1 /* $OpenBSD: isadma_bounce.c,v 1.5 2002/06/25 21:33:21 miod Exp $ */ 2 /* $NetBSD: isadma_bounce.c,v 1.3 2000/06/29 09:02:57 mrg Exp $ */ 3 4 /*- 5 * Copyright (c) 1996, 1997, 1998, 2000 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 #define _ALPHA_BUS_DMA_PRIVATE 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/syslog.h> 45 #include <sys/device.h> 46 #include <sys/malloc.h> 47 #include <sys/proc.h> 48 #include <sys/mbuf.h> 49 50 #include <machine/bus.h> 51 52 #include <dev/isa/isareg.h> 53 #include <dev/isa/isavar.h> 54 55 #include <uvm/uvm_extern.h> 56 57 extern paddr_t avail_end; 58 59 /* 60 * ISA can only DMA to 0-16M. 61 */ 62 #define ISA_DMA_BOUNCE_THRESHOLD (16 * 1024 * 1024) 63 64 /* 65 * Cookie used by bouncing ISA DMA. A pointer to one of these is stashed 66 * in the DMA map. 67 */ 68 struct isadma_bounce_cookie { 69 int id_flags; /* flags; see below */ 70 71 /* 72 * Information about the original buffer used during 73 * DMA map syncs. Note that origbuflen is only used 74 * for ID_BUFTYPE_LINEAR. 75 */ 76 void *id_origbuf; /* pointer to orig buffer if 77 bouncing */ 78 bus_size_t id_origbuflen; /* ...and size */ 79 int id_buftype; /* type of buffer */ 80 81 void *id_bouncebuf; /* pointer to the bounce buffer */ 82 bus_size_t id_bouncebuflen; /* ...and size */ 83 int id_nbouncesegs; /* number of valid bounce segs */ 84 bus_dma_segment_t id_bouncesegs[1]; /* array of bounce buffer 85 physical memory segments */ 86 }; 87 88 /* id_flags */ 89 #define ID_MIGHT_NEED_BOUNCE 0x01 /* map could need bounce buffers */ 90 #define ID_HAS_BOUNCE 0x02 /* map currently has bounce buffers */ 91 #define ID_IS_BOUNCING 0x04 /* map is bouncing current xfer */ 92 93 /* id_buftype */ 94 #define ID_BUFTYPE_INVALID 0 95 #define ID_BUFTYPE_LINEAR 1 96 #define ID_BUFTYPE_MBUF 2 97 #define ID_BUFTYPE_UIO 3 98 #define ID_BUFTYPE_RAW 4 99 100 int isadma_bounce_alloc_bouncebuf(bus_dma_tag_t, bus_dmamap_t, 101 bus_size_t, int); 102 void isadma_bounce_free_bouncebuf(bus_dma_tag_t, bus_dmamap_t); 103 104 /* 105 * Create an ISA DMA map. 106 */ 107 int 108 isadma_bounce_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments, 109 bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp) 110 { 111 struct isadma_bounce_cookie *cookie; 112 bus_dmamap_t map; 113 int error, cookieflags; 114 void *cookiestore; 115 size_t cookiesize; 116 117 /* Call common function to create the basic map. */ 118 error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, 119 flags, dmamp); 120 if (error) 121 return (error); 122 123 map = *dmamp; 124 map->_dm_cookie = NULL; 125 126 cookiesize = sizeof(*cookie); 127 128 /* 129 * ISA only has 24-bits of address space. This means 130 * we can't DMA to pages over 16M. In order to DMA to 131 * arbitrary buffers, we use "bounce buffers" - pages 132 * in memory below the 16M boundary. On DMA reads, 133 * DMA happens to the bounce buffers, and is copied into 134 * the caller's buffer. On writes, data is copied into 135 * but bounce buffer, and the DMA happens from those 136 * pages. To software using the DMA mapping interface, 137 * this looks simply like a data cache. 138 * 139 * If we have more than 16M of RAM in the system, we may 140 * need bounce buffers. We check and remember that here. 141 * 142 * ...or, there is an opposite case. The most segments 143 * a transfer will require is (maxxfer / PAGE_SIZE) + 1. If 144 * the caller can't handle that many segments (e.g. the 145 * ISA DMA controller), we may have to bounce it as well. 146 */ 147 cookieflags = 0; 148 if (avail_end > (t->_wbase + t->_wsize) || 149 ((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) { 150 cookieflags |= ID_MIGHT_NEED_BOUNCE; 151 cookiesize += (sizeof(bus_dma_segment_t) * 152 (map->_dm_segcnt - 1)); 153 } 154 155 /* 156 * Allocate our cookie. 