bus_dma.c revision 1.1 1 /* $NetBSD: bus_dma.c,v 1.1 1999/04/14 23:14:46 ragge Exp $ */
2
3 /*-
4 * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39 /*
40 * bus_dma routines for vax. File copied from arm32/bus_dma.c.
41 * NetBSD: bus_dma.c,v 1.11 1998/09/21 22:53:35 thorpej Exp
42 */
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/map.h>
48 #include <sys/proc.h>
49 #include <sys/buf.h>
50 #include <sys/reboot.h>
51 #include <sys/conf.h>
52 #include <sys/file.h>
53 #include <sys/malloc.h>
54 #include <sys/mbuf.h>
55 #include <sys/vnode.h>
56 #include <sys/device.h>
57
58 #include <vm/vm.h>
59 #include <vm/vm_kern.h>
60 #include <vm/vm_page.h>
61
62 #include <uvm/uvm_extern.h>
63
64 #define _VAX_BUS_DMA_PRIVATE
65 #include <machine/bus.h>
66
67 #include <machine/ka43.h>
68 #include <machine/sid.h>
69
70 extern vaddr_t avail_start, avail_end, virtual_avail;
71
72 int _bus_dmamap_load_buffer __P((bus_dma_tag_t, bus_dmamap_t, void *,
73 bus_size_t, struct proc *, int, vm_offset_t *, int *, int));
74 int _bus_dma_inrange __P((bus_dma_segment_t *, int, bus_addr_t));
75 int _bus_dmamem_alloc_range __P((bus_dma_tag_t, bus_size_t, bus_size_t,
76 bus_size_t, bus_dma_segment_t*, int, int *, int, vaddr_t, vaddr_t));
77 /*
78 * Common function for DMA map creation. May be called by bus-specific
79 * DMA map creation functions.
80 */
81 int
82 _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, flags, dmamp)
83 bus_dma_tag_t t;
84 bus_size_t size;
85 int nsegments;
86 bus_size_t maxsegsz;
87 bus_size_t boundary;
88 int flags;
89 bus_dmamap_t *dmamp;
90 {
91 struct vax_bus_dmamap *map;
92 void *mapstore;
93 size_t mapsize;
94
95 #ifdef DEBUG_DMA
96 printf("dmamap_create: t=%p size=%lx nseg=%x msegsz=%lx boundary=%lx flags=%x\n",
97 t, size, nsegments, maxsegsz, boundary, flags);
98 #endif /* DEBUG_DMA */
99
100 /*
101 * Allocate and initialize the DMA map. The end of the map
102 * is a variable-sized array of segments, so we allocate enough
103 * room for them in one shot.
104 *
105 * Note we don't preserve the WAITOK or NOWAIT flags. Preservation
106 * of ALLOCNOW notifies others that we've reserved these resources,
107 * and they are not to be freed.
108 *
109 * The bus_dmamap_t includes one bus_dma_segment_t, hence
110 * the (nsegments - 1).
111 */
112 mapsize = sizeof(struct vax_bus_dmamap) +
113 (sizeof(bus_dma_segment_t) * (nsegments - 1));
114 if ((mapstore = malloc(mapsize, M_DMAMAP,
115 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
116 return (ENOMEM);
117
118 bzero(mapstore, mapsize);
119 map = (struct vax_bus_dmamap *)mapstore;
120 map->_dm_size = size;
121 map->_dm_segcnt = nsegments;
122 map->_dm_maxsegsz = maxsegsz;
123 map->_dm_boundary = boundary;
124 map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
125 map->dm_mapsize = 0; /* no valid mappings */
126 map->dm_nsegs = 0;
127
128 *dmamp = map;
129 #ifdef DEBUG_DMA
130 printf("dmamap_create:map=%p\n", map);
131 #endif /* DEBUG_DMA */
132 return (0);
133 }
134
135 /*
136 * Common function for DMA map destruction. May be called by bus-specific
137 * DMA map destruction functions.
