drivers/net/wireless/b43legacy/dma.c

   1 /*
   2
   3   Broadcom B43legacy wireless driver
   4
   5   DMA ringbuffer and descriptor allocation/management
   6
   7   Copyright (c) 2005, 2006 Michael Buesch <m@bues.ch>
   8
   9   Some code in this file is derived from the b44.c driver
  10   Copyright (C) 2002 David S. Miller
  11   Copyright (C) Pekka Pietikainen
  12
  13   This program is free software; you can redistribute it and/or modify
  14   it under the terms of the GNU General Public License as published by
  15   the Free Software Foundation; either version 2 of the License, or
  16   (at your option) any later version.
  17
  18   This program is distributed in the hope that it will be useful,
  19   but WITHOUT ANY WARRANTY; without even the implied warranty of
  20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21   GNU General Public License for more details.
  22
  23   You should have received a copy of the GNU General Public License
  24   along with this program; see the file COPYING.  If not, write to
  25   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  26   Boston, MA 02110-1301, USA.
  27
  28 */
  29
  30 #include "b43legacy.h"
  31 #include "dma.h"
  32 #include "main.h"
  33 #include "debugfs.h"
  34 #include "xmit.h"
  35
  36 #include <linux/dma-mapping.h>
  37 #include <linux/pci.h>
  38 #include <linux/delay.h>
  39 #include <linux/skbuff.h>
  40 #include <linux/slab.h>
  41 #include <net/dst.h>
  42
  43 /* 32bit DMA ops. */
  44 static
  45 struct b43legacy_dmadesc32 *op32_idx2desc(struct b43legacy_dmaring *ring,
  46                                           int slot,
  47                                           struct b43legacy_dmadesc_meta **meta)
  48 {
  49         struct b43legacy_dmadesc32 *desc;
  50
  51         *meta = &(ring->meta[slot]);
  52         desc = ring->descbase;
  53         desc = &(desc[slot]);
  54
  55         return (struct b43legacy_dmadesc32 *)desc;
  56 }
  57
  58 static void op32_fill_descriptor(struct b43legacy_dmaring *ring,
  59                                  struct b43legacy_dmadesc32 *desc,
  60                                  dma_addr_t dmaaddr, u16 bufsize,
  61                                  int start, int end, int irq)
  62 {
  63         struct b43legacy_dmadesc32 *descbase = ring->descbase;
  64         int slot;
  65         u32 ctl;
  66         u32 addr;
  67         u32 addrext;
  68
  69         slot = (int)(desc - descbase);
  70         B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
  71
  72         addr = (u32)(dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
  73         addrext = (u32)(dmaaddr & SSB_DMA_TRANSLATION_MASK)
  74                    >> SSB_DMA_TRANSLATION_SHIFT;
  75         addr |= ring->dev->dma.translation;
  76         ctl = (bufsize - ring->frameoffset)
  77               & B43legacy_DMA32_DCTL_BYTECNT;
  78         if (slot == ring->nr_slots - 1)
  79                 ctl |= B43legacy_DMA32_DCTL_DTABLEEND;
  80         if (start)
  81                 ctl |= B43legacy_DMA32_DCTL_FRAMESTART;
  82         if (end)
  83                 ctl |= B43legacy_DMA32_DCTL_FRAMEEND;
  84         if (irq)
  85                 ctl |= B43legacy_DMA32_DCTL_IRQ;
  86         ctl |= (addrext << B43legacy_DMA32_DCTL_ADDREXT_SHIFT)
  87                & B43legacy_DMA32_DCTL_ADDREXT_MASK;
  88
  89         desc->control = cpu_to_le32(ctl);
  90         desc->address = cpu_to_le32(addr);
  91 }
  92
  93 static void op32_poke_tx(struct b43legacy_dmaring *ring, int slot)
  94 {
  95         b43legacy_dma_write(ring, B43legacy_DMA32_TXINDEX,
  96                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
  97 }
  98
  99 static void op32_tx_suspend(struct b43legacy_dmaring *ring)
 100 {
 101         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
 102                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
 103                             | B43legacy_DMA32_TXSUSPEND);
 104 }
 105
 106 static void op32_tx_resume(struct b43legacy_dmaring *ring)
 107 {
 108         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
 109                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
 110                             & ~B43legacy_DMA32_TXSUSPEND);
 111 }
 112
 113 static int op32_get_current_rxslot(struct b43legacy_dmaring *ring)
 114 {
 115         u32 val;
 116
 117         val = b43legacy_dma_read(ring, B43legacy_DMA32_RXSTATUS);
 118         val &= B43legacy_DMA32_RXDPTR;
 119
 120         return (val / sizeof(struct b43legacy_dmadesc32));
 121 }
 122
 123 static void op32_set_current_rxslot(struct b43legacy_dmaring *ring,
 124                                     int slot)
 125 {
 126         b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
 127                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
 128 }
 129
 130 static inline int free_slots(struct b43legacy_dmaring *ring)
 131 {
 132         return (ring->nr_slots - ring->used_slots);
 133 }
 134
 135 static inline int next_slot(struct b43legacy_dmaring *ring, int slot)
 136 {
 137         B43legacy_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
 138         if (slot == ring->nr_slots - 1)
 139                 return 0;
 140         return slot + 1;
 141 }
 142
 143 static inline int prev_slot(struct b43legacy_dmaring *ring, int slot)
 144 {
 145         B43legacy_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
 146         if (slot == 0)
 147                 return ring->nr_slots - 1;
 148         return slot - 1;
 149 }
 150
 151 #ifdef CONFIG_B43LEGACY_DEBUG
 152 static void update_max_used_slots(struct b43legacy_dmaring *ring,
 153                                   int current_used_slots)
 154 {
 155         if (current_used_slots <= ring->max_used_slots)
 156                 return;
 157         ring->max_used_slots = current_used_slots;
 158         if (b43legacy_debug(ring->dev, B43legacy_DBG_DMAVERBOSE))
 159                 b43legacydbg(ring->dev->wl,
 160                        "max_used_slots increased to %d on %s ring %d\n",
 161                        ring->max_used_slots,
 162                        ring->tx ? "TX" : "RX",
 163                        ring->index);
 164 }
 165 #else
 166 static inline
 167 void update_max_used_slots(struct b43legacy_dmaring *ring,
 168                            int current_used_slots)
 169 { }
 170 #endif /* DEBUG */
 171
 172 /* Request a slot for usage. */
 173 static inline
 174 int request_slot(struct b43legacy_dmaring *ring)
 175 {
 176         int slot;
 177
 178         B43legacy_WARN_ON(!ring->tx);
