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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2 
  3   Broadcom B43 wireless driver
  4 
  5   DMA ringbuffer and descriptor allocation/management
  6 
  7   Copyright (c) 2005, 2006 Michael Buesch <mb@bu3sch.de>
  8 
  9   Some code in this file is derived from the b44.c driver
 10   Copyright (C) 2002 David S. Miller
 11   Copyright (C) Pekka Pietikainen
 12 
 13   This program is free software; you can redistribute it and/or modify
 14   it under the terms of the GNU General Public License as published by
 15   the Free Software Foundation; either version 2 of the License, or
 16   (at your option) any later version.
 17 
 18   This program is distributed in the hope that it will be useful,
 19   but WITHOUT ANY WARRANTY; without even the implied warranty of
 20   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 21   GNU General Public License for more details.
 22 
 23   You should have received a copy of the GNU General Public License
 24   along with this program; see the file COPYING.  If not, write to
 25   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
 26   Boston, MA 02110-1301, USA.
 27 
 28 */
 29 
 30 #include "b43.h"
 31 #include "dma.h"
 32 #include "main.h"
 33 #include "debugfs.h"
 34 #include "xmit.h"
 35 
 36 #include <linux/dma-mapping.h>
 37 #include <linux/pci.h>
 38 #include <linux/delay.h>
 39 #include <linux/skbuff.h>
 40 #include <linux/etherdevice.h>
 41 
 42 
 43 /* 32bit DMA ops. */
 44 static
 45 struct b43_dmadesc_generic *op32_idx2desc(struct b43_dmaring *ring,
 46                                           int slot,
 47                                           struct b43_dmadesc_meta **meta)
 48 {
 49         struct b43_dmadesc32 *desc;
 50 
 51         *meta = &(ring->meta[slot]);
 52         desc = ring->descbase;
 53         desc = &(desc[slot]);
 54 
 55         return (struct b43_dmadesc_generic *)desc;
 56 }
 57 
 58 static void op32_fill_descriptor(struct b43_dmaring *ring,
 59                                  struct b43_dmadesc_generic *desc,
 60                                  dma_addr_t dmaaddr, u16 bufsize,
 61                                  int start, int end, int irq)
 62 {
 63         struct b43_dmadesc32 *descbase = ring->descbase;
 64         int slot;
 65         u32 ctl;
 66         u32 addr;
 67         u32 addrext;
 68 
 69         slot = (int)(&(desc->dma32) - descbase);
 70         B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
 71 
 72         addr = (u32) (dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
 73         addrext = (u32) (dmaaddr & SSB_DMA_TRANSLATION_MASK)
 74             >> SSB_DMA_TRANSLATION_SHIFT;
 75         addr |= ssb_dma_translation(ring->dev->dev);
 76         ctl = (bufsize - ring->frameoffset)
 77             & B43_DMA32_DCTL_BYTECNT;
 78         if (slot == ring->nr_slots - 1)
 79                 ctl |= B43_DMA32_DCTL_DTABLEEND;
 80         if (start)
 81                 ctl |= B43_DMA32_DCTL_FRAMESTART;
 82         if (end)
 83                 ctl |= B43_DMA32_DCTL_FRAMEEND;
 84         if (irq)
 85                 ctl |= B43_DMA32_DCTL_IRQ;
 86         ctl |= (addrext << B43_DMA32_DCTL_ADDREXT_SHIFT)
 87             & B43_DMA32_DCTL_ADDREXT_MASK;
 88 
 89         desc->dma32.control = cpu_to_le32(ctl);
 90         desc->dma32.address = cpu_to_le32(addr);
 91 }
 92 
 93 static void op32_poke_tx(struct b43_dmaring *ring, int slot)
 94 {
 95         b43_dma_write(ring, B43_DMA32_TXINDEX,
 96                       (u32) (slot * sizeof(struct b43_dmadesc32)));
 97 }
 98 
 99 static void op32_tx_suspend(struct b43_dmaring *ring)
100 {
101         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
102                       | B43_DMA32_TXSUSPEND);
103 }
104 
105 static void op32_tx_resume(struct b43_dmaring *ring)
106 {
107         b43_dma_write(ring, B43_DMA32_TXCTL, b43_dma_read(ring, B43_DMA32_TXCTL)
108                       & ~B43_DMA32_TXSUSPEND);
109 }
110 
111 static int op32_get_current_rxslot(struct b43_dmaring *ring)
112 {
113         u32 val;
114 
115         val = b43_dma_read(ring, B43_DMA32_RXSTATUS);
116         val &= B43_DMA32_RXDPTR;
117 
118         return (val / sizeof(struct b43_dmadesc32));
119 }
120 
121 static void op32_set_current_rxslot(struct b43_dmaring *ring, int slot)
122 {
123         b43_dma_write(ring, B43_DMA32_RXINDEX,
124                       (u32) (slot * sizeof(struct b43_dmadesc32)));
125 }
126 
127 static const struct b43_dma_ops dma32_ops = {
128         .idx2desc = op32_idx2desc,
129         .fill_descriptor = op32_fill_descriptor,
130         .poke_tx = op32_poke_tx,
131         .tx_suspend = op32_tx_suspend,
132         .tx_resume = op32_tx_resume,
133         .get_current_rxslot = op32_get_current_rxslot,
134         .set_current_rxslot = op32_set_current_rxslot,
135 };
136 
137 /* 64bit DMA ops. */
138 static
139 struct b43_dmadesc_generic *op64_idx2desc(struct b43_dmaring *ring,
140                                           int slot,
141                                           struct b43_dmadesc_meta **meta)
142 {
143         struct b43_dmadesc64 *desc;
144 
145         *meta = &(ring->meta[slot]);
146         desc = ring->descbase;
147         desc = &(desc[slot]);
148 
149         return (struct b43_dmadesc_generic *)desc;
150 }
151 
152 static void op64_fill_descriptor(struct b43_dmaring *ring,
153                                  struct b43_dmadesc_generic *desc,
154                                  dma_addr_t dmaaddr, u16 bufsize,
155                                  int start, int end, int irq)
156 {
157         struct b43_dmadesc64 *descbase = ring->descbase;
158         int slot;
159         u32 ctl0 = 0, ctl1 = 0;
160         u32 addrlo, addrhi;
161         u32 addrext;
162 
163         slot = (int)(&(desc->dma64) - descbase);
164         B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
165 
166         addrlo = (u32) (dmaaddr & 0xFFFFFFFF);
167         addrhi = (((u64) dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
168         addrext = (((u64) dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
169             >> SSB_DMA_TRANSLATION_SHIFT;
170         addrhi |= (ssb_dma_translation(ring->dev->dev) << 1);
171         if (slot == ring->nr_slots - 1)
172                 ctl0 |= B43_DMA64_DCTL0_DTABLEEND;
173         if (start)
174                 ctl0 |= B43_DMA64_DCTL0_FRAMESTART;
175         if (end)
176                 ctl0 |= B43_DMA64_DCTL0_FRAMEEND;
177         if (irq)
178                 ctl0 |= B43_DMA64_DCTL0_IRQ;
179         ctl1 |= (bufsize - ring->frameoffset)
180             & B43_DMA64_DCTL1_BYTECNT;
181         ctl1 |= (addrext << B43_DMA64_DCTL1_ADDREXT_SHIFT)
182             & B43_DMA64_DCTL1_ADDREXT_MASK;
183 
184         desc->dma64.control0 = cpu_to_le32(ctl0);
185         desc->dma64.control1 = cpu_to_le32(ctl1);
186         desc->dma64.address_low = cpu_to_le32(addrlo);
187         desc->dma64.address_high = cpu_to_le32(addrhi);
188 }
189 
190 static void op64_poke_tx(struct b43_dmaring *ring, int slot)
191 {
192         b43_dma_write(ring, B43_DMA64_TXINDEX,
193                       (u32) (slot * sizeof(struct b43_dmadesc64)));
194 }
195 
196 static void op64_tx_suspend(struct b43_dmaring *ring)
197 {
198         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
199                       | B43_DMA64_TXSUSPEND);
200 }
201 
202 static void op64_tx_resume(struct b43_dmaring *ring)
203 {
204         b43_dma_write(ring, B43_DMA64_TXCTL, b43_dma_read(ring, B43_DMA64_TXCTL)
205                       & ~B43_DMA64_TXSUSPEND);
206 }
207 
208 static int op64_get_current_rxslot(struct b43_dmaring *ring)
