1 /* $NetBSD: isadma_bounce.c,v 1.4 2002/04/26 04:15:19 thorpej Exp $ */ 2 3 /*- 4 * Copyright (c) 1996, 1997, 1998, 2000 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 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ 41 42 __KERNEL_RCSID(0, "$NetBSD: isadma_bounce.c,v 1.4 2002/04/26 04:15:19 thorpej Exp $"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/syslog.h> 47 #include <sys/device.h> 48 #include <sys/malloc.h> 49 #include <sys/proc.h> 50 #include <sys/mbuf.h> 51 52 #define _ALPHA_BUS_DMA_PRIVATE 53 #include <machine/bus.h> 54 55 #include <dev/isa/isareg.h> 56 #include <dev/isa/isavar.h> 57 58 #include <uvm/uvm_extern.h> 59 60 extern paddr_t avail_end; 61 62 /* 63 * ISA can only DMA to 0-16M. 64 */ 65 #define ISA_DMA_BOUNCE_THRESHOLD (16 * 1024 * 1024) 66 67 /* 68 * Cookie used by bouncing ISA DMA. A pointer to one of these is stashed 69 * in the DMA map. 70 */ 71 struct isadma_bounce_cookie { 72 int id_flags; /* flags; see below */ 73 74 /* 75 * Information about the original buffer used during 76 * DMA map syncs. Note that origbuflen is only used 77 * for ID_BUFTYPE_LINEAR. 78 */ 79 void *id_origbuf; /* pointer to orig buffer if 80 bouncing */ 81 bus_size_t id_origbuflen; /* ...and size */ 82 int id_buftype; /* type of buffer */ 83 84 void *id_bouncebuf; /* pointer to the bounce buffer */ 85 bus_size_t id_bouncebuflen; /* ...and size */ 86 int id_nbouncesegs; /* number of valid bounce segs */ 87 bus_dma_segment_t id_bouncesegs[1]; /* array of bounce buffer 88 physical memory segments */ 89 }; 90 91 /* id_flags */ 92 #define ID_MIGHT_NEED_BOUNCE 0x01 /* map could need bounce buffers */ 93 #define ID_HAS_BOUNCE 0x02 /* map currently has bounce buffers */ 94 #define ID_IS_BOUNCING 0x04 /* map is bouncing current xfer */ 95 96 /* id_buftype */ 97 #define ID_BUFTYPE_INVALID 0 98 #define ID_BUFTYPE_LINEAR 1 99 #define ID_BUFTYPE_MBUF 2 100 #define ID_BUFTYPE_UIO 3 101 #define ID_BUFTYPE_RAW 4 102 103 int isadma_bounce_alloc_bouncebuf __P((bus_dma_tag_t, bus_dmamap_t, 104 bus_size_t, int)); 105 void isadma_bounce_free_bouncebuf __P((bus_dma_tag_t, bus_dmamap_t)); 106 107 /* 108 * Create an ISA DMA map. 109 */ 110 int 111 isadma_bounce_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments, 112 bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp) 113 { 114 struct isadma_bounce_cookie *cookie; 115 bus_dmamap_t map; 116 int error, cookieflags; 117 void *cookiestore; 118 size_t cookiesize; 119 120 /* Call common function to create the basic map. */ 121 error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, 122 flags, dmamp); 123 if (error) 124 return (error); 125 126 map = *dmamp; 127 map->_dm_cookie = NULL; 128 129 cookiesize = sizeof(*cookie); 130 131 /* 132 * ISA only has 24-bits of address space. This means 133 * we can't DMA to pages over 16M. In order to DMA to 134 * arbitrary buffers, we use "bounce buffers" - pages 135 * in memory below the 16M boundary. On DMA reads, 136 * DMA happens to the bounce buffers, and is copied into 137 * the caller's buffer. On writes, data is copied into 138 * but bounce buffer, and the DMA happens from those 139 * pages. To software using the DMA mapping interface, 140 * this looks simply like a data cache. 141 * 142 * If we have more than 16M of RAM in the system, we may 143 * need bounce buffers. We check and remember that here. 144 * 145 * ...or, there is an opposite case. The most segments 146 * a transfer will require is (maxxfer / PAGE_SIZE) + 1. If 147 * the caller can't handle that many segments (e.g. the 148 * ISA DMA controller), we may have to bounce it as well. 149 */ 150 cookieflags = 0; 151 if (avail_end > (t->_wbase + t->_wsize) || 152 ((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) { 153 cookieflags |= ID_MIGHT_NEED_BOUNCE; 154 cookiesize += (sizeof(bus_dma_segment_t) * 155 (map->_dm_segcnt - 1)); 156 } 157 158 /* 159 * Allocate our cookie. 