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#if 0 277/* Dead code... wasn't called anyway :-) and causes some trouble, because at 278 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has 279 * to clear the DMA int pending bit before it allows other level 6 interrupts. 280 */ 281static void scsi_dma_buserr(int irq, void *dummy) 282{ 283 unsigned char dma_stat = tt_scsi_dma.dma_ctrl; 284 285 /* Don't do anything if a NCR interrupt is pending. Probably it's just 286 * masked... */ 287 if (atari_irq_pending(IRQ_TT_MFP_SCSI)) 288 return; 289 290 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n", 291 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt)); 292 if (dma_stat & 0x80) { 293 if (!scsi_dma_is_ignored_buserr(dma_stat)) 294 printk("SCSI DMA bus error -- bad DMA programming!\n"); 295 } else { 296 /* Under normal circumstances we never should get to this point, 297 * since both interrupts are triggered simultaneously and the 5380 298 * int has higher priority. When this irq is handled, that DMA 299 * interrupt is cleared. So a warning message is printed here. 300 */ 301 printk("SCSI DMA intr ?? -- this shouldn't happen!\n"); 302 } 303} 304#endif 305 306#endif 307 308 309static irqreturn_t scsi_tt_intr(int irq, void *dummy) 310{ 311#ifdef REAL_DMA 312 int dma_stat; 313 314 dma_stat = tt_scsi_dma.dma_ctrl; 315 316 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n", 317 atari_scsi_host->host_no, dma_stat & 0xff); 318 319 /* Look if it was the DMA that has interrupted: First possibility 320 * is that a bus error occurred... 321 */ 322 if (dma_stat & 0x80) { 323 if (!scsi_dma_is_ignored_buserr(dma_stat)) { 324 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", 325 SCSI_DMA_READ_P(dma_addr)); 326 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); 327 } 328 } 329 330 /* If the DMA is active but not finished, we have the case 331 * that some other 5380 interrupt occurred within the DMA transfer. 332 * This means we have residual bytes, if the desired end address 333 * is not yet reached. Maybe we have to fetch some bytes from the 334 * rest data register, too. The residual must be calculated from 335 * the address pointer, not the counter register, because only the 336 * addr reg counts bytes not yet written and pending in the rest 337 * data reg! 338 */ 339 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { 340 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); 341 342 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 343 atari_dma_residual); 344 345 if ((signed int)atari_dma_residual < 0) 346 atari_dma_residual = 0; 347 if ((dma_stat & 1) == 0) { 348 /* 349 * After read operations, we maybe have to 350 * transport some rest bytes 351 */ 352 atari_scsi_fetch_restbytes(); 353 } else { 354 /* 355 * There seems to be a nasty bug in some SCSI-DMA/NCR 356 * combinations: If a target disconnects while a write 357 * operation is going on, the address register of the 358 * DMA may be a few bytes farer than it actually read. 359 * This is probably due to DMA prefetching and a delay 360 * between DMA and NCR. Experiments showed that the 361 * dma_addr is 9 bytes to high, but this could vary. 362 * The problem is, that the residual is thus calculated 363 * wrong and the next transfer will start behind where 364 * it should. So we round up the residual to the next 365 * multiple of a sector size, if it isn't already a 366 * multiple and the originally expected transfer size 367 * was. The latter condition is there to ensure that 368 * the correction is taken only for "real" data 369 * transfers and not for, e.g., the parameters of some 370 * other command. These shouldn't disconnect anyway. 