busdma_machdep.c revision 137965 
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 137965 2004-11-21 04:43:28Z 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		total_bpages;
91	int		free_bpages;
92	int		reserved_bpages;
93	int		active_bpages;
94	int		total_bounced;
95	int		total_deferred;
96	bus_size_t	alignment;
97	bus_size_t	boundary;
98	bus_addr_t	lowaddr;
99	char		zoneid[8];
100	char		lowaddrid[20];
101	struct sysctl_ctx_list sysctl_tree;
102	struct sysctl_oid *sysctl_tree_top;
103};
104
105static struct mtx bounce_lock;
106static int total_bpages;
107static int busdma_zonecount;
108static STAILQ_HEAD(, bounce_zone) bounce_zone_list;
109static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
110
111SYSCTL_NODE(_hw, OID_AUTO, busdma, CTLFLAG_RD, 0, "Busdma parameters");
112SYSCTL_INT(_hw_busdma, OID_AUTO, total_bpages, CTLFLAG_RD, &total_bpages, 0,
113	   "Total bounce pages");
114
115struct bus_dmamap {
116	struct bp_list	       bpages;
117	int		       pagesneeded;
118	int		       pagesreserved;
119	bus_dma_tag_t	       dmat;
120	void		      *buf;		/* unmapped buffer pointer */
121	bus_size_t	       buflen;		/* unmapped buffer length */
122	bus_dmamap_callback_t *callback;
123	void		      *callback_arg;
124	STAILQ_ENTRY(bus_dmamap) links;
125};
126
127static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
128static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
129static struct bus_dmamap nobounce_dmamap;
130
131static void init_bounce_pages(void *dummy);
132static int alloc_bounce_zone(bus_dma_tag_t dmat);
133static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
134static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
135				int commit);
136static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
137				   vm_offset_t vaddr, bus_size_t size);
138static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
139static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
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)
151{
152	int retval;
153
154	retval = 0;
155
156	do {
157		if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
158		 || ((paddr & (dmat->alignment - 1)) != 0))
159		 && (dmat->filter == NULL
160		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
161			retval = 1;
162
163		dmat = dmat->parent;
164	} while (retval == 0 && dmat != NULL);
165	return (retval);
166}
167
168/*
169 * Convenience function for manipulating driver locks from busdma (during
170 * busdma_swi, for example).  Drivers that don't provide their own locks
171 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
172 * non-mutex locking scheme don't have to use this at all.
173 */
174void
175busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
176{
177	struct mtx *dmtx;
178
179	dmtx = (struct mtx *)arg;
180	switch (op) {
181	case BUS_DMA_LOCK:
182		mtx_lock(dmtx);
183		break;
184	case BUS_DMA_UNLOCK:
185		mtx_unlock(dmtx);
186		break;
187	default:
188		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
189	}
190}
191
192/*
193 * dflt_lock should never get called.  It gets put into the dma tag when
194 * lockfunc == NULL, which is only valid if the maps that are associated
195 * with the tag are meant to never be defered.
196 * XXX Should have a way to identify which driver is responsible here.
197 */
198static void
199dflt_lock(void *arg, bus_dma_lock_op_t op)
200{
201	panic("driver error: busdma dflt_lock called");
202}
203
204#define BUS_DMA_COULD_BOUNCE	BUS_DMA_BUS3
205#define BUS_DMA_MIN_ALLOC_COMP	BUS_DMA_BUS4
206/*
207 * Allocate a device specific dma_tag.
