ide-tape.c revision 91395a16309596c2e78439aa5f9f6004f0365ef9
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/* 219 * Most of our global data which we need to save even as we leave the driver due 220 * to an interrupt or a timer event is stored in the struct defined below. 221 */ 222typedef struct ide_tape_obj { 223 ide_drive_t *drive; 224 ide_driver_t *driver; 225 struct gendisk *disk; 226 struct kref kref; 227 228 /* 229 * Since a typical character device operation requires more 230 * than one packet command, we provide here enough memory 231 * for the maximum of interconnected packet commands. 232 * The packet commands are stored in the circular array pc_stack. 233 * pc_stack_index points to the last used entry, and warps around 234 * to the start when we get to the last array entry. 235 * 236 * pc points to the current processed packet command. 237 * 238 * failed_pc points to the last failed packet command, or contains 239 * NULL if we do not need to retry any packet command. This is 240 * required since an additional packet command is needed before the 241 * retry, to get detailed information on what went wrong. 242 */ 243 /* Current packet command */ 244 struct ide_atapi_pc *pc; 245 /* Last failed packet command */ 246 struct ide_atapi_pc *failed_pc; 247 /* Packet command stack */ 248 struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK]; 249 /* Next free packet command storage space */ 250 int pc_stack_index; 251 struct request rq_stack[IDETAPE_PC_STACK]; 252 /* We implement a circular array */ 253 int rq_stack_index; 254 255 /* 256 * DSC polling variables. 257 * 258 * While polling for DSC we use postponed_rq to postpone the current 259 * request so that ide.c will be able to service pending requests on the 260 * other device. Note that at most we will have only one DSC (usually 261 * data transfer) request in the device request queue. 262 */ 263 struct request *postponed_rq; 264 /* The time in which we started polling for DSC */ 265 unsigned long dsc_polling_start; 266 /* Timer used to poll for dsc */ 267 struct timer_list dsc_timer; 268 /* Read/Write dsc polling frequency */ 269 unsigned long best_dsc_rw_freq; 270 unsigned long dsc_poll_freq; 271 unsigned long dsc_timeout; 272 273 /* Read position information */ 274 u8 partition; 275 /* Current block */ 276 unsigned int first_frame; 277 278 /* Last error information */ 279 u8 sense_key, asc, ascq; 280 281 /* Character device operation */ 282 unsigned int minor; 283 /* device name */ 284 char name[4]; 285 /* Current character device data transfer direction */ 286 u8 chrdev_dir; 287 288 /* tape block size, usually 512 or 1024 bytes */ 289 unsigned short blk_size; 290 int user_bs_factor; 291 292 /* Copy of the tape's Capabilities and Mechanical Page */ 293 u8 caps[20]; 294 295 /* 296 * Active data transfer request parameters. 297 * 298 * At most, there is only one ide-tape originated data transfer request 299 * in the device request queue. This allows ide.c to easily service 300 * requests from the other device when we postpone our active request. 301 */ 302 303 /* Data buffer size chosen based on the tape's recommendation */ 304 int buffer_size; 305 /* merge buffer */ 306 struct idetape_bh *merge_bh; 307 /* size of the merge buffer */ 308 int merge_bh_size; 309 /* pointer to current buffer head within the merge buffer */ 310 struct idetape_bh *bh; 311 char *b_data; 312 int b_count; 313 314 int pages_per_buffer; 315 /* Wasted space in each stage */ 316 int excess_bh_size; 317 318 /* Status/Action flags: long for set_bit */ 319 unsigned long flags; 320 /* protects the ide-tape queue */ 321 spinlock_t lock; 322 323 /* Measures average tape speed */ 324 unsigned long avg_time; 325 int avg_size; 326 int avg_speed; 327 328 /* the door is currently locked */ 329 int door_locked; 330 /* the tape hardware is write protected */ 331 char drv_write_prot; 332 /* the tape is write protected (hardware or opened as read-only) */ 333 char write_prot; 334 335 u32 debug_mask; 336} idetape_tape_t; 337 338static DEFINE_MUTEX(idetape_ref_mutex); 339 340static struct class *idetape_sysfs_class; 341 342#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref) 343 344#define ide_tape_g(disk) \ 345 container_of((disk)->private_data, struct ide_tape_obj, driver) 346 347static struct ide_tape_obj *ide_tape_get(struct gendisk *disk) 348{ 349 struct ide_tape_obj *tape = NULL; 350 351 mutex_lock(&idetape_ref_mutex); 352 tape = ide_tape_g(disk); 353 if (tape) 354 kref_get(&tape->kref); 355 mutex_unlock(&idetape_ref_mutex); 356 return tape; 357} 358 359static void ide_tape_release(struct kref *); 360 361static void ide_tape_put(struct ide_tape_obj *tape) 362{ 363 mutex_lock(&idetape_ref_mutex); 364 kref_put(&tape->kref, ide_tape_release); 365 mutex_unlock(&idetape_ref_mutex); 366} 367 368/* 369 * The variables below are used for the character device interface. Additional 370 * state variables are defined in our ide_drive_t structure. 371 */ 372static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES]; 373 374#define ide_tape_f(file) ((file)->private_data) 375 376static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i) 377{ 378 struct ide_tape_obj *tape = NULL; 379 380 mutex_lock(&idetape_ref_mutex); 381 tape = idetape_devs[i]; 382 if (tape) 383 kref_get(&tape->kref); 384 mutex_unlock(&idetape_ref_mutex); 385 return tape; 386} 387 388static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, 389 unsigned int bcount) 390{ 391 struct idetape_bh *bh = pc->bh; 392 int count; 393 394 while (bcount) { 395 if (bh == NULL) { 396 printk(KERN_ERR "ide-tape: bh == NULL in " 397 "idetape_input_buffers\n"); 398 ide_pad_transfer(drive, 0, bcount); 399 return; 400 } 401 count = min( 402 (unsigned int)(bh->b_size - atomic_read(&bh->b_count)), 403 bcount); 404 drive->hwif->input_data(drive, NULL, bh->b_data + 405 atomic_read(&bh->b_count), count); 406 bcount -= count; 407 atomic_add(count, &bh->b_count); 408 if (atomic_read(&bh->b_count) == bh->b_size) { 409 bh = bh->b_reqnext; 410 if (bh) 411 atomic_set(&bh->b_count, 0); 412 } 413 } 414 pc->bh = bh; 415} 416 417static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, 418 unsigned int bcount) 419{ 420 struct idetape_bh *bh = pc->bh; 421 int count; 422 423 while (bcount) { 424 if (bh == NULL) { 425 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 426 __func__); 427 return; 428 } 429 count = min((unsigned int)pc->b_count, (unsigned int)bcount); 430 drive->hwif->output_data(drive, NULL, pc->b_data, count); 431 bcount -= count; 432 pc->b_data += count; 433 pc->b_count -= count; 434 if (!pc->b_count) { 435 bh = bh->b_reqnext; 436 pc->bh = bh; 437 if (bh) { 438 pc->b_data = bh->b_data; 439 pc->b_count = atomic_read(&bh->b_count); 440 } 441 } 442 } 443} 444 445static void idetape_update_buffers(struct ide_atapi_pc *pc) 446{ 447 struct idetape_bh *bh = pc->bh; 448 int count; 449 unsigned int bcount = pc->xferred; 450 451 if (pc->flags & PC_FLAG_WRITING) 452 return; 453 while (bcount) { 454 if (bh == NULL) { 455 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 456 __func__); 457 return; 458 } 459 count = min((unsigned int)bh->b_size, (unsigned int)bcount); 460 atomic_set(&bh->b_count, count); 461 if (atomic_read(&bh->b_count) == bh->b_size) 462 bh = bh->b_reqnext; 463 bcount -= count; 464 } 465 pc->bh = bh; 466} 467 468/* 469 * idetape_next_pc_storage returns a pointer to a place in which we can 470 * safely store a packet command, even though we intend to leave the 471 * driver. A storage space for a maximum of IDETAPE_PC_STACK packet 472 * commands is allocated at initialization time. 473 */ 474static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive) 475{ 476 idetape_tape_t *tape = drive->driver_data; 477 478 debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index); 479 480 if (tape->pc_stack_index == IDETAPE_PC_STACK) 481 tape->pc_stack_index = 0; 482 return (&tape->pc_stack[tape->pc_stack_index++]); 483} 484 485/* 486 * idetape_next_rq_storage is used along with idetape_next_pc_storage. 487 * Since we queue packet commands in the request queue, we need to 488 * allocate a request, along with the allocation of a packet command. 489 */ 490 491/************************************************************** 492 * * 493 * This should get fixed to use kmalloc(.., GFP_ATOMIC) * 494 * followed later on by kfree(). -ml * 495 * * 496 **************************************************************/ 497 498static struct request *idetape_next_rq_storage(ide_drive_t *drive) 499{ 500 idetape_tape_t *tape = drive->driver_data; 501 502 debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index); 503 504 if (tape->rq_stack_index == IDETAPE_PC_STACK) 505 tape->rq_stack_index = 0; 506 return (&tape->rq_stack[tape->rq_stack_index++]); 507} 508 509static void idetape_init_pc(struct ide_atapi_pc *pc) 510{ 511 memset(pc->c, 0, 12); 512 pc->retries = 0; 513 pc->flags = 0; 514 pc->req_xfer = 0; 515 pc->buf = pc->pc_buf; 516 pc->buf_size = IDETAPE_PC_BUFFER_SIZE; 517 pc->bh = NULL; 518 pc->b_data = NULL; 519} 520 521/* 522 * called on each failed packet command retry to analyze the request sense. We 523 * currently do not utilize this information. 524 */ 525static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) 526{ 527 idetape_tape_t *tape = drive->driver_data; 528 struct ide_atapi_pc *pc = tape->failed_pc; 529 530 tape->sense_key = sense[2] & 0xF; 531 tape->asc = sense[12]; 532 tape->ascq = sense[13]; 533 534 debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n", 535 pc->c[0], tape->sense_key, tape->asc, tape->ascq); 536 537 /* Correct pc->xferred by asking the tape. */ 538 if (pc->flags & PC_FLAG_DMA_ERROR) { 539 pc->xferred = pc->req_xfer - 540 tape->blk_size * 541 get_unaligned_be32(&sense[3]); 542 idetape_update_buffers(pc); 543 } 544 545 /* 546 * If error was the result of a zero-length read or write command, 547 * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives 548 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes. 549 */ 550 if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6) 551 /* length == 0 */ 552 && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { 553 if (tape->sense_key == 5) { 554 /* don't report an error, everything's ok */ 555 pc->error = 0; 556 /* don't retry read/write */ 557 pc->flags |= PC_FLAG_ABORT; 558 } 559 } 560 if (pc->c[0] == READ_6 && (sense[2] & 0x80)) { 561 pc->error = IDETAPE_ERROR_FILEMARK; 562 pc->flags |= PC_FLAG_ABORT; 563 } 564 if (pc->c[0] == WRITE_6) { 565 if ((sense[2] & 0x40) || (tape->sense_key == 0xd 566 && tape->asc == 0x0 && tape->ascq == 0x2)) { 567 pc->error = IDETAPE_ERROR_EOD; 568 pc->flags |= PC_FLAG_ABORT; 569 } 570 } 571 if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) { 572 if (tape->sense_key == 8) { 573 pc->error = IDETAPE_ERROR_EOD; 574 pc->flags |= PC_FLAG_ABORT; 575 } 576 if (!