git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/b43/dma.c

   1 /*
   2
   3   Broadcom B43 wireless driver
   4
   5   DMA ringbuffer and descriptor allocation/management
   6
   7   Copyright (c) 2005, 2006 Michael Buesch <mb@bu3sch.de>
   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 "b43.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/etherdevice.h>
  41
  42
  43 /* 32bit DMA ops. */
  44 static
  45 struct b43_dmadesc_generic *op32_idx2desc(struct b43_dmaring *ring,
  46                                           int slot,
  47                                           struct b43_dmadesc_meta **meta)
  48 {
  49         struct b43_dmadesc32 *desc;
  50
  51         *meta = &(ring->meta[slot]);
  52         desc = ring->descbase;
  53         desc = &(desc[slot]);
  54
  55         return (struct b43_dmadesc_generic *)desc;
  56 }
  57
  58 static void op32_fill_descriptor(struct b43_dmaring *ring,
  59                                  struct b43_dmadesc_generic *desc,
  60                                  dma_addr_t dmaaddr, u16 bufsize,
  61                                  int start, int end, int irq)
  62 {
  63         struct b43_dmadesc32 *descbase = ring->descbase;
  64         int slot;
  65         u32 ctl;
  66         u32 addr;
  67         u32 addrext;
  68
  69         slot = (int)(&(desc->dma32) - descbase);
  70         B43_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 |= ssb_dma_translation(ring->dev->dev);
  76         ctl = (bufsize - ring->frameoffset)
  77             & B43_DMA32_DCTL_BYTECNT;
  78         if (slot == ring->nr_slots - 1)
  79                 ctl |= B43_DMA32_DCTL_DTABLEEND;
  80         if (start)
  81                 ctl |= B43_DMA32_DCTL_FRAMESTART;
  82         if (end)
  83                 ctl |= B43_DMA32_DCTL_FRAMEEND;
  84         if (irq)
  85                 ctl |= B43_DMA32_DCTL_IRQ;
  86         ctl |= (addrext << B43_DMA32_DCTL_ADDREXT_SHIFT)
  87             & B43_DMA32_DCTL_ADDREXT_MASK;
  88
  89         desc->dma32.control = cpu_to_le32(ctl);
  90         desc->dma32.address = cpu_to_le32(addr);
  91 }
  92
  93 static void op32_poke_tx(struct b43_dmaring *ring, int slot)
  94 {
  95         b43_dma_write(ring, B43_DMA32_TXINDEX,
  96                       (u32) (slot * sizeof(struct b43_dmadesc32)));
  97 }
  98
  99 static void op32_tx_suspend(struct b43_dmaring *ring)
 100 {
 101         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
 102                       | B43_DMA32_TXSUSPEND);
 103 }
 104
 105 static void op32_tx_resume(struct b43_dmaring *ring)
 106 {
 107         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
 108                       & ~B43_DMA32_TXSUSPEND);
 109 }
 110
 111 static int op32_get_current_rxslot(struct b43_dmaring *ring)
 112 {
 113         u32 val;
 114
 115         val = b43_dma_read(ring, B43_DMA32_RXSTATUS);
 116         val &= B43_DMA32_RXDPTR;
 117
 118         return (val / sizeof(struct b43_dmadesc32));
 119 }
 120
 121 static void op32_set_current_rxslot(struct b43_dmaring *ring, int slot)
 122 {
 123         b43_dma_write(ring, B43_DMA32_RXINDEX,
 124                       (u32) (slot * sizeof(struct b43_dmadesc32)));
 125 }
 126
 127 static const struct b43_dma_ops dma32_ops = {
 128         .idx2desc = op32_idx2desc,
 129         .fill_descriptor = op32_fill_descriptor,
 130         .poke_tx = op32_poke_tx,
 131         .tx_suspend = op32_tx_suspend,
 132         .tx_resume = op32_tx_resume,
 133         .get_current_rxslot = op32_get_current_rxslot,
 134         .set_current_rxslot = op32_set_current_rxslot,
 135 };
 136
 137 /* 64bit DMA ops. */
 138 static
 139 struct b43_dmadesc_generic *op64_idx2desc(struct b43_dmaring *ring,
 140                                           int slot,
 141                                           struct b43_dmadesc_meta **meta)
 142 {
 143         struct b43_dmadesc64 *desc;
 144
 145         *meta = &(ring->meta[slot]);
 146         desc = ring->descbase;
 147         desc = &(desc[slot]);
 148
 149         return (struct b43_dmadesc_generic *)desc;
 150 }
 151
 152 static void op64_fill_descriptor(struct b43_dmaring *ring,
 153                                  struct b43_dmadesc_generic *desc,
 154                                  dma_addr_t dmaaddr, u16 bufsize,
 155                                  int start, int end, int irq)
 156 {
 157         struct b43_dmadesc64 *descbase = ring->descbase;
 158         int slot;
 159         u32 ctl0 = 0, ctl1 = 0;
 160         u32 addrlo, addrhi;
 161         u32 addrext;
 162
 163         slot = (int)(&(desc->dma64) - descbase);
 164         B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
 165
 166         addrlo = (u32) (dmaaddr & 0xFFFFFFFF);
 167         addrhi = (((u64) dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
 168         addrext = (((u64) dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
 169             >> SSB_DMA_TRANSLATION_SHIFT;
 170         addrhi |= (ssb_dma_translation(ring->dev->dev) << 1);
 171         if (slot == ring->nr_slots - 1)
 172                 ctl0 |= B43_DMA64_DCTL0_DTABLEEND;
 173         if (start)
 174                 ctl0 |= B43_DMA64_DCTL0_FRAMESTART;
 175         if (end)
 176                 ctl0 |= B43_DMA64_DCTL0_FRAMEEND;
 177         if (irq)
 178                 ctl0 |= B43_DMA64_DCTL0_IRQ;
 179         ctl1 |= (bufsize - ring->frameoffset)
 180             & B43_DMA64_DCTL1_BYTECNT;
 181         ctl1 |= (addrext << B43_DMA64_DCTL1_ADDREXT_SHIFT)
 182             & B43_DMA64_DCTL1_ADDREXT_MASK;
 183
 184         desc->dma64.control0 = cpu_to_le32(ctl0);
 185         desc->dma64.control1 = cpu_to_le32(ctl1);
 186         desc->dma64.address_low = cpu_to_le32(addrlo);
 187         desc->dma64.address_high = cpu_to_le32(addrhi);
 188 }
 189
 190 static void op64_poke_tx(struct b43_dmaring *ring, int slot)
 191 {
 192         b43_dma_write(ring, B43_DMA64_TXINDEX,
 193                       (u32) (slot * sizeof(struct b43_dmadesc64)));
 194 }
 195
 196 static void op64_tx_suspend(struct b43_dmaring *ring)
 197 {
 198         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
 199                       | B43_DMA64_TXSUSPEND);
 200 }
 201
 202 static void op64_tx_resume(struct b43_dmaring *ring)
 203 {
 204         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
 205                       & ~B43_DMA64_TXSUSPEND);
 206 }
 207
 208 static int op64_get_current_rxslot(struct b43_dmaring *ring)
 209 {
 210         u32 val;
 211
 212         val = b43_dma_read(ring, B43_DMA64_RXSTATUS);
 213         val &= B43_DMA64_RXSTATDPTR;
 214
 215         return (val / sizeof(struct b43_dmadesc64));
 216 }
 217
 218 static void op64_set_current_rxslot(struct b43_dmaring *ring, int slot)
 219 {
 220         b43_dma_write(ring, B43_DMA64_RXINDEX,
 221                       (u32) (slot * sizeof(struct b43_dmadesc64)));
 222 }
 223
 224 static const struct b43_dma_ops dma64_ops = {
 225         .idx2desc = op64_idx2desc,
 226         .fill_descriptor = op64_fill_descriptor,
 227         .poke_tx = op64_poke_tx,
 228         .tx_suspend = op64_tx_suspend,
