dma.c revision c1be5152860218dffea6a47cff5ea31a56c6cff5
1/*
2
3  Broadcom B43legacy 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 "b43legacy.h"
31#include "dma.h"
32#include "main.h"
33#include "debugfs.h"
34#include "xmit.h"
35
36#include <linux/dma-mapping.h>
37#include <linux/pci.h>
38#include <linux/delay.h>
39#include <linux/skbuff.h>
40#include <net/dst.h>
41
42/* 32bit DMA ops. */
43static
44struct b43legacy_dmadesc_generic *op32_idx2desc(
45					struct b43legacy_dmaring *ring,
46					int slot,
47					struct b43legacy_dmadesc_meta **meta)
48{
49	struct b43legacy_dmadesc32 *desc;
50
51	*meta = &(ring->meta[slot]);
52	desc = ring->descbase;
53	desc = &(desc[slot]);
54
55	return (struct b43legacy_dmadesc_generic *)desc;
56}
57
58static void op32_fill_descriptor(struct b43legacy_dmaring *ring,
59				 struct b43legacy_dmadesc_generic *desc,
60				 dma_addr_t dmaaddr, u16 bufsize,
61				 int start, int end, int irq)
62{
63	struct b43legacy_dmadesc32 *descbase = ring->descbase;
64	int slot;
65	u32 ctl;
66	u32 addr;
67	u32 addrext;
68
69	slot = (int)(&(desc->dma32) - descbase);
70	B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
71
72	addr = (u32)(dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
73	addrext = (u32)(dmaaddr & SSB_DMA_TRANSLATION_MASK)
74		   >> SSB_DMA_TRANSLATION_SHIFT;
75	addr |= ssb_dma_translation(ring->dev->dev);
76	ctl = (bufsize - ring->frameoffset)
77	      & B43legacy_DMA32_DCTL_BYTECNT;
78	if (slot == ring->nr_slots - 1)
79		ctl |= B43legacy_DMA32_DCTL_DTABLEEND;
80	if (start)
81		ctl |= B43legacy_DMA32_DCTL_FRAMESTART;
82	if (end)
83		ctl |= B43legacy_DMA32_DCTL_FRAMEEND;
84	if (irq)
85		ctl |= B43legacy_DMA32_DCTL_IRQ;
86	ctl |= (addrext << B43legacy_DMA32_DCTL_ADDREXT_SHIFT)
87	       & B43legacy_DMA32_DCTL_ADDREXT_MASK;
88
89	desc->dma32.control = cpu_to_le32(ctl);
90	desc->dma32.address = cpu_to_le32(addr);
91}
92
93static void op32_poke_tx(struct b43legacy_dmaring *ring, int slot)
94{
95	b43legacy_dma_write(ring, B43legacy_DMA32_TXINDEX,
96			    (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
97}
98
99static void op32_tx_suspend(struct b43legacy_dmaring *ring)
100{
101	b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
102			    b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
103			    | B43legacy_DMA32_TXSUSPEND);
104}
105
106static void op32_tx_resume(struct b43legacy_dmaring *ring)
107{
108	b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
109			    b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
110			    & ~B43legacy_DMA32_TXSUSPEND);
111}
112
113static int op32_get_current_rxslot(struct b43legacy_dmaring *ring)
114{
115	u32 val;
116
117	val = b43legacy_dma_read(ring, B43legacy_DMA32_RXSTATUS);
118	val &= B43legacy_DMA32_RXDPTR;
119
120	return (val / sizeof(struct b43legacy_dmadesc32));
121}
122
123static void op32_set_current_rxslot(struct b43legacy_dmaring *ring,
124				    int slot)
125{
126	b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
127			    (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
128}
129
130static const struct b43legacy_dma_ops dma32_ops = {
131	.idx2desc		= op32_idx2desc,
132	.fill_descriptor	= op32_fill_descriptor,
133	.poke_tx		= op32_poke_tx,
134	.tx_suspend		= op32_tx_suspend,
135	.tx_resume		= op32_tx_resume,
136	.get_current_rxslot	= op32_get_current_rxslot,
137	.set_current_rxslot	= op32_set_current_rxslot,
138};
139
140/* 64bit DMA ops. */
141static
142struct b43legacy_dmadesc_generic *op64_idx2desc(
143					struct b43legacy_dmaring *ring,
144					int slot,
145					struct b43legacy_dmadesc_meta
146					**meta)
147{
148	struct b43legacy_dmadesc64 *desc;
149
150	*meta = &(ring->meta[slot]);
151	desc = ring->descbase;
152	desc = &(desc[slot]);
153
154	return (struct b43legacy_dmadesc_generic *)desc;
155}
156
157static void op64_fill_descriptor(struct b43legacy_dmaring *ring,
158				 struct b43legacy_dmadesc_generic *desc,
159				 dma_addr_t dmaaddr, u16 bufsize,
160				 int start, int end, int irq)
161{
162	struct b43legacy_dmadesc64 *descbase = ring->descbase;
163	int slot;
164	u32 ctl0 = 0;
165	u32 ctl1 = 0;
166	u32 addrlo;
167	u32 addrhi;
168	u32 addrext;
169
170	slot = (int)(&(desc->dma64) - descbase);
171	B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
172
173	addrlo = (u32)(dmaaddr & 0xFFFFFFFF);
174	addrhi = (((u64)dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
175	addrext = (((u64)dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
176		  >> SSB_DMA_TRANSLATION_SHIFT;
177	addrhi |= ssb_dma_translation(ring->dev->dev);
178	if (slot == ring->nr_slots - 1)
179		ctl0 |= B43legacy_DMA64_DCTL0_DTABLEEND;
180	if (start)
181		ctl0 |= B43legacy_DMA64_DCTL0_FRAMESTART;
182	if (end)
183		ctl0 |= B43legacy_DMA64_DCTL0_FRAMEEND;
184	if (irq)
185		ctl0 |= B43legacy_DMA64_DCTL0_IRQ;
186	ctl1 |= (bufsize - ring->frameoffset)
187		& B43legacy_DMA64_DCTL1_BYTECNT;
188	ctl1 |= (addrext << B43legacy_DMA64_DCTL1_ADDREXT_SHIFT)
189		& B43legacy_DMA64_DCTL1_ADDREXT_MASK;
190
191	desc->dma64.control0 = cpu_to_le32(ctl0);
192	desc->dma64.control1 = cpu_to_le32(ctl1);
193	desc->dma64.address_low = cpu_to_le32(addrlo);
194	desc->dma64.address_high = cpu_to_le32(addrhi);
195}
196
197static void op64_poke_tx(struct b43legacy_dmaring *ring, int slot)
198{
199	b43legacy_dma_write(ring, B43legacy_DMA64_TXINDEX,
200			    (u32)(slot * sizeof(struct b43legacy_dmadesc64)));
201}
202
203static void op64_tx_suspend(struct b43legacy_dmaring *ring)
204{
205	b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
206			    b43legacy_dma_read(ring, B43legacy_DMA64_TXCTL)
207			    | B43legacy_DMA64_TXSUSPEND);
208}
209
210static void op64_tx_resume(struct b43legacy_dmaring *ring)
211{
212	b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
213			    b43legacy_dma_read(ring, B43legacy_DMA64_TXCTL)
214			    & ~B43legacy_DMA64_TXSUSPEND);
215}
216
217static int op64_get_current_rxslot(struct b43legacy_dmaring *ring)
218{
219	u32 val;
220
221	val = b43legacy_dma_read(ring, B43legacy_DMA64_RXSTATUS);
222	val &= B43legacy_DMA64_RXSTATDPTR;
223
224	return (val / sizeof(struct b43legacy_dmadesc64));
225}
226
227static void op64_set_current_rxslot(struct b43legacy_dmaring *ring,
228				    int slot)
229{
230	b43legacy_dma_write(ring, B43legacy_DMA64_RXINDEX,
231			    (u32)(slot * sizeof(struct b43legacy_dmadesc64)));
232}
233
234static const struct b43legacy_dma_ops dma64_ops = {
235	.idx2desc		= op64_idx2desc,
236	.fill_descriptor	= op64_fill_descriptor,
237	.poke_tx		= op64_poke_tx,