(pc->flags & PC_FLAG_ABORT) && 577 pc->xferred) 578 pc->retries = IDETAPE_MAX_PC_RETRIES + 1; 579 } 580} 581 582/* Free data buffers completely. */ 583static void ide_tape_kfree_buffer(idetape_tape_t *tape) 584{ 585 struct idetape_bh *prev_bh, *bh = tape->merge_bh; 586 587 while (bh) { 588 u32 size = bh->b_size; 589 590 while (size) { 591 unsigned int order = fls(size >> PAGE_SHIFT)-1; 592 593 if (bh->b_data) 594 free_pages((unsigned long)bh->b_data, order); 595 596 size &= (order-1); 597 bh->b_data += (1 << order) * PAGE_SIZE; 598 } 599 prev_bh = bh; 600 bh = bh->b_reqnext; 601 kfree(prev_bh); 602 } 603 kfree(tape->merge_bh); 604} 605 606static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects) 607{ 608 struct request *rq = HWGROUP(drive)->rq; 609 idetape_tape_t *tape = drive->driver_data; 610 unsigned long flags; 611 int error; 612 613 debug_log(DBG_PROCS, "Enter %s\n", __func__); 614 615 switch (uptodate) { 616 case 0: error = IDETAPE_ERROR_GENERAL; break; 617 case 1: error = 0; break; 618 default: error = uptodate; 619 } 620 rq->errors = error; 621 if (error) 622 tape->failed_pc = NULL; 623 624 if (!blk_special_request(rq)) { 625 ide_end_request(drive, uptodate, nr_sects); 626 return 0; 627 } 628 629 spin_lock_irqsave(&tape->lock, flags); 630 631 ide_end_drive_cmd(drive, 0, 0); 632 633 spin_unlock_irqrestore(&tape->lock, flags); 634 return 0; 635} 636 637static ide_startstop_t idetape_request_sense_callback(ide_drive_t *drive) 638{ 639 idetape_tape_t *tape = drive->driver_data; 640 641 debug_log(DBG_PROCS, "Enter %s\n", __func__); 642 643 if (!tape->pc->error) { 644 idetape_analyze_error(drive, tape->pc->buf); 645 idetape_end_request(drive, 1, 0); 646 } else { 647 printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - " 648 "Aborting request!\n"); 649 idetape_end_request(drive, 0, 0); 650 } 651 return ide_stopped; 652} 653 654static void idetape_create_request_sense_cmd(struct ide_atapi_pc *pc) 655{ 656 idetape_init_pc(pc); 657 pc->c[0] = REQUEST_SENSE; 658 pc->c[4] = 20; 659 pc->req_xfer = 20; 660 pc->idetape_callback = &idetape_request_sense_callback; 661} 662 663static void idetape_init_rq(struct request *rq, u8 cmd) 664{ 665 blk_rq_init(NULL, rq); 666 rq->cmd_type = REQ_TYPE_SPECIAL; 667 rq->cmd[0] = cmd; 668} 669 670/* 671 * Generate a new packet command request in front of the request queue, before 672 * the current request, so that it will be processed immediately, on the next 673 * pass through the driver. The function below is called from the request 674 * handling part of the driver (the "bottom" part). Safe storage for the request 675 * should be allocated with ide_tape_next_{pc,rq}_storage() prior to that. 676 * 677 * Memory for those requests is pre-allocated at initialization time, and is 678 * limited to IDETAPE_PC_STACK requests. We assume that we have enough space for 679 * the maximum possible number of inter-dependent packet commands. 680 * 681 * The higher level of the driver - The ioctl handler and the character device 682 * handling functions should queue request to the lower level part and wait for 683 * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail. 684 */ 685static void idetape_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc, 686 struct request *rq) 687{ 688 struct ide_tape_obj *tape = drive->driver_data; 689 690 idetape_init_rq(rq, REQ_IDETAPE_PC1); 691 rq->cmd_flags |= REQ_PREEMPT; 692 rq->buffer = (char *) pc; 693 rq->rq_disk = tape->disk; 694 ide_do_drive_cmd(drive, rq); 695} 696 697/* 698 * idetape_retry_pc is called when an error was detected during the 699 * last packet command. We queue a request sense packet command in 700 * the head of the request list. 701 */ 702static ide_startstop_t idetape_retry_pc (ide_drive_t *drive) 703{ 704 idetape_tape_t *tape = drive->driver_data; 705 struct ide_atapi_pc *pc; 706 struct request *rq; 707 708 (void)ide_read_error(drive); 709 pc = idetape_next_pc_storage(drive); 710 rq = idetape_next_rq_storage(drive); 711 idetape_create_request_sense_cmd(pc); 712 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 713 idetape_queue_pc_head(drive, pc, rq); 714 return ide_stopped; 715} 716 717/* 718 * Postpone the current request so that ide.c will be able to service requests 719 * from another device on the same hwgroup while we are polling for DSC. 720 */ 721static void idetape_postpone_request(ide_drive_t *drive) 722{ 723 idetape_tape_t *tape = drive->driver_data; 724 725 debug_log(DBG_PROCS, "Enter %s\n", __func__); 726 727 tape->postponed_rq = HWGROUP(drive)->rq; 728 ide_stall_queue(drive, tape->dsc_poll_freq); 729} 730 731typedef void idetape_io_buf(ide_drive_t *, struct ide_atapi_pc *, unsigned int); 732 733/* 734 * This is the usual interrupt handler which will be called during a packet 735 * command. We will transfer some of the data (as requested by the drive) and 736 * will re-point interrupt handler to us. When data transfer is finished, we 737 * will act according to the algorithm described before 738 * idetape_issue_pc. 739 */ 740static ide_startstop_t idetape_pc_intr(ide_drive_t *drive) 741{ 742 ide_hwif_t *hwif = drive->hwif; 743 idetape_tape_t *tape = drive->driver_data; 744 struct ide_atapi_pc *pc = tape->pc; 745 xfer_func_t *xferfunc; 746 idetape_io_buf *iobuf; 747 unsigned int temp; 748#if SIMULATE_ERRORS 749 static int error_sim_count; 750#endif 751 u16 bcount; 752 u8 stat, ireason; 753 754 debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__); 755 756 /* Clear the interrupt */ 757 stat = ide_read_status(drive); 758 759 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 760 if (hwif->dma_ops->dma_end(drive) || (stat & ERR_STAT)) { 761 /* 762 * A DMA error is sometimes expected. For example, 763 * if the tape is crossing a filemark during a 764 * READ command, it will issue an irq and position 765 * itself before the filemark, so that only a partial 766 * data transfer will occur (which causes the DMA 767 * error). In that case, we will later ask the tape 768 * how much bytes of the original request were 769 * actually transferred (we can't receive that 770 * information from the DMA engine on most chipsets). 771 */ 772 773 /* 774 * On the contrary, a DMA error is never expected; 775 * it usually indicates a hardware error or abort. 776 * If the tape crosses a filemark during a READ 777 * command, it will issue an irq and position itself 778 * after the filemark (not before). Only a partial 779 * data transfer will occur, but no DMA error. 780 * (AS, 19 Apr 2001) 781 */ 782 pc->flags |= PC_FLAG_DMA_ERROR; 783 } else { 784 pc->xferred = pc->req_xfer; 785 idetape_update_buffers(pc); 786 } 787 debug_log(DBG_PROCS, "DMA finished\n"); 788 789 } 790 791 /* No more interrupts */ 792 if ((stat & DRQ_STAT) == 0) { 793 debug_log(DBG_SENSE, "Packet command completed, %d bytes" 794 " transferred\n", pc->xferred); 795 796 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 797 local_irq_enable_in_hardirq(); 798 799#if SIMULATE_ERRORS 800 if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) && 801 (++error_sim_count % 100) == 0) { 802 printk(KERN_INFO "ide-tape: %s: simulating error\n", 803 tape->name); 804 stat |= ERR_STAT; 805 } 806#endif 807 if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE) 808 stat &= ~ERR_STAT; 809 if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) { 810 /* Error detected */ 811 debug_log(DBG_ERR, "%s: I/O error\n", tape->name); 812 813 if (pc->c[0] == REQUEST_SENSE) { 814 printk(KERN_ERR "ide-tape: I/O error in request" 815 " sense command\n"); 816 return ide_do_reset(drive); 817 } 818 debug_log(DBG_ERR, "[cmd %x]: check condition\n", 819 pc->c[0]); 820 821 /* Retry operation */ 822 return idetape_retry_pc(drive); 823 } 824 pc->error = 0; 825 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && 826 (stat & SEEK_STAT) == 0) { 827 /* Media access command */ 828 tape->dsc_polling_start = jiffies; 829 tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST; 830 tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT; 831 /* Allow ide.c to handle other requests */ 832 idetape_postpone_request(drive); 833 return ide_stopped; 834 } 835 if (tape->failed_pc == pc) 836 tape->failed_pc = NULL; 837 /* Command finished - Call the callback function */ 838 return pc->idetape_callback(drive); 839 } 840 841 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 842 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 843 printk(KERN_ERR "ide-tape: The tape wants to issue more " 844 "interrupts in DMA mode\n"); 845 ide_dma_off(drive); 846 return ide_do_reset(drive); 847 } 848 /* Get the number of bytes to transfer on this interrupt. */ 849 bcount = (hwif->INB(hwif->io_ports.lbah_addr) << 8) | 850 hwif->INB(hwif->io_ports.lbam_addr); 851 852 ireason = hwif->INB(hwif->io_ports.nsect_addr); 853 854 if (ireason & CD) { 855 printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__); 856 return ide_do_reset(drive); 857 } 858 if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) { 859 /* Hopefully, we will never get here */ 860 printk(KERN_ERR "ide-tape: We wanted to %s, ", 861 (ireason & IO) ? "Write" : "Read"); 862 printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n", 863 (ireason & IO) ? "Read" : "Write"); 864 return ide_do_reset(drive); 865 } 866 if (!(pc->flags & PC_FLAG_WRITING)) { 867 /* Reading - Check that we have enough space */ 868 temp = pc->xferred + bcount; 869 if (temp > pc->req_xfer) { 870 if (temp > pc->buf_size) { 871 printk(KERN_ERR "ide-tape: The tape wants to " 872 "send us more data than expected " 873 "- discarding data\n"); 874 ide_pad_transfer(drive, 0, bcount); 875 ide_set_handler(drive, &idetape_pc_intr, 876 IDETAPE_WAIT_CMD, NULL); 877 return ide_started; 878 } 879 debug_log(DBG_SENSE, "The tape wants to send us more " 880 "data than expected - allowing transfer\n"); 881 } 882 iobuf = &idetape_input_buffers; 883 xferfunc = hwif->input_data; 884 } else { 885 iobuf = &idetape_output_buffers; 886 xferfunc = hwif->output_data; 887 } 888 889 if (pc->bh) 890 iobuf(drive, pc, bcount); 891 else 892 xferfunc(drive, NULL, pc->cur_pos, bcount); 893 894 /* Update the current position */ 895 pc->xferred += bcount; 896 pc->cur_pos += bcount; 897 898 debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n", 899 pc->c[0], bcount); 900 901 /* And set the interrupt handler again */ 902 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); 903 return ide_started; 904} 905 906/* 907 * Packet Command Interface 908 * 909 * The current Packet Command is available in tape->pc, and will not change 910 * until we finish handling it. Each packet command is associated with a 911 * callback function that will be called when the command is finished. 