SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/net/wireless/bcm43xx/bcm43xx_dma.c

   1 /*
   2
   3   Broadcom BCM43xx wireless driver
   4
   5   DMA ringbuffer and descriptor allocation/management
   6
   7   Copyright (c) 2005 Michael Buesch <mbuesch@freenet.de>
   8
   9   Some code in this file is derived from the b44.c driver
  10   Copyright (C) 2002 David S. Miller
  11   Copyright (C) Pekka Pietikainen
  12
  13   This program is free software; you can redistribute it and/or modify
  14   it under the terms of the GNU General Public License as published by
  15   the Free Software Foundation; either version 2 of the License, or
  16   (at your option) any later version.
  17
  18   This program is distributed in the hope that it will be useful,
  19   but WITHOUT ANY WARRANTY; without even the implied warranty of
  20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21   GNU General Public License for more details.
  22
  23   You should have received a copy of the GNU General Public License
  24   along with this program; see the file COPYING.  If not, write to
  25   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
  26   Boston, MA 02110-1301, USA.
  27
  28 */
  29
  30 #include "bcm43xx.h"
  31 #include "bcm43xx_dma.h"
  32 #include "bcm43xx_main.h"
  33 #include "bcm43xx_debugfs.h"
  34 #include "bcm43xx_power.h"
  35 #include "bcm43xx_xmit.h"
  36
  37 #include <linux/dmapool.h>
  38 #include <linux/pci.h>
  39 #include <linux/delay.h>
  40 #include <linux/skbuff.h>
  41 #include <asm/semaphore.h>
  42
  43
  44 static inline int free_slots(struct bcm43xx_dmaring *ring)
  45 {
  46         return (ring->nr_slots - ring->used_slots);
  47 }
  48
  49 static inline int next_slot(struct bcm43xx_dmaring *ring, int slot)
  50 {
  51         assert(slot >= -1 && slot <= ring->nr_slots - 1);
  52         if (slot == ring->nr_slots - 1)
  53                 return 0;
  54         return slot + 1;
  55 }
  56
  57 static inline int prev_slot(struct bcm43xx_dmaring *ring, int slot)
  58 {
  59         assert(slot >= 0 && slot <= ring->nr_slots - 1);
  60         if (slot == 0)
  61                 return ring->nr_slots - 1;
  62         return slot - 1;
  63 }
  64
  65 /* Request a slot for usage. */
  66 static inline
  67 int request_slot(struct bcm43xx_dmaring *ring)
  68 {
  69         int slot;
  70
  71         assert(ring->tx);
  72         assert(!ring->suspended);
  73         assert(free_slots(ring) != 0);
  74
  75         slot = next_slot(ring, ring->current_slot);
  76         ring->current_slot = slot;
  77         ring->used_slots++;
  78
  79         /* Check the number of available slots and suspend TX,
  80          * if we are running low on free slots.
  81          */
  82         if (unlikely(free_slots(ring) < ring->suspend_mark)) {
  83                 netif_stop_queue(ring->bcm->net_dev);
  84                 ring->suspended = 1;
  85         }
  86 #ifdef CONFIG_BCM43XX_DEBUG
  87         if (ring->used_slots > ring->max_used_slots)
  88                 ring->max_used_slots = ring->used_slots;
  89 #endif /* CONFIG_BCM43XX_DEBUG*/
  90
  91         return slot;
  92 }
  93
  94 /* Return a slot to the free slots. */
  95 static inline
  96 void return_slot(struct bcm43xx_dmaring *ring, int slot)
  97 {
  98         assert(ring->tx);
  99
 100         ring->used_slots--;
 101
 102         /* Check if TX is suspended and check if we have
 103          * enough free slots to resume it again.