238	.tx_suspend		= op64_tx_suspend,
239	.tx_resume		= op64_tx_resume,
240	.get_current_rxslot	= op64_get_current_rxslot,
241	.set_current_rxslot	= op64_set_current_rxslot,
242};
243
244
245static inline int free_slots(struct b43legacy_dmaring *ring)
246{
247	return (ring->nr_slots - ring->used_slots);
248}
249
250static inline int next_slot(struct b43legacy_dmaring *ring, int slot)
251{
252	B43legacy_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
253	if (slot == ring->nr_slots - 1)
254		return 0;
255	return slot + 1;
256}
257
258static inline int prev_slot(struct b43legacy_dmaring *ring, int slot)
259{
260	B43legacy_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
261	if (slot == 0)
262		return ring->nr_slots - 1;
263	return slot - 1;
264}
265
266#ifdef CONFIG_B43LEGACY_DEBUG
267static void update_max_used_slots(struct b43legacy_dmaring *ring,
268				  int current_used_slots)
269{
270	if (current_used_slots <= ring->max_used_slots)
271		return;
272	ring->max_used_slots = current_used_slots;
273	if (b43legacy_debug(ring->dev, B43legacy_DBG_DMAVERBOSE))
274		b43legacydbg(ring->dev->wl,
275		       "max_used_slots increased to %d on %s ring %d\n",
276		       ring->max_used_slots,
277		       ring->tx ? "TX" : "RX",
278		       ring->index);
279}
280#else
281static inline
282void update_max_used_slots(struct b43legacy_dmaring *ring,
283			   int current_used_slots)
284{ }
285#endif /* DEBUG */
286
287/* Request a slot for usage. */
288static inline
289int request_slot(struct b43legacy_dmaring *ring)
290{
291	int slot;
292
293	B43legacy_WARN_ON(!ring->tx);
294	B43legacy_WARN_ON(ring->stopped);
295	B43legacy_WARN_ON(free_slots(ring) == 0);
296
297	slot = next_slot(ring, ring->current_slot);
298	ring->current_slot = slot;
299	ring->used_slots++;
300
301	update_max_used_slots(ring, ring->used_slots);
302
303	return slot;
304}
305
306/* Mac80211-queue to b43legacy-ring mapping */
307static struct b43legacy_dmaring *priority_to_txring(
308						struct b43legacy_wldev *dev,
309						int queue_priority)
310{
311	struct b43legacy_dmaring *ring;
312
313/*FIXME: For now we always run on TX-ring-1 */
314return dev->dma.tx_ring1;
315
316	/* 0 = highest priority */
317	switch (queue_priority) {
318	default:
319		B43legacy_WARN_ON(1);
320		/* fallthrough */
321	case 0:
322		ring = dev->dma.tx_ring3;
323		break;
324	case 1:
325		ring = dev->dma.tx_ring2;
326		break;
327	case 2:
328		ring = dev->dma.tx_ring1;
329		break;
330	case 3:
331		ring = dev->dma.tx_ring0;
332		break;
333	case 4:
334		ring = dev->dma.tx_ring4;
335		break;
336	case 5:
337		ring = dev->dma.tx_ring5;
338		break;
339	}
340
341	return ring;
342}
343
344/* Bcm4301-ring to mac80211-queue mapping */
345static inline int txring_to_priority(struct b43legacy_dmaring *ring)
346{
347	static const u8 idx_to_prio[] =
348		{ 3, 2, 1, 0, 4, 5, };
349
350/*FIXME: have only one queue, for now */
351return 0;
352
353	return idx_to_prio[ring->index];
354}
355
356
357static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
358					int controller_idx)
359{
360	static const u16 map64[] = {
361		B43legacy_MMIO_DMA64_BASE0,
362		B43legacy_MMIO_DMA64_BASE1,
363		B43legacy_MMIO_DMA64_BASE2,
364		B43legacy_MMIO_DMA64_BASE3,
365		B43legacy_MMIO_DMA64_BASE4,
366		B43legacy_MMIO_DMA64_BASE5,
367	};
368	static const u16 map32[] = {
369		B43legacy_MMIO_DMA32_BASE0,
370		B43legacy_MMIO_DMA32_BASE1,
371		B43legacy_MMIO_DMA32_BASE2,
372		B43legacy_MMIO_DMA32_BASE3,
373		B43legacy_MMIO_DMA32_BASE4,
374		B43legacy_MMIO_DMA32_BASE5,
375	};
376
377	if (type == B43legacy_DMA_64BIT) {
378		B43legacy_WARN_ON(!(controller_idx >= 0 &&
379				  controller_idx < ARRAY_SIZE(map64)));
380		return map64[controller_idx];
381	}
382	B43legacy_WARN_ON(!(controller_idx >= 0 &&
383			  controller_idx < ARRAY_SIZE(map32)));
384	return map32[controller_idx];
385}
386
387static inline
388dma_addr_t map_descbuffer(struct b43legacy_dmaring *ring,
389			  unsigned char *buf,
390			  size_t len,
391			  int tx)
392{
393	dma_addr_t dmaaddr;
394
395	if (tx)
396		dmaaddr = ssb_dma_map_single(ring->dev->dev,
397					     buf, len,
398					     DMA_TO_DEVICE);
399	else
400		dmaaddr = ssb_dma_map_single(ring->dev->dev,
401					     buf, len,
402					     DMA_FROM_DEVICE);
403
404	return dmaaddr;
405}
406
407static inline
408void unmap_descbuffer(struct b43legacy_dmaring *ring,
409		      dma_addr_t addr,
410		      size_t len,
411		      int tx)
412{
413	if (tx)
414		ssb_dma_unmap_single(ring->dev->dev,
415				     addr, len,
416				     DMA_TO_DEVICE);
417	else
418		ssb_dma_unmap_single(ring->dev->dev,
419				     addr, len,
420				     DMA_FROM_DEVICE);
421}
422
423static inline
424void sync_descbuffer_for_cpu(struct b43legacy_dmaring *ring,
425			     dma_addr_t addr,
426			     size_t len)
427{
428	B43legacy_WARN_ON(ring->tx);
429
430	ssb_dma_sync_single_for_cpu(ring->dev->dev,
431				    addr, len, DMA_FROM_DEVICE);
432}
433
434static inline
435void sync_descbuffer_for_device(struct b43legacy_dmaring *ring,
436				dma_addr_t addr,
437				size_t len)
438{
439	B43legacy_WARN_ON(ring->tx);
440
441	ssb_dma_sync_single_for_device(ring->dev->dev,
442				       addr, len, DMA_FROM_DEVICE);
443}
444
445static inline
446void free_descriptor_buffer(struct b43legacy_dmaring *ring,
447			    struct b43legacy_dmadesc_meta *meta,
448			    int irq_context)
449{
450	if (meta->skb) {
451		if (irq_context)
452			dev_kfree_skb_irq(meta->skb);
453		else
454			dev_kfree_skb(meta->skb);
455		meta->skb = NULL;
456	}
457}
458
459static int alloc_ringmemory(struct b43legacy_dmaring *ring)
460{
461	/* GFP flags must match the flags in free_ringmemory()! */
462	ring->descbase = ssb_dma_alloc_consistent(ring->dev->dev,
463						  B43legacy_DMA_RINGMEMSIZE,
464						  &(ring->dmabase),
465						  GFP_KERNEL);
466	if (!ring->descbase) {
467		b43legacyerr(ring->dev->wl, "DMA ringmemory allocation"
468			     " failed\n");
469		return -ENOMEM;
470	}
471	memset(ring->descbase, 0, B43legacy_DMA_RINGMEMSIZE);
472
473	return 0;
474}
475
476static void free_ringmemory(struct b43legacy_dmaring *ring)
477{
478	ssb_dma_free_consistent(ring->dev->dev, B43legacy_DMA_RINGMEMSIZE,
479				ring->descbase, ring->dmabase, GFP_KERNEL);
480}
481
482/* Reset the RX DMA channel */
483static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
484					    u16 mmio_base,
485					    enum b43legacy_dmatype type)
486{
487	int i;
488	u32 value;
489	u16 offset;
490
491	might_sleep();
492
493	offset = (type == B43legacy_DMA_64BIT) ?
