/* * IDE ATAPI streaming tape driver. * * Copyright (C) 1995-1999 Gadi Oxman * Copyright (C) 2003-2005 Bartlomiej Zolnierkiewicz * * This driver was constructed as a student project in the software laboratory * of the faculty of electrical engineering in the Technion - Israel's * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David. * * It is hereby placed under the terms of the GNU general public license. * (See linux/COPYING). * * For a historical changelog see * Documentation/ide/ChangeLog.ide-tape.1995-2002 */ #define IDETAPE_VERSION "1.20" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include enum { /* output errors only */ DBG_ERR = (1 << 0), /* output all sense key/asc */ DBG_SENSE = (1 << 1), /* info regarding all chrdev-related procedures */ DBG_CHRDEV = (1 << 2), /* all remaining procedures */ DBG_PROCS = (1 << 3), /* buffer alloc info (pc_stack & rq_stack) */ DBG_PCRQ_STACK = (1 << 4), }; /* define to see debug info */ #define IDETAPE_DEBUG_LOG 0 #if IDETAPE_DEBUG_LOG #define debug_log(lvl, fmt, args...) \ { \ if (tape->debug_mask & lvl) \ printk(KERN_INFO "ide-tape: " fmt, ## args); \ } #else #define debug_log(lvl, fmt, args...) do {} while (0) #endif /**************************** Tunable parameters *****************************/ /* * Pipelined mode parameters. * * We try to use the minimum number of stages which is enough to keep the tape * constantly streaming. To accomplish that, we implement a feedback loop around * the maximum number of stages: * * We start from MIN maximum stages (we will not even use MIN stages if we don't * need them), increment it by RATE*(MAX-MIN) whenever we sense that the * pipeline is empty, until we reach the optimum value or until we reach MAX. * * Setting the following parameter to 0 is illegal: the pipelined mode cannot be * disabled (idetape_calculate_speeds() divides by tape->max_stages.) */ #define IDETAPE_MIN_PIPELINE_STAGES 1 #define IDETAPE_MAX_PIPELINE_STAGES 400 #define IDETAPE_INCREASE_STAGES_RATE 20 /* * After each failed packet command we issue a request sense command and retry * the packet command IDETAPE_MAX_PC_RETRIES times. * * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries. */ #define IDETAPE_MAX_PC_RETRIES 3 /* * With each packet command, we allocate a buffer of IDETAPE_PC_BUFFER_SIZE * bytes. This is used for several packet commands (Not for READ/WRITE commands) */ #define IDETAPE_PC_BUFFER_SIZE 256 /* * In various places in the driver, we need to allocate storage * for packet commands and requests, which will remain valid while * we leave the driver to wait for an interrupt or a timeout event. */ #define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES) /* * Some drives (for example, Seagate STT3401A Travan) require a very long * timeout, because they don't return an interrupt or clear their busy bit * until after the command completes (even retension commands). */ #define IDETAPE_WAIT_CMD (900*HZ) /* * The following parameter is used to select the point in the internal tape fifo * in which we will start to refill the buffer. Decreasing the following * parameter will improve the system's latency and interactive response, while * using a high value might improve system throughput. */ #define IDETAPE_FIFO_THRESHOLD 2 /* * DSC polling parameters. * * Polling for DSC (a single bit in the status register) is a very important * function in ide-tape. There are two cases in which we poll for DSC: * * 1. Before a read/write packet command, to ensure that we can transfer data * from/to the tape's data buffers, without causing an actual media access. * In case the tape is not ready yet, we take out our request from the device * request queue, so that ide.c could service requests from the other device * on the same interface in the meantime. * * 2. After the successful initialization of a "media access packet command", * which is a command that can take a long time to complete (the interval can * range from several seconds to even an hour). Again, we postpone our request * in the middle to free the bus for the other device. The polling frequency * here should be lower than the read/write frequency since those media access * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min). * * We also set a timeout for the timer, in case something goes wrong. The * timeout should be longer then the maximum execution time of a tape operation. */ /* DSC timings. */ #define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */ #define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */ #define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */ #define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */ #define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */ #define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */ #define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */ /*************************** End of tunable parameters ***********************/ /* Read/Write error simulation */ #define SIMULATE_ERRORS 0 /* tape directions */ enum { IDETAPE_DIR_NONE = (1 << 0), IDETAPE_DIR_READ = (1 << 1), IDETAPE_DIR_WRITE = (1 << 2), }; struct idetape_bh { u32 b_size; atomic_t b_count; struct idetape_bh *b_reqnext; char *b_data; }; typedef struct idetape_packet_command_s { /* Actual packet bytes */ u8 c[12]; /* On each retry, we increment retries */ int retries; /* Error code */ int error; /* Bytes to transfer */ int request_transfer; /* Bytes actually transferred */ int actually_transferred; /* Size of our data buffer */ int buffer_size; struct idetape_bh *bh; char *b_data; int b_count; /* Data buffer */ u8 *buffer; /* Pointer into the above buffer */ u8 *current_position; /* Called when this packet command is completed */ ide_startstop_t (*callback) (ide_drive_t *); /* Temporary buffer */ u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Status/Action bit flags: long for set_bit */ unsigned long flags; } idetape_pc_t; /* * Packet command flag bits. */ /* Set when an error is considered normal - We won't retry */ #define PC_ABORT 0 /* 1 When polling for DSC on a media access command */ #define PC_WAIT_FOR_DSC 1 /* 1 when we prefer to use DMA if possible */ #define PC_DMA_RECOMMENDED 2 /* 1 while DMA in progress */ #define PC_DMA_IN_PROGRESS 3 /* 1 when encountered problem during DMA */ #define PC_DMA_ERROR 4 /* Data direction */ #define PC_WRITING 5 /* A pipeline stage. */ typedef struct idetape_stage_s { struct request rq; /* The corresponding request */ struct idetape_bh *bh; /* The data buffers */ struct idetape_stage_s *next; /* Pointer to the next stage */ } idetape_stage_t; /* * Most of our global data which we need to save even as we leave the driver due * to an interrupt or a timer event is stored in the struct defined below. */ typedef struct ide_tape_obj { ide_drive_t *drive; ide_driver_t *driver; struct gendisk *disk; struct kref kref; /* * Since a typical character device operation requires more * than one packet command, we provide here enough memory * for the maximum of interconnected packet commands. * The packet commands are stored in the circular array pc_stack. * pc_stack_index points to the last used entry, and warps around * to the start when we get to the last array entry. * * pc points to the current processed packet command. * * failed_pc points to the last failed packet command, or contains * NULL if we do not need to retry any packet command. This is * required since an additional packet command is needed before the * retry, to get detailed information on what went wrong. */ /* Current packet command */ idetape_pc_t *pc; /* Last failed packet command */ idetape_pc_t *failed_pc; /* Packet command stack */ idetape_pc_t pc_stack[IDETAPE_PC_STACK]; /* Next free packet command storage space */ int pc_stack_index; struct request rq_stack[IDETAPE_PC_STACK]; /* We implement a circular array */ int rq_stack_index; /* * DSC polling variables. * * While polling for DSC we use postponed_rq to postpone the current * request so that ide.c will be able to service pending requests on the * other device. Note that at most we will have only one DSC (usually * data transfer) request in the device request queue. Additional * requests can be queued in our internal pipeline, but they will be * visible to ide.c only one at a time. */ struct request *postponed_rq; /* The time in which we started polling for DSC */ unsigned long dsc_polling_start; /* Timer used to poll for dsc */ struct timer_list dsc_timer; /* Read/Write dsc polling frequency */ unsigned long best_dsc_rw_freq; unsigned long dsc_poll_freq; unsigned long dsc_timeout; /* Read position information */ u8 partition; /* Current block */ unsigned int first_frame; /* Last error information */ u8 sense_key, asc, ascq; /* Character device operation */ unsigned int minor; /* device name */ char name[4]; /* Current character device data transfer direction */ u8 chrdev_dir; /* tape block size, usually 512 or 1024 bytes */ unsigned short blk_size; int user_bs_factor; /* Copy of the tape's Capabilities and Mechanical Page */ u8 caps[20]; /* * Active data transfer request parameters. * * At most, there is only one ide-tape originated data transfer request * in the device request queue. This allows ide.c to easily service * requests from the other device when we postpone our active request. * In the pipelined operation mode, we use our internal pipeline * structure to hold more data requests. The data buffer size is chosen * based on the tape's recommendation. */ /* ptr to the request which is waiting in the device request queue */ struct request *active_data_rq; /* Data buffer size chosen based on the tape's recommendation */ int stage_size; idetape_stage_t *merge_stage; int merge_stage_size; struct idetape_bh *bh; char *b_data; int b_count; /* * Pipeline parameters. * * To accomplish non-pipelined mode, we simply set the following * variables to zero (or NULL, where appropriate). */ /* Number of currently used stages */ int nr_stages; /* Number of pending stages */ int nr_pending_stages; /* We will not allocate more than this number of stages */ int max_stages, min_pipeline, max_pipeline; /* The first stage which will be removed from the pipeline */ idetape_stage_t *first_stage; /* The currently active stage */ idetape_stage_t *active_stage; /* Will be serviced after the currently active request */ idetape_stage_t *next_stage; /* New requests will be added to the pipeline here */ idetape_stage_t *last_stage; /* Optional free stage which we can use */ idetape_stage_t *cache_stage; int pages_per_stage; /* Wasted space in each stage */ int excess_bh_size; /* Status/Action flags: long for set_bit */ unsigned long flags; /* protects the ide-tape queue */ spinlock_t lock; /* Measures average tape speed */ unsigned long avg_time; int avg_size; int avg_speed; /* the door is currently locked */ int door_locked; /* the tape hardware is write protected */ char drv_write_prot; /* the tape is write protected (hardware or opened as read-only) */ char write_prot; /* * Limit the number of times a request can be postponed, to avoid an * infinite postpone deadlock. */ int postpone_cnt; /* * Measures number of frames: * * 1. written/read to/from the driver pipeline (pipeline_head). * 2. written/read to/from the tape buffers (idetape_bh). * 3. written/read by the tape to/from the media (tape_head). */ int pipeline_head; int buffer_head; int tape_head; int last_tape_head; /* Speed control at the tape buffers input/output */ unsigned long insert_time; int insert_size; int insert_speed; int max_insert_speed; int measure_insert_time; /* Speed regulation negative feedback loop */ int speed_control; int pipeline_head_speed; int controlled_pipeline_head_speed; int uncontrolled_pipeline_head_speed; int controlled_last_pipeline_head; unsigned long uncontrolled_pipeline_head_time; unsigned long controlled_pipeline_head_time; int controlled_previous_pipeline_head; int uncontrolled_previous_pipeline_head; unsigned long controlled_previous_head_time; unsigned long uncontrolled_previous_head_time; int restart_speed_control_req; u32 debug_mask; } idetape_tape_t; static DEFINE_MUTEX(idetape_ref_mutex); static struct class *idetape_sysfs_class; #define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref) #define ide_tape_g(disk) \ container_of((disk)->private_data, struct ide_tape_obj, driver) static struct