 229         .tx_resume = op64_tx_resume,
 230         .get_current_rxslot = op64_get_current_rxslot,
 231         .set_current_rxslot = op64_set_current_rxslot,
 232 };
 233
 234 static inline int free_slots(struct b43_dmaring *ring)
 235 {
 236         return (ring->nr_slots - ring->used_slots);
 237 }
 238
 239 static inline int next_slot(struct b43_dmaring *ring, int slot)
 240 {
 241         B43_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
 242         if (slot == ring->nr_slots - 1)
 243                 return 0;
 244         return slot + 1;
 245 }
 246
 247 static inline int prev_slot(struct b43_dmaring *ring, int slot)
 248 {
 249         B43_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
 250         if (slot == 0)
 251                 return ring->nr_slots - 1;
 252         return slot - 1;
 253 }
 254
 255 #ifdef CONFIG_B43_DEBUG
 256 static void update_max_used_slots(struct b43_dmaring *ring,
 257                                   int current_used_slots)
 258 {
 259         if (current_used_slots <= ring->max_used_slots)
 260                 return;
 261         ring->max_used_slots = current_used_slots;
 262         if (b43_debug(ring->dev, B43_DBG_DMAVERBOSE)) {
 263                 b43dbg(ring->dev->wl,
 264                        "max_used_slots increased to %d on %s ring %d\n",
 265                        ring->max_used_slots,
 266                        ring->tx ? "TX" : "RX", ring->index);
 267         }
 268 }
 269 #else
 270 static inline
 271     void update_max_used_slots(struct b43_dmaring *ring, int current_used_slots)
 272 {
 273 }
 274 #endif /* DEBUG */
 275
 276 /* Request a slot for usage. */
 277 static inline int request_slot(struct b43_dmaring *ring)
 278 {
 279         int slot;
 280
 281         B43_WARN_ON(!ring->tx);
 282         B43_WARN_ON(ring->stopped);
 283         B43_WARN_ON(free_slots(ring) == 0);
 284
 285         slot = next_slot(ring, ring->current_slot);
 286         ring->current_slot = slot;
 287         ring->used_slots++;
 288
 289         update_max_used_slots(ring, ring->used_slots);
 290
 291         return slot;
 292 }
 293
 294 /* Mac80211-queue to b43-ring mapping */
 295 static struct b43_dmaring *priority_to_txring(struct b43_wldev *dev,
 296                                               int queue_priority)
 297 {
 298         struct b43_dmaring *ring;
 299
 300 /*FIXME: For now we always run on TX-ring-1 */
 301         return dev->dma.tx_ring1;
 302
 303         /* 0 = highest priority */
 304         switch (queue_priority) {
 305         default:
 306                 B43_WARN_ON(1);
 307                 /* fallthrough */
 308         case 0:
 309                 ring = dev->dma.tx_ring3;
 310                 break;
 311         case 1:
 312                 ring = dev->dma.tx_ring2;
 313                 break;
 314         case 2:
 315                 ring = dev->dma.tx_ring1;
 316                 break;
 317         case 3:
 318                 ring = dev->dma.tx_ring0;
 319                 break;
 320         }
 321
 322         return ring;
 323 }
 324
 325 /* b43-ring to mac80211-queue mapping */
 326 static inline int txring_to_priority(struct b43_dmaring *ring)
 327 {
 328         static const u8 idx_to_prio[] = { 3, 2, 1, 0, };
 329         unsigned int index;
 330
 331 /*FIXME: have only one queue, for now */
 332         return 0;
 333
 334         index = ring->index;
 335         if (B43_WARN_ON(index >= ARRAY_SIZE(idx_to_prio)))
 336                 index = 0;
 337         return idx_to_prio[index];
 338 }
 339
 340 static u16 b43_dmacontroller_base(enum b43_dmatype type, int controller_idx)
 341 {
 342         static const u16 map64[] = {
 343                 B43_MMIO_DMA64_BASE0,
 344                 B43_MMIO_DMA64_BASE1,
 345                 B43_MMIO_DMA64_BASE2,
 346                 B43_MMIO_DMA64_BASE3,
 347                 B43_MMIO_DMA64_BASE4,
 348                 B43_MMIO_DMA64_BASE5,
 349         };
 350         static const u16 map32[] = {
 351                 B43_MMIO_DMA32_BASE0,
 352                 B43_MMIO_DMA32_BASE1,
 353                 B43_MMIO_DMA32_BASE2,
 354                 B43_MMIO_DMA32_BASE3,
 355                 B43_MMIO_DMA32_BASE4,
 356                 B43_MMIO_DMA32_BASE5,
 357         };
 358
 359         if (type == B43_DMA_64BIT) {
 360                 B43_WARN_ON(!(controller_idx >= 0 &&
 361                               controller_idx < ARRAY_SIZE(map64)));
 362                 return map64[controller_idx];
 363         }
 364         B43_WARN_ON(!(controller_idx >= 0 &&
 365                       controller_idx < ARRAY_SIZE(map32)));
 366         return map32[controller_idx];
 367 }
 368
 369 static inline
 370     dma_addr_t map_descbuffer(struct b43_dmaring *ring,
 371                               unsigned char *buf, size_t len, int tx)
 372 {
 373         dma_addr_t dmaaddr;
 374
 375         if (tx) {
 376                 dmaaddr = dma_map_single(ring->dev->dev->dev,
 377                                          buf, len, DMA_TO_DEVICE);
 378         } else {
 379                 dmaaddr = dma_map_single(ring->dev->dev->dev,
 380                                          buf, len, DMA_FROM_DEVICE);
 381         }
 382
 383         return dmaaddr;
 384 }
 385
 386 static inline
 387     void unmap_descbuffer(struct b43_dmaring *ring,
 388                           dma_addr_t addr, size_t len, int tx)
 389 {
 390         if (tx) {
 391                 dma_unmap_single(ring->dev->dev->dev, addr, len, DMA_TO_DEVICE);
 392         } else {
 393                 dma_unmap_single(ring->dev->dev->dev,
 394                                  addr, len, DMA_FROM_DEVICE);
 395         }
 396 }
 397
 398 static inline
 399     void sync_descbuffer_for_cpu(struct b43_dmaring *ring,
 400                                  dma_addr_t addr, size_t len)
 401 {
 402         B43_WARN_ON(ring->tx);
 403         dma_sync_single_for_cpu(ring->dev->dev->dev,
 404                                 addr, len, DMA_FROM_DEVICE);
 405 }
 406
 407 static inline
 408     void sync_descbuffer_for_device(struct b43_dmaring *ring,
 409                                     dma_addr_t addr, size_t len)
 410 {
 411         B43_WARN_ON(ring->tx);
 412         dma_sync_single_for_device(ring->dev->dev->dev,
 413                                    addr, len, DMA_FROM_DEVICE);
 414 }
 415
 416 static inline
 417     void free_descriptor_buffer(struct b43_dmaring *ring,
 418                                 struct b43_dmadesc_meta *meta)
 419 {
 420         if (meta->skb) {
 421                 dev_kfree_skb_any(meta->skb);
 422                 meta->skb = NULL;
 423         }
 424 }
 425
 426 static int alloc_ringmemory(struct b43_dmaring *ring)
 427 {
 428         struct device *dev = ring->dev->dev->dev;
 429         gfp_t flags = GFP_KERNEL;
 430
 431         /* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
 432          * alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
 433          * has shown that 4K is sufficient for the latter as long as the buffer
 434          * does not cross an 8K boundary.