138 */
139 void
140 _bus_dmamap_destroy(t, map)
141 bus_dma_tag_t t;
142 bus_dmamap_t map;
143 {
144
145 #ifdef DEBUG_DMA
146 printf("dmamap_destroy: t=%p map=%p\n", t, map);
147 #endif /* DEBUG_DMA */
148 #ifdef DIAGNOSTIC
149 if (map->dm_nsegs > 0)
150 printf("bus_dmamap_destroy() called for map with valid mappings\n");
151 #endif /* DIAGNOSTIC */
152 free(map, M_DEVBUF);
153 }
154
155 /*
156 * Common function for loading a DMA map with a linear buffer. May
157 * be called by bus-specific DMA map load functions.
158 */
159 int
160 _bus_dmamap_load(t, map, buf, buflen, p, flags)
161 bus_dma_tag_t t;
162 bus_dmamap_t map;
163 void *buf;
164 bus_size_t buflen;
165 struct proc *p;
166 int flags;
167 {
168 vm_offset_t lastaddr;
169 int seg, error;
170
171 #ifdef DEBUG_DMA
172 printf("dmamap_load: t=%p map=%p buf=%p len=%lx p=%p f=%d\n",
173 t, map, buf, buflen, p, flags);
174 #endif /* DEBUG_DMA */
175
176 /*
177 * Make sure that on error condition we return "no valid mappings".
178 */
179 map->dm_mapsize = 0;
180 map->dm_nsegs = 0;
181
182 if (buflen > map->_dm_size)
183 return (EINVAL);
184
185 seg = 0;
186 error = _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags,
187 &lastaddr, &seg, 1);
188 if (error == 0) {
189 map->dm_mapsize = buflen;
190 map->dm_nsegs = seg + 1;
191 }
192 #ifdef DEBUG_DMA
193 printf("dmamap_load: error=%d\n", error);
194 #endif /* DEBUG_DMA */
195 return (error);
196 }
197
198 /*
199 * Like _bus_dmamap_load(), but for mbufs.
200 */
201 int
202 _bus_dmamap_load_mbuf(t, map, m0, flags)
203 bus_dma_tag_t t;
204 bus_dmamap_t map;
205 struct mbuf *m0;
206 int flags;
207 {
208 vm_offset_t lastaddr;
209 int seg, error, first;
210 struct mbuf *m;
211
212 #ifdef DEBUG_DMA
213 printf("dmamap_load_mbuf: t=%p map=%p m0=%p f=%d\n",
214 t, map, m0, flags);
215 #endif /* DEBUG_DMA */
216
217 /*
218 * Make sure that on error condition we return "no valid mappings."
219 */
220 map->dm_mapsize = 0;
221 map->dm_nsegs = 0;
222
223 #ifdef DIAGNOSTIC
224 if ((m0->m_flags & M_PKTHDR) == 0)
225 panic("_bus_dmamap_load_mbuf: no packet header");
226 #endif /* DIAGNOSTIC */
227
228 if (m0->m_pkthdr.len > map->_dm_size)
229 return (EINVAL);
230
231 first = 1;
232 seg = 0;
233 error = 0;
234 for (m = m0; m != NULL && error == 0; m = m->m_next) {
235 error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len,
236 NULL, flags, &lastaddr, &seg, first);
237 first = 0;
238 }
239 if (error == 0) {
240 map->dm_mapsize = m0->m_pkthdr.len;
241 map->dm_nsegs = seg + 1;
242 }
243 #ifdef DEBUG_DMA
244 printf("dmamap_load_mbuf: error=%d\n", error);
245 #endif /* DEBUG_DMA */
246 return (error);
247 }
248
249 /*
250 * Like _bus_dmamap_load(), but for uios.
251 */
252 int
253 _bus_dmamap_load_uio(t, map, uio, flags)
254 bus_dma_tag_t t;
255 bus_dmamap_t map;
256 struct uio *uio;
257 int flags;
258 {
259 vm_offset_t lastaddr;
260 int seg, i, error, first;
261 bus_size_t minlen, resid;
262 struct proc *p = NULL;
263 struct iovec *iov;
264 caddr_t addr;
265
266 /*
267 * Make sure that on error condition we return "no valid mappings."