ide_tape_obj *ide_tape_get(struct gendisk *disk) { struct ide_tape_obj *tape = NULL; mutex_lock(&idetape_ref_mutex); tape = ide_tape_g(disk); if (tape) kref_get(&tape->kref); mutex_unlock(&idetape_ref_mutex); return tape; } static void ide_tape_release(struct kref *); static void ide_tape_put(struct ide_tape_obj *tape) { mutex_lock(&idetape_ref_mutex); kref_put(&tape->kref, ide_tape_release); mutex_unlock(&idetape_ref_mutex); } /* Tape door status */ #define DOOR_UNLOCKED 0 #define DOOR_LOCKED 1 #define DOOR_EXPLICITLY_LOCKED 2 /* * Tape flag bits values. */ #define IDETAPE_IGNORE_DSC 0 #define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */ #define IDETAPE_BUSY 2 /* Device already opened */ #define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */ #define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */ #define IDETAPE_FILEMARK 5 /* Currently on a filemark */ #define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */ #define IDETAPE_READ_ERROR 7 #define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */ /* 0 = no tape is loaded, so we don't rewind after ejecting */ #define IDETAPE_MEDIUM_PRESENT 9 /* Some defines for the SPACE command */ #define IDETAPE_SPACE_OVER_FILEMARK 1 #define IDETAPE_SPACE_TO_EOD 3 /* Some defines for the LOAD UNLOAD command */ #define IDETAPE_LU_LOAD_MASK 1 #define IDETAPE_LU_RETENSION_MASK 2 #define IDETAPE_LU_EOT_MASK 4 /* * Special requests for our block device strategy routine. * * In order to service a character device command, we add special requests to * the tail of our block device request queue and wait for their completion. */ enum { REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */ REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */ REQ_IDETAPE_READ = (1 << 2), REQ_IDETAPE_WRITE = (1 << 3), }; /* Error codes returned in rq->errors to the higher part of the driver. */ #define IDETAPE_ERROR_GENERAL 101 #define IDETAPE_ERROR_FILEMARK 102 #define IDETAPE_ERROR_EOD 103 /* Structures related to the SELECT SENSE / MODE SENSE packet commands. */ #define IDETAPE_BLOCK_DESCRIPTOR 0 #define IDETAPE_CAPABILITIES_PAGE 0x2a /* * The variables below are used for the character device interface. Additional * state variables are defined in our ide_drive_t structure. */ static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES]; #define ide_tape_f(file) ((file)->private_data) static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i) { struct ide_tape_obj *tape = NULL; mutex_lock(&idetape_ref_mutex); tape = idetape_devs[i]; if (tape) kref_get(&tape->kref); mutex_unlock(&idetape_ref_mutex); return tape; } static void idetape_input_buffers(ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) { struct idetape_bh *bh = pc->bh; int count; while (bcount) { if (bh == NULL) { printk(KERN_ERR "ide-tape: bh == NULL in " "idetape_input_buffers\n"); ide_atapi_discard_data(drive, bcount); return; } count = min( (unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount); HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count); bcount -= count; atomic_add(count, &bh->b_count); if (atomic_read(&bh->b_count) == bh->b_size) { bh = bh->b_reqnext; if (bh) atomic_set(&bh->b_count, 0); } } pc->bh = bh; } static void idetape_output_buffers(ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) { struct idetape_bh *bh = pc->bh; int count; while (bcount) { if (bh == NULL) { printk(KERN_ERR "ide-tape: bh == NULL in %s\n", __func__); return; } count = min((unsigned int)pc->b_count, (unsigned int)bcount); HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count); bcount -= count; pc->b_data += count; pc->b_count -= count; if (!pc->b_count) { bh = bh->b_reqnext; pc->bh = bh; if (bh) { pc->b_data = bh->b_data; pc->b_count = atomic_read(&bh->b_count); } } } } static void idetape_update_buffers(idetape_pc_t *pc) { struct idetape_bh *bh = pc->bh; int count; unsigned int bcount = pc->actually_transferred; if (test_bit(PC_WRITING, &pc->flags)) return; while (bcount) { if (bh == NULL) { printk(KERN_ERR "ide-tape: bh == NULL in %s\n", __func__); return; } count = min((unsigned int)bh->b_size, (unsigned int)bcount); atomic_set(&bh->b_count, count); if (atomic_read(&bh->b_count) == bh->b_size) bh = bh->b_reqnext; bcount -= count; } pc->bh = bh; } /* * idetape_next_pc_storage returns a pointer to a place in which we can * safely store a packet command, even though we intend to leave the * driver. A storage space for a maximum of IDETAPE_PC_STACK packet * commands is allocated at initialization time. */ static idetape_pc_t *idetape_next_pc_storage(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index); if (tape->pc_stack_index == IDETAPE_PC_STACK) tape->pc_stack_index = 0; return (&tape->pc_stack[tape->pc_stack_index++]); } /* * idetape_next_rq_storage is used along with idetape_next_pc_storage. * Since we queue packet commands in the request queue, we need to * allocate a request, along with the allocation of a packet command. */ /************************************************************** * * * This should get fixed to use kmalloc(.., GFP_ATOMIC) * * followed later on by kfree(). -ml * * * **************************************************************/ static struct request *idetape_next_rq_storage(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index); if (tape->rq_stack_index == IDETAPE_PC_STACK) tape->rq_stack_index = 0; return (&tape->rq_stack[tape->rq_stack_index++]); } static void idetape_init_pc(idetape_pc_t *pc) { memset(pc->c, 0, 12); pc->retries = 0; pc->flags = 0; pc->request_transfer = 0; pc->buffer = pc->pc_buffer; pc->buffer_size = IDETAPE_PC_BUFFER_SIZE; pc->bh = NULL; pc->b_data = NULL; } /* * called on each failed packet command retry to analyze the request sense. We * currently do not utilize this information. */ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc = tape->failed_pc; tape->sense_key = sense[2] & 0xF; tape->asc = sense[12]; tape->ascq = sense[13]; debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n", pc->c[0], tape->sense_key, tape->asc, tape->ascq); /* Correct pc->actually_transferred by asking the tape. */ if (test_bit(PC_DMA_ERROR, &pc->flags)) { pc->actually_transferred = pc->request_transfer - tape->blk_size * be32_to_cpu(get_unaligned((u32 *)&sense[3])); idetape_update_buffers(pc); } /* * If error was the result of a zero-length read or write command, * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes. */ if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6) /* length == 0 */ && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { if (tape->sense_key == 5) { /* don't report an error, everything's ok */ pc->error = 0; /* don't retry read/write */ set_bit(PC_ABORT, &pc->flags); } } if (pc->c[0] == READ_6 && (sense[2] & 0x80)) { pc->error = IDETAPE_ERROR_FILEMARK; set_bit(PC_ABORT, &pc->flags); } if (pc->c[0] == WRITE_6) { if ((sense[2] & 0x40) || (tape->sense_key == 0xd && tape->asc == 0x0 && tape->ascq == 0x2)) { pc->error = IDETAPE_ERROR_EOD; set_bit(PC_ABORT, &pc->flags); } } if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) { if (tape->sense_key == 8) { pc->error = IDETAPE_ERROR_EOD; set_bit(PC_ABORT, &pc->flags); } if (!test_bit(PC_ABORT, &pc->flags) && pc->actually_transferred) pc->retries = IDETAPE_MAX_PC_RETRIES + 1; } } static void idetape_activate_next_stage(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *stage = tape->next_stage; struct request *rq = &stage->rq; debug_log(DBG_PROCS, "Enter %s\n", __func__); if (stage == NULL) { printk(KERN_ERR "ide-tape: bug: Trying to activate a non" " existing stage\n"); return; } rq->rq_disk = tape->disk; rq->buffer = NULL; rq->special = (void *)stage->bh; tape->active_data_rq = rq; tape->active_stage = stage; tape->next_stage = stage->next; } /* Free a stage along with its related buffers completely. */ static void __idetape_kfree_stage(idetape_stage_t *stage) { struct idetape_bh *prev_bh, *bh = stage->bh; int size; while (bh != NULL) { if (bh->b_data != NULL) { size = (int) bh->b_size; while (size > 0) { free_page((unsigned long) bh->b_data); size -= PAGE_SIZE; bh->b_data += PAGE_SIZE; } } prev_bh = bh; bh = bh->b_reqnext; kfree(prev_bh); } kfree(stage); } static void idetape_kfree_stage(idetape_tape_t *tape, idetape_stage_t *stage) { __idetape_kfree_stage(stage); } /* * Remove tape->first_stage from the pipeline. The caller should avoid race * conditions. */ static void idetape_remove_stage_head(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *stage; debug_log(DBG_PROCS, "Enter %s\n", __func__); if (tape->first_stage == NULL) { printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n"); return; } if (tape->active_stage == tape->first_stage) { printk(KERN_ERR "ide-tape: bug: Trying to free our active " "pipeline stage\n"); return; } stage = tape->first_stage; tape->first_stage = stage->next; idetape_kfree_stage(tape, stage); tape->nr_stages--; if (tape->first_stage == NULL) { tape->last_stage = NULL; if (tape->next_stage != NULL) printk(KERN_ERR "ide-tape: bug: tape->next_stage !=" " NULL\n"); if (tape->nr_stages) printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 " "now\n"); } } /* * This will free all the pipeline stages starting from new_last_stage->next * to the end of the list, and point tape->last_stage to new_last_stage. */ static void idetape_abort_pipeline(ide_drive_t *drive, idetape_stage_t *new_last_stage) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *stage = new_last_stage->next; idetape_stage_t *nstage; debug_log(DBG_PROCS, "%s: Enter %s\n", tape->name, __func__); while (stage) { nstage = stage->next; idetape_kfree_stage(tape, stage); --tape->nr_stages; --tape->nr_pending_stages; stage = nstage; } if (new_last_stage) new_last_stage->next = NULL; tape->last_stage = new_last_stage; tape->next_stage = NULL; } /* * Finish servicing a request and insert a pending pipeline request into the * main device queue. */ static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects) { struct request *rq = HWGROUP(drive)->rq; idetape_tape_t *tape = drive->driver_data; unsigned long flags; int error; int remove_stage = 0; idetape_stage_t *active_stage; debug_log(DBG_PROCS, "Enter %s\n", __func__); switch (uptodate) { case 0: error = IDETAPE_ERROR_GENERAL; break; case 1: error = 0; break; default: error = uptodate; } rq->errors = error; if (error) tape->failed_pc = NULL; if (!blk_special_request(rq)) { ide_end_request(drive, uptodate, nr_sects); return 0; } spin_lock_irqsave(&tape->lock, flags); /* The request was a pipelined data transfer request */ if (tape->active_data_rq == rq) { active_stage = tape->active_stage; tape->active_stage = NULL; tape->active_data_rq = NULL; tape->nr_pending_stages--; if (rq->cmd[0] & REQ_IDETAPE_WRITE) { remove_stage = 1; if (error) { set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); if (error == IDETAPE_ERROR_EOD) idetape_abort_pipeline(drive, active_stage); } } else if (rq->cmd[0] & REQ_IDETAPE_READ) { if (error == IDETAPE_ERROR_EOD) { set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); idetape_abort_pipeline(drive, active_stage); } } if (tape->next_stage != NULL) { idetape_activate_next_stage(drive); /* Insert the next request into the request queue. */ (void)ide_do_drive_cmd(drive, tape->active_data_rq, ide_end); } else if (!error) { /* * This is a part of the feedback loop which tries to * find the optimum number of stages. We are starting * from a minimum maximum number of stages, and if we * sense that the pipeline is empty, we try to increase * it, until we reach the user compile time memory * limit. */ int i = (tape->max_pipeline - tape->min_pipeline) / 10; tape->max_stages += max(i, 1); tape->max_stages = max(tape->max_stages, tape->min_pipeline); tape->max_stages = min(tape->max_stages, tape->max_pipeline); } } ide_end_drive_cmd(drive, 0, 0); if (remove_stage) idetape_remove_stage_head(drive); if (tape->active_data_rq == NULL) clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); spin_unlock_irqrestore(&tape->lock, flags); return 0; } static ide_startstop_t idetape_request_sense_callback(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; debug_log(DBG_PROCS, "Enter %s\n", __func__); if (!tape->pc->error) { idetape_analyze_error(drive, tape->pc->buffer); idetape_end_request(drive, 1, 0); } else { printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - " "Aborting request!