 435          *
 436          * For unknown reasons - possibly a hardware error - the BCM4311 rev
 437          * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
 438          * which accounts for the GFP_DMA flag below.
 439          */
 440         if (ring->type == B43_DMA_64BIT)
 441                 flags |= GFP_DMA;
 442         ring->descbase = dma_alloc_coherent(dev, B43_DMA_RINGMEMSIZE,
 443                                             &(ring->dmabase), flags);
 444         if (!ring->descbase) {
 445                 b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
 446                 return -ENOMEM;
 447         }
 448         memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
 449
 450         return 0;
 451 }
 452
 453 static void free_ringmemory(struct b43_dmaring *ring)
 454 {
 455         struct device *dev = ring->dev->dev->dev;
 456
 457         dma_free_coherent(dev, B43_DMA_RINGMEMSIZE,
 458                           ring->descbase, ring->dmabase);
 459 }
 460
 461 /* Reset the RX DMA channel */
 462 static int b43_dmacontroller_rx_reset(struct b43_wldev *dev, u16 mmio_base,
 463                                       enum b43_dmatype type)
 464 {
 465         int i;
 466         u32 value;
 467         u16 offset;
 468
 469         might_sleep();
 470
 471         offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
 472         b43_write32(dev, mmio_base + offset, 0);
 473         for (i = 0; i < 10; i++) {
 474                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXSTATUS :
 475                                                    B43_DMA32_RXSTATUS;
 476                 value = b43_read32(dev, mmio_base + offset);
 477                 if (type == B43_DMA_64BIT) {
 478                         value &= B43_DMA64_RXSTAT;
 479                         if (value == B43_DMA64_RXSTAT_DISABLED) {
 480                                 i = -1;
 481                                 break;
 482                         }
 483                 } else {
 484                         value &= B43_DMA32_RXSTATE;
 485                         if (value == B43_DMA32_RXSTAT_DISABLED) {
 486                                 i = -1;
 487                                 break;
 488                         }
 489                 }
 490                 msleep(1);
 491         }
 492         if (i != -1) {
 493                 b43err(dev->wl, "DMA RX reset timed out\n");
 494                 return -ENODEV;
 495         }
 496
 497         return 0;
 498 }
 499
 500 /* Reset the TX DMA channel */
 501 static int b43_dmacontroller_tx_reset(struct b43_wldev *dev, u16 mmio_base,
 502                                       enum b43_dmatype type)
 503 {
 504         int i;
 505         u32 value;
 506         u16 offset;
 507
 508         might_sleep();
 509
 510         for (i = 0; i < 10; i++) {
 511                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 512                                                    B43_DMA32_TXSTATUS;
 513                 value = b43_read32(dev, mmio_base + offset);
 514                 if (type == B43_DMA_64BIT) {
 515                         value &= B43_DMA64_TXSTAT;
 516                         if (value == B43_DMA64_TXSTAT_DISABLED ||
 517                             value == B43_DMA64_TXSTAT_IDLEWAIT ||
 518                             value == B43_DMA64_TXSTAT_STOPPED)
 519                                 break;
 520                 } else {
 521                         value &= B43_DMA32_TXSTATE;
 522                         if (value == B43_DMA32_TXSTAT_DISABLED ||
 523                             value == B43_DMA32_TXSTAT_IDLEWAIT ||
 524                             value == B43_DMA32_TXSTAT_STOPPED)
 525                                 break;
 526                 }
 527                 msleep(1);
 528         }
 529         offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXCTL : B43_DMA32_TXCTL;
 530         b43_write32(dev, mmio_base + offset, 0);
 531         for (i = 0; i < 10; i++) {
 532                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 533                                                    B43_DMA32_TXSTATUS;
 534                 value = b43_read32(dev, mmio_base + offset);
 535                 if (type == B43_DMA_64BIT) {
 536                         value &= B43_DMA64_TXSTAT;
 537                         if (value == B43_DMA64_TXSTAT_DISABLED) {
 538                                 i = -1;
 539                                 break;
 540                         }
 541                 } else {
 542                         value &= B43_DMA32_TXSTATE;
 543                         if (value == B43_DMA32_TXSTAT_DISABLED) {
 544                                 i = -1;
 545                                 break;
 546                         }
 547                 }
 548                 msleep(1);
 549         }
 550         if (i != -1) {
 551                 b43err(dev->wl, "DMA TX reset timed out\n");
 552                 return -ENODEV;
 553         }
 554         /* ensure the reset is completed. */
 555         msleep(1);
 556
 557         return 0;
 558 }
 559
 560 /* Check if a DMA mapping address is invalid. */
 561 static bool b43_dma_mapping_error(struct b43_dmaring *ring,
 562                                   dma_addr_t addr,
 563                                   size_t buffersize, bool dma_to_device)
 564 {
 565         if (unlikely(dma_mapping_error(addr)))
 566                 return 1;
 567
 568         switch (ring->type) {
 569         case B43_DMA_30BIT:
 570                 if ((u64)addr + buffersize > (1ULL << 30))
 571                         goto address_error;
 572                 break;
 573         case B43_DMA_32BIT:
 574                 if ((u64)addr + buffersize > (1ULL << 32))
 575                         goto address_error;
 576                 break;
 577         case B43_DMA_64BIT:
 578                 /* Currently we can't have addresses beyond
 579                  * 64bit in the kernel. */
 580                 break;
 581         }
 582
 583         /* The address is OK. */
 584         return 0;
 585
 586 address_error:
 587         /* We can't support this address. Unmap it again. */
 588         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 589
 590         return 1;
 591 }
 592
 593 static int setup_rx_descbuffer(struct b43_dmaring *ring,
 594                                struct b43_dmadesc_generic *desc,
 595                                struct b43_dmadesc_meta *meta, gfp_t gfp_flags)
 596 {
 597         struct b43_rxhdr_fw4 *rxhdr;
 598         struct b43_hwtxstatus *txstat;
 599         dma_addr_t dmaaddr;
 600         struct sk_buff *skb;
 601
 602         B43_WARN_ON(ring->tx);
 603
 604         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 605         if (unlikely(!skb))
 606                 return -ENOMEM;
 607         dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
 608         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 609                 /* ugh. try to realloc in zone_dma */
 610                 gfp_flags |= GFP_DMA;
 611
 612                 dev_kfree_skb_any(skb);
 613
 614                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 615                 if (unlikely(!skb))
 616                         return -ENOMEM;
 617                 dmaaddr = map_descbuffer(ring, skb->data,
 618                                          ring->rx_buffersize, 0);
 619         }
 620
 621         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 622                 dev_kfree_skb_any(skb);
 623                 return -EIO;
 624         }
 625
 626         meta->skb = skb;
 627         meta->dmaaddr = dmaaddr;
 628         ring->ops->fill_descriptor(ring, desc, dmaaddr,
 629                                    ring->rx_buffersize, 0, 0, 0);
 630
 631         rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
 632         rxhdr->frame_len = 0;
 633         txstat = (struct b43_hwtxstatus *)(skb->data);
 634         txstat->cookie = 0;
 635
 636         return 0;
 637 }
 638
 639 /* Allocate the initial descbuffers.
