bus_dma.c revision 1.15 1 /* $NetBSD: bus_dma.c,v 1.15 2002/09/25 22:21:29 thorpej 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/proc.h>
48 #include <sys/buf.h>
49 #include <sys/reboot.h>
50 #include <sys/conf.h>
51 #include <sys/file.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/vnode.h>
55 #include <sys/device.h>
56
57 #include <uvm/uvm_extern.h>
58
59 #define _VAX_BUS_DMA_PRIVATE
60 #include <machine/bus.h>
61
62 #include <machine/ka43.h>
63 #include <machine/sid.h>
64
65 extern vaddr_t avail_start, avail_end, virtual_avail;
66
67 int _bus_dmamap_load_buffer __P((bus_dma_tag_t, bus_dmamap_t, void *,
68 bus_size_t, struct proc *, int, vaddr_t *, int *, int));
69 int _bus_dma_inrange __P((bus_dma_segment_t *, int, bus_addr_t));
70 int _bus_dmamem_alloc_range __P((bus_dma_tag_t, bus_size_t, bus_size_t,
71 bus_size_t, bus_dma_segment_t*, int, int *, int, vaddr_t, vaddr_t));
72 /*
73 * Common function for DMA map creation. May be called by bus-specific
74 * DMA map creation functions.
75 */
76 int
77 _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, flags, dmamp)
78 bus_dma_tag_t t;
79 bus_size_t size;
80 int nsegments;
81 bus_size_t maxsegsz;
82 bus_size_t boundary;
83 int flags;
84 bus_dmamap_t *dmamp;
85 {
86 struct vax_bus_dmamap *map;
87 void *mapstore;
88 size_t mapsize;
89
90 #ifdef DEBUG_DMA
91 printf("dmamap_create: t=%p size=%lx nseg=%x msegsz=%lx boundary=%lx flags=%x\n",
92 t, size, nsegments, maxsegsz, boundary, flags);
93 #endif /* DEBUG_DMA */
94
95 /*
96 * Allocate and initialize the DMA map. The end of the map
97 * is a variable-sized array of segments, so we allocate enough
98 * room for them in one shot.
99 *
100 * Note we don't preserve the WAITOK or NOWAIT flags. Preservation
101 * of ALLOCNOW notifies others that we've reserved these resources,
102 * and they are not to be freed.
103 *
104 * The bus_dmamap_t includes one bus_dma_segment_t, hence
105 * the (nsegments - 1).
106 */
107 mapsize = sizeof(struct vax_bus_dmamap) +
108 (sizeof(bus_dma_segment_t) * (nsegments - 1));
109 if ((mapstore = malloc(mapsize, M_DMAMAP,
110 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
111 return (ENOMEM);
112
113 bzero(mapstore, mapsize);
114 map = (struct vax_bus_dmamap *)mapstore;
115 map->_dm_size = size;
116 map->_dm_segcnt = nsegments;
117 map->_dm_maxsegsz = maxsegsz;
118 map->_dm_boundary = boundary;
119 map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
120 map->dm_mapsize = 0; /* no valid mappings */
121 map->dm_nsegs = 0;
122
123 *dmamp = map;
124 #ifdef DEBUG_DMA
125 printf("dmamap_create:map=%p\n", map);
126 #endif /* DEBUG_DMA */
127 return (0);
128 }
129
130 /*
131 * Common function for DMA map destruction. May be called by bus-specific
132 * DMA map destruction functions.
133 */
134 void
135 _bus_dmamap_destroy(t, map)
136 bus_dma_tag_t t;
137 bus_dmamap_t map;
138 {
139
140 #ifdef DEBUG_DMA
141 printf("dmamap_destroy: t=%p map=%p\n", t, map);
142 #endif /* DEBUG_DMA */
143 #ifdef DIAGNOSTIC
144 if (map->dm_nsegs > 0)
145 printf("bus_dmamap_destroy() called for map with valid mappings\n");
146 #endif /* DIAGNOSTIC */
147 free(map, M_DEVBUF);
148 }
149
150 /*
151 * Common function for loading a DMA map with a linear buffer. May
152 * be called by bus-specific DMA map load functions.
153 */
154 int
155 _bus_dmamap_load(t, map, buf, buflen, p, flags)
156 bus_dma_tag_t t;
157 bus_dmamap_t map;
158 void *buf;
159 bus_size_t buflen;
160 struct proc *p;
161 int flags;
162 {
163 vaddr_t lastaddr;
164 int seg, error;
165
166 #ifdef DEBUG_DMA
167 printf("dmamap_load: t=%p map=%p buf=%p len=%lx p=%p f=%d\n",
168 t, map, buf, buflen, p, flags);
169 #endif /* DEBUG_DMA */
170
171 /*
172 * Make sure that on error condition we return "no valid mappings".