 104          */
 105         if (unlikely(ring->suspended)) {
 106                 if (free_slots(ring) >= ring->resume_mark) {
 107                         ring->suspended = 0;
 108                         netif_wake_queue(ring->bcm->net_dev);
 109                 }
 110         }
 111 }
 112
 113 static inline
 114 dma_addr_t map_descbuffer(struct bcm43xx_dmaring *ring,
 115                           unsigned char *buf,
 116                           size_t len,
 117                           int tx)
 118 {
 119         dma_addr_t dmaaddr;
 120
 121         if (tx) {
 122                 dmaaddr = dma_map_single(&ring->bcm->pci_dev->dev,
 123                                          buf, len,
 124                                          DMA_TO_DEVICE);
 125         } else {
 126                 dmaaddr = dma_map_single(&ring->bcm->pci_dev->dev,
 127                                          buf, len,
 128                                          DMA_FROM_DEVICE);
 129         }
 130
 131         return dmaaddr;
 132 }
 133
 134 static inline
 135 void unmap_descbuffer(struct bcm43xx_dmaring *ring,
 136                       dma_addr_t addr,
 137                       size_t len,
 138                       int tx)
 139 {
 140         if (tx) {
 141                 dma_unmap_single(&ring->bcm->pci_dev->dev,
 142                                  addr, len,
 143                                  DMA_TO_DEVICE);
 144         } else {
 145                 dma_unmap_single(&ring->bcm->pci_dev->dev,
 146                                  addr, len,
 147                                  DMA_FROM_DEVICE);
 148         }
 149 }
 150
 151 static inline
 152 void sync_descbuffer_for_cpu(struct bcm43xx_dmaring *ring,
 153                              dma_addr_t addr,
 154                              size_t len)
 155 {
 156         assert(!ring->tx);
 157
 158         dma_sync_single_for_cpu(&ring->bcm->pci_dev->dev,
 159                                 addr, len, DMA_FROM_DEVICE);
 160 }
 161
 162 static inline
 163 void sync_descbuffer_for_device(struct bcm43xx_dmaring *ring,
 164                                 dma_addr_t addr,
 165                                 size_t len)
 166 {
 167         assert(!ring->tx);
 168
 169         dma_sync_single_for_device(&ring->bcm->pci_dev->dev,
 170                                    addr, len, DMA_FROM_DEVICE);
 171 }
 172
 173 /* Unmap and free a descriptor buffer. */
 174 static inline
 175 void free_descriptor_buffer(struct bcm43xx_dmaring *ring,
 176                             struct bcm43xx_dmadesc *desc,
 177                             struct bcm43xx_dmadesc_meta *meta,
 178                             int irq_context)
 179 {
 180         assert(meta->skb);
 181         if (irq_context)
 182                 dev_kfree_skb_irq(meta->skb);
 183         else
 184                 dev_kfree_skb(meta->skb);
 185         meta->skb = NULL;
 186 }
 187
 188 static int alloc_ringmemory(struct bcm43xx_dmaring *ring)
 189 {
 190         struct device *dev = &(ring->bcm->pci_dev->dev);
 191
 192         ring->vbase = dma_alloc_coherent(dev, BCM43xx_DMA_RINGMEMSIZE,
 193                                          &(ring->dmabase), GFP_KERNEL);
 194         if (!ring->vbase) {
 195                 printk(KERN_ERR PFX "DMA ringmemory allocation failed\n");
 196                 return -ENOMEM;
 197         }
 198         if (ring->dmabase + BCM43xx_DMA_RINGMEMSIZE > BCM43xx_DMA_BUSADDRMAX) {
 199                 printk(KERN_ERR PFX ">>>FATAL ERROR<<<  DMA RINGMEMORY >1G "
 200                                     "(0x%08x, len: %lu)\n",
 201                        ring->dmabase, BCM43xx_DMA_RINGMEMSIZE);
 202                 dma_free_coherent(dev, BCM43xx_DMA_RINGMEMSIZE,
 203                                   ring->vbase, ring->dmabase);
 204                 return -ENOMEM;
 205         }
 206         assert(!(ring->dmabase & 0x000003FF));
 207         memset(ring->vbase, 0, BCM43xx_DMA_RINGMEMSIZE);
 208
 209         return 0;
 210 }
 211
 212 static void free_ringmemory(struct bcm43xx_dmaring *ring)
 213 {
 214         struct device *dev = &(ring->bcm->pci_dev->dev);
 215
 216         dma_free_coherent(dev, BCM43xx_DMA_RINGMEMSIZE,
 217                           ring->vbase, ring->dmabase);
 218 }
 219
 220 /* Reset the RX DMA channel */
 221 int bcm43xx_dmacontroller_rx_reset(struct bcm43xx_private *bcm,
 222                                    u16 mmio_base)
 223 {
 224         int i;
 225         u32 value;
 226
 227         bcm43xx_write32(bcm,
 228                         mmio_base + BCM43xx_DMA_RX_CONTROL,
 229                         0x00000000);
 230         for (i = 0; i < 1000; i++) {
 231                 value = bcm43xx_read32(bcm,
 232                                        mmio_base + BCM43xx_DMA_RX_STATUS);
 233                 value &= BCM43xx_DMA_RXSTAT_STAT_MASK;
 234                 if (value == BCM43xx_DMA_RXSTAT_STAT_DISABLED) {
 235                         i = -1;