494		 B43legacy_DMA64_RXCTL : B43legacy_DMA32_RXCTL;
495	b43legacy_write32(dev, mmio_base + offset, 0);
496	for (i = 0; i < 10; i++) {
497		offset = (type == B43legacy_DMA_64BIT) ?
498			 B43legacy_DMA64_RXSTATUS : B43legacy_DMA32_RXSTATUS;
499		value = b43legacy_read32(dev, mmio_base + offset);
500		if (type == B43legacy_DMA_64BIT) {
501			value &= B43legacy_DMA64_RXSTAT;
502			if (value == B43legacy_DMA64_RXSTAT_DISABLED) {
503				i = -1;
504				break;
505			}
506		} else {
507			value &= B43legacy_DMA32_RXSTATE;
508			if (value == B43legacy_DMA32_RXSTAT_DISABLED) {
509				i = -1;
510				break;
511			}
512		}
513		msleep(1);
514	}
515	if (i != -1) {
516		b43legacyerr(dev->wl, "DMA RX reset timed out\n");
517		return -ENODEV;
518	}
519
520	return 0;
521}
522
523/* Reset the RX DMA channel */
524static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
525					    u16 mmio_base,
526					    enum b43legacy_dmatype type)
527{
528	int i;
529	u32 value;
530	u16 offset;
531
532	might_sleep();
533
534	for (i = 0; i < 10; i++) {
535		offset = (type == B43legacy_DMA_64BIT) ?
536			 B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
537		value = b43legacy_read32(dev, mmio_base + offset);
538		if (type == B43legacy_DMA_64BIT) {
539			value &= B43legacy_DMA64_TXSTAT;
540			if (value == B43legacy_DMA64_TXSTAT_DISABLED ||
541			    value == B43legacy_DMA64_TXSTAT_IDLEWAIT ||
542			    value == B43legacy_DMA64_TXSTAT_STOPPED)
543				break;
544		} else {
545			value &= B43legacy_DMA32_TXSTATE;
546			if (value == B43legacy_DMA32_TXSTAT_DISABLED ||
547			    value == B43legacy_DMA32_TXSTAT_IDLEWAIT ||
548			    value == B43legacy_DMA32_TXSTAT_STOPPED)
549				break;
550		}
551		msleep(1);
552	}
553	offset = (type == B43legacy_DMA_64BIT) ? B43legacy_DMA64_TXCTL :
554						 B43legacy_DMA32_TXCTL;
555	b43legacy_write32(dev, mmio_base + offset, 0);
556	for (i = 0; i < 10; i++) {
557		offset = (type == B43legacy_DMA_64BIT) ?
558			 B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
559		value = b43legacy_read32(dev, mmio_base + offset);
560		if (type == B43legacy_DMA_64BIT) {
561			value &= B43legacy_DMA64_TXSTAT;
562			if (value == B43legacy_DMA64_TXSTAT_DISABLED) {
563				i = -1;
564				break;
565			}
566		} else {
567			value &= B43legacy_DMA32_TXSTATE;
568			if (value == B43legacy_DMA32_TXSTAT_DISABLED) {
569				i = -1;
570				break;
571			}
572		}
573		msleep(1);
574	}
575	if (i != -1) {
576		b43legacyerr(dev->wl, "DMA TX reset timed out\n");
577		return -ENODEV;
578	}
579	/* ensure the reset is completed. */
580	msleep(1);
581
582	return 0;
583}
584
585/* Check if a DMA mapping address is invalid. */
586static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
587					 dma_addr_t addr,
588					 size_t buffersize,
589					 bool dma_to_device)
590{
591	if (unlikely(ssb_dma_mapping_error(ring->dev->dev, addr)))
592		return 1;
593
594	switch (ring->type) {
595	case B43legacy_DMA_30BIT:
596		if ((u64)addr + buffersize > (1ULL << 30))
597			goto address_error;
598		break;
599	case B43legacy_DMA_32BIT:
600		if ((u64)addr + buffersize > (1ULL << 32))
601			goto address_error;
602		break;
603	case B43legacy_DMA_64BIT:
604		/* Currently we can't have addresses beyond 64 bits in the kernel. */
605		break;
606	}
607
608	/* The address is OK. */
609	return 0;
610
611address_error:
612	/* We can't support this address. Unmap it again. */
613	unmap_descbuffer(ring, addr, buffersize, dma_to_device);
614
615	return 1;
616}
617
618static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
619			       struct b43legacy_dmadesc_generic *desc,
620			       struct b43legacy_dmadesc_meta *meta,
621			       gfp_t gfp_flags)
622{
623	struct b43legacy_rxhdr_fw3 *rxhdr;
624	struct b43legacy_hwtxstatus *txstat;
625	dma_addr_t dmaaddr;
626	struct sk_buff *skb;
627
628	B43legacy_WARN_ON(ring->tx);
629
630	skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
631	if (unlikely(!skb))
632		return -ENOMEM;
633	dmaaddr = map_descbuffer(ring, skb->data,
634				 ring->rx_buffersize, 0);
635	if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
636		/* ugh. try to realloc in zone_dma */
637		gfp_flags |= GFP_DMA;
638
639		dev_kfree_skb_any(skb);
640
641		skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
642		if (unlikely(!skb))
643			return -ENOMEM;
644		dmaaddr = map_descbuffer(ring, skb->data,
645					 ring->rx_buffersize, 0);
646	}
647
648	if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
649		dev_kfree_skb_any(skb);
650		return -EIO;
651	}
652
653	meta->skb = skb;
654	meta->dmaaddr = dmaaddr;
655	ring->ops->fill_descriptor(ring, desc, dmaaddr,
656				   ring->rx_buffersize, 0, 0, 0);
657
658	rxhdr = (struct b43legacy_rxhdr_fw3 *)(skb->data);
659	rxhdr->frame_len = 0;
660	txstat = (struct b43legacy_hwtxstatus *)(skb->data);
661	txstat->cookie = 0;
662
663	return 0;
664}
665
666/* Allocate the initial descbuffers.
