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->dma_dev,
 377                                          buf, len, DMA_TO_DEVICE);
 378         } else {
 379                 dmaaddr = dma_map_single(ring->dev->dev->dma_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->dma_dev,
 392                                  addr, len, DMA_TO_DEVICE);
 393         } else {
 394                 dma_unmap_single(ring->dev->dev->dma_dev,
 395                                  addr, len, DMA_FROM_DEVICE);
 396         }
 397 }
 398
 399 static inline
 400     void sync_descbuffer_for_cpu(struct b43_dmaring *ring,
 401                                  dma_addr_t addr, size_t len)
 402 {
 403         B43_WARN_ON(ring->tx);
 404         dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
 405                                 addr, len, DMA_FROM_DEVICE);
 406 }
 407
 408 static inline
 409     void sync_descbuffer_for_device(struct b43_dmaring *ring,
 410                                     dma_addr_t addr, size_t len)
 411 {
 412         B43_WARN_ON(ring->tx);
 413         dma_sync_single_for_device(ring->dev->dev->dma_dev,
 414                                    addr, len, DMA_FROM_DEVICE);
 415 }
 416
 417 static inline
 418     void free_descriptor_buffer(struct b43_dmaring *ring,
 419                                 struct b43_dmadesc_meta *meta)
 420 {
 421         if (meta->skb) {
 422                 dev_kfree_skb_any(meta->skb);
 423                 meta->skb = NULL;
 424         }
 425 }
 426
 427 static int alloc_ringmemory(struct b43_dmaring *ring)
 428 {
 429         struct device *dma_dev = ring->dev->dev->dma_dev;
 430         gfp_t flags = GFP_KERNEL;
 431
 432         /* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
 433          * alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
 434          * has shown that 4K is sufficient for the latter as long as the buffer
 435          * does not cross an 8K boundary.
 436          *
 437          * For unknown reasons - possibly a hardware error - the BCM4311 rev
 438          * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
 439          * which accounts for the GFP_DMA flag below.
 440          */
 441         if (ring->type == B43_DMA_64BIT)
 442                 flags |= GFP_DMA;
 443         ring->descbase = dma_alloc_coherent(dma_dev, B43_DMA_RINGMEMSIZE,
 444                                             &(ring->dmabase), flags);
 445         if (!ring->descbase) {
 446                 b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
 447                 return -ENOMEM;
 448         }
 449         memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
 450
 451         return 0;
 452 }
 453
 454 static void free_ringmemory(struct b43_dmaring *ring)
 455 {
 456         struct device *dma_dev = ring->dev->dev->dma_dev;
 457
 458         dma_free_coherent(dma_dev, B43_DMA_RINGMEMSIZE,
 459                           ring->descbase, ring->dmabase);
 460 }
 461
 462 /* Reset the RX DMA channel */
 463 static int b43_dmacontroller_rx_reset(struct b43_wldev *dev, u16 mmio_base,
 464                                       enum b43_dmatype type)
 465 {
 466         int i;
 467         u32 value;
 468         u16 offset;
 469
 470         might_sleep();
 471
 472         offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
 473         b43_write32(dev, mmio_base + offset, 0);
 474         for (i = 0; i < 10; i++) {
 475                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXSTATUS :
 476                                                    B43_DMA32_RXSTATUS;
 477                 value = b43_read32(dev, mmio_base + offset);
 478                 if (type == B43_DMA_64BIT) {
 479                         value &= B43_DMA64_RXSTAT;
 480                         if (value == B43_DMA64_RXSTAT_DISABLED) {
 481                                 i = -1;
 482                                 break;
 483                         }
 484                 } else {
 485                         value &= B43_DMA32_RXSTATE;
 486                         if (value == B43_DMA32_RXSTAT_DISABLED) {
 487                                 i = -1;
 488                                 break;
 489                         }
 490                 }
 491                 msleep(1);
 492         }
 493         if (i != -1) {
 494                 b43err(dev->wl, "DMA RX reset timed out\n");
 495                 return -ENODEV;
 496         }
 497
 498         return 0;
 499 }
 500
 501 /* Reset the TX DMA channel */
 502 static int b43_dmacontroller_tx_reset(struct b43_wldev *dev, u16 mmio_base,
 503                                       enum b43_dmatype type)
 504 {
 505         int i;
 506         u32 value;
 507         u16 offset;
 508
 509         might_sleep();
 510
 511         for (i = 0; i < 10; i++) {
 512                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 513                                                    B43_DMA32_TXSTATUS;
 514                 value = b43_read32(dev, mmio_base + offset);
 515                 if (type == B43_DMA_64BIT) {
 516                         value &= B43_DMA64_TXSTAT;
 517                         if (value == B43_DMA64_TXSTAT_DISABLED ||
 518                             value == B43_DMA64_TXSTAT_IDLEWAIT ||
 519                             value == B43_DMA64_TXSTAT_STOPPED)
 520                                 break;
 521                 } else {
 522                         value &= B43_DMA32_TXSTATE;
 523                         if (value == B43_DMA32_TXSTAT_DISABLED ||
 524                             value == B43_DMA32_TXSTAT_IDLEWAIT ||
 525                             value == B43_DMA32_TXSTAT_STOPPED)
 526                                 break;