 179         B43legacy_WARN_ON(ring->stopped);
 180         B43legacy_WARN_ON(free_slots(ring) == 0);
 181
 182         slot = next_slot(ring, ring->current_slot);
 183         ring->current_slot = slot;
 184         ring->used_slots++;
 185
 186         update_max_used_slots(ring, ring->used_slots);
 187
 188         return slot;
 189 }
 190
 191 /* Mac80211-queue to b43legacy-ring mapping */
 192 static struct b43legacy_dmaring *priority_to_txring(
 193                                                 struct b43legacy_wldev *dev,
 194                                                 int queue_priority)
 195 {
 196         struct b43legacy_dmaring *ring;
 197
 198 /*FIXME: For now we always run on TX-ring-1 */
 199 return dev->dma.tx_ring1;
 200
 201         /* 0 = highest priority */
 202         switch (queue_priority) {
 203         default:
 204                 B43legacy_WARN_ON(1);
 205                 /* fallthrough */
 206         case 0:
 207                 ring = dev->dma.tx_ring3;
 208                 break;
 209         case 1:
 210                 ring = dev->dma.tx_ring2;
 211                 break;
 212         case 2:
 213                 ring = dev->dma.tx_ring1;
 214                 break;
 215         case 3:
 216                 ring = dev->dma.tx_ring0;
 217                 break;
 218         case 4:
 219                 ring = dev->dma.tx_ring4;
 220                 break;
 221         case 5:
 222                 ring = dev->dma.tx_ring5;
 223                 break;
 224         }
 225
 226         return ring;
 227 }
 228
 229 /* Bcm4301-ring to mac80211-queue mapping */
 230 static inline int txring_to_priority(struct b43legacy_dmaring *ring)
 231 {
 232         static const u8 idx_to_prio[] =
 233                 { 3, 2, 1, 0, 4, 5, };
 234
 235 /*FIXME: have only one queue, for now */
 236 return 0;
 237
 238         return idx_to_prio[ring->index];
 239 }
 240
 241
 242 static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
 243                                         int controller_idx)
 244 {
 245         static const u16 map32[] = {
 246                 B43legacy_MMIO_DMA32_BASE0,
 247                 B43legacy_MMIO_DMA32_BASE1,
 248                 B43legacy_MMIO_DMA32_BASE2,
 249                 B43legacy_MMIO_DMA32_BASE3,
 250                 B43legacy_MMIO_DMA32_BASE4,
 251                 B43legacy_MMIO_DMA32_BASE5,
 252         };
 253
 254         B43legacy_WARN_ON(!(controller_idx >= 0 &&
 255                           controller_idx < ARRAY_SIZE(map32)));
 256         return map32[controller_idx];
 257 }
 258
 259 static inline
 260 dma_addr_t map_descbuffer(struct b43legacy_dmaring *ring,
 261                           unsigned char *buf,
 262                           size_t len,
 263                           int tx)
 264 {
 265         dma_addr_t dmaaddr;
 266
 267         if (tx)
 268                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 269                                              buf, len,
 270                                              DMA_TO_DEVICE);
 271         else
 272                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 273                                              buf, len,
 274                                              DMA_FROM_DEVICE);
 275
 276         return dmaaddr;
 277 }
 278
 279 static inline
 280 void unmap_descbuffer(struct b43legacy_dmaring *ring,
 281                       dma_addr_t addr,
 282                       size_t len,
 283                       int tx)
 284 {
 285         if (tx)
 286                 dma_unmap_single(ring->dev->dev->dma_dev,
 287                                      addr, len,
 288                                      DMA_TO_DEVICE);
 289         else
 290                 dma_unmap_single(ring->dev->dev->dma_dev,
 291                                      addr, len,
 292                                      DMA_FROM_DEVICE);
 293 }
 294
 295 static inline
 296 void sync_descbuffer_for_cpu(struct b43legacy_dmaring *ring,
 297                              dma_addr_t addr,
 298                              size_t len)
 299 {
 300         B43legacy_WARN_ON(ring->tx);
 301
 302         dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
 303                                 addr, len, DMA_FROM_DEVICE);
 304 }
 305
 306 static inline
 307 void sync_descbuffer_for_device(struct b43legacy_dmaring *ring,
 308                                 dma_addr_t addr,
 309                                 size_t len)
 310 {
 311         B43legacy_WARN_ON(ring->tx);
 312
 313         dma_sync_single_for_device(ring->dev->dev->dma_dev,
 314                                    addr, len, DMA_FROM_DEVICE);
 315 }
 316
 317 static inline
 318 void free_descriptor_buffer(struct b43legacy_dmaring *ring,
 319                             struct b43legacy_dmadesc_meta *meta,
 320                             int irq_context)
 321 {
 322         if (meta->skb) {
 323                 if (irq_context)
 324                         dev_kfree_skb_irq(meta->skb);
 325                 else
 326                         dev_kfree_skb(meta->skb);
 327                 meta->skb = NULL;
 328         }
 329 }
 330
 331 static int alloc_ringmemory(struct b43legacy_dmaring *ring)
 332 {
 333         /* GFP flags must match the flags in free_ringmemory()! */
 334         ring->descbase = dma_alloc_coherent(ring->dev->dev->dma_dev,
 335                                             B43legacy_DMA_RINGMEMSIZE,
 336                                             &(ring->dmabase),
 337                                             GFP_KERNEL);
 338         if (!ring->descbase) {
 339                 b43legacyerr(ring->dev->wl, "DMA ringmemory allocation"
 340                              " failed\n");
 341                 return -ENOMEM;
 342         }
 343         memset(ring->descbase, 0, B43legacy_DMA_RINGMEMSIZE);
 344
 345         return 0;
 346 }
 347
 348 static void free_ringmemory(struct b43legacy_dmaring *ring)
 349 {
 350         dma_free_coherent(ring->dev->dev->dma_dev, B43legacy_DMA_RINGMEMSIZE,
 351                           ring->descbase, ring->dmabase);
 352 }
 353
 354 /* Reset the RX DMA channel */
 355 static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
 356                                             u16 mmio_base,
 357                                             enum b43legacy_dmatype type)
 358 {
 359         int i;
 360         u32 value;
 361         u16 offset;
 362
 363         might_sleep();
 364
 365         offset = B43legacy_DMA32_RXCTL;
 366         b43legacy_write32(dev, mmio_base + offset, 0);
