busdma_machdep-v4.c revision 147591
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 147591 2005-06-24 23:57:27Z cognet $");
33
34/*
35 * MacPPC 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
52#include <vm/vm.h>
53#include <vm/vm_page.h>
54#include <vm/vm_map.h>
55
56#include <machine/atomic.h>
57#include <machine/bus.h>
58#include <machine/cpufunc.h>
59
60struct bus_dma_tag {
61	bus_dma_tag_t		parent;
62	bus_size_t		alignment;
63	bus_size_t		boundary;
64	bus_addr_t		lowaddr;
65	bus_addr_t		highaddr;
66	bus_dma_filter_t	*filter;
67	void			*filterarg;
68	bus_size_t		maxsize;
69	u_int			nsegments;
70	bus_size_t		maxsegsz;
71	int			flags;
72	int			ref_count;
73	int			map_count;
74	bus_dma_lock_t		*lockfunc;
75	void			*lockfuncarg;
76	/*
77	 * DMA range for this tag.  If the page doesn't fall within
78	 * one of these ranges, an error is returned.  The caller
79	 * may then decide what to do with the transfer.  If the
80	 * range pointer is NULL, it is ignored.
81	 */
82	struct arm32_dma_range	*ranges;
83	int			_nranges;
84};
85
86#define DMAMAP_LINEAR		0x1
87#define DMAMAP_MBUF		0x2
88#define DMAMAP_UIO		0x4
89#define DMAMAP_ALLOCATED	0x10
90#define DMAMAP_TYPE_MASK	(DMAMAP_LINEAR|DMAMAP_MBUF|DMAMAP_UIO)
91#define DMAMAP_COHERENT		0x8
92struct bus_dmamap {
93        bus_dma_tag_t	dmat;
94	int		flags;
95	void 		*buffer;
96	TAILQ_ENTRY(bus_dmamap)	freelist;
97	int		len;
98};
99
100static TAILQ_HEAD(,bus_dmamap) dmamap_freelist =
101	TAILQ_HEAD_INITIALIZER(dmamap_freelist);
102
103#define BUSDMA_STATIC_MAPS	500
104static struct bus_dmamap map_pool[BUSDMA_STATIC_MAPS];
105
106static struct mtx busdma_mtx;
107
108MTX_SYSINIT(busdma_mtx, &busdma_mtx, "busdma lock", MTX_DEF);
109
110static void
111arm_dmamap_freelist_init(void *dummy)
112{
113	int i;
114
115	for (i = 0; i < BUSDMA_STATIC_MAPS; i++)
116		TAILQ_INSERT_HEAD(&dmamap_freelist, &map_pool[i], freelist);
117}
118
119SYSINIT(busdma, SI_SUB_VM, SI_ORDER_ANY, arm_dmamap_freelist_init, NULL);
120
121/*
122 * Check to see if the specified page is in an allowed DMA range.
123 */
124
125static __inline int
126bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
127    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
128    int flags, vm_offset_t *lastaddrp, int *segp);
129
130static __inline struct arm32_dma_range *
131_bus_dma_inrange(struct arm32_dma_range *ranges, int nranges,
132    bus_addr_t curaddr)
133{
134	struct arm32_dma_range *dr;
135	int i;
136
137	for (i = 0, dr = ranges; i < nranges; i++, dr++) {
138		if (curaddr >= dr->dr_sysbase &&
139		    round_page(curaddr) <= (dr->dr_sysbase + dr->dr_len))
140			return (dr);
141	}
142
143	return (NULL);
144}
145/*
146 * Convenience function for manipulating driver locks from busdma (during
147 * busdma_swi, for example).  Drivers that don't provide their own locks
148 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
149 * non-mutex locking scheme don't have to use this at all.
150 */
151void
152busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
153{
154	struct mtx *dmtx;
155
156	dmtx = (struct mtx *)arg;
157	switch (op) {
158	case BUS_DMA_LOCK:
159		mtx_lock(dmtx);
160		break;
161	case BUS_DMA_UNLOCK:
162		mtx_unlock(dmtx);
163		break;
164	default:
165		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
166	}
167}
168
169/*
170 * dflt_lock should never get called.  It gets put into the dma tag when
171 * lockfunc == NULL, which is only valid if the maps that are associated
172 * with the tag are meant to never be defered.
