ide-tape.c revision 01a63aebe4dcfcbe983c40a475e4650a4ae614de
1/* 2 * IDE ATAPI streaming tape driver. 3 * 4 * Copyright (C) 1995-1999 Gadi Oxman <gadio@netvision.net.il> 5 * Copyright (C) 2003-2005 Bartlomiej Zolnierkiewicz 6 * 7 * This driver was constructed as a student project in the software laboratory 8 * of the faculty of electrical engineering in the Technion - Israel's 9 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David. 10 * 11 * It is hereby placed under the terms of the GNU general public license. 12 * (See linux/COPYING). 13 * 14 * For a historical changelog see 15 * Documentation/ide/ChangeLog.ide-tape.1995-2002 16 */ 17 18#define IDETAPE_VERSION "1.20" 19 20#include <linux/module.h> 21#include <linux/types.h> 22#include <linux/string.h> 23#include <linux/kernel.h> 24#include <linux/delay.h> 25#include <linux/timer.h> 26#include <linux/mm.h> 27#include <linux/interrupt.h> 28#include <linux/jiffies.h> 29#include <linux/major.h> 30#include <linux/errno.h> 31#include <linux/genhd.h> 32#include <linux/slab.h> 33#include <linux/pci.h> 34#include <linux/ide.h> 35#include <linux/smp_lock.h> 36#include <linux/completion.h> 37#include <linux/bitops.h> 38#include <linux/mutex.h> 39#include <scsi/scsi.h> 40 41#include <asm/byteorder.h> 42#include <linux/irq.h> 43#include <linux/uaccess.h> 44#include <linux/io.h> 45#include <asm/unaligned.h> 46#include <linux/mtio.h> 47 48enum { 49 /* output errors only */ 50 DBG_ERR = (1 << 0), 51 /* output all sense key/asc */ 52 DBG_SENSE = (1 << 1), 53 /* info regarding all chrdev-related procedures */ 54 DBG_CHRDEV = (1 << 2), 55 /* all remaining procedures */ 56 DBG_PROCS = (1 << 3), 57 /* buffer alloc info (pc_stack & rq_stack) */ 58 DBG_PCRQ_STACK = (1 << 4), 59}; 60 61/* define to see debug info */ 62#define IDETAPE_DEBUG_LOG 0 63 64#if IDETAPE_DEBUG_LOG 65#define debug_log(lvl, fmt, args...) \ 66{ \ 67 if (tape->debug_mask & lvl) \ 68 printk(KERN_INFO "ide-tape: " fmt, ## args); \ 69} 70#else 71#define debug_log(lvl, fmt, args...) do {} while (0) 72#endif 73 74/**************************** Tunable parameters *****************************/ 75/* 76 * After each failed packet command we issue a request sense command and retry 77 * the packet command IDETAPE_MAX_PC_RETRIES times. 78 * 79 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries. 80 */ 81#define IDETAPE_MAX_PC_RETRIES 3 82 83/* 84 * With each packet command, we allocate a buffer of IDETAPE_PC_BUFFER_SIZE 85 * bytes. This is used for several packet commands (Not for READ/WRITE commands) 86 */ 87#define IDETAPE_PC_BUFFER_SIZE 256 88 89/* 90 * In various places in the driver, we need to allocate storage 91 * for packet commands and requests, which will remain valid while 92 * we leave the driver to wait for an interrupt or a timeout event. 93 */ 94#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES) 95 96/* 97 * Some drives (for example, Seagate STT3401A Travan) require a very long 98 * timeout, because they don't return an interrupt or clear their busy bit 99 * until after the command completes (even retension commands). 100 */ 101#define IDETAPE_WAIT_CMD (900*HZ) 102 103/* 104 * The following parameter is used to select the point in the internal tape fifo 105 * in which we will start to refill the buffer. Decreasing the following 106 * parameter will improve the system's latency and interactive response, while 107 * using a high value might improve system throughput. 108 */ 109#define IDETAPE_FIFO_THRESHOLD 2 110 111/* 112 * DSC polling parameters. 113 * 114 * Polling for DSC (a single bit in the status register) is a very important 115 * function in ide-tape. There are two cases in which we poll for DSC: 116 * 117 * 1. Before a read/write packet command, to ensure that we can transfer data 118 * from/to the tape's data buffers, without causing an actual media access. 119 * In case the tape is not ready yet, we take out our request from the device 120 * request queue, so that ide.c could service requests from the other device 121 * on the same interface in the meantime. 122 * 123 * 2. After the successful initialization of a "media access packet command", 124 * which is a command that can take a long time to complete (the interval can 125 * range from several seconds to even an hour). Again, we postpone our request 126 * in the middle to free the bus for the other device. The polling frequency 127 * here should be lower than the read/write frequency since those media access 128 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST 129 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD 130 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min). 131 * 132 * We also set a timeout for the timer, in case something goes wrong. The 133 * timeout should be longer then the maximum execution time of a tape operation. 134 */ 135 136/* DSC timings. */ 137#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */ 138#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */ 139#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */ 140#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */ 141#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */ 142#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */ 143#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */ 144 145/*************************** End of tunable parameters ***********************/ 146 147/* Read/Write error simulation */ 148#define SIMULATE_ERRORS 0 149 150/* tape directions */ 151enum { 152 IDETAPE_DIR_NONE = (1 << 0), 153 IDETAPE_DIR_READ = (1 << 1), 154 IDETAPE_DIR_WRITE = (1 << 2), 155}; 156 157struct idetape_bh { 158 u32 b_size; 159 atomic_t b_count; 160 struct idetape_bh *b_reqnext; 161 char *b_data; 162}; 163 164/* Tape door status */ 165#define DOOR_UNLOCKED 0 166#define DOOR_LOCKED 1 167#define DOOR_EXPLICITLY_LOCKED 2 168 169/* Some defines for the SPACE command */ 170#define IDETAPE_SPACE_OVER_FILEMARK 1 171#define IDETAPE_SPACE_TO_EOD 3 172 173/* Some defines for the LOAD UNLOAD command */ 174#define IDETAPE_LU_LOAD_MASK 1 175#define IDETAPE_LU_RETENSION_MASK 2 176#define IDETAPE_LU_EOT_MASK 4 177 178/* 179 * Special requests for our block device strategy routine. 180 * 181 * In order to service a character device command, we add special requests to 182 * the tail of our block device request queue and wait for their completion. 183 */ 184 185enum { 186 REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */ 187 REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */ 188 REQ_IDETAPE_READ = (1 << 2), 189 REQ_IDETAPE_WRITE = (1 << 3), 190}; 191 192/* Error codes returned in rq->errors to the higher part of the driver. */ 193#define IDETAPE_ERROR_GENERAL 101 194#define IDETAPE_ERROR_FILEMARK 102 195#define IDETAPE_ERROR_EOD 103 196 197/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */ 198#define IDETAPE_BLOCK_DESCRIPTOR 0 199#define IDETAPE_CAPABILITIES_PAGE 0x2a 200 201/* Tape flag bits values. */ 202enum { 203 IDETAPE_FLAG_IGNORE_DSC = (1 << 0), 204 /* 0 When the tape position is unknown */ 205 IDETAPE_FLAG_ADDRESS_VALID = (1 << 1), 206 /* Device already opened */ 207 IDETAPE_FLAG_BUSY = (1 << 2), 208 /* Attempt to auto-detect the current user block size */ 209 IDETAPE_FLAG_DETECT_BS = (1 << 3), 210 /* Currently on a filemark */ 211 IDETAPE_FLAG_FILEMARK = (1 << 4), 212 /* DRQ interrupt device */ 213 IDETAPE_FLAG_DRQ_INTERRUPT = (1 << 5), 214 /* 0 = no tape is loaded, so we don't rewind after ejecting */ 215 IDETAPE_FLAG_MEDIUM_PRESENT = (1 << 6), 216}; 217 218/* A pipeline stage. */ 219typedef struct idetape_stage_s { 220 struct request rq; /* The corresponding request */ 221 struct idetape_bh *bh; /* The data buffers */ 222 struct idetape_stage_s *next; /* Pointer to the next stage */ 223} idetape_stage_t; 224 225/* 226 * Most of our global data which we need to save even as we leave the driver due 227 * to an interrupt or a timer event is stored in the struct defined below. 228 */ 229typedef struct ide_tape_obj { 230 ide_drive_t *drive; 231 ide_driver_t *driver; 232 struct gendisk *disk; 233 struct kref kref; 234 235 /* 236 * Since a typical character device operation requires more 237 * than one packet command, we provide here enough memory 238 * for the maximum of interconnected packet commands. 239 * The packet commands are stored in the circular array pc_stack. 240 * pc_stack_index points to the last used entry, and warps around 241 * to the start when we get to the last array entry. 242 * 243 * pc points to the current processed packet command. 244 * 245 * failed_pc points to the last failed packet command, or contains 246 * NULL if we do not need to retry any packet command. This is 247 * required since an additional packet command is needed before the 248 * retry, to get detailed information on what went wrong. 249 */ 250 /* Current packet command */ 251 struct ide_atapi_pc *pc; 252 /* Last failed packet command */ 253 struct ide_atapi_pc *failed_pc; 254 /* Packet command stack */ 255 struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK]; 256 /* Next free packet command storage space */ 257 int pc_stack_index; 258 struct request rq_stack[IDETAPE_PC_STACK]; 259 /* We implement a circular array */ 260 int rq_stack_index; 261 262 /* 263 * DSC polling variables. 264 * 265 * While polling for DSC we use postponed_rq to postpone the current 266 * request so that ide.c will be able to service pending requests on the 267 * other device. Note that at most we will have only one DSC (usually 268 * data transfer) request in the device request queue. 269 */ 270 struct request *postponed_rq; 271 /* The time in which we started polling for DSC */ 272 unsigned long dsc_polling_start; 273 /* Timer used to poll for dsc */ 274 struct timer_list dsc_timer; 275 /* Read/Write dsc polling frequency */ 276 unsigned long best_dsc_rw_freq; 277 unsigned long dsc_poll_freq; 278 unsigned long dsc_timeout; 279 280 /* Read position information */ 281 u8 partition; 282 /* Current block */ 283 unsigned int first_frame; 284 285 /* Last error information */ 286 u8 sense_key, asc, ascq; 287 288 /* Character device operation */ 289 unsigned int minor; 290 /* device name */ 291 char name[4]; 292 /* Current character device data transfer direction */ 293 u8 chrdev_dir; 294 295 /* tape block size, usually 512 or 1024 bytes */ 296 unsigned short blk_size; 297 int user_bs_factor; 298 299 /* Copy of the tape's Capabilities and Mechanical Page */ 300 u8 caps[20]; 301 302 /* 303 * Active data transfer request parameters. 304 * 305 * At most, there is only one ide-tape originated data transfer request 306 * in the device request queue. This allows ide.c to easily service 307 * requests from the other device when we postpone our active request. 308 */ 309 310 /* Data buffer size chosen based on the tape's recommendation */ 311 int buffer_size; 312 idetape_stage_t *merge_stage; 313 /* size of the merge buffer */ 314 int merge_bh_size; 315 struct idetape_bh *bh; 316 char *b_data; 317 int b_count; 318 319 int pages_per_buffer; 320 /* Wasted space in each stage */ 321 int excess_bh_size; 322 323 /* Status/Action flags: long for set_bit */ 324 unsigned long flags; 325 /* protects the ide-tape queue */ 326 spinlock_t lock; 327 328 /* Measures average tape speed */ 329 unsigned long avg_time; 330 int avg_size; 331 int avg_speed; 332 333 /* the door is currently locked */ 334 int door_locked; 335 /* the tape hardware is write protected */ 336 char drv_write_prot; 337 /* the tape is write protected (hardware or opened as read-only) */ 338 char write_prot; 339 340 u32 debug_mask; 341} idetape_tape_t; 342 343static DEFINE_MUTEX(idetape_ref_mutex); 344 345static struct class *idetape_sysfs_class; 346 347#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref) 348 349#define ide_tape_g(disk) \ 350 container_of((disk)->private_data, struct ide_tape_obj, driver) 351 352static struct ide_tape_obj *ide_tape_get(struct gendisk *disk) 353{ 354 struct ide_tape_obj *tape = NULL; 355 356 mutex_lock(&idetape_ref_mutex); 357 tape = ide_tape_g(disk); 358 if (tape) 359 kref_get(&tape->kref); 360 mutex_unlock(&idetape_ref_mutex); 361 return tape; 362} 363 364static void ide_tape_release(struct kref *); 365 366static void ide_tape_put(struct ide_tape_obj *tape) 367{ 368 mutex_lock(&idetape_ref_mutex); 369 kref_put(&tape->kref, ide_tape_release); 370 mutex_unlock(&idetape_ref_mutex); 371} 372 373/* 374 * The variables below are used for the character device interface. Additional 375 * state variables are defined in our ide_drive_t structure. 