 640  * This is used for an RX ring only.
 641  */
 642 static int alloc_initial_descbuffers(struct b43_dmaring *ring)
 643 {
 644         int i, err = -ENOMEM;
 645         struct b43_dmadesc_generic *desc;
 646         struct b43_dmadesc_meta *meta;
 647
 648         for (i = 0; i < ring->nr_slots; i++) {
 649                 desc = ring->ops->idx2desc(ring, i, &meta);
 650
 651                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 652                 if (err) {
 653                         b43err(ring->dev->wl,
 654                                "Failed to allocate initial descbuffers\n");
 655                         goto err_unwind;
 656                 }
 657         }
 658         mb();
 659         ring->used_slots = ring->nr_slots;
 660         err = 0;
 661       out:
 662         return err;
 663
 664       err_unwind:
 665         for (i--; i >= 0; i--) {
 666                 desc = ring->ops->idx2desc(ring, i, &meta);
 667
 668                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 669                 dev_kfree_skb(meta->skb);
 670         }
 671         goto out;
 672 }
 673
 674 /* Do initial setup of the DMA controller.
 675  * Reset the controller, write the ring busaddress
 676  * and switch the "enable" bit on.
 677  */
 678 static int dmacontroller_setup(struct b43_dmaring *ring)
 679 {
 680         int err = 0;
 681         u32 value;
 682         u32 addrext;
 683         u32 trans = ssb_dma_translation(ring->dev->dev);
 684
 685         if (ring->tx) {
 686                 if (ring->type == B43_DMA_64BIT) {
 687                         u64 ringbase = (u64) (ring->dmabase);
 688
 689                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 690                             >> SSB_DMA_TRANSLATION_SHIFT;
 691                         value = B43_DMA64_TXENABLE;
 692                         value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
 693                             & B43_DMA64_TXADDREXT_MASK;
 694                         b43_dma_write(ring, B43_DMA64_TXCTL, value);
 695                         b43_dma_write(ring, B43_DMA64_TXRINGLO,
 696                                       (ringbase & 0xFFFFFFFF));
 697                         b43_dma_write(ring, B43_DMA64_TXRINGHI,
 698                                       ((ringbase >> 32) &
 699                                        ~SSB_DMA_TRANSLATION_MASK)
 700                                       | (trans << 1));
 701                 } else {
 702                         u32 ringbase = (u32) (ring->dmabase);
 703
 704                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 705                             >> SSB_DMA_TRANSLATION_SHIFT;
 706                         value = B43_DMA32_TXENABLE;
 707                         value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
 708                             & B43_DMA32_TXADDREXT_MASK;
 709                         b43_dma_write(ring, B43_DMA32_TXCTL, value);
 710                         b43_dma_write(ring, B43_DMA32_TXRING,
 711                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 712                                       | trans);
 713                 }
 714         } else {
 715                 err = alloc_initial_descbuffers(ring);
 716                 if (err)
 717                         goto out;
 718                 if (ring->type == B43_DMA_64BIT) {
 719                         u64 ringbase = (u64) (ring->dmabase);
 720
 721                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 722                             >> SSB_DMA_TRANSLATION_SHIFT;
 723                         value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
 724                         value |= B43_DMA64_RXENABLE;
 725                         value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
 726                             & B43_DMA64_RXADDREXT_MASK;
 727                         b43_dma_write(ring, B43_DMA64_RXCTL, value);
 728                         b43_dma_write(ring, B43_DMA64_RXRINGLO,
 729                                       (ringbase & 0xFFFFFFFF));
 730                         b43_dma_write(ring, B43_DMA64_RXRINGHI,
 731                                       ((ringbase >> 32) &
 732                                        ~SSB_DMA_TRANSLATION_MASK)
 733                                       | (trans << 1));
 734                         b43_dma_write(ring, B43_DMA64_RXINDEX, ring->nr_slots *
 735                                       sizeof(struct b43_dmadesc64));
 736                 } else {
 737                         u32 ringbase = (u32) (ring->dmabase);
 738
 739                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 740                             >> SSB_DMA_TRANSLATION_SHIFT;
 741                         value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
 742                         value |= B43_DMA32_RXENABLE;
 743                         value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
 744                             & B43_DMA32_RXADDREXT_MASK;
 745                         b43_dma_write(ring, B43_DMA32_RXCTL, value);
 746                         b43_dma_write(ring, B43_DMA32_RXRING,
 747                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 748                                       | trans);
 749                         b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
 750                                       sizeof(struct b43_dmadesc32));
 751                 }
 752         }
 753
 754 out:
 755         return err;
 756 }
 757
 758 /* Shutdown the DMA controller. */
 759 static void dmacontroller_cleanup(struct b43_dmaring *ring)
 760 {
 761         if (ring->tx) {
 762                 b43_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 763                                            ring->type);
 764                 if (ring->type == B43_DMA_64BIT) {
 765                         b43_dma_write(ring, B43_DMA64_TXRINGLO, 0);
 766                         b43_dma_write(ring, B43_DMA64_TXRINGHI, 0);
 767                 } else
 768                         b43_dma_write(ring, B43_DMA32_TXRING, 0);
 769         } else {
 770                 b43_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 771                                            ring->type);
 772                 if (ring->type == B43_DMA_64BIT) {
 773                         b43_dma_write(ring, B43_DMA64_RXRINGLO, 0);
 774                         b43_dma_write(ring, B43_DMA64_RXRINGHI, 0);
 775                 } else
 776                         b43_dma_write(ring, B43_DMA32_RXRING, 0);
 777         }
 778 }
 779
 780 static void free_all_descbuffers(struct b43_dmaring *ring)
 781 {
 782         struct b43_dmadesc_generic *desc;
 783         struct b43_dmadesc_meta *meta;
 784         int i;
 785
 786         if (!ring->used_slots)
 787                 return;
 788         for (i = 0; i < ring->nr_slots; i++) {
 789                 desc = ring->ops->idx2desc(ring, i, &meta);
 790
 791                 if (!meta->skb) {
 792                         B43_WARN_ON(!ring->tx);
 793                         continue;
 794                 }
 795                 if (ring->tx) {
 796                         unmap_descbuffer(ring, meta->dmaaddr,
 797                                          meta->skb->len, 1);
 798                 } else {
 799                         unmap_descbuffer(ring, meta->dmaaddr,
 800                                          ring->rx_buffersize, 0);
 801                 }
 802                 free_descriptor_buffer(ring, meta);
 803         }
 804 }
 805
 806 static u64 supported_dma_mask(struct b43_wldev *dev)
 807 {
 808         u32 tmp;
 809         u16 mmio_base;
 810
