busdma_machdep-v4.c revision 173988
1/*-
2 * Copyright (c) 2004 Olivier Houchard
3 * Copyright (c) 2002 Peter Grehan
4 * Copyright (c) 1997, 1998 Justin T. Gibbs.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions, and the following disclaimer,
12 *    without modification, immediately at the beginning of the file.
13 * 2. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *   From i386/busdma_machdep.c,v 1.26 2002/04/19 22:58:09 alfred
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: head/sys/arm/arm/busdma_machdep.c 173988 2007-11-27 17:28:12Z jhb $");
33
34/*
35 * ARM bus dma support routines
36 */
37
38#define _ARM32_BUS_DMA_PRIVATE
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/malloc.h>
42#include <sys/bus.h>
43#include <sys/interrupt.h>
44#include <sys/lock.h>
45#include <sys/proc.h>
46#include <sys/mutex.h>
47#include <sys/mbuf.h>
48#include <sys/uio.h>
49#include <sys/ktr.h>
50#include <sys/kernel.h>
51#include <sys/sysctl.h>
52
53#include <vm/vm.h>
54#include <vm/vm_page.h>
55#include <vm/vm_map.h>
56
57#include <machine/atomic.h>
58#include <machine/bus.h>
59#include <machine/cpufunc.h>
60#include <machine/md_var.h>
61
62#define MAX_BPAGES 64
63#define BUS_DMA_COULD_BOUNCE	BUS_DMA_BUS3
64#define BUS_DMA_MIN_ALLOC_COMP	BUS_DMA_BUS4
65
66struct bounce_zone;
67
68struct bus_dma_tag {
69	bus_dma_tag_t		parent;
70	bus_size_t		alignment;
71	bus_size_t		boundary;
72	bus_addr_t		lowaddr;
73	bus_addr_t		highaddr;
74	bus_dma_filter_t	*filter;
75	void			*filterarg;
76	bus_size_t		maxsize;
77	u_int			nsegments;
78	bus_size_t		maxsegsz;
79	int			flags;
80	int			ref_count;
81	int			map_count;
82	bus_dma_lock_t		*lockfunc;
83	void			*lockfuncarg;
84	/*
85	 * DMA range for this tag.  If the page doesn't fall within
86	 * one of these ranges, an error is returned.  The caller
87	 * may then decide what to do with the transfer.  If the
88	 * range pointer is NULL, it is ignored.
89	 */
90	struct arm32_dma_range	*ranges;
91	int			_nranges;
92	struct bounce_zone *bounce_zone;
93};
94
95struct bounce_page {
96	vm_offset_t	vaddr;		/* kva of bounce buffer */
97	vm_offset_t	vaddr_nocache;	/* kva of bounce buffer uncached */
98	bus_addr_t	busaddr;	/* Physical address */
99	vm_offset_t	datavaddr;	/* kva of client data */
100	bus_size_t	datacount;	/* client data count */
101	STAILQ_ENTRY(bounce_page) links;
102};
103
104int busdma_swi_pending;
105
106struct bounce_zone {
107	STAILQ_ENTRY(bounce_zone) links;
108	STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
109	int		total_bpages;
110	int		free_bpages;
111	int		reserved_bpages;
112	int		active_bpages;
113	int		total_bounced;
114	int		total_deferred;
115	bus_size_t	alignment;
116	bus_size_t	boundary;
117	bus_addr_t	lowaddr;
118	char		zoneid[8];
119	char		lowaddrid[20];
120	struct sysctl_ctx_list sysctl_tree;
121	struct sysctl_oid *sysctl_tree_top;
122};
123
124static struct mtx bounce_lock;
125static int total_bpages;
126static int busdma_zonecount;
127static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
128
129SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
130SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
131	   "Total bounce pages");
132
133#define DMAMAP_LINEAR		0x1
134#define DMAMAP_MBUF		0x2
135#define DMAMAP_UIO		0x4
136#define DMAMAP_ALLOCATED	0x10
137#define DMAMAP_TYPE_MASK	(DMAMAP_LINEAR|DMAMAP_MBUF|DMAMAP_UIO)
138#define DMAMAP_COHERENT		0x8
139struct bus_dmamap {
140	struct bp_list	bpages;
141	int		pagesneeded;
142	int		pagesreserved;
143        bus_dma_tag_t	dmat;
144	int		flags;
145	void 		*buffer;
146	void		*origbuffer;
147	void		*allocbuffer;
148	TAILQ_ENTRY(bus_dmamap)	freelist;
149	int		len;
150	STAILQ_ENTRY(bus_dmamap) links;
151	bus_dmamap_callback_t *callback;
152	void		      *callback_arg;
153
154};
155
156static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
157static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
158
159static TAILQ_HEAD(,bus_dmamap) dmamap_freelist =
160	TAILQ_HEAD_INITIALIZER(dmamap_freelist);
161
162#define BUSDMA_STATIC_MAPS	500
163static struct bus_dmamap map_pool[BUSDMA_STATIC_MAPS];
164
165static struct mtx busdma_mtx;
166
167MTX_SYSINIT(busdma_mtx, &busdma_mtx, "busdma lock", MTX_DEF);
168
169static void init_bounce_pages(void *dummy);
170static int alloc_bounce_zone(bus_dma_tag_t dmat);
171static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
172static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
173				int commit);
174static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
175				   vm_offset_t vaddr, bus_size_t size);
176static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
177
178/* Default tag, as most drivers provide no parent tag. */
179bus_dma_tag_t arm_root_dma_tag;
180
181/*
182 * Return true if a match is made.
183 *
184 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
185 *
186 * If paddr is within the bounds of the dma tag then call the filter callback
187 * to check for a match, if there is no filter callback then assume a match.
