busdma_machdep.c revision 137460 
1/*
2 * Copyright (c) 1997, 1998 Justin T. Gibbs.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions, and the following disclaimer,
10 *    without modification, immediately at the beginning of the file.
11 * 2. The name of the author may not be used to endorse or promote products
12 *    derived from this software without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
18 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/i386/i386/busdma_machdep.c 137460 2004-11-09 16:03:27Z scottl $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/malloc.h>
33#include <sys/bus.h>
34#include <sys/interrupt.h>
35#include <sys/kernel.h>
36#include <sys/ktr.h>
37#include <sys/lock.h>
38#include <sys/proc.h>
39#include <sys/mutex.h>
40#include <sys/mbuf.h>
41#include <sys/uio.h>
42#include <sys/sysctl.h>
43#include <sys/ktr.h>
44
45#include <vm/vm.h>
46#include <vm/vm_page.h>
47#include <vm/vm_map.h>
48
49#include <machine/atomic.h>
50#include <machine/bus.h>
51#include <machine/md_var.h>
52
53#define MAX_BPAGES 512
54
55struct bounce_zone;
56
57struct bus_dma_tag {
58	bus_dma_tag_t	  parent;
59	bus_size_t	  alignment;
60	bus_size_t	  boundary;
61	bus_addr_t	  lowaddr;
62	bus_addr_t	  highaddr;
63	bus_dma_filter_t *filter;
64	void		 *filterarg;
65	bus_size_t	  maxsize;
66	u_int		  nsegments;
67	bus_size_t	  maxsegsz;
68	int		  flags;
69	int		  ref_count;
70	int		  map_count;
71	bus_dma_lock_t	 *lockfunc;
72	void		 *lockfuncarg;
73	bus_dma_segment_t *segments;
74	struct bounce_zone *bounce_zone;
75};
76
77struct bounce_page {
78	vm_offset_t	vaddr;		/* kva of bounce buffer */
79	bus_addr_t	busaddr;	/* Physical address */
80	vm_offset_t	datavaddr;	/* kva of client data */
81	bus_size_t	datacount;	/* client data count */
82	STAILQ_ENTRY(bounce_page) links;
83};
84
85int busdma_swi_pending;
86
87struct bounce_zone {
88	STAILQ_ENTRY(bounce_zone) links;
89	STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
90	int		free_bpages;
91	int		reserved_bpages;
92	int		active_bpages;
93	int		total_bounced;
94	int		total_deferred;
95	bus_size_t	alignment;
96	bus_size_t	boundary;
97	bus_addr_t	lowaddr;
98	char		zoneid[8];
99	char		lowaddrid[20];
100	struct sysctl_ctx_list sysctl_tree;
101	struct sysctl_oid *sysctl_tree_top;
102};
103
104static struct mtx bounce_lock;
105static int total_bpages;
106static int busdma_zonecount;
107static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
108static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
109
110SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
111SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
112	   "Total bounce pages");
113
114struct bus_dmamap {
115	struct bp_list	       bpages;
116	int		       pagesneeded;
117	int		       pagesreserved;
118	bus_dma_tag_t	       dmat;
119	void		      *buf;		/* unmapped buffer pointer */
120	bus_size_t	       buflen;		/* unmapped buffer length */
121	bus_dmamap_callback_t *callback;
122	void		      *callback_arg;
123	STAILQ_ENTRY(bus_dmamap) links;
124};
125
126static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
127static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
128static struct bus_dmamap nobounce_dmamap;
129
130static void init_bounce_pages(void *dummy);
131static struct bounce_zone * alloc_bounce_zone(bus_dma_tag_t dmat);
132static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
133static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
134				int commit);
135static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
136				   vm_offset_t vaddr, bus_size_t size);
137static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
138static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr,
139			       bus_size_t len);
140
141/*
142 * Return true if a match is made.
143 *
144 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
145 *
146 * If paddr is within the bounds of the dma tag then call the filter callback
147 * to check for a match, if there is no filter callback then assume a match.
