busdma_machdep.c revision 137894 
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 137894 2004-11-19 17:56:22Z 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
140/*
141 * Return true if a match is made.
142 *
143 * To find a match walk the chain of bus_dma_tag_t's looking for 'paddr'.
144 *
145 * If paddr is within the bounds of the dma tag then call the filter callback
146 * to check for a match, if there is no filter callback then assume a match.
147 */
148static __inline int
149run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
150{
151	int retval;
152
153	retval = 0;
154
155	do {
156		if (((paddr > dmat->lowaddr && paddr <= dmat->highaddr)
157		 || ((paddr & (dmat->alignment - 1)) != 0))
158		 && (dmat->filter == NULL
159		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
160			retval = 1;
161
162		dmat = dmat->parent;
163	} while (retval == 0 && dmat != NULL);
164	return (retval);
165}
166
167/*
168 * Convenience function for manipulating driver locks from busdma (during
169 * busdma_swi, for example).  Drivers that don't provide their own locks
170 * should specify &Giant to dmat->lockfuncarg.  Drivers that use their own
171 * non-mutex locking scheme don't have to use this at all.
172 */
173void
174busdma_lock_mutex(void *arg, bus_dma_lock_op_t op)
175{
176	struct mtx *dmtx;
177
178	dmtx = (struct mtx *)arg;
179	switch (op) {
180	case BUS_DMA_LOCK:
181		mtx_lock(dmtx);
182		break;
183	case BUS_DMA_UNLOCK:
184		mtx_unlock(dmtx);
185		break;
186	default:
187		panic("Unknown operation 0x%x for busdma_lock_mutex!", op);
188	}
189}
190
191/*
192 * dflt_lock should never get called.  It gets put into the dma tag when
193 * lockfunc == NULL, which is only valid if the maps that are associated
194 * with the tag are meant to never be defered.
195 * XXX Should have a way to identify which driver is responsible here.
196 */
197static void
198dflt_lock(void *arg, bus_dma_lock_op_t op)
199{
200	panic("driver error: busdma dflt_lock called");
201}
202
203#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
204/*
205 * Allocate a device specific dma_tag.
206 */
207int
208bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
209		   bus_size_t boundary, bus_addr_t lowaddr,
210		   bus_addr_t highaddr, bus_dma_filter_t *filter,
211		   void *filterarg, bus_size_t maxsize, int nsegments,
212		   bus_size_t maxsegsz, int flags, bus_dma_lock_t *lockfunc,
213		   void *lockfuncarg, bus_dma_tag_t *dmat)
214{
215	bus_dma_tag_t newtag;
216	int error = 0;
217
218	/* Basic sanity checking */
219	if (boundary != 0 && boundary < maxsegsz)
220		maxsegsz = boundary;
221
222	/* Return a NULL tag on failure */
223	*dmat = NULL;
224
225	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF,
226	    M_ZERO | M_NOWAIT);
227	if (newtag == NULL) {
228		CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag "
229		    "flags 0x%x error %d", newtag, 0, error);
230		return (ENOMEM);
231	}
232
233	newtag->parent = parent;
234	newtag->alignment = alignment;
235	newtag->boundary = boundary;
236	newtag->lowaddr = trunc_page((vm_paddr_t)lowaddr) + (PAGE_SIZE - 1);
237	newtag->highaddr = trunc_page((vm_paddr_t)highaddr) +
238	    (PAGE_SIZE - 1);
239	newtag->filter = filter;
240	newtag->filterarg = filterarg;
241	newtag->maxsize = maxsize;
242	newtag->nsegments = nsegments;
243	newtag->maxsegsz = maxsegsz;
244	newtag->flags = flags;
245	newtag->ref_count = 1; /* Count ourself */
246	newtag->map_count = 0;
247	if (lockfunc != NULL) {
248		newtag->lockfunc = lockfunc;
249		newtag->lockfuncarg = lockfuncarg;
250	} else {
251		newtag->lockfunc = dflt_lock;
252		newtag->lockfuncarg = NULL;
253	}
254	newtag->segments = NULL;
255
256	/* Take into account any restrictions imposed by our parent tag */
257	if (parent != NULL) {
258		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
259		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
260		if (newtag->boundary == 0)
261			newtag->boundary = parent->boundary;
262		else if (parent->boundary != 0)
263			newtag->boundary = MIN(parent->boundary,
264					       newtag->boundary);
265		if (newtag->filter == NULL) {
266			/*
267			 * Short circuit looking at our parent directly
268			 * since we have encapsulated all of its information
269			 */
270			newtag->filter = parent->filter;
271			newtag->filterarg = parent->filterarg;
272			newtag->parent = parent->parent;
273		}
274		if (newtag->parent != NULL)
275			atomic_add_int(&parent->ref_count, 1);
276	}
277
278	if (newtag->lowaddr < ptoa((vm_paddr_t)Maxmem) &&
279	    (flags & BUS_DMA_ALLOCNOW) != 0) {
280		/* Must bounce */
281
282		if (lowaddr > bounce_lowaddr) {
283			/*
284			 * Go through the pool and kill any pages
285			 * that don't reside below lowaddr.