209 {
210         u32 val;
211 
212         val = b43_dma_read(ring, B43_DMA64_RXSTATUS);
213         val &= B43_DMA64_RXSTATDPTR;
214 
215         return (val / sizeof(struct b43_dmadesc64));
216 }
217 
218 static void op64_set_current_rxslot(struct b43_dmaring *ring, int slot)
219 {
220         b43_dma_write(ring, B43_DMA64_RXINDEX,
221                       (u32) (slot * sizeof(struct b43_dmadesc64)));
222 }
223 
224 static const struct b43_dma_ops dma64_ops = {
225         .idx2desc = op64_idx2desc,
226         .fill_descriptor = op64_fill_descriptor,
227         .poke_tx = op64_poke_tx,
228         .tx_suspend = op64_tx_suspend,
229         .tx_resume = op64_tx_resume,
230         .get_current_rxslot = op64_get_current_rxslot,
231         .set_current_rxslot = op64_set_current_rxslot,
232 };
233 
234 static inline int free_slots(struct b43_dmaring *ring)
235 {
236         return (ring->nr_slots - ring->used_slots);
237 }
238 
239 static inline int next_slot(struct b43_dmaring *ring, int slot)
240 {
241         B43_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
242         if (slot == ring->nr_slots - 1)
243                 return 0;
244         return slot + 1;
245 }
246 
247 static inline int prev_slot(struct b43_dmaring *ring, int slot)
248 {
249         B43_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
250         if (slot == 0)
251                 return ring->nr_slots - 1;
252         return slot - 1;
253 }
254 
255 #ifdef CONFIG_B43_DEBUG
256 static void update_max_used_slots(struct b43_dmaring *ring,
257                                   int current_used_slots)
258 {
259         if (current_used_slots <= ring->max_used_slots)
260                 return;
261         ring->max_used_slots = current_used_slots;
262         if (b43_debug(ring->dev, B43_DBG_DMAVERBOSE)) {
263                 b43dbg(ring->dev->wl,
264                        "max_used_slots increased to %d on %s ring %d\n",
265                        ring->max_used_slots,
266                        ring->tx ? "TX" : "RX", ring->index);
267         }
268 }
269 #else
270 static inline
271     void update_max_used_slots(struct b43_dmaring *ring, int current_used_slots)
272 {
273 }
274 #endif /* DEBUG */
275 
276 /* Request a slot for usage. */
277 static inline int request_slot(struct b43_dmaring *ring)
278 {
279         int slot;
280 
281         B43_WARN_ON(!ring->tx);
282         B43_WARN_ON(ring->stopped);
283         B43_WARN_ON(free_slots(ring) == 0);
284 
285         slot = next_slot(ring, ring->current_slot);
286         ring->current_slot = slot;
287         ring->used_slots++;
288 
289         update_max_used_slots(ring, ring->used_slots);
290 
291         return slot;
292 }
293 
294 /* Mac80211-queue to b43-ring mapping */
295 static struct b43_dmaring *priority_to_txring(struct b43_wldev *dev,
296                                               int queue_priority)
297 {
298         struct b43_dmaring *ring;
299 
300 /*FIXME: For now we always run on TX-ring-1 */
301         return dev->dma.tx_ring1;
302 
303         /* 0 = highest priority */
304         switch (queue_priority) {
305         default:
306                 B43_WARN_ON(1);
307                 /* fallthrough */
308         case 0:
309                 ring = dev->dma.tx_ring3;
310                 break;
311         case 1:
312                 ring = dev->dma.tx_ring2;
313                 break;
314         case 2:
315                 ring = dev->dma.tx_ring1;
316                 break;
317         case 3:
318                 ring = dev->dma.tx_ring0;
319                 break;
320         }
321 
322         return ring;
323 }
324 
325 /* b43-ring to mac80211-queue mapping */
326 static inline int txring_to_priority(struct b43_dmaring *ring)
327 {
328         static const u8 idx_to_prio[] = { 3, 2, 1, 0, };
329         unsigned int index;
330 
331 /*FIXME: have only one queue, for now */
332         return 0;
333 
334         index = ring->index;
335         if (B43_WARN_ON(index >= ARRAY_SIZE(idx_to_prio)))
336                 index = 0;
337         return idx_to_prio[index];
338 }
339 
340 static u16 b43_dmacontroller_base(enum b43_dmatype type, int controller_idx)
341 {
342         static const u16 map64[] = {
343                 B43_MMIO_DMA64_BASE0,
344                 B43_MMIO_DMA64_BASE1,
345                 B43_MMIO_DMA64_BASE2,
346                 B43_MMIO_DMA64_BASE3,
347                 B43_MMIO_DMA64_BASE4,
348                 B43_MMIO_DMA64_BASE5,
349         };
350         static const u16 map32[] = {
351                 B43_MMIO_DMA32_BASE0,
352                 B43_MMIO_DMA32_BASE1,
353                 B43_MMIO_DMA32_BASE2,
354                 B43_MMIO_DMA32_BASE3,
355                 B43_MMIO_DMA32_BASE4,
356                 B43_MMIO_DMA32_BASE5,
357         };
358 
359         if (type == B43_DMA_64BIT) {
360                 B43_WARN_ON(!(controller_idx >= 0 &&
361                               controller_idx < ARRAY_SIZE(map64)));
362                 return map64[controller_idx];
363         }
364         B43_WARN_ON(!(controller_idx >= 0 &&
365                       controller_idx < ARRAY_SIZE(map32)));
366         return map32[controller_idx];
367 }
368 
369 static inline
370     dma_addr_t map_descbuffer(struct b43_dmaring *ring,
371                               unsigned char *buf, size_t len, int tx)
372 {
373         dma_addr_t dmaaddr;
374 
375         if (tx) {
376                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
377                                          buf, len, DMA_TO_DEVICE);
378         } else {
379                 dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
380                                          buf, len, DMA_FROM_DEVICE);
381         }
382 
383         return dmaaddr;
384 }
385 
386 static inline
387     void unmap_descbuffer(struct b43_dmaring *ring,
388                           dma_addr_t addr, size_t len, int tx)
389 {
390         if (tx) {
391                 dma_unmap_single(ring->dev->dev->dma_dev,
392                                  addr, len, DMA_TO_DEVICE);
393         } else {
394                 dma_unmap_single(ring->dev->dev->dma_dev,
395                                  addr, len, DMA_FROM_DEVICE);
396         }
397 }
398 
399 static inline
400     void sync_descbuffer_for_cpu(struct b43_dmaring *ring,
401                                  dma_addr_t addr, size_t len)
402 {
403         B43_WARN_ON(ring->tx);
404         dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
405                                 addr, len, DMA_FROM_DEVICE);
406 }
407 
408 static inline
409     void sync_descbuffer_for_device(struct b43_dmaring *ring,
410                                     dma_addr_t addr, size_t len)
411 {
412         B43_WARN_ON(ring->tx);
413         dma_sync_single_for_device(ring->dev->dev->dma_dev,
414                                    addr, len, DMA_FROM_DEVICE);
415 }
416 
417 static inline
418     void free_descriptor_buffer(struct b43_dmaring *ring,
419                                 struct b43_dmadesc_meta *meta)
420 {
421         if (meta->skb) {
422                 dev_kfree_skb_any(meta->skb);
423                 meta->skb = NULL;
424         }
425 }
426 
427 static int alloc_ringmemory(struct b43_dmaring *ring)
428 {
429         struct device *dma_dev = ring->dev->dev->dma_dev;
430         gfp_t flags = GFP_KERNEL;
431 
432         /* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
433          * alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
434          * has shown that 4K is sufficient for the latter as long as the buffer
435          * does not cross an 8K boundary.
