isa_dma.c revision 50477
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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91 37 * $FreeBSD: head/sys/i386/isa/isa_dma.c 50477 1999-08-28 01:08:13Z peter $ 38 */ 39 40/* 41 * code to manage AT bus 42 * 43 * 92/08/18 Frank P. MacLachlan (fpm@crash.cts.com): 44 * Fixed uninitialized variable problem and added code to deal 45 * with DMA page boundaries in isa_dmarangecheck(). Fixed word 46 * mode DMA count compution and reorganized DMA setup code in 47 * isa_dmastart() 48 */ 49 50#include <sys/param.h> 51#include <sys/systm.h> 52#include <sys/buf.h> /* B_READ and B_RAW */ 53#include <sys/malloc.h> 54#include <vm/vm.h> 55#include <vm/vm_param.h> 56#include <vm/pmap.h> 57#include <i386/isa/isa.h> 58#include <i386/isa/isa_dma.h> 59#include <i386/isa/ic/i8237.h> 60 61/* 62** Register definitions for DMA controller 1 (channels 0..3): 63*/ 64#define DMA1_CHN(c) (IO_DMA1 + 1*(2*(c))) /* addr reg for channel c */ 65#define DMA1_SMSK (IO_DMA1 + 1*10) /* single mask register */ 66#define DMA1_MODE (IO_DMA1 + 1*11) /* mode register */ 67#define DMA1_FFC (IO_DMA1 + 1*12) /* clear first/last FF */ 68 69/* 70** Register definitions for DMA controller 2 (channels 4..7): 71*/ 72#define DMA2_CHN(c) (IO_DMA2 + 2*(2*(c))) /* addr reg for channel c */ 73#define DMA2_SMSK (IO_DMA2 + 2*10) /* single mask register */ 74#define DMA2_MODE (IO_DMA2 + 2*11) /* mode register */ 75#define DMA2_FFC (IO_DMA2 + 2*12) /* clear first/last FF */ 76 77static int isa_dmarangecheck __P((caddr_t va, u_int length, int chan)); 78 79static caddr_t dma_bouncebuf[8]; 80static u_int dma_bouncebufsize[8]; 81static u_int8_t dma_bounced = 0; 82static u_int8_t dma_busy = 0; /* Used in isa_dmastart() */ 83static u_int8_t dma_inuse = 0; /* User for acquire/release */ 84static u_int8_t dma_auto_mode = 0; 85 86#define VALID_DMA_MASK (7) 87 88/* high byte of address is stored in this port for i-th dma channel */ 89static int dmapageport[8] = { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a }; 90 91/* 92 * Setup a DMA channel's bounce buffer. 93 */ 94void 95isa_dmainit(chan, bouncebufsize) 96 int chan; 97 u_int bouncebufsize; 98{ 99 void *buf; 100 101#ifdef DIAGNOSTIC 102 if (chan & ~VALID_DMA_MASK) 103 panic("isa_dmainit: channel out of range"); 104 105 if (dma_bouncebuf[chan] != NULL) 106 panic("isa_dmainit: impossible request"); 107#endif 108 109 dma_bouncebufsize[chan] = bouncebufsize; 110 111 /* Try malloc() first. It works better if it works. */ 112 buf = malloc(bouncebufsize, M_DEVBUF, M_NOWAIT); 113 if (buf != NULL) { 114 if (isa_dmarangecheck(buf, bouncebufsize, chan) == 0) { 115 dma_bouncebuf[chan] = buf; 116 return; 117 } 118 free(buf, M_DEVBUF); 119 } 120 buf = contigmalloc(bouncebufsize, M_DEVBUF, M_NOWAIT, 0ul, 0xfffffful, 121 1ul, chan & 4 ? 0x20000ul : 0x10000ul); 122 if (buf == NULL) 123 printf("isa_dmainit(%d, %d) failed\n", chan, bouncebufsize); 124 else 125 dma_bouncebuf[chan] = buf; 126} 127 128/* 129 * Register a DMA channel's usage. Usually called from a device driver 130 * in open() or during its initialization. 