667 * This is used for an RX ring only.
668 */
669static int alloc_initial_descbuffers(struct b43legacy_dmaring *ring)
670{
671	int i;
672	int err = -ENOMEM;
673	struct b43legacy_dmadesc_generic *desc;
674	struct b43legacy_dmadesc_meta *meta;
675
676	for (i = 0; i < ring->nr_slots; i++) {
677		desc = ring->ops->idx2desc(ring, i, &meta);
678
679		err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
680		if (err) {
681			b43legacyerr(ring->dev->wl,
682			       "Failed to allocate initial descbuffers\n");
683			goto err_unwind;
684		}
685	}
686	mb(); /* all descbuffer setup before next line */
687	ring->used_slots = ring->nr_slots;
688	err = 0;
689out:
690	return err;
691
692err_unwind:
693	for (i--; i >= 0; i--) {
694		desc = ring->ops->idx2desc(ring, i, &meta);
695
696		unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
697		dev_kfree_skb(meta->skb);
698	}
699	goto out;
700}
701
702/* Do initial setup of the DMA controller.
703 * Reset the controller, write the ring busaddress
704 * and switch the "enable" bit on.
705 */
706static int dmacontroller_setup(struct b43legacy_dmaring *ring)
707{
708	int err = 0;
709	u32 value;
710	u32 addrext;
711	u32 trans = ssb_dma_translation(ring->dev->dev);
712
713	if (ring->tx) {
714		if (ring->type == B43legacy_DMA_64BIT) {
715			u64 ringbase = (u64)(ring->dmabase);
716
717			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
718				  >> SSB_DMA_TRANSLATION_SHIFT;
719			value = B43legacy_DMA64_TXENABLE;
720			value |= (addrext << B43legacy_DMA64_TXADDREXT_SHIFT)
721				& B43legacy_DMA64_TXADDREXT_MASK;
722			b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
723					    value);
724			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGLO,
725					    (ringbase & 0xFFFFFFFF));
726			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGHI,
727					    ((ringbase >> 32)
728					    & ~SSB_DMA_TRANSLATION_MASK)
729					    | trans);
730		} else {
731			u32 ringbase = (u32)(ring->dmabase);
732
733			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
734				  >> SSB_DMA_TRANSLATION_SHIFT;
735			value = B43legacy_DMA32_TXENABLE;
736			value |= (addrext << B43legacy_DMA32_TXADDREXT_SHIFT)
737				& B43legacy_DMA32_TXADDREXT_MASK;
738			b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
739					    value);
740			b43legacy_dma_write(ring, B43legacy_DMA32_TXRING,
741					    (ringbase &
742					    ~SSB_DMA_TRANSLATION_MASK)
743					    | trans);
744		}
745	} else {
746		err = alloc_initial_descbuffers(ring);
747		if (err)
748			goto out;
749		if (ring->type == B43legacy_DMA_64BIT) {
750			u64 ringbase = (u64)(ring->dmabase);
751
752			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
753				  >> SSB_DMA_TRANSLATION_SHIFT;
754			value = (ring->frameoffset <<
755				 B43legacy_DMA64_RXFROFF_SHIFT);
756			value |= B43legacy_DMA64_RXENABLE;
757			value |= (addrext << B43legacy_DMA64_RXADDREXT_SHIFT)
758				& B43legacy_DMA64_RXADDREXT_MASK;
759			b43legacy_dma_write(ring, B43legacy_DMA64_RXCTL,
760					    value);
761			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGLO,
762					    (ringbase & 0xFFFFFFFF));
763			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGHI,
764					    ((ringbase >> 32) &
765					    ~SSB_DMA_TRANSLATION_MASK) |
766					    trans);
767			b43legacy_dma_write(ring, B43legacy_DMA64_RXINDEX,
768					    200);
769		} else {
770			u32 ringbase = (u32)(ring->dmabase);
771
772			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
773				  >> SSB_DMA_TRANSLATION_SHIFT;
774			value = (ring->frameoffset <<
775				 B43legacy_DMA32_RXFROFF_SHIFT);
776			value |= B43legacy_DMA32_RXENABLE;
777			value |= (addrext <<
778				 B43legacy_DMA32_RXADDREXT_SHIFT)
779				 & B43legacy_DMA32_RXADDREXT_MASK;
780			b43legacy_dma_write(ring, B43legacy_DMA32_RXCTL,
781					    value);
782			b43legacy_dma_write(ring, B43legacy_DMA32_RXRING,
783					    (ringbase &
784					    ~SSB_DMA_TRANSLATION_MASK)
785					    | trans);
786			b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
787					    200);
788		}
789	}
790
791out:
792	return err;
793}
794
795/* Shutdown the DMA controller. */
796static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
797{
798	if (ring->tx) {
799		b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
800						 ring->type);
801		if (ring->type == B43legacy_DMA_64BIT) {
802			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGLO, 0);
803			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGHI, 0);
804		} else
805			b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
806	} else {
807		b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
808						 ring->type);
809		if (ring->type == B43legacy_DMA_64BIT) {
810			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGLO, 0);
811			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGHI, 0);
812		} else
813			b43legacy_dma_write(ring, B43legacy_DMA32_RXRING, 0);
814	}
815}
816
817static void free_all_descbuffers(struct b43legacy_dmaring *ring)
818{
819	struct b43legacy_dmadesc_generic *desc;
820	struct b43legacy_dmadesc_meta *meta;
821	int i;
822
823	if (!ring->used_slots)
824		return;
825	for (i = 0; i < ring->nr_slots; i++) {
826		desc = ring->ops->idx2desc(ring, i, &meta);
827
828		if (!meta->skb) {
829			B43legacy_WARN_ON(!ring->tx);
830			continue;
831		}
832		if (ring->tx)
833			unmap_descbuffer(ring, meta->dmaaddr,
834					 meta->skb->len, 1);
835		else
836			unmap_descbuffer(ring, meta->dmaaddr,
837					 ring->rx_buffersize, 0);
838		free_descriptor_buffer(ring, meta, 0);
839	}
840}
841
842static u64 supported_dma_mask(struct b43legacy_wldev *dev)
843{
844	u32 tmp;
845	u16 mmio_base;
846
847	tmp = b43legacy_read32(dev, SSB_TMSHIGH);
848	if (tmp & SSB_TMSHIGH_DMA64)
849		return DMA_BIT_MASK(64);
850	mmio_base = b43legacy_dmacontroller_base(0, 0);
851	b43legacy_write32(dev,
852			mmio_base + B43legacy_DMA32_TXCTL,
853			B43legacy_DMA32_TXADDREXT_MASK);
854	tmp = b43legacy_read32(dev, mmio_base +
855			       B43legacy_DMA32_TXCTL);
856	if (tmp & B43legacy_DMA32_TXADDREXT_MASK)
857		return DMA_BIT_MASK(32);
858
859	return DMA_BIT_MASK(30);
860}
861
862static enum b43legacy_dmatype dma_mask_to_engine_type(u64 dmamask)