268 */
269 map->dm_mapsize = 0;
270 map->dm_nsegs = 0;
271
272 resid = uio->uio_resid;
273 iov = uio->uio_iov;
274
275 if (uio->uio_segflg == UIO_USERSPACE) {
276 p = uio->uio_procp;
277 #ifdef DIAGNOSTIC
278 if (p == NULL)
279 panic("_bus_dmamap_load_uio: USERSPACE but no proc");
280 #endif
281 }
282
283 first = 1;
284 seg = 0;
285 error = 0;
286 for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
287 /*
288 * Now at the first iovec to load. Load each iovec
289 * until we have exhausted the residual count.
290 */
291 minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
292 addr = (caddr_t)iov[i].iov_base;
293
294 error = _bus_dmamap_load_buffer(t, map, addr, minlen,
295 p, flags, &lastaddr, &seg, first);
296 first = 0;
297
298 resid -= minlen;
299 }
300 if (error == 0) {
301 map->dm_mapsize = uio->uio_resid;
302 map->dm_nsegs = seg + 1;
303 }
304 return (error);
305 }
306
307 /*
308 * Like _bus_dmamap_load(), but for raw memory allocated with
309 * bus_dmamem_alloc().
310 */
311 int
312 _bus_dmamap_load_raw(t, map, segs, nsegs, size, flags)
313 bus_dma_tag_t t;
314 bus_dmamap_t map;
315 bus_dma_segment_t *segs;
316 int nsegs;
317 bus_size_t size;
318 int flags;
319 {
320
321 panic("_bus_dmamap_load_raw: not implemented");
322 }
323
324 /*
325 * Common function for unloading a DMA map. May be called by
326 * bus-specific DMA map unload functions.
327 */
328 void
329 _bus_dmamap_unload(t, map)
330 bus_dma_tag_t t;
331 bus_dmamap_t map;
332 {
333
334 #ifdef DEBUG_DMA
335 printf("dmamap_unload: t=%p map=%p\n", t, map);
336 #endif /* DEBUG_DMA */
337
338 /*
339 * No resources to free; just mark the mappings as
340 * invalid.
341 */
342 map->dm_mapsize = 0;
343 map->dm_nsegs = 0;
344 }
345
346 /*
347 * Common function for DMA map synchronization. May be called
348 * by bus-specific DMA map synchronization functions.
349 */
350 void
351 _bus_dmamap_sync(t, map, offset, len, ops)
352 bus_dma_tag_t t;
353 bus_dmamap_t map;
354 bus_addr_t offset;
355 bus_size_t len;
356 int ops;
357 {
358 #ifdef DEBUG_DMA
359 printf("dmamap_sync: t=%p map=%p offset=%lx len=%lx ops=%x\n",
360 t, map, offset, len, ops);
361 #endif /* DEBUG_DMA */
362 /*
363 * A vax only has snoop-cache, so this routine is a no-op.
364 */
365 return;
366 }
367
368 /*
369 * Common function for DMA-safe memory allocation. May be called
370 * by bus-specific DMA memory allocation functions.
371 */
372
373 int
374 _bus_dmamem_alloc(t, size, alignment, boundary, segs, nsegs, rsegs, flags)
375 bus_dma_tag_t t;
376 bus_size_t size, alignment, boundary;
377 bus_dma_segment_t *segs;
378 int nsegs;
379 int *rsegs;
380 int flags;
381 {
382 int error;
383
384 error = (_bus_dmamem_alloc_range(t, size, alignment, boundary,
385 segs, nsegs, rsegs, flags, round_page(avail_start),
386 trunc_page(avail_end)));
387 return(error);
388 }
389
390 /*
391 * Common function for freeing DMA-safe memory. May be called by
392 * bus-specific DMA memory free functions.
