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 #include <asm/div64.h>
  42
  43
  44 /* 32bit DMA ops. */
  45 static
  46 struct b43_dmadesc_generic *op32_idx2desc(struct b43_dmaring *ring,
  47                                           int slot,
  48                                           struct b43_dmadesc_meta **meta)
  49 {
  50         struct b43_dmadesc32 *desc;
  51
  52         *meta = &(ring->meta[slot]);
  53         desc = ring->descbase;
  54         desc = &(desc[slot]);
  55
  56         return (struct b43_dmadesc_generic *)desc;
  57 }
  58
  59 static void op32_fill_descriptor(struct b43_dmaring *ring,
  60                                  struct b43_dmadesc_generic *desc,
  61                                  dma_addr_t dmaaddr, u16 bufsize,
  62                                  int start, int end, int irq)
  63 {
  64         struct b43_dmadesc32 *descbase = ring->descbase;
  65         int slot;
  66         u32 ctl;
  67         u32 addr;
  68         u32 addrext;
  69
  70         slot = (int)(&(desc->dma32) - descbase);
  71         B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
  72
  73         addr = (u32) (dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
  74         addrext = (u32) (dmaaddr & SSB_DMA_TRANSLATION_MASK)
  75             >> SSB_DMA_TRANSLATION_SHIFT;
  76         addr |= ssb_dma_translation(ring->dev->dev);
  77         ctl = (bufsize - ring->frameoffset)
  78             & B43_DMA32_DCTL_BYTECNT;
  79         if (slot == ring->nr_slots - 1)
  80                 ctl |= B43_DMA32_DCTL_DTABLEEND;
  81         if (start)
  82                 ctl |= B43_DMA32_DCTL_FRAMESTART;
  83         if (end)
  84                 ctl |= B43_DMA32_DCTL_FRAMEEND;
  85         if (irq)
  86                 ctl |= B43_DMA32_DCTL_IRQ;
  87         ctl |= (addrext << B43_DMA32_DCTL_ADDREXT_SHIFT)
  88             & B43_DMA32_DCTL_ADDREXT_MASK;
  89
  90         desc->dma32.control = cpu_to_le32(ctl);
  91         desc->dma32.address = cpu_to_le32(addr);
  92 }
  93
  94 static void op32_poke_tx(struct b43_dmaring *ring, int slot)
  95 {
  96         b43_dma_write(ring, B43_DMA32_TXINDEX,
  97                       (u32) (slot * sizeof(struct b43_dmadesc32)));
  98 }
  99
 100 static void op32_tx_suspend(struct b43_dmaring *ring)
 101 {
 102         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
 103                       | B43_DMA32_TXSUSPEND);
 104 }
 105
 106 static void op32_tx_resume(struct b43_dmaring *ring)
 107 {
 108         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
 109                       & ~B43_DMA32_TXSUSPEND);
 110 }
 111
 112 static int op32_get_current_rxslot(struct b43_dmaring *ring)
 113 {
 114         u32 val;
 115
 116         val = b43_dma_read(ring, B43_DMA32_RXSTATUS);
 117         val &= B43_DMA32_RXDPTR;
 118
 119         return (val / sizeof(struct b43_dmadesc32));
 120 }
 121
 122 static void op32_set_current_rxslot(struct b43_dmaring *ring, int slot)
 123 {
 124         b43_dma_write(ring, B43_DMA32_RXINDEX,
 125                       (u32) (slot * sizeof(struct b43_dmadesc32)));
 126 }
 127
 128 static const struct b43_dma_ops dma32_ops = {
 129         .idx2desc = op32_idx2desc,
 130         .fill_descriptor = op32_fill_descriptor,
 131         .poke_tx = op32_poke_tx,
 132         .tx_suspend = op32_tx_suspend,
 133         .tx_resume = op32_tx_resume,
 134         .get_current_rxslot = op32_get_current_rxslot,
 135         .set_current_rxslot = op32_set_current_rxslot,
 136 };
 137
 138 /* 64bit DMA ops. */
 139 static
 140 struct b43_dmadesc_generic *op64_idx2desc(struct b43_dmaring *ring,
 141                                           int slot,
 142                                           struct b43_dmadesc_meta **meta)
 143 {
 144         struct b43_dmadesc64 *desc;
 145
 146         *meta = &(ring->meta[slot]);
 147         desc = ring->descbase;
 148         desc = &(desc[slot]);
 149
 150         return (struct b43_dmadesc_generic *)desc;
 151 }
 152
 153 static void op64_fill_descriptor(struct b43_dmaring *ring,
 154                                  struct b43_dmadesc_generic *desc,
 155                                  dma_addr_t dmaaddr, u16 bufsize,
 156                                  int start, int end, int irq)
 157 {
 158         struct b43_dmadesc64 *descbase = ring->descbase;
 159         int slot;
 160         u32 ctl0 = 0, ctl1 = 0;
 161         u32 addrlo, addrhi;
 162         u32 addrext;
 163
 164         slot = (int)(&(desc->dma64) - descbase);
 165         B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
 166
 167         addrlo = (u32) (dmaaddr & 0xFFFFFFFF);
 168         addrhi = (((u64) dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
 169         addrext = (((u64) dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
 170             >> SSB_DMA_TRANSLATION_SHIFT;
 171         addrhi |= (ssb_dma_translation(ring->dev->dev) << 1);
 172         if (slot == ring->nr_slots - 1)
 173                 ctl0 |= B43_DMA64_DCTL0_DTABLEEND;
 174         if (start)
 175                 ctl0 |= B43_DMA64_DCTL0_FRAMESTART;
 176         if (end)
 177                 ctl0 |= B43_DMA64_DCTL0_FRAMEEND;
 178         if (irq)
 179                 ctl0 |= B43_DMA64_DCTL0_IRQ;
 180         ctl1 |= (bufsize - ring->frameoffset)
 181             & B43_DMA64_DCTL1_BYTECNT;
 182         ctl1 |= (addrext << B43_DMA64_DCTL1_ADDREXT_SHIFT)
 183             & B43_DMA64_DCTL1_ADDREXT_MASK;
 184
 185         desc->dma64.control0 = cpu_to_le32(ctl0);
 186         desc->dma64.control1 = cpu_to_le32(ctl1);
 187         desc->dma64.address_low = cpu_to_le32(addrlo);
 188         desc->dma64.address_high = cpu_to_le32(addrhi);
 189 }
 190
 191 static void op64_poke_tx(struct b43_dmaring *ring, int slot)
 192 {
 193         b43_dma_write(ring, B43_DMA64_TXINDEX,
 194                       (u32) (slot * sizeof(struct b43_dmadesc64)));
 195 }
 196
 197 static void op64_tx_suspend(struct b43_dmaring *ring)
 198 {
 199         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
 200                       | B43_DMA64_TXSUSPEND);
 201 }
 202
 203 static void op64_tx_resume(struct b43_dmaring *ring)
 204 {
 205         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
 206                       & ~B43_DMA64_TXSUSPEND);
 207 }
 208
 209 static int op64_get_current_rxslot(struct b43_dmaring *ring)
 210 {
 211         u32 val;
 212
 213         val = b43_dma_read(ring, B43_DMA64_RXSTATUS);
