isa_dma.c revision 256281
1/*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: stable/10/sys/x86/isa/isa_dma.c 233675 2012-03-29 18:58:02Z jhb $"); 37 38/* 39 * code to manage AT bus 40 * 41 * 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com): 42 * Fixed uninitialized variable problem and added code to deal 43 * with DMA page boundaries in isa_dmarangecheck(). Fixed word 44 * mode DMA count compution and reorganized DMA setup code in 45 * isa_dmastart() 46 */ 47 48#include <sys/param.h> 49#include <sys/systm.h> 50#include <sys/bus.h> 51#include <sys/kernel.h> 52#include <sys/malloc.h> 53#include <sys/lock.h> 54#include <sys/proc.h> 55#include <sys/mutex.h> 56#include <sys/module.h> 57#include <vm/vm.h> 58#include <vm/vm_param.h> 59#include <vm/pmap.h> 60#include <isa/isareg.h> 61#include <isa/isavar.h> 62#include <isa/isa_dmareg.h> 63 64#define ISARAM_END RAM_END 65 66static int isa_dmarangecheck(caddr_t va, u_int length, int chan); 67 68static caddr_t dma_bouncebuf[8]; 69static u_int dma_bouncebufsize[8]; 70static u_int8_t dma_bounced = 0; 71static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */ 72static u_int8_t dma_inuse = 0; /* User for acquire/release */ 73static u_int8_t dma_auto_mode = 0; 74static struct mtx isa_dma_lock; 75MTX_SYSINIT(isa_dma_lock, &isa_dma_lock, "isa DMA lock", MTX_DEF); 76 77#define VALID_DMA_MASK (7) 78 79/* high byte of address is stored in this port for i-th dma channel */ 80static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a }; 81 82/* 83 * Setup a DMA channel's bounce buffer. 84 */ 85int 86isa_dma_init(int chan, u_int bouncebufsize, int flag) 87{ 88 void *buf; 89 int contig; 90 91#ifdef DIAGNOSTIC 92 if (chan & ~VALID_DMA_MASK) 93 panic("isa_dma_init: channel out of range"); 94#endif 95 96 97 /* Try malloc() first. It works better if it works. */ 98 buf = malloc(bouncebufsize, M_DEVBUF, flag); 99 if (buf != NULL) { 100 if (isa_dmarangecheck(buf, bouncebufsize, chan) != 0) { 101 free(buf, M_DEVBUF); 102 buf = NULL; 103 } 104 contig = 0; 105 } 106 107 if (buf == NULL) { 108 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful, 109 1ul, chan & 4 ? 0x20000ul : 0x10000ul); 110 contig = 1; 111 } 112 113 if (buf == NULL) 114 return (ENOMEM); 115 116 mtx_lock(&isa_dma_lock); 117 /* 118 * If a DMA channel is shared, both drivers have to call isa_dma_init 119 * since they don't know that the other driver will do it. 120 * Just return if we're already set up good. 121 * XXX: this only works if they agree on the bouncebuf size. This 122 * XXX: is typically the case since they are multiple instances of 123 * XXX: the same driver. 124 */ 125 if (dma_bouncebuf[chan] != NULL) { 126 if (contig) 127 contigfree(buf, bouncebufsize, M_DEVBUF); 128 else 129 free(buf, M_DEVBUF); 130 mtx_unlock(&isa_dma_lock); 131 return (0); 132 } 133 134 dma_bouncebufsize[chan] = bouncebufsize; 135 dma_bouncebuf[chan] = buf; 136 137 mtx_unlock(&isa_dma_lock); 138 139 return (0); 140} 141 142/* 143 * Register a DMA channel's usage. Usually called from a device driver 144 * in open() or during its initialization. 145 */ 146int 147isa_dma_acquire(chan) 148 int chan; 149{ 150#ifdef DIAGNOSTIC 151 if (chan & ~VALID_DMA_MASK) 152 panic("isa_dma_acquire: channel out of range"); 153#endif 154 155 mtx_lock(&isa_dma_lock); 156 if (dma_inuse & (1 << chan)) { 157 printf("isa_dma_acquire: channel %d already in use\n", chan); 158 mtx_unlock(&isa_dma_lock); 159 return (EBUSY); 160 } 161 dma_inuse |= (1 << chan); 162 dma_auto_mode &= ~(1 << chan); 163 mtx_unlock(&isa_dma_lock); 164 165 return (0); 166} 167 168/* 169 * Unregister a DMA channel's usage. Usually called from a device driver 170 * during close() or during its shutdown. 