root/drivers/net/wireless/broadcom/b43legacy/dma.c

DEFINITIONS

1. op32_idx2desc
2. op32_fill_descriptor
3. op32_poke_tx
4. op32_tx_suspend
5. op32_tx_resume
6. op32_get_current_rxslot
7. op32_set_current_rxslot
8. free_slots
9. next_slot
10. prev_slot
11. update_max_used_slots
12. update_max_used_slots
13. request_slot
14. priority_to_txring
15. txring_to_priority
16. b43legacy_dmacontroller_base
17. map_descbuffer
18. unmap_descbuffer
19. sync_descbuffer_for_cpu
20. sync_descbuffer_for_device
21. free_descriptor_buffer
22. alloc_ringmemory
23. free_ringmemory
24. b43legacy_dmacontroller_rx_reset
25. b43legacy_dmacontroller_tx_reset
26. b43legacy_dma_mapping_error
27. setup_rx_descbuffer
28. alloc_initial_descbuffers
29. dmacontroller_setup
30. dmacontroller_cleanup
31. free_all_descbuffers
32. b43legacy_engine_type
33. b43legacy_setup_dmaring
34. b43legacy_destroy_dmaring
35. b43legacy_dma_free
36. b43legacy_dma_init
37. generate_cookie
38. parse_cookie
39. dma_tx_fragment
40. should_inject_overflow
41. b43legacy_dma_tx
42. b43legacy_dma_handle_txstatus
43. dma_rx
44. b43legacy_dma_rx
45. b43legacy_dma_tx_suspend_ring
46. b43legacy_dma_tx_resume_ring
47. b43legacy_dma_tx_suspend
48. b43legacy_dma_tx_resume

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3 
   4   Broadcom B43legacy wireless driver
   5 
   6   DMA ringbuffer and descriptor allocation/management
   7 
   8   Copyright (c) 2005, 2006 Michael Buesch <m@bues.ch>
   9 
  10   Some code in this file is derived from the b44.c driver
  11   Copyright (C) 2002 David S. Miller
  12   Copyright (C) Pekka Pietikainen
  13 
  14 
  15 */
  16 
  17 #include "b43legacy.h"
  18 #include "dma.h"
  19 #include "main.h"
  20 #include "debugfs.h"
  21 #include "xmit.h"
  22 
  23 #include <linux/dma-mapping.h>
  24 #include <linux/pci.h>
  25 #include <linux/delay.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/slab.h>
  28 #include <net/dst.h>
  29 
  30 /* 32bit DMA ops. */
  31 static
  32 struct b43legacy_dmadesc32 *op32_idx2desc(struct b43legacy_dmaring *ring,
  33                                           int slot,
  34                                           struct b43legacy_dmadesc_meta **meta)
  35 {
  36         struct b43legacy_dmadesc32 *desc;
  37 
  38         *meta = &(ring->meta[slot]);
  39         desc = ring->descbase;
  40         desc = &(desc[slot]);
  41 
  42         return desc;
  43 }
  44 
  45 static void op32_fill_descriptor(struct b43legacy_dmaring *ring,
  46                                  struct b43legacy_dmadesc32 *desc,
  47                                  dma_addr_t dmaaddr, u16 bufsize,
  48                                  int start, int end, int irq)
  49 {
  50         struct b43legacy_dmadesc32 *descbase = ring->descbase;
  51         int slot;
  52         u32 ctl;
  53         u32 addr;
  54         u32 addrext;
  55 
  56         slot = (int)(desc - descbase);
  57         B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
  58 
  59         addr = (u32)(dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
  60         addrext = (u32)(dmaaddr & SSB_DMA_TRANSLATION_MASK)
  61                    >> SSB_DMA_TRANSLATION_SHIFT;
  62         addr |= ring->dev->dma.translation;
  63         ctl = (bufsize - ring->frameoffset)
  64               & B43legacy_DMA32_DCTL_BYTECNT;
  65         if (slot == ring->nr_slots - 1)
  66                 ctl |= B43legacy_DMA32_DCTL_DTABLEEND;
  67         if (start)
  68                 ctl |= B43legacy_DMA32_DCTL_FRAMESTART;
  69         if (end)
  70                 ctl |= B43legacy_DMA32_DCTL_FRAMEEND;
  71         if (irq)
  72                 ctl |= B43legacy_DMA32_DCTL_IRQ;
  73         ctl |= (addrext << B43legacy_DMA32_DCTL_ADDREXT_SHIFT)
  74                & B43legacy_DMA32_DCTL_ADDREXT_MASK;
  75 
  76         desc->control = cpu_to_le32(ctl);
  77         desc->address = cpu_to_le32(addr);
  78 }
  79 
  80 static void op32_poke_tx(struct b43legacy_dmaring *ring, int slot)
  81 {
  82         b43legacy_dma_write(ring, B43legacy_DMA32_TXINDEX,
  83                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
  84 }
  85 
  86 static void op32_tx_suspend(struct b43legacy_dmaring *ring)
  87 {
  88         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
  89                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
  90                             | B43legacy_DMA32_TXSUSPEND);
  91 }
  92 
  93 static void op32_tx_resume(struct b43legacy_dmaring *ring)
  94 {
  95         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
  96                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
  97                             & ~B43legacy_DMA32_TXSUSPEND);
  98 }
  99 
 100 static int op32_get_current_rxslot(struct b43legacy_dmaring *ring)
 101 {
 102         u32 val;
 103 
 104         val = b43legacy_dma_read(ring, B43legacy_DMA32_RXSTATUS);
 105         val &= B43legacy_DMA32_RXDPTR;
 106 
 107         return (val / sizeof(struct b43legacy_dmadesc32));
 108 }
 109 
 110 static void op32_set_current_rxslot(struct b43legacy_dmaring *ring,
 111                                     int slot)
 112 {
 113         b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
 114                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
 115 }
 116 
 117 static inline int free_slots(struct b43legacy_dmaring *ring)
 118 {
 119         return (ring->nr_slots - ring->used_slots);
 120 }
 121 
 122 static inline int next_slot(struct b43legacy_dmaring *ring, int slot)
 123 {
 124         B43legacy_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
 125         if (slot == ring->nr_slots - 1)
 126                 return 0;
 127         return slot + 1;
 128 }
 129 
 130 static inline int prev_slot(struct b43legacy_dmaring *ring, int slot)
 131 {
 132         B43legacy_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
 133         if (slot == 0)
 134                 return ring->nr_slots - 1;
 135         return slot - 1;
 136 }
 137 
 138 #ifdef CONFIG_B43LEGACY_DEBUG
 139 static void update_max_used_slots(struct b43legacy_dmaring *ring,
 140                                   int current_used_slots)
 141 {
 142         if (current_used_slots <= ring->max_used_slots)
 143                 return;
 144         ring->max_used_slots = current_used_slots;
 145         if (b43legacy_debug(ring->dev, B43legacy_DBG_DMAVERBOSE))
 146                 b43legacydbg(ring->dev->wl,
 147                        "max_used_slots increased to %d on %s ring %d\n",
 148                        ring->max_used_slots,
 149                        ring->tx ? "TX" : "RX",
 150                        ring->index);
