Annotation of sys/arch/mvme88k/mvme88k/bus_dma.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: bus_dma.c,v 1.5 2007/02/11 12:49:38 miod Exp $ */
! 2: /* $NetBSD: bus_dma.c,v 1.2 2001/06/10 02:31:25 briggs Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
! 6: * All rights reserved.
! 7: *
! 8: * This code is derived from software contributed to The NetBSD Foundation
! 9: * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
! 10: * NASA Ames Research Center.
! 11: *
! 12: * Redistribution and use in source and binary forms, with or without
! 13: * modification, are permitted provided that the following conditions
! 14: * are met:
! 15: * 1. Redistributions of source code must retain the above copyright
! 16: * notice, this list of conditions and the following disclaimer.
! 17: * 2. Redistributions in binary form must reproduce the above copyright
! 18: * notice, this list of conditions and the following disclaimer in the
! 19: * documentation and/or other materials provided with the distribution.
! 20: * 3. All advertising materials mentioning features or use of this software
! 21: * must display the following acknowledgement:
! 22: * This product includes software developed by the NetBSD
! 23: * Foundation, Inc. and its contributors.
! 24: * 4. Neither the name of The NetBSD Foundation nor the names of its
! 25: * contributors may be used to endorse or promote products derived
! 26: * from this software without specific prior written permission.
! 27: *
! 28: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
! 29: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
! 30: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
! 31: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
! 32: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
! 33: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
! 34: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
! 35: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
! 36: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
! 37: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
! 38: * POSSIBILITY OF SUCH DAMAGE.
! 39: */
! 40:
! 41: #include <sys/param.h>
! 42: #include <sys/proc.h>
! 43: #include <sys/user.h>
! 44: #include <sys/extent.h>
! 45: #include <sys/buf.h>
! 46: #include <sys/device.h>
! 47: #include <sys/systm.h>
! 48: #include <sys/conf.h>
! 49: #include <sys/file.h>
! 50: #include <sys/malloc.h>
! 51: #include <sys/mbuf.h>
! 52: #include <sys/mount.h>
! 53:
! 54: #include <uvm/uvm_extern.h>
! 55:
! 56: #include <machine/bus.h>
! 57: #include <machine/cmmu.h>
! 58: #include <machine/intr.h>
! 59:
! 60: int _bus_dmamap_load_buffer(bus_dma_tag_t, bus_dmamap_t, void *,
! 61: bus_size_t, struct proc *, int, paddr_t *, int *, int);
! 62:
! 63: int _bus_dmamem_alloc_range(bus_dma_tag_t, bus_size_t, bus_size_t,
! 64: bus_size_t, bus_dma_segment_t *, int, int *, int, paddr_t, paddr_t);
! 65:
! 66: /*
! 67: * Common function for DMA map creation. May be called by bus-specific
! 68: * DMA map creation functions.
! 69: */
! 70: int
! 71: bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, flags, dmamp)
! 72: bus_dma_tag_t t;
! 73: bus_size_t size;
! 74: int nsegments;
! 75: bus_size_t maxsegsz;
! 76: bus_size_t boundary;
! 77: int flags;
! 78: bus_dmamap_t *dmamp;
! 79: {
! 80: struct m88k_bus_dmamap *map;
! 81: void *mapstore;
! 82: size_t mapsize;
! 83:
! 84: /*
! 85: * Allocate and initialize the DMA map. The end of the map
! 86: * is a variable-sized array of segments, so we allocate enough
! 87: * room for them in one shot.
! 88: *
! 89: * Note we don't preserve the WAITOK or NOWAIT flags. Preservation
! 90: * of ALLOCNOW notifies others that we've reserved these resources,
! 91: * and they are not to be freed.
! 92: *
! 93: * The bus_dmamap_t includes one bus_dma_segment_t, hence
! 94: * the (nsegments - 1).
