q->queue_prio);
 603                 q->stopped = 0;
 604         }
 605
 606         spin_unlock(&q->lock);
 607 }
 608
 609 void b43_pio_get_tx_stats(struct b43_wldev *dev,
 610                           struct ieee80211_tx_queue_stats *stats)
 611 {
 612         const int nr_queues = dev->wl->hw->queues;
 613         struct b43_pio_txqueue *q;
 614         struct ieee80211_tx_queue_stats_data *data;
 615         unsigned long flags;
 616         int i;
 617
 618         for (i = 0; i < nr_queues; i++) {
 619                 data = &(stats->data[i]);
 620                 q = select_queue_by_priority(dev, i);
 621
 622                 spin_lock_irqsave(&q->lock, flags);
 623                 data->len = B43_PIO_MAX_NR_TXPACKETS - q->free_packet_slots;
 624                 data->limit = B43_PIO_MAX_NR_TXPACKETS;
 625                 data->count = q->nr_tx_packets;
 626                 spin_unlock_irqrestore(&q->lock, flags);
 627         }
 628 }
 629
 630 /* Returns whether we should fetch another frame. */
 631 static bool pio_rx_frame(struct b43_pio_rxqueue *q)
 632 {
 633         struct b43_wldev *dev = q->dev;
 634         struct b43_rxhdr_fw4 rxhdr;
 635         u16 len;
 636         u32 macstat;
 637         unsigned int i, padding;
 638         struct sk_buff *skb;
 639         const char *err_msg = NULL;
 640
 641         memset(&rxhdr, 0, sizeof(rxhdr));
 642
 643         /* Check if we have data and wait for it to get ready. */
 644         if (q->rev >= 8) {
 645                 u32 ctl;
 646
 647                 ctl = b43_piorx_read32(q, B43_PIO8_RXCTL);
 648                 if (!(ctl & B43_PIO8_RXCTL_FRAMERDY))
 649                         return 0;
 650                 b43_piorx_write32(q, B43_PIO8_RXCTL,
 651                                   B43_PIO8_RXCTL_FRAMERDY);
 652                 for (i = 0; i < 10; i++) {
 653                         ctl = b43_piorx_read32(q, B43_PIO8_RXCTL);
 654                         if (ctl & B43_PIO8_RXCTL_DATARDY)
 655                                 goto data_ready;
 656                         udelay(10);
 657                 }
 658         } else {
 659                 u16 ctl;
 660
 661                 ctl = b43_piorx_read16(q, B43_PIO_RXCTL);
 662                 if (!(ctl & B43_PIO_RXCTL_FRAMERDY))
 663                         return 0;
 664                 b43_piorx_write16(q, B43_PIO_RXCTL,
 665                                   B43_PIO_RXCTL_FRAMERDY);
 666                 for (i = 0; i < 10; i++) {
 667                         ctl = b43_piorx_read16(q, B43_PIO_RXCTL);
 668                         if (ctl & B43_PIO_RXCTL_DATARDY)
 669                                 goto data_ready;
 670                         udelay(10);
 671                 }
 672         }
 673         b43dbg(q->dev->wl, "PIO RX timed out\n");
 674         return 1;
 675 data_ready:
 676
 677         /* Get the preamble (RX header) */
 678         if (q->rev >= 8) {
 679                 ssb_block_read(dev->dev, &rxhdr, sizeof(rxhdr),
 680                                q->mmio_base + B43_PIO8_RXDATA,
 681                                sizeof(u32));
 682         } else {
 683                 ssb_block_read(dev->dev, &rxhdr, sizeof(rxhdr),
 684                                q->mmio_base + B43_PIO_RXDATA,
 685                                sizeof(u16));
 686         }
 687         /* Sanity checks. */
 688         len = le16_to_cpu(rxhdr.frame_len);
 689         if (unlikely(len > 0x700)) {
 690                 err_msg = "len > 0x700";
 691                 goto rx_error;
 692         }
 693         if (unlikely(len == 0)) {
 694                 err_msg = "len == 0";
 695                 goto rx_error;
 696         }
 697
 698         macstat = le32_to_cpu(rxhdr.mac_status);
 699         if (macstat & B43_RX_MAC_FCSERR) {
 700                 if (!(q->dev->wl->filter_flags & FIF_FCSFAIL)) {
 701                         /* Drop frames with failed FCS. */
 702                         err_msg = "Frame FCS error";
 703                         goto rx_error;
 704                 }
 705         }
 706
 707         /* We always pad 2 bytes, as that's what upstream code expects
 708          * due to the RX-header being 30 bytes. In case the frame is
 709          * unaligned, we pad another 2 bytes. */
 710         padding = (macstat & B43_RX_MAC_PADDING) ? 2 : 0;
 711         skb = dev_alloc_skb(len + padding + 2);
 712         if (unlikely(!skb)) {
 713                 err_msg = "Out of memory";
 714                 goto rx_error;
 715         }
 716         skb_reserve(skb, 2);
 717         skb_put(skb, len + padding);
 718         if (q->rev >= 8) {
 719                 ssb_block_read(dev->dev, skb->data + padding, (len & ~3),
 720                                q->mmio_base + B43_PIO8_RXDATA,
 721                                sizeof(u32));
 722                 if (len & 3) {