912 * 913 * The handling will be done in three stages: 914 * 915 * 1. idetape_issue_pc will send the packet command to the drive, and will set 916 * the interrupt handler to idetape_pc_intr. 917 * 918 * 2. On each interrupt, idetape_pc_intr will be called. This step will be 919 * repeated until the device signals us that no more interrupts will be issued. 920 * 921 * 3. ATAPI Tape media access commands have immediate status with a delayed 922 * process. In case of a successful initiation of a media access packet command, 923 * the DSC bit will be set when the actual execution of the command is finished. 924 * Since the tape drive will not issue an interrupt, we have to poll for this 925 * event. In this case, we define the request as "low priority request" by 926 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and 927 * exit the driver. 928 * 929 * ide.c will then give higher priority to requests which originate from the 930 * other device, until will change rq_status to RQ_ACTIVE. 931 * 932 * 4. When the packet command is finished, it will be checked for errors. 933 * 934 * 5. In case an error was found, we queue a request sense packet command in 935 * front of the request queue and retry the operation up to 936 * IDETAPE_MAX_PC_RETRIES times. 937 * 938 * 6. In case no error was found, or we decided to give up and not to retry 939 * again, the callback function will be called and then we will handle the next 940 * request. 941 */ 942static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive) 943{ 944 ide_hwif_t *hwif = drive->hwif; 945 idetape_tape_t *tape = drive->driver_data; 946 struct ide_atapi_pc *pc = tape->pc; 947 int retries = 100; 948 ide_startstop_t startstop; 949 u8 ireason; 950 951 if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) { 952 printk(KERN_ERR "ide-tape: Strange, packet command initiated " 953 "yet DRQ isn't asserted\n"); 954 return startstop; 955 } 956 ireason = hwif->INB(hwif->io_ports.nsect_addr); 957 while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) { 958 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing " 959 "a packet command, retrying\n"); 960 udelay(100); 961 ireason = hwif->INB(hwif->io_ports.nsect_addr); 962 if (retries == 0) { 963 printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while " 964 "issuing a packet command, ignoring\n"); 965 ireason |= CD; 966 ireason &= ~IO; 967 } 968 } 969 if ((ireason & CD) == 0 || (ireason & IO)) { 970 printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing " 971 "a packet command\n"); 972 return ide_do_reset(drive); 973 } 974 /* Set the interrupt routine */ 975 ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); 976 977 /* Begin DMA, if necessary */ 978 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) 979 hwif->dma_ops->dma_start(drive); 980 981 /* Send the actual packet */ 982 hwif->output_data(drive, NULL, pc->c, 12); 983 984 return ide_started; 985} 986 987static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, 988 struct ide_atapi_pc *pc) 989{ 990 ide_hwif_t *hwif = drive->hwif; 991 idetape_tape_t *tape = drive->driver_data; 992 int dma_ok = 0; 993 u16 bcount; 994 995 if (tape->pc->c[0] == REQUEST_SENSE && 996 pc->c[0] == REQUEST_SENSE) { 997 printk(KERN_ERR "ide-tape: possible ide-tape.c bug - " 998 "Two request sense in serial were issued\n"); 999 } 1000 1001 if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE) 1002 tape->failed_pc = pc; 1003 /* Set the current packet command */ 1004 tape->pc = pc; 1005 1006 if (pc->retries > IDETAPE_MAX_PC_RETRIES || 1007 (pc->flags & PC_FLAG_ABORT)) { 1008 /* 1009 * We will "abort" retrying a packet command in case legitimate 1010 * error code was received (crossing a filemark, or end of the 1011 * media, for example). 1012 */ 1013 if (!(pc->flags & PC_FLAG_ABORT)) { 1014 if (!(pc->c[0] == TEST_UNIT_READY && 1015 tape->sense_key == 2 && tape->asc == 4 && 1016 (tape->ascq == 1 || tape->ascq == 8))) { 1017 printk(KERN_ERR "ide-tape: %s: I/O error, " 1018 "pc = %2x, key = %2x, " 1019 "asc = %2x, ascq = %2x\n", 1020 tape->name, pc->c[0], 1021 tape->sense_key, tape->asc, 1022 tape->ascq); 1023 } 1024 /* Giving up */ 1025 pc->error = IDETAPE_ERROR_GENERAL; 1026 } 1027 tape->failed_pc = NULL; 1028 return pc->idetape_callback(drive); 1029 } 1030 debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]); 1031 1032 pc->retries++; 1033 /* We haven't transferred any data yet */ 1034 pc->xferred = 0; 1035 pc->cur_pos = pc->buf; 1036 /* Request to transfer the entire buffer at once */ 1037 bcount = pc->req_xfer; 1038 1039 if (pc->flags & PC_FLAG_DMA_ERROR) { 1040 pc->flags &= ~PC_FLAG_DMA_ERROR; 1041 ide_dma_off(drive); 1042 } 1043 if ((pc->flags & PC_FLAG_DMA_RECOMMENDED) && drive->using_dma) 1044 dma_ok = !hwif->dma_ops->dma_setup(drive); 1045 1046 ide_pktcmd_tf_load(drive, IDE_TFLAG_OUT_DEVICE, bcount, dma_ok); 1047 1048 if (dma_ok) 1049 /* Will begin DMA later */ 1050 pc->flags |= PC_FLAG_DMA_IN_PROGRESS; 1051 if (test_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags)) { 1052 ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc, 1053 IDETAPE_WAIT_CMD, NULL); 1054 return ide_started; 1055 } else { 1056 ide_execute_pkt_cmd(drive); 1057 return idetape_transfer_pc(drive); 1058 } 1059} 1060 1061static ide_startstop_t idetape_pc_callback(ide_drive_t *drive) 1062{ 1063 idetape_tape_t *tape = drive->driver_data; 1064 1065 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1066 1067 idetape_end_request(drive, tape->pc->error ? 0 : 1, 0); 1068 return ide_stopped; 1069} 1070 1071/* A mode sense command is used to "sense" tape parameters. */ 1072static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code) 1073{ 1074 idetape_init_pc(pc); 1075 pc->c[0] = MODE_SENSE; 1076 if (page_code != IDETAPE_BLOCK_DESCRIPTOR) 1077 /* DBD = 1 - Don't return block descriptors */ 1078 pc->c[1] = 8; 1079 pc->c[2] = page_code; 1080 /* 1081 * Changed pc->c[3] to 0 (255 will at best return unused info). 1082 * 1083 * For SCSI this byte is defined as subpage instead of high byte 1084 * of length and some IDE drives seem to interpret it this way 1085 * and return an error when 255 is used. 1086 */ 1087 pc->c[3] = 0; 1088 /* We will just discard data in that case */ 1089 pc->c[4] = 255; 1090 if (page_code == IDETAPE_BLOCK_DESCRIPTOR) 1091 pc->req_xfer = 12; 1092 else if (page_code == IDETAPE_CAPABILITIES_PAGE) 1093 pc->req_xfer = 24; 1094 else 1095 pc->req_xfer = 50; 1096 pc->idetape_callback = &idetape_pc_callback; 1097} 1098 1099static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive) 1100{ 1101 idetape_tape_t *tape = drive->driver_data; 1102 struct ide_atapi_pc *pc = tape->pc; 1103 u8 stat; 1104 1105 stat = ide_read_status(drive); 1106 1107 if (stat & SEEK_STAT) { 1108 if (stat & ERR_STAT) { 1109 /* Error detected */ 1110 if (pc->c[0] != TEST_UNIT_READY) 1111 printk(KERN_ERR "ide-tape: %s: I/O error, ", 1112 tape->name); 1113 /* Retry operation */ 1114 return idetape_retry_pc(drive); 1115 } 1116 pc->error = 0; 1117 if (tape->failed_pc == pc) 1118 tape->failed_pc = NULL; 1119 } else { 1120 pc->error = IDETAPE_ERROR_GENERAL; 1121 tape->failed_pc = NULL; 1122 } 1123 return pc->idetape_callback(drive); 1124} 1125 1126static ide_startstop_t idetape_rw_callback(ide_drive_t *drive) 1127{ 1128 idetape_tape_t *tape = drive->driver_data; 1129 struct request *rq = HWGROUP(drive)->rq; 1130 int blocks = tape->pc->xferred / tape->blk_size; 1131 1132 tape->avg_size += blocks * tape->blk_size; 1133 1134 if (time_after_eq(jiffies, tape->avg_time + HZ)) { 1135 tape->avg_speed = tape->avg_size * HZ / 1136 (jiffies - tape->avg_time) / 1024; 1137 tape->avg_size = 0; 1138 tape->avg_time = jiffies; 1139 } 1140 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1141 1142 tape->first_frame += blocks; 1143 rq->current_nr_sectors -= blocks; 1144 1145 if (!tape->pc->error) 1146 idetape_end_request(drive, 1, 0); 1147 else 1148 idetape_end_request(drive, tape->pc->error, 0); 1149 return ide_stopped; 1150} 1151 1152static void idetape_create_read_cmd(idetape_tape_t *tape, 1153 struct ide_atapi_pc *pc, 1154 unsigned int length, struct idetape_bh *bh) 1155{ 1156 idetape_init_pc(pc); 1157 pc->c[0] = READ_6; 1158 put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); 1159 pc->c[1] = 1; 1160 pc->idetape_callback = &idetape_rw_callback; 1161 pc->bh = bh; 1162 atomic_set(&bh->b_count, 0); 1163 pc->buf = NULL; 1164 pc->buf_size = length * tape->blk_size; 1165 pc->req_xfer = pc->buf_size; 1166 if (pc->req_xfer == tape->buffer_size) 1167 pc->flags |= PC_FLAG_DMA_RECOMMENDED; 1168} 1169 1170static void idetape_create_write_cmd(idetape_tape_t *tape, 1171 struct ide_atapi_pc *pc, 1172 unsigned int length, struct idetape_bh *bh) 1173{ 1174 idetape_init_pc(pc); 1175 pc->c[0] = WRITE_6; 1176 put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); 1177 pc->c[1] = 1; 1178 pc->idetape_callback = &idetape_rw_callback; 1179 pc->flags |= PC_FLAG_WRITING; 1180 pc->bh = bh; 1181 pc->b_data = bh->b_data; 1182 pc->b_count = atomic_read(&bh->b_count); 1183 pc->buf = NULL; 1184 pc->buf_size = length * tape->blk_size; 1185 pc->req_xfer = pc->buf_size; 1186 if (pc->req_xfer == tape->buffer_size) 1187 pc->flags |= PC_FLAG_DMA_RECOMMENDED; 1188} 1189 1190static ide_startstop_t idetape_do_request(ide_drive_t *drive, 1191 struct request *rq, sector_t block) 1192{ 1193 idetape_tape_t *tape = drive->driver_data; 1194 struct ide_atapi_pc *pc = NULL; 1195 struct request *postponed_rq = tape->postponed_rq; 1196 u8 stat; 1197 1198 debug_log(DBG_SENSE, "sector: %ld, nr_sectors: %ld," 1199 " current_nr_sectors: %d\n", 1200 rq->sector, rq->nr_sectors, rq->current_nr_sectors); 1201 1202 if (!blk_special_request(rq)) { 1203 /* We do not support buffer cache originated requests. */ 1204 printk(KERN_NOTICE "ide-tape: %s: Unsupported request in " 1205 "request queue (%d)\n", drive->name, rq->cmd_type); 1206 ide_end_request(drive, 0, 0); 1207 return ide_stopped; 1208 } 1209 1210 /* Retry a failed packet command */ 1211 if (tape->failed_pc && tape->pc->c[0] == REQUEST_SENSE) 1212 return idetape_issue_pc(drive, tape->failed_pc); 1213 1214 if (postponed_rq != NULL) 1215 if (rq != postponed_rq) { 1216 printk(KERN_ERR "ide-tape: ide-tape.c bug - " 1217 "Two DSC requests were queued\n"); 1218 idetape_end_request(drive, 0, 0); 1219 return ide_stopped; 1220 } 1221 1222 tape->postponed_rq = NULL; 1223 1224 /* 1225 * If the tape is still busy, postpone our request and service 1226 * the other device meanwhile. 