busdma_machdep-v4.c revision 188403
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 188403 2009-02-09 18:03:31Z cognet $");
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	int		map_count;
116	bus_size_t	alignment;
117	bus_size_t	boundary;
118	bus_addr_t	lowaddr;
119	char		zoneid[8];
120	char		lowaddrid[20];
121	struct sysctl_ctx_list sysctl_tree;
122	struct sysctl_oid *sysctl_tree_top;
123};
124
125static struct mtx bounce_lock;
126static int total_bpages;
127static int busdma_zonecount;
128static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
129
130SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
131SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
132	   "Total bounce pages");
133
134#define DMAMAP_LINEAR		0x1
135#define DMAMAP_MBUF		0x2
136#define DMAMAP_UIO		0x4
137#define DMAMAP_ALLOCATED	0x10
138#define DMAMAP_TYPE_MASK	(DMAMAP_LINEAR|DMAMAP_MBUF|DMAMAP_UIO)
139#define DMAMAP_COHERENT		0x8
140struct bus_dmamap {
141	struct bp_list	bpages;
142	int		pagesneeded;
143	int		pagesreserved;
144        bus_dma_tag_t	dmat;
145	int		flags;
146	void 		*buffer;
147	void		*origbuffer;
148	void		*allocbuffer;
149	TAILQ_ENTRY(bus_dmamap)	freelist;
150	int		len;
151	STAILQ_ENTRY(bus_dmamap) links;
152	bus_dmamap_callback_t *callback;
153	void		      *callback_arg;
154
155};
156
157static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
158static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
159
160static TAILQ_HEAD(,bus_dmamap) dmamap_freelist =
161	TAILQ_HEAD_INITIALIZER(dmamap_freelist);
162
163#define BUSDMA_STATIC_MAPS	500
164static struct bus_dmamap map_pool[BUSDMA_STATIC_MAPS];
165
166static struct mtx busdma_mtx;
167
168MTX_SYSINIT(busdma_mtx, &busdma_mtx, "busdma lock", MTX_DEF);
169
170static void init_bounce_pages(void *dummy);
171static int alloc_bounce_zone(bus_dma_tag_t dmat);
172static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
173static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
174				int commit);
175static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
176				   vm_offset_t vaddr, bus_size_t size);
177static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
178
179/* Default tag, as most drivers provide no parent tag. */
180bus_dma_tag_t arm_root_dma_tag;
181
182/*
183 * Return true if a match is made.
184 *
185 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
186 *
187 * If paddr is within the bounds of the dma tag then call the filter callback
188 * to check for a match, if there is no filter callback then assume a match.
189 */
190static int
191run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
192{
193	int retval;
194
195	retval = 0;
196
197	do {
198		if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
199		 || ((paddr & (dmat->alignment - 1)) != 0))
200		 && (dmat->filter == NULL
201		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
202			retval = 1;
203
204		dmat = dmat->parent;
205	} while (retval == 0 && dmat != NULL);
206	return (retval);
207}
208
209static void
210arm_dmamap_freelist_init(void *dummy)
211{
212	int i;
213
214	for (i = 0; i < BUSDMA_STATIC_MAPS; i++)
215		TAILQ_INSERT_HEAD(&dmamap_freelist, &map_pool[i], freelist);
216}
217
218SYSINIT(busdma, SI_SUB_VM, SI_ORDER_ANY, arm_dmamap_freelist_init, NULL);
219
220/*
221 * Check to see if the specified page is in an allowed DMA range.
222 */
223
224static __inline int
225bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
226    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
227    int flags, vm_offset_t *lastaddrp, int *segp);
228
229static __inline int
230_bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr)
231{
232	int i;
233	for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) {
234		if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1])
235		    || (lowaddr < phys_avail[i] &&
236		    highaddr > phys_avail[i]))
237			return (1);
238	}
239	return (0);
240}
241
242static __inline struct arm32_dma_range *
243_bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
244    bus_addr_t curaddr)
245{
246	struct arm32_dma_range *dr;
247	int i;
248
249	for (i = 0, dr = ranges; i < nranges; i++, dr++) {
250		if (curaddr >= dr->dr_sysbase &&
251		    round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
252			return (dr);
253	}
254
255	return (NULL);
256}
257/*
258 * Convenience function for manipulating driver locks from busdma (during
259 * busdma_swi, for example).  Drivers that don't provide their own locks
260 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
261 * non-mutex locking scheme don't have to use this at all.
262 */
263void
264busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
265{
266	struct mtx *dmtx;
267
268	dmtx = (struct mtx *)arg;
269	switch (op) {
270	case BUS_DMA_LOCK:
271		mtx_lock(dmtx);
272		break;
273	case BUS_DMA_UNLOCK:
274		mtx_unlock(dmtx);
275		break;
276	default:
277		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
278	}
279}
280
281/*
282 * dflt_lock should never get called.  It gets put into the dma tag when
283 * lockfunc == NULL, which is only valid if the maps that are associated
284 * with the tag are meant to never be defered.
285 * XXX Should have a way to identify which driver is responsible here.
