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/**************************************************************************/ 19/* */ 20/* Notes for Falcon SCSI: */ 21/* ---------------------- */ 22/* */ 23/* Since the Falcon SCSI uses the ST-DMA chip, that is shared among */ 24/* several device drivers, locking and unlocking the access to this */ 25/* chip is required. But locking is not possible from an interrupt, */ 26/* since it puts the process to sleep if the lock is not available. */ 27/* This prevents "late" locking of the DMA chip, i.e. locking it just */ 28/* before using it, since in case of disconnection-reconnection */ 29/* commands, the DMA is started from the reselection interrupt. */ 30/* */ 31/* Two possible schemes for ST-DMA-locking would be: */ 32/* 1) The lock is taken for each command separately and disconnecting */ 33/* is forbidden (i.e. can_queue = 1). */ 34/* 2) The DMA chip is locked when the first command comes in and */ 35/* released when the last command is finished and all queues are */ 36/* empty. */ 37/* The first alternative would result in bad performance, since the */ 38/* interleaving of commands would not be used. The second is unfair to */ 39/* other drivers using the ST-DMA, because the queues will seldom be */ 40/* totally empty if there is a lot of disk traffic. */ 41/* */ 42/* For this reasons I decided to employ a more elaborate scheme: */ 43/* - First, we give up the lock every time we can (for fairness), this */ 44/* means every time a command finishes and there are no other commands */ 45/* on the disconnected queue. */ 46/* - If there are others waiting to lock the DMA chip, we stop */ 47/* issuing commands, i.e. moving them onto the issue queue. */ 48/* Because of that, the disconnected queue will run empty in a */ 49/* while. Instead we go to sleep on a 'fairness_queue'. */ 50/* - If the lock is released, all processes waiting on the fairness */ 51/* queue will be woken. The first of them tries to re-lock the DMA, */ 52/* the others wait for the first to finish this task. After that, */ 53/* they can all run on and do their commands... */ 54/* This sounds complicated (and it is it :-(), but it seems to be a */ 55/* good compromise between fairness and performance: As long as no one */ 56/* else wants to work with the ST-DMA chip, SCSI can go along as */ 57/* usual. If now someone else comes, this behaviour is changed to a */ 58/* "fairness mode": just already initiated commands are finished and */ 59/* then the lock is released. The other one waiting will probably win */ 60/* the race for locking the DMA, since it was waiting for longer. And */ 61/* after it has finished, SCSI can go ahead again. Finally: I hope I */ 62/* have not produced any deadlock possibilities! */ 63/* */ 64/**************************************************************************/ 65 66 67 68#include <linux/module.h> 69 70#define NDEBUG (0) 71 72#define NDEBUG_ABORT 0x00100000 73#define NDEBUG_TAGS 0x00200000 74#define NDEBUG_MERGING 0x00400000 75 76#define AUTOSENSE 77/* For the Atari version, use only polled IO or REAL_DMA */ 78#define REAL_DMA 79/* Support tagged queuing? (on devices that are able to... :-) */ 80#define SUPPORT_TAGS 81#define MAX_TAGS 32 82 83#include <linux/types.h> 84#include <linux/stddef.h> 85#include <linux/ctype.h> 86#include <linux/delay.h> 87#include <linux/mm.h> 88#include <linux/blkdev.h> 89#include <linux/interrupt.h> 90#include <linux/init.h> 91#include <linux/nvram.h> 92#include <linux/bitops.h> 93 94#include <asm/setup.h> 95#include <asm/atarihw.h> 96#include <asm/atariints.h> 97#include <asm/page.h> 98#include <asm/pgtable.h> 99#include <asm/irq.h> 100#include <asm/traps.h> 101 102#include "scsi.h" 103#include <scsi/scsi_host.h> 104#include "atari_scsi.h" 105#include "NCR5380.h" 106#include <asm/atari_stdma.h> 107#include <asm/atari_stram.h> 108#include <asm/io.h> 109 110#include <linux/stat.h> 111 112#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI) 113 114#define SCSI_DMA_WRITE_P(elt,val) \ 115 do { \ 116 unsigned long v = val; \ 117 tt_scsi_dma.elt##_lo = v & 0xff; \ 118 v >>= 8; \ 119 tt_scsi_dma.elt##_lmd = v & 0xff; \ 120 v >>= 8; \ 121 tt_scsi_dma.elt##_hmd = v & 0xff; \ 122 v >>= 8; \ 123 tt_scsi_dma.elt##_hi = v & 0xff; \ 124 } while(0) 125 126#define SCSI_DMA_READ_P(elt) \ 127 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \ 128 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \ 129 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \ 130 (unsigned long)tt_scsi_dma.elt##_lo) 131 132 133static inline void SCSI_DMA_SETADR(unsigned long adr) 134{ 135 st_dma.dma_lo = (unsigned char)adr; 136 MFPDELAY(); 137 adr >>= 8; 138 st_dma.dma_md = (unsigned char)adr; 139 MFPDELAY(); 140 adr >>= 8; 141 st_dma.dma_hi = (unsigned char)adr; 142 MFPDELAY(); 143} 144 145static inline unsigned long SCSI_DMA_GETADR(void) 146{ 147 unsigned long adr; 148 adr = st_dma.dma_lo; 149 MFPDELAY(); 150 adr |= (st_dma.dma_md & 0xff) << 8; 151 MFPDELAY(); 152 adr |= (st_dma.dma_hi & 0xff) << 16; 153 MFPDELAY(); 154 return adr; 155} 156 157static inline void ENABLE_IRQ(void) 158{ 159 if (IS_A_TT()) 160 atari_enable_irq(IRQ_TT_MFP_SCSI); 161 else 162 atari_enable_irq(IRQ_MFP_FSCSI); 163} 164 165static inline void DISABLE_IRQ(void) 166{ 167 if (IS_A_TT()) 168 atari_disable_irq(IRQ_TT_MFP_SCSI); 169 else 170 atari_disable_irq(IRQ_MFP_FSCSI); 171} 172 173 174#define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \ 175 (atari_scsi_host->hostdata))->dma_len) 176 177/* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms, 178 * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more 179 * need ten times the standard value... */ 180#ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY 181#define AFTER_RESET_DELAY (HZ/2) 182#else 183#define AFTER_RESET_DELAY (5*HZ/2) 184#endif 185 186/***************************** Prototypes *****************************/ 187 188#ifdef REAL_DMA 189static int scsi_dma_is_ignored_buserr(unsigned char dma_stat); 190static void atari_scsi_fetch_restbytes(void); 191static long atari_scsi_dma_residual(struct Scsi_Host *instance); 192static int falcon_classify_cmd(Scsi_Cmnd *cmd); 193static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 194 Scsi_Cmnd *cmd, int write_flag); 195#endif 196static irqreturn_t scsi_tt_intr(int irq, void *dummy); 197static irqreturn_t scsi_falcon_intr(int irq, void *dummy); 198static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata); 199static void falcon_get_lock(void); 200#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 201static void atari_scsi_reset_boot(void); 202#endif 203static unsigned char atari_scsi_tt_reg_read(unsigned char reg); 204static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value); 205static unsigned char atari_scsi_falcon_reg_read(unsigned char reg); 206static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value); 207 208/************************* End of Prototypes **************************/ 209 210 211static struct Scsi_Host *atari_scsi_host; 212static unsigned char (*atari_scsi_reg_read)(unsigned char reg); 213static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value); 214 215#ifdef REAL_DMA 216static unsigned long atari_dma_residual, atari_dma_startaddr; 217static short atari_dma_active; 218/* pointer to the dribble buffer */ 219static char *atari_dma_buffer; 220/* precalculated physical address of the dribble buffer */ 221static unsigned long atari_dma_phys_buffer; 222/* != 0 tells the Falcon int handler to copy data from the dribble buffer */ 223static char *atari_dma_orig_addr; 224/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use 225 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare 226 * cases where requests to physical contiguous buffers have been merged, this 227 * request is <= 4k (one page). So I don't think we have to split transfers 228 * just due to this buffer size... 229 */ 230#define STRAM_BUFFER_SIZE (4096) 231/* mask for address bits that can't be used with the ST-DMA */ 232static unsigned long atari_dma_stram_mask; 233#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0) 234/* number of bytes to cut from a transfer to handle NCR overruns */ 235static int atari_read_overruns; 236#endif 237 238static int setup_can_queue = -1; 239module_param(setup_can_queue, int, 0); 240static int setup_cmd_per_lun = -1; 241module_param(setup_cmd_per_lun, int, 0); 242static int setup_sg_tablesize = -1; 243module_param(setup_sg_tablesize, int, 0); 244#ifdef SUPPORT_TAGS 245static int setup_use_tagged_queuing = -1; 246module_param(setup_use_tagged_queuing, int, 0); 247#endif 248static int setup_hostid = -1; 249module_param(setup_hostid, int, 0); 250 251 252#if defined(REAL_DMA) 253 254static int