160 */ 161 if ((cookiestore = malloc(cookiesize, M_DMAMAP, 162 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL) { 163 error = ENOMEM; 164 goto out; 165 } 166 memset(cookiestore, 0, cookiesize); 167 cookie = (struct isadma_bounce_cookie *)cookiestore; 168 cookie->id_flags = cookieflags; 169 map->_dm_cookie = cookie; 170 171 if (cookieflags & ID_MIGHT_NEED_BOUNCE) { 172 /* 173 * Allocate the bounce pages now if the caller 174 * wishes us to do so. 175 */ 176 if ((flags & BUS_DMA_ALLOCNOW) == 0) 177 goto out; 178 179 error = isadma_bounce_alloc_bouncebuf(t, map, size, flags); 180 } 181 182 out: 183 if (error) { 184 if (map->_dm_cookie != NULL) 185 free(map->_dm_cookie, M_DMAMAP); 186 _bus_dmamap_destroy(t, map); 187 } 188 return (error); 189 } 190 191 /* 192 * Destroy an ISA DMA map. 193 */ 194 void 195 isadma_bounce_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) 196 { 197 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 198 199 /* 200 * Free any bounce pages this map might hold. 201 */ 202 if (cookie->id_flags & ID_HAS_BOUNCE) 203 isadma_bounce_free_bouncebuf(t, map); 204 205 free(cookie, M_DMAMAP); 206 _bus_dmamap_destroy(t, map); 207 } 208 209 /* 210 * Load an ISA DMA map with a linear buffer. 211 */ 212 int 213 isadma_bounce_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf, 214 size_t buflen, struct proc *p, int flags) 215 { 216 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 217 int error; 218 219 /* 220 * Make sure that on error condition we return "no valid mappings." 221 */ 222 map->dm_mapsize = 0; 223 map->dm_nsegs = 0; 224 225 /* 226 * Try to load the map the normal way. If this errors out, 227 * and we can bounce, we will. 228 */ 229 error = _bus_dmamap_load_direct(t, map, buf, buflen, p, flags); 230 if (error == 0 || 231 (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) 232 return (error); 233 234 /* 235 * First attempt failed; bounce it. 236 */ 237 238 /* 239 * Allocate bounce pages, if necessary. 240 */ 241 if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { 242 error = isadma_bounce_alloc_bouncebuf(t, map, buflen, flags); 243 if (error) 244 return (error); 245 } 246 247 /* 248 * Cache a pointer to the caller's buffer and load the DMA map 249 * with the bounce buffer. 250 */ 251 cookie->id_origbuf = buf; 252 cookie->id_origbuflen = buflen; 253 cookie->id_buftype = ID_BUFTYPE_LINEAR; 254 error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, buflen, 255 p, flags); 256 if (error) { 257 /* 258 * Free the bounce pages, unless our resources 259 * are reserved for our exclusive use. 260 */ 261 if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 262 isadma_bounce_free_bouncebuf(t, map); 263 return (error); 264 } 265 266 /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ 267 cookie->id_flags |= ID_IS_BOUNCING; 268 map->_dm_window = t; 269 return (0); 270 } 271 272 /* 273 * Like isadma_bounce_dmamap_load(), but for mbufs. 274 */ 275 int 276 isadma_bounce_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, 277 struct mbuf *m0, int flags) 278 { 279 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 280 int error; 281 282 /* 283 * Make sure on error condition we return "no valid mappings." 284 */ 285 map->dm_mapsize = 0; 286 map->dm_nsegs = 0; 287 288 #ifdef DIAGNOSTIC 289 if ((m0->m_flags & M_PKTHDR) == 0) 290 panic("isadma_bounce_dmamap_load_mbuf: no packet header"); 291 #endif 292 293 if (m0->m_pkthdr.len > map->_dm_size) 294 return (EINVAL); 295 296 /* 297 * Try to load the map the normal way. If this errors out, 298 * and we can bounce, we will. 299 */ 300 error = _bus_dmamap_load_mbuf_direct(t, map, m0, flags); 301 if (error == 0 || 302 (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) 303 return (error); 304 305 /* 306 * First attempt failed; bounce it. 307 */ 308 309 /* 310 * Allocate bounce pages, if necessary. 