286 */
287static void
288dflt_lock(void *arg, bus_dma_lock_op_t op)
289{
290#ifdef INVARIANTS
291	panic("driver error: busdma dflt_lock called");
292#else
293	printf("DRIVER_ERROR: busdma dflt_lock called\n");
294#endif
295}
296
297static __inline bus_dmamap_t
298_busdma_alloc_dmamap(void)
299{
300	bus_dmamap_t map;
301
302	mtx_lock(&busdma_mtx);
303	map = TAILQ_FIRST(&dmamap_freelist);
304	if (map)
305		TAILQ_REMOVE(&dmamap_freelist, map, freelist);
306	mtx_unlock(&busdma_mtx);
307	if (!map) {
308		map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT | M_ZERO);
309		if (map)
310			map->flags = DMAMAP_ALLOCATED;
311	} else
312		map->flags = 0;
313	STAILQ_INIT(&map->bpages);
314	return (map);
315}
316
317static __inline void
318_busdma_free_dmamap(bus_dmamap_t map)
319{
320	if (map->flags & DMAMAP_ALLOCATED)
321		free(map, M_DEVBUF);
322	else {
323		mtx_lock(&busdma_mtx);
324		TAILQ_INSERT_HEAD(&dmamap_freelist, map, freelist);
325		mtx_unlock(&busdma_mtx);
326	}
327}
328
329/*
330 * Allocate a device specific dma_tag.
331 */
332#define SEG_NB 1024
333
334int
335bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
336		   bus_size_t boundary, bus_addr_t lowaddr,
337		   bus_addr_t highaddr, bus_dma_filter_t *filter,
338		   void *filterarg, bus_size_t maxsize, int nsegments,
339		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
340		   void *lockfuncarg, bus_dma_tag_t *dmat)
341{
342	bus_dma_tag_t newtag;
343	int error = 0;
344	/* Return a NULL tag on failure */
345	*dmat = NULL;
346	if (!parent)
347		parent = arm_root_dma_tag;
348
349	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
350	if (newtag == NULL) {
351		CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
352		    __func__, newtag, 0, error);
353		return (ENOMEM);
354	}
355
356	newtag->parent = parent;
357	newtag->alignment = alignment;
358	newtag->boundary = boundary;
359	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
360	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
361	newtag->filter = filter;
362	newtag->filterarg = filterarg;
363        newtag->maxsize = maxsize;
364        newtag->nsegments = nsegments;
365	newtag->maxsegsz = maxsegsz;
366	newtag->flags = flags;
367	newtag->ref_count = 1; /* Count ourself */
368	newtag->map_count = 0;
369	newtag->ranges = bus_dma_get_range();
370	newtag->_nranges = bus_dma_get_range_nb();
371	if (lockfunc != NULL) {
372		newtag->lockfunc = lockfunc;
373		newtag->lockfuncarg = lockfuncarg;
374	} else {
375		newtag->lockfunc = dflt_lock;
376		newtag->lockfuncarg = NULL;
377	}
378        /*
379	 * Take into account any restrictions imposed by our parent tag
380	 */
381        if (parent != NULL) {
382                newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
383                newtag->highaddr = max(parent->highaddr, newtag->highaddr);
384		if (newtag->boundary == 0)
385			newtag->boundary = parent->boundary;
386		else if (parent->boundary != 0)
387                	newtag->boundary = min(parent->boundary,
388					       newtag->boundary);
389		if ((newtag->filter != NULL) ||
390		    ((parent->flags & BUS_DMA_COULD_BOUNCE) != 0))
391			newtag->flags |= BUS_DMA_COULD_BOUNCE;
392                if (newtag->filter == NULL) {
393                        /*
394                         * Short circuit looking at our parent directly
395                         * since we have encapsulated all of its information
396                         */
397                        newtag->filter = parent->filter;
398                        newtag->filterarg = parent->filterarg;
399                        newtag->parent = parent->parent;
400		}
401		if (newtag->parent != NULL)
402			atomic_add_int(&parent->ref_count, 1);
403	}
404	if (_bus_dma_can_bounce(newtag->lowaddr, newtag->highaddr)
405	 || newtag->alignment > 1)
406		newtag->flags |= BUS_DMA_COULD_BOUNCE;
407
408	if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
409	    (flags & BUS_DMA_ALLOCNOW) != 0) {
410		struct bounce_zone *bz;
411
412		/* Must bounce */
413
414		if ((error = alloc_bounce_zone(newtag)) != 0) {
415			free(newtag, M_DEVBUF);
416			return (error);
417		}
418		bz = newtag->bounce_zone;
419
420		if (ptoa(bz->total_bpages) < maxsize) {
421			int pages;
422
423			pages = atop(maxsize) - bz->total_bpages;
424
425			/* Add pages to our bounce pool */
426			if (alloc_bounce_pages(newtag, pages) < pages)
427				error = ENOMEM;
428		}
429		/* Performed initial allocation */
430		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
431	} else
432		newtag->bounce_zone = NULL;
433	if (error != 0)
434		free(newtag, M_DEVBUF);
435	else
436		*dmat = newtag;
437	CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
438	    __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
439
440	return (error);
441}
442
443int
444bus_dma_tag_destroy(bus_dma_tag_t dmat)
445{
446#ifdef KTR
447	bus_dma_tag_t dmat_copy = dmat;
448#endif
449
450	if (dmat != NULL) {
451
452                if (dmat->map_count != 0)
453                        return (EBUSY);
454
455                while (dmat != NULL) {
456                        bus_dma_tag_t parent;
457
458                        parent = dmat->parent;
459                        atomic_subtract_int(&dmat->ref_count, 1);
460                        if (dmat->ref_count == 0) {
461                                free(dmat, M_DEVBUF);
462                                /*
463                                 * Last reference count, so
464                                 * release our reference
465                                 * count on our parent.
