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 #include <linux/wait.h> 94 95 #include <asm/setup.h> 96 #include <asm/atarihw.h> 97 #include <asm/atariints.h> 98 #include <asm/page.h> 99 #include <asm/pgtable.h> 100 #include <asm/irq.h> 101 #include <asm/traps.h> 102 103 #include "scsi.h" 104 #include <scsi/scsi_host.h> 105 #include "atari_scsi.h" 106 #include "NCR5380.h" 107 #include <asm/atari_stdma.h> 108 #include <asm/atari_stram.h> 109 #include <asm/io.h> 110 111 #include <linux/stat.h> 112 113 #define IS_A_TT() ATARIHW_PRESENT(TT_SCSI) 114 115 #define SCSI_DMA_WRITE_P(elt,val) \ 116 do { \ 117 unsigned long v = val; \ 118 tt_scsi_dma.elt##_lo = v & 0xff; \ 119 v >>= 8; \ 120 tt_scsi_dma.elt##_lmd = v & 0xff; \ 121 v >>= 8; \ 122 tt_scsi_dma.elt##_hmd = v & 0xff; \ 123 v >>= 8; \ 124 tt_scsi_dma.elt##_hi = v & 0xff; \ 125 } while(0) 126 127 #define SCSI_DMA_READ_P(elt) \ 128 (((((((unsigned long)tt_scsi_dma.elt##_hi << 8) | \ 129 (unsigned long)tt_scsi_dma.elt##_hmd) << 8) | \ 130 (unsigned long)tt_scsi_dma.elt##_lmd) << 8) | \ 131 (unsigned long)tt_scsi_dma.elt##_lo) 132 133 134 static inline void SCSI_DMA_SETADR(unsigned long adr) 135 { 136 st_dma.dma_lo = (unsigned char)adr; 137 MFPDELAY(); 138 adr >>= 8; 139 st_dma.dma_md = (unsigned char)adr; 140 MFPDELAY(); 141 adr >>= 8; 142 st_dma.dma_hi = (unsigned char)adr; 143 MFPDELAY(); 144 } 145 146 static inline unsigned long SCSI_DMA_GETADR(void) 147 { 148 unsigned long adr; 149 adr = st_dma.dma_lo; 150 MFPDELAY(); 151 adr |= (st_dma.dma_md & 0xff) << 8; 152 MFPDELAY(); 153 adr |= (st_dma.dma_hi & 0xff) << 16; 154 MFPDELAY(); 155 return adr; 156 } 157 158 static inline void ENABLE_IRQ(void) 159 { 160 if (IS_A_TT()) 161 atari_enable_irq(IRQ_TT_MFP_SCSI); 162 else 163 atari_enable_irq(IRQ_MFP_FSCSI); 164 } 165 166 static inline void DISABLE_IRQ(void) 167 { 168 if (IS_A_TT()) 169 atari_disable_irq(IRQ_TT_MFP_SCSI); 170 else 171 atari_disable_irq(IRQ_MFP_FSCSI); 172 } 173 174 175 #define HOSTDATA_DMALEN (((struct NCR5380_hostdata *) \ 176 (atari_scsi_host->hostdata))->dma_len) 177 178 /* Time (in jiffies) to wait after a reset; the SCSI standard calls for 250ms, 179 * we usually do 0.5s to be on the safe side. But Toshiba CD-ROMs once more 180 * need ten times the standard value... */ 181 #ifndef CONFIG_ATARI_SCSI_TOSHIBA_DELAY 182 #define AFTER_RESET_DELAY (HZ/2) 183 #else 184 #define AFTER_RESET_DELAY (5*HZ/2) 185 #endif 186 187 /***************************** Prototypes *****************************/ 188 189 #ifdef REAL_DMA 190 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat); 191 static void atari_scsi_fetch_restbytes(void); 192 static long atari_scsi_dma_residual(struct Scsi_Host *instance); 193 static int falcon_classify_cmd(Scsi_Cmnd *cmd); 194 static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 195 Scsi_Cmnd *cmd, int write_flag); 196 #endif 197 static irqreturn_t scsi_tt_intr(int irq, void *dummy); 198 static irqreturn_t scsi_falcon_intr(int irq, void *dummy); 199 static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata); 200 static void falcon_get_lock(void); 201 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT 202 static void atari_scsi_reset_boot(void); 203 #endif 204 static unsigned char atari_scsi_tt_reg_read(unsigned char reg); 205 static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value); 206 static unsigned char atari_scsi_falcon_reg_read(unsigned char reg); 207 static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value); 208 209 /************************* End of Prototypes **************************/ 210 211 212 static struct Scsi_Host *atari_scsi_host; 213 static unsigned char (*atari_scsi_reg_read)(unsigned char reg); 214 static void (*atari_scsi_reg_write)(unsigned char reg, unsigned char value); 215 216 #ifdef REAL_DMA 217 static unsigned long atari_dma_residual, atari_dma_startaddr; 218 static short atari_dma_active; 219 /* pointer to the dribble buffer */ 220 static char *atari_dma_buffer; 221 /* precalculated physical address of the dribble buffer */ 222 static unsigned long atari_dma_phys_buffer; 223 /* != 0 tells the Falcon int handler to copy data from the dribble buffer */ 224 static char *atari_dma_orig_addr; 225 /* size