1 /* 2 * atari_scsi.c -- Device dependent functions for the Atari generic SCSI port 3 * 4 * Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> 5 * 6 * Loosely based on the work of Robert De Vries' team and added: 7 * - working real DMA 8 * - Falcon support (untested yet!) ++bjoern fixed and now it works 9 * - lots of extensions and bug fixes. 10 * 11 * This file is subject to the terms and conditions of the GNU General Public 12 * License. See the file COPYING in the main directory of this archive 13 * for more details. 14 * 15 */ 16 17 /* 18 * Notes for Falcon SCSI DMA 19 * 20 * The 5380 device is one of several that all share the DMA chip. Hence 21 * "locking" and "unlocking" access to this chip is required. 22 * 23 * Two possible schemes for ST DMA acquisition by atari_scsi are: 24 * 1) The lock is taken for each command separately (i.e. can_queue == 1). 25 * 2) The lock is taken when the first command arrives and released 26 * when the last command is finished (i.e. can_queue > 1). 27 * 28 * The first alternative limits SCSI bus utilization, since interleaving 29 * commands is not possible. The second gives better performance but is 30 * unfair to other drivers needing to use the ST DMA chip. In order to 31 * allow the IDE and floppy drivers equal access to the ST DMA chip 32 * the default is can_queue == 1. 33 */ 34 35 #include <linux/module.h> 36 #include <linux/types.h> 37 #include <linux/blkdev.h> 38 #include <linux/interrupt.h> 39 #include <linux/init.h> 40 #include <linux/nvram.h> 41 #include <linux/bitops.h> 42 #include <linux/wait.h> 43 #include <linux/platform_device.h> 44 45 #include <asm/setup.h> 46 #include <asm/atarihw.h> 47 #include <asm/atariints.h> 48 #include <asm/atari_stdma.h> 49 #include <asm/atari_stram.h> 50 #include <asm/io.h> 51 52 #include <scsi/scsi_host.h> 53 54 #define DMA_MIN_SIZE 32 55 56 /* Definitions for the core NCR5380 driver. */ 57 58 #define NCR5380_implementation_fields /* none */ 59 60 static u8 (*atari_scsi_reg_read)(unsigned int); 61 static void (*atari_scsi_reg_write)(unsigned int, u8); 62 63 #define NCR5380_read(reg) atari_scsi_reg_read(reg) 64 #define NCR5380_write(reg, value) atari_scsi_reg_write(reg, value) 65 66 #define NCR5380_queue_command atari_scsi_queue_command 67 #define NCR5380_abort atari_scsi_abort 68 #define NCR5380_info atari_scsi_info 69 70 #define NCR5380_dma_xfer_len atari_scsi_dma_xfer_len 71 #define NCR5380_dma_recv_setup atari_scsi_dma_recv_setup 72 #define NCR5380_dma_send_setup atari_scsi_dma_send_setup 73 #define NCR5380_dma_residual atari_scsi_dma_residual 74 75 #define NCR5380_acquire_dma_irq(instance) falcon_get_lock(instance) 76 #define NCR5380_release_dma_irq(instance) falcon_release_lock() 77 78 #include "NCR5380.h" 79 80 81 #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI) 82 83 #define SCSI_DMA_WRITE_P(elt,val) \ 84 do { \ 85 unsigned long v = val; \ 86 tt_scsi_dma.elt##_lo = v & 0xff; \ 87 v >>= 8; \ 88 tt_scsi_dma.elt##_lmd = v & 0xff; \ 89 v >>= 8; \ 90 tt_scsi_dma.elt##_hmd = v & 0xff; \ 91 v >>= 8; \ 92 tt_scsi_dma.elt##_hi = v & 0xff; \ 93 } while(0) 94 95 #define SCSI_DMA_READ_P(elt) \ 96 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \ 97 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \ 98 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \ 99 (unsigned long)tt_scsi_dma.elt##_lo) 100 101 102 static inline void SCSI_DMA_SETADR(unsigned long adr) 103 { 104 st_dma.dma_lo = (unsigned char)adr; 105 MFPDELAY(); 106 adr >>= 8; 107 st_dma.dma_md = (unsigned char)adr; 108 MFPDELAY(); 109 adr >>= 8; 110 st_dma.dma_hi = (unsigned char)adr; 111 MFPDELAY(); 112 } 113 114 static inline unsigned long SCSI_DMA_GETADR(void) 115 { 116 unsigned long adr; 117 adr = st_dma.dma_lo; 118 MFPDELAY(); 119 adr |= (st_dma.dma_md & 0xff) << 8; 120 MFPDELAY(); 121 adr |= (st_dma.dma_hi & 0xff) << 16; 122 MFPDELAY(); 123 return adr; 124 } 125 126 static void atari_scsi_fetch_restbytes(void); 127 128 static unsigned long atari_dma_residual, atari_dma_startaddr; 129 static short atari_dma_active; 130 /* pointer to the dribble buffer */ 131 static char *atari_dma_buffer; 132 /* precalculated physical address of the dribble buffer */ 133 static unsigned long atari_dma_phys_buffer; 134 /* != 0 tells the Falcon int handler to copy data from the dribble buffer */ 135 static char *atari_dma_orig_addr; 136 /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use 137 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare 138 * cases where requests to physical contiguous buffers have been merged, this 139 * request is <= 4k (one page). So I don't think we have to split transfers 140 * just due to this buffer size... 141 */ 142 #define STRAM_BUFFER_SIZE (4096) 143 /* mask for address bits that can't be used with the ST-DMA */ 144 static unsigned long atari_dma_stram_mask; 145 #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0) 146 147 static int setup_can_queue = -1; 148 module_param(setup_can_queue, int, 0); 149 static int setup_cmd_per_lun = -1; 150 module_param(setup_cmd_per_lun, int, 0); 151 static int setup_sg_tablesize = -1; 152 module_param(setup_sg_tablesize, int, 0); 153 static int setup_hostid = -1; 154 module_param(setup_hostid, int, 0); 155 static int setup_toshiba_delay = -1; 156 module_param(setup_toshiba_delay, int, 0); 157 158 159 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat) 160 { 161 int i; 162 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr; 163 164 if (dma_stat & 0x01) { 165 166 /* A bus error happens when DMA-ing from the last page of a 167 * physical memory chunk (DMA prefetch!), but that doesn't hurt. 168 * Check for this case: 169 */ 170 171 for (i = 0; i < m68k_num_memory; ++i) { 172 end_addr = m68k_memory[i].addr + m68k_memory[i].size; 173 if (end_addr <= addr && addr <= end_addr + 4) 174 return 1; 175 } 176 } 177 return 0; 178 } 179 180 181 static irqreturn_t scsi_tt_intr(int irq, void *dev) 182 { 183 struct Scsi_Host *instance = dev; 184 struct NCR5380_hostdata *hostdata = shost_priv(instance); 185 int dma_stat; 186 187 dma_stat = tt_scsi_dma.dma_ctrl; 188 189 dsprintk(NDEBUG_INTR, instance, "NCR5380 interrupt, DMA status = %02x\n", 190 dma_stat & 0xff); 191 192 /* Look if it was the DMA that has interrupted: First possibility 193 * is that a bus error occurred... 194 */ 195 if (dma_stat & 0x80) { 196 if (!scsi_dma_is_ignored_buserr(dma_stat)) { 197 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", 198 SCSI_DMA_READ_P(dma_addr)); 199 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); 200 } 201 } 202 203 /* If the DMA is active but not finished, we have the case 204 * that some other 5380 interrupt occurred within the DMA transfer. 