isa_dma.c revision 146214
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: head/sys/i386/isa/isa_dma.c 146214 2005-05-14 10:14:56Z nyan $"); 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 64static int isa_dmarangecheck(caddr_t va, u_int length, int chan); 65 66static caddr_t dma_bouncebuf[8]; 67static u_int dma_bouncebufsize[8]; 68static u_int8_t dma_bounced = 0; 69static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */ 70static u_int8_t dma_inuse = 0; /* User for acquire/release */ 71static u_int8_t dma_auto_mode = 0; 72 73#define VALID_DMA_MASK (7) 74 75/* high byte of address is stored in this port for i-th dma channel */ 76static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a }; 77 78/* 79 * Setup a DMA channel's bounce buffer. 80 */ 81int 82isa_dma_init(int chan, u_int bouncebufsize, int flag) 83{ 84 void *buf; 85 86 /* 87 * If a DMA channel is shared, both drivers have to call isa_dma_init 88 * since they don't know that the other driver will do it. 89 * Just return if we're already set up good. 90 * XXX: this only works if they agree on the bouncebuf size. This 91 * XXX: is typically the case since they are multiple instances of 92 * XXX: the same driver. 93 */ 94 if (dma_bouncebuf[chan] != NULL) 95 return (0); 96 97#ifdef DIAGNOSTIC 98 if (chan & ~VALID_DMA_MASK) 99 panic("isa_dma_init: channel out of range"); 100#endif 101 102 dma_bouncebufsize[chan] = bouncebufsize; 103 104 /* Try malloc() first. It works better if it works. */ 105 buf = malloc(bouncebufsize, M_DEVBUF, flag); 106 if (buf != NULL) { 107 if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) { 108 dma_bouncebuf[chan] = buf; 109 return (0); 110 } 111 free(buf, M_DEVBUF); 112 } 113 buf = contigmalloc(bouncebufsize, M_DEVBUF, flag, 0ul, 0xfffffful, 114 1ul, chan & 4 ? 0x20000ul : 0x10000ul); 115 if (buf == NULL) 116 return (ENOMEM); 117 dma_bouncebuf[chan] = buf; 118 return (0); 119} 120 121/* 122 * Register a DMA channel's usage. Usually called from a device driver 123 * in open() or during its initialization. 124 */ 125int 126isa_dma_acquire(chan) 127 int chan; 128{ 129#ifdef DIAGNOSTIC 130 if (chan & ~VALID_DMA_MASK) 131 panic("isa_dma_acquire: channel out of range"); 132#endif 133 134 if (dma_inuse & (1 << chan)) { 135 printf("isa_dma_acquire: channel %d already in use\n", chan); 136 return (EBUSY); 137 } 138 dma_inuse |= (1 << chan); 139 dma_auto_mode &= ~(1 << chan); 140 141 return (0); 142} 143 144/* 145 * Unregister a DMA channel's usage. Usually called from a device driver 146 * during close() or during its shutdown. 147 */ 148void 149isa_dma_release(chan) 150 int chan; 151{ 152#ifdef DIAGNOSTIC 153 if (chan & ~VALID_DMA_MASK) 154 panic("isa_dma_release: channel out of range"); 155 156 if ((dma_inuse & (1 << chan)) == 0) 157 printf("isa_dma_release: channel %d not in use\n", chan); 158#endif 159 160 if (dma_busy & (1 << chan)) { 161 dma_busy &= ~(1 << chan); 162 /* 163 * XXX We should also do "dma_bounced &= (1 << chan);" 164 * because we are acting on behalf of isa_dmadone() which 165 * was not called to end the last DMA operation. This does 166 * not matter now, but it may in the future. 167 */ 168 } 169 170 dma_inuse &= ~(1 << chan); 171 dma_auto_mode &= ~(1 << chan); 172} 173 174/* 175 * isa_dmacascade(): program 8237 DMA controller channel to accept 176 * external dma control by a board. 