drivers/net/wireless/b43legacy/dma.c

   1 /*
   2
   3   Broadcom B43legacy wireless driver
   4
   5   DMA ringbuffer and descriptor allocation/management
   6
   7   Copyright (c) 2005, 2006 Michael Buesch <[email protected]>
   8
   9   Some code in this file is derived from the b44.c driver
  10   Copyright (C) 2002 David S. Miller
  11   Copyright (C) Pekka Pietikainen
  12
  13   This program is free software; you can redistribute it and/or modify
  14   it under the terms of the GNU General Public License as published by
  15   the Free Software Foundation; either version 2 of the License, or
  16   (at your option) any later version.
  17
  18   This program is distributed in the hope that it will be useful,
  19   but WITHOUT ANY WARRANTY; without even the implied warranty of
  20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21   GNU General Public License for more details.
  22
  23   You should have received a copy of the GNU General Public License
  24   along with this program; see the file COPYING.  If not, write to
  25   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  26   Boston, MA 02110-1301, USA.
  27
  28 */
  29
  30 #include "b43legacy.h"
  31 #include "dma.h"
  32 #include "main.h"
  33 #include "debugfs.h"
  34 #include "xmit.h"
  35
  36 #include <linux/dma-mapping.h>
  37 #include <linux/pci.h>
  38 #include <linux/delay.h>
  39 #include <linux/skbuff.h>
  40 #include <linux/slab.h>
  41 #include <net/dst.h>
  42
  43 /* 32bit DMA ops. */
  44 static
  45 struct b43legacy_dmadesc32 *op32_idx2desc(struct b43legacy_dmaring *ring,
  46                                           int slot,
  47                                           struct b43legacy_dmadesc_meta **meta)
  48 {
  49         struct b43legacy_dmadesc32 *desc;
  50
  51         *meta = &(ring->meta[slot]);
  52         desc = ring->descbase;
  53         desc = &(desc[slot]);
  54
  55         return desc;
  56 }
  57
  58 static void op32_fill_descriptor(struct b43legacy_dmaring *ring,
  59                                  struct b43legacy_dmadesc32 *desc,
  60                                  dma_addr_t dmaaddr, u16 bufsize,
  61                                  int start, int end, int irq)
  62 {
  63         struct b43legacy_dmadesc32 *descbase = ring->descbase;
  64         int slot;
  65         u32 ctl;
  66         u32 addr;
  67         u32 addrext;
  68
  69         slot = (int)(desc - descbase);
  70         B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
  71
  72         addr = (u32)(dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
  73         addrext = (u32)(dmaaddr & SSB_DMA_TRANSLATION_MASK)
  74                    >> SSB_DMA_TRANSLATION_SHIFT;
  75         addr |= ring->dev->dma.translation;
  76         ctl = (bufsize - ring->frameoffset)
  77               & B43legacy_DMA32_DCTL_BYTECNT;
  78         if (slot == ring->nr_slots - 1)
  79                 ctl |= B43legacy_DMA32_DCTL_DTABLEEND;
  80         if (start)
  81                 ctl |= B43legacy_DMA32_DCTL_FRAMESTART;
  82         if (end)
  83                 ctl |= B43legacy_DMA32_DCTL_FRAMEEND;
  84         if (irq)
  85                 ctl |= B43legacy_DMA32_DCTL_IRQ;
  86         ctl |= (addrext << B43legacy_DMA32_DCTL_ADDREXT_SHIFT)
  87                & B43legacy_DMA32_DCTL_ADDREXT_MASK;
  88
  89         desc->control = cpu_to_le32(ctl);
  90         desc->address = cpu_to_le32(addr);
  91 }
  92
  93 static void op32_poke_tx(struct b43legacy_dmaring *ring, int slot)
  94 {
  95         b43legacy_dma_write(ring, B43legacy_DMA32_TXINDEX,
  96                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
  97 }
  98
  99 static void op32_tx_suspend(struct b43legacy_dmaring *ring)
 100 {
 101         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
 102                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
 103                             | B43legacy_DMA32_TXSUSPEND);
 104 }
 105
 106 static void op32_tx_resume(struct b43legacy_dmaring *ring)
 107 {
 108         b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
 109                             b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
 110                             & ~B43legacy_DMA32_TXSUSPEND);
 111 }
 112
 113 static int op32_get_current_rxslot(struct b43legacy_dmaring *ring)
 114 {
 115         u32 val;
 116
 117         val = b43legacy_dma_read(ring, B43legacy_DMA32_RXSTATUS);
 118         val &= B43legacy_DMA32_RXDPTR;
 119
 120         return (val / sizeof(struct b43legacy_dmadesc32));
 121 }
 122
 123 static void op32_set_current_rxslot(struct b43legacy_dmaring *ring,
 124                                     int slot)
 125 {
 126         b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
 127                             (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
 128 }
 129
 130 static inline int free_slots(struct b43legacy_dmaring *ring)
 131 {
 132         return (ring->nr_slots - ring->used_slots);
 133 }
 134
 135 static inline int next_slot(struct b43legacy_dmaring *ring, int slot)
 136 {
 137         B43legacy_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
 138         if (slot == ring->nr_slots - 1)
 139                 return 0;
 140         return slot + 1;
 141 }
 142
 143 static inline int prev_slot(struct b43legacy_dmaring *ring, int slot)
 144 {
 145         B43legacy_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
 146         if (slot == 0)
 147                 return ring->nr_slots - 1;
 148         return slot - 1;
 149 }
 150
 151 #ifdef CONFIG_B43LEGACY_DEBUG
 152 static void update_max_used_slots(struct b43legacy_dmaring *ring,
 153                                   int current_used_slots)
 154 {
 155         if (current_used_slots <= ring->max_used_slots)
 156                 return;
 157         ring->max_used_slots = current_used_slots;
 158         if (b43legacy_debug(ring->dev, B43legacy_DBG_DMAVERBOSE))
 159                 b43legacydbg(ring->dev->wl,
 160                        "max_used_slots increased to %d on %s ring %d\n",
 161                        ring->max_used_slots,
 162                        ring->tx ? "TX" : "RX",
 163                        ring->index);
 164 }
 165 #else
 166 static inline
 167 void update_max_used_slots(struct b43legacy_dmaring *ring,
 168                            int current_used_slots)
 169 { }
 170 #endif /* DEBUG */
 171
 172 /* Request a slot for usage. */
 173 static inline
 174 int request_slot(struct b43legacy_dmaring *ring)