 151 }
 152 #else
 153 static inline
 154 void update_max_used_slots(struct b43legacy_dmaring *ring,
 155                            int current_used_slots)
 156 { }
 157 #endif /* DEBUG */
 158 
 159 /* Request a slot for usage. */
 160 static inline
 161 int request_slot(struct b43legacy_dmaring *ring)
 162 {
 163         int slot;
 164 
 165         B43legacy_WARN_ON(!ring->tx);
 166         B43legacy_WARN_ON(ring->stopped);
 167         B43legacy_WARN_ON(free_slots(ring) == 0);
 168 
 169         slot = next_slot(ring, ring->current_slot);
 170         ring->current_slot = slot;
 171         ring->used_slots++;
 172 
 173         update_max_used_slots(ring, ring->used_slots);
 174 
 175         return slot;
 176 }
 177 
 178 /* Mac80211-queue to b43legacy-ring mapping */
 179 static struct b43legacy_dmaring *priority_to_txring(
 180                                                 struct b43legacy_wldev *dev,
 181                                                 int queue_priority)
 182 {
 183         struct b43legacy_dmaring *ring;
 184 
 185 /*FIXME: For now we always run on TX-ring-1 */
 186 return dev->dma.tx_ring1;
 187 
 188         /* 0 = highest priority */
 189         switch (queue_priority) {
 190         default:
 191                 B43legacy_WARN_ON(1);
 192                 /* fallthrough */
 193         case 0:
 194                 ring = dev->dma.tx_ring3;
 195                 break;
 196         case 1:
 197                 ring = dev->dma.tx_ring2;
 198                 break;
 199         case 2:
 200                 ring = dev->dma.tx_ring1;
 201                 break;
 202         case 3:
 203                 ring = dev->dma.tx_ring0;
 204                 break;
 205         case 4:
 206                 ring = dev->dma.tx_ring4;
 207                 break;
 208         case 5:
 209                 ring = dev->dma.tx_ring5;
 210                 break;
 211         }
 212 
 213         return ring;
 214 }
 215 
 216 /* Bcm4301-ring to mac80211-queue mapping */
 217 static inline int txring_to_priority(struct b43legacy_dmaring *ring)
 218 {
 219         static const u8 idx_to_prio[] =
 220                 { 3, 2, 1, 0, 4, 5, };
 221 
 222 /*FIXME: have only one queue, for now */
 223 return 0;
 224 
 225         return idx_to_prio[ring->index];
 226 }
 227 
 228 
 229 static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
 230                                         int controller_idx)
 231 {
 232         static const u16 map32[] = {
 233                 B43legacy_MMIO_DMA32_BASE0,
 234                 B43legacy_MMIO_DMA32_BASE1,
 235                 B43legacy_MMIO_DMA32_BASE2,
 236                 B43legacy_MMIO_DMA32_BASE3,
 237                 B43legacy_MMIO_DMA32_BASE4,
 238                 B43legacy_MMIO_DMA32_BASE5,
 239         };
 240 
 241         B43legacy_WARN_ON(!(controller_idx >= 0 &&
 242                           controller_idx < ARRAY_SIZE(map32)));
 243         return map32[controller_idx];
 244 }
 245 
 246 static inline
 247 dma_addr_t map_descbuffer(struct b43legacy_dmaring *ring,
 248                           unsigned char *buf,
 249                           size_t len,
 250                           int tx)
 251 {
 252         dma_addr_t dmaaddr;
 253 
 254         if (tx)
 255                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 256                                              buf, len,
 257                                              DMA_TO_DEVICE);
 258         else
 259                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 260                                              buf, len,
 261                                              DMA_FROM_DEVICE);
 262 
 263         return dmaaddr;
 264 }
 265 
 266 static inline
 267 void unmap_descbuffer(struct b43legacy_dmaring *ring,
 268                       dma_addr_t addr,
 269                       size_t len,
 270                       int tx)
 271 {
 272         if (tx)
 273                 dma_unmap_single(ring->dev->dev->dma_dev,
 274                                      addr, len,
 275                                      DMA_TO_DEVICE);
 276         else
 277                 dma_unmap_single(ring->dev->dev->dma_dev,
 278                                      addr, len,
 279                                      DMA_FROM_DEVICE);
 280 }
 281 
 282 static inline
 283 void sync_descbuffer_for_cpu(struct b43legacy_dmaring *ring,
 284                              dma_addr_t addr,
 285                              size_t len)
 286 {
 287         B43legacy_WARN_ON(ring->tx);
 288 
 289         dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
 290                                 addr, len, DMA_FROM_DEVICE);
 291 }
 292 
 293 static inline
 294 void sync_descbuffer_for_device(struct b43legacy_dmaring *ring,
 295                                 dma_addr_t addr,
 296                                 size_t len)
 297 {
 298         B43legacy_WARN_ON(ring->tx);
 299 
 300         dma_sync_single_for_device(ring->dev->dev->dma_dev,
 301                                    addr, len, DMA_FROM_DEVICE);
 302 }
 303 
 304 static inline
 305 void free_descriptor_buffer(struct b43legacy_dmaring *ring,
 306                             struct b43legacy_dmadesc_meta *meta,
 307                             int irq_context)
 308 {
 309         if (meta->skb) {
 310                 if (irq_context)
 311                         dev_kfree_skb_irq(meta->skb);
 312                 else
 313                         dev_kfree_skb(meta->skb);
 314                 meta->skb = NULL;
 315         }
 316 }
 317 
 318 static int alloc_ringmemory(struct b43legacy_dmaring *ring)
 319 {
 320         /* GFP flags must match the flags in free_ringmemory()! */
 321         ring->descbase = dma_alloc_coherent(ring->dev->dev->dma_dev,
 322                                             B43legacy_DMA_RINGMEMSIZE,
 323                                             &(ring->dmabase), GFP_KERNEL);
 324         if (!ring->descbase)
 325                 return -ENOMEM;
 326 
 327         return 0;
 328 }
 329 
 330 static void free_ringmemory(struct b43legacy_dmaring *ring)
 331 {
 332         dma_free_coherent(ring->dev->dev->dma_dev, B43legacy_DMA_RINGMEMSIZE,
 333                           ring->descbase, ring->dmabase);
 334 }
 335 
 336 /* Reset the RX DMA channel */
 337 static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
 338                                             u16 mmio_base,
 339                                             enum b43legacy_dmatype type)
 340 {
 341         int i;
 342         u32 value;
 343         u16 offset;
 344 
 345         might_sleep();
