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 AUTOSENSE 71/* For the Atari version, use only polled IO or REAL_DMA */ 72#define REAL_DMA 73/* Support tagged queuing? (on devices that are able to... :-) */ 74#define SUPPORT_TAGS 75#define MAX_TAGS 32 76 77#include <linux/types.h> 78#include <linux/stddef.h> 79#include <linux/ctype.h> 80#include <linux/delay.h> 81#include <linux/mm.h> 82#include <linux/blkdev.h> 83#include <linux/interrupt.h> 84#include <linux/init.h> 85#include <linux/nvram.h> 86#include <linux/bitops.h> 87#include <linux/wait.h> 88 89#include <asm/setup.h> 90#include <asm/atarihw.h> 91#include <asm/atariints.h> 92#include <asm/page.h> 93#include <asm/pgtable.h> 94#include <asm/irq.h> 95#include <asm/traps.h> 96 97#include "scsi.h" 98#include <scsi/scsi_host.h> 99#include "atari_scsi.h" 100#include "NCR5380.h" 101#include <asm/atari_stdma.h> 102#include <asm/atari_stram.h> 103#include <asm/io.h> 104 105#include <linux/stat.h> 106 107#define IS_A_TT() ATARIHW_PRESENT(TT_SCSI) 108 109#define SCSI_DMA_WRITE_P(elt,val) \ 110 do { \ 111 unsigned long v = val; \ 112 tt_scsi_dma.elt##_lo = v & 0xff; \ 113 v >>= 8; \ 114 tt_scsi_dma.elt##_lmd = v & 0xff; \ 115 v >>= 8; \ 116 tt_scsi_dma.elt##_hmd = v & 0xff; \ 117 v >>= 8; \ 118 tt_scsi_dma.elt##_hi = v & 0xff; \ 119 } while(0) 120 121#define SCSI_DMA_READ_P(elt) \ 122 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \ 123 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \ 124 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \ 125 (unsigned long)tt_scsi_dma.elt##_lo) 126 127 128static inline void SCSI_DMA_SETADR(unsigned long adr) 129{ 130 st_dma.dma_lo = (unsigned char)adr; 131 MFPDELAY(); 132 adr >>= 8; 133 st_dma.dma_md = (unsigned char)adr; 134 MFPDELAY(); 135 adr >>= 8; 136 st_dma.dma_hi = (unsigned char)adr; 137 MFPDELAY(); 138} 139 140static inline unsigned long SCSI_DMA_GETADR(void) 141{ 142 unsigned long adr; 143 adr = st_dma.dma_lo; 144 MFPDELAY(); 145 adr |= (st_dma.dma_md & 0xff) << 8; 146 MFPDELAY(); 147 adr |= (st_dma.dma_hi & 0xff) << 16; 148 MFPDELAY(); 149 return adr; 150} 151 152static inline void ENABLE_IRQ(void) 153{ 154 if (IS_A_TT()) 155 atari_enable_irq(IRQ_TT_MFP_SCSI); 156 else 157 atari_enable_irq(IRQ_MFP_FSCSI); 158} 159 160static inline void DISABLE_IRQ(void) 161{ 162 if (IS_A_TT()) 163 atari_disable_irq(IRQ_TT_MFP_SCSI); 164 else 165 atari_disable_irq(IRQ_MFP_FSCSI); 166} 167 168 169#define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \ 170 (atari_scsi_host->hostdata))->dma_len) 171 172/* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms, 173 * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more 174 * need ten times the standard value... */ 175#ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY 176#define AFTER_RESET_DELAY (HZ/2) 177#else 178#define AFTER_RESET_DELAY (5*HZ/2) 179#endif 180 181/***************************** Prototypes *****************************/ 182 183#ifdef REAL_DMA 184static int scsi_dma_is_ignored_buserr(unsigned char dma_stat); 185static void atari_scsi_fetch_restbytes(void); 186static long atari_scsi_dma_residual(struct Scsi_Host *instance); 187static int falcon_classify_cmd(Scsi_Cmnd *cmd); 188static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 189 Scsi_Cmnd *cmd, int write_flag); 190#endif 191static irqreturn_t scsi_tt_intr(int irq, void *dummy); 192static irqreturn_t scsi_falcon_intr(int irq, void *dummy); 193static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata); 194static void falcon_get_lock(void); 195#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 