171 */ 172void 173isa_dma_release(chan) 174 int chan; 175{ 176#ifdef DIAGNOSTIC 177 if (chan & ~VALID_DMA_MASK) 178 panic("isa_dma_release: channel out of range"); 179 180 mtx_lock(&isa_dma_lock); 181 if ((dma_inuse & (1 << chan)) == 0) 182 printf("isa_dma_release: channel %d not in use\n", chan); 183#else 184 mtx_lock(&isa_dma_lock); 185#endif 186 187 if (dma_busy & (1 << chan)) { 188 dma_busy &= ~(1 << chan); 189 /* 190 * XXX We should also do "dma_bounced &= (1 << chan);" 191 * because we are acting on behalf of isa_dmadone() which 192 * was not called to end the last DMA operation. This does 193 * not matter now, but it may in the future. 194 */ 195 } 196 197 dma_inuse &= ~(1 << chan); 198 dma_auto_mode &= ~(1 << chan); 199 200 mtx_unlock(&isa_dma_lock); 201} 202 203/* 204 * isa_dmacascade(): program 8237 DMA controller channel to accept 205 * external dma control by a board. 206 */ 207void 208isa_dmacascade(chan) 209 int chan; 210{ 211#ifdef DIAGNOSTIC 212 if (chan & ~VALID_DMA_MASK) 213 panic("isa_dmacascade: channel out of range"); 214#endif 215 216 mtx_lock(&isa_dma_lock); 217 /* set dma channel mode, and set dma channel mode */ 218 if ((chan & 4) == 0) { 219 outb(DMA1_MODE, DMA37MD_CASCADE | chan); 220 outb(DMA1_SMSK, chan); 221 } else { 222 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3)); 223 outb(DMA2_SMSK, chan & 3); 224 } 225 mtx_unlock(&isa_dma_lock); 226} 227 228/* 229 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment 230 * problems by using a bounce buffer. 231 */ 232void 233isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan) 234{ 235 vm_paddr_t phys; 236 int waport; 237 caddr_t newaddr; 238 int dma_range_checked; 239 240 dma_range_checked = isa_dmarangecheck(addr, nbytes, chan); 241 242#ifdef DIAGNOSTIC 243 if (chan & ~VALID_DMA_MASK) 244 panic("isa_dmastart: channel out of range"); 245 246 if ((chan < 4 && nbytes > (1<<16)) 247 || (chan >= 4 && (nbytes > (1<<17) || (uintptr_t)addr & 1))) 248 panic("isa_dmastart: impossible request"); 249 250 mtx_lock(&isa_dma_lock); 251 if ((dma_inuse & (1 << chan)) == 0) 252 printf("isa_dmastart: channel %d not acquired\n", chan); 253#else 254 mtx_lock(&isa_dma_lock); 255#endif 256 257#if 0 258 /* 259 * XXX This should be checked, but drivers like ad1848 only call 260 * isa_dmastart() once because they use Auto DMA mode. If we 261 * leave this in, drivers that do this will print this continuously. 262 */ 263 if (dma_busy & (1 << chan)) 264 printf("isa_dmastart: channel %d busy\n", chan); 265#endif 266 267 dma_busy |= (1 << chan); 268 269 if (dma_range_checked) { 270 if (dma_bouncebuf[chan] == NULL 271 || dma_bouncebufsize[chan] < nbytes) 272 panic("isa_dmastart: bad bounce buffer"); 273 dma_bounced |= (1 << chan); 274 newaddr = dma_bouncebuf[chan]; 275 276 /* copy bounce buffer on write */ 277 if (!(flags & ISADMA_READ)) 278 bcopy(addr, newaddr, nbytes); 279 addr = newaddr; 280 } 281 282 /* translate to physical */ 283 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr); 284 285 if (flags & ISADMA_RAW) { 286 dma_auto_mode |= (1 << chan); 287 } else { 288 dma_auto_mode &= ~(1 << chan); 289 } 290 291 if ((chan & 4) == 0) { 292 /* 293 * Program one of DMA channels 0..3. These are 294 * byte mode channels. 295 */ 296 /* set dma channel mode, and reset address ff */ 297 298 /* If ISADMA_RAW flag is set, then use autoinitialise mode */ 299 if (flags & ISADMA_RAW) { 300 if (flags & ISADMA_READ) 301 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan); 302 else 303 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan); 304 } 305 else 306 if (flags & ISADMA_READ) 307 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan); 308 else 309 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan); 310 outb(DMA1_FFC, 0); 311 312 /* send start address */ 313 waport = DMA1_CHN(chan); 314 outb(waport, phys); 315 outb(waport, phys>>8); 316 outb(dmapageport[chan], phys>>16); 317 318 /* send count */ 319 outb(waport + 1, --nbytes); 320 outb(waport + 1, nbytes>>8); 321 322 /* unmask channel */ 323 outb(DMA1_SMSK, chan); 324 } else { 325 /* 326 * Program one of DMA channels 4..7. These are 327 * word mode channels. 