188 */
189static int
190run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
191{
192	int retval;
193
194	retval = 0;
195
196	do {
197		if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
198		 || ((paddr & (dmat->alignment - 1)) != 0))
199		 && (dmat->filter == NULL
200		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
201			retval = 1;
202
203		dmat = dmat->parent;
204	} while (retval == 0 && dmat != NULL);
205	return (retval);
206}
207
208static void
209arm_dmamap_freelist_init(void *dummy)
210{
211	int i;
212
213	for (i = 0; i < BUSDMA_STATIC_MAPS; i++)
214		TAILQ_INSERT_HEAD(&dmamap_freelist, &map_pool[i], freelist);
215}
216
217SYSINIT(busdma, SI_SUB_VM, SI_ORDER_ANY, arm_dmamap_freelist_init, NULL);
218
219/*
220 * Check to see if the specified page is in an allowed DMA range.
221 */
222
223static __inline int
224bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
225    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
226    int flags, vm_offset_t *lastaddrp, int *segp);
227
228static __inline int
229_bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
230{
231	int i;
232	for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) {
233		if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1])
234		    || (lowaddr < phys_avail[i] &&
235		    highaddr > phys_avail[i]))
236			return (1);
237	}
238	return (0);
239}
240
241static __inline struct arm32_dma_range *
242_bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
243    bus_addr_t curaddr)
244{
245	struct arm32_dma_range *dr;
246	int i;
247
248	for (i = 0, dr = ranges; i < nranges; i++, dr++) {
249		if (curaddr >= dr->dr_sysbase &&
250		    round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
251			return (dr);
252	}
253
254	return (NULL);
255}
256/*
257 * Convenience function for manipulating driver locks from busdma (during
258 * busdma_swi, for example).  Drivers that don't provide their own locks
259 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
260 * non-mutex locking scheme don't have to use this at all.
261 */
262void
263busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
264{
265	struct mtx *dmtx;
266
267	dmtx = (struct mtx *)arg;
268	switch (op) {
269	case BUS_DMA_LOCK:
270		mtx_lock(dmtx);
271		break;
272	case BUS_DMA_UNLOCK:
273		mtx_unlock(dmtx);
274		break;
275	default:
276		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
277	}
278}
279
280/*
281 * dflt_lock should never get called.  It gets put into the dma tag when
282 * lockfunc == NULL, which is only valid if the maps that are associated
283 * with the tag are meant to never be defered.
284 * XXX Should have a way to identify which driver is responsible here.
285 */
286static void
287dflt_lock(void *arg, bus_dma_lock_op_t op)
288{
289#ifdef INVARIANTS
290	panic("driver error: busdma dflt_lock called");
291#else
292	printf("DRIVER_ERROR: busdma dflt_lock called\n");
293#endif
294}
295
296static __inline bus_dmamap_t
297_busdma_alloc_dmamap(void)
298{
299	bus_dmamap_t map;
300
301	mtx_lock(&busdma_mtx);
302	map = TAILQ_FIRST(&dmamap_freelist);
303	if (map)
304		TAILQ_REMOVE(&dmamap_freelist, map, freelist);
305	mtx_unlock(&busdma_mtx);
306	if (!map) {
307		map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT | M_ZERO);
308		if (map)
309			map->flags = DMAMAP_ALLOCATED;
310	} else
311		map->flags = 0;
312	STAILQ_INIT(&map->bpages);
313	return (map);
314}
315
316static __inline void
317_busdma_free_dmamap(bus_dmamap_t map)
318{
319	if (map->flags & DMAMAP_ALLOCATED)
320		free(map, M_DEVBUF);
321	else {
322		mtx_lock(&busdma_mtx);
323		TAILQ_INSERT_HEAD(&dmamap_freelist, map, freelist);
324		mtx_unlock(&busdma_mtx);
325	}
326}
327
328/*
329 * Allocate a device specific dma_tag.
330 */
331#define SEG_NB 1024
332
333int
334bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
335		   bus_size_t boundary, bus_addr_t lowaddr,
336		   bus_addr_t highaddr, bus_dma_filter_t *filter,
337		   void *filterarg, bus_size_t maxsize, int nsegments,
338		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
339		   void *lockfuncarg, bus_dma_tag_t *dmat)
340{
341	bus_dma_tag_t newtag;
342	int error = 0;
343	/* Return a NULL tag on failure */
344	*dmat = NULL;
345	if (!parent)
346		parent = arm_root_dma_tag;
347
348	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
349	if (newtag == NULL) {
350		CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
351		    __func__, newtag, 0, error);
352		return (ENOMEM);
353	}
354
355	newtag->parent = parent;
356	newtag->alignment = alignment;
357	newtag->boundary = boundary;
358	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
359	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
360	newtag->filter = filter;
361	newtag->filterarg = filterarg;
362        newtag->maxsize = maxsize;
363        newtag->nsegments = nsegments;
364	newtag->maxsegsz = maxsegsz;
365	newtag->flags = flags;
366	newtag->ref_count = 1; /* Count ourself */
367	newtag->map_count = 0;
368	newtag->ranges = bus_dma_get_range();
369	newtag->_nranges = bus_dma_get_range_nb();
370	if (lockfunc != NULL) {
371		newtag->lockfunc = lockfunc;
372		newtag->lockfuncarg = lockfuncarg;
373	} else {
374		newtag->lockfunc = dflt_lock;
375		newtag->lockfuncarg = NULL;
376	}
377        /*
378	 * Take into account any restrictions imposed by our parent tag
379	 */
380        if (parent != NULL) {
381                newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
382                newtag->highaddr = max(parent->highaddr, newtag->highaddr);
383		if (newtag->boundary == 0)
384			newtag->boundary = parent->boundary;