196static void atari_scsi_reset_boot(void); 197#endif 198static unsigned char atari_scsi_tt_reg_read(unsigned char reg); 199static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value); 200static unsigned char atari_scsi_falcon_reg_read(unsigned char reg); 201static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value); 202 203/************************* End of Prototypes **************************/ 204 205 206static struct Scsi_Host *atari_scsi_host; 207static unsigned char (*atari_scsi_reg_read)(unsigned char reg); 208static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value); 209 210#ifdef REAL_DMA 211static unsigned long atari_dma_residual, atari_dma_startaddr; 212static short atari_dma_active; 213/* pointer to the dribble buffer */ 214static char *atari_dma_buffer; 215/* precalculated physical address of the dribble buffer */ 216static unsigned long atari_dma_phys_buffer; 217/* != 0 tells the Falcon int handler to copy data from the dribble buffer */ 218static char *atari_dma_orig_addr; 219/* size of the dribble buffer; 4k seems enough, since the Falcon cannot use 220 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare 221 * cases where requests to physical contiguous buffers have been merged, this 222 * request is <= 4k (one page). So I don't think we have to split transfers 223 * just due to this buffer size... 224 */ 225#define STRAM_BUFFER_SIZE (4096) 226/* mask for address bits that can't be used with the ST-DMA */ 227static unsigned long atari_dma_stram_mask; 228#define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0) 229/* number of bytes to cut from a transfer to handle NCR overruns */ 230static int atari_read_overruns; 231#endif 232 233static int setup_can_queue = -1; 234module_param(setup_can_queue, int, 0); 235static int setup_cmd_per_lun = -1; 236module_param(setup_cmd_per_lun, int, 0); 237static int setup_sg_tablesize = -1; 238module_param(setup_sg_tablesize, int, 0); 239#ifdef SUPPORT_TAGS 240static int setup_use_tagged_queuing = -1; 241module_param(setup_use_tagged_queuing, int, 0); 242#endif 243static int setup_hostid = -1; 244module_param(setup_hostid, int, 0); 245 246 247#if defined(REAL_DMA) 248 249static int scsi_dma_is_ignored_buserr(unsigned char dma_stat) 250{ 251 int i; 252 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr; 253 254 if (dma_stat & 0x01) { 255 256 /* A bus error happens when DMA-ing from the last page of a 257 * physical memory chunk (DMA prefetch!), but that doesn't hurt. 258 * Check for this case: 259 */ 260 261 for (i = 0; i < m68k_num_memory; ++i) { 262 end_addr = m68k_memory[i].addr + m68k_memory[i].size; 263 if (end_addr <= addr && addr <= end_addr + 4) 264 return 1; 265 } 266 } 267 return 0; 268} 269 270 271#if 0 272/* Dead code... wasn't called anyway :-) and causes some trouble, because at 273 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has 274 * to clear the DMA int pending bit before it allows other level 6 interrupts. 275 */ 276static void scsi_dma_buserr(int irq, void *dummy) 277{ 278 unsigned char dma_stat = tt_scsi_dma.dma_ctrl; 279 280 /* Don't do anything if a NCR interrupt is pending. Probably it's just 281 * masked... */ 282 if (atari_irq_pending(IRQ_TT_MFP_SCSI)) 283 return; 284 285 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n", 286 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt)); 287 if (dma_stat & 0x80) { 288 if (!scsi_dma_is_ignored_buserr(dma_stat)) 289 printk("SCSI DMA bus error -- bad DMA programming!