of the dribble buffer; 4k seems enough, since the Falcon cannot use 226 * scatter-gather anyway, so most transfers are 1024 byte only. In the rare 227 * cases where requests to physical contiguous buffers have been merged, this 228 * request is <= 4k (one page). So I don't think we have to split transfers 229 * just due to this buffer size... 230 */ 231 #define STRAM_BUFFER_SIZE (4096) 232 /* mask for address bits that can't be used with the ST-DMA */ 233 static unsigned long atari_dma_stram_mask; 234 #define STRAM_ADDR(a) (((a) & atari_dma_stram_mask) == 0) 235 /* number of bytes to cut from a transfer to handle NCR overruns */ 236 static int atari_read_overruns; 237 #endif 238 239 static int setup_can_queue = -1; 240 module_param(setup_can_queue, int, 0); 241 static int setup_cmd_per_lun = -1; 242 module_param(setup_cmd_per_lun, int, 0); 243 static int setup_sg_tablesize = -1; 244 module_param(setup_sg_tablesize, int, 0); 245 #ifdef SUPPORT_TAGS 246 static int setup_use_tagged_queuing = -1; 247 module_param(setup_use_tagged_queuing, int, 0); 248 #endif 249 static int setup_hostid = -1; 250 module_param(setup_hostid, int, 0); 251 252 253 #if defined(REAL_DMA) 254 255 static int scsi_dma_is_ignored_buserr(unsigned char dma_stat) 256 { 257 int i; 258 unsigned long addr = SCSI_DMA_READ_P(dma_addr), end_addr; 259 260 if (dma_stat & 0x01) { 261 262 /* A bus error happens when DMA-ing from the last page of a 263 * physical memory chunk (DMA prefetch!), but that doesn't hurt. 264 * Check for this case: 265 */ 266 267 for (i = 0; i < m68k_num_memory; ++i) { 268 end_addr = m68k_memory[i].addr + m68k_memory[i].size; 269 if (end_addr <= addr && addr <= end_addr + 4) 270 return 1; 271 } 272 } 273 return 0; 274 } 275 276 277 #if 0 278 /* Dead code... wasn't called anyway :-) and causes some trouble, because at 279 * end-of-DMA, both SCSI ints are triggered simultaneously, so the NCR int has 280 * to clear the DMA int pending bit before it allows other level 6 interrupts. 281 */ 282 static void scsi_dma_buserr(int irq, void *dummy) 283 { 284 unsigned char dma_stat = tt_scsi_dma.dma_ctrl; 285 286 /* Don't do anything if a NCR interrupt is pending. Probably it's just 287 * masked... */ 288 if (atari_irq_pending(IRQ_TT_MFP_SCSI)) 289 return; 290 291 printk("Bad SCSI DMA interrupt! dma_addr=0x%08lx dma_stat=%02x dma_cnt=%08lx\n", 292 SCSI_DMA_READ_P(dma_addr), dma_stat, SCSI_DMA_READ_P(dma_cnt)); 293 if (dma_stat & 0x80) { 294 if (!scsi_dma_is_ignored_buserr(dma_stat)) 295 printk("SCSI DMA bus error -- bad DMA programming!\n"); 296 } else { 297 /* Under normal circumstances we never should get to this point, 298 * since both interrupts are triggered simultaneously and the 5380 299 * int has higher priority. When this irq is handled, that DMA 300 * interrupt is cleared. So a warning message is printed here. 301 */ 302 printk("SCSI DMA intr ?? -- this shouldn't happen!\n"); 303 } 304 } 305 #endif 306 307 #endif 308 309 310 static irqreturn_t scsi_tt_intr(int irq, void *dummy) 311 { 312 #ifdef REAL_DMA 313 int dma_stat; 314 315 dma_stat = tt_scsi_dma.dma_ctrl; 316 317 INT_PRINTK("scsi%d: NCR5380 interrupt, DMA status = %02x\n", 318 atari_scsi_host->host_no, dma_stat & 0xff); 319 320 /* Look if it was the DMA that has interrupted: First possibility 321 * is that a bus error occurred... 322 */ 323 if (dma_stat & 0x80) { 324 if (!scsi_dma_is_ignored_buserr(dma_stat)) { 325 printk(KERN_ERR "SCSI DMA caused bus error near 0x%08lx\n", 326 SCSI_DMA_READ_P(dma_addr)); 327 printk(KERN_CRIT "SCSI DMA bus error -- bad DMA programming!"); 328 } 329 } 330 331 /* If the DMA is active but not finished, we have the case 332 * that some other 5380 interrupt occurred within the DMA transfer. 333 * This means we have residual bytes, if the desired end address 334 * is not yet reached. Maybe we have to fetch some bytes from the 335 * rest data register, too. The residual must be calculated from 336 * the address pointer, not the counter register, because only the 337 * addr reg counts bytes not yet written and pending in the rest 338 * data reg! 339 */ 340 if ((dma_stat & 0x02) && !