436          *
437          * For unknown reasons - possibly a hardware error - the BCM4311 rev
438          * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
439          * which accounts for the GFP_DMA flag below.
440          */
441         if (ring->type == B43_DMA_64BIT)
442                 flags |= GFP_DMA;
443         ring->descbase = dma_alloc_coherent(dma_dev, B43_DMA_RINGMEMSIZE,
444                                             &(ring->dmabase), flags);
445         if (!ring->descbase) {
446                 b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
447                 return -ENOMEM;
448         }
449         memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
450 
451         return 0;
452 }
453 
454 static void free_ringmemory(struct b43_dmaring *ring)
455 {
456         struct device *dma_dev = ring->dev->dev->dma_dev;
457 
458         dma_free_coherent(dma_dev, B43_DMA_RINGMEMSIZE,
459                           ring->descbase, ring->dmabase);
460 }
461 
462 /* Reset the RX DMA channel */
463 static int b43_dmacontroller_rx_reset(struct b43_wldev *dev, u16 mmio_base,
464                                       enum b43_dmatype type)
465 {
466         int i;
467         u32 value;
468         u16 offset;
469 
470         might_sleep();
471 
472         offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
473         b43_write32(dev, mmio_base + offset, 0);
474         for (i = 0; i < 10; i++) {
475                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXSTATUS :
476                                                    B43_DMA32_RXSTATUS;
477                 value = b43_read32(dev, mmio_base + offset);
478                 if (type == B43_DMA_64BIT) {
479                         value &= B43_DMA64_RXSTAT;
480                         if (value == B43_DMA64_RXSTAT_DISABLED) {
481                                 i = -1;
482                                 break;
483                         }
484                 } else {
485                         value &= B43_DMA32_RXSTATE;
486                         if (value == B43_DMA32_RXSTAT_DISABLED) {
487                                 i = -1;
488                                 break;
489                         }
490                 }
491                 msleep(1);
492         }
493         if (i != -1) {
494                 b43err(dev->wl, "DMA RX reset timed out\n");
495                 return -ENODEV;
496         }
497 
498         return 0;
499 }
500 
501 /* Reset the TX DMA channel */
502 static int b43_dmacontroller_tx_reset(struct b43_wldev *dev, u16 mmio_base,
503                                       enum b43_dmatype type)
504 {
505         int i;
506         u32 value;
507         u16 offset;
508 
509         might_sleep();
510 
511         for (i = 0; i < 10; i++) {
512                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
513                                                    B43_DMA32_TXSTATUS;
514                 value = b43_read32(dev, mmio_base + offset);
515                 if (type == B43_DMA_64BIT) {
516                         value &= B43_DMA64_TXSTAT;
517                         if (value == B43_DMA64_TXSTAT_DISABLED ||
518                             value == B43_DMA64_TXSTAT_IDLEWAIT ||
519                             value == B43_DMA64_TXSTAT_STOPPED)
520                                 break;
521                 } else {
522                         value &= B43_DMA32_TXSTATE;
523                         if (value == B43_DMA32_TXSTAT_DISABLED ||
524                             value == B43_DMA32_TXSTAT_IDLEWAIT ||
525                             value == B43_DMA32_TXSTAT_STOPPED)
526                                 break;
527                 }
528                 msleep(1);
529         }
530         offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXCTL : B43_DMA32_TXCTL;
531         b43_write32(dev, mmio_base + offset, 0);
532         for (i = 0; i < 10; i++) {
533                 offset = (type == B43_DMA_64BIT) ? B43_DMA64_TXSTATUS :
534                                                    B43_DMA32_TXSTATUS;
535                 value = b43_read32(dev, mmio_base + offset);
536                 if (type == B43_DMA_64BIT) {
537                         value &= B43_DMA64_TXSTAT;
538                         if (value == B43_DMA64_TXSTAT_DISABLED) {
539                                 i = -1;
540                                 break;
541                         }
542                 } else {
543                         value &= B43_DMA32_TXSTATE;
544                         if (value == B43_DMA32_TXSTAT_DISABLED) {
545                                 i = -1;
546                                 break;
547                         }
548                 }
549                 msleep(1);
550         }
551         if (i != -1) {
552                 b43err(dev->wl, "DMA TX reset timed out\n");
553                 return -ENODEV;
554         }
555         /* ensure the reset is completed. */
556         msleep(1);
557 
558         return 0;
559 }
560 
561 /* Check if a DMA mapping address is invalid. */
562 static bool b43_dma_mapping_error(struct b43_dmaring *ring,
563                                   dma_addr_t addr,
564                                   size_t buffersize, bool dma_to_device)
565 {
566         if (unlikely(dma_mapping_error(addr)))
567                 return 1;
568 
569         switch (ring->type) {
570         case B43_DMA_30BIT:
571                 if ((u64)addr + buffersize > (1ULL << 30))
572                         goto address_error;
573                 break;
574         case B43_DMA_32BIT:
575                 if ((u64)addr + buffersize > (1ULL << 32))
576                         goto address_error;
577                 break;
578         case B43_DMA_64BIT:
579                 /* Currently we can't have addresses beyond
580                  * 64bit in the kernel. */
581                 break;
582         }
583 
584         /* The address is OK. */
585         return 0;
586 
587 address_error:
588         /* We can't support this address. Unmap it again. */
589         unmap_descbuffer(ring, addr, buffersize, dma_to_device);
590 
591         return 1;
592 }
593 
594 static int setup_rx_descbuffer(struct b43_dmaring *ring,
595                                struct b43_dmadesc_generic *desc,
596                                struct b43_dmadesc_meta *meta, gfp_t gfp_flags)
597 {
598         struct b43_rxhdr_fw4 *rxhdr;
599         struct b43_hwtxstatus *txstat;
600         dma_addr_t dmaaddr;
601         struct sk_buff *skb;
602 
603         B43_WARN_ON(ring->tx);
604 
605         skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
606         if (unlikely(!skb))
607                 return -ENOMEM;
608         dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0);
609         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
610                 /* ugh. try to realloc in zone_dma */
611                 gfp_flags |= GFP_DMA;
612 
613                 dev_kfree_skb_any(skb);
614 
615                 skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
616                 if (unlikely(!skb))
617                         return -ENOMEM;
618                 dmaaddr = map_descbuffer(ring, skb->data,
619                                          ring->rx_buffersize, 0);
620         }
621 
622         if (b43_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
623                 b43err(ring->dev->wl, "RX DMA buffer allocation failed\n");
624                 dev_kfree_skb_any(skb);
625                 return -EIO;
626         }
627 
628         meta->skb = skb;
629         meta->dmaaddr = dmaaddr;
630         ring->ops->fill_descriptor(ring, desc, dmaaddr,
631                                    ring->rx_buffersize, 0, 0, 0);
632 
633         rxhdr = (struct b43_rxhdr_fw4 *)(skb->data);
634         rxhdr->frame_len = 0;
635         txstat = (struct b43_hwtxstatus *)(skb->data);
636         txstat->cookie = 0;
637 
638         return 0;
639 }
640 
641 /* Allocate the initial descbuffers.