173 * XXX Should have a way to identify which driver is responsible here.
174 */
175static void
176dflt_lock(void *arg, bus_dma_lock_op_t op)
177{
178#ifdef INVARIANTS
179	panic("driver error: busdma dflt_lock called");
180#else
181	printf("DRIVER_ERROR: busdma dflt_lock called\n");
182#endif
183}
184
185static __inline bus_dmamap_t
186_busdma_alloc_dmamap(void)
187{
188	bus_dmamap_t map;
189
190	mtx_lock(&busdma_mtx);
191	map = TAILQ_FIRST(&dmamap_freelist);
192	TAILQ_REMOVE(&dmamap_freelist, map, freelist);
193	mtx_unlock(&busdma_mtx);
194	if (!map) {
195		map = malloc(sizeof(*map), M_DEVBUF, M_NOWAIT);
196		if (map)
197			map->flags = DMAMAP_ALLOCATED;
198	} else
199		map->flags = 0;
200	return (map);
201}
202
203static __inline void
204_busdma_free_dmamap(bus_dmamap_t map)
205{
206	if (map->flags & DMAMAP_ALLOCATED)
207		free(map, M_DEVBUF);
208	else {
209		mtx_lock(&busdma_mtx);
210		TAILQ_INSERT_HEAD(&dmamap_freelist, map, freelist);
211		mtx_unlock(&busdma_mtx);
212	}
213}
214
215/*
216 * Allocate a device specific dma_tag.
217 */
218#define SEG_NB 1024
219
220int
221bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
222		   bus_size_t boundary, bus_addr_t lowaddr,
223		   bus_addr_t highaddr, bus_dma_filter_t *filter,
224		   void *filterarg, bus_size_t maxsize, int nsegments,
225		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
226		   void *lockfuncarg, bus_dma_tag_t *dmat)
227{
228	bus_dma_tag_t newtag;
229	int error = 0;
230	/* Return a NULL tag on failure */
231	*dmat = NULL;
232
233	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
234	if (newtag == NULL) {
235		CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
236		    __func__, newtag, 0, error);
237		return (ENOMEM);
238	}
239
240	newtag->parent = parent;
241	newtag->alignment = alignment;
242	newtag->boundary = boundary;
243	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
244	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
245	newtag->filter = filter;
246	newtag->filterarg = filterarg;
247        newtag->maxsize = maxsize;
248        newtag->nsegments = nsegments;
249	newtag->maxsegsz = maxsegsz;
250	newtag->flags = flags;
251	newtag->ref_count = 1; /* Count ourself */
252	newtag->map_count = 0;
253	newtag->ranges = bus_dma_get_range();
254	newtag->_nranges = bus_dma_get_range_nb();
255	if (lockfunc != NULL) {
256		newtag->lockfunc = lockfunc;
257		newtag->lockfuncarg = lockfuncarg;
258	} else {
259		newtag->lockfunc = dflt_lock;
260		newtag->lockfuncarg = NULL;
261	}
262        /*
263	 * Take into account any restrictions imposed by our parent tag
264	 */
265        if (parent != NULL) {
266                newtag->lowaddr = min(parent->lowaddr, newtag->lowaddr);
267                newtag->highaddr = max(parent->highaddr, newtag->highaddr);
268		if (newtag->boundary == 0)
269			newtag->boundary = parent->boundary;
270		else if (parent->boundary != 0)
271                	newtag->boundary = min(parent->boundary,
272					       newtag->boundary);
273                if (newtag->filter == NULL) {
274                        /*
275                         * Short circuit looking at our parent directly
276                         * since we have encapsulated all of its information
277                         */
278                        newtag->filter = parent->filter;
279                        newtag->filterarg = parent->filterarg;
280                        newtag->parent = parent->parent;
281		}
282		if (newtag->parent != NULL)
283			atomic_add_int(&parent->ref_count, 1);
284	}
285
286	*dmat = newtag;
287	CTR4(KTR_BUSDMA, "%s returned tag %p tag flags 0x%x error %d",
288	    __func__, newtag, (newtag != NULL ? newtag->flags : 0), error);
289
290	return (error);
291}
292
293int
294bus_dma_tag_destroy(bus_dma_tag_t dmat)
295{
296#ifdef KTR
297	bus_dma_tag_t dmat_copy = dmat;
298#endif
299
300	if (dmat != NULL) {
301
302                if (dmat->map_count != 0)
303                        return (EBUSY);
304
305                while (dmat != NULL) {
306                        bus_dma_tag_t parent;
307
308                        parent = dmat->parent;
309                        atomic_subtract_int(&dmat->ref_count, 1);
310                        if (dmat->ref_count == 0) {
311                                free(dmat, M_DEVBUF);
312                                /*
313                                 * Last reference count, so
314                                 * release our reference
315                                 * count on our parent.