 367         for (i = 0; i < 10; i++) {
 368                 offset = B43legacy_DMA32_RXSTATUS;
 369                 value = b43legacy_read32(dev, mmio_base + offset);
 370                 value &= B43legacy_DMA32_RXSTATE;
 371                 if (value == B43legacy_DMA32_RXSTAT_DISABLED) {
 372                         i = -1;
 373                         break;
 374                 }
 375                 msleep(1);
 376         }
 377         if (i != -1) {
 378                 b43legacyerr(dev->wl, "DMA RX reset timed out\n");
 379                 return -ENODEV;
 380         }
 381
 382         return 0;
 383 }
 384
 385 /* Reset the RX DMA channel */
 386 static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
 387                                             u16 mmio_base,
 388                                             enum b43legacy_dmatype type)
 389 {
 390         int i;
 391         u32 value;
 392         u16 offset;
 393
 394         might_sleep();
 395
 396         for (i = 0; i < 10; i++) {
 397                 offset = B43legacy_DMA32_TXSTATUS;
 398                 value = b43legacy_read32(dev, mmio_base + offset);
 399                 value &= B43legacy_DMA32_TXSTATE;
 400                 if (value == B43legacy_DMA32_TXSTAT_DISABLED ||
 401                     value == B43legacy_DMA32_TXSTAT_IDLEWAIT ||
 402                     value == B43legacy_DMA32_TXSTAT_STOPPED)
 403                         break;
 404                 msleep(1);
 405         }
 406         offset = B43legacy_DMA32_TXCTL;
 407         b43legacy_write32(dev, mmio_base + offset, 0);
 408         for (i = 0; i < 10; i++) {
 409                 offset = B43legacy_DMA32_TXSTATUS;
 410                 value = b43legacy_read32(dev, mmio_base + offset);
 411                 value &= B43legacy_DMA32_TXSTATE;
 412                 if (value == B43legacy_DMA32_TXSTAT_DISABLED) {
 413                         i = -1;
 414                         break;
 415                 }
 416                 msleep(1);
 417         }
 418         if (i != -1) {
 419                 b43legacyerr(dev->wl, "DMA TX reset timed out\n");
 420                 return -ENODEV;
 421         }
 422         /* ensure the reset is completed. */
 423         msleep(1);
 424
 425         return 0;
 426 }
 427
 428 /* Check if a DMA mapping address is invalid. */
 429 static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
 430                                          dma_addr_t addr,
 431                                          size_t buffersize,
 432                                          bool dma_to_device)
 433 {
 434         if (unlikely(dma_mapping_error(ring->dev->dev->dma_dev, addr)))
 435                 return 1;
 436
 437         switch (ring->type) {
 438         case B43legacy_DMA_30BIT:
 439                 if ((u64)addr + buffersize > (1ULL << 30))
 440                         goto address_error;
 441                 break;
 442         case B43legacy_DMA_32BIT:
 443                 if ((u64)addr + buffersize > (1ULL << 32))
 444                         goto address_error;
 445                 break;
 446         }
 447
 448         /* The address is OK. */
 449         return 0;
 450
 451 address_error:
 452         /* We can't support this address. Unmap it again. */
 453         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 454
 455         return 1;
 456 }
 457
 458 static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
 459                                struct b43legacy_dmadesc32 *desc,
 460                                struct b43legacy_dmadesc_meta *meta,
 461                                gfp_t gfp_flags)
 462 {
 463         struct b43legacy_rxhdr_fw3 *rxhdr;
 464         struct b43legacy_hwtxstatus *txstat;
 465         dma_addr_t dmaaddr;
 466         struct sk_buff *skb;
 467
 468         B43legacy_WARN_ON(ring->tx);
 469
 470         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 471         if (unlikely(!skb))
 472                 return -ENOMEM;
 473         dmaaddr = map_descbuffer(ring, skb->data,
 474                                  ring->rx_buffersize, 0);
 475         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 476                 /* ugh. try to realloc in zone_dma */
 477                 gfp_flags |= GFP_DMA;
 478
 479                 dev_kfree_skb_any(skb);
 480
 481                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 482                 if (unlikely(!skb))
 483                         return -ENOMEM;
 484                 dmaaddr = map_descbuffer(ring, skb->data,
 485                                          ring->rx_buffersize, 0);
 486         }
 487
 488         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 489                 dev_kfree_skb_any(skb);
 490                 return -EIO;
 491         }
 492
 493         meta->skb = skb;
 494         meta->dmaaddr = dmaaddr;
 495         op32_fill_descriptor(ring, desc, dmaaddr, ring->rx_buffersize, 0, 0, 0);
 496
 497         rxhdr = (struct b43legacy_rxhdr_fw3 *)(skb->data);
 498         rxhdr->frame_len = 0;
 499         txstat = (struct b43legacy_hwtxstatus *)(skb->data);
 500         txstat->cookie = 0;
 501
 502         return 0;
 503 }
 504
 505 /* Allocate the initial descbuffers.
 506  * This is used for an RX ring only.
 507  */
 508 static int alloc_initial_descbuffers(struct b43legacy_dmaring *ring)
 509 {
 510         int i;
 511         int err = -ENOMEM;
 512         struct b43legacy_dmadesc32 *desc;
 513         struct b43legacy_dmadesc_meta *meta;
 514
 515         for (i = 0; i < ring->nr_slots; i++) {
 516                 desc = op32_idx2desc(ring, i, &meta);
 517
 518                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 519                 if (err) {
 520                         b43legacyerr(ring->dev->wl,
 521                                "Failed to allocate initial descbuffers\n");
 522                         goto err_unwind;
 523                 }
 524         }
 525         mb(); /* all descbuffer setup before next line */
 526         ring->used_slots = ring->nr_slots;
 527         err = 0;
 528 out:
 529         return err;
 530
 531 err_unwind:
 532         for (i--; i >= 0; i--) {
 533                 desc = op32_idx2desc(ring, i, &meta);
 534
 535                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 536                 dev_kfree_skb(meta->skb);
 537         }
 538         goto out;
 539 }
 540
 541 /* Do initial setup of the DMA controller.
 542  * Reset the controller, write the ring busaddress
 543  * and switch the "enable" bit on.