(dma_stat & 0x40)) { 341 atari_dma_residual = HOSTDATA_DMALEN - (SCSI_DMA_READ_P(dma_addr) - atari_dma_startaddr); 342 343 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 344 atari_dma_residual); 345 346 if ((signed int)atari_dma_residual < 0) 347 atari_dma_residual = 0; 348 if ((dma_stat & 1) == 0) { 349 /* 350 * After read operations, we maybe have to 351 * transport some rest bytes 352 */ 353 atari_scsi_fetch_restbytes(); 354 } else { 355 /* 356 * There seems to be a nasty bug in some SCSI-DMA/NCR 357 * combinations: If a target disconnects while a write 358 * operation is going on, the address register of the 359 * DMA may be a few bytes farer than it actually read. 360 * This is probably due to DMA prefetching and a delay 361 * between DMA and NCR. Experiments showed that the 362 * dma_addr is 9 bytes to high, but this could vary. 363 * The problem is, that the residual is thus calculated 364 * wrong and the next transfer will start behind where 365 * it should. So we round up the residual to the next 366 * multiple of a sector size, if it isn't already a 367 * multiple and the originally expected transfer size 368 * was. The latter condition is there to ensure that 369 * the correction is taken only for "real" data 370 * transfers and not for, e.g., the parameters of some 371 * other command. These shouldn't disconnect anyway. 372 */ 373 if (atari_dma_residual & 0x1ff) { 374 DMA_PRINTK("SCSI DMA: DMA bug corrected, " 375 "difference %ld bytes\n", 376 512 - (atari_dma_residual & 0x1ff)); 377 atari_dma_residual = (atari_dma_residual + 511) & ~0x1ff; 378 } 379 } 380 tt_scsi_dma.dma_ctrl = 0; 381 } 382 383 /* If the DMA is finished, fetch the rest bytes and turn it off */ 384 if (dma_stat & 0x40) { 385 atari_dma_residual = 0; 386 if ((dma_stat & 1) == 0) 387 atari_scsi_fetch_restbytes(); 388 tt_scsi_dma.dma_ctrl = 0; 389 } 390 391 #endif /* REAL_DMA */ 392 393 NCR5380_intr(irq, dummy); 394 395 #if 0 396 /* To be sure the int is not masked */ 397 atari_enable_irq(IRQ_TT_MFP_SCSI); 398 #endif 399 return IRQ_HANDLED; 400 } 401 402 403 static irqreturn_t scsi_falcon_intr(int irq, void *dummy) 404 { 405 #ifdef REAL_DMA 406 int dma_stat; 407 408 /* Turn off DMA and select sector counter register before 409 * accessing the status register (Atari recommendation!) 410 */ 411 st_dma.dma_mode_status = 0x90; 412 dma_stat = st_dma.dma_mode_status; 413 414 /* Bit 0 indicates some error in the DMA process... don't know 415 * what happened exactly (no further docu). 416 */ 417 if (!(dma_stat & 0x01)) { 418 /* DMA error */ 419 printk(KERN_CRIT "SCSI DMA error near 0x%08lx!\n", SCSI_DMA_GETADR()); 420 } 421 422 /* If the DMA was active, but now bit 1 is not clear, it is some 423 * other 5380 interrupt that finishes the DMA transfer. We have to 424 * calculate the number of residual bytes and give a warning if 425 * bytes are stuck in the ST-DMA fifo (there's no way to reach them!) 426 */ 427 if (atari_dma_active && (dma_stat & 0x02)) { 428 unsigned long transferred; 429 430 transferred = SCSI_DMA_GETADR() - atari_dma_startaddr; 431 /* The ST-DMA address is incremented in 2-byte steps, but the 432 * data are written only in 16-byte chunks. If the number of 433 * transferred bytes is not divisible by 16, the remainder is 434 * lost somewhere in outer space. 435 */ 436 if (transferred & 15) 437 printk(KERN_ERR "SCSI DMA error: %ld bytes lost in " 438 "ST-DMA fifo\n", transferred & 15); 439 440 atari_dma_residual = HOSTDATA_DMALEN - transferred; 441 DMA_PRINTK("SCSI DMA: There are %ld residual bytes.\n", 442 atari_dma_residual); 443 } else 444 atari_dma_residual = 0; 445 atari_dma_active = 0; 446 447 if (atari_dma_orig_addr) { 448 /* If the dribble buffer was used on a read operation, copy the DMA-ed 449 * data to the original destination address. 