376 */ 377static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES]; 378 379#define ide_tape_f(file) ((file)->private_data) 380 381static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i) 382{ 383 struct ide_tape_obj *tape = NULL; 384 385 mutex_lock(&idetape_ref_mutex); 386 tape = idetape_devs[i]; 387 if (tape) 388 kref_get(&tape->kref); 389 mutex_unlock(&idetape_ref_mutex); 390 return tape; 391} 392 393static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, 394 unsigned int bcount) 395{ 396 struct idetape_bh *bh = pc->bh; 397 int count; 398 399 while (bcount) { 400 if (bh == NULL) { 401 printk(KERN_ERR "ide-tape: bh == NULL in " 402 "idetape_input_buffers\n"); 403 ide_atapi_discard_data(drive, bcount); 404 return; 405 } 406 count = min( 407 (unsigned int)(bh->b_size - atomic_read(&bh->b_count)), 408 bcount); 409 HWIF(drive)->atapi_input_bytes(drive, bh->b_data + 410 atomic_read(&bh->b_count), count); 411 bcount -= count; 412 atomic_add(count, &bh->b_count); 413 if (atomic_read(&bh->b_count) == bh->b_size) { 414 bh = bh->b_reqnext; 415 if (bh) 416 atomic_set(&bh->b_count, 0); 417 } 418 } 419 pc->bh = bh; 420} 421 422static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, 423 unsigned int bcount) 424{ 425 struct idetape_bh *bh = pc->bh; 426 int count; 427 428 while (bcount) { 429 if (bh == NULL) { 430 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 431 __func__); 432 return; 433 } 434 count = min((unsigned int)pc->b_count, (unsigned int)bcount); 435 HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count); 436 bcount -= count; 437 pc->b_data += count; 438 pc->b_count -= count; 439 if (!pc->b_count) { 440 bh = bh->b_reqnext; 441 pc->bh = bh; 442 if (bh) { 443 pc->b_data = bh->b_data; 444 pc->b_count = atomic_read(&bh->b_count); 445 } 446 } 447 } 448} 449 450static void idetape_update_buffers(struct ide_atapi_pc *pc) 451{ 452 struct idetape_bh *bh = pc->bh; 453 int count; 454 unsigned int bcount = pc->xferred; 455 456 if (pc->flags & PC_FLAG_WRITING) 457 return; 458 while (bcount) { 459 if (bh == NULL) { 460 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 461 __func__); 462 return; 463 } 464 count = min((unsigned int)bh->b_size, (unsigned int)bcount); 465 atomic_set(&bh->b_count, count); 466 if (atomic_read(&bh->b_count) == bh->b_size) 467 bh = bh->b_reqnext; 468 bcount -= count; 469 } 470 pc->bh = bh; 471} 472 473/* 474 * idetape_next_pc_storage returns a pointer to a place in which we can 475 * safely store a packet command, even though we intend to leave the 476 * driver. A storage space for a maximum of IDETAPE_PC_STACK packet 477 * commands is allocated at initialization time. 478 */ 479static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive) 480{ 481 idetape_tape_t *tape = drive->driver_data; 482 483 debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index); 484 485 if (tape->pc_stack_index == IDETAPE_PC_STACK) 486 tape->pc_stack_index = 0; 487 return (&tape->pc_stack[tape->pc_stack_index++]); 488} 489 490/* 491 * idetape_next_rq_storage is used along with idetape_next_pc_storage. 492 * Since we queue packet commands in the request queue, we need to 493 * allocate a request, along with the allocation of a packet command. 494 */ 495 496/************************************************************** 497 * * 498 * This should get fixed to use kmalloc(.., GFP_ATOMIC) * 499 * followed later on by kfree(). -ml * 500 * * 501 **************************************************************/ 502 503static struct request *idetape_next_rq_storage(ide_drive_t *drive) 504{ 505 idetape_tape_t *tape = drive->driver_data; 506 507 debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index); 508 509 if (tape->rq_stack_index == IDETAPE_PC_STACK) 510 tape->rq_stack_index = 0; 511 return (&tape->rq_stack[tape->rq_stack_index++]); 512} 513 514static void idetape_init_pc(struct ide_atapi_pc *pc) 515{ 516 memset(pc->c, 0, 12); 517 pc->retries = 0; 518 pc->flags = 0; 519 pc->req_xfer = 0; 520 pc->buf = pc->pc_buf; 521 pc->buf_size = IDETAPE_PC_BUFFER_SIZE; 522 pc->bh = NULL; 523 pc->b_data = NULL; 524} 525 526/* 527 * called on each failed packet command retry to analyze the request sense. We 528 * currently do not utilize this information. 529 */ 530static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) 531{ 532 idetape_tape_t *tape = drive->driver_data; 533 struct ide_atapi_pc *pc = tape->failed_pc; 534 535 tape->sense_key = sense[2] & 0xF; 536 tape->asc = sense[12]; 537 tape->ascq = sense[13]; 538 539 debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n", 540 pc->c[0], tape->sense_key, tape->asc, tape->ascq); 541 542 /* Correct pc->xferred by asking the tape. */ 543 if (pc->flags & PC_FLAG_DMA_ERROR) { 544 pc->xferred = pc->req_xfer - 545 tape->blk_size * 546 be32_to_cpu(get_unaligned((u32 *)&sense[3])); 547 idetape_update_buffers(pc); 548 } 549 550 /* 551 * If error was the result of a zero-length read or write command, 552 * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives 553 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes. 554 */ 555 if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6) 556 /* length == 0 */ 557 && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { 558 if (tape->sense_key == 5) { 559 /* don't report an error, everything's ok */ 560 pc->error = 0; 561 /* don't retry read/write */ 562 pc->flags |= PC_FLAG_ABORT; 563 } 564 } 565 if (pc->c[0] == READ_6 && (sense[2] & 0x80)) { 566 pc->error = IDETAPE_ERROR_FILEMARK; 567 pc->flags |= PC_FLAG_ABORT; 568 } 569 if (pc->c[0] == WRITE_6) { 570 if ((sense[2] & 0x40) || (tape->sense_key == 0xd 571 && tape->asc == 0x0 && tape->ascq == 0x2)) { 572 pc->error = IDETAPE_ERROR_EOD; 573 pc->flags |= PC_FLAG_ABORT; 574 } 575 } 576 if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) { 577 if (tape->sense_key == 8) { 578 pc->error = IDETAPE_ERROR_EOD; 579 pc->flags |= PC_FLAG_ABORT; 580 } 581 if (!(pc->flags & PC_FLAG_ABORT) && 582 pc->xferred) 583 pc->retries = IDETAPE_MAX_PC_RETRIES + 1; 584 } 585} 586 587/* Free data buffers completely. */ 588static void ide_tape_kfree_buffer(idetape_stage_t *stage) 589{ 590 struct idetape_bh *prev_bh, *bh = stage->bh; 591 592 while (bh) { 593 u32 size = bh->b_size; 594 595 while (size) { 596 unsigned int order = fls(size >> PAGE_SHIFT)-1; 597 598 if (bh->b_data) 599 free_pages((unsigned long)bh->b_data, order); 600 601 size &= (order-1); 602 bh->b_data += (1 << order) * PAGE_SIZE; 603 } 604 prev_bh = bh; 605 bh = bh->b_reqnext; 606 kfree(prev_bh); 607 } 608 kfree(stage); 609} 610 611static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects) 612{ 613 struct request *rq = HWGROUP(drive)->rq; 614 idetape_tape_t *tape = drive->driver_data; 615 unsigned long flags; 616 int error; 617 618 debug_log(DBG_PROCS, "Enter %s\n", __func__); 619 620 switch (uptodate) { 621 case 0: error = IDETAPE_ERROR_GENERAL; break; 622 case 1: error = 0; break; 623 default: error = uptodate; 624 } 625 rq->errors = error; 626 if (error) 627 tape->failed_pc = NULL; 628 629 if (!blk_special_request(rq)) { 630 ide_end_request(drive, uptodate, nr_sects); 631 return 0; 632 } 633 634 spin_lock_irqsave(&tape->lock, flags); 635 636 ide_end_drive_cmd(drive, 0, 0); 637 638 spin_unlock_irqrestore(&tape->lock, flags); 639 return 0; 640} 641 642static ide_startstop_t idetape_request_sense_callback(ide_drive_t *drive) 643{ 644 idetape_tape_t *tape = drive->driver_data; 645 646 debug_log(DBG_PROCS, "Enter %s\n", __func__); 647 648 if (!tape->pc->error) { 649 idetape_analyze_error(drive, tape->pc->buf); 650 idetape_end_request(drive, 1, 0); 651 } else { 652 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - " 653 "Aborting request!\n"); 654 idetape_end_request(drive, 0, 0); 655 } 656 return ide_stopped; 657} 658 659static void idetape_create_request_sense_cmd(struct ide_atapi_pc *pc) 660{ 661 idetape_init_pc(pc); 662 pc->c[0] = REQUEST_SENSE; 663 pc->c[4] = 20; 664 pc->req_xfer = 20; 665 pc->idetape_callback = &idetape_request_sense_callback; 666} 667 668static void idetape_init_rq(struct request *rq, u8 cmd) 669{ 670 memset(rq, 0, sizeof(*rq)); 671 rq->cmd_type = REQ_TYPE_SPECIAL; 672 rq->cmd[0] = cmd; 673} 674 675/* 676 * Generate a new packet command request in front of the request queue, before 677 * the current request, so that it will be processed immediately, on the next 678 * pass through the driver. The function below is called from the request 679 * handling part of the driver (the "bottom" part). Safe storage for the request 680 * should be allocated with ide_tape_next_{pc,rq}_storage() prior to that. 681 * 682 * Memory for those requests is pre-allocated at initialization time, and is 683 * limited to IDETAPE_PC_STACK requests. We assume that we have enough space for 684 * the maximum possible number of inter-dependent packet commands. 685 * 686 * The higher level of the driver - The ioctl handler and the character device 687 * handling functions should queue request to the lower level part and wait for 688 * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail. 689 */ 690static void idetape_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc, 691 struct request *rq) 692{ 693 struct ide_tape_obj *tape = drive->driver_data; 694 695 idetape_init_rq(rq, REQ_IDETAPE_PC1); 696 rq->buffer = (char *) pc; 697 rq->rq_disk = tape->disk; 698 (void) ide_do_drive_cmd(drive, rq, ide_preempt); 699} 700 701/* 702 * idetape_retry_pc is called when an error was detected during the 703 * last packet command. We queue a request sense packet command in 704 * the head of the request list. 705 */ 706static ide_startstop_t idetape_retry_pc (ide_drive_t *drive) 707{ 708 idetape_tape_t *tape = drive->driver_data; 709 struct ide_atapi_pc *pc; 710 struct request *rq; 711 712 (void)ide_read_error(drive); 713 pc = idetape_next_pc_storage(drive); 714 rq = idetape_next_rq_storage(drive); 715 idetape_create_request_sense_cmd(pc); 716 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 717 idetape_queue_pc_head(drive, pc, rq); 718 return ide_stopped; 719} 720 721/* 722 * Postpone the current request so that ide.c will be able to service requests 723 * from another device on the same hwgroup while we are polling for DSC. 724 */ 725static void idetape_postpone_request(ide_drive_t *drive) 726{ 727 idetape_tape_t *tape = drive->driver_data; 728 729 debug_log(DBG_PROCS, "Enter %s\n", __func__); 730 731 tape->postponed_rq = HWGROUP(drive)->rq; 732 ide_stall_queue(drive, tape->dsc_poll_freq); 733} 734 735typedef void idetape_io_buf(ide_drive_t *, struct ide_atapi_pc *, unsigned int); 736 737/* 738 * This is the usual interrupt handler which will be called during a packet 739 * command. We will transfer some of the data (as requested by the drive) and 740 * will re-point interrupt handler to us. When data transfer is finished, we 741 * will act according to the algorithm described before 742 * idetape_issue_pc. 743 */ 744static ide_startstop_t idetape_pc_intr(ide_drive_t *drive) 745{ 746 ide_hwif_t *hwif = drive->hwif; 747 idetape_tape_t *tape = drive->driver_data; 748 struct ide_atapi_pc *pc = tape->pc; 749 xfer_func_t *xferfunc; 750 idetape_io_buf *iobuf; 751 unsigned int temp; 752#if SIMULATE_ERRORS 753 static int error_sim_count; 754#endif 755 u16 bcount; 756 u8 stat, ireason; 757 758 debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__); 759 760 /* Clear the interrupt */ 761 stat = ide_read_status(drive); 762 763 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 764 if (hwif->dma_ops->dma_end(drive) || (stat & ERR_STAT)) { 765 /* 766 * A DMA error is sometimes expected. For example, 767 * if the tape is crossing a filemark during a 768 * READ command, it will issue an irq and position 769 * itself before the filemark, so that only a partial 770 * data transfer will occur (which causes the DMA 771 * error). In that case, we will later ask the tape 772 * how much bytes of the original request were 773 * actually transferred (we can't receive that 774 * information from the DMA engine on most chipsets). 