286			 */
287			panic("bus_dma_tag_create: page reallocation "
288			      "not implemented");
289		}
290		if (ptoa(total_bpages) < maxsize) {
291			int pages;
292
293			pages = atop(maxsize) - total_bpages;
294
295			/* Add pages to our bounce pool */
296			if (alloc_bounce_pages(newtag, pages) < pages)
297				error = ENOMEM;
298		}
299		/* Performed initial allocation */
300		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
301	}
302
303	if (error != 0) {
304		free(newtag, M_DEVBUF);
305	} else {
306		*dmat = newtag;
307	}
308	CTR3(KTR_BUSDMA, "bus_dma_tag_create returned tag %p tag flags 0x%x "
309	    "error %d", newtag, (newtag != NULL ? newtag->flags : 0), error);
310	return (error);
311}
312
313int
314bus_dma_tag_destroy(bus_dma_tag_t dmat)
315{
316	bus_dma_tag_t dmat_copy;
317	int error;
318
319	error = 0;
320	dmat_copy = dmat;
321
322	if (dmat != NULL) {
323
324		if (dmat->map_count != 0) {
325			error = EBUSY;
326			goto out;
327		}
328
329		while (dmat != NULL) {
330			bus_dma_tag_t parent;
331
332			parent = dmat->parent;
333			atomic_subtract_int(&dmat->ref_count, 1);
334			if (dmat->ref_count == 0) {
335				if (dmat->segments != NULL)
336					free(dmat->segments, M_DEVBUF);
337				free(dmat, M_DEVBUF);
338				/*
339				 * Last reference count, so
340				 * release our reference
341				 * count on our parent.
342				 */
343				dmat = parent;
344			} else
345				dmat = NULL;
346		}
347	}
348out:
349	CTR2(KTR_BUSDMA, "bus_dma_tag_destroy tag %p error %d", dmat_copy,
350	    error);
351	return (error);
352}
353
354/*
355 * Allocate a handle for mapping from kva/uva/physical
356 * address space into bus device space.
357 */
358int
359bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
360{
361	int error;
362
363	error = 0;
364
365	if (dmat->segments == NULL) {
366		dmat->segments = (bus_dma_segment_t *)malloc(
367		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
368		    M_NOWAIT);
369		if (dmat->segments == NULL) {
370			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
371			    dmat, ENOMEM);
372			return (ENOMEM);
373		}
374	}
375
376	/*
377	 * Bouncing might be required if the driver asks for an active
378	 * exclusion region, a data alignment that is stricter than 1, and/or
379	 * an active address boundary.
380	 */
381	if (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)
382	 || dmat->alignment > 1 || dmat->boundary > 0) {
383
384		/* Must bounce */
385		int maxpages;
386
387		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
388					     M_NOWAIT | M_ZERO);
389		if (*mapp == NULL) {
390			CTR2(KTR_BUSDMA, "bus_dmamap_create: tag %p error %d",
391			    dmat, ENOMEM);
392			return (ENOMEM);
393		}
394
395		/* Initialize the new map */
396		STAILQ_INIT(&((*mapp)->bpages));
397
398		/*
399		 * Attempt to add pages to our pool on a per-instance
400		 * basis up to a sane limit.