157 */ 158 if ((cookiestore = malloc(cookiesize, M_DEVBUF, 159 (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL) { 160 error = ENOMEM; 161 goto out; 162 } 163 memset(cookiestore, 0, cookiesize); 164 cookie = (struct isadma_bounce_cookie *)cookiestore; 165 cookie->id_flags = cookieflags; 166 map->_dm_cookie = cookie; 167 168 if (cookieflags & ID_MIGHT_NEED_BOUNCE) { 169 /* 170 * Allocate the bounce pages now if the caller 171 * wishes us to do so. 172 */ 173 if ((flags & BUS_DMA_ALLOCNOW) == 0) 174 goto out; 175 176 error = isadma_bounce_alloc_bouncebuf(t, map, size, flags); 177 } 178 179 out: 180 if (error) { 181 if (map->_dm_cookie != NULL) 182 free(map->_dm_cookie, M_DEVBUF); 183 _bus_dmamap_destroy(t, map); 184 } 185 return (error); 186 } 187 188 /* 189 * Destroy an ISA DMA map. 190 */ 191 void 192 isadma_bounce_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) 193 { 194 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 195 196 /* 197 * Free any bounce pages this map might hold. 198 */ 199 if (cookie->id_flags & ID_HAS_BOUNCE) 200 isadma_bounce_free_bouncebuf(t, map); 201 202 free(cookie, M_DEVBUF); 203 _bus_dmamap_destroy(t, map); 204 } 205 206 /* 207 * Load an ISA DMA map with a linear buffer. 208 */ 209 int 210 isadma_bounce_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf, 211 size_t buflen, struct proc *p, int flags) 212 { 213 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 214 int error; 215 216 /* 217 * Make sure that on error condition we return "no valid mappings." 218 */ 219 map->dm_mapsize = 0; 220 map->dm_nsegs = 0; 221 222 /* 223 * Try to load the map the normal way. If this errors out, 224 * and we can bounce, we will. 225 */ 226 error = _bus_dmamap_load_direct(t, map, buf, buflen, p, flags); 227 if (error == 0 || 228 (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) 229 return (error); 230 231 /* 232 * First attempt failed; bounce it. 233 */ 234 235 /* 236 * Allocate bounce pages, if necessary. 237 */ 238 if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { 239 error = isadma_bounce_alloc_bouncebuf(t, map, buflen, flags); 240 if (error) 241 return (error); 242 } 243 244 /* 245 * Cache a pointer to the caller's buffer and load the DMA map 246 * with the bounce buffer. 247 */ 248 cookie->id_origbuf = buf; 249 cookie->id_origbuflen = buflen; 250 cookie->id_buftype = ID_BUFTYPE_LINEAR; 251 error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, buflen, 252 p, flags); 253 if (error) { 254 /* 255 * Free the bounce pages, unless our resources 256 * are reserved for our exclusive use. 257 */ 258 if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 259 isadma_bounce_free_bouncebuf(t, map); 260 return (error); 261 } 262 263 /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ 264 cookie->id_flags |= ID_IS_BOUNCING; 265 return (0); 266 } 267 268 /* 269 * Like isadma_bounce_dmamap_load(), but for mbufs. 270 */ 271 int 272 isadma_bounce_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, 273 struct mbuf *m0, int flags) 274 { 275 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 276 int error; 277 278 /* 279 * Make sure on error condition we return "no valid mappings." 280 */ 281 map->dm_mapsize = 0; 282 map->dm_nsegs = 0; 283 284 #ifdef DIAGNOSTIC 285 if ((m0->m_flags & M_PKTHDR) == 0) 286 panic("isadma_bounce_dmamap_load_mbuf: no packet header"); 287 #endif 288 289 if (m0->m_pkthdr.len > map->_dm_size) 290 return (EINVAL); 291 292 /* 293 * Try to load the map the normal way. If this errors out, 294 * and we can bounce, we will. 295 */ 296 error = _bus_dmamap_load_mbuf_direct(t, map, m0, flags); 297 if (error == 0 || 298 (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) 299 return (error); 300 301 /* 302 * First attempt failed; bounce it. 303 */ 304 305 /* 306 * Allocate bounce pages, if necessary. 