! 95: */
! 96: mapsize = sizeof(struct m88k_bus_dmamap) +
! 97: (sizeof(bus_dma_segment_t) * (nsegments - 1));
! 98: if ((mapstore = malloc(mapsize, M_DEVBUF,
! 99: (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
! 100: return (ENOMEM);
! 101:
! 102: memset(mapstore, 0, mapsize);
! 103: map = (struct m88k_bus_dmamap *)mapstore;
! 104: map->_dm_size = size;
! 105: map->_dm_segcnt = nsegments;
! 106: map->_dm_maxsegsz = maxsegsz;
! 107: map->_dm_boundary = boundary;
! 108: map->dm_mapsize = 0; /* no valid mappings */
! 109: map->dm_nsegs = 0;
! 110:
! 111: *dmamp = map;
! 112: return (0);
! 113: }
! 114:
! 115: /*
! 116: * Common function for DMA map destruction. May be called by bus-specific
! 117: * DMA map destruction functions.
! 118: */
! 119: void
! 120: bus_dmamap_destroy(t, map)
! 121: bus_dma_tag_t t;
! 122: bus_dmamap_t map;
! 123: {
! 124:
! 125: free(map, M_DEVBUF);
! 126: }
! 127:
! 128: /*
! 129: * Utility function to load a linear buffer. lastaddrp holds state
! 130: * between invocations (for multiple-buffer loads). segp contains
! 131: * the starting segment on entrance, and the ending segment on exit.
! 132: * first indicates if this is the first invocation of this function.
! 133: */
! 134: int
! 135: _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags, lastaddrp, segp, first)
! 136: bus_dma_tag_t t;
! 137: bus_dmamap_t map;
! 138: void *buf;
! 139: bus_size_t buflen;
! 140: struct proc *p;
! 141: int flags;
! 142: paddr_t *lastaddrp;
! 143: int *segp;
! 144: int first;
! 145: {
! 146: bus_size_t sgsize;
! 147: bus_addr_t curaddr, lastaddr, baddr, bmask;
! 148: vaddr_t vaddr = (vaddr_t)buf;
! 149: int seg;
! 150: pmap_t pmap;
! 151:
! 152: if (p != NULL)
! 153: pmap = vm_map_pmap(&p->p_vmspace->vm_map);
! 154: else
! 155: pmap = pmap_kernel();
! 156:
! 157: lastaddr = *lastaddrp;
! 158: bmask = ~(map->_dm_boundary - 1);
! 159:
! 160: for (seg = *segp; buflen > 0 ; ) {
! 161: /*
! 162: * Get the physical address for this segment.
! 163: */
! 164: if (pmap_extract(pmap, vaddr, (paddr_t *)&curaddr) == FALSE)
! 165: return (EINVAL);
! 166:
! 167: /*
! 168: * Compute the segment size, and adjust counts.
! 169: */
! 170: sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET);
! 171: if (buflen < sgsize)
! 172: sgsize = buflen;
! 173:
! 174: /*
! 175: * Make sure we don't cross any boundaries.
! 176: */
! 177: if (map->_dm_boundary > 0) {
! 178: baddr = (curaddr + map->_dm_boundary) & bmask;
! 179: if (sgsize > (baddr - curaddr))
! 180: sgsize = (baddr - curaddr);
! 181: }
! 182:
! 183: /*
! 184: * Insert chunk into a segment, coalescing with
! 185: * the previous segment if possible.
! 186: */
! 187: if (first) {
! 188: map->dm_segs[seg].ds_addr = curaddr;
! 189: map->dm_segs[seg].ds_len = sgsize;
! 190: first = 0;
! 191: } else {
! 192: if (curaddr == lastaddr &&
! 193: (map->dm_segs[seg].ds_len + sgsize) <=
! 194: map->_dm_maxsegsz &&
! 195: (map->_dm_boundary == 0 ||
! 196: (map->dm_segs[seg].ds_addr & bmask) ==
! 197: (curaddr & bmask)))
! 198: map->dm_segs[seg].ds_len += sgsize;
! 199: else {
! 200: if (++seg >= map->_dm_segcnt)
! 201: break;
! 202: map->dm_segs[seg].ds_addr = curaddr;
! 203: map->dm_segs[seg].ds_len = sgsize;
! 204: }
! 205: }
! 206:
! 207: lastaddr = curaddr + sgsize;
! 208: vaddr += sgsize;
! 209: buflen -= sgsize;
! 210: }
! 211:
! 212: *segp = seg;
! 213: *lastaddrp = lastaddr;
! 214:
! 215: /*
! 216: * Did we fit?