177 */ 178void 179isa_dmacascade(chan) 180 int chan; 181{ 182#ifdef DIAGNOSTIC 183 if (chan & ~VALID_DMA_MASK) 184 panic("isa_dmacascade: channel out of range"); 185#endif 186 187 /* set dma channel mode, and set dma channel mode */ 188 if ((chan & 4) == 0) { 189 outb(DMA1_MODE, DMA37MD_CASCADE | chan); 190 outb(DMA1_SMSK, chan); 191 } else { 192 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3)); 193 outb(DMA2_SMSK, chan & 3); 194 } 195} 196 197/* 198 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment 199 * problems by using a bounce buffer. 200 */ 201void 202isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan) 203{ 204 vm_paddr_t phys; 205 int waport; 206 caddr_t newaddr; 207 208 GIANT_REQUIRED; 209 210#ifdef DIAGNOSTIC 211 if (chan & ~VALID_DMA_MASK) 212 panic("isa_dmastart: channel out of range"); 213 214 if ((chan < 4 && nbytes > (1<<16)) 215 || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1))) 216 panic("isa_dmastart: impossible request"); 217 218 if ((dma_inuse & (1 << chan)) == 0) 219 printf("isa_dmastart: channel %d not acquired\n", chan); 220#endif 221 222#if 0 223 /* 224 * XXX This should be checked, but drivers like ad1848 only call 225 * isa_dmastart() once because they use Auto DMA mode. If we 226 * leave this in, drivers that do this will print this continuously. 227 */ 228 if (dma_busy & (1 << chan)) 229 printf("isa_dmastart: channel %d busy\n", chan); 230#endif 231 232 dma_busy |= (1 << chan); 233 234 if (isa_dmarangecheck(addr, nbytes, chan)) { 235 if (dma_bouncebuf[chan] == NULL 236 || dma_bouncebufsize[chan] < nbytes) 237 panic("isa_dmastart: bad bounce buffer"); 238 dma_bounced |= (1 << chan); 239 newaddr = dma_bouncebuf[chan]; 240 241 /* copy bounce buffer on write */ 242 if (!(flags & ISADMA_READ)) 243 bcopy(addr, newaddr, nbytes); 244 addr = newaddr; 245 } 246 247 /* translate to physical */ 248 phys = pmap_extract(kernel_pmap, (vm_offset_t)addr); 249 250 if (flags & ISADMA_RAW) { 251 dma_auto_mode |= (1 << chan); 252 } else { 253 dma_auto_mode &= ~(1 << chan); 254 } 255 256 if ((chan & 4) == 0) { 257 /* 258 * Program one of DMA channels 0..3. These are 259 * byte mode channels. 260 */ 261 /* set dma channel mode, and reset address ff */ 262 263 /* If ISADMA_RAW flag is set, then use autoinitialise mode */ 264 if (flags & ISADMA_RAW) { 265 if (flags & ISADMA_READ) 266 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan); 267 else 268 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan); 269 } 270 else 271 if (flags & ISADMA_READ) 272 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan); 273 else 274 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan); 275 outb(DMA1_FFC, 0); 276 277 /* send start address */ 278 waport = DMA1_CHN(chan); 279 outb(waport, phys); 280 outb(waport, phys>>8); 281 outb(dmapageport[chan], phys>>16); 282 283 /* send count */ 284 outb(waport + 1, --nbytes); 285 outb(waport + 1, nbytes>>8); 286 287 /* unmask channel */ 288 outb(DMA1_SMSK, chan); 289 } else { 290 /* 291 * Program one of DMA channels 4..7. These are 292 * word mode channels. 