642  * This is used for an RX ring only.
643  */
644 static int alloc_initial_descbuffers(struct b43_dmaring *ring)
645 {
646         int i, err = -ENOMEM;
647         struct b43_dmadesc_generic *desc;
648         struct b43_dmadesc_meta *meta;
649 
650         for (i = 0; i < ring->nr_slots; i++) {
651                 desc = ring->ops->idx2desc(ring, i, &meta);
652 
653                 err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
654                 if (err) {
655                         b43err(ring->dev->wl,
656                                "Failed to allocate initial descbuffers\n");
657                         goto err_unwind;
658                 }
659         }
660         mb();
661         ring->used_slots = ring->nr_slots;
662         err = 0;
663       out:
664         return err;
665 
666       err_unwind:
667         for (i--; i >= 0; i--) {
668                 desc = ring->ops->idx2desc(ring, i, &meta);
669 
670                 unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
671                 dev_kfree_skb(meta->skb);
672         }
673         goto out;
674 }
675 
676 /* Do initial setup of the DMA controller.
677  * Reset the controller, write the ring busaddress
678  * and switch the "enable" bit on.
679  */
680 static int dmacontroller_setup(struct b43_dmaring *ring)
681 {
682         int err = 0;
683         u32 value;
684         u32 addrext;
685         u32 trans = ssb_dma_translation(ring->dev->dev);
686 
687         if (ring->tx) {
688                 if (ring->type == B43_DMA_64BIT) {
689                         u64 ringbase = (u64) (ring->dmabase);
690 
691                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
692                             >> SSB_DMA_TRANSLATION_SHIFT;
693                         value = B43_DMA64_TXENABLE;
694                         value |= (addrext << B43_DMA64_TXADDREXT_SHIFT)
695                             & B43_DMA64_TXADDREXT_MASK;
696                         b43_dma_write(ring, B43_DMA64_TXCTL, value);
697                         b43_dma_write(ring, B43_DMA64_TXRINGLO,
698                                       (ringbase & 0xFFFFFFFF));
699                         b43_dma_write(ring, B43_DMA64_TXRINGHI,
700                                       ((ringbase >> 32) &
701                                        ~SSB_DMA_TRANSLATION_MASK)
702                                       | (trans << 1));
703                 } else {
704                         u32 ringbase = (u32) (ring->dmabase);
705 
706                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
707                             >> SSB_DMA_TRANSLATION_SHIFT;
708                         value = B43_DMA32_TXENABLE;
709                         value |= (addrext << B43_DMA32_TXADDREXT_SHIFT)
710                             & B43_DMA32_TXADDREXT_MASK;
711                         b43_dma_write(ring, B43_DMA32_TXCTL, value);
712                         b43_dma_write(ring, B43_DMA32_TXRING,
713                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
714                                       | trans);
715                 }
716         } else {
717                 err = alloc_initial_descbuffers(ring);
718                 if (err)
719                         goto out;
720                 if (ring->type == B43_DMA_64BIT) {
721                         u64 ringbase = (u64) (ring->dmabase);
722 
723                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
724                             >> SSB_DMA_TRANSLATION_SHIFT;
725                         value = (ring->frameoffset << B43_DMA64_RXFROFF_SHIFT);
726                         value |= B43_DMA64_RXENABLE;
727                         value |= (addrext << B43_DMA64_RXADDREXT_SHIFT)
728                             & B43_DMA64_RXADDREXT_MASK;
729                         b43_dma_write(ring, B43_DMA64_RXCTL, value);
730                         b43_dma_write(ring, B43_DMA64_RXRINGLO,
731                                       (ringbase & 0xFFFFFFFF));
732                         b43_dma_write(ring, B43_DMA64_RXRINGHI,
733                                       ((ringbase >> 32) &
734                                        ~SSB_DMA_TRANSLATION_MASK)
735                                       | (trans << 1));
736                         b43_dma_write(ring, B43_DMA64_RXINDEX, ring->nr_slots *
737                                       sizeof(struct b43_dmadesc64));
738                 } else {
739                         u32 ringbase = (u32) (ring->dmabase);
740 
741                         addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
742                             >> SSB_DMA_TRANSLATION_SHIFT;
743                         value = (ring->frameoffset << B43_DMA32_RXFROFF_SHIFT);
744                         value |= B43_DMA32_RXENABLE;
745                         value |= (addrext << B43_DMA32_RXADDREXT_SHIFT)
746                             & B43_DMA32_RXADDREXT_MASK;
747                         b43_dma_write(ring, B43_DMA32_RXCTL, value);
748                         b43_dma_write(ring, B43_DMA32_RXRING,
749                                       (ringbase & ~SSB_DMA_TRANSLATION_MASK)
750                                       | trans);
751                         b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
752                                       sizeof(struct b43_dmadesc32));
753                 }
754         }
755 
756 out:
757         return err;
758 }
759 
760 /* Shutdown the DMA controller. */
761 static void dmacontroller_cleanup(struct b43_dmaring *ring)
762 {
763         if (ring->tx) {
764                 b43_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
765                                            ring->type);
766                 if (ring->type == B43_DMA_64BIT) {
767                         b43_dma_write(ring, B43_DMA64_TXRINGLO, 0);
768                         b43_dma_write(ring, B43_DMA64_TXRINGHI, 0);
769                 } else
770                         b43_dma_write(ring, B43_DMA32_TXRING, 0);
771         } else {
772                 b43_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
773                                            ring->type);
774                 if (ring->type == B43_DMA_64BIT) {
775                         b43_dma_write(ring, B43_DMA64_RXRINGLO, 0);
776                         b43_dma_write(ring, B43_DMA64_RXRINGHI, 0);
777                 } else
778                         b43_dma_write(ring, B43_DMA32_RXRING, 0);
779         }
780 }
781 
782 static void free_all_descbuffers(struct b43_dmaring *ring)
783 {
784         struct b43_dmadesc_generic *desc;
785         struct b43_dmadesc_meta *meta;
786         int i;
787 
788         if (!ring->used_slots)
789                 return;
790         for (i = 0; i < ring->nr_slots; i++) {
791                 desc = ring->ops->idx2desc(ring, i, &meta);
792 
793                 if (!meta->skb) {
794                         B43_WARN_ON(!ring->tx);
795                         continue;
796                 }
797                 if (ring->tx) {
798                         unmap_descbuffer(ring, meta->dmaaddr,
799                                          meta->skb->len, 1);
800                 } else {
801                         unmap_descbuffer(ring, meta->dmaaddr,
802                                          ring->rx_buffersize, 0);
803                 }
804                 free_descriptor_buffer(ring, meta);
805         }
806 }
807 
808 static u64 supported_dma_mask(struct b43_wldev *dev)
809 {
810         u32 tmp;
811         u16 mmio_base;
812 
813         tmp = b43_read32(dev, SSB_TMSHIGH);
814         if (tmp & SSB_TMSHIGH_DMA64)
815                 return DMA_64BIT_MASK;
816         mmio_base = b43_dmacontroller_base(0, 0);
817         b43_write32(dev, mmio_base + B43_DMA32_TXCTL, B43_DMA32_TXADDREXT_MASK);
818         tmp = b43_read32(dev, mmio_base + B43_DMA32_TXCTL);
819         if (tmp & B43_DMA32_TXADDREXT_MASK)
820                 return DMA_32BIT_MASK;
821 
822         return DMA_30BIT_MASK;