148 */
149static __inline int
150run_filter(bus_dma_tag_t dmat, bus_addr_t paddr, bus_size_t len)
151{
152	bus_size_t bndy;
153	int retval;
154
155	retval = 0;
156	bndy = dmat->boundary;
157
158	do {
159		if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
160		 || ((paddr & (dmat->alignment - 1)) != 0)
161		 || ((paddr & bndy) != ((paddr + len) & bndy)))
162		 && (dmat->filter == NULL
163		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
164			retval = 1;
165
166		dmat = dmat->parent;
167	} while (retval == 0 && dmat != NULL);
168	return (retval);
169}
170
171/*
172 * Convenience function for manipulating driver locks from busdma (during
173 * busdma_swi, for example).  Drivers that don't provide their own locks
174 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
175 * non-mutex locking scheme don't have to use this at all.
176 */
177void
178busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
179{
180	struct mtx *dmtx;
181
182	dmtx = (struct mtx *)arg;
183	switch (op) {
184	case BUS_DMA_LOCK:
185		mtx_lock(dmtx);
186		break;
187	case BUS_DMA_UNLOCK:
188		mtx_unlock(dmtx);
189		break;
190	default:
191		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
192	}
193}
194
195/*
196 * dflt_lock should never get called.  It gets put into the dma tag when
197 * lockfunc == NULL, which is only valid if the maps that are associated
198 * with the tag are meant to never be defered.
199 * XXX Should have a way to identify which driver is responsible here.
200 */
201static void
202dflt_lock(void *arg, bus_dma_lock_op_t op)
203{
204	panic("driver error: busdma dflt_lock called");
205}
206
207#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
208/*
209 * Allocate a device specific dma_tag.
210 */
211int
212bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
213		   bus_size_t boundary, bus_addr_t lowaddr,
214		   bus_addr_t highaddr, bus_dma_filter_t *filter,
215		   void *filterarg, bus_size_t maxsize, int nsegments,
216		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
217		   void *lockfuncarg, bus_dma_tag_t *dmat)
218{
219	bus_dma_tag_t newtag;
220	int error = 0;
221
222	/* Basic sanity checking */
223	if (boundary != 0 && boundary < maxsegsz)
224		maxsegsz = boundary;
225
226	/* Return a NULL tag on failure */
227	*dmat = NULL;
228
229	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
230	    M_ZERO | M_NOWAIT);
231	if (newtag == NULL) {
232		CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag "
233		    "flags 0x%x error %d", newtag, 0, error);
234		return (ENOMEM);
235	}
236
237	newtag->parent = parent;
238	newtag->alignment = alignment;
239	newtag->boundary = boundary;
240	newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
241	newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
242	    (PAGE_SIZE - 1);
243	newtag->filter = filter;
244	newtag->filterarg = filterarg;
245	newtag->maxsize = maxsize;
246	newtag->nsegments = nsegments;
247	newtag->maxsegsz = maxsegsz;
248	newtag->flags = flags;
249	newtag->ref_count = 1; /* Count ourself */
250	newtag->map_count = 0;
251	if (lockfunc != NULL) {
252		newtag->lockfunc = lockfunc;
253		newtag->lockfuncarg = lockfuncarg;
254	} else {
255		newtag->lockfunc = dflt_lock;
256		newtag->lockfuncarg = NULL;
257	}
258	newtag->segments = NULL;
259
260	/* Take into account any restrictions imposed by our parent tag */
261	if (parent != NULL) {
262		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
263		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
264		if (newtag->boundary == 0)
265			newtag->boundary = parent->boundary;
266		else if (parent->boundary != 0)
267			newtag->boundary = MIN(parent->boundary,
268					       newtag->boundary);
269		if (newtag->filter == NULL) {
270			/*
271			 * Short circuit looking at our parent directly
272			 * since we have encapsulated all of its information
273			 */
274			newtag->filter = parent->filter;
275			newtag->filterarg = parent->filterarg;
276			newtag->parent = parent->parent;
277		}
278		if (newtag->parent != NULL)
279			atomic_add_int(&parent->ref_count, 1);
280	}
281
282	if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) &&
283	    (flags & BUS_DMA_ALLOCNOW) != 0) {
284		/* Must bounce */
285
286		if (lowaddr > bounce_lowaddr) {
287			/*
288			 * Go through the pool and kill any pages
289			 * that don't reside below lowaddr.