 544  */
 545 static int dmacontroller_setup(struct b43legacy_dmaring *ring)
 546 {
 547         int err = 0;
 548         u32 value;
 549         u32 addrext;
 550         u32 trans = ring->dev->dma.translation;
 551         u32 ringbase = (u32)(ring->dmabase);
 552
 553         if (ring->tx) {
 554                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 555                           >> SSB_DMA_TRANSLATION_SHIFT;
 556                 value = B43legacy_DMA32_TXENABLE;
 557                 value |= (addrext << B43legacy_DMA32_TXADDREXT_SHIFT)
 558                         & B43legacy_DMA32_TXADDREXT_MASK;
 559                 b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL, value);
 560                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING,
 561                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 562                                     | trans);
 563         } else {
 564                 err = alloc_initial_descbuffers(ring);
 565                 if (err)
 566                         goto out;
 567
 568                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 569                           >> SSB_DMA_TRANSLATION_SHIFT;
 570                 value = (ring->frameoffset <<
 571                          B43legacy_DMA32_RXFROFF_SHIFT);
 572                 value |= B43legacy_DMA32_RXENABLE;
 573                 value |= (addrext << B43legacy_DMA32_RXADDREXT_SHIFT)
 574                          & B43legacy_DMA32_RXADDREXT_MASK;
 575                 b43legacy_dma_write(ring, B43legacy_DMA32_RXCTL, value);
 576                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING,
 577                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 578                                     | trans);
 579                 b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX, 200);
 580         }
 581
 582 out:
 583         return err;
 584 }
 585
 586 /* Shutdown the DMA controller. */
 587 static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
 588 {
 589         if (ring->tx) {
 590                 b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 591                                                  ring->type);
 592                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
 593         } else {
 594                 b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 595                                                  ring->type);
 596                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING, 0);
 597         }
 598 }
 599
 600 static void free_all_descbuffers(struct b43legacy_dmaring *ring)
 601 {
 602         struct b43legacy_dmadesc_meta *meta;
 603         int i;
 604
 605         if (!ring->used_slots)
 606                 return;
 607         for (i = 0; i < ring->nr_slots; i++) {
 608                 op32_idx2desc(ring, i, &meta);
 609
 610                 if (!meta->skb) {
 611                         B43legacy_WARN_ON(!ring->tx);
 612                         continue;
 613                 }
 614                 if (ring->tx)
 615                         unmap_descbuffer(ring, meta->dmaaddr,
 616                                          meta->skb->len, 1);
 617                 else
 618                         unmap_descbuffer(ring, meta->dmaaddr,
 619                                          ring->rx_buffersize, 0);
 620                 free_descriptor_buffer(ring, meta, 0);
 621         }
 622 }
 623
 624 static u64 supported_dma_mask(struct b43legacy_wldev *dev)
 625 {
 626         u32 tmp;
 627         u16 mmio_base;
 628
 629         mmio_base = b43legacy_dmacontroller_base(0, 0);
 630         b43legacy_write32(dev,
 631                         mmio_base + B43legacy_DMA32_TXCTL,
 632                         B43legacy_DMA32_TXADDREXT_MASK);
 633         tmp = b43legacy_read32(dev, mmio_base +
 634                                B43legacy_DMA32_TXCTL);
 635         if (tmp & B43legacy_DMA32_TXADDREXT_MASK)
 636                 return DMA_BIT_MASK(32);
 637
 638         return DMA_BIT_MASK(30);
 639 }
 640
 641 static enum b43legacy_dmatype dma_mask_to_engine_type(u64 dmamask)
 642 {
 643         if (dmamask == DMA_BIT_MASK(30))
 644                 return B43legacy_DMA_30BIT;
 645         if (dmamask == DMA_BIT_MASK(32))
 646                 return B43legacy_DMA_32BIT;
 647         B43legacy_WARN_ON(1);
 648         return B43legacy_DMA_30BIT;
 649 }
 650
 651 /* Main initialization function. */
 652 static
 653 struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
 654                                                   int controller_index,
 655                                                   int for_tx,
 656                                                   enum b43legacy_dmatype type)
 657 {
 658         struct b43legacy_dmaring *ring;
 659         int err;
 660         int nr_slots;
 661         dma_addr_t dma_test;
 662
 663         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 664         if (!ring)
 665                 goto out;
 666         ring->type = type;
 667         ring->dev = dev;
 668
 669         nr_slots = B43legacy_RXRING_SLOTS;
 670         if (for_tx)
 671                 nr_slots = B43legacy_TXRING_SLOTS;
 672
 673         ring->meta = kcalloc(nr_slots, sizeof(struct b43legacy_dmadesc_meta),
 674                              GFP_KERNEL);
 675         if (!ring->meta)
 676                 goto err_kfree_ring;
 677         if (for_tx) {
 678                 ring->txhdr_cache = kcalloc(nr_slots,
 679                                         sizeof(struct b43legacy_txhdr_fw3),
 680                                         GFP_KERNEL);
 681                 if (!ring->txhdr_cache)
 682                         goto err_kfree_meta;
 683
 684                 /* test for ability to dma to txhdr_cache */
 685                 dma_test = dma_map_single(dev->dev->dma_dev, ring->txhdr_cache,
 686                                               sizeof(struct b43legacy_txhdr_fw3),
 687                                               DMA_TO_DEVICE);
 688
 689                 if (b43legacy_dma_mapping_error(ring, dma_test,
 690                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
 691                         /* ugh realloc */
 692                         kfree(ring->txhdr_cache);
 693                         ring->txhdr_cache = kcalloc(nr_slots,
 694                                         sizeof(struct b43legacy_txhdr_fw3),
 695                                         GFP_KERNEL | GFP_DMA);
 696                         if (!ring->txhdr_cache)
 697                                 goto err_kfree_meta;
 698
 699                         dma_test = dma_map_single(dev->dev->dma_dev,
 700                                         ring->txhdr_cache,
 701                                         sizeof(struct b43legacy_txhdr_fw3),
 702                                         DMA_TO_DEVICE);
 703
 704                         if (b43legacy_dma_mapping_error(ring, dma_test,
 705                                         sizeof(struct b43legacy_txhdr_fw3), 1))
 706                                 goto err_kfree_txhdr_cache;
 707                 }
 708
 709                 dma_unmap_single(dev->dev->dma_dev, dma_test,
 710                                  sizeof(struct b43legacy_txhdr_fw3),
 711                                  DMA_TO_DEVICE);
 712         }
 713
 714         ring->nr_slots = nr_slots;
 715         ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
 716         ring->index = controller_index;
 717         if (for_tx) {
 718                 ring->tx = 1;
 719                 ring->current_slot = -1;
 720         } else {
 721                 if (ring->index == 0) {
 722                         ring->rx_buffersize = B43legacy_DMA0_RX_BUFFERSIZE;
 723                         ring->frameoffset = B43legacy_DMA0_RX_FRAMEOFFSET;
 724                 } else if (ring->index == 3) {
 725                         ring->rx_buffersize = B43legacy_DMA3_RX_BUFFERSIZE;
 726                         ring->frameoffset = B43legacy_DMA3_RX_FRAMEOFFSET;
 727                 } else
 728                         B43legacy_WARN_ON(1);
 729         }
 730         spin_lock_init(&ring->lock);
 731 #ifdef CONFIG_B43LEGACY_DEBUG
 732         ring->last_injected_overflow = jiffies;
 733 #endif
 734
 735         err = alloc_ringmemory(ring);
 736         if (err)
 737                 goto err_kfree_txhdr_cache;
 738         err = dmacontroller_setup(ring);
 739         if (err)
 740                 goto err_free_ringmemory;
 741
 742 out:
 743         return ring;
 744
 745 err_free_ringmemory:
 746         free_ringmemory(ring);
 747 err_kfree_txhdr_cache:
 748         kfree(ring->txhdr_cache);
 749 err_kfree_meta:
 750         kfree(ring->meta);
 751 err_kfree_ring:
 752         kfree(ring);
 753         ring = NULL;
 754         goto out;
 755 }
 756
 757 /* Main cleanup function. */
 758 static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
 759 {
 760         if (!ring)
 761                 return;
 762
 763         b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
 764                      " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
 765                      (ring->tx) ? "TX" : "RX", ring->max_used_slots,
 766                      ring->nr_slots);
 767         /* Device IRQs are disabled prior entering this function,
 768          * so no need to take care of concurrency with rx handler stuff.
