linux/drivers/net/wireless/broadcom/b43legacy/dma.c
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   1/*
   2
   3  Broadcom B43legacy wireless driver
   4
   5  DMA ringbuffer and descriptor allocation/management
   6
   7  Copyright (c) 2005, 2006 Michael Buesch <m@bues.ch>
   8
   9  Some code in this file is derived from the b44.c driver
  10  Copyright (C) 2002 David S. Miller
  11  Copyright (C) Pekka Pietikainen
  12
  13  This program is free software; you can redistribute it and/or modify
  14  it under the terms of the GNU General Public License as published by
  15  the Free Software Foundation; either version 2 of the License, or
  16  (at your option) any later version.
  17
  18  This program is distributed in the hope that it will be useful,
  19  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  GNU General Public License for more details.
  22
  23  You should have received a copy of the GNU General Public License
  24  along with this program; see the file COPYING.  If not, write to
  25  the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  26  Boston, MA 02110-1301, USA.
  27
  28*/
  29
  30#include "b43legacy.h"
  31#include "dma.h"
  32#include "main.h"
  33#include "debugfs.h"
  34#include "xmit.h"
  35
  36#include <linux/dma-mapping.h>
  37#include <linux/pci.h>
  38#include <linux/delay.h>
  39#include <linux/skbuff.h>
  40#include <linux/slab.h>
  41#include <net/dst.h>
  42
  43/* 32bit DMA ops. */
  44static
  45struct 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
  58static 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
  93static 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
  99static 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
 106static 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
 113static 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
 123static 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
 130static inline int free_slots(struct b43legacy_dmaring *ring)
 131{
 132        return (ring->nr_slots - ring->used_slots);
 133}
 134
 135static 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
 143static 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
 152static 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
 166static inline
 167void update_max_used_slots(struct b43legacy_dmaring *ring,
 168                           int current_used_slots)
 169{ }
 170#endif /* DEBUG */
 171
 172/* Request a slot for usage. */
 173static inline
 174int 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 */
 192static 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 */
 199return 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 */
 230static 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 */
 236return 0;
 237
 238        return idx_to_prio[ring->index];
 239}
 240
 241
 242static 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
 259static inline
 260dma_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
 279static inline
 280void 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
 295static inline
 296void 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
 306static inline
 307void 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
 317static inline
 318void 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
 331static 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
 343static 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 */
 350static 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 */
 381static 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. */
 424static 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 true;
 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 false;
 445
 446address_error:
 447        /* We can't support this address. Unmap it again. */
 448        unmap_descbuffer(ring, addr, buffersize, dma_to_device);
 449
 450        return true;
 451}
 452
 453static 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 */
 503static 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;
 523out:
 524        return err;
 525
 526err_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 */
 540static 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
 577out:
 578        return err;
 579}
 580
 581/* Shutdown the DMA controller. */
 582static 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
 595static 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
 619static 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
 636static 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. */
 647static
 648struct 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
 736out:
 737        return ring;
 738
 739err_free_ringmemory:
 740        free_ringmemory(ring);
 741err_kfree_txhdr_cache:
 742        kfree(ring->txhdr_cache);
 743err_kfree_meta:
 744        kfree(ring->meta);
 745err_kfree_ring:
 746        kfree(ring);
 747        ring = NULL;
 748        goto out;
 749}
 750
 751/* Main cleanup function. */
 752static 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
 773void 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
 800static 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
 837int 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;
 909out:
 910        return err;
 911
 912err_destroy_rx0:
 913        b43legacy_destroy_dmaring(dma->rx_ring0);
 914        dma->rx_ring0 = NULL;
 915err_destroy_tx5:
 916        b43legacy_destroy_dmaring(dma->tx_ring5);
 917        dma->tx_ring5 = NULL;
 918err_destroy_tx4:
 919        b43legacy_destroy_dmaring(dma->tx_ring4);
 920        dma->tx_ring4 = NULL;
 921err_destroy_tx3:
 922        b43legacy_destroy_dmaring(dma->tx_ring3);
 923        dma->tx_ring3 = NULL;
 924err_destroy_tx2:
 925        b43legacy_destroy_dmaring(dma->tx_ring2);
 926        dma->tx_ring2 = NULL;
 927err_destroy_tx1:
 928        b43legacy_destroy_dmaring(dma->tx_ring1);
 929        dma->tx_ring1 = NULL;
 930err_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. */
 937static 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. */
 975static
 976struct 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
1010static 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
1102out_free_bounce:
1103        dev_kfree_skb_any(skb);
1104out_unmap_hdr:
1105        unmap_descbuffer(ring, meta_hdr->dmaaddr,
1106                         sizeof(struct b43legacy_txhdr_fw3), 1);
1107        return err;
1108}
1109
1110static inline
1111int 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
1133int 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
1186void 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
1305static 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);
1399drop:
1400        return;
1401}
1402
1403void 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
1423static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1424{
1425        B43legacy_WARN_ON(!ring->tx);
1426        op32_tx_suspend(ring);
1427}
1428
1429static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1430{
1431        B43legacy_WARN_ON(!ring->tx);
1432        op32_tx_resume(ring);
1433}
1434
1435void 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
1446void 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}
1456