 236                         break;
 237                 }
 238                 udelay(10);
 239         }
 240         if (i != -1) {
 241                 printk(KERN_ERR PFX "Error: Wait on DMA RX status timed out.\n");
 242                 return -ENODEV;
 243         }
 244
 245         return 0;
 246 }
 247
 248 /* Reset the RX DMA channel */
 249 int bcm43xx_dmacontroller_tx_reset(struct bcm43xx_private *bcm,
 250                                    u16 mmio_base)
 251 {
 252         int i;
 253         u32 value;
 254
 255         for (i = 0; i < 1000; i++) {
 256                 value = bcm43xx_read32(bcm,
 257                                        mmio_base + BCM43xx_DMA_TX_STATUS);
 258                 value &= BCM43xx_DMA_TXSTAT_STAT_MASK;
 259                 if (value == BCM43xx_DMA_TXSTAT_STAT_DISABLED ||
 260                     value == BCM43xx_DMA_TXSTAT_STAT_IDLEWAIT ||
 261                     value == BCM43xx_DMA_TXSTAT_STAT_STOPPED)
 262                         break;
 263                 udelay(10);
 264         }
 265         bcm43xx_write32(bcm,
 266                         mmio_base + BCM43xx_DMA_TX_CONTROL,
 267                         0x00000000);
 268         for (i = 0; i < 1000; i++) {
 269                 value = bcm43xx_read32(bcm,
 270                                        mmio_base + BCM43xx_DMA_TX_STATUS);
 271                 value &= BCM43xx_DMA_TXSTAT_STAT_MASK;
 272                 if (value == BCM43xx_DMA_TXSTAT_STAT_DISABLED) {
 273                         i = -1;
 274                         break;
 275                 }
 276                 udelay(10);
 277         }
 278         if (i != -1) {
 279                 printk(KERN_ERR PFX "Error: Wait on DMA TX status timed out.\n");
 280                 return -ENODEV;
 281         }
 282         /* ensure the reset is completed. */
 283         udelay(300);
 284
 285         return 0;
 286 }
 287
 288 static int setup_rx_descbuffer(struct bcm43xx_dmaring *ring,
 289                                struct bcm43xx_dmadesc *desc,
 290                                struct bcm43xx_dmadesc_meta *meta,
 291                                gfp_t gfp_flags)
 292 {
 293         struct bcm43xx_rxhdr *rxhdr;
 294         dma_addr_t dmaaddr;
 295         u32 desc_addr;
 296         u32 desc_ctl;
 297         const int slot = (int)(desc - ring->vbase);
 298         struct sk_buff *skb;
 299
 300         assert(slot >= 0 && slot < ring->nr_slots);
 301         assert(!ring->tx);
 302
 303         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
 304         if (unlikely(!skb))
 305                 return -ENOMEM;
 306         dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
 307         if (unlikely(dmaaddr + ring->rx_buffersize > BCM43xx_DMA_BUSADDRMAX)) {
 308                 unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
 309                 dev_kfree_skb_any(skb);
 310                 printk(KERN_ERR PFX ">>>FATAL ERROR<<<  DMA RX SKB >1G "
 311                                     "(0x%08x, len: %u)\n",
 312                        dmaaddr, ring->rx_buffersize);
 313                 return -ENOMEM;
 314         }
 315         meta->skb = skb;
 316         meta->dmaaddr = dmaaddr;
 317         skb->dev = ring->bcm->net_dev;
 318         desc_addr = (u32)(dmaaddr + ring->memoffset);
 319         desc_ctl = (BCM43xx_DMADTOR_BYTECNT_MASK &
 320                     (u32)(ring->rx_buffersize - ring->frameoffset));
 321         if (slot == ring->nr_slots - 1)
 322                 desc_ctl |= BCM43xx_DMADTOR_DTABLEEND;
 323         set_desc_addr(desc, desc_addr);
 324         set_desc_ctl(desc, desc_ctl);
 325
 326         rxhdr = (struct bcm43xx_rxhdr *)(skb->data);
 327         rxhdr->frame_length = 0;
 328         rxhdr->flags1 = 0;
 329
 330         return 0;
 331 }
 332
 333 /* Allocate the initial descbuffers.
 334  * This is used for an RX ring only.
 335  */
 336 static int alloc_initial_descbuffers(struct bcm43xx_dmaring *ring)
 337 {
 338         int i, err = -ENOMEM;
 339         struct bcm43xx_dmadesc *desc;
 340         struct bcm43xx_dmadesc_meta *meta;
 341
 342         for (i = 0; i < ring->nr_slots; i++) {
 343                 desc = ring->vbase + i;
 344                 meta = ring->meta + i;
 345
 346                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
 347                 if (err)
 348                         goto err_unwind;
 349         }
 350         ring->used_slots = ring->nr_slots;
 351         err = 0;
 352 out:
 353         return err;
 354
 355 err_unwind:
 356         for (i--; i >= 0; i--) {
 357                 desc = ring->vbase + i;
 358                 meta = ring->meta + i;
 359
 360                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
 361                 dev_kfree_skb(meta->skb);
 362         }
 363         goto out;
 364 }
 365
 366 /* Do initial setup of the DMA controller.
 367  * Reset the controller, write the ring busaddress
 368  * and switch the "enable" bit on.