\n"); idetape_end_request(drive, 0, 0); } return ide_stopped; } static void idetape_create_request_sense_cmd(idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = REQUEST_SENSE; pc->c[4] = 20; pc->request_transfer = 20; pc->callback = &idetape_request_sense_callback; } static void idetape_init_rq(struct request *rq, u8 cmd) { memset(rq, 0, sizeof(*rq)); rq->cmd_type = REQ_TYPE_SPECIAL; rq->cmd[0] = cmd; } /* * Generate a new packet command request in front of the request queue, before * the current request, so that it will be processed immediately, on the next * pass through the driver. The function below is called from the request * handling part of the driver (the "bottom" part). Safe storage for the request * should be allocated with ide_tape_next_{pc,rq}_storage() prior to that. * * Memory for those requests is pre-allocated at initialization time, and is * limited to IDETAPE_PC_STACK requests. We assume that we have enough space for * the maximum possible number of inter-dependent packet commands. * * The higher level of the driver - The ioctl handler and the character device * handling functions should queue request to the lower level part and wait for * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail. */ static void idetape_queue_pc_head(ide_drive_t *drive, idetape_pc_t *pc, struct request *rq) { struct ide_tape_obj *tape = drive->driver_data; idetape_init_rq(rq, REQ_IDETAPE_PC1); rq->buffer = (char *) pc; rq->rq_disk = tape->disk; (void) ide_do_drive_cmd(drive, rq, ide_preempt); } /* * idetape_retry_pc is called when an error was detected during the * last packet command. We queue a request sense packet command in * the head of the request list. */ static ide_startstop_t idetape_retry_pc (ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc; struct request *rq; (void)ide_read_error(drive); pc = idetape_next_pc_storage(drive); rq = idetape_next_rq_storage(drive); idetape_create_request_sense_cmd(pc); set_bit(IDETAPE_IGNORE_DSC, &tape->flags); idetape_queue_pc_head(drive, pc, rq); return ide_stopped; } /* * Postpone the current request so that ide.c will be able to service requests * from another device on the same hwgroup while we are polling for DSC. */ static void idetape_postpone_request(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; debug_log(DBG_PROCS, "Enter %s\n", __func__); tape->postponed_rq = HWGROUP(drive)->rq; ide_stall_queue(drive, tape->dsc_poll_freq); } typedef void idetape_io_buf(ide_drive_t *, idetape_pc_t *, unsigned int); /* * This is the usual interrupt handler which will be called during a packet * command. We will transfer some of the data (as requested by the drive) and * will re-point interrupt handler to us. When data transfer is finished, we * will act according to the algorithm described before * idetape_issue_pc. */ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive) { ide_hwif_t *hwif = drive->hwif; idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc = tape->pc; xfer_func_t *xferfunc; idetape_io_buf *iobuf; unsigned int temp; #if SIMULATE_ERRORS static int error_sim_count; #endif u16 bcount; u8 stat, ireason; debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__); /* Clear the interrupt */ stat = ide_read_status(drive); if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) { if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) { /* * A DMA error is sometimes expected. For example, * if the tape is crossing a filemark during a * READ command, it will issue an irq and position * itself before the filemark, so that only a partial * data transfer will occur (which causes the DMA * error). In that case, we will later ask the tape * how much bytes of the original request were * actually transferred (we can't receive that * information from the DMA engine on most chipsets). */ /* * On the contrary, a DMA error is never expected; * it usually indicates a hardware error or abort. * If the tape crosses a filemark during a READ * command, it will issue an irq and position itself * after the filemark (not before). Only a partial * data transfer will occur, but no DMA error. * (AS, 19 Apr 2001) */ set_bit(PC_DMA_ERROR, &pc->flags); } else { pc->actually_transferred = pc->request_transfer; idetape_update_buffers(pc); } debug_log(DBG_PROCS, "DMA finished\n"); } /* No more interrupts */ if ((stat & DRQ_STAT) == 0) { debug_log(DBG_SENSE, "Packet command completed, %d bytes" " transferred\n", pc->actually_transferred); clear_bit(PC_DMA_IN_PROGRESS, &pc->flags); local_irq_enable(); #if SIMULATE_ERRORS if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) && (++error_sim_count % 100) == 0) { printk(KERN_INFO "ide-tape: %s: simulating error\n", tape->name); stat |= ERR_STAT; } #endif if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE) stat &= ~ERR_STAT; if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) { /* Error detected */ debug_log(DBG_ERR, "%s: I/O error\n", tape->name); if (pc->c[0] == REQUEST_SENSE) { printk(KERN_ERR "ide-tape: I/O error in request" " sense command\n"); return ide_do_reset(drive); } debug_log(DBG_ERR, "[cmd %x]: check condition\n", pc->c[0]); /* Retry operation */ return idetape_retry_pc(drive); } pc->error = 0; if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) && (stat & SEEK_STAT) == 0) { /* Media access command */ tape->dsc_polling_start = jiffies; tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST; tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT; /* Allow ide.c to handle other requests */ idetape_postpone_request(drive); return ide_stopped; } if (tape->failed_pc == pc) tape->failed_pc = NULL; /* Command finished - Call the callback function */ return pc->callback(drive); } if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) { printk(KERN_ERR "ide-tape: The tape wants to issue more " "interrupts in DMA mode\n"); printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n"); ide_dma_off(drive); return ide_do_reset(drive); } /* Get the number of bytes to transfer on this interrupt. */ bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) | hwif->INB(IDE_BCOUNTL_REG); ireason = hwif->INB(IDE_IREASON_REG); if (ireason & CD) { printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__); return ide_do_reset(drive); } if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) { /* Hopefully, we will never get here */ printk(KERN_ERR "ide-tape: We wanted to %s, ", (ireason & IO) ? "Write" : "Read"); printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n", (ireason & IO) ? "Read" : "Write"); return ide_do_reset(drive); } if (!test_bit(PC_WRITING, &pc->flags)) { /* Reading - Check that we have enough space */ temp = pc->actually_transferred + bcount; if (temp > pc->request_transfer) { if (temp > pc->buffer_size) { printk(KERN_ERR "ide-tape: The tape wants to " "send us more data than expected " "- discarding data\n"); ide_atapi_discard_data(drive, bcount); ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); return ide_started; } debug_log(DBG_SENSE, "The tape wants to send us more " "data than expected - allowing transfer\n"); } iobuf = &idetape_input_buffers; xferfunc = hwif->atapi_input_bytes; } else { iobuf = &idetape_output_buffers; xferfunc = hwif->atapi_output_bytes; } if (pc->bh) iobuf(drive, pc, bcount); else xferfunc(drive, pc->current_position, bcount); /* Update the current position */ pc->actually_transferred += bcount; pc->current_position += bcount; debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n", pc->c[0], bcount); /* And set the interrupt handler again */ ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); return ide_started; } /* * Packet Command Interface * * The current Packet Command is available in tape->pc, and will not change * until we finish handling it. Each packet command is associated with a * callback function that will be called when the command is finished. * * The handling will be done in three stages: * * 1. idetape_issue_pc will send the packet command to the drive, and will set * the interrupt handler to idetape_pc_intr. * * 2. On each interrupt, idetape_pc_intr will be called. This step will be * repeated until the device signals us that no more interrupts will be issued. * * 3. ATAPI Tape media access commands have immediate status with a delayed * process. In case of a successful initiation of a media access packet command, * the DSC bit will be set when the actual execution of the command is finished. * Since the tape drive will not issue an interrupt, we have to poll for this * event. In this case, we define the request as "low priority request" by * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and * exit the driver. * * ide.c will then give higher priority to requests which originate from the * other device, until will change rq_status to RQ_ACTIVE. * * 4. When the packet command is finished, it will be checked for errors. * * 5. In case an error was found, we queue a request sense packet command in * front of the request queue and retry the operation up to * IDETAPE_MAX_PC_RETRIES times. * * 6. In case no error was found, or we decided to give up and not to retry * again, the callback function will be called and then we will handle the next * request. */ static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive) { ide_hwif_t *hwif = drive->hwif; idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc = tape->pc; int retries = 100; ide_startstop_t startstop; u8 ireason; if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) { printk(KERN_ERR "ide-tape: Strange, packet command initiated " "yet DRQ isn't asserted\n"); return startstop; } ireason = hwif->INB(IDE_IREASON_REG); while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) { printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing " "a packet command, retrying\n"); udelay(100); ireason = hwif->INB(IDE_IREASON_REG); if (retries == 0) { printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while " "issuing a packet command, ignoring\n"); ireason |= CD; ireason &= ~IO; } } if ((ireason & CD) == 0 || (ireason & IO)) { printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing " "a packet command\n"); return ide_do_reset(drive); } /* Set the interrupt routine */ ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); #ifdef CONFIG_BLK_DEV_IDEDMA /* Begin DMA, if necessary */ if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) hwif->dma_start(drive); #endif /* Send the actual packet */ HWIF(drive)->atapi_output_bytes(drive, pc->c, 12); return ide_started; } static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, idetape_pc_t *pc) { ide_hwif_t *hwif = drive->hwif; idetape_tape_t *tape = drive->driver_data; int dma_ok = 0; u16 bcount; if (tape->pc->c[0] == REQUEST_SENSE && pc->c[0] == REQUEST_SENSE) { printk(KERN_ERR "ide-tape: possible ide-tape.c bug - " "Two request sense in serial were issued\n"); } if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE) tape->failed_pc = pc; /* Set the current packet command */ tape->pc = pc; if (pc->retries > IDETAPE_MAX_PC_RETRIES || test_bit(PC_ABORT, &pc->flags)) { /* * We will "abort" retrying a packet command in case legitimate * error code was received (crossing a filemark, or end of the * media, for example). */ if (!test_bit(PC_ABORT, &pc->flags)) { if (!(pc->c[0] == TEST_UNIT_READY && tape->sense_key == 2 && tape->asc == 4 && (tape->ascq == 1 || tape->ascq == 8))) { printk(KERN_ERR "ide-tape: %s: I/O error, " "pc = %2x, key = %2x, " "asc = %2x, ascq = %2x\n", tape->name, pc->c[0], tape->sense_key, tape->asc, tape->ascq); } /* Giving up */ pc->error = IDETAPE_ERROR_GENERAL; } tape->failed_pc = NULL; return pc->callback(drive); } debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]); pc->retries++; /* We haven't transferred any data yet */ pc->actually_transferred = 0; pc->current_position = pc->buffer; /* Request to transfer the entire buffer at once */ bcount = pc->request_transfer; if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) { printk(KERN_WARNING "ide-tape: DMA disabled, " "reverting to PIO\n"); ide_dma_off(drive); } if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma) dma_ok = !hwif->dma_setup(drive); ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK | IDE_TFLAG_OUT_DEVICE, bcount, dma_ok); if (dma_ok) /* Will begin DMA later */ set_bit(PC_DMA_IN_PROGRESS, &pc->flags); if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) { ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL); return ide_started; } else { hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG); return idetape_transfer_pc(drive); } } static ide_startstop_t idetape_pc_callback(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; debug_log(DBG_PROCS, "Enter %s\n", __func__); idetape_end_request(drive, tape->pc->error ? 