316                                 */
317                                dmat = parent;
318                        } else
319                                dmat = NULL;
320                }
321        }
322	CTR2(KTR_BUSDMA, "%s tag %p", __func__, dmat_copy);
323
324        return (0);
325}
326
327/*
328 * Allocate a handle for mapping from kva/uva/physical
329 * address space into bus device space.
330 */
331int
332bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
333{
334	bus_dmamap_t newmap;
335#ifdef KTR
336	int error = 0;
337#endif
338
339	newmap = _busdma_alloc_dmamap();
340	if (newmap == NULL) {
341		CTR3(KTR_BUSDMA, "%s: tag %p error %d", __func__, dmat, ENOMEM);
342		return (ENOMEM);
343	}
344	*mapp = newmap;
345	newmap->dmat = dmat;
346	dmat->map_count++;
347
348	CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
349	    __func__, dmat, dmat->flags, error);
350
351	return (0);
352}
353
354/*
355 * Destroy a handle for mapping from kva/uva/physical
356 * address space into bus device space.
357 */
358int
359bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
360{
361
362	_busdma_free_dmamap(map);
363        dmat->map_count--;
364	CTR2(KTR_BUSDMA, "%s: tag %p error 0", __func__, dmat);
365        return (0);
366}
367
368/*
369 * Allocate a piece of memory that can be efficiently mapped into
370 * bus device space based on the constraints lited in the dma tag.
371 * A dmamap to for use with dmamap_load is also allocated.
372 */
373int
374bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
375                 bus_dmamap_t *mapp)
376{
377	bus_dmamap_t newmap = NULL;
378
379	int mflags;
380
381	if (flags & BUS_DMA_NOWAIT)
382		mflags = M_NOWAIT;
383	else
384		mflags = M_WAITOK;
385	if (flags & BUS_DMA_ZERO)
386		mflags |= M_ZERO;
387
388	newmap = _busdma_alloc_dmamap();
389	if (newmap == NULL) {
390		CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
391		    __func__, dmat, dmat->flags, ENOMEM);
392		return (ENOMEM);
393	}
394	dmat->map_count++;
395	*mapp = newmap;
396	newmap->dmat = dmat;
397
398        if (dmat->maxsize <= PAGE_SIZE) {
399                *vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
400        } else {
401                /*
402                 * XXX Use Contigmalloc until it is merged into this facility
403                 *     and handles multi-seg allocations.  Nobody is doing
404                 *     multi-seg allocations yet though.
405                 */
406                *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
407                    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
408                    dmat->boundary);
409        }
410        if (*vaddr == NULL) {
411		if (newmap != NULL) {
412			_busdma_free_dmamap(newmap);
413			dmat->map_count--;
414		}
415		*mapp = NULL;
416                return (ENOMEM);
417	}
418        return (0);
419}
420
421/*
422 * Free a piece of memory and it's allocated dmamap, that was allocated
423 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
424 */
425void
426bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
427{
428        if (dmat->maxsize <= PAGE_SIZE)
429		free(vaddr, M_DEVBUF);
430        else {
431		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
432	}
433	dmat->map_count--;
434	_busdma_free_dmamap(map);
435	CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
436}
437
438/*
439 * Utility function to load a linear buffer.  lastaddrp holds state
440 * between invocations (for multiple-buffer loads).  segp contains
441 * the starting segment on entrance, and the ending segment on exit.
442 * first indicates if this is the first invocation of this function.