 527                 }
 528                 msleep(1);
 529         }
 530         offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXCTL : B43_DMA32_TXCTL;
 531         b43_write32(dev, mmio_base + offset, 0);
 532         for (i = 0; i < 10; i++) {
 533                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 534                                                    B43_DMA32_TXSTATUS;
 535                 value = b43_read32(dev, mmio_base + offset);
 536                 if (type == B43_DMA_64BIT) {
 537                         value &= B43_DMA64_TXSTAT;
 538                         if (value == B43_DMA64_TXSTAT_DISABLED) {
 539                                 i = -1;
 540                                 break;
 541                         }
 542                 } else {
 543                         value &= B43_DMA32_TXSTATE;
 544                         if (value == B43_DMA32_TXSTAT_DISABLED) {
 545                                 i = -1;
 546                                 break;
 547                         }
 548                 }
 549                 msleep(1);
 550         }
 551         if (i != -1) {
 552                 b43err(dev->wl, "DMA TX reset timed out\n");
 553                 return -ENODEV;
 554         }
 555         /* ensure the reset is completed. */
 556         msleep(1);
 557
 558         return 0;
 559 }
 560
 561 /* Check if a DMA mapping address is invalid. */
 562 static bool b43_dma_mapping_error(struct b43_dmaring *ring,
 563                                   dma_addr_t addr,
 564                                   size_t buffersize, bool dma_to_device)
 565 {
 566         if (unlikely(dma_mapping_error(addr)))
 567                 return 1;
 568
 569         switch (ring->type) {
 570         case B43_DMA_30BIT:
 571                 if ((u64)addr + buffersize > (1ULL << 30))
 572                         goto address_error;
 573                 break;
 574         case B43_DMA_32BIT:
 575                 if ((u64)addr + buffersize > (1ULL << 32))
 576                         goto address_error;
 577                 break;
 578         case B43_DMA_64BIT:
 579                 /* Currently we can't have addresses beyond
 580                  * 64bit in the kernel. */
 581                 break;
 582         }
 583
 584         /* The address is OK. */
 585         return 0;
 586
 587 address_error:
 588         /* We can't support this address. Unmap it again. */
 589         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 590
 591         return 1;
 592 }
 593
 594 static int setup_rx_descbuffer(struct b43_dmaring *ring,
 595                                struct b43_dmadesc_generic *desc,
 596                                struct b43_dmadesc_meta *meta, gfp_t gfp_flags)
 597 {
 598         struct b43_rxhdr_fw4 *rxhdr;
 599         struct b43_hwtxstatus *txstat;
 600         dma_addr_t dmaaddr;
 601         struct sk_buff *skb;
 602
 603         B43_WARN_ON(ring->tx);
 604
 605         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 606         if (unlikely(!skb))
 607                 return -ENOMEM;
 608         dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
 609         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 610                 /* ugh. try to realloc in zone_dma */
 611                 gfp_flags |= GFP_DMA;
 612
 613                 dev_kfree_skb_any(skb);
 614
 615                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 616                 if (unlikely(!skb))
 617                         return -ENOMEM;
 618                 dmaaddr = map_descbuffer(ring, skb->data,
 619                                          ring->rx_buffersize, 0);
 620         }
 621
 622         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 623                 b43err(ring->dev->wl, "RX DMA buffer allocation failed\n");
 624                 dev_kfree_skb_any(skb);
 625                 return -EIO;
 626         }
 627
 628         meta->skb = skb;
 629         meta->dmaaddr = dmaaddr;
 630         ring->ops->fill_descriptor(ring, desc, dmaaddr,
 631                                    ring->rx_buffersize, 0, 0, 0);
 632
 633         rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
 634         rxhdr->frame_len = 0;
 635         txstat = (struct b43_hwtxstatus *)(skb->data);
 636         txstat->cookie = 0;
 637
 638         return 0;
 639 }
 640
 641 /* Allocate the initial descbuffers.
 642  * This is used for an RX ring only.
 643  */
 644 static int alloc_initial_descbuffers(struct b43_dmaring *ring)
 645 {
 646         int i, err = -ENOMEM;
 647         struct b43_dmadesc_generic *desc;
 648         struct b43_dmadesc_meta *meta;
 649
 650         for (i = 0; i < ring->nr_slots; i++) {
 651                 desc = ring->ops->idx2desc(ring, i, &meta);
 652
 653                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 654                 if (err) {
 655                         b43err(ring->dev->wl,
 656                                "Failed to allocate initial descbuffers\n");
 657                         goto err_unwind;
 658                 }
 659         }
 660         mb();
 661         ring->used_slots = ring->nr_slots;
 662         err = 0;
 663       out:
 664         return err;
 665
 666       err_unwind:
 667         for (i--; i >= 0; i--) {
 668                 desc = ring->ops->idx2desc(ring, i, &meta);
 669
 670                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 671                 dev_kfree_skb(meta->skb);
 672         }
 673         goto out;
 674 }
 675
 676 /* Do initial setup of the DMA controller.
 677  * Reset the controller, write the ring busaddress
 678  * and switch the "enable" bit on.