 214         val &= B43_DMA64_RXSTATDPTR;
 215
 216         return (val / sizeof(struct b43_dmadesc64));
 217 }
 218
 219 static void op64_set_current_rxslot(struct b43_dmaring *ring, int slot)
 220 {
 221         b43_dma_write(ring, B43_DMA64_RXINDEX,
 222                       (u32) (slot * sizeof(struct b43_dmadesc64)));
 223 }
 224
 225 static const struct b43_dma_ops dma64_ops = {
 226         .idx2desc = op64_idx2desc,
 227         .fill_descriptor = op64_fill_descriptor,
 228         .poke_tx = op64_poke_tx,
 229         .tx_suspend = op64_tx_suspend,
 230         .tx_resume = op64_tx_resume,
 231         .get_current_rxslot = op64_get_current_rxslot,
 232         .set_current_rxslot = op64_set_current_rxslot,
 233 };
 234
 235 static inline int free_slots(struct b43_dmaring *ring)
 236 {
 237         return (ring->nr_slots - ring->used_slots);
 238 }
 239
 240 static inline int next_slot(struct b43_dmaring *ring, int slot)
 241 {
 242         B43_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
 243         if (slot == ring->nr_slots - 1)
 244                 return 0;
 245         return slot + 1;
 246 }
 247
 248 static inline int prev_slot(struct b43_dmaring *ring, int slot)
 249 {
 250         B43_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
 251         if (slot == 0)
 252                 return ring->nr_slots - 1;
 253         return slot - 1;
 254 }
 255
 256 #ifdef CONFIG_B43_DEBUG
 257 static void update_max_used_slots(struct b43_dmaring *ring,
 258                                   int current_used_slots)
 259 {
 260         if (current_used_slots <= ring->max_used_slots)
 261                 return;
 262         ring->max_used_slots = current_used_slots;
 263         if (b43_debug(ring->dev, B43_DBG_DMAVERBOSE)) {
 264                 b43dbg(ring->dev->wl,
 265                        "max_used_slots increased to %d on %s ring %d\n",
 266                        ring->max_used_slots,
 267                        ring->tx ? "TX" : "RX", ring->index);
 268         }
 269 }
 270 #else
 271 static inline
 272     void update_max_used_slots(struct b43_dmaring *ring, int current_used_slots)
 273 {
 274 }
 275 #endif /* DEBUG */
 276
 277 /* Request a slot for usage. */
 278 static inline int request_slot(struct b43_dmaring *ring)
 279 {
 280         int slot;
 281
 282         B43_WARN_ON(!ring->tx);
 283         B43_WARN_ON(ring->stopped);
 284         B43_WARN_ON(free_slots(ring) == 0);
 285
 286         slot = next_slot(ring, ring->current_slot);
 287         ring->current_slot = slot;
 288         ring->used_slots++;
 289
 290         update_max_used_slots(ring, ring->used_slots);
 291
 292         return slot;
 293 }
 294
 295 static u16 b43_dmacontroller_base(enum b43_dmatype type, int controller_idx)
 296 {
 297         static const u16 map64[] = {
 298                 B43_MMIO_DMA64_BASE0,
 299                 B43_MMIO_DMA64_BASE1,
 300                 B43_MMIO_DMA64_BASE2,
 301                 B43_MMIO_DMA64_BASE3,
 302                 B43_MMIO_DMA64_BASE4,
 303                 B43_MMIO_DMA64_BASE5,
 304         };
 305         static const u16 map32[] = {
 306                 B43_MMIO_DMA32_BASE0,
 307                 B43_MMIO_DMA32_BASE1,
 308                 B43_MMIO_DMA32_BASE2,
 309                 B43_MMIO_DMA32_BASE3,
 310                 B43_MMIO_DMA32_BASE4,
 311                 B43_MMIO_DMA32_BASE5,
 312         };
 313
 314         if (type == B43_DMA_64BIT) {
 315                 B43_WARN_ON(!(controller_idx >= 0 &&
 316                               controller_idx < ARRAY_SIZE(map64)));
 317                 return map64[controller_idx];
 318         }
 319         B43_WARN_ON(!(controller_idx >= 0 &&
 320                       controller_idx < ARRAY_SIZE(map32)));
 321         return map32[controller_idx];
 322 }
 323
 324 static inline
 325     dma_addr_t map_descbuffer(struct b43_dmaring *ring,
 326                               unsigned char *buf, size_t len, int tx)
 327 {
 328         dma_addr_t dmaaddr;
 329
 330         if (tx) {
 331                 dmaaddr = dma_map_single(ring->dev->dev->dev,
 332                                          buf, len, DMA_TO_DEVICE);
 333         } else {
 334                 dmaaddr = dma_map_single(ring->dev->dev->dev,
 335                                          buf, len, DMA_FROM_DEVICE);
 336         }
 337
 338         return dmaaddr;
 339 }
 340
 341 static inline
 342     void unmap_descbuffer(struct b43_dmaring *ring,
 343                           dma_addr_t addr, size_t len, int tx)
 344 {
 345         if (tx) {
 346                 dma_unmap_single(ring->dev->dev->dev, addr, len, DMA_TO_DEVICE);
 347         } else {
 348                 dma_unmap_single(ring->dev->dev->dev,
 349                                  addr, len, DMA_FROM_DEVICE);
 350         }
 351 }
 352
 353 static inline
 354     void sync_descbuffer_for_cpu(struct b43_dmaring *ring,
 355                                  dma_addr_t addr, size_t len)
 356 {
 357         B43_WARN_ON(ring->tx);
 358         dma_sync_single_for_cpu(ring->dev->dev->dev,
 359                                 addr, len, DMA_FROM_DEVICE);
 360 }
 361
 362 static inline
 363     void sync_descbuffer_for_device(struct b43_dmaring *ring,
 364                                     dma_addr_t addr, size_t len)
 365 {
 366         B43_WARN_ON(ring->tx);
 367         dma_sync_single_for_device(ring->dev->dev->dev,
 368                                    addr, len, DMA_FROM_DEVICE);
 369 }
 370
 371 static inline
 372     void free_descriptor_buffer(struct b43_dmaring *ring,
 373                                 struct b43_dmadesc_meta *meta)
 374 {
 375         if (meta->skb) {
 376                 dev_kfree_skb_any(meta->skb);
 377                 meta->skb = NULL;
 378         }
 379 }
 380
 381 static int alloc_ringmemory(struct b43_dmaring *ring)
 382 {
 383         struct device *dev = ring->dev->dev->dev;
 384         gfp_t flags = GFP_KERNEL;
 385
 386         /* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
 387          * alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
 388          * has shown that 4K is sufficient for the latter as long as the buffer
 389          * does not cross an 8K boundary.
 390          *
 391          * For unknown reasons - possibly a hardware error - the BCM4311 rev
 392          * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
 393          * which accounts for the GFP_DMA flag below.