205 * This means we have residual bytes, if the desired end address 206 * is not yet reached. Maybe we have to fetch some bytes from the 207 * rest data register, too. The residual must be calculated from 208 * the address pointer, not the counter register, because only the 209 * addr reg counts bytes not yet written and pending in the rest 210 * data reg! 211 */ 212 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { 213 atari_dma_residual = hostdata->dma_len - 214 (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); 215 216 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n", 217 atari_dma_residual); 218 219 if ((signed int)atari_dma_residual < 0) 220 atari_dma_residual = 0; 221 if ((dma_stat & 1) == 0) { 222 /* 223 * After read operations, we maybe have to 224 * transport some rest bytes 225 */ 226 atari_scsi_fetch_restbytes(); 227 } else { 228 /* 229 * There seems to be a nasty bug in some SCSI-DMA/NCR 230 * combinations: If a target disconnects while a write 231 * operation is going on, the address register of the 232 * DMA may be a few bytes farer than it actually read. 233 * This is probably due to DMA prefetching and a delay 234 * between DMA and NCR. Experiments showed that the 235 * dma_addr is 9 bytes to high, but this could vary. 236 * The problem is, that the residual is thus calculated 237 * wrong and the next transfer will start behind where 238 * it should. So we round up the residual to the next 239 * multiple of a sector size, if it isn't already a 240 * multiple and the originally expected transfer size 241 * was. The latter condition is there to ensure that 242 * the correction is taken only for "real" data 243 * transfers and not for, e.g., the parameters of some 244 * other command. These shouldn't disconnect anyway. 245 */ 246 if (atari_dma_residual & 0x1ff) { 247 dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, " 248 "difference %ld bytes\n", 249 512 - (atari_dma_residual & 0x1ff)); 250 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; 251 } 252 } 253 tt_scsi_dma.dma_ctrl = 0; 254 } 255 256 /* If the DMA is finished, fetch the rest bytes and turn it off */ 257 if (dma_stat & 0x40) { 258 atari_dma_residual = 0; 259 if ((dma_stat & 1) == 0) 260 atari_scsi_fetch_restbytes(); 261 tt_scsi_dma.dma_ctrl = 0; 262 } 263 264 NCR5380_intr(irq, dev); 265 266 return IRQ_HANDLED; 267 } 268 269 270 static irqreturn_t scsi_falcon_intr(int irq, void *dev) 271 { 272 struct Scsi_Host *instance = dev; 273 struct NCR5380_hostdata *hostdata = shost_priv(instance); 274 int dma_stat; 275 276 /* Turn off DMA and select sector counter register before 277 * accessing the status register (Atari recommendation!) 278 */ 279 st_dma.dma_mode_status = 0x90; 280 dma_stat = st_dma.dma_mode_status; 281 282 /* Bit 0 indicates some error in the DMA process... don't know 283 * what happened exactly (no further docu). 284 */ 285 if (!(dma_stat & 0x01)) { 286 /* DMA error */ 287 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); 288 } 289 290 /* If the DMA was active, but now bit 1 is not clear, it is some 291 * other 5380 interrupt that finishes the DMA transfer. We have to 292 * calculate the number of residual bytes and give a warning if 293 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) 294 */ 295 if (atari_dma_active && (dma_stat & 0x02)) { 296 unsigned long transferred; 297 298 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; 299 /* The ST-DMA address is incremented in 2-byte steps, but the 300 * data are written only in 16-byte chunks. If the number of 301 * transferred bytes is not divisible by 16, the remainder is 302 * lost somewhere in outer space. 303 */ 304 if (transferred & 15) 305 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " 306 "ST-DMA fifo\n", transferred & 15); 307 308 atari_dma_residual = hostdata->dma_len - transferred; 309 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n", 310 atari_dma_residual); 311 } else 312 atari_dma_residual = 0; 313 atari_dma_active = 0; 314 315 if (atari_dma_orig_addr) { 316 /* If the dribble buffer was used on a read operation, copy the DMA-ed 317 * data to the original destination address. 