208 */
209int
210bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
211		   bus_size_t boundary, bus_addr_t lowaddr,
212		   bus_addr_t highaddr, bus_dma_filter_t *filter,
213		   void *filterarg, bus_size_t maxsize, int nsegments,
214		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
215		   void *lockfuncarg, bus_dma_tag_t *dmat)
216{
217	bus_dma_tag_t newtag;
218	int error = 0;
219
220	/* Basic sanity checking */
221	if (boundary != 0 && boundary < maxsegsz)
222		maxsegsz = boundary;
223
224	/* Return a NULL tag on failure */
225	*dmat = NULL;
226
227	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
228	    M_ZERO | M_NOWAIT);
229	if (newtag == NULL) {
230		CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag "
231		    "flags 0x%x error %d", newtag, 0, error);
232		return (ENOMEM);
233	}
234
235	newtag->parent = parent;
236	newtag->alignment = alignment;
237	newtag->boundary = boundary;
238	newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
239	newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
240	    (PAGE_SIZE - 1);
241	newtag->filter = filter;
242	newtag->filterarg = filterarg;
243	newtag->maxsize = maxsize;
244	newtag->nsegments = nsegments;
245	newtag->maxsegsz = maxsegsz;
246	newtag->flags = flags;
247	newtag->ref_count = 1; /* Count ourself */
248	newtag->map_count = 0;
249	if (lockfunc != NULL) {
250		newtag->lockfunc = lockfunc;
251		newtag->lockfuncarg = lockfuncarg;
252	} else {
253		newtag->lockfunc = dflt_lock;
254		newtag->lockfuncarg = NULL;
255	}
256	newtag->segments = NULL;
257
258	/* Take into account any restrictions imposed by our parent tag */
259	if (parent != NULL) {
260		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
261		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
262		if (newtag->boundary == 0)
263			newtag->boundary = parent->boundary;
264		else if (parent->boundary != 0)
265			newtag->boundary = MIN(parent->boundary,
266					       newtag->boundary);
267		if (newtag->filter == NULL) {
268			/*
269			 * Short circuit looking at our parent directly
270			 * since we have encapsulated all of its information
271			 */
272			newtag->filter = parent->filter;
273			newtag->filterarg = parent->filterarg;
274			newtag->parent = parent->parent;
275		}
276		if (newtag->parent != NULL)
277			atomic_add_int(&parent->ref_count, 1);
278	}
279
280	if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem)
281	 || newtag->alignment > 1 || newtag->boundary > 0)
282		newtag->flags |= BUS_DMA_COULD_BOUNCE;
283
284	if (((newtag->flags & BUS_DMA_COULD_BOUNCE) != 0) &&
285	    (flags & BUS_DMA_ALLOCNOW) != 0) {
286		struct bounce_zone *bz;
287
288		/* Must bounce */
289
290		if ((error = alloc_bounce_zone(newtag)) != 0)
291			return (error);
292		bz = newtag->bounce_zone;
293
294		if (lowaddr > bounce_lowaddr) {
295			/*
296			 * Go through the pool and kill any pages
297			 * that don't reside below lowaddr.
298			 */
299			panic("bus_dma_tag_create: page reallocation "
300			      "not implemented");
301		}
302		if (ptoa(bz->total_bpages) < maxsize) {
303			int pages;
304
305			pages = atop(maxsize) - bz->total_bpages;
306
307			/* Add pages to our bounce pool */
308			if (alloc_bounce_pages(newtag, pages) < pages)
309				error = ENOMEM;
310		}
311		/* Performed initial allocation */
312		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
313	}
314
315	if (error != 0) {
316		free(newtag, M_DEVBUF);
317	} else {
318		*dmat = newtag;
319	}
320	CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag flags 0x%x "
321	    "error %d", newtag, (newtag != NULL ? newtag->flags : 0), error);
322	return (error);
323}
324
325int
326bus_dma_tag_destroy(bus_dma_tag_t dmat)
327{
328	bus_dma_tag_t dmat_copy;
329	int error;
330
331	error = 0;
332	dmat_copy = dmat;
333
334	if (dmat != NULL) {
335
336		if (dmat->map_count != 0) {
337			error = EBUSY;
338			goto out;
339		}
340
341		while (dmat != NULL) {
342			bus_dma_tag_t parent;
343
344			parent = dmat->parent;
345			atomic_subtract_int(&dmat->ref_count, 1);
346			if (dmat->ref_count == 0) {
347				if (dmat->segments != NULL)
348					free(dmat->segments, M_DEVBUF);
349				free(dmat, M_DEVBUF);
350				/*
351				 * Last reference count, so
352				 * release our reference
353				 * count on our parent.
354				 */
355				dmat = parent;
356			} else
357				dmat = NULL;
358		}
359	}
360out:
361	CTR2(KTR_BUSDMA, "bus_dma_tag_destroy tag %p error %d", dmat_copy,
362	    error);
363	return (error);
364}
365
366/*
367 * Allocate a handle for mapping from kva/uva/physical
368 * address space into bus device space.