131 */ 132int 133isa_dma_acquire(chan) 134 int chan; 135{ 136#ifdef DIAGNOSTIC 137 if (chan & ~VALID_DMA_MASK) 138 panic("isa_dma_acquire: channel out of range"); 139#endif 140 141 if (dma_inuse & (1 << chan)) { 142 printf("isa_dma_acquire: channel %d already in use\n", chan); 143 return (EBUSY); 144 } 145 dma_inuse |= (1 << chan); 146 dma_auto_mode &= ~(1 << chan); 147 148 return (0); 149} 150 151/* 152 * Unregister a DMA channel's usage. Usually called from a device driver 153 * during close() or during its shutdown. 154 */ 155void 156isa_dma_release(chan) 157 int chan; 158{ 159#ifdef DIAGNOSTIC 160 if (chan & ~VALID_DMA_MASK) 161 panic("isa_dma_release: channel out of range"); 162 163 if ((dma_inuse & (1 << chan)) == 0) 164 printf("isa_dma_release: channel %d not in use\n", chan); 165#endif 166 167 if (dma_busy & (1 << chan)) { 168 dma_busy &= ~(1 << chan); 169 /* 170 * XXX We should also do "dma_bounced &= (1 << chan);" 171 * because we are acting on behalf of isa_dmadone() which 172 * was not called to end the last DMA operation. This does 173 * not matter now, but it may in the future. 174 */ 175 } 176 177 dma_inuse &= ~(1 << chan); 178 dma_auto_mode &= ~(1 << chan); 179} 180 181/* 182 * isa_dmacascade(): program 8237 DMA controller channel to accept 183 * external dma control by a board. 184 */ 185void 186isa_dmacascade(chan) 187 int chan; 188{ 189#ifdef DIAGNOSTIC 190 if (chan & ~VALID_DMA_MASK) 191 panic("isa_dmacascade: channel out of range"); 192#endif 193 194 /* set dma channel mode, and set dma channel mode */ 195 if ((chan & 4) == 0) { 196 outb(DMA1_MODE, DMA37MD_CASCADE | chan); 197 outb(DMA1_SMSK, chan); 198 } else { 199 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3)); 200 outb(DMA2_SMSK, chan & 3); 201 } 202} 203 204/* 205 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment 206 * problems by using a bounce buffer. 207 */ 208void 209isa_dmastart(int flags, caddr_t addr, u_int nbytes, int chan) 210{ 211 vm_offset_t phys; 212 int waport; 213 caddr_t newaddr; 214 215#ifdef DIAGNOSTIC 216 if (chan & ~VALID_DMA_MASK) 217 panic("isa_dmastart: channel out of range"); 218 219 if ((chan < 4 && nbytes > (1<<16)) 220 || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1))) 221 panic("isa_dmastart: impossible request"); 222 223 if ((dma_inuse & (1 << chan)) == 0) 224 printf("isa_dmastart: channel %d not acquired\n", chan); 225#endif 226 227#if 0 228 /* 229 * XXX This should be checked, but drivers like ad1848 only call 230 * isa_dmastart() once because they use Auto DMA mode. If we 231 * leave this in, drivers that do this will print this continuously. 232 */ 233 if (dma_busy & (1 << chan)) 234 printf("isa_dmastart: channel %d busy\n", chan); 235#endif 236 237 dma_busy |= (1 << chan); 238 239 if (isa_dmarangecheck(addr, nbytes, chan)) { 240 if (dma_bouncebuf[chan] == NULL 241 || dma_bouncebufsize[chan] < nbytes) 242 panic("isa_dmastart: bad bounce buffer"); 243 dma_bounced |= (1 << chan); 244 newaddr = dma_bouncebuf[chan]; 245 246 /* copy bounce buffer on write */ 247 if (!(flags & B_READ)) 248 bcopy(addr, newaddr, nbytes); 249 addr = newaddr; 250 } 251 252 /* translate to physical */ 253 phys = pmap_extract(pmap_kernel(), (vm_offset_t)addr); 254 255 if (flags & B_RAW) { 256 dma_auto_mode |= (1 << chan); 257 } else { 258 dma_auto_mode &= ~(1 << chan); 259 } 260 261 if ((chan & 4) == 0) { 262 /* 263 * Program one of DMA channels 0..3. These are 264 * byte mode channels. 