318 */ 319 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), 320 hostdata->dma_len - atari_dma_residual); 321 atari_dma_orig_addr = NULL; 322 } 323 324 NCR5380_intr(irq, dev); 325 326 return IRQ_HANDLED; 327 } 328 329 330 static void atari_scsi_fetch_restbytes(void) 331 { 332 int nr; 333 char *src, *dst; 334 unsigned long phys_dst; 335 336 /* fetch rest bytes in the DMA register */ 337 phys_dst = SCSI_DMA_READ_P(dma_addr); 338 nr = phys_dst & 3; 339 if (nr) { 340 /* there are 'nr' bytes left for the last long address 341 before the DMA pointer */ 342 phys_dst ^= nr; 343 dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", 344 nr, phys_dst); 345 /* The content of the DMA pointer is a physical address! */ 346 dst = phys_to_virt(phys_dst); 347 dprintk(NDEBUG_DMA, " = virt addr %p\n", dst); 348 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) 349 *dst++ = *src++; 350 } 351 } 352 353 354 /* This function releases the lock on the DMA chip if there is no 355 * connected command and the disconnected queue is empty. 356 */ 357 358 static void falcon_release_lock(void) 359 { 360 if (IS_A_TT()) 361 return; 362 363 if (stdma_is_locked_by(scsi_falcon_intr)) 364 stdma_release(); 365 } 366 367 /* This function manages the locking of the ST-DMA. 368 * If the DMA isn't locked already for SCSI, it tries to lock it by 369 * calling stdma_lock(). But if the DMA is locked by the SCSI code and 370 * there are other drivers waiting for the chip, we do not issue the 371 * command immediately but tell the SCSI mid-layer to defer. 372 */ 373 374 static int falcon_get_lock(struct Scsi_Host *instance) 375 { 376 if (IS_A_TT()) 377 return 1; 378 379 if (stdma_is_locked_by(scsi_falcon_intr)) 380 return 1; 381 382 /* stdma_lock() may sleep which means it can't be used here */ 383 return stdma_try_lock(scsi_falcon_intr, instance); 384 } 385 386 #ifndef MODULE 387 static int __init atari_scsi_setup(char *str) 388 { 389 /* Format of atascsi parameter is: 390 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 391 * Defaults depend on TT or Falcon, determined at run time. 392 * Negative values mean don't change. 393 */ 394 int ints[8]; 395 396 get_options(str, ARRAY_SIZE(ints), ints); 397 398 if (ints[0] < 1) { 399 printk("atari_scsi_setup: no arguments!\n"); 400 return 0; 401 } 402 if (ints[0] >= 1) 403 setup_can_queue = ints[1]; 404 if (ints[0] >= 2) 405 setup_cmd_per_lun = ints[2]; 406 if (ints[0] >= 3) 407 setup_sg_tablesize = ints[3]; 408 if (ints[0] >= 4) 409 setup_hostid = ints[4]; 410 /* ints[5] (use_tagged_queuing) is ignored */ 411 /* ints[6] (use_pdma) is ignored */ 412 if (ints[0] >= 7) 413 setup_toshiba_delay = ints[7]; 414 415 return 1; 416 } 417 418 __setup("atascsi=", atari_scsi_setup); 419 #endif /* !MODULE */ 420 421 static unsigned long atari_scsi_dma_setup(struct NCR5380_hostdata *hostdata, 422 void *data, unsigned long count, 423 int dir) 424 { 425 unsigned long addr = virt_to_phys(data); 426 427 dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, dir = %d\n", 428 hostdata->host->host_no, data, addr, count, dir); 429 430 if (!IS_A_TT() && !STRAM_ADDR(addr)) { 431 /* If we have a non-DMAable address on a Falcon, use the dribble 432 * buffer; 'orig_addr' != 0 in the read case tells the interrupt 433 * handler to copy data from the dribble buffer to the originally 434 * wanted address. 