775 */ 776 777 /* 778 * On the contrary, a DMA error is never expected; 779 * it usually indicates a hardware error or abort. 780 * If the tape crosses a filemark during a READ 781 * command, it will issue an irq and position itself 782 * after the filemark (not before). Only a partial 783 * data transfer will occur, but no DMA error. 784 * (AS, 19 Apr 2001) 785 */ 786 pc->flags |= PC_FLAG_DMA_ERROR; 787 } else { 788 pc->xferred = pc->req_xfer; 789 idetape_update_buffers(pc); 790 } 791 debug_log(DBG_PROCS, "DMA finished\n"); 792 793 } 794 795 /* No more interrupts */ 796 if ((stat & DRQ_STAT) == 0) { 797 debug_log(DBG_SENSE, "Packet command completed, %d bytes" 798 " transferred\n", pc->xferred); 799 800 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 801 local_irq_enable(); 802 803#if SIMULATE_ERRORS 804 if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) && 805 (++error_sim_count % 100) == 0) { 806 printk(KERN_INFO "ide-tape: %s: simulating error\n", 807 tape->name); 808 stat |= ERR_STAT; 809 } 810#endif 811 if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE) 812 stat &= ~ERR_STAT; 813 if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) { 814 /* Error detected */ 815 debug_log(DBG_ERR, "%s: I/O error\n", tape->name); 816 817 if (pc->c[0] == REQUEST_SENSE) { 818 printk(KERN_ERR "ide-tape: I/O error in request" 819 " sense command\n"); 820 return ide_do_reset(drive); 821 } 822 debug_log(DBG_ERR, "[cmd %x]: check condition\n", 823 pc->c[0]); 824 825 /* Retry operation */ 826 return idetape_retry_pc(drive); 827 } 828 pc->error = 0; 829 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && 830 (stat & SEEK_STAT) == 0) { 831 /* Media access command */ 832 tape->dsc_polling_start = jiffies; 833 tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST; 834 tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT; 835 /* Allow ide.c to handle other requests */ 836 idetape_postpone_request(drive); 837 return ide_stopped; 838 } 839 if (tape->failed_pc == pc) 840 tape->failed_pc = NULL; 841 /* Command finished - Call the callback function */ 842 return pc->idetape_callback(drive); 843 } 844 845 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 846 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 847 printk(KERN_ERR "ide-tape: The tape wants to issue more " 848 "interrupts in DMA mode\n"); 849 printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n"); 850 ide_dma_off(drive); 851 return ide_do_reset(drive); 852 } 853 /* Get the number of bytes to transfer on this interrupt. */ 854 bcount = (hwif->INB(hwif->io_ports.lbah_addr) << 8) | 855 hwif->INB(hwif->io_ports.lbam_addr); 856 857 ireason = hwif->INB(hwif->io_ports.nsect_addr); 858 859 if (ireason & CD) { 860 printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__); 861 return ide_do_reset(drive); 862 } 863 if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) { 864 /* Hopefully, we will never get here */ 865 printk(KERN_ERR "ide-tape: We wanted to %s, ", 866 (ireason & IO) ? "Write" : "Read"); 867 printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n", 868 (ireason & IO) ? "Read" : "Write"); 869 return ide_do_reset(drive); 870 } 871 if (!(pc->flags & PC_FLAG_WRITING)) { 872 /* Reading - Check that we have enough space */ 873 temp = pc->xferred + bcount; 874 if (temp > pc->req_xfer) { 875 if (temp > pc->buf_size) { 876 printk(KERN_ERR "ide-tape: The tape wants to " 877 "send us more data than expected " 878 "- discarding data\n"); 879 ide_atapi_discard_data(drive, bcount); 880 ide_set_handler(drive, &idetape_pc_intr, 881 IDETAPE_WAIT_CMD, NULL); 882 return ide_started; 883 } 884 debug_log(DBG_SENSE, "The tape wants to send us more " 885 "data than expected - allowing transfer\n"); 886 } 887 iobuf = &idetape_input_buffers; 888 xferfunc = hwif->atapi_input_bytes; 889 } else { 890 iobuf = &idetape_output_buffers; 891 xferfunc = hwif->atapi_output_bytes; 892 } 893 894 if (pc->bh) 895 iobuf(drive, pc, bcount); 896 else 897 xferfunc(drive, pc->cur_pos, bcount); 898 899 /* Update the current position */ 900 pc->xferred += bcount; 901 pc->cur_pos += bcount; 902 903 debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n", 904 pc->c[0], bcount); 905 906 /* And set the interrupt handler again */ 907 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); 908 return ide_started; 909} 910 911/* 912 * Packet Command Interface 913 * 914 * The current Packet Command is available in tape->pc, and will not change 915 * until we finish handling it. Each packet command is associated with a 916 * callback function that will be called when the command is finished. 917 * 918 * The handling will be done in three stages: 919 * 920 * 1. idetape_issue_pc will send the packet command to the drive, and will set 921 * the interrupt handler to idetape_pc_intr. 922 * 923 * 2. On each interrupt, idetape_pc_intr will be called. This step will be 924 * repeated until the device signals us that no more interrupts will be issued. 925 * 926 * 3. ATAPI Tape media access commands have immediate status with a delayed 927 * process. In case of a successful initiation of a media access packet command, 928 * the DSC bit will be set when the actual execution of the command is finished. 929 * Since the tape drive will not issue an interrupt, we have to poll for this 930 * event. In this case, we define the request as "low priority request" by 931 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and 932 * exit the driver. 933 * 934 * ide.c will then give higher priority to requests which originate from the 935 * other device, until will change rq_status to RQ_ACTIVE. 936 * 937 * 4. When the packet command is finished, it will be checked for errors. 938 * 939 * 5. In case an error was found, we queue a request sense packet command in 940 * front of the request queue and retry the operation up to 941 * IDETAPE_MAX_PC_RETRIES times. 942 * 943 * 6. In case no error was found, or we decided to give up and not to retry 944 * again, the callback function will be called and then we will handle the next 945 * request. 946 */ 947static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive) 948{ 949 ide_hwif_t *hwif = drive->hwif; 950 idetape_tape_t *tape = drive->driver_data; 951 struct ide_atapi_pc *pc = tape->pc; 952 int retries = 100; 953 ide_startstop_t startstop; 954 u8 ireason; 955 956 if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) { 957 printk(KERN_ERR "ide-tape: Strange, packet command initiated " 958 "yet DRQ isn't asserted\n"); 959 return startstop; 960 } 961 ireason = hwif->INB(hwif->io_ports.nsect_addr); 962 while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) { 963 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing " 964 "a packet command, retrying\n"); 965 udelay(100); 966 ireason = hwif->INB(hwif->io_ports.nsect_addr); 967 if (retries == 0) { 968 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while " 969 "issuing a packet command, ignoring\n"); 970 ireason |= CD; 971 ireason &= ~IO; 972 } 973 } 974 if ((ireason & CD) == 0 || (ireason & IO)) { 975 printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing " 976 "a packet command\n"); 977 return ide_do_reset(drive); 978 } 979 /* Set the interrupt routine */ 980 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); 981#ifdef CONFIG_BLK_DEV_IDEDMA 982 /* Begin DMA, if necessary */ 983 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) 984 hwif->dma_ops->dma_start(drive); 985#endif 986 /* Send the actual packet */ 987 HWIF(drive)->atapi_output_bytes(drive, pc->c, 12); 988 return ide_started; 989} 990 991static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, 992 struct ide_atapi_pc *pc) 993{ 994 ide_hwif_t *hwif = drive->hwif; 995 idetape_tape_t *tape = drive->driver_data; 996 int dma_ok = 0; 997 u16 bcount; 998 999 if (tape->pc->c[0] == REQUEST_SENSE && 1000 pc->c[0] == REQUEST_SENSE) { 1001 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - " 1002 "Two request sense in serial were issued\n"); 1003 } 1004 1005 if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE) 1006 tape->failed_pc = pc; 1007 /* Set the current packet command */ 1008 tape->pc = pc; 1009 1010 if (pc->retries > IDETAPE_MAX_PC_RETRIES || 1011 (pc->flags & PC_FLAG_ABORT)) { 1012 /* 1013 * We will "abort" retrying a packet command in case legitimate 1014 * error code was received (crossing a filemark, or end of the 1015 * media, for example). 1016 */ 1017 if (!(pc->flags & PC_FLAG_ABORT)) { 1018 if (!(pc->c[0] == TEST_UNIT_READY && 1019 tape->sense_key == 2 && tape->asc == 4 && 1020 (tape->ascq == 1 || tape->ascq == 8))) { 1021 printk(KERN_ERR "ide-tape: %s: I/O error, " 1022 "pc = %2x, key = %2x, " 1023 "asc = %2x, ascq = %2x\n", 1024 tape->name, pc->c[0], 1025 tape->sense_key, tape->asc, 1026 tape->ascq); 1027 } 1028 /* Giving up */ 1029 pc->error = IDETAPE_ERROR_GENERAL; 1030 } 1031 tape->failed_pc = NULL; 1032 return pc->idetape_callback(drive); 1033 } 1034 debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]); 1035 1036 pc->retries++; 1037 /* We haven't transferred any data yet */ 1038 pc->xferred = 0; 1039 pc->cur_pos = pc->buf; 1040 /* Request to transfer the entire buffer at once */ 1041 bcount = pc->req_xfer; 1042 1043 if (pc->flags & PC_FLAG_DMA_ERROR) { 1044 pc->flags &= ~PC_FLAG_DMA_ERROR; 1045 printk(KERN_WARNING "ide-tape: DMA disabled, " 1046 "reverting to PIO\n"); 1047 ide_dma_off(drive); 1048 } 1049 if ((pc->flags & PC_FLAG_DMA_RECOMMENDED) && drive->using_dma) 1050 dma_ok = !hwif->dma_ops->dma_setup(drive); 1051 1052 ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK | 1053 IDE_TFLAG_OUT_DEVICE, bcount, dma_ok); 1054 1055 if (dma_ok) 1056 /* Will begin DMA later */ 1057 pc->flags |= PC_FLAG_DMA_IN_PROGRESS; 1058 if (test_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags)) { 1059 ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc, 1060 IDETAPE_WAIT_CMD, NULL); 1061 return ide_started; 1062 } else { 1063 hwif->OUTB(WIN_PACKETCMD, hwif->io_ports.command_addr); 1064 return idetape_transfer_pc(drive); 1065 } 1066} 1067 1068static ide_startstop_t idetape_pc_callback(ide_drive_t *drive) 1069{ 1070 idetape_tape_t *tape = drive->driver_data; 1071 1072 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1073 1074 idetape_end_request(drive, tape->pc->error ? 0 : 1, 0); 1075 return ide_stopped; 1076} 1077 1078/* A mode sense command is used to "sense" tape parameters. */ 1079static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code) 1080{ 1081 idetape_init_pc(pc); 1082 pc->c[0] = MODE_SENSE; 1083 if (page_code != IDETAPE_BLOCK_DESCRIPTOR) 1084 /* DBD = 1 - Don't return block descriptors */ 1085 pc->c[1] = 8; 1086 pc->c[2] = page_code; 1087 /* 1088 * Changed pc->c[3] to 0 (255 will at best return unused info). 