385		else if (parent->boundary != 0)
386                	newtag->boundary = min(parent->boundary,
387					       newtag->boundary);
388		if ((newtag->filter != NULL) ||
389		    ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
390			newtag->flags |= BUS_DMA_COULD_BOUNCE;
391                if (newtag->filter == NULL) {
392                        /*
393                         * Short circuit looking at our parent directly
394                         * since we have encapsulated all of its information
395                         */
396                        newtag->filter = parent->filter;
397                        newtag->filterarg = parent->filterarg;
398                        newtag->parent = parent->parent;
399		}
400		if (newtag->parent != NULL)
401			atomic_add_int(&parent->ref_count, 1);
402	}
403	if (_bus_dma_can_bounce(newtag->lowaddr, newtag->highaddr)
404	 || newtag->alignment > 1)
405		newtag->flags |= BUS_DMA_COULD_BOUNCE;
406
407	if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
408	    (flags & BUS_DMA_ALLOCNOW) != 0) {
409		struct bounce_zone *bz;
410
411		/* Must bounce */
412
413		if ((error = alloc_bounce_zone(newtag)) != 0) {
414			free(newtag, M_DEVBUF);
415			return (error);
416		}
417		bz = newtag->bounce_zone;
418
419		if (ptoa(bz->total_bpages) < maxsize) {
420			int pages;
421
422			pages = atop(maxsize) - bz->total_bpages;
423
424			/* Add pages to our bounce pool */
425			if (alloc_bounce_pages(newtag, pages) < pages)
426				error = ENOMEM;
427		}
428		/* Performed initial allocation */
429		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
430	} else
431		newtag->bounce_zone = NULL;
432	if (error != 0)
433		free(newtag, M_DEVBUF);
434	else
435		*dmat = newtag;
436	CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
437	    __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
438
439	return (error);
440}
441
442int
443bus_dma_tag_destroy(bus_dma_tag_t dmat)
444{
445#ifdef KTR
446	bus_dma_tag_t dmat_copy = dmat;
447#endif
448
449	if (dmat != NULL) {
450
451                if (dmat->map_count != 0)
452                        return (EBUSY);
453
454                while (dmat != NULL) {
455                        bus_dma_tag_t parent;
456
457                        parent = dmat->parent;
458                        atomic_subtract_int(&dmat->ref_count, 1);
459                        if (dmat->ref_count == 0) {
460                                free(dmat, M_DEVBUF);
461                                /*
462                                 * Last reference count, so
463                                 * release our reference
464                                 * count on our parent.
465                                 */
466                                dmat = parent;
467                        } else
468                                dmat = NULL;
469                }
470        }
471	CTR2(KTR_BUSDMA, "%s tag %p", __func__, dmat_copy);
472
473        return (0);
474}
475
476#include <sys/kdb.h>
477/*
478 * Allocate a handle for mapping from kva/uva/physical
479 * address space into bus device space.
480 */
481int
482bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
483{
484	bus_dmamap_t newmap;
485	int error = 0;
486
487	newmap = _busdma_alloc_dmamap();
488	if (newmap == NULL) {
489		CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
490		return (ENOMEM);
491	}
492	*mapp = newmap;
493	newmap->dmat = dmat;
494	newmap->allocbuffer = NULL;
495	dmat->map_count++;
496
497	/*
498	 * Bouncing might be required if the driver asks for an active
499	 * exclusion region, a data alignment that is stricter than 1, and/or
500	 * an active address boundary.
501	 */
502	if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
503
504		/* Must bounce */
505		struct bounce_zone *bz;
506		int maxpages;
507
508		if (dmat->bounce_zone == NULL) {
509			if ((error = alloc_bounce_zone(dmat)) != 0) {
510				_busdma_free_dmamap(newmap);
511				*mapp = NULL;
512				return (error);
513			}
514		}
515		bz = dmat->bounce_zone;
516
517		/* Initialize the new map */
518		STAILQ_INIT(&((*mapp)->bpages));
519
520		/*
521		 * Attempt to add pages to our pool on a per-instance
522		 * basis up to a sane limit.
523		 */
524		maxpages = MAX_BPAGES;
525		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
526		 || (dmat->map_count > 0 && bz->total_bpages < maxpages)) {
527			int pages;
528
529			pages = MAX(atop(dmat->maxsize), 1);
530			pages = MIN(maxpages - bz->total_bpages, pages);
531			pages = MAX(pages, 1);
532			if (alloc_bounce_pages(dmat, pages) < pages)
533				error = ENOMEM;
534
535			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
536				if (error == 0)
537					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
538			} else {
539				error = 0;
540			}
541		}
542	}
543	CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
544	    __func__, dmat, dmat->flags, error);
545
546	return (0);
547}
548
549/*
550 * Destroy a handle for mapping from kva/uva/physical
551 * address space into bus device space.
552 */
553int
554bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
555{
556
557	_busdma_free_dmamap(map);
558	if (STAILQ_FIRST(&map->bpages) != NULL) {
559		CTR3(KTR_BUSDMA, "%s: tag %p error %d",
560		    __func__, dmat, EBUSY);
561		return (EBUSY);
562	}
563        dmat->map_count--;
564	CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
565        return (0);
566}
567
568/*
569 * Allocate a piece of memory that can be efficiently mapped into
570 * bus device space based on the constraints lited in the dma tag.
571 * A dmamap to for use with dmamap_load is also allocated.