 175 {
 176         int slot;
 177
 178         B43legacy_WARN_ON(!ring->tx);
 179         B43legacy_WARN_ON(ring->stopped);
 180         B43legacy_WARN_ON(free_slots(ring) == 0);
 181
 182         slot = next_slot(ring, ring->current_slot);
 183         ring->current_slot = slot;
 184         ring->used_slots++;
 185
 186         update_max_used_slots(ring, ring->used_slots);
 187
 188         return slot;
 189 }
 190
 191 /* Mac80211-queue to b43legacy-ring mapping */
 192 static struct b43legacy_dmaring *priority_to_txring(
 193                                                 struct b43legacy_wldev *dev,
 194                                                 int queue_priority)
 195 {
 196         struct b43legacy_dmaring *ring;
 197
 198 /*FIXME: For now we always run on TX-ring-1 */
 199 return dev->dma.tx_ring1;
 200
 201         /* 0 = highest priority */
 202         switch (queue_priority) {
 203         default:
 204                 B43legacy_WARN_ON(1);
 205                 /* fallthrough */
 206         case 0:
 207                 ring = dev->dma.tx_ring3;
 208                 break;
 209         case 1:
 210                 ring = dev->dma.tx_ring2;
 211                 break;
 212         case 2:
 213                 ring = dev->dma.tx_ring1;
 214                 break;
 215         case 3:
 216                 ring = dev->dma.tx_ring0;
 217                 break;
 218         case 4:
 219                 ring = dev->dma.tx_ring4;
 220                 break;
 221         case 5:
 222                 ring = dev->dma.tx_ring5;
 223                 break;
 224         }
 225
 226         return ring;
 227 }
 228
 229 /* Bcm4301-ring to mac80211-queue mapping */
 230 static inline int txring_to_priority(struct b43legacy_dmaring *ring)
 231 {
 232         static const u8 idx_to_prio[] =
 233                 { 3, 2, 1, 0, 4, 5, };
 234
 235 /*FIXME: have only one queue, for now */
 236 return 0;
 237
 238         return idx_to_prio[ring->index];
 239 }
 240
 241
 242 static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
 243                                         int controller_idx)
 244 {
 245         static const u16 map32[] = {
 246                 B43legacy_MMIO_DMA32_BASE0,
 247                 B43legacy_MMIO_DMA32_BASE1,
 248                 B43legacy_MMIO_DMA32_BASE2,
 249                 B43legacy_MMIO_DMA32_BASE3,
 250                 B43legacy_MMIO_DMA32_BASE4,
 251                 B43legacy_MMIO_DMA32_BASE5,
 252         };
 253
 254         B43legacy_WARN_ON(!(controller_idx >= 0 &&
 255                           controller_idx < ARRAY_SIZE(map32)));
 256         return map32[controller_idx];
 257 }
 258
 259 static inline
 260 dma_addr_t map_descbuffer(struct b43legacy_dmaring *ring,
 261                           unsigned char *buf,
 262                           size_t len,
 263                           int tx)
 264 {
 265         dma_addr_t dmaaddr;
 266
 267         if (tx)
 268                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 269                                              buf, len,
 270                                              DMA_TO_DEVICE);
 271         else
 272                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
 273                                              buf, len,
 274                                              DMA_FROM_DEVICE);
 275
 276         return dmaaddr;
 277 }
 278
 279 static inline
 280 void unmap_descbuffer(struct b43legacy_dmaring *ring,
 281                       dma_addr_t addr,
 282                       size_t len,
 283                       int tx)
 284 {
 285         if (tx)
 286                 dma_unmap_single(ring->dev->dev->dma_dev,
 287                                      addr, len,
 288                                      DMA_TO_DEVICE);
 289         else
 290                 dma_unmap_single(ring->dev->dev->dma_dev,
 291                                      addr, len,
 292                                      DMA_FROM_DEVICE);
 293 }
 294
 295 static inline
 296 void sync_descbuffer_for_cpu(struct b43legacy_dmaring *ring,
 297                              dma_addr_t addr,
 298                              size_t len)
 299 {
 300         B43legacy_WARN_ON(ring->tx);
 301
 302         dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
 303                                 addr, len, DMA_FROM_DEVICE);
 304 }
 305
 306 static inline
 307 void sync_descbuffer_for_device(struct b43legacy_dmaring *ring,
 308                                 dma_addr_t addr,
 309                                 size_t len)
 310 {
 311         B43legacy_WARN_ON(ring->tx);
 312
 313         dma_sync_single_for_device(ring->dev->dev->dma_dev,
 314                                    addr, len, DMA_FROM_DEVICE);
 315 }
 316
 317 static inline
 318 void free_descriptor_buffer(struct b43legacy_dmaring *ring,
 319                             struct b43legacy_dmadesc_meta *meta,
 320                             int irq_context)
 321 {
 322         if (meta->skb) {
 323                 if (irq_context)
 324                         dev_kfree_skb_irq(meta->skb);
 325                 else
 326                         dev_kfree_skb(meta->skb);
 327                 meta->skb = NULL;
 328         }
 329 }
 330
 331 static int alloc_ringmemory(struct b43legacy_dmaring *ring)
 332 {
 333         /* GFP flags must match the flags in free_ringmemory()! */
 334         ring->descbase = dma_zalloc_coherent(ring->dev->dev->dma_dev,
 335                                              B43legacy_DMA_RINGMEMSIZE,
 336                                              &(ring->dmabase), GFP_KERNEL);
 337         if (!ring->descbase)
 338                 return -ENOMEM;
 339
 340         return 0;
 341 }
 342
 343 static void free_ringmemory(struct b43legacy_dmaring *ring)
 344 {
 345         dma_free_coherent(ring->dev->dev->dma_dev, B43legacy_DMA_RINGMEMSIZE,
 346                           ring->descbase, ring->dmabase);
 347 }
 348
 349 /* Reset the RX DMA channel */
 350 static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
 351                                             u16 mmio_base,
 352                                             enum b43legacy_dmatype type)
 353 {
 354         int i;
 355         u32 value;
 356         u16 offset;
 357
 358         might_sleep();
 359
 360         offset = B43legacy_DMA32_RXCTL;
 361         b43legacy_write32(dev, mmio_base + offset, 0);
 362         for (i = 0; i < 10; i++) {
 363                 offset = B43legacy_DMA32_RXSTATUS;