401		 */
402		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
403		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
404		 || (dmat->map_count > 0 && total_bpages < maxpages)) {
405			int pages;
406
407			if (dmat->lowaddr > bounce_lowaddr) {
408				/*
409				 * Go through the pool and kill any pages
410				 * that don't reside below lowaddr.
411				 */
412				panic("bus_dmamap_create: page reallocation "
413				      "not implemented");
414			}
415			pages = MAX(atop(dmat->maxsize), 1);
416			pages = MIN(maxpages - total_bpages, pages);
417			if (alloc_bounce_pages(dmat, pages) < pages)
418				error = ENOMEM;
419
420			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
421				if (error == 0)
422					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
423			} else {
424				error = 0;
425			}
426		}
427	} else {
428		*mapp = NULL;
429	}
430	if (error == 0)
431		dmat->map_count++;
432	CTR3(KTR_BUSDMA, "bus_dmamap_create: tag %p tag flags 0x%x error %d",
433	    dmat, dmat->flags, error);
434	return (error);
435}
436
437/*
438 * Destroy a handle for mapping from kva/uva/physical
439 * address space into bus device space.
440 */
441int
442bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
443{
444	if (map != NULL && map != &nobounce_dmamap) {
445		if (STAILQ_FIRST(&map->bpages) != NULL) {
446			CTR2(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error %d",
447			    dmat, EBUSY);
448			return (EBUSY);
449		}
450		free(map, M_DEVBUF);
451	}
452	dmat->map_count--;
453	CTR1(KTR_BUSDMA, "bus_dmamap_destroy: tag %p error 0", dmat);
454	return (0);
455}
456
457
458/*
459 * Allocate a piece of memory that can be efficiently mapped into
460 * bus device space based on the constraints lited in the dma tag.
461 * A dmamap to for use with dmamap_load is also allocated.
462 */
463int
464bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
465		 bus_dmamap_t *mapp)
466{
467	int mflags;
468
469	if (flags & BUS_DMA_NOWAIT)
470		mflags = M_NOWAIT;
471	else
472		mflags = M_WAITOK;
473	if (flags & BUS_DMA_ZERO)
474		mflags |= M_ZERO;
475
476	/* If we succeed, no mapping/bouncing will be required */
477	*mapp = NULL;
478
479	if (dmat->segments == NULL) {
480		dmat->segments = (bus_dma_segment_t *)malloc(
481		    sizeof(bus_dma_segment_t) * dmat->nsegments, M_DEVBUF,
482		    M_NOWAIT);
483		if (dmat->segments == NULL) {
484			CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag "
485			    "flags 0x%x error %d", dmat, dmat->flags, ENOMEM);
486			return (ENOMEM);
487		}
488	}
489
490	if ((dmat->maxsize <= PAGE_SIZE) &&
491	    dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
492		*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
493	} else {
494		/*
495		 * XXX Use Contigmalloc until it is merged into this facility
496		 *     and handles multi-seg allocations.  Nobody is doing
497		 *     multi-seg allocations yet though.
498		 * XXX Certain AGP hardware does.
499		 */
500		*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
501		    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
502		    dmat->boundary);
503	}
504	if (*vaddr == NULL) {
505		CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x "
506		    "error %d", dmat, dmat->flags, ENOMEM);
507		return (ENOMEM);
508	}
509	CTR3(KTR_BUSDMA, "bus_dmamem_alloc: tag %p tag flags 0x%x error %d",
510	    dmat, dmat->flags, ENOMEM);
511	return (0);
512}
513
514/*
515 * Free a piece of memory and it's allociated dmamap, that was allocated
516 * via bus_dmamem_alloc.  Make the same choice for free/contigfree.