823 }
824 
825 static enum b43_dmatype dma_mask_to_engine_type(u64 dmamask)
826 {
827         if (dmamask == DMA_30BIT_MASK)
828                 return B43_DMA_30BIT;
829         if (dmamask == DMA_32BIT_MASK)
830                 return B43_DMA_32BIT;
831         if (dmamask == DMA_64BIT_MASK)
832                 return B43_DMA_64BIT;
833         B43_WARN_ON(1);
834         return B43_DMA_30BIT;
835 }
836 
837 /* Main initialization function. */
838 static
839 struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
840                                       int controller_index,
841                                       int for_tx,
842                                       enum b43_dmatype type)
843 {
844         struct b43_dmaring *ring;
845         int err;
846         int nr_slots;
847         dma_addr_t dma_test;
848 
849         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
850         if (!ring)
851                 goto out;
852         ring->type = type;
853         ring->dev = dev;
854 
855         nr_slots = B43_RXRING_SLOTS;
856         if (for_tx)
857                 nr_slots = B43_TXRING_SLOTS;
858 
859         ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
860                              GFP_KERNEL);
861         if (!ring->meta)
862                 goto err_kfree_ring;
863         if (for_tx) {
864                 ring->txhdr_cache = kcalloc(nr_slots,
865                                             b43_txhdr_size(dev),
866                                             GFP_KERNEL);
867                 if (!ring->txhdr_cache)
868                         goto err_kfree_meta;
869 
870                 /* test for ability to dma to txhdr_cache */
871                 dma_test = dma_map_single(dev->dev->dma_dev,
872                                           ring->txhdr_cache,
873                                           b43_txhdr_size(dev),
874                                           DMA_TO_DEVICE);
875 
876                 if (b43_dma_mapping_error(ring, dma_test,
877                                           b43_txhdr_size(dev), 1)) {
878                         /* ugh realloc */
879                         kfree(ring->txhdr_cache);
880                         ring->txhdr_cache = kcalloc(nr_slots,
881                                                     b43_txhdr_size(dev),
882                                                     GFP_KERNEL | GFP_DMA);
883                         if (!ring->txhdr_cache)
884                                 goto err_kfree_meta;
885 
886                         dma_test = dma_map_single(dev->dev->dma_dev,
887                                                   ring->txhdr_cache,
888                                                   b43_txhdr_size(dev),
889                                                   DMA_TO_DEVICE);
890 
891                         if (b43_dma_mapping_error(ring, dma_test,
892                                                   b43_txhdr_size(dev), 1)) {
893 
894                                 b43err(dev->wl,
895                                        "TXHDR DMA allocation failed\n");
896                                 goto err_kfree_txhdr_cache;
897                         }
898                 }
899 
900                 dma_unmap_single(dev->dev->dma_dev,
901                                  dma_test, b43_txhdr_size(dev),
902                                  DMA_TO_DEVICE);
903         }
904 
905         ring->nr_slots = nr_slots;
906         ring->mmio_base = b43_dmacontroller_base(type, controller_index);
907         ring->index = controller_index;
908         if (type == B43_DMA_64BIT)
909                 ring->ops = &dma64_ops;
910         else
911                 ring->ops = &dma32_ops;
912         if (for_tx) {
913                 ring->tx = 1;
914                 ring->current_slot = -1;
915         } else {
916                 if (ring->index == 0) {
917                         ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
918                         ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
919                 } else if (ring->index == 3) {
920                         ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
921                         ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
922                 } else
923                         B43_WARN_ON(1);
924         }
925         spin_lock_init(&ring->lock);
926 #ifdef CONFIG_B43_DEBUG
927         ring->last_injected_overflow = jiffies;
928 #endif
929 
930         err = alloc_ringmemory(ring);
931         if (err)
932                 goto err_kfree_txhdr_cache;
933         err = dmacontroller_setup(ring);
934         if (err)
935                 goto err_free_ringmemory;
936 
937       out:
938         return ring;
939 
940       err_free_ringmemory:
941         free_ringmemory(ring);
942       err_kfree_txhdr_cache:
943         kfree(ring->txhdr_cache);
944       err_kfree_meta:
945         kfree(ring->meta);
946       err_kfree_ring:
947         kfree(ring);
948         ring = NULL;
949         goto out;
950 }
951 
952 /* Main cleanup function. */
953 static void b43_destroy_dmaring(struct b43_dmaring *ring)
954 {
955         if (!ring)
956                 return;
957 
958         b43dbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots: %d/%d\n",
959                (unsigned int)(ring->type),
960                ring->mmio_base,
961                (ring->tx) ? "TX" : "RX", ring->max_used_slots, ring->nr_slots);
962         /* Device IRQs are disabled prior entering this function,
963          * so no need to take care of concurrency with rx handler stuff.
964          */
965         dmacontroller_cleanup(ring);
966         free_all_descbuffers(ring);
967         free_ringmemory(ring);
968 
969         kfree(ring->txhdr_cache);
970         kfree(ring->meta);
971         kfree(ring);
972 }
973 
974 void b43_dma_free(struct b43_wldev *dev)
975 {
976         struct b43_dma *dma = &dev->dma;
977 
978         b43_destroy_dmaring(dma->rx_ring3);
979         dma->rx_ring3 = NULL;
980         b43_destroy_dmaring(dma->rx_ring0);
981         dma->rx_ring0 = NULL;
982 
983         b43_destroy_dmaring(dma->tx_ring5);
984         dma->tx_ring5 = NULL;
985         b43_destroy_dmaring(dma->tx_ring4);
986         dma->tx_ring4 = NULL;
987         b43_destroy_dmaring(dma->tx_ring3);
988         dma->tx_ring3 = NULL;
989         b43_destroy_dmaring(dma->tx_ring2);
990         dma->tx_ring2 = NULL;
991         b43_destroy_dmaring(dma->tx_ring1);
992         dma->tx_ring1 = NULL;
993         b43_destroy_dmaring(dma->tx_ring0);
994         dma->tx_ring0 = NULL;
995 }
996 
997 static int b43_dma_set_mask(struct b43_wldev *dev, u64 mask)
998 {
999         u64 orig_mask = mask;
1000         bool fallback = 0;
1001         int err;
1002 
1003         /* Try to set the DMA mask. If it fails, try falling back to a
1004          * lower mask, as we can always also support a lower one. */
1005         while (1) {
1006                 err = ssb_dma_set_mask(dev->dev, mask);
1007                 if (!err)
1008                         break;
1009                 if (mask == DMA_64BIT_MASK) {
1010                         mask = DMA_32BIT_MASK;
1011                         fallback = 1;
1012                         continue;
1013                 }
1014                 if (mask == DMA_32BIT_MASK) {
1015                         mask = DMA_30BIT_MASK;
1016                         fallback = 1;
1017                         continue;
1018                 }
1019                 b43err(dev->wl, "The machine/kernel does not support "
1020                        "the required %u-bit DMA mask\n",
1021                        (unsigned int)dma_mask_to_engine_type(orig_mask));
1022                 return -EOPNOTSUPP;
1023         }
1024         if (fallback) {
1025                 b43info(dev->wl, "DMA mask fallback from %u-bit to %u-bit\n",
1026                         (unsigned int)dma_mask_to_engine_type(orig_mask),
1027                         (unsigned int)dma_mask_to_engine_type(mask));