scsi_dma_is_ignored_buserr(unsigned char dma_stat) 255{ 256 int i; 257 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr; 258 259 if (dma_stat & 0x01) { 260 261 /* A bus error happens when DMA-ing from the last page of a 262 * physical memory chunk (DMA prefetch!), but that doesn't hurt. 263 * Check for this case: 264 */ 265 266 for (i = 0; i < m68k_num_memory; ++i) { 267 end_addr = m68k_memory[i].addr + m68k_memory[i].size; 268 if (end_addr <= addr && addr <= end_addr + 4) 269 return 1; 270 } 271 } 272 return 0; 273} 274 275 276 277#endif 278 279 280static irqreturn_t scsi_tt_intr(int irq, void *dummy) 281{ 282#ifdef REAL_DMA 283 int dma_stat; 284 285 dma_stat = tt_scsi_dma.dma_ctrl; 286 287 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n", 288 atari_scsi_host->host_no, dma_stat & 0xff); 289 290 /* Look if it was the DMA that has interrupted: First possibility 291 * is that a bus error occurred... 292 */ 293 if (dma_stat & 0x80) { 294 if (!scsi_dma_is_ignored_buserr(dma_stat)) { 295 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", 296 SCSI_DMA_READ_P(dma_addr)); 297 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); 298 } 299 } 300 301 /* If the DMA is active but not finished, we have the case 302 * that some other 5380 interrupt occurred within the DMA transfer. 303 * This means we have residual bytes, if the desired end address 304 * is not yet reached. Maybe we have to fetch some bytes from the 305 * rest data register, too. The residual must be calculated from 306 * the address pointer, not the counter register, because only the 307 * addr reg counts bytes not yet written and pending in the rest 308 * data reg! 309 */ 310 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { 311 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); 312 313 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 314 atari_dma_residual); 315 316 if ((signed int)atari_dma_residual < 0) 317 atari_dma_residual = 0; 318 if ((dma_stat & 1) == 0) { 319 /* 320 * After read operations, we maybe have to 321 * transport some rest bytes 322 */ 323 atari_scsi_fetch_restbytes(); 324 } else { 325 /* 326 * There seems to be a nasty bug in some SCSI-DMA/NCR 327 * combinations: If a target disconnects while a write 328 * operation is going on, the address register of the 329 * DMA may be a few bytes farer than it actually read. 330 * This is probably due to DMA prefetching and a delay 331 * between DMA and NCR. Experiments showed that the 332 * dma_addr is 9 bytes to high, but this could vary. 333 * The problem is, that the residual is thus calculated 334 * wrong and the next transfer will start behind where 335 * it should. So we round up the residual to the next 336 * multiple of a sector size, if it isn't already a 337 * multiple and the originally expected transfer size 338 * was. The latter condition is there to ensure that 339 * the correction is taken only for "real" data 340 * transfers and not for, e.g., the parameters of some 341 * other command. These shouldn't disconnect anyway. 342 */ 343 if (atari_dma_residual & 0x1ff) { 344 DMA_PRINTK("SCSI DMA: DMA bug corrected, " 345 "difference %ld bytes\n", 346 512 - (atari_dma_residual & 0x1ff)); 347 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; 348 } 349 } 350 tt_scsi_dma.dma_ctrl = 0; 351 } 352 353 /* If the DMA is finished, fetch the rest bytes and turn it off */ 354 if (dma_stat & 0x40) { 355 atari_dma_residual = 0; 356 if ((dma_stat & 1) == 0) 357 atari_scsi_fetch_restbytes(); 358 tt_scsi_dma.dma_ctrl = 0; 359 } 360 361#endif /* REAL_DMA */ 362 363 NCR5380_intr(irq, dummy); 364 365 return IRQ_HANDLED; 366} 367 368 369static irqreturn_t scsi_falcon_intr(int irq, void *dummy) 370{ 371#ifdef REAL_DMA 372 int dma_stat; 373 374 /* Turn off DMA and select sector counter register before 375 * accessing the status register (Atari recommendation!) 376 */ 377 st_dma.dma_mode_status = 0x90; 378 dma_stat = st_dma.dma_mode_status; 379 380 /* Bit 0 indicates some error in the DMA process... don't know 381 * what happened exactly (no further docu). 382 */ 383 if (!