307 */ 308 if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { 309 error = isadma_bounce_alloc_bouncebuf(t, map, m0->m_pkthdr.len, 310 flags); 311 if (error) 312 return (error); 313 } 314 315 /* 316 * Cache a pointer to the caller's buffer and load the DMA map 317 * with the bounce buffer. 318 */ 319 cookie->id_origbuf = m0; 320 cookie->id_origbuflen = m0->m_pkthdr.len; /* not really used */ 321 cookie->id_buftype = ID_BUFTYPE_MBUF; 322 error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, 323 m0->m_pkthdr.len, NULL, flags); 324 if (error) { 325 /* 326 * Free the bounce pages, unless our resources 327 * are reserved for our exclusive use. 328 */ 329 if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 330 isadma_bounce_free_bouncebuf(t, map); 331 return (error); 332 } 333 334 /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ 335 cookie->id_flags |= ID_IS_BOUNCING; 336 return (0); 337 } 338 339 /* 340 * Like isadma_bounce_dmamap_load(), but for uios. 341 */ 342 int 343 isadma_bounce_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, 344 struct uio *uio, int flags) 345 { 346 347 panic("isadma_bounce_dmamap_load_uio: not implemented"); 348 } 349 350 /* 351 * Like isadma_bounce_dmamap_load(), but for raw memory allocated with 352 * bus_dmamem_alloc(). 353 */ 354 int 355 isadma_bounce_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map, 356 bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags) 357 { 358 359 panic("isadma_bounce_dmamap_load_raw: not implemented"); 360 } 361 362 /* 363 * Unload an ISA DMA map. 364 */ 365 void 366 isadma_bounce_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map) 367 { 368 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 369 370 /* 371 * If we have bounce pages, free them, unless they're 372 * reserved for our exclusive use. 373 */ 374 if ((cookie->id_flags & ID_HAS_BOUNCE) && 375 (map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) 376 isadma_bounce_free_bouncebuf(t, map); 377 378 cookie->id_flags &= ~ID_IS_BOUNCING; 379 cookie->id_buftype = ID_BUFTYPE_INVALID; 380 381 /* 382 * Do the generic bits of the unload. 383 */ 384 _bus_dmamap_unload(t, map); 385 } 386 387 void 388 isadma_bounce_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset, 389 bus_size_t len, int ops) 390 { 391 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 392 393 /* 394 * Mixing PRE and POST operations is not allowed. 395 */ 396 if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 && 397 (ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0) 398 panic("isadma_bounce_dmamap_sync: mix PRE and POST"); 399 400 #ifdef DIAGNOSTIC 401 if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) { 402 if (offset >= map->dm_mapsize) 403 panic("isadma_bounce_dmamap_sync: bad offset"); 404 if (len == 0 || (offset + len) > map->dm_mapsize) 405 panic("isadma_bounce_dmamap_sync: bad length"); 406 } 407 #endif 408 409 /* 410 * If we're not bouncing, just drain the write buffer 411 * and return. 412 */ 413 if ((cookie->id_flags & ID_IS_BOUNCING) == 0) { 414 alpha_mb(); 415 return; 416 } 417 418 switch (cookie->id_buftype) { 419 case ID_BUFTYPE_LINEAR: 420 /* 421 * Nothing to do for pre-read. 422 */ 423 424 if (ops & BUS_DMASYNC_PREWRITE) { 425 /* 426 * Copy the caller's buffer to the bounce buffer. 427 */ 428 memcpy((char *)cookie->id_bouncebuf + offset, 429 (char *)cookie->id_origbuf + offset, len); 430 } 431 432 if (ops & BUS_DMASYNC_POSTREAD) { 433 /* 434 * Copy the bounce buffer to the caller's buffer. 