1089 * 1090 * For SCSI this byte is defined as subpage instead of high byte 1091 * of length and some IDE drives seem to interpret it this way 1092 * and return an error when 255 is used. 1093 */ 1094 pc->c[3] = 0; 1095 /* We will just discard data in that case */ 1096 pc->c[4] = 255; 1097 if (page_code == IDETAPE_BLOCK_DESCRIPTOR) 1098 pc->req_xfer = 12; 1099 else if (page_code == IDETAPE_CAPABILITIES_PAGE) 1100 pc->req_xfer = 24; 1101 else 1102 pc->req_xfer = 50; 1103 pc->idetape_callback = &idetape_pc_callback; 1104} 1105 1106static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive) 1107{ 1108 idetape_tape_t *tape = drive->driver_data; 1109 struct ide_atapi_pc *pc = tape->pc; 1110 u8 stat; 1111 1112 stat = ide_read_status(drive); 1113 1114 if (stat & SEEK_STAT) { 1115 if (stat & ERR_STAT) { 1116 /* Error detected */ 1117 if (pc->c[0] != TEST_UNIT_READY) 1118 printk(KERN_ERR "ide-tape: %s: I/O error, ", 1119 tape->name); 1120 /* Retry operation */ 1121 return idetape_retry_pc(drive); 1122 } 1123 pc->error = 0; 1124 if (tape->failed_pc == pc) 1125 tape->failed_pc = NULL; 1126 } else { 1127 pc->error = IDETAPE_ERROR_GENERAL; 1128 tape->failed_pc = NULL; 1129 } 1130 return pc->idetape_callback(drive); 1131} 1132 1133static ide_startstop_t idetape_rw_callback(ide_drive_t *drive) 1134{ 1135 idetape_tape_t *tape = drive->driver_data; 1136 struct request *rq = HWGROUP(drive)->rq; 1137 int blocks = tape->pc->xferred / tape->blk_size; 1138 1139 tape->avg_size += blocks * tape->blk_size; 1140 1141 if (time_after_eq(jiffies, tape->avg_time + HZ)) { 1142 tape->avg_speed = tape->avg_size * HZ / 1143 (jiffies - tape->avg_time) / 1024; 1144 tape->avg_size = 0; 1145 tape->avg_time = jiffies; 1146 } 1147 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1148 1149 tape->first_frame += blocks; 1150 rq->current_nr_sectors -= blocks; 1151 1152 if (!tape->pc->error) 1153 idetape_end_request(drive, 1, 0); 1154 else 1155 idetape_end_request(drive, tape->pc->error, 0); 1156 return ide_stopped; 1157} 1158 1159static void idetape_create_read_cmd(idetape_tape_t *tape, 1160 struct ide_atapi_pc *pc, 1161 unsigned int length, struct idetape_bh *bh) 1162{ 1163 idetape_init_pc(pc); 1164 pc->c[0] = READ_6; 1165 put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); 1166 pc->c[1] = 1; 1167 pc->idetape_callback = &idetape_rw_callback; 1168 pc->bh = bh; 1169 atomic_set(&bh->b_count, 0); 1170 pc->buf = NULL; 1171 pc->buf_size = length * tape->blk_size; 1172 pc->req_xfer = pc->buf_size; 1173 if (pc->req_xfer == tape->buffer_size) 1174 pc->flags |= PC_FLAG_DMA_RECOMMENDED; 1175} 1176 1177static void idetape_create_write_cmd(idetape_tape_t *tape, 1178 struct ide_atapi_pc *pc, 1179 unsigned int length, struct idetape_bh *bh) 1180{ 1181 idetape_init_pc(pc); 1182 pc->c[0] = WRITE_6; 1183 put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); 1184 pc->c[1] = 1; 1185 pc->idetape_callback = &idetape_rw_callback; 1186 pc->flags |= PC_FLAG_WRITING; 1187 pc->bh = bh; 1188 pc->b_data = bh->b_data; 1189 pc->b_count = atomic_read(&bh->b_count); 1190 pc->buf = NULL; 1191 pc->buf_size = length * tape->blk_size; 1192 pc->req_xfer = pc->buf_size; 1193 if (pc->req_xfer == tape->buffer_size) 1194 pc->flags |= PC_FLAG_DMA_RECOMMENDED; 1195} 1196 1197static ide_startstop_t idetape_do_request(ide_drive_t *drive, 1198 struct request *rq, sector_t block) 1199{ 1200 idetape_tape_t *tape = drive->driver_data; 1201 struct ide_atapi_pc *pc = NULL; 1202 struct request *postponed_rq = tape->postponed_rq; 1203 u8 stat; 1204 1205 debug_log(DBG_SENSE, "sector: %ld, nr_sectors: %ld," 1206 " current_nr_sectors: %d\n", 1207 rq->sector, rq->nr_sectors, rq->current_nr_sectors); 1208 1209 if (!blk_special_request(rq)) { 1210 /* We do not support buffer cache originated requests. */ 1211 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in " 1212 "request queue (%d)\n", drive->name, rq->cmd_type); 1213 ide_end_request(drive, 0, 0); 1214 return ide_stopped; 1215 } 1216 1217 /* Retry a failed packet command */ 1218 if (tape->failed_pc && tape->pc->c[0] == REQUEST_SENSE) 1219 return idetape_issue_pc(drive, tape->failed_pc); 1220 1221 if (postponed_rq != NULL) 1222 if (rq != postponed_rq) { 1223 printk(KERN_ERR "ide-tape: ide-tape.c bug - " 1224 "Two DSC requests were queued\n"); 1225 idetape_end_request(drive, 0, 0); 1226 return ide_stopped; 1227 } 1228 1229 tape->postponed_rq = NULL; 1230 1231 /* 1232 * If the tape is still busy, postpone our request and service 1233 * the other device meanwhile. 1234 */ 1235 stat = ide_read_status(drive); 1236 1237 if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2)) 1238 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 1239 1240 if (drive->post_reset == 1) { 1241 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 1242 drive->post_reset = 0; 1243 } 1244 1245 if (!test_and_clear_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags) && 1246 (stat & SEEK_STAT) == 0) { 1247 if (postponed_rq == NULL) { 1248 tape->dsc_polling_start = jiffies; 1249 tape->dsc_poll_freq = tape->best_dsc_rw_freq; 1250 tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT; 1251 } else if (time_after(jiffies, tape->dsc_timeout)) { 1252 printk(KERN_ERR "ide-tape: %s: DSC timeout\n", 1253 tape->name); 1254 if (rq->cmd[0] & REQ_IDETAPE_PC2) { 1255 idetape_media_access_finished(drive); 1256 return ide_stopped; 1257 } else { 1258 return ide_do_reset(drive); 1259 } 1260 } else if (time_after(jiffies, 1261 tape->dsc_polling_start + 1262 IDETAPE_DSC_MA_THRESHOLD)) 1263 tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW; 1264 idetape_postpone_request(drive); 1265 return ide_stopped; 1266 } 1267 if (rq->cmd[0] & REQ_IDETAPE_READ) { 1268 pc = idetape_next_pc_storage(drive); 1269 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, 1270 (struct idetape_bh *)rq->special); 1271 goto out; 1272 } 1273 if (rq->cmd[0] & REQ_IDETAPE_WRITE) { 1274 pc = idetape_next_pc_storage(drive); 1275 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, 1276 (struct idetape_bh *)rq->special); 1277 goto out; 1278 } 1279 if (rq->cmd[0] & REQ_IDETAPE_PC1) { 1280 pc = (struct ide_atapi_pc *) rq->buffer; 1281 rq->cmd[0] &= ~(REQ_IDETAPE_PC1); 1282 rq->cmd[0] |= REQ_IDETAPE_PC2; 1283 goto out; 1284 } 1285 if (rq->cmd[0] & REQ_IDETAPE_PC2) { 1286 idetape_media_access_finished(drive); 1287 return ide_stopped; 1288 } 1289 BUG(); 1290out: 1291 return idetape_issue_pc(drive, pc); 1292} 1293 1294/* 1295 * The function below uses __get_free_pages to allocate a data buffer of size 1296 * tape->buffer_size (or a bit more). We attempt to combine sequential pages as 1297 * much as possible. 1298 * 1299 * It returns a pointer to the newly allocated buffer, or NULL in case of 1300 * failure. 1301 */ 1302static idetape_stage_t *ide_tape_kmalloc_buffer(idetape_tape_t *tape, int full, 1303 int clear) 1304{ 1305 idetape_stage_t *stage; 1306 struct idetape_bh *prev_bh, *bh; 1307 int pages = tape->pages_per_buffer; 1308 unsigned int order, b_allocd; 1309 char *b_data = NULL; 1310 1311 stage = kmalloc(sizeof(idetape_stage_t), GFP_KERNEL); 1312 if (!stage) 1313 return NULL; 1314 stage->next = NULL; 1315 1316 stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); 1317 bh = stage->bh; 1318 if (bh == NULL) 1319 goto abort; 1320 1321 order = fls(pages) - 1; 1322 bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order); 1323 if (!bh->b_data) 1324 goto abort; 1325 b_allocd = (1 << order) * PAGE_SIZE; 1326 pages &= (order-1); 1327 1328 if (clear) 1329 memset(bh->b_data, 0, b_allocd); 1330 bh->b_reqnext = NULL; 1331 bh->b_size = b_allocd; 1332 atomic_set(&bh->b_count, full ? bh->b_size : 0); 1333 1334 while (pages) { 1335 order = fls(pages) - 1; 1336 b_data = (char *) __get_free_pages(GFP_KERNEL, order); 1337 if (!b_data) 1338 goto abort; 1339 b_allocd = (1 << order) * PAGE_SIZE; 1340 1341 if (clear) 1342 memset(b_data, 0, b_allocd); 1343 1344 /* newly allocated page frames below buffer header or ...*/ 1345 if (bh->b_data == b_data + b_allocd) { 1346 bh->b_size += b_allocd; 1347 bh->b_data -= b_allocd; 1348 if (full) 1349 atomic_add(b_allocd, &bh->b_count); 1350 continue; 1351 } 1352 /* they are above the header */ 1353 if (b_data == bh->b_data + bh->b_size) { 1354 bh->b_size += b_allocd; 1355 if (full) 1356 atomic_add(b_allocd, &bh->b_count); 1357 continue; 1358 } 1359 prev_bh = bh; 1360 bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); 1361 if (!bh) { 1362 free_pages((unsigned long) b_data, order); 1363 goto abort; 1364 } 1365 bh->b_reqnext = NULL; 1366 bh->b_data = b_data; 1367 bh->b_size = b_allocd; 1368 atomic_set(&bh->b_count, full ? bh->b_size : 0); 1369 prev_bh->b_reqnext = bh; 1370 1371 pages &= (order-1); 1372 } 1373 1374 bh->b_size -= tape->excess_bh_size; 1375 if (full) 1376 atomic_sub(tape->excess_bh_size, &bh->b_count); 1377 return stage; 1378abort: 1379 ide_tape_kfree_buffer(stage); 1380 return NULL; 1381} 1382 1383static int idetape_copy_stage_from_user(idetape_tape_t *tape, 1384 const char __user *buf, int n) 1385{ 1386 struct idetape_bh *bh = tape->bh; 1387 int count; 1388 int ret = 0; 1389 1390 while (n) { 1391 if (bh == NULL) { 1392 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 1393 __func__); 1394 return 1; 1395 } 1396 count = min((unsigned int) 1397 (bh->b_size - atomic_read(&bh->b_count)), 1398 (unsigned int)n); 1399 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, 1400 count)) 1401 ret = 1; 1402 n -= count; 1403 atomic_add(count, &bh->b_count); 1404 buf += count; 1405 if (atomic_read(&bh->b_count) == bh->b_size) { 1406 bh = bh->b_reqnext; 1407 if (bh) 1408 atomic_set(&bh->b_count, 0); 1409 } 1410 } 1411 tape->bh = bh; 1412 return ret; 1413} 1414 1415static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf, 1416 int n) 1417{ 1418 struct idetape_bh *bh = tape->bh; 1419 int count; 1420 int ret = 0; 1421 1422 while (n) { 1423 if (bh == NULL) { 1424 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 1425 __func__); 1426 return 1; 1427 } 1428 count = min(tape->b_count, n); 1429 if (copy_to_user(buf, tape->b_data, count)) 1430 ret = 1; 1431 n -= count; 1432 tape->b_data += count; 1433 tape->b_count -= count; 1434 buf += count; 1435 if (!tape->b_count) { 1436 bh = bh->b_reqnext; 1437 tape->bh = bh; 1438 if (bh) { 1439 tape->b_data = bh->b_data; 1440 tape->b_count = atomic_read(&bh->b_count); 1441 } 1442 } 1443 } 1444 return ret; 1445} 1446 1447static void idetape_init_merge_stage(idetape_tape_t *tape) 1448{ 1449 struct idetape_bh *bh = tape->merge_stage->bh; 1450 1451 tape->bh = bh; 1452 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) 1453 atomic_set(&bh->b_count, 0); 1454 else { 1455 tape->b_data = bh->b_data; 1456 tape->b_count = atomic_read(&bh->b_count); 1457 } 1458} 1459 1460static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive) 1461{ 1462 idetape_tape_t *tape = drive->driver_data; 1463 u8 *readpos = tape->pc->buf; 1464 1465 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1466 1467 if (!tape->pc->error) { 1468 debug_log(DBG_SENSE, "BOP - %s\n", 1469 (readpos[0] & 0x80) ? "Yes" : "No"); 1470 debug_log(DBG_SENSE, "EOP - %s\n", 1471 (readpos[0] & 0x40) ? "Yes" : "No"); 1472 1473 if (readpos[0] & 0x4) { 1474 printk(KERN_INFO "ide-tape: Block location is unknown" 1475 "to the tape\n"); 1476 clear_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags); 1477 idetape_end_request(drive, 0, 0); 1478 } else { 1479 debug_log(DBG_SENSE, "Block Location - %u\n", 1480 be32_to_cpu(*(u32 *)&readpos[4])); 1481 1482 tape->partition = readpos[1]; 1483 tape->first_frame = 1484 be32_to_cpu(*(u32 *)&readpos[4]); 1485 set_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags); 1486 idetape_end_request(drive, 1, 0); 1487 } 1488 } else { 1489 idetape_end_request(drive, 0, 0); 1490 } 1491 return ide_stopped; 1492} 1493 1494/* 1495 * Write a filemark if write_filemark=1. Flush the device buffers without 1496 * writing a filemark otherwise. 