863{
864	if (dmamask == DMA_BIT_MASK(30))
865		return B43legacy_DMA_30BIT;
866	if (dmamask == DMA_BIT_MASK(32))
867		return B43legacy_DMA_32BIT;
868	if (dmamask == DMA_BIT_MASK(64))
869		return B43legacy_DMA_64BIT;
870	B43legacy_WARN_ON(1);
871	return B43legacy_DMA_30BIT;
872}
873
874/* Main initialization function. */
875static
876struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
877						  int controller_index,
878						  int for_tx,
879						  enum b43legacy_dmatype type)
880{
881	struct b43legacy_dmaring *ring;
882	int err;
883	int nr_slots;
884	dma_addr_t dma_test;
885
886	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
887	if (!ring)
888		goto out;
889	ring->type = type;
890	ring->dev = dev;
891
892	nr_slots = B43legacy_RXRING_SLOTS;
893	if (for_tx)
894		nr_slots = B43legacy_TXRING_SLOTS;
895
896	ring->meta = kcalloc(nr_slots, sizeof(struct b43legacy_dmadesc_meta),
897			     GFP_KERNEL);
898	if (!ring->meta)
899		goto err_kfree_ring;
900	if (for_tx) {
901		ring->txhdr_cache = kcalloc(nr_slots,
902					sizeof(struct b43legacy_txhdr_fw3),
903					GFP_KERNEL);
904		if (!ring->txhdr_cache)
905			goto err_kfree_meta;
906
907		/* test for ability to dma to txhdr_cache */
908		dma_test = ssb_dma_map_single(dev->dev, ring->txhdr_cache,
909					      sizeof(struct b43legacy_txhdr_fw3),
910					      DMA_TO_DEVICE);
911
912		if (b43legacy_dma_mapping_error(ring, dma_test,
913					sizeof(struct b43legacy_txhdr_fw3), 1)) {
914			/* ugh realloc */
915			kfree(ring->txhdr_cache);
916			ring->txhdr_cache = kcalloc(nr_slots,
917					sizeof(struct b43legacy_txhdr_fw3),
918					GFP_KERNEL | GFP_DMA);
919			if (!ring->txhdr_cache)
920				goto err_kfree_meta;
921
922			dma_test = ssb_dma_map_single(dev->dev,
923					ring->txhdr_cache,
924					sizeof(struct b43legacy_txhdr_fw3),
925					DMA_TO_DEVICE);
926
927			if (b43legacy_dma_mapping_error(ring, dma_test,
928					sizeof(struct b43legacy_txhdr_fw3), 1))
929				goto err_kfree_txhdr_cache;
930		}
931
932		ssb_dma_unmap_single(dev->dev, dma_test,
933				     sizeof(struct b43legacy_txhdr_fw3),
934				     DMA_TO_DEVICE);
935	}
936
937	ring->nr_slots = nr_slots;
938	ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
939	ring->index = controller_index;
940	if (type == B43legacy_DMA_64BIT)
941		ring->ops = &dma64_ops;
942	else
943		ring->ops = &dma32_ops;
944	if (for_tx) {
945		ring->tx = 1;
946		ring->current_slot = -1;
947	} else {
948		if (ring->index == 0) {
949			ring->rx_buffersize = B43legacy_DMA0_RX_BUFFERSIZE;
950			ring->frameoffset = B43legacy_DMA0_RX_FRAMEOFFSET;
951		} else if (ring->index == 3) {
952			ring->rx_buffersize = B43legacy_DMA3_RX_BUFFERSIZE;
953			ring->frameoffset = B43legacy_DMA3_RX_FRAMEOFFSET;
954		} else
955			B43legacy_WARN_ON(1);
956	}
957	spin_lock_init(&ring->lock);
958#ifdef CONFIG_B43LEGACY_DEBUG
959	ring->last_injected_overflow = jiffies;
960#endif
961
962	err = alloc_ringmemory(ring);
963	if (err)
964		goto err_kfree_txhdr_cache;
965	err = dmacontroller_setup(ring);
966	if (err)
967		goto err_free_ringmemory;
968
969out:
970	return ring;
971
972err_free_ringmemory:
973	free_ringmemory(ring);
974err_kfree_txhdr_cache:
975	kfree(ring->txhdr_cache);
976err_kfree_meta:
977	kfree(ring->meta);
978err_kfree_ring:
979	kfree(ring);
980	ring = NULL;
981	goto out;
982}
983
984/* Main cleanup function. */
985static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
986{
987	if (!ring)
988		return;
989
990	b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
991		     " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
992		     (ring->tx) ? "TX" : "RX", ring->max_used_slots,
993		     ring->nr_slots);
994	/* Device IRQs are disabled prior entering this function,
995	 * so no need to take care of concurrency with rx handler stuff.
996	 */
997	dmacontroller_cleanup(ring);
998	free_all_descbuffers(ring);
999	free_ringmemory(ring);
1000
1001	kfree(ring->txhdr_cache);
1002	kfree(ring->meta);
1003	kfree(ring);
1004}
1005
1006void b43legacy_dma_free(struct b43legacy_wldev *dev)
1007{
1008	struct b43legacy_dma *dma;
1009
1010	if (b43legacy_using_pio(dev))
1011		return;
1012	dma = &dev->dma;
1013
1014	b43legacy_destroy_dmaring(dma->rx_ring3);
1015	dma->rx_ring3 = NULL;
1016	b43legacy_destroy_dmaring(dma->rx_ring0);
1017	dma->rx_ring0 = NULL;
1018
1019	b43legacy_destroy_dmaring(dma->tx_ring5);
1020	dma->tx_ring5 = NULL;
1021	b43legacy_destroy_dmaring(dma->tx_ring4);
1022	dma->tx_ring4 = NULL;
1023	b43legacy_destroy_dmaring(dma->tx_ring3);
1024	dma->tx_ring3 = NULL;
1025	b43legacy_destroy_dmaring(dma->tx_ring2);
1026	dma->tx_ring2 = NULL;
1027	b43legacy_destroy_dmaring(dma->tx_ring1);
1028	dma->tx_ring1 = NULL;
1029	b43legacy_destroy_dmaring(dma->tx_ring0);
1030	dma->tx_ring0 = NULL;
1031}
1032
1033static int b43legacy_dma_set_mask(struct b43legacy_wldev *dev, u64 mask)
1034{
1035	u64 orig_mask = mask;
1036	bool fallback = 0;
1037	int err;
1038
1039	/* Try to set the DMA mask. If it fails, try falling back to a
1040	 * lower mask, as we can always also support a lower one. */
1041	while (1) {
1042		err = ssb_dma_set_mask(dev->dev, mask);
1043		if (!err)
1044			break;
1045		if (mask == DMA_BIT_MASK(64)) {
1046			mask = DMA_BIT_MASK(32);
1047			fallback = 1;
1048			continue;
1049		}
1050		if (mask == DMA_BIT_MASK(32)) {
1051			mask = DMA_BIT_MASK(30);
1052			fallback = 1;
1053			continue;
1054		}
1055		b43legacyerr(dev->wl, "The machine/kernel does not support "
1056		       "the required %u-bit DMA mask\n",
1057		       (unsigned int)dma_mask_to_engine_type(orig_mask));
1058		return -EOPNOTSUPP;
1059	}
1060	if (fallback) {
1061		b43legacyinfo(dev->wl, "DMA mask fallback from %u-bit to %u-"
1062			"bit\n",
1063			(unsigned int)dma_mask_to_engine_type(orig_mask),
1064			(unsigned int)dma_mask_to_engine_type(mask));
1065	}
1066
1067	return 0;
1068}
1069
1070int b43legacy_dma_init(struct b43legacy_wldev *dev)
1071{
1072	struct b43legacy_dma *dma = &dev->dma;
1073	struct b43legacy_dmaring *ring;
1074	int err;
1075	u64 dmamask;
1076	enum b43legacy_dmatype type;
1077
1078	dmamask = supported_dma_mask(dev);
1079	type = dma_mask_to_engine_type(dmamask);