371 */ 372 if (atari_dma_residual & 0x1ff) { 373 DMA_PRINTK("SCSI DMA: DMA bug corrected, " 374 "difference %ld bytes\n", 375 512 - (atari_dma_residual & 0x1ff)); 376 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; 377 } 378 } 379 tt_scsi_dma.dma_ctrl = 0; 380 } 381 382 /* If the DMA is finished, fetch the rest bytes and turn it off */ 383 if (dma_stat & 0x40) { 384 atari_dma_residual = 0; 385 if ((dma_stat & 1) == 0) 386 atari_scsi_fetch_restbytes(); 387 tt_scsi_dma.dma_ctrl = 0; 388 } 389 390#endif /* REAL_DMA */ 391 392 NCR5380_intr(irq, dummy); 393 394#if 0 395 /* To be sure the int is not masked */ 396 atari_enable_irq(IRQ_TT_MFP_SCSI); 397#endif 398 return IRQ_HANDLED; 399} 400 401 402static irqreturn_t scsi_falcon_intr(int irq, void *dummy) 403{ 404#ifdef REAL_DMA 405 int dma_stat; 406 407 /* Turn off DMA and select sector counter register before 408 * accessing the status register (Atari recommendation!) 409 */ 410 st_dma.dma_mode_status = 0x90; 411 dma_stat = st_dma.dma_mode_status; 412 413 /* Bit 0 indicates some error in the DMA process... don't know 414 * what happened exactly (no further docu). 415 */ 416 if (!(dma_stat & 0x01)) { 417 /* DMA error */ 418 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); 419 } 420 421 /* If the DMA was active, but now bit 1 is not clear, it is some 422 * other 5380 interrupt that finishes the DMA transfer. We have to 423 * calculate the number of residual bytes and give a warning if 424 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) 425 */ 426 if (atari_dma_active && (dma_stat & 0x02)) { 427 unsigned long transferred; 428 429 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; 430 /* The ST-DMA address is incremented in 2-byte steps, but the 431 * data are written only in 16-byte chunks. If the number of 432 * transferred bytes is not divisible by 16, the remainder is 433 * lost somewhere in outer space. 434 */ 435 if (transferred & 15) 436 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " 437 "ST-DMA fifo\n", transferred & 15); 438 439 atari_dma_residual = HOSTDATA_DMALEN - transferred; 440 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 441 atari_dma_residual); 442 } else 443 atari_dma_residual = 0; 444 atari_dma_active = 0; 445 446 if (atari_dma_orig_addr) { 447 /* If the dribble buffer was used on a read operation, copy the DMA-ed 448 * data to the original destination address. 449 */ 450 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), 451 HOSTDATA_DMALEN - atari_dma_residual); 452 atari_dma_orig_addr = NULL; 453 } 454 455#endif /* REAL_DMA */ 456 457 NCR5380_intr(irq, dummy); 458 return IRQ_HANDLED; 459} 460 461 462#ifdef REAL_DMA 463static void atari_scsi_fetch_restbytes(void) 464{ 465 int nr; 466 char *src, *dst; 467 unsigned long phys_dst; 468 469 /* fetch rest bytes in the DMA register */ 470 phys_dst = SCSI_DMA_READ_P(dma_addr); 471 nr = phys_dst & 3; 472 if (nr) { 473 /* there are 'nr' bytes left for the last long address 474 before the DMA pointer */ 475 phys_dst ^= nr; 476 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", 477 nr, phys_dst); 478 /* The content of the DMA pointer is a physical address! */ 479 dst = phys_to_virt(phys_dst); 480 DMA_PRINTK(" = virt addr %p\n", dst); 481 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) 482 *dst++ = *src++; 483 } 484} 485#endif /* REAL_DMA */ 486 487 488static int falcon_got_lock = 0; 489static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); 490static int falcon_trying_lock = 0; 491static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); 492static int falcon_dont_release = 0; 493 494/* This function releases the lock on the DMA chip if there is no 495 * connected command and the disconnected queue is empty. On 496 * releasing, instances of falcon_get_lock are awoken, that put 497 * themselves to sleep for fairness. They can now try to get the lock 498 * again (but others waiting longer more probably will win). 