1497 */ 1498static void idetape_create_write_filemark_cmd(ide_drive_t *drive, 1499 struct ide_atapi_pc *pc, int write_filemark) 1500{ 1501 idetape_init_pc(pc); 1502 pc->c[0] = WRITE_FILEMARKS; 1503 pc->c[4] = write_filemark; 1504 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1505 pc->idetape_callback = &idetape_pc_callback; 1506} 1507 1508static void idetape_create_test_unit_ready_cmd(struct ide_atapi_pc *pc) 1509{ 1510 idetape_init_pc(pc); 1511 pc->c[0] = TEST_UNIT_READY; 1512 pc->idetape_callback = &idetape_pc_callback; 1513} 1514 1515/* 1516 * We add a special packet command request to the tail of the request queue, and 1517 * wait for it to be serviced. This is not to be called from within the request 1518 * handling part of the driver! We allocate here data on the stack and it is 1519 * valid until the request is finished. This is not the case for the bottom part 1520 * of the driver, where we are always leaving the functions to wait for an 1521 * interrupt or a timer event. 1522 * 1523 * From the bottom part of the driver, we should allocate safe memory using 1524 * idetape_next_pc_storage() and ide_tape_next_rq_storage(), and add the request 1525 * to the request list without waiting for it to be serviced! In that case, we 1526 * usually use idetape_queue_pc_head(). 1527 */ 1528static int idetape_queue_pc_tail(ide_drive_t *drive, struct ide_atapi_pc *pc) 1529{ 1530 struct ide_tape_obj *tape = drive->driver_data; 1531 struct request rq; 1532 1533 idetape_init_rq(&rq, REQ_IDETAPE_PC1); 1534 rq.buffer = (char *) pc; 1535 rq.rq_disk = tape->disk; 1536 return ide_do_drive_cmd(drive, &rq, ide_wait); 1537} 1538 1539static void idetape_create_load_unload_cmd(ide_drive_t *drive, 1540 struct ide_atapi_pc *pc, int cmd) 1541{ 1542 idetape_init_pc(pc); 1543 pc->c[0] = START_STOP; 1544 pc->c[4] = cmd; 1545 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1546 pc->idetape_callback = &idetape_pc_callback; 1547} 1548 1549static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout) 1550{ 1551 idetape_tape_t *tape = drive->driver_data; 1552 struct ide_atapi_pc pc; 1553 int load_attempted = 0; 1554 1555 /* Wait for the tape to become ready */ 1556 set_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags); 1557 timeout += jiffies; 1558 while (time_before(jiffies, timeout)) { 1559 idetape_create_test_unit_ready_cmd(&pc); 1560 if (!idetape_queue_pc_tail(drive, &pc)) 1561 return 0; 1562 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) 1563 || (tape->asc == 0x3A)) { 1564 /* no media */ 1565 if (load_attempted) 1566 return -ENOMEDIUM; 1567 idetape_create_load_unload_cmd(drive, &pc, 1568 IDETAPE_LU_LOAD_MASK); 1569 idetape_queue_pc_tail(drive, &pc); 1570 load_attempted = 1; 1571 /* not about to be ready */ 1572 } else if (!(tape->sense_key == 2 && tape->asc == 4 && 1573 (tape->ascq == 1 || tape->ascq == 8))) 1574 return -EIO; 1575 msleep(100); 1576 } 1577 return -EIO; 1578} 1579 1580static int idetape_flush_tape_buffers(ide_drive_t *drive) 1581{ 1582 struct ide_atapi_pc pc; 1583 int rc; 1584 1585 idetape_create_write_filemark_cmd(drive, &pc, 0); 1586 rc = idetape_queue_pc_tail(drive, &pc); 1587 if (rc) 1588 return rc; 1589 idetape_wait_ready(drive, 60 * 5 * HZ); 1590 return 0; 1591} 1592 1593static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc) 1594{ 1595 idetape_init_pc(pc); 1596 pc->c[0] = READ_POSITION; 1597 pc->req_xfer = 20; 1598 pc->idetape_callback = &idetape_read_position_callback; 1599} 1600 1601static int idetape_read_position(ide_drive_t *drive) 1602{ 1603 idetape_tape_t *tape = drive->driver_data; 1604 struct ide_atapi_pc pc; 1605 int position; 1606 1607 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1608 1609 idetape_create_read_position_cmd(&pc); 1610 if (idetape_queue_pc_tail(drive, &pc)) 1611 return -1; 1612 position = tape->first_frame; 1613 return position; 1614} 1615 1616static void idetape_create_locate_cmd(ide_drive_t *drive, 1617 struct ide_atapi_pc *pc, 1618 unsigned int block, u8 partition, int skip) 1619{ 1620 idetape_init_pc(pc); 1621 pc->c[0] = POSITION_TO_ELEMENT; 1622 pc->c[1] = 2; 1623 put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]); 1624 pc->c[8] = partition; 1625 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1626 pc->idetape_callback = &idetape_pc_callback; 1627} 1628 1629static int idetape_create_prevent_cmd(ide_drive_t *drive, 1630 struct ide_atapi_pc *pc, int prevent) 1631{ 1632 idetape_tape_t *tape = drive->driver_data; 1633 1634 /* device supports locking according to capabilities page */ 1635 if (!(tape->caps[6] & 0x01)) 1636 return 0; 1637 1638 idetape_init_pc(pc); 1639 pc->c[0] = ALLOW_MEDIUM_REMOVAL; 1640 pc->c[4] = prevent; 1641 pc->idetape_callback = &idetape_pc_callback; 1642 return 1; 1643} 1644 1645static void __ide_tape_discard_merge_buffer(ide_drive_t *drive) 1646{ 1647 idetape_tape_t *tape = drive->driver_data; 1648 1649 if (tape->chrdev_dir != IDETAPE_DIR_READ) 1650 return; 1651 1652 clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags); 1653 tape->merge_bh_size = 0; 1654 if (tape->merge_stage != NULL) { 1655 ide_tape_kfree_buffer(tape->merge_stage); 1656 tape->merge_stage = NULL; 1657 } 1658 1659 tape->chrdev_dir = IDETAPE_DIR_NONE; 1660} 1661 1662/* 1663 * Position the tape to the requested block using the LOCATE packet command. 1664 * A READ POSITION command is then issued to check where we are positioned. Like 1665 * all higher level operations, we queue the commands at the tail of the request 1666 * queue and wait for their completion. 1667 */ 1668static int idetape_position_tape(ide_drive_t *drive, unsigned int block, 1669 u8 partition, int skip) 1670{ 1671 idetape_tape_t *tape = drive->driver_data; 1672 int retval; 1673 struct ide_atapi_pc pc; 1674 1675 if (tape->chrdev_dir == IDETAPE_DIR_READ) 1676 __ide_tape_discard_merge_buffer(drive); 1677 idetape_wait_ready(drive, 60 * 5 * HZ); 1678 idetape_create_locate_cmd(drive, &pc, block, partition, skip); 1679 retval = idetape_queue_pc_tail(drive, &pc); 1680 if (retval) 1681 return (retval); 1682 1683 idetape_create_read_position_cmd(&pc); 1684 return (idetape_queue_pc_tail(drive, &pc)); 1685} 1686 1687static void ide_tape_discard_merge_buffer(ide_drive_t *drive, 1688 int restore_position) 1689{ 1690 idetape_tape_t *tape = drive->driver_data; 1691 int seek, position; 1692 1693 __ide_tape_discard_merge_buffer(drive); 1694 if (restore_position) { 1695 position = idetape_read_position(drive); 1696 seek = position > 0 ? position : 0; 1697 if (idetape_position_tape(drive, seek, 0, 0)) { 1698 printk(KERN_INFO "ide-tape: %s: position_tape failed in" 1699 " %s\n", tape->name, __func__); 1700 return; 1701 } 1702 } 1703} 1704 1705/* 1706 * Generate a read/write request for the block device interface and wait for it 1707 * to be serviced. 1708 */ 1709static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, 1710 struct idetape_bh *bh) 1711{ 1712 idetape_tape_t *tape = drive->driver_data; 1713 struct request rq; 1714 1715 debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd); 1716 1717 idetape_init_rq(&rq, cmd); 1718 rq.rq_disk = tape->disk; 1719 rq.special = (void *)bh; 1720 rq.sector = tape->first_frame; 1721 rq.nr_sectors = blocks; 1722 rq.current_nr_sectors = blocks; 1723 (void) ide_do_drive_cmd(drive, &rq, ide_wait); 1724 1725 if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0) 1726 return 0; 1727 1728 if (tape->merge_stage) 1729 idetape_init_merge_stage(tape); 1730 if (rq.errors == IDETAPE_ERROR_GENERAL) 1731 return -EIO; 1732 return (tape->blk_size * (blocks-rq.current_nr_sectors)); 1733} 1734 1735static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc) 1736{ 1737 idetape_init_pc(pc); 1738 pc->c[0] = INQUIRY; 1739 pc->c[4] = 254; 1740 pc->req_xfer = 254; 1741 pc->idetape_callback = &idetape_pc_callback; 1742} 1743 1744static void idetape_create_rewind_cmd(ide_drive_t *drive, 1745 struct ide_atapi_pc *pc) 1746{ 1747 idetape_init_pc(pc); 1748 pc->c[0] = REZERO_UNIT; 1749 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1750 pc->idetape_callback = &idetape_pc_callback; 1751} 1752 1753static void idetape_create_erase_cmd(struct ide_atapi_pc *pc) 1754{ 1755 idetape_init_pc(pc); 1756 pc->c[0] = ERASE; 1757 pc->c[1] = 1; 1758 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1759 pc->idetape_callback = &idetape_pc_callback; 1760} 1761 1762static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd) 1763{ 1764 idetape_init_pc(pc); 1765 pc->c[0] = SPACE; 1766 put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]); 1767 pc->c[1] = cmd; 1768 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1769 pc->idetape_callback = &idetape_pc_callback; 1770} 1771 1772/* Queue up a character device originated write request. */ 1773static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks) 1774{ 1775 idetape_tape_t *tape = drive->driver_data; 1776 1777 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 1778 1779 return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 1780 blocks, tape->merge_stage->bh); 1781} 1782 1783static void ide_tape_flush_merge_buffer(ide_drive_t *drive) 1784{ 1785 idetape_tape_t *tape = drive->driver_data; 1786 int blocks, min; 1787 struct idetape_bh *bh; 1788 1789 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { 1790 printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline," 1791 " but we are not writing.\n"); 1792 return; 1793 } 1794 if (tape->merge_bh_size > tape->buffer_size) { 1795 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n"); 1796 tape->merge_bh_size = tape->buffer_size; 1797 } 1798 if (tape->merge_bh_size) { 1799 blocks = tape->merge_bh_size / tape->blk_size; 1800 if (tape->merge_bh_size % tape->blk_size) { 1801 unsigned int i; 1802 1803 blocks++; 1804 i = tape->blk_size - tape->merge_bh_size % 1805 tape->blk_size; 1806 bh = tape->bh->b_reqnext; 1807 while (bh) { 1808 atomic_set(&bh->b_count, 0); 1809 bh = bh->b_reqnext; 1810 } 1811 bh = tape->bh; 1812 while (i) { 1813 if (bh == NULL) { 1814 printk(KERN_INFO "ide-tape: bug," 1815 " bh NULL\n"); 1816 break; 1817 } 1818 min = min(i, (unsigned int)(bh->b_size - 1819 atomic_read(&bh->b_count))); 1820 memset(bh->b_data + atomic_read(&bh->b_count), 1821 0, min); 1822 atomic_add(min, &bh->b_count); 1823 i -= min; 1824 bh = bh->b_reqnext; 1825 } 1826 } 1827 (void) idetape_add_chrdev_write_request(drive, blocks); 1828 tape->merge_bh_size = 0; 1829 } 1830 if (tape->merge_stage != NULL) { 1831 ide_tape_kfree_buffer(tape->merge_stage); 1832 tape->merge_stage = NULL; 1833 } 1834 tape->chrdev_dir = IDETAPE_DIR_NONE; 1835} 1836 1837static int idetape_init_read(ide_drive_t *drive) 1838{ 1839 idetape_tape_t *tape = drive->driver_data; 1840 int bytes_read; 1841 1842 /* Initialize read operation */ 1843 if (tape->chrdev_dir != IDETAPE_DIR_READ) { 1844 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { 1845 ide_tape_flush_merge_buffer(drive); 1846 idetape_flush_tape_buffers(drive); 1847 } 1848 if (tape->merge_stage || tape->merge_bh_size) { 1849 printk(KERN_ERR "ide-tape: merge_bh_size should be" 1850 " 0 now\n"); 1851 tape->merge_bh_size = 0; 1852 } 1853 tape->merge_stage = ide_tape_kmalloc_buffer(tape, 0, 0); 1854 if (!tape->merge_stage) 1855 return -ENOMEM; 1856 tape->chrdev_dir = IDETAPE_DIR_READ; 1857 1858 /* 1859 * Issue a read 0 command to ensure that DSC handshake is 1860 * switched from completion mode to buffer available mode. 1861 * No point in issuing this if DSC overlap isn't supported, some 1862 * drives (Seagate STT3401A) will return an error. 