572 */
573int
574bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
575                 bus_dmamap_t *mapp)
576{
577	bus_dmamap_t newmap = NULL;
578
579	int mflags;
580
581	if (flags & BUS_DMA_NOWAIT)
582		mflags = M_NOWAIT;
583	else
584		mflags = M_WAITOK;
585	if (flags & BUS_DMA_ZERO)
586		mflags |= M_ZERO;
587
588	newmap = _busdma_alloc_dmamap();
589	if (newmap == NULL) {
590		CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
591		    __func__, dmat, dmat->flags, ENOMEM);
592		return (ENOMEM);
593	}
594	dmat->map_count++;
595	*mapp = newmap;
596	newmap->dmat = dmat;
597
598        if (dmat->maxsize <= PAGE_SIZE &&
599	   (dmat->alignment < dmat->maxsize) &&
600	   !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr)) {
601                *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
602        } else {
603                /*
604                 * XXX Use Contigmalloc until it is merged into this facility
605                 *     and handles multi-seg allocations.  Nobody is doing
606                 *     multi-seg allocations yet though.
607                 */
608                *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
609                    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
610                    dmat->boundary);
611        }
612        if (*vaddr == NULL) {
613		if (newmap != NULL) {
614			_busdma_free_dmamap(newmap);
615			dmat->map_count--;
616		}
617		*mapp = NULL;
618                return (ENOMEM);
619	}
620	if (flags & BUS_DMA_COHERENT) {
621		void *tmpaddr = arm_remap_nocache(
622		    (void *)((vm_offset_t)*vaddr &~ PAGE_MASK),
623		    dmat->maxsize + ((vm_offset_t)*vaddr & PAGE_MASK));
624
625		if (tmpaddr) {
626			tmpaddr = (void *)((vm_offset_t)(tmpaddr) +
627			    ((vm_offset_t)*vaddr & PAGE_MASK));
628			newmap->origbuffer = *vaddr;
629			newmap->allocbuffer = tmpaddr;
630			cpu_idcache_wbinv_range((vm_offset_t)*vaddr,
631			    dmat->maxsize);
632			*vaddr = tmpaddr;
633		} else
634			newmap->origbuffer = newmap->allocbuffer = NULL;
635	} else
636		newmap->origbuffer = newmap->allocbuffer = NULL;
637        return (0);
638}
639
640/*
641 * Free a piece of memory and it's allocated dmamap, that was allocated
642 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
643 */
644void
645bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
646{
647	if (map->allocbuffer) {
648		KASSERT(map->allocbuffer == vaddr,
649		    ("Trying to freeing the wrong DMA buffer"));
650		vaddr = map->origbuffer;
651		arm_unmap_nocache(map->allocbuffer, dmat->maxsize);
652	}
653        if (dmat->maxsize <= PAGE_SIZE &&
654	   dmat->alignment < dmat->maxsize &&
655	    !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
656		free(vaddr, M_DEVBUF);
657        else {
658		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
659	}
660	dmat->map_count--;
661	_busdma_free_dmamap(map);
662	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
663}
664
665static int
666_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
667			bus_size_t buflen, int flags)
668{
669	vm_offset_t vaddr;
670	vm_offset_t vendaddr;
671	bus_addr_t paddr;
672
673	if ((map->pagesneeded == 0)) {
674		CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
675		    "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
676		    dmat->boundary, dmat->alignment);
677		CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
678		    map, map->pagesneeded);
679		/*
680		 * Count the number of bounce pages
681		 * needed in order to complete this transfer
682		 */
683		vaddr = trunc_page((vm_offset_t)buf);
684		vendaddr = (vm_offset_t)buf + buflen;
685
686		while (vaddr < vendaddr) {
687			paddr = pmap_kextract(vaddr);
688			if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
689			    run_filter(dmat, paddr) != 0)
690				map->pagesneeded++;
691			vaddr += PAGE_SIZE;
692		}
693		CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
694	}
695
696	/* Reserve Necessary Bounce Pages */
697	if (map->pagesneeded != 0) {
698		mtx_lock(&bounce_lock);
699		if (flags & BUS_DMA_NOWAIT) {
700			if (reserve_bounce_pages(dmat, map, 0) != 0) {
701				mtx_unlock(&bounce_lock);
702				return (ENOMEM);
703			}
704		} else {
705			if (reserve_bounce_pages(dmat, map, 1) != 0) {
706				/* Queue us for resources */
707				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
708				    map, links);
709				mtx_unlock(&bounce_lock);
710				return (EINPROGRESS);
711			}
712		}
713		mtx_unlock(&bounce_lock);
714	}
715
716	return (0);
717}
718
719/*
720 * Utility function to load a linear buffer.  lastaddrp holds state
721 * between invocations (for multiple-buffer loads).  segp contains
722 * the starting segment on entrance, and the ending segment on exit.
723 * first indicates if this is the first invocation of this function.
724 */
725static __inline int
726bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
727    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
728    int flags, vm_offset_t *lastaddrp, int *segp)
729{
730	bus_size_t sgsize;
731	bus_addr_t curaddr, lastaddr, baddr, bmask;
732	vm_offset_t vaddr = (vm_offset_t)buf;
733	int seg;
734	int error = 0;
735	pd_entry_t *pde;
736	pt_entry_t pte;
737	pt_entry_t *ptep;
738
739	lastaddr = *lastaddrp;
740	bmask = ~(dmat->boundary - 1);
741
742	if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
743		error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags);
744		if (error)
745			return (error);
746	}
747	CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
748	    "alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
749
750	for (seg = *segp; buflen > 0 ; ) {
751		/*
752		 * Get the physical address for this segment.
753		 *
754		 * XXX Don't support checking for coherent mappings
755		 * XXX in user address space.