499 */ 500 501static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata) 502{ 503 unsigned long flags; 504 505 if (IS_A_TT()) 506 return; 507 508 local_irq_save(flags); 509 510 if (falcon_got_lock && !hostdata->disconnected_queue && 511 !hostdata->issue_queue && !hostdata->connected) { 512 513 if (falcon_dont_release) { 514#if 0 515 printk("WARNING: Lock release not allowed. Ignored\n"); 516#endif 517 local_irq_restore(flags); 518 return; 519 } 520 falcon_got_lock = 0; 521 stdma_release(); 522 wake_up(&falcon_fairness_wait); 523 } 524 525 local_irq_restore(flags); 526} 527 528/* This function manages the locking of the ST-DMA. 529 * If the DMA isn't locked already for SCSI, it tries to lock it by 530 * calling stdma_lock(). But if the DMA is locked by the SCSI code and 531 * there are other drivers waiting for the chip, we do not issue the 532 * command immediately but wait on 'falcon_fairness_queue'. We will be 533 * waked up when the DMA is unlocked by some SCSI interrupt. After that 534 * we try to get the lock again. 535 * But we must be prepared that more than one instance of 536 * falcon_get_lock() is waiting on the fairness queue. They should not 537 * try all at once to call stdma_lock(), one is enough! For that, the 538 * first one sets 'falcon_trying_lock', others that see that variable 539 * set wait on the queue 'falcon_try_wait'. 540 * Complicated, complicated.... Sigh... 541 */ 542 543static void falcon_get_lock(void) 544{ 545 unsigned long flags; 546 547 if (IS_A_TT()) 548 return; 549 550 local_irq_save(flags); 551 552 while (!in_irq() && falcon_got_lock && stdma_others_waiting()) 553 sleep_on(&falcon_fairness_wait); 554 555 while (!falcon_got_lock) { 556 if (in_irq()) 557 panic("Falcon SCSI hasn't ST-DMA lock in interrupt"); 558 if (!falcon_trying_lock) { 559 falcon_trying_lock = 1; 560 stdma_lock(scsi_falcon_intr, NULL); 561 falcon_got_lock = 1; 562 falcon_trying_lock = 0; 563 wake_up(&falcon_try_wait); 564 } else { 565 sleep_on(&falcon_try_wait); 566 } 567 } 568 569 local_irq_restore(flags); 570 if (!falcon_got_lock) 571 panic("Falcon SCSI: someone stole the lock :-(\n"); 572} 573 574 575int __init atari_scsi_detect(struct scsi_host_template *host) 576{ 577 static int called = 0; 578 struct Scsi_Host *instance; 579 580 if (!MACH_IS_ATARI || 581 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) || 582 called) 583 return 0; 584 585 host->proc_name = "Atari"; 586 587 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read : 588 atari_scsi_falcon_reg_read; 589 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write : 590 atari_scsi_falcon_reg_write; 591 592 /* setup variables */ 593 host->can_queue = 594 (setup_can_queue > 0) ? setup_can_queue : 595 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE; 596 host->cmd_per_lun = 597 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun : 598 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN; 599 /* Force sg_tablesize to 0 on a Falcon! */ 600 host->sg_tablesize = 601 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE : 602 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE; 603 604 if (setup_hostid >= 0) 605 host->this_id = setup_hostid; 606 else { 607 /* use 7 as default */ 608 host->this_id = 7; 609 /* Test if a host id is set in the NVRam */ 610 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { 611 unsigned char b = nvram_read_byte( 14 ); 612 /* Arbitration enabled? (for TOS) If yes, use configured host ID */ 613 if (b & 0x80) 614 host->this_id = b & 7; 615 } 616 } 617 618#ifdef SUPPORT_TAGS 619 if (setup_use_tagged_queuing < 0) 620 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING; 621#endif 622#ifdef REAL_DMA 623 /* If running on a Falcon and if there's TT-Ram (i.e., more than one 624 * memory block, since there's always ST-Ram in a Falcon), then allocate a 625 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative 626 * Ram. 627 */ 628 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) && 629 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) { 630 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI"); 631 if (!atari_dma_buffer) { 632 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM " 633 "double buffer\n"); 634 return 0; 635 } 636 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer); 637 atari_dma_orig_addr = 0; 638 } 639#endif 640 instance = scsi_register(host, sizeof(struct NCR5380_hostdata)); 641 if (instance == NULL) { 642 atari_stram_free(atari_dma_buffer); 643 atari_dma_buffer = 0; 644 return 0; 645 } 646 atari_scsi_host = instance; 647 /* 648 * Set irq to 0, to avoid that the mid-level code disables our interrupt 649 * during queue_command calls. This is completely unnecessary, and even 650 * worse causes bad problems on the Falcon, where the int is shared with 651 * IDE and floppy! 652 */ 653 instance->irq = 0; 654 655#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 656 atari_scsi_reset_boot(); 657#endif 658 NCR5380_init(instance, 0); 659 660 if (IS_A_TT()) { 661 662 /* This int is actually "pseudo-slow", i.e. it acts like a slow 663 * interrupt after having cleared the pending flag for the DMA 664 * interrupt. */ 665 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW, 666 "SCSI NCR5380", instance)) { 667 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI); 668 scsi_unregister(atari_scsi_host); 669 atari_stram_free(atari_dma_buffer); 670 atari_dma_buffer = 0; 671 return 0; 672 } 673 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ 674#ifdef REAL_DMA 675 tt_scsi_dma.dma_ctrl = 0; 676 atari_dma_residual = 0; 677 678 if (MACH_IS_MEDUSA) { 679 /* While the read overruns (described by Drew Eckhardt in 680 * NCR5380.c) never happened on TTs, they do in fact on the Medusa 681 * (This was the cause why SCSI didn't work right for so long 682 * there.) Since handling the overruns slows down a bit, I turned 683 * the #ifdef's into a runtime condition. 684 * 685 * In principle it should be sufficient to do max. 1 byte with 686 * PIO, but there is another problem on the Medusa with the DMA 687 * rest data register. So 'atari_read_overruns' is currently set 688 * to 4 to avoid having transfers that aren't a multiple of 4. If 689 * the rest data bug is fixed, this can be lowered to 1. 690 */ 691 atari_read_overruns = 4; 692 } 693#endif /*REAL_DMA*/ 694 } else { /* ! IS_A_TT */ 695 696 /* Nothing to do for the interrupt: the ST-DMA is initialized 697 * already by atari_init_INTS() 698 */ 699 700#ifdef REAL_DMA 701 atari_dma_residual = 0; 702 atari_dma_active = 0; 703 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 704 : 0xff000000); 705#endif 706 } 707 708 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d " 709#ifdef SUPPORT_TAGS 710 "TAGGED-QUEUING=%s " 711#endif 712 "HOSTID=%d", 713 instance->host_no, instance->hostt->can_queue, 714 instance->hostt->cmd_per_lun, 715 instance->hostt->sg_tablesize, 716#ifdef SUPPORT_TAGS 717 setup_use_tagged_queuing ? "yes" : "no", 718#endif 719 instance->hostt->this_id ); 720 NCR5380_print_options(instance); 721 printk("\n"); 722 723 called = 1; 724 return 1; 725} 726 727int atari_scsi_release(struct Scsi_Host *sh) 728{ 729 if (IS_A_TT()) 730 free_irq(IRQ_TT_MFP_SCSI, sh); 731 if (atari_dma_buffer) 732 atari_stram_free(atari_dma_buffer); 733 NCR5380_exit(sh); 734 return 1; 735} 736 737void __init atari_scsi_setup(char *str, int *ints) 738{ 739 /* Format of atascsi parameter is: 740 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 741 * Defaults depend on TT or Falcon, hostid determined at run time. 742 * Negative values mean don't change. 743 */ 744 745 if (ints[0] < 1) { 746 printk("atari_scsi_setup: no arguments!