 769          */
 770         dmacontroller_cleanup(ring);
 771         free_all_descbuffers(ring);
 772         free_ringmemory(ring);
 773
 774         kfree(ring->txhdr_cache);
 775         kfree(ring->meta);
 776         kfree(ring);
 777 }
 778
 779 void b43legacy_dma_free(struct b43legacy_wldev *dev)
 780 {
 781         struct b43legacy_dma *dma;
 782
 783         if (b43legacy_using_pio(dev))
 784                 return;
 785         dma = &dev->dma;
 786
 787         b43legacy_destroy_dmaring(dma->rx_ring3);
 788         dma->rx_ring3 = NULL;
 789         b43legacy_destroy_dmaring(dma->rx_ring0);
 790         dma->rx_ring0 = NULL;
 791
 792         b43legacy_destroy_dmaring(dma->tx_ring5);
 793         dma->tx_ring5 = NULL;
 794         b43legacy_destroy_dmaring(dma->tx_ring4);
 795         dma->tx_ring4 = NULL;
 796         b43legacy_destroy_dmaring(dma->tx_ring3);
 797         dma->tx_ring3 = NULL;
 798         b43legacy_destroy_dmaring(dma->tx_ring2);
 799         dma->tx_ring2 = NULL;
 800         b43legacy_destroy_dmaring(dma->tx_ring1);
 801         dma->tx_ring1 = NULL;
 802         b43legacy_destroy_dmaring(dma->tx_ring0);
 803         dma->tx_ring0 = NULL;
 804 }
 805
 806 static int b43legacy_dma_set_mask(struct b43legacy_wldev *dev, u64 mask)
 807 {
 808         u64 orig_mask = mask;
 809         bool fallback = 0;
 810         int err;
 811
 812         /* Try to set the DMA mask. If it fails, try falling back to a
 813          * lower mask, as we can always also support a lower one. */
 814         while (1) {
 815                 err = dma_set_mask(dev->dev->dma_dev, mask);
 816                 if (!err) {
 817                         err = dma_set_coherent_mask(dev->dev->dma_dev, mask);
 818                         if (!err)
 819                                 break;
 820                 }
 821                 if (mask == DMA_BIT_MASK(64)) {
 822                         mask = DMA_BIT_MASK(32);
 823                         fallback = 1;
 824                         continue;
 825                 }
 826                 if (mask == DMA_BIT_MASK(32)) {
 827                         mask = DMA_BIT_MASK(30);
 828                         fallback = 1;
 829                         continue;
 830                 }
 831                 b43legacyerr(dev->wl, "The machine/kernel does not support "
 832                        "the required %u-bit DMA mask\n",
 833                        (unsigned int)dma_mask_to_engine_type(orig_mask));
 834                 return -EOPNOTSUPP;
 835         }
 836         if (fallback) {
 837                 b43legacyinfo(dev->wl, "DMA mask fallback from %u-bit to %u-"
 838                         "bit\n",
 839                         (unsigned int)dma_mask_to_engine_type(orig_mask),
 840                         (unsigned int)dma_mask_to_engine_type(mask));
 841         }
 842
 843         return 0;
 844 }
 845
 846 int b43legacy_dma_init(struct b43legacy_wldev *dev)
 847 {
 848         struct b43legacy_dma *dma = &dev->dma;
 849         struct b43legacy_dmaring *ring;
 850         int err;
 851         u64 dmamask;
 852         enum b43legacy_dmatype type;
 853
 854         dmamask = supported_dma_mask(dev);
 855         type = dma_mask_to_engine_type(dmamask);
 856         err = b43legacy_dma_set_mask(dev, dmamask);
 857         if (err) {
 858 #ifdef CONFIG_B43LEGACY_PIO
 859                 b43legacywarn(dev->wl, "DMA for this device not supported. "
 860                         "Falling back to PIO\n");
 861                 dev->__using_pio = 1;
 862                 return -EAGAIN;
 863 #else
 864                 b43legacyerr(dev->wl, "DMA for this device not supported and "
 865                        "no PIO support compiled in\n");
 866                 return -EOPNOTSUPP;
 867 #endif
 868         }
 869         dma->translation = ssb_dma_translation(dev->dev);
 870
 871         err = -ENOMEM;
 872         /* setup TX DMA channels. */
 873         ring = b43legacy_setup_dmaring(dev, 0, 1, type);
 874         if (!ring)
 875                 goto out;
 876         dma->tx_ring0 = ring;
 877
 878         ring = b43legacy_setup_dmaring(dev, 1, 1, type);
 879         if (!ring)
 880                 goto err_destroy_tx0;
 881         dma->tx_ring1 = ring;
 882
 883         ring = b43legacy_setup_dmaring(dev, 2, 1, type);
 884         if (!ring)
 885                 goto err_destroy_tx1;
 886         dma->tx_ring2 = ring;
 887
 888         ring = b43legacy_setup_dmaring(dev, 3, 1, type);
 889         if (!ring)
 890                 goto err_destroy_tx2;
 891         dma->tx_ring3 = ring;
 892
 893         ring = b43legacy_setup_dmaring(dev, 4, 1, type);
 894         if (!ring)
 895                 goto err_destroy_tx3;
 896         dma->tx_ring4 = ring;
 897
 898         ring = b43legacy_setup_dmaring(dev, 5, 1, type);
 899         if (!ring)
 900                 goto err_destroy_tx4;
 901         dma->tx_ring5 = ring;
 902
 903         /* setup RX DMA channels. */
 904         ring = b43legacy_setup_dmaring(dev, 0, 0, type);
 905         if (!ring)
 906                 goto err_destroy_tx5;
 907         dma->rx_ring0 = ring;
 908
 909         if (dev->dev->id.revision < 5) {
 910                 ring = b43legacy_setup_dmaring(dev, 3, 0, type);
 911                 if (!ring)
 912                         goto err_destroy_rx0;
 913                 dma->rx_ring3 = ring;
 914         }
 915
 916         b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
 917         err = 0;
 918 out:
 919         return err;
 920
 921 err_destroy_rx0:
 922         b43legacy_destroy_dmaring(dma->rx_ring0);
 923         dma->rx_ring0 = NULL;
 924 err_destroy_tx5:
 925         b43legacy_destroy_dmaring(dma->tx_ring5);
 926         dma->tx_ring5 = NULL;
 927 err_destroy_tx4:
 928         b43legacy_destroy_dmaring(dma->tx_ring4);
 929         dma->tx_ring4 = NULL;
 930 err_destroy_tx3:
 931         b43legacy_destroy_dmaring(dma->tx_ring3);
 932         dma->tx_ring3 = NULL;
 933 err_destroy_tx2:
 934         b43legacy_destroy_dmaring(dma->tx_ring2);
 935         dma->tx_ring2 = NULL;
 936 err_destroy_tx1:
 937         b43legacy_destroy_dmaring(dma->tx_ring1);
 938         dma->tx_ring1 = NULL;
 939 err_destroy_tx0:
 940         b43legacy_destroy_dmaring(dma->tx_ring0);
 941         dma->tx_ring0 = NULL;
 942         goto out;
 943 }
 944
 945 /* Generate a cookie for the TX header. */
