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1/*
2
3  Broadcom B43legacy wireless driver
4
5  DMA ringbuffer and descriptor allocation/management
6
7  Copyright (c) 2005, 2006 Michael Buesch <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 <linux/slab.h>
41#include <net/dst.h>
42
43/* 32bit DMA ops. */
44static
45struct b43legacy_dmadesc_generic *op32_idx2desc(
46					struct b43legacy_dmaring *ring,
47					int slot,
48					struct b43legacy_dmadesc_meta **meta)
49{
50	struct b43legacy_dmadesc32 *desc;
51
52	*meta = &(ring->meta[slot]);
53	desc = ring->descbase;
54	desc = &(desc[slot]);
55
56	return (struct b43legacy_dmadesc_generic *)desc;
57}
58
59static void op32_fill_descriptor(struct b43legacy_dmaring *ring,
60				 struct b43legacy_dmadesc_generic *desc,
61				 dma_addr_t dmaaddr, u16 bufsize,
62				 int start, int end, int irq)
63{
64	struct b43legacy_dmadesc32 *descbase = ring->descbase;
65	int slot;
66	u32 ctl;
67	u32 addr;
68	u32 addrext;
69
70	slot = (int)(&(desc->dma32) - descbase);
71	B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
72
73	addr = (u32)(dmaaddr & ~SSB_DMA_TRANSLATION_MASK);
74	addrext = (u32)(dmaaddr & SSB_DMA_TRANSLATION_MASK)
75		   >> SSB_DMA_TRANSLATION_SHIFT;
76	addr |= ssb_dma_translation(ring->dev->dev);
77	ctl = (bufsize - ring->frameoffset)
78	      & B43legacy_DMA32_DCTL_BYTECNT;
79	if (slot == ring->nr_slots - 1)
80		ctl |= B43legacy_DMA32_DCTL_DTABLEEND;
81	if (start)
82		ctl |= B43legacy_DMA32_DCTL_FRAMESTART;
83	if (end)
84		ctl |= B43legacy_DMA32_DCTL_FRAMEEND;
85	if (irq)
86		ctl |= B43legacy_DMA32_DCTL_IRQ;
87	ctl |= (addrext << B43legacy_DMA32_DCTL_ADDREXT_SHIFT)
88	       & B43legacy_DMA32_DCTL_ADDREXT_MASK;
89
90	desc->dma32.control = cpu_to_le32(ctl);
91	desc->dma32.address = cpu_to_le32(addr);
92}
93
94static void op32_poke_tx(struct b43legacy_dmaring *ring, int slot)
95{
96	b43legacy_dma_write(ring, B43legacy_DMA32_TXINDEX,
97			    (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
98}
99
100static void op32_tx_suspend(struct b43legacy_dmaring *ring)
101{
102	b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
103			    b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
104			    | B43legacy_DMA32_TXSUSPEND);
105}
106
107static void op32_tx_resume(struct b43legacy_dmaring *ring)
108{
109	b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
110			    b43legacy_dma_read(ring, B43legacy_DMA32_TXCTL)
111			    & ~B43legacy_DMA32_TXSUSPEND);
112}
113
114static int op32_get_current_rxslot(struct b43legacy_dmaring *ring)
115{
116	u32 val;
117
118	val = b43legacy_dma_read(ring, B43legacy_DMA32_RXSTATUS);
119	val &= B43legacy_DMA32_RXDPTR;
120
121	return (val / sizeof(struct b43legacy_dmadesc32));
122}
123
124static void op32_set_current_rxslot(struct b43legacy_dmaring *ring,
125				    int slot)
126{
127	b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
128			    (u32)(slot * sizeof(struct b43legacy_dmadesc32)));
129}
130
131static const struct b43legacy_dma_ops dma32_ops = {
132	.idx2desc		= op32_idx2desc,
133	.fill_descriptor	= op32_fill_descriptor,
134	.poke_tx		= op32_poke_tx,
135	.tx_suspend		= op32_tx_suspend,
136	.tx_resume		= op32_tx_resume,
137	.get_current_rxslot	= op32_get_current_rxslot,
138	.set_current_rxslot	= op32_set_current_rxslot,
139};
140
141/* 64bit DMA ops. */
142static
143struct b43legacy_dmadesc_generic *op64_idx2desc(
144					struct b43legacy_dmaring *ring,
145					int slot,
146					struct b43legacy_dmadesc_meta
147					**meta)
148{
149	struct b43legacy_dmadesc64 *desc;
150
151	*meta = &(ring->meta[slot]);
152	desc = ring->descbase;
153	desc = &(desc[slot]);
154
155	return (struct b43legacy_dmadesc_generic *)desc;
156}
157
158static void op64_fill_descriptor(struct b43legacy_dmaring *ring,
159				 struct b43legacy_dmadesc_generic *desc,
160				 dma_addr_t dmaaddr, u16 bufsize,
161				 int start, int end, int irq)
162{
163	struct b43legacy_dmadesc64 *descbase = ring->descbase;
164	int slot;
165	u32 ctl0 = 0;
166	u32 ctl1 = 0;
167	u32 addrlo;
168	u32 addrhi;
169	u32 addrext;
170
171	slot = (int)(&(desc->dma64) - descbase);
172	B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
173
174	addrlo = (u32)(dmaaddr & 0xFFFFFFFF);
175	addrhi = (((u64)dmaaddr >> 32) & ~SSB_DMA_TRANSLATION_MASK);
176	addrext = (((u64)dmaaddr >> 32) & SSB_DMA_TRANSLATION_MASK)
177		  >> SSB_DMA_TRANSLATION_SHIFT;
178	addrhi |= ssb_dma_translation(ring->dev->dev);
179	if (slot == ring->nr_slots - 1)
180		ctl0 |= B43legacy_DMA64_DCTL0_DTABLEEND;
181	if (start)
182		ctl0 |= B43legacy_DMA64_DCTL0_FRAMESTART;
183	if (end)
184		ctl0 |= B43legacy_DMA64_DCTL0_FRAMEEND;
185	if (irq)
186		ctl0 |= B43legacy_DMA64_DCTL0_IRQ;
187	ctl1 |= (bufsize - ring->frameoffset)
188		& B43legacy_DMA64_DCTL1_BYTECNT;
189	ctl1 |= (addrext << B43legacy_DMA64_DCTL1_ADDREXT_SHIFT)
190		& B43legacy_DMA64_DCTL1_ADDREXT_MASK;
191
192	desc->dma64.control0 = cpu_to_le32(ctl0);
193	desc->dma64.control1 = cpu_to_le32(ctl1);
194	desc->dma64.address_low = cpu_to_le32(addrlo);
195	desc->dma64.address_high = cpu_to_le32(addrhi);
196}
197
198static void op64_poke_tx(struct b43legacy_dmaring *ring, int slot)
199{
200	b43legacy_dma_write(ring, B43legacy_DMA64_TXINDEX,
201			    (u32)(slot * sizeof(struct b43legacy_dmadesc64)));
202}
203
204static void op64_tx_suspend(struct b43legacy_dmaring *ring)
205{
206	b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
207			    b43legacy_dma_read(ring, B43legacy_DMA64_TXCTL)
208			    | B43legacy_DMA64_TXSUSPEND);
209}
210
211static void op64_tx_resume(struct b43legacy_dmaring *ring)
212{
213	b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
214			    b43legacy_dma_read(ring, B43legacy_DMA64_TXCTL)
215			    & ~B43legacy_DMA64_TXSUSPEND);
216}
217
218static int op64_get_current_rxslot(struct b43legacy_dmaring *ring)
219{
220	u32 val;
221
222	val = b43legacy_dma_read(ring, B43legacy_DMA64_RXSTATUS);
223	val &= B43legacy_DMA64_RXSTATDPTR;
224
225	return (val / sizeof(struct b43legacy_dmadesc64));
226}
227
228static void op64_set_current_rxslot(struct b43legacy_dmaring *ring,