517 */
518void
519bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
520{
521	/*
522	 * dmamem does not need to be bounced, so the map should be
523	 * NULL
524	 */
525	if (map != NULL)
526		panic("bus_dmamem_free: Invalid map freed\n");
527	if ((dmat->maxsize <= PAGE_SIZE)
528	 && dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
529		free(vaddr, M_DEVBUF);
530	else {
531		contigfree(vaddr, dmat->maxsize, M_DEVBUF);
532	}
533	CTR2(KTR_BUSDMA, "bus_dmamem_free: tag %p flags 0x%x", dmat,
534	    dmat->flags);
535}
536
537/*
538 * Utility function to load a linear buffer.  lastaddrp holds state
539 * between invocations (for multiple-buffer loads).  segp contains
540 * the starting segment on entrace, and the ending segment on exit.
541 * first indicates if this is the first invocation of this function.
542 */
543static __inline int
544_bus_dmamap_load_buffer(bus_dma_tag_t dmat,
545    			bus_dmamap_t map,
546			void *buf, bus_size_t buflen,
547			pmap_t pmap,
548			int flags,
549			bus_addr_t *lastaddrp,
550			int *segp,
551			int first)
552{
553	bus_dma_segment_t *segs;
554	bus_size_t sgsize;
555	bus_addr_t curaddr, lastaddr, baddr, bmask;
556	vm_offset_t vaddr;
557	bus_addr_t paddr;
558	int needbounce = 0;
559	int seg;
560
561	segs = dmat->segments;
562
563	if (map == NULL)
564		map = &nobounce_dmamap;
565
566	if ((map != &nobounce_dmamap && map->pagesneeded == 0)
567	 && (dmat->lowaddr < ptoa((vm_paddr_t)Maxmem)
568	 || dmat->boundary > 0 || dmat->alignment > 1)) {
569		vm_offset_t	vendaddr;
570
571		CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
572		    "alignment= %d", dmat->lowaddr, ptoa((vm_paddr_t)Maxmem),
573		    dmat->boundary, dmat->alignment);
574		CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
575		    map, &nobounce_dmamap, map->pagesneeded);
576		/*
577		 * Count the number of bounce pages
578		 * needed in order to complete this transfer
579		 */
580		vaddr = trunc_page((vm_offset_t)buf);
581		vendaddr = (vm_offset_t)buf + buflen;
582
583		while (vaddr < vendaddr) {
584			paddr = pmap_kextract(vaddr);
585			if (run_filter(dmat, paddr) != 0) {
586				needbounce = 1;
587				map->pagesneeded++;
588			}
589			vaddr += PAGE_SIZE;
590		}
591		CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
592	}
593
594	/* Reserve Necessary Bounce Pages */
595	if (map->pagesneeded != 0) {
596		mtx_lock(&bounce_lock);
597		if (flags & BUS_DMA_NOWAIT) {
598			if (reserve_bounce_pages(dmat, map, 0) != 0) {
599				mtx_unlock(&bounce_lock);
600				return (ENOMEM);
601			}
602		} else {
603			if (reserve_bounce_pages(dmat, map, 1) != 0) {
604				/* Queue us for resources */
605				map->dmat = dmat;
606				map->buf = buf;
607				map->buflen = buflen;
608				STAILQ_INSERT_TAIL(&bounce_map_waitinglist,
609				    map, links);
610				mtx_unlock(&bounce_lock);
611				return (EINPROGRESS);
612			}
613		}
614		mtx_unlock(&bounce_lock);
615	}
616
617	vaddr = (vm_offset_t)buf;
618	lastaddr = *lastaddrp;
619	bmask = ~(dmat->boundary - 1);
620
621	for (seg = *segp; buflen > 0 ; ) {
622		/*
623		 * Get the physical address for this segment.
624		 */
625		if (pmap)
626			curaddr = pmap_extract(pmap, vaddr);
627		else
628			curaddr = pmap_kextract(vaddr);
629
630		/*
631		 * Compute the segment size, and adjust counts.
632		 */
633		sgsize = PAGE_SIZE - ((u_long)curaddr & PAGE_MASK);
634		if (buflen < sgsize)
635			sgsize = buflen;
636
637		/*
638		 * Make sure we don't cross any boundaries.