 811         tmp = b43_read32(dev, SSB_TMSHIGH);
 812         if (tmp & SSB_TMSHIGH_DMA64)
 813                 return DMA_64BIT_MASK;
 814         mmio_base = b43_dmacontroller_base(0, 0);
 815         b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
 816         tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
 817         if (tmp & B43_DMA32_TXADDREXT_MASK)
 818                 return DMA_32BIT_MASK;
 819
 820         return DMA_30BIT_MASK;
 821 }
 822
 823 /* Main initialization function. */
 824 static
 825 struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 826                                       int controller_index,
 827                                       int for_tx,
 828                                       enum b43_dmatype type)
 829 {
 830         struct b43_dmaring *ring;
 831         int err;
 832         int nr_slots;
 833         dma_addr_t dma_test;
 834
 835         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 836         if (!ring)
 837                 goto out;
 838         ring->type = type;
 839
 840         nr_slots = B43_RXRING_SLOTS;
 841         if (for_tx)
 842                 nr_slots = B43_TXRING_SLOTS;
 843
 844         ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
 845                              GFP_KERNEL);
 846         if (!ring->meta)
 847                 goto err_kfree_ring;
 848         if (for_tx) {
 849                 ring->txhdr_cache = kcalloc(nr_slots,
 850                                             b43_txhdr_size(dev),
 851                                             GFP_KERNEL);
 852                 if (!ring->txhdr_cache)
 853                         goto err_kfree_meta;
 854
 855                 /* test for ability to dma to txhdr_cache */
 856                 dma_test = dma_map_single(dev->dev->dev,
 857                                           ring->txhdr_cache,
 858                                           b43_txhdr_size(dev),
 859                                           DMA_TO_DEVICE);
 860
 861                 if (b43_dma_mapping_error(ring, dma_test,
 862                                           b43_txhdr_size(dev), 1)) {
 863                         /* ugh realloc */
 864                         kfree(ring->txhdr_cache);
 865                         ring->txhdr_cache = kcalloc(nr_slots,
 866                                                     b43_txhdr_size(dev),
 867                                                     GFP_KERNEL | GFP_DMA);
 868                         if (!ring->txhdr_cache)
 869                                 goto err_kfree_meta;
 870
 871                         dma_test = dma_map_single(dev->dev->dev,
 872                                                   ring->txhdr_cache,
 873                                                   b43_txhdr_size(dev),
 874                                                   DMA_TO_DEVICE);
 875
 876                         if (b43_dma_mapping_error(ring, dma_test,
 877                                                   b43_txhdr_size(dev), 1))
 878                                 goto err_kfree_txhdr_cache;
 879                 }
 880
 881                 dma_unmap_single(dev->dev->dev,
 882                                  dma_test, b43_txhdr_size(dev),
 883                                  DMA_TO_DEVICE);
 884         }
 885
 886         ring->dev = dev;
 887         ring->nr_slots = nr_slots;
 888         ring->mmio_base = b43_dmacontroller_base(type, controller_index);
 889         ring->index = controller_index;
 890         if (type == B43_DMA_64BIT)
 891                 ring->ops = &dma64_ops;
 892         else
 893                 ring->ops = &dma32_ops;
 894         if (for_tx) {
 895                 ring->tx = 1;
 896                 ring->current_slot = -1;
 897         } else {
 898                 if (ring->index == 0) {
 899                         ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
 900                         ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
 901                 } else if (ring->index == 3) {
 902                         ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
 903                         ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
 904                 } else
 905                         B43_WARN_ON(1);
 906         }
 907         spin_lock_init(&ring->lock);
 908 #ifdef CONFIG_B43_DEBUG
 909         ring->last_injected_overflow = jiffies;
 910 #endif
 911
 912         err = alloc_ringmemory(ring);
 913         if (err)
 914                 goto err_kfree_txhdr_cache;
 915         err = dmacontroller_setup(ring);
 916         if (err)
 917                 goto err_free_ringmemory;
 918
 919       out:
 920         return ring;
 921
 922       err_free_ringmemory:
 923         free_ringmemory(ring);
 924       err_kfree_txhdr_cache:
 925         kfree(ring->txhdr_cache);
 926       err_kfree_meta:
 927         kfree(ring->meta);
 928       err_kfree_ring:
 929         kfree(ring);
 930         ring = NULL;
 931         goto out;
 932 }
 933
 934 /* Main cleanup function. */
 935 static void b43_destroy_dmaring(struct b43_dmaring *ring)
 936 {
 937         if (!ring)
 938                 return;
 939
 940         b43dbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots: %d/%d\n",
 941                (unsigned int)(ring->type),
 942                ring->mmio_base,
 943                (ring->tx) ? "TX" : "RX", ring->max_used_slots, ring->nr_slots);
 944         /* Device IRQs are disabled prior entering this function,
 945          * so no need to take care of concurrency with rx handler stuff.
 946          */
 947         dmacontroller_cleanup(ring);
 948         free_all_descbuffers(ring);
 949         free_ringmemory(ring);
 950
 951         kfree(ring->txhdr_cache);
 952         kfree(ring->meta);
 953         kfree(ring);
 954 }
 955
 956 void b43_dma_free(struct b43_wldev *dev)
 957 {
 958         struct b43_dma *dma = &dev->dma;
 959
 960         b43_destroy_dmaring(dma->rx_ring3);
 961         dma->rx_ring3 = NULL;
 962         b43_destroy_dmaring(dma->rx_ring0);
 963         dma->rx_ring0 = NULL;
 964
 965         b43_destroy_dmaring(dma->tx_ring5);
 966         dma->tx_ring5 = NULL;
 967         b43_destroy_dmaring(dma->tx_ring4);
 968         dma->tx_ring4 = NULL;
 969         b43_destroy_dmaring(dma->tx_ring3);
 970         dma->tx_ring3 = NULL;
 971         b43_destroy_dmaring(dma->tx_ring2);
 972         dma->tx_ring2 = NULL;
 973         b43_destroy_dmaring(dma->tx_ring1);
 974         dma->tx_ring1 = NULL;
 975         b43_destroy_dmaring(dma->tx_ring0);
 976         dma->tx_ring0 = NULL;
 977 }
 978
 979 int b43_dma_init(struct b43_wldev *dev)
 980 {
 981         struct b43_dma *dma = &dev->dma;
 982         struct b43_dmaring *ring;
 983         int err;
 984         u64 dmamask;
 985         enum b43_dmatype type;
 986
 987         dmamask = supported_dma_mask(dev);
 988         switch (dmamask) {
 989         default:
 990                 B43_WARN_ON(1);
 991         case DMA_30BIT_MASK:
 992                 type = B43_DMA_30BIT;
 993                 break;
 994         case DMA_32BIT_MASK:
 995                 type = B43_DMA_32BIT;
 996                 break;
 997         case DMA_64BIT_MASK:
 998                 type = B43_DMA_64BIT;
 999                 break;
1000         }
1001         err = ssb_dma_set_mask(dev->dev, dmamask);
1002         if (err) {
1003                 b43err(dev->wl, "The machine/kernel does not support "
1004                        "the required DMA mask (0x%08X%08X)\n",
1005                        (unsigned int)((dmamask & 0xFFFFFFFF00000000ULL) >> 32),
1006                        (unsigned int)(dmamask & 0x00000000FFFFFFFFULL));
1007                 return -EOPNOTSUPP;