229				    int slot)
230{
231	b43legacy_dma_write(ring, B43legacy_DMA64_RXINDEX,
232			    (u32)(slot * sizeof(struct b43legacy_dmadesc64)));
233}
234
235static const struct b43legacy_dma_ops dma64_ops = {
236	.idx2desc		= op64_idx2desc,
237	.fill_descriptor	= op64_fill_descriptor,
238	.poke_tx		= op64_poke_tx,
239	.tx_suspend		= op64_tx_suspend,
240	.tx_resume		= op64_tx_resume,
241	.get_current_rxslot	= op64_get_current_rxslot,
242	.set_current_rxslot	= op64_set_current_rxslot,
243};
244
245
246static inline int free_slots(struct b43legacy_dmaring *ring)
247{
248	return (ring->nr_slots - ring->used_slots);
249}
250
251static inline int next_slot(struct b43legacy_dmaring *ring, int slot)
252{
253	B43legacy_WARN_ON(!(slot >= -1 && slot <= ring->nr_slots - 1));
254	if (slot == ring->nr_slots - 1)
255		return 0;
256	return slot + 1;
257}
258
259static inline int prev_slot(struct b43legacy_dmaring *ring, int slot)
260{
261	B43legacy_WARN_ON(!(slot >= 0 && slot <= ring->nr_slots - 1));
262	if (slot == 0)
263		return ring->nr_slots - 1;
264	return slot - 1;
265}
266
267#ifdef CONFIG_B43LEGACY_DEBUG
268static void update_max_used_slots(struct b43legacy_dmaring *ring,
269				  int current_used_slots)
270{
271	if (current_used_slots <= ring->max_used_slots)
272		return;
273	ring->max_used_slots = current_used_slots;
274	if (b43legacy_debug(ring->dev, B43legacy_DBG_DMAVERBOSE))
275		b43legacydbg(ring->dev->wl,
276		       "max_used_slots increased to %d on %s ring %d\n",
277		       ring->max_used_slots,
278		       ring->tx ? "TX" : "RX",
279		       ring->index);
280}
281#else
282static inline
283void update_max_used_slots(struct b43legacy_dmaring *ring,
284			   int current_used_slots)
285{ }
286#endif /* DEBUG */
287
288/* Request a slot for usage. */
289static inline
290int request_slot(struct b43legacy_dmaring *ring)
291{
292	int slot;
293
294	B43legacy_WARN_ON(!ring->tx);
295	B43legacy_WARN_ON(ring->stopped);
296	B43legacy_WARN_ON(free_slots(ring) == 0);
297
298	slot = next_slot(ring, ring->current_slot);
299	ring->current_slot = slot;
300	ring->used_slots++;
301
302	update_max_used_slots(ring, ring->used_slots);
303
304	return slot;
305}
306
307/* Mac80211-queue to b43legacy-ring mapping */
308static struct b43legacy_dmaring *priority_to_txring(
309						struct b43legacy_wldev *dev,
310						int queue_priority)
311{
312	struct b43legacy_dmaring *ring;
313
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
350return 0;
351
352	return idx_to_prio[ring->index];
353}
354
355
356static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
357					int controller_idx)
358{
359	static const u16 map64[] = {
360		B43legacy_MMIO_DMA64_BASE0,
361		B43legacy_MMIO_DMA64_BASE1,
362		B43legacy_MMIO_DMA64_BASE2,
363		B43legacy_MMIO_DMA64_BASE3,
364		B43legacy_MMIO_DMA64_BASE4,
365		B43legacy_MMIO_DMA64_BASE5,
366	};
367	static const u16 map32[] = {
368		B43legacy_MMIO_DMA32_BASE0,
369		B43legacy_MMIO_DMA32_BASE1,
370		B43legacy_MMIO_DMA32_BASE2,
371		B43legacy_MMIO_DMA32_BASE3,
372		B43legacy_MMIO_DMA32_BASE4,
373		B43legacy_MMIO_DMA32_BASE5,
374	};
375
376	if (type == B43legacy_DMA_64BIT) {
377		B43legacy_WARN_ON(!(controller_idx >= 0 &&
378				  controller_idx < ARRAY_SIZE(map64)));
379		return map64[controller_idx];
380	}
381	B43legacy_WARN_ON(!(controller_idx >= 0 &&
382			  controller_idx < ARRAY_SIZE(map32)));
383	return map32[controller_idx];
384}
385
386static inline
387dma_addr_t map_descbuffer(struct b43legacy_dmaring *ring,
388			  unsigned char *buf,
389			  size_t len,
390			  int tx)
391{
392	dma_addr_t dmaaddr;
393
394	if (tx)
395		dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
396					     buf, len,
397					     DMA_TO_DEVICE);
398	else
399		dmaaddr = dma_map_single(ring->dev->dev->dma_dev,
400					     buf, len,
401					     DMA_FROM_DEVICE);
402
403	return dmaaddr;
404}
405
406static inline
407void unmap_descbuffer(struct b43legacy_dmaring *ring,
408		      dma_addr_t addr,
409		      size_t len,
410		      int tx)
411{
412	if (tx)
413		dma_unmap_single(ring->dev->dev->dma_dev,
414				     addr, len,
415				     DMA_TO_DEVICE);
416	else
417		dma_unmap_single(ring->dev->dev->dma_dev,
418				     addr, len,
419				     DMA_FROM_DEVICE);
420}
421
422static inline
423void sync_descbuffer_for_cpu(struct b43legacy_dmaring *ring,
424			     dma_addr_t addr,
425			     size_t len)
426{
427	B43legacy_WARN_ON(ring->tx);
428
429	dma_sync_single_for_cpu(ring->dev->dev->dma_dev,
430				addr, len, DMA_FROM_DEVICE);
431}
432
433static inline
434void sync_descbuffer_for_device(struct b43legacy_dmaring *ring,
435				dma_addr_t addr,
436				size_t len)
437{
438	B43legacy_WARN_ON(ring->tx);
439
440	dma_sync_single_for_device(ring->dev->dev->dma_dev,
441				   addr, len, DMA_FROM_DEVICE);
442}
443
444static inline
445void free_descriptor_buffer(struct b43legacy_dmaring *ring,
446			    struct b43legacy_dmadesc_meta *meta,
447			    int irq_context)
448{
449	if (meta->skb) {
450		if (irq_context)
451			dev_kfree_skb_irq(meta->skb);
452		else
453			dev_kfree_skb(meta->skb);
454		meta->skb = NULL;
455	}
456}
457
458static int alloc_ringmemory(struct b43legacy_dmaring *ring)
459{
460	/* GFP flags must match the flags in free_ringmemory()! */
461	ring->descbase = dma_alloc_coherent(ring->dev->dev->dma_dev,
462					    B43legacy_DMA_RINGMEMSIZE,
463					    &(ring->dmabase),
464					    GFP_KERNEL);
465	if (!ring->descbase) {
466		b43legacyerr(ring->dev->wl, "DMA ringmemory allocation"
467			     " failed\n");
468		return -ENOMEM;
469	}
470	memset(ring->descbase, 0, B43legacy_DMA_RINGMEMSIZE);
471
472	return 0;
473}
474
475static void free_ringmemory(struct b43legacy_dmaring *ring)
476{
477	dma_free_coherent(ring->dev->dev->dma_dev, B43legacy_DMA_RINGMEMSIZE,
478			  ring->descbase, ring->dmabase);
479}
480
481/* Reset the RX DMA channel */
482static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
483					    u16 mmio_base,
484					    enum b43legacy_dmatype type)
485{
486	int i;
487	u32 value;
488	u16 offset;
489
490	might_sleep();
491
492	offset = (type == B43legacy_DMA_64BIT) ?