1028         }
1029 
1030         return 0;
1031 }
1032 
1033 int b43_dma_init(struct b43_wldev *dev)
1034 {
1035         struct b43_dma *dma = &dev->dma;
1036         struct b43_dmaring *ring;
1037         int err;
1038         u64 dmamask;
1039         enum b43_dmatype type;
1040 
1041         dmamask = supported_dma_mask(dev);
1042         type = dma_mask_to_engine_type(dmamask);
1043         err = b43_dma_set_mask(dev, dmamask);
1044         if (err)
1045                 return err;
1046 
1047         err = -ENOMEM;
1048         /* setup TX DMA channels. */
1049         ring = b43_setup_dmaring(dev, 0, 1, type);
1050         if (!ring)
1051                 goto out;
1052         dma->tx_ring0 = ring;
1053 
1054         ring = b43_setup_dmaring(dev, 1, 1, type);
1055         if (!ring)
1056                 goto err_destroy_tx0;
1057         dma->tx_ring1 = ring;
1058 
1059         ring = b43_setup_dmaring(dev, 2, 1, type);
1060         if (!ring)
1061                 goto err_destroy_tx1;
1062         dma->tx_ring2 = ring;
1063 
1064         ring = b43_setup_dmaring(dev, 3, 1, type);
1065         if (!ring)
1066                 goto err_destroy_tx2;
1067         dma->tx_ring3 = ring;
1068 
1069         ring = b43_setup_dmaring(dev, 4, 1, type);
1070         if (!ring)
1071                 goto err_destroy_tx3;
1072         dma->tx_ring4 = ring;
1073 
1074         ring = b43_setup_dmaring(dev, 5, 1, type);
1075         if (!ring)
1076                 goto err_destroy_tx4;
1077         dma->tx_ring5 = ring;
1078 
1079         /* setup RX DMA channels. */
1080         ring = b43_setup_dmaring(dev, 0, 0, type);
1081         if (!ring)
1082                 goto err_destroy_tx5;
1083         dma->rx_ring0 = ring;
1084 
1085         if (dev->dev->id.revision < 5) {
1086                 ring = b43_setup_dmaring(dev, 3, 0, type);
1087                 if (!ring)
1088                         goto err_destroy_rx0;
1089                 dma->rx_ring3 = ring;
1090         }
1091 
1092         b43dbg(dev->wl, "%u-bit DMA initialized\n",
1093                (unsigned int)type);
1094         err = 0;
1095       out:
1096         return err;
1097 
1098       err_destroy_rx0:
1099         b43_destroy_dmaring(dma->rx_ring0);
1100         dma->rx_ring0 = NULL;
1101       err_destroy_tx5:
1102         b43_destroy_dmaring(dma->tx_ring5);
1103         dma->tx_ring5 = NULL;
1104       err_destroy_tx4:
1105         b43_destroy_dmaring(dma->tx_ring4);
1106         dma->tx_ring4 = NULL;
1107       err_destroy_tx3:
1108         b43_destroy_dmaring(dma->tx_ring3);
1109         dma->tx_ring3 = NULL;
1110       err_destroy_tx2:
1111         b43_destroy_dmaring(dma->tx_ring2);
1112         dma->tx_ring2 = NULL;
1113       err_destroy_tx1:
1114         b43_destroy_dmaring(dma->tx_ring1);
1115         dma->tx_ring1 = NULL;
1116       err_destroy_tx0:
1117         b43_destroy_dmaring(dma->tx_ring0);
1118         dma->tx_ring0 = NULL;
1119         goto out;
1120 }
1121 
1122 /* Generate a cookie for the TX header. */
1123 static u16 generate_cookie(struct b43_dmaring *ring, int slot)
1124 {
1125         u16 cookie = 0x1000;
1126 
1127         /* Use the upper 4 bits of the cookie as
1128          * DMA controller ID and store the slot number
1129          * in the lower 12 bits.
1130          * Note that the cookie must never be 0, as this
1131          * is a special value used in RX path.
1132          * It can also not be 0xFFFF because that is special
1133          * for multicast frames.
1134          */
1135         switch (ring->index) {
1136         case 0:
1137                 cookie = 0x1000;
1138                 break;
1139         case 1:
1140                 cookie = 0x2000;
1141                 break;
1142         case 2:
1143                 cookie = 0x3000;
1144                 break;
1145         case 3:
1146                 cookie = 0x4000;
1147                 break;
1148         case 4:
1149                 cookie = 0x5000;
1150                 break;
1151         case 5:
1152                 cookie = 0x6000;
1153                 break;
1154         default:
1155                 B43_WARN_ON(1);
1156         }
1157         B43_WARN_ON(slot & ~0x0FFF);
1158         cookie |= (u16) slot;
1159 
1160         return cookie;
1161 }
1162 
1163 /* Inspect a cookie and find out to which controller/slot it belongs. */
1164 static
1165 struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
1166 {
1167         struct b43_dma *dma = &dev->dma;
1168         struct b43_dmaring *ring = NULL;
1169 
1170         switch (cookie & 0xF000) {
1171         case 0x1000:
1172                 ring = dma->tx_ring0;
1173                 break;
1174         case 0x2000:
1175                 ring = dma->tx_ring1;
1176                 break;
1177         case 0x3000:
1178                 ring = dma->tx_ring2;
1179                 break;
1180         case 0x4000:
1181                 ring = dma->tx_ring3;
1182                 break;
1183         case 0x5000:
1184                 ring = dma->tx_ring4;
1185                 break;
1186         case 0x6000:
1187                 ring = dma->tx_ring5;
1188                 break;
1189         default:
1190                 B43_WARN_ON(1);
1191         }
1192         *slot = (cookie & 0x0FFF);
1193         B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1194 
1195         return ring;
1196 }
1197 
1198 static int dma_tx_fragment(struct b43_dmaring *ring,
1199                            struct sk_buff *skb,
1200                            struct ieee80211_tx_control *ctl)
1201 {
1202         const struct b43_dma_ops *ops = ring->ops;
1203         u8 *header;
1204         int slot, old_top_slot, old_used_slots;
1205         int err;
1206         struct b43_dmadesc_generic *desc;
1207         struct b43_dmadesc_meta *meta;
1208         struct b43_dmadesc_meta *meta_hdr;
1209         struct sk_buff *bounce_skb;
1210         u16 cookie;
1211         size_t hdrsize = b43_txhdr_size(ring->dev);
1212 
1213 #define SLOTS_PER_PACKET  2
1214         B43_WARN_ON(skb_shinfo(skb)->nr_frags);
1215 
1216         old_top_slot = ring->current_slot;
1217         old_used_slots = ring->used_slots;
1218 
1219         /* Get a slot for the header. */
1220         slot = request_slot(ring);
1221         desc = ops->idx2desc(ring, slot, &meta_hdr);
1222         memset(meta_hdr, 0, sizeof(*meta_hdr));
1223 
1224         header = &(ring->txhdr_cache[slot * hdrsize]);
1225         cookie = generate_cookie(ring, slot);
1226         err = b43_generate_txhdr(ring->dev, header,
1227                                  skb->data, skb->len, ctl, cookie);
1228         if (unlikely(err)) {
1229                 ring->current_slot = old_top_slot;
1230                 ring->used_slots = old_used_slots;
1231                 return err;
1232         }
1233 
1234         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1235                                            hdrsize, 1);
1236         if (b43_dma_mapping_error(ring, meta_hdr->dmaaddr, hdrsize, 1)) {
1237                 ring->current_slot = old_top_slot;
1238                 ring->used_slots = old_used_slots;
1239                 return -EIO;
1240         }
1241         ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1242                              hdrsize, 1, 0, 0);
1243 
1244         /* Get a slot for the payload. */
1245         slot = request_slot(ring);
1246         desc = ops->idx2desc(ring, slot, &meta);
1247         memset(meta, 0, sizeof(*meta));
1248 
1249         memcpy(&meta->txstat.control, ctl, sizeof(*ctl));
1250         meta->skb = skb;
1251         meta->is_last_fragment = 1;
1252 
1253         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1254         /* create a bounce buffer in zone_dma on mapping failure. */
1255         if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1256                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1257                 if (!bounce_skb) {
1258                         ring->current_slot = old_top_slot;