 394          */
 395         if (ring->type == B43_DMA_64BIT)
 396                 flags |= GFP_DMA;
 397         ring->descbase = dma_alloc_coherent(dev, B43_DMA_RINGMEMSIZE,
 398                                             &(ring->dmabase), flags);
 399         if (!ring->descbase) {
 400                 b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
 401                 return -ENOMEM;
 402         }
 403         memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
 404
 405         return 0;
 406 }
 407
 408 static void free_ringmemory(struct b43_dmaring *ring)
 409 {
 410         struct device *dev = ring->dev->dev->dev;
 411
 412         dma_free_coherent(dev, B43_DMA_RINGMEMSIZE,
 413                           ring->descbase, ring->dmabase);
 414 }
 415
 416 /* Reset the RX DMA channel */
 417 static int b43_dmacontroller_rx_reset(struct b43_wldev *dev, u16 mmio_base,
 418                                       enum b43_dmatype type)
 419 {
 420         int i;
 421         u32 value;
 422         u16 offset;
 423
 424         might_sleep();
 425
 426         offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
 427         b43_write32(dev, mmio_base + offset, 0);
 428         for (i = 0; i < 10; i++) {
 429                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXSTATUS :
 430                                                    B43_DMA32_RXSTATUS;
 431                 value = b43_read32(dev, mmio_base + offset);
 432                 if (type == B43_DMA_64BIT) {
 433                         value &= B43_DMA64_RXSTAT;
 434                         if (value == B43_DMA64_RXSTAT_DISABLED) {
 435                                 i = -1;
 436                                 break;
 437                         }
 438                 } else {
 439                         value &= B43_DMA32_RXSTATE;
 440                         if (value == B43_DMA32_RXSTAT_DISABLED) {
 441                                 i = -1;
 442                                 break;
 443                         }
 444                 }
 445                 msleep(1);
 446         }
 447         if (i != -1) {
 448                 b43err(dev->wl, "DMA RX reset timed out\n");
 449                 return -ENODEV;
 450         }
 451
 452         return 0;
 453 }
 454
 455 /* Reset the TX DMA channel */
 456 static int b43_dmacontroller_tx_reset(struct b43_wldev *dev, u16 mmio_base,
 457                                       enum b43_dmatype type)
 458 {
 459         int i;
 460         u32 value;
 461         u16 offset;
 462
 463         might_sleep();
 464
 465         for (i = 0; i < 10; i++) {
 466                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 467                                                    B43_DMA32_TXSTATUS;
 468                 value = b43_read32(dev, mmio_base + offset);
 469                 if (type == B43_DMA_64BIT) {
 470                         value &= B43_DMA64_TXSTAT;
 471                         if (value == B43_DMA64_TXSTAT_DISABLED ||
 472                             value == B43_DMA64_TXSTAT_IDLEWAIT ||
 473                             value == B43_DMA64_TXSTAT_STOPPED)
 474                                 break;
 475                 } else {
 476                         value &= B43_DMA32_TXSTATE;
 477                         if (value == B43_DMA32_TXSTAT_DISABLED ||
 478                             value == B43_DMA32_TXSTAT_IDLEWAIT ||
 479                             value == B43_DMA32_TXSTAT_STOPPED)
 480                                 break;
 481                 }
 482                 msleep(1);
 483         }
 484         offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXCTL : B43_DMA32_TXCTL;
 485         b43_write32(dev, mmio_base + offset, 0);
 486         for (i = 0; i < 10; i++) {
 487                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
 488                                                    B43_DMA32_TXSTATUS;
 489                 value = b43_read32(dev, mmio_base + offset);
 490                 if (type == B43_DMA_64BIT) {
 491                         value &= B43_DMA64_TXSTAT;
 492                         if (value == B43_DMA64_TXSTAT_DISABLED) {
 493                                 i = -1;
 494                                 break;
 495                         }
 496                 } else {
 497                         value &= B43_DMA32_TXSTATE;
 498                         if (value == B43_DMA32_TXSTAT_DISABLED) {
 499                                 i = -1;
 500                                 break;
 501                         }
 502                 }
 503                 msleep(1);
 504         }
 505         if (i != -1) {
 506                 b43err(dev->wl, "DMA TX reset timed out\n");
 507                 return -ENODEV;
 508         }
 509         /* ensure the reset is completed. */
 510         msleep(1);
 511
 512         return 0;
 513 }
 514
 515 /* Check if a DMA mapping address is invalid. */
 516 static bool b43_dma_mapping_error(struct b43_dmaring *ring,
 517                                   dma_addr_t addr,
 518                                   size_t buffersize)
 519 {
 520         if (unlikely(dma_mapping_error(addr)))
 521                 return 1;
 522
 523         switch (ring->type) {
 524         case B43_DMA_30BIT:
 525                 if ((u64)addr + buffersize > (1ULL << 30))
 526                         return 1;
 527                 break;
 528         case B43_DMA_32BIT:
 529                 if ((u64)addr + buffersize > (1ULL << 32))
 530                         return 1;
 531                 break;
 532         case B43_DMA_64BIT:
 533                 /* Currently we can't have addresses beyond
 534                  * 64bit in the kernel. */
 535                 break;
 536         }
 537
 538         /* The address is OK. */
 539         return 0;
 540 }
 541
 542 static int setup_rx_descbuffer(struct b43_dmaring *ring,
 543                                struct b43_dmadesc_generic *desc,
 544                                struct b43_dmadesc_meta *meta, gfp_t gfp_flags)
 545 {
 546         struct b43_rxhdr_fw4 *rxhdr;
 547         struct b43_hwtxstatus *txstat;
 548         dma_addr_t dmaaddr;
 549         struct sk_buff *skb;
 550
 551         B43_WARN_ON(ring->tx);
 552
 553         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 554         if (unlikely(!skb))
 555                 return -ENOMEM;
 556         dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
 557         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
 558                 /* ugh. try to realloc in zone_dma */
 559                 gfp_flags |= GFP_DMA;
 560
 561                 dev_kfree_skb_any(skb);
 562
 563                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 564                 if (unlikely(!skb))
 565                         return -ENOMEM;
 566                 dmaaddr = map_descbuffer(ring, skb->data,
 567                                          ring->rx_buffersize, 0);
 568         }
 569
 570         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
 571                 dev_kfree_skb_any(skb);
 572                 return -EIO;
 573         }
 574
 575         meta->skb = skb;
 576         meta->dmaaddr = dmaaddr;
 577         ring->ops->fill_descriptor(ring, desc, dmaaddr,
 578                                    ring->rx_buffersize, 0, 0, 0);
 579
 580         rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
 581         rxhdr->frame_len = 0;
 582         txstat = (struct b43_hwtxstatus *)(skb->data);
 583         txstat->cookie = 0;
 584
 585         return 0;
 586 }
 587
 588 /* Allocate the initial descbuffers.
 589  * This is used for an RX ring only.
 590  */
 591 static int alloc_initial_descbuffers(struct b43_dmaring *ring)
 592 {
 593         int i, err = -ENOMEM;
 594         struct b43_dmadesc_generic *desc;
 595         struct b43_dmadesc_meta *meta;
 596
 597         for (i = 0; i < ring->nr_slots; i++) {
 598                 desc = ring->ops->idx2desc(ring, i, &meta);
 599
 600                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 601                 if (err) {
 602                         b43err(ring->dev->wl,
 603                                "Failed to allocate initial descbuffers\n");
 604                         goto err_unwind;
 605                 }
 606         }
 607         mb();
 608         ring->used_slots = ring->nr_slots;
 609         err = 0;
 610       out:
 611         return err;
 612
 613       err_unwind:
 614         for (i--; i >= 0; i--) {
 615                 desc = ring->ops->idx2desc(ring, i, &meta);
 616
 617                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 618                 dev_kfree_skb(meta->skb);
 619         }
 620         goto out;
 621 }
 622
 623 /* Do initial setup of the DMA controller.