369 */
370int
371bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
372{
373	int error;
374
375	error = 0;
376
377	if (dmat->segments == NULL) {
378		dmat->segments = (bus_dma_segment_t *)malloc(
379		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
380		    M_NOWAIT);
381		if (dmat->segments == NULL) {
382			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
383			    dmat, ENOMEM);
384			return (ENOMEM);
385		}
386	}
387
388	/*
389	 * Bouncing might be required if the driver asks for an active
390	 * exclusion region, a data alignment that is stricter than 1, and/or
391	 * an active address boundary.
392	 */
393	if (dmat->flags & BUS_DMA_COULD_BOUNCE) {
394
395		/* Must bounce */
396		int maxpages;
397
398		if (dmat->bounce_zone == NULL) {
399			if ((error = alloc_bounce_zone(dmat)) != 0)
400				return (error);
401		}
402
403		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
404					     M_NOWAIT | M_ZERO);
405		if (*mapp == NULL) {
406			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
407			    dmat, ENOMEM);
408			return (ENOMEM);
409		}
410
411		/* Initialize the new map */
412		STAILQ_INIT(&((*mapp)->bpages));
413
414		/*
415		 * Attempt to add pages to our pool on a per-instance
416		 * basis up to a sane limit.
417		 */
418		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
419		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
420		 || (dmat->map_count > 0 && total_bpages < maxpages)) {
421			int pages;
422
423			if (dmat->lowaddr > bounce_lowaddr) {
424				/*
425				 * Go through the pool and kill any pages
426				 * that don't reside below lowaddr.
427				 */
428				panic("bus_dmamap_create: page reallocation "
429				      "not implemented");
430			}
431			pages = MAX(atop(dmat->maxsize), 1);
432			pages = MIN(maxpages - total_bpages, pages);
433			if (alloc_bounce_pages(dmat, pages) < pages)
434				error = ENOMEM;
435
436			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
437				if (error == 0)
438					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
439			} else {
440				error = 0;
441			}
442		}
443	} else {
444		*mapp = NULL;
445	}
446	if (error == 0)
447		dmat->map_count++;
448	CTR3(KTR_BUSDMA, "bus_dmamap_create: tag %p tag flags 0x%x error %d",
449	    dmat, dmat->flags, error);
450	return (error);
451}
452
453/*
454 * Destroy a handle for mapping from kva/uva/physical
455 * address space into bus device space.
456 */
457int
458bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
459{
460	if (map != NULL && map != &nobounce_dmamap) {
461		if (STAILQ_FIRST(&map->bpages) != NULL) {
462			CTR2(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error %d",
463			    dmat, EBUSY);
464			return (EBUSY);
465		}
466		free(map, M_DEVBUF);
467	}
468	dmat->map_count--;
469	CTR1(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error 0", dmat);
470	return (0);
471}
472
473
474/*
475 * Allocate a piece of memory that can be efficiently mapped into
476 * bus device space based on the constraints lited in the dma tag.
477 * A dmamap to for use with dmamap_load is also allocated.
478 */
479int
480bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
481		 bus_dmamap_t *mapp)
482{
483	int mflags;
484
485	if (flags & BUS_DMA_NOWAIT)
486		mflags = M_NOWAIT;
487	else
488		mflags = M_WAITOK;
489	if (flags & BUS_DMA_ZERO)
490		mflags |= M_ZERO;
491
492	/* If we succeed, no mapping/bouncing will be required */
493	*mapp = NULL;
494
495	if (dmat->segments == NULL) {
496		dmat->segments = (bus_dma_segment_t *)malloc(
497		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
498		    M_NOWAIT);
499		if (dmat->segments == NULL) {
500			CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag "
501			    "flags 0x%x error %d", dmat, dmat->flags, ENOMEM);
502			return (ENOMEM);
503		}
504	}
505
506	if ((dmat->maxsize <= PAGE_SIZE) &&
507	    dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
508		*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
509	} else {
510		/*
511		 * XXX Use Contigmalloc until it is merged into this facility
512		 *     and handles multi-seg allocations.  Nobody is doing
513		 *     multi-seg allocations yet though.
514		 * XXX Certain AGP hardware does.