1008         }
1009
1010         err = -ENOMEM;
1011         /* setup TX DMA channels. */
1012         ring = b43_setup_dmaring(dev, 0, 1, type);
1013         if (!ring)
1014                 goto out;
1015         dma->tx_ring0 = ring;
1016
1017         ring = b43_setup_dmaring(dev, 1, 1, type);
1018         if (!ring)
1019                 goto err_destroy_tx0;
1020         dma->tx_ring1 = ring;
1021
1022         ring = b43_setup_dmaring(dev, 2, 1, type);
1023         if (!ring)
1024                 goto err_destroy_tx1;
1025         dma->tx_ring2 = ring;
1026
1027         ring = b43_setup_dmaring(dev, 3, 1, type);
1028         if (!ring)
1029                 goto err_destroy_tx2;
1030         dma->tx_ring3 = ring;
1031
1032         ring = b43_setup_dmaring(dev, 4, 1, type);
1033         if (!ring)
1034                 goto err_destroy_tx3;
1035         dma->tx_ring4 = ring;
1036
1037         ring = b43_setup_dmaring(dev, 5, 1, type);
1038         if (!ring)
1039                 goto err_destroy_tx4;
1040         dma->tx_ring5 = ring;
1041
1042         /* setup RX DMA channels. */
1043         ring = b43_setup_dmaring(dev, 0, 0, type);
1044         if (!ring)
1045                 goto err_destroy_tx5;
1046         dma->rx_ring0 = ring;
1047
1048         if (dev->dev->id.revision < 5) {
1049                 ring = b43_setup_dmaring(dev, 3, 0, type);
1050                 if (!ring)
1051                         goto err_destroy_rx0;
1052                 dma->rx_ring3 = ring;
1053         }
1054
1055         b43dbg(dev->wl, "%u-bit DMA initialized\n",
1056                (unsigned int)type);
1057         err = 0;
1058       out:
1059         return err;
1060
1061       err_destroy_rx0:
1062         b43_destroy_dmaring(dma->rx_ring0);
1063         dma->rx_ring0 = NULL;
1064       err_destroy_tx5:
1065         b43_destroy_dmaring(dma->tx_ring5);
1066         dma->tx_ring5 = NULL;
1067       err_destroy_tx4:
1068         b43_destroy_dmaring(dma->tx_ring4);
1069         dma->tx_ring4 = NULL;
1070       err_destroy_tx3:
1071         b43_destroy_dmaring(dma->tx_ring3);
1072         dma->tx_ring3 = NULL;
1073       err_destroy_tx2:
1074         b43_destroy_dmaring(dma->tx_ring2);
1075         dma->tx_ring2 = NULL;
1076       err_destroy_tx1:
1077         b43_destroy_dmaring(dma->tx_ring1);
1078         dma->tx_ring1 = NULL;
1079       err_destroy_tx0:
1080         b43_destroy_dmaring(dma->tx_ring0);
1081         dma->tx_ring0 = NULL;
1082         goto out;
1083 }
1084
1085 /* Generate a cookie for the TX header. */
1086 static u16 generate_cookie(struct b43_dmaring *ring, int slot)
1087 {
1088         u16 cookie = 0x1000;
1089
1090         /* Use the upper 4 bits of the cookie as
1091          * DMA controller ID and store the slot number
1092          * in the lower 12 bits.
1093          * Note that the cookie must never be 0, as this
1094          * is a special value used in RX path.
1095          * It can also not be 0xFFFF because that is special
1096          * for multicast frames.
1097          */
1098         switch (ring->index) {
1099         case 0:
1100                 cookie = 0x1000;
1101                 break;
1102         case 1:
1103                 cookie = 0x2000;
1104                 break;
1105         case 2:
1106                 cookie = 0x3000;
1107                 break;
1108         case 3:
1109                 cookie = 0x4000;
1110                 break;
1111         case 4:
1112                 cookie = 0x5000;
1113                 break;
1114         case 5:
1115                 cookie = 0x6000;
1116                 break;
1117         default:
1118                 B43_WARN_ON(1);
1119         }
1120         B43_WARN_ON(slot & ~0x0FFF);
1121         cookie |= (u16) slot;
1122
1123         return cookie;
1124 }
1125
1126 /* Inspect a cookie and find out to which controller/slot it belongs. */
1127 static
1128 struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
1129 {
1130         struct b43_dma *dma = &dev->dma;
1131         struct b43_dmaring *ring = NULL;
1132
1133         switch (cookie & 0xF000) {
1134         case 0x1000:
1135                 ring = dma->tx_ring0;
1136                 break;
1137         case 0x2000:
1138                 ring = dma->tx_ring1;
1139                 break;
1140         case 0x3000:
1141                 ring = dma->tx_ring2;
1142                 break;
1143         case 0x4000:
1144                 ring = dma->tx_ring3;
1145                 break;
1146         case 0x5000:
1147                 ring = dma->tx_ring4;
1148                 break;
1149         case 0x6000:
1150                 ring = dma->tx_ring5;
1151                 break;
1152         default:
1153                 B43_WARN_ON(1);
1154         }
1155         *slot = (cookie & 0x0FFF);
1156         B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1157
1158         return ring;
1159 }
1160
1161 static int dma_tx_fragment(struct b43_dmaring *ring,
1162                            struct sk_buff *skb,
1163                            struct ieee80211_tx_control *ctl)
1164 {
1165         const struct b43_dma_ops *ops = ring->ops;
1166         u8 *header;
1167         int slot, old_top_slot, old_used_slots;
1168         int err;
1169         struct b43_dmadesc_generic *desc;
1170         struct b43_dmadesc_meta *meta;
1171         struct b43_dmadesc_meta *meta_hdr;
1172         struct sk_buff *bounce_skb;
1173         u16 cookie;
1174         size_t hdrsize = b43_txhdr_size(ring->dev);
1175
1176 #define SLOTS_PER_PACKET  2
1177         B43_WARN_ON(skb_shinfo(skb)->nr_frags);
1178
1179         old_top_slot = ring->current_slot;
1180         old_used_slots = ring->used_slots;
1181
1182         /* Get a slot for the header. */
1183         slot = request_slot(ring);
1184         desc = ops->idx2desc(ring, slot, &meta_hdr);
1185         memset(meta_hdr, 0, sizeof(*meta_hdr));
1186
1187         header = &(ring->txhdr_cache[slot * hdrsize]);
1188         cookie = generate_cookie(ring, slot);
1189         err = b43_generate_txhdr(ring->dev, header,
1190                                  skb->data, skb->len, ctl, cookie);
1191         if (unlikely(err)) {
1192                 ring->current_slot = old_top_slot;
1193                 ring->used_slots = old_used_slots;
1194                 return err;
1195         }
1196
1197         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1198                                            hdrsize, 1);
1199         if (b43_dma_mapping_error(ring, meta_hdr->dmaaddr, hdrsize, 1)) {
1200                 ring->current_slot = old_top_slot;
1201                 ring->used_slots = old_used_slots;
1202                 return -EIO;
1203         }
1204         ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1205                              hdrsize, 1, 0, 0);
1206
1207         /* Get a slot for the payload. */
1208         slot = request_slot(ring);
1209         desc = ops->idx2desc(ring, slot, &meta);
1210         memset(meta, 0, sizeof(*meta));
1211
1212         memcpy(&meta->txstat.control, ctl, sizeof(*ctl));
1213         meta->skb = skb;
1214         meta->is_last_fragment = 1;
1215
1216         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1217         /* create a bounce buffer in zone_dma on mapping failure. */
1218         if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1219                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1220                 if (!bounce_skb) {
1221                         ring->current_slot = old_top_slot;
1222                         ring->used_slots = old_used_slots;
1223                         err = -ENOMEM;
1224                         goto out_unmap_hdr;
1225                 }
1226
