busdma_machdep.c revision 67551 
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 67551 2000-10-25 05:19:40Z jhb $
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
35#include <vm/vm.h>
36#include <vm/vm_page.h>
37
38#include <machine/bus.h>
39#include <machine/md_var.h>
40
41#define MAX(a,b) (((a) > (b)) ? (a) : (b))
42#define MIN(a,b) (((a) < (b)) ? (a) : (b))
43#define MAX_BPAGES 128
44
45struct bus_dma_tag {
46	bus_dma_tag_t	  parent;
47	bus_size_t	  alignment;
48	bus_size_t	  boundary;
49	bus_addr_t	  lowaddr;
50	bus_addr_t	  highaddr;
51	bus_dma_filter_t *filter;
52	void		 *filterarg;
53	bus_size_t	  maxsize;
54	u_int		  nsegments;
55	bus_size_t	  maxsegsz;
56	int		  flags;
57	int		  ref_count;
58	int		  map_count;
59};
60
61struct bounce_page {
62	vm_offset_t	vaddr;		/* kva of bounce buffer */
63	bus_addr_t	busaddr;	/* Physical address */
64	vm_offset_t	datavaddr;	/* kva of client data */
65	bus_size_t	datacount;	/* client data count */
66	STAILQ_ENTRY(bounce_page) links;
67};
68
69int busdma_swi_pending;
70
71static STAILQ_HEAD(bp_list, bounce_page) bounce_page_list;
72static int free_bpages;
73static int reserved_bpages;
74static int active_bpages;
75static int total_bpages;
76static bus_addr_t bounce_lowaddr = BUS_SPACE_MAXADDR;
77
78struct bus_dmamap {
79	struct bp_list	       bpages;
80	int		       pagesneeded;
81	int		       pagesreserved;
82	bus_dma_tag_t	       dmat;
83	void		      *buf;		/* unmapped buffer pointer */
84	bus_size_t	       buflen;		/* unmapped buffer length */
85	bus_dmamap_callback_t *callback;
86	void		      *callback_arg;
87	STAILQ_ENTRY(bus_dmamap) links;
88};
89
90static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
91static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
92static struct bus_dmamap nobounce_dmamap;
93
94static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
95static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map);
96static vm_offset_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
97				   vm_offset_t vaddr, bus_size_t size);
98static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
99static __inline int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
100
101static __inline int
102run_filter(bus_dma_tag_t dmat, bus_addr_t paddr)
103{
104	int retval;
105
106	retval = 0;
107	do {
108		if (paddr > dmat->lowaddr
109		 && paddr <= dmat->highaddr
110		 && (dmat->filter == NULL
111		  || (*dmat->filter)(dmat->filterarg, paddr) != 0))
112			retval = 1;
113
114		dmat = dmat->parent;
115	} while (retval == 0 && dmat != NULL);
116	return (retval);
117}
118
119#define BUS_DMA_MIN_ALLOC_COMP BUS_DMA_BUS4
120/*
121 * Allocate a device specific dma_tag.
122 */
123int
124bus_dma_tag_create(bus_dma_tag_t parent, bus_size_t alignment,
125		   bus_size_t boundary, bus_addr_t lowaddr,
126		   bus_addr_t highaddr, bus_dma_filter_t *filter,
127		   void *filterarg, bus_size_t maxsize, int nsegments,
128		   bus_size_t maxsegsz, int flags, bus_dma_tag_t *dmat)
129{
130	bus_dma_tag_t newtag;
131	int error = 0;
132
133	/* Return a NULL tag on failure */
134	*dmat = NULL;
135
136	newtag = (bus_dma_tag_t)malloc(sizeof(*newtag), M_DEVBUF, M_NOWAIT);
137	if (newtag == NULL)
138		return (ENOMEM);
139
140	newtag->parent = parent;
141	newtag->alignment = alignment;
142	newtag->boundary = boundary;
143	newtag->lowaddr = trunc_page((vm_offset_t)lowaddr) + (PAGE_SIZE - 1);
144	newtag->highaddr = trunc_page((vm_offset_t)highaddr) + (PAGE_SIZE - 1);
145	newtag->filter = filter;
146	newtag->filterarg = filterarg;
147	newtag->maxsize = maxsize;
148	newtag->nsegments = nsegments;
149	newtag->maxsegsz = maxsegsz;
150	newtag->flags = flags;
151	newtag->ref_count = 1; /* Count ourself */
152	newtag->map_count = 0;
153
154	/* Take into account any restrictions imposed by our parent tag */
155	if (parent != NULL) {
156		newtag->lowaddr = MIN(parent->lowaddr, newtag->lowaddr);
157		newtag->highaddr = MAX(parent->highaddr, newtag->highaddr);
158		/*
159		 * XXX Not really correct??? Probably need to honor boundary
160		 *     all the way up the inheritence chain.