 364                 value = b43legacy_read32(dev, mmio_base + offset);
 365                 value &= B43legacy_DMA32_RXSTATE;
 366                 if (value == B43legacy_DMA32_RXSTAT_DISABLED) {
 367                         i = -1;
 368                         break;
 369                 }
 370                 msleep(1);
 371         }
 372         if (i != -1) {
 373                 b43legacyerr(dev->wl, "DMA RX reset timed out\n");
 374                 return -ENODEV;
 375         }
 376
 377         return 0;
 378 }
 379
 380 /* Reset the RX DMA channel */
 381 static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
 382                                             u16 mmio_base,
 383                                             enum b43legacy_dmatype type)
 384 {
 385         int i;
 386         u32 value;
 387         u16 offset;
 388
 389         might_sleep();
 390
 391         for (i = 0; i < 10; i++) {
 392                 offset = B43legacy_DMA32_TXSTATUS;
 393                 value = b43legacy_read32(dev, mmio_base + offset);
 394                 value &= B43legacy_DMA32_TXSTATE;
 395                 if (value == B43legacy_DMA32_TXSTAT_DISABLED ||
 396                     value == B43legacy_DMA32_TXSTAT_IDLEWAIT ||
 397                     value == B43legacy_DMA32_TXSTAT_STOPPED)
 398                         break;
 399                 msleep(1);
 400         }
 401         offset = B43legacy_DMA32_TXCTL;
 402         b43legacy_write32(dev, mmio_base + offset, 0);
 403         for (i = 0; i < 10; i++) {
 404                 offset = B43legacy_DMA32_TXSTATUS;
 405                 value = b43legacy_read32(dev, mmio_base + offset);
 406                 value &= B43legacy_DMA32_TXSTATE;
 407                 if (value == B43legacy_DMA32_TXSTAT_DISABLED) {
 408                         i = -1;
 409                         break;
 410                 }
 411                 msleep(1);
 412         }
 413         if (i != -1) {
 414                 b43legacyerr(dev->wl, "DMA TX reset timed out\n");
 415                 return -ENODEV;
 416         }
 417         /* ensure the reset is completed. */
 418         msleep(1);
 419
 420         return 0;
 421 }
 422
 423 /* Check if a DMA mapping address is invalid. */
 424 static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
 425                                          dma_addr_t addr,
 426                                          size_t buffersize,
 427                                          bool dma_to_device)
 428 {
 429         if (unlikely(dma_mapping_error(ring->dev->dev->dma_dev, addr)))
 430                 return 1;
 431
 432         switch (ring->type) {
 433         case B43legacy_DMA_30BIT:
 434                 if ((u64)addr + buffersize > (1ULL << 30))
 435                         goto address_error;
 436                 break;
 437         case B43legacy_DMA_32BIT:
 438                 if ((u64)addr + buffersize > (1ULL << 32))
 439                         goto address_error;
 440                 break;
 441         }
 442
 443         /* The address is OK. */
 444         return 0;
 445
 446 address_error:
 447         /* We can't support this address. Unmap it again. */
 448         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 449
 450         return 1;
 451 }
 452
 453 static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
 454                                struct b43legacy_dmadesc32 *desc,
 455                                struct b43legacy_dmadesc_meta *meta,
 456                                gfp_t gfp_flags)
 457 {
 458         struct b43legacy_rxhdr_fw3 *rxhdr;
 459         struct b43legacy_hwtxstatus *txstat;
 460         dma_addr_t dmaaddr;
 461         struct sk_buff *skb;
 462
 463         B43legacy_WARN_ON(ring->tx);
 464
 465         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 466         if (unlikely(!skb))
 467                 return -ENOMEM;
 468         dmaaddr = map_descbuffer(ring, skb->data,
 469                                  ring->rx_buffersize, 0);
 470         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 471                 /* ugh. try to realloc in zone_dma */
 472                 gfp_flags |= GFP_DMA;
 473
 474                 dev_kfree_skb_any(skb);
 475
 476                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 477                 if (unlikely(!skb))
 478                         return -ENOMEM;
 479                 dmaaddr = map_descbuffer(ring, skb->data,
 480                                          ring->rx_buffersize, 0);
 481         }
 482
 483         if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
 484                 dev_kfree_skb_any(skb);
 485                 return -EIO;
 486         }
 487
 488         meta->skb = skb;
 489         meta->dmaaddr = dmaaddr;
 490         op32_fill_descriptor(ring, desc, dmaaddr, ring->rx_buffersize, 0, 0, 0);
 491
 492         rxhdr = (struct b43legacy_rxhdr_fw3 *)(skb->data);
 493         rxhdr->frame_len = 0;
 494         txstat = (struct b43legacy_hwtxstatus *)(skb->data);
 495         txstat->cookie = 0;
 496
 497         return 0;
 498 }
 499
 500 /* Allocate the initial descbuffers.
 501  * This is used for an RX ring only.
 502  */
 503 static int alloc_initial_descbuffers(struct b43legacy_dmaring *ring)
 504 {
 505         int i;
 506         int err = -ENOMEM;
 507         struct b43legacy_dmadesc32 *desc;
 508         struct b43legacy_dmadesc_meta *meta;
 509
 510         for (i = 0; i < ring->nr_slots; i++) {
 511                 desc = op32_idx2desc(ring, i, &meta);
 512
 513                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 514                 if (err) {
 515                         b43legacyerr(ring->dev->wl,
 516                                "Failed to allocate initial descbuffers\n");
 517                         goto err_unwind;
 518                 }
 519         }
 520         mb(); /* all descbuffer setup before next line */
 521         ring->used_slots = ring->nr_slots;
 522         err = 0;
 523 out:
 524         return err;
 525
 526 err_unwind:
 527         for (i--; i >= 0; i--) {
 528                 desc = op32_idx2desc(ring, i, &meta);
 529
 530                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 531                 dev_kfree_skb(meta->skb);
 532         }
 533         goto out;
 534 }
 535
 536 /* Do initial setup of the DMA controller.
 537  * Reset the controller, write the ring busaddress
 538  * and switch the "enable" bit on.