 369  */
 370 static int dmacontroller_setup(struct bcm43xx_dmaring *ring)
 371 {
 372         int err = 0;
 373         u32 value;
 374
 375         if (ring->tx) {
 376                 /* Set Transmit Control register to "transmit enable" */
 377                 bcm43xx_dma_write(ring, BCM43xx_DMA_TX_CONTROL,
 378                                   BCM43xx_DMA_TXCTRL_ENABLE);
 379                 /* Set Transmit Descriptor ring address. */
 380                 bcm43xx_dma_write(ring, BCM43xx_DMA_TX_DESC_RING,
 381                                   ring->dmabase + ring->memoffset);
 382         } else {
 383                 err = alloc_initial_descbuffers(ring);
 384                 if (err)
 385                         goto out;
 386                 /* Set Receive Control "receive enable" and frame offset */
 387                 value = (ring->frameoffset << BCM43xx_DMA_RXCTRL_FRAMEOFF_SHIFT);
 388                 value |= BCM43xx_DMA_RXCTRL_ENABLE;
 389                 bcm43xx_dma_write(ring, BCM43xx_DMA_RX_CONTROL, value);
 390                 /* Set Receive Descriptor ring address. */
 391                 bcm43xx_dma_write(ring, BCM43xx_DMA_RX_DESC_RING,
 392                                   ring->dmabase + ring->memoffset);
 393                 /* Init the descriptor pointer. */
 394                 bcm43xx_dma_write(ring, BCM43xx_DMA_RX_DESC_INDEX, 200);
 395         }
 396
 397 out:
 398         return err;
 399 }
 400
 401 /* Shutdown the DMA controller. */
 402 static void dmacontroller_cleanup(struct bcm43xx_dmaring *ring)
 403 {
 404         if (ring->tx) {
 405                 bcm43xx_dmacontroller_tx_reset(ring->bcm, ring->mmio_base);
 406                 /* Zero out Transmit Descriptor ring address. */
 407                 bcm43xx_dma_write(ring, BCM43xx_DMA_TX_DESC_RING, 0);
 408         } else {
 409                 bcm43xx_dmacontroller_rx_reset(ring->bcm, ring->mmio_base);
 410                 /* Zero out Receive Descriptor ring address. */
 411                 bcm43xx_dma_write(ring, BCM43xx_DMA_RX_DESC_RING, 0);
 412         }
 413 }
 414
 415 static void free_all_descbuffers(struct bcm43xx_dmaring *ring)
 416 {
 417         struct bcm43xx_dmadesc *desc;
 418         struct bcm43xx_dmadesc_meta *meta;
 419         int i;
 420
 421         if (!ring->used_slots)
 422                 return;
 423         for (i = 0; i < ring->nr_slots; i++) {
 424                 desc = ring->vbase + i;
 425                 meta = ring->meta + i;
 426
 427                 if (!meta->skb) {
 428                         assert(ring->tx);
 429                         continue;
 430                 }
 431                 if (ring->tx) {
 432                         unmap_descbuffer(ring, meta->dmaaddr,
 433                                          meta->skb->len, 1);
 434                 } else {
 435                         unmap_descbuffer(ring, meta->dmaaddr,
 436                                          ring->rx_buffersize, 0);
 437                 }
 438                 free_descriptor_buffer(ring, desc, meta, 0);
 439         }
 440 }
 441
 442 /* Main initialization function. */
 443 static
 444 struct bcm43xx_dmaring * bcm43xx_setup_dmaring(struct bcm43xx_private *bcm,
 445                                                u16 dma_controller_base,
 446                                                int nr_descriptor_slots,
 447                                                int tx)
 448 {
 449         struct bcm43xx_dmaring *ring;
 450         int err;
 451
 452         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 453         if (!ring)
 454                 goto out;
 455
 456         ring->meta = kzalloc(sizeof(*ring->meta) * nr_descriptor_slots,
 457                              GFP_KERNEL);
 458         if (!ring->meta)
 459                 goto err_kfree_ring;
 460
 461         ring->memoffset = BCM43xx_DMA_DMABUSADDROFFSET;
 462 #ifdef CONFIG_BCM947XX
 463         if (bcm->pci_dev->bus->number == 0)
 464                 ring->memoffset = 0;
 465 #endif
 466
 467         ring->bcm = bcm;
 468         ring->nr_slots = nr_descriptor_slots;
 469         ring->suspend_mark = ring->nr_slots * BCM43xx_TXSUSPEND_PERCENT / 100;
 470         ring->resume_mark = ring->nr_slots * BCM43xx_TXRESUME_PERCENT / 100;
 471         assert(ring->suspend_mark < ring->resume_mark);
 472         ring->mmio_base = dma_controller_base;
 473         if (tx) {
 474                 ring->tx = 1;
 475                 ring->current_slot = -1;
 476         } else {
 477                 switch (dma_controller_base) {
 478                 case BCM43xx_MMIO_DMA1_BASE:
 479                         ring->rx_buffersize = BCM43xx_DMA1_RXBUFFERSIZE;
 480                         ring->frameoffset = BCM43xx_DMA1_RX_FRAMEOFFSET;
 481                         break;
 482                 case BCM43xx_MMIO_DMA4_BASE:
 483                         ring->rx_buffersize = BCM43xx_DMA4_RXBUFFERSIZE;
 484                         ring->frameoffset = BCM43xx_DMA4_RX_FRAMEOFFSET;
 485                         break;
 486                 default:
 487                         assert(0);
 488                 }
 489         }
 490
 491         err = alloc_ringmemory(ring);
 492         if (err)
 493                 goto err_kfree_meta;
 494         err = dmacontroller_setup(ring);
 495         if (err)
 496                 goto err_free_ringmemory;
 497
 498 out:
 499         return ring;
 500
 501 err_free_ringmemory:
 502         free_ringmemory(ring);
 503 err_kfree_meta:
 504         kfree(ring->meta);
 505 err_kfree_ring:
 506         kfree(ring);
 507         ring = NULL;
 508         goto out;
 509 }
 510
 511 /* Main cleanup function. */
 512 static void bcm43xx_destroy_dmaring(struct bcm43xx_dmaring *ring)
 513 {
 514         if (!ring)
 515                 return;
 516
 517         dprintk(KERN_INFO PFX "DMA 0x%04x (%s) max used slots: %d/%d\n",
 518                 ring->mmio_base,
 519                 (ring->tx) ? "TX" : "RX",
 520                 ring->max_used_slots, ring->nr_slots);
 521         /* Device IRQs are disabled prior entering this function,
 522          * so no need to take care of concurrency with rx handler stuff.