 679  */
 680 static int dmacontroller_setup(struct b43_dmaring *ring)
 681 {
 682         int err = 0;
 683         u32 value;
 684         u32 addrext;
 685         u32 trans = ssb_dma_translation(ring->dev->dev);
 686
 687         if (ring->tx) {
 688                 if (ring->type == B43_DMA_64BIT) {
 689                         u64 ringbase = (u64) (ring->dmabase);
 690
 691                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 692                             >> SSB_DMA_TRANSLATION_SHIFT;
 693                         value = B43_DMA64_TXENABLE;
 694                         value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
 695                             & B43_DMA64_TXADDREXT_MASK;
 696                         b43_dma_write(ring, B43_DMA64_TXCTL, value);
 697                         b43_dma_write(ring, B43_DMA64_TXRINGLO,
 698                                       (ringbase & 0xFFFFFFFF));
 699                         b43_dma_write(ring, B43_DMA64_TXRINGHI,
 700                                       ((ringbase >> 32) &
 701                                        ~SSB_DMA_TRANSLATION_MASK)
 702                                       | (trans << 1));
 703                 } else {
 704                         u32 ringbase = (u32) (ring->dmabase);
 705
 706                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 707                             >> SSB_DMA_TRANSLATION_SHIFT;
 708                         value = B43_DMA32_TXENABLE;
 709                         value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
 710                             & B43_DMA32_TXADDREXT_MASK;
 711                         b43_dma_write(ring, B43_DMA32_TXCTL, value);
 712                         b43_dma_write(ring, B43_DMA32_TXRING,
 713                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 714                                       | trans);
 715                 }
 716         } else {
 717                 err = alloc_initial_descbuffers(ring);
 718                 if (err)
 719                         goto out;
 720                 if (ring->type == B43_DMA_64BIT) {
 721                         u64 ringbase = (u64) (ring->dmabase);
 722
 723                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 724                             >> SSB_DMA_TRANSLATION_SHIFT;
 725                         value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
 726                         value |= B43_DMA64_RXENABLE;
 727                         value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
 728                             & B43_DMA64_RXADDREXT_MASK;
 729                         b43_dma_write(ring, B43_DMA64_RXCTL, value);
 730                         b43_dma_write(ring, B43_DMA64_RXRINGLO,
 731                                       (ringbase & 0xFFFFFFFF));
 732                         b43_dma_write(ring, B43_DMA64_RXRINGHI,
 733                                       ((ringbase >> 32) &
 734                                        ~SSB_DMA_TRANSLATION_MASK)
 735                                       | (trans << 1));
 736                         b43_dma_write(ring, B43_DMA64_RXINDEX, ring->nr_slots *
 737                                       sizeof(struct b43_dmadesc64));
 738                 } else {
 739                         u32 ringbase = (u32) (ring->dmabase);
 740
 741                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 742                             >> SSB_DMA_TRANSLATION_SHIFT;
 743                         value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
 744                         value |= B43_DMA32_RXENABLE;
 745                         value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
 746                             & B43_DMA32_RXADDREXT_MASK;
 747                         b43_dma_write(ring, B43_DMA32_RXCTL, value);
 748                         b43_dma_write(ring, B43_DMA32_RXRING,
 749                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 750                                       | trans);
 751                         b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
 752                                       sizeof(struct b43_dmadesc32));
 753                 }
 754         }
 755
 756 out:
 757         return err;
 758 }
 759
 760 /* Shutdown the DMA controller. */
 761 static void dmacontroller_cleanup(struct b43_dmaring *ring)
 762 {
 763         if (ring->tx) {
 764                 b43_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 765                                            ring->type);
 766                 if (ring->type == B43_DMA_64BIT) {
 767                         b43_dma_write(ring, B43_DMA64_TXRINGLO, 0);
 768                         b43_dma_write(ring, B43_DMA64_TXRINGHI, 0);
 769                 } else
 770                         b43_dma_write(ring, B43_DMA32_TXRING, 0);
 771         } else {
 772                 b43_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 773                                            ring->type);
 774                 if (ring->type == B43_DMA_64BIT) {
 775                         b43_dma_write(ring, B43_DMA64_RXRINGLO, 0);
 776                         b43_dma_write(ring, B43_DMA64_RXRINGHI, 0);
 777                 } else
 778                         b43_dma_write(ring, B43_DMA32_RXRING, 0);
 779         }
 780 }
 781
 782 static void free_all_descbuffers(struct b43_dmaring *ring)
 783 {
 784         struct b43_dmadesc_generic *desc;
 785         struct b43_dmadesc_meta *meta;
 786         int i;
 787
 788         if (!ring->used_slots)
 789                 return;
 790         for (i = 0; i < ring->nr_slots; i++) {
 791                 desc = ring->ops->idx2desc(ring, i, &meta);
 792
 793                 if (!meta->skb) {
 794                         B43_WARN_ON(!ring->tx);