 539  */
 540 static int dmacontroller_setup(struct b43legacy_dmaring *ring)
 541 {
 542         int err = 0;
 543         u32 value;
 544         u32 addrext;
 545         u32 trans = ring->dev->dma.translation;
 546         u32 ringbase = (u32)(ring->dmabase);
 547
 548         if (ring->tx) {
 549                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 550                           >> SSB_DMA_TRANSLATION_SHIFT;
 551                 value = B43legacy_DMA32_TXENABLE;
 552                 value |= (addrext << B43legacy_DMA32_TXADDREXT_SHIFT)
 553                         & B43legacy_DMA32_TXADDREXT_MASK;
 554                 b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL, value);
 555                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING,
 556                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 557                                     | trans);
 558         } else {
 559                 err = alloc_initial_descbuffers(ring);
 560                 if (err)
 561                         goto out;
 562
 563                 addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
 564                           >> SSB_DMA_TRANSLATION_SHIFT;
 565                 value = (ring->frameoffset <<
 566                          B43legacy_DMA32_RXFROFF_SHIFT);
 567                 value |= B43legacy_DMA32_RXENABLE;
 568                 value |= (addrext << B43legacy_DMA32_RXADDREXT_SHIFT)
 569                          & B43legacy_DMA32_RXADDREXT_MASK;
 570                 b43legacy_dma_write(ring, B43legacy_DMA32_RXCTL, value);
 571                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING,
 572                                     (ringbase & ~SSB_DMA_TRANSLATION_MASK)
 573                                     | trans);
 574                 b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX, 200);
 575         }
 576
 577 out:
 578         return err;
 579 }
 580
 581 /* Shutdown the DMA controller. */
 582 static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
 583 {
 584         if (ring->tx) {
 585                 b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
 586                                                  ring->type);
 587                 b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
 588         } else {
 589                 b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
 590                                                  ring->type);
 591                 b43legacy_dma_write(ring, B43legacy_DMA32_RXRING, 0);
 592         }
 593 }
 594
 595 static void free_all_descbuffers(struct b43legacy_dmaring *ring)
 596 {
 597         struct b43legacy_dmadesc_meta *meta;
 598         int i;
 599
 600         if (!ring->used_slots)
 601                 return;
 602         for (i = 0; i < ring->nr_slots; i++) {
 603                 op32_idx2desc(ring, i, &meta);
 604
 605                 if (!meta->skb) {
 606                         B43legacy_WARN_ON(!ring->tx);
 607                         continue;
 608                 }
 609                 if (ring->tx)
 610                         unmap_descbuffer(ring, meta->dmaaddr,
 611                                          meta->skb->len, 1);
 612                 else
 613                         unmap_descbuffer(ring, meta->dmaaddr,
 614                                          ring->rx_buffersize, 0);
 615                 free_descriptor_buffer(ring, meta, 0);
 616         }
 617 }
 618
 619 static u64 supported_dma_mask(struct b43legacy_wldev *dev)
 620 {
 621         u32 tmp;
 622         u16 mmio_base;
 623
 624         mmio_base = b43legacy_dmacontroller_base(0, 0);
 625         b43legacy_write32(dev,
 626                         mmio_base + B43legacy_DMA32_TXCTL,
 627                         B43legacy_DMA32_TXADDREXT_MASK);
 628         tmp = b43legacy_read32(dev, mmio_base +
 629                                B43legacy_DMA32_TXCTL);
 630         if (tmp & B43legacy_DMA32_TXADDREXT_MASK)
 631                 return DMA_BIT_MASK(32);
 632
 633         return DMA_BIT_MASK(30);
 634 }
 635
 636 static enum b43legacy_dmatype dma_mask_to_engine_type(u64 dmamask)
 637 {
 638         if (dmamask == DMA_BIT_MASK(30))
 639                 return B43legacy_DMA_30BIT;
 640         if (dmamask == DMA_BIT_MASK(32))
 641                 return B43legacy_DMA_32BIT;
 642         B43legacy_WARN_ON(1);
 643         return B43legacy_DMA_30BIT;
 644 }
 645
 646 /* Main initialization function. */
 647 static
 648 struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
 649                                                   int controller_index,
 650                                                   int for_tx,
 651                                                   enum b43legacy_dmatype type)
 652 {
 653         struct b43legacy_dmaring *ring;
 654         int err;
 655         int nr_slots;
 656         dma_addr_t dma_test;
 657
 658         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 659         if (!ring)
 660                 goto out;
 661         ring->type = type;
 662         ring->dev = dev;
 663
 664         nr_slots = B43legacy_RXRING_SLOTS;
 665         if (for_tx)
 666                 nr_slots = B43legacy_TXRING_SLOTS;
 667
 668         ring->meta = kcalloc(nr_slots, sizeof(struct b43legacy_dmadesc_meta),
 669                              GFP_KERNEL);
 670         if (!ring->meta)
 671                 goto err_kfree_ring;
 672         if (for_tx) {
 673                 ring->txhdr_cache = kcalloc(nr_slots,
 674                                         sizeof(struct b43legacy_txhdr_fw3),
 675                                         GFP_KERNEL);
 676                 if (!ring->txhdr_cache)
 677                         goto err_kfree_meta;
 678
 679                 /* test for ability to dma to txhdr_cache */
 680                 dma_test = dma_map_single(dev->dev->dma_dev, ring->txhdr_cache,
 681                                               sizeof(struct b43legacy_txhdr_fw3),
 682                                               DMA_TO_DEVICE);
 683
 684                 if (b43legacy_dma_mapping_error(ring, dma_test,
 685                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
 686                         /* ugh realloc */
 687                         kfree(ring->txhdr_cache);
 688                         ring->txhdr_cache = kcalloc(nr_slots,
 689                                         sizeof(struct b43legacy_txhdr_fw3),
 690                                         GFP_KERNEL | GFP_DMA);
 691                         if (!ring->txhdr_cache)
 692                                 goto err_kfree_meta;
 693
 694                         dma_test = dma_map_single(dev->dev->dma_dev,
 695                                         ring->txhdr_cache,
 696                                         sizeof(struct b43legacy_txhdr_fw3),
 697                                         DMA_TO_DEVICE);
 698
 699                         if (b43legacy_dma_mapping_error(ring, dma_test,
 700                                         sizeof(struct b43legacy_txhdr_fw3), 1))
 701                                 goto err_kfree_txhdr_cache;
 702                 }
 703
 704                 dma_unmap_single(dev->dev->dma_dev, dma_test,
 705                                  sizeof(struct b43legacy_txhdr_fw3),
 706                                  DMA_TO_DEVICE);
 707         }
 708
 709         ring->nr_slots = nr_slots;
 710         ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
 711         ring->index = controller_index;
 712         if (for_tx) {
 713                 ring->tx = true;
 714                 ring->current_slot = -1;
 715         } else {
 716                 if (ring->index == 0) {
 717                         ring->rx_buffersize = B43legacy_DMA0_RX_BUFFERSIZE;
 718                         ring->frameoffset = B43legacy_DMA0_RX_FRAMEOFFSET;
 719                 } else if (ring->index == 3) {
 720                         ring->rx_buffersize = B43legacy_DMA3_RX_BUFFERSIZE;
 721                         ring->frameoffset = B43legacy_DMA3_RX_FRAMEOFFSET;
 722                 } else
 723                         B43legacy_WARN_ON(1);
 724         }
 725 #ifdef CONFIG_B43LEGACY_DEBUG
 726         ring->last_injected_overflow = jiffies;
 727 #endif
 728
 729         err = alloc_ringmemory(ring);
 730         if (err)
 731                 goto err_kfree_txhdr_cache;
 732         err = dmacontroller_setup(ring);
 733         if (err)
 734                 goto err_free_ringmemory;
 735
 736 out:
 737         return ring;
 738
 739 err_free_ringmemory:
 740         free_ringmemory(ring);
 741 err_kfree_txhdr_cache:
 742         kfree(ring->txhdr_cache);
 743 err_kfree_meta:
 744         kfree(ring->meta);
 745 err_kfree_ring:
 746         kfree(ring);
 747         ring = NULL;
 748         goto out;
 749 }
 750
 751 /* Main cleanup function. */
 752 static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
 753 {
 754         if (!ring)
 755                 return;
 756
 757         b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
 758                      " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
 759                      (ring->tx) ? "TX" : "RX", ring->max_used_slots,
 760                      ring->nr_slots);
 761         /* Device IRQs are disabled prior entering this function,
 762          * so no need to take care of concurrency with rx handler stuff.