 523          */
 524         dmacontroller_cleanup(ring);
 525         free_all_descbuffers(ring);
 526         free_ringmemory(ring);
 527
 528         kfree(ring->meta);
 529         kfree(ring);
 530 }
 531
 532 void bcm43xx_dma_free(struct bcm43xx_private *bcm)
 533 {
 534         struct bcm43xx_dma *dma = bcm43xx_current_dma(bcm);
 535
 536         bcm43xx_destroy_dmaring(dma->rx_ring1);
 537         dma->rx_ring1 = NULL;
 538         bcm43xx_destroy_dmaring(dma->rx_ring0);
 539         dma->rx_ring0 = NULL;
 540         bcm43xx_destroy_dmaring(dma->tx_ring3);
 541         dma->tx_ring3 = NULL;
 542         bcm43xx_destroy_dmaring(dma->tx_ring2);
 543         dma->tx_ring2 = NULL;
 544         bcm43xx_destroy_dmaring(dma->tx_ring1);
 545         dma->tx_ring1 = NULL;
 546         bcm43xx_destroy_dmaring(dma->tx_ring0);
 547         dma->tx_ring0 = NULL;
 548 }
 549
 550 int bcm43xx_dma_init(struct bcm43xx_private *bcm)
 551 {
 552         struct bcm43xx_dma *dma = bcm43xx_current_dma(bcm);
 553         struct bcm43xx_dmaring *ring;
 554         int err = -ENOMEM;
 555
 556         /* setup TX DMA channels. */
 557         ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA1_BASE,
 558                                      BCM43xx_TXRING_SLOTS, 1);
 559         if (!ring)
 560                 goto out;
 561         dma->tx_ring0 = ring;
 562
 563         ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA2_BASE,
 564                                      BCM43xx_TXRING_SLOTS, 1);
 565         if (!ring)
 566                 goto err_destroy_tx0;
 567         dma->tx_ring1 = ring;
 568
 569         ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA3_BASE,
 570                                      BCM43xx_TXRING_SLOTS, 1);
 571         if (!ring)
 572                 goto err_destroy_tx1;
 573         dma->tx_ring2 = ring;
 574
 575         ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA4_BASE,
 576                                      BCM43xx_TXRING_SLOTS, 1);
 577         if (!ring)
 578                 goto err_destroy_tx2;
 579         dma->tx_ring3 = ring;
 580
 581         /* setup RX DMA channels. */
 582         ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA1_BASE,
 583                                      BCM43xx_RXRING_SLOTS, 0);
 584         if (!ring)
 585                 goto err_destroy_tx3;
 586         dma->rx_ring0 = ring;
 587
 588         if (bcm->current_core->rev < 5) {
 589                 ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA4_BASE,
 590                                              BCM43xx_RXRING_SLOTS, 0);
 591                 if (!ring)
 592                         goto err_destroy_rx0;
 593                 dma->rx_ring1 = ring;
 594         }
 595
 596         dprintk(KERN_INFO PFX "DMA initialized\n");
 597         err = 0;
 598 out:
 599         return err;
 600
 601 err_destroy_rx0:
 602         bcm43xx_destroy_dmaring(dma->rx_ring0);
 603         dma->rx_ring0 = NULL;
 604 err_destroy_tx3:
 605         bcm43xx_destroy_dmaring(dma->tx_ring3);
 606         dma->tx_ring3 = NULL;
 607 err_destroy_tx2:
 608         bcm43xx_destroy_dmaring(dma->tx_ring2);
 609         dma->tx_ring2 = NULL;
 610 err_destroy_tx1:
 611         bcm43xx_destroy_dmaring(dma->tx_ring1);
 612         dma->tx_ring1 = NULL;
 613 err_destroy_tx0:
 614         bcm43xx_destroy_dmaring(dma->tx_ring0);
 615         dma->tx_ring0 = NULL;
 616         goto out;
 617 }
 618
 619 /* Generate a cookie for the TX header. */
 620 static u16 generate_cookie(struct bcm43xx_dmaring *ring,
 621                            int slot)
 622 {
 623         u16 cookie = 0x0000;
 624
 625         /* Use the upper 4 bits of the cookie as
 626          * DMA controller ID and store the slot number
 627          * in the lower 12 bits
 628          */
 629         switch (ring->mmio_base) {
 630         default:
 631                 assert(0);
 632         case BCM43xx_MMIO_DMA1_BASE:
 633                 break;
 634         case BCM43xx_MMIO_DMA2_BASE:
 635                 cookie = 0x1000;
 636                 break;
 637         case BCM43xx_MMIO_DMA3_BASE:
 638                 cookie = 0x2000;
 639                 break;
 640         case BCM43xx_MMIO_DMA4_BASE:
 641                 cookie = 0x3000;
 642                 break;
 643         }