435 */ 436 if (dir) 437 memcpy(atari_dma_buffer, data, count); 438 else 439 atari_dma_orig_addr = data; 440 addr = atari_dma_phys_buffer; 441 } 442 443 atari_dma_startaddr = addr; /* Needed for calculating residual later. */ 444 445 /* Cache cleanup stuff: On writes, push any dirty cache out before sending 446 * it to the peripheral. (Must be done before DMA setup, since at least 447 * the ST-DMA begins to fill internal buffers right after setup. For 448 * reads, invalidate any cache, may be altered after DMA without CPU 449 * knowledge. 450 * 451 * ++roman: For the Medusa, there's no need at all for that cache stuff, 452 * because the hardware does bus snooping (fine!). 453 */ 454 dma_cache_maintenance(addr, count, dir); 455 456 if (IS_A_TT()) { 457 tt_scsi_dma.dma_ctrl = dir; 458 SCSI_DMA_WRITE_P(dma_addr, addr); 459 SCSI_DMA_WRITE_P(dma_cnt, count); 460 tt_scsi_dma.dma_ctrl = dir | 2; 461 } else { /* ! IS_A_TT */ 462 463 /* set address */ 464 SCSI_DMA_SETADR(addr); 465 466 /* toggle direction bit to clear FIFO and set DMA direction */ 467 dir <<= 8; 468 st_dma.dma_mode_status = 0x90 | dir; 469 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); 470 st_dma.dma_mode_status = 0x90 | dir; 471 udelay(40); 472 /* On writes, round up the transfer length to the next multiple of 512 473 * (see also comment at atari_dma_xfer_len()). */ 474 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; 475 udelay(40); 476 st_dma.dma_mode_status = 0x10 | dir; 477 udelay(40); 478 /* need not restore value of dir, only boolean value is tested */ 479 atari_dma_active = 1; 480 } 481 482 return count; 483 } 484 485 static inline int atari_scsi_dma_recv_setup(struct NCR5380_hostdata *hostdata, 486 unsigned char *data, int count) 487 { 488 return atari_scsi_dma_setup(hostdata, data, count, 0); 489 } 490 491 static inline int atari_scsi_dma_send_setup(struct NCR5380_hostdata *hostdata, 492 unsigned char *data, int count) 493 { 494 return atari_scsi_dma_setup(hostdata, data, count, 1); 495 } 496 497 static int atari_scsi_dma_residual(struct NCR5380_hostdata *hostdata) 498 { 499 return atari_dma_residual; 500 } 501 502 503 #define CMD_SURELY_BLOCK_MODE 0 504 #define CMD_SURELY_BYTE_MODE 1 505 #define CMD_MODE_UNKNOWN 2 506 507 static int falcon_classify_cmd(struct scsi_cmnd *cmd) 508 { 509 unsigned char opcode = cmd->cmnd[0]; 510 511 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || 512 opcode == READ_BUFFER) 513 return CMD_SURELY_BYTE_MODE; 514 else if (opcode == READ_6 || opcode == READ_10 || 515 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || 516 opcode == RECOVER_BUFFERED_DATA) { 517 /* In case of a sequential-access target (tape), special care is 518 * needed here: The transfer is block-mode only if the 'fixed' bit is 519 * set! */ 520 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) 521 return CMD_SURELY_BYTE_MODE; 522 else 523 return CMD_SURELY_BLOCK_MODE; 524 } else 525 return CMD_MODE_UNKNOWN; 526 } 527 528 529 /* This function calculates the number of bytes that can be transferred via 530 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the 531 * ST-DMA chip. There are only multiples of 512 bytes possible and max. 532 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not 533 * possible on the Falcon, since that would require to program the DMA for 534 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have 535 * the overrun problem, so this question is academic :-) 536 */ 537 538 static int atari_scsi_dma_xfer_len(struct NCR5380_hostdata *hostdata, 539 struct scsi_cmnd *cmd) 540 { 541 int wanted_len = NCR5380_to_ncmd(cmd)->this_residual; 542 int possible_len, limit; 543 544 if (wanted_len < DMA_MIN_SIZE) 545 return 0; 546 547 if (IS_A_TT()) 548 /* TT SCSI DMA can transfer arbitrary #bytes */ 549 return wanted_len; 550 551 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. 