 763          */
 764         dmacontroller_cleanup(ring);
 765         free_all_descbuffers(ring);
 766         free_ringmemory(ring);
 767
 768         kfree(ring->txhdr_cache);
 769         kfree(ring->meta);
 770         kfree(ring);
 771 }
 772
 773 void b43legacy_dma_free(struct b43legacy_wldev *dev)
 774 {
 775         struct b43legacy_dma *dma;
 776
 777         if (b43legacy_using_pio(dev))
 778                 return;
 779         dma = &dev->dma;
 780
 781         b43legacy_destroy_dmaring(dma->rx_ring3);
 782         dma->rx_ring3 = NULL;
 783         b43legacy_destroy_dmaring(dma->rx_ring0);
 784         dma->rx_ring0 = NULL;
 785
 786         b43legacy_destroy_dmaring(dma->tx_ring5);
 787         dma->tx_ring5 = NULL;
 788         b43legacy_destroy_dmaring(dma->tx_ring4);
 789         dma->tx_ring4 = NULL;
 790         b43legacy_destroy_dmaring(dma->tx_ring3);
 791         dma->tx_ring3 = NULL;
 792         b43legacy_destroy_dmaring(dma->tx_ring2);
 793         dma->tx_ring2 = NULL;
 794         b43legacy_destroy_dmaring(dma->tx_ring1);
 795         dma->tx_ring1 = NULL;
 796         b43legacy_destroy_dmaring(dma->tx_ring0);
 797         dma->tx_ring0 = NULL;
 798 }
 799
 800 static int b43legacy_dma_set_mask(struct b43legacy_wldev *dev, u64 mask)
 801 {
 802         u64 orig_mask = mask;
 803         bool fallback = false;
 804         int err;
 805
 806         /* Try to set the DMA mask. If it fails, try falling back to a
 807          * lower mask, as we can always also support a lower one. */
 808         while (1) {
 809                 err = dma_set_mask_and_coherent(dev->dev->dma_dev, mask);
 810                 if (!err)
 811                         break;
 812                 if (mask == DMA_BIT_MASK(64)) {
 813                         mask = DMA_BIT_MASK(32);
 814                         fallback = true;
 815                         continue;
 816                 }
 817                 if (mask == DMA_BIT_MASK(32)) {
 818                         mask = DMA_BIT_MASK(30);
 819                         fallback = true;
 820                         continue;
 821                 }
 822                 b43legacyerr(dev->wl, "The machine/kernel does not support "
 823                        "the required %u-bit DMA mask\n",
 824                        (unsigned int)dma_mask_to_engine_type(orig_mask));
 825                 return -EOPNOTSUPP;
 826         }
 827         if (fallback) {
 828                 b43legacyinfo(dev->wl, "DMA mask fallback from %u-bit to %u-"
 829                         "bit\n",
 830                         (unsigned int)dma_mask_to_engine_type(orig_mask),
 831                         (unsigned int)dma_mask_to_engine_type(mask));
 832         }
 833
 834         return 0;
 835 }
 836
 837 int b43legacy_dma_init(struct b43legacy_wldev *dev)
 838 {
 839         struct b43legacy_dma *dma = &dev->dma;
 840         struct b43legacy_dmaring *ring;
 841         int err;
 842         u64 dmamask;
 843         enum b43legacy_dmatype type;
 844
 845         dmamask = supported_dma_mask(dev);
 846         type = dma_mask_to_engine_type(dmamask);
 847         err = b43legacy_dma_set_mask(dev, dmamask);
 848         if (err) {
 849 #ifdef CONFIG_B43LEGACY_PIO
 850                 b43legacywarn(dev->wl, "DMA for this device not supported. "
 851                         "Falling back to PIO\n");
 852                 dev->__using_pio = true;
 853                 return -EAGAIN;
 854 #else
 855                 b43legacyerr(dev->wl, "DMA for this device not supported and "
 856                        "no PIO support compiled in\n");
 857                 return -EOPNOTSUPP;
 858 #endif
 859         }
 860         dma->translation = ssb_dma_translation(dev->dev);
 861
 862         err = -ENOMEM;
 863         /* setup TX DMA channels. */
 864         ring = b43legacy_setup_dmaring(dev, 0, 1, type);
 865         if (!ring)
 866                 goto out;
 867         dma->tx_ring0 = ring;
 868
 869         ring = b43legacy_setup_dmaring(dev, 1, 1, type);
 870         if (!ring)
 871                 goto err_destroy_tx0;
 872         dma->tx_ring1 = ring;
 873
 874         ring = b43legacy_setup_dmaring(dev, 2, 1, type);
 875         if (!ring)
 876                 goto err_destroy_tx1;
 877         dma->tx_ring2 = ring;
 878
 879         ring = b43legacy_setup_dmaring(dev, 3, 1, type);
 880         if (!ring)
 881                 goto err_destroy_tx2;
 882         dma->tx_ring3 = ring;
 883
 884         ring = b43legacy_setup_dmaring(dev, 4, 1, type);
 885         if (!ring)
 886                 goto err_destroy_tx3;
 887         dma->tx_ring4 = ring;
 888
 889         ring = b43legacy_setup_dmaring(dev, 5, 1, type);
 890         if (!ring)
 891                 goto err_destroy_tx4;
 892         dma->tx_ring5 = ring;
 893
 894         /* setup RX DMA channels. */
 895         ring = b43legacy_setup_dmaring(dev, 0, 0, type);
 896         if (!ring)
 897                 goto err_destroy_tx5;
 898         dma->rx_ring0 = ring;
 899
 900         if (dev->dev->id.revision < 5) {
 901                 ring = b43legacy_setup_dmaring(dev, 3, 0, type);
 902                 if (!ring)
 903                         goto err_destroy_rx0;
 904                 dma->rx_ring3 = ring;
 905         }
 906
 907         b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
 908         err = 0;
 909 out:
 910         return err;
 911
 912 err_destroy_rx0:
 913         b43legacy_destroy_dmaring(dma->rx_ring0);
 914         dma->rx_ring0 = NULL;
 915 err_destroy_tx5:
 916         b43legacy_destroy_dmaring(dma->tx_ring5);
 917         dma->tx_ring5 = NULL;
 918 err_destroy_tx4:
 919         b43legacy_destroy_dmaring(dma->tx_ring4);
 920         dma->tx_ring4 = NULL;
 921 err_destroy_tx3:
 922         b43legacy_destroy_dmaring(dma->tx_ring3);
 923         dma->tx_ring3 = NULL;
 924 err_destroy_tx2:
 925         b43legacy_destroy_dmaring(dma->tx_ring2);
 926         dma->tx_ring2 = NULL;
 927 err_destroy_tx1:
 928         b43legacy_destroy_dmaring(dma->tx_ring1);
 929         dma->tx_ring1 = NULL;
 930 err_destroy_tx0:
 931         b43legacy_destroy_dmaring(dma->tx_ring0);
 932         dma->tx_ring0 = NULL;
 933         goto out;
 934 }
 935
 936 /* Generate a cookie for the TX header. */
 937 static u16 generate_cookie(struct b43legacy_dmaring *ring,
 938                            int slot)
 939 {
 940         u16 cookie = 0x1000;
 941
 942         /* Use the upper 4 bits of the cookie as
 943          * DMA controller ID and store the slot number
 944          * in the lower 12 bits.