 946 static u16 generate_cookie(struct b43legacy_dmaring *ring,
 947                            int slot)
 948 {
 949         u16 cookie = 0x1000;
 950
 951         /* Use the upper 4 bits of the cookie as
 952          * DMA controller ID and store the slot number
 953          * in the lower 12 bits.
 954          * Note that the cookie must never be 0, as this
 955          * is a special value used in RX path.
 956          */
 957         switch (ring->index) {
 958         case 0:
 959                 cookie = 0xA000;
 960                 break;
 961         case 1:
 962                 cookie = 0xB000;
 963                 break;
 964         case 2:
 965                 cookie = 0xC000;
 966                 break;
 967         case 3:
 968                 cookie = 0xD000;
 969                 break;
 970         case 4:
 971                 cookie = 0xE000;
 972                 break;
 973         case 5:
 974                 cookie = 0xF000;
 975                 break;
 976         }
 977         B43legacy_WARN_ON(!(((u16)slot & 0xF000) == 0x0000));
 978         cookie |= (u16)slot;
 979
 980         return cookie;
 981 }
 982
 983 /* Inspect a cookie and find out to which controller/slot it belongs. */
 984 static
 985 struct b43legacy_dmaring *parse_cookie(struct b43legacy_wldev *dev,
 986                                       u16 cookie, int *slot)
 987 {
 988         struct b43legacy_dma *dma = &dev->dma;
 989         struct b43legacy_dmaring *ring = NULL;
 990
 991         switch (cookie & 0xF000) {
 992         case 0xA000:
 993                 ring = dma->tx_ring0;
 994                 break;
 995         case 0xB000:
 996                 ring = dma->tx_ring1;
 997                 break;
 998         case 0xC000:
 999                 ring = dma->tx_ring2;
1000                 break;
1001         case 0xD000:
1002                 ring = dma->tx_ring3;
1003                 break;
1004         case 0xE000:
1005                 ring = dma->tx_ring4;
1006                 break;
1007         case 0xF000:
1008                 ring = dma->tx_ring5;
1009                 break;
1010         default:
1011                 B43legacy_WARN_ON(1);
1012         }
1013         *slot = (cookie & 0x0FFF);
1014         B43legacy_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1015
1016         return ring;
1017 }
1018
1019 static int dma_tx_fragment(struct b43legacy_dmaring *ring,
1020                             struct sk_buff **in_skb)
1021 {
1022         struct sk_buff *skb = *in_skb;
1023         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1024         u8 *header;
1025         int slot, old_top_slot, old_used_slots;
1026         int err;
1027         struct b43legacy_dmadesc32 *desc;
1028         struct b43legacy_dmadesc_meta *meta;
1029         struct b43legacy_dmadesc_meta *meta_hdr;
1030         struct sk_buff *bounce_skb;
1031
1032 #define SLOTS_PER_PACKET  2
1033         B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
1034
1035         old_top_slot = ring->current_slot;
1036         old_used_slots = ring->used_slots;
1037
1038         /* Get a slot for the header. */
1039         slot = request_slot(ring);
1040         desc = op32_idx2desc(ring, slot, &meta_hdr);
1041         memset(meta_hdr, 0, sizeof(*meta_hdr));
1042
1043         header = &(ring->txhdr_cache[slot * sizeof(
1044                                struct b43legacy_txhdr_fw3)]);
1045         err = b43legacy_generate_txhdr(ring->dev, header,
1046                                  skb->data, skb->len, info,
1047                                  generate_cookie(ring, slot));
1048         if (unlikely(err)) {
1049                 ring->current_slot = old_top_slot;
1050                 ring->used_slots = old_used_slots;
1051                 return err;
1052         }
1053
1054         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1055                                            sizeof(struct b43legacy_txhdr_fw3), 1);
1056         if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
1057                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
1058                 ring->current_slot = old_top_slot;
1059                 ring->used_slots = old_used_slots;
1060                 return -EIO;
1061         }
1062         op32_fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1063                              sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
1064
1065         /* Get a slot for the payload. */
1066         slot = request_slot(ring);
1067         desc = op32_idx2desc(ring, slot, &meta);
1068         memset(meta, 0, sizeof(*meta));
1069
1070         meta->skb = skb;
1071         meta->is_last_fragment = 1;
1072
1073         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1074         /* create a bounce buffer in zone_dma on mapping failure. */
1075         if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1076                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1077                 if (!bounce_skb) {
1078                         ring->current_slot = old_top_slot;
1079                         ring->used_slots = old_used_slots;
1080                         err = -ENOMEM;
1081                         goto out_unmap_hdr;
1082                 }
1083
1084                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1085                 memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
1086                 bounce_skb->dev = skb->dev;
1087                 skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
1088                 info = IEEE80211_SKB_CB(bounce_skb);
1089
1090                 dev_kfree_skb_any(skb);
1091                 skb = bounce_skb;
1092                 *in_skb = bounce_skb;
1093                 meta->skb = skb;
1094                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1095                 if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1096                         ring->current_slot = old_top_slot;
1097                         ring->used_slots = old_used_slots;
1098                         err = -EIO;
1099                         goto out_free_bounce;
1100                 }
1101         }
1102
1103         op32_fill_descriptor(ring, desc, meta->dmaaddr,
1104                              skb->len, 0, 1, 1);
1105
1106         wmb();  /* previous stuff MUST be done */
1107         /* Now transfer the whole frame. */