493		 B43legacy_DMA64_RXCTL : B43legacy_DMA32_RXCTL;
494	b43legacy_write32(dev, mmio_base + offset, 0);
495	for (i = 0; i < 10; i++) {
496		offset = (type == B43legacy_DMA_64BIT) ?
497			 B43legacy_DMA64_RXSTATUS : B43legacy_DMA32_RXSTATUS;
498		value = b43legacy_read32(dev, mmio_base + offset);
499		if (type == B43legacy_DMA_64BIT) {
500			value &= B43legacy_DMA64_RXSTAT;
501			if (value == B43legacy_DMA64_RXSTAT_DISABLED) {
502				i = -1;
503				break;
504			}
505		} else {
506			value &= B43legacy_DMA32_RXSTATE;
507			if (value == B43legacy_DMA32_RXSTAT_DISABLED) {
508				i = -1;
509				break;
510			}
511		}
512		msleep(1);
513	}
514	if (i != -1) {
515		b43legacyerr(dev->wl, "DMA RX reset timed out\n");
516		return -ENODEV;
517	}
518
519	return 0;
520}
521
522/* Reset the RX DMA channel */
523static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
524					    u16 mmio_base,
525					    enum b43legacy_dmatype type)
526{
527	int i;
528	u32 value;
529	u16 offset;
530
531	might_sleep();
532
533	for (i = 0; i < 10; i++) {
534		offset = (type == B43legacy_DMA_64BIT) ?
535			 B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
536		value = b43legacy_read32(dev, mmio_base + offset);
537		if (type == B43legacy_DMA_64BIT) {
538			value &= B43legacy_DMA64_TXSTAT;
539			if (value == B43legacy_DMA64_TXSTAT_DISABLED ||
540			    value == B43legacy_DMA64_TXSTAT_IDLEWAIT ||
541			    value == B43legacy_DMA64_TXSTAT_STOPPED)
542				break;
543		} else {
544			value &= B43legacy_DMA32_TXSTATE;
545			if (value == B43legacy_DMA32_TXSTAT_DISABLED ||
546			    value == B43legacy_DMA32_TXSTAT_IDLEWAIT ||
547			    value == B43legacy_DMA32_TXSTAT_STOPPED)
548				break;
549		}
550		msleep(1);
551	}
552	offset = (type == B43legacy_DMA_64BIT) ? B43legacy_DMA64_TXCTL :
553						 B43legacy_DMA32_TXCTL;
554	b43legacy_write32(dev, mmio_base + offset, 0);
555	for (i = 0; i < 10; i++) {
556		offset = (type == B43legacy_DMA_64BIT) ?
557			 B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
558		value = b43legacy_read32(dev, mmio_base + offset);
559		if (type == B43legacy_DMA_64BIT) {
560			value &= B43legacy_DMA64_TXSTAT;
561			if (value == B43legacy_DMA64_TXSTAT_DISABLED) {
562				i = -1;
563				break;
564			}
565		} else {
566			value &= B43legacy_DMA32_TXSTATE;
567			if (value == B43legacy_DMA32_TXSTAT_DISABLED) {
568				i = -1;
569				break;
570			}
571		}
572		msleep(1);
573	}
574	if (i != -1) {
575		b43legacyerr(dev->wl, "DMA TX reset timed out\n");
576		return -ENODEV;
577	}
578	/* ensure the reset is completed. */
579	msleep(1);
580
581	return 0;
582}
583
584/* Check if a DMA mapping address is invalid. */
585static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
586					 dma_addr_t addr,
587					 size_t buffersize,
588					 bool dma_to_device)
589{
590	if (unlikely(dma_mapping_error(ring->dev->dev->dma_dev, addr)))
591		return 1;
592
593	switch (ring->type) {
594	case B43legacy_DMA_30BIT:
595		if ((u64)addr + buffersize > (1ULL << 30))
596			goto address_error;
597		break;
598	case B43legacy_DMA_32BIT:
599		if ((u64)addr + buffersize > (1ULL << 32))
600			goto address_error;
601		break;
602	case B43legacy_DMA_64BIT:
603		/* Currently we can't have addresses beyond 64 bits in the kernel. */
604		break;
605	}
606
607	/* The address is OK. */
608	return 0;
609
610address_error:
611	/* We can't support this address. Unmap it again. */
612	unmap_descbuffer(ring, addr, buffersize, dma_to_device);
613
614	return 1;
615}
616
617static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
618			       struct b43legacy_dmadesc_generic *desc,
619			       struct b43legacy_dmadesc_meta *meta,
620			       gfp_t gfp_flags)
621{
622	struct b43legacy_rxhdr_fw3 *rxhdr;
623	struct b43legacy_hwtxstatus *txstat;
624	dma_addr_t dmaaddr;
625	struct sk_buff *skb;
626
627	B43legacy_WARN_ON(ring->tx);
628
629	skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
630	if (unlikely(!skb))
631		return -ENOMEM;
632	dmaaddr = map_descbuffer(ring, skb->data,
633				 ring->rx_buffersize, 0);
634	if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
635		/* ugh. try to realloc in zone_dma */
636		gfp_flags |= GFP_DMA;
637
638		dev_kfree_skb_any(skb);
639
640		skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags);
641		if (unlikely(!skb))
642			return -ENOMEM;
643		dmaaddr = map_descbuffer(ring, skb->data,
644					 ring->rx_buffersize, 0);
645	}
646
647	if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
648		dev_kfree_skb_any(skb);
649		return -EIO;
650	}
651
652	meta->skb = skb;
653	meta->dmaaddr = dmaaddr;
654	ring->ops->fill_descriptor(ring, desc, dmaaddr,
655				   ring->rx_buffersize, 0, 0, 0);
656
657	rxhdr = (struct b43legacy_rxhdr_fw3 *)(skb->data);
658	rxhdr->frame_len = 0;
659	txstat = (struct b43legacy_hwtxstatus *)(skb->data);
660	txstat->cookie = 0;
661
662	return 0;
663}
664
665/* Allocate the initial descbuffers.
666 * This is used for an RX ring only.
667 */
668static int alloc_initial_descbuffers(struct b43legacy_dmaring *ring)
669{
670	int i;
671	int err = -ENOMEM;
672	struct b43legacy_dmadesc_generic *desc;
673	struct b43legacy_dmadesc_meta *meta;
674
675	for (i = 0; i < ring->nr_slots; i++) {
676		desc = ring->ops->idx2desc(ring, i, &meta);
677
678		err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL);
679		if (err) {
680			b43legacyerr(ring->dev->wl,
681			       "Failed to allocate initial descbuffers\n");
682			goto err_unwind;
683		}
684	}
685	mb(); /* all descbuffer setup before next line */
686	ring->used_slots = ring->nr_slots;
687	err = 0;
688out:
689	return err;
690
691err_unwind:
692	for (i--; i >= 0; i--) {
693		desc = ring->ops->idx2desc(ring, i, &meta);
694
695		unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0);
696		dev_kfree_skb(meta->skb);
697	}
698	goto out;
699}
700
701/* Do initial setup of the DMA controller.