 945          * Note that the cookie must never be 0, as this
 946          * is a special value used in RX path.
 947          */
 948         switch (ring->index) {
 949         case 0:
 950                 cookie = 0xA000;
 951                 break;
 952         case 1:
 953                 cookie = 0xB000;
 954                 break;
 955         case 2:
 956                 cookie = 0xC000;
 957                 break;
 958         case 3:
 959                 cookie = 0xD000;
 960                 break;
 961         case 4:
 962                 cookie = 0xE000;
 963                 break;
 964         case 5:
 965                 cookie = 0xF000;
 966                 break;
 967         }
 968         B43legacy_WARN_ON(!(((u16)slot & 0xF000) == 0x0000));
 969         cookie |= (u16)slot;
 970
 971         return cookie;
 972 }
 973
 974 /* Inspect a cookie and find out to which controller/slot it belongs. */
 975 static
 976 struct b43legacy_dmaring *parse_cookie(struct b43legacy_wldev *dev,
 977                                       u16 cookie, int *slot)
 978 {
 979         struct b43legacy_dma *dma = &dev->dma;
 980         struct b43legacy_dmaring *ring = NULL;
 981
 982         switch (cookie & 0xF000) {
 983         case 0xA000:
 984                 ring = dma->tx_ring0;
 985                 break;
 986         case 0xB000:
 987                 ring = dma->tx_ring1;
 988                 break;
 989         case 0xC000:
 990                 ring = dma->tx_ring2;
 991                 break;
 992         case 0xD000:
 993                 ring = dma->tx_ring3;
 994                 break;
 995         case 0xE000:
 996                 ring = dma->tx_ring4;
 997                 break;
 998         case 0xF000:
 999                 ring = dma->tx_ring5;
1000                 break;
1001         default:
1002                 B43legacy_WARN_ON(1);
1003         }
1004         *slot = (cookie & 0x0FFF);
1005         B43legacy_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1006
1007         return ring;
1008 }
1009
1010 static int dma_tx_fragment(struct b43legacy_dmaring *ring,
1011                             struct sk_buff **in_skb)
1012 {
1013         struct sk_buff *skb = *in_skb;
1014         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1015         u8 *header;
1016         int slot, old_top_slot, old_used_slots;
1017         int err;
1018         struct b43legacy_dmadesc32 *desc;
1019         struct b43legacy_dmadesc_meta *meta;
1020         struct b43legacy_dmadesc_meta *meta_hdr;
1021         struct sk_buff *bounce_skb;
1022
1023 #define SLOTS_PER_PACKET  2
1024         B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
1025
1026         old_top_slot = ring->current_slot;
1027         old_used_slots = ring->used_slots;
1028
1029         /* Get a slot for the header. */
1030         slot = request_slot(ring);
1031         desc = op32_idx2desc(ring, slot, &meta_hdr);
1032         memset(meta_hdr, 0, sizeof(*meta_hdr));
1033
1034         header = &(ring->txhdr_cache[slot * sizeof(
1035                                struct b43legacy_txhdr_fw3)]);
1036         err = b43legacy_generate_txhdr(ring->dev, header,
1037                                  skb->data, skb->len, info,
1038                                  generate_cookie(ring, slot));
1039         if (unlikely(err)) {
1040                 ring->current_slot = old_top_slot;
1041                 ring->used_slots = old_used_slots;
1042                 return err;
1043         }
1044
1045         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1046                                            sizeof(struct b43legacy_txhdr_fw3), 1);
1047         if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
1048                                         sizeof(struct b43legacy_txhdr_fw3), 1)) {
1049                 ring->current_slot = old_top_slot;
1050                 ring->used_slots = old_used_slots;
1051                 return -EIO;
1052         }
1053         op32_fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1054                              sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
1055
1056         /* Get a slot for the payload. */
1057         slot = request_slot(ring);
1058         desc = op32_idx2desc(ring, slot, &meta);
1059         memset(meta, 0, sizeof(*meta));
1060
1061         meta->skb = skb;
1062         meta->is_last_fragment = true;
1063
1064         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1065         /* create a bounce buffer in zone_dma on mapping failure. */
1066         if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1067                 bounce_skb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1068                 if (!bounce_skb) {
1069                         ring->current_slot = old_top_slot;
1070                         ring->used_slots = old_used_slots;
1071                         err = -ENOMEM;
1072                         goto out_unmap_hdr;
1073                 }
1074
1075                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1076                 memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
1077                 bounce_skb->dev = skb->dev;
1078                 skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
1079                 info = IEEE80211_SKB_CB(bounce_skb);
1080
1081                 dev_kfree_skb_any(skb);
1082                 skb = bounce_skb;
1083                 *in_skb = bounce_skb;
1084                 meta->skb = skb;
1085                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1086                 if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1087                         ring->current_slot = old_top_slot;
1088                         ring->used_slots = old_used_slots;
1089                         err = -EIO;
1090                         goto out_free_bounce;
1091                 }
1092         }
1093
1094         op32_fill_descriptor(ring, desc, meta->dmaaddr,
1095                              skb->len, 0, 1, 1);
1096
1097         wmb();  /* previous stuff MUST be done */
1098         /* Now transfer the whole frame. */
1099         op32_poke_tx(ring, next_slot(ring, slot));
1100         return 0;
1101
1102 out_free_bounce:
1103         dev_kfree_skb_any(skb);
1104 out_unmap_hdr:
1105         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1106                          sizeof(struct b43legacy_txhdr_fw3), 1);
1107         return err;
1108 }
1109
1110 static inline
1111 int should_inject_overflow(struct b43legacy_dmaring *ring)
1112 {
1113 #ifdef CONFIG_B43LEGACY_DEBUG