! 217: */
! 218: if (buflen != 0)
! 219: return (EFBIG); /* XXX better return value here? */
! 220:
! 221: return (0);
! 222: }
! 223:
! 224: /*
! 225: * Common function for loading a DMA map with a linear buffer. May
! 226: * be called by bus-specific DMA map load functions.
! 227: */
! 228: int
! 229: bus_dmamap_load(t, map, buf, buflen, p, flags)
! 230: bus_dma_tag_t t;
! 231: bus_dmamap_t map;
! 232: void *buf;
! 233: bus_size_t buflen;
! 234: struct proc *p;
! 235: int flags;
! 236: {
! 237: paddr_t lastaddr;
! 238: int seg, error;
! 239:
! 240: /*
! 241: * Make sure that on error condition we return "no valid mappings".
! 242: */
! 243: map->dm_mapsize = 0;
! 244: map->dm_nsegs = 0;
! 245:
! 246: if (buflen > map->_dm_size)
! 247: return (EINVAL);
! 248:
! 249: seg = 0;
! 250: error = _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags,
! 251: &lastaddr, &seg, 1);
! 252: if (error == 0) {
! 253: map->dm_mapsize = buflen;
! 254: map->dm_nsegs = seg + 1;
! 255: }
! 256: return (error);
! 257: }
! 258:
! 259: /*
! 260: * Like _bus_dmamap_load(), but for mbufs.
! 261: */
! 262: int
! 263: bus_dmamap_load_mbuf(t, map, m0, flags)
! 264: bus_dma_tag_t t;
! 265: bus_dmamap_t map;
! 266: struct mbuf *m0;
! 267: int flags;
! 268: {
! 269: paddr_t lastaddr;
! 270: int seg, error, first;
! 271: struct mbuf *m;
! 272:
! 273: /*
! 274: * Make sure that on error condition we return "no valid mappings."
! 275: */
! 276: map->dm_mapsize = 0;
! 277: map->dm_nsegs = 0;
! 278:
! 279: #ifdef DIAGNOSTIC
! 280: if ((m0->m_flags & M_PKTHDR) == 0)
! 281: panic("bus_dmamap_load_mbuf: no packet header");
! 282: #endif
! 283:
! 284: if (m0->m_pkthdr.len > map->_dm_size)
! 285: return (EINVAL);
! 286:
! 287: first = 1;
! 288: seg = 0;
! 289: error = 0;
! 290: for (m = m0; m != NULL && error == 0; m = m->m_next) {
! 291: if (m->m_len == 0)
! 292: continue;
! 293: error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len,
! 294: NULL, flags, &lastaddr, &seg, first);
! 295: first = 0;
! 296: }
! 297: if (error == 0) {
! 298: map->dm_mapsize = m0->m_pkthdr.len;
! 299: map->dm_nsegs = seg + 1;
! 300: }
! 301: return (error);
! 302: }
! 303:
! 304: /*
! 305: * Like _bus_dmamap_load(), but for uios.
! 306: */
! 307: int
! 308: bus_dmamap_load_uio(t, map, uio, flags)
! 309: bus_dma_tag_t t;
! 310: bus_dmamap_t map;
! 311: struct uio *uio;
! 312: int flags;
! 313: {
! 314: paddr_t lastaddr;
! 315: int seg, i, error, first;
! 316: bus_size_t minlen, resid;
! 317: struct proc *p = NULL;
! 318: struct iovec *iov;
! 319: caddr_t addr;
! 320:
! 321: /*
! 322: * Make sure that on error condition we return "no valid mappings."
! 323: */
! 324: map->dm_mapsize = 0;
! 325: map->dm_nsegs = 0;
! 326:
! 327: resid = uio->uio_resid;
! 328: iov = uio->uio_iov;
! 329:
! 330: if (resid > map->_dm_size)
! 331: return (EINVAL);
! 332:
! 333: if (uio->uio_segflg == UIO_USERSPACE) {
! 334: p = uio->uio_procp;
! 335: #ifdef DIAGNOSTIC
! 336: if (p == NULL)
! 337: panic("bus_dmamap_load_uio: USERSPACE but no proc");
! 338: #endif
! 339: }
! 340:
! 341: first = 1;
! 342: seg = 0;
! 343: error = 0;
! 344: for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) {
! 345: /*
! 346: * Now at the first iovec to load. Load each iovec
! 347: * until we have exhausted the residual count.