 346 
 347         offset = B43legacy_DMA32_RXCTL;
 348         b43legacy_write32(dev, mmio_base + offset, 0);
 349         for (i = 0; i < 10; i++) {
 350                 offset = B43legacy_DMA32_RXSTATUS;
 351                 value = b43legacy_read32(dev, mmio_base + offset);
 352                 value &= B43legacy_DMA32_RXSTATE;
 353                 if (value == B43legacy_DMA32_RXSTAT_DISABLED) {
 354                         i = -1;
 355                         break;
 356                 }
 357                 msleep(1);
 358         }
 359         if (i != -1) {
 360                 b43legacyerr(dev->wl, "DMA RX reset timed out\n");
 361                 return -ENODEV;
 362         }
 363 
 364         return 0;
 365 }
 366 
 367 /* Reset the RX DMA channel */
 368 static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
 369                                             u16 mmio_base,
 370                                             enum b43legacy_dmatype type)
 371 {
 372         int i;
 373         u32 value;
 374         u16 offset;
 375 
 376         might_sleep();
 377 
 378         for (i = 0; i < 10; i++) {
 379                 offset = B43legacy_DMA32_TXSTATUS;
 380                 value = b43legacy_read32(dev, mmio_base + offset);
 381                 value &= B43legacy_DMA32_TXSTATE;
 382                 if (value == B43legacy_DMA32_TXSTAT_DISABLED ||
 383                     value == B43legacy_DMA32_TXSTAT_IDLEWAIT ||
 384                     value == B43legacy_DMA32_TXSTAT_STOPPED)
 385                         break;
 386                 msleep(1);
 387         }
 388         offset = B43legacy_DMA32_TXCTL;
 389         b43legacy_write32(dev, mmio_base + offset, 0);
 390         for (i = 0; i < 10; i++) {
 391                 offset = B43legacy_DMA32_TXSTATUS;
 392                 value = b43legacy_read32(dev, mmio_base + offset);
 393                 value &= B43legacy_DMA32_TXSTATE;
 394                 if (value == B43legacy_DMA32_TXSTAT_DISABLED) {
 395                         i = -1;
 396                         break;
 397                 }
 398                 msleep(1);
 399         }
 400         if (i != -1) {
 401                 b43legacyerr(dev->wl, "DMA TX reset timed out\n");
 402                 return -ENODEV;
 403         }
 404         /* ensure the reset is completed. */
 405         msleep(1);
 406 
 407         return 0;
 408 }
 409 
 410 /* Check if a DMA mapping address is invalid. */
 411 static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
 412                                          dma_addr_t addr,
 413                                          size_t buffersize,
 414                                          bool dma_to_device)
 415 {
 416         if (unlikely(dma_mapping_error(ring->dev->dev->dma_dev, addr)))
 417                 return true;
 418 
 419         switch (ring->type) {
 420         case B43legacy_DMA_30BIT:
 421                 if ((u64)addr + buffersize > (1ULL << 30))
 422                         goto address_error;
 423                 break;
 424         case B43legacy_DMA_32BIT:
 425                 if ((u64)addr + buffersize > (1ULL << 32))
 426                         goto address_error;
 427                 break;
 428         }
 429 
 430         /* The address is OK. */
 431         return false;
 432 
 433 address_error:
 434         /* We can't support this address. Unmap it again. */
 435         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 436 
 437         return true;
 438 }
 439 
 440 static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
 441                                struct b43legacy_dmadesc32 *desc,
 442                                struct b43legacy_dmadesc_meta *meta,
 443                                gfp_t gfp_flags)
 444 {
 445         struct b43legacy_rxhdr_fw3 *rxhdr;
 446         struct b43legacy_hwtxstatus *txstat;
 447         dma_addr_t dmaaddr;
 448         struct sk_buff *skb;
 449 
 450         B43legacy_WARN_ON(ring->tx);
 451 
 452         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 453         if (unlikely(!skb))
 454                 return -ENOMEM;
 455         dmaaddr = map_descbuffer(ring, skb->data,
 456                                  ring->rx_buffersize, 0);
 457         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 458                 /* ugh. try to realloc in zone_dma */
 459                 gfp_flags |= GFP_DMA;
 460 
 461                 dev_kfree_skb_any(skb);
 462 
 463                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 464                 if (unlikely(!skb))
 465                         return -ENOMEM;
 466                 dmaaddr = map_descbuffer(ring, skb->data,
 467                                          ring->rx_buffersize, 0);
 468         }
 469 
 470         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 471                 dev_kfree_skb_any(skb);
 472                 return -EIO;
 473         }
 474 
 475         meta->skb = skb;
 476         meta->dmaaddr = dmaaddr;
 477         op32_fill_descriptor(ring, desc, dmaaddr, ring->rx_buffersize, 0, 0, 0);
 478 
 479         rxhdr = (struct b43legacy_rxhdr_fw3 *)(skb->data);
 480         rxhdr->frame_len = 0;
 481         txstat = (struct b43legacy_hwtxstatus *)(skb->data);
 482         txstat->cookie = 0;
 483 
 484         return 0;
 485 }
 486 
 487 /* Allocate the initial descbuffers.
 488  * This is used for an RX ring only.
 489  */
 490 static int alloc_initial_descbuffers(struct b43legacy_dmaring *ring)
 491 {
 492         int i;
 493         int err = -ENOMEM;
 494         struct b43legacy_dmadesc32 *desc;
 495         struct b43legacy_dmadesc_meta *meta;
 496 
 497         for (i = 0; i < ring->nr_slots; i++) {
 498                 desc = op32_idx2desc(ring, i, &meta);
 499 
 500                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 501                 if (err) {
 502                         b43legacyerr(ring->dev->wl,
 503                                "Failed to allocate initial descbuffers\n");
 504                         goto err_unwind;
 505                 }
 506         }
 507         mb(); /* all descbuffer setup before next line */
 508         ring->used_slots = ring->nr_slots;
 509         err = 0;
 510 out:
 511         return err;
 512 
 513 err_unwind:
 514         for (i--; i >= 0; i--) {
 515                 desc = op32_idx2desc(ring, i, &meta);
 516 
 517                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 518                 dev_kfree_skb(meta->skb);
 519         }
 520         goto out;
 521 }
 522 
 523 /* Do initial setup of the DMA controller.