450 */ 451 memcpy(atari_dma_orig_addr, phys_to_virt(atari_dma_startaddr), 452 HOSTDATA_DMALEN - atari_dma_residual); 453 atari_dma_orig_addr = NULL; 454 } 455 456 #endif /* REAL_DMA */ 457 458 NCR5380_intr(irq, dummy); 459 return IRQ_HANDLED; 460 } 461 462 463 #ifdef REAL_DMA 464 static void atari_scsi_fetch_restbytes(void) 465 { 466 int nr; 467 char *src, *dst; 468 unsigned long phys_dst; 469 470 /* fetch rest bytes in the DMA register */ 471 phys_dst = SCSI_DMA_READ_P(dma_addr); 472 nr = phys_dst & 3; 473 if (nr) { 474 /* there are 'nr' bytes left for the last long address 475 before the DMA pointer */ 476 phys_dst ^= nr; 477 DMA_PRINTK("SCSI DMA: there are %d rest bytes for phys addr 0x%08lx", 478 nr, phys_dst); 479 /* The content of the DMA pointer is a physical address! */ 480 dst = phys_to_virt(phys_dst); 481 DMA_PRINTK(" = virt addr %p\n", dst); 482 for (src = (char *)&tt_scsi_dma.dma_restdata; nr != 0; --nr) 483 *dst++ = *src++; 484 } 485 } 486 #endif /* REAL_DMA */ 487 488 489 static int falcon_got_lock = 0; 490 static DECLARE_WAIT_QUEUE_HEAD(falcon_fairness_wait); 491 static int falcon_trying_lock = 0; 492 static DECLARE_WAIT_QUEUE_HEAD(falcon_try_wait); 493 static int falcon_dont_release = 0; 494 495 /* This function releases the lock on the DMA chip if there is no 496 * connected command and the disconnected queue is empty. On 497 * releasing, instances of falcon_get_lock are awoken, that put 498 * themselves to sleep for fairness. They can now try to get the lock 499 * again (but others waiting longer more probably will win). 500 */ 501 502 static void falcon_release_lock_if_possible(struct NCR5380_hostdata *hostdata) 503 { 504 unsigned long flags; 505 506 if (IS_A_TT()) 507 return; 508 509 local_irq_save(flags); 510 511 if (falcon_got_lock && !hostdata->disconnected_queue && 512 !hostdata->issue_queue && !hostdata->connected) { 513 514 if (falcon_dont_release) { 515 #if 0 516 printk("WARNING: Lock release not allowed. Ignored\n"); 517 #endif 518 local_irq_restore(flags); 519 return; 520 } 521 falcon_got_lock = 0; 522 stdma_release(); 523 wake_up(&falcon_fairness_wait); 524 } 525 526 local_irq_restore(flags); 527 } 528 529 /* This function manages the locking of the ST-DMA. 530 * If the DMA isn't locked already for SCSI, it tries to lock it by 531 * calling stdma_lock(). But if the DMA is locked by the SCSI code and 532 * there are other drivers waiting for the chip, we do not issue the 533 * command immediately but wait on 'falcon_fairness_queue'. We will be 534 * waked up when the DMA is unlocked by some SCSI interrupt. After that 535 * we try to get the lock again. 536 * But we must be prepared that more than one instance of 537 * falcon_get_lock() is waiting on the fairness queue. They should not 538 * try all at once to call stdma_lock(), one is enough! For that, the 539 * first one sets 'falcon_trying_lock', others that see that variable 540 * set wait on the queue 'falcon_try_wait'. 541 * Complicated, complicated.... Sigh... 542 */ 543 544 static void falcon_get_lock(void) 545 { 546 unsigned long flags; 547 548 if (IS_A_TT()) 549 return; 550 551 local_irq_save(flags); 552 553 wait_event_cmd(falcon_fairness_wait, 554 in_interrupt() || !falcon_got_lock || !stdma_others_waiting(), 555 local_irq_restore(flags), 556 local_irq_save(flags)); 557 558 while (!falcon_got_lock) { 559 if (in_irq()) 560 panic("Falcon SCSI hasn't ST-DMA lock in interrupt"); 561 if (!falcon_trying_lock) { 562 falcon_trying_lock = 1; 563 stdma_lock(scsi_falcon_intr, NULL); 564 falcon_got_lock = 1; 565 falcon_trying_lock = 0; 566 wake_up(&falcon_try_wait); 567 } else { 568 wait_event_cmd(falcon_try_wait, 569 falcon_got_lock && !falcon_trying_lock, 570 local_irq_restore(flags), 571 local_irq_save(flags)); 572 } 573 } 574 575 local_irq_restore(flags); 576 if (!falcon_got_lock) 577 panic("Falcon SCSI: someone stole the lock :-(\n"); 578 } 579 580 581 static int __init atari_scsi_detect(struct scsi_host_template *host) 582 { 583 static int called = 0; 584 struct Scsi_Host *instance; 585 586 if (!MACH_IS_ATARI || 587 (!ATARIHW_PRESENT(ST_SCSI) && !ATARIHW_PRESENT(TT_SCSI)) || 588 called) 589 return 0; 590 591 host->proc_name = "Atari"; 592 593 atari_scsi_reg_read = IS_A_TT() ? atari_scsi_tt_reg_read : 594 atari_scsi_falcon_reg_read; 595 atari_scsi_reg_write = IS_A_TT() ? atari_scsi_tt_reg_write : 596 atari_scsi_falcon_reg_write; 597 598 /* setup variables */ 599 host->can_queue = 600 (setup_can_queue > 0) ? setup_can_queue : 601 IS_A_TT() ? ATARI_TT_CAN_QUEUE : ATARI_FALCON_CAN_QUEUE; 602 host->cmd_per_lun = 603 (setup_cmd_per_lun > 0) ? setup_cmd_per_lun : 604 IS_A_TT() ? ATARI_TT_CMD_PER_LUN : ATARI_FALCON_CMD_PER_LUN; 605 /* Force sg_tablesize to 0 on a Falcon! */ 606 