 624  * Reset the controller, write the ring busaddress
 625  * and switch the "enable" bit on.
 626  */
 627 static int dmacontroller_setup(struct b43_dmaring *ring)
 628 {
 629         int err = 0;
 630         u32 value;
 631         u32 addrext;
 632         u32 trans = ssb_dma_translation(ring->dev->dev);
 633
 634         if (ring->tx) {
 635                 if (ring->type == B43_DMA_64BIT) {
 636                         u64 ringbase = (u64) (ring->dmabase);
 637
 638                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 639                             >> SSB_DMA_TRANSLATION_SHIFT;
 640                         value = B43_DMA64_TXENABLE;
 641                         value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
 642                             & B43_DMA64_TXADDREXT_MASK;
 643                         b43_dma_write(ring, B43_DMA64_TXCTL, value);
 644                         b43_dma_write(ring, B43_DMA64_TXRINGLO,
 645                                       (ringbase & 0xFFFFFFFF));
 646                         b43_dma_write(ring, B43_DMA64_TXRINGHI,
 647                                       ((ringbase >> 32) &
 648                                        ~SSB_DMA_TRANSLATION_MASK)
 649                                       | (trans << 1));
 650                 } else {
 651                         u32 ringbase = (u32) (ring->dmabase);
 652
 653                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 654                             >> SSB_DMA_TRANSLATION_SHIFT;
 655                         value = B43_DMA32_TXENABLE;
 656                         value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
 657                             & B43_DMA32_TXADDREXT_MASK;
 658                         b43_dma_write(ring, B43_DMA32_TXCTL, value);
 659                         b43_dma_write(ring, B43_DMA32_TXRING,
 660                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 661                                       | trans);
 662                 }
 663         } else {
 664                 err = alloc_initial_descbuffers(ring);
 665                 if (err)
 666                         goto out;
 667                 if (ring->type == B43_DMA_64BIT) {
 668                         u64 ringbase = (u64) (ring->dmabase);
 669
 670                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
 671                             >> SSB_DMA_TRANSLATION_SHIFT;
 672                         value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
 673                         value |= B43_DMA64_RXENABLE;
 674                         value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
 675                             & B43_DMA64_RXADDREXT_MASK;
 676                         b43_dma_write(ring, B43_DMA64_RXCTL, value);
 677                         b43_dma_write(ring, B43_DMA64_RXRINGLO,
 678                                       (ringbase & 0xFFFFFFFF));
 679                         b43_dma_write(ring, B43_DMA64_RXRINGHI,
 680                                       ((ringbase >> 32) &
 681                                        ~SSB_DMA_TRANSLATION_MASK)
 682                                       | (trans << 1));
 683                         b43_dma_write(ring, B43_DMA64_RXINDEX, ring->nr_slots *
 684                                       sizeof(struct b43_dmadesc64));
 685                 } else {
 686                         u32 ringbase = (u32) (ring->dmabase);
 687
 688                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 689                             >> SSB_DMA_TRANSLATION_SHIFT;
 690                         value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
 691                         value |= B43_DMA32_RXENABLE;
 692                         value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
 693                             & B43_DMA32_RXADDREXT_MASK;
 694                         b43_dma_write(ring, B43_DMA32_RXCTL, value);
 695                         b43_dma_write(ring, B43_DMA32_RXRING,
 696                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 697                                       | trans);
 698                         b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
 699                                       sizeof(struct b43_dmadesc32));
 700                 }
 701         }
 702
 703 out:
 704         return err;
 705 }
 706
 707 /* Shutdown the DMA controller. */
 708 static void dmacontroller_cleanup(struct b43_dmaring *ring)
 709 {
 710         if (ring->tx) {
 711                 b43_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 712                                            ring->type);
 713                 if (ring->type == B43_DMA_64BIT) {
 714                         b43_dma_write(ring, B43_DMA64_TXRINGLO, 0);
 715                         b43_dma_write(ring, B43_DMA64_TXRINGHI, 0);
 716                 } else
 717                         b43_dma_write(ring, B43_DMA32_TXRING, 0);
 718         } else {
 719                 b43_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 720                                            ring->type);
 721                 if (ring->type == B43_DMA_64BIT) {
 722                         b43_dma_write(ring, B43_DMA64_RXRINGLO, 0);
 723                         b43_dma_write(ring, B43_DMA64_RXRINGHI, 0);
 724                 } else
 725                         b43_dma_write(ring, B43_DMA32_RXRING, 0);
 726         }
 727 }
 728
 729 static void free_all_descbuffers(struct b43_dmaring *ring)
 730 {
 731         struct b43_dmadesc_generic *desc;
 732         struct b43_dmadesc_meta *meta;
 733         int i;
 734
 735         if (!ring->used_slots)
 736                 return;
 737         for (i = 0; i < ring->nr_slots; i++) {
 738                 desc = ring->ops->idx2desc(ring, i, &meta);
 739
 740                 if (!meta->skb) {
 741                         B43_WARN_ON(!ring->tx);
 742                         continue;
 743                 }
 744                 if (ring->tx) {
 745                         unmap_descbuffer(ring, meta->dmaaddr,
 746                                          meta->skb->len, 1);
 747                 } else {
 748                         unmap_descbuffer(ring, meta->dmaaddr,
 749                                          ring->rx_buffersize, 0);
 750                 }
 751                 free_descriptor_buffer(ring, meta);
 752         }
 753 }
 754
 755 static u64 supported_dma_mask(struct b43_wldev *dev)
 756 {
 757         u32 tmp;
 758         u16 mmio_base;
 759
 760         tmp = b43_read32(dev, SSB_TMSHIGH);
 761         if (tmp & SSB_TMSHIGH_DMA64)
 762                 return DMA_64BIT_MASK;
 763         mmio_base = b43_dmacontroller_base(0, 0);
 764         b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
 765         tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
 766         if (tmp & B43_DMA32_TXADDREXT_MASK)
 767                 return DMA_32BIT_MASK;
 768
 769         return DMA_30BIT_MASK;
 770 }
 771
 772 /* Main initialization function. */
 773 static
 774 struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 775                                       int controller_index,
 776                                       int for_tx,
 777                                       enum b43_dmatype type)
 778 {
 779         struct b43_dmaring *ring;
 780         int err;
 781         int nr_slots;
 782         dma_addr_t dma_test;
 783
 784         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 785         if (!ring)
 786                 goto out;
 787         ring->type = type;
 788
 789         nr_slots = B43_RXRING_SLOTS;
 790         if (for_tx)
 791                 nr_slots = B43_TXRING_SLOTS;
 792
 793         ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