0 : 1, 0); return ide_stopped; } /* A mode sense command is used to "sense" tape parameters. */ static void idetape_create_mode_sense_cmd(idetape_pc_t *pc, u8 page_code) { idetape_init_pc(pc); pc->c[0] = MODE_SENSE; if (page_code != IDETAPE_BLOCK_DESCRIPTOR) /* DBD = 1 - Don't return block descriptors */ pc->c[1] = 8; pc->c[2] = page_code; /* * Changed pc->c[3] to 0 (255 will at best return unused info). * * For SCSI this byte is defined as subpage instead of high byte * of length and some IDE drives seem to interpret it this way * and return an error when 255 is used. */ pc->c[3] = 0; /* We will just discard data in that case */ pc->c[4] = 255; if (page_code == IDETAPE_BLOCK_DESCRIPTOR) pc->request_transfer = 12; else if (page_code == IDETAPE_CAPABILITIES_PAGE) pc->request_transfer = 24; else pc->request_transfer = 50; pc->callback = &idetape_pc_callback; } static void idetape_calculate_speeds(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) { tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head; tape->controlled_previous_head_time = tape->controlled_pipeline_head_time; tape->controlled_last_pipeline_head = tape->pipeline_head; tape->controlled_pipeline_head_time = jiffies; } if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ)) tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time); else if (time_after(jiffies, tape->controlled_previous_head_time)) tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time); if (tape->nr_pending_stages < tape->max_stages/*- 1 */) { /* -1 for read mode error recovery */ if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) { tape->uncontrolled_pipeline_head_time = jiffies; tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time); } } else { tape->uncontrolled_previous_head_time = jiffies; tape->uncontrolled_previous_pipeline_head = tape->pipeline_head; if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) tape->uncontrolled_pipeline_head_time = jiffies; } tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed); if (tape->speed_control == 1) { if (tape->nr_pending_stages >= tape->max_stages / 2) tape->max_insert_speed = tape->pipeline_head_speed + (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages; else tape->max_insert_speed = 500 + (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages; if (tape->nr_pending_stages >= tape->max_stages * 99 / 100) tape->max_insert_speed = 5000; } else tape->max_insert_speed = tape->speed_control; tape->max_insert_speed = max(tape->max_insert_speed, 500); } static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc = tape->pc; u8 stat; stat = ide_read_status(drive); if (stat & SEEK_STAT) { if (stat & ERR_STAT) { /* Error detected */ if (pc->c[0] != TEST_UNIT_READY) printk(KERN_ERR "ide-tape: %s: I/O error, ", tape->name); /* Retry operation */ return idetape_retry_pc(drive); } pc->error = 0; if (tape->failed_pc == pc) tape->failed_pc = NULL; } else { pc->error = IDETAPE_ERROR_GENERAL; tape->failed_pc = NULL; } return pc->callback(drive); } static ide_startstop_t idetape_rw_callback(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; struct request *rq = HWGROUP(drive)->rq; int blocks = tape->pc->actually_transferred / tape->blk_size; tape->avg_size += blocks * tape->blk_size; tape->insert_size += blocks * tape->blk_size; if (tape->insert_size > 1024 * 1024) tape->measure_insert_time = 1; if (tape->measure_insert_time) { tape->measure_insert_time = 0; tape->insert_time = jiffies; tape->insert_size = 0; } if (time_after(jiffies, tape->insert_time)) tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time); if (time_after_eq(jiffies, tape->avg_time + HZ)) { tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024; tape->avg_size = 0; tape->avg_time = jiffies; } debug_log(DBG_PROCS, "Enter %s\n", __func__); tape->first_frame += blocks; rq->current_nr_sectors -= blocks; if (!tape->pc->error) idetape_end_request(drive, 1, 0); else idetape_end_request(drive, tape->pc->error, 0); return ide_stopped; } static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh) { idetape_init_pc(pc); pc->c[0] = READ_6; put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); pc->c[1] = 1; pc->callback = &idetape_rw_callback; pc->bh = bh; atomic_set(&bh->b_count, 0); pc->buffer = NULL; pc->buffer_size = length * tape->blk_size; pc->request_transfer = pc->buffer_size; if (pc->request_transfer == tape->stage_size) set_bit(PC_DMA_RECOMMENDED, &pc->flags); } static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh) { idetape_init_pc(pc); pc->c[0] = WRITE_6; put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); pc->c[1] = 1; pc->callback = &idetape_rw_callback; set_bit(PC_WRITING, &pc->flags); pc->bh = bh; pc->b_data = bh->b_data; pc->b_count = atomic_read(&bh->b_count); pc->buffer = NULL; pc->buffer_size = length * tape->blk_size; pc->request_transfer = pc->buffer_size; if (pc->request_transfer == tape->stage_size) set_bit(PC_DMA_RECOMMENDED, &pc->flags); } static ide_startstop_t idetape_do_request(ide_drive_t *drive, struct request *rq, sector_t block) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t *pc = NULL; struct request *postponed_rq = tape->postponed_rq; u8 stat; debug_log(DBG_SENSE, "sector: %ld, nr_sectors: %ld," " current_nr_sectors: %d\n", rq->sector, rq->nr_sectors, rq->current_nr_sectors); if (!blk_special_request(rq)) { /* We do not support buffer cache originated requests. */ printk(KERN_NOTICE "ide-tape: %s: Unsupported request in " "request queue (%d)\n", drive->name, rq->cmd_type); ide_end_request(drive, 0, 0); return ide_stopped; } /* Retry a failed packet command */ if (tape->failed_pc && tape->pc->c[0] == REQUEST_SENSE) return idetape_issue_pc(drive, tape->failed_pc); if (postponed_rq != NULL) if (rq != postponed_rq) { printk(KERN_ERR "ide-tape: ide-tape.c bug - " "Two DSC requests were queued\n"); idetape_end_request(drive, 0, 0); return ide_stopped; } tape->postponed_rq = NULL; /* * If the tape is still busy, postpone our request and service * the other device meanwhile. */ stat = ide_read_status(drive); if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2)) set_bit(IDETAPE_IGNORE_DSC, &tape->flags); if (drive->post_reset == 1) { set_bit(IDETAPE_IGNORE_DSC, &tape->flags); drive->post_reset = 0; } if (time_after(jiffies, tape->insert_time)) tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time); idetape_calculate_speeds(drive); if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) && (stat & SEEK_STAT) == 0) { if (postponed_rq == NULL) { tape->dsc_polling_start = jiffies; tape->dsc_poll_freq = tape->best_dsc_rw_freq; tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT; } else if (time_after(jiffies, tape->dsc_timeout)) { printk(KERN_ERR "ide-tape: %s: DSC timeout\n", tape->name); if (rq->cmd[0] & REQ_IDETAPE_PC2) { idetape_media_access_finished(drive); return ide_stopped; } else { return ide_do_reset(drive); } } else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD)) tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW; idetape_postpone_request(drive); return ide_stopped; } if (rq->cmd[0] & REQ_IDETAPE_READ) { tape->buffer_head++; tape->postpone_cnt = 0; pc = idetape_next_pc_storage(drive); idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special); goto out; } if (rq->cmd[0] & REQ_IDETAPE_WRITE) { tape->buffer_head++; tape->postpone_cnt = 0; pc = idetape_next_pc_storage(drive); idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special); goto out; } if (rq->cmd[0] & REQ_IDETAPE_PC1) { pc = (idetape_pc_t *) rq->buffer; rq->cmd[0] &= ~(REQ_IDETAPE_PC1); rq->cmd[0] |= REQ_IDETAPE_PC2; goto out; } if (rq->cmd[0] & REQ_IDETAPE_PC2) { idetape_media_access_finished(drive); return ide_stopped; } BUG(); out: return idetape_issue_pc(drive, pc); } /* Pipeline related functions */ static inline int idetape_pipeline_active(idetape_tape_t *tape) { int rc1, rc2; rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); rc2 = (tape->active_data_rq != NULL); return rc1; } /* * The function below uses __get_free_page to allocate a pipeline stage, along * with all the necessary small buffers which together make a buffer of size * tape->stage_size (or a bit more). We attempt to combine sequential pages as * much as possible. * * It returns a pointer to the new allocated stage, or NULL if we can't (or * don't want to) allocate a stage. * * Pipeline stages are optional and are used to increase performance. If we * can't allocate them, we'll manage without them. */ static idetape_stage_t *__idetape_kmalloc_stage(idetape_tape_t *tape, int full, int clear) { idetape_stage_t *stage; struct idetape_bh *prev_bh, *bh; int pages = tape->pages_per_stage; char *b_data = NULL; stage = kmalloc(sizeof(idetape_stage_t), GFP_KERNEL); if (!stage) return NULL; stage->next = NULL; stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); bh = stage->bh; if (bh == NULL) goto abort; bh->b_reqnext = NULL; bh->b_data = (char *) __get_free_page(GFP_KERNEL); if (!bh->b_data) goto abort; if (clear) memset(bh->b_data, 0, PAGE_SIZE); bh->b_size = PAGE_SIZE; atomic_set(&bh->b_count, full ? bh->b_size : 0); while (--pages) { b_data = (char *) __get_free_page(GFP_KERNEL); if (!b_data) goto abort; if (clear) memset(b_data, 0, PAGE_SIZE); if (bh->b_data == b_data + PAGE_SIZE) { bh->b_size += PAGE_SIZE; bh->b_data -= PAGE_SIZE; if (full) atomic_add(PAGE_SIZE, &bh->b_count); continue; } if (b_data == bh->b_data + bh->b_size) { bh->b_size += PAGE_SIZE; if (full) atomic_add(PAGE_SIZE, &bh->b_count); continue; } prev_bh = bh; bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); if (!bh) { free_page((unsigned long) b_data); goto abort; } bh->b_reqnext = NULL; bh->b_data = b_data; bh->b_size = PAGE_SIZE; atomic_set(&bh->b_count, full ? bh->b_size : 0); prev_bh->b_reqnext = bh; } bh->b_size -= tape->excess_bh_size; if (full) atomic_sub(tape->excess_bh_size, &bh->b_count); return stage; abort: __idetape_kfree_stage(stage); return NULL; } static idetape_stage_t *idetape_kmalloc_stage(idetape_tape_t *tape) { idetape_stage_t *cache_stage = tape->cache_stage; debug_log(DBG_PROCS, "Enter %s\n", __func__); if (tape->nr_stages >= tape->max_stages) return NULL; if (cache_stage != NULL) { tape->cache_stage = NULL; return cache_stage; } return __idetape_kmalloc_stage(tape, 0, 0); } static int idetape_copy_stage_from_user(idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n) { struct idetape_bh *bh = tape->bh; int count; int ret = 0; while (n) { if (bh == NULL) { printk(KERN_ERR "ide-tape: bh == NULL in %s\n", __func__); return 1; } count = min((unsigned int) (bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n); if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count)) ret = 1; n -= count; atomic_add(count, &bh->b_count); buf += count; if (atomic_read(&bh->b_count) == bh->b_size) { bh = bh->b_reqnext; if (bh) atomic_set(&bh->b_count, 0); } } tape->bh = bh; return ret; } static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n) { struct idetape_bh *bh = tape->bh; int count; int ret = 0; while (n) { if (bh == NULL) { printk(KERN_ERR "ide-tape: bh == NULL in %s\n", __func__); return 1; } count = min(tape->b_count, n); if (copy_to_user(buf, tape->b_data, count)) ret = 1; n -= count; tape->b_data += count; tape->b_count -= count; buf += count; if (!tape->b_count) { bh = bh->b_reqnext; tape->bh = bh; if (bh) { tape->b_data = bh->b_data; tape->b_count = atomic_read(&bh->b_count); } } } return ret; } static void idetape_init_merge_stage(idetape_tape_t *tape) { struct idetape_bh *bh = tape->merge_stage->bh; tape->bh = bh; if (tape->chrdev_dir == IDETAPE_DIR_WRITE) atomic_set(&bh->b_count, 0); else { tape->b_data = bh->b_data; tape->b_count = atomic_read(&bh->b_count); } } static void idetape_switch_buffers(idetape_tape_t *tape, idetape_stage_t *stage) { struct idetape_bh *tmp; tmp = stage->bh; stage->bh = tape->merge_stage->bh; tape->merge_stage->bh = tmp; idetape_init_merge_stage(tape); } /* Add