 644         assert(((u16)slot & 0xF000) == 0x0000);
 645         cookie |= (u16)slot;
 646
 647         return cookie;
 648 }
 649
 650 /* Inspect a cookie and find out to which controller/slot it belongs. */
 651 static
 652 struct bcm43xx_dmaring * parse_cookie(struct bcm43xx_private *bcm,
 653                                       u16 cookie, int *slot)
 654 {
 655         struct bcm43xx_dma *dma = bcm43xx_current_dma(bcm);
 656         struct bcm43xx_dmaring *ring = NULL;
 657
 658         switch (cookie & 0xF000) {
 659         case 0x0000:
 660                 ring = dma->tx_ring0;
 661                 break;
 662         case 0x1000:
 663                 ring = dma->tx_ring1;
 664                 break;
 665         case 0x2000:
 666                 ring = dma->tx_ring2;
 667                 break;
 668         case 0x3000:
 669                 ring = dma->tx_ring3;
 670                 break;
 671         default:
 672                 assert(0);
 673         }
 674         *slot = (cookie & 0x0FFF);
 675         assert(*slot >= 0 && *slot < ring->nr_slots);
 676
 677         return ring;
 678 }
 679
 680 static void dmacontroller_poke_tx(struct bcm43xx_dmaring *ring,
 681                                   int slot)
 682 {
 683         /* Everything is ready to start. Buffers are DMA mapped and
 684          * associated with slots.
 685          * "slot" is the last slot of the new frame we want to transmit.
 686          * Close your seat belts now, please.
 687          */
 688         wmb();
 689         slot = next_slot(ring, slot);
 690         bcm43xx_dma_write(ring, BCM43xx_DMA_TX_DESC_INDEX,
 691                           (u32)(slot * sizeof(struct bcm43xx_dmadesc)));
 692 }
 693
 694 static int dma_tx_fragment(struct bcm43xx_dmaring *ring,
 695                            struct sk_buff *skb,
 696                            u8 cur_frag)
 697 {
 698         int slot;
 699         struct bcm43xx_dmadesc *desc;
 700         struct bcm43xx_dmadesc_meta *meta;
 701         u32 desc_ctl;
 702         u32 desc_addr;
 703
 704         assert(skb_shinfo(skb)->nr_frags == 0);
 705
 706         slot = request_slot(ring);
 707         desc = ring->vbase + slot;
 708         meta = ring->meta + slot;
 709
 710         /* Add a device specific TX header. */
 711         assert(skb_headroom(skb) >= sizeof(struct bcm43xx_txhdr));
 712         /* Reserve enough headroom for the device tx header. */
 713         __skb_push(skb, sizeof(struct bcm43xx_txhdr));
 714         /* Now calculate and add the tx header.
 715          * The tx header includes the PLCP header.
 716          */
 717         bcm43xx_generate_txhdr(ring->bcm,
 718                                (struct bcm43xx_txhdr *)skb->data,
 719                                skb->data + sizeof(struct bcm43xx_txhdr),
 720                                skb->len - sizeof(struct bcm43xx_txhdr),
 721                                (cur_frag == 0),
 722                                generate_cookie(ring, slot));
 723
 724         meta->skb = skb;
 725         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
 726         if (unlikely(meta->dmaaddr + skb->len > BCM43xx_DMA_BUSADDRMAX)) {
 727                 return_slot(ring, slot);
 728                 printk(KERN_ERR PFX ">>>FATAL ERROR<<<  DMA TX SKB >1G "
 729                                     "(0x%08x, len: %u)\n",
 730                        meta->dmaaddr, skb->len);
 731                 return -ENOMEM;
 732         }
 733
 734         desc_addr = (u32)(meta->dmaaddr + ring->memoffset);
 735         desc_ctl = BCM43xx_DMADTOR_FRAMESTART | BCM43xx_DMADTOR_FRAMEEND;
 736         desc_ctl |= BCM43xx_DMADTOR_COMPIRQ;
 737         desc_ctl |= (BCM43xx_DMADTOR_BYTECNT_MASK &
 738                      (u32)(meta->skb->len - ring->frameoffset));
 739         if (slot == ring->nr_slots - 1)
 740                 desc_ctl |= BCM43xx_DMADTOR_DTABLEEND;
 741
 742         set_desc_ctl(desc, desc_ctl);
 743         set_desc_addr(desc, desc_addr);
 744         /* Now transfer the whole frame. */
 745         dmacontroller_poke_tx(ring, slot);
 746
 747         return 0;
 748 }
 749
 750 int bcm43xx_dma_tx(struct bcm43xx_private *bcm,
 751                    struct ieee80211_txb *txb)
 752 {
 753         /* We just received a packet from the kernel network subsystem.