435 */ 436 memcpy((char *)cookie->id_origbuf + offset, 437 (char *)cookie->id_bouncebuf + offset, len); 438 } 439 440 /* 441 * Nothing to do for post-write. 442 */ 443 break; 444 445 case ID_BUFTYPE_MBUF: 446 { 447 struct mbuf *m, *m0 = cookie->id_origbuf; 448 bus_size_t minlen, moff; 449 450 /* 451 * Nothing to do for pre-read. 452 */ 453 454 if (ops & BUS_DMASYNC_PREWRITE) { 455 /* 456 * Copy the caller's buffer to the bounce buffer. 457 */ 458 m_copydata(m0, offset, len, 459 (char *)cookie->id_bouncebuf + offset); 460 } 461 462 if (ops & BUS_DMASYNC_POSTREAD) { 463 /* 464 * Copy the bounce buffer to the caller's buffer. 465 */ 466 for (moff = offset, m = m0; m != NULL && len != 0; 467 m = m->m_next) { 468 /* Find the beginning mbuf. */ 469 if (moff >= m->m_len) { 470 moff -= m->m_len; 471 continue; 472 } 473 474 /* 475 * Now at the first mbuf to sync; nail 476 * each one until we have exhausted the 477 * length. 478 */ 479 minlen = len < m->m_len - moff ? 480 len : m->m_len - moff; 481 482 memcpy(mtod(m, caddr_t) + moff, 483 (char *)cookie->id_bouncebuf + offset, 484 minlen); 485 486 moff = 0; 487 len -= minlen; 488 offset += minlen; 489 } 490 } 491 492 /* 493 * Nothing to do for post-write. 494 */ 495 break; 496 } 497 498 case ID_BUFTYPE_UIO: 499 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_UIO"); 500 break; 501 502 case ID_BUFTYPE_RAW: 503 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_RAW"); 504 break; 505 506 case ID_BUFTYPE_INVALID: 507 panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_INVALID"); 508 break; 509 510 default: 511 panic("isadma_bounce_dmamap_sync: unknown buffer type %d", 512 cookie->id_buftype); 513 } 514 515 /* Drain the write buffer. */ 516 alpha_mb(); 517 } 518 519 /* 520 * Allocate memory safe for ISA DMA. 521 */ 522 int 523 isadma_bounce_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, 524 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 525 int nsegs, int *rsegs, int flags) 526 { 527 paddr_t high; 528 529 if (avail_end > ISA_DMA_BOUNCE_THRESHOLD) 530 high = trunc_page(ISA_DMA_BOUNCE_THRESHOLD); 531 else 532 high = trunc_page(avail_end); 533 534 return (_bus_dmamem_alloc_range(t, size, alignment, boundary, 535 segs, nsegs, rsegs, flags, 0, high)); 536 } 537 538 /********************************************************************** 539 * ISA DMA utility functions 540 **********************************************************************/ 541 542 int 543 isadma_bounce_alloc_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map, 544 bus_size_t size, int flags) 545 { 546 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 547 int error = 0; 548 549 cookie->id_bouncebuflen = round_page(size); 550 error = isadma_bounce_dmamem_alloc(t, cookie->id_bouncebuflen, 551 PAGE_SIZE, map->_dm_boundary, cookie->id_bouncesegs, 552 map->_dm_segcnt, &cookie->id_nbouncesegs, flags); 553 if (error) 554 goto out; 555 error = _bus_dmamem_map(t, cookie->id_bouncesegs, 556 cookie->id_nbouncesegs, cookie->id_bouncebuflen, 557 (caddr_t *)&cookie->id_bouncebuf, flags); 558 559 out: 560 if (error) { 561 _bus_dmamem_free(t, cookie->id_bouncesegs, 562 cookie->id_nbouncesegs); 563 cookie->id_bouncebuflen = 0; 564 cookie->id_nbouncesegs = 0; 565 } else 566 cookie->id_flags |= ID_HAS_BOUNCE; 567 568 return (error); 569 } 570 571 void 572 isadma_bounce_free_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map) 573 { 574 struct isadma_bounce_cookie *cookie = map->_dm_cookie; 575 576 _bus_dmamem_unmap(t, cookie->id_bouncebuf, 577 cookie->id_bouncebuflen); 578 _bus_dmamem_free(t, cookie->id_bouncesegs, 579 cookie->id_nbouncesegs); 580 cookie->id_bouncebuflen = 0; 581 cookie->id_nbouncesegs = 0; 582 cookie->id_flags &= ~ID_HAS_BOUNCE; 583 } 584