443 */
444static __inline int
445bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dma_segment_t *segs,
446    bus_dmamap_t map, void *buf, bus_size_t buflen, struct pmap *pmap,
447    int flags, vm_offset_t *lastaddrp, int *segp)
448{
449	bus_size_t sgsize;
450	bus_addr_t curaddr, lastaddr, baddr, bmask;
451	vm_offset_t vaddr = (vm_offset_t)buf;
452	int seg;
453	int error = 0;
454	pd_entry_t *pde;
455	pt_entry_t pte;
456	pt_entry_t *ptep;
457
458	lastaddr = *lastaddrp;
459	bmask = ~(dmat->boundary - 1);
460
461	CTR3(KTR_BUSDMA, "lowaddr= %d boundary= %d, "
462	    "alignment= %d", dmat->lowaddr, dmat->boundary, dmat->alignment);
463
464	for (seg = *segp; buflen > 0 ; ) {
465		/*
466		 * Get the physical address for this segment.
467		 *
468		 * XXX Don't support checking for coherent mappings
469		 * XXX in user address space.
470		 */
471		if (__predict_true(pmap == pmap_kernel())) {
472			(void) pmap_get_pde_pte(pmap, vaddr, &pde, &ptep);
473			if (__predict_false(pmap_pde_section(pde))) {
474				curaddr = (*pde & L1_S_FRAME) |
475				    (vaddr & L1_S_OFFSET);
476				if (*pde & L1_S_CACHE_MASK) {
477					map->flags &=
478					    ~DMAMAP_COHERENT;
479				}
480			} else {
481				pte = *ptep;
482				KASSERT((pte & L2_TYPE_MASK) != L2_TYPE_INV,
483				    ("INV type"));
484				if (__predict_false((pte & L2_TYPE_MASK)
485						    == L2_TYPE_L)) {
486					curaddr = (pte & L2_L_FRAME) |
487					    (vaddr & L2_L_OFFSET);
488					if (pte & L2_L_CACHE_MASK) {
489						map->flags &=
490						    ~DMAMAP_COHERENT;
491
492					}
493				} else {
494					curaddr = (pte & L2_S_FRAME) |
495					    (vaddr & L2_S_OFFSET);
496					if (pte & L2_S_CACHE_MASK) {
497						map->flags &=
498						    ~DMAMAP_COHERENT;
499					}
500				}
501			}
502		} else {
503			curaddr = pmap_extract(pmap, vaddr);
504			map->flags &= ~DMAMAP_COHERENT;
505		}
506
507		if (dmat->ranges) {
508			struct arm32_dma_range *dr;
509
510			dr = _bus_dma_inrange(dmat->ranges, dmat->_nranges,
511			    curaddr);
512			if (dr == NULL)
513				return (EINVAL);
514			/*
515		     	 * In a valid DMA range.  Translate the physical
516			 * memory address to an address in the DMA window.
517			 */
518			curaddr = (curaddr - dr->dr_sysbase) + dr->dr_busbase;
519
520		}
521		/*
522		 * Compute the segment size, and adjust counts.
523		 */
524		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
525		if (buflen < sgsize)
526			sgsize = buflen;
527
528		/*
529		 * Make sure we don't cross any boundaries.
530		 */
531		if (dmat->boundary > 0) {
532			baddr = (curaddr + dmat->boundary) & bmask;
533			if (sgsize > (baddr - curaddr))
534				sgsize = (baddr - curaddr);
535		}
536
537		/*
538		 * Insert chunk into a segment, coalescing with
539		 * the previous segment if possible.
540		 */
541		if (seg >= 0 && curaddr == lastaddr &&
542		    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
543		    (dmat->boundary == 0 ||
544		     (segs[seg].ds_addr & bmask) ==
545		     (curaddr & bmask))) {
546			segs[seg].ds_len += sgsize;
547			goto segdone;
548		} else {
549			if (++seg >= dmat->nsegments)
550				break;
551			segs[seg].ds_addr = curaddr;
552			segs[seg].ds_len = sgsize;
553		}
554		if (error)
555			break;
556segdone:
557		lastaddr = curaddr + sgsize;
558		vaddr += sgsize;
559		buflen -= sgsize;
560	}
561
562	*segp = seg;
563	*lastaddrp = lastaddr;
564
565	/*
566	 * Did we fit?
567	 */
568	if (buflen != 0)
569		error = EFBIG; /* XXX better return value here? */
570	return (error);
571}
572
573/*
574 * Map the buffer buf into bus space using the dmamap map.