552 * 255*512 bytes, but this should be enough) 553 * 554 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands 555 * that return a number of bytes which cannot be known beforehand. In this 556 * case, the given transfer length is an "allocation length". Now it 557 * can happen that this allocation length is a multiple of 512 bytes and 558 * the DMA is used. But if not n*512 bytes really arrive, some input data 559 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish 560 * between commands that do block transfers and those that do byte 561 * transfers. But this isn't easy... there are lots of vendor specific 562 * commands, and the user can issue any command via the 563 * SCSI_IOCTL_SEND_COMMAND. 564 * 565 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, 566 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) 567 * and 3), the thing to do is obvious: allow any number of blocks via DMA 568 * or none. In case 2), we apply some heuristic: Byte mode is assumed if 569 * the transfer (allocation) length is < 1024, hoping that no cmd. not 570 * explicitly known as byte mode have such big allocation lengths... 571 * BTW, all the discussion above applies only to reads. DMA writes are 572 * unproblematic anyways, since the targets aborts the transfer after 573 * receiving a sufficient number of bytes. 574 * 575 * Another point: If the transfer is from/to an non-ST-RAM address, we 576 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. 577 */ 578 579 if (cmd->sc_data_direction == DMA_TO_DEVICE) { 580 /* Write operation can always use the DMA, but the transfer size must 581 * be rounded up to the next multiple of 512 (atari_dma_setup() does 582 * this). 583 */ 584 possible_len = wanted_len; 585 } else { 586 /* Read operations: if the wanted transfer length is not a multiple of 587 * 512, we cannot use DMA, since the ST-DMA cannot split transfers 588 * (no interrupt on DMA finished!) 589 */ 590 if (wanted_len & 0x1ff) 591 possible_len = 0; 592 else { 593 /* Now classify the command (see above) and decide whether it is 594 * allowed to do DMA at all */ 595 switch (falcon_classify_cmd(cmd)) { 596 case CMD_SURELY_BLOCK_MODE: 597 possible_len = wanted_len; 598 break; 599 case CMD_SURELY_BYTE_MODE: 600 possible_len = 0; /* DMA prohibited */ 601 break; 602 case CMD_MODE_UNKNOWN: 603 default: 604 /* For unknown commands assume block transfers if the transfer 605 * size/allocation length is >= 1024 */ 606 possible_len = (wanted_len < 1024) ? 0 : wanted_len; 607 break; 608 } 609 } 610 } 611 612 /* Last step: apply the hard limit on DMA transfers */ 613 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(NCR5380_to_ncmd(cmd)->ptr))) ? 614 STRAM_BUFFER_SIZE : 255*512; 615 if (possible_len > limit) 616 possible_len = limit; 617 618 if (possible_len != wanted_len) 619 dprintk(NDEBUG_DMA, "DMA transfer now %d bytes instead of %d\n", 620 possible_len, wanted_len); 621 622 return possible_len; 623 } 624 625 626 /* NCR5380 register access functions 627 * 628 * There are separate functions for TT and Falcon, because the access 629 * methods are quite different. The calling macros NCR5380_read and 630 * NCR5380_write call these functions via function pointers. 