1080	err = b43legacy_dma_set_mask(dev, dmamask);
1081	if (err) {
1082#ifdef CONFIG_B43LEGACY_PIO
1083		b43legacywarn(dev->wl, "DMA for this device not supported. "
1084			"Falling back to PIO\n");
1085		dev->__using_pio = 1;
1086		return -EAGAIN;
1087#else
1088		b43legacyerr(dev->wl, "DMA for this device not supported and "
1089		       "no PIO support compiled in\n");
1090		return -EOPNOTSUPP;
1091#endif
1092	}
1093
1094	err = -ENOMEM;
1095	/* setup TX DMA channels. */
1096	ring = b43legacy_setup_dmaring(dev, 0, 1, type);
1097	if (!ring)
1098		goto out;
1099	dma->tx_ring0 = ring;
1100
1101	ring = b43legacy_setup_dmaring(dev, 1, 1, type);
1102	if (!ring)
1103		goto err_destroy_tx0;
1104	dma->tx_ring1 = ring;
1105
1106	ring = b43legacy_setup_dmaring(dev, 2, 1, type);
1107	if (!ring)
1108		goto err_destroy_tx1;
1109	dma->tx_ring2 = ring;
1110
1111	ring = b43legacy_setup_dmaring(dev, 3, 1, type);
1112	if (!ring)
1113		goto err_destroy_tx2;
1114	dma->tx_ring3 = ring;
1115
1116	ring = b43legacy_setup_dmaring(dev, 4, 1, type);
1117	if (!ring)
1118		goto err_destroy_tx3;
1119	dma->tx_ring4 = ring;
1120
1121	ring = b43legacy_setup_dmaring(dev, 5, 1, type);
1122	if (!ring)
1123		goto err_destroy_tx4;
1124	dma->tx_ring5 = ring;
1125
1126	/* setup RX DMA channels. */
1127	ring = b43legacy_setup_dmaring(dev, 0, 0, type);
1128	if (!ring)
1129		goto err_destroy_tx5;
1130	dma->rx_ring0 = ring;
1131
1132	if (dev->dev->id.revision < 5) {
1133		ring = b43legacy_setup_dmaring(dev, 3, 0, type);
1134		if (!ring)
1135			goto err_destroy_rx0;
1136		dma->rx_ring3 = ring;
1137	}
1138
1139	b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
1140	err = 0;
1141out:
1142	return err;
1143
1144err_destroy_rx0:
1145	b43legacy_destroy_dmaring(dma->rx_ring0);
1146	dma->rx_ring0 = NULL;
1147err_destroy_tx5:
1148	b43legacy_destroy_dmaring(dma->tx_ring5);
1149	dma->tx_ring5 = NULL;
1150err_destroy_tx4:
1151	b43legacy_destroy_dmaring(dma->tx_ring4);
1152	dma->tx_ring4 = NULL;
1153err_destroy_tx3:
1154	b43legacy_destroy_dmaring(dma->tx_ring3);
1155	dma->tx_ring3 = NULL;
1156err_destroy_tx2:
1157	b43legacy_destroy_dmaring(dma->tx_ring2);
1158	dma->tx_ring2 = NULL;
1159err_destroy_tx1:
1160	b43legacy_destroy_dmaring(dma->tx_ring1);
1161	dma->tx_ring1 = NULL;
1162err_destroy_tx0:
1163	b43legacy_destroy_dmaring(dma->tx_ring0);
1164	dma->tx_ring0 = NULL;
1165	goto out;
1166}
1167
1168/* Generate a cookie for the TX header. */
1169static u16 generate_cookie(struct b43legacy_dmaring *ring,
1170			   int slot)
1171{
1172	u16 cookie = 0x1000;
1173
1174	/* Use the upper 4 bits of the cookie as
1175	 * DMA controller ID and store the slot number
1176	 * in the lower 12 bits.
1177	 * Note that the cookie must never be 0, as this
1178	 * is a special value used in RX path.
1179	 */
1180	switch (ring->index) {
1181	case 0:
1182		cookie = 0xA000;
1183		break;
1184	case 1:
1185		cookie = 0xB000;
1186		break;
1187	case 2:
1188		cookie = 0xC000;
1189		break;
1190	case 3:
1191		cookie = 0xD000;
1192		break;
1193	case 4:
1194		cookie = 0xE000;
1195		break;
1196	case 5:
1197		cookie = 0xF000;
1198		break;
1199	}
1200	B43legacy_WARN_ON(!(((u16)slot & 0xF000) == 0x0000));
1201	cookie |= (u16)slot;
1202
1203	return cookie;
1204}
1205
1206/* Inspect a cookie and find out to which controller/slot it belongs. */
1207static
1208struct b43legacy_dmaring *parse_cookie(struct b43legacy_wldev *dev,
1209				      u16 cookie, int *slot)
1210{
1211	struct b43legacy_dma *dma = &dev->dma;
1212	struct b43legacy_dmaring *ring = NULL;
1213
1214	switch (cookie & 0xF000) {
1215	case 0xA000:
1216		ring = dma->tx_ring0;
1217		break;
1218	case 0xB000:
1219		ring = dma->tx_ring1;
1220		break;
1221	case 0xC000:
1222		ring = dma->tx_ring2;
1223		break;
1224	case 0xD000:
1225		ring = dma->tx_ring3;
1226		break;
1227	case 0xE000:
1228		ring = dma->tx_ring4;
1229		break;
1230	case 0xF000:
1231		ring = dma->tx_ring5;
1232		break;
1233	default:
1234		B43legacy_WARN_ON(1);
1235	}
1236	*slot = (cookie & 0x0FFF);
1237	B43legacy_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1238
1239	return ring;
1240}
1241
1242static int dma_tx_fragment(struct b43legacy_dmaring *ring,
1243			    struct sk_buff *skb)
1244{
1245	const struct b43legacy_dma_ops *ops = ring->ops;
1246	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1247	u8 *header;
1248	int slot, old_top_slot, old_used_slots;
1249	int err;
1250	struct b43legacy_dmadesc_generic *desc;
1251	struct b43legacy_dmadesc_meta *meta;
1252	struct b43legacy_dmadesc_meta *meta_hdr;
1253	struct sk_buff *bounce_skb;
1254
1255#define SLOTS_PER_PACKET  2
1256	B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
1257
1258	old_top_slot = ring->current_slot;
1259	old_used_slots = ring->used_slots;
1260
1261	/* Get a slot for the header. */
1262	slot = request_slot(ring);
1263	desc = ops->idx2desc(ring, slot, &meta_hdr);
1264	memset(meta_hdr, 0, sizeof(*meta_hdr));
1265
1266	header = &(ring->txhdr_cache[slot * sizeof(
1267			       struct b43legacy_txhdr_fw3)]);
1268	err = b43legacy_generate_txhdr(ring->dev, header,
1269				 skb->data, skb->len, info,
1270				 generate_cookie(ring, slot));
1271	if (unlikely(err)) {
1272		ring->current_slot = old_top_slot;
1273		ring->used_slots = old_used_slots;
1274		return err;
1275	}
1276
1277	meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1278					   sizeof(struct b43legacy_txhdr_fw3), 1);
1279	if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
1280					sizeof(struct b43legacy_txhdr_fw3), 1)) {
1281		ring->current_slot = old_top_slot;
1282		ring->used_slots = old_used_slots;
1283		return -EIO;
1284	}
1285	ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1286			     sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
1287
1288	/* Get a slot for the payload. */
1289	slot = request_slot(ring);
1290	desc = ops->idx2desc(ring, slot, &meta);
1291	memset(meta, 0, sizeof(*meta));
1292
1293	meta->skb = skb;
1294	meta->is_last_fragment = 1;
1295
1296	meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1297	/* create a bounce buffer in zone_dma on mapping failure. */