293 */ 294 /* set dma channel mode, and reset address ff */ 295 296 /* If ISADMA_RAW flag is set, then use autoinitialise mode */ 297 if (flags & ISADMA_RAW) { 298 if (flags & ISADMA_READ) 299 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3)); 300 else 301 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3)); 302 } 303 else 304 if (flags & ISADMA_READ) 305 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3)); 306 else 307 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3)); 308 outb(DMA2_FFC, 0); 309 310 /* send start address */ 311 waport = DMA2_CHN(chan - 4); 312 outb(waport, phys>>1); 313 outb(waport, phys>>9); 314 outb(dmapageport[chan], phys>>16); 315 316 /* send count */ 317 nbytes >>= 1; 318 outb(waport + 2, --nbytes); 319 outb(waport + 2, nbytes>>8); 320 321 /* unmask channel */ 322 outb(DMA2_SMSK, chan & 3); 323 } 324} 325 326void 327isa_dmadone(int flags, caddr_t addr, int nbytes, int chan) 328{ 329#ifdef DIAGNOSTIC 330 if (chan & ~VALID_DMA_MASK) 331 panic("isa_dmadone: channel out of range"); 332 333 if ((dma_inuse & (1 << chan)) == 0) 334 printf("isa_dmadone: channel %d not acquired\n", chan); 335#endif 336 337 if (((dma_busy & (1 << chan)) == 0) && 338 (dma_auto_mode & (1 << chan)) == 0 ) 339 printf("isa_dmadone: channel %d not busy\n", chan); 340 341 if ((dma_auto_mode & (1 << chan)) == 0) 342 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4); 343 344 if (dma_bounced & (1 << chan)) { 345 /* copy bounce buffer on read */ 346 if (flags & ISADMA_READ) 347 bcopy(dma_bouncebuf[chan], addr, nbytes); 348 349 dma_bounced &= ~(1 << chan); 350 } 351 dma_busy &= ~(1 << chan); 352} 353 354/* 355 * Check for problems with the address range of a DMA transfer 356 * (non-contiguous physical pages, outside of bus address space, 357 * crossing DMA page boundaries). 358 * Return true if special handling needed. 359 */ 360 361static int 362isa_dmarangecheck(caddr_t va, u_int length, int chan) 363{ 364 vm_paddr_t phys, priorpage = 0; 365 vm_offset_t endva; 366 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1); 367 368 GIANT_REQUIRED; 369 370 endva = (vm_offset_t)round_page((vm_offset_t)va + length); 371 for (; va < (caddr_t) endva ; va += PAGE_SIZE) { 372 phys = trunc_page(pmap_extract(kernel_pmap, (vm_offset_t)va)); 373#define ISARAM_END RAM_END 374 if (phys == 0) 375 panic("isa_dmacheck: no physical page present"); 376 if (phys >= ISARAM_END) 377 return (1); 378 if (priorpage) { 379 if (priorpage + PAGE_SIZE != phys) 380 return (1); 381 /* check if crossing a DMA page boundary */ 382 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk) 383 return (1); 384 } 385 priorpage = phys; 386 } 387 return (0); 388} 389 390/* 391 * Query the progress of a transfer on a DMA channel. 392 * 393 * To avoid having to interrupt a transfer in progress, we sample 394 * each of the high and low databytes twice, and apply the following 395 * logic to determine the correct count. 396 * 397 * Reads are performed with interrupts disabled, thus it is to be 398 * expected that the time between reads is very small. At most 399 * one rollover in the low count byte can be expected within the 400 * four reads that are performed. 401 * 402 * There are three gaps in which a rollover can occur : 403 * 404 * - read low1 405 * gap1 406 * - read high1 407 * gap2 408 * - read low2 409 * gap3 410 * - read high2 411 * 412 * If a rollover occurs in gap1 or gap2, the low2 value will be 413 * greater than the low1 value. In this case, low2 and high2 are a 414 * corresponding pair. 415 * 416 * In any other case, low1 and high1 can be considered to be correct. 417 * 418 * The function returns the number of bytes remaining in the transfer, 419 * or -1 if the channel requested is not active. 