1227 */ 1228 stat = ide_read_status(drive); 1229 1230 if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2)) 1231 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 1232 1233 if (drive->post_reset == 1) { 1234 set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags); 1235 drive->post_reset = 0; 1236 } 1237 1238 if (!test_and_clear_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags) && 1239 (stat & SEEK_STAT) == 0) { 1240 if (postponed_rq == NULL) { 1241 tape->dsc_polling_start = jiffies; 1242 tape->dsc_poll_freq = tape->best_dsc_rw_freq; 1243 tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT; 1244 } else if (time_after(jiffies, tape->dsc_timeout)) { 1245 printk(KERN_ERR "ide-tape: %s: DSC timeout\n", 1246 tape->name); 1247 if (rq->cmd[0] & REQ_IDETAPE_PC2) { 1248 idetape_media_access_finished(drive); 1249 return ide_stopped; 1250 } else { 1251 return ide_do_reset(drive); 1252 } 1253 } else if (time_after(jiffies, 1254 tape->dsc_polling_start + 1255 IDETAPE_DSC_MA_THRESHOLD)) 1256 tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW; 1257 idetape_postpone_request(drive); 1258 return ide_stopped; 1259 } 1260 if (rq->cmd[0] & REQ_IDETAPE_READ) { 1261 pc = idetape_next_pc_storage(drive); 1262 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, 1263 (struct idetape_bh *)rq->special); 1264 goto out; 1265 } 1266 if (rq->cmd[0] & REQ_IDETAPE_WRITE) { 1267 pc = idetape_next_pc_storage(drive); 1268 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, 1269 (struct idetape_bh *)rq->special); 1270 goto out; 1271 } 1272 if (rq->cmd[0] & REQ_IDETAPE_PC1) { 1273 pc = (struct ide_atapi_pc *) rq->buffer; 1274 rq->cmd[0] &= ~(REQ_IDETAPE_PC1); 1275 rq->cmd[0] |= REQ_IDETAPE_PC2; 1276 goto out; 1277 } 1278 if (rq->cmd[0] & REQ_IDETAPE_PC2) { 1279 idetape_media_access_finished(drive); 1280 return ide_stopped; 1281 } 1282 BUG(); 1283out: 1284 return idetape_issue_pc(drive, pc); 1285} 1286 1287/* 1288 * The function below uses __get_free_pages to allocate a data buffer of size 1289 * tape->buffer_size (or a bit more). We attempt to combine sequential pages as 1290 * much as possible. 1291 * 1292 * It returns a pointer to the newly allocated buffer, or NULL in case of 1293 * failure. 1294 */ 1295static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape, 1296 int full, int clear) 1297{ 1298 struct idetape_bh *prev_bh, *bh, *merge_bh; 1299 int pages = tape->pages_per_buffer; 1300 unsigned int order, b_allocd; 1301 char *b_data = NULL; 1302 1303 merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); 1304 bh = merge_bh; 1305 if (bh == NULL) 1306 goto abort; 1307 1308 order = fls(pages) - 1; 1309 bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order); 1310 if (!bh->b_data) 1311 goto abort; 1312 b_allocd = (1 << order) * PAGE_SIZE; 1313 pages &= (order-1); 1314 1315 if (clear) 1316 memset(bh->b_data, 0, b_allocd); 1317 bh->b_reqnext = NULL; 1318 bh->b_size = b_allocd; 1319 atomic_set(&bh->b_count, full ? bh->b_size : 0); 1320 1321 while (pages) { 1322 order = fls(pages) - 1; 1323 b_data = (char *) __get_free_pages(GFP_KERNEL, order); 1324 if (!b_data) 1325 goto abort; 1326 b_allocd = (1 << order) * PAGE_SIZE; 1327 1328 if (clear) 1329 memset(b_data, 0, b_allocd); 1330 1331 /* newly allocated page frames below buffer header or ...*/ 1332 if (bh->b_data == b_data + b_allocd) { 1333 bh->b_size += b_allocd; 1334 bh->b_data -= b_allocd; 1335 if (full) 1336 atomic_add(b_allocd, &bh->b_count); 1337 continue; 1338 } 1339 /* they are above the header */ 1340 if (b_data == bh->b_data + bh->b_size) { 1341 bh->b_size += b_allocd; 1342 if (full) 1343 atomic_add(b_allocd, &bh->b_count); 1344 continue; 1345 } 1346 prev_bh = bh; 1347 bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); 1348 if (!bh) { 1349 free_pages((unsigned long) b_data, order); 1350 goto abort; 1351 } 1352 bh->b_reqnext = NULL; 1353 bh->b_data = b_data; 1354 bh->b_size = b_allocd; 1355 atomic_set(&bh->b_count, full ? bh->b_size : 0); 1356 prev_bh->b_reqnext = bh; 1357 1358 pages &= (order-1); 1359 } 1360 1361 bh->b_size -= tape->excess_bh_size; 1362 if (full) 1363 atomic_sub(tape->excess_bh_size, &bh->b_count); 1364 return merge_bh; 1365abort: 1366 ide_tape_kfree_buffer(tape); 1367 return NULL; 1368} 1369 1370static int idetape_copy_stage_from_user(idetape_tape_t *tape, 1371 const char __user *buf, int n) 1372{ 1373 struct idetape_bh *bh = tape->bh; 1374 int count; 1375 int ret = 0; 1376 1377 while (n) { 1378 if (bh == NULL) { 1379 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 1380 __func__); 1381 return 1; 1382 } 1383 count = min((unsigned int) 1384 (bh->b_size - atomic_read(&bh->b_count)), 1385 (unsigned int)n); 1386 if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, 1387 count)) 1388 ret = 1; 1389 n -= count; 1390 atomic_add(count, &bh->b_count); 1391 buf += count; 1392 if (atomic_read(&bh->b_count) == bh->b_size) { 1393 bh = bh->b_reqnext; 1394 if (bh) 1395 atomic_set(&bh->b_count, 0); 1396 } 1397 } 1398 tape->bh = bh; 1399 return ret; 1400} 1401 1402static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf, 1403 int n) 1404{ 1405 struct idetape_bh *bh = tape->bh; 1406 int count; 1407 int ret = 0; 1408 1409 while (n) { 1410 if (bh == NULL) { 1411 printk(KERN_ERR "ide-tape: bh == NULL in %s\n", 1412 __func__); 1413 return 1; 1414 } 1415 count = min(tape->b_count, n); 1416 if (copy_to_user(buf, tape->b_data, count)) 1417 ret = 1; 1418 n -= count; 1419 tape->b_data += count; 1420 tape->b_count -= count; 1421 buf += count; 1422 if (!tape->b_count) { 1423 bh = bh->b_reqnext; 1424 tape->bh = bh; 1425 if (bh) { 1426 tape->b_data = bh->b_data; 1427 tape->b_count = atomic_read(&bh->b_count); 1428 } 1429 } 1430 } 1431 return ret; 1432} 1433 1434static void idetape_init_merge_buffer(idetape_tape_t *tape) 1435{ 1436 struct idetape_bh *bh = tape->merge_bh; 1437 tape->bh = tape->merge_bh; 1438 1439 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) 1440 atomic_set(&bh->b_count, 0); 1441 else { 1442 tape->b_data = bh->b_data; 1443 tape->b_count = atomic_read(&bh->b_count); 1444 } 1445} 1446 1447static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive) 1448{ 1449 idetape_tape_t *tape = drive->driver_data; 1450 u8 *readpos = tape->pc->buf; 1451 1452 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1453 1454 if (!tape->pc->error) { 1455 debug_log(DBG_SENSE, "BOP - %s\n", 1456 (readpos[0] & 0x80) ? "Yes" : "No"); 1457 debug_log(DBG_SENSE, "EOP - %s\n", 1458 (readpos[0] & 0x40) ? "Yes" : "No"); 1459 1460 if (readpos[0] & 0x4) { 1461 printk(KERN_INFO "ide-tape: Block location is unknown" 1462 "to the tape\n"); 1463 clear_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags); 1464 idetape_end_request(drive, 0, 0); 1465 } else { 1466 debug_log(DBG_SENSE, "Block Location - %u\n", 1467 be32_to_cpu(*(u32 *)&readpos[4])); 1468 1469 tape->partition = readpos[1]; 1470 tape->first_frame = 1471 be32_to_cpu(*(u32 *)&readpos[4]); 1472 set_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags); 1473 idetape_end_request(drive, 1, 0); 1474 } 1475 } else { 1476 idetape_end_request(drive, 0, 0); 1477 } 1478 return ide_stopped; 1479} 1480 1481/* 1482 * Write a filemark if write_filemark=1. Flush the device buffers without 1483 * writing a filemark otherwise. 1484 */ 1485static void idetape_create_write_filemark_cmd(ide_drive_t *drive, 1486 struct ide_atapi_pc *pc, int write_filemark) 1487{ 1488 idetape_init_pc(pc); 1489 pc->c[0] = WRITE_FILEMARKS; 1490 pc->c[4] = write_filemark; 1491 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1492 pc->idetape_callback = &idetape_pc_callback; 1493} 1494 1495static void idetape_create_test_unit_ready_cmd(struct ide_atapi_pc *pc) 1496{ 1497 idetape_init_pc(pc); 1498 pc->c[0] = TEST_UNIT_READY; 1499 pc->idetape_callback = &idetape_pc_callback; 1500} 1501 1502/* 1503 * We add a special packet command request to the tail of the request queue, and 1504 * wait for it to be serviced. This is not to be called from within the request 1505 * handling part of the driver! We allocate here data on the stack and it is 1506 * valid until the request is finished. This is not the case for the bottom part 1507 * of the driver, where we are always leaving the functions to wait for an 1508 * interrupt or a timer event. 1509 * 1510 * From the bottom part of the driver, we should allocate safe memory using 1511 * idetape_next_pc_storage() and ide_tape_next_rq_storage(), and add the request 1512 * to the request list without waiting for it to be serviced! In that case, we 1513 * usually use idetape_queue_pc_head(). 1514 */ 1515static int idetape_queue_pc_tail(ide_drive_t *drive, struct ide_atapi_pc *pc) 1516{ 1517 struct ide_tape_obj *tape = drive->driver_data; 1518 struct request *rq; 1519 int error; 1520 1521 rq = blk_get_request(drive->queue, READ, __GFP_WAIT); 1522 rq->cmd_type = REQ_TYPE_SPECIAL; 1523 rq->cmd[0] = REQ_IDETAPE_PC1; 1524 rq->buffer = (char *)pc; 1525 error = blk_execute_rq(drive->queue, tape->disk, rq, 0); 1526 blk_put_request(rq); 1527 return error; 1528} 1529 1530static void idetape_create_load_unload_cmd(ide_drive_t *drive, 1531 struct ide_atapi_pc *pc, int cmd) 1532{ 1533 idetape_init_pc(pc); 1534 pc->c[0] = START_STOP; 1535 pc->c[4] = cmd; 1536 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1537 pc->idetape_callback = &idetape_pc_callback; 1538} 1539 1540static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout) 1541{ 1542 idetape_tape_t *tape = drive->driver_data; 1543 struct ide_atapi_pc pc; 1544 int load_attempted = 0; 1545 1546 /* Wait for the tape to become ready */ 1547 set_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags); 1548 timeout += jiffies; 1549 while (time_before(jiffies, timeout)) { 1550 idetape_create_test_unit_ready_cmd(&pc); 1551 if (!idetape_queue_pc_tail(drive, &pc)) 1552 return 0; 1553 if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) 1554 || (tape->asc == 0x3A)) { 1555 /* no media */ 1556 if (load_attempted) 1557 return -ENOMEDIUM; 1558 idetape_create_load_unload_cmd(drive, &pc, 1559 IDETAPE_LU_LOAD_MASK); 1560 idetape_queue_pc_tail(drive, &pc); 1561 load_attempted = 1; 1562 /* not about to be ready */ 1563 } else if (!(tape->sense_key == 2 && tape->asc == 4 && 1564 (tape->ascq == 1 || tape->ascq == 8))) 1565 return -EIO; 1566 msleep(100); 1567 } 1568 return -EIO; 1569} 1570 1571static int idetape_flush_tape_buffers(ide_drive_t *drive) 1572{ 1573 struct ide_atapi_pc pc; 1574 int rc; 1575 1576 idetape_create_write_filemark_cmd(drive, &pc, 0); 1577 rc = idetape_queue_pc_tail(drive, &pc); 1578 if (rc) 1579 return rc; 1580 idetape_wait_ready(drive, 60 * 5 * HZ); 1581 return 0; 1582} 1583 1584static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc) 1585{ 1586 idetape_init_pc(pc); 1587 pc->c[0] = READ_POSITION; 1588 pc->req_xfer = 20; 1589 pc->idetape_callback = &idetape_read_position_callback; 1590} 1591 1592static int idetape_read_position(ide_drive_t *drive) 1593{ 1594 idetape_tape_t *tape = drive->driver_data; 1595 struct ide_atapi_pc pc; 1596 int position; 1597 1598 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1599 1600 idetape_create_read_position_cmd(&pc); 1601 if (idetape_queue_pc_tail(drive, &pc)) 1602 return -1; 1603 position = tape->first_frame; 1604 return position; 1605} 1606 1607static void idetape_create_locate_cmd(ide_drive_t *drive, 1608 struct ide_atapi_pc *pc, 1609 unsigned int block, u8 partition, int skip) 1610{ 1611 idetape_init_pc(pc); 1612 pc->c[0] = POSITION_TO_ELEMENT; 1613 pc->c[1] = 2; 1614 put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]); 1615 pc->c[8] = partition; 1616 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1617 pc->idetape_callback = &idetape_pc_callback; 1618} 1619 1620static int idetape_create_prevent_cmd(ide_drive_t *drive, 1621 struct ide_atapi_pc *pc, int prevent) 1622{ 1623 idetape_tape_t *tape = drive->driver_data; 1624 1625 /* device supports locking according to capabilities page */ 1626 if (!