466                                 */
467                                dmat = parent;
468                        } else
469                                dmat = NULL;
470                }
471        }
472	CTR2(KTR_BUSDMA, "%s tag %p", __func__, dmat_copy);
473
474        return (0);
475}
476
477#include <sys/kdb.h>
478/*
479 * Allocate a handle for mapping from kva/uva/physical
480 * address space into bus device space.
481 */
482int
483bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
484{
485	bus_dmamap_t newmap;
486	int error = 0;
487
488	newmap = _busdma_alloc_dmamap();
489	if (newmap == NULL) {
490		CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
491		return (ENOMEM);
492	}
493	*mapp = newmap;
494	newmap->dmat = dmat;
495	newmap->allocbuffer = NULL;
496	dmat->map_count++;
497
498	/*
499	 * Bouncing might be required if the driver asks for an active
500	 * exclusion region, a data alignment that is stricter than 1, and/or
501	 * an active address boundary.
502	 */
503	if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
504
505		/* Must bounce */
506		struct bounce_zone *bz;
507		int maxpages;
508
509		if (dmat->bounce_zone == NULL) {
510			if ((error = alloc_bounce_zone(dmat)) != 0) {
511				_busdma_free_dmamap(newmap);
512				*mapp = NULL;
513				return (error);
514			}
515		}
516		bz = dmat->bounce_zone;
517
518		/* Initialize the new map */
519		STAILQ_INIT(&((*mapp)->bpages));
520
521		/*
522		 * Attempt to add pages to our pool on a per-instance
523		 * basis up to a sane limit.
524		 */
525		maxpages = MAX_BPAGES;
526		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
527		 || (bz->map_count > 0 && bz->total_bpages < maxpages)) {
528			int pages;
529
530			pages = MAX(atop(dmat->maxsize), 1);
531			pages = MIN(maxpages - bz->total_bpages, pages);
532			pages = MAX(pages, 1);
533			if (alloc_bounce_pages(dmat, pages) < pages)
534				error = ENOMEM;
535
536			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
537				if (error == 0)
538					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
539			} else {
540				error = 0;
541			}
542		}
543		bz->map_count++;
544	}
545	CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
546	    __func__, dmat, dmat->flags, error);
547
548	return (0);
549}
550
551/*
552 * Destroy a handle for mapping from kva/uva/physical
553 * address space into bus device space.
554 */
555int
556bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
557{
558
559	_busdma_free_dmamap(map);
560	if (STAILQ_FIRST(&map->bpages) != NULL) {
561		CTR3(KTR_BUSDMA, "%s: tag %p error %d",
562		    __func__, dmat, EBUSY);
563		return (EBUSY);
564	}
565	if (dmat->bounce_zone)
566		dmat->bounce_zone->map_count--;
567        dmat->map_count--;
568	CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
569        return (0);
570}
571
572/*
573 * Allocate a piece of memory that can be efficiently mapped into
574 * bus device space based on the constraints lited in the dma tag.
575 * A dmamap to for use with dmamap_load is also allocated.
576 */
577int
578bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
579                 bus_dmamap_t *mapp)
580{
581	bus_dmamap_t newmap = NULL;
582
583	int mflags;
584
585	if (flags & BUS_DMA_NOWAIT)
586		mflags = M_NOWAIT;
587	else
588		mflags = M_WAITOK;
589	if (flags & BUS_DMA_ZERO)
590		mflags |= M_ZERO;
591
592	newmap = _busdma_alloc_dmamap();
593	if (newmap == NULL) {
594		CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
595		    __func__, dmat, dmat->flags, ENOMEM);
596		return (ENOMEM);
597	}
598	dmat->map_count++;
599	*mapp = newmap;
600	newmap->dmat = dmat;
601
602        if (dmat->maxsize <= PAGE_SIZE &&
603	   (dmat->alignment < dmat->maxsize) &&
604	   !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr)) {
605                *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
606        } else {
607                /*
608                 * XXX Use Contigmalloc until it is merged into this facility
609                 *     and handles multi-seg allocations.  Nobody is doing
610                 *     multi-seg allocations yet though.