 795                         continue;
 796                 }
 797                 if (ring->tx) {
 798                         unmap_descbuffer(ring, meta->dmaaddr,
 799                                          meta->skb->len, 1);
 800                 } else {
 801                         unmap_descbuffer(ring, meta->dmaaddr,
 802                                          ring->rx_buffersize, 0);
 803                 }
 804                 free_descriptor_buffer(ring, meta);
 805         }
 806 }
 807
 808 static u64 supported_dma_mask(struct b43_wldev *dev)
 809 {
 810         u32 tmp;
 811         u16 mmio_base;
 812
 813         tmp = b43_read32(dev, SSB_TMSHIGH);
 814         if (tmp & SSB_TMSHIGH_DMA64)
 815                 return DMA_64BIT_MASK;
 816         mmio_base = b43_dmacontroller_base(0, 0);
 817         b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
 818         tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
 819         if (tmp & B43_DMA32_TXADDREXT_MASK)
 820                 return DMA_32BIT_MASK;
 821
 822         return DMA_30BIT_MASK;
 823 }
 824
 825 /* Main initialization function. */
 826 static
 827 struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 828                                       int controller_index,
 829                                       int for_tx,
 830                                       enum b43_dmatype type)
 831 {
 832         struct b43_dmaring *ring;
 833         int err;
 834         int nr_slots;
 835         dma_addr_t dma_test;
 836
 837         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 838         if (!ring)
 839                 goto out;
 840         ring->type = type;
 841
 842         nr_slots = B43_RXRING_SLOTS;
 843         if (for_tx)
 844                 nr_slots = B43_TXRING_SLOTS;
 845
 846         ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
 847                              GFP_KERNEL);
 848         if (!ring->meta)
 849                 goto err_kfree_ring;
 850         if (for_tx) {
 851                 ring->txhdr_cache = kcalloc(nr_slots,
 852                                             b43_txhdr_size(dev),
 853                                             GFP_KERNEL);
 854                 if (!ring->txhdr_cache)
 855                         goto err_kfree_meta;
 856
 857                 /* test for ability to dma to txhdr_cache */
 858                 dma_test = dma_map_single(dev->dev->dma_dev,
 859                                           ring->txhdr_cache,
 860                                           b43_txhdr_size(dev),
 861                                           DMA_TO_DEVICE);
 862
 863                 if (b43_dma_mapping_error(ring, dma_test,
 864                                           b43_txhdr_size(dev), 1)) {
 865                         /* ugh realloc */
 866                         kfree(ring->txhdr_cache);
 867                         ring->txhdr_cache = kcalloc(nr_slots,
 868                                                     b43_txhdr_size(dev),
 869                                                     GFP_KERNEL | GFP_DMA);
 870                         if (!ring->txhdr_cache)
 871                                 goto err_kfree_meta;
 872
 873                         dma_test = dma_map_single(dev->dev->dma_dev,
 874                                                   ring->txhdr_cache,
 875                                                   b43_txhdr_size(dev),
 876                                                   DMA_TO_DEVICE);
 877
 878                         if (b43_dma_mapping_error(ring, dma_test,
 879                                                   b43_txhdr_size(dev), 1)) {
 880
 881                                 b43err(dev->wl,
 882                                        "TXHDR DMA allocation failed\n");
 883                                 goto err_kfree_txhdr_cache;
 884                         }
 885                 }
 886
 887                 dma_unmap_single(dev->dev->dma_dev,
 888                                  dma_test, b43_txhdr_size(dev),
 889                                  DMA_TO_DEVICE);
 890         }
 891
 892         ring->dev = dev;
 893         ring->nr_slots = nr_slots;
 894         ring->mmio_base = b43_dmacontroller_base(type, controller_index);
 895         ring->index = controller_index;
 896         if (type == B43_DMA_64BIT)
 897                 ring->ops = &dma64_ops;
 898         else
 899                 ring->ops = &dma32_ops;
 900         if (for_tx) {
 901                 ring->tx = 1;
 902                 ring->current_slot = -1;
 903         } else {
 904                 if (ring->index == 0) {
 905                         ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
 906                         ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
 907                 } else if (ring->index == 3) {
 908                         ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
 909                         ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
 910                 } else
 911                         B43_WARN_ON(1);
 912         }
 913         spin_lock_init(&ring->lock);
 914 #ifdef CONFIG_B43_DEBUG
 915         ring->last_injected_overflow = jiffies;
 916 #endif
 917
 918         err = alloc_ringmemory(ring);
 919         if (err)
 920                 goto err_kfree_txhdr_cache;
 921         err = dmacontroller_setup(ring);
 922         if (err)
 923                 goto err_free_ringmemory;
 924
 925       out:
 926         return ring;
 927
 928       err_free_ringmemory:
 929         free_ringmemory(ring);
 930       err_kfree_txhdr_cache:
 931         kfree(ring->txhdr_cache);
 932       err_kfree_meta:
 933         kfree(ring->meta);
 934       err_kfree_ring:
 935         kfree(ring);