639		 */
640		if (dmat->boundary > 0) {
641			baddr = (curaddr + dmat->boundary) & bmask;
642			if (sgsize > (baddr - curaddr))
643				sgsize = (baddr - curaddr);
644		}
645
646		if (map->pagesneeded != 0 && run_filter(dmat, curaddr))
647			curaddr = add_bounce_page(dmat, map, vaddr, sgsize);
648
649		/*
650		 * Insert chunk into a segment, coalescing with
651		 * previous segment if possible.
652		 */
653		if (first) {
654			segs[seg].ds_addr = curaddr;
655			segs[seg].ds_len = sgsize;
656			first = 0;
657		} else {
658			if (needbounce == 0 && curaddr == lastaddr &&
659			    (segs[seg].ds_len + sgsize) <= dmat->maxsegsz &&
660			    (dmat->boundary == 0 ||
661			     (segs[seg].ds_addr & bmask) == (curaddr & bmask)))
662				segs[seg].ds_len += sgsize;
663			else {
664				if (++seg >= dmat->nsegments)
665					break;
666				segs[seg].ds_addr = curaddr;
667				segs[seg].ds_len = sgsize;
668			}
669		}
670
671		lastaddr = curaddr + sgsize;
672		vaddr += sgsize;
673		buflen -= sgsize;
674	}
675
676	*segp = seg;
677	*lastaddrp = lastaddr;
678
679	/*
680	 * Did we fit?
681	 */
682	return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
683}
684
685/*
686 * Map the buffer buf into bus space using the dmamap map.
687 */
688int
689bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
690		bus_size_t buflen, bus_dmamap_callback_t *callback,
691		void *callback_arg, int flags)
692{
693	bus_addr_t		lastaddr = 0;
694	int			error, nsegs = 0;
695
696	if (map != NULL) {
697		flags |= BUS_DMA_WAITOK;
698		map->callback = callback;
699		map->callback_arg = callback_arg;
700	}
701
702	error = _bus_dmamap_load_buffer(dmat, map, buf, buflen, NULL, flags,
703	     &lastaddr, &nsegs, 1);
704
705	if (error == EINPROGRESS) {
706		CTR3(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x "
707		    "error %d", dmat, dmat->flags, error);
708		return (error);
709	}
710
711	if (error)
712		(*callback)(callback_arg, dmat->segments, 0, error);
713	else
714		(*callback)(callback_arg, dmat->segments, nsegs + 1, 0);
715
716	CTR2(KTR_BUSDMA, "bus_dmamap_load: tag %p tag flags 0x%x error 0",
717	    dmat, dmat->flags);
718	return (0);
719}
720
721
722/*
723 * Like _bus_dmamap_load(), but for mbufs.
724 */
725int
726bus_dmamap_load_mbuf(bus_dma_tag_t dmat, bus_dmamap_t map,
727		     struct mbuf *m0,
728		     bus_dmamap_callback2_t *callback, void *callback_arg,
729		     int flags)
730{
731	int nsegs, error;
732
733	M_ASSERTPKTHDR(m0);
734
735	flags |= BUS_DMA_NOWAIT;
736	nsegs = 0;
737	error = 0;
738	if (m0->m_pkthdr.len <= dmat->maxsize) {
739		int first = 1;
740		bus_addr_t lastaddr = 0;
741		struct mbuf *m;
742
743		for (m = m0; m != NULL && error == 0; m = m->m_next) {
744			if (m->m_len > 0) {
745				error = _bus_dmamap_load_buffer(dmat, map,
746						m->m_data, m->m_len,
747						NULL, flags, &lastaddr,
748						&nsegs, first);
749				first = 0;
750			}
751		}
752	} else {
753		error = EINVAL;
754	}
755
756	if (error) {
757		/* force "no valid mappings" in callback */
758		(*callback)(callback_arg, dmat->segments, 0, 0, error);
759	} else {
760		(*callback)(callback_arg, dmat->segments,
761			    nsegs+1, m0->m_pkthdr.len, error);
762	}
763	CTR3(KTR_BUSDMA, "bus_dmamap_load_mbuf: tag %p tag flags 0x%x "
764	    "error %d", dmat, dmat->flags, error);
765	return (error);
766}
767
768/*
769 * Like _bus_dmamap_load(), but for uios.