290			 */
291			panic("bus_dma_tag_create: page reallocation "
292			      "not implemented");
293		}
294		if (ptoa(total_bpages) < maxsize) {
295			int pages;
296
297			pages = atop(maxsize) - total_bpages;
298
299			/* Add pages to our bounce pool */
300			if (alloc_bounce_pages(newtag, pages) < pages)
301				error = ENOMEM;
302		}
303		/* Performed initial allocation */
304		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
305	}
306
307	if (error != 0) {
308		free(newtag, M_DEVBUF);
309	} else {
310		*dmat = newtag;
311	}
312	CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag flags 0x%x "
313	    "error %d", newtag, (newtag != NULL ? newtag->flags : 0), error);
314	return (error);
315}
316
317int
318bus_dma_tag_destroy(bus_dma_tag_t dmat)
319{
320	bus_dma_tag_t dmat_copy;
321	int error;
322
323	error = 0;
324	dmat_copy = dmat;
325
326	if (dmat != NULL) {
327
328		if (dmat->map_count != 0) {
329			error = EBUSY;
330			goto out;
331		}
332
333		while (dmat != NULL) {
334			bus_dma_tag_t parent;
335
336			parent = dmat->parent;
337			atomic_subtract_int(&dmat->ref_count, 1);
338			if (dmat->ref_count == 0) {
339				if (dmat->segments != NULL)
340					free(dmat->segments, M_DEVBUF);
341				free(dmat, M_DEVBUF);
342				/*
343				 * Last reference count, so
344				 * release our reference
345				 * count on our parent.
346				 */
347				dmat = parent;
348			} else
349				dmat = NULL;
350		}
351	}
352out:
353	CTR2(KTR_BUSDMA, "bus_dma_tag_destroy tag %p error %d", dmat_copy,
354	    error);
355	return (error);
356}
357
358/*
359 * Allocate a handle for mapping from kva/uva/physical
360 * address space into bus device space.
361 */
362int
363bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
364{
365	int error;
366
367	error = 0;
368
369	if (dmat->segments == NULL) {
370		dmat->segments = (bus_dma_segment_t *)malloc(
371		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
372		    M_NOWAIT);
373		if (dmat->segments == NULL) {
374			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
375			    dmat, ENOMEM);
376			return (ENOMEM);
377		}
378	}
379
380	/*
381	 * Bouncing might be required if the driver asks for an active
382	 * exclusion region, a data alignment that is stricter than 1, and/or
383	 * an active address boundary.
384	 */
385	if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)
386	 || dmat->alignment > 1 || dmat->boundary > 0) {
387
388		/* Must bounce */
389		int maxpages;
390
391		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
392					     M_NOWAIT | M_ZERO);
393		if (*mapp == NULL) {
394			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
395			    dmat, ENOMEM);
396			return (ENOMEM);
397		}
398
399		/* Initialize the new map */
400		STAILQ_INIT(&((*mapp)->bpages));
401
402		/*
403		 * Attempt to add pages to our pool on a per-instance
404		 * basis up to a sane limit.
405		 */
406		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
407		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
408		 || (dmat->map_count > 0 && total_bpages < maxpages)) {
409			int pages;
410
411			if (dmat->lowaddr > bounce_lowaddr) {
412				/*
413				 * Go through the pool and kill any pages
414				 * that don't reside below lowaddr.