328 */ 329 /* set dma channel mode, and reset address ff */ 330 331 /* If ISADMA_RAW flag is set, then use autoinitialise mode */ 332 if (flags & ISADMA_RAW) { 333 if (flags & ISADMA_READ) 334 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3)); 335 else 336 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3)); 337 } 338 else 339 if (flags & ISADMA_READ) 340 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3)); 341 else 342 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3)); 343 outb(DMA2_FFC, 0); 344 345 /* send start address */ 346 waport = DMA2_CHN(chan - 4); 347 outb(waport, phys>>1); 348 outb(waport, phys>>9); 349 outb(dmapageport[chan], phys>>16); 350 351 /* send count */ 352 nbytes >>= 1; 353 outb(waport + 2, --nbytes); 354 outb(waport + 2, nbytes>>8); 355 356 /* unmask channel */ 357 outb(DMA2_SMSK, chan & 3); 358 } 359 mtx_unlock(&isa_dma_lock); 360} 361 362void 363isa_dmadone(int flags, caddr_t addr, int nbytes, int chan) 364{ 365#ifdef DIAGNOSTIC 366 if (chan & ~VALID_DMA_MASK) 367 panic("isa_dmadone: channel out of range"); 368 369 if ((dma_inuse & (1 << chan)) == 0) 370 printf("isa_dmadone: channel %d not acquired\n", chan); 371#endif 372 373 mtx_lock(&isa_dma_lock); 374 if (((dma_busy & (1 << chan)) == 0) && 375 (dma_auto_mode & (1 << chan)) == 0 ) 376 printf("isa_dmadone: channel %d not busy\n", chan); 377 378 if ((dma_auto_mode & (1 << chan)) == 0) 379 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4); 380 381 if (dma_bounced & (1 << chan)) { 382 /* copy bounce buffer on read */ 383 if (flags & ISADMA_READ) 384 bcopy(dma_bouncebuf[chan], addr, nbytes); 385 386 dma_bounced &= ~(1 << chan); 387 } 388 dma_busy &= ~(1 << chan); 389 mtx_unlock(&isa_dma_lock); 390} 391 392/* 393 * Check for problems with the address range of a DMA transfer 394 * (non-contiguous physical pages, outside of bus address space, 395 * crossing DMA page boundaries). 396 * Return true if special handling needed. 397 */ 398 399static int 400isa_dmarangecheck(caddr_t va, u_int length, int chan) 401{ 402 vm_paddr_t phys, priorpage = 0; 403 vm_offset_t endva; 404 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1); 405 406 endva = (vm_offset_t)round_page((vm_offset_t)va + length); 407 for (; va < (caddr_t) endva ; va += PAGE_SIZE) { 408 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va)); 409 if (phys == 0) 410 panic("isa_dmacheck: no physical page present"); 411 if (phys >= ISARAM_END) 412 return (1); 413 if (priorpage) { 414 if (priorpage + PAGE_SIZE != phys) 415 return (1); 416 /* check if crossing a DMA page boundary */ 417 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk) 418 return (1); 419 } 420 priorpage = phys; 421 } 422 return (0); 423} 424 425/* 426 * Query the progress of a transfer on a DMA channel. 427 * 428 * To avoid having to interrupt a transfer in progress, we sample 429 * each of the high and low databytes twice, and apply the following 430 * logic to determine the correct count. 431 * 432 * Reads are performed with interrupts disabled, thus it is to be 433 * expected that the time between reads is very small. At most 434 * one rollover in the low count byte can be expected within the 435 * four reads that are performed. 436 * 437 * There are three gaps in which a rollover can occur : 438 * 439 * - read low1 440 * gap1 441 * - read high1 442 * gap2 443 * - read low2 444 * gap3 445 * - read high2 446 * 447 * If a rollover occurs in gap1 or gap2, the low2 value will be 448 * greater than the low1 value. In this case, low2 and high2 are a 449 * corresponding pair. 450 * 451 * In any other case, low1 and high1 can be considered to be correct. 