173 */
174 map->dm_mapsize = 0;
175 map->dm_nsegs = 0;
176
177 if (buflen > map->_dm_size)
178 return (EINVAL);
179
180 seg = 0;
181 error = _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags,
182 &lastaddr, &seg, 1);
183 if (error == 0) {
184 map->dm_mapsize = buflen;
185 map->dm_nsegs = seg + 1;
186 }
187 #ifdef DEBUG_DMA
188 printf("dmamap_load: error=%d\n", error);
189 #endif /* DEBUG_DMA */
190 return (error);
191 }
192
193 /*
194 * Like _bus_dmamap_load(), but for mbufs.
195 */
196 int
197 _bus_dmamap_load_mbuf(t, map, m0, flags)
198 bus_dma_tag_t t;
199 bus_dmamap_t map;
200 struct mbuf *m0;
201 int flags;
202 {
203 vaddr_t lastaddr;
204 int seg, error, first;
205 struct mbuf *m;
206
207 #ifdef DEBUG_DMA
208 printf("dmamap_load_mbuf: t=%p map=%p m0=%p f=%d\n",
209 t, map, m0, flags);
210 #endif /* DEBUG_DMA */
211
212 /*
213 * Make sure that on error condition we return "no valid mappings."
214 */
215 map->dm_mapsize = 0;
216 map->dm_nsegs = 0;
217
218 #ifdef DIAGNOSTIC
219 if ((m0->m_flags & M_PKTHDR) == 0)
220 panic("_bus_dmamap_load_mbuf: no packet header");
221 #endif /* DIAGNOSTIC */
222
223 if (m0->m_pkthdr.len > map->_dm_size)
224 return (EINVAL);
225
226 first = 1;
227 seg = 0;
228 error = 0;
229 for (m = m0; m != NULL && error == 0; m = m->m_next) {
230 error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len,
231 NULL, flags, &lastaddr, &seg, first);
232 first = 0;
233 }
234 if (error == 0) {
235 map->dm_mapsize = m0->m_pkthdr.len;
236 map->dm_nsegs = seg + 1;
237 }
238 #ifdef DEBUG_DMA
239 printf("dmamap_load_mbuf: error=%d\n", error);
240 #endif /* DEBUG_DMA */
241 return (error);
242 }
243
244 /*
245 * Like _bus_dmamap_load(), but for uios.
246 */
247 int
248 _bus_dmamap_load_uio(t, map, uio, flags)
249 bus_dma_tag_t t;
250 bus_dmamap_t map;
251 struct uio *uio;
252 int flags;
253 {
254 vaddr_t lastaddr;
255 int seg, i, error, first;
256 bus_size_t minlen, resid;
257 struct proc *p = NULL;
258 struct iovec *iov;
259 caddr_t addr;
260
261 /*
262 * Make sure that on error condition we return "no valid mappings."
263 */
264 map->dm_mapsize = 0;
265 map->dm_nsegs = 0;
266
267 resid = uio->uio_resid;
268 iov = uio->uio_iov;
269
270 if (uio->uio_segflg == UIO_USERSPACE) {
271 p = uio->uio_procp;
272 #ifdef DIAGNOSTIC
273 if (p == NULL)
274 panic("_bus_dmamap_load_uio: USERSPACE but no proc");
275 #endif
276 }
277
278 first = 1;
279 seg = 0;
280 error = 0;
281 for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
282 /*
283 * Now at the first iovec to load. Load each iovec
284 * until we have exhausted the residual count.
285 */
286 minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
287 addr = (caddr_t)iov[i].iov_base;
288
289 error = _bus_dmamap_load_buffer(t, map, addr, minlen,
290 p, flags, &lastaddr, &seg, first);
291 first = 0;
292
293 resid -= minlen;
294 }
295 if (error == 0) {
296 map->dm_mapsize = uio->uio_resid;
297 map->dm_nsegs = seg + 1;
298 }
299 return (error);
300 }
301
302 /*
303 * Like _bus_dmamap_load(), but for raw memory allocated with
304 * bus_dmamem_alloc().
305 */
306 int
307 _bus_dmamap_load_raw(t, map, segs, nsegs, size, flags)
308 bus_dma_tag_t t;
309 bus_dmamap_t map;
310 bus_dma_segment_t *segs;
311 int nsegs;
312 bus_size_t size;
313 int flags;
314 {
315
316 panic("_bus_dmamap_load_raw: not implemented");
317 }
318
319 /*
320 * Common function for unloading a DMA map. May be called by
321 * bus-specific DMA map unload functions.