611                 */
612                *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
613                    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
614                    dmat->boundary);
615        }
616        if (*vaddr == NULL) {
617		if (newmap != NULL) {
618			_busdma_free_dmamap(newmap);
619			dmat->map_count--;
620		}
621		*mapp = NULL;
622                return (ENOMEM);
623	}
624	if (flags & BUS_DMA_COHERENT) {
625		void *tmpaddr = arm_remap_nocache(
626		    (void *)((vm_offset_t)*vaddr &~ PAGE_MASK),
627		    dmat->maxsize + ((vm_offset_t)*vaddr & PAGE_MASK));
628
629		if (tmpaddr) {
630			tmpaddr = (void *)((vm_offset_t)(tmpaddr) +
631			    ((vm_offset_t)*vaddr & PAGE_MASK));
632			newmap->origbuffer = *vaddr;
633			newmap->allocbuffer = tmpaddr;
634			cpu_idcache_wbinv_range((vm_offset_t)*vaddr,
635			    dmat->maxsize);
636			cpu_l2cache_wbinv_range((vm_offset_t)*vaddr,
637			    dmat->maxsize);
638			*vaddr = tmpaddr;
639		} else
640			newmap->origbuffer = newmap->allocbuffer = NULL;
641	} else
642		newmap->origbuffer = newmap->allocbuffer = NULL;
643        return (0);
644}
645
646/*
647 * Free a piece of memory and it's allocated dmamap, that was allocated
648 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
649 */
650void
651bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
652{
653	if (map->allocbuffer) {
654		KASSERT(map->allocbuffer == vaddr,
655		    ("Trying to freeing the wrong DMA buffer"));
656		vaddr = map->origbuffer;
657		arm_unmap_nocache(map->allocbuffer, dmat->maxsize);
658	}
659        if (dmat->maxsize <= PAGE_SIZE &&
660	   dmat->alignment < dmat->maxsize &&
661	    !_bus_dma_can_bounce(dmat->lowaddr, dmat->highaddr))
662		free(vaddr, M_DEVBUF);
663        else {
664		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
665	}
666	dmat->map_count--;
667	_busdma_free_dmamap(map);
668	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
669}
670
671static int
672_bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
673			bus_size_t buflen, int flags)
674{
675	vm_offset_t vaddr;
676	vm_offset_t vendaddr;
677	bus_addr_t paddr;
678
679	if ((map->pagesneeded == 0)) {
680		CTR3(KTR_BUSDMA, "lowaddr= %d, boundary= %d, alignment= %d",
681		    dmat->lowaddr, dmat->boundary, dmat->alignment);
682		CTR2(KTR_BUSDMA, "map= %p, pagesneeded= %d",
683		    map, map->pagesneeded);
684		/*
685		 * Count the number of bounce pages
686		 * needed in order to complete this transfer
687		 */
688		vaddr = trunc_page((vm_offset_t)buf);
689		vendaddr = (vm_offset_t)buf + buflen;
690
691		while (vaddr < vendaddr) {
692			paddr = pmap_kextract(vaddr);
693			if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
694			    run_filter(dmat, paddr) != 0)
695				map->pagesneeded++;
696			vaddr += PAGE_SIZE;
697		}
698		CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
699	}
700
701	/* Reserve Necessary Bounce Pages */
702	if (map->pagesneeded != 0) {
703		mtx_lock(&bounce_lock);
704		if (flags & BUS_DMA_NOWAIT) {
705			if (reserve_bounce_pages(dmat, map, 0) != 0) {
706				mtx_unlock(&bounce_lock);
707				return (ENOMEM);
708			}
709		} else {
710			if (reserve_bounce_pages(dmat, map, 1) != 0) {
711				/* Queue us for resources */
712				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
713				    map, links);
714				mtx_unlock(&bounce_lock);
715				return (EINPROGRESS);
716			}
717		}
718		mtx_unlock(&bounce_lock);
719	}
720
721	return (0);
722}
723
724/*
725 * Utility function to load a linear buffer.  lastaddrp holds state
726 * between invocations (for multiple-buffer loads).  segp contains
727 * the starting segment on entrance, and the ending segment on exit.
728 * first indicates if this is the first invocation of this function.
729 */
730static __inline int
731bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
732    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
733    int flags, vm_offset_t *lastaddrp, int *segp)
734{
735	bus_size_t sgsize;
736	bus_addr_t curaddr, lastaddr, baddr, bmask;
737	vm_offset_t vaddr = (vm_offset_t)buf;
738	int seg;
739	int error = 0;
740	pd_entry_t *pde;
741	pt_entry_t pte;
742	pt_entry_t *ptep;
743
744	lastaddr = *lastaddrp;
745	bmask = ~(dmat->boundary - 1);
746
747	if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
748		error = _bus_dmamap_count_pages(dmat, map, buf, buflen, flags);
749		if (error)
750			return (error);
751	}
752	CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
753	    "alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
754
755	for (seg = *segp; buflen > 0 ; ) {
756		/*
757		 * Get the physical address for this segment.
758		 *
759		 * XXX Don't support checking for coherent mappings
760		 * XXX in user address space.
761		 */
762		if (__predict_true(pmap == pmap_kernel())) {
763			if (pmap_get_pde_pte(pmap, vaddr, &pde, &ptep) == FALSE)
764				return (EFAULT);
765
766			if (__predict_false(pmap_pde_section(pde))) {
767				if (*pde & L1_S_SUPERSEC)
768					curaddr = (*pde & L1_SUP_FRAME) |
769					    (vaddr & L1_SUP_OFFSET);
770				else
771					curaddr = (*pde & L1_S_FRAME) |
772					    (vaddr & L1_S_OFFSET);
773				if (*pde & L1_S_CACHE_MASK) {
774					map->flags &=
775					    ~DMAMAP_COHERENT;
776				}
777			} else {
778				pte = *ptep;
779				KASSERT((pte & L2_TYPE_MASK) != L2_TYPE_INV,
780				    ("INV type"));
781				if (__predict_false((pte & L2_TYPE_MASK)
782						    == L2_TYPE_L)) {
783					curaddr = (pte & L2_L_FRAME) |
784					    (vaddr & L2_L_OFFSET);
785					if (pte & L2_L_CACHE_MASK) {
786						map->flags &=
787						    ~DMAMAP_COHERENT;
788
789					}
790				} else {
791					curaddr = (pte & L2_S_FRAME) |
792					    (vaddr & L2_S_OFFSET);
793					if (pte & L2_S_CACHE_MASK) {
794						map->flags &=
795						    ~DMAMAP_COHERENT;
796					}
797				}
798			}
799		} else {
800			curaddr = pmap_extract(pmap, vaddr);
801			map->flags &= ~DMAMAP_COHERENT;
802		}
803
804		/*
805		 * Compute the segment size, and adjust counts.
806		 */
807		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
808		if (sgsize > dmat->maxsegsz)
809			sgsize = dmat->maxsegsz;
810		if (buflen < sgsize)
811			sgsize = buflen;
812
813		/*
814		 * Make sure we don't cross any boundaries.