host->sg_tablesize = 607 !IS_A_TT() ? ATARI_FALCON_SG_TABLESIZE : 608 (setup_sg_tablesize >= 0) ? setup_sg_tablesize : ATARI_TT_SG_TABLESIZE; 609 610 if (setup_hostid >= 0) 611 host->this_id = setup_hostid; 612 else { 613 /* use 7 as default */ 614 host->this_id = 7; 615 /* Test if a host id is set in the NVRam */ 616 if (ATARIHW_PRESENT(TT_CLK) && nvram_check_checksum()) { 617 unsigned char b = nvram_read_byte( 14 ); 618 /* Arbitration enabled? (for TOS) If yes, use configured host ID */ 619 if (b & 0x80) 620 host->this_id = b & 7; 621 } 622 } 623 624 #ifdef SUPPORT_TAGS 625 if (setup_use_tagged_queuing < 0) 626 setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING; 627 #endif 628 #ifdef REAL_DMA 629 /* If running on a Falcon and if there's TT-Ram (i.e., more than one 630 * memory block, since there's always ST-Ram in a Falcon), then allocate a 631 * STRAM_BUFFER_SIZE byte dribble buffer for transfers from/to alternative 632 * Ram. 633 */ 634 if (MACH_IS_ATARI && ATARIHW_PRESENT(ST_SCSI) && 635 !ATARIHW_PRESENT(EXTD_DMA) && m68k_num_memory > 1) { 636 atari_dma_buffer = atari_stram_alloc(STRAM_BUFFER_SIZE, "SCSI"); 637 if (!atari_dma_buffer) { 638 printk(KERN_ERR "atari_scsi_detect: can't allocate ST-RAM " 639 "double buffer\n"); 640 return 0; 641 } 642 atari_dma_phys_buffer = virt_to_phys(atari_dma_buffer); 643 atari_dma_orig_addr = 0; 644 } 645 #endif 646 instance = scsi_register(host, sizeof(struct NCR5380_hostdata)); 647 if (instance == NULL) { 648 atari_stram_free(atari_dma_buffer); 649 atari_dma_buffer = 0; 650 return 0; 651 } 652 atari_scsi_host = instance; 653 /* 654 * Set irq to 0, to avoid that the mid-level code disables our interrupt 655 * during queue_command calls. This is completely unnecessary, and even 656 * worse causes bad problems on the Falcon, where the int is shared with 657 * IDE and floppy! 658 */ 659 instance->irq = 0; 660 661 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT 662 atari_scsi_reset_boot(); 663 #endif 664 NCR5380_init(instance, 0); 665 666 if (IS_A_TT()) { 667 668 /* This int is actually "pseudo-slow", i.e. it acts like a slow 669 * interrupt after having cleared the pending flag for the DMA 670 * interrupt. */ 671 if (request_irq(IRQ_TT_MFP_SCSI, scsi_tt_intr, IRQ_TYPE_SLOW, 672 "SCSI NCR5380", instance)) { 673 printk(KERN_ERR "atari_scsi_detect: cannot allocate irq %d, aborting",IRQ_TT_MFP_SCSI); 674 scsi_unregister(atari_scsi_host); 675 atari_stram_free(atari_dma_buffer); 676 atari_dma_buffer = 0; 677 return 0; 678 } 679 tt_mfp.active_edge |= 0x80; /* SCSI int on L->H */ 680 #ifdef REAL_DMA 681 tt_scsi_dma.dma_ctrl = 0; 682 atari_dma_residual = 0; 683 684 if (MACH_IS_MEDUSA) { 685 /* While the read overruns (described by Drew Eckhardt in 686 * NCR5380.c) never happened on TTs, they do in fact on the Medusa 687 * (This was the cause why SCSI didn't work right for so long 688 * there.) Since handling the overruns slows down a bit, I turned 689 * the #ifdef's into a runtime condition. 690 * 691 * In principle it should be sufficient to do max. 1 byte with 692 * PIO, but there is another problem on the Medusa with the DMA 693 * rest data register. So 'atari_read_overruns' is currently set 694 * to 4 to avoid having transfers that aren't a multiple of 4. If 695 * the rest data bug is fixed, this can be lowered to 1. 696 */ 697 atari_read_overruns = 4; 698 } 699 #endif /*REAL_DMA*/ 700 } else { /* ! IS_A_TT */ 701 702 /* Nothing to do for the interrupt: the ST-DMA is initialized 703 * already by atari_init_INTS() 704 */ 705 706 #ifdef REAL_DMA 707 atari_dma_residual = 0; 708 atari_dma_active = 0; 709 atari_dma_stram_mask = (ATARIHW_PRESENT(EXTD_DMA) ? 0x00000000 710 : 0xff000000); 711 #endif 712 } 713 714 printk(KERN_INFO "scsi%d: options CAN_QUEUE=%d CMD_PER_LUN=%d SCAT-GAT=%d " 715 #ifdef SUPPORT_TAGS 716 "TAGGED-QUEUING=%s " 717 #endif 718 "HOSTID=%d", 719 instance->host_no, instance->hostt->can_queue, 720 instance->hostt->cmd_per_lun, 721 instance->hostt->sg_tablesize, 722 #ifdef SUPPORT_TAGS 723 setup_use_tagged_queuing ? "yes" : "no", 724 #endif 725 instance->hostt->this_id ); 726 NCR5380_print_options(instance); 727 printk("\n"); 728 729 called = 1; 730 return 1; 731 } 732 733 static int atari_scsi_release(struct Scsi_Host *sh) 734 { 735 if (IS_A_TT()) 736 free_irq(IRQ_TT_MFP_SCSI, sh); 737 if (atari_dma_buffer) 738 atari_stram_free(atari_dma_buffer); 739 NCR5380_exit(sh); 740 return 1; 741 } 742 743 #ifndef MODULE 744 static int __init atari_scsi_setup(char *str) 745 { 746 /* Format of atascsi parameter is: 747 * atascsi=<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags> 748 * Defaults depend on TT or Falcon, hostid determined at run time. 749 * Negative values mean don't change. 