! 348: */
! 349: minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len;
! 350: addr = (caddr_t)iov[i].iov_base;
! 351:
! 352: error = _bus_dmamap_load_buffer(t, map, addr, minlen,
! 353: p, flags, &lastaddr, &seg, first);
! 354: first = 0;
! 355:
! 356: resid -= minlen;
! 357: }
! 358: if (error == 0) {
! 359: map->dm_mapsize = uio->uio_resid;
! 360: map->dm_nsegs = seg + 1;
! 361: }
! 362: return (error);
! 363: }
! 364:
! 365: /*
! 366: * Like bus_dmamap_load(), but for raw memory allocated with
! 367: * bus_dmamem_alloc().
! 368: */
! 369: int
! 370: bus_dmamap_load_raw(t, map, segs, nsegs, size, flags)
! 371: bus_dma_tag_t t;
! 372: bus_dmamap_t map;
! 373: bus_dma_segment_t *segs;
! 374: int nsegs;
! 375: bus_size_t size;
! 376: int flags;
! 377: {
! 378: if (nsegs > map->_dm_segcnt || size > map->_dm_size)
! 379: return (EINVAL);
! 380:
! 381: /*
! 382: * Make sure we don't cross any boundaries.
! 383: */
! 384: if (map->_dm_boundary) {
! 385: bus_addr_t bmask = ~(map->_dm_boundary - 1);
! 386: int i;
! 387:
! 388: for (i = 0; i < nsegs; i++) {
! 389: if (segs[i].ds_len > map->_dm_maxsegsz)
! 390: return (EINVAL);
! 391: if ((segs[i].ds_addr & bmask) !=
! 392: ((segs[i].ds_addr + segs[i].ds_len - 1) & bmask))
! 393: return (EINVAL);
! 394: }
! 395: }
! 396:
! 397: bcopy(segs, map->dm_segs, nsegs * sizeof(*segs));
! 398: map->dm_nsegs = nsegs;
! 399: return (0);
! 400: }
! 401:
! 402: /*
! 403: * Common function for unloading a DMA map. May be called by
! 404: * chipset-specific DMA map unload functions.
! 405: */
! 406: void
! 407: bus_dmamap_unload(t, map)
! 408: bus_dma_tag_t t;
! 409: bus_dmamap_t map;
! 410: {
! 411:
! 412: /*
! 413: * No resources to free; just mark the mappings as
! 414: * invalid.
! 415: */
! 416: map->dm_mapsize = 0;
! 417: map->dm_nsegs = 0;
! 418: }
! 419:
! 420: /*
! 421: * Common function for DMA map synchronization. May be called
! 422: * by chipset-specific DMA map synchronization functions.
! 423: */
! 424:
! 425: void
! 426: bus_dmamap_sync(t, map, offset, len, op)
! 427: bus_dma_tag_t t;
! 428: bus_dmamap_t map;
! 429: bus_addr_t offset;
! 430: bus_size_t len;
! 431: int op;
! 432: {
! 433: u_int nsegs;
! 434: bus_dma_segment_t *seg;
! 435:
! 436: if (op & BUS_DMASYNC_PREREAD)
! 437: op = DMA_CACHE_SYNC_INVAL;
! 438: else if (op & BUS_DMASYNC_PREWRITE)
! 439: op = DMA_CACHE_SYNC;
! 440: else if (op & BUS_DMASYNC_POSTREAD)
! 441: op = DMA_CACHE_INV;
! 442: else
! 443: return;
! 444:
! 445: nsegs = map->dm_nsegs;
! 446: seg = map->dm_segs;
! 447: while (nsegs != 0 && len != 0) {
! 448: if (offset >= seg->ds_len) {
! 449: offset -= seg->ds_len;
! 450: } else {
! 451: bus_addr_t addr;
! 452: bus_size_t sublen;
! 453:
! 454: addr = seg->ds_addr + offset;
! 455: sublen = seg->ds_len - offset;
! 456: if (sublen > len)
! 457: sublen = len;
! 458:
! 459: dma_cachectl_pa(addr, sublen, op);
! 460:
! 461: offset = 0;
! 462: len -= sublen;
! 463: }
! 464: seg++;
! 465: nsegs--;
! 466: }
! 467: }
! 468:
! 469: /*
! 470: * Common function for DMA-safe memory allocation. May be called
! 471: * by bus-specific DMA memory allocation functions.