\n"); 747 return; 748 } 749 750 if (ints[0] >= 1) { 751 if (ints[1] > 0) 752 /* no limits on this, just > 0 */ 753 setup_can_queue = ints[1]; 754 } 755 if (ints[0] >= 2) { 756 if (ints[2] > 0) 757 setup_cmd_per_lun = ints[2]; 758 } 759 if (ints[0] >= 3) { 760 if (ints[3] >= 0) { 761 setup_sg_tablesize = ints[3]; 762 /* Must be <= SG_ALL (255) */ 763 if (setup_sg_tablesize > SG_ALL) 764 setup_sg_tablesize = SG_ALL; 765 } 766 } 767 if (ints[0] >= 4) { 768 /* Must be between 0 and 7 */ 769 if (ints[4] >= 0 && ints[4] <= 7) 770 setup_hostid = ints[4]; 771 else if (ints[4] > 7) 772 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]); 773 } 774#ifdef SUPPORT_TAGS 775 if (ints[0] >= 5) { 776 if (ints[5] >= 0) 777 setup_use_tagged_queuing = !!ints[5]; 778 } 779#endif 780} 781 782int atari_scsi_bus_reset(Scsi_Cmnd *cmd) 783{ 784 int rv; 785 struct NCR5380_hostdata *hostdata = 786 (struct NCR5380_hostdata *)cmd->device->host->hostdata; 787 788 /* For doing the reset, SCSI interrupts must be disabled first, 789 * since the 5380 raises its IRQ line while _RST is active and we 790 * can't disable interrupts completely, since we need the timer. 791 */ 792 /* And abort a maybe active DMA transfer */ 793 if (IS_A_TT()) { 794 atari_turnoff_irq(IRQ_TT_MFP_SCSI); 795#ifdef REAL_DMA 796 tt_scsi_dma.dma_ctrl = 0; 797#endif /* REAL_DMA */ 798 } else { 799 atari_turnoff_irq(IRQ_MFP_FSCSI); 800#ifdef REAL_DMA 801 st_dma.dma_mode_status = 0x90; 802 atari_dma_active = 0; 803 atari_dma_orig_addr = NULL; 804#endif /* REAL_DMA */ 805 } 806 807 rv = NCR5380_bus_reset(cmd); 808 809 /* Re-enable ints */ 810 if (IS_A_TT()) { 811 atari_turnon_irq(IRQ_TT_MFP_SCSI); 812 } else { 813 atari_turnon_irq(IRQ_MFP_FSCSI); 814 } 815 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS) 816 falcon_release_lock_if_possible(hostdata); 817 818 return rv; 819} 820 821 822#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 823static void __init atari_scsi_reset_boot(void) 824{ 825 unsigned long end; 826 827 /* 828 * Do a SCSI reset to clean up the bus during initialization. No messing 829 * with the queues, interrupts, or locks necessary here. 830 */ 831 832 printk("Atari SCSI: resetting the SCSI bus..."); 833 834 /* get in phase */ 835 NCR5380_write(TARGET_COMMAND_REG, 836 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG))); 837 838 /* assert RST */ 839 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); 840 /* The min. reset hold time is 25us, so 40us should be enough */ 841 udelay(50); 842 /* reset RST and interrupt */ 843 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); 844 NCR5380_read(RESET_PARITY_INTERRUPT_REG); 845 846 end = jiffies + AFTER_RESET_DELAY; 847 while (time_before(jiffies, end)) 848 barrier(); 849 850 printk(" done\n"); 851} 852#endif 853 854 855const char *atari_scsi_info(struct Scsi_Host *host) 856{ 857 /* atari_scsi_detect() is verbose enough... */ 858 static const char string[] = "Atari native SCSI"; 859 return string; 860} 861 862 863#if defined(REAL_DMA) 864 865unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, void *data, 866 unsigned long count, int dir) 867{ 868 unsigned long addr = virt_to_phys(data); 869 870 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " 871 "dir = %d\n", instance->host_no, data, addr, count, dir); 872 873 if (!IS_A_TT() && !STRAM_ADDR(addr)) { 874 /* If we have a non-DMAable address on a Falcon, use the dribble 875 * buffer; 'orig_addr' != 0 in the read case tells the interrupt 876 * handler to copy data from the dribble buffer to the originally 877 * wanted address. 878 */ 879 if (dir) 880 memcpy(atari_dma_buffer, data, count); 881 else 882 atari_dma_orig_addr = data; 883 addr = atari_dma_phys_buffer; 884 } 885 886 atari_dma_startaddr = addr; /* Needed for calculating residual later. */ 887 888 /* Cache cleanup stuff: On writes, push any dirty cache out before sending 889 * it to the peripheral. (Must be done before DMA setup, since at least 890 * the ST-DMA begins to fill internal buffers right after setup. For 891 * reads, invalidate any cache, may be altered after DMA without CPU 892 * knowledge. 