415				 */
416				panic("bus_dmamap_create: page reallocation "
417				      "not implemented");
418			}
419			pages = MAX(atop(dmat->maxsize), 1);
420			pages = MIN(maxpages - total_bpages, pages);
421			if (alloc_bounce_pages(dmat, pages) < pages)
422				error = ENOMEM;
423
424			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
425				if (error == 0)
426					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
427			} else {
428				error = 0;
429			}
430		}
431	} else {
432		*mapp = NULL;
433	}
434	if (error == 0)
435		dmat->map_count++;
436	CTR3(KTR_BUSDMA, "bus_dmamap_create: tag %p tag flags 0x%x error %d",
437	    dmat, dmat->flags, error);
438	return (error);
439}
440
441/*
442 * Destroy a handle for mapping from kva/uva/physical
443 * address space into bus device space.
444 */
445int
446bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
447{
448	if (map != NULL && map != &nobounce_dmamap) {
449		if (STAILQ_FIRST(&map->bpages) != NULL) {
450			CTR2(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error %d",
451			    dmat, EBUSY);
452			return (EBUSY);
453		}
454		free(map, M_DEVBUF);
455	}
456	dmat->map_count--;
457	CTR1(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error 0", dmat);
458	return (0);
459}
460
461
462/*
463 * Allocate a piece of memory that can be efficiently mapped into
464 * bus device space based on the constraints lited in the dma tag.
465 * A dmamap to for use with dmamap_load is also allocated.
466 */
467int
468bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
469		 bus_dmamap_t *mapp)
470{
471	int mflags;
472
473	if (flags & BUS_DMA_NOWAIT)
474		mflags = M_NOWAIT;
475	else
476		mflags = M_WAITOK;
477	if (flags & BUS_DMA_ZERO)
478		mflags |= M_ZERO;
479
480	/* If we succeed, no mapping/bouncing will be required */
481	*mapp = NULL;
482
483	if (dmat->segments == NULL) {
484		dmat->segments = (bus_dma_segment_t *)malloc(
485		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
486		    M_NOWAIT);
487		if (dmat->segments == NULL) {
488			CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag "
489			    "flags 0x%x error %d", dmat, dmat->flags, ENOMEM);
490			return (ENOMEM);
491		}
492	}
493
494	if ((dmat->maxsize <= PAGE_SIZE) &&
495	    dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
496		*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
497	} else {
498		/*
499		 * XXX Use Contigmalloc until it is merged into this facility
500		 *     and handles multi-seg allocations.  Nobody is doing
501		 *     multi-seg allocations yet though.
502		 * XXX Certain AGP hardware does.
503		 */
504		*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
505		    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
506		    dmat->boundary);
507	}
508	if (*vaddr == NULL) {
509		CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x "
510		    "error %d", dmat, dmat->flags, ENOMEM);
511		return (ENOMEM);
512	}
513	CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x error %d",
514	    dmat, dmat->flags, ENOMEM);
515	return (0);
516}
517
518/*
519 * Free a piece of memory and it's allociated dmamap, that was allocated
520 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
521 */
522void
523bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
524{
525	/*
526	 * dmamem does not need to be bounced, so the map should be
527	 * NULL
528	 */
529	if (map != NULL)
530		panic("bus_dmamem_free: Invalid map freed\n");
531	if ((dmat->maxsize <= PAGE_SIZE)
532	 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
533		free(vaddr, M_DEVBUF);
534	else {
535		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
536	}
537	CTR2(KTR_BUSDMA, "bus_dmamem_free: tag %p flags 0x%x", dmat,
538	    dmat->flags);
539}
540
541/*
542 * Utility function to load a linear buffer.  lastaddrp holds state
543 * between invocations (for multiple-buffer loads).  segp contains
544 * the starting segment on entrace, and the ending segment on exit.
545 * first indicates if this is the first invocation of this function.