 936         ring = NULL;
 937         goto out;
 938 }
 939
 940 /* Main cleanup function. */
 941 static void b43_destroy_dmaring(struct b43_dmaring *ring)
 942 {
 943         if (!ring)
 944                 return;
 945
 946         b43dbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots: %d/%d\n",
 947                (unsigned int)(ring->type),
 948                ring->mmio_base,
 949                (ring->tx) ? "TX" : "RX", ring->max_used_slots, ring->nr_slots);
 950         /* Device IRQs are disabled prior entering this function,
 951          * so no need to take care of concurrency with rx handler stuff.
 952          */
 953         dmacontroller_cleanup(ring);
 954         free_all_descbuffers(ring);
 955         free_ringmemory(ring);
 956
 957         kfree(ring->txhdr_cache);
 958         kfree(ring->meta);
 959         kfree(ring);
 960 }
 961
 962 void b43_dma_free(struct b43_wldev *dev)
 963 {
 964         struct b43_dma *dma = &dev->dma;
 965
 966         b43_destroy_dmaring(dma->rx_ring3);
 967         dma->rx_ring3 = NULL;
 968         b43_destroy_dmaring(dma->rx_ring0);
 969         dma->rx_ring0 = NULL;
 970
 971         b43_destroy_dmaring(dma->tx_ring5);
 972         dma->tx_ring5 = NULL;
 973         b43_destroy_dmaring(dma->tx_ring4);
 974         dma->tx_ring4 = NULL;
 975         b43_destroy_dmaring(dma->tx_ring3);
 976         dma->tx_ring3 = NULL;
 977         b43_destroy_dmaring(dma->tx_ring2);
 978         dma->tx_ring2 = NULL;
 979         b43_destroy_dmaring(dma->tx_ring1);
 980         dma->tx_ring1 = NULL;
 981         b43_destroy_dmaring(dma->tx_ring0);
 982         dma->tx_ring0 = NULL;
 983 }
 984
 985 int b43_dma_init(struct b43_wldev *dev)
 986 {
 987         struct b43_dma *dma = &dev->dma;
 988         struct b43_dmaring *ring;
 989         int err;
 990         u64 dmamask;
 991         enum b43_dmatype type;
 992
 993         dmamask = supported_dma_mask(dev);
 994         switch (dmamask) {
 995         default:
 996                 B43_WARN_ON(1);
 997         case DMA_30BIT_MASK:
 998                 type = B43_DMA_30BIT;
 999                 break;
1000         case DMA_32BIT_MASK:
1001                 type = B43_DMA_32BIT;
1002                 break;
1003         case DMA_64BIT_MASK:
1004                 type = B43_DMA_64BIT;
1005                 break;
1006         }
1007         err = ssb_dma_set_mask(dev->dev, dmamask);
1008         if (err) {
1009                 b43err(dev->wl, "The machine/kernel does not support "
1010                        "the required DMA mask (0x%08X%08X)\n",
1011                        (unsigned int)((dmamask & 0xFFFFFFFF00000000ULL) >> 32),
1012                        (unsigned int)(dmamask & 0x00000000FFFFFFFFULL));
1013                 return -EOPNOTSUPP;
1014         }
1015
1016         err = -ENOMEM;
1017         /* setup TX DMA channels. */
1018         ring = b43_setup_dmaring(dev, 0, 1, type);
1019         if (!ring)
1020                 goto out;
1021         dma->tx_ring0 = ring;
1022
1023         ring = b43_setup_dmaring(dev, 1, 1, type);
1024         if (!ring)
1025                 goto err_destroy_tx0;
1026         dma->tx_ring1 = ring;
1027
1028         ring = b43_setup_dmaring(dev, 2, 1, type);
1029         if (!ring)
1030                 goto err_destroy_tx1;
1031         dma->tx_ring2 = ring;
1032
1033         ring = b43_setup_dmaring(dev, 3, 1, type);
1034         if (!ring)
1035                 goto err_destroy_tx2;
1036         dma->tx_ring3 = ring;
1037
1038         ring = b43_setup_dmaring(dev, 4, 1, type);
1039         if (!ring)
1040                 goto err_destroy_tx3;
1041         dma->tx_ring4 = ring;
1042
1043         ring = b43_setup_dmaring(dev, 5, 1, type);
1044         if (!ring)
1045                 goto err_destroy_tx4;
1046         dma->tx_ring5 = ring;
1047
1048         /* setup RX DMA channels. */
1049         ring = b43_setup_dmaring(dev, 0, 0, type);
1050         if (!ring)
1051                 goto err_destroy_tx5;
1052         dma->rx_ring0 = ring;
1053
1054         if (dev->dev->id.revision < 5) {
1055                 ring = b43_setup_dmaring(dev, 3, 0, type);
1056                 if (!ring)
1057                         goto err_destroy_rx0;
1058                 dma->rx_ring3 = ring;
1059         }
1060
1061         b43dbg(dev->wl, "%u-bit DMA initialized\n",
1062                (unsigned int)type);
1063         err = 0;
1064       out:
1065         return err;
1066
1067       err_destroy_rx0:
1068         b43_destroy_dmaring(dma->rx_ring0);
1069         dma->rx_ring0 = NULL;
1070       err_destroy_tx5:
1071         b43_destroy_dmaring(dma->tx_ring5);
1072         dma->tx_ring5 = NULL;
1073       err_destroy_tx4:
1074         b43_destroy_dmaring(dma->tx_ring4);
1075         dma->tx_ring4 = NULL;
1076       err_destroy_tx3:
1077         b43_destroy_dmaring(dma->tx_ring3);
1078         dma->tx_ring3 = NULL;
1079       err_destroy_tx2:
1080         b43_destroy_dmaring(dma->tx_ring2);
1081         dma->tx_ring2 = NULL;
1082       err_destroy_tx1:
1083         b43_destroy_dmaring(dma->tx_ring1);
1084         dma->tx_ring1 = NULL;
1085       err_destroy_tx0:
1086         b43_destroy_dmaring(dma->tx_ring0);
1087         dma->tx_ring0 = NULL;
1088         goto out;
1089 }
1090
1091 /* Generate a cookie for the TX header. */
1092 static u16 generate_cookie(struct b43_dmaring *ring, int slot)
1093 {
1094         u16 cookie = 0x1000;
1095
1096         /* Use the upper 4 bits of the cookie as
1097          * DMA controller ID and store the slot number
1098          * in the lower 12 bits.
1099          * Note that the cookie must never be 0, as this
1100          * is a special value used in RX path.
1101          * It can also not be 0xFFFF because that is special
1102          * for multicast frames.