 794                              GFP_KERNEL);
 795         if (!ring->meta)
 796                 goto err_kfree_ring;
 797         if (for_tx) {
 798                 ring->txhdr_cache = kcalloc(nr_slots,
 799                                             b43_txhdr_size(dev),
 800                                             GFP_KERNEL);
 801                 if (!ring->txhdr_cache)
 802                         goto err_kfree_meta;
 803
 804                 /* test for ability to dma to txhdr_cache */
 805                 dma_test = dma_map_single(dev->dev->dev,
 806                                           ring->txhdr_cache,
 807                                           b43_txhdr_size(dev),
 808                                           DMA_TO_DEVICE);
 809
 810                 if (b43_dma_mapping_error(ring, dma_test, b43_txhdr_size(dev))) {
 811                         /* ugh realloc */
 812                         kfree(ring->txhdr_cache);
 813                         ring->txhdr_cache = kcalloc(nr_slots,
 814                                                     b43_txhdr_size(dev),
 815                                                     GFP_KERNEL | GFP_DMA);
 816                         if (!ring->txhdr_cache)
 817                                 goto err_kfree_meta;
 818
 819                         dma_test = dma_map_single(dev->dev->dev,
 820                                                   ring->txhdr_cache,
 821                                                   b43_txhdr_size(dev),
 822                                                   DMA_TO_DEVICE);
 823
 824                         if (b43_dma_mapping_error(ring, dma_test,
 825                                                   b43_txhdr_size(dev)))
 826                                 goto err_kfree_txhdr_cache;
 827                 }
 828
 829                 dma_unmap_single(dev->dev->dev,
 830                                  dma_test, b43_txhdr_size(dev),
 831                                  DMA_TO_DEVICE);
 832         }
 833
 834         ring->dev = dev;
 835         ring->nr_slots = nr_slots;
 836         ring->mmio_base = b43_dmacontroller_base(type, controller_index);
 837         ring->index = controller_index;
 838         if (type == B43_DMA_64BIT)
 839                 ring->ops = &dma64_ops;
 840         else
 841                 ring->ops = &dma32_ops;
 842         if (for_tx) {
 843                 ring->tx = 1;
 844                 ring->current_slot = -1;
 845         } else {
 846                 if (ring->index == 0) {
 847                         ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
 848                         ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
 849                 } else if (ring->index == 3) {
 850                         ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
 851                         ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
 852                 } else
 853                         B43_WARN_ON(1);
 854         }
 855         spin_lock_init(&ring->lock);
 856 #ifdef CONFIG_B43_DEBUG
 857         ring->last_injected_overflow = jiffies;
 858 #endif
 859
 860         err = alloc_ringmemory(ring);
 861         if (err)
 862                 goto err_kfree_txhdr_cache;
 863         err = dmacontroller_setup(ring);
 864         if (err)
 865                 goto err_free_ringmemory;
 866
 867       out:
 868         return ring;
 869
 870       err_free_ringmemory:
 871         free_ringmemory(ring);
 872       err_kfree_txhdr_cache:
 873         kfree(ring->txhdr_cache);
 874       err_kfree_meta:
 875         kfree(ring->meta);
 876       err_kfree_ring:
 877         kfree(ring);
 878         ring = NULL;
 879         goto out;
 880 }
 881
 882 #define divide(a, b)    ({      \
 883         typeof(a) __a = a;      \
 884         do_div(__a, b);         \
 885         __a;                    \
 886   })
 887
 888 #define modulo(a, b)    ({      \
 889         typeof(a) __a = a;      \
 890         do_div(__a, b);         \
 891   })
 892
 893 /* Main cleanup function. */
 894 static void b43_destroy_dmaring(struct b43_dmaring *ring,
 895                                 const char *ringname)
 896 {
 897         if (!ring)
 898                 return;
 899
 900 #ifdef CONFIG_B43_DEBUG
 901         {
 902                 /* Print some statistics. */
 903                 u64 failed_packets = ring->nr_failed_tx_packets;
 904                 u64 succeed_packets = ring->nr_succeed_tx_packets;
 905                 u64 nr_packets = failed_packets + succeed_packets;
 906                 u64 permille_failed = 0, average_tries = 0;
 907
 908                 if (nr_packets)
 909                         permille_failed = divide(failed_packets * 1000, nr_packets);
 910                 if (nr_packets)
 911                         average_tries = divide(ring->nr_total_packet_tries * 100, nr_packets);
 912
 913                 b43dbg(ring->dev->wl, "DMA-%u %s: "
 914                        "Used slots %d/%d, Failed frames %llu/%llu = %llu.%01llu%%, "
 915                        "Average tries %llu.%02llu\n",
 916                        (unsigned int)(ring->type), ringname,
 917                        ring->max_used_slots,
 918                        ring->nr_slots,
 919                        (unsigned long long)failed_packets,
 920                        (unsigned long long)nr_packets,
 921                        (unsigned long long)divide(permille_failed, 10),
 922                        (unsigned long long)modulo(permille_failed, 10),
 923                        (unsigned long long)divide(average_tries, 100),
 924                        (unsigned long long)modulo(average_tries, 100));
 925         }
 926 #endif /* DEBUG */
 927
 928         /* Device IRQs are disabled prior entering this function,
 929          * so no need to take care of concurrency with rx handler stuff.
 930          */
 931         dmacontroller_cleanup(ring);
 932         free_all_descbuffers(ring);
 933         free_ringmemory(ring);
 934
 935         kfree(ring->txhdr_cache);
 936         kfree(ring->meta);
 937         kfree(ring);
 938 }
 939
 940 #define destroy_ring(dma, ring) do {                            \
 941         b43_destroy_dmaring((dma)->ring, __stringify(ring));    \
 942         (dma)->ring = NULL;                                     \
 943     } while (0)
 944
 945 void b43_dma_free(struct b43_wldev *dev)
 946 {
 947         struct b43_dma *dma = &dev->dma;
 948
 949         destroy_ring(dma, rx_ring);
 950         destroy_ring(dma, tx_ring_AC_BK);
 951         destroy_ring(dma, tx_ring_AC_BE);
 952         destroy_ring(dma, tx_ring_AC_VI);
 953         destroy_ring(dma, tx_ring_AC_VO);
 954         destroy_ring(dma, tx_ring_mcast);
 955 }
 956
 957 int b43_dma_init(struct b43_wldev *dev)
 958 {
 959         struct b43_dma *dma = &dev->dma;
 960         int err;
 961         u64 dmamask;
 962         enum b43_dmatype type;
 963
 964         dmamask = supported_dma_mask(dev);
 965         switch (dmamask) {
 966         default:
 967                 B43_WARN_ON(1);
 968         case DMA_30BIT_MASK:
 969                 type = B43_DMA_30BIT;
 970                 break;
 971         case DMA_32BIT_MASK:
 972                 type = B43_DMA_32BIT;
 973                 break;
 974         case DMA_64BIT_MASK:
 975                 type = B43_DMA_64BIT;
 976                 break;
 977         }
 978         err = ssb_dma_set_mask(dev->dev, dmamask);
 979         if (err) {
 980                 b43err(dev->wl, "The machine/kernel does not support "
 981                        "the required DMA mask (0x%08X%08X)\n",
 982                        (unsigned int)((dmamask & 0xFFFFFFFF00000000ULL) >> 32),