815		 */
816		if (dmat->boundary > 0) {
817			baddr = (curaddr + dmat->boundary) & bmask;
818			if (sgsize > (baddr - curaddr))
819				sgsize = (baddr - curaddr);
820		}
821		if (((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
822		    map->pagesneeded != 0 && run_filter(dmat, curaddr))
823			curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
824
825		if (dmat->ranges) {
826			struct arm32_dma_range *dr;
827
828			dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
829			    curaddr);
830			if (dr == NULL)
831				return (EINVAL);
832			/*
833		     	 * In a valid DMA range.  Translate the physical
834			 * memory address to an address in the DMA window.
835			 */
836			curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
837
838		}
839
840		/*
841		 * Insert chunk into a segment, coalescing with
842		 * the previous segment if possible.
843		 */
844		if (seg >= 0 && curaddr == lastaddr &&
845		    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
846		    (dmat->boundary == 0 ||
847		     (segs[seg].ds_addr & bmask) ==
848		     (curaddr & bmask))) {
849			segs[seg].ds_len += sgsize;
850			goto segdone;
851		} else {
852			if (++seg >= dmat->nsegments)
853				break;
854			segs[seg].ds_addr = curaddr;
855			segs[seg].ds_len = sgsize;
856		}
857		if (error)
858			break;
859segdone:
860		lastaddr = curaddr + sgsize;
861		vaddr += sgsize;
862		buflen -= sgsize;
863	}
864
865	*segp = seg;
866	*lastaddrp = lastaddr;
867
868	/*
869	 * Did we fit?
870	 */
871	if (buflen != 0)
872		error = EFBIG; /* XXX better return value here? */
873	return (error);
874}
875
876/*
877 * Map the buffer buf into bus space using the dmamap map.
878 */
879int
880bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
881                bus_size_t buflen, bus_dmamap_callback_t *callback,
882                void *callback_arg, int flags)
883{
884     	vm_offset_t	lastaddr = 0;
885	int		error, nsegs = -1;
886#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
887	bus_dma_segment_t dm_segments[dmat->nsegments];
888#else
889	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
890#endif
891
892	KASSERT(dmat != NULL, ("dmatag is NULL"));
893	KASSERT(map != NULL, ("dmamap is NULL"));
894	map->callback = callback;
895	map->callback_arg = callback_arg;
896	map->flags &= ~DMAMAP_TYPE_MASK;
897	map->flags |= DMAMAP_LINEAR|DMAMAP_COHERENT;
898	map->buffer = buf;
899	map->len = buflen;
900	error = bus_dmamap_load_buffer(dmat,
901	    dm_segments, map, buf, buflen, kernel_pmap,
902	    flags, &lastaddr, &nsegs);
903	if (error == EINPROGRESS)
904		return (error);
905	if (error)
906		(*callback)(callback_arg, NULL, 0, error);
907	else
908		(*callback)(callback_arg, dm_segments, nsegs + 1, error);
909
910	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
911	    __func__, dmat, dmat->flags, nsegs + 1, error);
912
913	return (error);
914}
915
916/*
917 * Like bus_dmamap_load(), but for mbufs.
918 */
919int
920bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
921		     bus_dmamap_callback2_t *callback, void *callback_arg,
922		     int flags)
923{
924#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
925	bus_dma_segment_t dm_segments[dmat->nsegments];
926#else
927	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
928#endif
929	int nsegs = -1, error = 0;
930
931	M_ASSERTPKTHDR(m0);
932
933	map->flags &= ~DMAMAP_TYPE_MASK;
934	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
935	map->buffer = m0;
936	map->len = 0;
937	if (m0->m_pkthdr.len <= dmat->maxsize) {
938		vm_offset_t lastaddr = 0;
939		struct mbuf *m;
940
941		for (m = m0; m != NULL && error == 0; m = m->m_next) {
942			if (m->m_len > 0) {
943				error = bus_dmamap_load_buffer(dmat,
944				    dm_segments, map, m->m_data, m->m_len,
945				    pmap_kernel(), flags, &lastaddr, &nsegs);
946				map->len += m->m_len;
947			}
948		}
949	} else {
950		error = EINVAL;
951	}
952
953	if (error) {
954		/*
955		 * force "no valid mappings" on error in callback.
956		 */
957		(*callback)(callback_arg, dm_segments, 0, 0, error);
958	} else {
959		(*callback)(callback_arg, dm_segments, nsegs + 1,
960		    m0->m_pkthdr.len, error);
961	}
962	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
963	    __func__, dmat, dmat->flags, error, nsegs + 1);
964
965	return (error);
966}
967
968int
969bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
970			struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
971			int flags)
972{
973	int error = 0;
974	M_ASSERTPKTHDR(m0);
975
976	flags |= BUS_DMA_NOWAIT;
977	*nsegs = -1;
978	map->flags &= ~DMAMAP_TYPE_MASK;
979	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
980	map->buffer = m0;
981	map->len = 0;
982	if (m0->m_pkthdr.len <= dmat->maxsize) {
983		vm_offset_t lastaddr = 0;
984		struct mbuf *m;
985
986		for (m = m0; m != NULL && error == 0; m = m->m_next) {
987			if (m->m_len > 0) {
988				error = bus_dmamap_load_buffer(dmat, segs, map,
989						m->m_data, m->m_len,
990						pmap_kernel(), flags, &lastaddr,
991						nsegs);
992				map->len += m->m_len;
993			}
994		}
995	} else {
996		error = EINVAL;
997	}
998
999	/* XXX FIXME: Having to increment nsegs is really annoying */
1000	++*nsegs;
1001	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
1002	    __func__, dmat, dmat->flags, error, *nsegs);
1003	return (error);
1004}
1005
1006/*
1007 * Like bus_dmamap_load(), but for uios.