311 */ 312 if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { 313 error = isadma_bounce_alloc_bouncebuf(t, map, m0->m_pkthdr.len, 314 flags); 315 if (error) 316 return (error); 317 } 318 319 /* 320 * Cache a pointer to the caller's buffer and load the DMA map 321 * with the bounce buffer. 322 */ 323 cookie->id_origbuf = m0; 324 cookie->id_origbuflen = m0->m_pkthdr.len; /* not really used */ 325 cookie->id_buftype = ID_BUFTYPE_MBUF; 326 error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, 327 m0->m_pkthdr.len, NULL, flags); 328 if (error) { 329 /* 330 * Free the bounce pages, unless our resources 331 * are reserved for our exclusive use. 332 */ 333 if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 334 isadma_bounce_free_bouncebuf(t, map); 335 return (error); 336 } 337 338 /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ 339 cookie->id_flags |= ID_IS_BOUNCING; 340 map->_dm_window = t; 341 return (0); 342 } 343 344 /* 345 * Like isadma_bounce_dmamap_load(), but for uios. 346 */ 347 int 348 isadma_bounce_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, 349 struct uio *uio, int flags) 350 { 351 352 panic("isadma_bounce_dmamap_load_uio: not implemented"); 353 } 354 355 /* 356 * Like isadma_bounce_dmamap_load(), but for raw memory allocated with 357 * bus_dmamem_alloc(). 358 */ 359 int 360 isadma_bounce_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map, 361 bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags) 362 { 363 364 panic("isadma_bounce_dmamap_load_raw: not implemented"); 365 } 366 367 /* 368 * Unload an ISA DMA map. 369 */ 370 void 371 isadma_bounce_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map) 372 { 373 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 374 375 /* 376 * If we have bounce pages, free them, unless they're 377 * reserved for our exclusive use. 378 */ 379 if ((cookie->id_flags & ID_HAS_BOUNCE) && 380 (map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 381 isadma_bounce_free_bouncebuf(t, map); 382 383 cookie->id_flags &= ~ID_IS_BOUNCING; 384 cookie->id_buftype = ID_BUFTYPE_INVALID; 385 386 /* 387 * Do the generic bits of the unload. 388 */ 389 _bus_dmamap_unload(t, map); 390 } 391 392 /* 393 * Synchronize an ISA DMA map. 394 */ 395 void 396 isadma_bounce_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset, 397 bus_size_t len, int ops) 398 { 399 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 400 401 /* 402 * Mixing PRE and POST operations is not allowed. 403 */ 404 if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 && 405 (ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0) 406 panic("isadma_bounce_dmamap_sync: mix PRE and POST"); 407 408 #ifdef DIAGNOSTIC 409 if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) { 410 if (offset >= map->dm_mapsize) 411 panic("isadma_bounce_dmamap_sync: bad offset"); 412 if (len == 0 || (offset + len) > map->dm_mapsize) 413 panic("isadma_bounce_dmamap_sync: bad length"); 414 } 415 #endif 416 417 /* 418 * If we're not bouncing, just drain the write buffer 419 * and return. 420 */ 421 if ((cookie->id_flags & ID_IS_BOUNCING) == 0) { 422 alpha_mb(); 423 return; 424 } 425 426 switch (cookie->id_buftype) { 427 case ID_BUFTYPE_LINEAR: 428 /* 429 * Nothing to do for pre-read. 430 */ 431 432 if (ops & BUS_DMASYNC_PREWRITE) { 433 /* 434 * Copy the caller's buffer to the bounce buffer. 435 */ 436 memcpy((char *)cookie->id_bouncebuf + offset, 437 (char *)cookie->id_origbuf + offset, len); 438 } 439 440 if (ops & BUS_DMASYNC_POSTREAD) { 441 /* 442 * Copy the bounce buffer to the caller's buffer. 