393 */
394 void
395 _bus_dmamem_free(t, segs, nsegs)
396 bus_dma_tag_t t;
397 bus_dma_segment_t *segs;
398 int nsegs;
399 {
400 vm_page_t m;
401 bus_addr_t addr;
402 struct pglist mlist;
403 int curseg;
404
405 #ifdef DEBUG_DMA
406 printf("dmamem_free: t=%p segs=%p nsegs=%x\n", t, segs, nsegs);
407 #endif /* DEBUG_DMA */
408
409 /*
410 * Build a list of pages to free back to the VM system.
411 */
412 TAILQ_INIT(&mlist);
413 for (curseg = 0; curseg < nsegs; curseg++) {
414 for (addr = segs[curseg].ds_addr;
415 addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
416 addr += PAGE_SIZE) {
417 m = PHYS_TO_VM_PAGE(addr);
418 TAILQ_INSERT_TAIL(&mlist, m, pageq);
419 }
420 }
421 uvm_pglistfree(&mlist);
422 }
423
424 /*
425 * Common function for mapping DMA-safe memory. May be called by
426 * bus-specific DMA memory map functions.
427 */
428 int
429 _bus_dmamem_map(t, segs, nsegs, size, kvap, flags)
430 bus_dma_tag_t t;
431 bus_dma_segment_t *segs;
432 int nsegs;
433 size_t size;
434 caddr_t *kvap;
435 int flags;
436 {
437 vm_offset_t va;
438 bus_addr_t addr;
439 int curseg;
440
441 /*
442 * Special case (but common):
443 * If there is only one physical segment then the already-mapped
444 * virtual address is returned, since all physical memory is already
445 * in the beginning of kernel virtual memory.
446 */
447 if (nsegs == 1) {
448 *kvap = (caddr_t)(segs[0].ds_addr | KERNBASE);
449 /*
450 * KA43 (3100/m76) must have its DMA-safe memory accessed
451 * through DIAGMEM. Remap it here.
452 */
453 if (vax_boardtype == VAX_BTYP_43) {
454 pmap_map((vaddr_t)*kvap, segs[0].ds_addr|KA43_DIAGMEM,
455 (segs[0].ds_addr|KA43_DIAGMEM) + size,
456 VM_PROT_READ|VM_PROT_WRITE);
457 }
458 return 0;
459 }
460 size = round_page(size);
461 va = uvm_km_valloc(kernel_map, size);
462
463 if (va == 0)
464 return (ENOMEM);
465
466 *kvap = (caddr_t)va;
467
468 for (curseg = 0; curseg < nsegs; curseg++) {
469 for (addr = segs[curseg].ds_addr;
470 addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
471 addr += NBPG, va += NBPG, size -= NBPG) {
472 if (size == 0)
473 panic("_bus_dmamem_map: size botch");
474 if (vax_boardtype == VAX_BTYP_43)
475 addr |= KA43_DIAGMEM;
476 pmap_kenter_pa(va, addr, VM_PROT_READ | VM_PROT_WRITE);
477 }
478 }
479 return (0);
480 }
481
482 /*
483 * Common function for unmapping DMA-safe memory. May be called by
484 * bus-specific DMA memory unmapping functions.
485 */
486 void
487 _bus_dmamem_unmap(t, kva, size)
488 bus_dma_tag_t t;
489 caddr_t kva;
490 size_t size;
491 {
492
493 #ifdef DEBUG_DMA
494 printf("dmamem_unmap: t=%p kva=%p size=%x\n", t, kva, size);
495 #endif /* DEBUG_DMA */
496 #ifdef DIAGNOSTIC
497 if ((u_long)kva & PGOFSET)
498 panic("_bus_dmamem_unmap");
499 #endif /* DIAGNOSTIC */
500
501 /* Avoid free'ing if not mapped */
502 if (kva >= (caddr_t)virtual_avail)
503 uvm_km_free(kernel_map, (vm_offset_t)kva, round_page(size));
504 }
505
506 /*
507 * Common functin for mmap(2)'ing DMA-safe memory. May be called by
508 * bus-specific DMA mmap(2)'ing functions.