756		 */
757		if (__predict_true(pmap == pmap_kernel())) {
758			(void) pmap_get_pde_pte(pmap, vaddr, &pde, &ptep);
759			if (__predict_false(pmap_pde_section(pde))) {
760				if (*pde & L1_S_SUPERSEC)
761					curaddr = (*pde & L1_SUP_FRAME) |
762					    (vaddr & L1_SUP_OFFSET);
763				else
764					curaddr = (*pde & L1_S_FRAME) |
765					    (vaddr & L1_S_OFFSET);
766				if (*pde & L1_S_CACHE_MASK) {
767					map->flags &=
768					    ~DMAMAP_COHERENT;
769				}
770			} else {
771				pte = *ptep;
772				KASSERT((pte & L2_TYPE_MASK) != L2_TYPE_INV,
773				    ("INV type"));
774				if (__predict_false((pte & L2_TYPE_MASK)
775						    == L2_TYPE_L)) {
776					curaddr = (pte & L2_L_FRAME) |
777					    (vaddr & L2_L_OFFSET);
778					if (pte & L2_L_CACHE_MASK) {
779						map->flags &=
780						    ~DMAMAP_COHERENT;
781
782					}
783				} else {
784					curaddr = (pte & L2_S_FRAME) |
785					    (vaddr & L2_S_OFFSET);
786					if (pte & L2_S_CACHE_MASK) {
787						map->flags &=
788						    ~DMAMAP_COHERENT;
789					}
790				}
791			}
792		} else {
793			curaddr = pmap_extract(pmap, vaddr);
794			map->flags &= ~DMAMAP_COHERENT;
795		}
796
797		/*
798		 * Compute the segment size, and adjust counts.
799		 */
800		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
801		if (sgsize > dmat->maxsegsz)
802			sgsize = dmat->maxsegsz;
803		if (buflen < sgsize)
804			sgsize = buflen;
805
806		/*
807		 * Make sure we don't cross any boundaries.
808		 */
809		if (dmat->boundary > 0) {
810			baddr = (curaddr + dmat->boundary) & bmask;
811			if (sgsize > (baddr - curaddr))
812				sgsize = (baddr - curaddr);
813		}
814		if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
815		    map->pagesneeded != 0 && run_filter(dmat, curaddr))
816			curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
817
818		if (dmat->ranges) {
819			struct arm32_dma_range *dr;
820
821			dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
822			    curaddr);
823			if (dr == NULL)
824				return (EINVAL);
825			/*
826		     	 * In a valid DMA range.  Translate the physical
827			 * memory address to an address in the DMA window.
828			 */
829			curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
830
831		}
832
833		/*
834		 * Insert chunk into a segment, coalescing with
835		 * the previous segment if possible.
836		 */
837		if (seg >= 0 && curaddr == lastaddr &&
838		    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
839		    (dmat->boundary == 0 ||
840		     (segs[seg].ds_addr & bmask) ==
841		     (curaddr & bmask))) {
842			segs[seg].ds_len += sgsize;
843			goto segdone;
844		} else {
845			if (++seg >= dmat->nsegments)
846				break;
847			segs[seg].ds_addr = curaddr;
848			segs[seg].ds_len = sgsize;
849		}
850		if (error)
851			break;
852segdone:
853		lastaddr = curaddr + sgsize;
854		vaddr += sgsize;
855		buflen -= sgsize;
856	}
857
858	*segp = seg;
859	*lastaddrp = lastaddr;
860
861	/*
862	 * Did we fit?
863	 */
864	if (buflen != 0)
865		error = EFBIG; /* XXX better return value here? */
866	return (error);
867}
868
869/*
870 * Map the buffer buf into bus space using the dmamap map.
871 */
872int
873bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
874                bus_size_t buflen, bus_dmamap_callback_t *callback,
875                void *callback_arg, int flags)
876{
877     	vm_offset_t	lastaddr = 0;
878	int		error, nsegs = -1;
879#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
880	bus_dma_segment_t dm_segments[dmat->nsegments];
881#else
882	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
883#endif
884
885	KASSERT(dmat != NULL, ("dmatag is NULL"));
886	KASSERT(map != NULL, ("dmamap is NULL"));
887	map->callback = callback;
888	map->callback_arg = callback_arg;
889	map->flags &= ~DMAMAP_TYPE_MASK;
890	map->flags |= DMAMAP_LINEAR|DMAMAP_COHERENT;
891	map->buffer = buf;
892	map->len = buflen;
893	error = bus_dmamap_load_buffer(dmat,
894	    dm_segments, map, buf, buflen, kernel_pmap,
895	    flags, &lastaddr, &nsegs);
896	if (error == EINPROGRESS)
897		return (error);
898	if (error)
899		(*callback)(callback_arg, NULL, 0, error);
900	else
901		(*callback)(callback_arg, dm_segments, nsegs + 1, error);
902
903	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
904	    __func__, dmat, dmat->flags, nsegs + 1, error);
905
906	return (0);
907}
908
909/*
910 * Like bus_dmamap_load(), but for mbufs.
911 */
912int
913bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
914		     bus_dmamap_callback2_t *callback, void *callback_arg,
915		     int flags)
916{
917#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
918	bus_dma_segment_t dm_segments[dmat->nsegments];
919#else
920	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
921#endif
922	int nsegs = -1, error = 0;
923
924	M_ASSERTPKTHDR(m0);
925
926	map->flags &= ~DMAMAP_TYPE_MASK;
927	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
928	map->buffer = m0;
929	map->len = 0;
930	if (m0->m_pkthdr.len <= dmat->maxsize) {
931		vm_offset_t lastaddr = 0;
932		struct mbuf *m;
933
934		for (m = m0; m != NULL && error == 0; m = m->m_next) {
935			if (m->m_len > 0) {
936				error = bus_dmamap_load_buffer(dmat,
937				    dm_segments, map, m->m_data, m->m_len,
938				    pmap_kernel(), flags, &lastaddr, &nsegs);
939				map->len += m->m_len;
940			}
941		}
942	} else {
943		error = EINVAL;
944	}
945
946	if (error) {
947		/*
948		 * force "no valid mappings" on error in callback.