265 */ 266 /* set dma channel mode, and reset address ff */ 267 268 /* If B_RAW flag is set, then use autoinitialise mode */ 269 if (flags & B_RAW) { 270 if (flags & B_READ) 271 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_WRITE|chan); 272 else 273 outb(DMA1_MODE, DMA37MD_AUTO|DMA37MD_READ|chan); 274 } 275 else 276 if (flags & B_READ) 277 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan); 278 else 279 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan); 280 outb(DMA1_FFC, 0); 281 282 /* send start address */ 283 waport = DMA1_CHN(chan); 284 outb(waport, phys); 285 outb(waport, phys>>8); 286 outb(dmapageport[chan], phys>>16); 287 288 /* send count */ 289 outb(waport + 1, --nbytes); 290 outb(waport + 1, nbytes>>8); 291 292 /* unmask channel */ 293 outb(DMA1_SMSK, chan); 294 } else { 295 /* 296 * Program one of DMA channels 4..7. These are 297 * word mode channels. 298 */ 299 /* set dma channel mode, and reset address ff */ 300 301 /* If B_RAW flag is set, then use autoinitialise mode */ 302 if (flags & B_RAW) { 303 if (flags & B_READ) 304 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_WRITE|(chan&3)); 305 else 306 outb(DMA2_MODE, DMA37MD_AUTO|DMA37MD_READ|(chan&3)); 307 } 308 else 309 if (flags & B_READ) 310 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3)); 311 else 312 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3)); 313 outb(DMA2_FFC, 0); 314 315 /* send start address */ 316 waport = DMA2_CHN(chan - 4); 317 outb(waport, phys>>1); 318 outb(waport, phys>>9); 319 outb(dmapageport[chan], phys>>16); 320 321 /* send count */ 322 nbytes >>= 1; 323 outb(waport + 2, --nbytes); 324 outb(waport + 2, nbytes>>8); 325 326 /* unmask channel */ 327 outb(DMA2_SMSK, chan & 3); 328 } 329} 330 331void 332isa_dmadone(int flags, caddr_t addr, int nbytes, int chan) 333{ 334#ifdef DIAGNOSTIC 335 if (chan & ~VALID_DMA_MASK) 336 panic("isa_dmadone: channel out of range"); 337 338 if ((dma_inuse & (1 << chan)) == 0) 339 printf("isa_dmadone: channel %d not acquired\n", chan); 340#endif 341 342 if (((dma_busy & (1 << chan)) == 0) && 343 (dma_auto_mode & (1 << chan)) == 0 ) 344 printf("isa_dmadone: channel %d not busy\n", chan); 345 346 if ((dma_auto_mode & (1 << chan)) == 0) 347 outb(chan & 4 ? DMA2_SMSK : DMA1_SMSK, (chan & 3) | 4); 348 349 if (dma_bounced & (1 << chan)) { 350 /* copy bounce buffer on read */ 351 if (flags & B_READ) 352 bcopy(dma_bouncebuf[chan], addr, nbytes); 353 354 dma_bounced &= ~(1 << chan); 355 } 356 dma_busy &= ~(1 << chan); 357} 358 359/* 360 * Check for problems with the address range of a DMA transfer 361 * (non-contiguous physical pages, outside of bus address space, 362 * crossing DMA page boundaries). 363 * Return true if special handling needed. 364 */ 365 366static int 367isa_dmarangecheck(caddr_t va, u_int length, int chan) 368{ 369 vm_offset_t phys, priorpage = 0, endva; 370 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1); 371 372 endva = (vm_offset_t)round_page((vm_offset_t)va + length); 373 for (; va < (caddr_t) endva ; va += PAGE_SIZE) { 374 phys = trunc_page(pmap_extract(pmap_kernel(), (vm_offset_t)va)); 375#define ISARAM_END RAM_END 376 if (phys == 0) 377 panic("isa_dmacheck: no physical page present"); 378 if (phys >= ISARAM_END) 379 return (1); 380 if (priorpage) { 381 if (priorpage + PAGE_SIZE != phys) 382 return (1); 383 /* check if crossing a DMA page boundary */ 384 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk) 385 return (1); 386 } 387 priorpage = phys; 388 } 389 return (0); 390} 391 392/* 393 * Query the progress of a transfer on a DMA channel. 