702 * Reset the controller, write the ring busaddress
703 * and switch the "enable" bit on.
704 */
705static int dmacontroller_setup(struct b43legacy_dmaring *ring)
706{
707	int err = 0;
708	u32 value;
709	u32 addrext;
710	u32 trans = ssb_dma_translation(ring->dev->dev);
711
712	if (ring->tx) {
713		if (ring->type == B43legacy_DMA_64BIT) {
714			u64 ringbase = (u64)(ring->dmabase);
715
716			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
717				  >> SSB_DMA_TRANSLATION_SHIFT;
718			value = B43legacy_DMA64_TXENABLE;
719			value |= (addrext << B43legacy_DMA64_TXADDREXT_SHIFT)
720				& B43legacy_DMA64_TXADDREXT_MASK;
721			b43legacy_dma_write(ring, B43legacy_DMA64_TXCTL,
722					    value);
723			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGLO,
724					    (ringbase & 0xFFFFFFFF));
725			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGHI,
726					    ((ringbase >> 32)
727					    & ~SSB_DMA_TRANSLATION_MASK)
728					    | trans);
729		} else {
730			u32 ringbase = (u32)(ring->dmabase);
731
732			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
733				  >> SSB_DMA_TRANSLATION_SHIFT;
734			value = B43legacy_DMA32_TXENABLE;
735			value |= (addrext << B43legacy_DMA32_TXADDREXT_SHIFT)
736				& B43legacy_DMA32_TXADDREXT_MASK;
737			b43legacy_dma_write(ring, B43legacy_DMA32_TXCTL,
738					    value);
739			b43legacy_dma_write(ring, B43legacy_DMA32_TXRING,
740					    (ringbase &
741					    ~SSB_DMA_TRANSLATION_MASK)
742					    | trans);
743		}
744	} else {
745		err = alloc_initial_descbuffers(ring);
746		if (err)
747			goto out;
748		if (ring->type == B43legacy_DMA_64BIT) {
749			u64 ringbase = (u64)(ring->dmabase);
750
751			addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
752				  >> SSB_DMA_TRANSLATION_SHIFT;
753			value = (ring->frameoffset <<
754				 B43legacy_DMA64_RXFROFF_SHIFT);
755			value |= B43legacy_DMA64_RXENABLE;
756			value |= (addrext << B43legacy_DMA64_RXADDREXT_SHIFT)
757				& B43legacy_DMA64_RXADDREXT_MASK;
758			b43legacy_dma_write(ring, B43legacy_DMA64_RXCTL,
759					    value);
760			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGLO,
761					    (ringbase & 0xFFFFFFFF));
762			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGHI,
763					    ((ringbase >> 32) &
764					    ~SSB_DMA_TRANSLATION_MASK) |
765					    trans);
766			b43legacy_dma_write(ring, B43legacy_DMA64_RXINDEX,
767					    200);
768		} else {
769			u32 ringbase = (u32)(ring->dmabase);
770
771			addrext = (ringbase & SSB_DMA_TRANSLATION_MASK)
772				  >> SSB_DMA_TRANSLATION_SHIFT;
773			value = (ring->frameoffset <<
774				 B43legacy_DMA32_RXFROFF_SHIFT);
775			value |= B43legacy_DMA32_RXENABLE;
776			value |= (addrext <<
777				 B43legacy_DMA32_RXADDREXT_SHIFT)
778				 & B43legacy_DMA32_RXADDREXT_MASK;
779			b43legacy_dma_write(ring, B43legacy_DMA32_RXCTL,
780					    value);
781			b43legacy_dma_write(ring, B43legacy_DMA32_RXRING,
782					    (ringbase &
783					    ~SSB_DMA_TRANSLATION_MASK)
784					    | trans);
785			b43legacy_dma_write(ring, B43legacy_DMA32_RXINDEX,
786					    200);
787		}
788	}
789
790out:
791	return err;
792}
793
794/* Shutdown the DMA controller. */
795static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
796{
797	if (ring->tx) {
798		b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
799						 ring->type);
800		if (ring->type == B43legacy_DMA_64BIT) {
801			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGLO, 0);
802			b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGHI, 0);
803		} else
804			b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
805	} else {
806		b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
807						 ring->type);
808		if (ring->type == B43legacy_DMA_64BIT) {
809			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGLO, 0);
810			b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGHI, 0);
811		} else
812			b43legacy_dma_write(ring, B43legacy_DMA32_RXRING, 0);
813	}
814}
815
816static void free_all_descbuffers(struct b43legacy_dmaring *ring)
817{
818	struct b43legacy_dmadesc_generic *desc;
819	struct b43legacy_dmadesc_meta *meta;
820	int i;
821
822	if (!ring->used_slots)
823		return;
824	for (i = 0; i < ring->nr_slots; i++) {
825		desc = ring->ops->idx2desc(ring, i, &meta);
826
827		if (!meta->skb) {
828			B43legacy_WARN_ON(!ring->tx);
829			continue;
830		}
831		if (ring->tx)
832			unmap_descbuffer(ring, meta->dmaaddr,
833					 meta->skb->len, 1);
834		else
835			unmap_descbuffer(ring, meta->dmaaddr,
836					 ring->rx_buffersize, 0);
837		free_descriptor_buffer(ring, meta, 0);
838	}
839}
840
841static u64 supported_dma_mask(struct b43legacy_wldev *dev)
842{
843	u32 tmp;
844	u16 mmio_base;
845
846	tmp = b43legacy_read32(dev, SSB_TMSHIGH);
847	if (tmp & SSB_TMSHIGH_DMA64)
848		return DMA_BIT_MASK(64);
849	mmio_base = b43legacy_dmacontroller_base(0, 0);
850	b43legacy_write32(dev,
851			mmio_base + B43legacy_DMA32_TXCTL,
852			B43legacy_DMA32_TXADDREXT_MASK);
853	tmp = b43legacy_read32(dev, mmio_base +
854			       B43legacy_DMA32_TXCTL);
855	if (tmp & B43legacy_DMA32_TXADDREXT_MASK)
856		return DMA_BIT_MASK(32);
857
858	return DMA_BIT_MASK(30);
859}
860
861static enum b43legacy_dmatype dma_mask_to_engine_type(u64 dmamask)
862{
863	if (dmamask == DMA_BIT_MASK(30))
864		return B43legacy_DMA_30BIT;
865	if (dmamask == DMA_BIT_MASK(32))
866		return B43legacy_DMA_32BIT;
867	if (dmamask == DMA_BIT_MASK(64))
868		return B43legacy_DMA_64BIT;
869	B43legacy_WARN_ON(1);
870	return B43legacy_DMA_30BIT;
871}
872
873/* Main initialization function. */
874static
875struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
876						  int controller_index,
877						  int for_tx,
878						  enum b43legacy_dmatype type)
879{
880	struct b43legacy_dmaring *ring;
881	int err;
882	int nr_slots;
883	dma_addr_t dma_test;
884
885	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
886	if (!ring)
887		goto out;
888	ring->type = type;