1103          */
1104         switch (ring->index) {
1105         case 0:
1106                 cookie = 0x1000;
1107                 break;
1108         case 1:
1109                 cookie = 0x2000;
1110                 break;
1111         case 2:
1112                 cookie = 0x3000;
1113                 break;
1114         case 3:
1115                 cookie = 0x4000;
1116                 break;
1117         case 4:
1118                 cookie = 0x5000;
1119                 break;
1120         case 5:
1121                 cookie = 0x6000;
1122                 break;
1123         default:
1124                 B43_WARN_ON(1);
1125         }
1126         B43_WARN_ON(slot & ~0x0FFF);
1127         cookie |= (u16) slot;
1128
1129         return cookie;
1130 }
1131
1132 /* Inspect a cookie and find out to which controller/slot it belongs. */
1133 static
1134 struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
1135 {
1136         struct b43_dma *dma = &dev->dma;
1137         struct b43_dmaring *ring = NULL;
1138
1139         switch (cookie & 0xF000) {
1140         case 0x1000:
1141                 ring = dma->tx_ring0;
1142                 break;
1143         case 0x2000:
1144                 ring = dma->tx_ring1;
1145                 break;
1146         case 0x3000:
1147                 ring = dma->tx_ring2;
1148                 break;
1149         case 0x4000:
1150                 ring = dma->tx_ring3;
1151                 break;
1152         case 0x5000:
1153                 ring = dma->tx_ring4;
1154                 break;
1155         case 0x6000:
1156                 ring = dma->tx_ring5;
1157                 break;
1158         default:
1159                 B43_WARN_ON(1);
1160         }
1161         *slot = (cookie & 0x0FFF);
1162         B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1163
1164         return ring;
1165 }
1166
1167 static int dma_tx_fragment(struct b43_dmaring *ring,
1168                            struct sk_buff *skb,
1169                            struct ieee80211_tx_control *ctl)
1170 {
1171         const struct b43_dma_ops *ops = ring->ops;
1172         u8 *header;
1173         int slot, old_top_slot, old_used_slots;
1174         int err;
1175         struct b43_dmadesc_generic *desc;
1176         struct b43_dmadesc_meta *meta;
1177         struct b43_dmadesc_meta *meta_hdr;
1178         struct sk_buff *bounce_skb;
1179         u16 cookie;
1180         size_t hdrsize = b43_txhdr_size(ring->dev);
1181
1182 #define SLOTS_PER_PACKET  2
1183         B43_WARN_ON(skb_shinfo(skb)->nr_frags);
1184
1185         old_top_slot = ring->current_slot;
1186         old_used_slots = ring->used_slots;
1187
1188         /* Get a slot for the header. */
1189         slot = request_slot(ring);
1190         desc = ops->idx2desc(ring, slot, &meta_hdr);
1191         memset(meta_hdr, 0, sizeof(*meta_hdr));
1192
1193         header = &(ring->txhdr_cache[slot * hdrsize]);
1194         cookie = generate_cookie(ring, slot);
1195         err = b43_generate_txhdr(ring->dev, header,
1196                                  skb->data, skb->len, ctl, cookie);
1197         if (unlikely(err)) {
1198                 ring->current_slot = old_top_slot;
1199                 ring->used_slots = old_used_slots;
1200                 return err;
1201         }
1202
1203         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1204                                            hdrsize, 1);
1205         if (b43_dma_mapping_error(ring, meta_hdr->dmaaddr, hdrsize, 1)) {
1206                 ring->current_slot = old_top_slot;
1207                 ring->used_slots = old_used_slots;
1208                 return -EIO;
1209         }
1210         ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1211                              hdrsize, 1, 0, 0);
1212
1213         /* Get a slot for the payload. */
1214         slot = request_slot(ring);
1215         desc = ops->idx2desc(ring, slot, &meta);
1216         memset(meta, 0, sizeof(*meta));
1217
1218         memcpy(&meta->txstat.control, ctl, sizeof(*ctl));
1219         meta->skb = skb;
1220         meta->is_last_fragment = 1;
1221
1222         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1223         /* create a bounce buffer in zone_dma on mapping failure. */
1224         if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1225                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1226                 if (!bounce_skb) {
1227                         ring->current_slot = old_top_slot;
1228                         ring->used_slots = old_used_slots;
1229                         err = -ENOMEM;
1230                         goto out_unmap_hdr;
1231                 }
1232
1233                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1234                 dev_kfree_skb_any(skb);
1235                 skb = bounce_skb;
1236                 meta->skb = skb;
1237                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1238                 if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1239                         ring->current_slot = old_top_slot;
1240                         ring->used_slots = old_used_slots;
1241                         err = -EIO;
1242                         goto out_free_bounce;
1243                 }
1244         }
1245
1246         ops->fill_descriptor(ring, desc, meta->dmaaddr, skb->len, 0, 1, 1);
1247
1248         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1249                 /* Tell the firmware about the cookie of the last
1250                  * mcast frame, so it can clear the more-data bit in it. */
1251                 b43_shm_write16(ring->dev, B43_SHM_SHARED,
1252                                 B43_SHM_SH_MCASTCOOKIE, cookie);
1253         }
1254         /* Now transfer the whole frame. */
1255         wmb();
1256         ops->poke_tx(ring, next_slot(ring, slot));
1257         return 0;
1258
1259 out_free_bounce:
1260         dev_kfree_skb_any(skb);
1261 out_unmap_hdr:
1262         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1263                          hdrsize, 1);
1264         return err;
1265 }
1266
1267 static inline int should_inject_overflow(struct b43_dmaring *ring)
1268 {
1269 #ifdef CONFIG_B43_DEBUG
1270         if (unlikely(b43_debug(ring->dev, B43_DBG_DMAOVERFLOW))) {
1271                 /* Check if we should inject another ringbuffer overflow
1272                  * to test handling of this situation in the stack. */
1273                 unsigned long next_overflow;
1274
1275                 next_overflow = ring->last_injected_overflow + HZ;
1276                 if (time_after(jiffies, next_overflow)) {
1277                         ring->last_injected_overflow = jiffies;
1278                         b43dbg(ring->dev->wl,
1279                                "Injecting TX ring overflow on "
1280                                "DMA controller %d\n", ring->index);
1281                         return 1;
1282                 }
1283         }
1284 #endif /* CONFIG_B43_DEBUG */
1285         return 0;
1286 }
1287
1288 int b43_dma_tx(struct b43_wldev *dev,
1289                struct sk_buff *skb, struct ieee80211_tx_control *ctl)
1290 {
1291         struct b43_dmaring *ring;
1292         struct ieee80211_hdr *hdr;
1293         int err = 0;
1294         unsigned long flags;
1295
1296         if (unlikely(skb->len < 2 + 2 + 6)) {
1297                 /* Too short, this can't be a valid frame. */
1298                 return -EINVAL;
1299         }
1300
1301         hdr = (struct ieee80211_hdr *)skb->data;
1302         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1303                 /* The multicast ring will be sent after the DTIM */
1304                 ring = dev->dma.tx_ring4;
1305                 /* Set the more-data bit. Ucode will clear it on
1306                  * the last frame for us. */
1307                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1308         } else {
1309                 /* Decide by priority where to put this frame. */
1310                 ring = priority_to_txring(dev, ctl->queue);
1311         }
1312
1313         spin_lock_irqsave(&ring->lock, flags);
1314         B43_WARN_ON(!ring->tx);
1315         if (unlikely(free_slots(ring) < SLOTS_PER_PACKET)) {
1316                 b43warn(dev->wl, "DMA queue overflow\n");
1317                 err = -ENOSPC;
1318                 goto out_unlock;
1319         }
1320         /* Check if the queue was stopped in mac80211,
1321          * but we got called nevertheless.