1114         if (unlikely(b43legacy_debug(ring->dev,
1115                                      B43legacy_DBG_DMAOVERFLOW))) {
1116                 /* Check if we should inject another ringbuffer overflow
1117                  * to test handling of this situation in the stack. */
1118                 unsigned long next_overflow;
1119
1120                 next_overflow = ring->last_injected_overflow + HZ;
1121                 if (time_after(jiffies, next_overflow)) {
1122                         ring->last_injected_overflow = jiffies;
1123                         b43legacydbg(ring->dev->wl,
1124                                "Injecting TX ring overflow on "
1125                                "DMA controller %d\n", ring->index);
1126                         return 1;
1127                 }
1128         }
1129 #endif /* CONFIG_B43LEGACY_DEBUG */
1130         return 0;
1131 }
1132
1133 int b43legacy_dma_tx(struct b43legacy_wldev *dev,
1134                      struct sk_buff *skb)
1135 {
1136         struct b43legacy_dmaring *ring;
1137         int err = 0;
1138
1139         ring = priority_to_txring(dev, skb_get_queue_mapping(skb));
1140         B43legacy_WARN_ON(!ring->tx);
1141
1142         if (unlikely(ring->stopped)) {
1143                 /* We get here only because of a bug in mac80211.
1144                  * Because of a race, one packet may be queued after
1145                  * the queue is stopped, thus we got called when we shouldn't.
1146                  * For now, just refuse the transmit. */
1147                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1148                         b43legacyerr(dev->wl, "Packet after queue stopped\n");
1149                 return -ENOSPC;
1150         }
1151
1152         if (unlikely(WARN_ON(free_slots(ring) < SLOTS_PER_PACKET))) {
1153                 /* If we get here, we have a real error with the queue
1154                  * full, but queues not stopped. */
1155                 b43legacyerr(dev->wl, "DMA queue overflow\n");
1156                 return -ENOSPC;
1157         }
1158
1159         /* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
1160          * into the skb data or cb now. */
1161         err = dma_tx_fragment(ring, &skb);
1162         if (unlikely(err == -ENOKEY)) {
1163                 /* Drop this packet, as we don't have the encryption key
1164                  * anymore and must not transmit it unencrypted. */
1165                 dev_kfree_skb_any(skb);
1166                 return 0;
1167         }
1168         if (unlikely(err)) {
1169                 b43legacyerr(dev->wl, "DMA tx mapping failure\n");
1170                 return err;
1171         }
1172         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1173             should_inject_overflow(ring)) {
1174                 /* This TX ring is full. */
1175                 unsigned int skb_mapping = skb_get_queue_mapping(skb);
1176                 ieee80211_stop_queue(dev->wl->hw, skb_mapping);
1177                 dev->wl->tx_queue_stopped[skb_mapping] = 1;
1178                 ring->stopped = true;
1179                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1180                         b43legacydbg(dev->wl, "Stopped TX ring %d\n",
1181                                ring->index);
1182         }
1183         return err;
1184 }
1185
1186 void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
1187                                  const struct b43legacy_txstatus *status)
1188 {
1189         struct b43legacy_dmaring *ring;
1190         struct b43legacy_dmadesc_meta *meta;
1191         int retry_limit;
1192         int slot;
1193         int firstused;
1194
1195         ring = parse_cookie(dev, status->cookie, &slot);
1196         if (unlikely(!ring))
1197                 return;
1198         B43legacy_WARN_ON(!ring->tx);
1199
1200         /* Sanity check: TX packets are processed in-order on one ring.
1201          * Check if the slot deduced from the cookie really is the first
1202          * used slot. */
1203         firstused = ring->current_slot - ring->used_slots + 1;
1204         if (firstused < 0)
1205                 firstused = ring->nr_slots + firstused;
1206         if (unlikely(slot != firstused)) {
1207                 /* This possibly is a firmware bug and will result in
1208                  * malfunction, memory leaks and/or stall of DMA functionality.
1209                  */
1210                 b43legacydbg(dev->wl, "Out of order TX status report on DMA "
1211                              "ring %d. Expected %d, but got %d\n",
1212                              ring->index, firstused, slot);
1213                 return;
1214         }
1215
1216         while (1) {
1217                 B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1218                 op32_idx2desc(ring, slot, &meta);
1219
1220                 if (meta->skb)
1221                         unmap_descbuffer(ring, meta->dmaaddr,
1222                                          meta->skb->len, 1);
1223                 else
1224                         unmap_descbuffer(ring, meta->dmaaddr,
1225                                          sizeof(struct b43legacy_txhdr_fw3),
1226                                          1);
1227
1228                 if (meta->is_last_fragment) {
1229                         struct ieee80211_tx_info *info;
1230                         BUG_ON(!meta->skb);
1231                         info = IEEE80211_SKB_CB(meta->skb);
1232
1233                         /* preserve the confiured retry limit before clearing the status
1234                          * The xmit function has overwritten the rc's value with the actual
1235                          * retry limit done by the hardware */
1236                         retry_limit = info->status.rates[0].count;
1237                         ieee80211_tx_info_clear_status(info);
1238
1239                         if (status->acked)
1240                                 info->flags |= IEEE80211_TX_STAT_ACK;
1241
1242                         if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
1243                                 /*
1244                                  * If the short retries (RTS, not data frame) have exceeded
1245                                  * the limit, the hw will not have tried the selected rate,
1246                                  * but will have used the fallback rate instead.
1247                                  * Don't let the rate control count attempts for the selected
1248                                  * rate in this case, otherwise the statistics will be off.