 524  * Reset the controller, write the ring busaddress
 525  * and switch the "enable" bit on.
 526  */
 527 static int dmacontroller_setup(struct b43legacy_dmaring *ring)
 528 {
 529         int err = 0;
 530         u32 value;
 531         u32 addrext;
 532         u32 trans = ring->dev->dma.translation;
 533         u32 ringbase = (u32)(ring->dmabase);
 534 
 535         if (ring->tx) {
 536                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 537                           >> SSB_DMA_TRANSLATION_SHIFT;
 538                 value = B43legacy_DMA32_TXENABLE;
 539                 value |= (addrext << B43legacy_DMA32_TXADDREXT_SHIFT)
 540                         & B43legacy_DMA32_TXADDREXT_MASK;
 541                 b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL, value);
 542                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING,
 543                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 544                                     | trans);
 545         } else {
 546                 err = alloc_initial_descbuffers(ring);
 547                 if (err)
 548                         goto out;
 549 
 550                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 551                           >> SSB_DMA_TRANSLATION_SHIFT;
 552                 value = (ring->frameoffset <<
 553                          B43legacy_DMA32_RXFROFF_SHIFT);
 554                 value |= B43legacy_DMA32_RXENABLE;
 555                 value |= (addrext << B43legacy_DMA32_RXADDREXT_SHIFT)
 556                          & B43legacy_DMA32_RXADDREXT_MASK;
 557                 b43legacy_dma_write(ring, B43legacy_DMA32_RXCTL, value);
 558                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING,
 559                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 560                                     | trans);
 561                 b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX, 200);
 562         }
 563 
 564 out:
 565         return err;
 566 }
 567 
 568 /* Shutdown the DMA controller. */
 569 static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
 570 {
 571         if (ring->tx) {
 572                 b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 573                                                  ring->type);
 574                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
 575         } else {
 576                 b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 577                                                  ring->type);
 578                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING, 0);
 579         }
 580 }
 581 
 582 static void free_all_descbuffers(struct b43legacy_dmaring *ring)
 583 {
 584         struct b43legacy_dmadesc_meta *meta;
 585         int i;
 586 
 587         if (!ring->used_slots)
 588                 return;
 589         for (i = 0; i < ring->nr_slots; i++) {
 590                 op32_idx2desc(ring, i, &meta);
 591 
 592                 if (!meta->skb) {
 593                         B43legacy_WARN_ON(!ring->tx);
 594                         continue;
 595                 }
 596                 if (ring->tx)
 597                         unmap_descbuffer(ring, meta->dmaaddr,
 598                                          meta->skb->len, 1);
 599                 else
 600                         unmap_descbuffer(ring, meta->dmaaddr,
 601                                          ring->rx_buffersize, 0);
 602                 free_descriptor_buffer(ring, meta, 0);
 603         }
 604 }
 605 
 606 static enum b43legacy_dmatype b43legacy_engine_type(struct b43legacy_wldev *dev)
 607 {
 608         u32 tmp;
 609         u16 mmio_base;
 610 
 611         mmio_base = b43legacy_dmacontroller_base(0, 0);
 612         b43legacy_write32(dev,
 613                         mmio_base + B43legacy_DMA32_TXCTL,
 614                         B43legacy_DMA32_TXADDREXT_MASK);
 615         tmp = b43legacy_read32(dev, mmio_base +
 616                                B43legacy_DMA32_TXCTL);
 617         if (tmp & B43legacy_DMA32_TXADDREXT_MASK)
 618                 return B43legacy_DMA_32BIT;
 619         return B43legacy_DMA_30BIT;
 620 }
 621 
 622 /* Main initialization function. */
 623 static
 624 struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
 625                                                   int controller_index,
 626                                                   int for_tx,
 627                                                   enum b43legacy_dmatype type)
 628 {
 629         struct b43legacy_dmaring *ring;
 630         int err;
 631         int nr_slots;
 632         dma_addr_t dma_test;
 633 
 634         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 635         if (!ring)
 636                 goto out;
 637         ring->type = type;
 638         ring->dev = dev;
 639 
 640         nr_slots = B43legacy_RXRING_SLOTS;
 641         if (for_tx)
 642                 nr_slots = B43legacy_TXRING_SLOTS;
 643 
 644         ring->meta = kcalloc(nr_slots, sizeof(struct b43legacy_dmadesc_meta),
 645                              GFP_KERNEL);
 646         if (!ring->meta)
 647                 goto err_kfree_ring;
 648         if (for_tx) {
 649                 ring->txhdr_cache = kcalloc(nr_slots,
 650                                         sizeof(struct b43legacy_txhdr_fw3),
 651                                         GFP_KERNEL);
 652                 if (!ring->txhdr_cache)
 653                         goto err_kfree_meta;
 654 
 655                 /* test for ability to dma to txhdr_cache */
 656                 dma_test = dma_map_single(dev->dev->dma_dev, ring->txhdr_cache,
 657                                               sizeof(struct b43legacy_txhdr_fw3),
 658                                               DMA_TO_DEVICE);
 659 
 660                 if (b43legacy_dma_mapping_error(ring, dma_test,
 661                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
 662                         /* ugh realloc */
 663                         kfree(ring->txhdr_cache);
 664                         ring->txhdr_cache = kcalloc(nr_slots,
 665                                         sizeof(struct b43legacy_txhdr_fw3),
 666                                         GFP_KERNEL | GFP_DMA);
 667                         if (!ring->txhdr_cache)
 668                                 goto err_kfree_meta;
 669 
 670                         dma_test = dma_map_single(dev->dev->dma_dev,
 671                                         ring->txhdr_cache,
 672                                         sizeof(struct b43legacy_txhdr_fw3),
 673                                         DMA_TO_DEVICE);
 674 
 675                         if (b43legacy_dma_mapping_error(ring, dma_test,
 676                                         sizeof(struct b43legacy_txhdr_fw3), 1))
 677                                 goto err_kfree_txhdr_cache;
 678                 }
 679 
 680                 dma_unmap_single(dev->dev->dma_dev, dma_test,
 681                                  sizeof(struct b43legacy_txhdr_fw3),