a new stage at the end of the pipeline. */ static void idetape_add_stage_tail(ide_drive_t *drive, idetape_stage_t *stage) { idetape_tape_t *tape = drive->driver_data; unsigned long flags; debug_log(DBG_PROCS, "Enter %s\n", __func__); spin_lock_irqsave(&tape->lock, flags); stage->next = NULL; if (tape->last_stage != NULL) tape->last_stage->next = stage; else tape->first_stage = stage; tape->next_stage = stage; tape->last_stage = stage; if (tape->next_stage == NULL) tape->next_stage = tape->last_stage; tape->nr_stages++; tape->nr_pending_stages++; spin_unlock_irqrestore(&tape->lock, flags); } /* Install a completion in a pending request and sleep until it is serviced. The * caller should ensure that the request will not be serviced before we install * the completion (usually by disabling interrupts). */ static void idetape_wait_for_request(ide_drive_t *drive, struct request *rq) { DECLARE_COMPLETION_ONSTACK(wait); idetape_tape_t *tape = drive->driver_data; if (rq == NULL || !blk_special_request(rq)) { printk(KERN_ERR "ide-tape: bug: Trying to sleep on non-valid" " request\n"); return; } rq->end_io_data = &wait; rq->end_io = blk_end_sync_rq; spin_unlock_irq(&tape->lock); wait_for_completion(&wait); /* The stage and its struct request have been deallocated */ spin_lock_irq(&tape->lock); } static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; u8 *readpos = tape->pc->buffer; debug_log(DBG_PROCS, "Enter %s\n", __func__); if (!tape->pc->error) { debug_log(DBG_SENSE, "BOP - %s\n", (readpos[0] & 0x80) ? "Yes" : "No"); debug_log(DBG_SENSE, "EOP - %s\n", (readpos[0] & 0x40) ? "Yes" : "No"); if (readpos[0] & 0x4) { printk(KERN_INFO "ide-tape: Block location is unknown" "to the tape\n"); clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags); idetape_end_request(drive, 0, 0); } else { debug_log(DBG_SENSE, "Block Location - %u\n", be32_to_cpu(*(u32 *)&readpos[4])); tape->partition = readpos[1]; tape->first_frame = be32_to_cpu(*(u32 *)&readpos[4]); set_bit(IDETAPE_ADDRESS_VALID, &tape->flags); idetape_end_request(drive, 1, 0); } } else { idetape_end_request(drive, 0, 0); } return ide_stopped; } /* * Write a filemark if write_filemark=1. Flush the device buffers without * writing a filemark otherwise. */ static void idetape_create_write_filemark_cmd(ide_drive_t *drive, idetape_pc_t *pc, int write_filemark) { idetape_init_pc(pc); pc->c[0] = WRITE_FILEMARKS; pc->c[4] = write_filemark; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = TEST_UNIT_READY; pc->callback = &idetape_pc_callback; } /* * We add a special packet command request to the tail of the request queue, and * wait for it to be serviced. This is not to be called from within the request * handling part of the driver! We allocate here data on the stack and it is * valid until the request is finished. This is not the case for the bottom part * of the driver, where we are always leaving the functions to wait for an * interrupt or a timer event. * * From the bottom part of the driver, we should allocate safe memory using * idetape_next_pc_storage() and ide_tape_next_rq_storage(), and add the request * to the request list without waiting for it to be serviced! In that case, we * usually use idetape_queue_pc_head(). */ static int __idetape_queue_pc_tail(ide_drive_t *drive, idetape_pc_t *pc) { struct ide_tape_obj *tape = drive->driver_data; struct request rq; idetape_init_rq(&rq, REQ_IDETAPE_PC1); rq.buffer = (char *) pc; rq.rq_disk = tape->disk; return ide_do_drive_cmd(drive, &rq, ide_wait); } static void idetape_create_load_unload_cmd(ide_drive_t *drive, idetape_pc_t *pc, int cmd) { idetape_init_pc(pc); pc->c[0] = START_STOP; pc->c[4] = cmd; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; int load_attempted = 0; /* Wait for the tape to become ready */ set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags); timeout += jiffies; while (time_before(jiffies, timeout)) { idetape_create_test_unit_ready_cmd(&pc); if (!__idetape_queue_pc_tail(drive, &pc)) return 0; if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) || (tape->asc == 0x3A)) { /* no media */ if (load_attempted) return -ENOMEDIUM; idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK); __idetape_queue_pc_tail(drive, &pc); load_attempted = 1; /* not about to be ready */ } else if (!(tape->sense_key == 2 && tape->asc == 4 && (tape->ascq == 1 || tape->ascq == 8))) return -EIO; msleep(100); } return -EIO; } static int idetape_queue_pc_tail(ide_drive_t *drive, idetape_pc_t *pc) { return __idetape_queue_pc_tail(drive, pc); } static int idetape_flush_tape_buffers(ide_drive_t *drive) { idetape_pc_t pc; int rc; idetape_create_write_filemark_cmd(drive, &pc, 0); rc = idetape_queue_pc_tail(drive, &pc); if (rc) return rc; idetape_wait_ready(drive, 60 * 5 * HZ); return 0; } static void idetape_create_read_position_cmd(idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = READ_POSITION; pc->request_transfer = 20; pc->callback = &idetape_read_position_callback; } static int idetape_read_position(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; int position; debug_log(DBG_PROCS, "Enter %s\n", __func__); idetape_create_read_position_cmd(&pc); if (idetape_queue_pc_tail(drive, &pc)) return -1; position = tape->first_frame; return position; } static void idetape_create_locate_cmd(ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip) { idetape_init_pc(pc); pc->c[0] = POSITION_TO_ELEMENT; pc->c[1] = 2; put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]); pc->c[8] = partition; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static int idetape_create_prevent_cmd(ide_drive_t *drive, idetape_pc_t *pc, int prevent) { idetape_tape_t *tape = drive->driver_data; /* device supports locking according to capabilities page */ if (!(tape->caps[6] & 0x01)) return 0; idetape_init_pc(pc); pc->c[0] = ALLOW_MEDIUM_REMOVAL; pc->c[4] = prevent; pc->callback = &idetape_pc_callback; return 1; } static int __idetape_discard_read_pipeline(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; unsigned long flags; int cnt; if (tape->chrdev_dir != IDETAPE_DIR_READ) return 0; /* Remove merge stage. */ cnt = tape->merge_stage_size / tape->blk_size; if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags)) ++cnt; /* Filemarks count as 1 sector */ tape->merge_stage_size = 0; if (tape->merge_stage != NULL) { __idetape_kfree_stage(tape->merge_stage); tape->merge_stage = NULL; } /* Clear pipeline flags. */ clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); tape->chrdev_dir = IDETAPE_DIR_NONE; /* Remove pipeline stages. */ if (tape->first_stage == NULL) return 0; spin_lock_irqsave(&tape->lock, flags); tape->next_stage = NULL; if (idetape_pipeline_active(tape)) idetape_wait_for_request(drive, tape->active_data_rq); spin_unlock_irqrestore(&tape->lock, flags); while (tape->first_stage != NULL) { struct request *rq_ptr = &tape->first_stage->rq; cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors; if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK) ++cnt; idetape_remove_stage_head(drive); } tape->nr_pending_stages = 0; tape->max_stages = tape->min_pipeline; return cnt; } /* * Position the tape to the requested block using the LOCATE packet command. * A READ POSITION command is then issued to check where we are positioned. Like * all higher level operations, we queue the commands at the tail of the request * queue and wait for their completion. */ static int idetape_position_tape(ide_drive_t *drive, unsigned int block, u8 partition, int skip) { idetape_tape_t *tape = drive->driver_data; int retval; idetape_pc_t pc; if (tape->chrdev_dir == IDETAPE_DIR_READ) __idetape_discard_read_pipeline(drive); idetape_wait_ready(drive, 60 * 5 * HZ); idetape_create_locate_cmd(drive, &pc, block, partition, skip); retval = idetape_queue_pc_tail(drive, &pc); if (retval) return (retval); idetape_create_read_position_cmd(&pc); return (idetape_queue_pc_tail(drive, &pc)); } static void idetape_discard_read_pipeline(ide_drive_t *drive, int restore_position) { idetape_tape_t *tape = drive->driver_data; int cnt; int seek, position; cnt = __idetape_discard_read_pipeline(drive); if (restore_position) { position = idetape_read_position(drive); seek = position > cnt ? position - cnt : 0; if (idetape_position_tape(drive, seek, 0, 0)) { printk(KERN_INFO "ide-tape: %s: position_tape failed in" " discard_pipeline()\n", tape->name); return; } } } /* * Generate a read/write request for the block device interface and wait for it * to be serviced. */ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh) { idetape_tape_t *tape = drive->driver_data; struct request rq; debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd); if (idetape_pipeline_active(tape)) { printk(KERN_ERR "ide-tape: bug: the pipeline is active in %s\n", __func__); return (0); } idetape_init_rq(&rq, cmd); rq.rq_disk = tape->disk; rq.special = (void *)bh; rq.sector = tape->first_frame; rq.nr_sectors = blocks; rq.current_nr_sectors = blocks; (void) ide_do_drive_cmd(drive, &rq, ide_wait); if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0) return 0; if (tape->merge_stage) idetape_init_merge_stage(tape); if (rq.errors == IDETAPE_ERROR_GENERAL) return -EIO; return (tape->blk_size * (blocks-rq.current_nr_sectors)); } /* start servicing the pipeline stages, starting from tape->next_stage. */ static void idetape_plug_pipeline(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; if (tape->next_stage == NULL) return; if (!idetape_pipeline_active(tape)) { set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); idetape_activate_next_stage(drive); (void) ide_do_drive_cmd(drive, tape->active_data_rq, ide_end); } } static void idetape_create_inquiry_cmd(idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = INQUIRY; pc->c[4] = 254; pc->request_transfer = 254; pc->callback = &idetape_pc_callback; } static void idetape_create_rewind_cmd(ide_drive_t *drive, idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = REZERO_UNIT; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static void idetape_create_erase_cmd(idetape_pc_t *pc) { idetape_init_pc(pc); pc->c[0] = ERASE; pc->c[1] = 1; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static void idetape_create_space_cmd(idetape_pc_t *pc, int count, u8 cmd) { idetape_init_pc(pc); pc->c[0] = SPACE; put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]); pc->c[1] = cmd; set_bit(PC_WAIT_FOR_DSC, &pc->flags); pc->callback = &idetape_pc_callback; } static void idetape_wait_first_stage(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; unsigned long flags; if (tape->first_stage == NULL) return; spin_lock_irqsave(&tape->lock, flags); if (tape->active_stage == tape->first_stage) idetape_wait_for_request(drive, tape->active_data_rq); spin_unlock_irqrestore(&tape->lock, flags); } /* * Try to add a character device originated write request to our pipeline. In * case we don't succeed, we revert to non-pipelined operation mode for this * request. In order to accomplish that, we * * 1. Try to allocate a new pipeline stage. * 2. If we can't, wait for more and more requests to be serviced and try again * each time. * 3. If we still can't allocate a stage, fallback to non-pipelined operation * mode for this request. */ static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *new_stage; unsigned long flags; struct request *rq; debug_log(DBG_CHRDEV, "Enter %s\n", __func__); /* Attempt to allocate a new stage. Beware possible race conditions. */ while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) { spin_lock_irqsave(&tape->lock, flags); if (idetape_pipeline_active(tape)) { idetape_wait_for_request(drive, tape->active_data_rq); spin_unlock_irqrestore(&tape->lock, flags); } else { spin_unlock_irqrestore(&tape->lock, flags); idetape_plug_pipeline(drive); if (idetape_pipeline_active(tape)) continue; /* * The machine is short on memory. Fallback to non- * pipelined operation mode for this request. */ return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh); } } rq = &new_stage->rq; idetape_init_rq(rq, REQ_IDETAPE_WRITE); /* Doesn't actually matter - We always assume sequential access */ rq->sector = tape->first_frame; rq->current_nr_sectors = blocks; rq->nr_sectors = blocks; idetape_switch_buffers(tape, new_stage); idetape_add_stage_tail(drive, new_stage); tape->pipeline_head++; idetape_calculate_speeds(drive); /* * Estimate whether the tape has stopped writing by checking if our * write pipeline is currently empty. If we are not writing anymore, * wait for the pipeline to be almost completely full (90%) before * starting to service requests, so that we will be able to keep up with * the higher speeds of the tape. */ if (!idetape_pipeline_active(tape)) { if (tape->nr_stages >= tape->max_stages * 9 / 10 || tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->blk_size) { tape->measure_insert_time = 1; tape->insert_time = jiffies; tape->insert_size = 0; tape->insert_speed = 0; idetape_plug_pipeline(drive); } } if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags)) /* Return a deferred error */ return -EIO; return blocks; } /* * Wait until all pending pipeline requests are serviced. Typically called on * device close. */ static void idetape_wait_for_pipeline(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; unsigned long flags; while (tape->next_stage || idetape_pipeline_active(tape)) { idetape_plug_pipeline(drive); spin_lock_irqsave(&tape->lock, flags); if (idetape_pipeline_active(tape)) idetape_wait_for_request(drive, tape->active_data_rq); spin_unlock_irqrestore(&tape->lock, flags); } } static void idetape_empty_write_pipeline(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; int blocks, min; struct idetape_bh *bh; if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline," " but we are not writing.