busdma_machdep.c revision 79224 
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 * $FreeBSD: head/sys/i386/i386/busdma_machdep.c 79224 2001-07-04 16:20:28Z dillon $
27 */
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/malloc.h>
32#include <sys/bus.h>
33#include <sys/interrupt.h>
34#include <sys/lock.h>
35#include <sys/proc.h>
36#include <sys/mutex.h>
37
38#include <vm/vm.h>
39#include <vm/vm_page.h>
40
41#include <machine/bus.h>
42#include <machine/md_var.h>
43
44#define MAX(a,b) (((a) > (b)) ? (a) : (b))
45#define MIN(a,b) (((a) < (b)) ? (a) : (b))
46#define MAX_BPAGES 128
47
48struct bus_dma_tag {
49	bus_dma_tag_t	  parent;
50	bus_size_t	  alignment;
51	bus_size_t	  boundary;
52	bus_addr_t	  lowaddr;
53	bus_addr_t	  highaddr;
54	bus_dma_filter_t *filter;
55	void		 *filterarg;
56	bus_size_t	  maxsize;
57	u_int		  nsegments;
58	bus_size_t	  maxsegsz;
59	int		  flags;
60	int		  ref_count;
61	int		  map_count;
62};
63
64struct bounce_page {
65	vm_offset_t	vaddr;		/* kva of bounce buffer */
66	bus_addr_t	busaddr;	/* Physical address */
67	vm_offset_t	datavaddr;	/* kva of client data */
68	bus_size_t	datacount;	/* client data count */
69	STAILQ_ENTRY(bounce_page) links;
70};
71
72int busdma_swi_pending;
73
74static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
75static int free_bpages;
76static int reserved_bpages;
77static int active_bpages;
78static int total_bpages;
79static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
80
81struct bus_dmamap {
82	struct bp_list	       bpages;
83	int		       pagesneeded;
84	int		       pagesreserved;
85	bus_dma_tag_t	       dmat;
86	void		      *buf;		/* unmapped buffer pointer */
87	bus_size_t	       buflen;		/* unmapped buffer length */
88	bus_dmamap_callback_t *callback;
89	void		      *callback_arg;
90	STAILQ_ENTRY(bus_dmamap) links;
91};
92
93static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
94static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
95static struct bus_dmamap nobounce_dmamap;
96
97static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
98static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
99static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
100				   vm_offset_t vaddr, bus_size_t size);
101static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
102static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
103
104static __inline int
105run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
106{
107	int retval;
108
109	retval = 0;
110	do {
111		if (paddr > dmat->lowaddr
112		 && paddr <= dmat->highaddr
113		 && (dmat->filter == NULL
114		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
115			retval = 1;
116
117		dmat = dmat->parent;
118	} while (retval == 0 && dmat != NULL);
119	return (retval);
120}
121
122#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
123/*
124 * Allocate a device specific dma_tag.
125 */
126int
127bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
128		   bus_size_t boundary, bus_addr_t lowaddr,
129		   bus_addr_t highaddr, bus_dma_filter_t *filter,
130		   void *filterarg, bus_size_t maxsize, int nsegments,
131		   bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
132{
133	bus_dma_tag_t newtag;
134	int error = 0;
135
136	/* Return a NULL tag on failure */
137	*dmat = NULL;
138
139	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
140	if (newtag == NULL)
141		return (ENOMEM);
142
143	newtag->parent = parent;
144	newtag->alignment = alignment;
145	newtag->boundary = boundary;
146	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
147	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
148	newtag->filter = filter;
149	newtag->filterarg = filterarg;
150	newtag->maxsize = maxsize;
151	newtag->nsegments = nsegments;
152	newtag->maxsegsz = maxsegsz;
153	newtag->flags = flags;
154	newtag->ref_count = 1; /* Count ourself */
155	newtag->map_count = 0;
156
157	/* Take into account any restrictions imposed by our parent tag */
158	if (parent != NULL) {
159		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
160		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
161		/*
162		 * XXX Not really correct??? Probably need to honor boundary
163		 *     all the way up the inheritence chain.