949		 */
950		(*callback)(callback_arg, dm_segments, 0, 0, error);
951	} else {
952		(*callback)(callback_arg, dm_segments, nsegs + 1,
953		    m0->m_pkthdr.len, error);
954	}
955	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
956	    __func__, dmat, dmat->flags, error, nsegs + 1);
957
958	return (error);
959}
960
961int
962bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
963			struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
964			int flags)
965{
966	int error = 0;
967	M_ASSERTPKTHDR(m0);
968
969	flags |= BUS_DMA_NOWAIT;
970	*nsegs = -1;
971	map->flags &= ~DMAMAP_TYPE_MASK;
972	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
973	map->buffer = m0;
974	map->len = 0;
975	if (m0->m_pkthdr.len <= dmat->maxsize) {
976		vm_offset_t lastaddr = 0;
977		struct mbuf *m;
978
979		for (m = m0; m != NULL && error == 0; m = m->m_next) {
980			if (m->m_len > 0) {
981				error = bus_dmamap_load_buffer(dmat, segs, map,
982						m->m_data, m->m_len,
983						pmap_kernel(), flags, &lastaddr,
984						nsegs);
985				map->len += m->m_len;
986			}
987		}
988	} else {
989		error = EINVAL;
990	}
991
992	/* XXX FIXME: Having to increment nsegs is really annoying */
993	++*nsegs;
994	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
995	    __func__, dmat, dmat->flags, error, *nsegs);
996	return (error);
997}
998
999/*
1000 * Like bus_dmamap_load(), but for uios.
1001 */
1002int
1003bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
1004    bus_dmamap_callback2_t *callback, void *callback_arg,
1005    int flags)
1006{
1007	vm_offset_t lastaddr = 0;
1008#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
1009	bus_dma_segment_t dm_segments[dmat->nsegments];
1010#else
1011	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
1012#endif
1013	int nsegs, i, error;
1014	bus_size_t resid;
1015	struct iovec *iov;
1016	struct pmap *pmap;
1017
1018	resid = uio->uio_resid;
1019	iov = uio->uio_iov;
1020	map->flags &= ~DMAMAP_TYPE_MASK;
1021	map->flags |= DMAMAP_UIO|DMAMAP_COHERENT;
1022	map->buffer = uio;
1023	map->len = 0;
1024
1025	if (uio->uio_segflg == UIO_USERSPACE) {
1026		KASSERT(uio->uio_td != NULL,
1027		    ("bus_dmamap_load_uio: USERSPACE but no proc"));
1028		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
1029	} else
1030		pmap = kernel_pmap;
1031
1032	error = 0;
1033	nsegs = -1;
1034	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1035		/*
1036		 * Now at the first iovec to load.  Load each iovec
1037		 * until we have exhausted the residual count.
1038		 */
1039		bus_size_t minlen =
1040		    resid < iov[i].iov_len ? resid : iov[i].iov_len;
1041		caddr_t addr = (caddr_t) iov[i].iov_base;
1042
1043		if (minlen > 0) {
1044			error = bus_dmamap_load_buffer(dmat, dm_segments, map,
1045			    addr, minlen, pmap, flags, &lastaddr, &nsegs);
1046
1047			map->len += minlen;
1048			resid -= minlen;
1049		}
1050	}
1051
1052	if (error) {
1053		/*
1054		 * force "no valid mappings" on error in callback.
1055		 */
1056		(*callback)(callback_arg, dm_segments, 0, 0, error);
1057	} else {
1058		(*callback)(callback_arg, dm_segments, nsegs+1,
1059		    uio->uio_resid, error);
1060	}
1061
1062	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
1063	    __func__, dmat, dmat->flags, error, nsegs + 1);
1064	return (error);
1065}
1066
1067/*
1068 * Release the mapping held by map.
1069 */
1070void
1071_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1072{
1073	struct bounce_page *bpage;
1074
1075	map->flags &= ~DMAMAP_TYPE_MASK;
1076	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1077		STAILQ_REMOVE_HEAD(&map->bpages, links);
1078		free_bounce_page(dmat, bpage);
1079	}
1080	return;
1081}
1082
1083static void
1084bus_dmamap_sync_buf(void *buf, int len, bus_dmasync_op_t op)
1085{
1086	char _tmp_cl[arm_dcache_align], _tmp_clend[arm_dcache_align];
1087
1088	if ((op & BUS_DMASYNC_PREWRITE) && !(op & BUS_DMASYNC_PREREAD)) {
1089		cpu_dcache_wb_range((vm_offset_t)buf, len);
1090		cpu_l2cache_wb_range((vm_offset_t)buf, len);
1091	}
1092	if (op & BUS_DMASYNC_PREREAD) {
1093		if ((op & BUS_DMASYNC_PREWRITE) ||
1094		    ((((vm_offset_t)(buf) | len) & arm_dcache_align_mask) == 0)) {
1095			cpu_dcache_inv_range((vm_offset_t)buf, len);
1096			cpu_l2cache_inv_range((vm_offset_t)buf, len);
1097		} else {
1098		    	cpu_dcache_wbinv_range((vm_offset_t)buf, len);
1099	    		cpu_l2cache_wbinv_range((vm_offset_t)buf, len);
1100		}
1101	}
1102	if (op & BUS_DMASYNC_POSTREAD) {
1103		if ((vm_offset_t)buf & arm_dcache_align_mask) {
1104			memcpy(_tmp_cl, (void *)((vm_offset_t)buf & ~
1105			    arm_dcache_align_mask),
1106			    (vm_offset_t)buf & arm_dcache_align_mask);
1107		}
1108		if (((vm_offset_t)buf + len) & arm_dcache_align_mask) {
1109			memcpy(_tmp_clend, (void *)((vm_offset_t)buf + len),
1110			    arm_dcache_align - (((vm_offset_t)(buf) + len) &
1111			   arm_dcache_align_mask));
1112		}
1113		cpu_dcache_inv_range((vm_offset_t)buf, len);
1114		cpu_l2cache_inv_range((vm_offset_t)buf, len);
1115
1116		if ((vm_offset_t)buf & arm_dcache_align_mask)
1117			memcpy((void *)((vm_offset_t)buf &
1118			    ~arm_dcache_align_mask), _tmp_cl,
1119			    (vm_offset_t)buf & arm_dcache_align_mask);
1120		if (((vm_offset_t)buf + len) & arm_dcache_align_mask)
1121			memcpy((void *)((vm_offset_t)buf + len), _tmp_clend,
1122			    arm_dcache_align - (((vm_offset_t)(buf) + len) &
1123			   arm_dcache_align_mask));
1124	}
1125}
1126
1127static void
1128_bus_dmamap_sync_bp(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1129{
1130	struct bounce_page *bpage;
1131
1132	STAILQ_FOREACH(bpage, &map->bpages, links) {
1133		if (op & BUS_DMASYNC_PREWRITE) {
1134			bcopy((void *)bpage->datavaddr,
1135			    (void *)(bpage->vaddr_nocache != 0 ?