(tape->caps[6] & 0x01)) 1627 return 0; 1628 1629 idetape_init_pc(pc); 1630 pc->c[0] = ALLOW_MEDIUM_REMOVAL; 1631 pc->c[4] = prevent; 1632 pc->idetape_callback = &idetape_pc_callback; 1633 return 1; 1634} 1635 1636static void __ide_tape_discard_merge_buffer(ide_drive_t *drive) 1637{ 1638 idetape_tape_t *tape = drive->driver_data; 1639 1640 if (tape->chrdev_dir != IDETAPE_DIR_READ) 1641 return; 1642 1643 clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags); 1644 tape->merge_bh_size = 0; 1645 if (tape->merge_bh != NULL) { 1646 ide_tape_kfree_buffer(tape); 1647 tape->merge_bh = NULL; 1648 } 1649 1650 tape->chrdev_dir = IDETAPE_DIR_NONE; 1651} 1652 1653/* 1654 * Position the tape to the requested block using the LOCATE packet command. 1655 * A READ POSITION command is then issued to check where we are positioned. Like 1656 * all higher level operations, we queue the commands at the tail of the request 1657 * queue and wait for their completion. 1658 */ 1659static int idetape_position_tape(ide_drive_t *drive, unsigned int block, 1660 u8 partition, int skip) 1661{ 1662 idetape_tape_t *tape = drive->driver_data; 1663 int retval; 1664 struct ide_atapi_pc pc; 1665 1666 if (tape->chrdev_dir == IDETAPE_DIR_READ) 1667 __ide_tape_discard_merge_buffer(drive); 1668 idetape_wait_ready(drive, 60 * 5 * HZ); 1669 idetape_create_locate_cmd(drive, &pc, block, partition, skip); 1670 retval = idetape_queue_pc_tail(drive, &pc); 1671 if (retval) 1672 return (retval); 1673 1674 idetape_create_read_position_cmd(&pc); 1675 return (idetape_queue_pc_tail(drive, &pc)); 1676} 1677 1678static void ide_tape_discard_merge_buffer(ide_drive_t *drive, 1679 int restore_position) 1680{ 1681 idetape_tape_t *tape = drive->driver_data; 1682 int seek, position; 1683 1684 __ide_tape_discard_merge_buffer(drive); 1685 if (restore_position) { 1686 position = idetape_read_position(drive); 1687 seek = position > 0 ? position : 0; 1688 if (idetape_position_tape(drive, seek, 0, 0)) { 1689 printk(KERN_INFO "ide-tape: %s: position_tape failed in" 1690 " %s\n", tape->name, __func__); 1691 return; 1692 } 1693 } 1694} 1695 1696/* 1697 * Generate a read/write request for the block device interface and wait for it 1698 * to be serviced. 1699 */ 1700static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, 1701 struct idetape_bh *bh) 1702{ 1703 idetape_tape_t *tape = drive->driver_data; 1704 struct request *rq; 1705 int ret, errors; 1706 1707 debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd); 1708 1709 rq = blk_get_request(drive->queue, READ, __GFP_WAIT); 1710 rq->cmd_type = REQ_TYPE_SPECIAL; 1711 rq->cmd[0] = cmd; 1712 rq->rq_disk = tape->disk; 1713 rq->special = (void *)bh; 1714 rq->sector = tape->first_frame; 1715 rq->nr_sectors = blocks; 1716 rq->current_nr_sectors = blocks; 1717 blk_execute_rq(drive->queue, tape->disk, rq, 0); 1718 1719 errors = rq->errors; 1720 ret = tape->blk_size * (blocks - rq->current_nr_sectors); 1721 blk_put_request(rq); 1722 1723 if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0) 1724 return 0; 1725 1726 if (tape->merge_bh) 1727 idetape_init_merge_buffer(tape); 1728 if (errors == IDETAPE_ERROR_GENERAL) 1729 return -EIO; 1730 return ret; 1731} 1732 1733static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc) 1734{ 1735 idetape_init_pc(pc); 1736 pc->c[0] = INQUIRY; 1737 pc->c[4] = 254; 1738 pc->req_xfer = 254; 1739 pc->idetape_callback = &idetape_pc_callback; 1740} 1741 1742static void idetape_create_rewind_cmd(ide_drive_t *drive, 1743 struct ide_atapi_pc *pc) 1744{ 1745 idetape_init_pc(pc); 1746 pc->c[0] = REZERO_UNIT; 1747 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1748 pc->idetape_callback = &idetape_pc_callback; 1749} 1750 1751static void idetape_create_erase_cmd(struct ide_atapi_pc *pc) 1752{ 1753 idetape_init_pc(pc); 1754 pc->c[0] = ERASE; 1755 pc->c[1] = 1; 1756 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1757 pc->idetape_callback = &idetape_pc_callback; 1758} 1759 1760static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd) 1761{ 1762 idetape_init_pc(pc); 1763 pc->c[0] = SPACE; 1764 put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]); 1765 pc->c[1] = cmd; 1766 pc->flags |= PC_FLAG_WAIT_FOR_DSC; 1767 pc->idetape_callback = &idetape_pc_callback; 1768} 1769 1770/* Queue up a character device originated write request. */ 1771static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks) 1772{ 1773 idetape_tape_t *tape = drive->driver_data; 1774 1775 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 1776 1777 return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 1778 blocks, tape->merge_bh); 1779} 1780 1781static void ide_tape_flush_merge_buffer(ide_drive_t *drive) 1782{ 1783 idetape_tape_t *tape = drive->driver_data; 1784 int blocks, min; 1785 struct idetape_bh *bh; 1786 1787 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { 1788 printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer" 1789 " but we are not writing.\n"); 1790 return; 1791 } 1792 if (tape->merge_bh_size > tape->buffer_size) { 1793 printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n"); 1794 tape->merge_bh_size = tape->buffer_size; 1795 } 1796 if (tape->merge_bh_size) { 1797 blocks = tape->merge_bh_size / tape->blk_size; 1798 if (tape->merge_bh_size % tape->blk_size) { 1799 unsigned int i; 1800 1801 blocks++; 1802 i = tape->blk_size - tape->merge_bh_size % 1803 tape->blk_size; 1804 bh = tape->bh->b_reqnext; 1805 while (bh) { 1806 atomic_set(&bh->b_count, 0); 1807 bh = bh->b_reqnext; 1808 } 1809 bh = tape->bh; 1810 while (i) { 1811 if (bh == NULL) { 1812 printk(KERN_INFO "ide-tape: bug," 1813 " bh NULL\n"); 1814 break; 1815 } 1816 min = min(i, (unsigned int)(bh->b_size - 1817 atomic_read(&bh->b_count))); 1818 memset(bh->b_data + atomic_read(&bh->b_count), 1819 0, min); 1820 atomic_add(min, &bh->b_count); 1821 i -= min; 1822 bh = bh->b_reqnext; 1823 } 1824 } 1825 (void) idetape_add_chrdev_write_request(drive, blocks); 1826 tape->merge_bh_size = 0; 1827 } 1828 if (tape->merge_bh != NULL) { 1829 ide_tape_kfree_buffer(tape); 1830 tape->merge_bh = NULL; 1831 } 1832 tape->chrdev_dir = IDETAPE_DIR_NONE; 1833} 1834 1835static int idetape_init_read(ide_drive_t *drive) 1836{ 1837 idetape_tape_t *tape = drive->driver_data; 1838 int bytes_read; 1839 1840 /* Initialize read operation */ 1841 if (tape->chrdev_dir != IDETAPE_DIR_READ) { 1842 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { 1843 ide_tape_flush_merge_buffer(drive); 1844 idetape_flush_tape_buffers(drive); 1845 } 1846 if (tape->merge_bh || tape->merge_bh_size) { 1847 printk(KERN_ERR "ide-tape: merge_bh_size should be" 1848 " 0 now\n"); 1849 tape->merge_bh_size = 0; 1850 } 1851 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0); 1852 if (!tape->merge_bh) 1853 return -ENOMEM; 1854 tape->chrdev_dir = IDETAPE_DIR_READ; 1855 1856 /* 1857 * Issue a read 0 command to ensure that DSC handshake is 1858 * switched from completion mode to buffer available mode. 1859 * No point in issuing this if DSC overlap isn't supported, some 1860 * drives (Seagate STT3401A) will return an error. 1861 */ 1862 if (drive->dsc_overlap) { 1863 bytes_read = idetape_queue_rw_tail(drive, 1864 REQ_IDETAPE_READ, 0, 1865 tape->merge_bh); 1866 if (bytes_read < 0) { 1867 ide_tape_kfree_buffer(tape); 1868 tape->merge_bh = NULL; 1869 tape->chrdev_dir = IDETAPE_DIR_NONE; 1870 return bytes_read; 1871 } 1872 } 1873 } 1874 1875 return 0; 1876} 1877 1878/* called from idetape_chrdev_read() to service a chrdev read request. */ 1879static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) 1880{ 1881 idetape_tape_t *tape = drive->driver_data; 1882 1883 debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks); 1884 1885 /* If we are at a filemark, return a read length of 0 */ 1886 if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) 1887 return 0; 1888 1889 idetape_init_read(drive); 1890 1891 return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, 1892 tape->merge_bh); 1893} 1894 1895static void idetape_pad_zeros(ide_drive_t *drive, int bcount) 1896{ 1897 idetape_tape_t *tape = drive->driver_data; 1898 struct idetape_bh *bh; 1899 int blocks; 1900 1901 while (bcount) { 1902 unsigned int count; 1903 1904 bh = tape->merge_bh; 1905 count = min(tape->buffer_size, bcount); 1906 bcount -= count; 1907 blocks = count / tape->blk_size; 1908 while (count) { 1909 atomic_set(&bh->b_count, 1910 min(count, (unsigned int)bh->b_size)); 1911 memset(bh->b_data, 0, atomic_read(&bh->b_count)); 1912 count -= atomic_read(&bh->b_count); 1913 bh = bh->b_reqnext; 1914 } 1915 idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, 1916 tape->merge_bh); 1917 } 1918} 1919 1920/* 1921 * Rewinds the tape to the Beginning Of the current Partition (BOP). We 1922 * currently support only one partition. 1923 */ 1924static int idetape_rewind_tape(ide_drive_t *drive) 1925{ 1926 int retval; 1927 struct ide_atapi_pc pc; 1928 idetape_tape_t *tape; 1929 tape = drive->driver_data; 1930 1931 debug_log(DBG_SENSE, "Enter %s\n", __func__); 1932 1933 idetape_create_rewind_cmd(drive, &pc); 1934 retval = idetape_queue_pc_tail(drive, &pc); 1935 if (retval) 1936 return retval; 1937 1938 idetape_create_read_position_cmd(&pc); 1939 retval = idetape_queue_pc_tail(drive, &pc); 1940 if (retval) 1941 return retval; 1942 return 0; 1943} 1944 1945/* mtio.h compatible commands should be issued to the chrdev interface. */ 1946static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, 1947 unsigned long arg) 1948{ 1949 idetape_tape_t *tape = drive->driver_data; 1950 void __user *argp = (void __user *)arg; 1951 1952 struct idetape_config { 1953 int dsc_rw_frequency; 1954 int dsc_media_access_frequency; 1955 int nr_stages; 1956 } config; 1957 1958 debug_log(DBG_PROCS, "Enter %s\n", __func__); 1959 1960 switch (cmd) { 1961 case 0x0340: 1962 if (copy_from_user(&config, argp, sizeof(config))) 1963 return -EFAULT; 1964 tape->best_dsc_rw_freq = config.dsc_rw_frequency; 1965 break; 1966 case 0x0350: 1967 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq; 1968 config.nr_stages = 1; 1969 if (copy_to_user(argp, &config, sizeof(config))) 1970 return -EFAULT; 1971 break; 1972 default: 1973 return -EIO; 1974 } 1975 return 0; 1976} 1977 1978static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op, 1979 int mt_count) 1980{ 1981 idetape_tape_t *tape = drive->driver_data; 1982 struct ide_atapi_pc pc; 1983 int retval, count = 0; 1984 int sprev = !!