164		 */
165		newtag->boundary = MAX(parent->boundary, newtag->boundary);
166		if (newtag->filter == NULL) {
167			/*
168			 * Short circuit looking at our parent directly
169			 * since we have encapsulated all of its information
170			 */
171			newtag->filter = parent->filter;
172			newtag->filterarg = parent->filterarg;
173			newtag->parent = parent->parent;
174		}
175		if (newtag->parent != NULL) {
176			parent->ref_count++;
177		}
178	}
179
180	if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) {
181		/* Must bounce */
182
183		if (lowaddr > bounce_lowaddr) {
184			/*
185			 * Go through the pool and kill any pages
186			 * that don't reside below lowaddr.
187			 */
188			panic("bus_dma_tag_create: page reallocation "
189			      "not implemented");
190		}
191		if (ptoa(total_bpages) < maxsize) {
192			int pages;
193
194			pages = atop(maxsize) - total_bpages;
195
196			/* Add pages to our bounce pool */
197			if (alloc_bounce_pages(newtag, pages) < pages)
198				error = ENOMEM;
199		}
200		/* Performed initial allocation */
201		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
202	}
203
204	if (error != 0) {
205		free(newtag, M_DEVBUF);
206	} else {
207		*dmat = newtag;
208	}
209	return (error);
210}
211
212int
213bus_dma_tag_destroy(bus_dma_tag_t dmat)
214{
215	if (dmat != NULL) {
216
217		if (dmat->map_count != 0)
218			return (EBUSY);
219
220		while (dmat != NULL) {
221			bus_dma_tag_t parent;
222
223			parent = dmat->parent;
224			dmat->ref_count--;
225			if (dmat->ref_count == 0) {
226				free(dmat, M_DEVBUF);
227				/*
228				 * Last reference count, so
229				 * release our reference
230				 * count on our parent.
231				 */
232				dmat = parent;
233			} else
234				dmat = NULL;
235		}
236	}
237	return (0);
238}
239
240/*
241 * Allocate a handle for mapping from kva/uva/physical
242 * address space into bus device space.
243 */
244int
245bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
246{
247	int error;
248
249	error = 0;
250
251	if (dmat->lowaddr < ptoa(Maxmem)) {
252		/* Must bounce */
253		int maxpages;
254
255		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
256					     M_NOWAIT | M_ZERO);
257		if (*mapp == NULL)
258			return (ENOMEM);
259
260		/* Initialize the new map */
261		STAILQ_INIT(&((*mapp)->bpages));
262
263		/*
264		 * Attempt to add pages to our pool on a per-instance
265		 * basis up to a sane limit.
266		 */
267		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
268		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
269		 || (dmat->map_count > 0
270		  && total_bpages < maxpages)) {
271			int pages;
272
273			if (dmat->lowaddr > bounce_lowaddr) {
274				/*
275				 * Go through the pool and kill any pages
276				 * that don't reside below lowaddr.
277				 */
278				panic("bus_dmamap_create: page reallocation "
279				      "not implemented");
280			}
281			pages = atop(dmat->maxsize);
282			pages = MIN(maxpages - total_bpages, pages);
283			error = alloc_bounce_pages(dmat, pages);
284
285			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
286				if (error == 0)
287					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
288			} else {
289				error = 0;
290			}
291		}
292	} else {
293		*mapp = NULL;
294	}
295	if (error == 0)
296		dmat->map_count++;
297	return (error);
298}
299
300/*
301 * Destroy a handle for mapping from kva/uva/physical
302 * address space into bus device space.
303 */
304int
305bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
306{
307	if (map != NULL) {
308		if (STAILQ_FIRST(&map->bpages) != NULL)
309			return (EBUSY);
310		free(map, M_DEVBUF);
311	}
312	dmat->map_count--;
313	return (0);
314}
315
316
317/*
318 * Allocate a piece of memory that can be efficiently mapped into
319 * bus device space based on the constraints lited in the dma tag.
320 * A dmamap to for use with dmamap_load is also allocated.
321 */
322int
323bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
324		 bus_dmamap_t *mapp)
325{
326	/* If we succeed, no mapping/bouncing will be required */
327	*mapp = NULL;
328
329	if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) {
330		*vaddr = malloc(dmat->maxsize, M_DEVBUF,
331				(flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK);
332	} else {
333		/*
334		 * XXX Use Contigmalloc until it is merged into this facility
335		 *     and handles multi-seg allocations.  Nobody is doing
336		 *     multi-seg allocations yet though.