 682                                  DMA_TO_DEVICE);
 683         }
 684 
 685         ring->nr_slots = nr_slots;
 686         ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
 687         ring->index = controller_index;
 688         if (for_tx) {
 689                 ring->tx = true;
 690                 ring->current_slot = -1;
 691         } else {
 692                 if (ring->index == 0) {
 693                         ring->rx_buffersize = B43legacy_DMA0_RX_BUFFERSIZE;
 694                         ring->frameoffset = B43legacy_DMA0_RX_FRAMEOFFSET;
 695                 } else if (ring->index == 3) {
 696                         ring->rx_buffersize = B43legacy_DMA3_RX_BUFFERSIZE;
 697                         ring->frameoffset = B43legacy_DMA3_RX_FRAMEOFFSET;
 698                 } else
 699                         B43legacy_WARN_ON(1);
 700         }
 701 #ifdef CONFIG_B43LEGACY_DEBUG
 702         ring->last_injected_overflow = jiffies;
 703 #endif
 704 
 705         err = alloc_ringmemory(ring);
 706         if (err)
 707                 goto err_kfree_txhdr_cache;
 708         err = dmacontroller_setup(ring);
 709         if (err)
 710                 goto err_free_ringmemory;
 711 
 712 out:
 713         return ring;
 714 
 715 err_free_ringmemory:
 716         free_ringmemory(ring);
 717 err_kfree_txhdr_cache:
 718         kfree(ring->txhdr_cache);
 719 err_kfree_meta:
 720         kfree(ring->meta);
 721 err_kfree_ring:
 722         kfree(ring);
 723         ring = NULL;
 724         goto out;
 725 }
 726 
 727 /* Main cleanup function. */
 728 static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
 729 {
 730         if (!ring)
 731                 return;
 732 
 733         b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
 734                      " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
 735                      (ring->tx) ? "TX" : "RX", ring->max_used_slots,
 736                      ring->nr_slots);
 737         /* Device IRQs are disabled prior entering this function,
 738          * so no need to take care of concurrency with rx handler stuff.
 739          */
 740         dmacontroller_cleanup(ring);
 741         free_all_descbuffers(ring);
 742         free_ringmemory(ring);
 743 
 744         kfree(ring->txhdr_cache);
 745         kfree(ring->meta);
 746         kfree(ring);
 747 }
 748 
 749 void b43legacy_dma_free(struct b43legacy_wldev *dev)
 750 {
 751         struct b43legacy_dma *dma;
 752 
 753         if (b43legacy_using_pio(dev))
 754                 return;
 755         dma = &dev->dma;
 756 
 757         b43legacy_destroy_dmaring(dma->rx_ring3);
 758         dma->rx_ring3 = NULL;
 759         b43legacy_destroy_dmaring(dma->rx_ring0);
 760         dma->rx_ring0 = NULL;
 761 
 762         b43legacy_destroy_dmaring(dma->tx_ring5);
 763         dma->tx_ring5 = NULL;
 764         b43legacy_destroy_dmaring(dma->tx_ring4);
 765         dma->tx_ring4 = NULL;
 766         b43legacy_destroy_dmaring(dma->tx_ring3);
 767         dma->tx_ring3 = NULL;
 768         b43legacy_destroy_dmaring(dma->tx_ring2);
 769         dma->tx_ring2 = NULL;
 770         b43legacy_destroy_dmaring(dma->tx_ring1);
 771         dma->tx_ring1 = NULL;
 772         b43legacy_destroy_dmaring(dma->tx_ring0);
 773         dma->tx_ring0 = NULL;
 774 }
 775 
 776 int b43legacy_dma_init(struct b43legacy_wldev *dev)
 777 {
 778         struct b43legacy_dma *dma = &dev->dma;
 779         struct b43legacy_dmaring *ring;
 780         enum b43legacy_dmatype type = b43legacy_engine_type(dev);
 781         int err;
 782 
 783         err = dma_set_mask_and_coherent(dev->dev->dma_dev, DMA_BIT_MASK(type));
 784         if (err) {
 785 #ifdef CONFIG_B43LEGACY_PIO
 786                 b43legacywarn(dev->wl, "DMA for this device not supported. "
 787                         "Falling back to PIO\n");
 788                 dev->__using_pio = true;
 789                 return -EAGAIN;
 790 #else
 791                 b43legacyerr(dev->wl, "DMA for this device not supported and "
 792                        "no PIO support compiled in\n");
 793                 return -EOPNOTSUPP;
 794 #endif
 795         }
 796         dma->translation = ssb_dma_translation(dev->dev);
 797 
 798         err = -ENOMEM;
 799         /* setup TX DMA channels. */
 800         ring = b43legacy_setup_dmaring(dev, 0, 1, type);
 801         if (!ring)
 802                 goto out;
 803         dma->tx_ring0 = ring;
 804 
 805         ring = b43legacy_setup_dmaring(dev, 1, 1, type);
 806         if (!ring)
 807                 goto err_destroy_tx0;
 808         dma->tx_ring1 = ring;
 809 
 810         ring = b43legacy_setup_dmaring(dev, 2, 1, type);
 811         if (!ring)
 812                 goto err_destroy_tx1;
 813         dma->tx_ring2 = ring;
 814 
 815         ring = b43legacy_setup_dmaring(dev, 3, 1, type);
 816         if (!ring)
 817                 goto err_destroy_tx2;
 818         dma->tx_ring3 = ring;
 819 
 820         ring = b43legacy_setup_dmaring(dev, 4, 1, type);
 821         if (!ring)
 822                 goto err_destroy_tx3;
 823         dma->tx_ring4 = ring;
 824 
 825         ring = b43legacy_setup_dmaring(dev, 5, 1, type);
 826         if (!ring)
 827                 goto err_destroy_tx4;
 828         dma->tx_ring5 = ring;
 829 
 830         /* setup RX DMA channels. */
 831         ring = b43legacy_setup_dmaring(dev, 0, 0, type);
 832         if (!ring)
 833                 goto err_destroy_tx5;
 834         dma->rx_ring0 = ring;
 835 
 836         if (dev->dev->id.revision < 5) {
 837                 ring = b43legacy_setup_dmaring(dev, 3, 0, type);
 838                 if (!ring)
 839                         goto err_destroy_rx0;
 840                 dma->rx_ring3 = ring;
 841         }
 842 
 843         b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
 844         err = 0;
 845 out:
 846         return err;
 847 
 848 err_destroy_rx0:
 849         b43legacy_destroy_dmaring(dma->rx_ring0);
 850         dma->rx_ring0 = NULL;
 851 err_destroy_tx5:
 852         b43legacy_destroy_dmaring(dma->tx_ring5);
 853         dma->tx_ring5 = NULL;
 854 err_destroy_tx4:
 855         b43legacy_destroy_dmaring(dma->tx_ring4);
 856         dma->tx_ring4 = NULL;
 857 err_destroy_tx3:
 858         b43legacy_destroy_dmaring(dma->tx_ring3);
 859         dma->tx_ring3 = NULL;
 860 err_destroy_tx2:
 861         b43legacy_destroy_dmaring(dma->tx_ring2);
 862         dma->tx_ring2 = NULL;
 863 err_destroy_tx1:
 864         b43legacy_destroy_dmaring(dma->tx_ring1);
 865         dma->tx_ring1 = NULL;
 866 err_destroy_tx0:
 867         b43legacy_destroy_dmaring(dma->tx_ring0);
 868         dma->tx_ring0 = NULL;
 869         goto out;
 870 }
 871 
 872 /* Generate a cookie for the TX header. */
 873 static u16 generate_cookie(struct b43legacy_dmaring *ring,
 874                            int slot)
 875 {
 876         u16 cookie = 0x1000;
 877 
 878         /* Use the upper 4 bits of the cookie as
 879          * DMA controller ID and store the slot number
 880          * in the lower 12 bits.