1008 */
1009int
1010bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
1011    bus_dmamap_callback2_t *callback, void *callback_arg,
1012    int flags)
1013{
1014	vm_offset_t lastaddr = 0;
1015#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
1016	bus_dma_segment_t dm_segments[dmat->nsegments];
1017#else
1018	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
1019#endif
1020	int nsegs, i, error;
1021	bus_size_t resid;
1022	struct iovec *iov;
1023	struct pmap *pmap;
1024
1025	resid = uio->uio_resid;
1026	iov = uio->uio_iov;
1027	map->flags &= ~DMAMAP_TYPE_MASK;
1028	map->flags |= DMAMAP_UIO|DMAMAP_COHERENT;
1029	map->buffer = uio;
1030	map->len = 0;
1031
1032	if (uio->uio_segflg == UIO_USERSPACE) {
1033		KASSERT(uio->uio_td != NULL,
1034		    ("bus_dmamap_load_uio: USERSPACE but no proc"));
1035		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
1036	} else
1037		pmap = kernel_pmap;
1038
1039	error = 0;
1040	nsegs = -1;
1041	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
1042		/*
1043		 * Now at the first iovec to load.  Load each iovec
1044		 * until we have exhausted the residual count.
1045		 */
1046		bus_size_t minlen =
1047		    resid < iov[i].iov_len ? resid : iov[i].iov_len;
1048		caddr_t addr = (caddr_t) iov[i].iov_base;
1049
1050		if (minlen > 0) {
1051			error = bus_dmamap_load_buffer(dmat, dm_segments, map,
1052			    addr, minlen, pmap, flags, &lastaddr, &nsegs);
1053
1054			map->len += minlen;
1055			resid -= minlen;
1056		}
1057	}
1058
1059	if (error) {
1060		/*
1061		 * force "no valid mappings" on error in callback.
1062		 */
1063		(*callback)(callback_arg, dm_segments, 0, 0, error);
1064	} else {
1065		(*callback)(callback_arg, dm_segments, nsegs+1,
1066		    uio->uio_resid, error);
1067	}
1068
1069	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
1070	    __func__, dmat, dmat->flags, error, nsegs + 1);
1071	return (error);
1072}
1073
1074/*
1075 * Release the mapping held by map.
1076 */
1077void
1078_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
1079{
1080	struct bounce_page *bpage;
1081
1082	map->flags &= ~DMAMAP_TYPE_MASK;
1083	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
1084		STAILQ_REMOVE_HEAD(&map->bpages, links);
1085		free_bounce_page(dmat, bpage);
1086	}
1087	return;
1088}
1089
1090static void
1091bus_dmamap_sync_buf(void *buf, int len, bus_dmasync_op_t op)
1092{
1093	char _tmp_cl[arm_dcache_align], _tmp_clend[arm_dcache_align];
1094
1095	if ((op & BUS_DMASYNC_PREWRITE) && !(op & BUS_DMASYNC_PREREAD)) {
1096		cpu_dcache_wb_range((vm_offset_t)buf, len);
1097		cpu_l2cache_wb_range((vm_offset_t)buf, len);
1098	}
1099	if (op & BUS_DMASYNC_PREREAD) {
1100		if (!(op & BUS_DMASYNC_PREWRITE) &&
1101		    ((((vm_offset_t)(buf) | len) & arm_dcache_align_mask) == 0)) {
1102			cpu_dcache_inv_range((vm_offset_t)buf, len);
1103			cpu_l2cache_inv_range((vm_offset_t)buf, len);
1104		} else {
1105		    	cpu_dcache_wbinv_range((vm_offset_t)buf, len);
1106	    		cpu_l2cache_wbinv_range((vm_offset_t)buf, len);
1107		}
1108	}
1109	if (op & BUS_DMASYNC_POSTREAD) {
1110		if ((vm_offset_t)buf & arm_dcache_align_mask) {
1111			memcpy(_tmp_cl, (void *)((vm_offset_t)buf & ~
1112			    arm_dcache_align_mask),
1113			    (vm_offset_t)buf & arm_dcache_align_mask);
1114		}
1115		if (((vm_offset_t)buf + len) & arm_dcache_align_mask) {
1116			memcpy(_tmp_clend, (void *)((vm_offset_t)buf + len),
1117			    arm_dcache_align - (((vm_offset_t)(buf) + len) &
1118			   arm_dcache_align_mask));
1119		}
1120		cpu_dcache_inv_range((vm_offset_t)buf, len);
1121		cpu_l2cache_inv_range((vm_offset_t)buf, len);
1122
1123		if ((vm_offset_t)buf & arm_dcache_align_mask)
1124			memcpy((void *)((vm_offset_t)buf &
1125			    ~arm_dcache_align_mask), _tmp_cl,
1126			    (vm_offset_t)buf & arm_dcache_align_mask);
1127		if (((vm_offset_t)buf + len) & arm_dcache_align_mask)
1128			memcpy((void *)((vm_offset_t)buf + len), _tmp_clend,
1129			    arm_dcache_align - (((vm_offset_t)(buf) + len) &
1130			   arm_dcache_align_mask));
1131	}
1132}
1133
1134static void
1135_bus_dmamap_sync_bp(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1136{
1137	struct bounce_page *bpage;
1138
1139	STAILQ_FOREACH(bpage, &map->bpages, links) {
1140		if (op & BUS_DMASYNC_PREWRITE) {
1141			bcopy((void *)bpage->datavaddr,
1142			    (void *)(bpage->vaddr_nocache != 0 ?