337		 */
338		*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF,
339		    (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK,
340		    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
341		    dmat->boundary);
342	}
343	if (*vaddr == NULL)
344		return (ENOMEM);
345	return (0);
346}
347
348/*
349 * Free a piece of memory and it's allociated dmamap, that was allocated
350 * via bus_dmamem_alloc.
351 */
352void
353bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
354{
355	/*
356	 * dmamem does not need to be bounced, so the map should be
357	 * NULL
358	 */
359	if (map != NULL)
360		panic("bus_dmamem_free: Invalid map freed\n");
361	/* XXX There is no "contigfree" and "free" doesn't work */
362	if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem))
363		free(vaddr, M_DEVBUF);
364}
365
366#define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
367
368/*
369 * Map the buffer buf into bus space using the dmamap map.
370 */
371int
372bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
373		bus_size_t buflen, bus_dmamap_callback_t *callback,
374		void *callback_arg, int flags)
375{
376	vm_offset_t		vaddr;
377	vm_offset_t		paddr;
378#ifdef __GNUC__
379	bus_dma_segment_t	dm_segments[dmat->nsegments];
380#else
381	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
382#endif
383	bus_dma_segment_t      *sg;
384	int			seg;
385	int			error;
386	vm_offset_t		nextpaddr;
387
388	if (map == NULL)
389		map = &nobounce_dmamap;
390
391	error = 0;
392	/*
393	 * If we are being called during a callback, pagesneeded will
394	 * be non-zero, so we can avoid doing the work twice.
395	 */
396	if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
397		vm_offset_t	vendaddr;
398
399		/*
400		 * Count the number of bounce pages
401		 * needed in order to complete this transfer
402		 */
403		vaddr = trunc_page((vm_offset_t)buf);
404		vendaddr = (vm_offset_t)buf + buflen;
405
406		while (vaddr < vendaddr) {
407			paddr = pmap_kextract(vaddr);
408			if (run_filter(dmat, paddr) != 0) {
409
410				map->pagesneeded++;
411			}
412			vaddr += PAGE_SIZE;
413		}
414	}
415
416	/* Reserve Necessary Bounce Pages */
417	if (map->pagesneeded != 0) {
418		int s;
419
420		s = splhigh();
421	 	if (reserve_bounce_pages(dmat, map) != 0) {
422
423			/* Queue us for resources */
424			map->dmat = dmat;
425			map->buf = buf;
426			map->buflen = buflen;
427			map->callback = callback;
428			map->callback_arg = callback_arg;
429
430			STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
431			splx(s);
432
433			return (EINPROGRESS);
434		}
435		splx(s);
436	}
437
438	vaddr = (vm_offset_t)buf;
439	sg = &dm_segments[0];
440	seg = 1;
441	sg->ds_len = 0;
442
443	nextpaddr = 0;
444	do {
445		bus_size_t	size;
446
447		paddr = pmap_kextract(vaddr);
448		size = PAGE_SIZE - (paddr & PAGE_MASK);
449		if (size > buflen)
450			size = buflen;
451
452		if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
453			paddr = add_bounce_page(dmat, map, vaddr, size);
454		}
455
456		if (sg->ds_len == 0) {
457			sg->ds_addr = paddr;
458			sg->ds_len = size;
459		} else if (paddr == nextpaddr) {
460			sg->ds_len += size;
461		} else {
462			/* Go to the next segment */
463			sg++;
464			seg++;
465			if (seg > dmat->nsegments)
466				break;
467			sg->ds_addr = paddr;
468			sg->ds_len = size;
469		}
470		vaddr += size;
471		nextpaddr = paddr + size;
472		buflen -= size;
473
474	} while (buflen > 0);
475
476	if (buflen != 0) {
477		printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
478		       (u_long)buflen);
479		error = EFBIG;
480	}
481
482	(*callback)(callback_arg, dm_segments, seg, error);
483
484	return (0);
485}
486
487/*
488 * Release the mapping held by map.