1108         op32_poke_tx(ring, next_slot(ring, slot));
1109         return 0;
1110
1111 out_free_bounce:
1112         dev_kfree_skb_any(skb);
1113 out_unmap_hdr:
1114         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1115                          sizeof(struct b43legacy_txhdr_fw3), 1);
1116         return err;
1117 }
1118
1119 static inline
1120 int should_inject_overflow(struct b43legacy_dmaring *ring)
1121 {
1122 #ifdef CONFIG_B43LEGACY_DEBUG
1123         if (unlikely(b43legacy_debug(ring->dev,
1124                                      B43legacy_DBG_DMAOVERFLOW))) {
1125                 /* Check if we should inject another ringbuffer overflow
1126                  * to test handling of this situation in the stack. */
1127                 unsigned long next_overflow;
1128
1129                 next_overflow = ring->last_injected_overflow + HZ;
1130                 if (time_after(jiffies, next_overflow)) {
1131                         ring->last_injected_overflow = jiffies;
1132                         b43legacydbg(ring->dev->wl,
1133                                "Injecting TX ring overflow on "
1134                                "DMA controller %d\n", ring->index);
1135                         return 1;
1136                 }
1137         }
1138 #endif /* CONFIG_B43LEGACY_DEBUG */
1139         return 0;
1140 }
1141
1142 int b43legacy_dma_tx(struct b43legacy_wldev *dev,
1143                      struct sk_buff *skb)
1144 {
1145         struct b43legacy_dmaring *ring;
1146         int err = 0;
1147         unsigned long flags;
1148
1149         ring = priority_to_txring(dev, skb_get_queue_mapping(skb));
1150         spin_lock_irqsave(&ring->lock, flags);
1151         B43legacy_WARN_ON(!ring->tx);
1152
1153         if (unlikely(ring->stopped)) {
1154                 /* We get here only because of a bug in mac80211.
1155                  * Because of a race, one packet may be queued after
1156                  * the queue is stopped, thus we got called when we shouldn't.
1157                  * For now, just refuse the transmit. */
1158                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1159                         b43legacyerr(dev->wl, "Packet after queue stopped\n");
1160                 err = -ENOSPC;
1161                 goto out_unlock;
1162         }
1163
1164         if (unlikely(WARN_ON(free_slots(ring) < SLOTS_PER_PACKET))) {
1165                 /* If we get here, we have a real error with the queue
1166                  * full, but queues not stopped. */
1167                 b43legacyerr(dev->wl, "DMA queue overflow\n");
1168                 err = -ENOSPC;
1169                 goto out_unlock;
1170         }
1171
1172         /* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
1173          * into the skb data or cb now. */
1174         err = dma_tx_fragment(ring, &skb);
1175         if (unlikely(err == -ENOKEY)) {
1176                 /* Drop this packet, as we don't have the encryption key
1177                  * anymore and must not transmit it unencrypted. */
1178                 dev_kfree_skb_any(skb);
1179                 err = 0;
1180                 goto out_unlock;
1181         }
1182         if (unlikely(err)) {
1183                 b43legacyerr(dev->wl, "DMA tx mapping failure\n");
1184                 goto out_unlock;
1185         }
1186         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1187             should_inject_overflow(ring)) {
1188                 /* This TX ring is full. */
1189                 ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1190                 ring->stopped = 1;
1191                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1192                         b43legacydbg(dev->wl, "Stopped TX ring %d\n",
1193                                ring->index);
1194         }
1195 out_unlock:
1196         spin_unlock_irqrestore(&ring->lock, flags);
1197
1198         return err;
1199 }
1200
1201 void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
1202                                  const struct b43legacy_txstatus *status)
1203 {
1204         struct b43legacy_dmaring *ring;
1205         struct b43legacy_dmadesc_meta *meta;
1206         int retry_limit;
1207         int slot;
1208
1209         ring = parse_cookie(dev, status->cookie, &slot);
1210         if (unlikely(!ring))
1211                 return;
1212         B43legacy_WARN_ON(!irqs_disabled());
1213         spin_lock(&ring->lock);
1214
1215         B43legacy_WARN_ON(!ring->tx);
1216         while (1) {
1217                 B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1218                 op32_idx2desc(ring, slot, &meta);
1219
1220                 if (meta->skb)
1221                         unmap_descbuffer(ring, meta->dmaaddr,
1222                                          meta->skb->len, 1);
1223                 else
1224                         unmap_descbuffer(ring, meta->dmaaddr,
1225                                          sizeof(struct b43legacy_txhdr_fw3),
1226                                          1);
1227
1228                 if (meta->is_last_fragment) {
1229                         struct ieee80211_tx_info *info;
1230                         BUG_ON(!meta->skb);
1231                         info = IEEE80211_SKB_CB(meta->skb);
1232
1233                         /* preserve the confiured retry limit before clearing the status
1234                          * The xmit function has overwritten the rc's value with the actual
1235                          * retry limit done by the hardware */
1236                         retry_limit = info->status.rates[0].count;
1237                         ieee80211_tx_info_clear_status(info);
1238
1239                         if (status->acked)
1240                                 info->flags |= IEEE80211_TX_STAT_ACK;
1241
1242                         if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
1243                                 /*
1244                                  * If the short retries (RTS, not data frame) have exceeded
1245                                  * the limit, the hw will not have tried the selected rate,
1246                                  * but will have used the fallback rate instead.
1247                                  * Don't let the rate control count attempts for the selected
1248                                  * rate in this case, otherwise the statistics will be off.