\n"); 290 } else { 291 /* Under normal circumstances we never should get to this point, 292 * since both interrupts are triggered simultaneously and the 5380 293 * int has higher priority. When this irq is handled, that DMA 294 * interrupt is cleared. So a warning message is printed here. 295 */ 296 printk("SCSI DMA intr ?? -- this shouldn't happen!\n"); 297 } 298} 299#endif 300 301#endif 302 303 304static irqreturn_t scsi_tt_intr(int irq, void *dummy) 305{ 306#ifdef REAL_DMA 307 int dma_stat; 308 309 dma_stat = tt_scsi_dma.dma_ctrl; 310 311 dprintk(NDEBUG_INTR, "scsi%d: NCR5380 interrupt, DMA status = %02x\n", 312 atari_scsi_host->host_no, dma_stat & 0xff); 313 314 /* Look if it was the DMA that has interrupted: First possibility 315 * is that a bus error occurred... 316 */ 317 if (dma_stat & 0x80) { 318 if (!scsi_dma_is_ignored_buserr(dma_stat)) { 319 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", 320 SCSI_DMA_READ_P(dma_addr)); 321 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); 322 } 323 } 324 325 /* If the DMA is active but not finished, we have the case 326 * that some other 5380 interrupt occurred within the DMA transfer. 327 * This means we have residual bytes, if the desired end address 328 * is not yet reached. Maybe we have to fetch some bytes from the 329 * rest data register, too. The residual must be calculated from 330 * the address pointer, not the counter register, because only the 331 * addr reg counts bytes not yet written and pending in the rest 332 * data reg! 333 */ 334 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { 335 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); 336 337 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n", 338 atari_dma_residual); 339 340 if ((signed int)atari_dma_residual < 0) 341 atari_dma_residual = 0; 342 if ((dma_stat & 1) == 0) { 343 /* 344 * After read operations, we maybe have to 345 * transport some rest bytes 346 */ 347 atari_scsi_fetch_restbytes(); 348 } else { 349 /* 350 * There seems to be a nasty bug in some SCSI-DMA/NCR 351 * combinations: If a target disconnects while a write 352 * operation is going on, the address register of the 353 * DMA may be a few bytes farer than it actually read. 354 * This is probably due to DMA prefetching and a delay 355 * between DMA and NCR. Experiments showed that the 356 * dma_addr is 9 bytes to high, but this could vary. 357 * The problem is, that the residual is thus calculated 358 * wrong and the next transfer will start behind where 359 * it should. So we round up the residual to the next 360 * multiple of a sector size, if it isn't already a 361 * multiple and the originally expected transfer size 362 * was. The latter condition is there to ensure that 363 * the correction is taken only for "real" data 364 * transfers and not for, e.g., the parameters of some 365 * other command. These shouldn't disconnect anyway. 366 */ 367 if (atari_dma_residual & 0x1ff) { 368 dprintk(NDEBUG_DMA, "SCSI DMA: DMA bug corrected, " 369 "difference %ld bytes\n", 370 512 - (atari_dma_residual & 0x1ff)); 371 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; 372 } 373 } 374 tt_scsi_dma.dma_ctrl = 0; 375 } 376 377 /* If the DMA is finished, fetch the rest bytes and turn it off */ 378 if (dma_stat & 0x40) { 379 atari_dma_residual = 0; 380 if ((dma_stat & 1) == 0) 381 atari_scsi_fetch_restbytes(); 382 tt_scsi_dma.dma_ctrl = 0; 383 } 384 385#endif /* REAL_DMA */ 386 387 NCR5380_intr(irq, dummy); 388 389#if 0 390 /* To be sure the int is not masked */ 391 atari_enable_irq(IRQ_TT_MFP_SCSI); 392#endif 393 return IRQ_HANDLED; 394} 395 396 397static irqreturn_t scsi_falcon_intr(int irq, void *dummy) 398{ 399#ifdef REAL_DMA 400 int dma_stat; 401 402 /* Turn off DMA and select sector counter register before 403 * accessing the status register (Atari recommendation!) 