1136				     bpage->vaddr_nocache : bpage->vaddr),
1137			    bpage->datacount);
1138			if (bpage->vaddr_nocache == 0) {
1139				cpu_dcache_wb_range(bpage->vaddr,
1140				    bpage->datacount);
1141				cpu_l2cache_wb_range(bpage->vaddr,
1142				    bpage->datacount);
1143			}
1144		}
1145		if (op & BUS_DMASYNC_POSTREAD) {
1146			if (bpage->vaddr_nocache == 0) {
1147				cpu_dcache_inv_range(bpage->vaddr,
1148				    bpage->datacount);
1149				cpu_l2cache_inv_range(bpage->vaddr,
1150				    bpage->datacount);
1151			}
1152			bcopy((void *)(bpage->vaddr_nocache != 0 ?
1153	       		    bpage->vaddr_nocache : bpage->vaddr),
1154			    (void *)bpage->datavaddr, bpage->datacount);
1155		}
1156	}
1157}
1158
1159static __inline int
1160_bus_dma_buf_is_in_bp(bus_dmamap_t map, void *buf, int len)
1161{
1162	struct bounce_page *bpage;
1163
1164	STAILQ_FOREACH(bpage, &map->bpages, links) {
1165		if ((vm_offset_t)buf >= bpage->datavaddr &&
1166		    (vm_offset_t)buf + len < bpage->datavaddr +
1167		    bpage->datacount)
1168			return (1);
1169	}
1170	return (0);
1171
1172}
1173
1174void
1175_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1176{
1177	struct mbuf *m;
1178	struct uio *uio;
1179	int resid;
1180	struct iovec *iov;
1181
1182	if (op == BUS_DMASYNC_POSTWRITE)
1183		return;
1184	if (STAILQ_FIRST(&map->bpages))
1185		_bus_dmamap_sync_bp(dmat, map, op);
1186	if (map->flags & DMAMAP_COHERENT)
1187		return;
1188	CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
1189	switch(map->flags & DMAMAP_TYPE_MASK) {
1190	case DMAMAP_LINEAR:
1191		if (!(_bus_dma_buf_is_in_bp(map, map->buffer, map->len)))
1192			bus_dmamap_sync_buf(map->buffer, map->len, op);
1193		break;
1194	case DMAMAP_MBUF:
1195		m = map->buffer;
1196		while (m) {
1197			if (m->m_len > 0 &&
1198			    !(_bus_dma_buf_is_in_bp(map, m->m_data, m->m_len)))
1199				bus_dmamap_sync_buf(m->m_data, m->m_len, op);
1200			m = m->m_next;
1201		}
1202		break;
1203	case DMAMAP_UIO:
1204		uio = map->buffer;
1205		iov = uio->uio_iov;
1206		resid = uio->uio_resid;
1207		for (int i = 0; i < uio->uio_iovcnt && resid != 0; i++) {
1208			bus_size_t minlen = resid < iov[i].iov_len ? resid :
1209			    iov[i].iov_len;
1210			if (minlen > 0) {
1211				if (!_bus_dma_buf_is_in_bp(map, iov[i].iov_base,
1212				    minlen))
1213					bus_dmamap_sync_buf(iov[i].iov_base,
1214					    minlen, op);
1215				resid -= minlen;
1216			}
1217		}
1218		break;
1219	default:
1220		break;
1221	}
1222	cpu_drain_writebuf();
1223}
1224
1225static void
1226init_bounce_pages(void *dummy __unused)
1227{
1228
1229	total_bpages = 0;
1230	STAILQ_INIT(&bounce_zone_list);
1231	STAILQ_INIT(&bounce_map_waitinglist);
1232	STAILQ_INIT(&bounce_map_callbacklist);
1233	mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1234}
1235SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1236
1237static struct sysctl_ctx_list *
1238busdma_sysctl_tree(struct bounce_zone *bz)
1239{
1240	return (&bz->sysctl_tree);
1241}
1242
1243static struct sysctl_oid *
1244busdma_sysctl_tree_top(struct bounce_zone *bz)
1245{
1246	return (bz->sysctl_tree_top);
1247}
1248
1249static int
1250alloc_bounce_zone(bus_dma_tag_t dmat)
1251{
1252	struct bounce_zone *bz;
1253
1254	/* Check to see if we already have a suitable zone */
1255	STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1256		if ((dmat->alignment <= bz->alignment)
1257		 && (dmat->boundary <= bz->boundary)
1258		 && (dmat->lowaddr >= bz->lowaddr)) {
1259			dmat->bounce_zone = bz;
1260			return (0);
1261		}
1262	}
1263
1264	if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1265	    M_NOWAIT | M_ZERO)) == NULL)
1266		return (ENOMEM);
1267
1268	STAILQ_INIT(&bz->bounce_page_list);
1269	bz->free_bpages = 0;
1270	bz->reserved_bpages = 0;
1271	bz->active_bpages = 0;
1272	bz->lowaddr = dmat->lowaddr;
1273	bz->alignment = dmat->alignment;
1274	bz->boundary = dmat->boundary;
1275	snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1276	busdma_zonecount++;
1277	snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1278	STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1279	dmat->bounce_zone = bz;
1280
1281	sysctl_ctx_init(&bz->sysctl_tree);
1282	bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1283	    SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1284	    CTLFLAG_RD, 0, "");
1285	if (bz->sysctl_tree_top == NULL) {
1286		sysctl_ctx_free(&bz->sysctl_tree);
1287		return (0);	/* XXX error code? */
1288	}
1289
1290	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1291	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1292	    "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1293	    "Total bounce pages");
1294	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1295	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1296	    "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1297	    "Free bounce pages");
1298	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1299	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1300	    "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1301	    "Reserved bounce pages");