893 * 894 * ++roman: For the Medusa, there's no need at all for that cache stuff, 895 * because the hardware does bus snooping (fine!). 896 */ 897 dma_cache_maintenance(addr, count, dir); 898 899 if (count == 0) 900 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); 901 902 if (IS_A_TT()) { 903 tt_scsi_dma.dma_ctrl = dir; 904 SCSI_DMA_WRITE_P(dma_addr, addr); 905 SCSI_DMA_WRITE_P(dma_cnt, count); 906 tt_scsi_dma.dma_ctrl = dir | 2; 907 } else { /* ! IS_A_TT */ 908 909 /* set address */ 910 SCSI_DMA_SETADR(addr); 911 912 /* toggle direction bit to clear FIFO and set DMA direction */ 913 dir <<= 8; 914 st_dma.dma_mode_status = 0x90 | dir; 915 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); 916 st_dma.dma_mode_status = 0x90 | dir; 917 udelay(40); 918 /* On writes, round up the transfer length to the next multiple of 512 919 * (see also comment at atari_dma_xfer_len()). */ 920 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; 921 udelay(40); 922 st_dma.dma_mode_status = 0x10 | dir; 923 udelay(40); 924 /* need not restore value of dir, only boolean value is tested */ 925 atari_dma_active = 1; 926 } 927 928 return count; 929} 930 931 932static long atari_scsi_dma_residual(struct Scsi_Host *instance) 933{ 934 return atari_dma_residual; 935} 936 937 938#define CMD_SURELY_BLOCK_MODE 0 939#define CMD_SURELY_BYTE_MODE 1 940#define CMD_MODE_UNKNOWN 2 941 942static int falcon_classify_cmd(Scsi_Cmnd *cmd) 943{ 944 unsigned char opcode = cmd->cmnd[0]; 945 946 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || 947 opcode == READ_BUFFER) 948 return CMD_SURELY_BYTE_MODE; 949 else if (opcode == READ_6 || opcode == READ_10 || 950 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || 951 opcode == RECOVER_BUFFERED_DATA) { 952 /* In case of a sequential-access target (tape), special care is 953 * needed here: The transfer is block-mode only if the 'fixed' bit is 954 * set! */ 955 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) 956 return CMD_SURELY_BYTE_MODE; 957 else 958 return CMD_SURELY_BLOCK_MODE; 959 } else 960 return CMD_MODE_UNKNOWN; 961} 962 963 964/* This function calculates the number of bytes that can be transferred via 965 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the 966 * ST-DMA chip. There are only multiples of 512 bytes possible and max. 967 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not 968 * possible on the Falcon, since that would require to program the DMA for 969 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have 970 * the overrun problem, so this question is academic :-) 971 */ 972 973static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 974 Scsi_Cmnd *cmd, int write_flag) 975{ 976 unsigned long possible_len, limit; 977 978 if (IS_A_TT()) 979 /* TT SCSI DMA can transfer arbitrary #bytes */ 980 return wanted_len; 981 982 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. 983 * 255*512 bytes, but this should be enough) 984 * 985 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands 986 * that return a number of bytes which cannot be known beforehand. In this 987 * case, the given transfer length is an "allocation length". Now it 988 * can happen that this allocation length is a multiple of 512 bytes and 989 * the DMA is used. But if not n*512 bytes really arrive, some input data 990 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish 991 * between commands that do block transfers and those that do byte 992 * transfers. But this isn't easy... there are lots of vendor specific 993 * commands, and the user can issue any command via the 994 * SCSI_IOCTL_SEND_COMMAND. 