515		 */
516		*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
517		    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
518		    dmat->boundary);
519	}
520	if (*vaddr == NULL) {
521		CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x "
522		    "error %d", dmat, dmat->flags, ENOMEM);
523		return (ENOMEM);
524	}
525	CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x error %d",
526	    dmat, dmat->flags, ENOMEM);
527	return (0);
528}
529
530/*
531 * Free a piece of memory and it's allociated dmamap, that was allocated
532 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
533 */
534void
535bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
536{
537	/*
538	 * dmamem does not need to be bounced, so the map should be
539	 * NULL
540	 */
541	if (map != NULL)
542		panic("bus_dmamem_free: Invalid map freed\n");
543	if ((dmat->maxsize <= PAGE_SIZE)
544	 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
545		free(vaddr, M_DEVBUF);
546	else {
547		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
548	}
549	CTR2(KTR_BUSDMA, "bus_dmamem_free: tag %p flags 0x%x", dmat,
550	    dmat->flags);
551}
552
553/*
554 * Utility function to load a linear buffer.  lastaddrp holds state
555 * between invocations (for multiple-buffer loads).  segp contains
556 * the starting segment on entrace, and the ending segment on exit.
557 * first indicates if this is the first invocation of this function.
558 */
559static __inline int
560_bus_dmamap_load_buffer(bus_dma_tag_t dmat,
561    			bus_dmamap_t map,
562			void *buf, bus_size_t buflen,
563			pmap_t pmap,
564			int flags,
565			bus_addr_t *lastaddrp,
566			int *segp,
567			int first)
568{
569	bus_dma_segment_t *segs;
570	bus_size_t sgsize;
571	bus_addr_t curaddr, lastaddr, baddr, bmask;
572	vm_offset_t vaddr;
573	bus_addr_t paddr;
574	int needbounce = 0;
575	int seg;
576
577	segs = dmat->segments;
578
579	if (map == NULL)
580		map = &nobounce_dmamap;
581
582	if ((map != &nobounce_dmamap && map->pagesneeded == 0)
583	 && ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0)) {
584		vm_offset_t	vendaddr;
585
586		CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
587		    "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
588		    dmat->boundary, dmat->alignment);
589		CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
590		    map, &nobounce_dmamap, map->pagesneeded);
591		/*
592		 * Count the number of bounce pages
593		 * needed in order to complete this transfer
594		 */
595		vaddr = trunc_page((vm_offset_t)buf);
596		vendaddr = (vm_offset_t)buf + buflen;
597
598		while (vaddr < vendaddr) {
599			paddr = pmap_kextract(vaddr);
600			if (run_filter(dmat, paddr) != 0) {
601				needbounce = 1;
602				map->pagesneeded++;
603			}
604			vaddr += PAGE_SIZE;
605		}
606		CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
607	}
608
609	/* Reserve Necessary Bounce Pages */
610	if (map->pagesneeded != 0) {
611		mtx_lock(&bounce_lock);
612		if (flags & BUS_DMA_NOWAIT) {
613			if (reserve_bounce_pages(dmat, map, 0) != 0) {
614				mtx_unlock(&bounce_lock);
615				return (ENOMEM);
616			}
617		} else {
618			if (reserve_bounce_pages(dmat, map, 1) != 0) {
619				/* Queue us for resources */
620				map->dmat = dmat;
621				map->buf = buf;
622				map->buflen = buflen;
623				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
624				    map, links);
625				mtx_unlock(&bounce_lock);
626				return (EINPROGRESS);
627			}
628		}
629		mtx_unlock(&bounce_lock);
630	}
631
632	vaddr = (vm_offset_t)buf;
633	lastaddr = *lastaddrp;
634	bmask = ~(dmat->boundary - 1);
635
636	for (seg = *segp; buflen > 0 ; ) {
637		/*
638		 * Get the physical address for this segment.
639		 */
640		if (pmap)
641			curaddr = pmap_extract(pmap, vaddr);
642		else
643			curaddr = pmap_kextract(vaddr);
644
645		/*
646		 * Compute the segment size, and adjust counts.
647		 */
648		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
649		if (buflen < sgsize)
650			sgsize = buflen;
651
652		/*
653		 * Make sure we don't cross any boundaries.
654		 */
655		if (dmat->boundary > 0) {
656			baddr = (curaddr + dmat->boundary) & bmask;
657			if (sgsize > (baddr - curaddr))
658				sgsize = (baddr - curaddr);
659		}
660
661		if (map->pagesneeded != 0 && run_filter(dmat, curaddr))
662			curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
663
664		/*
665		 * Insert chunk into a segment, coalescing with
666		 * previous segment if possible.