546 */
547static __inline int
548_bus_dmamap_load_buffer(bus_dma_tag_t dmat,
549    			bus_dmamap_t map,
550			void *buf, bus_size_t buflen,
551			pmap_t pmap,
552			int flags,
553			bus_addr_t *lastaddrp,
554			int *segp,
555			int first)
556{
557	bus_dma_segment_t *segs;
558	bus_size_t sgsize;
559	bus_addr_t curaddr, lastaddr, baddr, bmask;
560	vm_offset_t vaddr;
561	bus_addr_t paddr;
562	int needbounce = 0;
563	int seg;
564
565	segs = dmat->segments;
566
567	if (map == NULL)
568		map = &nobounce_dmamap;
569
570	if ((map != &nobounce_dmamap && map->pagesneeded == 0)
571	 && (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)
572	 || dmat->boundary > 0 || dmat->alignment > 1)) {
573		vm_offset_t	vendaddr;
574
575		CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
576		    "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
577		    dmat->boundary, dmat->alignment);
578		CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
579		    map, &nobounce_dmamap, map->pagesneeded);
580		/*
581		 * Count the number of bounce pages
582		 * needed in order to complete this transfer
583		 */
584		vaddr = trunc_page((vm_offset_t)buf);
585		vendaddr = (vm_offset_t)buf + buflen;
586
587		while (vaddr < vendaddr) {
588			paddr = pmap_kextract(vaddr);
589			if (run_filter(dmat, paddr, 0) != 0) {
590				needbounce = 1;
591				map->pagesneeded++;
592			}
593			vaddr += PAGE_SIZE;
594		}
595		CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
596	}
597
598	/* Reserve Necessary Bounce Pages */
599	if (map->pagesneeded != 0) {
600		mtx_lock(&bounce_lock);
601		if (flags & BUS_DMA_NOWAIT) {
602			if (reserve_bounce_pages(dmat, map, 0) != 0) {
603				mtx_unlock(&bounce_lock);
604				return (ENOMEM);
605			}
606		} else {
607			if (reserve_bounce_pages(dmat, map, 1) != 0) {
608				/* Queue us for resources */
609				map->dmat = dmat;
610				map->buf = buf;
611				map->buflen = buflen;
612				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
613				    map, links);
614				mtx_unlock(&bounce_lock);
615				return (EINPROGRESS);
616			}
617		}
618		mtx_unlock(&bounce_lock);
619	}
620
621	vaddr = (vm_offset_t)buf;
622	lastaddr = *lastaddrp;
623	bmask = ~(dmat->boundary - 1);
624
625	for (seg = *segp; buflen > 0 ; ) {
626		/*
627		 * Get the physical address for this segment.
628		 */
629		if (pmap)
630			curaddr = pmap_extract(pmap, vaddr);
631		else
632			curaddr = pmap_kextract(vaddr);
633
634		/*
635		 * Compute the segment size, and adjust counts.
636		 */
637		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
638		if (buflen < sgsize)
639			sgsize = buflen;
640
641		/*
642		 * Make sure we don't cross any boundaries.
643		 */
644		if (dmat->boundary > 0) {
645			baddr = (curaddr + dmat->boundary) & bmask;
646			if (sgsize > (baddr - curaddr))
647				sgsize = (baddr - curaddr);
648		}
649
650		if (map->pagesneeded != 0 && run_filter(dmat, curaddr, sgsize))
651			curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
652
653		/*
654		 * Insert chunk into a segment, coalescing with
655		 * previous segment if possible.
656		 */
657		if (first) {
658			segs[seg].ds_addr = curaddr;
659			segs[seg].ds_len = sgsize;
660			first = 0;
661		} else {
662			if (needbounce == 0 && curaddr == lastaddr &&
663			    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
664			    (dmat->boundary == 0 ||
665			     (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
666				segs[seg].ds_len += sgsize;
667			else {
668				if (++seg >= dmat->nsegments)
669					break;
670				segs[seg].ds_addr = curaddr;
671				segs[seg].ds_len = sgsize;
672			}
673		}
674
675		lastaddr = curaddr + sgsize;
676		vaddr += sgsize;
677		buflen -= sgsize;
678	}
679
680	*segp = seg;
681	*lastaddrp = lastaddr;
682
683	/*
684	 * Did we fit?
685	 */
686	return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
687}
688
689/*
690 * Map the buffer buf into bus space using the dmamap map.