631 */ 632 633 static u8 atari_scsi_tt_reg_read(unsigned int reg) 634 { 635 return tt_scsi_regp[reg * 2]; 636 } 637 638 static void atari_scsi_tt_reg_write(unsigned int reg, u8 value) 639 { 640 tt_scsi_regp[reg * 2] = value; 641 } 642 643 static u8 atari_scsi_falcon_reg_read(unsigned int reg) 644 { 645 unsigned long flags; 646 u8 result; 647 648 reg += 0x88; 649 local_irq_save(flags); 650 dma_wd.dma_mode_status = (u_short)reg; 651 result = (u8)dma_wd.fdc_acces_seccount; 652 local_irq_restore(flags); 653 return result; 654 } 655 656 static void atari_scsi_falcon_reg_write(unsigned int reg, u8 value) 657 { 658 unsigned long flags; 659 660 reg += 0x88; 661 local_irq_save(flags); 662 dma_wd.dma_mode_status = (u_short)reg; 663 dma_wd.fdc_acces_seccount = (u_short)value; 664 local_irq_restore(flags); 665 } 666 667 668 #include "NCR5380.c" 669 670 static int atari_scsi_host_reset(struct scsi_cmnd *cmd) 671 { 672 int rv; 673 unsigned long flags; 674 675 local_irq_save(flags); 676 677 /* Abort a maybe active DMA transfer */ 678 if (IS_A_TT()) { 679 tt_scsi_dma.dma_ctrl = 0; 680 } else { 681 if (stdma_is_locked_by(scsi_falcon_intr)) 682 st_dma.dma_mode_status = 0x90; 683 atari_dma_active = 0; 684 atari_dma_orig_addr = NULL; 685 } 686 687 rv = NCR5380_host_reset(cmd); 688 689 /* The 5380 raises its IRQ line while _RST is active but the ST DMA 690 * "lock" has been released so this interrupt may end up handled by 691 * floppy or IDE driver (if one of them holds the lock). The NCR5380 692 * interrupt flag has been cleared already. 693 */ 694 695 local_irq_restore(flags); 696 697 return rv; 698 } 699 700 #define DRV_MODULE_NAME "atari_scsi" 701 #define PFX DRV_MODULE_NAME ": " 702 703 static struct scsi_host_template atari_scsi_template = { 704 .module = THIS_MODULE, 705 .proc_name = DRV_MODULE_NAME, 706 .name = "Atari native SCSI", 707 .info = atari_scsi_info, 708 .queuecommand = atari_scsi_queue_command, 709 .eh_abort_handler = atari_scsi_abort, 710 .eh_host_reset_handler = atari_scsi_host_reset, 711 .this_id = 7, 712 .cmd_per_lun = 2, 713 .dma_boundary = PAGE_SIZE - 1, 714 .cmd_size = sizeof(struct NCR5380_cmd), 715 }; 716 717 static int __init atari_scsi_probe(struct platform_device *pdev) 718 { 719 struct Scsi_Host *instance; 720 int error; 721 struct resource *irq; 722 int host_flags = 0; 723 724 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 725 if (!irq) 726 return -ENODEV; 727 728 if (ATARIHW_PRESENT(TT_SCSI)) { 729 atari_scsi_reg_read = atari_scsi_tt_reg_read; 730 atari_scsi_reg_write = atari_scsi_tt_reg_write; 731 } else { 732 atari_scsi_reg_read = atari_scsi_falcon_reg_read; 733 atari_scsi_reg_write = atari_scsi_falcon_reg_write; 734 } 735 736 if (ATARIHW_PRESENT(TT_SCSI)) { 737 atari_scsi_template.can_queue = 16; 738 atari_scsi_template.sg_tablesize = SG_ALL; 739 } else { 740 atari_scsi_template.can_queue = 1; 741 atari_scsi_template.sg_tablesize = 1; 742 } 743 744 if (setup_can_queue > 0) 745 atari_scsi_template.can_queue = setup_can_queue; 746 747 if (setup_cmd_per_lun > 0) 748 atari_scsi_template.cmd_per_lun = setup_cmd_per_lun; 749 750 /* Don't increase sg_tablesize on Falcon! */ 751 if (ATARIHW_PRESENT(TT_SCSI) && setup_sg_tablesize > 0) 752 atari_scsi_template.sg_tablesize = setup_sg_tablesize; 753 754 if (setup_hostid >= 0) { 755 atari_scsi_template.this_id = setup_hostid & 7; 756 } else if (IS_REACHABLE(CONFIG_NVRAM)) { 757 /* Test if a host id is set in the NVRam */ 758 if (ATARIHW_PRESENT(TT_CLK)) { 759 unsigned char b; 760 loff_t offset = 16; 761 ssize_t count = nvram_read(&b, 1, &offset); 762 763 /* Arbitration enabled? (for TOS) 764 * If yes, use configured host ID 765 */ 766 if ((count == 1) && (b & 0x80)) 767 atari_scsi_template.this_id = b & 7; 768 } 769 } 770 771 /* If running