161		 */
162		newtag->boundary = MAX(parent->boundary, newtag->boundary);
163		if (newtag->filter == NULL) {
164			/*
165			 * Short circuit looking at our parent directly
166			 * since we have encapsulated all of its information
167			 */
168			newtag->filter = parent->filter;
169			newtag->filterarg = parent->filterarg;
170			newtag->parent = parent->parent;
171		}
172		if (newtag->parent != NULL) {
173			parent->ref_count++;
174		}
175	}
176
177	if (newtag->lowaddr < ptoa(Maxmem) && (flags & BUS_DMA_ALLOCNOW) != 0) {
178		/* Must bounce */
179
180		if (lowaddr > bounce_lowaddr) {
181			/*
182			 * Go through the pool and kill any pages
183			 * that don't reside below lowaddr.
184			 */
185			panic("bus_dma_tag_create: page reallocation "
186			      "not implemented");
187		}
188		if (ptoa(total_bpages) < maxsize) {
189			int pages;
190
191			pages = atop(maxsize) - total_bpages;
192
193			/* Add pages to our bounce pool */
194			if (alloc_bounce_pages(newtag, pages) < pages)
195				error = ENOMEM;
196		}
197		/* Performed initial allocation */
198		newtag->flags |= BUS_DMA_MIN_ALLOC_COMP;
199	}
200
201	if (error != 0) {
202		free(newtag, M_DEVBUF);
203	} else {
204		*dmat = newtag;
205	}
206	return (error);
207}
208
209int
210bus_dma_tag_destroy(bus_dma_tag_t dmat)
211{
212	if (dmat != NULL) {
213
214		if (dmat->map_count != 0)
215			return (EBUSY);
216
217		while (dmat != NULL) {
218			bus_dma_tag_t parent;
219
220			parent = dmat->parent;
221			dmat->ref_count--;
222			if (dmat->ref_count == 0) {
223				free(dmat, M_DEVBUF);
224				/*
225				 * Last reference count, so
226				 * release our reference
227				 * count on our parent.
228				 */
229				dmat = parent;
230			} else
231				dmat = NULL;
232		}
233	}
234	return (0);
235}
236
237/*
238 * Allocate a handle for mapping from kva/uva/physical
239 * address space into bus device space.
240 */
241int
242bus_dmamap_create(bus_dma_tag_t dmat, int flags, bus_dmamap_t *mapp)
243{
244	int error;
245
246	error = 0;
247
248	if (dmat->lowaddr < ptoa(Maxmem)) {
249		/* Must bounce */
250		int maxpages;
251
252		*mapp = (bus_dmamap_t)malloc(sizeof(**mapp), M_DEVBUF,
253					     M_NOWAIT);
254		if (*mapp == NULL) {
255			return (ENOMEM);
256		} else {
257			/* Initialize the new map */
258			bzero(*mapp, sizeof(**mapp));
259			STAILQ_INIT(&((*mapp)->bpages));
260		}
261		/*
262		 * Attempt to add pages to our pool on a per-instance
263		 * basis up to a sane limit.