575 */
576int
577bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
578                bus_size_t buflen, bus_dmamap_callback_t *callback,
579                void *callback_arg, int flags)
580{
581     	vm_offset_t	lastaddr = 0;
582	int		error, nsegs = -1;
583#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
584	bus_dma_segment_t dm_segments[dmat->nsegments];
585#else
586	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
587#endif
588
589	KASSERT(dmat != NULL, ("dmatag is NULL"));
590	KASSERT(map != NULL, ("dmamap is NULL"));
591	map->flags &= ~DMAMAP_TYPE_MASK;
592	map->flags |= DMAMAP_LINEAR|DMAMAP_COHERENT;
593	map->buffer = buf;
594	map->len = buflen;
595	error = bus_dmamap_load_buffer(dmat,
596	    dm_segments, map, buf, buflen, kernel_pmap,
597	    flags, &lastaddr, &nsegs);
598	if (error)
599		(*callback)(callback_arg, NULL, 0, error);
600	else
601		(*callback)(callback_arg, dm_segments, nsegs + 1, error);
602
603	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
604	    __func__, dmat, dmat->flags, nsegs + 1, error);
605
606	return (0);
607}
608
609/*
610 * Like bus_dmamap_load(), but for mbufs.
611 */
612int
613bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map, struct mbuf *m0,
614		     bus_dmamap_callback2_t *callback, void *callback_arg,
615		     int flags)
616{
617#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
618	bus_dma_segment_t dm_segments[dmat->nsegments];
619#else
620	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
621#endif
622	int nsegs = -1, error = 0;
623
624	M_ASSERTPKTHDR(m0);
625
626	map->flags &= ~DMAMAP_TYPE_MASK;
627	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
628	map->buffer = m0;
629	map->len = 0;
630	if (m0->m_pkthdr.len <= dmat->maxsize) {
631		vm_offset_t lastaddr = 0;
632		struct mbuf *m;
633
634		for (m = m0; m != NULL && error == 0; m = m->m_next) {
635			if (m->m_len > 0) {
636				error = bus_dmamap_load_buffer(dmat,
637				    dm_segments, map, m->m_data, m->m_len,
638				    pmap_kernel(), flags, &lastaddr, &nsegs);
639				map->len += m->m_len;
640			}
641		}
642	} else {
643		error = EINVAL;
644	}
645
646	if (error) {
647		/*
648		 * force "no valid mappings" on error in callback.
649		 */
650		(*callback)(callback_arg, dm_segments, 0, 0, error);
651	} else {
652		(*callback)(callback_arg, dm_segments, nsegs + 1,
653		    m0->m_pkthdr.len, error);
654	}
655	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
656	    __func__, dmat, dmat->flags, error, nsegs + 1);
657
658	return (error);
659}
660
661int
662bus_dmamap_load_mbuf_sg(bus_dma_tag_t dmat, bus_dmamap_t map,
663			struct mbuf *m0, bus_dma_segment_t *segs, int *nsegs,
664			int flags)
665{
666	int error = 0;
667	M_ASSERTPKTHDR(m0);
668
669	flags |= BUS_DMA_NOWAIT;
670	*nsegs = -1;
671	map->flags &= ~DMAMAP_TYPE_MASK;
672	map->flags |= DMAMAP_MBUF | DMAMAP_COHERENT;
673	map->buffer = m0;
674	map->len = 0;
675	if (m0->m_pkthdr.len <= dmat->maxsize) {
676		vm_offset_t lastaddr = 0;
677		struct mbuf *m;
678
679		for (m = m0; m != NULL && error == 0; m = m->m_next) {
680			if (m->m_len > 0) {
681				error = bus_dmamap_load_buffer(dmat, segs, map,
682						m->m_data, m->m_len,
683						pmap_kernel(), flags, &lastaddr,
684						nsegs);
685				map->len += m->m_len;
686			}
687		}
688	} else {
689		error = EINVAL;
690	}
691
692	/* XXX FIXME: Having to increment nsegs is really annoying */
693	++*nsegs;
694	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
695	    __func__, dmat, dmat->flags, error, *nsegs);
696	return (error);
697}
698
699/*
700 * Like bus_dmamap_load(), but for uios.