770 */
771int
772bus_dmamap_load_uio(bus_dma_tag_t dmat, bus_dmamap_t map,
773		    struct uio *uio,
774		    bus_dmamap_callback2_t *callback, void *callback_arg,
775		    int flags)
776{
777	bus_addr_t lastaddr;
778	int nsegs, error, first, i;
779	bus_size_t resid;
780	struct iovec *iov;
781	pmap_t pmap;
782
783	flags |= BUS_DMA_NOWAIT;
784	resid = uio->uio_resid;
785	iov = uio->uio_iov;
786
787	if (uio->uio_segflg == UIO_USERSPACE) {
788		KASSERT(uio->uio_td != NULL,
789			("bus_dmamap_load_uio: USERSPACE but no proc"));
790		pmap = vmspace_pmap(uio->uio_td->td_proc->p_vmspace);
791	} else
792		pmap = NULL;
793
794	nsegs = 0;
795	error = 0;
796	first = 1;
797	for (i = 0; i < uio->uio_iovcnt && resid != 0 && !error; i++) {
798		/*
799		 * Now at the first iovec to load.  Load each iovec
800		 * until we have exhausted the residual count.
801		 */
802		bus_size_t minlen =
803			resid < iov[i].iov_len ? resid : iov[i].iov_len;
804		caddr_t addr = (caddr_t) iov[i].iov_base;
805
806		if (minlen > 0) {
807			error = _bus_dmamap_load_buffer(dmat, map,
808					addr, minlen,
809					pmap, flags, &lastaddr, &nsegs, first);
810			first = 0;
811
812			resid -= minlen;
813		}
814	}
815
816	if (error) {
817		/* force "no valid mappings" in callback */
818		(*callback)(callback_arg, dmat->segments, 0, 0, error);
819	} else {
820		(*callback)(callback_arg, dmat->segments,
821			    nsegs+1, uio->uio_resid, error);
822	}
823	CTR3(KTR_BUSDMA, "bus_dmamap_load_uio: tag %p tag flags 0x%x "
824	    "error %d", dmat, dmat->flags, error);
825	return (error);
826}
827
828/*
829 * Release the mapping held by map.
830 */
831void
832_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
833{
834	struct bounce_page *bpage;
835
836	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
837		STAILQ_REMOVE_HEAD(&map->bpages, links);
838		free_bounce_page(dmat, bpage);
839	}
840}
841
842void
843_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
844{
845	struct bounce_page *bpage;
846
847	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
848		/*
849		 * Handle data bouncing.  We might also
850		 * want to add support for invalidating
851		 * the caches on broken hardware
852		 */
853		dmat->bounce_zone->total_bounced++;
854		CTR3(KTR_BUSDMA, "_bus_dmamap_sync: tag %p tag flags 0x%x "
855		    "op 0x%x performing bounce", op, dmat, dmat->flags);
856
857		if (op & BUS_DMASYNC_PREWRITE) {
858			while (bpage != NULL) {
859				bcopy((void *)bpage->datavaddr,
860				      (void *)bpage->vaddr,
861				      bpage->datacount);
862				bpage = STAILQ_NEXT(bpage, links);
863			}
864		}
865
866		if (op & BUS_DMASYNC_POSTREAD) {
867			while (bpage != NULL) {
868				bcopy((void *)bpage->vaddr,
869				      (void *)bpage->datavaddr,
870				      bpage->datacount);
871				bpage = STAILQ_NEXT(bpage, links);
872			}
873		}
874	}
875}
876
877static void
878init_bounce_pages(void *dummy __unused)
879{
880
881	total_bpages = 0;
882	STAILQ_INIT(&bounce_zone_list);
883	STAILQ_INIT(&bounce_map_waitinglist);
884	STAILQ_INIT(&bounce_map_callbacklist);
885	mtx_init(&bounce_lock, "bounce pages lock", NULL, MTX_DEF);
886}
887SYSINIT(bpages, SI_SUB_LOCK, SI_ORDER_ANY, init_bounce_pages, NULL);
888
889static struct sysctl_ctx_list *
890busdma_sysctl_tree(struct bounce_zone *bz)
891{
892	return (&bz->sysctl_tree);
893}
894
895static struct sysctl_oid *
896busdma_sysctl_tree_top(struct bounce_zone *bz)
897{
898	return (bz->sysctl_tree_top);
899}
900