(tape->caps[4] & 0x20); 1985 1986 if (mt_count == 0) 1987 return 0; 1988 if (MTBSF == mt_op || MTBSFM == mt_op) { 1989 if (!sprev) 1990 return -EIO; 1991 mt_count = -mt_count; 1992 } 1993 1994 if (tape->chrdev_dir == IDETAPE_DIR_READ) { 1995 tape->merge_bh_size = 0; 1996 if (test_and_clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) 1997 ++count; 1998 ide_tape_discard_merge_buffer(drive, 0); 1999 } 2000 2001 switch (mt_op) { 2002 case MTFSF: 2003 case MTBSF: 2004 idetape_create_space_cmd(&pc, mt_count - count, 2005 IDETAPE_SPACE_OVER_FILEMARK); 2006 return idetape_queue_pc_tail(drive, &pc); 2007 case MTFSFM: 2008 case MTBSFM: 2009 if (!sprev) 2010 return -EIO; 2011 retval = idetape_space_over_filemarks(drive, MTFSF, 2012 mt_count - count); 2013 if (retval) 2014 return retval; 2015 count = (MTBSFM == mt_op ? 1 : -1); 2016 return idetape_space_over_filemarks(drive, MTFSF, count); 2017 default: 2018 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", 2019 mt_op); 2020 return -EIO; 2021 } 2022} 2023 2024/* 2025 * Our character device read / write functions. 2026 * 2027 * The tape is optimized to maximize throughput when it is transferring an 2028 * integral number of the "continuous transfer limit", which is a parameter of 2029 * the specific tape (26kB on my particular tape, 32kB for Onstream). 2030 * 2031 * As of version 1.3 of the driver, the character device provides an abstract 2032 * continuous view of the media - any mix of block sizes (even 1 byte) on the 2033 * same backup/restore procedure is supported. The driver will internally 2034 * convert the requests to the recommended transfer unit, so that an unmatch 2035 * between the user's block size to the recommended size will only result in a 2036 * (slightly) increased driver overhead, but will no longer hit performance. 2037 * This is not applicable to Onstream. 2038 */ 2039static ssize_t idetape_chrdev_read(struct file *file, char __user *buf, 2040 size_t count, loff_t *ppos) 2041{ 2042 struct ide_tape_obj *tape = ide_tape_f(file); 2043 ide_drive_t *drive = tape->drive; 2044 ssize_t bytes_read, temp, actually_read = 0, rc; 2045 ssize_t ret = 0; 2046 u16 ctl = *(u16 *)&tape->caps[12]; 2047 2048 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); 2049 2050 if (tape->chrdev_dir != IDETAPE_DIR_READ) { 2051 if (test_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags)) 2052 if (count > tape->blk_size && 2053 (count % tape->blk_size) == 0) 2054 tape->user_bs_factor = count / tape->blk_size; 2055 } 2056 rc = idetape_init_read(drive); 2057 if (rc < 0) 2058 return rc; 2059 if (count == 0) 2060 return (0); 2061 if (tape->merge_bh_size) { 2062 actually_read = min((unsigned int)(tape->merge_bh_size), 2063 (unsigned int)count); 2064 if (idetape_copy_stage_to_user(tape, buf, actually_read)) 2065 ret = -EFAULT; 2066 buf += actually_read; 2067 tape->merge_bh_size -= actually_read; 2068 count -= actually_read; 2069 } 2070 while (count >= tape->buffer_size) { 2071 bytes_read = idetape_add_chrdev_read_request(drive, ctl); 2072 if (bytes_read <= 0) 2073 goto finish; 2074 if (idetape_copy_stage_to_user(tape, buf, bytes_read)) 2075 ret = -EFAULT; 2076 buf += bytes_read; 2077 count -= bytes_read; 2078 actually_read += bytes_read; 2079 } 2080 if (count) { 2081 bytes_read = idetape_add_chrdev_read_request(drive, ctl); 2082 if (bytes_read <= 0) 2083 goto finish; 2084 temp = min((unsigned long)count, (unsigned long)bytes_read); 2085 if (idetape_copy_stage_to_user(tape, buf, temp)) 2086 ret = -EFAULT; 2087 actually_read += temp; 2088 tape->merge_bh_size = bytes_read-temp; 2089 } 2090finish: 2091 if (!actually_read && test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) { 2092 debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name); 2093 2094 idetape_space_over_filemarks(drive, MTFSF, 1); 2095 return 0; 2096 } 2097 2098 return ret ? ret : actually_read; 2099} 2100 2101static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, 2102 size_t count, loff_t *ppos) 2103{ 2104 struct ide_tape_obj *tape = ide_tape_f(file); 2105 ide_drive_t *drive = tape->drive; 2106 ssize_t actually_written = 0; 2107 ssize_t ret = 0; 2108 u16 ctl = *(u16 *)&tape->caps[12]; 2109 2110 /* The drive is write protected. */ 2111 if (tape->write_prot) 2112 return -EACCES; 2113 2114 debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); 2115 2116 /* Initialize write operation */ 2117 if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { 2118 if (tape->chrdev_dir == IDETAPE_DIR_READ) 2119 ide_tape_discard_merge_buffer(drive, 1); 2120 if (tape->merge_bh || tape->merge_bh_size) { 2121 printk(KERN_ERR "ide-tape: merge_bh_size " 2122 "should be 0 now\n"); 2123 tape->merge_bh_size = 0; 2124 } 2125 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0); 2126 if (!tape->merge_bh) 2127 return -ENOMEM; 2128 tape->chrdev_dir = IDETAPE_DIR_WRITE; 2129 idetape_init_merge_buffer(tape); 2130 2131 /* 2132 * Issue a write 0 command to ensure that DSC handshake is 2133 * switched from completion mode to buffer available mode. No 2134 * point in issuing this if DSC overlap isn't supported, some 2135 * drives (Seagate STT3401A) will return an error. 2136 */ 2137 if (drive->dsc_overlap) { 2138 ssize_t retval = idetape_queue_rw_tail(drive, 2139 REQ_IDETAPE_WRITE, 0, 2140 tape->merge_bh); 2141 if (retval < 0) { 2142 ide_tape_kfree_buffer(tape); 2143 tape->merge_bh = NULL; 2144 tape->chrdev_dir = IDETAPE_DIR_NONE; 2145 return retval; 2146 } 2147 } 2148 } 2149 if (count == 0) 2150 return (0); 2151 if (tape->merge_bh_size) { 2152 if (tape->merge_bh_size >= tape->buffer_size) { 2153 printk(KERN_ERR "ide-tape: bug: merge buf too big\n"); 2154 tape->merge_bh_size = 0; 2155 } 2156 actually_written = min((unsigned int) 2157 (tape->buffer_size - tape->merge_bh_size), 2158 (unsigned int)count); 2159 if (idetape_copy_stage_from_user(tape, buf, actually_written)) 2160 ret = -EFAULT; 2161 buf += actually_written; 2162 tape->merge_bh_size += actually_written; 2163 count -= actually_written; 2164 2165 if (tape->merge_bh_size == tape->buffer_size) { 2166 ssize_t retval; 2167 tape->merge_bh_size = 0; 2168 retval = idetape_add_chrdev_write_request(drive, ctl); 2169 if (retval <= 0) 2170 return (retval); 2171 } 2172 } 2173 while (count >= tape->buffer_size) { 2174 ssize_t retval; 2175 if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size)) 2176 ret = -EFAULT; 2177 buf += tape->buffer_size; 2178 count -= tape->buffer_size; 2179 retval = idetape_add_chrdev_write_request(drive, ctl); 2180 actually_written += tape->buffer_size; 2181 if (retval <= 0) 2182 return (retval); 2183 } 2184 if (count) { 2185 actually_written += count; 2186 if (idetape_copy_stage_from_user(tape, buf, count)) 2187 ret = -EFAULT; 2188 tape->merge_bh_size += count; 2189 } 2190 return ret ? ret : actually_written; 2191} 2192 2193static int idetape_write_filemark(ide_drive_t *drive) 2194{ 2195 struct ide_atapi_pc pc; 2196 2197 /* Write a filemark */ 2198 idetape_create_write_filemark_cmd(drive, &pc, 1); 2199 if (idetape_queue_pc_tail(drive, &pc)) { 2200 printk(KERN_ERR "ide-tape: Couldn't write a filemark\n"); 2201 return -EIO; 2202 } 2203 return 0; 2204} 2205 2206/* 2207 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is 2208 * requested. 2209 * 2210 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support 2211 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also 2212 * usually not supported. 2213 * 2214 * The following commands are currently not supported: 2215 * 2216 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS, 2217 * MT_ST_WRITE_THRESHOLD. 2218 */ 2219static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count) 2220{ 2221 idetape_tape_t *tape = drive->driver_data; 2222 struct ide_atapi_pc pc; 2223 int i, retval; 2224 2225 debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n", 2226 mt_op, mt_count); 2227 2228 switch (mt_op) { 2229 case MTFSF: 2230 case MTFSFM: 2231 case MTBSF: 2232 case MTBSFM: 2233 if (!mt_count) 2234 return 0; 2235 return idetape_space_over_filemarks(drive, mt_op, mt_count); 2236 default: 2237 break; 2238 } 2239 2240 switch (mt_op) { 2241 case MTWEOF: 2242 if (tape->write_prot) 2243 return -EACCES; 2244 ide_tape_discard_merge_buffer(drive, 1); 2245 for (i = 0; i < mt_count; i++) { 2246 retval = idetape_write_filemark(drive); 2247 if (retval) 2248 return retval; 2249 } 2250 return 0; 2251 case MTREW: 2252 ide_tape_discard_merge_buffer(drive, 0); 2253 if (idetape_rewind_tape(drive)) 2254 return -EIO; 2255 return 0; 2256 case MTLOAD: 2257 ide_tape_discard_merge_buffer(drive, 0); 2258 idetape_create_load_unload_cmd(drive, &pc, 2259 IDETAPE_LU_LOAD_MASK); 2260 return idetape_queue_pc_tail(drive, &pc); 2261 case MTUNLOAD: 2262 case MTOFFL: 2263 /* 2264 * If door is locked, attempt to unlock before 2265 * attempting to eject. 2266 */ 2267 if (tape->door_locked) { 2268 if (idetape_create_prevent_cmd(drive, &pc, 0)) 2269 if (!idetape_queue_pc_tail(drive, &pc)) 2270 tape->door_locked = DOOR_UNLOCKED; 2271 } 2272 ide_tape_discard_merge_buffer(drive, 0); 2273 idetape_create_load_unload_cmd(drive, &pc, 2274 !IDETAPE_LU_LOAD_MASK); 2275 retval = idetape_queue_pc_tail(drive, &pc); 2276 if (!retval) 2277 clear_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags); 2278 return retval; 2279 case MTNOP: 2280 ide_tape_discard_merge_buffer(drive, 0); 2281 return idetape_flush_tape_buffers(drive); 2282 case MTRETEN: 2283 ide_tape_discard_merge_buffer(drive, 0); 2284 idetape_create_load_unload_cmd(drive, &pc, 2285 IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); 2286 return idetape_queue_pc_tail(drive, &pc); 2287 case MTEOM: 2288 idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD); 2289 return idetape_queue_pc_tail(drive, &pc); 2290 case MTERASE: 2291 (void)idetape_rewind_tape(drive); 2292 idetape_create_erase_cmd(&pc); 2293 return idetape_queue_pc_tail(drive, &pc); 2294 case MTSETBLK: 2295 if (mt_count) { 2296 if (mt_count < tape->blk_size || 2297 mt_count % tape->blk_size) 2298 return -EIO; 2299 tape->user_bs_factor = mt_count / tape->blk_size; 2300 clear_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags); 2301 } else 2302 set_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags); 2303 return 0; 2304 case MTSEEK: 2305 ide_tape_discard_merge_buffer(drive, 0); 2306 return idetape_position_tape(drive, 2307 mt_count * tape->user_bs_factor, tape->partition, 0); 2308 case MTSETPART: 2309 ide_tape_discard_merge_buffer(drive, 0); 2310 return idetape_position_tape(drive, 0, mt_count, 0); 2311 case MTFSR: 2312 case MTBSR: 2313 case MTLOCK: 2314 if (!idetape_create_prevent_cmd(drive, &pc, 1)) 2315 return 0; 2316 retval = idetape_queue_pc_tail(drive, &pc); 2317 if (retval) 2318 return retval; 2319 tape->door_locked = DOOR_EXPLICITLY_LOCKED; 2320 return 0; 2321 case MTUNLOCK: 2322 if (!idetape_create_prevent_cmd(drive, &pc, 0)) 2323 return 0; 2324 retval = idetape_queue_pc_tail(drive, &pc); 2325 if (retval) 2326 return retval; 2327 tape->door_locked = DOOR_UNLOCKED; 2328 return 0; 2329 default: 2330 printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", 2331 mt_op); 2332 return -EIO; 2333 } 2334} 2335 2336/* 2337 * Our character device ioctls. General mtio.h magnetic io commands are 2338 * supported here, and not in the corresponding block interface. Our own 2339 * ide-tape ioctls are supported on both interfaces. 