 983                        (unsigned int)(dmamask & 0x00000000FFFFFFFFULL));
 984                 return -EOPNOTSUPP;
 985         }
 986
 987         err = -ENOMEM;
 988         /* setup TX DMA channels. */
 989         dma->tx_ring_AC_BK = b43_setup_dmaring(dev, 0, 1, type);
 990         if (!dma->tx_ring_AC_BK)
 991                 goto out;
 992
 993         dma->tx_ring_AC_BE = b43_setup_dmaring(dev, 1, 1, type);
 994         if (!dma->tx_ring_AC_BE)
 995                 goto err_destroy_bk;
 996
 997         dma->tx_ring_AC_VI = b43_setup_dmaring(dev, 2, 1, type);
 998         if (!dma->tx_ring_AC_VI)
 999                 goto err_destroy_be;
1000
1001         dma->tx_ring_AC_VO = b43_setup_dmaring(dev, 3, 1, type);
1002         if (!dma->tx_ring_AC_VO)
1003                 goto err_destroy_vi;
1004
1005         dma->tx_ring_mcast = b43_setup_dmaring(dev, 4, 1, type);
1006         if (!dma->tx_ring_mcast)
1007                 goto err_destroy_vo;
1008
1009         /* setup RX DMA channel. */
1010         dma->rx_ring = b43_setup_dmaring(dev, 0, 0, type);
1011         if (!dma->rx_ring)
1012                 goto err_destroy_mcast;
1013
1014         /* No support for the TX status DMA ring. */
1015         B43_WARN_ON(dev->dev->id.revision < 5);
1016
1017         b43dbg(dev->wl, "%u-bit DMA initialized\n",
1018                (unsigned int)type);
1019         err = 0;
1020 out:
1021         return err;
1022
1023 err_destroy_mcast:
1024         destroy_ring(dma, tx_ring_mcast);
1025 err_destroy_vo:
1026         destroy_ring(dma, tx_ring_AC_VO);
1027 err_destroy_vi:
1028         destroy_ring(dma, tx_ring_AC_VI);
1029 err_destroy_be:
1030         destroy_ring(dma, tx_ring_AC_BE);
1031 err_destroy_bk:
1032         destroy_ring(dma, tx_ring_AC_BK);
1033         return err;
1034 }
1035
1036 /* Generate a cookie for the TX header. */
1037 static u16 generate_cookie(struct b43_dmaring *ring, int slot)
1038 {
1039         u16 cookie;
1040
1041         /* Use the upper 4 bits of the cookie as
1042          * DMA controller ID and store the slot number
1043          * in the lower 12 bits.
1044          * Note that the cookie must never be 0, as this
1045          * is a special value used in RX path.
1046          * It can also not be 0xFFFF because that is special
1047          * for multicast frames.
1048          */
1049         cookie = (((u16)ring->index + 1) << 12);
1050         B43_WARN_ON(slot & ~0x0FFF);
1051         cookie |= (u16)slot;
1052
1053         return cookie;
1054 }
1055
1056 /* Inspect a cookie and find out to which controller/slot it belongs. */
1057 static
1058 struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
1059 {
1060         struct b43_dma *dma = &dev->dma;
1061         struct b43_dmaring *ring = NULL;
1062
1063         switch (cookie & 0xF000) {
1064         case 0x1000:
1065                 ring = dma->tx_ring_AC_BK;
1066                 break;
1067         case 0x2000:
1068                 ring = dma->tx_ring_AC_BE;
1069                 break;
1070         case 0x3000:
1071                 ring = dma->tx_ring_AC_VI;
1072                 break;
1073         case 0x4000:
1074                 ring = dma->tx_ring_AC_VO;
1075                 break;
1076         case 0x5000:
1077                 ring = dma->tx_ring_mcast;
1078                 break;
1079         default:
1080                 B43_WARN_ON(1);
1081         }
1082         *slot = (cookie & 0x0FFF);
1083         B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1084
1085         return ring;
1086 }
1087
1088 static int dma_tx_fragment(struct b43_dmaring *ring,
1089                            struct sk_buff *skb,
1090                            struct ieee80211_tx_control *ctl)
1091 {
1092         const struct b43_dma_ops *ops = ring->ops;
1093         u8 *header;
1094         int slot, old_top_slot, old_used_slots;
1095         int err;
1096         struct b43_dmadesc_generic *desc;
1097         struct b43_dmadesc_meta *meta;
1098         struct b43_dmadesc_meta *meta_hdr;
1099         struct sk_buff *bounce_skb;
1100         u16 cookie;
1101         size_t hdrsize = b43_txhdr_size(ring->dev);
1102
1103 #define SLOTS_PER_PACKET  2
1104         B43_WARN_ON(skb_shinfo(skb)->nr_frags);
1105
1106         old_top_slot = ring->current_slot;
1107         old_used_slots = ring->used_slots;
1108
1109         /* Get a slot for the header. */
1110         slot = request_slot(ring);
1111         desc = ops->idx2desc(ring, slot, &meta_hdr);
1112         memset(meta_hdr, 0, sizeof(*meta_hdr));
1113
1114         header = &(ring->txhdr_cache[slot * hdrsize]);
1115         cookie = generate_cookie(ring, slot);
1116         err = b43_generate_txhdr(ring->dev, header,
1117                                  skb->data, skb->len, ctl, cookie);
1118         if (unlikely(err)) {
1119                 ring->current_slot = old_top_slot;
1120                 ring->used_slots = old_used_slots;
1121                 return err;
1122         }
1123
1124         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1125                                            hdrsize, 1);
1126         if (b43_dma_mapping_error(ring, meta_hdr->dmaaddr, hdrsize)) {
1127                 ring->current_slot = old_top_slot;
1128                 ring->used_slots = old_used_slots;
1129                 return -EIO;
1130         }
1131         ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1132                              hdrsize, 1, 0, 0);
1133
1134         /* Get a slot for the payload. */
1135         slot = request_slot(ring);
1136         desc = ops->idx2desc(ring, slot, &meta);
1137         memset(meta, 0, sizeof(*meta));
1138
1139         memcpy(&meta->txstat.control, ctl, sizeof(*ctl));
1140         meta->skb = skb;
1141         meta->is_last_fragment = 1;
1142
1143         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1144         /* create a bounce buffer in zone_dma on mapping failure. */
1145         if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
1146                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1147                 if (!bounce_skb) {
1148                         ring->current_slot = old_top_slot;
1149                         ring->used_slots = old_used_slots;
1150                         err = -ENOMEM;
1151                         goto out_unmap_hdr;
1152                 }
1153
1154                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1155                 dev_kfree_skb_any(skb);
1156                 skb = bounce_skb;
1157                 meta->skb = skb;
1158                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1159                 if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
1160                         ring->current_slot = old_top_slot;
1161                         ring->used_slots = old_used_slots;
1162                         err = -EIO;
1163                         goto out_free_bounce;
1164                 }
1165         }
1166
1167         ops->fill_descriptor(ring, desc, meta->dmaaddr, skb->len, 0, 1, 1);
1168
1169         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1170                 /* Tell the firmware about the cookie of the last
1171                  * mcast frame, so it can clear the more-data bit in it. */
1172                 b43_shm_write16(ring->dev, B43_SHM_SHARED,
1173                                 B43_SHM_SH_MCASTCOOKIE, cookie);
1174         }
1175         /* Now transfer the whole frame. */
1176         wmb();
1177         ops->poke_tx(ring, next_slot(ring, slot));
1178         return 0;
1179
1180 out_free_bounce:
1181         dev_kfree_skb_any(skb);
1182 out_unmap_hdr:
1183         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1184                          hdrsize, 1);
1185         return err;
1186 }
1187