667		 */
668		if (first) {
669			segs[seg].ds_addr = curaddr;
670			segs[seg].ds_len = sgsize;
671			first = 0;
672		} else {
673			if (needbounce == 0 && curaddr == lastaddr &&
674			    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
675			    (dmat->boundary == 0 ||
676			     (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
677				segs[seg].ds_len += sgsize;
678			else {
679				if (++seg >= dmat->nsegments)
680					break;
681				segs[seg].ds_addr = curaddr;
682				segs[seg].ds_len = sgsize;
683			}
684		}
685
686		lastaddr = curaddr + sgsize;
687		vaddr += sgsize;
688		buflen -= sgsize;
689	}
690
691	*segp = seg;
692	*lastaddrp = lastaddr;
693
694	/*
695	 * Did we fit?
696	 */
697	return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
698}
699
700/*
701 * Map the buffer buf into bus space using the dmamap map.
702 */
703int
704bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
705		bus_size_t buflen, bus_dmamap_callback_t *callback,
706		void *callback_arg, int flags)
707{
708	bus_addr_t		lastaddr = 0;
709	int			error, nsegs = 0;
710
711	if (map != NULL) {
712		flags |= BUS_DMA_WAITOK;
713		map->callback = callback;
714		map->callback_arg = callback_arg;
715	}
716
717	error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
718	     &lastaddr, &nsegs, 1);
719
720	if (error == EINPROGRESS) {
721		CTR3(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x "
722		    "error %d", dmat, dmat->flags, error);
723		return (error);
724	}
725
726	if (error)
727		(*callback)(callback_arg, dmat->segments, 0, error);
728	else
729		(*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
730
731	CTR2(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x error 0",
732	    dmat, dmat->flags);
733	return (0);
734}
735
736
737/*
738 * Like _bus_dmamap_load(), but for mbufs.
739 */
740int
741bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
742		     struct mbuf *m0,
743		     bus_dmamap_callback2_t *callback, void *callback_arg,
744		     int flags)
745{
746	int nsegs, error;
747
748	M_ASSERTPKTHDR(m0);
749
750	flags |= BUS_DMA_NOWAIT;
751	nsegs = 0;
752	error = 0;
753	if (m0->m_pkthdr.len <= dmat->maxsize) {
754		int first = 1;
755		bus_addr_t lastaddr = 0;
756		struct mbuf *m;
757
758		for (m = m0; m != NULL && error == 0; m = m->m_next) {
759			if (m->m_len > 0) {
760				error = _bus_dmamap_load_buffer(dmat, map,
761						m->m_data, m->m_len,
762						NULL, flags, &lastaddr,
763						&nsegs, first);
764				first = 0;
765			}
766		}
767	} else {
768		error = EINVAL;
769	}
770
771	if (error) {
772		/* force "no valid mappings" in callback */
773		(*callback)(callback_arg, dmat->segments, 0, 0, error);
774	} else {
775		(*callback)(callback_arg, dmat->segments,
776			    nsegs+1, m0->m_pkthdr.len, error);
777	}
778	CTR3(KTR_BUSDMA, "bus_dmamap_load_mbuf: tag %p tag flags 0x%x "
779	    "error %d", dmat, dmat->flags, error);
780	return (error);
781}
782
783/*
784 * Like _bus_dmamap_load(), but for uios.
785 */
786int
787bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
788		    struct uio *uio,
789		    bus_dmamap_callback2_t *callback, void *callback_arg,
790		    int flags)
791{
792	bus_addr_t lastaddr;
793	int nsegs, error, first, i;
794	bus_size_t resid;
795	struct iovec *iov;
796	pmap_t pmap;
797
798	flags |= BUS_DMA_NOWAIT;
799	resid = uio->uio_resid;
800	iov = uio->uio_iov;
801
802	if (uio->uio_segflg == UIO_USERSPACE) {
803		KASSERT(uio->uio_td != NULL,
804			("bus_dmamap_load_uio: USERSPACE but no proc"));
805		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
806	} else
807		pmap = NULL;
808
809	nsegs = 0;
810	error = 0;
811	first = 1;
812	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
813		/*
814		 * Now at the first iovec to load.  Load each iovec
815		 * until we have exhausted the residual count.