452 * 453 * The function returns the number of bytes remaining in the transfer, 454 * or -1 if the channel requested is not active. 455 * 456 */ 457static int 458isa_dmastatus_locked(int chan) 459{ 460 u_long cnt = 0; 461 int ffport, waport; 462 u_long low1, high1, low2, high2; 463 464 mtx_assert(&isa_dma_lock, MA_OWNED); 465 466 /* channel active? */ 467 if ((dma_inuse & (1 << chan)) == 0) { 468 printf("isa_dmastatus: channel %d not active\n", chan); 469 return(-1); 470 } 471 /* channel busy? */ 472 473 if (((dma_busy & (1 << chan)) == 0) && 474 (dma_auto_mode & (1 << chan)) == 0 ) { 475 printf("chan %d not busy\n", chan); 476 return -2 ; 477 } 478 if (chan < 4) { /* low DMA controller */ 479 ffport = DMA1_FFC; 480 waport = DMA1_CHN(chan) + 1; 481 } else { /* high DMA controller */ 482 ffport = DMA2_FFC; 483 waport = DMA2_CHN(chan - 4) + 2; 484 } 485 486 disable_intr(); /* no interrupts Mr Jones! */ 487 outb(ffport, 0); /* clear register LSB flipflop */ 488 low1 = inb(waport); 489 high1 = inb(waport); 490 outb(ffport, 0); /* clear again */ 491 low2 = inb(waport); 492 high2 = inb(waport); 493 enable_intr(); /* enable interrupts again */ 494 495 /* 496 * Now decide if a wrap has tried to skew our results. 497 * Note that after TC, the count will read 0xffff, while we want 498 * to return zero, so we add and then mask to compensate. 499 */ 500 if (low1 >= low2) { 501 cnt = (low1 + (high1 << 8) + 1) & 0xffff; 502 } else { 503 cnt = (low2 + (high2 << 8) + 1) & 0xffff; 504 } 505 506 if (chan >= 4) /* high channels move words */ 507 cnt *= 2; 508 return(cnt); 509} 510 511int 512isa_dmastatus(int chan) 513{ 514 int status; 515 516 mtx_lock(&isa_dma_lock); 517 status = isa_dmastatus_locked(chan); 518 mtx_unlock(&isa_dma_lock); 519 520 return (status); 521} 522 523/* 524 * Reached terminal count yet ? 525 */ 526int 527isa_dmatc(int chan) 528{ 529 530 if (chan < 4) 531 return(inb(DMA1_STATUS) & (1 << chan)); 532 else 533 return(inb(DMA2_STATUS) & (1 << (chan & 3))); 534} 535 536/* 537 * Stop a DMA transfer currently in progress. 538 */ 539int 540isa_dmastop(int chan) 541{ 542 int status; 543 544 mtx_lock(&isa_dma_lock); 545 if ((dma_inuse & (1 << chan)) == 0) 546 printf("isa_dmastop: channel %d not acquired\n", chan); 547 548 if (((dma_busy & (1 << chan)) == 0) && 549 ((dma_auto_mode & (1 << chan)) == 0)) { 550 printf("chan %d not busy\n", chan); 551 mtx_unlock(&isa_dma_lock); 552 return -2 ; 553 } 554 555 if ((chan & 4) == 0) { 556 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */); 557 } else { 558 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */); 559 } 560 561 status = isa_dmastatus_locked(chan); 562 563 mtx_unlock(&isa_dma_lock); 564 565 return (status); 566} 567 568/* 569 * Attach to the ISA PnP descriptor for the AT DMA controller 570 */ 571static struct isa_pnp_id atdma_ids[] = { 572 { 0x0002d041 /* PNP0200 */, "AT DMA controller" }, 573 { 0 } 574}; 575 576static int 577atdma_probe(device_t dev) 578{ 579 int result; 580 581 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0) 582 device_quiet(dev); 583 return(result); 584} 585 586static int 587atdma_attach(device_t dev) 588{ 589 return(0); 590} 591 592static device_method_t atdma_methods[] = { 593 /* Device interface */ 594 DEVMETHOD(device_probe, atdma_probe), 595 DEVMETHOD(device_attach, atdma_attach), 596 DEVMETHOD(device_detach, bus_generic_detach), 597 DEVMETHOD(device_shutdown, bus_generic_shutdown), 598 DEVMETHOD(device_suspend, bus_generic_suspend), 599 DEVMETHOD(device_resume, bus_generic_resume), 600 { 0, 0 } 601}; 602 603static driver_t atdma_driver = { 604 "atdma", 605 atdma_methods, 606 1, /* no softc */ 607}; 608 609static devclass_t atdma_devclass; 610 611DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0); 612DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0); 613