1188 static inline int should_inject_overflow(struct b43_dmaring *ring)
1189 {
1190 #ifdef CONFIG_B43_DEBUG
1191         if (unlikely(b43_debug(ring->dev, B43_DBG_DMAOVERFLOW))) {
1192                 /* Check if we should inject another ringbuffer overflow
1193                  * to test handling of this situation in the stack. */
1194                 unsigned long next_overflow;
1195
1196                 next_overflow = ring->last_injected_overflow + HZ;
1197                 if (time_after(jiffies, next_overflow)) {
1198                         ring->last_injected_overflow = jiffies;
1199                         b43dbg(ring->dev->wl,
1200                                "Injecting TX ring overflow on "
1201                                "DMA controller %d\n", ring->index);
1202                         return 1;
1203                 }
1204         }
1205 #endif /* CONFIG_B43_DEBUG */
1206         return 0;
1207 }
1208
1209 /* Static mapping of mac80211's queues (priorities) to b43 DMA rings. */
1210 static struct b43_dmaring * select_ring_by_priority(struct b43_wldev *dev,
1211                                                     u8 queue_prio)
1212 {
1213         struct b43_dmaring *ring;
1214
1215         if (b43_modparam_qos) {
1216                 /* 0 = highest priority */
1217                 switch (queue_prio) {
1218                 default:
1219                         B43_WARN_ON(1);
1220                         /* fallthrough */
1221                 case 0:
1222                         ring = dev->dma.tx_ring_AC_VO;
1223                         break;
1224                 case 1:
1225                         ring = dev->dma.tx_ring_AC_VI;
1226                         break;
1227                 case 2:
1228                         ring = dev->dma.tx_ring_AC_BE;
1229                         break;
1230                 case 3:
1231                         ring = dev->dma.tx_ring_AC_BK;
1232                         break;
1233                 }
1234         } else
1235                 ring = dev->dma.tx_ring_AC_BE;
1236
1237         return ring;
1238 }
1239
1240 int b43_dma_tx(struct b43_wldev *dev,
1241                struct sk_buff *skb, struct ieee80211_tx_control *ctl)
1242 {
1243         struct b43_dmaring *ring;
1244         struct ieee80211_hdr *hdr;
1245         int err = 0;
1246         unsigned long flags;
1247
1248         if (unlikely(skb->len < 2 + 2 + 6)) {
1249                 /* Too short, this can't be a valid frame. */
1250                 return -EINVAL;
1251         }
1252
1253         hdr = (struct ieee80211_hdr *)skb->data;
1254         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1255                 /* The multicast ring will be sent after the DTIM */
1256                 ring = dev->dma.tx_ring_mcast;
1257                 /* Set the more-data bit. Ucode will clear it on
1258                  * the last frame for us. */
1259                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1260         } else {
1261                 /* Decide by priority where to put this frame. */
1262                 ring = select_ring_by_priority(dev, ctl->queue);
1263         }
1264
1265         spin_lock_irqsave(&ring->lock, flags);
1266         B43_WARN_ON(!ring->tx);
1267         if (unlikely(free_slots(ring) < SLOTS_PER_PACKET)) {
1268                 b43warn(dev->wl, "DMA queue overflow\n");
1269                 err = -ENOSPC;
1270                 goto out_unlock;
1271         }
1272         /* Check if the queue was stopped in mac80211,
1273          * but we got called nevertheless.
1274          * That would be a mac80211 bug. */
1275         B43_WARN_ON(ring->stopped);
1276
1277         /* Assign the queue number to the ring (if not already done before)
1278          * so TX status handling can use it. The queue to ring mapping is
1279          * static, so we don't need to store it per frame. */
1280         ring->queue_prio = ctl->queue;
1281
1282         err = dma_tx_fragment(ring, skb, ctl);
1283         if (unlikely(err == -ENOKEY)) {
1284                 /* Drop this packet, as we don't have the encryption key
1285                  * anymore and must not transmit it unencrypted. */
1286                 dev_kfree_skb_any(skb);
1287                 err = 0;
1288                 goto out_unlock;
1289         }
1290         if (unlikely(err)) {
1291                 b43err(dev->wl, "DMA tx mapping failure\n");
1292                 goto out_unlock;
1293         }
1294         ring->nr_tx_packets++;
1295         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1296             should_inject_overflow(ring)) {
1297                 /* This TX ring is full. */
1298                 ieee80211_stop_queue(dev->wl->hw, ctl->queue);
1299                 ring->stopped = 1;
1300                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1301                         b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
1302                 }
1303         }
1304 out_unlock:
1305         spin_unlock_irqrestore(&ring->lock, flags);
1306
1307         return err;
1308 }
1309
1310 static void b43_fill_txstatus_report(struct b43_dmaring *ring,
1311                                     struct ieee80211_tx_status *report,
1312                                     const struct b43_txstatus *status)
1313 {
1314         bool frame_failed = 0;
1315
1316         if (status->acked) {
1317                 /* The frame was ACKed. */
1318                 report->flags |= IEEE80211_TX_STATUS_ACK;
1319         } else {
1320                 /* The frame was not ACKed... */
1321                 if (!(report->control.flags & IEEE80211_TXCTL_NO_ACK)) {
1322                         /* ...but we expected an ACK. */
1323                         frame_failed = 1;
1324                         report->excessive_retries = 1;
1325                 }
1326         }
1327         if (status->frame_count == 0) {
1328                 /* The frame was not transmitted at all. */
1329                 report->retry_count = 0;
1330         } else {
1331                 report->retry_count = status->frame_count - 1;
1332 #ifdef CONFIG_B43_DEBUG
1333                 if (frame_failed)
1334                         ring->nr_failed_tx_packets++;
1335                 else
1336                         ring->nr_succeed_tx_packets++;
1337                 ring->nr_total_packet_tries += status->frame_count;
1338 #endif /* DEBUG */
1339         }
1340 }
1341
1342 void b43_dma_handle_txstatus(struct b43_wldev *dev,
1343                              const struct b43_txstatus *status)
1344 {
1345         const struct b43_dma_ops *ops;
1346         struct b43_dmaring *ring;
1347         struct b43_dmadesc_generic *desc;
1348         struct b43_dmadesc_meta *meta;
1349         int slot;
1350
1351         ring = parse_cookie(dev, status->cookie, &slot);
1352         if (unlikely(!ring))
1353                 return;
1354         B43_WARN_ON(!irqs_disabled());
1355         spin_lock(&ring->lock);
1356
1357         B43_WARN_ON(!ring->tx);
1358         ops = ring->ops;
1359         while (1) {
1360                 B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1361                 desc = ops->idx2desc(ring, slot, &meta);
1362
1363                 if (meta->skb)
1364                         unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
1365                                          1);
1366                 else
1367                         unmap_descbuffer(ring, meta->dmaaddr,
1368                                          b43_txhdr_size(dev), 1);
1369
1370                 if (meta->is_last_fragment) {
1371                         B43_WARN_ON(!meta->skb);
1372                         /* Call back to inform the ieee80211 subsystem about the
1373                          * status of the transmission.