1298	if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1299		bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1300		if (!bounce_skb) {
1301			ring->current_slot = old_top_slot;
1302			ring->used_slots = old_used_slots;
1303			err = -ENOMEM;
1304			goto out_unmap_hdr;
1305		}
1306
1307		memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1308		dev_kfree_skb_any(skb);
1309		skb = bounce_skb;
1310		meta->skb = skb;
1311		meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1312		if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1313			ring->current_slot = old_top_slot;
1314			ring->used_slots = old_used_slots;
1315			err = -EIO;
1316			goto out_free_bounce;
1317		}
1318	}
1319
1320	ops->fill_descriptor(ring, desc, meta->dmaaddr,
1321			     skb->len, 0, 1, 1);
1322
1323	wmb();	/* previous stuff MUST be done */
1324	/* Now transfer the whole frame. */
1325	ops->poke_tx(ring, next_slot(ring, slot));
1326	return 0;
1327
1328out_free_bounce:
1329	dev_kfree_skb_any(skb);
1330out_unmap_hdr:
1331	unmap_descbuffer(ring, meta_hdr->dmaaddr,
1332			 sizeof(struct b43legacy_txhdr_fw3), 1);
1333	return err;
1334}
1335
1336static inline
1337int should_inject_overflow(struct b43legacy_dmaring *ring)
1338{
1339#ifdef CONFIG_B43LEGACY_DEBUG
1340	if (unlikely(b43legacy_debug(ring->dev,
1341				     B43legacy_DBG_DMAOVERFLOW))) {
1342		/* Check if we should inject another ringbuffer overflow
1343		 * to test handling of this situation in the stack. */
1344		unsigned long next_overflow;
1345
1346		next_overflow = ring->last_injected_overflow + HZ;
1347		if (time_after(jiffies, next_overflow)) {
1348			ring->last_injected_overflow = jiffies;
1349			b43legacydbg(ring->dev->wl,
1350			       "Injecting TX ring overflow on "
1351			       "DMA controller %d\n", ring->index);
1352			return 1;
1353		}
1354	}
1355#endif /* CONFIG_B43LEGACY_DEBUG */
1356	return 0;
1357}
1358
1359int b43legacy_dma_tx(struct b43legacy_wldev *dev,
1360		     struct sk_buff *skb)
1361{
1362	struct b43legacy_dmaring *ring;
1363	int err = 0;
1364	unsigned long flags;
1365
1366	ring = priority_to_txring(dev, skb_get_queue_mapping(skb));
1367	spin_lock_irqsave(&ring->lock, flags);
1368	B43legacy_WARN_ON(!ring->tx);
1369
1370	if (unlikely(ring->stopped)) {
1371		/* We get here only because of a bug in mac80211.
1372		 * Because of a race, one packet may be queued after
1373		 * the queue is stopped, thus we got called when we shouldn't.
1374		 * For now, just refuse the transmit. */
1375		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1376			b43legacyerr(dev->wl, "Packet after queue stopped\n");
1377		err = -ENOSPC;
1378		goto out_unlock;
1379	}
1380
1381	if (unlikely(WARN_ON(free_slots(ring) < SLOTS_PER_PACKET))) {
1382		/* If we get here, we have a real error with the queue
1383		 * full, but queues not stopped. */
1384		b43legacyerr(dev->wl, "DMA queue overflow\n");
1385		err = -ENOSPC;
1386		goto out_unlock;
1387	}
1388
1389	err = dma_tx_fragment(ring, skb);
1390	if (unlikely(err == -ENOKEY)) {
1391		/* Drop this packet, as we don't have the encryption key
1392		 * anymore and must not transmit it unencrypted. */
1393		dev_kfree_skb_any(skb);
1394		err = 0;
1395		goto out_unlock;
1396	}
1397	if (unlikely(err)) {
1398		b43legacyerr(dev->wl, "DMA tx mapping failure\n");
1399		goto out_unlock;
1400	}
1401	ring->nr_tx_packets++;
1402	if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1403	    should_inject_overflow(ring)) {
1404		/* This TX ring is full. */
1405		ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1406		ring->stopped = 1;
1407		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1408			b43legacydbg(dev->wl, "Stopped TX ring %d\n",
1409			       ring->index);
1410	}
1411out_unlock:
1412	spin_unlock_irqrestore(&ring->lock, flags);
1413
1414	return err;
1415}
1416
1417void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
1418				 const struct b43legacy_txstatus *status)
1419{
1420	const struct b43legacy_dma_ops *ops;
1421	struct b43legacy_dmaring *ring;
1422	struct b43legacy_dmadesc_generic *desc;
1423	struct b43legacy_dmadesc_meta *meta;
1424	int retry_limit;
1425	int slot;
1426
1427	ring = parse_cookie(dev, status->cookie, &slot);
1428	if (unlikely(!ring))
1429		return;
1430	B43legacy_WARN_ON(!irqs_disabled());
1431	spin_lock(&ring->lock);
1432
1433	B43legacy_WARN_ON(!ring->tx);
1434	ops = ring->ops;
1435	while (1) {
1436		B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1437		desc = ops->idx2desc(ring, slot, &meta);
1438
1439		if (meta->skb)
1440			unmap_descbuffer(ring, meta->dmaaddr,
1441					 meta->skb->len, 1);
1442		else
1443			unmap_descbuffer(ring, meta->dmaaddr,
1444					 sizeof(struct b43legacy_txhdr_fw3),
1445					 1);
1446
1447		if (meta->is_last_fragment) {
1448			struct ieee80211_tx_info *info;
1449			BUG_ON(!meta->skb);
1450			info = IEEE80211_SKB_CB(meta->skb);
1451
1452			/* preserve the confiured retry limit before clearing the status
1453			 * The xmit function has overwritten the rc's value with the actual
1454			 * retry limit done by the hardware */
1455			retry_limit = info->status.rates[0].count;
1456			ieee80211_tx_info_clear_status(info);
1457
1458			if (status->acked)
1459				info->flags |= IEEE80211_TX_STAT_ACK;
1460
1461			if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
1462				/*
1463				 * If the short retries (RTS, not data frame) have exceeded
1464				 * the limit, the hw will not have tried the selected rate,
1465				 * but will have used the fallback rate instead.
1466				 * Don't let the rate control count attempts for the selected
1467				 * rate in this case, otherwise the statistics will be off.
1468				 */
1469				info->status.rates[0].count = 0;
1470				info->status.rates[1].count = status->frame_count;
1471			} else {
1472				if (status->frame_count > retry_limit) {
1473					info->status.rates[0].count = retry_limit;
1474					info->status.rates[1].count = status->frame_count -
1475							retry_limit;
1476
1477				} else {
1478					info->status.rates[0].count = status->frame_count;
1479					info->status.rates[1].idx = -1;
1480				}
1481			}
1482
1483			/* Call back to inform the ieee80211 subsystem about the
1484			 * status of the transmission.