750 */ 751 int ints[6]; 752 753 get_options(str, ARRAY_SIZE(ints), ints); 754 755 if (ints[0] < 1) { 756 printk("atari_scsi_setup: no arguments!\n"); 757 return 0; 758 } 759 760 if (ints[0] >= 1) { 761 if (ints[1] > 0) 762 /* no limits on this, just > 0 */ 763 setup_can_queue = ints[1]; 764 } 765 if (ints[0] >= 2) { 766 if (ints[2] > 0) 767 setup_cmd_per_lun = ints[2]; 768 } 769 if (ints[0] >= 3) { 770 if (ints[3] >= 0) { 771 setup_sg_tablesize = ints[3]; 772 /* Must be <= SG_ALL (255) */ 773 if (setup_sg_tablesize > SG_ALL) 774 setup_sg_tablesize = SG_ALL; 775 } 776 } 777 if (ints[0] >= 4) { 778 /* Must be between 0 and 7 */ 779 if (ints[4] >= 0 && ints[4] <= 7) 780 setup_hostid = ints[4]; 781 else if (ints[4] > 7) 782 printk("atari_scsi_setup: invalid host ID %d !\n", ints[4]); 783 } 784 #ifdef SUPPORT_TAGS 785 if (ints[0] >= 5) { 786 if (ints[5] >= 0) 787 setup_use_tagged_queuing = !!ints[5]; 788 } 789 #endif 790 791 return 1; 792 } 793 794 __setup("atascsi=", atari_scsi_setup); 795 #endif /* !MODULE */ 796 797 static int atari_scsi_bus_reset(Scsi_Cmnd *cmd) 798 { 799 int rv; 800 struct NCR5380_hostdata *hostdata = 801 (struct NCR5380_hostdata *)cmd->device->host->hostdata; 802 803 /* For doing the reset, SCSI interrupts must be disabled first, 804 * since the 5380 raises its IRQ line while _RST is active and we 805 * can't disable interrupts completely, since we need the timer. 806 */ 807 /* And abort a maybe active DMA transfer */ 808 if (IS_A_TT()) { 809 atari_turnoff_irq(IRQ_TT_MFP_SCSI); 810 #ifdef REAL_DMA 811 tt_scsi_dma.dma_ctrl = 0; 812 #endif /* REAL_DMA */ 813 } else { 814 atari_turnoff_irq(IRQ_MFP_FSCSI); 815 #ifdef REAL_DMA 816 st_dma.dma_mode_status = 0x90; 817 atari_dma_active = 0; 818 atari_dma_orig_addr = NULL; 819 #endif /* REAL_DMA */ 820 } 821 822 rv = NCR5380_bus_reset(cmd); 823 824 /* Re-enable ints */ 825 if (IS_A_TT()) { 826 atari_turnon_irq(IRQ_TT_MFP_SCSI); 827 } else { 828 atari_turnon_irq(IRQ_MFP_FSCSI); 829 } 830 if ((rv & SCSI_RESET_ACTION) == SCSI_RESET_SUCCESS) 831 falcon_release_lock_if_possible(hostdata); 832 833 return rv; 834 } 835 836 837 #ifdef CONFIG_ATARI_SCSI_RESET_BOOT 838 static void __init atari_scsi_reset_boot(void) 839 { 840 unsigned long end; 841 842 /* 843 * Do a SCSI reset to clean up the bus during initialization. No messing 844 * with the queues, interrupts, or locks necessary here. 845 */ 846 847 printk("Atari SCSI: resetting the SCSI bus..."); 848 849 /* get in phase */ 850 NCR5380_write(TARGET_COMMAND_REG, 851 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG))); 852 853 /* assert RST */ 854 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST); 855 /* The min. reset hold time is 25us, so 40us should be enough */ 856 udelay(50); 857 /* reset RST and interrupt */ 858 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE); 859 NCR5380_read(RESET_PARITY_INTERRUPT_REG); 860 861 end = jiffies + AFTER_RESET_DELAY; 862 while (time_before(jiffies, end)) 863 barrier(); 864 865 printk(" done\n"); 866 } 867 #endif 868 869 870 static const char *atari_scsi_info(struct Scsi_Host *host) 871 { 872 /* atari_scsi_detect() is verbose enough... */ 873 static const char string[] = "Atari native SCSI"; 874 return string; 875 } 876 877 878 #if defined(REAL_DMA) 879 880 static unsigned long atari_scsi_dma_setup(struct Scsi_Host *instance, 881 void *data, unsigned long count, 882 int dir) 883 { 884 unsigned long addr = virt_to_phys(data); 885 886 DMA_PRINTK("scsi%d: setting up dma, data = %p, phys = %lx, count = %ld, " 887 "dir = %d\n", instance->host_no, data, addr, count, dir); 888 889 if (!IS_A_TT() && !STRAM_ADDR(addr)) { 890 /* If we have a non-DMAable address on a Falcon, use the dribble 891 * buffer; 'orig_addr' != 0 in the read case tells the interrupt 892 * handler to copy data from the dribble buffer to the originally 893 * wanted address. 