2340 */ 2341static int idetape_chrdev_ioctl(struct inode *inode, struct file *file, 2342 unsigned int cmd, unsigned long arg) 2343{ 2344 struct ide_tape_obj *tape = ide_tape_f(file); 2345 ide_drive_t *drive = tape->drive; 2346 struct mtop mtop; 2347 struct mtget mtget; 2348 struct mtpos mtpos; 2349 int block_offset = 0, position = tape->first_frame; 2350 void __user *argp = (void __user *)arg; 2351 2352 debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd); 2353 2354 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { 2355 ide_tape_flush_merge_buffer(drive); 2356 idetape_flush_tape_buffers(drive); 2357 } 2358 if (cmd == MTIOCGET || cmd == MTIOCPOS) { 2359 block_offset = tape->merge_bh_size / 2360 (tape->blk_size * tape->user_bs_factor); 2361 position = idetape_read_position(drive); 2362 if (position < 0) 2363 return -EIO; 2364 } 2365 switch (cmd) { 2366 case MTIOCTOP: 2367 if (copy_from_user(&mtop, argp, sizeof(struct mtop))) 2368 return -EFAULT; 2369 return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count); 2370 case MTIOCGET: 2371 memset(&mtget, 0, sizeof(struct mtget)); 2372 mtget.mt_type = MT_ISSCSI2; 2373 mtget.mt_blkno = position / tape->user_bs_factor - block_offset; 2374 mtget.mt_dsreg = 2375 ((tape->blk_size * tape->user_bs_factor) 2376 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK; 2377 2378 if (tape->drv_write_prot) 2379 mtget.mt_gstat |= GMT_WR_PROT(0xffffffff); 2380 2381 if (copy_to_user(argp, &mtget, sizeof(struct mtget))) 2382 return -EFAULT; 2383 return 0; 2384 case MTIOCPOS: 2385 mtpos.mt_blkno = position / tape->user_bs_factor - block_offset; 2386 if (copy_to_user(argp, &mtpos, sizeof(struct mtpos))) 2387 return -EFAULT; 2388 return 0; 2389 default: 2390 if (tape->chrdev_dir == IDETAPE_DIR_READ) 2391 ide_tape_discard_merge_buffer(drive, 1); 2392 return idetape_blkdev_ioctl(drive, cmd, arg); 2393 } 2394} 2395 2396/* 2397 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape 2398 * block size with the reported value. 2399 */ 2400static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive) 2401{ 2402 idetape_tape_t *tape = drive->driver_data; 2403 struct ide_atapi_pc pc; 2404 2405 idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR); 2406 if (idetape_queue_pc_tail(drive, &pc)) { 2407 printk(KERN_ERR "ide-tape: Can't get block descriptor\n"); 2408 if (tape->blk_size == 0) { 2409 printk(KERN_WARNING "ide-tape: Cannot deal with zero " 2410 "block size, assuming 32k\n"); 2411 tape->blk_size = 32768; 2412 } 2413 return; 2414 } 2415 tape->blk_size = (pc.buf[4 + 5] << 16) + 2416 (pc.buf[4 + 6] << 8) + 2417 pc.buf[4 + 7]; 2418 tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7; 2419} 2420 2421static int idetape_chrdev_open(struct inode *inode, struct file *filp) 2422{ 2423 unsigned int minor = iminor(inode), i = minor & ~0xc0; 2424 ide_drive_t *drive; 2425 idetape_tape_t *tape; 2426 struct ide_atapi_pc pc; 2427 int retval; 2428 2429 if (i >= MAX_HWIFS * MAX_DRIVES) 2430 return -ENXIO; 2431 2432 tape = ide_tape_chrdev_get(i); 2433 if (!tape) 2434 return -ENXIO; 2435 2436 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 2437 2438 /* 2439 * We really want to do nonseekable_open(inode, filp); here, but some 2440 * versions of tar incorrectly call lseek on tapes and bail out if that 2441 * fails. So we disallow pread() and pwrite(), but permit lseeks. 2442 */ 2443 filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); 2444 2445 drive = tape->drive; 2446 2447 filp->private_data = tape; 2448 2449 if (test_and_set_bit(IDETAPE_FLAG_BUSY, &tape->flags)) { 2450 retval = -EBUSY; 2451 goto out_put_tape; 2452 } 2453 2454 retval = idetape_wait_ready(drive, 60 * HZ); 2455 if (retval) { 2456 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2457 printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name); 2458 goto out_put_tape; 2459 } 2460 2461 idetape_read_position(drive); 2462 if (!test_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags)) 2463 (void)idetape_rewind_tape(drive); 2464 2465 /* Read block size and write protect status from drive. */ 2466 ide_tape_get_bsize_from_bdesc(drive); 2467 2468 /* Set write protect flag if device is opened as read-only. */ 2469 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) 2470 tape->write_prot = 1; 2471 else 2472 tape->write_prot = tape->drv_write_prot; 2473 2474 /* Make sure drive isn't write protected if user wants to write. */ 2475 if (tape->write_prot) { 2476 if ((filp->f_flags & O_ACCMODE) == O_WRONLY || 2477 (filp->f_flags & O_ACCMODE) == O_RDWR) { 2478 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2479 retval = -EROFS; 2480 goto out_put_tape; 2481 } 2482 } 2483 2484 /* Lock the tape drive door so user can't eject. */ 2485 if (tape->chrdev_dir == IDETAPE_DIR_NONE) { 2486 if (idetape_create_prevent_cmd(drive, &pc, 1)) { 2487 if (!idetape_queue_pc_tail(drive, &pc)) { 2488 if (tape->door_locked != DOOR_EXPLICITLY_LOCKED) 2489 tape->door_locked = DOOR_LOCKED; 2490 } 2491 } 2492 } 2493 return 0; 2494 2495out_put_tape: 2496 ide_tape_put(tape); 2497 return retval; 2498} 2499 2500static void idetape_write_release(ide_drive_t *drive, unsigned int minor) 2501{ 2502 idetape_tape_t *tape = drive->driver_data; 2503 2504 ide_tape_flush_merge_buffer(drive); 2505 tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0); 2506 if (tape->merge_bh != NULL) { 2507 idetape_pad_zeros(drive, tape->blk_size * 2508 (tape->user_bs_factor - 1)); 2509 ide_tape_kfree_buffer(tape); 2510 tape->merge_bh = NULL; 2511 } 2512 idetape_write_filemark(drive); 2513 idetape_flush_tape_buffers(drive); 2514 idetape_flush_tape_buffers(drive); 2515} 2516 2517static int idetape_chrdev_release(struct inode *inode, struct file *filp) 2518{ 2519 struct ide_tape_obj *tape = ide_tape_f(filp); 2520 ide_drive_t *drive = tape->drive; 2521 struct ide_atapi_pc pc; 2522 unsigned int minor = iminor(inode); 2523 2524 lock_kernel(); 2525 tape = drive->driver_data; 2526 2527 debug_log(DBG_CHRDEV, "Enter %s\n", __func__); 2528 2529 if (tape->chrdev_dir == IDETAPE_DIR_WRITE) 2530 idetape_write_release(drive, minor); 2531 if (tape->chrdev_dir == IDETAPE_DIR_READ) { 2532 if (minor < 128) 2533 ide_tape_discard_merge_buffer(drive, 1); 2534 } 2535 2536 if (minor < 128 && test_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags)) 2537 (void) idetape_rewind_tape(drive); 2538 if (tape->chrdev_dir == IDETAPE_DIR_NONE) { 2539 if (tape->door_locked == DOOR_LOCKED) { 2540 if (idetape_create_prevent_cmd(drive, &pc, 0)) { 2541 if (!idetape_queue_pc_tail(drive, &pc)) 2542 tape->door_locked = DOOR_UNLOCKED; 2543 } 2544 } 2545 } 2546 clear_bit(IDETAPE_FLAG_BUSY, &tape->flags); 2547 ide_tape_put(tape); 2548 unlock_kernel(); 2549 return 0; 2550} 2551 2552/* 2553 * check the contents of the ATAPI IDENTIFY command results. We return: 2554 * 2555 * 1 - If the tape can be supported by us, based on the information we have so 2556 * far. 2557 * 2558 * 0 - If this tape driver is not currently supported by us. 2559 */ 2560static int idetape_identify_device(ide_drive_t *drive) 2561{ 2562 u8 gcw[2], protocol, device_type, removable, packet_size; 2563 2564 if (drive->id_read == 0) 2565 return 1; 2566 2567 *((unsigned short *) &gcw) = drive->id->config; 2568 2569 protocol = (gcw[1] & 0xC0) >> 6; 2570 device_type = gcw[1] & 0x1F; 2571 removable = !!(gcw[0] & 0x80); 2572 packet_size = gcw[0] & 0x3; 2573 2574 /* Check that we can support this device */ 2575 if (protocol != 2) 2576 printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n", 2577 protocol); 2578 else if (device_type != 1) 2579 printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set " 2580 "to tape\n", device_type); 2581 else if (!removable) 2582 printk(KERN_ERR "ide-tape: The removable flag is not set\n"); 2583 else if (packet_size != 0) { 2584 printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12" 2585 " bytes\n", packet_size); 2586 } else 2587 return 1; 2588 return 0; 2589} 2590 2591static void idetape_get_inquiry_results(ide_drive_t *drive) 2592{ 2593 idetape_tape_t *tape = drive->driver_data; 2594 struct ide_atapi_pc pc; 2595 char fw_rev[6], vendor_id[10], product_id[18]; 2596 2597 idetape_create_inquiry_cmd(&pc); 2598 if (idetape_queue_pc_tail(drive, &pc)) { 2599 printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", 2600 tape->name); 2601 return; 2602 } 2603 memcpy(vendor_id, &pc.buf[8], 8); 2604 memcpy(product_id, &pc.buf[16], 16); 2605 memcpy(fw_rev, &pc.buf[32], 4); 2606 2607 ide_fixstring(vendor_id, 10, 0); 2608 ide_fixstring(product_id, 18, 0); 2609 ide_fixstring(fw_rev, 6, 0); 2610 2611 printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", 2612 drive->name, tape->name, vendor_id, product_id, fw_rev); 2613} 2614 2615/* 2616 * Ask the tape about its various parameters. In particular, we will adjust our 2617 * data transfer buffer size to the recommended value as returned by the tape. 2618 */ 2619static void idetape_get_mode_sense_results(ide_drive_t *drive) 2620{ 2621 idetape_tape_t *tape = drive->driver_data; 2622 struct ide_atapi_pc pc; 2623 u8 *caps; 2624 u8 speed, max_speed; 2625 2626 idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE); 2627 if (idetape_queue_pc_tail(drive, &pc)) { 2628 printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming" 2629 " some default values\n"); 2630 tape->blk_size = 512; 2631 put_unaligned(52, (u16 *)&tape->caps[12]); 2632 put_unaligned(540, (u16 *)&tape->caps[14]); 2633 put_unaligned(6*52, (u16 *)&tape->caps[16]); 2634 return; 2635 } 2636 caps = pc.buf + 4 + pc.buf[3]; 2637 2638 /* convert to host order and save for later use */ 2639 speed = be16_to_cpu(*(u16 *)&caps[14]); 2640 max_speed = be16_to_cpu(*(u16 *)&caps[8]); 2641 2642 put_unaligned(max_speed, (u16 *)&caps[8]); 2643 put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]); 2644 put_unaligned(speed, (u16 *)&caps[14]); 2645 put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]); 2646 2647 if (!speed) { 2648 printk(KERN_INFO "ide-tape: %s: invalid tape speed " 2649 "(assuming 650KB/sec)\n", drive->name); 2650 put_unaligned(650, (u16 *)&caps[14]); 2651 } 2652 if (!max_speed) { 2653 printk(KERN_INFO "ide-tape: %s: invalid max_speed " 2654 "(assuming 650KB/sec)\n", drive->name); 2655 put_unaligned(650, (u16 *)&caps[8]); 2656 } 2657 2658 memcpy(&tape->caps, caps, 20); 2659 if (caps[7] & 0x02) 2660 tape->blk_size = 512; 2661 else if (caps[7] & 0x04) 2662 tape->blk_size = 1024; 2663} 2664 2665#ifdef CONFIG_IDE_PROC_FS 2666static void idetape_add_settings(ide_drive_t *drive) 2667{ 2668 idetape_tape_t *tape = drive->driver_data; 2669 2670 ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff, 2671 1, 2, (u16 *)&tape->caps[16], NULL); 2672 ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff, 2673 1, 1, (u16 *)&tape->caps[14], NULL); 2674 ide_add_setting(drive, "buffer_size", SETTING_READ, TYPE_INT, 0, 0xffff, 2675 1, 1024, &tape->buffer_size, NULL); 2676 ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN, 2677 IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq, 2678 NULL); 2679 ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1, 2680 1, &drive->dsc_overlap, NULL); 2681 ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff, 2682 1, 1, &tape->avg_speed, NULL); 2683 ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1, 2684 1, &tape->debug_mask, NULL); 2685} 2686#else 2687static inline void idetape_add_settings(ide_drive_t *drive) { ; } 2688#endif 2689 2690/* 2691 * The function below is called to: 2692 * 2693 * 1. Initialize our various state variables. 