1322          * That would be a mac80211 bug. */
1323         B43_WARN_ON(ring->stopped);
1324
1325         err = dma_tx_fragment(ring, skb, ctl);
1326         if (unlikely(err == -ENOKEY)) {
1327                 /* Drop this packet, as we don't have the encryption key
1328                  * anymore and must not transmit it unencrypted. */
1329                 dev_kfree_skb_any(skb);
1330                 err = 0;
1331                 goto out_unlock;
1332         }
1333         if (unlikely(err)) {
1334                 b43err(dev->wl, "DMA tx mapping failure\n");
1335                 goto out_unlock;
1336         }
1337         ring->nr_tx_packets++;
1338         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1339             should_inject_overflow(ring)) {
1340                 /* This TX ring is full. */
1341                 ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1342                 ring->stopped = 1;
1343                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1344                         b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
1345                 }
1346         }
1347 out_unlock:
1348         spin_unlock_irqrestore(&ring->lock, flags);
1349
1350         return err;
1351 }
1352
1353 /* Called with IRQs disabled. */
1354 void b43_dma_handle_txstatus(struct b43_wldev *dev,
1355                              const struct b43_txstatus *status)
1356 {
1357         const struct b43_dma_ops *ops;
1358         struct b43_dmaring *ring;
1359         struct b43_dmadesc_generic *desc;
1360         struct b43_dmadesc_meta *meta;
1361         int slot;
1362
1363         ring = parse_cookie(dev, status->cookie, &slot);
1364         if (unlikely(!ring))
1365                 return;
1366
1367         spin_lock(&ring->lock); /* IRQs are already disabled. */
1368
1369         B43_WARN_ON(!ring->tx);
1370         ops = ring->ops;
1371         while (1) {
1372                 B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1373                 desc = ops->idx2desc(ring, slot, &meta);
1374
1375                 if (meta->skb)
1376                         unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
1377                                          1);
1378                 else
1379                         unmap_descbuffer(ring, meta->dmaaddr,
1380                                          b43_txhdr_size(dev), 1);
1381
1382                 if (meta->is_last_fragment) {
1383                         B43_WARN_ON(!meta->skb);
1384                         /* Call back to inform the ieee80211 subsystem about the
1385                          * status of the transmission.
1386                          * Some fields of txstat are already filled in dma_tx().
1387                          */
1388                         if (status->acked) {
1389                                 meta->txstat.flags |= IEEE80211_TX_STATUS_ACK;
1390                         } else {
1391                                 if (!(meta->txstat.control.flags
1392                                       & IEEE80211_TXCTL_NO_ACK))
1393                                         meta->txstat.excessive_retries = 1;
1394                         }
1395                         if (status->frame_count == 0) {
1396                                 /* The frame was not transmitted at all. */
1397                                 meta->txstat.retry_count = 0;
1398                         } else
1399                                 meta->txstat.retry_count = status->frame_count - 1;
1400                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb,
1401                                                     &(meta->txstat));
1402                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1403                         meta->skb = NULL;
1404                 } else {
1405                         /* No need to call free_descriptor_buffer here, as
1406                          * this is only the txhdr, which is not allocated.
1407                          */
1408                         B43_WARN_ON(meta->skb);
1409                 }
1410
1411                 /* Everything unmapped and free'd. So it's not used anymore. */
1412                 ring->used_slots--;
1413
1414                 if (meta->is_last_fragment)
1415                         break;
1416                 slot = next_slot(ring, slot);
1417         }
1418         dev->stats.last_tx = jiffies;
1419         if (ring->stopped) {
1420                 B43_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1421                 ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1422                 ring->stopped = 0;
1423                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1424                         b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index);
1425                 }
1426         }
1427
1428         spin_unlock(&ring->lock);
1429 }
1430
1431 void b43_dma_get_tx_stats(struct b43_wldev *dev,
1432                           struct ieee80211_tx_queue_stats *stats)
1433 {
1434         const int nr_queues = dev->wl->hw->queues;
1435         struct b43_dmaring *ring;
1436         struct ieee80211_tx_queue_stats_data *data;
1437         unsigned long flags;
1438         int i;
1439
1440         for (i = 0; i < nr_queues; i++) {
1441                 data = &(stats->data[i]);
1442                 ring = priority_to_txring(dev, i);
1443
1444                 spin_lock_irqsave(&ring->lock, flags);
1445                 data->len = ring->used_slots / SLOTS_PER_PACKET;
1446                 data->limit = ring->nr_slots / SLOTS_PER_PACKET;
1447                 data->count = ring->nr_tx_packets;
1448                 spin_unlock_irqrestore(&ring->lock, flags);
1449         }
1450 }
1451
1452 static void dma_rx(struct b43_dmaring *ring, int *slot)
1453 {
1454         const struct b43_dma_ops *ops = ring->ops;
1455         struct b43_dmadesc_generic *desc;
1456         struct b43_dmadesc_meta *meta;