420 * 421 */ 422int 423isa_dmastatus(int chan) 424{ 425 u_long cnt = 0; 426 int ffport, waport; 427 u_long low1, high1, low2, high2; 428 429 /* channel active? */ 430 if ((dma_inuse & (1 << chan)) == 0) { 431 printf("isa_dmastatus: channel %d not active\n", chan); 432 return(-1); 433 } 434 /* channel busy? */ 435 436 if (((dma_busy & (1 << chan)) == 0) && 437 (dma_auto_mode & (1 << chan)) == 0 ) { 438 printf("chan %d not busy\n", chan); 439 return -2 ; 440 } 441 if (chan < 4) { /* low DMA controller */ 442 ffport = DMA1_FFC; 443 waport = DMA1_CHN(chan) + 1; 444 } else { /* high DMA controller */ 445 ffport = DMA2_FFC; 446 waport = DMA2_CHN(chan - 4) + 2; 447 } 448 449 disable_intr(); /* no interrupts Mr Jones! */ 450 outb(ffport, 0); /* clear register LSB flipflop */ 451 low1 = inb(waport); 452 high1 = inb(waport); 453 outb(ffport, 0); /* clear again */ 454 low2 = inb(waport); 455 high2 = inb(waport); 456 enable_intr(); /* enable interrupts again */ 457 458 /* 459 * Now decide if a wrap has tried to skew our results. 460 * Note that after TC, the count will read 0xffff, while we want 461 * to return zero, so we add and then mask to compensate. 462 */ 463 if (low1 >= low2) { 464 cnt = (low1 + (high1 << 8) + 1) & 0xffff; 465 } else { 466 cnt = (low2 + (high2 << 8) + 1) & 0xffff; 467 } 468 469 if (chan >= 4) /* high channels move words */ 470 cnt *= 2; 471 return(cnt); 472} 473 474/* 475 * Reached terminal count yet ? 476 */ 477int 478isa_dmatc(int chan) 479{ 480 481 if (chan < 4) 482 return(inb(DMA1_STATUS) & (1 << chan)); 483 else 484 return(inb(DMA2_STATUS) & (1 << (chan & 3))); 485} 486 487/* 488 * Stop a DMA transfer currently in progress. 489 */ 490int 491isa_dmastop(int chan) 492{ 493 if ((dma_inuse & (1 << chan)) == 0) 494 printf("isa_dmastop: channel %d not acquired\n", chan); 495 496 if (((dma_busy & (1 << chan)) == 0) && 497 ((dma_auto_mode & (1 << chan)) == 0)) { 498 printf("chan %d not busy\n", chan); 499 return -2 ; 500 } 501 502 if ((chan & 4) == 0) { 503 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */); 504 } else { 505 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */); 506 } 507 return(isa_dmastatus(chan)); 508} 509 510/* 511 * Attach to the ISA PnP descriptor for the AT DMA controller 512 */ 513static struct isa_pnp_id atdma_ids[] = { 514 { 0x0002d041 /* PNP0200 */, "AT DMA controller" }, 515 { 0 } 516}; 517 518static int 519atdma_probe(device_t dev) 520{ 521 int result; 522 523 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, atdma_ids)) <= 0) 524 device_quiet(dev); 525 return(result); 526} 527 528static int 529atdma_attach(device_t dev) 530{ 531 return(0); 532} 533 534static device_method_t atdma_methods[] = { 535 /* Device interface */ 536 DEVMETHOD(device_probe, atdma_probe), 537 DEVMETHOD(device_attach, atdma_attach), 538 DEVMETHOD(device_detach, bus_generic_detach), 539 DEVMETHOD(device_shutdown, bus_generic_shutdown), 540 DEVMETHOD(device_suspend, bus_generic_suspend), 541 DEVMETHOD(device_resume, bus_generic_resume), 542 { 0, 0 } 543}; 544 545static driver_t atdma_driver = { 546 "atdma", 547 atdma_methods, 548 1, /* no softc */ 549}; 550 551static devclass_t atdma_devclass; 552 553DRIVER_MODULE(atdma, isa, atdma_driver, atdma_devclass, 0, 0); 554DRIVER_MODULE(atdma, acpi, atdma_driver, atdma_devclass, 0, 0); 555