509 */
510 int
511 _bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
512 bus_dma_tag_t t;
513 bus_dma_segment_t *segs;
514 int nsegs, off, prot, flags;
515 {
516 int i;
517
518 for (i = 0; i < nsegs; i++) {
519 #ifdef DIAGNOSTIC
520 if (off & PGOFSET)
521 panic("_bus_dmamem_mmap: offset unaligned");
522 if (segs[i].ds_addr & PGOFSET)
523 panic("_bus_dmamem_mmap: segment unaligned");
524 if (segs[i].ds_len & PGOFSET)
525 panic("_bus_dmamem_mmap: segment size not multiple"
526 " of page size");
527 #endif /* DIAGNOSTIC */
528 if (off >= segs[i].ds_len) {
529 off -= segs[i].ds_len;
530 continue;
531 }
532
533 return (btop((u_long)segs[i].ds_addr + off));
534 }
535
536 /* Page not found. */
537 return (-1);
538 }
539
540 /**********************************************************************
541 * DMA utility functions
542 **********************************************************************/
543
544 /*
545 * Utility function to load a linear buffer. lastaddrp holds state
546 * between invocations (for multiple-buffer loads). segp contains
547 * the starting segment on entrace, and the ending segment on exit.
548 * first indicates if this is the first invocation of this function.
549 */
550 int
551 _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags, lastaddrp, segp, first)
552 bus_dma_tag_t t;
553 bus_dmamap_t map;
554 void *buf;
555 bus_size_t buflen;
556 struct proc *p;
557 int flags;
558 vm_offset_t *lastaddrp;
559 int *segp;
560 int first;
561 {
562 bus_size_t sgsize;
563 bus_addr_t curaddr, lastaddr, baddr, bmask;
564 vm_offset_t vaddr = (vm_offset_t)buf;
565 int seg;
566 pmap_t pmap;
567
568 #ifdef DEBUG_DMA
569 printf("_bus_dmamem_load_buffer(buf=%p, len=%lx, flags=%d, 1st=%d)\n",
570 buf, buflen, flags, first);
571 #endif /* DEBUG_DMA */
572
573 if (p != NULL)
574 pmap = p->p_vmspace->vm_map.pmap;
575 else
576 pmap = pmap_kernel();
577
578 lastaddr = *lastaddrp;
579 bmask = ~(map->_dm_boundary - 1);
580
581 for (seg = *segp; buflen > 0; ) {
582 /*
583 * Get the physical address for this segment.
584 */
585 curaddr = pmap_extract(pmap, (vm_offset_t)vaddr);
586
587 #if 0
588 /*
589 * Make sure we're in an allowed DMA range.
590 */
591 if (t->_ranges != NULL &&
592 _bus_dma_inrange(t->_ranges, t->_nranges, curaddr) == 0)
593 return (EINVAL);
594 #endif
595
596 /*
597 * Compute the segment size, and adjust counts.
598 */
599 sgsize = NBPG - ((u_long)vaddr & PGOFSET);
600 if (buflen < sgsize)
601 sgsize = buflen;
602
603 /*
604 * Make sure we don't cross any boundaries.
605 */
606 if (map->_dm_boundary > 0) {
607 baddr = (curaddr + map->_dm_boundary) & bmask;
608 if (sgsize > (baddr - curaddr))
609 sgsize = (baddr - curaddr);
610 }
611
612 /*
613 * Insert chunk into a segment, coalescing with
614 * previous segment if possible.