404 */ 405 st_dma.dma_mode_status = 0x90; 406 dma_stat = st_dma.dma_mode_status; 407 408 /* Bit 0 indicates some error in the DMA process... don't know 409 * what happened exactly (no further docu). 410 */ 411 if (!(dma_stat & 0x01)) { 412 /* DMA error */ 413 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); 414 } 415 416 /* If the DMA was active, but now bit 1 is not clear, it is some 417 * other 5380 interrupt that finishes the DMA transfer. We have to 418 * calculate the number of residual bytes and give a warning if 419 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) 420 */ 421 if (atari_dma_active && (dma_stat & 0x02)) { 422 unsigned long transferred; 423 424 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; 425 /* The ST-DMA address is incremented in 2-byte steps, but the 426 * data are written only in 16-byte chunks. If the number of 427 * transferred bytes is not divisible by 16, the remainder is 428 * lost somewhere in outer space. 429 */ 430 if (transferred & 15) 431 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " 432 "ST-DMA fifo\n", transferred & 15); 433 434 atari_dma_residual = HOSTDATA_DMALEN - transferred; 435 dprintk(NDEBUG_DMA, "SCSI DMA: There are %ld residual bytes.\n", 436 atari_dma_residual); 437 } else 438 atari_dma_residual = 0; 439 atari_dma_active = 0; 440 441 if (atari_dma_orig_addr) { 442 /* If the dribble buffer was used on a read operation, copy the DMA-ed 443 * data to the original destination address. 444 */ 445 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), 446 HOSTDATA_DMALEN - atari_dma_residual); 447 atari_dma_orig_addr = NULL; 448 } 449 450#endif /* REAL_DMA */ 451 452 NCR5380_intr(irq, dummy); 453 return IRQ_HANDLED; 454} 455 456 457#ifdef REAL_DMA 458static void atari_scsi_fetch_restbytes(void) 459{ 460 int nr; 461 char *src, *dst; 462 unsigned long phys_dst; 463 464 /* fetch rest bytes in the DMA register */ 465 phys_dst = SCSI_DMA_READ_P(dma_addr); 466 nr = phys_dst & 3; 467 if (nr) { 468 /* there are 'nr' bytes left for the last long address 469 before the DMA pointer */ 470 phys_dst ^= nr; 471 dprintk(NDEBUG_DMA, "SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", 472 nr, phys_dst); 473 /* The content of the DMA pointer is a physical address! */ 474 dst = phys_to_virt(phys_dst); 475 dprintk(NDEBUG_DMA, " = virt addr %p\n", dst); 476 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) 477 *dst++ = *src++; 478 } 479} 480#endif /* REAL_DMA */ 481 482 483static int falcon_got_lock = 0; 484static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); 485static int falcon_trying_lock = 0; 486static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); 487static int falcon_dont_release = 0; 488 489/* This function releases the lock on the DMA chip if there is no 490 * connected command and the disconnected queue is empty. On 491 * releasing, instances of falcon_get_lock are awoken, that put 492 * themselves to sleep for fairness. They can now try to get the lock 493 * again (but others waiting longer more probably will win). 