889	ring->dev = dev;
890
891	nr_slots = B43legacy_RXRING_SLOTS;
892	if (for_tx)
893		nr_slots = B43legacy_TXRING_SLOTS;
894
895	ring->meta = kcalloc(nr_slots, sizeof(struct b43legacy_dmadesc_meta),
896			     GFP_KERNEL);
897	if (!ring->meta)
898		goto err_kfree_ring;
899	if (for_tx) {
900		ring->txhdr_cache = kcalloc(nr_slots,
901					sizeof(struct b43legacy_txhdr_fw3),
902					GFP_KERNEL);
903		if (!ring->txhdr_cache)
904			goto err_kfree_meta;
905
906		/* test for ability to dma to txhdr_cache */
907		dma_test = dma_map_single(dev->dev->dma_dev, ring->txhdr_cache,
908					      sizeof(struct b43legacy_txhdr_fw3),
909					      DMA_TO_DEVICE);
910
911		if (b43legacy_dma_mapping_error(ring, dma_test,
912					sizeof(struct b43legacy_txhdr_fw3), 1)) {
913			/* ugh realloc */
914			kfree(ring->txhdr_cache);
915			ring->txhdr_cache = kcalloc(nr_slots,
916					sizeof(struct b43legacy_txhdr_fw3),
917					GFP_KERNEL | GFP_DMA);
918			if (!ring->txhdr_cache)
919				goto err_kfree_meta;
920
921			dma_test = dma_map_single(dev->dev->dma_dev,
922					ring->txhdr_cache,
923					sizeof(struct b43legacy_txhdr_fw3),
924					DMA_TO_DEVICE);
925
926			if (b43legacy_dma_mapping_error(ring, dma_test,
927					sizeof(struct b43legacy_txhdr_fw3), 1))
928				goto err_kfree_txhdr_cache;
929		}
930
931		dma_unmap_single(dev->dev->dma_dev, dma_test,
932				 sizeof(struct b43legacy_txhdr_fw3),
933				 DMA_TO_DEVICE);
934	}
935
936	ring->nr_slots = nr_slots;
937	ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
938	ring->index = controller_index;
939	if (type == B43legacy_DMA_64BIT)
940		ring->ops = &dma64_ops;
941	else
942		ring->ops = &dma32_ops;
943	if (for_tx) {
944		ring->tx = 1;
945		ring->current_slot = -1;
946	} else {
947		if (ring->index == 0) {
948			ring->rx_buffersize = B43legacy_DMA0_RX_BUFFERSIZE;
949			ring->frameoffset = B43legacy_DMA0_RX_FRAMEOFFSET;
950		} else if (ring->index == 3) {
951			ring->rx_buffersize = B43legacy_DMA3_RX_BUFFERSIZE;
952			ring->frameoffset = B43legacy_DMA3_RX_FRAMEOFFSET;
953		} else
954			B43legacy_WARN_ON(1);
955	}
956	spin_lock_init(&ring->lock);
957#ifdef CONFIG_B43LEGACY_DEBUG
958	ring->last_injected_overflow = jiffies;
959#endif
960
961	err = alloc_ringmemory(ring);
962	if (err)
963		goto err_kfree_txhdr_cache;
964	err = dmacontroller_setup(ring);
965	if (err)
966		goto err_free_ringmemory;
967
968out:
969	return ring;
970
971err_free_ringmemory:
972	free_ringmemory(ring);
973err_kfree_txhdr_cache:
974	kfree(ring->txhdr_cache);
975err_kfree_meta:
976	kfree(ring->meta);
977err_kfree_ring:
978	kfree(ring);
979	ring = NULL;
980	goto out;
981}
982
983/* Main cleanup function. */
984static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
985{
986	if (!ring)
987		return;
988
989	b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
990		     " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
991		     (ring->tx) ? "TX" : "RX", ring->max_used_slots,
992		     ring->nr_slots);
993	/* Device IRQs are disabled prior entering this function,
994	 * so no need to take care of concurrency with rx handler stuff.
995	 */
996	dmacontroller_cleanup(ring);
997	free_all_descbuffers(ring);
998	free_ringmemory(ring);
999
1000	kfree(ring->txhdr_cache);
1001	kfree(ring->meta);
1002	kfree(ring);
1003}
1004
1005void b43legacy_dma_free(struct b43legacy_wldev *dev)
1006{
1007	struct b43legacy_dma *dma;
1008
1009	if (b43legacy_using_pio(dev))
1010		return;
1011	dma = &dev->dma;
1012
1013	b43legacy_destroy_dmaring(dma->rx_ring3);
1014	dma->rx_ring3 = NULL;
1015	b43legacy_destroy_dmaring(dma->rx_ring0);
1016	dma->rx_ring0 = NULL;
1017
1018	b43legacy_destroy_dmaring(dma->tx_ring5);
1019	dma->tx_ring5 = NULL;
1020	b43legacy_destroy_dmaring(dma->tx_ring4);
1021	dma->tx_ring4 = NULL;
1022	b43legacy_destroy_dmaring(dma->tx_ring3);
1023	dma->tx_ring3 = NULL;
1024	b43legacy_destroy_dmaring(dma->tx_ring2);
1025	dma->tx_ring2 = NULL;
1026	b43legacy_destroy_dmaring(dma->tx_ring1);
1027	dma->tx_ring1 = NULL;
1028	b43legacy_destroy_dmaring(dma->tx_ring0);
1029	dma->tx_ring0 = NULL;
1030}
1031
1032static int b43legacy_dma_set_mask(struct b43legacy_wldev *dev, u64 mask)
1033{
1034	u64 orig_mask = mask;
1035	bool fallback = 0;
1036	int err;
1037
1038	/* Try to set the DMA mask. If it fails, try falling back to a
1039	 * lower mask, as we can always also support a lower one. */
1040	while (1) {
1041		err = dma_set_mask(dev->dev->dma_dev, mask);
1042		if (!err) {
1043			err = dma_set_coherent_mask(dev->dev->dma_dev, mask);
1044			if (!err)
1045				break;
1046		}
1047		if (mask == DMA_BIT_MASK(64)) {
1048			mask = DMA_BIT_MASK(32);
1049			fallback = 1;
1050			continue;
1051		}
1052		if (mask == DMA_BIT_MASK(32)) {
1053			mask = DMA_BIT_MASK(30);
1054			fallback = 1;
1055			continue;
1056		}
1057		b43legacyerr(dev->wl, "The machine/kernel does not support "
1058		       "the required %u-bit DMA mask\n",
1059		       (unsigned int)dma_mask_to_engine_type(orig_mask));
1060		return -EOPNOTSUPP;
1061	}
1062	if (fallback) {
1063		b43legacyinfo(dev->wl, "DMA mask fallback from %u-bit to %u-"
1064			"bit\n",
1065			(unsigned int)dma_mask_to_engine_type(orig_mask),
1066			(unsigned int)dma_mask_to_engine_type(mask));
1067	}
1068
1069	return 0;
1070}
1071
1072int b43legacy_dma_init(struct b43legacy_wldev *dev)
1073{
1074	struct b43legacy_dma *dma = &dev->dma;
1075	struct b43legacy_dmaring *ring;
1076	int err;
1077	u64 dmamask;
1078	enum b43legacy_dmatype type;
1079
1080	dmamask = supported_dma_mask(dev);
1081	type = dma_mask_to_engine_type(dmamask);
1082	err = b43legacy_dma_set_mask(dev, dmamask);
1083	if (err) {
1084#ifdef CONFIG_B43LEGACY_PIO
1085		b43legacywarn(dev->wl, "DMA for this device not supported. "
1086			"Falling back to PIO\n");
1087		dev->__using_pio = 1;
1088		return -EAGAIN;
1089#else
1090		b43legacyerr(dev->wl, "DMA for this device not supported and "
1091		       "no PIO support compiled in\n");
1092		return -EOPNOTSUPP;