1143				     bpage->vaddr_nocache : bpage->vaddr),
1144			    bpage->datacount);
1145			if (bpage->vaddr_nocache == 0) {
1146				cpu_dcache_wb_range(bpage->vaddr,
1147				    bpage->datacount);
1148				cpu_l2cache_wb_range(bpage->vaddr,
1149				    bpage->datacount);
1150			}
1151			dmat->bounce_zone->total_bounced++;
1152		}
1153		if (op & BUS_DMASYNC_POSTREAD) {
1154			if (bpage->vaddr_nocache == 0) {
1155				cpu_dcache_inv_range(bpage->vaddr,
1156				    bpage->datacount);
1157				cpu_l2cache_inv_range(bpage->vaddr,
1158				    bpage->datacount);
1159			}
1160			bcopy((void *)(bpage->vaddr_nocache != 0 ?
1161	       		    bpage->vaddr_nocache : bpage->vaddr),
1162			    (void *)bpage->datavaddr, bpage->datacount);
1163			dmat->bounce_zone->total_bounced++;
1164		}
1165	}
1166}
1167
1168static __inline int
1169_bus_dma_buf_is_in_bp(bus_dmamap_t map, void *buf, int len)
1170{
1171	struct bounce_page *bpage;
1172
1173	STAILQ_FOREACH(bpage, &map->bpages, links) {
1174		if ((vm_offset_t)buf >= bpage->datavaddr &&
1175		    (vm_offset_t)buf + len <= bpage->datavaddr +
1176		    bpage->datacount)
1177			return (1);
1178	}
1179	return (0);
1180
1181}
1182
1183void
1184_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
1185{
1186	struct mbuf *m;
1187	struct uio *uio;
1188	int resid;
1189	struct iovec *iov;
1190
1191	if (op == BUS_DMASYNC_POSTWRITE)
1192		return;
1193	if (STAILQ_FIRST(&map->bpages))
1194		_bus_dmamap_sync_bp(dmat, map, op);
1195	if (map->flags & DMAMAP_COHERENT)
1196		return;
1197	CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
1198	switch(map->flags & DMAMAP_TYPE_MASK) {
1199	case DMAMAP_LINEAR:
1200		if (!(_bus_dma_buf_is_in_bp(map, map->buffer, map->len)))
1201			bus_dmamap_sync_buf(map->buffer, map->len, op);
1202		break;
1203	case DMAMAP_MBUF:
1204		m = map->buffer;
1205		while (m) {
1206			if (m->m_len > 0 &&
1207			    !(_bus_dma_buf_is_in_bp(map, m->m_data, m->m_len)))
1208				bus_dmamap_sync_buf(m->m_data, m->m_len, op);
1209			m = m->m_next;
1210		}
1211		break;
1212	case DMAMAP_UIO:
1213		uio = map->buffer;
1214		iov = uio->uio_iov;
1215		resid = uio->uio_resid;
1216		for (int i = 0; i < uio->uio_iovcnt && resid != 0; i++) {
1217			bus_size_t minlen = resid < iov[i].iov_len ? resid :
1218			    iov[i].iov_len;
1219			if (minlen > 0) {
1220				if (!_bus_dma_buf_is_in_bp(map, iov[i].iov_base,
1221				    minlen))
1222					bus_dmamap_sync_buf(iov[i].iov_base,
1223					    minlen, op);
1224				resid -= minlen;
1225			}
1226		}
1227		break;
1228	default:
1229		break;
1230	}
1231	cpu_drain_writebuf();
1232}
1233
1234static void
1235init_bounce_pages(void *dummy __unused)
1236{
1237
1238	total_bpages = 0;
1239	STAILQ_INIT(&bounce_zone_list);
1240	STAILQ_INIT(&bounce_map_waitinglist);
1241	STAILQ_INIT(&bounce_map_callbacklist);
1242	mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
1243}
1244SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
1245
1246static struct sysctl_ctx_list *
1247busdma_sysctl_tree(struct bounce_zone *bz)
1248{
1249	return (&bz->sysctl_tree);
1250}
1251
1252static struct sysctl_oid *
1253busdma_sysctl_tree_top(struct bounce_zone *bz)
1254{
1255	return (bz->sysctl_tree_top);
1256}
1257
1258static int
1259alloc_bounce_zone(bus_dma_tag_t dmat)
1260{
1261	struct bounce_zone *bz;
1262
1263	/* Check to see if we already have a suitable zone */
1264	STAILQ_FOREACH(bz, &bounce_zone_list, links) {
1265		if ((dmat->alignment <= bz->alignment)
1266		 && (dmat->boundary <= bz->boundary)
1267		 && (dmat->lowaddr >= bz->lowaddr)) {
1268			dmat->bounce_zone = bz;
1269			return (0);
1270		}
1271	}
1272
1273	if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
1274	    M_NOWAIT | M_ZERO)) == NULL)
1275		return (ENOMEM);
1276
1277	STAILQ_INIT(&bz->bounce_page_list);
1278	bz->free_bpages = 0;
1279	bz->reserved_bpages = 0;
1280	bz->active_bpages = 0;
1281	bz->lowaddr = dmat->lowaddr;
1282	bz->alignment = dmat->alignment;
1283	bz->boundary = dmat->boundary;
1284	bz->map_count = 0;
1285	snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
1286	busdma_zonecount++;
1287	snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
1288	STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
1289	dmat->bounce_zone = bz;
1290
1291	sysctl_ctx_init(&bz->sysctl_tree);
1292	bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
1293	    SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
1294	    CTLFLAG_RD, 0, "");
1295	if (bz->sysctl_tree_top == NULL) {
1296		sysctl_ctx_free(&bz->sysctl_tree);
1297		return (0);	/* XXX error code? */
1298	}
1299
1300	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1301	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1302	    "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
1303	    "Total bounce pages");
1304	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1305	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1306	    "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
1307	    "Free bounce pages");
1308	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1309	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1310	    "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
1311	    "Reserved bounce pages");
1312	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1313	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1314	    "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