691 */
692int
693bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
694		bus_size_t buflen, bus_dmamap_callback_t *callback,
695		void *callback_arg, int flags)
696{
697	bus_addr_t		lastaddr = 0;
698	int			error, nsegs = 0;
699
700	if (map != NULL) {
701		flags |= BUS_DMA_WAITOK;
702		map->callback = callback;
703		map->callback_arg = callback_arg;
704	}
705
706	error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
707	     &lastaddr, &nsegs, 1);
708
709	if (error == EINPROGRESS) {
710		CTR3(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x "
711		    "error %d", dmat, dmat->flags, error);
712		return (error);
713	}
714
715	if (error)
716		(*callback)(callback_arg, dmat->segments, 0, error);
717	else
718		(*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
719
720	CTR2(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x error 0",
721	    dmat, dmat->flags);
722	return (0);
723}
724
725
726/*
727 * Like _bus_dmamap_load(), but for mbufs.
728 */
729int
730bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
731		     struct mbuf *m0,
732		     bus_dmamap_callback2_t *callback, void *callback_arg,
733		     int flags)
734{
735	int nsegs, error;
736
737	M_ASSERTPKTHDR(m0);
738
739	flags |= BUS_DMA_NOWAIT;
740	nsegs = 0;
741	error = 0;
742	if (m0->m_pkthdr.len <= dmat->maxsize) {
743		int first = 1;
744		bus_addr_t lastaddr = 0;
745		struct mbuf *m;
746
747		for (m = m0; m != NULL && error == 0; m = m->m_next) {
748			if (m->m_len > 0) {
749				error = _bus_dmamap_load_buffer(dmat, map,
750						m->m_data, m->m_len,
751						NULL, flags, &lastaddr,
752						&nsegs, first);
753				first = 0;
754			}
755		}
756	} else {
757		error = EINVAL;
758	}
759
760	if (error) {
761		/* force "no valid mappings" in callback */
762		(*callback)(callback_arg, dmat->segments, 0, 0, error);
763	} else {
764		(*callback)(callback_arg, dmat->segments,
765			    nsegs+1, m0->m_pkthdr.len, error);
766	}
767	CTR3(KTR_BUSDMA, "bus_dmamap_load_mbuf: tag %p tag flags 0x%x "
768	    "error %d", dmat, dmat->flags, error);
769	return (error);
770}
771
772/*
773 * Like _bus_dmamap_load(), but for uios.
774 */
775int
776bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
777		    struct uio *uio,
778		    bus_dmamap_callback2_t *callback, void *callback_arg,
779		    int flags)
780{
781	bus_addr_t lastaddr;
782	int nsegs, error, first, i;
783	bus_size_t resid;
784	struct iovec *iov;
785	pmap_t pmap;
786
787	flags |= BUS_DMA_NOWAIT;
788	resid = uio->uio_resid;
789	iov = uio->uio_iov;
790
791	if (uio->uio_segflg == UIO_USERSPACE) {
792		KASSERT(uio->uio_td != NULL,
793			("bus_dmamap_load_uio: USERSPACE but no proc"));
794		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
795	} else
796		pmap = NULL;
797
798	nsegs = 0;
799	error = 0;
800	first = 1;
801	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
802		/*
803		 * Now at the first iovec to load.  Load each iovec
804		 * until we have exhausted the residual count.
805		 */
806		bus_size_t minlen =
807			resid < iov[i].iov_len ? resid : iov[i].iov_len;
808		caddr_t addr = (caddr_t) iov[i].iov_base;
809
810		if (minlen > 0) {
811			error = _bus_dmamap_load_buffer(dmat, map,
812					addr, minlen,
813					pmap, flags, &lastaddr, &nsegs, first);
814			first = 0;
815
816			resid -= minlen;
817		}
818	}
819
820	if (error) {
821		/* force "no valid mappings" in callback */
822		(*callback)(callback_arg, dmat->segments, 0, 0, error);
823	} else {
824		(*callback)(callback_arg, dmat->segments,
825			    nsegs+1, uio->uio_resid, error);
826	}
827	CTR3(KTR_BUSDMA, "bus_dmamap_load_uio: tag %p tag flags 0x%x "
828	    "error %d", dmat, dmat->flags, error);
829	return (error);
830}
831
832/*
833 * Release the mapping held by map.