443 */ 444 memcpy((char *)cookie->id_origbuf + offset, 445 (char *)cookie->id_bouncebuf + offset, len); 446 } 447 448 /* 449 * Nothing to do for post-write. 450 */ 451 break; 452 453 case ID_BUFTYPE_MBUF: 454 { 455 struct mbuf *m, *m0 = cookie->id_origbuf; 456 bus_size_t minlen, moff; 457 458 /* 459 * Nothing to do for pre-read. 460 */ 461 462 if (ops & BUS_DMASYNC_PREWRITE) { 463 /* 464 * Copy the caller's buffer to the bounce buffer. 465 */ 466 m_copydata(m0, offset, len, 467 (char *)cookie->id_bouncebuf + offset); 468 } 469 470 if (ops & BUS_DMASYNC_POSTREAD) { 471 /* 472 * Copy the bounce buffer to the caller's buffer. 473 */ 474 for (moff = offset, m = m0; m != NULL && len != 0; 475 m = m->m_next) { 476 /* Find the beginning mbuf. */ 477 if (moff >= m->m_len) { 478 moff -= m->m_len; 479 continue; 480 } 481 482 /* 483 * Now at the first mbuf to sync; nail 484 * each one until we have exhausted the 485 * length. 486 */ 487 minlen = len < m->m_len - moff ? 488 len : m->m_len - moff; 489 490 memcpy(mtod(m, caddr_t) + moff, 491 (char *)cookie->id_bouncebuf + offset, 492 minlen); 493 494 moff = 0; 495 len -= minlen; 496 offset += minlen; 497 } 498 } 499 500 /* 501 * Nothing to do for post-write. 502 */ 503 break; 504 } 505 506 case ID_BUFTYPE_UIO: 507 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_UIO"); 508 break; 509 510 case ID_BUFTYPE_RAW: 511 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_RAW"); 512 break; 513 514 case ID_BUFTYPE_INVALID: 515 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_INVALID"); 516 break; 517 518 default: 519 printf("unknown buffer type %d\n", cookie->id_buftype); 520 panic("isadma_bounce_dmamap_sync"); 521 } 522 523 /* Drain the write buffer. */ 524 alpha_mb(); 525 } 526 527 /* 528 * Allocate memory safe for ISA DMA. 529 */ 530 int 531 isadma_bounce_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, 532 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 533 int nsegs, int *rsegs, int flags) 534 { 535 paddr_t high; 536 537 if (avail_end > ISA_DMA_BOUNCE_THRESHOLD) 538 high = trunc_page(ISA_DMA_BOUNCE_THRESHOLD); 539 else 540 high = trunc_page(avail_end); 541 542 return (_bus_dmamem_alloc_range(t, size, alignment, boundary, 543 segs, nsegs, rsegs, flags, 0, high)); 544 } 545 546 /********************************************************************** 547 * ISA DMA utility functions 548 **********************************************************************/ 549 550 int 551 isadma_bounce_alloc_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map, 552 bus_size_t size, int flags) 553 { 554 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 555 int error = 0; 556 557 cookie->id_bouncebuflen = round_page(size); 558 error = isadma_bounce_dmamem_alloc(t, cookie->id_bouncebuflen, 559 PAGE_SIZE, map->_dm_boundary, cookie->id_bouncesegs, 560 map->_dm_segcnt, &cookie->id_nbouncesegs, flags); 561 if (error) 562 goto out; 563 error = _bus_dmamem_map(t, cookie->id_bouncesegs, 564 cookie->id_nbouncesegs, cookie->id_bouncebuflen, 565 (caddr_t *)&cookie->id_bouncebuf, flags); 566 567 out: 568 if (error) { 569 _bus_dmamem_free(t, cookie->id_bouncesegs, 570 cookie->id_nbouncesegs); 571 cookie->id_bouncebuflen = 0; 572 cookie->id_nbouncesegs = 0; 573 } else 574 cookie->id_flags |= ID_HAS_BOUNCE; 575 576 return (error); 577 } 578 579 void 580 isadma_bounce_free_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map) 581 { 582 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 583 584 _bus_dmamem_unmap(t, cookie->id_bouncebuf, 585 cookie->id_bouncebuflen); 586 _bus_dmamem_free(t, cookie->id_bouncesegs, 587 cookie->id_nbouncesegs); 588 cookie->id_bouncebuflen = 0; 589 cookie->id_nbouncesegs = 0; 590 cookie->id_flags &= ~ID_HAS_BOUNCE; 591 } 592