1249                                  */
1250                                 info->status.rates[0].count = 0;
1251                                 info->status.rates[1].count = status->frame_count;
1252                         } else {
1253                                 if (status->frame_count > retry_limit) {
1254                                         info->status.rates[0].count = retry_limit;
1255                                         info->status.rates[1].count = status->frame_count -
1256                                                         retry_limit;
1257
1258                                 } else {
1259                                         info->status.rates[0].count = status->frame_count;
1260                                         info->status.rates[1].idx = -1;
1261                                 }
1262                         }
1263
1264                         /* Call back to inform the ieee80211 subsystem about the
1265                          * status of the transmission.
1266                          * Some fields of txstat are already filled in dma_tx().
1267                          */
1268                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
1269                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1270                         meta->skb = NULL;
1271                 } else {
1272                         /* No need to call free_descriptor_buffer here, as
1273                          * this is only the txhdr, which is not allocated.
1274                          */
1275                         B43legacy_WARN_ON(meta->skb != NULL);
1276                 }
1277
1278                 /* Everything unmapped and free'd. So it's not used anymore. */
1279                 ring->used_slots--;
1280
1281                 if (meta->is_last_fragment)
1282                         break;
1283                 slot = next_slot(ring, slot);
1284         }
1285         dev->stats.last_tx = jiffies;
1286         if (ring->stopped) {
1287                 B43legacy_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1288                 ring->stopped = false;
1289         }
1290
1291         if (dev->wl->tx_queue_stopped[ring->queue_prio]) {
1292                 dev->wl->tx_queue_stopped[ring->queue_prio] = 0;
1293         } else {
1294                 /* If the driver queue is running wake the corresponding
1295                  * mac80211 queue. */
1296                 ieee80211_wake_queue(dev->wl->hw, ring->queue_prio);
1297                 if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1298                         b43legacydbg(dev->wl, "Woke up TX ring %d\n",
1299                                      ring->index);
1300         }
1301         /* Add work to the queue. */
1302         ieee80211_queue_work(dev->wl->hw, &dev->wl->tx_work);
1303 }
1304
1305 static void dma_rx(struct b43legacy_dmaring *ring,
1306                    int *slot)
1307 {
1308         struct b43legacy_dmadesc32 *desc;
1309         struct b43legacy_dmadesc_meta *meta;
1310         struct b43legacy_rxhdr_fw3 *rxhdr;
1311         struct sk_buff *skb;
1312         u16 len;
1313         int err;
1314         dma_addr_t dmaaddr;
1315
1316         desc = op32_idx2desc(ring, *slot, &meta);
1317
1318         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1319         skb = meta->skb;
1320
1321         if (ring->index == 3) {
1322                 /* We received an xmit status. */
1323                 struct b43legacy_hwtxstatus *hw =
1324                                 (struct b43legacy_hwtxstatus *)skb->data;
1325                 int i = 0;
1326
1327                 while (hw->cookie == 0) {
1328                         if (i > 100)
1329                                 break;
1330                         i++;
1331                         udelay(2);
1332                         barrier();
1333                 }
1334                 b43legacy_handle_hwtxstatus(ring->dev, hw);
1335                 /* recycle the descriptor buffer. */
1336                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1337                                            ring->rx_buffersize);
1338
1339                 return;
1340         }
1341         rxhdr = (struct b43legacy_rxhdr_fw3 *)skb->data;
1342         len = le16_to_cpu(rxhdr->frame_len);
1343         if (len == 0) {
1344                 int i = 0;
1345
1346                 do {
1347                         udelay(2);
1348                         barrier();
1349                         len = le16_to_cpu(rxhdr->frame_len);
1350                 } while (len == 0 && i++ < 5);
1351                 if (unlikely(len == 0)) {
1352                         /* recycle the descriptor buffer. */
1353                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1354                                                    ring->rx_buffersize);
1355                         goto drop;
1356                 }
1357         }
1358         if (unlikely(len > ring->rx_buffersize)) {
1359                 /* The data did not fit into one descriptor buffer
1360                  * and is split over multiple buffers.
1361                  * This should never happen, as we try to allocate buffers
1362                  * big enough. So simply ignore this packet.
1363                  */
1364                 int cnt = 0;
1365                 s32 tmp = len;
1366
1367                 while (1) {
1368                         desc = op32_idx2desc(ring, *slot, &meta);
1369                         /* recycle the descriptor buffer. */
1370                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1371                                                    ring->rx_buffersize);
1372                         *slot = next_slot(ring, *slot);
1373                         cnt++;
1374                         tmp -= ring->rx_buffersize;
1375                         if (tmp <= 0)
1376                                 break;
1377                 }
1378                 b43legacyerr(ring->dev->wl, "DMA RX buffer too small "
1379                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1380                        len, ring->rx_buffersize, cnt);
1381                 goto drop;
1382         }
1383
1384         dmaaddr = meta->dmaaddr;
1385         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1386         if (unlikely(err)) {
1387                 b43legacydbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer()"
1388                              " failed\n");
1389                 sync_descbuffer_for_device(ring, dmaaddr,
1390                                            ring->rx_buffersize);
1391                 goto drop;
1392         }
1393
1394         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1395         skb_put(skb, len + ring->frameoffset);
1396         skb_pull(skb, ring->frameoffset);
1397
1398         b43legacy_rx(ring->dev, skb, rxhdr);
1399 drop:
1400         return;
1401 }
1402
1403 void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
1404 {
1405         int slot;
1406         int current_slot;
1407         int used_slots = 0;
1408
1409         B43legacy_WARN_ON(ring->tx);
1410         current_slot = op32_get_current_rxslot(ring);
1411         B43legacy_WARN_ON(!(current_slot >= 0 && current_slot <
1412                            ring->nr_slots));
1413
1414         slot = ring->current_slot;
1415         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1416                 dma_rx(ring, &slot);
1417                 update_max_used_slots(ring, ++used_slots);
1418         }
1419         op32_set_current_rxslot(ring, slot);
1420         ring->current_slot = slot;
1421 }
1422
1423 static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1424 {
1425         B43legacy_WARN_ON(!ring->tx);
1426         op32_tx_suspend(ring);
1427 }
1428
1429 static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1430 {
1431         B43legacy_WARN_ON(!ring->tx);
1432         op32_tx_resume(ring);
1433 }
1434
1435 void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
1436 {
1437         b43legacy_power_saving_ctl_bits(dev, -1, 1);
1438         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring0);
1439         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring1);
1440         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring2);
1441         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring3);
1442         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring4);
1443         b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring5);
1444 }
1445
1446 void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
1447 {
1448         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring5);
1449         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring4);
1450         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring3);
1451         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring2);
1452         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring1);
1453         b43legacy_dma_tx_resume_ring(dev->dma.tx_ring0);
1454         b43legacy_power_saving_ctl_bits(dev, -1, -1);
1455 }