! 472: */
! 473: int
! 474: bus_dmamem_alloc(t, size, alignment, boundary, segs, nsegs, rsegs, flags)
! 475: bus_dma_tag_t t;
! 476: bus_size_t size, alignment, boundary;
! 477: bus_dma_segment_t *segs;
! 478: int nsegs;
! 479: int *rsegs;
! 480: int flags;
! 481: {
! 482: paddr_t avail_start = (paddr_t)-1, avail_end = 0;
! 483: int bank;
! 484:
! 485: for (bank = 0; bank < vm_nphysseg; bank++) {
! 486: if (avail_start > vm_physmem[bank].avail_start << PGSHIFT)
! 487: avail_start = vm_physmem[bank].avail_start << PGSHIFT;
! 488: if (avail_end < vm_physmem[bank].avail_end << PGSHIFT)
! 489: avail_end = vm_physmem[bank].avail_end << PGSHIFT;
! 490: }
! 491:
! 492: return _bus_dmamem_alloc_range(t, size, alignment, boundary, segs,
! 493: nsegs, rsegs, flags, avail_start, avail_end - PAGE_SIZE);
! 494: }
! 495:
! 496: /*
! 497: * Common function for freeing DMA-safe memory. May be called by
! 498: * bus-specific DMA memory free functions.
! 499: */
! 500: void
! 501: bus_dmamem_free(t, segs, nsegs)
! 502: bus_dma_tag_t t;
! 503: bus_dma_segment_t *segs;
! 504: int nsegs;
! 505: {
! 506: struct vm_page *m;
! 507: bus_addr_t addr;
! 508: struct pglist mlist;
! 509: int curseg;
! 510:
! 511: /*
! 512: * Build a list of pages to free back to the VM system.
! 513: */
! 514: TAILQ_INIT(&mlist);
! 515: for (curseg = 0; curseg < nsegs; curseg++) {
! 516: for (addr = segs[curseg].ds_addr;
! 517: addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
! 518: addr += PAGE_SIZE) {
! 519: m = PHYS_TO_VM_PAGE(addr);
! 520: TAILQ_INSERT_TAIL(&mlist, m, pageq);
! 521: }
! 522: }
! 523:
! 524: uvm_pglistfree(&mlist);
! 525: }
! 526:
! 527: /*
! 528: * Common function for mapping DMA-safe memory. May be called by
! 529: * bus-specific DMA memory map functions.
! 530: */
! 531: int
! 532: bus_dmamem_map(t, segs, nsegs, size, kvap, flags)
! 533: bus_dma_tag_t t;
! 534: bus_dma_segment_t *segs;
! 535: int nsegs;
! 536: size_t size;
! 537: caddr_t *kvap;
! 538: int flags;
! 539: {
! 540: vaddr_t va;
! 541: bus_addr_t addr;
! 542: int curseg;
! 543:
! 544: size = round_page(size);
! 545:
! 546: va = uvm_km_valloc(kernel_map, size);
! 547:
! 548: if (va == 0)
! 549: return (ENOMEM);
! 550:
! 551: *kvap = (caddr_t)va;
! 552:
! 553: for (curseg = 0; curseg < nsegs; curseg++) {
! 554: for (addr = segs[curseg].ds_addr;
! 555: addr < (segs[curseg].ds_addr + segs[curseg].ds_len);
! 556: addr += PAGE_SIZE, va += PAGE_SIZE, size -= PAGE_SIZE) {
! 557: if (size == 0)
! 558: panic("bus_dmamem_map: size botch");
! 559: pmap_enter(pmap_kernel(), va, addr,
! 560: VM_PROT_READ | VM_PROT_WRITE,
! 561: VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED);
! 562: }
! 563: }
! 564: pmap_update(pmap_kernel());
! 565:
! 566: return (0);
! 567: }
! 568:
! 569: /*
! 570: * Common function for unmapping DMA-safe memory. May be called by
! 571: * bus-specific DMA memory unmapping functions.