1259                         ring->used_slots = old_used_slots;
1260                         err = -ENOMEM;
1261                         goto out_unmap_hdr;
1262                 }
1263 
1264                 memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1265                 dev_kfree_skb_any(skb);
1266                 skb = bounce_skb;
1267                 meta->skb = skb;
1268                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1269                 if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1270                         ring->current_slot = old_top_slot;
1271                         ring->used_slots = old_used_slots;
1272                         err = -EIO;
1273                         goto out_free_bounce;
1274                 }
1275         }
1276 
1277         ops->fill_descriptor(ring, desc, meta->dmaaddr, skb->len, 0, 1, 1);
1278 
1279         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1280                 /* Tell the firmware about the cookie of the last
1281                  * mcast frame, so it can clear the more-data bit in it. */
1282                 b43_shm_write16(ring->dev, B43_SHM_SHARED,
1283                                 B43_SHM_SH_MCASTCOOKIE, cookie);
1284         }
1285         /* Now transfer the whole frame. */
1286         wmb();
1287         ops->poke_tx(ring, next_slot(ring, slot));
1288         return 0;
1289 
1290 out_free_bounce:
1291         dev_kfree_skb_any(skb);
1292 out_unmap_hdr:
1293         unmap_descbuffer(ring, meta_hdr->dmaaddr,
1294                          hdrsize, 1);
1295         return err;
1296 }
1297 
1298 static inline int should_inject_overflow(struct b43_dmaring *ring)
1299 {
1300 #ifdef CONFIG_B43_DEBUG
1301         if (unlikely(b43_debug(ring->dev, B43_DBG_DMAOVERFLOW))) {
1302                 /* Check if we should inject another ringbuffer overflow
1303                  * to test handling of this situation in the stack. */
1304                 unsigned long next_overflow;
1305 
1306                 next_overflow = ring->last_injected_overflow + HZ;
1307                 if (time_after(jiffies, next_overflow)) {
1308                         ring->last_injected_overflow = jiffies;
1309                         b43dbg(ring->dev->wl,
1310                                "Injecting TX ring overflow on "
1311                                "DMA controller %d\n", ring->index);
1312                         return 1;
1313                 }
1314         }
1315 #endif /* CONFIG_B43_DEBUG */
1316         return 0;
1317 }
1318 
1319 int b43_dma_tx(struct b43_wldev *dev,
1320                struct sk_buff *skb, struct ieee80211_tx_control *ctl)
1321 {
1322         struct b43_dmaring *ring;
1323         struct ieee80211_hdr *hdr;
1324         int err = 0;
1325         unsigned long flags;
1326 
1327         if (unlikely(skb->len < 2 + 2 + 6)) {
1328                 /* Too short, this can't be a valid frame. */
1329                 return -EINVAL;
1330         }
1331 
1332         hdr = (struct ieee80211_hdr *)skb->data;
1333         if (ctl->flags & IEEE80211_TXCTL_SEND_AFTER_DTIM) {
1334                 /* The multicast ring will be sent after the DTIM */
1335                 ring = dev->dma.tx_ring4;
1336                 /* Set the more-data bit. Ucode will clear it on
1337                  * the last frame for us. */
1338                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1339         } else {
1340                 /* Decide by priority where to put this frame. */
1341                 ring = priority_to_txring(dev, ctl->queue);
1342         }
1343 
1344         spin_lock_irqsave(&ring->lock, flags);
1345         B43_WARN_ON(!ring->tx);
1346         if (unlikely(free_slots(ring) < SLOTS_PER_PACKET)) {
1347                 b43warn(dev->wl, "DMA queue overflow\n");
1348                 err = -ENOSPC;
1349                 goto out_unlock;
1350         }
1351         /* Check if the queue was stopped in mac80211,
1352          * but we got called nevertheless.
1353          * That would be a mac80211 bug. */
1354         B43_WARN_ON(ring->stopped);
1355 
1356         err = dma_tx_fragment(ring, skb, ctl);
1357         if (unlikely(err == -ENOKEY)) {
1358                 /* Drop this packet, as we don't have the encryption key
1359                  * anymore and must not transmit it unencrypted. */
1360                 dev_kfree_skb_any(skb);
1361                 err = 0;
1362                 goto out_unlock;
1363         }
1364         if (unlikely(err)) {
1365                 b43err(dev->wl, "DMA tx mapping failure\n");
1366                 goto out_unlock;
1367         }
1368         ring->nr_tx_packets++;
1369         if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1370             should_inject_overflow(ring)) {
1371                 /* This TX ring is full. */
1372                 ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1373                 ring->stopped = 1;
1374                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1375                         b43dbg(dev->wl, "Stopped TX ring %d\n", ring->index);
1376                 }
1377         }
1378 out_unlock:
1379         spin_unlock_irqrestore(&ring->lock, flags);
1380 
1381         return err;
1382 }
1383 
1384 /* Called with IRQs disabled. */
1385 void b43_dma_handle_txstatus(struct b43_wldev *dev,
1386                              const struct b43_txstatus *status)
1387 {
1388         const struct b43_dma_ops *ops;
1389         struct b43_dmaring *ring;
1390         struct b43_dmadesc_generic *desc;
1391         struct b43_dmadesc_meta *meta;
1392         int slot;
1393 
1394         ring = parse_cookie(dev, status->cookie, &slot);
1395         if (unlikely(!ring))
1396                 return;
1397 
1398         spin_lock(&ring->lock); /* IRQs are already disabled. */
1399 
1400         B43_WARN_ON(!ring->tx);
1401         ops = ring->ops;
1402         while (1) {
1403                 B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1404                 desc = ops->idx2desc(ring, slot, &meta);
1405 
1406                 if (meta->skb)
1407                         unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
1408                                          1);
1409                 else
1410                         unmap_descbuffer(ring, meta->dmaaddr,
1411                                          b43_txhdr_size(dev), 1);
1412 
1413                 if (meta->is_last_fragment) {
1414                         B43_WARN_ON(!meta->skb);
1415                         /* Call back to inform the ieee80211 subsystem about the
1416                          * status of the transmission.
1417                          * Some fields of txstat are already filled in dma_tx().
1418                          */
1419                         if (status->acked) {
1420                                 meta->txstat.flags |= IEEE80211_TX_STATUS_ACK;
1421                         } else {
1422                                 if (!(meta->txstat.control.flags
1423                                       & IEEE80211_TXCTL_NO_ACK))
1424                                         meta->txstat.excessive_retries = 1;
1425                         }
1426                         if (status->frame_count == 0) {
1427                                 /* The frame was not transmitted at all. */
1428                                 meta->txstat.retry_count = 0;
1429                         } else
1430                                 meta->txstat.retry_count = status->frame_count - 1;
1431                         ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb,
1432                                                     &(meta->txstat));
1433                         /* skb is freed by ieee80211_tx_status_irqsafe() */
1434                         meta->skb = NULL;
1435                 } else {
1436                         /* No need to call free_descriptor_buffer here, as
1437                          * this is only the txhdr, which is not allocated.