816		 */
817		bus_size_t minlen =
818			resid < iov[i].iov_len ? resid : iov[i].iov_len;
819		caddr_t addr = (caddr_t) iov[i].iov_base;
820
821		if (minlen > 0) {
822			error = _bus_dmamap_load_buffer(dmat, map,
823					addr, minlen,
824					pmap, flags, &lastaddr, &nsegs, first);
825			first = 0;
826
827			resid -= minlen;
828		}
829	}
830
831	if (error) {
832		/* force "no valid mappings" in callback */
833		(*callback)(callback_arg, dmat->segments, 0, 0, error);
834	} else {
835		(*callback)(callback_arg, dmat->segments,
836			    nsegs+1, uio->uio_resid, error);
837	}
838	CTR3(KTR_BUSDMA, "bus_dmamap_load_uio: tag %p tag flags 0x%x "
839	    "error %d", dmat, dmat->flags, error);
840	return (error);
841}
842
843/*
844 * Release the mapping held by map.
845 */
846void
847_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
848{
849	struct bounce_page *bpage;
850
851	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
852		STAILQ_REMOVE_HEAD(&map->bpages, links);
853		free_bounce_page(dmat, bpage);
854	}
855}
856
857void
858_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
859{
860	struct bounce_page *bpage;
861
862	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
863		/*
864		 * Handle data bouncing.  We might also
865		 * want to add support for invalidating
866		 * the caches on broken hardware
867		 */
868		dmat->bounce_zone->total_bounced++;
869		CTR3(KTR_BUSDMA, "_bus_dmamap_sync: tag %p tag flags 0x%x "
870		    "op 0x%x performing bounce", op, dmat, dmat->flags);
871
872		if (op & BUS_DMASYNC_PREWRITE) {
873			while (bpage != NULL) {
874				bcopy((void *)bpage->datavaddr,
875				      (void *)bpage->vaddr,
876				      bpage->datacount);
877				bpage = STAILQ_NEXT(bpage, links);
878			}
879		}
880
881		if (op & BUS_DMASYNC_POSTREAD) {
882			while (bpage != NULL) {
883				bcopy((void *)bpage->vaddr,
884				      (void *)bpage->datavaddr,
885				      bpage->datacount);
886				bpage = STAILQ_NEXT(bpage, links);
887			}
888		}
889	}
890}
891
892static void
893init_bounce_pages(void *dummy __unused)
894{
895
896	total_bpages = 0;
897	STAILQ_INIT(&bounce_zone_list);
898	STAILQ_INIT(&bounce_map_waitinglist);
899	STAILQ_INIT(&bounce_map_callbacklist);
900	mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
901}
902SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
903
904static struct sysctl_ctx_list *
905busdma_sysctl_tree(struct bounce_zone *bz)
906{
907	return (&bz->sysctl_tree);
908}
909
910static struct sysctl_oid *
911busdma_sysctl_tree_top(struct bounce_zone *bz)
912{
913	return (bz->sysctl_tree_top);
914}
915
916static int
917alloc_bounce_zone(bus_dma_tag_t dmat)
918{
919	struct bounce_zone *bz;
920
921	/* Check to see if we already have a suitable zone */
922	STAILQ_FOREACH(bz, &bounce_zone_list, links) {
923		if ((dmat->alignment <= bz->alignment)
924		 && (dmat->boundary <= bz->boundary)
925		 && (dmat->lowaddr >= bz->lowaddr)) {
926			dmat->bounce_zone = bz;
927			return (0);
928		}
929	}
930
931	if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
932	    M_NOWAIT | M_ZERO)) == NULL)
933		return (ENOMEM);
934
935	STAILQ_INIT(&bz->bounce_page_list);
936	bz->free_bpages = 0;
937	bz->reserved_bpages = 0;
938	bz->active_bpages = 0;
939	bz->lowaddr = dmat->lowaddr;
940	bz->alignment = dmat->alignment;
941	bz->boundary = dmat->boundary;
942	snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
943	busdma_zonecount++;
944	snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
945	STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
946	dmat->bounce_zone = bz;
947
948	sysctl_ctx_init(&bz->sysctl_tree);
949	bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
950	    SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
951	    CTLFLAG_RD, 0, "");
952	if (bz->sysctl_tree_top == NULL) {
953		sysctl_ctx_free(&bz->sysctl_tree);
954		return (0);	/* XXX error code? */
955	}
956
957	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
958	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
959	    "total_bpages", CTLFLAG_RD, &bz->total_bpages, 0,
960	    "Totoal bounce pages");
961	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
962	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
963	    "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
964	    "Free bounce pages");
965	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
966	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
967	    "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
968	    "Reserved bounce pages");
969	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
970	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
971	    "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
972	    "Active bounce pages");
973	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
974	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