! 572: */
! 573: void
! 574: bus_dmamem_unmap(t, kva, size)
! 575: bus_dma_tag_t t;
! 576: caddr_t kva;
! 577: size_t size;
! 578: {
! 579:
! 580: #ifdef DIAGNOSTIC
! 581: if ((u_long)kva & PGOFSET)
! 582: panic("bus_dmamem_unmap");
! 583: #endif
! 584:
! 585: size = round_page(size);
! 586: uvm_km_free(kernel_map, (vaddr_t)kva, size);
! 587: }
! 588:
! 589: /*
! 590: * Common functin for mmap(2)'ing DMA-safe memory. May be called by
! 591: * bus-specific DMA mmap(2)'ing functions.
! 592: */
! 593: paddr_t
! 594: bus_dmamem_mmap(t, segs, nsegs, off, prot, flags)
! 595: bus_dma_tag_t t;
! 596: bus_dma_segment_t *segs;
! 597: int nsegs;
! 598: off_t off;
! 599: int prot, flags;
! 600: {
! 601: int i;
! 602:
! 603: for (i = 0; i < nsegs; i++) {
! 604: #ifdef DIAGNOSTIC
! 605: if (off & PGOFSET)
! 606: panic("bus_dmamem_mmap: offset unaligned");
! 607: if (segs[i].ds_addr & PGOFSET)
! 608: panic("bus_dmamem_mmap: segment unaligned");
! 609: if (segs[i].ds_len & PGOFSET)
! 610: panic("bus_dmamem_mmap: segment size not multiple"
! 611: " of page size");
! 612: #endif
! 613: if (off >= segs[i].ds_len) {
! 614: off -= segs[i].ds_len;
! 615: continue;
! 616: }
! 617:
! 618: return (atop(segs[i].ds_addr + off));
! 619: }
! 620:
! 621: /* Page not found. */
! 622: return (-1);
! 623: }
! 624:
! 625: /*
! 626: * Allocate physical memory from the given physical address range.
! 627: * Called by DMA-safe memory allocation methods.
! 628: */
! 629: int
! 630: _bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs,
! 631: flags, low, high)
! 632: bus_dma_tag_t t;
! 633: bus_size_t size, alignment, boundary;
! 634: bus_dma_segment_t *segs;
! 635: int nsegs;
! 636: int *rsegs;
! 637: int flags;
! 638: paddr_t low;
! 639: paddr_t high;
! 640: {
! 641: paddr_t curaddr, lastaddr;
! 642: struct vm_page *m;
! 643: struct pglist mlist;
! 644: int curseg, error;
! 645:
! 646: /* Always round the size. */
! 647: size = round_page(size);
! 648:
! 649: /*
! 650: * Allocate pages from the VM system.
! 651: */
! 652: TAILQ_INIT(&mlist);
! 653: error = uvm_pglistalloc(size, low, high, alignment, boundary,
! 654: &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
! 655: if (error)
! 656: return (error);
! 657:
! 658: /*
! 659: * Compute the location, size, and number of segments actually
! 660: * returned by the VM code.
! 661: */
! 662: m = TAILQ_FIRST(&mlist);
! 663: curseg = 0;
! 664: lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
! 665: segs[curseg].ds_len = PAGE_SIZE;
! 666: m = TAILQ_NEXT(m, pageq);
! 667:
! 668: for (; m != TAILQ_END(&mlist); m = TAILQ_NEXT(m, pageq)) {
! 669: curaddr = VM_PAGE_TO_PHYS(m);
! 670: #ifdef DIAGNOSTIC
! 671: if (curaddr < low || curaddr >= high) {
! 672: panic("_bus_dmamem_alloc_range: uvm_pglistalloc "
! 673: "returned non-sensical address 0x%lx\n", curaddr);
! 674: }
! 675: #endif
! 676: if (curaddr == (lastaddr + PAGE_SIZE))
! 677: segs[curseg].ds_len += PAGE_SIZE;
! 678: else {
! 679: curseg++;
! 680: segs[curseg].ds_addr = curaddr;
! 681: segs[curseg].ds_len = PAGE_SIZE;
! 682: }
! 683: lastaddr = curaddr;
! 684: }
! 685:
! 686: *rsegs = curseg + 1;
! 687:
! 688: return (0);
! 689: }
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