1438                          */
1439                         B43_WARN_ON(meta->skb);
1440                 }
1441 
1442                 /* Everything unmapped and free'd. So it's not used anymore. */
1443                 ring->used_slots--;
1444 
1445                 if (meta->is_last_fragment)
1446                         break;
1447                 slot = next_slot(ring, slot);
1448         }
1449         dev->stats.last_tx = jiffies;
1450         if (ring->stopped) {
1451                 B43_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1452                 ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1453                 ring->stopped = 0;
1454                 if (b43_debug(dev, B43_DBG_DMAVERBOSE)) {
1455                         b43dbg(dev->wl, "Woke up TX ring %d\n", ring->index);
1456                 }
1457         }
1458 
1459         spin_unlock(&ring->lock);
1460 }
1461 
1462 void b43_dma_get_tx_stats(struct b43_wldev *dev,
1463                           struct ieee80211_tx_queue_stats *stats)
1464 {
1465         const int nr_queues = dev->wl->hw->queues;
1466         struct b43_dmaring *ring;
1467         struct ieee80211_tx_queue_stats_data *data;
1468         unsigned long flags;
1469         int i;
1470 
1471         for (i = 0; i < nr_queues; i++) {
1472                 data = &(stats->data[i]);
1473                 ring = priority_to_txring(dev, i);
1474 
1475                 spin_lock_irqsave(&ring->lock, flags);
1476                 data->len = ring->used_slots / SLOTS_PER_PACKET;
1477                 data->limit = ring->nr_slots / SLOTS_PER_PACKET;
1478                 data->count = ring->nr_tx_packets;
1479                 spin_unlock_irqrestore(&ring->lock, flags);
1480         }
1481 }
1482 
1483 static void dma_rx(struct b43_dmaring *ring, int *slot)
1484 {
1485         const struct b43_dma_ops *ops = ring->ops;
1486         struct b43_dmadesc_generic *desc;
1487         struct b43_dmadesc_meta *meta;
1488         struct b43_rxhdr_fw4 *rxhdr;
1489         struct sk_buff *skb;
1490         u16 len;
1491         int err;
1492         dma_addr_t dmaaddr;
1493 
1494         desc = ops->idx2desc(ring, *slot, &meta);
1495 
1496         sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1497         skb = meta->skb;
1498 
1499         if (ring->index == 3) {
1500                 /* We received an xmit status. */
1501                 struct b43_hwtxstatus *hw = (struct b43_hwtxstatus *)skb->data;
1502                 int i = 0;
1503 
1504                 while (hw->cookie == 0) {
1505                         if (i > 100)
1506                                 break;
1507                         i++;
1508                         udelay(2);
1509                         barrier();
1510                 }
1511                 b43_handle_hwtxstatus(ring->dev, hw);
1512                 /* recycle the descriptor buffer. */
1513                 sync_descbuffer_for_device(ring, meta->dmaaddr,
1514                                            ring->rx_buffersize);
1515 
1516                 return;
1517         }
1518         rxhdr = (struct b43_rxhdr_fw4 *)skb->data;
1519         len = le16_to_cpu(rxhdr->frame_len);
1520         if (len == 0) {
1521                 int i = 0;
1522 
1523                 do {
1524                         udelay(2);
1525                         barrier();
1526                         len = le16_to_cpu(rxhdr->frame_len);
1527                 } while (len == 0 && i++ < 5);
1528                 if (unlikely(len == 0)) {
1529                         /* recycle the descriptor buffer. */
1530                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1531                                                    ring->rx_buffersize);
1532                         goto drop;
1533                 }
1534         }
1535         if (unlikely(len > ring->rx_buffersize)) {
1536                 /* The data did not fit into one descriptor buffer
1537                  * and is split over multiple buffers.
1538                  * This should never happen, as we try to allocate buffers
1539                  * big enough. So simply ignore this packet.
1540                  */
1541                 int cnt = 0;
1542                 s32 tmp = len;
1543 
1544                 while (1) {
1545                         desc = ops->idx2desc(ring, *slot, &meta);
1546                         /* recycle the descriptor buffer. */
1547                         sync_descbuffer_for_device(ring, meta->dmaaddr,
1548                                                    ring->rx_buffersize);
1549                         *slot = next_slot(ring, *slot);
1550                         cnt++;
1551                         tmp -= ring->rx_buffersize;
1552                         if (tmp <= 0)
1553                                 break;
1554                 }
1555                 b43err(ring->dev->wl, "DMA RX buffer too small "
1556                        "(len: %u, buffer: %u, nr-dropped: %d)\n",
1557                        len, ring->rx_buffersize, cnt);
1558                 goto drop;
1559         }
1560 
1561         dmaaddr = meta->dmaaddr;
1562         err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1563         if (unlikely(err)) {
1564                 b43dbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer() failed\n");
1565                 sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
1566                 goto drop;
1567         }
1568 
1569         unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1570         skb_put(skb, len + ring->frameoffset);
1571         skb_pull(skb, ring->frameoffset);
1572 
1573         b43_rx(ring->dev, skb, rxhdr);
1574       drop:
1575         return;
1576 }
1577 
1578 void b43_dma_rx(struct b43_dmaring *ring)
1579 {
1580         const struct b43_dma_ops *ops = ring->ops;
1581         int slot, current_slot;
1582         int used_slots = 0;
1583 
1584         B43_WARN_ON(ring->tx);
1585         current_slot = ops->get_current_rxslot(ring);
1586         B43_WARN_ON(!(current_slot >= 0 && current_slot < ring->nr_slots));
1587 
1588         slot = ring->current_slot;
1589         for (; slot != current_slot; slot = next_slot(ring, slot)) {
1590                 dma_rx(ring, &slot);
1591                 update_max_used_slots(ring, ++used_slots);
1592         }
1593         ops->set_current_rxslot(ring, slot);
1594         ring->current_slot = slot;
1595 }
1596 
1597 static void b43_dma_tx_suspend_ring(struct b43_dmaring *ring)
1598 {
1599         unsigned long flags;
1600 
1601         spin_lock_irqsave(&ring->lock, flags);
1602         B43_WARN_ON(!ring->tx);
1603         ring->ops->tx_suspend(ring);
1604         spin_unlock_irqrestore(&ring->lock, flags);
1605 }
1606 
1607 static void b43_dma_tx_resume_ring(struct b43_dmaring *ring)
1608 {
1609         unsigned long flags;
1610 
1611         spin_lock_irqsave(&ring->lock, flags);
1612         B43_WARN_ON(!ring->tx);
1613         ring->ops->tx_resume(ring);
1614         spin_unlock_irqrestore(&ring->lock, flags);
1615 }
1616 
1617 void b43_dma_tx_suspend(struct b43_wldev *dev)
1618 {
1619         b43_power_saving_ctl_bits(dev, B43_PS_AWAKE);
1620         b43_dma_tx_suspend_ring(dev->dma.tx_ring0);
1621         b43_dma_tx_suspend_ring(dev->dma.tx_ring1);
1622         b43_dma_tx_suspend_ring(dev->dma.tx_ring2);
1623         b43_dma_tx_suspend_ring(dev->dma.tx_ring3);
1624         b43_dma_tx_suspend_ring(dev->dma.tx_ring4);
1625         b43_dma_tx_suspend_ring(dev->dma.tx_ring5);
1626 }
1627 
1628 void b43_dma_tx_resume(struct b43_wldev *dev)
1629 {
1630         b43_dma_tx_resume_ring(dev->dma.tx_ring5);
1631         b43_dma_tx_resume_ring(dev->dma.tx_ring4);
1632         b43_dma_tx_resume_ring(dev->dma.tx_ring3);
1633         b43_dma_tx_resume_ring(dev->dma.tx_ring2);
1634         b43_dma_tx_resume_ring(dev->dma.tx_ring1);
1635         b43_dma_tx_resume_ring(dev->dma.tx_ring0);
1636         b43_power_saving_ctl_bits(dev, 0);
1637 }
1638 
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