494 */ 495 496static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata) 497{ 498 unsigned long flags; 499 500 if (IS_A_TT()) 501 return; 502 503 local_irq_save(flags); 504 505 if (falcon_got_lock && !hostdata->disconnected_queue && 506 !hostdata->issue_queue && !hostdata->connected) { 507 508 if (falcon_dont_release) { 509#if 0 510 printk("WARNING: Lock release not allowed. Ignored\n"); 511#endif 512 local_irq_restore(flags); 513 return; 514 } 515 falcon_got_lock = 0; 516 stdma_release(); 517 wake_up(&falcon_fairness_wait); 518 } 519 520 local_irq_restore(flags); 521} 522 523/* This function manages the locking of the ST-DMA. 524 * If the DMA isn't locked already for SCSI, it tries to lock it by 525 * calling stdma_lock(). But if the DMA is locked by the SCSI code and 526 * there are other drivers waiting for the chip, we do not issue the 527 * command immediately but wait on 'falcon_fairness_queue'. We will be 528 * waked up when the DMA is unlocked by some SCSI interrupt. After that 529 * we try to get the lock again. 530 * But we must be prepared that more than one instance of 531 * falcon_get_lock() is waiting on the fairness queue. They should not 532 * try all at once to call stdma_lock(), one is enough! For that, the 533 * first one sets 'falcon_trying_lock', others that see that variable 534 * set wait on the queue 'falcon_try_wait'. 535 * Complicated, complicated.... Sigh... 536 */ 537 538static void falcon_get_lock(void) 539{ 540 unsigned long flags; 541 542 if (IS_A_TT()) 543 return; 544 545 local_irq_save(flags); 546 547 wait_event_cmd(falcon_fairness_wait, 548 in_interrupt() || !falcon_got_lock || !stdma_others_waiting(), 549 local_irq_restore(flags), 550 local_irq_save(flags)); 551 552 while (!falcon_got_lock) { 553 if (in_irq()) 554 panic("Falcon SCSI hasn't ST-DMA lock in interrupt"); 555 if (!falcon_trying_lock) { 556 falcon_trying_lock = 1; 557 stdma_lock(scsi_falcon_intr, NULL); 558 falcon_got_lock = 1; 559 falcon_trying_lock = 0; 560 wake_up(&falcon_try_wait); 561 } else { 562 wait_event_cmd(falcon_try_wait, 563 falcon_got_lock && !falcon_trying_lock, 564 local_irq_restore(flags), 565 local_irq_save(flags)); 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 575static int __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 = atari_stram_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 727static int 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} 736 737#ifndef MODULE 738static int __init atari_scsi_setup(char *str) 739{ 740 /* Format of atascsi parameter is: 741 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 742 * Defaults depend on TT or Falcon, hostid determined at run time. 743 * Negative values mean don't change. 744 */ 745 int ints[6]; 746 747 get_options(str, ARRAY_SIZE(ints), ints); 748 749 if (ints[0] < 1) { 750 printk("atari_scsi_setup: no arguments!\n"); 751 return 0; 752 } 753 754 if (ints[0] >= 1) { 755 if (ints[1] > 0) 756 /* no limits on this, just > 0 */ 757 setup_can_queue = ints[1]; 758 } 759 if (ints[0] >= 2) { 760 if (ints[2] > 0) 761 setup_cmd_per_lun = ints[2]; 762 } 763 if (ints[0] >= 3) { 764 if (ints[3] >= 0) { 765 setup_sg_tablesize = ints[3]; 766 /* Must be <= SG_ALL (255) */ 767 if (setup_sg_tablesize > SG_ALL) 768 setup_sg_tablesize = SG_ALL; 769 } 770 } 771 if (ints[0] >= 4) { 772 /* Must be between 0 and 7 */ 773 if (ints[4] >= 0 && ints[4] <= 7) 774 setup_hostid = ints[4]; 775 else if (ints[4] > 7) 776 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]); 777 } 778#ifdef SUPPORT_TAGS 779 if (ints[0] >= 5) { 780 if (ints[5] >= 0) 781 setup_use_tagged_queuing = !!ints[5]; 782 } 783#endif 784 785 return 1; 786} 787 788__setup("atascsi=", atari_scsi_setup); 789#endif /* !MODULE */ 790 791static int atari_scsi_bus_reset(Scsi_Cmnd *cmd) 792{ 793 int rv; 794 struct NCR5380_hostdata *hostdata = 795 (struct NCR5380_hostdata *)cmd->device->host->hostdata; 796 797 /* For doing the reset, SCSI interrupts must be disabled first, 798 * since the 5380 raises its IRQ line while _RST is active and we 799 * can't disable interrupts completely, since we need the timer. 