264		 */
265		maxpages = MIN(MAX_BPAGES, Maxmem - atop(dmat->lowaddr));
266		if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0
267		 || (dmat->map_count > 0
268		  && total_bpages < maxpages)) {
269			int pages;
270
271			if (dmat->lowaddr > bounce_lowaddr) {
272				/*
273				 * Go through the pool and kill any pages
274				 * that don't reside below lowaddr.
275				 */
276				panic("bus_dmamap_create: page reallocation "
277				      "not implemented");
278			}
279			pages = atop(dmat->maxsize);
280			pages = MIN(maxpages - total_bpages, pages);
281			error = alloc_bounce_pages(dmat, pages);
282
283			if ((dmat->flags & BUS_DMA_MIN_ALLOC_COMP) == 0) {
284				if (error == 0)
285					dmat->flags |= BUS_DMA_MIN_ALLOC_COMP;
286			} else {
287				error = 0;
288			}
289		}
290	} else {
291		*mapp = NULL;
292	}
293	if (error == 0)
294		dmat->map_count++;
295	return (error);
296}
297
298/*
299 * Destroy a handle for mapping from kva/uva/physical
300 * address space into bus device space.
301 */
302int
303bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
304{
305	if (map != NULL) {
306		if (STAILQ_FIRST(&map->bpages) != NULL)
307			return (EBUSY);
308		free(map, M_DEVBUF);
309	}
310	dmat->map_count--;
311	return (0);
312}
313
314
315/*
316 * Allocate a piece of memory that can be efficiently mapped into
317 * bus device space based on the constraints lited in the dma tag.
318 * A dmamap to for use with dmamap_load is also allocated.
319 */
320int
321bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
322		 bus_dmamap_t *mapp)
323{
324	/* If we succeed, no mapping/bouncing will be required */
325	*mapp = NULL;
326
327	if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem)) {
328		*vaddr = malloc(dmat->maxsize, M_DEVBUF,
329				(flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK);
330	} else {
331		/*
332		 * XXX Use Contigmalloc until it is merged into this facility
333		 *     and handles multi-seg allocations.  Nobody is doing
334		 *     multi-seg allocations yet though.
335		 */
336		*vaddr = contigmalloc(dmat->maxsize, M_DEVBUF,
337		    (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK,
338		    0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
339		    dmat->boundary);
340	}
341	if (*vaddr == NULL)
342		return (ENOMEM);
343	return (0);
344}
345
346/*
347 * Free a piece of memory and it's allociated dmamap, that was allocated
348 * via bus_dmamem_alloc.
349 */
350void
351bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
352{
353	/*
354	 * dmamem does not need to be bounced, so the map should be
355	 * NULL
356	 */
357	if (map != NULL)
358		panic("bus_dmamem_free: Invalid map freed\n");
359	/* XXX There is no "contigfree" and "free" doesn't work */
360	if ((dmat->maxsize <= PAGE_SIZE) && dmat->lowaddr >= ptoa(Maxmem))
361		free(vaddr, M_DEVBUF);
362}
363
364#define BUS_DMAMAP_NSEGS ((BUS_SPACE_MAXSIZE / PAGE_SIZE) + 1)
365
366/*
367 * Map the buffer buf into bus space using the dmamap map.
368 */
369int
370bus_dmamap_load(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
371		bus_size_t buflen, bus_dmamap_callback_t *callback,
372		void *callback_arg, int flags)
373{
374	vm_offset_t		vaddr;
375	vm_offset_t		paddr;
376#ifdef __GNUC__
377	bus_dma_segment_t	dm_segments[dmat->nsegments];
378#else
379	bus_dma_segment_t	dm_segments[BUS_DMAMAP_NSEGS];
380#endif
381	bus_dma_segment_t      *sg;
382	int			seg;
383	int			error;
384	vm_offset_t		nextpaddr;
385
386	if (map == NULL)
387		map = &nobounce_dmamap;
388
389	error = 0;
390	/*
391	 * If we are being called during a callback, pagesneeded will
392	 * be non-zero, so we can avoid doing the work twice.