1249                                  */
1250                                 info->status.rates[0].count = 0;
1251                                 info->status.rates[1].count = status->frame_count;
1252                         } else {
1253                                 if (status->frame_count > retry_limit) {
1254                                         info->status.rates[0].count = retry_limit;
1255                                         info->status.rates[1].count = status->frame_count -
1256                                                         retry_limit;
1257
1258                                 } else {
1259                                         info->status.rates[0].count = status->frame_count;
1260                                         info->status.rates[1].idx = -1;
1261                                 }
1262                         }
1263
1264                         /* Call back to inform the ieee80211 subsystem about the
1265                          * status of the transmission.
1266                          * Some fields of txstat are already filled in dma_tx().
1267                          */
1268                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
1269                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1270                         meta->skb = NULL;
1271                 } else {
1272                         /* No need to call free_descriptor_buffer here, as
1273                          * this is only the txhdr, which is not allocated.
1274                          */
1275                         B43legacy_WARN_ON(meta->skb != NULL);
1276                 }
1277
1278                 /* Everything unmapped and free'd. So it's not used anymore. */
1279                 ring->used_slots--;
1280
1281                 if (meta->is_last_fragment)
1282                         break;
1283                 slot = next_slot(ring, slot);
1284         }
1285         dev->stats.last_tx = jiffies;
1286         if (ring->stopped) {
1287                 B43legacy_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1288                 ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1289                 ring->stopped = 0;
1290                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1291                         b43legacydbg(dev->wl, "Woke up TX ring %d\n",
1292                                ring->index);
1293         }
1294
1295         spin_unlock(&ring->lock);
1296 }
1297
1298 static void dma_rx(struct b43legacy_dmaring *ring,
1299                    int *slot)
1300 {
1301         struct b43legacy_dmadesc32 *desc;
1302         struct b43legacy_dmadesc_meta *meta;
1303         struct b43legacy_rxhdr_fw3 *rxhdr;
1304         struct sk_buff *skb;
1305         u16 len;
1306         int err;
1307         dma_addr_t dmaaddr;
1308
1309         desc = op32_idx2desc(ring, *slot, &meta);
1310
1311         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1312         skb = meta->skb;
1313
1314         if (ring->index == 3) {
1315                 /* We received an xmit status. */
1316                 struct b43legacy_hwtxstatus *hw =
1317                                 (struct b43legacy_hwtxstatus *)skb->data;
1318                 int i = 0;
1319
1320                 while (hw->cookie == 0) {
1321                         if (i > 100)
1322                                 break;
1323                         i++;
1324                         udelay(2);
1325                         barrier();
1326                 }
1327                 b43legacy_handle_hwtxstatus(ring->dev, hw);
1328                 /* recycle the descriptor buffer. */
1329                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1330                                            ring->rx_buffersize);
1331
1332                 return;
1333         }
1334         rxhdr = (struct b43legacy_rxhdr_fw3 *)skb->data;
1335         len = le16_to_cpu(rxhdr->frame_len);
1336         if (len == 0) {
1337                 int i = 0;
1338
1339                 do {
1340                         udelay(2);
1341                         barrier();
1342                         len = le16_to_cpu(rxhdr->frame_len);
1343                 } while (len == 0 && i++ < 5);
1344                 if (unlikely(len == 0)) {
1345                         /* recycle the descriptor buffer. */
1346                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1347                                                    ring->rx_buffersize);
1348                         goto drop;
1349                 }
1350         }
1351         if (unlikely(len > ring->rx_buffersize)) {
1352                 /* The data did not fit into one descriptor buffer
1353                  * and is split over multiple buffers.
1354                  * This should never happen, as we try to allocate buffers
1355                  * big enough. So simply ignore this packet.
1356                  */
1357                 int cnt = 0;
1358                 s32 tmp = len;
1359
1360                 while (1) {
1361                         desc = op32_idx2desc(ring, *slot, &meta);
1362                         /* recycle the descriptor buffer. */
1363                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1364                                                    ring->rx_buffersize);
1365                         *slot = next_slot(ring, *slot);
1366                         cnt++;
1367                         tmp -= ring->rx_buffersize;
1368                         if (tmp <= 0)
1369                                 break;
1370                 }
1371                 b43legacyerr(ring->dev->wl, "DMA RX buffer too small "
1372                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1373                        len, ring->rx_buffersize, cnt);
1374                 goto drop;
1375         }
1376
1377         dmaaddr = meta->dmaaddr;
1378         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1379         if (unlikely(err)) {
1380                 b43legacydbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer()"
1381                              " failed\n");
1382                 sync_descbuffer_for_device(ring, dmaaddr,
1383                                            ring->rx_buffersize);
1384                 goto drop;
1385         }
1386
1387         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1388         skb_put(skb, len + ring->frameoffset);
1389         skb_pull(skb, ring->frameoffset);
1390
1391         b43legacy_rx(ring->dev, skb, rxhdr);
1392 drop:
1393         return;
1394 }
1395
1396 void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
1397 {
1398         int slot;
1399         int current_slot;
1400         int used_slots = 0;
1401
1402         B43legacy_WARN_ON(ring->tx);
1403         current_slot = op32_get_current_rxslot(ring);
1404         B43legacy_WARN_ON(!(current_slot >= 0 && current_slot <
1405                            ring->nr_slots));
1406
1407         slot = ring->current_slot;
1408         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1409                 dma_rx(ring, &slot);
1410                 update_max_used_slots(ring, ++used_slots);
1411         }
1412         op32_set_current_rxslot(ring, slot);
1413         ring->current_slot = slot;
1414 }
1415
1416 static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1417 {
1418         unsigned long flags;
1419
1420         spin_lock_irqsave(&ring->lock, flags);
1421         B43legacy_WARN_ON(!ring->tx);
1422         op32_tx_suspend(ring);
1423         spin_unlock_irqrestore(&ring->lock, flags);
1424 }
1425
1426 static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1427 {
1428         unsigned long flags;
1429
1430         spin_lock_irqsave(&ring->lock, flags);
1431         B43legacy_WARN_ON(!ring->tx);
1432         op32_tx_resume(ring);
1433         spin_unlock_irqrestore(&ring->lock, flags);
1434 }
1435
1436 void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
1437 {
1438         b43legacy_power_saving_ctl_bits(dev, -1, 1);
1439         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring0);
1440         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring1);
1441         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring2);
1442         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring3);
1443         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring4);
1444         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring5);
1445 }
1446
1447 void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
1448 {
1449         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring5);
1450         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring4);
1451         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring3);
1452         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring2);
1453         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring1);
1454         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring0);
1455         b43legacy_power_saving_ctl_bits(dev, -1, -1);
1456 }