322 */
323 void
324 _bus_dmamap_unload(t, map)
325 bus_dma_tag_t t;
326 bus_dmamap_t map;
327 {
328
329 #ifdef DEBUG_DMA
330 printf("dmamap_unload: t=%p map=%p\n", t, map);
331 #endif /* DEBUG_DMA */
332
333 /*
334 * No resources to free; just mark the mappings as
335 * invalid.
336 */
337 map->dm_mapsize = 0;
338 map->dm_nsegs = 0;
339 }
340
341 /*
342 * Common function for DMA map synchronization. May be called
343 * by bus-specific DMA map synchronization functions.
344 */
345 void
346 _bus_dmamap_sync(t, map, offset, len, ops)
347 bus_dma_tag_t t;
348 bus_dmamap_t map;
349 bus_addr_t offset;
350 bus_size_t len;
351 int ops;
352 {
353 #ifdef DEBUG_DMA
354 printf("dmamap_sync: t=%p map=%p offset=%lx len=%lx ops=%x\n",
355 t, map, offset, len, ops);
356 #endif /* DEBUG_DMA */
357 /*
358 * A vax only has snoop-cache, so this routine is a no-op.
359 */
360 return;
361 }
362
363 /*
364 * Common function for DMA-safe memory allocation. May be called
365 * by bus-specific DMA memory allocation functions.
366 */
367
368 int
369 _bus_dmamem_alloc(t, size, alignment, boundary, segs, nsegs, rsegs, flags)
370 bus_dma_tag_t t;
371 bus_size_t size, alignment, boundary;
372 bus_dma_segment_t *segs;
373 int nsegs;
374 int *rsegs;
375 int flags;
376 {
377 int error;
378
379 error = (_bus_dmamem_alloc_range(t, size, alignment, boundary,
380 segs, nsegs, rsegs, flags, round_page(avail_start),
381 trunc_page(avail_end)));
382 return(error);
383 }
384
385 /*
386 * Common function for freeing DMA-safe memory. May be called by
387 * bus-specific DMA memory free functions.
388 */
389 void
390 _bus_dmamem_free(t, segs, nsegs)
391 bus_dma_tag_t t;
392 bus_dma_segment_t *segs;
393 int nsegs;
394 {
395 struct vm_page *m;
396 bus_addr_t addr;
397 struct pglist mlist;
398 int curseg;
399
400 #ifdef DEBUG_DMA
401 printf("dmamem_free: t=%p segs=%p nsegs=%x\n", t, segs, nsegs);
402 #endif /* DEBUG_DMA */
403
404 /*
405 * Build a list of pages to free back to the VM system.
406 */
407 TAILQ_INIT(&mlist);
408 for (curseg = 0; curseg < nsegs; curseg++) {
409 for (addr = segs[curseg].ds_addr;
410 addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
411 addr += PAGE_SIZE) {
412 m = PHYS_TO_VM_PAGE(addr);
413 TAILQ_INSERT_TAIL(&mlist, m, pageq);
414 }
415 }
416 uvm_pglistfree(&mlist);
417 }
418
419 /*
420 * Common function for mapping DMA-safe memory. May be called by
421 * bus-specific DMA memory map functions.
422 */
423 int
424 _bus_dmamem_map(t, segs, nsegs, size, kvap, flags)
425 bus_dma_tag_t t;
426 bus_dma_segment_t *segs;
427 int nsegs;
428 size_t size;
429 caddr_t *kvap;
430 int flags;
431 {
432 vaddr_t va;
433 bus_addr_t addr;
434 int curseg;
435
436 /*
437 * Special case (but common):
438 * If there is only one physical segment then the already-mapped
439 * virtual address is returned, since all physical memory is already
440 * in the beginning of kernel virtual memory.
441 */
442 if (nsegs == 1) {
443 *kvap = (caddr_t)(segs[0].ds_addr | KERNBASE);
444 /*
445 * KA43 (3100/m76) must have its DMA-safe memory accessed
446 * through DIAGMEM. Remap it here.