800 */ 801 /* And abort a maybe active DMA transfer */ 802 if (IS_A_TT()) { 803 atari_turnoff_irq(IRQ_TT_MFP_SCSI); 804#ifdef REAL_DMA 805 tt_scsi_dma.dma_ctrl = 0; 806#endif /* REAL_DMA */ 807 } else { 808 atari_turnoff_irq(IRQ_MFP_FSCSI); 809#ifdef REAL_DMA 810 st_dma.dma_mode_status = 0x90; 811 atari_dma_active = 0; 812 atari_dma_orig_addr = NULL; 813#endif /* REAL_DMA */ 814 } 815 816 rv = NCR5380_bus_reset(cmd); 817 818 /* Re-enable ints */ 819 if (IS_A_TT()) { 820 atari_turnon_irq(IRQ_TT_MFP_SCSI); 821 } else { 822 atari_turnon_irq(IRQ_MFP_FSCSI); 823 } 824 if (rv == SUCCESS) 825 falcon_release_lock_if_possible(hostdata); 826 827 return rv; 828} 829 830 831#ifdef CONFIG_ATARI_SCSI_RESET_BOOT 832static void __init atari_scsi_reset_boot(void) 833{ 834 unsigned long end; 835 836 /* 837 * Do a SCSI reset to clean up the bus during initialization. No messing 838 * with the queues, interrupts, or locks necessary here. 839 */ 840 841 printk("Atari SCSI: resetting the SCSI bus..."); 842 843 /* get in phase */ 844 NCR5380_write(TARGET_COMMAND_REG, 845 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG))); 846 847 /* assert RST */ 848 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); 849 /* The min. reset hold time is 25us, so 40us should be enough */ 850 udelay(50); 851 /* reset RST and interrupt */ 852 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); 853 NCR5380_read(RESET_PARITY_INTERRUPT_REG); 854 855 end = jiffies + AFTER_RESET_DELAY; 856 while (time_before(jiffies, end)) 857 barrier(); 858 859 printk(" done\n"); 860} 861#endif 862 863 864static const char *atari_scsi_info(struct Scsi_Host *host) 865{ 866 /* atari_scsi_detect() is verbose enough... */ 867 static const char string[] = "Atari native SCSI"; 868 return string; 869} 870 871 872#if defined(REAL_DMA) 873 874static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, 875 void *data, unsigned long count, 876 int dir) 877{ 878 unsigned long addr = virt_to_phys(data); 879 880 dprintk(NDEBUG_DMA, "scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " 881 "dir = %d\n", instance->host_no, data, addr, count, dir); 882 883 if (!IS_A_TT() && !STRAM_ADDR(addr)) { 884 /* If we have a non-DMAable address on a Falcon, use the dribble 885 * buffer; 'orig_addr' != 0 in the read case tells the interrupt 886 * handler to copy data from the dribble buffer to the originally 887 * wanted address. 888 */ 889 if (dir) 890 memcpy(atari_dma_buffer, data, count); 891 else 892 atari_dma_orig_addr = data; 893 addr = atari_dma_phys_buffer; 894 } 895 896 atari_dma_startaddr = addr; /* Needed for calculating residual later. */ 897 898 /* Cache cleanup stuff: On writes, push any dirty cache out before sending 899 * it to the peripheral. (Must be done before DMA setup, since at least 900 * the ST-DMA begins to fill internal buffers right after setup. For 901 * reads, invalidate any cache, may be altered after DMA without CPU 902 * knowledge. 903 * 904 * ++roman: For the Medusa, there's no need at all for that cache stuff, 905 * because the hardware does bus snooping (fine!). 