(dma_stat & 0x01)) { 384 /* DMA error */ 385 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); 386 } 387 388 /* If the DMA was active, but now bit 1 is not clear, it is some 389 * other 5380 interrupt that finishes the DMA transfer. We have to 390 * calculate the number of residual bytes and give a warning if 391 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) 392 */ 393 if (atari_dma_active && (dma_stat & 0x02)) { 394 unsigned long transferred; 395 396 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; 397 /* The ST-DMA address is incremented in 2-byte steps, but the 398 * data are written only in 16-byte chunks. If the number of 399 * transferred bytes is not divisible by 16, the remainder is 400 * lost somewhere in outer space. 401 */ 402 if (transferred & 15) 403 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " 404 "ST-DMA fifo\n", transferred & 15); 405 406 atari_dma_residual = HOSTDATA_DMALEN - transferred; 407 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 408 atari_dma_residual); 409 } else 410 atari_dma_residual = 0; 411 atari_dma_active = 0; 412 413 if (atari_dma_orig_addr) { 414 /* If the dribble buffer was used on a read operation, copy the DMA-ed 415 * data to the original destination address. 416 */ 417 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), 418 HOSTDATA_DMALEN - atari_dma_residual); 419 atari_dma_orig_addr = NULL; 420 } 421 422#endif /* REAL_DMA */ 423 424 NCR5380_intr(irq, dummy); 425 return IRQ_HANDLED; 426} 427 428 429#ifdef REAL_DMA 430static void atari_scsi_fetch_restbytes(void) 431{ 432 int nr; 433 char *src, *dst; 434 unsigned long phys_dst; 435 436 /* fetch rest bytes in the DMA register */ 437 phys_dst = SCSI_DMA_READ_P(dma_addr); 438 nr = phys_dst & 3; 439 if (nr) { 440 /* there are 'nr' bytes left for the last long address 441 before the DMA pointer */ 442 phys_dst ^= nr; 443 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", 444 nr, phys_dst); 445 /* The content of the DMA pointer is a physical address! */ 446 dst = phys_to_virt(phys_dst); 447 DMA_PRINTK(" = virt addr %p\n", dst); 448 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) 449 *dst++ = *src++; 450 } 451} 452#endif /* REAL_DMA */ 453 454 455static int falcon_got_lock = 0; 456static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); 457static int falcon_trying_lock = 0; 458static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); 459static int falcon_dont_release = 0; 460 461/* This function releases the lock on the DMA chip if there is no 462 * connected command and the disconnected queue is empty. On 463 * releasing, instances of falcon_get_lock are awoken, that put 464 * themselves to sleep for fairness. They can now try to get the lock 465 * again (but others waiting longer more probably will win). 466 */ 467 468static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata) 469{ 470 unsigned long flags; 471 472 if (IS_A_TT()) 473 return; 474 475 local_irq_save(flags); 476 477 if (falcon_got_lock && !hostdata->disconnected_queue && 478 !hostdata->issue_queue && !hostdata->connected) { 479 480 if (falcon_dont_release) { 481 local_irq_restore(flags); 482 return; 483 } 484 falcon_got_lock = 0; 485 stdma_release(); 486 wake_up(&falcon_fairness_wait); 487 } 488 489 local_irq_restore(flags); 490} 491 492/* This function manages the locking of the ST-DMA. 493 * If the DMA isn't locked already for SCSI, it tries to lock it by 494 * calling stdma_lock(). But if the DMA is locked by the SCSI code and 495 * there are other drivers waiting for the chip, we do not issue the 496 * command immediately but wait on 'falcon_fairness_queue'. We will be 497 * waked up when the DMA is unlocked by some SCSI interrupt. After that 498 * we try to get the lock again. 499 * But we must be prepared that more than one instance of 500 * falcon_get_lock() is waiting on the fairness queue. They should not 501 * try all at once to call stdma_lock(), one is enough! For that, the 502 * first one sets 'falcon_trying_lock', others that see that variable 503 * set wait on the queue 'falcon_try_wait'. 504 * Complicated, complicated.... Sigh... 505 */ 506 507static void falcon_get_lock(void) 508{ 509 unsigned long flags; 510 511 if (IS_A_TT()) 512 return; 513 514 local_irq_save(flags); 515 516 while (!in_irq() && falcon_got_lock && stdma_others_waiting()) 517 sleep_on(&falcon_fairness_wait); 518 519 while (!falcon_got_lock) { 520 if (in_irq()) 521 panic("Falcon SCSI hasn't ST-DMA lock in interrupt"); 522 if (!falcon_trying_lock) { 523 falcon_trying_lock = 1; 524 stdma_lock(scsi_falcon_intr, NULL); 525 falcon_got_lock = 1; 526 falcon_trying_lock = 0; 527 wake_up(&falcon_try_wait); 528 } else { 529 sleep_on(&falcon_try_wait); 530 } 531 } 532 533 local_irq_restore(flags); 534 if (!falcon_got_lock) 535 panic("Falcon SCSI: someone stole the lock :-(\n"); 536} 537 538 539/* This is the wrapper function for NCR5380_queue_command(). It just 540 * tries to get the lock on the ST-DMA (see above) and then calls the 541 * original function. 