447 */
448 if (vax_boardtype == VAX_BTYP_43) {
449 pmap_map((vaddr_t)*kvap, segs[0].ds_addr|KA43_DIAGMEM,
450 (segs[0].ds_addr|KA43_DIAGMEM) + size,
451 VM_PROT_READ|VM_PROT_WRITE);
452 }
453 return 0;
454 }
455 size = round_page(size);
456 va = uvm_km_valloc(kernel_map, size);
457
458 if (va == 0)
459 return (ENOMEM);
460
461 *kvap = (caddr_t)va;
462
463 for (curseg = 0; curseg < nsegs; curseg++) {
464 for (addr = segs[curseg].ds_addr;
465 addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
466 addr += NBPG, va += NBPG, size -= NBPG) {
467 if (size == 0)
468 panic("_bus_dmamem_map: size botch");
469 if (vax_boardtype == VAX_BTYP_43)
470 addr |= KA43_DIAGMEM;
471 pmap_enter(pmap_kernel(), va, addr,
472 VM_PROT_READ | VM_PROT_WRITE,
473 VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED);
474 }
475 }
476 pmap_update(pmap_kernel());
477 return (0);
478 }
479
480 /*
481 * Common function for unmapping DMA-safe memory. May be called by
482 * bus-specific DMA memory unmapping functions.
483 */
484 void
485 _bus_dmamem_unmap(t, kva, size)
486 bus_dma_tag_t t;
487 caddr_t kva;
488 size_t size;
489 {
490
491 #ifdef DEBUG_DMA
492 printf("dmamem_unmap: t=%p kva=%p size=%x\n", t, kva, size);
493 #endif /* DEBUG_DMA */
494 #ifdef DIAGNOSTIC
495 if ((u_long)kva & PGOFSET)
496 panic("_bus_dmamem_unmap");
497 #endif /* DIAGNOSTIC */
498
499 /* Avoid free'ing if not mapped */
500 if (kva >= (caddr_t)virtual_avail)
501 uvm_km_free(kernel_map, (vaddr_t)kva, round_page(size));
502 }
503
504 /*
505 * Common functin for mmap(2)'ing DMA-safe memory. May be called by
506 * bus-specific DMA mmap(2)'ing functions.
507 */
508 paddr_t
509 _bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
510 bus_dma_tag_t t;
511 bus_dma_segment_t *segs;
512 int nsegs;
513 off_t off;
514 int 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 vaddr_t *lastaddrp;
559 int *segp;
560 int first;
561 {
562 bus_size_t sgsize;
563 bus_addr_t curaddr, lastaddr, baddr, bmask;
564 vaddr_t vaddr = (vaddr_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 (void) pmap_extract(pmap, (vaddr_t)vaddr, &curaddr);
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 vaddr_t low;
687 vaddr_t high;
688 {
689 vaddr_t curaddr, lastaddr;
690 struct vm_page *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 error = uvm_pglistalloc(size, low, high, alignment, boundary,
706 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
707 if (error)
708 return (error);
709
710 /*
711 * Compute the location, size, and number of segments actually
712 * returned by the VM code.
713 */
714 m = mlist.tqh_first;
715 curseg = 0;
716 lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
717 segs[curseg].ds_len = PAGE_SIZE;
718 #ifdef DEBUG_DMA
719 printf("alloc: page %lx\n", lastaddr);
720 #endif /* DEBUG_DMA */
721 m = m->pageq.tqe_next;
722
723 for (; m != NULL; m = m->pageq.tqe_next) {
724 curaddr = VM_PAGE_TO_PHYS(m);
725 #ifdef DIAGNOSTIC
726 if (curaddr < low || curaddr >= high) {
727 printf("uvm_pglistalloc returned non-sensical"
728 " address 0x%lx\n", curaddr);
729 panic("_bus_dmamem_alloc_range");
730 }
731 #endif /* DIAGNOSTIC */
732 #ifdef DEBUG_DMA
733 printf("alloc: page %lx\n", curaddr);
734 #endif /* DEBUG_DMA */
735 if (curaddr == (lastaddr + PAGE_SIZE))
736 segs[curseg].ds_len += PAGE_SIZE;
737 else {
738 curseg++;
739 segs[curseg].ds_addr = curaddr;
740 segs[curseg].ds_len = PAGE_SIZE;
741 }
742 lastaddr = curaddr;
743 }
744
745 *rsegs = curseg + 1;
746
747 return (0);
748 }
749
750 /*
751 * "generic" DMA struct, nothing special.
752 */
753 struct vax_bus_dma_tag vax_bus_dma_tag = {
754 NULL,
755 0,
756 0,
757 0,
758 0,
759 0,
760 _bus_dmamap_create,
761 _bus_dmamap_destroy,
762 _bus_dmamap_load,
763 _bus_dmamap_load_mbuf,
764 _bus_dmamap_load_uio,
765 _bus_dmamap_load_raw,
766 _bus_dmamap_unload,
767 _bus_dmamap_sync,
768 _bus_dmamem_alloc,
769 _bus_dmamem_free,
770 _bus_dmamem_map,
771 _bus_dmamem_unmap,
772 _bus_dmamem_mmap,
773 };
774