901static struct bounce_zone *
902alloc_bounce_zone(bus_dma_tag_t dmat)
903{
904	struct bounce_zone *bz;
905
906	if ((bz = (struct bounce_zone *)malloc(sizeof(*bz), M_DEVBUF,
907	    M_NOWAIT | M_ZERO)) == NULL)
908		return (NULL);
909
910	STAILQ_INIT(&bz->bounce_page_list);
911	bz->free_bpages = 0;
912	bz->reserved_bpages = 0;
913	bz->active_bpages = 0;
914	bz->lowaddr = dmat->lowaddr;
915	bz->alignment = dmat->alignment;
916	bz->boundary = dmat->boundary;
917	snprintf(bz->zoneid, 8, "zone%d", busdma_zonecount);
918	busdma_zonecount++;
919	snprintf(bz->lowaddrid, 18, "%#jx", (uintmax_t)bz->lowaddr);
920	STAILQ_INSERT_TAIL(&bounce_zone_list, bz, links);
921
922	sysctl_ctx_init(&bz->sysctl_tree);
923	bz->sysctl_tree_top = SYSCTL_ADD_NODE(&bz->sysctl_tree,
924	    SYSCTL_STATIC_CHILDREN(_hw_busdma), OID_AUTO, bz->zoneid,
925	    CTLFLAG_RD, 0, "");
926	if (bz->sysctl_tree_top == NULL) {
927		sysctl_ctx_free(&bz->sysctl_tree);
928		return (bz);
929	}
930
931	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
932	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
933	    "free_bpages", CTLFLAG_RD, &bz->free_bpages, 0,
934	    "Free bounce pages");
935	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
936	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
937	    "reserved_bpages", CTLFLAG_RD, &bz->reserved_bpages, 0,
938	    "Reserved bounce pages");
939	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
940	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
941	    "active_bpages", CTLFLAG_RD, &bz->active_bpages, 0,
942	    "Active bounce pages");
943	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
944	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
945	    "total_bounced", CTLFLAG_RD, &bz->total_bounced, 0,
946	    "Total bounce requests");
947	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
948	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
949	    "total_deferred", CTLFLAG_RD, &bz->total_deferred, 0,
950	    "Total bounce requests that were deferred");
951	SYSCTL_ADD_STRING(busdma_sysctl_tree(bz),
952	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
953	    "lowaddr", CTLFLAG_RD, bz->lowaddrid, 0, "");
954	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
955	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
956	    "alignment", CTLFLAG_RD, &bz->alignment, 0, "");
957	SYSCTL_ADD_INT(busdma_sysctl_tree(bz),
958	    SYSCTL_CHILDREN(busdma_sysctl_tree_top(bz)), OID_AUTO,
959	    "boundary", CTLFLAG_RD, &bz->boundary, 0, "");
960
961	return (bz);
962}
963
964static int
965alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
966{
967	struct bounce_zone *bz;
968	int count;
969
970	bz = dmat->bounce_zone;
971	if (bz == NULL) {
972		STAILQ_FOREACH(bz, &bounce_zone_list, links) {
973			if ((dmat->alignment <= bz->alignment)
974			 && (dmat->boundary <= bz->boundary)
975			 && (dmat->lowaddr >= bz->lowaddr))
976				break;
977		}
978
979		if (bz == NULL) {
980			if ((bz = alloc_bounce_zone(dmat)) == NULL)
981				return (ENOMEM);
982		}
983		dmat->bounce_zone = bz;
984	}
985
986	count = 0;
987	while (numpages > 0) {
988		struct bounce_page *bpage;
989
990		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
991						     M_NOWAIT | M_ZERO);
992
993		if (bpage == NULL)
994			break;
995		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
996							 M_NOWAIT, 0ul,
997							 bz->lowaddr,
998							 PAGE_SIZE,
999							 bz->boundary);