834 */
835void
836_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
837{
838	struct bounce_page *bpage;
839
840	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
841		STAILQ_REMOVE_HEAD(&map->bpages, links);
842		free_bounce_page(dmat, bpage);
843	}
844}
845
846void
847_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
848{
849	struct bounce_page *bpage;
850
851	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
852		/*
853		 * Handle data bouncing.  We might also
854		 * want to add support for invalidating
855		 * the caches on broken hardware
856		 */
857		dmat->bounce_zone->total_bounced++;
858		CTR3(KTR_BUSDMA, "_bus_dmamap_sync: tag %p tag flags 0x%x "
859		    "op 0x%x performing bounce", op, dmat, dmat->flags);
860
861		if (op & BUS_DMASYNC_PREWRITE) {
862			while (bpage != NULL) {
863				bcopy((void *)bpage->datavaddr,
864				      (void *)bpage->vaddr,
865				      bpage->datacount);
866				bpage = STAILQ_NEXT(bpage, links);
867			}
868		}
869
870		if (op & BUS_DMASYNC_POSTREAD) {
871			while (bpage != NULL) {
872				bcopy((void *)bpage->vaddr,
873				      (void *)bpage->datavaddr,
874				      bpage->datacount);
875				bpage = STAILQ_NEXT(bpage, links);
876			}
877		}
878	}
879}
880
881static void
882init_bounce_pages(void *dummy __unused)
883{
884
885	total_bpages = 0;
886	STAILQ_INIT(&bounce_zone_list);
887	STAILQ_INIT(&bounce_map_waitinglist);
888	STAILQ_INIT(&bounce_map_callbacklist);
889	mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
890}
891SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
892
893static struct sysctl_ctx_list *
894busdma_sysctl_tree(struct bounce_zone *bz)
895{
896	return (&bz->sysctl_tree);
897}
898
899static struct sysctl_oid *
900busdma_sysctl_tree_top(struct bounce_zone *bz)
901{
902	return (bz->sysctl_tree_top);
903}
904
905static struct bounce_zone *
906alloc_bounce_zone(bus_dma_tag_t dmat)
907{
908	struct bounce_zone *bz;
909
910	if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
911	    M_NOWAIT | M_ZERO)) == NULL)
912		return (NULL);
913
914	STAILQ_INIT(&bz->bounce_page_list);
915	bz->free_bpages = 0;
916	bz->reserved_bpages = 0;
917	bz->active_bpages = 0;
918	bz->lowaddr = dmat->lowaddr;
919	bz->alignment = dmat->alignment;
920	bz->boundary = dmat->boundary;
921	snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
922	busdma_zonecount++;
923	snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
924	STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
925
926	sysctl_ctx_init(&bz->sysctl_tree);
927	bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
928	    SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
929	    CTLFLAG_RD, 0, "");
930	if (bz->sysctl_tree_top == NULL) {
931		sysctl_ctx_free(&bz->sysctl_tree);
932		return (bz);
933	}
934
935	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
936	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
937	    "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
938	    "Free bounce pages");
939	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
940	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
941	    "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
942	    "Reserved bounce pages");
943	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
944	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
945	    "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
946	    "Active bounce pages");
947	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
948	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
949	    "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
950	    "Total bounce requests");
951	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
952	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
953	    "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
954	    "Total bounce requests that were deferred");
955	SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
956	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
957	    "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
958	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
959	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
960	    "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
961	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
962	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
963	    "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