\n"); return; } if (tape->merge_stage_size > tape->stage_size) { printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n"); tape->merge_stage_size = tape->stage_size; } if (tape->merge_stage_size) { blocks = tape->merge_stage_size / tape->blk_size; if (tape->merge_stage_size % tape->blk_size) { unsigned int i; blocks++; i = tape->blk_size - tape->merge_stage_size % tape->blk_size; bh = tape->bh->b_reqnext; while (bh) { atomic_set(&bh->b_count, 0); bh = bh->b_reqnext; } bh = tape->bh; while (i) { if (bh == NULL) { printk(KERN_INFO "ide-tape: bug," " bh NULL\n"); break; } min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count))); memset(bh->b_data + atomic_read(&bh->b_count), 0, min); atomic_add(min, &bh->b_count); i -= min; bh = bh->b_reqnext; } } (void) idetape_add_chrdev_write_request(drive, blocks); tape->merge_stage_size = 0; } idetape_wait_for_pipeline(drive); if (tape->merge_stage != NULL) { __idetape_kfree_stage(tape->merge_stage); tape->merge_stage = NULL; } clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); tape->chrdev_dir = IDETAPE_DIR_NONE; /* * On the next backup, perform the feedback loop again. (I don't want to * keep sense information between backups, as some systems are * constantly on, and the system load can be totally different on the * next backup). */ tape->max_stages = tape->min_pipeline; if (tape->first_stage != NULL || tape->next_stage != NULL || tape->last_stage != NULL || tape->nr_stages != 0) { printk(KERN_ERR "ide-tape: ide-tape pipeline bug, " "first_stage %p, next_stage %p, " "last_stage %p, nr_stages %d\n", tape->first_stage, tape->next_stage, tape->last_stage, tape->nr_stages); } } static void idetape_restart_speed_control(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; tape->restart_speed_control_req = 0; tape->pipeline_head = 0; tape->controlled_last_pipeline_head = 0; tape->controlled_previous_pipeline_head = 0; tape->uncontrolled_previous_pipeline_head = 0; tape->controlled_pipeline_head_speed = 5000; tape->pipeline_head_speed = 5000; tape->uncontrolled_pipeline_head_speed = 0; tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies; tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies; } static int idetape_init_read(ide_drive_t *drive, int max_stages) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *new_stage; struct request rq; int bytes_read; u16 blocks = *(u16 *)&tape->caps[12]; /* Initialize read operation */ if (tape->chrdev_dir != IDETAPE_DIR_READ) { if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { idetape_empty_write_pipeline(drive); idetape_flush_tape_buffers(drive); } if (tape->merge_stage || tape->merge_stage_size) { printk(KERN_ERR "ide-tape: merge_stage_size should be" " 0 now\n"); tape->merge_stage_size = 0; } tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0); if (!tape->merge_stage) return -ENOMEM; tape->chrdev_dir = IDETAPE_DIR_READ; /* * Issue a read 0 command to ensure that DSC handshake is * switched from completion mode to buffer available mode. * No point in issuing this if DSC overlap isn't supported, some * drives (Seagate STT3401A) will return an error. */ if (drive->dsc_overlap) { bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh); if (bytes_read < 0) { __idetape_kfree_stage(tape->merge_stage); tape->merge_stage = NULL; tape->chrdev_dir = IDETAPE_DIR_NONE; return bytes_read; } } } if (tape->restart_speed_control_req) idetape_restart_speed_control(drive); idetape_init_rq(&rq, REQ_IDETAPE_READ); rq.sector = tape->first_frame; rq.nr_sectors = blocks; rq.current_nr_sectors = blocks; if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) && tape->nr_stages < max_stages) { new_stage = idetape_kmalloc_stage(tape); while (new_stage != NULL) { new_stage->rq = rq; idetape_add_stage_tail(drive, new_stage); if (tape->nr_stages >= max_stages) break; new_stage = idetape_kmalloc_stage(tape); } } if (!idetape_pipeline_active(tape)) { if (tape->nr_pending_stages >= 3 * max_stages / 4) { tape->measure_insert_time = 1; tape->insert_time = jiffies; tape->insert_size = 0; tape->insert_speed = 0; idetape_plug_pipeline(drive); } } return 0; } /* * Called from idetape_chrdev_read() to service a character device read request * and add read-ahead requests to our pipeline. */ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) { idetape_tape_t *tape = drive->driver_data; unsigned long flags; struct request *rq_ptr; int bytes_read; debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks); /* If we are at a filemark, return a read length of 0 */ if (test_bit(IDETAPE_FILEMARK, &tape->flags)) return 0; /* Wait for the next block to reach the head of the pipeline. */ idetape_init_read(drive, tape->max_stages); if (tape->first_stage == NULL) { if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags)) return 0; return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh); } idetape_wait_first_stage(drive); rq_ptr = &tape->first_stage->rq; bytes_read = tape->blk_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors); rq_ptr->nr_sectors = 0; rq_ptr->current_nr_sectors = 0; if (rq_ptr->errors == IDETAPE_ERROR_EOD) return 0; else { idetape_switch_buffers(tape, tape->first_stage); if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK) set_bit(IDETAPE_FILEMARK, &tape->flags); spin_lock_irqsave(&tape->lock, flags); idetape_remove_stage_head(drive); spin_unlock_irqrestore(&tape->lock, flags); tape->pipeline_head++; idetape_calculate_speeds(drive); } if (bytes_read > blocks * tape->blk_size) { printk(KERN_ERR "ide-tape: bug: trying to return more bytes" " than requested\n"); bytes_read = blocks * tape->blk_size; } return (bytes_read); } static void idetape_pad_zeros(ide_drive_t *drive, int bcount) { idetape_tape_t *tape = drive->driver_data; struct idetape_bh *bh; int blocks; while (bcount) { unsigned int count; bh = tape->merge_stage->bh; count = min(tape->stage_size, bcount); bcount -= count; blocks = count / tape->blk_size; while (count) { atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size)); memset(bh->b_data, 0, atomic_read(&bh->b_count)); count -= atomic_read(&bh->b_count); bh = bh->b_reqnext; } idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh); } } static int idetape_pipeline_size(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_stage_t *stage; struct request *rq; int size = 0; idetape_wait_for_pipeline(drive); stage = tape->first_stage; while (stage != NULL) { rq = &stage->rq; size += tape->blk_size * (rq->nr_sectors - rq->current_nr_sectors); if (rq->errors == IDETAPE_ERROR_FILEMARK) size += tape->blk_size; stage = stage->next; } size += tape->merge_stage_size; return size; } /* * Rewinds the tape to the Beginning Of the current Partition (BOP). We * currently support only one partition. */ static int idetape_rewind_tape(ide_drive_t *drive) { int retval; idetape_pc_t pc; idetape_tape_t *tape; tape = drive->driver_data; debug_log(DBG_SENSE, "Enter %s\n", __func__); idetape_create_rewind_cmd(drive, &pc); retval = idetape_queue_pc_tail(drive, &pc); if (retval) return retval; idetape_create_read_position_cmd(&pc); retval = idetape_queue_pc_tail(drive, &pc); if (retval) return retval; return 0; } /* mtio.h compatible commands should be issued to the chrdev interface. */ static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg) { idetape_tape_t *tape = drive->driver_data; void __user *argp = (void __user *)arg; struct idetape_config { int dsc_rw_frequency; int dsc_media_access_frequency; int nr_stages; } config; debug_log(DBG_PROCS, "Enter %s\n", __func__); switch (cmd) { case 0x0340: if (copy_from_user(&config, argp, sizeof(config))) return -EFAULT; tape->best_dsc_rw_freq = config.dsc_rw_frequency; tape->max_stages = config.nr_stages; break; case 0x0350: config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq; config.nr_stages = tape->max_stages; if (copy_to_user(argp, &config, sizeof(config))) return -EFAULT; break; default: return -EIO; } return 0; } /* * The function below is now a bit more complicated than just passing the * command to the tape since we may have crossed some filemarks during our * pipelined read-ahead mode. As a minor side effect, the pipeline enables us to * support MTFSFM when the filemark is in our internal pipeline even if the tape * doesn't support spacing over filemarks in the reverse direction. */ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op, int mt_count) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; unsigned long flags; int retval, count = 0; int sprev = !!(tape->caps[4] & 0x20); if (mt_count == 0) return 0; if (MTBSF == mt_op || MTBSFM == mt_op) { if (!sprev) return -EIO; mt_count = -mt_count; } if (tape->chrdev_dir == IDETAPE_DIR_READ) { /* its a read-ahead buffer, scan it for crossed filemarks. */ tape->merge_stage_size = 0; if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags)) ++count; while (tape->first_stage != NULL) { if (count == mt_count) { if (mt_op == MTFSFM) set_bit(IDETAPE_FILEMARK, &tape->flags); return 0; } spin_lock_irqsave(&tape->lock, flags); if (tape->first_stage == tape->active_stage) { /* * We have reached the active stage in the read * pipeline. There is no point in allowing the * drive to continue reading any farther, so we * stop the pipeline. * * This section should be moved to a separate * subroutine because similar operations are * done in __idetape_discard_read_pipeline(), * for example. */ tape->next_stage = NULL; spin_unlock_irqrestore(&tape->lock, flags); idetape_wait_first_stage(drive); tape->next_stage = tape->first_stage->next; } else spin_unlock_irqrestore(&tape->lock, flags); if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK) ++count; idetape_remove_stage_head(drive); } idetape_discard_read_pipeline(drive, 0); } /* * The filemark was not found in our internal pipeline; now we can issue * the space command. */ switch (mt_op) { case MTFSF: case MTBSF: idetape_create_space_cmd(&pc, mt_count - count, IDETAPE_SPACE_OVER_FILEMARK); return idetape_queue_pc_tail(drive, &pc); case MTFSFM: case MTBSFM: if (!sprev) return -EIO; retval = idetape_space_over_filemarks(drive, MTFSF, mt_count - count); if (retval) return retval; count = (MTBSFM == mt_op ? 