1093#endif
1094	}
1095
1096	err = -ENOMEM;
1097	/* setup TX DMA channels. */
1098	ring = b43legacy_setup_dmaring(dev, 0, 1, type);
1099	if (!ring)
1100		goto out;
1101	dma->tx_ring0 = ring;
1102
1103	ring = b43legacy_setup_dmaring(dev, 1, 1, type);
1104	if (!ring)
1105		goto err_destroy_tx0;
1106	dma->tx_ring1 = ring;
1107
1108	ring = b43legacy_setup_dmaring(dev, 2, 1, type);
1109	if (!ring)
1110		goto err_destroy_tx1;
1111	dma->tx_ring2 = ring;
1112
1113	ring = b43legacy_setup_dmaring(dev, 3, 1, type);
1114	if (!ring)
1115		goto err_destroy_tx2;
1116	dma->tx_ring3 = ring;
1117
1118	ring = b43legacy_setup_dmaring(dev, 4, 1, type);
1119	if (!ring)
1120		goto err_destroy_tx3;
1121	dma->tx_ring4 = ring;
1122
1123	ring = b43legacy_setup_dmaring(dev, 5, 1, type);
1124	if (!ring)
1125		goto err_destroy_tx4;
1126	dma->tx_ring5 = ring;
1127
1128	/* setup RX DMA channels. */
1129	ring = b43legacy_setup_dmaring(dev, 0, 0, type);
1130	if (!ring)
1131		goto err_destroy_tx5;
1132	dma->rx_ring0 = ring;
1133
1134	if (dev->dev->id.revision < 5) {
1135		ring = b43legacy_setup_dmaring(dev, 3, 0, type);
1136		if (!ring)
1137			goto err_destroy_rx0;
1138		dma->rx_ring3 = ring;
1139	}
1140
1141	b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
1142	err = 0;
1143out:
1144	return err;
1145
1146err_destroy_rx0:
1147	b43legacy_destroy_dmaring(dma->rx_ring0);
1148	dma->rx_ring0 = NULL;
1149err_destroy_tx5:
1150	b43legacy_destroy_dmaring(dma->tx_ring5);
1151	dma->tx_ring5 = NULL;
1152err_destroy_tx4:
1153	b43legacy_destroy_dmaring(dma->tx_ring4);
1154	dma->tx_ring4 = NULL;
1155err_destroy_tx3:
1156	b43legacy_destroy_dmaring(dma->tx_ring3);
1157	dma->tx_ring3 = NULL;
1158err_destroy_tx2:
1159	b43legacy_destroy_dmaring(dma->tx_ring2);
1160	dma->tx_ring2 = NULL;
1161err_destroy_tx1:
1162	b43legacy_destroy_dmaring(dma->tx_ring1);
1163	dma->tx_ring1 = NULL;
1164err_destroy_tx0:
1165	b43legacy_destroy_dmaring(dma->tx_ring0);
1166	dma->tx_ring0 = NULL;
1167	goto out;
1168}
1169
1170/* Generate a cookie for the TX header. */
1171static u16 generate_cookie(struct b43legacy_dmaring *ring,
1172			   int slot)
1173{
1174	u16 cookie = 0x1000;
1175
1176	/* Use the upper 4 bits of the cookie as
1177	 * DMA controller ID and store the slot number
1178	 * in the lower 12 bits.
1179	 * Note that the cookie must never be 0, as this
1180	 * is a special value used in RX path.
1181	 */
1182	switch (ring->index) {
1183	case 0:
1184		cookie = 0xA000;
1185		break;
1186	case 1:
1187		cookie = 0xB000;
1188		break;
1189	case 2:
1190		cookie = 0xC000;
1191		break;
1192	case 3:
1193		cookie = 0xD000;
1194		break;
1195	case 4:
1196		cookie = 0xE000;
1197		break;
1198	case 5:
1199		cookie = 0xF000;
1200		break;
1201	}
1202	B43legacy_WARN_ON(!(((u16)slot & 0xF000) == 0x0000));
1203	cookie |= (u16)slot;
1204
1205	return cookie;
1206}
1207
1208/* Inspect a cookie and find out to which controller/slot it belongs. */
1209static
1210struct b43legacy_dmaring *parse_cookie(struct b43legacy_wldev *dev,
1211				      u16 cookie, int *slot)
1212{
1213	struct b43legacy_dma *dma = &dev->dma;
1214	struct b43legacy_dmaring *ring = NULL;
1215
1216	switch (cookie & 0xF000) {
1217	case 0xA000:
1218		ring = dma->tx_ring0;
1219		break;
1220	case 0xB000:
1221		ring = dma->tx_ring1;
1222		break;
1223	case 0xC000:
1224		ring = dma->tx_ring2;
1225		break;
1226	case 0xD000:
1227		ring = dma->tx_ring3;
1228		break;
1229	case 0xE000:
1230		ring = dma->tx_ring4;
1231		break;
1232	case 0xF000:
1233		ring = dma->tx_ring5;
1234		break;
1235	default:
1236		B43legacy_WARN_ON(1);
1237	}
1238	*slot = (cookie & 0x0FFF);
1239	B43legacy_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
1240
1241	return ring;
1242}
1243
1244static int dma_tx_fragment(struct b43legacy_dmaring *ring,
1245			    struct sk_buff **in_skb)
1246{
1247	struct sk_buff *skb = *in_skb;
1248	const struct b43legacy_dma_ops *ops = ring->ops;
1249	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1250	u8 *header;
1251	int slot, old_top_slot, old_used_slots;
1252	int err;
1253	struct b43legacy_dmadesc_generic *desc;
1254	struct b43legacy_dmadesc_meta *meta;
1255	struct b43legacy_dmadesc_meta *meta_hdr;
1256	struct sk_buff *bounce_skb;
1257
1258#define SLOTS_PER_PACKET  2
1259	B43legacy_WARN_ON(skb_shinfo(skb)->nr_frags != 0);
1260
1261	old_top_slot = ring->current_slot;
1262	old_used_slots = ring->used_slots;
1263
1264	/* Get a slot for the header. */
1265	slot = request_slot(ring);
1266	desc = ops->idx2desc(ring, slot, &meta_hdr);
1267	memset(meta_hdr, 0, sizeof(*meta_hdr));
1268
1269	header = &(ring->txhdr_cache[slot * sizeof(
1270			       struct b43legacy_txhdr_fw3)]);
1271	err = b43legacy_generate_txhdr(ring->dev, header,
1272				 skb->data, skb->len, info,
1273				 generate_cookie(ring, slot));
1274	if (unlikely(err)) {
1275		ring->current_slot = old_top_slot;
1276		ring->used_slots = old_used_slots;
1277		return err;
1278	}
1279
1280	meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
1281					   sizeof(struct b43legacy_txhdr_fw3), 1);
1282	if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
1283					sizeof(struct b43legacy_txhdr_fw3), 1)) {
1284		ring->current_slot = old_top_slot;
1285		ring->used_slots = old_used_slots;
1286		return -EIO;
1287	}
1288	ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
1289			     sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
1290
1291	/* Get a slot for the payload. */
1292	slot = request_slot(ring);
1293	desc = ops->idx2desc(ring, slot, &meta);
1294	memset(meta, 0, sizeof(*meta));
1295
1296	meta->skb = skb;
1297	meta->is_last_fragment = 1;
1298
1299	meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1300	/* create a bounce buffer in zone_dma on mapping failure. */
1301	if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1302		bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
1303		if (!bounce_skb) {
1304			ring->current_slot = old_top_slot;