894 */ 895 if (dir) 896 memcpy(atari_dma_buffer, data, count); 897 else 898 atari_dma_orig_addr = data; 899 addr = atari_dma_phys_buffer; 900 } 901 902 atari_dma_startaddr = addr; /* Needed for calculating residual later. */ 903 904 /* Cache cleanup stuff: On writes, push any dirty cache out before sending 905 * it to the peripheral. (Must be done before DMA setup, since at least 906 * the ST-DMA begins to fill internal buffers right after setup. For 907 * reads, invalidate any cache, may be altered after DMA without CPU 908 * knowledge. 909 * 910 * ++roman: For the Medusa, there's no need at all for that cache stuff, 911 * because the hardware does bus snooping (fine!). 912 */ 913 dma_cache_maintenance(addr, count, dir); 914 915 if (count == 0) 916 printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); 917 918 if (IS_A_TT()) { 919 tt_scsi_dma.dma_ctrl = dir; 920 SCSI_DMA_WRITE_P(dma_addr, addr); 921 SCSI_DMA_WRITE_P(dma_cnt, count); 922 tt_scsi_dma.dma_ctrl = dir | 2; 923 } else { /* ! IS_A_TT */ 924 925 /* set address */ 926 SCSI_DMA_SETADR(addr); 927 928 /* toggle direction bit to clear FIFO and set DMA direction */ 929 dir <<= 8; 930 st_dma.dma_mode_status = 0x90 | dir; 931 st_dma.dma_mode_status = 0x90 | (dir ^ 0x100); 932 st_dma.dma_mode_status = 0x90 | dir; 933 udelay(40); 934 /* On writes, round up the transfer length to the next multiple of 512 935 * (see also comment at atari_dma_xfer_len()). */ 936 st_dma.fdc_acces_seccount = (count + (dir ? 511 : 0)) >> 9; 937 udelay(40); 938 st_dma.dma_mode_status = 0x10 | dir; 939 udelay(40); 940 /* need not restore value of dir, only boolean value is tested */ 941 atari_dma_active = 1; 942 } 943 944 return count; 945 } 946 947 948 static long atari_scsi_dma_residual(struct Scsi_Host *instance) 949 { 950 return atari_dma_residual; 951 } 952 953 954 #define CMD_SURELY_BLOCK_MODE 0 955 #define CMD_SURELY_BYTE_MODE 1 956 #define CMD_MODE_UNKNOWN 2 957 958 static int falcon_classify_cmd(Scsi_Cmnd *cmd) 959 { 960 unsigned char opcode = cmd->cmnd[0]; 961 962 if (opcode == READ_DEFECT_DATA || opcode == READ_LONG || 963 opcode == READ_BUFFER) 964 return CMD_SURELY_BYTE_MODE; 965 else if (opcode == READ_6 || opcode == READ_10 || 966 opcode == 0xa8 /* READ_12 */ || opcode == READ_REVERSE || 967 opcode == RECOVER_BUFFERED_DATA) { 968 /* In case of a sequential-access target (tape), special care is 969 * needed here: The transfer is block-mode only if the 'fixed' bit is 970 * set! */ 971 if (cmd->device->type == TYPE_TAPE && !(cmd->cmnd[1] & 1)) 972 return CMD_SURELY_BYTE_MODE; 973 else 974 return CMD_SURELY_BLOCK_MODE; 975 } else 976 return CMD_MODE_UNKNOWN; 977 } 978 979 980 /* This function calculates the number of bytes that can be transferred via 981 * DMA. On the TT, this is arbitrary, but on the Falcon we have to use the 982 * ST-DMA chip. There are only multiples of 512 bytes possible and max. 983 * 255*512 bytes :-( This means also, that defining READ_OVERRUNS is not 984 * possible on the Falcon, since that would require to program the DMA for 985 * n*512 - atari_read_overrun bytes. But it seems that the Falcon doesn't have 986 * the overrun problem, so this question is academic :-) 987 */ 988 989 static unsigned long atari_dma_xfer_len(unsigned long wanted_len, 990 Scsi_Cmnd *cmd, int write_flag) 991 { 992 unsigned long possible_len, limit; 993 994 if (IS_A_TT()) 995 /* TT SCSI DMA can transfer arbitrary #bytes */ 996 return wanted_len; 997 998 /* ST DMA chip is stupid -- only multiples of 512 bytes! (and max. 999 * 255*512 bytes, but this should be enough) 1000 * 1001 * ++roman: Aaargl! Another Falcon-SCSI problem... There are some commands 1002 * that return a number of bytes which cannot be known beforehand. In this 1003 * case, the given transfer length is an "allocation length". Now it 1004 * can happen that this allocation length is a multiple of 512 bytes and 1005 * the DMA is used. But if not n*512 bytes really arrive, some input data 1006 * will be lost in the ST-DMA's FIFO :-( Thus, we have to distinguish 1007 * between commands that do block transfers and those that do byte 1008 * transfers. But this isn't easy... there are lots of vendor specific 1009 * commands, and the user can issue any command via the 1010 * SCSI_IOCTL_SEND_COMMAND. 