542 */ 543 544 545 546int __init atari_scsi_detect(struct scsi_host_template *host) 547{ 548 static int called = 0; 549 struct Scsi_Host *instance; 550 551 if (!MACH_IS_ATARI || 552 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) || 553 called) 554 return 0; 555 556 host->proc_name = "Atari"; 557 558 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read : 559 atari_scsi_falcon_reg_read; 560 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write : 561 atari_scsi_falcon_reg_write; 562 563 /* setup variables */ 564 host->can_queue = 565 (setup_can_queue > 0) ? setup_can_queue : 566 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE; 567 host->cmd_per_lun = 568 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun : 569 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN; 570 /* Force sg_tablesize to 0 on a Falcon! */ 571 host->sg_tablesize = 572 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE : 573 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE; 574 575 if (setup_hostid >= 0) 576 host->this_id = setup_hostid; 577 else { 578 /* use 7 as default */ 579 host->this_id = 7; 580 /* Test if a host id is set in the NVRam */ 581 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { 582 unsigned char b = nvram_read_byte( 14 ); 583 /* Arbitration enabled? (for TOS) If yes, use configured host ID */ 584 if (b & 0x80) 585 host->this_id = b & 7; 586 } 587 } 588 589#ifdef SUPPORT_TAGS 590 if (setup_use_tagged_queuing < 0) 591 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING; 592#endif 593#ifdef REAL_DMA 594 /* If running on a Falcon and if there's TT-Ram (i.e., more than one 595 * memory block, since there's always ST-Ram in a Falcon), then allocate a 596 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative 597 * Ram. 598 */ 599 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) && 600 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) { 601 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI"); 602 if (!atari_dma_buffer) { 603 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM " 604 "double buffer\n"); 605 return 0; 606 } 607 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer); 608 atari_dma_orig_addr = 0; 609 } 610#endif 611 instance = scsi_register(host, sizeof(struct NCR5380_hostdata)); 612 if (instance == NULL) { 613 atari_stram_free(atari_dma_buffer); 614 atari_dma_buffer = 0; 615 return 0; 616 } 617 atari_scsi_host = instance; 618 /* 619 * Set irq to 0, to avoid that the mid-level code disables our interrupt 620 * during queue_command calls. This is completely unnecessary, and even 621 * worse causes bad problems on the Falcon, where the int is shared with 622 * IDE and floppy! 623 */ 624 instance->irq = 0; 625 626#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 627 atari_scsi_reset_boot(); 628#endif 629 NCR5380_init(instance, 0); 630 631 if (IS_A_TT()) { 632 633 /* This int is actually "pseudo-slow", i.e. it acts like a slow 634 * interrupt after having cleared the pending flag for the DMA 635 * interrupt. */ 636 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW, 637 "SCSI NCR5380", instance)) { 638 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI); 639 scsi_unregister(atari_scsi_host); 640 atari_stram_free(atari_dma_buffer); 641 atari_dma_buffer = 0; 642 return 0; 643 } 644 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ 645#ifdef REAL_DMA 646 tt_scsi_dma.dma_ctrl = 0; 647 atari_dma_residual = 0; 648 649 if (MACH_IS_MEDUSA) { 650 /* While the read overruns (described by Drew Eckhardt in 651 * NCR5380.c) never happened on TTs, they do in fact on the Medusa 652 * (This was the cause why SCSI didn't work right for so long 653 * there.) Since handling the overruns slows down a bit, I turned 654 * the #ifdef's into a runtime condition. 655 * 656 * In principle it should be sufficient to do max. 1 byte with 657 * PIO, but there is another problem on the Medusa with the DMA 658 * rest data register. So 'atari_read_overruns' is currently set 659 * to 4 to avoid having transfers that aren't a multiple of 4. If 660 * the rest data bug is fixed, this can be lowered to 1. 