1315	    "Active bounce pages");
1316	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1317	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1318	    "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
1319	    "Total bounce requests");
1320	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1321	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1322	    "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
1323	    "Total bounce requests that were deferred");
1324	SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
1325	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1326	    "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
1327	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1328	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1329	    "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
1330	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
1331	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
1332	    "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
1333
1334	return (0);
1335}
1336
1337static int
1338alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
1339{
1340	struct bounce_zone *bz;
1341	int count;
1342
1343	bz = dmat->bounce_zone;
1344	count = 0;
1345	while (numpages > 0) {
1346		struct bounce_page *bpage;
1347
1348		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1349						     M_NOWAIT | M_ZERO);
1350
1351		if (bpage == NULL)
1352			break;
1353		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1354							 M_NOWAIT, 0ul,
1355							 bz->lowaddr,
1356							 PAGE_SIZE,
1357							 bz->boundary);
1358		if (bpage->vaddr == 0) {
1359			free(bpage, M_DEVBUF);
1360			break;
1361		}
1362		bpage->busaddr = pmap_kextract(bpage->vaddr);
1363		bpage->vaddr_nocache = (vm_offset_t)arm_remap_nocache(
1364		    (void *)bpage->vaddr, PAGE_SIZE);
1365		mtx_lock(&bounce_lock);
1366		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1367		total_bpages++;
1368		bz->total_bpages++;
1369		bz->free_bpages++;
1370		mtx_unlock(&bounce_lock);
1371		count++;
1372		numpages--;
1373	}
1374	return (count);
1375}
1376
1377static int
1378reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1379{
1380	struct bounce_zone *bz;
1381	int pages;
1382
1383	mtx_assert(&bounce_lock, MA_OWNED);
1384	bz = dmat->bounce_zone;
1385	pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1386	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1387		return (map->pagesneeded - (map->pagesreserved + pages));
1388	bz->free_bpages -= pages;
1389	bz->reserved_bpages += pages;
1390	map->pagesreserved += pages;
1391	pages = map->pagesneeded - map->pagesreserved;
1392
1393	return (pages);
1394}
1395
1396static bus_addr_t
1397add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1398		bus_size_t size)
1399{
1400	struct bounce_zone *bz;
1401	struct bounce_page *bpage;
1402
1403	KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1404	KASSERT(map != NULL, ("add_bounce_page: bad map %p", map));
1405
1406	bz = dmat->bounce_zone;
1407	if (map->pagesneeded == 0)
1408		panic("add_bounce_page: map doesn't need any pages");
1409	map->pagesneeded--;
1410
1411	if (map->pagesreserved == 0)
1412		panic("add_bounce_page: map doesn't need any pages");
1413	map->pagesreserved--;
1414
1415	mtx_lock(&bounce_lock);
1416	bpage = STAILQ_FIRST(&bz->bounce_page_list);
1417	if (bpage == NULL)
1418		panic("add_bounce_page: free page list is empty");
1419
1420	STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1421	bz->reserved_bpages--;
1422	bz->active_bpages++;
1423	mtx_unlock(&bounce_lock);
1424
1425	if (dmat->flags & BUS_DMA_KEEP_PG_OFFSET) {
1426		/* page offset needs to be preserved */
1427		bpage->vaddr &= ~PAGE_MASK;
1428		bpage->busaddr &= ~PAGE_MASK;
1429		bpage->vaddr |= vaddr & PAGE_MASK;
1430		bpage->busaddr |= vaddr & PAGE_MASK;
1431	}
1432	bpage->datavaddr = vaddr;
1433	bpage->datacount = size;
1434	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1435	return (bpage->busaddr);
1436}
1437
1438static void
1439free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1440{
1441	struct bus_dmamap *map;
1442	struct bounce_zone *bz;
1443
1444	bz = dmat->bounce_zone;
1445	bpage->datavaddr = 0;
1446	bpage->datacount = 0;
1447
1448	mtx_lock(&bounce_lock);
1449	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1450	bz->free_bpages++;
1451	bz->active_bpages--;
1452	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1453		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1454			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1455			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1456					   map, links);
1457			busdma_swi_pending = 1;
1458			bz->total_deferred++;
1459			swi_sched(vm_ih, 0);
1460		}
1461	}
1462	mtx_unlock(&bounce_lock);
1463}
1464
1465void
1466busdma_swi(void)
1467{
1468	bus_dma_tag_t dmat;
1469	struct bus_dmamap *map;
1470
1471	mtx_lock(&bounce_lock);
1472	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1473		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1474		mtx_unlock(&bounce_lock);
1475		dmat = map->dmat;
1476		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1477		bus_dmamap_load(map->dmat, map, map->buffer, map->len,
1478		    map->callback, map->callback_arg, /*flags*/0);
1479		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1480		mtx_lock(&bounce_lock);
1481	}
1482	mtx_unlock(&bounce_lock);
1483}
1484