1227                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1228                 dev_kfree_skb_any(skb);
1229                 skb = bounce_skb;
1230                 meta->skb = skb;
1231                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1232                 if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1233                         ring->current_slot = old_top_slot;
1234                         ring->used_slots = old_used_slots;
1235                         err = -EIO;
1236                         goto out_free_bounce;
1237                 }
1238         }
1239
1240         ops->fill_descriptor(ring, desc, meta->dmaaddr, skb->len, 0, 1, 1);
1241
1242         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1243                 /* Tell the firmware about the cookie of the last
1244                  * mcast frame, so it can clear the more-data bit in it. */
1245                 b43_shm_write16(ring->dev, B43_SHM_SHARED,
1246                                 B43_SHM_SH_MCASTCOOKIE, cookie);
1247         }
1248         /* Now transfer the whole frame. */
1249         wmb();
1250         ops->poke_tx(ring, next_slot(ring, slot));
1251         return 0;
1252
1253 out_free_bounce:
1254         dev_kfree_skb_any(skb);
1255 out_unmap_hdr:
1256         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1257                          hdrsize, 1);
1258         return err;
1259 }
1260
1261 static inline int should_inject_overflow(struct b43_dmaring *ring)
1262 {
1263 #ifdef CONFIG_B43_DEBUG
1264         if (unlikely(b43_debug(ring->dev, B43_DBG_DMAOVERFLOW))) {
1265                 /* Check if we should inject another ringbuffer overflow
1266                  * to test handling of this situation in the stack. */
1267                 unsigned long next_overflow;
1268
1269                 next_overflow = ring->last_injected_overflow + HZ;
1270                 if (time_after(jiffies, next_overflow)) {
1271                         ring->last_injected_overflow = jiffies;
1272                         b43dbg(ring->dev->wl,
1273                                "Injecting TX ring overflow on "
1274                                "DMA controller %d\n", ring->index);
1275                         return 1;
1276                 }
1277         }
1278 #endif /* CONFIG_B43_DEBUG */
1279         return 0;
1280 }
1281
1282 int b43_dma_tx(struct b43_wldev *dev,
1283                struct sk_buff *skb, struct ieee80211_tx_control *ctl)
1284 {
1285         struct b43_dmaring *ring;
1286         struct ieee80211_hdr *hdr;
1287         int err = 0;
1288         unsigned long flags;
1289
1290         if (unlikely(skb->len < 2 + 2 + 6)) {
1291                 /* Too short, this can't be a valid frame. */
1292                 return -EINVAL;
1293         }
1294
1295         hdr = (struct ieee80211_hdr *)skb->data;
1296         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1297                 /* The multicast ring will be sent after the DTIM */
1298                 ring = dev->dma.tx_ring4;
1299                 /* Set the more-data bit. Ucode will clear it on
1300                  * the last frame for us. */
1301                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1302         } else {
1303                 /* Decide by priority where to put this frame. */
1304                 ring = priority_to_txring(dev, ctl->queue);
1305         }
1306
1307         spin_lock_irqsave(&ring->lock, flags);
1308         B43_WARN_ON(!ring->tx);
1309         if (unlikely(free_slots(ring) < SLOTS_PER_PACKET)) {
1310                 b43warn(dev->wl, "DMA queue overflow\n");
1311                 err = -ENOSPC;
1312                 goto out_unlock;
1313         }
1314         /* Check if the queue was stopped in mac80211,
1315          * but we got called nevertheless.
1316          * That would be a mac80211 bug. */
1317         B43_WARN_ON(ring->stopped);
1318
1319         err = dma_tx_fragment(ring, skb, ctl);
1320         if (unlikely(err == -ENOKEY)) {
1321                 /* Drop this packet, as we don't have the encryption key
1322                  * anymore and must not transmit it unencrypted. */
1323                 dev_kfree_skb_any(skb);
1324                 err = 0;
1325                 goto out_unlock;
1326         }
1327         if (unlikely(err)) {
1328                 b43err(dev->wl, "DMA tx mapping failure\n");
1329                 goto out_unlock;
1330         }
1331         ring->nr_tx_packets++;
1332         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1333             should_inject_overflow(ring)) {
1334                 /* This TX ring is full. */
1335                 ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1336                 ring->stopped = 1;
1337                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1338                         b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
1339                 }
1340         }
1341 out_unlock:
1342         spin_unlock_irqrestore(&ring->lock, flags);
1343
1344         return err;
1345 }
1346
1347 /* Called with IRQs disabled. */
1348 void b43_dma_handle_txstatus(struct b43_wldev *dev,
1349                              const struct b43_txstatus *status)
1350 {
1351         const struct b43_dma_ops *ops;
1352         struct b43_dmaring *ring;
1353         struct b43_dmadesc_generic *desc;
1354         struct b43_dmadesc_meta *meta;
1355         int slot;
1356
1357         ring = parse_cookie(dev, status->cookie, &slot);
1358         if (unlikely(!ring))
1359                 return;
1360
1361         spin_lock(&ring->lock); /* IRQs are already disabled. */
1362
1363         B43_WARN_ON(!ring->tx);
1364         ops = ring->ops;
1365         while (1) {
1366                 B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1367                 desc = ops->idx2desc(ring, slot, &meta);
1368
1369                 if (meta->skb)
1370                         unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
1371                                          1);
1372                 else
1373                         unmap_descbuffer(ring, meta->dmaaddr,
1374                                          b43_txhdr_size(dev), 1);
1375
1376                 if (meta->is_last_fragment) {
1377                         B43_WARN_ON(!meta->skb);
1378                         /* Call back to inform the ieee80211 subsystem about the
1379                          * status of the transmission.
1380                          * Some fields of txstat are already filled in dma_tx().
1381                          */
1382                         if (status->acked) {
1383                                 meta->txstat.flags |= IEEE80211_TX_STATUS_ACK;
1384                         } else {
1385                                 if (!(meta->txstat.control.flags
1386                                       & IEEE80211_TXCTL_NO_ACK))
1387                                         meta->txstat.excessive_retries = 1;
1388                         }
1389                         if (status->frame_count == 0) {
1390                                 /* The frame was not transmitted at all. */
1391                                 meta->txstat.retry_count = 0;
1392                         } else
1393                                 meta->txstat.retry_count = status->frame_count - 1;
1394                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb,
1395                                                     &(meta->txstat));
1396                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1397                         meta->skb = NULL;
1398                 } else {
1399                         /* No need to call free_descriptor_buffer here, as
1400                          * this is only the txhdr, which is not allocated.