1485			 * Some fields of txstat are already filled in dma_tx().
1486			 */
1487			ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
1488			/* skb is freed by ieee80211_tx_status_irqsafe() */
1489			meta->skb = NULL;
1490		} else {
1491			/* No need to call free_descriptor_buffer here, as
1492			 * this is only the txhdr, which is not allocated.
1493			 */
1494			B43legacy_WARN_ON(meta->skb != NULL);
1495		}
1496
1497		/* Everything unmapped and free'd. So it's not used anymore. */
1498		ring->used_slots--;
1499
1500		if (meta->is_last_fragment)
1501			break;
1502		slot = next_slot(ring, slot);
1503	}
1504	dev->stats.last_tx = jiffies;
1505	if (ring->stopped) {
1506		B43legacy_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1507		ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1508		ring->stopped = 0;
1509		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1510			b43legacydbg(dev->wl, "Woke up TX ring %d\n",
1511			       ring->index);
1512	}
1513
1514	spin_unlock(&ring->lock);
1515}
1516
1517void b43legacy_dma_get_tx_stats(struct b43legacy_wldev *dev,
1518			      struct ieee80211_tx_queue_stats *stats)
1519{
1520	const int nr_queues = dev->wl->hw->queues;
1521	struct b43legacy_dmaring *ring;
1522	unsigned long flags;
1523	int i;
1524
1525	for (i = 0; i < nr_queues; i++) {
1526		ring = priority_to_txring(dev, i);
1527
1528		spin_lock_irqsave(&ring->lock, flags);
1529		stats[i].len = ring->used_slots / SLOTS_PER_PACKET;
1530		stats[i].limit = ring->nr_slots / SLOTS_PER_PACKET;
1531		stats[i].count = ring->nr_tx_packets;
1532		spin_unlock_irqrestore(&ring->lock, flags);
1533	}
1534}
1535
1536static void dma_rx(struct b43legacy_dmaring *ring,
1537		   int *slot)
1538{
1539	const struct b43legacy_dma_ops *ops = ring->ops;
1540	struct b43legacy_dmadesc_generic *desc;
1541	struct b43legacy_dmadesc_meta *meta;
1542	struct b43legacy_rxhdr_fw3 *rxhdr;
1543	struct sk_buff *skb;
1544	u16 len;
1545	int err;
1546	dma_addr_t dmaaddr;
1547
1548	desc = ops->idx2desc(ring, *slot, &meta);
1549
1550	sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1551	skb = meta->skb;
1552
1553	if (ring->index == 3) {
1554		/* We received an xmit status. */
1555		struct b43legacy_hwtxstatus *hw =
1556				(struct b43legacy_hwtxstatus *)skb->data;
1557		int i = 0;
1558
1559		while (hw->cookie == 0) {
1560			if (i > 100)
1561				break;
1562			i++;
1563			udelay(2);
1564			barrier();
1565		}
1566		b43legacy_handle_hwtxstatus(ring->dev, hw);
1567		/* recycle the descriptor buffer. */
1568		sync_descbuffer_for_device(ring, meta->dmaaddr,
1569					   ring->rx_buffersize);
1570
1571		return;
1572	}
1573	rxhdr = (struct b43legacy_rxhdr_fw3 *)skb->data;
1574	len = le16_to_cpu(rxhdr->frame_len);
1575	if (len == 0) {
1576		int i = 0;
1577
1578		do {
1579			udelay(2);
1580			barrier();
1581			len = le16_to_cpu(rxhdr->frame_len);
1582		} while (len == 0 && i++ < 5);
1583		if (unlikely(len == 0)) {
1584			/* recycle the descriptor buffer. */
1585			sync_descbuffer_for_device(ring, meta->dmaaddr,
1586						   ring->rx_buffersize);
1587			goto drop;
1588		}
1589	}
1590	if (unlikely(len > ring->rx_buffersize)) {
1591		/* The data did not fit into one descriptor buffer
1592		 * and is split over multiple buffers.
1593		 * This should never happen, as we try to allocate buffers
1594		 * big enough. So simply ignore this packet.
1595		 */
1596		int cnt = 0;
1597		s32 tmp = len;
1598
1599		while (1) {
1600			desc = ops->idx2desc(ring, *slot, &meta);
1601			/* recycle the descriptor buffer. */
1602			sync_descbuffer_for_device(ring, meta->dmaaddr,
1603						   ring->rx_buffersize);
1604			*slot = next_slot(ring, *slot);
1605			cnt++;
1606			tmp -= ring->rx_buffersize;
1607			if (tmp <= 0)
1608				break;
1609		}
1610		b43legacyerr(ring->dev->wl, "DMA RX buffer too small "
1611		       "(len: %u, buffer: %u, nr-dropped: %d)\n",
1612		       len, ring->rx_buffersize, cnt);
1613		goto drop;
1614	}
1615
1616	dmaaddr = meta->dmaaddr;
1617	err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1618	if (unlikely(err)) {
1619		b43legacydbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer()"
1620			     " failed\n");
1621		sync_descbuffer_for_device(ring, dmaaddr,
1622					   ring->rx_buffersize);
1623		goto drop;
1624	}
1625
1626	unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1627	skb_put(skb, len + ring->frameoffset);
1628	skb_pull(skb, ring->frameoffset);
1629
1630	b43legacy_rx(ring->dev, skb, rxhdr);
1631drop:
1632	return;
1633}
1634
1635void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
1636{
1637	const struct b43legacy_dma_ops *ops = ring->ops;
1638	int slot;
1639	int current_slot;
1640	int used_slots = 0;
1641
1642	B43legacy_WARN_ON(ring->tx);
1643	current_slot = ops->get_current_rxslot(ring);
1644	B43legacy_WARN_ON(!(current_slot >= 0 && current_slot <
1645			   ring->nr_slots));
1646
1647	slot = ring->current_slot;
1648	for (; slot != current_slot; slot = next_slot(ring, slot)) {
1649		dma_rx(ring, &slot);
1650		update_max_used_slots(ring, ++used_slots);
1651	}
1652	ops->set_current_rxslot(ring, slot);
1653	ring->current_slot = slot;
1654}
1655
1656static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1657{
1658	unsigned long flags;
1659
1660	spin_lock_irqsave(&ring->lock, flags);
1661	B43legacy_WARN_ON(!ring->tx);
1662	ring->ops->tx_suspend(ring);
1663	spin_unlock_irqrestore(&ring->lock, flags);
1664}
1665
1666static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1667{
1668	unsigned long flags;
1669
1670	spin_lock_irqsave(&ring->lock, flags);
1671	B43legacy_WARN_ON(!ring->tx);
1672	ring->ops->tx_resume(ring);
1673	spin_unlock_irqrestore(&ring->lock, flags);
1674}
1675
1676void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
1677{
1678	b43legacy_power_saving_ctl_bits(dev, -1, 1);
1679	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring0);
1680	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring1);
1681	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring2);
1682	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring3);
1683	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring4);
1684	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring5);
1685}
1686
1687void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
1688{
1689	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring5);
1690	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring4);
1691	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring3);
1692	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring2);
1693	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring1);
1694	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring0);
1695	b43legacy_power_saving_ctl_bits(dev, -1, -1);
1696}
1697