1305			ring->used_slots = old_used_slots;
1306			err = -ENOMEM;
1307			goto out_unmap_hdr;
1308		}
1309
1310		memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
1311		memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
1312		bounce_skb->dev = skb->dev;
1313		skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
1314		info = IEEE80211_SKB_CB(bounce_skb);
1315
1316		dev_kfree_skb_any(skb);
1317		skb = bounce_skb;
1318		*in_skb = bounce_skb;
1319		meta->skb = skb;
1320		meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
1321		if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
1322			ring->current_slot = old_top_slot;
1323			ring->used_slots = old_used_slots;
1324			err = -EIO;
1325			goto out_free_bounce;
1326		}
1327	}
1328
1329	ops->fill_descriptor(ring, desc, meta->dmaaddr,
1330			     skb->len, 0, 1, 1);
1331
1332	wmb();	/* previous stuff MUST be done */
1333	/* Now transfer the whole frame. */
1334	ops->poke_tx(ring, next_slot(ring, slot));
1335	return 0;
1336
1337out_free_bounce:
1338	dev_kfree_skb_any(skb);
1339out_unmap_hdr:
1340	unmap_descbuffer(ring, meta_hdr->dmaaddr,
1341			 sizeof(struct b43legacy_txhdr_fw3), 1);
1342	return err;
1343}
1344
1345static inline
1346int should_inject_overflow(struct b43legacy_dmaring *ring)
1347{
1348#ifdef CONFIG_B43LEGACY_DEBUG
1349	if (unlikely(b43legacy_debug(ring->dev,
1350				     B43legacy_DBG_DMAOVERFLOW))) {
1351		/* Check if we should inject another ringbuffer overflow
1352		 * to test handling of this situation in the stack. */
1353		unsigned long next_overflow;
1354
1355		next_overflow = ring->last_injected_overflow + HZ;
1356		if (time_after(jiffies, next_overflow)) {
1357			ring->last_injected_overflow = jiffies;
1358			b43legacydbg(ring->dev->wl,
1359			       "Injecting TX ring overflow on "
1360			       "DMA controller %d\n", ring->index);
1361			return 1;
1362		}
1363	}
1364#endif /* CONFIG_B43LEGACY_DEBUG */
1365	return 0;
1366}
1367
1368int b43legacy_dma_tx(struct b43legacy_wldev *dev,
1369		     struct sk_buff *skb)
1370{
1371	struct b43legacy_dmaring *ring;
1372	struct ieee80211_hdr *hdr;
1373	int err = 0;
1374	unsigned long flags;
1375	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1376
1377	ring = priority_to_txring(dev, skb_get_queue_mapping(skb));
1378	spin_lock_irqsave(&ring->lock, flags);
1379	B43legacy_WARN_ON(!ring->tx);
1380
1381	if (unlikely(ring->stopped)) {
1382		/* We get here only because of a bug in mac80211.
1383		 * Because of a race, one packet may be queued after
1384		 * the queue is stopped, thus we got called when we shouldn't.
1385		 * For now, just refuse the transmit. */
1386		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1387			b43legacyerr(dev->wl, "Packet after queue stopped\n");
1388		err = -ENOSPC;
1389		goto out_unlock;
1390	}
1391
1392	if (unlikely(WARN_ON(free_slots(ring) < SLOTS_PER_PACKET))) {
1393		/* If we get here, we have a real error with the queue
1394		 * full, but queues not stopped. */
1395		b43legacyerr(dev->wl, "DMA queue overflow\n");
1396		err = -ENOSPC;
1397		goto out_unlock;
1398	}
1399
1400	/* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
1401	 * into the skb data or cb now. */
1402	hdr = NULL;
1403	info = NULL;
1404	err = dma_tx_fragment(ring, &skb);
1405	if (unlikely(err == -ENOKEY)) {
1406		/* Drop this packet, as we don't have the encryption key
1407		 * anymore and must not transmit it unencrypted. */
1408		dev_kfree_skb_any(skb);
1409		err = 0;
1410		goto out_unlock;
1411	}
1412	if (unlikely(err)) {
1413		b43legacyerr(dev->wl, "DMA tx mapping failure\n");
1414		goto out_unlock;
1415	}
1416	if ((free_slots(ring) < SLOTS_PER_PACKET) ||
1417	    should_inject_overflow(ring)) {
1418		/* This TX ring is full. */
1419		ieee80211_stop_queue(dev->wl->hw, txring_to_priority(ring));
1420		ring->stopped = 1;
1421		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1422			b43legacydbg(dev->wl, "Stopped TX ring %d\n",
1423			       ring->index);
1424	}
1425out_unlock:
1426	spin_unlock_irqrestore(&ring->lock, flags);
1427
1428	return err;
1429}
1430
1431void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
1432				 const struct b43legacy_txstatus *status)
1433{
1434	const struct b43legacy_dma_ops *ops;
1435	struct b43legacy_dmaring *ring;
1436	struct b43legacy_dmadesc_generic *desc;
1437	struct b43legacy_dmadesc_meta *meta;
1438	int retry_limit;
1439	int slot;
1440
1441	ring = parse_cookie(dev, status->cookie, &slot);
1442	if (unlikely(!ring))
1443		return;
1444	B43legacy_WARN_ON(!irqs_disabled());
1445	spin_lock(&ring->lock);
1446
1447	B43legacy_WARN_ON(!ring->tx);
1448	ops = ring->ops;
1449	while (1) {
1450		B43legacy_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
1451		desc = ops->idx2desc(ring, slot, &meta);
1452
1453		if (meta->skb)
1454			unmap_descbuffer(ring, meta->dmaaddr,
1455					 meta->skb->len, 1);
1456		else
1457			unmap_descbuffer(ring, meta->dmaaddr,
1458					 sizeof(struct b43legacy_txhdr_fw3),
1459					 1);
1460
1461		if (meta->is_last_fragment) {
1462			struct ieee80211_tx_info *info;
1463			BUG_ON(!meta->skb);
1464			info = IEEE80211_SKB_CB(meta->skb);
1465
1466			/* preserve the confiured retry limit before clearing the status
1467			 * The xmit function has overwritten the rc's value with the actual
1468			 * retry limit done by the hardware */
1469			retry_limit = info->status.rates[0].count;
1470			ieee80211_tx_info_clear_status(info);
1471
1472			if (status->acked)
1473				info->flags |= IEEE80211_TX_STAT_ACK;
1474
1475			if (status->rts_count > dev->wl->hw->conf.short_frame_max_tx_count) {
1476				/*
1477				 * If the short retries (RTS, not data frame) have exceeded
1478				 * the limit, the hw will not have tried the selected rate,
1479				 * but will have used the fallback rate instead.
1480				 * Don't let the rate control count attempts for the selected
1481				 * rate in this case, otherwise the statistics will be off.