 881          * Note that the cookie must never be 0, as this
 882          * is a special value used in RX path.
 883          */
 884         switch (ring->index) {
 885         case 0:
 886                 cookie = 0xA000;
 887                 break;
 888         case 1:
 889                 cookie = 0xB000;
 890                 break;
 891         case 2:
 892                 cookie = 0xC000;
 893                 break;
 894         case 3:
 895                 cookie = 0xD000;
 896                 break;
 897         case 4:
 898                 cookie = 0xE000;
 899                 break;
 900         case 5:
 901                 cookie = 0xF000;
 902                 break;
 903         }
 904         B43legacy_WARN_ON(!(((u16)slot & 0xF000) == 0x0000));
 905         cookie |= (u16)slot;
 906 
 907         return cookie;
 908 }
 909 
 910 /* Inspect a cookie and find out to which controller/slot it belongs. */
 911 static
 912 struct b43legacy_dmaring *parse_cookie(struct b43legacy_wldev *dev,
 913                                       u16 cookie, int *slot)
 914 {
 915         struct b43legacy_dma *dma = &dev->dma;
 916         struct b43legacy_dmaring *ring = NULL;
 917 
 918         switch (cookie & 0xF000) {
 919         case 0xA000:
 920                 ring = dma->tx_ring0;
 921                 break;
 922         case 0xB000:
 923                 ring = dma->tx_ring1;
 924                 break;
 925         case 0xC000:
 926                 ring = dma->tx_ring2;
 927                 break;
 928         case 0xD000:
 929                 ring = dma->tx_ring3;
 930                 break;
 931         case 0xE000:
 932                 ring = dma->tx_ring4;
 933                 break;
 934         case 0xF000:
 935                 ring = dma->tx_ring5;
 936                 break;
 937         default:
 938                 B43legacy_WARN_ON(1);
 939         }
 940         *slot = (cookie & 0x0FFF);
 941         B43legacy_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
 942 
 943         return ring;
 944 }
 945 
 946 static int dma_tx_fragment(struct b43legacy_dmaring *ring,
 947                             struct sk_buff **in_skb)
 948 {
 949         struct sk_buff *skb = *in_skb;
 950         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 951         u8 *header;
 952         int slot, old_top_slot, old_used_slots;
 953         int err;
 954         struct b43legacy_dmadesc32 *desc;
 955         struct b43legacy_dmadesc_meta *meta;
 956         struct b43legacy_dmadesc_meta *meta_hdr;
 957         struct sk_buff *bounce_skb;
 958 
 959 #define SLOTS_PER_PACKET  2
 960         B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
 961 
 962         old_top_slot = ring->current_slot;
 963         old_used_slots = ring->used_slots;
 964 
 965         /* Get a slot for the header. */
 966         slot = request_slot(ring);
 967         desc = op32_idx2desc(ring, slot, &meta_hdr);
 968         memset(meta_hdr, 0, sizeof(*meta_hdr));
 969 
 970         header = &(ring->txhdr_cache[slot * sizeof(
 971                                struct b43legacy_txhdr_fw3)]);
 972         err = b43legacy_generate_txhdr(ring->dev, header,
 973                                  skb->data, skb->len, info,
 974                                  generate_cookie(ring, slot));
 975         if (unlikely(err)) {
 976                 ring->current_slot = old_top_slot;
 977                 ring->used_slots = old_used_slots;
 978                 return err;
 979         }
 980 
 981         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
 982                                            sizeof(struct b43legacy_txhdr_fw3), 1);
 983         if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
 984                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
 985                 ring->current_slot = old_top_slot;
 986                 ring->used_slots = old_used_slots;
 987                 return -EIO;
 988         }
 989         op32_fill_descriptor(ring, desc, meta_hdr->dmaaddr,
 990                              sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
 991 
 992         /* Get a slot for the payload. */
 993         slot = request_slot(ring);
 994         desc = op32_idx2desc(ring, slot, &meta);
 995         memset(meta, 0, sizeof(*meta));
 996 
 997         meta->skb = skb;
 998         meta->is_last_fragment = true;
 999 
1000         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1001         /* create a bounce buffer in zone_dma on mapping failure. */
1002         if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1003                 bounce_skb = alloc_skb(skb->len, GFP_KERNEL | GFP_DMA);
1004                 if (!bounce_skb) {
1005                         ring->current_slot = old_top_slot;
1006                         ring->used_slots = old_used_slots;
1007                         err = -ENOMEM;
1008                         goto out_unmap_hdr;
1009                 }
1010 
1011                 skb_put_data(bounce_skb, skb->data, skb->len);
1012                 memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
1013                 bounce_skb->dev = skb->dev;
1014                 skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
1015                 info = IEEE80211_SKB_CB(bounce_skb);
1016 
1017                 dev_kfree_skb_any(skb);
1018                 skb = bounce_skb;
1019                 *in_skb = bounce_skb;
1020                 meta->skb = skb;
1021                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1022                 if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1023                         ring->current_slot = old_top_slot;
1024                         ring->used_slots = old_used_slots;
1025                         err = -EIO;
1026                         goto out_free_bounce;
1027                 }
1028         }
1029 
1030         op32_fill_descriptor(ring, desc, meta->dmaaddr,
1031                              skb->len, 0, 1, 1);
1032 
1033         wmb();  /* previous stuff MUST be done */
1034         /* Now transfer the whole frame. */
1035         op32_poke_tx(ring, next_slot(ring, slot));
1036         return 0;
1037 
1038 out_free_bounce:
1039         dev_kfree_skb_any(skb);
1040 out_unmap_hdr:
1041         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1042                          sizeof(struct b43legacy_txhdr_fw3), 1);
1043         return err;
1044 }
1045 
1046 static inline
1047 int should_inject_overflow(struct b43legacy_dmaring *ring)
1048 {
1049 #ifdef CONFIG_B43LEGACY_DEBUG
1050         if (unlikely(b43legacy_debug(ring->dev,
1051                                      B43legacy_DBG_DMAOVERFLOW))) {
1052                 /* Check if we should inject another ringbuffer overflow
1053                  * to test handling of this situation in the stack. */
1054                 unsigned long next_overflow;
1055 
1056                 next_overflow = ring->last_injected_overflow + HZ;
1057                 if (time_after(jiffies, next_overflow)) {
1058                         ring->last_injected_overflow = jiffies;
1059                         b43legacydbg(ring->dev->wl,
1060                                "Injecting TX ring overflow on "
1061                                "DMA controller %d\n", ring->index);
1062                         return 1;
1063                 }
1064         }
1065 #endif /* CONFIG_B43LEGACY_DEBUG */
1066         return 0;
1067 }
1068 
1069 int b43legacy_dma_tx(struct b43legacy_wldev *dev,
1070                      struct sk_buff *skb)
1071 {
1072         struct b43legacy_dmaring *ring;
1073         int err = 0;
1074 
1075         ring = priority_to_txring(dev, skb_get_queue_mapping(skb));
1076         B43legacy_WARN_ON(!ring->tx);
1077 
1078         if (unlikely(ring->stopped)) {
1079                 /* We get here only because of a bug in mac80211.