1863 */ 1864 if (drive->dsc_overlap) { 1865 bytes_read = idetape_queue_rw_tail(drive, 1866 REQ_IDETAPE_READ, 0, 1867 tape->merge_stage->bh); 1868 if (bytes_read < 0) { 1869 ide_tape_kfree_buffer(tape->merge_stage); 1870 tape->merge_stage = NULL; 1871 tape->chrdev_dir = IDETAPE_DIR_NONE; 1872 return bytes_read; 1873 } 1874 } 1875 } 1876 1877 return 0; 1878} 1879 1880/* called from idetape_chrdev_read() to service a chrdev read request. */ 1881static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) 1882{ 1883 idetape_tape_t *tape = drive->driver_data; 1884 1885 debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks); 1886 1887 /* If we are at a filemark, return a read length of 0 */ 1888 if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) 1889 return 0; 1890 1891 idetape_init_read(drive); 1892 1893 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, 1894 tape->merge_stage->bh); 1895} 1896 1897static void idetape_pad_zeros(ide_drive_t *drive, int bcount) 1898{ 1899 idetape_tape_t *tape = drive->driver_data; 1900 struct idetape_bh *bh; 1901 int blocks; 1902 1903 while (bcount) { 1904 unsigned int count; 1905 1906 bh = tape->merge_stage->bh; 1907 count = min(tape->buffer_size, bcount); 1908 bcount -= count; 1909 blocks = count / tape->blk_size; 1910 while (count) { 1911 atomic_set(&bh->b_count, 1912 min(count, (unsigned int)bh->b_size)); 1913 memset(bh->b_data, 0, atomic_read(&bh->b_count)); 1914 count -= atomic_read(&bh->b_count); 1915 bh = bh->b_reqnext; 1916 } 1917 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, 1918 tape->merge_stage->bh); 1919 } 1920} 1921 1922/* 1923 * Rewinds the tape to the Beginning Of the current Partition (BOP). We 1924 * currently support only one partition. 1925 */ 1926static int idetape_rewind_tape(ide_drive_t *drive) 1927{ 1928 int retval; 1929 struct ide_atapi_pc pc; 1930 idetape_tape_t *tape; 1931 tape = drive->driver_data; 1932 1933 debug_log(DBG_SENSE, "Enter %s\n", __func__); 1934 1935 idetape_create_rewind_cmd(drive, &pc); 1936 retval = idetape_queue_pc_tail(drive, &pc); 1937 if (retval) 1938 return retval; 1939 1940 idetape_create_read_position_cmd(&pc); 1941 retval = idetape_queue_pc_tail(drive, &pc); 1942 if (retval) 1943 return retval; 1944 return 0; 1945} 1946 1947/* mtio.h compatible commands should be issued to the chrdev interface. */ 1948static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, 1949 unsigned long arg) 1950{ 1951 idetape_tape_t *tape = drive->driver_data; 1952 void __user *argp = (void __user *)arg; 1953 1954 struct idetape_config { 1955 int dsc_rw_frequency; 1956 int dsc_media_access_frequency; 1957 int nr_stages; 1958 } config; 1959 1960 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1961 1962 switch (cmd) { 1963 case 0x0340: 1964 if (copy_from_user(&config, argp, sizeof(config))) 1965 return -EFAULT; 1966 tape->best_dsc_rw_freq = config.dsc_rw_frequency; 1967 break; 1968 case 0x0350: 1969 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq; 1970 config.nr_stages = 1; 1971 if (copy_to_user(argp, &config, sizeof(config))) 1972 return -EFAULT; 1973 break; 1974 default: 1975 return -EIO; 1976 } 1977 return 0; 1978} 1979 1980static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op, 1981 int mt_count) 1982{ 1983 idetape_tape_t *tape = drive->driver_data; 1984 struct ide_atapi_pc pc; 1985 int retval, count = 0; 1986 int sprev = !!(tape->caps[4] & 0x20); 1987 1988 if (mt_count == 0) 1989 return 0; 1990 if (MTBSF == mt_op || MTBSFM == mt_op) { 1991 if (!sprev) 1992 return -EIO; 1993 mt_count = -mt_count; 1994 } 1995 1996 if (tape->chrdev_dir == IDETAPE_DIR_READ) { 1997 tape->merge_bh_size = 0; 1998 if (test_and_clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) 1999 ++count; 2000 ide_tape_discard_merge_buffer(drive, 0); 2001 } 2002 2003 /* 2004 * The filemark was not found in our internal pipeline; now we can issue 2005 * the space command. 2006 */ 2007 switch (mt_op) { 2008 case MTFSF: 2009 case MTBSF: 2010 idetape_create_space_cmd(&pc, mt_count - count, 2011 IDETAPE_SPACE_OVER_FILEMARK); 2012 return idetape_queue_pc_tail(drive, &pc); 2013 case MTFSFM: 2014 case MTBSFM: 2015 if (!sprev) 2016 return -EIO; 2017 retval = idetape_space_over_filemarks(drive, MTFSF, 2018 mt_count - count); 2019 if (retval) 2020 return retval; 2021 count = (MTBSFM == mt_op ? 1 : -1); 2022 return idetape_space_over_filemarks(drive, MTFSF, count); 2023 default: 2024 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", 2025 mt_op); 2026 return -EIO; 2027 } 2028} 2029 2030/* 2031 * Our character device read / write functions. 2032 * 2033 * The tape is optimized to maximize throughput when it is transferring an 2034 * integral number of the "continuous transfer limit", which is a parameter of 2035 * the specific tape (26kB on my particular tape, 32kB for Onstream). 2036 * 2037 * As of version 1.3 of the driver, the character device provides an abstract 2038 * continuous view of the media - any mix of block sizes (even 1 byte) on the 2039 * same backup/restore procedure is supported. The driver will internally 2040 * convert the requests to the recommended transfer unit, so that an unmatch 2041 * between the user's block size to the recommended size will only result in a 2042 * (slightly) increased driver overhead, but will no longer hit performance. 2043 * This is not applicable to Onstream. 2044 */ 2045static ssize_t idetape_chrdev_read(struct file *file, char __user *buf, 2046 size_t count, loff_t *ppos) 2047{ 2048 struct ide_tape_obj *tape = ide_tape_f(file); 2049 ide_drive_t *drive = tape->drive; 2050 ssize_t bytes_read, temp, actually_read = 0, rc; 2051 ssize_t ret = 0; 2052 u16 ctl = *(u16 *)&tape->caps[12]; 2053 2054 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); 2055 2056 if (tape->chrdev_dir != IDETAPE_DIR_READ) { 2057 if (test_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags)) 2058 if (count > tape->blk_size && 2059 (count % tape->blk_size) == 0) 2060 tape->user_bs_factor = count / tape->blk_size; 2061 } 2062 rc = idetape_init_read(drive); 2063 if (rc < 0) 2064 return rc; 2065 if (count == 0) 2066 return (0); 2067 if (tape->merge_bh_size) { 2068 actually_read = min((unsigned int)(tape->merge_bh_size), 2069 (unsigned int)count); 2070 if (idetape_copy_stage_to_user(tape, buf, actually_read)) 2071 ret = -EFAULT; 2072 buf += actually_read; 2073 tape->merge_bh_size -= actually_read; 2074 count -= actually_read; 2075 } 2076 while (count >= tape->buffer_size) { 2077 bytes_read = idetape_add_chrdev_read_request(drive, ctl); 2078 if (bytes_read <= 0) 2079 goto finish; 2080 if (idetape_copy_stage_to_user(tape, buf, bytes_read)) 2081 ret = -EFAULT; 2082 buf += bytes_read; 2083 count -= bytes_read; 2084 actually_read += bytes_read; 2085 } 2086 if (count) { 2087 bytes_read = idetape_add_chrdev_read_request(drive, ctl); 2088 if (bytes_read <= 0) 2089 goto finish; 2090 temp = min((unsigned long)count, (unsigned long)bytes_read); 2091 if (idetape_copy_stage_to_user(tape, buf, temp)) 2092 ret = -EFAULT; 2093 actually_read += temp; 2094 tape->merge_bh_size = bytes_read-temp; 2095 } 2096finish: 2097 if (!actually_read && test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) { 2098 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name); 2099 2100 idetape_space_over_filemarks(drive, MTFSF, 1); 2101 return 0; 2102 } 2103 2104 return ret ? ret : actually_read; 2105} 2106 2107static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 2108 size_t count, loff_t *ppos) 2109{ 2110 struct ide_tape_obj *tape = ide_tape_f(file); 2111 ide_drive_t *drive = tape->drive; 2112 ssize_t actually_written = 0; 2113 ssize_t ret = 0; 2114 u16 ctl = *(u16 *)&tape->caps[12]; 2115 2116 /* The drive is write protected. */ 2117 if (tape->write_prot) 2118 return -EACCES; 2119 2120 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); 2121 2122 /* Initialize write operation */ 2123 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { 2124 if (tape->chrdev_dir == IDETAPE_DIR_READ) 2125 ide_tape_discard_merge_buffer(drive, 1); 2126 if (tape->merge_stage || tape->merge_bh_size) { 2127 printk(KERN_ERR "ide-tape: merge_bh_size " 2128 "should be 0 now\n"); 2129 tape->merge_bh_size = 0; 2130 } 2131 tape->merge_stage = ide_tape_kmalloc_buffer(tape, 0, 0); 2132 if (!tape->merge_stage) 2133 return -ENOMEM; 2134 tape->chrdev_dir = IDETAPE_DIR_WRITE; 2135 idetape_init_merge_stage(tape); 2136 2137 /* 2138 * Issue a write 0 command to ensure that DSC handshake is 2139 * switched from completion mode to buffer available mode. No 2140 * point in issuing this if DSC overlap isn't supported, some 2141 * drives (Seagate STT3401A) will return an error. 2142 */ 2143 if (drive->dsc_overlap) { 2144 ssize_t retval = idetape_queue_rw_tail(drive, 2145 REQ_IDETAPE_WRITE, 0, 2146 tape->merge_stage->bh); 2147 if (retval < 0) { 2148 ide_tape_kfree_buffer(tape->merge_stage); 2149 tape->merge_stage = NULL; 2150 tape->chrdev_dir = IDETAPE_DIR_NONE; 2151 return retval; 2152 } 2153 } 2154 } 2155 if (count == 0) 2156 return (0); 2157 if (tape->merge_bh_size) { 2158 if (tape->merge_bh_size >= tape->buffer_size) { 2159 printk(KERN_ERR "ide-tape: bug: merge buf too big\n"); 2160 tape->merge_bh_size = 0; 2161 } 2162 actually_written = min((unsigned int) 2163 (tape->buffer_size - tape->merge_bh_size), 2164 (unsigned int)count); 2165 if (idetape_copy_stage_from_user(tape, buf, actually_written)) 2166 ret = -EFAULT; 2167 buf += actually_written; 2168 tape->merge_bh_size += actually_written; 2169 count -= actually_written; 2170 2171 if (tape->merge_bh_size == tape->buffer_size) { 2172 ssize_t retval; 2173 tape->merge_bh_size = 0; 2174 retval = idetape_add_chrdev_write_request(drive, ctl); 2175 if (retval <= 0) 2176 return (retval); 2177 } 2178 } 2179 while (count >= tape->buffer_size) { 2180 ssize_t retval; 2181 if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size)) 2182 ret = -EFAULT; 2183 buf += tape->buffer_size; 2184 count -= tape->buffer_size; 2185 retval = idetape_add_chrdev_write_request(drive, ctl); 2186 actually_written += tape->buffer_size; 2187 if (retval <= 0) 2188 return (retval); 2189 } 2190 if (count) { 2191 actually_written += count; 2192 if (idetape_copy_stage_from_user(tape, buf, count)) 2193 ret = -EFAULT; 2194 tape->merge_bh_size += count; 2195 } 2196 return ret ? ret : actually_written; 2197} 2198 2199static int idetape_write_filemark(ide_drive_t *drive) 2200{ 2201 struct ide_atapi_pc pc; 2202 2203 /* Write a filemark */ 2204 idetape_create_write_filemark_cmd(drive, &pc, 1); 2205 if (idetape_queue_pc_tail(drive, &pc)) { 2206 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n"); 2207 return -EIO; 2208 } 2209 return 0; 2210} 2211 2212/* 2213 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is 2214 * requested. 2215 * 2216 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support 2217 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also 2218 * usually not supported. 2219 * 2220 * The following commands are currently not supported: 2221 * 2222 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS, 2223 * MT_ST_WRITE_THRESHOLD. 2224 */ 2225static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count) 2226{ 2227 idetape_tape_t *tape = drive->driver_data; 2228 struct ide_atapi_pc pc; 2229 int i, retval; 2230 2231 debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n", 2232 mt_op, mt_count); 2233 2234 switch (mt_op) { 2235 case MTFSF: 2236 case MTFSFM: 2237 case MTBSF: 2238 case MTBSFM: 2239 if (!mt_count) 2240 return 0; 2241 return idetape_space_over_filemarks(drive, mt_op, mt_count); 2242 default: 2243 break; 2244 } 2245 2246 switch (mt_op) { 2247 case MTWEOF: 2248 if (tape->write_prot) 2249 return -EACCES; 2250 ide_tape_discard_merge_buffer(drive, 1); 2251 for (i = 0; i < mt_count; i++) { 2252 retval = idetape_write_filemark(drive); 2253 if (retval) 2254 return retval; 2255 } 2256 return 0; 2257 case MTREW: 2258 ide_tape_discard_merge_buffer(drive, 0); 2259 if (idetape_rewind_tape(drive)) 2260 return -EIO; 2261 return 0; 2262 case MTLOAD: 2263 ide_tape_discard_merge_buffer(drive, 0); 2264 idetape_create_load_unload_cmd(drive, &pc, 2265 IDETAPE_LU_LOAD_MASK); 2266 return idetape_queue_pc_tail(drive, &pc); 2267 case MTUNLOAD: 2268 case MTOFFL: 2269 /* 2270 * If door is locked, attempt to unlock before 2271 * attempting to eject. 