701 */
702int
703bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map, struct uio *uio,
704    bus_dmamap_callback2_t *callback, void *callback_arg,
705    int flags)
706{
707	vm_offset_t lastaddr;
708#ifdef __CC_SUPPORTS_DYNAMIC_ARRAY_INIT
709	bus_dma_segment_t dm_segments[dmat->nsegments];
710#else
711	bus_dma_segment_t dm_segments[BUS_DMAMAP_NSEGS];
712#endif
713	int nsegs, i, error;
714	bus_size_t resid;
715	struct iovec *iov;
716	struct pmap *pmap;
717
718	resid = uio->uio_resid;
719	iov = uio->uio_iov;
720	map->flags &= ~DMAMAP_TYPE_MASK;
721	map->flags |= DMAMAP_UIO|DMAMAP_COHERENT;
722	map->buffer = uio;
723	map->len = 0;
724
725	if (uio->uio_segflg == UIO_USERSPACE) {
726		KASSERT(uio->uio_td != NULL,
727		    ("bus_dmamap_load_uio: USERSPACE but no proc"));
728		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
729	} else
730		pmap = kernel_pmap;
731
732	error = 0;
733	nsegs = -1;
734	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
735		/*
736		 * Now at the first iovec to load.  Load each iovec
737		 * until we have exhausted the residual count.
738		 */
739		bus_size_t minlen =
740		    resid < iov[i].iov_len ? resid : iov[i].iov_len;
741		caddr_t addr = (caddr_t) iov[i].iov_base;
742
743		if (minlen > 0) {
744			error = bus_dmamap_load_buffer(dmat, dm_segments, map,
745			    addr, minlen, pmap, flags, &lastaddr, &nsegs);
746
747			map->len += minlen;
748			resid -= minlen;
749		}
750	}
751
752	if (error) {
753		/*
754		 * force "no valid mappings" on error in callback.
755		 */
756		(*callback)(callback_arg, dm_segments, 0, 0, error);
757	} else {
758		(*callback)(callback_arg, dm_segments, nsegs+1,
759		    uio->uio_resid, error);
760	}
761
762	CTR5(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d nsegs %d",
763	    __func__, dmat, dmat->flags, error, nsegs + 1);
764	return (error);
765}
766
767/*
768 * Release the mapping held by map.
769 */
770void
771_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
772{
773	map->flags &= ~DMAMAP_TYPE_MASK;
774	return;
775}
776
777static __inline void
778bus_dmamap_sync_buf(void *buf, int len, bus_dmasync_op_t op)
779{
780
781	if (op & BUS_DMASYNC_PREWRITE)
782		cpu_dcache_wb_range((vm_offset_t)buf, len);
783	if (op & BUS_DMASYNC_POSTREAD) {
784		if ((((vm_offset_t)buf | len) & arm_dcache_align_mask) == 0)
785			cpu_dcache_inv_range((vm_offset_t)buf, len);
786		else
787			cpu_dcache_wbinv_range((vm_offset_t)buf, len);
788
789	}
790}
791
792void
793_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
794{
795	struct mbuf *m;
796	struct uio *uio;
797	int resid;
798	struct iovec *iov;
799
800	if (!(op & (BUS_DMASYNC_PREWRITE | BUS_DMASYNC_POSTREAD)))
801		return;
802	if (map->flags & DMAMAP_COHERENT)
803		return;
804	if ((op && BUS_DMASYNC_POSTREAD) && (map->len > PAGE_SIZE)) {
805		cpu_dcache_wbinv_all();
806		return;
807	}
808	CTR3(KTR_BUSDMA, "%s: op %x flags %x", __func__, op, map->flags);
809	switch(map->flags & DMAMAP_TYPE_MASK) {
810	case DMAMAP_LINEAR:
811		bus_dmamap_sync_buf(map->buffer, map->len, op);
812		break;
813	case DMAMAP_MBUF:
814		m = map->buffer;
815		while (m) {
816			if (m->m_len > 0)
817				bus_dmamap_sync_buf(m->m_data, m->m_len, op);
818			m = m->m_next;
819		}
820		break;
821	case DMAMAP_UIO:
822		uio = map->buffer;
823		iov = uio->uio_iov;
824		resid = uio->uio_resid;
825		for (int i = 0; i < uio->uio_iovcnt && resid != 0; i++) {
826			bus_size_t minlen = resid < iov[i].iov_len ? resid :
827			    iov[i].iov_len;
828			if (minlen > 0) {
829				bus_dmamap_sync_buf(iov[i].iov_base, minlen,
830				    op);
831				resid -= minlen;
832			}
833		}
834		break;
835	default:
836		break;
837	}
838	cpu_drain_writebuf();
839}
840