1457         struct b43_rxhdr_fw4 *rxhdr;
1458         struct sk_buff *skb;
1459         u16 len;
1460         int err;
1461         dma_addr_t dmaaddr;
1462
1463         desc = ops->idx2desc(ring, *slot, &meta);
1464
1465         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1466         skb = meta->skb;
1467
1468         if (ring->index == 3) {
1469                 /* We received an xmit status. */
1470                 struct b43_hwtxstatus *hw = (struct b43_hwtxstatus *)skb->data;
1471                 int i = 0;
1472
1473                 while (hw->cookie == 0) {
1474                         if (i > 100)
1475                                 break;
1476                         i++;
1477                         udelay(2);
1478                         barrier();
1479                 }
1480                 b43_handle_hwtxstatus(ring->dev, hw);
1481                 /* recycle the descriptor buffer. */
1482                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1483                                            ring->rx_buffersize);
1484
1485                 return;
1486         }
1487         rxhdr = (struct b43_rxhdr_fw4 *)skb->data;
1488         len = le16_to_cpu(rxhdr->frame_len);
1489         if (len == 0) {
1490                 int i = 0;
1491
1492                 do {
1493                         udelay(2);
1494                         barrier();
1495                         len = le16_to_cpu(rxhdr->frame_len);
1496                 } while (len == 0 && i++ < 5);
1497                 if (unlikely(len == 0)) {
1498                         /* recycle the descriptor buffer. */
1499                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1500                                                    ring->rx_buffersize);
1501                         goto drop;
1502                 }
1503         }
1504         if (unlikely(len > ring->rx_buffersize)) {
1505                 /* The data did not fit into one descriptor buffer
1506                  * and is split over multiple buffers.
1507                  * This should never happen, as we try to allocate buffers
1508                  * big enough. So simply ignore this packet.
1509                  */
1510                 int cnt = 0;
1511                 s32 tmp = len;
1512
1513                 while (1) {
1514                         desc = ops->idx2desc(ring, *slot, &meta);
1515                         /* recycle the descriptor buffer. */
1516                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1517                                                    ring->rx_buffersize);
1518                         *slot = next_slot(ring, *slot);
1519                         cnt++;
1520                         tmp -= ring->rx_buffersize;
1521                         if (tmp <= 0)
1522                                 break;
1523                 }
1524                 b43err(ring->dev->wl, "DMA RX buffer too small "
1525                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1526                        len, ring->rx_buffersize, cnt);
1527                 goto drop;
1528         }
1529
1530         dmaaddr = meta->dmaaddr;
1531         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1532         if (unlikely(err)) {
1533                 b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
1534                 sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
1535                 goto drop;
1536         }
1537
1538         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1539         skb_put(skb, len + ring->frameoffset);
1540         skb_pull(skb, ring->frameoffset);
1541
1542         b43_rx(ring->dev, skb, rxhdr);
1543       drop:
1544         return;
1545 }
1546
1547 void b43_dma_rx(struct b43_dmaring *ring)
1548 {
1549         const struct b43_dma_ops *ops = ring->ops;
1550         int slot, current_slot;
1551         int used_slots = 0;
1552
1553         B43_WARN_ON(ring->tx);
1554         current_slot = ops->get_current_rxslot(ring);
1555         B43_WARN_ON(!(current_slot >= 0 && current_slot < ring->nr_slots));
1556
1557         slot = ring->current_slot;
1558         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1559                 dma_rx(ring, &slot);
1560                 update_max_used_slots(ring, ++used_slots);
1561         }
1562         ops->set_current_rxslot(ring, slot);
1563         ring->current_slot = slot;
1564 }
1565
1566 static void b43_dma_tx_suspend_ring(struct b43_dmaring *ring)
1567 {
1568         unsigned long flags;
1569
1570         spin_lock_irqsave(&ring->lock, flags);
1571         B43_WARN_ON(!ring->tx);
1572         ring->ops->tx_suspend(ring);
1573         spin_unlock_irqrestore(&ring->lock, flags);
1574 }
1575
1576 static void b43_dma_tx_resume_ring(struct b43_dmaring *ring)
1577 {
1578         unsigned long flags;
1579
1580         spin_lock_irqsave(&ring->lock, flags);
1581         B43_WARN_ON(!ring->tx);
1582         ring->ops->tx_resume(ring);
1583         spin_unlock_irqrestore(&ring->lock, flags);
1584 }
1585
1586 void b43_dma_tx_suspend(struct b43_wldev *dev)
1587 {
1588         b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
1589         b43_dma_tx_suspend_ring(dev->dma.tx_ring0);
1590         b43_dma_tx_suspend_ring(dev->dma.tx_ring1);
1591         b43_dma_tx_suspend_ring(dev->dma.tx_ring2);
1592         b43_dma_tx_suspend_ring(dev->dma.tx_ring3);
1593         b43_dma_tx_suspend_ring(dev->dma.tx_ring4);
1594         b43_dma_tx_suspend_ring(dev->dma.tx_ring5);
1595 }
1596
1597 void b43_dma_tx_resume(struct b43_wldev *dev)
1598 {
1599         b43_dma_tx_resume_ring(dev->dma.tx_ring5);
1600         b43_dma_tx_resume_ring(dev->dma.tx_ring4);
1601         b43_dma_tx_resume_ring(dev->dma.tx_ring3);
1602         b43_dma_tx_resume_ring(dev->dma.tx_ring2);
1603         b43_dma_tx_resume_ring(dev->dma.tx_ring1);
1604         b43_dma_tx_resume_ring(dev->dma.tx_ring0);
1605         b43_power_saving_ctl_bits(dev, 0);
1606 }