489 */
490void
491_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
492{
493	struct bounce_page *bpage;
494
495	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
496		STAILQ_REMOVE_HEAD(&map->bpages, links);
497		free_bounce_page(dmat, bpage);
498	}
499}
500
501void
502_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
503{
504	struct bounce_page *bpage;
505
506	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
507
508		/*
509		 * Handle data bouncing.  We might also
510		 * want to add support for invalidating
511		 * the caches on broken hardware
512		 */
513		switch (op) {
514		case BUS_DMASYNC_PREWRITE:
515			while (bpage != NULL) {
516				bcopy((void *)bpage->datavaddr,
517				      (void *)bpage->vaddr,
518				      bpage->datacount);
519				bpage = STAILQ_NEXT(bpage, links);
520			}
521			break;
522
523		case BUS_DMASYNC_POSTREAD:
524			while (bpage != NULL) {
525				bcopy((void *)bpage->vaddr,
526				      (void *)bpage->datavaddr,
527				      bpage->datacount);
528				bpage = STAILQ_NEXT(bpage, links);
529			}
530			break;
531		case BUS_DMASYNC_PREREAD:
532		case BUS_DMASYNC_POSTWRITE:
533			/* No-ops */
534			break;
535		}
536	}
537}
538
539static int
540alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
541{
542	int count;
543
544	count = 0;
545	if (total_bpages == 0) {
546		STAILQ_INIT(&bounce_page_list);
547		STAILQ_INIT(&bounce_map_waitinglist);
548		STAILQ_INIT(&bounce_map_callbacklist);
549	}
550
551	while (numpages > 0) {
552		struct bounce_page *bpage;
553		int s;
554
555		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
556						     M_NOWAIT | M_ZERO);
557
558		if (bpage == NULL)
559			break;
560		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
561							 M_NOWAIT, 0ul,
562							 dmat->lowaddr,
563							 PAGE_SIZE,
564							 0);
565		if (bpage->vaddr == NULL) {
566			free(bpage, M_DEVBUF);
567			break;
568		}
569		bpage->busaddr = pmap_kextract(bpage->vaddr);
570		s = splhigh();
571		STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
572		total_bpages++;
573		free_bpages++;
574		splx(s);
575		count++;
576		numpages--;
577	}
578	return (count);
579}
580
581static int
582reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
583{
584	int pages;
585
586	pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
587	free_bpages -= pages;
588	reserved_bpages += pages;
589	map->pagesreserved += pages;
590	pages = map->pagesneeded - map->pagesreserved;
591
592	return (pages);
593}
594
595static vm_offset_t
596add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
597		bus_size_t size)
598{
599	int s;
600	struct bounce_page *bpage;
601
602	if (map->pagesneeded == 0)
603		panic("add_bounce_page: map doesn't need any pages");
604	map->pagesneeded--;
605
606	if (map->pagesreserved == 0)
607		panic("add_bounce_page: map doesn't need any pages");
608	map->pagesreserved--;
609
610	s = splhigh();
611	bpage = STAILQ_FIRST(&bounce_page_list);
612	if (bpage == NULL)
613		panic("add_bounce_page: free page list is empty");
614
615	STAILQ_REMOVE_HEAD(&bounce_page_list, links);
616	reserved_bpages--;
617	active_bpages++;
618	splx(s);
619
620	bpage->datavaddr = vaddr;
621	bpage->datacount = size;
622	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
623	return (bpage->busaddr);
624}
625
626static void
627free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
628{
629	int s;
630	struct bus_dmamap *map;
631
632	bpage->datavaddr = 0;
633	bpage->datacount = 0;
634
635	s = splhigh();
636	STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
637	free_bpages++;
638	active_bpages--;
639	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
640		if (reserve_bounce_pages(map->dmat, map) == 0) {
641			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
642			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
643					   map, links);
644			busdma_swi_pending = 1;
645			swi_sched(vm_ih, SWI_NOSWITCH);
646		}
647	}
648	splx(s);
649}
650
651void
652busdma_swi()
653{
654	int s;
655	struct bus_dmamap *map;
656
657	s = splhigh();
658	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
659		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
660		splx(s);
661		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
662				map->callback, map->callback_arg, /*flags*/0);
663		s = splhigh();
664	}
665	splx(s);
666}
667