393	 */
394	if (dmat->lowaddr < ptoa(Maxmem) && map->pagesneeded == 0) {
395		vm_offset_t	vendaddr;
396
397		/*
398		 * Count the number of bounce pages
399		 * needed in order to complete this transfer
400		 */
401		vaddr = trunc_page((vm_offset_t)buf);
402		vendaddr = (vm_offset_t)buf + buflen;
403
404		while (vaddr < vendaddr) {
405			paddr = pmap_kextract(vaddr);
406			if (run_filter(dmat, paddr) != 0) {
407
408				map->pagesneeded++;
409			}
410			vaddr += PAGE_SIZE;
411		}
412	}
413
414	/* Reserve Necessary Bounce Pages */
415	if (map->pagesneeded != 0) {
416		int s;
417
418		s = splhigh();
419	 	if (reserve_bounce_pages(dmat, map) != 0) {
420
421			/* Queue us for resources */
422			map->dmat = dmat;
423			map->buf = buf;
424			map->buflen = buflen;
425			map->callback = callback;
426			map->callback_arg = callback_arg;
427
428			STAILQ_INSERT_TAIL(&bounce_map_waitinglist, map, links);
429			splx(s);
430
431			return (EINPROGRESS);
432		}
433		splx(s);
434	}
435
436	vaddr = (vm_offset_t)buf;
437	sg = &dm_segments[0];
438	seg = 1;
439	sg->ds_len = 0;
440
441	nextpaddr = 0;
442	do {
443		bus_size_t	size;
444
445		paddr = pmap_kextract(vaddr);
446		size = PAGE_SIZE - (paddr & PAGE_MASK);
447		if (size > buflen)
448			size = buflen;
449
450		if (map->pagesneeded != 0 && run_filter(dmat, paddr)) {
451			paddr = add_bounce_page(dmat, map, vaddr, size);
452		}
453
454		if (sg->ds_len == 0) {
455			sg->ds_addr = paddr;
456			sg->ds_len = size;
457		} else if (paddr == nextpaddr) {
458			sg->ds_len += size;
459		} else {
460			/* Go to the next segment */
461			sg++;
462			seg++;
463			if (seg > dmat->nsegments)
464				break;
465			sg->ds_addr = paddr;
466			sg->ds_len = size;
467		}
468		vaddr += size;
469		nextpaddr = paddr + size;
470		buflen -= size;
471
472	} while (buflen > 0);
473
474	if (buflen != 0) {
475		printf("bus_dmamap_load: Too many segs! buf_len = 0x%lx\n",
476		       (u_long)buflen);
477		error = EFBIG;
478	}
479
480	(*callback)(callback_arg, dm_segments, seg, error);
481
482	return (0);
483}
484
485/*
486 * Release the mapping held by map.