906 */ 907 dma_cache_maintenance(addr, count, dir); 908 909 if (count == 0) 910 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); 911 912 if (IS_A_TT()) { 913 tt_scsi_dma.dma_ctrl = dir; 914 SCSI_DMA_WRITE_P(dma_addr, addr); 915 SCSI_DMA_WRITE_P(dma_cnt, count); 916 tt_scsi_dma.dma_ctrl = dir | 2; 917 } else { /* ! IS_A_TT */ 918 919 /* set address */ 920 SCSI_DMA_SETADR(addr); 921 922 /* toggle direction bit to clear FIFO and set DMA direction */ 923 dir <<= 8; 924 st_dma.dma_mode_status = 0x90 | dir; 925 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); 926 st_dma.dma_mode_status = 0x90 | dir; 927 udelay(40); 928 /* On writes, round up the transfer length to the next multiple of 512 929 * (see also comment at atari_dma_xfer_len()). */ 930 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; 931 udelay(40); 932 st_dma.dma_mode_status = 0x10 | dir; 933 udelay(40); 934 /* need not restore value of dir, only boolean value is tested */ 935 atari_dma_active = 1; 936 } 937 938 return count; 939} 940 941 942static long atari_scsi_dma_residual(struct Scsi_Host *instance) 943{ 944 return atari_dma_residual; 945} 946 947 948#define CMD_SURELY_BLOCK_MODE 0 949#define CMD_SURELY_BYTE_MODE 1 950#define CMD_MODE_UNKNOWN 2 951 952static int falcon_classify_cmd(Scsi_Cmnd *cmd) 953{ 954 unsigned char opcode = cmd->cmnd[0]; 955 956 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || 957 opcode == READ_BUFFER) 958 return CMD_SURELY_BYTE_MODE; 959 else if (opcode == READ_6 || opcode == READ_10 || 960 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || 961 opcode == RECOVER_BUFFERED_DATA) { 962 /* In case of a sequential-access target (tape), special care is 963 * needed here: The transfer is block-mode only if the 'fixed' bit is 964 * set! */ 965 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) 966 return CMD_SURELY_BYTE_MODE; 967 else 968 return CMD_SURELY_BLOCK_MODE; 969 } else 970 return CMD_MODE_UNKNOWN; 971} 972 973 974/* This function calculates the number of bytes that can be transferred via 975 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the 976 * ST-DMA chip. There are only multiples of 512 bytes possible and max. 977 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not 978 * possible on the Falcon, since that would require to program the DMA for 979 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have 980 * the overrun problem, so this question is academic :-) 981 */ 982 983static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 984 Scsi_Cmnd *cmd, int write_flag) 985{ 986 unsigned long possible_len, limit; 987 988 if (IS_A_TT()) 989 /* TT SCSI DMA can transfer arbitrary #bytes */ 990 return wanted_len; 991 992 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. 993 * 255*512 bytes, but this should be enough) 994 * 995 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands 996 * that return a number of bytes which cannot be known beforehand. In this 997 * case, the given transfer length is an "allocation length". Now it 998 * can happen that this allocation length is a multiple of 512 bytes and 999 * the DMA is used. But if not n*512 bytes really arrive, some input data 1000 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish 1001 * between commands that do block transfers and those that do byte 1002 * transfers. But this isn't easy... there are lots of vendor specific 1003 * commands, and the user can issue any command via the 1004 * SCSI_IOCTL_SEND_COMMAND. 1005 * 1006 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, 1007 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) 1008 * and 3), the thing to do is obvious: allow any number of blocks via DMA 1009 * or none. In case 2), we apply some heuristic: Byte mode is assumed if 1010 * the transfer (allocation) length is < 1024, hoping that no cmd. not 1011 * explicitly known as byte mode have such big allocation lengths... 