 754          * Add headers and DMA map the memory. Poke
 755          * the device to send the stuff.
 756          * Note that this is called from atomic context.
 757          */
 758         struct bcm43xx_dmaring *ring = bcm43xx_current_dma(bcm)->tx_ring1;
 759         u8 i;
 760         struct sk_buff *skb;
 761
 762         assert(ring->tx);
 763         if (unlikely(free_slots(ring) < txb->nr_frags)) {
 764                 /* The queue should be stopped,
 765                  * if we are low on free slots.
 766                  * If this ever triggers, we have to lower the suspend_mark.
 767                  */
 768                 dprintkl(KERN_ERR PFX "Out of DMA descriptor slots!\n");
 769                 return -ENOMEM;
 770         }
 771
 772         for (i = 0; i < txb->nr_frags; i++) {
 773                 skb = txb->fragments[i];
 774                 /* Take skb from ieee80211_txb_free */
 775                 txb->fragments[i] = NULL;
 776                 dma_tx_fragment(ring, skb, i);
 777                 //TODO: handle failure of dma_tx_fragment
 778         }
 779         ieee80211_txb_free(txb);
 780
 781         return 0;
 782 }
 783
 784 void bcm43xx_dma_handle_xmitstatus(struct bcm43xx_private *bcm,
 785                                    struct bcm43xx_xmitstatus *status)
 786 {
 787         struct bcm43xx_dma *dma = bcm43xx_current_dma(bcm);
 788         struct bcm43xx_dmaring *ring;
 789         struct bcm43xx_dmadesc *desc;
 790         struct bcm43xx_dmadesc_meta *meta;
 791         int is_last_fragment;
 792         int slot;
 793
 794         ring = parse_cookie(bcm, status->cookie, &slot);
 795         assert(ring);
 796         assert(ring->tx);
 797         assert(get_desc_ctl(ring->vbase + slot) & BCM43xx_DMADTOR_FRAMESTART);
 798         while (1) {
 799                 assert(slot >= 0 && slot < ring->nr_slots);
 800                 desc = ring->vbase + slot;
 801                 meta = ring->meta + slot;
 802
 803                 is_last_fragment = !!(get_desc_ctl(desc) & BCM43xx_DMADTOR_FRAMEEND);
 804                 unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len, 1);
 805                 free_descriptor_buffer(ring, desc, meta, 1);
 806                 /* Everything belonging to the slot is unmapped
 807                  * and freed, so we can return it.
 808                  */
 809                 return_slot(ring, slot);
 810
 811                 if (is_last_fragment)
 812                         break;
 813                 slot = next_slot(ring, slot);
 814         }
 815         bcm->stats.last_tx = jiffies;
 816 }
 817
 818 static void dma_rx(struct bcm43xx_dmaring *ring,
 819                    int *slot)
 820 {
 821         struct bcm43xx_dmadesc *desc;
 822         struct bcm43xx_dmadesc_meta *meta;
 823         struct bcm43xx_rxhdr *rxhdr;
 824         struct sk_buff *skb;
 825         u16 len;
 826         int err;
 827         dma_addr_t dmaaddr;
 828
 829         desc = ring->vbase + *slot;
 830         meta = ring->meta + *slot;
 831
 832         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
 833         skb = meta->skb;
 834
 835         if (ring->mmio_base == BCM43xx_MMIO_DMA4_BASE) {
 836                 /* We received an xmit status. */
 837                 struct bcm43xx_hwxmitstatus *hw = (struct bcm43xx_hwxmitstatus *)skb->data;
 838                 struct bcm43xx_xmitstatus stat;
 839
 840                 stat.cookie = le16_to_cpu(hw->cookie);
 841                 stat.flags = hw->flags;
 842                 stat.cnt1 = hw->cnt1;
 843                 stat.cnt2 = hw->cnt2;
 844                 stat.seq = le16_to_cpu(hw->seq);
 845                 stat.unknown = le16_to_cpu(hw->unknown);
 846
 847                 bcm43xx_debugfs_log_txstat(ring->bcm, &stat);
 848                 bcm43xx_dma_handle_xmitstatus(ring->bcm, &stat);
 849                 /* recycle the descriptor buffer. */
 850                 sync_descbuffer_for_device(ring, meta->dmaaddr, ring->rx_buffersize);
 851
 852                 return;
 853         }
 854         rxhdr = (struct bcm43xx_rxhdr *)skb->data;
 855         len = le16_to_cpu(rxhdr->frame_length);
 856         if (len == 0) {
 857                 int i = 0;
 858
 859                 do {
 860                         udelay(2);
 861                         barrier();
 862                         len = le16_to_cpu(rxhdr->frame_length);
 863                 } while (len == 0 && i++ < 5);
 864                 if (unlikely(len == 0)) {
 865                         /* recycle the descriptor buffer. */
 866                         sync_descbuffer_for_device(ring, meta->dmaaddr,
 867                                                    ring->rx_buffersize);
 868                         goto drop;
 869                 }
 870         }
 871         if (unlikely(len > ring->rx_buffersize)) {
 872                 /* The data did not fit into one descriptor buffer
 873                  * and is split over multiple buffers.