1000		if (bpage->vaddr == 0) {
1001			free(bpage, M_DEVBUF);
1002			break;
1003		}
1004		bpage->busaddr = pmap_kextract(bpage->vaddr);
1005		mtx_lock(&bounce_lock);
1006		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
1007		total_bpages++;
1008		bz->free_bpages++;
1009		mtx_unlock(&bounce_lock);
1010		count++;
1011		numpages--;
1012	}
1013	return (count);
1014}
1015
1016static int
1017reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
1018{
1019	struct bounce_zone *bz;
1020	int pages;
1021
1022	mtx_assert(&bounce_lock, MA_OWNED);
1023	bz = dmat->bounce_zone;
1024	pages = MIN(bz->free_bpages, map->pagesneeded - map->pagesreserved);
1025	if (commit == 0 && map->pagesneeded > (map->pagesreserved + pages))
1026		return (map->pagesneeded - (map->pagesreserved + pages));
1027	bz->free_bpages -= pages;
1028	bz->reserved_bpages += pages;
1029	map->pagesreserved += pages;
1030	pages = map->pagesneeded - map->pagesreserved;
1031
1032	return (pages);
1033}
1034
1035static bus_addr_t
1036add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
1037		bus_size_t size)
1038{
1039	struct bounce_zone *bz;
1040	struct bounce_page *bpage;
1041
1042	KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
1043	KASSERT(map != NULL && map != &nobounce_dmamap,
1044	    ("add_bounce_page: bad map %p", map));
1045
1046	bz = dmat->bounce_zone;
1047	if (map->pagesneeded == 0)
1048		panic("add_bounce_page: map doesn't need any pages");
1049	map->pagesneeded--;
1050
1051	if (map->pagesreserved == 0)
1052		panic("add_bounce_page: map doesn't need any pages");
1053	map->pagesreserved--;
1054
1055	mtx_lock(&bounce_lock);
1056	bpage = STAILQ_FIRST(&bz->bounce_page_list);
1057	if (bpage == NULL)
1058		panic("add_bounce_page: free page list is empty");
1059
1060	STAILQ_REMOVE_HEAD(&bz->bounce_page_list, links);
1061	bz->reserved_bpages--;
1062	bz->active_bpages++;
1063	mtx_unlock(&bounce_lock);
1064
1065	bpage->datavaddr = vaddr;
1066	bpage->datacount = size;
1067	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
1068	return (bpage->busaddr);
1069}
1070
1071static void
1072free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
1073{
1074	struct bus_dmamap *map;
1075	struct bounce_zone *bz;
1076
1077	bz = dmat->bounce_zone;
1078	bpage->datavaddr = 0;
1079	bpage->datacount = 0;
1080
1081	mtx_lock(&bounce_lock);
1082	STAILQ_INSERT_HEAD(&bz->bounce_page_list, bpage, links);
1083	bz->free_bpages++;
1084	bz->active_bpages--;
1085	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
1086		if (reserve_bounce_pages(map->dmat, map, 1) == 0) {
1087			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
1088			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
1089					   map, links);
1090			busdma_swi_pending = 1;
1091			bz->total_deferred++;
1092			swi_sched(vm_ih, 0);
1093		}
1094	}
1095	mtx_unlock(&bounce_lock);
1096}
1097
1098void
1099busdma_swi(void)
1100{
1101	bus_dma_tag_t dmat;
1102	struct bus_dmamap *map;
1103
1104	mtx_lock(&bounce_lock);
1105	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
1106		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
1107		mtx_unlock(&bounce_lock);
1108		dmat = map->dmat;
1109		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_LOCK);
1110		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
1111				map->callback, map->callback_arg, /*flags*/0);
1112		(dmat->lockfunc)(dmat->lockfuncarg, BUS_DMA_UNLOCK);
1113		mtx_lock(&bounce_lock);
1114	}
1115	mtx_unlock(&bounce_lock);
1116}
1117