1011 * 1012 * The solution: We classify SCSI commands in 1) surely block-mode cmd.s, 1013 * 2) surely byte-mode cmd.s and 3) cmd.s with unknown mode. In case 1) 1014 * and 3), the thing to do is obvious: allow any number of blocks via DMA 1015 * or none. In case 2), we apply some heuristic: Byte mode is assumed if 1016 * the transfer (allocation) length is < 1024, hoping that no cmd. not 1017 * explicitly known as byte mode have such big allocation lengths... 1018 * BTW, all the discussion above applies only to reads. DMA writes are 1019 * unproblematic anyways, since the targets aborts the transfer after 1020 * receiving a sufficient number of bytes. 1021 * 1022 * Another point: If the transfer is from/to an non-ST-RAM address, we 1023 * use the dribble buffer and thus can do only STRAM_BUFFER_SIZE bytes. 1024 */ 1025 1026 if (write_flag) { 1027 /* Write operation can always use the DMA, but the transfer size must 1028 * be rounded up to the next multiple of 512 (atari_dma_setup() does 1029 * this). 1030 */ 1031 possible_len = wanted_len; 1032 } else { 1033 /* Read operations: if the wanted transfer length is not a multiple of 1034 * 512, we cannot use DMA, since the ST-DMA cannot split transfers 1035 * (no interrupt on DMA finished!) 1036 */ 1037 if (wanted_len & 0x1ff) 1038 possible_len = 0; 1039 else { 1040 /* Now classify the command (see above) and decide whether it is 1041 * allowed to do DMA at all */ 1042 switch (falcon_classify_cmd(cmd)) { 1043 case CMD_SURELY_BLOCK_MODE: 1044 possible_len = wanted_len; 1045 break; 1046 case CMD_SURELY_BYTE_MODE: 1047 possible_len = 0; /* DMA prohibited */ 1048 break; 1049 case CMD_MODE_UNKNOWN: 1050 default: 1051 /* For unknown commands assume block transfers if the transfer 1052 * size/allocation length is >= 1024 */ 1053 possible_len = (wanted_len < 1024) ? 0 : wanted_len; 1054 break; 1055 } 1056 } 1057 } 1058 1059 /* Last step: apply the hard limit on DMA transfers */ 1060 limit = (atari_dma_buffer && !STRAM_ADDR(virt_to_phys(cmd->SCp.ptr))) ? 1061 STRAM_BUFFER_SIZE : 255*512; 1062 if (possible_len > limit) 1063 possible_len = limit; 1064 1065 if (possible_len != wanted_len) 1066 DMA_PRINTK("Sorry, must cut DMA transfer size to %ld bytes " 1067 "instead of %ld\n", possible_len, wanted_len); 1068 1069 return possible_len; 1070 } 1071 1072 1073 #endif /* REAL_DMA */ 1074 1075 1076 /* NCR5380 register access functions 1077 * 1078 * There are separate functions for TT and Falcon, because the access 1079 * methods are quite different. The calling macros NCR5380_read and 1080 * NCR5380_write call these functions via function pointers. 1081 */ 1082 1083 static unsigned char atari_scsi_tt_reg_read(unsigned char reg) 1084 { 1085 return tt_scsi_regp[reg * 2]; 1086 } 1087 1088 static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value) 1089 { 1090 tt_scsi_regp[reg * 2] = value; 1091 } 1092 1093 static unsigned char atari_scsi_falcon_reg_read(unsigned char reg) 1094 { 1095 dma_wd.dma_mode_status= (u_short)(0x88 + reg); 1096 return (u_char)dma_wd.fdc_acces_seccount; 1097 } 1098 1099 static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value) 1100 { 1101 dma_wd.dma_mode_status = (u_short)(0x88 + reg); 1102 dma_wd.fdc_acces_seccount = (u_short)value; 1103 } 1104 1105 1106 #include "atari_NCR5380.c" 1107 1108 static struct scsi_host_template driver_template = { 1109 .show_info = atari_scsi_show_info, 1110 .name = "Atari native SCSI", 1111 .detect = atari_scsi_detect, 1112 .release = atari_scsi_release, 1113 .info = atari_scsi_info, 1114 .queuecommand = atari_scsi_queue_command, 1115 .eh_abort_handler = atari_scsi_abort, 1116 .eh_bus_reset_handler = atari_scsi_bus_reset, 1117 .can_queue = 0, /* initialized at run-time */ 1118 .this_id = 0, /* initialized at run-time */ 1119 .sg_tablesize = 0, /* initialized at run-time */ 1120 .cmd_per_lun = 0, /* initialized at run-time */ 1121 .use_clustering = DISABLE_CLUSTERING 1122 }; 1123 1124 1125 #include "scsi_module.c" 1126 1127 MODULE_LICENSE("GPL"); 1128