1482				 */
1483				info->status.rates[0].count = 0;
1484				info->status.rates[1].count = status->frame_count;
1485			} else {
1486				if (status->frame_count > retry_limit) {
1487					info->status.rates[0].count = retry_limit;
1488					info->status.rates[1].count = status->frame_count -
1489							retry_limit;
1490
1491				} else {
1492					info->status.rates[0].count = status->frame_count;
1493					info->status.rates[1].idx = -1;
1494				}
1495			}
1496
1497			/* Call back to inform the ieee80211 subsystem about the
1498			 * status of the transmission.
1499			 * Some fields of txstat are already filled in dma_tx().
1500			 */
1501			ieee80211_tx_status_irqsafe(dev->wl->hw, meta->skb);
1502			/* skb is freed by ieee80211_tx_status_irqsafe() */
1503			meta->skb = NULL;
1504		} else {
1505			/* No need to call free_descriptor_buffer here, as
1506			 * this is only the txhdr, which is not allocated.
1507			 */
1508			B43legacy_WARN_ON(meta->skb != NULL);
1509		}
1510
1511		/* Everything unmapped and free'd. So it's not used anymore. */
1512		ring->used_slots--;
1513
1514		if (meta->is_last_fragment)
1515			break;
1516		slot = next_slot(ring, slot);
1517	}
1518	dev->stats.last_tx = jiffies;
1519	if (ring->stopped) {
1520		B43legacy_WARN_ON(free_slots(ring) < SLOTS_PER_PACKET);
1521		ieee80211_wake_queue(dev->wl->hw, txring_to_priority(ring));
1522		ring->stopped = 0;
1523		if (b43legacy_debug(dev, B43legacy_DBG_DMAVERBOSE))
1524			b43legacydbg(dev->wl, "Woke up TX ring %d\n",
1525			       ring->index);
1526	}
1527
1528	spin_unlock(&ring->lock);
1529}
1530
1531static void dma_rx(struct b43legacy_dmaring *ring,
1532		   int *slot)
1533{
1534	const struct b43legacy_dma_ops *ops = ring->ops;
1535	struct b43legacy_dmadesc_generic *desc;
1536	struct b43legacy_dmadesc_meta *meta;
1537	struct b43legacy_rxhdr_fw3 *rxhdr;
1538	struct sk_buff *skb;
1539	u16 len;
1540	int err;
1541	dma_addr_t dmaaddr;
1542
1543	desc = ops->idx2desc(ring, *slot, &meta);
1544
1545	sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize);
1546	skb = meta->skb;
1547
1548	if (ring->index == 3) {
1549		/* We received an xmit status. */
1550		struct b43legacy_hwtxstatus *hw =
1551				(struct b43legacy_hwtxstatus *)skb->data;
1552		int i = 0;
1553
1554		while (hw->cookie == 0) {
1555			if (i > 100)
1556				break;
1557			i++;
1558			udelay(2);
1559			barrier();
1560		}
1561		b43legacy_handle_hwtxstatus(ring->dev, hw);
1562		/* recycle the descriptor buffer. */
1563		sync_descbuffer_for_device(ring, meta->dmaaddr,
1564					   ring->rx_buffersize);
1565
1566		return;
1567	}
1568	rxhdr = (struct b43legacy_rxhdr_fw3 *)skb->data;
1569	len = le16_to_cpu(rxhdr->frame_len);
1570	if (len == 0) {
1571		int i = 0;
1572
1573		do {
1574			udelay(2);
1575			barrier();
1576			len = le16_to_cpu(rxhdr->frame_len);
1577		} while (len == 0 && i++ < 5);
1578		if (unlikely(len == 0)) {
1579			/* recycle the descriptor buffer. */
1580			sync_descbuffer_for_device(ring, meta->dmaaddr,
1581						   ring->rx_buffersize);
1582			goto drop;
1583		}
1584	}
1585	if (unlikely(len > ring->rx_buffersize)) {
1586		/* The data did not fit into one descriptor buffer
1587		 * and is split over multiple buffers.
1588		 * This should never happen, as we try to allocate buffers
1589		 * big enough. So simply ignore this packet.
1590		 */
1591		int cnt = 0;
1592		s32 tmp = len;
1593
1594		while (1) {
1595			desc = ops->idx2desc(ring, *slot, &meta);
1596			/* recycle the descriptor buffer. */
1597			sync_descbuffer_for_device(ring, meta->dmaaddr,
1598						   ring->rx_buffersize);
1599			*slot = next_slot(ring, *slot);
1600			cnt++;
1601			tmp -= ring->rx_buffersize;
1602			if (tmp <= 0)
1603				break;
1604		}
1605		b43legacyerr(ring->dev->wl, "DMA RX buffer too small "
1606		       "(len: %u, buffer: %u, nr-dropped: %d)\n",
1607		       len, ring->rx_buffersize, cnt);
1608		goto drop;
1609	}
1610
1611	dmaaddr = meta->dmaaddr;
1612	err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC);
1613	if (unlikely(err)) {
1614		b43legacydbg(ring->dev->wl, "DMA RX: setup_rx_descbuffer()"
1615			     " failed\n");
1616		sync_descbuffer_for_device(ring, dmaaddr,
1617					   ring->rx_buffersize);
1618		goto drop;
1619	}
1620
1621	unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0);
1622	skb_put(skb, len + ring->frameoffset);
1623	skb_pull(skb, ring->frameoffset);
1624
1625	b43legacy_rx(ring->dev, skb, rxhdr);
1626drop:
1627	return;
1628}
1629
1630void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
1631{
1632	const struct b43legacy_dma_ops *ops = ring->ops;
1633	int slot;
1634	int current_slot;
1635	int used_slots = 0;
1636
1637	B43legacy_WARN_ON(ring->tx);
1638	current_slot = ops->get_current_rxslot(ring);
1639	B43legacy_WARN_ON(!(current_slot >= 0 && current_slot <
1640			   ring->nr_slots));
1641
1642	slot = ring->current_slot;
1643	for (; slot != current_slot; slot = next_slot(ring, slot)) {
1644		dma_rx(ring, &slot);
1645		update_max_used_slots(ring, ++used_slots);
1646	}
1647	ops->set_current_rxslot(ring, slot);
1648	ring->current_slot = slot;
1649}
1650
1651static void b43legacy_dma_tx_suspend_ring(struct b43legacy_dmaring *ring)
1652{
1653	unsigned long flags;
1654
1655	spin_lock_irqsave(&ring->lock, flags);
1656	B43legacy_WARN_ON(!ring->tx);
1657	ring->ops->tx_suspend(ring);
1658	spin_unlock_irqrestore(&ring->lock, flags);
1659}
1660
1661static void b43legacy_dma_tx_resume_ring(struct b43legacy_dmaring *ring)
1662{
1663	unsigned long flags;
1664
1665	spin_lock_irqsave(&ring->lock, flags);
1666	B43legacy_WARN_ON(!ring->tx);
1667	ring->ops->tx_resume(ring);
1668	spin_unlock_irqrestore(&ring->lock, flags);
1669}
1670
1671void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
1672{
1673	b43legacy_power_saving_ctl_bits(dev, -1, 1);
1674	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring0);
1675	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring1);
1676	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring2);
1677	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring3);
1678	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring4);
1679	b43legacy_dma_tx_suspend_ring(dev->dma.tx_ring5);
1680}
1681
1682void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
1683{
1684	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring5);
1685	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring4);
1686	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring3);
1687	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring2);
1688	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring1);
1689	b43legacy_dma_tx_resume_ring(dev->dma.tx_ring0);
1690	b43legacy_power_saving_ctl_bits(dev, -1, -1);
1691}
1692