 874                  * This should never happen, as we try to allocate buffers
 875                  * big enough. So simply ignore this packet.
 876                  */
 877                 int cnt = 0;
 878                 s32 tmp = len;
 879
 880                 while (1) {
 881                         desc = ring->vbase + *slot;
 882                         meta = ring->meta + *slot;
 883                         /* recycle the descriptor buffer. */
 884                         sync_descbuffer_for_device(ring, meta->dmaaddr,
 885                                                    ring->rx_buffersize);
 886                         *slot = next_slot(ring, *slot);
 887                         cnt++;
 888                         tmp -= ring->rx_buffersize;
 889                         if (tmp <= 0)
 890                                 break;
 891                 }
 892                 printkl(KERN_ERR PFX "DMA RX buffer too small "
 893                                      "(len: %u, buffer: %u, nr-dropped: %d)\n",
 894                         len, ring->rx_buffersize, cnt);
 895                 goto drop;
 896         }
 897         len -= IEEE80211_FCS_LEN;
 898
 899         dmaaddr = meta->dmaaddr;
 900         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
 901         if (unlikely(err)) {
 902                 dprintkl(KERN_ERR PFX "DMA RX: setup_rx_descbuffer() failed\n");
 903                 sync_descbuffer_for_device(ring, dmaaddr,
 904                                            ring->rx_buffersize);
 905                 goto drop;
 906         }
 907
 908         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
 909         skb_put(skb, len + ring->frameoffset);
 910         skb_pull(skb, ring->frameoffset);
 911
 912         err = bcm43xx_rx(ring->bcm, skb, rxhdr);
 913         if (err) {
 914                 dev_kfree_skb_irq(skb);
 915                 goto drop;
 916         }
 917
 918 drop:
 919         return;
 920 }
 921
 922 void bcm43xx_dma_rx(struct bcm43xx_dmaring *ring)
 923 {
 924         u32 status;
 925         u16 descptr;
 926         int slot, current_slot;
 927 #ifdef CONFIG_BCM43XX_DEBUG
 928         int used_slots = 0;
 929 #endif
 930
 931         assert(!ring->tx);
 932         status = bcm43xx_dma_read(ring, BCM43xx_DMA_RX_STATUS);
 933         descptr = (status & BCM43xx_DMA_RXSTAT_DPTR_MASK);
 934         current_slot = descptr / sizeof(struct bcm43xx_dmadesc);
 935         assert(current_slot >= 0 && current_slot < ring->nr_slots);
 936
 937         slot = ring->current_slot;
 938         for ( ; slot != current_slot; slot = next_slot(ring, slot)) {
 939                 dma_rx(ring, &slot);
 940 #ifdef CONFIG_BCM43XX_DEBUG
 941                 if (++used_slots > ring->max_used_slots)
 942                         ring->max_used_slots = used_slots;
 943 #endif
 944         }
 945         bcm43xx_dma_write(ring, BCM43xx_DMA_RX_DESC_INDEX,
 946                           (u32)(slot * sizeof(struct bcm43xx_dmadesc)));
 947         ring->current_slot = slot;
 948 }
 949
 950 void bcm43xx_dma_tx_suspend(struct bcm43xx_dmaring *ring)
 951 {
 952         assert(ring->tx);
 953         bcm43xx_power_saving_ctl_bits(ring->bcm, -1, 1);
 954         bcm43xx_dma_write(ring, BCM43xx_DMA_TX_CONTROL,
 955                           bcm43xx_dma_read(ring, BCM43xx_DMA_TX_CONTROL)
 956                           | BCM43xx_DMA_TXCTRL_SUSPEND);
 957 }
 958
 959 void bcm43xx_dma_tx_resume(struct bcm43xx_dmaring *ring)
 960 {
 961         assert(ring->tx);
 962         bcm43xx_dma_write(ring, BCM43xx_DMA_TX_CONTROL,
 963                           bcm43xx_dma_read(ring, BCM43xx_DMA_TX_CONTROL)
 964                           & ~BCM43xx_DMA_TXCTRL_SUSPEND);
 965         bcm43xx_power_saving_ctl_bits(ring->bcm, -1, -1);
 966 }
 967
 968 /* vim: set ts=8 sw=8 sts=8: */