1374                          * Some fields of txstat are already filled in dma_tx().
1375                          */
1376                         b43_fill_txstatus_report(ring, &(meta->txstat), status);
1377                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb,
1378                                                     &(meta->txstat));
1379                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1380                         meta->skb = NULL;
1381                 } else {
1382                         /* No need to call free_descriptor_buffer here, as
1383                          * this is only the txhdr, which is not allocated.
1384                          */
1385                         B43_WARN_ON(meta->skb);
1386                 }
1387
1388                 /* Everything unmapped and free'd. So it's not used anymore. */
1389                 ring->used_slots--;
1390
1391                 if (meta->is_last_fragment)
1392                         break;
1393                 slot = next_slot(ring, slot);
1394         }
1395         dev->stats.last_tx = jiffies;
1396         if (ring->stopped) {
1397                 B43_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1398                 ieee80211_wake_queue(dev->wl->hw, ring->queue_prio);
1399                 ring->stopped = 0;
1400                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1401                         b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index);
1402                 }
1403         }
1404
1405         spin_unlock(&ring->lock);
1406 }
1407
1408 void b43_dma_get_tx_stats(struct b43_wldev *dev,
1409                           struct ieee80211_tx_queue_stats *stats)
1410 {
1411         const int nr_queues = dev->wl->hw->queues;
1412         struct b43_dmaring *ring;
1413         struct ieee80211_tx_queue_stats_data *data;
1414         unsigned long flags;
1415         int i;
1416
1417         for (i = 0; i < nr_queues; i++) {
1418                 data = &(stats->data[i]);
1419                 ring = select_ring_by_priority(dev, i);
1420
1421                 spin_lock_irqsave(&ring->lock, flags);
1422                 data->len = ring->used_slots / SLOTS_PER_PACKET;
1423                 data->limit = ring->nr_slots / SLOTS_PER_PACKET;
1424                 data->count = ring->nr_tx_packets;
1425                 spin_unlock_irqrestore(&ring->lock, flags);
1426         }
1427 }
1428
1429 static void dma_rx(struct b43_dmaring *ring, int *slot)
1430 {
1431         const struct b43_dma_ops *ops = ring->ops;
1432         struct b43_dmadesc_generic *desc;
1433         struct b43_dmadesc_meta *meta;
1434         struct b43_rxhdr_fw4 *rxhdr;
1435         struct sk_buff *skb;
1436         u16 len;
1437         int err;
1438         dma_addr_t dmaaddr;
1439
1440         desc = ops->idx2desc(ring, *slot, &meta);
1441
1442         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1443         skb = meta->skb;
1444
1445         rxhdr = (struct b43_rxhdr_fw4 *)skb->data;
1446         len = le16_to_cpu(rxhdr->frame_len);
1447         if (len == 0) {
1448                 int i = 0;
1449
1450                 do {
1451                         udelay(2);
1452                         barrier();
1453                         len = le16_to_cpu(rxhdr->frame_len);
1454                 } while (len == 0 && i++ < 5);
1455                 if (unlikely(len == 0)) {
1456                         /* recycle the descriptor buffer. */
1457                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1458                                                    ring->rx_buffersize);
1459                         goto drop;
1460                 }
1461         }
1462         if (unlikely(len > ring->rx_buffersize)) {
1463                 /* The data did not fit into one descriptor buffer
1464                  * and is split over multiple buffers.
1465                  * This should never happen, as we try to allocate buffers
1466                  * big enough. So simply ignore this packet.
1467                  */
1468                 int cnt = 0;
1469                 s32 tmp = len;
1470
1471                 while (1) {
1472                         desc = ops->idx2desc(ring, *slot, &meta);
1473                         /* recycle the descriptor buffer. */
1474                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1475                                                    ring->rx_buffersize);
1476                         *slot = next_slot(ring, *slot);
1477                         cnt++;
1478                         tmp -= ring->rx_buffersize;
1479                         if (tmp <= 0)
1480                                 break;
1481                 }
1482                 b43err(ring->dev->wl, "DMA RX buffer too small "
1483                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1484                        len, ring->rx_buffersize, cnt);
1485                 goto drop;
1486         }
1487
1488         dmaaddr = meta->dmaaddr;
1489         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1490         if (unlikely(err)) {
1491                 b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
1492                 sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
1493                 goto drop;
1494         }
1495
1496         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1497         skb_put(skb, len + ring->frameoffset);
1498         skb_pull(skb, ring->frameoffset);
1499
1500         b43_rx(ring->dev, skb, rxhdr);
1501 drop:
1502         return;
1503 }
1504
1505 void b43_dma_rx(struct b43_dmaring *ring)
1506 {
1507         const struct b43_dma_ops *ops = ring->ops;
1508         int slot, current_slot;
1509         int used_slots = 0;
1510
1511         B43_WARN_ON(ring->tx);
1512         current_slot = ops->get_current_rxslot(ring);
1513         B43_WARN_ON(!(current_slot >= 0 && current_slot < ring->nr_slots));
1514
1515         slot = ring->current_slot;
1516         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1517                 dma_rx(ring, &slot);
1518                 update_max_used_slots(ring, ++used_slots);
1519         }
1520         ops->set_current_rxslot(ring, slot);
1521         ring->current_slot = slot;
1522 }
1523
1524 static void b43_dma_tx_suspend_ring(struct b43_dmaring *ring)
1525 {
1526         unsigned long flags;
1527
1528         spin_lock_irqsave(&ring->lock, flags);
1529         B43_WARN_ON(!ring->tx);
1530         ring->ops->tx_suspend(ring);
1531         spin_unlock_irqrestore(&ring->lock, flags);
1532 }
1533
1534 static void b43_dma_tx_resume_ring(struct b43_dmaring *ring)
1535 {
1536         unsigned long flags;
1537
1538         spin_lock_irqsave(&ring->lock, flags);
1539         B43_WARN_ON(!ring->tx);
1540         ring->ops->tx_resume(ring);
1541         spin_unlock_irqrestore(&ring->lock, flags);
1542 }
1543
1544 void b43_dma_tx_suspend(struct b43_wldev *dev)
1545 {
1546         b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
1547         b43_dma_tx_suspend_ring(dev->dma.tx_ring_AC_BK);
1548         b43_dma_tx_suspend_ring(dev->dma.tx_ring_AC_BE);
1549         b43_dma_tx_suspend_ring(dev->dma.tx_ring_AC_VI);
1550         b43_dma_tx_suspend_ring(dev->dma.tx_ring_AC_VO);
1551         b43_dma_tx_suspend_ring(dev->dma.tx_ring_mcast);
1552 }
1553
1554 void b43_dma_tx_resume(struct b43_wldev *dev)
1555 {
1556         b43_dma_tx_resume_ring(dev->dma.tx_ring_mcast);
1557         b43_dma_tx_resume_ring(dev->dma.tx_ring_AC_VO);
1558         b43_dma_tx_resume_ring(dev->dma.tx_ring_AC_VI);
1559         b43_dma_tx_resume_ring(dev->dma.tx_ring_AC_BE);
1560         b43_dma_tx_resume_ring(dev->dma.tx_ring_AC_BK);
1561         b43_power_saving_ctl_bits(dev, 0);
1562 }