2694 * 2. Ask the tape for its capabilities. 2695 * 3. Allocate a buffer which will be used for data transfer. The buffer size 2696 * is chosen based on the recommendation which we received in step 2. 2697 * 2698 * Note that at this point ide.c already assigned us an irq, so that we can 2699 * queue requests here and wait for their completion. 2700 */ 2701static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor) 2702{ 2703 unsigned long t; 2704 int speed; 2705 int buffer_size; 2706 u8 gcw[2]; 2707 u16 *ctl = (u16 *)&tape->caps[12]; 2708 2709 spin_lock_init(&tape->lock); 2710 drive->dsc_overlap = 1; 2711 if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) { 2712 printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", 2713 tape->name); 2714 drive->dsc_overlap = 0; 2715 } 2716 /* Seagate Travan drives do not support DSC overlap. */ 2717 if (strstr(drive->id->model, "Seagate STT3401")) 2718 drive->dsc_overlap = 0; 2719 tape->minor = minor; 2720 tape->name[0] = 'h'; 2721 tape->name[1] = 't'; 2722 tape->name[2] = '0' + minor; 2723 tape->chrdev_dir = IDETAPE_DIR_NONE; 2724 tape->pc = tape->pc_stack; 2725 *((unsigned short *) &gcw) = drive->id->config; 2726 2727 /* Command packet DRQ type */ 2728 if (((gcw[0] & 0x60) >> 5) == 1) 2729 set_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags); 2730 2731 idetape_get_inquiry_results(drive); 2732 idetape_get_mode_sense_results(drive); 2733 ide_tape_get_bsize_from_bdesc(drive); 2734 tape->user_bs_factor = 1; 2735 tape->buffer_size = *ctl * tape->blk_size; 2736 while (tape->buffer_size > 0xffff) { 2737 printk(KERN_NOTICE "ide-tape: decreasing stage size\n"); 2738 *ctl /= 2; 2739 tape->buffer_size = *ctl * tape->blk_size; 2740 } 2741 buffer_size = tape->buffer_size; 2742 tape->pages_per_buffer = buffer_size / PAGE_SIZE; 2743 if (buffer_size % PAGE_SIZE) { 2744 tape->pages_per_buffer++; 2745 tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE; 2746 } 2747 2748 /* select the "best" DSC read/write polling freq */ 2749 speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]); 2750 2751 t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000); 2752 2753 /* 2754 * Ensure that the number we got makes sense; limit it within 2755 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX. 2756 */ 2757 tape->best_dsc_rw_freq = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN, 2758 IDETAPE_DSC_RW_MAX); 2759 printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, " 2760 "%lums tDSC%s\n", 2761 drive->name, tape->name, *(u16 *)&tape->caps[14], 2762 (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size, 2763 tape->buffer_size / 1024, 2764 tape->best_dsc_rw_freq * 1000 / HZ, 2765 drive->using_dma ? ", DMA":""); 2766 2767 idetape_add_settings(drive); 2768} 2769 2770static void ide_tape_remove(ide_drive_t *drive) 2771{ 2772 idetape_tape_t *tape = drive->driver_data; 2773 2774 ide_proc_unregister_driver(drive, tape->driver); 2775 2776 ide_unregister_region(tape->disk); 2777 2778 ide_tape_put(tape); 2779} 2780 2781static void ide_tape_release(struct kref *kref) 2782{ 2783 struct ide_tape_obj *tape = to_ide_tape(kref); 2784 ide_drive_t *drive = tape->drive; 2785 struct gendisk *g = tape->disk; 2786 2787 BUG_ON(tape->merge_bh_size); 2788 2789 drive->dsc_overlap = 0; 2790 drive->driver_data = NULL; 2791 device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor)); 2792 device_destroy(idetape_sysfs_class, 2793 MKDEV(IDETAPE_MAJOR, tape->minor + 128)); 2794 idetape_devs[tape->minor] = NULL; 2795 g->private_data = NULL; 2796 put_disk(g); 2797 kfree(tape); 2798} 2799 2800#ifdef CONFIG_IDE_PROC_FS 2801static int proc_idetape_read_name 2802 (char *page, char **start, off_t off, int count, int *eof, void *data) 2803{ 2804 ide_drive_t *drive = (ide_drive_t *) data; 2805 idetape_tape_t *tape = drive->driver_data; 2806 char *out = page; 2807 int len; 2808 2809 len = sprintf(out, "%s\n", tape->name); 2810 PROC_IDE_READ_RETURN(page, start, off, count, eof, len); 2811} 2812 2813static ide_proc_entry_t idetape_proc[] = { 2814 { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL }, 2815 { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL }, 2816 { NULL, 0, NULL, NULL } 2817}; 2818#endif 2819 2820static int ide_tape_probe(ide_drive_t *); 2821 2822static ide_driver_t idetape_driver = { 2823 .gen_driver = { 2824 .owner = THIS_MODULE, 2825 .name = "ide-tape", 2826 .bus = &ide_bus_type, 2827 }, 2828 .probe = ide_tape_probe, 2829 .remove = ide_tape_remove, 2830 .version = IDETAPE_VERSION, 2831 .media = ide_tape, 2832 .supports_dsc_overlap = 1, 2833 .do_request = idetape_do_request, 2834 .end_request = idetape_end_request, 2835 .error = __ide_error, 2836 .abort = __ide_abort, 2837#ifdef CONFIG_IDE_PROC_FS 2838 .proc = idetape_proc, 2839#endif 2840}; 2841 2842/* Our character device supporting functions, passed to register_chrdev. */ 2843static const struct file_operations idetape_fops = { 2844 .owner = THIS_MODULE, 2845 .read = idetape_chrdev_read, 2846 .write = idetape_chrdev_write, 2847 .ioctl = idetape_chrdev_ioctl, 2848 .open = idetape_chrdev_open, 2849 .release = idetape_chrdev_release, 2850}; 2851 2852static int idetape_open(struct inode *inode, struct file *filp) 2853{ 2854 struct gendisk *disk = inode->i_bdev->bd_disk; 2855 struct ide_tape_obj *tape; 2856 2857 tape = ide_tape_get(disk); 2858 if (!tape) 2859 return -ENXIO; 2860 2861 return 0; 2862} 2863 2864static int idetape_release(struct inode *inode, struct file *filp) 2865{ 2866 struct gendisk *disk = inode->i_bdev->bd_disk; 2867 struct ide_tape_obj *tape = ide_tape_g(disk); 2868 2869 ide_tape_put(tape); 2870 2871 return 0; 2872} 2873 2874static int idetape_ioctl(struct inode *inode, struct file *file, 2875 unsigned int cmd, unsigned long arg) 2876{ 2877 struct block_device *bdev = inode->i_bdev; 2878 struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk); 2879 ide_drive_t *drive = tape->drive; 2880 int err = generic_ide_ioctl(drive, file, bdev, cmd, arg); 2881 if (err == -EINVAL) 2882 err = idetape_blkdev_ioctl(drive, cmd, arg); 2883 return err; 2884} 2885 2886static struct block_device_operations idetape_block_ops = { 2887 .owner = THIS_MODULE, 2888 .open = idetape_open, 2889 .release = idetape_release, 2890 .ioctl = idetape_ioctl, 2891}; 2892 2893static int ide_tape_probe(ide_drive_t *drive) 2894{ 2895 idetape_tape_t *tape; 2896 struct gendisk *g; 2897 int minor; 2898 2899 if (!strstr("ide-tape", drive->driver_req)) 2900 goto failed; 2901 if (!drive->present) 2902 goto failed; 2903 if (drive->media != ide_tape) 2904 goto failed; 2905 if (!idetape_identify_device(drive)) { 2906 printk(KERN_ERR "ide-tape: %s: not supported by this version of" 2907 " the driver\n", drive->name); 2908 goto failed; 2909 } 2910 if (drive->scsi) { 2911 printk(KERN_INFO "ide-tape: passing drive %s to ide-scsi" 2912 " emulation.\n", drive->name); 2913 goto failed; 2914 } 2915 tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL); 2916 if (tape == NULL) { 2917 printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n", 2918 drive->name); 2919 goto failed; 2920 } 2921 2922 g = alloc_disk(1 << PARTN_BITS); 2923 if (!g) 2924 goto out_free_tape; 2925 2926 ide_init_disk(g, drive); 2927 2928 ide_proc_register_driver(drive, &idetape_driver); 2929 2930 kref_init(&tape->kref); 2931 2932 tape->drive = drive; 2933 tape->driver = &idetape_driver; 2934 tape->disk = g; 2935 2936 g->private_data = &tape->driver; 2937 2938 drive->driver_data = tape; 2939 2940 mutex_lock(&idetape_ref_mutex); 2941 for (minor = 0; idetape_devs[minor]; minor++) 2942 ; 2943 idetape_devs[minor] = tape; 2944 mutex_unlock(&idetape_ref_mutex); 2945 2946 idetape_setup(drive, tape, minor); 2947 2948 device_create(idetape_sysfs_class, &drive->gendev, 2949 MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name); 2950 device_create(idetape_sysfs_class, &drive->gendev, 2951 MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name); 2952 2953 g->fops = &idetape_block_ops; 2954 ide_register_region(g); 2955 2956 return 0; 2957 2958out_free_tape: 2959 kfree(tape); 2960failed: 2961 return -ENODEV; 2962} 2963 2964static void __exit idetape_exit(void) 2965{ 2966 driver_unregister(&idetape_driver.gen_driver); 2967 class_destroy(idetape_sysfs_class); 2968 unregister_chrdev(IDETAPE_MAJOR, "ht"); 2969} 2970 2971static int __init idetape_init(void) 2972{ 2973 int error = 1; 2974 idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape"); 2975 if (IS_ERR(idetape_sysfs_class)) { 2976 idetape_sysfs_class = NULL; 2977 printk(KERN_ERR "Unable to create sysfs class for ide tapes\n"); 2978 error = -EBUSY; 2979 goto out; 2980 } 2981 2982 if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) { 2983 printk(KERN_ERR "ide-tape: Failed to register chrdev" 2984 " interface\n"); 2985 error = -EBUSY; 2986 goto out_free_class; 2987 } 2988 2989 error = driver_register(&idetape_driver.gen_driver); 2990 if (error) 2991 goto out_free_driver; 2992 2993 return 0; 2994 2995out_free_driver: 2996 driver_unregister(&idetape_driver.gen_driver); 2997out_free_class: 2998 class_destroy(idetape_sysfs_class); 2999out: 3000 return error; 3001} 3002 3003MODULE_ALIAS("ide:*m-tape*"); 3004module_init(idetape_init); 3005module_exit(idetape_exit); 3006MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR); 3007MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver"); 3008MODULE_LICENSE("GPL"); 3009