on a Falcon and if there's TT-Ram (i.e., more than one 772 * memory block, since there's always ST-Ram in a Falcon), then 773 * allocate a STRAM_BUFFER_SIZE byte dribble buffer for transfers 774 * from/to alternative Ram. 775 */ 776 if (ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(EXTD_DMA) && 777 m68k_realnum_memory > 1) { 778 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI"); 779 if (!atari_dma_buffer) { 780 pr_err(PFX "can't allocate ST-RAM double buffer\n"); 781 return -ENOMEM; 782 } 783 atari_dma_phys_buffer = atari_stram_to_phys(atari_dma_buffer); 784 atari_dma_orig_addr = NULL; 785 } 786 787 instance = scsi_host_alloc(&atari_scsi_template, 788 sizeof(struct NCR5380_hostdata)); 789 if (!instance) { 790 error = -ENOMEM; 791 goto fail_alloc; 792 } 793 794 instance->irq = irq->start; 795 796 host_flags |= IS_A_TT() ? 0 : FLAG_LATE_DMA_SETUP; 797 host_flags |= setup_toshiba_delay > 0 ? FLAG_TOSHIBA_DELAY : 0; 798 799 error = NCR5380_init(instance, host_flags); 800 if (error) 801 goto fail_init; 802 803 if (IS_A_TT()) { 804 error = request_irq(instance->irq, scsi_tt_intr, 0, 805 "NCR5380", instance); 806 if (error) { 807 pr_err(PFX "request irq %d failed, aborting\n", 808 instance->irq); 809 goto fail_irq; 810 } 811 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ 812 813 tt_scsi_dma.dma_ctrl = 0; 814 atari_dma_residual = 0; 815 816 /* While the read overruns (described by Drew Eckhardt in 817 * NCR5380.c) never happened on TTs, they do in fact on the 818 * Medusa (This was the cause why SCSI didn't work right for 819 * so long there.) Since handling the overruns slows down 820 * a bit, I turned the #ifdef's into a runtime condition. 821 * 822 * In principle it should be sufficient to do max. 1 byte with 823 * PIO, but there is another problem on the Medusa with the DMA 824 * rest data register. So read_overruns is currently set 825 * to 4 to avoid having transfers that aren't a multiple of 4. 826 * If the rest data bug is fixed, this can be lowered to 1. 827 */ 828 if (MACH_IS_MEDUSA) { 829 struct NCR5380_hostdata *hostdata = 830 shost_priv(instance); 831 832 hostdata->read_overruns = 4; 833 } 834 } else { 835 /* Nothing to do for the interrupt: the ST-DMA is initialized 836 * already. 837 */ 838 atari_dma_residual = 0; 839 atari_dma_active = 0; 840 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 841 : 0xff000000); 842 } 843 844 NCR5380_maybe_reset_bus(instance); 845 846 error = scsi_add_host(instance, NULL); 847 if (error) 848 goto fail_host; 849 850 platform_set_drvdata(pdev, instance); 851 852 scsi_scan_host(instance); 853 return 0; 854 855 fail_host: 856 if (IS_A_TT()) 857 free_irq(instance->irq, instance); 858 fail_irq: 859 NCR5380_exit(instance); 860 fail_init: 861 scsi_host_put(instance); 862 fail_alloc: 863 if (atari_dma_buffer) 864 atari_stram_free(atari_dma_buffer); 865 return error; 866 } 867 868 static int __exit atari_scsi_remove(struct platform_device *pdev) 869 { 870 struct Scsi_Host *instance = platform_get_drvdata(pdev); 871 872 scsi_remove_host(instance); 873 if (IS_A_TT()) 874 free_irq(instance->irq, instance); 875 NCR5380_exit(instance); 876 scsi_host_put(instance); 877 if (atari_dma_buffer) 878 atari_stram_free(atari_dma_buffer); 879 return 0; 880 } 881 882 static struct platform_driver atari_scsi_driver = { 883 .remove = __exit_p(atari_scsi_remove), 884 .driver = { 885 .name = DRV_MODULE_NAME, 886 }, 887 }; 888 889 module_platform_driver_probe(atari_scsi_driver, atari_scsi_probe); 890 891 MODULE_ALIAS("platform:" DRV_MODULE_NAME); 892 MODULE_LICENSE("GPL"); 893