 723                         u32 value;
 724                         char *data;
 725
 726                         /* Read the last few bytes. */
 727                         value = b43_piorx_read32(q, B43_PIO8_RXDATA);
 728                         data = &(skb->data[len + padding - 1]);
 729                         switch (len & 3) {
 730                         case 3:
 731                                 *data = (value >> 16);
 732                                 data--;
 733                         case 2:
 734                                 *data = (value >> 8);
 735                                 data--;
 736                         case 1:
 737                                 *data = value;
 738                         }
 739                 }
 740         } else {
 741                 ssb_block_read(dev->dev, skb->data + padding, (len & ~1),
 742                                q->mmio_base + B43_PIO_RXDATA,
 743                                sizeof(u16));
 744                 if (len & 1) {
 745                         u16 value;
 746
 747                         /* Read the last byte. */
 748                         value = b43_piorx_read16(q, B43_PIO_RXDATA);
 749                         skb->data[len + padding - 1] = value;
 750                 }
 751         }
 752
 753         b43_rx(q->dev, skb, &rxhdr);
 754
 755         return 1;
 756
 757 rx_error:
 758         if (err_msg)
 759                 b43dbg(q->dev->wl, "PIO RX error: %s\n", err_msg);
 760         b43_piorx_write16(q, B43_PIO_RXCTL, B43_PIO_RXCTL_DATARDY);
 761         return 1;
 762 }
 763
 764 /* RX workqueue. We can sleep, yay! */
 765 static void b43_pio_rx_work(struct work_struct *work)
 766 {
 767         struct b43_pio_rxqueue *q = container_of(work, struct b43_pio_rxqueue,
 768                                                  rx_work);
 769         unsigned int budget = 50;
 770         bool stop;
 771
 772         do {
 773                 spin_lock_irq(&q->lock);
 774                 stop = (pio_rx_frame(q) == 0);
 775                 spin_unlock_irq(&q->lock);
 776                 cond_resched();
 777                 if (stop)
 778                         break;
 779         } while (--budget);
 780 }
 781
 782 /* Called with IRQs disabled. */
 783 void b43_pio_rx(struct b43_pio_rxqueue *q)
 784 {
 785         /* Due to latency issues we must run the RX path in
 786          * a workqueue to be able to schedule between packets. */
 787         queue_work(q->dev->wl->hw->workqueue, &q->rx_work);
 788 }
 789
 790 static void b43_pio_tx_suspend_queue(struct b43_pio_txqueue *q)
 791 {
 792         unsigned long flags;
 793
 794         spin_lock_irqsave(&q->lock, flags);
 795         if (q->rev >= 8) {
 796                 b43_piotx_write32(q, B43_PIO8_TXCTL,
 797                                   b43_piotx_read32(q, B43_PIO8_TXCTL)
 798                                   | B43_PIO8_TXCTL_SUSPREQ);
 799         } else {
 800                 b43_piotx_write16(q, B43_PIO_TXCTL,
 801                                   b43_piotx_read16(q, B43_PIO_TXCTL)
 802                                   | B43_PIO_TXCTL_SUSPREQ);
 803         }
 804         spin_unlock_irqrestore(&q->lock, flags);
 805 }
 806
 807 static void b43_pio_tx_resume_queue(struct b43_pio_txqueue *q)
 808 {
 809         unsigned long flags;
 810
 811         spin_lock_irqsave(&q->lock, flags);
 812         if (q->rev >= 8) {
 813                 b43_piotx_write32(q, B43_PIO8_TXCTL,
 814                                   b43_piotx_read32(q, B43_PIO8_TXCTL)
 815                                   & ~B43_PIO8_TXCTL_SUSPREQ);
 816         } else {
 817                 b43_piotx_write16(q, B43_PIO_TXCTL,
 818                                   b43_piotx_read16(q, B43_PIO_TXCTL)
 819                                   & ~B43_PIO_TXCTL_SUSPREQ);
 820         }
 821         spin_unlock_irqrestore(&q->lock, flags);
 822 }
 823
 824 void b43_pio_tx_suspend(struct b43_wldev *dev)
 825 {
 826         b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
 827         b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_BK);
 828         b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_BE);
 829         b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_VI);
 830         b43_pio_tx_suspend_queue(dev->pio.tx_queue_AC_VO);
 831         b43_pio_tx_suspend_queue(dev->pio.tx_queue_mcast);
 832 }
 833
 834 void b43_pio_tx_resume(struct b43_wldev *dev)
 835 {
 836         b43_pio_tx_resume_queue(dev->pio.tx_queue_mcast);
 837         b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_VO);
 838         b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_VI);
 839         b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_BE);
 840         b43_pio_tx_resume_queue(dev->pio.tx_queue_AC_BK);
 841         b43_power_saving_ctl_bits(dev, 0);
 842 }