1302	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1303	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1304	    "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1305	    "Active bounce pages");
1306	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1307	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1308	    "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1309	    "Total bounce requests");
1310	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1311	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1312	    "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1313	    "Total bounce requests that were deferred");
1314	SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1315	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1316	    "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1317	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1318	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1319	    "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1320	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1321	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1322	    "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
1323
1324	return (0);
1325}
1326
1327static int
1328alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1329{
1330	struct bounce_zone *bz;
1331	int count;
1332
1333	bz = dmat->bounce_zone;
1334	count = 0;
1335	while (numpages > 0) {
1336		struct bounce_page *bpage;
1337
1338		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1339						     M_NOWAIT | M_ZERO);
1340
1341		if (bpage == NULL)
1342			break;
1343		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1344							 M_NOWAIT, 0ul,
1345							 bz->lowaddr,
1346							 PAGE_SIZE,
1347							 bz->boundary);
1348		if (bpage->vaddr == 0) {
1349			free(bpage, M_DEVBUF);
1350			break;
1351		}
1352		bpage->busaddr = pmap_kextract(bpage->vaddr);
1353		bpage->vaddr_nocache = (vm_offset_t)arm_remap_nocache(
1354		    (void *)bpage->vaddr, PAGE_SIZE);
1355		mtx_lock(&bounce_lock);
1356		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1357		total_bpages++;
1358		bz->total_bpages++;
1359		bz->free_bpages++;
1360		mtx_unlock(&bounce_lock);
1361		count++;
1362		numpages--;
1363	}
1364	return (count);
1365}
1366
1367static int
1368reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1369{
1370	struct bounce_zone *bz;
1371	int pages;
1372
1373	mtx_assert(&bounce_lock, MA_OWNED);
1374	bz = dmat->bounce_zone;
1375	pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1376	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1377		return (map->pagesneeded - (map->pagesreserved + pages));
1378	bz->free_bpages -= pages;
1379	bz->reserved_bpages += pages;
1380	map->pagesreserved += pages;
1381	pages = map->pagesneeded - map->pagesreserved;
1382
1383	return (pages);
1384}
1385
1386static bus_addr_t
1387add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1388		bus_size_t size)
1389{
1390	struct bounce_zone *bz;
1391	struct bounce_page *bpage;
1392
1393	KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1394	KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
1395
1396	bz = dmat->bounce_zone;
1397	if (map->pagesneeded == 0)
1398		panic("add_bounce_page: map doesn't need any pages");
1399	map->pagesneeded--;
1400
1401	if (map->pagesreserved == 0)
1402		panic("add_bounce_page: map doesn't need any pages");
1403	map->pagesreserved--;
1404
1405	mtx_lock(&bounce_lock);
1406	bpage = STAILQ_FIRST(&bz->bounce_page_list);
1407	if (bpage == NULL)
1408		panic("add_bounce_page: free page list is empty");
1409
1410	STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1411	bz->reserved_bpages--;
1412	bz->active_bpages++;
1413	mtx_unlock(&bounce_lock);
1414
1415	bpage->datavaddr = vaddr;
1416	bpage->datacount = size;
1417	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1418	return (bpage->busaddr);
1419}
1420
1421static void
1422free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1423{
1424	struct bus_dmamap *map;
1425	struct bounce_zone *bz;
1426
1427	bz = dmat->bounce_zone;
1428	bpage->datavaddr = 0;
1429	bpage->datacount = 0;
1430
1431	mtx_lock(&bounce_lock);
1432	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1433	bz->free_bpages++;
1434	bz->active_bpages--;
1435	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1436		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1437			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1438			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1439					   map, links);
1440			busdma_swi_pending = 1;
1441			bz->total_deferred++;
1442			swi_sched(vm_ih, 0);
1443		}
1444	}
1445	mtx_unlock(&bounce_lock);
1446}
1447
1448void
1449busdma_swi(void)
1450{
1451	bus_dma_tag_t dmat;
1452	struct bus_dmamap *map;
1453
1454	mtx_lock(&bounce_lock);
1455	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1456		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1457		mtx_unlock(&bounce_lock);
1458		dmat = map->dmat;
1459		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1460		bus_dmamap_load(map->dmat, map, map->buffer, map->len,
1461		    map->callback, map->callback_arg, /*flags*/0);
1462		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1463		mtx_lock(&bounce_lock);
1464	}
1465	mtx_unlock(&bounce_lock);
1466}
1467