661 */ 662 atari_read_overruns = 4; 663 } 664#endif /*REAL_DMA*/ 665 } else { /* ! IS_A_TT */ 666 667 /* Nothing to do for the interrupt: the ST-DMA is initialized 668 * already by atari_init_INTS() 669 */ 670 671#ifdef REAL_DMA 672 atari_dma_residual = 0; 673 atari_dma_active = 0; 674 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 675 : 0xff000000); 676#endif 677 } 678 679 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d " 680#ifdef SUPPORT_TAGS 681 "TAGGED-QUEUING=%s " 682#endif 683 "HOSTID=%d", 684 instance->host_no, instance->hostt->can_queue, 685 instance->hostt->cmd_per_lun, 686 instance->hostt->sg_tablesize, 687#ifdef SUPPORT_TAGS 688 setup_use_tagged_queuing ? "yes" : "no", 689#endif 690 instance->hostt->this_id ); 691 NCR5380_print_options(instance); 692 printk("\n"); 693 694 called = 1; 695 return 1; 696} 697 698int atari_scsi_release(struct Scsi_Host *sh) 699{ 700 if (IS_A_TT()) 701 free_irq(IRQ_TT_MFP_SCSI, sh); 702 if (atari_dma_buffer) 703 atari_stram_free(atari_dma_buffer); 704 return 1; 705} 706 707void __init atari_scsi_setup(char *str, int *ints) 708{ 709 /* Format of atascsi parameter is: 710 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 711 * Defaults depend on TT or Falcon, hostid determined at run time. 712 * Negative values mean don't change. 713 */ 714 715 if (ints[0] < 1) { 716 printk("atari_scsi_setup: no arguments!\n"); 717 return; 718 } 719 720 if (ints[0] >= 1) { 721 if (ints[1] > 0) 722 /* no limits on this, just > 0 */ 723 setup_can_queue = ints[1]; 724 } 725 if (ints[0] >= 2) { 726 if (ints[2] > 0) 727 setup_cmd_per_lun = ints[2]; 728 } 729 if (ints[0] >= 3) { 730 if (ints[3] >= 0) { 731 setup_sg_tablesize = ints[3]; 732 /* Must be <= SG_ALL (255) */ 733 if (setup_sg_tablesize > SG_ALL) 734 setup_sg_tablesize = SG_ALL; 735 } 736 } 737 if (ints[0] >= 4) { 738 /* Must be between 0 and 7 */ 739 if (ints[4] >= 0 && ints[4] <= 7) 740 setup_hostid = ints[4]; 741 else if (ints[4] > 7) 742 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]); 743 } 744#ifdef SUPPORT_TAGS 745 if (ints[0] >= 5) { 746 if (ints[5] >= 0) 747 setup_use_tagged_queuing = !!ints[5]; 748 } 749#endif 750} 751 752int atari_scsi_bus_reset(Scsi_Cmnd *cmd) 753{ 754 int rv; 755 struct NCR5380_hostdata *hostdata = 756 (struct NCR5380_hostdata *)cmd->device->host->hostdata; 757 758 /* For doing the reset, SCSI interrupts must be disabled first, 759 * since the 5380 raises its IRQ line while _RST is active and we 760 * can't disable interrupts completely, since we need the timer. 761 */ 762 /* And abort a maybe active DMA transfer */ 763 if (IS_A_TT()) { 764 atari_turnoff_irq(IRQ_TT_MFP_SCSI); 765#ifdef REAL_DMA 766 tt_scsi_dma.dma_ctrl = 0; 767#endif /* REAL_DMA */ 768 } else { 769 atari_turnoff_irq(IRQ_MFP_FSCSI); 770#ifdef REAL_DMA 771 st_dma.dma_mode_status = 0x90; 772 atari_dma_active = 0; 773 atari_dma_orig_addr = NULL; 774#endif /* REAL_DMA */ 775 } 776 777 rv = NCR5380_bus_reset(cmd); 778 779 /* Re-enable ints */ 780 if (IS_A_TT()) { 781 atari_turnon_irq(IRQ_TT_MFP_SCSI); 782 } else { 783 atari_turnon_irq(IRQ_MFP_FSCSI); 784 } 785 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS) 786 falcon_release_lock_if_possible(hostdata); 787 788 return rv; 789} 790 791 792#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 793static void __init atari_scsi_reset_boot(void) 794{ 795 unsigned long end; 796 797 /* 798 * Do a SCSI reset to clean up the bus during initialization. No messing 799 * with the queues, interrupts, or locks necessary here. 800 */ 801 802 printk("Atari SCSI: resetting the SCSI bus..."); 803 804 /* get in phase */ 805 NCR5380_write(TARGET_COMMAND_REG, 806 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG))); 807 808 /* assert RST */ 809 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); 810 /* The min. reset hold time is 25us, so 40us should be enough */ 811 udelay(50); 812 /* reset RST and interrupt */ 813 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); 814 NCR5380_read(RESET_PARITY_INTERRUPT_REG); 815 816 end = jiffies + AFTER_RESET_DELAY; 817 while (time_before(jiffies, end)) 818 barrier(); 819 820 printk(" done\n"); 821} 822#endif 823 824 825const char *atari_scsi_info(struct Scsi_Host *host) 826{ 827 /* atari_scsi_detect() is verbose enough... */ 828 static const char string[] = "Atari native SCSI"; 829 return string; 830} 831 832 833#if defined(REAL_DMA) 834 835unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, void *data, 836 unsigned long count, int dir) 837{ 838 unsigned long addr = virt_to_phys(data); 839 840 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " 841 "dir = %d\n", instance->host_no, data, addr, count, dir); 842 843 if (!IS_A_TT() && !STRAM_ADDR(addr)) { 844 /* If we have a non-DMAable address on a Falcon, use the dribble 845 * buffer; 'orig_addr' != 0 in the read case tells the interrupt 846 * handler to copy data from the dribble buffer to the originally 847 * wanted address. 848 */ 849 if (dir) 850 memcpy(atari_dma_buffer, data, count); 851 else 852 atari_dma_orig_addr = data; 853 addr = atari_dma_phys_buffer; 854 } 855 856 atari_dma_startaddr = addr; /* Needed for calculating residual later. */ 857 858 /* Cache cleanup stuff: On writes, push any dirty cache out before sending 859 * it to the peripheral. (Must be done before DMA setup, since at least 860 * the ST-DMA begins to fill internal buffers right after setup. For 861 * reads, invalidate any cache, may be altered after DMA without CPU 862 * knowledge. 863 * 864 * ++roman: For the Medusa, there's no need at all for that cache stuff, 865 * because the hardware does bus snooping (fine!). 866 */ 867 dma_cache_maintenance(addr, count, dir); 868 869 if (count == 0) 870 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); 871 872 if (IS_A_TT()) { 873 tt_scsi_dma.dma_ctrl = dir; 874 SCSI_DMA_WRITE_P(dma_addr, addr); 875 SCSI_DMA_WRITE_P(dma_cnt, count); 876 tt_scsi_dma.dma_ctrl = dir | 2; 877 } else { /* ! IS_A_TT */ 878 879 /* set address */ 880 SCSI_DMA_SETADR(addr); 881 882 /* toggle direction bit to clear FIFO and set DMA direction */ 883 dir <<= 8; 884 st_dma.dma_mode_status = 0x90 | dir; 885 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); 886 st_dma.dma_mode_status = 0x90 | dir; 887 udelay(40); 888 /* On writes, round up the transfer length to the next multiple of 512 889 * (see also comment at atari_dma_xfer_len()). */ 890 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; 891 udelay(40); 892 st_dma.dma_mode_status = 0x10 | dir; 893 udelay(40); 894 /* need not restore value of dir, only boolean value is tested */ 895 atari_dma_active = 1; 896 } 897 898 return count; 899} 900 901 902static long atari_scsi_dma_residual(struct Scsi_Host *instance) 903{ 904 return atari_dma_residual; 905} 906 907 908#define CMD_SURELY_BLOCK_MODE 0 909#define CMD_SURELY_BYTE_MODE 1 910#define CMD_MODE_UNKNOWN 2 911 912static int falcon_classify_cmd(Scsi_Cmnd *cmd) 913{ 914 unsigned char opcode = cmd->cmnd[0]; 915 916 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || 917 opcode == READ_BUFFER) 918 return CMD_SURELY_BYTE_MODE; 919 else if (opcode == READ_6 || opcode == READ_10 || 920 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || 921 opcode == RECOVER_BUFFERED_DATA) { 922 /* In case of a sequential-access target (tape), special care is 923 * needed here: The transfer is block-mode only if the 'fixed' bit is 924 * set! */ 925 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) 926 return CMD_SURELY_BYTE_MODE; 927 else 928 return CMD_SURELY_BLOCK_MODE; 929 } else 930 return CMD_MODE_UNKNOWN; 931} 932 933 934/* This function calculates the number of bytes that can be transferred via 935 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the 936 * ST-DMA chip. There are only multiples of 512 bytes possible and max. 937 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not 938 * possible on the Falcon, since that would require to program the DMA for 939 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have 940 * the overrun problem, so this question is academic :-) 941 */ 942 943static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 944 Scsi_Cmnd *cmd, int write_flag) 945{ 946 unsigned long possible_len, limit; 947 948 if (IS_A_TT()) 949 /* TT SCSI DMA can transfer arbitrary #bytes */ 950 return wanted_len; 951 952 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. 