1401                          */
1402                         B43_WARN_ON(meta->skb);
1403                 }
1404
1405                 /* Everything unmapped and free'd. So it's not used anymore. */
1406                 ring->used_slots--;
1407
1408                 if (meta->is_last_fragment)
1409                         break;
1410                 slot = next_slot(ring, slot);
1411         }
1412         dev->stats.last_tx = jiffies;
1413         if (ring->stopped) {
1414                 B43_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1415                 ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1416                 ring->stopped = 0;
1417                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1418                         b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index);
1419                 }
1420         }
1421
1422         spin_unlock(&ring->lock);
1423 }
1424
1425 void b43_dma_get_tx_stats(struct b43_wldev *dev,
1426                           struct ieee80211_tx_queue_stats *stats)
1427 {
1428         const int nr_queues = dev->wl->hw->queues;
1429         struct b43_dmaring *ring;
1430         struct ieee80211_tx_queue_stats_data *data;
1431         unsigned long flags;
1432         int i;
1433
1434         for (i = 0; i < nr_queues; i++) {
1435                 data = &(stats->data[i]);
1436                 ring = priority_to_txring(dev, i);
1437
1438                 spin_lock_irqsave(&ring->lock, flags);
1439                 data->len = ring->used_slots / SLOTS_PER_PACKET;
1440                 data->limit = ring->nr_slots / SLOTS_PER_PACKET;
1441                 data->count = ring->nr_tx_packets;
1442                 spin_unlock_irqrestore(&ring->lock, flags);
1443         }
1444 }
1445
1446 static void dma_rx(struct b43_dmaring *ring, int *slot)
1447 {
1448         const struct b43_dma_ops *ops = ring->ops;
1449         struct b43_dmadesc_generic *desc;
1450         struct b43_dmadesc_meta *meta;
1451         struct b43_rxhdr_fw4 *rxhdr;
1452         struct sk_buff *skb;
1453         u16 len;
1454         int err;
1455         dma_addr_t dmaaddr;
1456
1457         desc = ops->idx2desc(ring, *slot, &meta);
1458
1459         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1460         skb = meta->skb;
1461
1462         if (ring->index == 3) {
1463                 /* We received an xmit status. */
1464                 struct b43_hwtxstatus *hw = (struct b43_hwtxstatus *)skb->data;
1465                 int i = 0;
1466
1467                 while (hw->cookie == 0) {
1468                         if (i > 100)
1469                                 break;
1470                         i++;
1471                         udelay(2);
1472                         barrier();
1473                 }
1474                 b43_handle_hwtxstatus(ring->dev, hw);
1475                 /* recycle the descriptor buffer. */
1476                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1477                                            ring->rx_buffersize);
1478
1479                 return;
1480         }
1481         rxhdr = (struct b43_rxhdr_fw4 *)skb->data;
1482         len = le16_to_cpu(rxhdr->frame_len);
1483         if (len == 0) {
1484                 int i = 0;
1485
1486                 do {
1487                         udelay(2);
1488                         barrier();
1489                         len = le16_to_cpu(rxhdr->frame_len);
1490                 } while (len == 0 && i++ < 5);
1491                 if (unlikely(len == 0)) {
1492                         /* recycle the descriptor buffer. */
1493                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1494                                                    ring->rx_buffersize);
1495                         goto drop;
1496                 }
1497         }
1498         if (unlikely(len > ring->rx_buffersize)) {
1499                 /* The data did not fit into one descriptor buffer
1500                  * and is split over multiple buffers.
1501                  * This should never happen, as we try to allocate buffers
1502                  * big enough. So simply ignore this packet.
1503                  */
1504                 int cnt = 0;
1505                 s32 tmp = len;
1506
1507                 while (1) {
1508                         desc = ops->idx2desc(ring, *slot, &meta);
1509                         /* recycle the descriptor buffer. */
1510                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1511                                                    ring->rx_buffersize);
1512                         *slot = next_slot(ring, *slot);
1513                         cnt++;
1514                         tmp -= ring->rx_buffersize;
1515                         if (tmp <= 0)
1516                                 break;
1517                 }
1518                 b43err(ring->dev->wl, "DMA RX buffer too small "
1519                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1520                        len, ring->rx_buffersize, cnt);
1521                 goto drop;
1522         }
1523
1524         dmaaddr = meta->dmaaddr;
1525         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1526         if (unlikely(err)) {
1527                 b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
1528                 sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
1529                 goto drop;
1530         }
1531
1532         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1533         skb_put(skb, len + ring->frameoffset);
1534         skb_pull(skb, ring->frameoffset);
1535
1536         b43_rx(ring->dev, skb, rxhdr);
1537       drop:
1538         return;
1539 }
1540
1541 void b43_dma_rx(struct b43_dmaring *ring)
1542 {
1543         const struct b43_dma_ops *ops = ring->ops;
1544         int slot, current_slot;
1545         int used_slots = 0;
1546
1547         B43_WARN_ON(ring->tx);
1548         current_slot = ops->get_current_rxslot(ring);
1549         B43_WARN_ON(!(current_slot >= 0 && current_slot < ring->nr_slots));
1550
1551         slot = ring->current_slot;
1552         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1553                 dma_rx(ring, &slot);
1554                 update_max_used_slots(ring, ++used_slots);
1555         }
1556         ops->set_current_rxslot(ring, slot);
1557         ring->current_slot = slot;
1558 }
1559
1560 static void b43_dma_tx_suspend_ring(struct b43_dmaring *ring)
1561 {
1562         unsigned long flags;
1563
1564         spin_lock_irqsave(&ring->lock, flags);
1565         B43_WARN_ON(!ring->tx);
1566         ring->ops->tx_suspend(ring);
1567         spin_unlock_irqrestore(&ring->lock, flags);
1568 }
1569
1570 static void b43_dma_tx_resume_ring(struct b43_dmaring *ring)
1571 {
1572         unsigned long flags;
1573
1574         spin_lock_irqsave(&ring->lock, flags);
1575         B43_WARN_ON(!ring->tx);
1576         ring->ops->tx_resume(ring);
1577         spin_unlock_irqrestore(&ring->lock, flags);
1578 }
1579
1580 void b43_dma_tx_suspend(struct b43_wldev *dev)
1581 {
1582         b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
1583         b43_dma_tx_suspend_ring(dev->dma.tx_ring0);
1584         b43_dma_tx_suspend_ring(dev->dma.tx_ring1);
1585         b43_dma_tx_suspend_ring(dev->dma.tx_ring2);
1586         b43_dma_tx_suspend_ring(dev->dma.tx_ring3);
1587         b43_dma_tx_suspend_ring(dev->dma.tx_ring4);
1588         b43_dma_tx_suspend_ring(dev->dma.tx_ring5);
1589 }
1590
1591 void b43_dma_tx_resume(struct b43_wldev *dev)
1592 {
1593         b43_dma_tx_resume_ring(dev->dma.tx_ring5);
1594         b43_dma_tx_resume_ring(dev->dma.tx_ring4);
1595         b43_dma_tx_resume_ring(dev->dma.tx_ring3);
1596         b43_dma_tx_resume_ring(dev->dma.tx_ring2);
1597         b43_dma_tx_resume_ring(dev->dma.tx_ring1);
1598         b43_dma_tx_resume_ring(dev->dma.tx_ring0);
1599         b43_power_saving_ctl_bits(dev, 0);
1600 }