995 * 996 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, 997 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) 998 * and 3), the thing to do is obvious: allow any number of blocks via DMA 999 * or none. In case 2), we apply some heuristic: Byte mode is assumed if 1000 * the transfer (allocation) length is < 1024, hoping that no cmd. not 1001 * explicitly known as byte mode have such big allocation lengths... 1002 * BTW, all the discussion above applies only to reads. DMA writes are 1003 * unproblematic anyways, since the targets aborts the transfer after 1004 * receiving a sufficient number of bytes. 1005 * 1006 * Another point: If the transfer is from/to an non-ST-RAM address, we 1007 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. 1008 */ 1009 1010 if (write_flag) { 1011 /* Write operation can always use the DMA, but the transfer size must 1012 * be rounded up to the next multiple of 512 (atari_dma_setup() does 1013 * this). 1014 */ 1015 possible_len = wanted_len; 1016 } else { 1017 /* Read operations: if the wanted transfer length is not a multiple of 1018 * 512, we cannot use DMA, since the ST-DMA cannot split transfers 1019 * (no interrupt on DMA finished!) 1020 */ 1021 if (wanted_len & 0x1ff) 1022 possible_len = 0; 1023 else { 1024 /* Now classify the command (see above) and decide whether it is 1025 * allowed to do DMA at all */ 1026 switch (falcon_classify_cmd(cmd)) { 1027 case CMD_SURELY_BLOCK_MODE: 1028 possible_len = wanted_len; 1029 break; 1030 case CMD_SURELY_BYTE_MODE: 1031 possible_len = 0; /* DMA prohibited */ 1032 break; 1033 case CMD_MODE_UNKNOWN: 1034 default: 1035 /* For unknown commands assume block transfers if the transfer 1036 * size/allocation length is >= 1024 */ 1037 possible_len = (wanted_len < 1024) ? 0 : wanted_len; 1038 break; 1039 } 1040 } 1041 } 1042 1043 /* Last step: apply the hard limit on DMA transfers */ 1044 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ? 1045 STRAM_BUFFER_SIZE : 255*512; 1046 if (possible_len > limit) 1047 possible_len = limit; 1048 1049 if (possible_len != wanted_len) 1050 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes " 1051 "instead of %ld\n", possible_len, wanted_len); 1052 1053 return possible_len; 1054} 1055 1056 1057#endif /* REAL_DMA */ 1058 1059 1060/* NCR5380 register access functions 1061 * 1062 * There are separate functions for TT and Falcon, because the access 1063 * methods are quite different. The calling macros NCR5380_read and 1064 * NCR5380_write call these functions via function pointers. 1065 */ 1066 1067static unsigned char atari_scsi_tt_reg_read(unsigned char reg) 1068{ 1069 return tt_scsi_regp[reg * 2]; 1070} 1071 1072static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value) 1073{ 1074 tt_scsi_regp[reg * 2] = value; 1075} 1076 1077static unsigned char atari_scsi_falcon_reg_read(unsigned char reg) 1078{ 1079 dma_wd.dma_mode_status= (u_short)(0x88 + reg); 1080 return (u_char)dma_wd.fdc_acces_seccount; 1081} 1082 1083static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value) 1084{ 1085 dma_wd.dma_mode_status = (u_short)(0x88 + reg); 1086 dma_wd.fdc_acces_seccount = (u_short)value; 1087} 1088 1089 1090#include "atari_NCR5380.c" 1091 1092static struct scsi_host_template driver_template = { 1093 .proc_info = atari_scsi_proc_info, 1094 .name = "Atari native SCSI", 1095 .detect = atari_scsi_detect, 1096 .release = atari_scsi_release, 1097 .info = atari_scsi_info, 1098 .queuecommand = atari_scsi_queue_command, 1099 .eh_abort_handler = atari_scsi_abort, 1100 .eh_bus_reset_handler = atari_scsi_bus_reset, 1101 .can_queue = 0, /* initialized at run-time */ 1102 .this_id = 0, /* initialized at run-time */ 1103 .sg_tablesize = 0, /* initialized at run-time */ 1104 .cmd_per_lun = 0, /* initialized at run-time */ 1105 .use_clustering = DISABLE_CLUSTERING 1106}; 1107 1108 1109#include "scsi_module.c" 1110 1111MODULE_LICENSE("GPL"); 1112