953 * 255*512 bytes, but this should be enough) 954 * 955 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands 956 * that return a number of bytes which cannot be known beforehand. In this 957 * case, the given transfer length is an "allocation length". Now it 958 * can happen that this allocation length is a multiple of 512 bytes and 959 * the DMA is used. But if not n*512 bytes really arrive, some input data 960 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish 961 * between commands that do block transfers and those that do byte 962 * transfers. But this isn't easy... there are lots of vendor specific 963 * commands, and the user can issue any command via the 964 * SCSI_IOCTL_SEND_COMMAND. 965 * 966 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, 967 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) 968 * and 3), the thing to do is obvious: allow any number of blocks via DMA 969 * or none. In case 2), we apply some heuristic: Byte mode is assumed if 970 * the transfer (allocation) length is < 1024, hoping that no cmd. not 971 * explicitly known as byte mode have such big allocation lengths... 972 * BTW, all the discussion above applies only to reads. DMA writes are 973 * unproblematic anyways, since the targets aborts the transfer after 974 * receiving a sufficient number of bytes. 975 * 976 * Another point: If the transfer is from/to an non-ST-RAM address, we 977 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. 978 */ 979 980 if (write_flag) { 981 /* Write operation can always use the DMA, but the transfer size must 982 * be rounded up to the next multiple of 512 (atari_dma_setup() does 983 * this). 984 */ 985 possible_len = wanted_len; 986 } else { 987 /* Read operations: if the wanted transfer length is not a multiple of 988 * 512, we cannot use DMA, since the ST-DMA cannot split transfers 989 * (no interrupt on DMA finished!) 990 */ 991 if (wanted_len & 0x1ff) 992 possible_len = 0; 993 else { 994 /* Now classify the command (see above) and decide whether it is 995 * allowed to do DMA at all */ 996 switch (falcon_classify_cmd(cmd)) { 997 case CMD_SURELY_BLOCK_MODE: 998 possible_len = wanted_len; 999 break; 1000 case CMD_SURELY_BYTE_MODE: 1001 possible_len = 0; /* DMA prohibited */ 1002 break; 1003 case CMD_MODE_UNKNOWN: 1004 default: 1005 /* For unknown commands assume block transfers if the transfer 1006 * size/allocation length is >= 1024 */ 1007 possible_len = (wanted_len < 1024) ? 0 : wanted_len; 1008 break; 1009 } 1010 } 1011 } 1012 1013 /* Last step: apply the hard limit on DMA transfers */ 1014 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ? 1015 STRAM_BUFFER_SIZE : 255*512; 1016 if (possible_len > limit) 1017 possible_len = limit; 1018 1019 if (possible_len != wanted_len) 1020 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes " 1021 "instead of %ld\n", possible_len, wanted_len); 1022 1023 return possible_len; 1024} 1025 1026 1027#endif /* REAL_DMA */ 1028 1029 1030/* NCR5380 register access functions 1031 * 1032 * There are separate functions for TT and Falcon, because the access 1033 * methods are quite different. The calling macros NCR5380_read and 1034 * NCR5380_write call these functions via function pointers. 1035 */ 1036 1037static unsigned char atari_scsi_tt_reg_read(unsigned char reg) 1038{ 1039 return tt_scsi_regp[reg * 2]; 1040} 1041 1042static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value) 1043{ 1044 tt_scsi_regp[reg * 2] = value; 1045} 1046 1047static unsigned char atari_scsi_falcon_reg_read(unsigned char reg) 1048{ 1049 dma_wd.dma_mode_status= (u_short)(0x88 + reg); 1050 return (u_char)dma_wd.fdc_acces_seccount; 1051} 1052 1053static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value) 1054{ 1055 dma_wd.dma_mode_status = (u_short)(0x88 + reg); 1056 dma_wd.fdc_acces_seccount = (u_short)value; 1057} 1058 1059 1060#include "atari_NCR5380.c" 1061 1062static struct scsi_host_template driver_template = { 1063 .proc_info = atari_scsi_proc_info, 1064 .name = "Atari native SCSI", 1065 .detect = atari_scsi_detect, 1066 .release = atari_scsi_release, 1067 .info = atari_scsi_info, 1068 .queuecommand = atari_scsi_queue_command, 1069 .eh_abort_handler = atari_scsi_abort, 1070 .eh_bus_reset_handler = atari_scsi_bus_reset, 1071 .can_queue = 0, /* initialized at run-time */ 1072 .this_id = 0, /* initialized at run-time */ 1073 .sg_tablesize = 0, /* initialized at run-time */ 1074 .cmd_per_lun = 0, /* initialized at run-time */ 1075 .use_clustering = DISABLE_CLUSTERING 1076}; 1077 1078 1079#include "scsi_module.c" 1080 1081MODULE_LICENSE("GPL"); 1082