1080                  * Because of a race, one packet may be queued after
1081                  * the queue is stopped, thus we got called when we shouldn't.
1082                  * For now, just refuse the transmit. */
1083                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1084                         b43legacyerr(dev->wl, "Packet after queue stopped\n");
1085                 return -ENOSPC;
1086         }
1087 
1088         if (WARN_ON(free_slots(ring) < SLOTS_PER_PACKET)) {
1089                 /* If we get here, we have a real error with the queue
1090                  * full, but queues not stopped. */
1091                 b43legacyerr(dev->wl, "DMA queue overflow\n");
1092                 return -ENOSPC;
1093         }
1094 
1095         /* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
1096          * into the skb data or cb now. */
1097         err = dma_tx_fragment(ring, &skb);
1098         if (unlikely(err == -ENOKEY)) {
1099                 /* Drop this packet, as we don't have the encryption key
1100                  * anymore and must not transmit it unencrypted. */
1101                 dev_kfree_skb_any(skb);
1102                 return 0;
1103         }
1104         if (unlikely(err)) {
1105                 b43legacyerr(dev->wl, "DMA tx mapping failure\n");
1106                 return err;
1107         }
1108         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1109             should_inject_overflow(ring)) {
1110                 /* This TX ring is full. */
1111                 unsigned int skb_mapping = skb_get_queue_mapping(skb);
1112                 ieee80211_stop_queue(dev->wl->hw, skb_mapping);
1113                 dev->wl->tx_queue_stopped[skb_mapping] = 1;
1114                 ring->stopped = true;
1115                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1116                         b43legacydbg(dev->wl, "Stopped TX ring %d\n",
1117                                ring->index);
1118         }
1119         return err;
1120 }
1121 
1122 void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
1123                                  const struct b43legacy_txstatus *status)
1124 {
1125         struct b43legacy_dmaring *ring;
1126         struct b43legacy_dmadesc_meta *meta;
1127         int retry_limit;
1128         int slot;
1129         int firstused;
1130 
1131         ring = parse_cookie(dev, status->cookie, &slot);
1132         if (unlikely(!ring))
1133                 return;
1134         B43legacy_WARN_ON(!ring->tx);
1135 
1136         /* Sanity check: TX packets are processed in-order on one ring.
1137          * Check if the slot deduced from the cookie really is the first
1138          * used slot. */
1139         firstused = ring->current_slot - ring->used_slots + 1;
1140         if (firstused < 0)
1141                 firstused = ring->nr_slots + firstused;
1142         if (unlikely(slot != firstused)) {
1143                 /* This possibly is a firmware bug and will result in
1144                  * malfunction, memory leaks and/or stall of DMA functionality.
1145                  */
1146                 b43legacydbg(dev->wl, "Out of order TX status report on DMA "
1147                              "ring %d. Expected %d, but got %d\n",
1148                              ring->index, firstused, slot);
1149                 return;
1150         }
1151 
1152         while (1) {
1153                 B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1154                 op32_idx2desc(ring, slot, &meta);
1155 
1156                 if (meta->skb)
1157                         unmap_descbuffer(ring, meta->dmaaddr,
1158                                          meta->skb->len, 1);
1159                 else
1160                         unmap_descbuffer(ring, meta->dmaaddr,
1161                                          sizeof(struct b43legacy_txhdr_fw3),
1162                                          1);
1163 
1164                 if (meta->is_last_fragment) {
1165                         struct ieee80211_tx_info *info;
1166                         BUG_ON(!meta->skb);
1167                         info = IEEE80211_SKB_CB(meta->skb);
1168 
1169                         /* preserve the confiured retry limit before clearing the status
1170                          * The xmit function has overwritten the rc's value with the actual
1171                          * retry limit done by the hardware */
1172                         retry_limit = info->status.rates[0].count;
1173                         ieee80211_tx_info_clear_status(info);
1174 
1175                         if (status->acked)
1176                                 info->flags |= IEEE80211_TX_STAT_ACK;
1177 
1178                         if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
1179                                 /*
1180                                  * If the short retries (RTS, not data frame) have exceeded
1181                                  * the limit, the hw will not have tried the selected rate,
1182                                  * but will have used the fallback rate instead.
1183                                  * Don't let the rate control count attempts for the selected
1184                                  * rate in this case, otherwise the statistics will be off.
1185                                  */
1186                                 info->status.rates[0].count = 0;
1187                                 info->status.rates[1].count = status->frame_count;
1188                         } else {
1189                                 if (status->frame_count > retry_limit) {
1190                                         info->status.rates[0].count = retry_limit;
1191                                         info->status.rates[1].count = status->frame_count -
1192                                                         retry_limit;
1193 
1194                                 } else {
1195                                         info->status.rates[0].count = status->frame_count;
1196                                         info->status.rates[1].idx = -1;
1197                                 }
1198                         }
1199 
1200                         /* Call back to inform the ieee80211 subsystem about the
1201                          * status of the transmission.