964
965	return (bz);
966}
967
968static int
969alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
970{
971	struct bounce_zone *bz;
972	int count;
973
974	bz = dmat->bounce_zone;
975	if (bz == NULL) {
976		STAILQ_FOREACH(bz, &bounce_zone_list, links) {
977			if ((dmat->alignment <= bz->alignment)
978			 && (dmat->boundary <= bz->boundary)
979			 && (dmat->lowaddr >= bz->lowaddr))
980				break;
981		}
982
983		if (bz == NULL) {
984			if ((bz = alloc_bounce_zone(dmat)) == NULL)
985				return (ENOMEM);
986		}
987		dmat->bounce_zone = bz;
988	}
989
990	count = 0;
991	while (numpages > 0) {
992		struct bounce_page *bpage;
993
994		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
995						     M_NOWAIT | M_ZERO);
996
997		if (bpage == NULL)
998			break;
999		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1000							 M_NOWAIT, 0ul,
1001							 bz->lowaddr,
1002							 PAGE_SIZE,
1003							 bz->boundary);
1004		if (bpage->vaddr == 0) {
1005			free(bpage, M_DEVBUF);
1006			break;
1007		}
1008		bpage->busaddr = pmap_kextract(bpage->vaddr);
1009		mtx_lock(&bounce_lock);
1010		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1011		total_bpages++;
1012		bz->free_bpages++;
1013		mtx_unlock(&bounce_lock);
1014		count++;
1015		numpages--;
1016	}
1017	return (count);
1018}
1019
1020static int
1021reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1022{
1023	struct bounce_zone *bz;
1024	int pages;
1025
1026	mtx_assert(&bounce_lock, MA_OWNED);
1027	bz = dmat->bounce_zone;
1028	pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1029	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1030		return (map->pagesneeded - (map->pagesreserved + pages));
1031	bz->free_bpages -= pages;
1032	bz->reserved_bpages += pages;
1033	map->pagesreserved += pages;
1034	pages = map->pagesneeded - map->pagesreserved;
1035
1036	return (pages);
1037}
1038
1039static bus_addr_t
1040add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1041		bus_size_t size)
1042{
1043	struct bounce_zone *bz;
1044	struct bounce_page *bpage;
1045
1046	KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1047	KASSERT(map != NULL && map != &nobounce_dmamap,
1048	    ("add_bounce_page: bad map %p", map));
1049
1050	bz = dmat->bounce_zone;
1051	if (map->pagesneeded == 0)
1052		panic("add_bounce_page: map doesn't need any pages");
1053	map->pagesneeded--;
1054
1055	if (map->pagesreserved == 0)
1056		panic("add_bounce_page: map doesn't need any pages");
1057	map->pagesreserved--;
1058
1059	mtx_lock(&bounce_lock);
1060	bpage = STAILQ_FIRST(&bz->bounce_page_list);
1061	if (bpage == NULL)
1062		panic("add_bounce_page: free page list is empty");
1063
1064	STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1065	bz->reserved_bpages--;
1066	bz->active_bpages++;
1067	mtx_unlock(&bounce_lock);
1068
1069	bpage->datavaddr = vaddr;
1070	bpage->datacount = size;
1071	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1072	return (bpage->busaddr);
1073}
1074
1075static void
1076free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1077{
1078	struct bus_dmamap *map;
1079	struct bounce_zone *bz;
1080
1081	bz = dmat->bounce_zone;
1082	bpage->datavaddr = 0;
1083	bpage->datacount = 0;
1084
1085	mtx_lock(&bounce_lock);
1086	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1087	bz->free_bpages++;
1088	bz->active_bpages--;
1089	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1090		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1091			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1092			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1093					   map, links);
1094			busdma_swi_pending = 1;
1095			bz->total_deferred++;
1096			swi_sched(vm_ih, 0);
1097		}
1098	}
1099	mtx_unlock(&bounce_lock);
1100}
1101
1102void
1103busdma_swi(void)
1104{
1105	bus_dma_tag_t dmat;
1106	struct bus_dmamap *map;
1107
1108	mtx_lock(&bounce_lock);
1109	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1110		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1111		mtx_unlock(&bounce_lock);
1112		dmat = map->dmat;
1113		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1114		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1115				map->callback, map->callback_arg, /*flags*/0);
1116		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1117		mtx_lock(&bounce_lock);
1118	}
1119	mtx_unlock(&bounce_lock);
1120}
1121