487 */
488void
489_bus_dmamap_unload(bus_dma_tag_t dmat, bus_dmamap_t map)
490{
491	struct bounce_page *bpage;
492
493	while ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
494		STAILQ_REMOVE_HEAD(&map->bpages, links);
495		free_bounce_page(dmat, bpage);
496	}
497}
498
499void
500_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, bus_dmasync_op_t op)
501{
502	struct bounce_page *bpage;
503
504	if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) {
505
506		/*
507		 * Handle data bouncing.  We might also
508		 * want to add support for invalidating
509		 * the caches on broken hardware
510		 */
511		switch (op) {
512		case BUS_DMASYNC_PREWRITE:
513			while (bpage != NULL) {
514				bcopy((void *)bpage->datavaddr,
515				      (void *)bpage->vaddr,
516				      bpage->datacount);
517				bpage = STAILQ_NEXT(bpage, links);
518			}
519			break;
520
521		case BUS_DMASYNC_POSTREAD:
522			while (bpage != NULL) {
523				bcopy((void *)bpage->vaddr,
524				      (void *)bpage->datavaddr,
525				      bpage->datacount);
526				bpage = STAILQ_NEXT(bpage, links);
527			}
528			break;
529		case BUS_DMASYNC_PREREAD:
530		case BUS_DMASYNC_POSTWRITE:
531			/* No-ops */
532			break;
533		}
534	}
535}
536
537static int
538alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
539{
540	int count;
541
542	count = 0;
543	if (total_bpages == 0) {
544		STAILQ_INIT(&bounce_page_list);
545		STAILQ_INIT(&bounce_map_waitinglist);
546		STAILQ_INIT(&bounce_map_callbacklist);
547	}
548
549	while (numpages > 0) {
550		struct bounce_page *bpage;
551		int s;
552
553		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
554						     M_NOWAIT);
555
556		if (bpage == NULL)
557			break;
558		bzero(bpage, sizeof(*bpage));
559		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
560							 M_NOWAIT, 0ul,
561							 dmat->lowaddr,
562							 PAGE_SIZE,
563							 0);
564		if (bpage->vaddr == NULL) {
565			free(bpage, M_DEVBUF);
566			break;
567		}
568		bpage->busaddr = pmap_kextract(bpage->vaddr);
569		s = splhigh();
570		STAILQ_INSERT_TAIL(&bounce_page_list, bpage, links);
571		total_bpages++;
572		free_bpages++;
573		splx(s);
574		count++;
575		numpages--;
576	}
577	return (count);
578}
579
580static int
581reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map)
582{
583	int pages;
584
585	pages = MIN(free_bpages, map->pagesneeded - map->pagesreserved);
586	free_bpages -= pages;
587	reserved_bpages += pages;
588	map->pagesreserved += pages;
589	pages = map->pagesneeded - map->pagesreserved;
590
591	return (pages);
592}
593
594static vm_offset_t
595add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
596		bus_size_t size)
597{
598	int s;
599	struct bounce_page *bpage;
600
601	if (map->pagesneeded == 0)
602		panic("add_bounce_page: map doesn't need any pages");
603	map->pagesneeded--;
604
605	if (map->pagesreserved == 0)
606		panic("add_bounce_page: map doesn't need any pages");
607	map->pagesreserved--;
608
609	s = splhigh();
610	bpage = STAILQ_FIRST(&bounce_page_list);
611	if (bpage == NULL)
612		panic("add_bounce_page: free page list is empty");
613
614	STAILQ_REMOVE_HEAD(&bounce_page_list, links);
615	reserved_bpages--;
616	active_bpages++;
617	splx(s);
618
619	bpage->datavaddr = vaddr;
620	bpage->datacount = size;
621	STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
622	return (bpage->busaddr);
623}
624
625static void
626free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage)
627{
628	int s;
629	struct bus_dmamap *map;
630
631	bpage->datavaddr = 0;
632	bpage->datacount = 0;
633
634	s = splhigh();
635	STAILQ_INSERT_HEAD(&bounce_page_list, bpage, links);
636	free_bpages++;
637	active_bpages--;
638	if ((map = STAILQ_FIRST(&bounce_map_waitinglist)) != NULL) {
639		if (reserve_bounce_pages(map->dmat, map) == 0) {
640			STAILQ_REMOVE_HEAD(&bounce_map_waitinglist, links);
641			STAILQ_INSERT_TAIL(&bounce_map_callbacklist,
642					   map, links);
643			busdma_swi_pending = 1;
644			sched_swi(vm_ih, SWI_NOSWITCH);
645		}
646	}
647	splx(s);
648}
649
650void
651busdma_swi()
652{
653	int s;
654	struct bus_dmamap *map;
655
656	s = splhigh();
657	while ((map = STAILQ_FIRST(&bounce_map_callbacklist)) != NULL) {
658		STAILQ_REMOVE_HEAD(&bounce_map_callbacklist, links);
659		splx(s);
660		bus_dmamap_load(map->dmat, map, map->buf, map->buflen,
661				map->callback, map->callback_arg, /*flags*/0);
662		s = splhigh();
663	}
664	splx(s);
665}
666