615 */
616 if (first) {
617 map->dm_segs[seg].ds_addr = curaddr;
618 map->dm_segs[seg].ds_len = sgsize;
619 first = 0;
620 } else {
621 if (curaddr == lastaddr &&
622 (map->dm_segs[seg].ds_len + sgsize) <=
623 map->_dm_maxsegsz &&
624 (map->_dm_boundary == 0 ||
625 (map->dm_segs[seg].ds_addr & bmask) ==
626 (curaddr & bmask)))
627 map->dm_segs[seg].ds_len += sgsize;
628 else {
629 if (++seg >= map->_dm_segcnt)
630 break;
631 map->dm_segs[seg].ds_addr = curaddr;
632 map->dm_segs[seg].ds_len = sgsize;
633 }
634 }
635
636 lastaddr = curaddr + sgsize;
637 vaddr += sgsize;
638 buflen -= sgsize;
639 }
640
641 *segp = seg;
642 *lastaddrp = lastaddr;
643
644 /*
645 * Did we fit?
646 */
647 if (buflen != 0)
648 return (EFBIG); /* XXX better return value here? */
649 return (0);
650 }
651
652 /*
653 * Check to see if the specified page is in an allowed DMA range.
654 */
655 int
656 _bus_dma_inrange(ranges, nranges, curaddr)
657 bus_dma_segment_t *ranges;
658 int nranges;
659 bus_addr_t curaddr;
660 {
661 bus_dma_segment_t *ds;
662 int i;
663
664 for (i = 0, ds = ranges; i < nranges; i++, ds++) {
665 if (curaddr >= ds->ds_addr &&
666 round_page(curaddr) <= (ds->ds_addr + ds->ds_len))
667 return (1);
668 }
669
670 return (0);
671 }
672
673 /*
674 * Allocate physical memory from the given physical address range.
675 * Called by DMA-safe memory allocation methods.
676 */
677 int
678 _bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs,
679 flags, low, high)
680 bus_dma_tag_t t;
681 bus_size_t size, alignment, boundary;
682 bus_dma_segment_t *segs;
683 int nsegs;
684 int *rsegs;
685 int flags;
686 vm_offset_t low;
687 vm_offset_t high;
688 {
689 vm_offset_t curaddr, lastaddr;
690 vm_page_t m;
691 struct pglist mlist;
692 int curseg, error;
693
694 #ifdef DEBUG_DMA
695 printf("alloc_range: t=%p size=%lx align=%lx boundary=%lx segs=%p nsegs=%x rsegs=%p flags=%x lo=%lx hi=%lx\n",
696 t, size, alignment, boundary, segs, nsegs, rsegs, flags, low, high);
697 #endif /* DEBUG_DMA */
698
699 /* Always round the size. */
700 size = round_page(size);
701
702 /*
703 * Allocate pages from the VM system.
704 */
705 TAILQ_INIT(&mlist);
706 error = uvm_pglistalloc(size, low, high, alignment, boundary,
707 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
708 if (error)
709 return (error);
710
711 /*
712 * Compute the location, size, and number of segments actually
713 * returned by the VM code.
714 */
715 m = mlist.tqh_first;
716 curseg = 0;
717 lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
718 segs[curseg].ds_len = PAGE_SIZE;
719 #ifdef DEBUG_DMA
720 printf("alloc: page %lx\n", lastaddr);
721 #endif /* DEBUG_DMA */
722 m = m->pageq.tqe_next;
723
724 for (; m != NULL; m = m->pageq.tqe_next) {
725 curaddr = VM_PAGE_TO_PHYS(m);
726 #ifdef DIAGNOSTIC
727 if (curaddr < low || curaddr >= high) {
728 printf("vm_page_alloc_memory returned non-sensical"
729 " address 0x%lx\n", curaddr);
730 panic("_bus_dmamem_alloc_range");
731 }
732 #endif /* DIAGNOSTIC */
733 #ifdef DEBUG_DMA
734 printf("alloc: page %lx\n", curaddr);
735 #endif /* DEBUG_DMA */
736 if (curaddr == (lastaddr + PAGE_SIZE))
737 segs[curseg].ds_len += PAGE_SIZE;
738 else {
739 curseg++;
740 segs[curseg].ds_addr = curaddr;
741 segs[curseg].ds_len = PAGE_SIZE;
742 }
743 lastaddr = curaddr;
744 }
745
746 *rsegs = curseg + 1;
747
748 return (0);
749 }
750