2272 */ 2273 if (tape->door_locked) { 2274 if (idetape_create_prevent_cmd(drive, &pc, 0)) 2275 if (!idetape_queue_pc_tail(drive, &pc)) 2276 tape->door_locked = DOOR_UNLOCKED; 2277 } 2278 ide_tape_discard_merge_buffer(drive, 0); 2279 idetape_create_load_unload_cmd(drive, &pc, 2280 !IDETAPE_LU_LOAD_MASK); 2281 retval = idetape_queue_pc_tail(drive, &pc); 2282 if (!retval) 2283 clear_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags); 2284 return retval; 2285 case MTNOP: 2286 ide_tape_discard_merge_buffer(drive, 0); 2287 return idetape_flush_tape_buffers(drive); 2288 case MTRETEN: 2289 ide_tape_discard_merge_buffer(drive, 0); 2290 idetape_create_load_unload_cmd(drive, &pc, 2291 IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); 2292 return idetape_queue_pc_tail(drive, &pc); 2293 case MTEOM: 2294 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD); 2295 return idetape_queue_pc_tail(drive, &pc); 2296 case MTERASE: 2297 (void)idetape_rewind_tape(drive); 2298 idetape_create_erase_cmd(&pc); 2299 return idetape_queue_pc_tail(drive, &pc); 2300 case MTSETBLK: 2301 if (mt_count) { 2302 if (mt_count < tape->blk_size || 2303 mt_count % tape->blk_size) 2304 return -EIO; 2305 tape->user_bs_factor = mt_count / tape->blk_size; 2306 clear_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags); 2307 } else 2308 set_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags); 2309 return 0; 2310 case MTSEEK: 2311 ide_tape_discard_merge_buffer(drive, 0); 2312 return idetape_position_tape(drive, 2313 mt_count * tape->user_bs_factor, tape->partition, 0); 2314 case MTSETPART: 2315 ide_tape_discard_merge_buffer(drive, 0); 2316 return idetape_position_tape(drive, 0, mt_count, 0); 2317 case MTFSR: 2318 case MTBSR: 2319 case MTLOCK: 2320 if (!idetape_create_prevent_cmd(drive, &pc, 1)) 2321 return 0; 2322 retval = idetape_queue_pc_tail(drive, &pc); 2323 if (retval) 2324 return retval; 2325 tape->door_locked = DOOR_EXPLICITLY_LOCKED; 2326 return 0; 2327 case MTUNLOCK: 2328 if (!idetape_create_prevent_cmd(drive, &pc, 0)) 2329 return 0; 2330 retval = idetape_queue_pc_tail(drive, &pc); 2331 if (retval) 2332 return retval; 2333 tape->door_locked = DOOR_UNLOCKED; 2334 return 0; 2335 default: 2336 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", 2337 mt_op); 2338 return -EIO; 2339 } 2340} 2341 2342/* 2343 * Our character device ioctls. General mtio.h magnetic io commands are 2344 * supported here, and not in the corresponding block interface. Our own 2345 * ide-tape ioctls are supported on both interfaces. 2346 */ 2347static int idetape_chrdev_ioctl(struct inode *inode, struct file *file, 2348 unsigned int cmd, unsigned long arg) 2349{ 2350 struct ide_tape_obj *tape = ide_tape_f(file); 2351 ide_drive_t *drive = tape->drive; 2352 struct mtop mtop; 2353 struct mtget mtget; 2354 struct mtpos mtpos; 2355 int block_offset = 0, position = tape->first_frame; 2356 void __user *argp = (void __user *)arg; 2357 2358 debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd); 2359 2360 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { 2361 ide_tape_flush_merge_buffer(drive); 2362 idetape_flush_tape_buffers(drive); 2363 } 2364 if (cmd == MTIOCGET || cmd == MTIOCPOS) { 2365 block_offset = tape->merge_bh_size / 2366 (tape->blk_size * tape->user_bs_factor); 2367 position = idetape_read_position(drive); 2368 if (position < 0) 2369 return -EIO; 2370 } 2371 switch (cmd) { 2372 case MTIOCTOP: 2373 if (copy_from_user(&mtop, argp, sizeof(struct mtop))) 2374 return -EFAULT; 2375 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count); 2376 case MTIOCGET: 2377 memset(&mtget, 0, sizeof(struct mtget)); 2378 mtget.mt_type = MT_ISSCSI2; 2379 mtget.mt_blkno = position / tape->user_bs_factor - block_offset; 2380 mtget.mt_dsreg = 2381 ((tape->blk_size * tape->user_bs_factor) 2382 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK; 2383 2384 if (tape->drv_write_prot) 2385 mtget.mt_gstat |= GMT_WR_PROT(0xffffffff); 2386 2387 if (copy_to_user(argp, &mtget, sizeof(struct mtget))) 2388 return -EFAULT; 2389 return 0; 2390 case MTIOCPOS: 2391 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset; 2392 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos))) 2393 return -EFAULT; 2394 return 0; 2395 default: 2396 if (tape->chrdev_dir == IDETAPE_DIR_READ) 2397 ide_tape_discard_merge_buffer(drive, 1); 2398 return idetape_blkdev_ioctl(drive, cmd, arg); 2399 } 2400} 2401 2402/* 2403 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape 2404 * block size with the reported value. 2405 */ 2406static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive) 2407{ 2408 idetape_tape_t *tape = drive->driver_data; 2409 struct ide_atapi_pc pc; 2410 2411 idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR); 2412 if (idetape_queue_pc_tail(drive, &pc)) { 2413 printk(KERN_ERR "ide-tape: Can't get block descriptor\n"); 2414 if (tape->blk_size == 0) { 2415 printk(KERN_WARNING "ide-tape: Cannot deal with zero " 2416 "block size, assuming 32k\n"); 2417 tape->blk_size = 32768; 2418 } 2419 return; 2420 } 2421 tape->blk_size = (pc.buf[4 + 5] << 16) + 2422 (pc.buf[4 + 6] << 8) + 2423 pc.buf[4 + 7]; 2424 tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7; 2425} 2426 2427static int idetape_chrdev_open(struct inode *inode, struct file *filp) 2428{ 2429 unsigned int minor = iminor(inode), i = minor & ~0xc0; 2430 ide_drive_t *drive; 2431 idetape_tape_t *tape; 2432 struct ide_atapi_pc pc; 2433 int retval; 2434 2435 if (i >= MAX_HWIFS * MAX_DRIVES) 2436 return -ENXIO; 2437 2438 tape = ide_tape_chrdev_get(i); 2439 if (!tape) 2440 return -ENXIO; 2441 2442 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 2443 2444 /* 2445 * We really want to do nonseekable_open(inode, filp); here, but some 2446 * versions of tar incorrectly call lseek on tapes and bail out if that 2447 * fails. So we disallow pread() and pwrite(), but permit lseeks. 2448 */ 2449 filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); 2450 2451 drive = tape->drive; 2452 2453 filp->private_data = tape; 2454 2455 if (test_and_set_bit(IDETAPE_FLAG_BUSY, &tape->flags)) { 2456 retval = -EBUSY; 2457 goto out_put_tape; 2458 } 2459 2460 retval = idetape_wait_ready(drive, 60 * HZ); 2461 if (retval) { 2462 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2463 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name); 2464 goto out_put_tape; 2465 } 2466 2467 idetape_read_position(drive); 2468 if (!test_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags)) 2469 (void)idetape_rewind_tape(drive); 2470 2471 /* Read block size and write protect status from drive. */ 2472 ide_tape_get_bsize_from_bdesc(drive); 2473 2474 /* Set write protect flag if device is opened as read-only. */ 2475 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) 2476 tape->write_prot = 1; 2477 else 2478 tape->write_prot = tape->drv_write_prot; 2479 2480 /* Make sure drive isn't write protected if user wants to write. */ 2481 if (tape->write_prot) { 2482 if ((filp->f_flags & O_ACCMODE) == O_WRONLY || 2483 (filp->f_flags & O_ACCMODE) == O_RDWR) { 2484 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2485 retval = -EROFS; 2486 goto out_put_tape; 2487 } 2488 } 2489 2490 /* Lock the tape drive door so user can't eject. */ 2491 if (tape->chrdev_dir == IDETAPE_DIR_NONE) { 2492 if (idetape_create_prevent_cmd(drive, &pc, 1)) { 2493 if (!idetape_queue_pc_tail(drive, &pc)) { 2494 if (tape->door_locked != DOOR_EXPLICITLY_LOCKED) 2495 tape->door_locked = DOOR_LOCKED; 2496 } 2497 } 2498 } 2499 return 0; 2500 2501out_put_tape: 2502 ide_tape_put(tape); 2503 return retval; 2504} 2505 2506static void idetape_write_release(ide_drive_t *drive, unsigned int minor) 2507{ 2508 idetape_tape_t *tape = drive->driver_data; 2509 2510 ide_tape_flush_merge_buffer(drive); 2511 tape->merge_stage = ide_tape_kmalloc_buffer(tape, 1, 0); 2512 if (tape->merge_stage != NULL) { 2513 idetape_pad_zeros(drive, tape->blk_size * 2514 (tape->user_bs_factor - 1)); 2515 ide_tape_kfree_buffer(tape->merge_stage); 2516 tape->merge_stage = NULL; 2517 } 2518 idetape_write_filemark(drive); 2519 idetape_flush_tape_buffers(drive); 2520 idetape_flush_tape_buffers(drive); 2521} 2522 2523static int idetape_chrdev_release(struct inode *inode, struct file *filp) 2524{ 2525 struct ide_tape_obj *tape = ide_tape_f(filp); 2526 ide_drive_t *drive = tape->drive; 2527 struct ide_atapi_pc pc; 2528 unsigned int minor = iminor(inode); 2529 2530 lock_kernel(); 2531 tape = drive->driver_data; 2532 2533 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 2534 2535 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) 2536 idetape_write_release(drive, minor); 2537 if (tape->chrdev_dir == IDETAPE_DIR_READ) { 2538 if (minor < 128) 2539 ide_tape_discard_merge_buffer(drive, 1); 2540 } 2541 2542 if (minor < 128 && test_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags)) 2543 (void) idetape_rewind_tape(drive); 2544 if (tape->chrdev_dir == IDETAPE_DIR_NONE) { 2545 if (tape->door_locked == DOOR_LOCKED) { 2546 if (idetape_create_prevent_cmd(drive, &pc, 0)) { 2547 if (!idetape_queue_pc_tail(drive, &pc)) 2548 tape->door_locked = DOOR_UNLOCKED; 2549 } 2550 } 2551 } 2552 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2553 ide_tape_put(tape); 2554 unlock_kernel(); 2555 return 0; 2556} 2557 2558/* 2559 * check the contents of the ATAPI IDENTIFY command results. We return: 2560 * 2561 * 1 - If the tape can be supported by us, based on the information we have so 2562 * far. 2563 * 2564 * 0 - If this tape driver is not currently supported by us. 2565 */ 2566static int idetape_identify_device(ide_drive_t *drive) 2567{ 2568 u8 gcw[2], protocol, device_type, removable, packet_size; 2569 2570 if (drive->id_read == 0) 2571 return 1; 2572 2573 *((unsigned short *) &gcw) = drive->id->config; 2574 2575 protocol = (gcw[1] & 0xC0) >> 6; 2576 device_type = gcw[1] & 0x1F; 2577 removable = !!