975	    "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
976	    "Total bounce requests");
977	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
978	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
979	    "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
980	    "Total bounce requests that were deferred");
981	SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
982	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
983	    "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
984	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
985	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
986	    "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
987	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
988	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
989	    "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
990
991	return (0);
992}
993
994static int
995alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
996{
997	struct bounce_zone *bz;
998	int count;
999
1000	bz = dmat->bounce_zone;
1001	count = 0;
1002	while (numpages > 0) {
1003		struct bounce_page *bpage;
1004
1005		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
1006						     M_NOWAIT | M_ZERO);
1007
1008		if (bpage == NULL)
1009			break;
1010		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
1011							 M_NOWAIT, 0ul,
1012							 bz->lowaddr,
1013							 PAGE_SIZE,
1014							 bz->boundary);
1015		if (bpage->vaddr == 0) {
1016			free(bpage, M_DEVBUF);
1017			break;
1018		}
1019		bpage->busaddr = pmap_kextract(bpage->vaddr);
1020		mtx_lock(&bounce_lock);
1021		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1022		total_bpages++;
1023		bz->total_bpages++;
1024		bz->free_bpages++;
1025		mtx_unlock(&bounce_lock);
1026		count++;
1027		numpages--;
1028	}
1029	return (count);
1030}
1031
1032static int
1033reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1034{
1035	struct bounce_zone *bz;
1036	int pages;
1037
1038	mtx_assert(&bounce_lock, MA_OWNED);
1039	bz = dmat->bounce_zone;
1040	pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1041	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1042		return (map->pagesneeded - (map->pagesreserved + pages));
1043	bz->free_bpages -= pages;
1044	bz->reserved_bpages += pages;
1045	map->pagesreserved += pages;
1046	pages = map->pagesneeded - map->pagesreserved;
1047
1048	return (pages);
1049}
1050
1051static bus_addr_t
1052add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1053		bus_size_t size)
1054{
1055	struct bounce_zone *bz;
1056	struct bounce_page *bpage;
1057
1058	KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1059	KASSERT(map != NULL && map != &nobounce_dmamap,
1060	    ("add_bounce_page: bad map %p", map));
1061
1062	bz = dmat->bounce_zone;
1063	if (map->pagesneeded == 0)
1064		panic("add_bounce_page: map doesn't need any pages");
1065	map->pagesneeded--;
1066
1067	if (map->pagesreserved == 0)
1068		panic("add_bounce_page: map doesn't need any pages");
1069	map->pagesreserved--;
1070
1071	mtx_lock(&bounce_lock);
1072	bpage = STAILQ_FIRST(&bz->bounce_page_list);
1073	if (bpage == NULL)
1074		panic("add_bounce_page: free page list is empty");
1075
1076	STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1077	bz->reserved_bpages--;
1078	bz->active_bpages++;
1079	mtx_unlock(&bounce_lock);
1080
1081	bpage->datavaddr = vaddr;
1082	bpage->datacount = size;
1083	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1084	return (bpage->busaddr);
1085}
1086
1087static void
1088free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1089{
1090	struct bus_dmamap *map;
1091	struct bounce_zone *bz;
1092
1093	bz = dmat->bounce_zone;
1094	bpage->datavaddr = 0;
1095	bpage->datacount = 0;
1096
1097	mtx_lock(&bounce_lock);
1098	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1099	bz->free_bpages++;
1100	bz->active_bpages--;
1101	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1102		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1103			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1104			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1105					   map, links);
1106			busdma_swi_pending = 1;
1107			bz->total_deferred++;
1108			swi_sched(vm_ih, 0);
1109		}
1110	}
1111	mtx_unlock(&bounce_lock);
1112}
1113
1114void
1115busdma_swi(void)
1116{
1117	bus_dma_tag_t dmat;
1118	struct bus_dmamap *map;
1119
1120	mtx_lock(&bounce_lock);
1121	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1122		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1123		mtx_unlock(&bounce_lock);
1124		dmat = map->dmat;
1125		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1126		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1127				map->callback, map->callback_arg, /*flags*/0);
1128		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1129		mtx_lock(&bounce_lock);
1130	}
1131	mtx_unlock(&bounce_lock);
1132}
1133