394 * 395 * To avoid having to interrupt a transfer in progress, we sample 396 * each of the high and low databytes twice, and apply the following 397 * logic to determine the correct count. 398 * 399 * Reads are performed with interrupts disabled, thus it is to be 400 * expected that the time between reads is very small. At most 401 * one rollover in the low count byte can be expected within the 402 * four reads that are performed. 403 * 404 * There are three gaps in which a rollover can occur : 405 * 406 * - read low1 407 * gap1 408 * - read high1 409 * gap2 410 * - read low2 411 * gap3 412 * - read high2 413 * 414 * If a rollover occurs in gap1 or gap2, the low2 value will be 415 * greater than the low1 value. In this case, low2 and high2 are a 416 * corresponding pair. 417 * 418 * In any other case, low1 and high1 can be considered to be correct. 419 * 420 * The function returns the number of bytes remaining in the transfer, 421 * or -1 if the channel requested is not active. 422 * 423 */ 424int 425isa_dmastatus(int chan) 426{ 427 u_long cnt = 0; 428 int ffport, waport; 429 u_long low1, high1, low2, high2; 430 431 /* channel active? */ 432 if ((dma_inuse & (1 << chan)) == 0) { 433 printf("isa_dmastatus: channel %d not active\n", chan); 434 return(-1); 435 } 436 /* channel busy? */ 437 438 if (((dma_busy & (1 << chan)) == 0) && 439 (dma_auto_mode & (1 << chan)) == 0 ) { 440 printf("chan %d not busy\n", chan); 441 return -2 ; 442 } 443 if (chan < 4) { /* low DMA controller */ 444 ffport = DMA1_FFC; 445 waport = DMA1_CHN(chan) + 1; 446 } else { /* high DMA controller */ 447 ffport = DMA2_FFC; 448 waport = DMA2_CHN(chan - 4) + 2; 449 } 450 451 disable_intr(); /* no interrupts Mr Jones! */ 452 outb(ffport, 0); /* clear register LSB flipflop */ 453 low1 = inb(waport); 454 high1 = inb(waport); 455 outb(ffport, 0); /* clear again */ 456 low2 = inb(waport); 457 high2 = inb(waport); 458 enable_intr(); /* enable interrupts again */ 459 460 /* 461 * Now decide if a wrap has tried to skew our results. 462 * Note that after TC, the count will read 0xffff, while we want 463 * to return zero, so we add and then mask to compensate. 464 */ 465 if (low1 >= low2) { 466 cnt = (low1 + (high1 << 8) + 1) & 0xffff; 467 } else { 468 cnt = (low2 + (high2 << 8) + 1) & 0xffff; 469 } 470 471 if (chan >= 4) /* high channels move words */ 472 cnt *= 2; 473 return(cnt); 474} 475 476/* 477 * Stop a DMA transfer currently in progress. 478 */ 479int 480isa_dmastop(int chan) 481{ 482 if ((dma_inuse & (1 << chan)) == 0) 483 printf("isa_dmastop: channel %d not acquired\n", chan); 484 485 if (((dma_busy & (1 << chan)) == 0) && 486 ((dma_auto_mode & (1 << chan)) == 0)) { 487 printf("chan %d not busy\n", chan); 488 return -2 ; 489 } 490 491 if ((chan & 4) == 0) { 492 outb(DMA1_SMSK, (chan & 3) | 4 /* disable mask */); 493 } else { 494 outb(DMA2_SMSK, (chan & 3) | 4 /* disable mask */); 495 } 496 return(isa_dmastatus(chan)); 497} 498