(gcw[0] & 0x80); 2578 packet_size = gcw[0] & 0x3; 2579 2580 /* Check that we can support this device */ 2581 if (protocol != 2) 2582 printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n", 2583 protocol); 2584 else if (device_type != 1) 2585 printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set " 2586 "to tape\n", device_type); 2587 else if (!removable) 2588 printk(KERN_ERR "ide-tape: The removable flag is not set\n"); 2589 else if (packet_size != 0) { 2590 printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12" 2591 " bytes\n", packet_size); 2592 } else 2593 return 1; 2594 return 0; 2595} 2596 2597static void idetape_get_inquiry_results(ide_drive_t *drive) 2598{ 2599 idetape_tape_t *tape = drive->driver_data; 2600 struct ide_atapi_pc pc; 2601 char fw_rev[6], vendor_id[10], product_id[18]; 2602 2603 idetape_create_inquiry_cmd(&pc); 2604 if (idetape_queue_pc_tail(drive, &pc)) { 2605 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", 2606 tape->name); 2607 return; 2608 } 2609 memcpy(vendor_id, &pc.buf[8], 8); 2610 memcpy(product_id, &pc.buf[16], 16); 2611 memcpy(fw_rev, &pc.buf[32], 4); 2612 2613 ide_fixstring(vendor_id, 10, 0); 2614 ide_fixstring(product_id, 18, 0); 2615 ide_fixstring(fw_rev, 6, 0); 2616 2617 printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", 2618 drive->name, tape->name, vendor_id, product_id, fw_rev); 2619} 2620 2621/* 2622 * Ask the tape about its various parameters. In particular, we will adjust our 2623 * data transfer buffer size to the recommended value as returned by the tape. 2624 */ 2625static void idetape_get_mode_sense_results(ide_drive_t *drive) 2626{ 2627 idetape_tape_t *tape = drive->driver_data; 2628 struct ide_atapi_pc pc; 2629 u8 *caps; 2630 u8 speed, max_speed; 2631 2632 idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE); 2633 if (idetape_queue_pc_tail(drive, &pc)) { 2634 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming" 2635 " some default values\n"); 2636 tape->blk_size = 512; 2637 put_unaligned(52, (u16 *)&tape->caps[12]); 2638 put_unaligned(540, (u16 *)&tape->caps[14]); 2639 put_unaligned(6*52, (u16 *)&tape->caps[16]); 2640 return; 2641 } 2642 caps = pc.buf + 4 + pc.buf[3]; 2643 2644 /* convert to host order and save for later use */ 2645 speed = be16_to_cpu(*(u16 *)&caps[14]); 2646 max_speed = be16_to_cpu(*(u16 *)&caps[8]); 2647 2648 put_unaligned(max_speed, (u16 *)&caps[8]); 2649 put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]); 2650 put_unaligned(speed, (u16 *)&caps[14]); 2651 put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]); 2652 2653 if (!speed) { 2654 printk(KERN_INFO "ide-tape: %s: invalid tape speed " 2655 "(assuming 650KB/sec)\n", drive->name); 2656 put_unaligned(650, (u16 *)&caps[14]); 2657 } 2658 if (!max_speed) { 2659 printk(KERN_INFO "ide-tape: %s: invalid max_speed " 2660 "(assuming 650KB/sec)\n", drive->name); 2661 put_unaligned(650, (u16 *)&caps[8]); 2662 } 2663 2664 memcpy(&tape->caps, caps, 20); 2665 if (caps[7] & 0x02) 2666 tape->blk_size = 512; 2667 else if (caps[7] & 0x04) 2668 tape->blk_size = 1024; 2669} 2670 2671#ifdef CONFIG_IDE_PROC_FS 2672static void idetape_add_settings(ide_drive_t *drive) 2673{ 2674 idetape_tape_t *tape = drive->driver_data; 2675 2676 ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff, 2677 1, 2, (u16 *)&tape->caps[16], NULL); 2678 ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff, 2679 1, 1, (u16 *)&tape->caps[14], NULL); 2680 ide_add_setting(drive, "buffer_size", SETTING_READ, TYPE_INT, 0, 0xffff, 2681 1, 1024, &tape->buffer_size, NULL); 2682 ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN, 2683 IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq, 2684 NULL); 2685 ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1, 2686 1, &drive->dsc_overlap, NULL); 2687 ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff, 2688 1, 1, &tape->avg_speed, NULL); 2689 ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1, 2690 1, &tape->debug_mask, NULL); 2691} 2692#else 2693static inline void idetape_add_settings(ide_drive_t *drive) { ; } 2694#endif 2695 2696/* 2697 * The function below is called to: 2698 * 2699 * 1. Initialize our various state variables. 2700 * 2. Ask the tape for its capabilities. 2701 * 3. Allocate a buffer which will be used for data transfer. The buffer size 2702 * is chosen based on the recommendation which we received in step 2. 2703 * 2704 * Note that at this point ide.c already assigned us an irq, so that we can 2705 * queue requests here and wait for their completion. 2706 */ 2707static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor) 2708{ 2709 unsigned long t; 2710 int speed; 2711 int buffer_size; 2712 u8 gcw[2]; 2713 u16 *ctl = (u16 *)&tape->caps[12]; 2714 2715 spin_lock_init(&tape->lock); 2716 drive->dsc_overlap = 1; 2717 if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) { 2718 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", 2719 tape->name); 2720 drive->dsc_overlap = 0; 2721 } 2722 /* Seagate Travan drives do not support DSC overlap. */ 2723 if (strstr(drive->id->model, "Seagate STT3401")) 2724 drive->dsc_overlap = 0; 2725 tape->minor = minor; 2726 tape->name[0] = 'h'; 2727 tape->name[1] = 't'; 2728 tape->name[2] = '0' + minor; 2729 tape->chrdev_dir = IDETAPE_DIR_NONE; 2730 tape->pc = tape->pc_stack; 2731 *((unsigned short *) &gcw) = drive->id->config; 2732 2733 /* Command packet DRQ type */ 2734 if (((gcw[0] & 0x60) >> 5) == 1) 2735 set_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags); 2736 2737 idetape_get_inquiry_results(drive); 2738 idetape_get_mode_sense_results(drive); 2739 ide_tape_get_bsize_from_bdesc(drive); 2740 tape->user_bs_factor = 1; 2741 tape->buffer_size = *ctl * tape->blk_size; 2742 while (tape->buffer_size > 0xffff) { 2743 printk(KERN_NOTICE "ide-tape: decreasing stage size\n"); 2744 *ctl /= 2; 2745 tape->buffer_size = *ctl * tape->blk_size; 2746 } 2747 buffer_size = tape->buffer_size; 2748 tape->pages_per_buffer = buffer_size / PAGE_SIZE; 2749 if (buffer_size % PAGE_SIZE) { 2750 tape->pages_per_buffer++; 2751 tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE; 2752 } 2753 2754 /* select the "best" DSC read/write polling freq */ 2755 speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]); 2756 2757 t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000); 2758 2759 /* 2760 * Ensure that the number we got makes sense; limit it within 2761 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX. 2762 */ 2763 tape->best_dsc_rw_freq = max_t(unsigned long, 2764 min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), 2765 IDETAPE_DSC_RW_MIN); 2766 printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, " 2767 "%lums tDSC%s\n", 2768 drive->name, tape->name, *(u16 *)&tape->caps[14], 2769 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size, 2770 tape->buffer_size / 1024, 2771 tape->best_dsc_rw_freq * 1000 / HZ, 2772 drive->using_dma ? ", DMA":""); 2773 2774 idetape_add_settings(drive); 2775} 2776 2777static void ide_tape_remove(ide_drive_t *drive) 2778{ 2779 idetape_tape_t *tape = drive->driver_data; 2780 2781 ide_proc_unregister_driver(drive, tape->driver); 2782 2783 ide_unregister_region(tape->disk); 2784 2785 ide_tape_put(tape); 2786} 2787 2788static void ide_tape_release(struct kref *kref) 2789{ 2790 struct ide_tape_obj *tape = to_ide_tape(kref); 2791 ide_drive_t *drive = tape->drive; 2792 struct gendisk *g = tape->disk; 2793 2794 BUG_ON(tape->merge_bh_size); 2795 2796 drive->dsc_overlap = 0; 2797 drive->driver_data = NULL; 2798 device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor)); 2799 device_destroy(idetape_sysfs_class, 2800 MKDEV(IDETAPE_MAJOR, tape->minor + 128)); 2801 idetape_devs[tape->minor] = NULL; 2802 g->private_data = NULL; 2803 put_disk(g); 2804 kfree(tape); 2805} 2806 2807#ifdef CONFIG_IDE_PROC_FS 2808static int proc_idetape_read_name 2809 (char *page, char **start, off_t off, int count, int *eof, void *data) 2810{ 2811 ide_drive_t *drive = (ide_drive_t *) data; 2812 idetape_tape_t *tape = drive->driver_data; 2813 char *out = page; 2814 int len; 2815 2816 len = sprintf(out, "%s\n", tape->name); 2817 PROC_IDE_READ_RETURN(page, start, off, count, eof, len); 2818} 2819 2820static ide_proc_entry_t idetape_proc[] = { 2821 { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL }, 2822 { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL }, 2823 { NULL, 0, NULL, NULL } 2824}; 2825#endif 2826 2827static int ide_tape_probe(ide_drive_t *); 2828 2829static ide_driver_t idetape_driver = { 2830 .gen_driver = { 2831 .owner = THIS_MODULE, 2832 .name = "ide-tape", 2833 .bus = &ide_bus_type, 2834 }, 2835 .probe = ide_tape_probe, 2836 .remove = ide_tape_remove, 2837 .version = IDETAPE_VERSION, 2838 .media = ide_tape, 2839 .supports_dsc_overlap = 1, 2840 .do_request = idetape_do_request, 2841 .end_request = idetape_end_request, 2842 .error = __ide_error, 2843 .abort = __ide_abort, 2844#ifdef CONFIG_IDE_PROC_FS 2845 .proc = idetape_proc, 2846#endif 2847}; 2848 2849/* Our character device supporting functions, passed to register_chrdev. */ 2850static const struct file_operations idetape_fops = { 2851 .owner = THIS_MODULE, 2852 .read = idetape_chrdev_read, 2853 .write = idetape_chrdev_write, 2854 .ioctl = idetape_chrdev_ioctl, 2855 .open = idetape_chrdev_open, 2856 .release = idetape_chrdev_release, 2857}; 2858 2859static int idetape_open(struct inode *inode, struct file *filp) 2860{ 2861 struct gendisk *disk = inode->i_bdev->bd_disk; 2862 struct ide_tape_obj *tape; 2863 2864 tape = ide_tape_get(disk); 2865 if (!tape) 2866 return -ENXIO; 2867 2868 return 0; 2869} 2870 2871static int idetape_release(struct inode *inode, struct file *filp) 2872{ 2873 struct gendisk *disk = inode->i_bdev->bd_disk; 2874 struct ide_tape_obj *tape = ide_tape_g(disk); 2875 2876 ide_tape_put(tape); 2877 2878 return 0; 2879} 2880 2881static int idetape_ioctl(struct inode *inode, struct file *file, 2882 unsigned int cmd, unsigned long arg) 2883{ 2884 struct block_device *bdev = inode->i_bdev; 2885 struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk); 2886 ide_drive_t *drive = tape->drive; 2887 int err = generic_ide_ioctl(drive, file, bdev, cmd, arg); 2888 if (err == -EINVAL) 2889 err = idetape_blkdev_ioctl(drive, cmd, arg); 2890 return err; 2891} 2892 2893static struct block_device_operations idetape_block_ops = { 2894 .owner = THIS_MODULE, 2895 .open = idetape_open, 2896 .release = idetape_release, 2897 .ioctl = idetape_ioctl, 2898}; 2899 2900static int ide_tape_probe(ide_drive_t *drive) 2901{ 2902 idetape_tape_t *tape; 2903 struct gendisk *g; 2904 int minor; 2905 2906 if (!strstr("ide-tape", drive->driver_req)) 2907 goto failed; 2908 if (!drive->present) 2909 goto failed; 2910 if (drive->media != ide_tape) 2911 goto failed; 2912 if (!idetape_identify_device(drive)) { 2913 printk(KERN_ERR "ide-tape: %s: not supported by this version of" 2914 " the driver\n", drive->name); 2915 goto failed; 2916 } 2917 if (drive->scsi) { 2918 printk(KERN_INFO "ide-tape: passing drive %s to ide-scsi" 2919 " emulation.\n", drive->name); 2920 goto failed; 2921 } 2922 tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL); 2923 if (tape == NULL) { 2924 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n", 2925 drive->name); 2926 goto failed; 2927 } 2928 2929 g = alloc_disk(1 << PARTN_BITS); 2930 if (!g) 2931 goto out_free_tape; 2932 2933 ide_init_disk(g, drive); 2934 2935 ide_proc_register_driver(drive, &idetape_driver); 2936 2937 kref_init(&tape->kref); 2938 2939 tape->drive = drive; 2940 tape->driver = &idetape_driver; 2941 tape->disk = g; 2942 2943 g->private_data = &tape->driver; 2944 2945 drive->driver_data = tape; 2946 2947 mutex_lock(&idetape_ref_mutex); 2948 for (minor = 0; idetape_devs[minor]; minor++) 2949 ; 2950 idetape_devs[minor] = tape; 2951 mutex_unlock(&idetape_ref_mutex); 2952 2953 idetape_setup(drive, tape, minor); 2954 2955 device_create(idetape_sysfs_class, &drive->gendev, 2956 MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name); 2957 device_create(idetape_sysfs_class, &drive->gendev, 2958 MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name); 2959 2960 g->fops = &idetape_block_ops; 2961 ide_register_region(g); 2962 2963 return 0; 2964 2965out_free_tape: 2966 kfree(tape); 2967failed: 2968 return -ENODEV; 2969} 2970 2971static void __exit idetape_exit(void) 2972{ 2973 driver_unregister(&idetape_driver.gen_driver); 2974 class_destroy(idetape_sysfs_class); 2975 unregister_chrdev(IDETAPE_MAJOR, "ht"); 2976} 2977 2978static int __init idetape_init(void) 2979{ 2980 int error = 1; 2981 idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape"); 2982 if (IS_ERR(idetape_sysfs_class)) { 2983 idetape_sysfs_class = NULL; 2984 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n"); 2985 error = -EBUSY; 2986 goto out; 2987 } 2988 2989 if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) { 2990 printk(KERN_ERR "ide-tape: Failed to register chrdev" 2991 " interface\n"); 2992 error = -EBUSY; 2993 goto out_free_class; 2994 } 2995 2996 error = driver_register(&idetape_driver.gen_driver); 2997 if (error) 2998 goto out_free_driver; 2999 3000 return 0; 3001 3002out_free_driver: 3003 driver_unregister(&idetape_driver.gen_driver); 3004out_free_class: 3005 class_destroy(idetape_sysfs_class); 3006out: 3007 return error; 3008} 3009 3010MODULE_ALIAS("ide:*m-tape*"); 3011module_init(idetape_init); 3012module_exit(idetape_exit); 3013MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR); 3014MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver"); 3015MODULE_LICENSE("GPL"); 3016