1202                          * Some fields of txstat are already filled in dma_tx().
1203                          */
1204                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
1205                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1206                         meta->skb = NULL;
1207                 } else {
1208                         /* No need to call free_descriptor_buffer here, as
1209                          * this is only the txhdr, which is not allocated.
1210                          */
1211                         B43legacy_WARN_ON(meta->skb != NULL);
1212                 }
1213 
1214                 /* Everything unmapped and free'd. So it's not used anymore. */
1215                 ring->used_slots--;
1216 
1217                 if (meta->is_last_fragment)
1218                         break;
1219                 slot = next_slot(ring, slot);
1220         }
1221         dev->stats.last_tx = jiffies;
1222         if (ring->stopped) {
1223                 B43legacy_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1224                 ring->stopped = false;
1225         }
1226 
1227         if (dev->wl->tx_queue_stopped[ring->queue_prio]) {
1228                 dev->wl->tx_queue_stopped[ring->queue_prio] = 0;
1229         } else {
1230                 /* If the driver queue is running wake the corresponding
1231                  * mac80211 queue. */
1232                 ieee80211_wake_queue(dev->wl->hw, ring->queue_prio);
1233                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1234                         b43legacydbg(dev->wl, "Woke up TX ring %d\n",
1235                                      ring->index);
1236         }
1237         /* Add work to the queue. */
1238         ieee80211_queue_work(dev->wl->hw, &dev->wl->tx_work);
1239 }
1240 
1241 static void dma_rx(struct b43legacy_dmaring *ring,
1242                    int *slot)
1243 {
1244         struct b43legacy_dmadesc32 *desc;
1245         struct b43legacy_dmadesc_meta *meta;
1246         struct b43legacy_rxhdr_fw3 *rxhdr;
1247         struct sk_buff *skb;
1248         u16 len;
1249         int err;
1250         dma_addr_t dmaaddr;
1251 
1252         desc = op32_idx2desc(ring, *slot, &meta);
1253 
1254         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1255         skb = meta->skb;
1256 
1257         if (ring->index == 3) {
1258                 /* We received an xmit status. */
1259                 struct b43legacy_hwtxstatus *hw =
1260                                 (struct b43legacy_hwtxstatus *)skb->data;
1261                 int i = 0;
1262 
1263                 while (hw->cookie == 0) {
1264                         if (i > 100)
1265                                 break;
1266                         i++;
1267                         udelay(2);
1268                         barrier();
1269                 }
1270                 b43legacy_handle_hwtxstatus(ring->dev, hw);
1271                 /* recycle the descriptor buffer. */
1272                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1273                                            ring->rx_buffersize);
1274 
1275                 return;
1276         }
1277         rxhdr = (struct b43legacy_rxhdr_fw3 *)skb->data;
1278         len = le16_to_cpu(rxhdr->frame_len);
1279         if (len == 0) {
1280                 int i = 0;
1281 
1282                 do {
1283                         udelay(2);
1284                         barrier();
1285                         len = le16_to_cpu(rxhdr->frame_len);
1286                 } while (len == 0 && i++ < 5);
1287                 if (unlikely(len == 0)) {
1288                         /* recycle the descriptor buffer. */
1289                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1290                                                    ring->rx_buffersize);
1291                         goto drop;
1292                 }
1293         }
1294         if (unlikely(len > ring->rx_buffersize)) {
1295                 /* The data did not fit into one descriptor buffer
1296                  * and is split over multiple buffers.
1297                  * This should never happen, as we try to allocate buffers
1298                  * big enough. So simply ignore this packet.
1299                  */
1300                 int cnt = 0;
1301                 s32 tmp = len;
1302 
1303                 while (1) {
1304                         desc = op32_idx2desc(ring, *slot, &meta);
1305                         /* recycle the descriptor buffer. */
1306                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1307                                                    ring->rx_buffersize);
1308                         *slot = next_slot(ring, *slot);
1309                         cnt++;
1310                         tmp -= ring->rx_buffersize;
1311                         if (tmp <= 0)
1312                                 break;
1313                 }
1314                 b43legacyerr(ring->dev->wl, "DMA RX buffer too small "
1315                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1316                        len, ring->rx_buffersize, cnt);
1317                 goto drop;
1318         }
1319 
1320         dmaaddr = meta->dmaaddr;
1321         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1322         if (unlikely(err)) {
1323                 b43legacydbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer()"
1324                              " failed\n");
1325                 sync_descbuffer_for_device(ring, dmaaddr,
1326                                            ring->rx_buffersize);
1327                 goto drop;
1328         }
1329 
1330         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1331         skb_put(skb, len + ring->frameoffset);
1332         skb_pull(skb, ring->frameoffset);
1333 
1334         b43legacy_rx(ring->dev, skb, rxhdr);
1335 drop:
1336         return;
1337 }
1338 
1339 void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
1340 {
1341         int slot;
1342         int current_slot;
1343         int used_slots = 0;
1344 
1345         B43legacy_WARN_ON(ring->tx);
1346         current_slot = op32_get_current_rxslot(ring);
1347         B43legacy_WARN_ON(!(current_slot >= 0 && current_slot <
1348                            ring->nr_slots));
1349 
1350         slot = ring->current_slot;
1351         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1352                 dma_rx(ring, &slot);
1353                 update_max_used_slots(ring, ++used_slots);
1354         }
1355         op32_set_current_rxslot(ring, slot);
1356         ring->current_slot = slot;
1357 }
1358 
1359 static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1360 {
1361         B43legacy_WARN_ON(!ring->tx);
1362         op32_tx_suspend(ring);
1363 }
1364 
1365 static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1366 {
1367         B43legacy_WARN_ON(!ring->tx);
1368         op32_tx_resume(ring);
1369 }
1370 
1371 void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
1372 {
1373         b43legacy_power_saving_ctl_bits(dev, -1, 1);
1374         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring0);
1375         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring1);
1376         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring2);
1377         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring3);
1378         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring4);
1379         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring5);
1380 }
1381 
1382 void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
1383 {
1384         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring5);
1385         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring4);
1386         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring3);
1387         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring2);
1388         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring1);
1389         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring0);
1390         b43legacy_power_saving_ctl_bits(dev, -1, -1);
1391 }