1012 * BTW, all the discussion above applies only to reads. DMA writes are 1013 * unproblematic anyways, since the targets aborts the transfer after 1014 * receiving a sufficient number of bytes. 1015 * 1016 * Another point: If the transfer is from/to an non-ST-RAM address, we 1017 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. 1018 */ 1019 1020 if (write_flag) { 1021 /* Write operation can always use the DMA, but the transfer size must 1022 * be rounded up to the next multiple of 512 (atari_dma_setup() does 1023 * this). 1024 */ 1025 possible_len = wanted_len; 1026 } else { 1027 /* Read operations: if the wanted transfer length is not a multiple of 1028 * 512, we cannot use DMA, since the ST-DMA cannot split transfers 1029 * (no interrupt on DMA finished!) 1030 */ 1031 if (wanted_len & 0x1ff) 1032 possible_len = 0; 1033 else { 1034 /* Now classify the command (see above) and decide whether it is 1035 * allowed to do DMA at all */ 1036 switch (falcon_classify_cmd(cmd)) { 1037 case CMD_SURELY_BLOCK_MODE: 1038 possible_len = wanted_len; 1039 break; 1040 case CMD_SURELY_BYTE_MODE: 1041 possible_len = 0; /* DMA prohibited */ 1042 break; 1043 case CMD_MODE_UNKNOWN: 1044 default: 1045 /* For unknown commands assume block transfers if the transfer 1046 * size/allocation length is >= 1024 */ 1047 possible_len = (wanted_len < 1024) ? 0 : wanted_len; 1048 break; 1049 } 1050 } 1051 } 1052 1053 /* Last step: apply the hard limit on DMA transfers */ 1054 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ? 1055 STRAM_BUFFER_SIZE : 255*512; 1056 if (possible_len > limit) 1057 possible_len = limit; 1058 1059 if (possible_len != wanted_len) 1060 dprintk(NDEBUG_DMA, "Sorry, must cut DMA transfer size to %ld bytes " 1061 "instead of %ld\n", possible_len, wanted_len); 1062 1063 return possible_len; 1064} 1065 1066 1067#endif /* REAL_DMA */ 1068 1069 1070/* NCR5380 register access functions 1071 * 1072 * There are separate functions for TT and Falcon, because the access 1073 * methods are quite different. The calling macros NCR5380_read and 1074 * NCR5380_write call these functions via function pointers. 1075 */ 1076 1077static unsigned char atari_scsi_tt_reg_read(unsigned char reg) 1078{ 1079 return tt_scsi_regp[reg * 2]; 1080} 1081 1082static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value) 1083{ 1084 tt_scsi_regp[reg * 2] = value; 1085} 1086 1087static unsigned char atari_scsi_falcon_reg_read(unsigned char reg) 1088{ 1089 dma_wd.dma_mode_status= (u_short)(0x88 + reg); 1090 return (u_char)dma_wd.fdc_acces_seccount; 1091} 1092 1093static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value) 1094{ 1095 dma_wd.dma_mode_status = (u_short)(0x88 + reg); 1096 dma_wd.fdc_acces_seccount = (u_short)value; 1097} 1098 1099 1100#include "atari_NCR5380.c" 1101 1102static struct scsi_host_template driver_template = { 1103 .show_info = atari_scsi_show_info, 1104 .name = "Atari native SCSI", 1105 .detect = atari_scsi_detect, 1106 .release = atari_scsi_release, 1107 .info = atari_scsi_info, 1108 .queuecommand = atari_scsi_queue_command, 1109 .eh_abort_handler = atari_scsi_abort, 1110 .eh_bus_reset_handler = atari_scsi_bus_reset, 1111 .can_queue = 0, /* initialized at run-time */ 1112 .this_id = 0, /* initialized at run-time */ 1113 .sg_tablesize = 0, /* initialized at run-time */ 1114 .cmd_per_lun = 0, /* initialized at run-time */ 1115 .use_clustering = DISABLE_CLUSTERING 1116}; 1117 1118 1119#include "scsi_module.c" 1120 1121MODULE_LICENSE("GPL"); 1122