1 : -1); return idetape_space_over_filemarks(drive, MTFSF, count); default: printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", mt_op); return -EIO; } } /* * Our character device read / write functions. * * The tape is optimized to maximize throughput when it is transferring an * integral number of the "continuous transfer limit", which is a parameter of * the specific tape (26kB on my particular tape, 32kB for Onstream). * * As of version 1.3 of the driver, the character device provides an abstract * continuous view of the media - any mix of block sizes (even 1 byte) on the * same backup/restore procedure is supported. The driver will internally * convert the requests to the recommended transfer unit, so that an unmatch * between the user's block size to the recommended size will only result in a * (slightly) increased driver overhead, but will no longer hit performance. * This is not applicable to Onstream. */ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct ide_tape_obj *tape = ide_tape_f(file); ide_drive_t *drive = tape->drive; ssize_t bytes_read, temp, actually_read = 0, rc; ssize_t ret = 0; u16 ctl = *(u16 *)&tape->caps[12]; debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); if (tape->chrdev_dir != IDETAPE_DIR_READ) { if (test_bit(IDETAPE_DETECT_BS, &tape->flags)) if (count > tape->blk_size && (count % tape->blk_size) == 0) tape->user_bs_factor = count / tape->blk_size; } rc = idetape_init_read(drive, tape->max_stages); if (rc < 0) return rc; if (count == 0) return (0); if (tape->merge_stage_size) { actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count); if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read)) ret = -EFAULT; buf += actually_read; tape->merge_stage_size -= actually_read; count -= actually_read; } while (count >= tape->stage_size) { bytes_read = idetape_add_chrdev_read_request(drive, ctl); if (bytes_read <= 0) goto finish; if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read)) ret = -EFAULT; buf += bytes_read; count -= bytes_read; actually_read += bytes_read; } if (count) { bytes_read = idetape_add_chrdev_read_request(drive, ctl); if (bytes_read <= 0) goto finish; temp = min((unsigned long)count, (unsigned long)bytes_read); if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp)) ret = -EFAULT; actually_read += temp; tape->merge_stage_size = bytes_read-temp; } finish: if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) { debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name); idetape_space_over_filemarks(drive, MTFSF, 1); return 0; } return ret ? ret : actually_read; } static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct ide_tape_obj *tape = ide_tape_f(file); ide_drive_t *drive = tape->drive; ssize_t actually_written = 0; ssize_t ret = 0; u16 ctl = *(u16 *)&tape->caps[12]; /* The drive is write protected. */ if (tape->write_prot) return -EACCES; debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count); /* Initialize write operation */ if (tape->chrdev_dir != IDETAPE_DIR_WRITE) { if (tape->chrdev_dir == IDETAPE_DIR_READ) idetape_discard_read_pipeline(drive, 1); if (tape->merge_stage || tape->merge_stage_size) { printk(KERN_ERR "ide-tape: merge_stage_size " "should be 0 now\n"); tape->merge_stage_size = 0; } tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0); if (!tape->merge_stage) return -ENOMEM; tape->chrdev_dir = IDETAPE_DIR_WRITE; idetape_init_merge_stage(tape); /* * Issue a write 0 command to ensure that DSC handshake is * switched from completion mode to buffer available mode. No * point in issuing this if DSC overlap isn't supported, some * drives (Seagate STT3401A) will return an error. */ if (drive->dsc_overlap) { ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh); if (retval < 0) { __idetape_kfree_stage(tape->merge_stage); tape->merge_stage = NULL; tape->chrdev_dir = IDETAPE_DIR_NONE; return retval; } } } if (count == 0) return (0); if (tape->restart_speed_control_req) idetape_restart_speed_control(drive); if (tape->merge_stage_size) { if (tape->merge_stage_size >= tape->stage_size) { printk(KERN_ERR "ide-tape: bug: merge buf too big\n"); tape->merge_stage_size = 0; } actually_written = min((unsigned int) (tape->stage_size - tape->merge_stage_size), (unsigned int)count); if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written)) ret = -EFAULT; buf += actually_written; tape->merge_stage_size += actually_written; count -= actually_written; if (tape->merge_stage_size == tape->stage_size) { ssize_t retval; tape->merge_stage_size = 0; retval = idetape_add_chrdev_write_request(drive, ctl); if (retval <= 0) return (retval); } } while (count >= tape->stage_size) { ssize_t retval; if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size)) ret = -EFAULT; buf += tape->stage_size; count -= tape->stage_size; retval = idetape_add_chrdev_write_request(drive, ctl); actually_written += tape->stage_size; if (retval <= 0) return (retval); } if (count) { actually_written += count; if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count)) ret = -EFAULT; tape->merge_stage_size += count; } return ret ? ret : actually_written; } static int idetape_write_filemark(ide_drive_t *drive) { idetape_pc_t pc; /* Write a filemark */ idetape_create_write_filemark_cmd(drive, &pc, 1); if (idetape_queue_pc_tail(drive, &pc)) { printk(KERN_ERR "ide-tape: Couldn't write a filemark\n"); return -EIO; } return 0; } /* * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is * requested. * * Note: MTBSF and MTBSFM are not supported when the tape doesn't support * spacing over filemarks in the reverse direction. In this case, MTFSFM is also * usually not supported (it is supported in the rare case in which we crossed * the filemark during our read-ahead pipelined operation mode). * * The following commands are currently not supported: * * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS, * MT_ST_WRITE_THRESHOLD. */ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; int i, retval; debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n", mt_op, mt_count); /* Commands which need our pipelined read-ahead stages. */ switch (mt_op) { case MTFSF: case MTFSFM: case MTBSF: case MTBSFM: if (!mt_count) return 0; return idetape_space_over_filemarks(drive, mt_op, mt_count); default: break; } switch (mt_op) { case MTWEOF: if (tape->write_prot) return -EACCES; idetape_discard_read_pipeline(drive, 1); for (i = 0; i < mt_count; i++) { retval = idetape_write_filemark(drive); if (retval) return retval; } return 0; case MTREW: idetape_discard_read_pipeline(drive, 0); if (idetape_rewind_tape(drive)) return -EIO; return 0; case MTLOAD: idetape_discard_read_pipeline(drive, 0); idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK); return idetape_queue_pc_tail(drive, &pc); case MTUNLOAD: case MTOFFL: /* * If door is locked, attempt to unlock before * attempting to eject. */ if (tape->door_locked) { if (idetape_create_prevent_cmd(drive, &pc, 0)) if (!idetape_queue_pc_tail(drive, &pc)) tape->door_locked = DOOR_UNLOCKED; } idetape_discard_read_pipeline(drive, 0); idetape_create_load_unload_cmd(drive, &pc, !IDETAPE_LU_LOAD_MASK); retval = idetape_queue_pc_tail(drive, &pc); if (!retval) clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags); return retval; case MTNOP: idetape_discard_read_pipeline(drive, 0); return idetape_flush_tape_buffers(drive); case MTRETEN: idetape_discard_read_pipeline(drive, 0); idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); return idetape_queue_pc_tail(drive, &pc); case MTEOM: idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD); return idetape_queue_pc_tail(drive, &pc); case MTERASE: (void)idetape_rewind_tape(drive); idetape_create_erase_cmd(&pc); return idetape_queue_pc_tail(drive, &pc); case MTSETBLK: if (mt_count) { if (mt_count < tape->blk_size || mt_count % tape->blk_size) return -EIO; tape->user_bs_factor = mt_count / tape->blk_size; clear_bit(IDETAPE_DETECT_BS, &tape->flags); } else set_bit(IDETAPE_DETECT_BS, &tape->flags); return 0; case MTSEEK: idetape_discard_read_pipeline(drive, 0); return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0); case MTSETPART: idetape_discard_read_pipeline(drive, 0); return idetape_position_tape(drive, 0, mt_count, 0); case MTFSR: case MTBSR: case MTLOCK: if (!idetape_create_prevent_cmd(drive, &pc, 1)) return 0; retval = idetape_queue_pc_tail(drive, &pc); if (retval) return retval; tape->door_locked = DOOR_EXPLICITLY_LOCKED; return 0; case MTUNLOCK: if (!idetape_create_prevent_cmd(drive, &pc, 0)) return 0; retval = idetape_queue_pc_tail(drive, &pc); if (retval) return retval; tape->door_locked = DOOR_UNLOCKED; return 0; default: printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n", mt_op); return -EIO; } } /* * Our character device ioctls. General mtio.h magnetic io commands are * supported here, and not in the corresponding block interface. Our own * ide-tape ioctls are supported on both interfaces. */ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct ide_tape_obj *tape = ide_tape_f(file); ide_drive_t *drive = tape->drive; struct mtop mtop; struct mtget mtget; struct mtpos mtpos; int block_offset = 0, position = tape->first_frame; void __user *argp = (void __user *)arg; debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd); tape->restart_speed_control_req = 1; if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { idetape_empty_write_pipeline(drive); idetape_flush_tape_buffers(drive); } if (cmd == MTIOCGET || cmd == MTIOCPOS) { block_offset = idetape_pipeline_size(drive) / (tape->blk_size * tape->user_bs_factor); position = idetape_read_position(drive); if (position < 0) return -EIO; } switch (cmd) { case MTIOCTOP: if (copy_from_user(&mtop, argp, sizeof(struct mtop))) return -EFAULT; return idetape_mtioctop(drive, mtop.mt_op, mtop.mt_count); case MTIOCGET: memset(&mtget, 0, sizeof(struct mtget)); mtget.mt_type = MT_ISSCSI2; mtget.mt_blkno = position / tape->user_bs_factor - block_offset; mtget.mt_dsreg = ((tape->blk_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK; if (tape->drv_write_prot) mtget.mt_gstat |= GMT_WR_PROT(0xffffffff); if (copy_to_user(argp, &mtget, sizeof(struct mtget))) return -EFAULT; return 0; case MTIOCPOS: mtpos.mt_blkno = position / tape->user_bs_factor - block_offset; if (copy_to_user(argp, &mtpos, sizeof(struct mtpos))) return -EFAULT; return 0; default: if (tape->chrdev_dir == IDETAPE_DIR_READ) idetape_discard_read_pipeline(drive, 1); return idetape_blkdev_ioctl(drive, cmd, arg); } } /* * Do a mode sense page 0 with block descriptor and if it succeeds set the tape * block size with the reported value. */ static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR); if (idetape_queue_pc_tail(drive, &pc)) { printk(KERN_ERR "ide-tape: Can't get block descriptor\n"); if (tape->blk_size == 0) { printk(KERN_WARNING "ide-tape: Cannot deal with zero " "block size, assuming 32k\n"); tape->blk_size = 32768; } return; } tape->blk_size = (pc.buffer[4 + 5] << 16) + (pc.buffer[4 + 6] << 8) + pc.buffer[4 + 7]; tape->drv_write_prot = (pc.buffer[2] & 0x80) >> 7; } static int idetape_chrdev_open(struct inode *inode, struct file *filp) { unsigned int minor = iminor(inode), i = minor & ~0xc0; ide_drive_t *drive; idetape_tape_t *tape; idetape_pc_t pc; int retval; if (i >= MAX_HWIFS * MAX_DRIVES) return -ENXIO; tape = ide_tape_chrdev_get(i); if (!tape) return -ENXIO; debug_log(DBG_CHRDEV, "Enter %s\n", __func__); /* * We really want to do nonseekable_open(inode, filp); here, but some * versions of tar incorrectly call lseek on tapes and bail out if that * fails. So we disallow pread() and pwrite(), but permit lseeks. */ filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); drive = tape->drive; filp->private_data = tape; if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) { retval = -EBUSY; goto out_put_tape; } retval = idetape_wait_ready(drive, 60 * HZ); if (retval) { clear_bit(IDETAPE_BUSY, &tape->flags); printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name); goto out_put_tape; } idetape_read_position(drive); if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags)) (void)idetape_rewind_tape(drive); if (tape->chrdev_dir != IDETAPE_DIR_READ) clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); /* Read block size and write protect status from drive. */ ide_tape_get_bsize_from_bdesc(drive); /* Set write protect flag if device is opened as read-only. */ if ((filp->f_flags & O_ACCMODE) == O_RDONLY) tape->write_prot = 1; else tape->write_prot = tape->drv_write_prot; /* Make sure drive isn't write protected if user wants to write. */ if (tape->write_prot) { if ((filp->f_flags & O_ACCMODE) == O_WRONLY || (filp->f_flags & O_ACCMODE) == O_RDWR) { clear_bit(IDETAPE_BUSY, &tape->flags); retval = -EROFS; goto out_put_tape; } } /* Lock the tape drive door so user can't eject. */ if (tape->chrdev_dir == IDETAPE_DIR_NONE) { if (idetape_create_prevent_cmd(drive, &pc, 1)) { if (!idetape_queue_pc_tail(drive, &pc)) { if (tape->door_locked != DOOR_EXPLICITLY_LOCKED) tape->door_locked = DOOR_LOCKED; } } } idetape_restart_speed_control(drive); tape->restart_speed_control_req = 0; return 0; out_put_tape: ide_tape_put(tape); return retval; } static void idetape_write_release(ide_drive_t *drive, unsigned int minor) { idetape_tape_t *tape = drive->driver_data; idetape_empty_write_pipeline(drive); tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0); if (tape->merge_stage != NULL) { idetape_pad_zeros(drive, tape->blk_size * (tape->user_bs_factor - 1)); __idetape_kfree_stage(tape->merge_stage); tape->merge_stage = NULL; } idetape_write_filemark(drive); idetape_flush_tape_buffers(drive); idetape_flush_tape_buffers(drive); } static int idetape_chrdev_release(struct inode *inode, struct file *filp) { struct ide_tape_obj *tape = ide_tape_f(filp); ide_drive_t *drive = tape->drive; idetape_pc_t pc; unsigned int minor = iminor(inode); lock_kernel(); tape = drive->driver_data; debug_log(DBG_CHRDEV, "Enter %s\n", __func__); if (tape->chrdev_dir == IDETAPE_DIR_WRITE) idetape_write_release(drive, minor); if (tape->chrdev_dir == IDETAPE_DIR_READ) { if (minor < 128) idetape_discard_read_pipeline(drive, 1); else idetape_wait_for_pipeline(drive); } if (tape->cache_stage != NULL) { __idetape_kfree_stage(tape->cache_stage); tape->cache_stage = NULL; } if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags)) (void) idetape_rewind_tape(drive); if (tape->chrdev_dir == IDETAPE_DIR_NONE) { if (tape->door_locked == DOOR_LOCKED) { if (idetape_create_prevent_cmd(drive, &pc, 0)) { if (!idetape_queue_pc_tail(drive, &pc)) tape->door_locked = DOOR_UNLOCKED; } } } clear_bit(IDETAPE_BUSY, &tape->flags); ide_tape_put(tape); unlock_kernel(); return 0; } /* * check the contents of the ATAPI IDENTIFY command results. We return: * * 1 - If the tape can be supported by us, based on the information we have so * far. * * 0 - If this tape driver is not currently supported by us. */ static int idetape_identify_device(ide_drive_t *drive) { u8 gcw[2], protocol, device_type, removable, packet_size; if (drive->id_read == 0) return 1; *((unsigned short *) &gcw) = drive->id->config; protocol = (gcw[1] & 0xC0) >> 6; device_type = gcw[1] & 0x1F; removable = !!(gcw[0] & 0x80); packet_size = gcw[0] & 0x3; /* Check that we can support this device */ if (protocol != 2) printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n", protocol); else if (device_type != 1) printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set " "to tape\n", device_type); else if (!removable) printk(KERN_ERR "ide-tape: The removable flag is not set\n"); else if (packet_size != 0) { printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12" " bytes\n", packet_size); } else return 1; return 0; } static void idetape_get_inquiry_results(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; char fw_rev[6], vendor_id[10], product_id[18]; idetape_create_inquiry_cmd(&pc); if (idetape_queue_pc_tail(drive, &pc)) { printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", tape->name); return; } memcpy(vendor_id, &pc.buffer[8], 8); memcpy(product_id, &pc.buffer[16], 16); memcpy(fw_rev, &pc.buffer[32], 4); ide_fixstring(vendor_id, 10, 0); ide_fixstring(product_id, 18, 0); ide_fixstring(fw_rev, 6, 0); printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", drive->name, tape->name, vendor_id, product_id, fw_rev); } /* * Ask the tape about its various parameters. In particular, we will adjust our * data transfer buffer size to the recommended value as returned by the tape. */ static void idetape_get_mode_sense_results(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; idetape_pc_t pc; u8 *caps; u8 speed, max_speed; idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE); if (idetape_queue_pc_tail(drive, &pc)) { printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming" " some default values\n"); tape->blk_size = 512; put_unaligned(52, (u16 *)&tape->caps[12]); put_unaligned(540, (u16 *)&tape->caps[14]); put_unaligned(6*52, (u16 *)&tape->caps[16]); return; } caps = pc.buffer + 4 + pc.buffer[3]; /* convert to host order and save for later use */ speed = be16_to_cpu(*(u16 *)&caps[14]); max_speed = be16_to_cpu(*(u16 *)&caps[8]); put_unaligned(max_speed, (u16 *)&caps[8]); put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]); put_unaligned(speed, (u16 *)&caps[14]); put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]); if (!speed) { printk(KERN_INFO "ide-tape: %s: invalid tape speed " "(assuming 650KB/sec)\n", drive->name); put_unaligned(650, (u16 *)&caps[14]); } if (!max_speed) { printk(KERN_INFO "ide-tape: %s: invalid max_speed " "(assuming 650KB/sec)\n", drive->name); put_unaligned(650, (u16 *)&caps[8]); } memcpy(&tape->caps, caps, 20); if (caps[7] & 0x02) tape->blk_size = 512; else if (caps[7] & 0x04) tape->blk_size = 1024; } #ifdef CONFIG_IDE_PROC_FS static void idetape_add_settings(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff, 1, 2, (u16 *)&tape->caps[16], NULL); ide_add_setting(drive, "pipeline_min", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->min_pipeline, NULL); ide_add_setting(drive, "pipeline", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_stages, NULL); ide_add_setting(drive, "pipeline_max", SETTING_RW, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_pipeline, NULL); ide_add_setting(drive, "pipeline_used", SETTING_READ, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_stages, NULL); ide_add_setting(drive, "pipeline_pending", SETTING_READ, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_pending_stages, NULL); ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff, 1, 1, (u16 *)&tape->caps[14], NULL); ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1024, &tape->stage_size, NULL); ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq, NULL); ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1, 1, &drive->dsc_overlap, NULL); ide_add_setting(drive, "pipeline_head_speed_c", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed, NULL); ide_add_setting(drive, "pipeline_head_speed_u", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->uncontrolled_pipeline_head_speed, NULL); ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff, 1, 1, &tape->avg_speed, NULL); ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1, 1, &tape->debug_mask, NULL); } #else static inline void idetape_add_settings(ide_drive_t *drive) { ; } #endif /* * The function below is called to: * * 1. Initialize our various state variables. * 2. Ask the tape for its capabilities. * 3. Allocate a buffer which will be used for data transfer. The buffer size * is chosen based on the recommendation which we received in step 2. * * Note that at this point ide.c already assigned us an irq, so that we can * queue requests here and wait for their completion. */ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor) { unsigned long t1, tmid, tn, t; int speed; int stage_size; u8 gcw[2]; struct sysinfo si; u16 *ctl = (u16 *)&tape->caps[12]; spin_lock_init(&tape->lock); drive->dsc_overlap = 1; if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) { printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", tape->name); drive->dsc_overlap = 0; } /* Seagate Travan drives do not support DSC overlap. */ if (strstr(drive->id->model, "Seagate STT3401")) drive->dsc_overlap = 0; tape->minor = minor; tape->name[0] = 'h'; tape->name[1] = 't'; tape->name[2] = '0' + minor; tape->chrdev_dir = IDETAPE_DIR_NONE; tape->pc = tape->pc_stack; tape->max_insert_speed = 10000; tape->speed_control = 1; *((unsigned short *) &gcw) = drive->id->config; /* Command packet DRQ type */ if (((gcw[0] & 0x60) >> 5) == 1) set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags); tape->min_pipeline = 10; tape->max_pipeline = 10; tape->max_stages = 10; idetape_get_inquiry_results(drive); idetape_get_mode_sense_results(drive); ide_tape_get_bsize_from_bdesc(drive); tape->user_bs_factor = 1; tape->stage_size = *ctl * tape->blk_size; while (tape->stage_size > 0xffff) { printk(KERN_NOTICE "ide-tape: decreasing stage size\n"); *ctl /= 2; tape->stage_size = *ctl * tape->blk_size; } stage_size = tape->stage_size; tape->pages_per_stage = stage_size / PAGE_SIZE; if (stage_size % PAGE_SIZE) { tape->pages_per_stage++; tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE; } /* Select the "best" DSC read/write polling freq and pipeline size. */ speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]); tape->max_stages = speed * 1000 * 10 / tape->stage_size; /* Limit memory use for pipeline to 10% of physical memory */ si_meminfo(&si); if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10) tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size); tape->max_stages = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES); tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES); tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES); if (tape->max_stages == 0) { tape->max_stages = 1; tape->min_pipeline = 1; tape->max_pipeline = 1; } t1 = (tape->stage_size * HZ) / (speed * 1000); tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125); tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000); if (tape->max_stages) t = tn; else t = t1; /* * Ensure that the number we got makes sense; limit it within * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX. */ tape->best_dsc_rw_freq = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN); printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, " "%dkB pipeline, %lums tDSC%s\n", drive->name, tape->name, *(u16 *)&tape->caps[14], (*(u16 *)&tape->caps[16] * 512) / tape->stage_size, tape->stage_size / 1024, tape->max_stages * tape->stage_size / 1024, tape->best_dsc_rw_freq * 1000 / HZ, drive->using_dma ? ", DMA":""); idetape_add_settings(drive); } static void ide_tape_remove(ide_drive_t *drive) { idetape_tape_t *tape = drive->driver_data; ide_proc_unregister_driver(drive, tape->driver); ide_unregister_region(tape->disk); ide_tape_put(tape); } static void ide_tape_release(struct kref *kref) { struct ide_tape_obj *tape = to_ide_tape(kref); ide_drive_t *drive = tape->drive; struct gendisk *g = tape->disk; BUG_ON(tape->first_stage != NULL || tape->merge_stage_size); drive->dsc_overlap = 0; drive->driver_data = NULL; device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor)); device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor + 128)); idetape_devs[tape->minor] = NULL; g->private_data = NULL; put_disk(g); kfree(tape); } #ifdef CONFIG_IDE_PROC_FS static int proc_idetape_read_name (char *page, char **start, off_t off, int count, int *eof, void *data) { ide_drive_t *drive = (ide_drive_t *) data; idetape_tape_t *tape = drive->driver_data; char *out = page; int len; len = sprintf(out, "%s\n", tape->name); PROC_IDE_READ_RETURN(page, start, off, count, eof, len); } static ide_proc_entry_t idetape_proc[] = { { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL }, { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL }, { NULL, 0, NULL, NULL } }; #endif static int ide_tape_probe(ide_drive_t *); static ide_driver_t idetape_driver = { .gen_driver = { .owner = THIS_MODULE, .name = "ide-tape", .bus = &ide_bus_type, }, .probe = ide_tape_probe, .remove = ide_tape_remove, .version = IDETAPE_VERSION, .media = ide_tape, .supports_dsc_overlap = 1, .do_request = idetape_do_request, .end_request = idetape_end_request, .error = __ide_error, .abort = __ide_abort, #ifdef CONFIG_IDE_PROC_FS .proc = idetape_proc, #endif }; /* Our character device supporting functions, passed to register_chrdev. */ static const struct file_operations idetape_fops = { .owner = THIS_MODULE, .read = idetape_chrdev_read, .write = idetape_chrdev_write, .ioctl = idetape_chrdev_ioctl, .open = idetape_chrdev_open, .release = idetape_chrdev_release, }; static int idetape_open(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; struct ide_tape_obj *tape; tape = ide_tape_get(disk); if (!tape) return -ENXIO; return 0; } static int idetape_release(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; struct ide_tape_obj *tape = ide_tape_g(disk); ide_tape_put(tape); return 0; } static int idetape_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct block_device *bdev = inode->i_bdev; struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk); ide_drive_t *drive = tape->drive; int err = generic_ide_ioctl(drive, file, bdev, cmd, arg); if (err == -EINVAL) err = idetape_blkdev_ioctl(drive, cmd, arg); return err; } static struct block_device_operations idetape_block_ops = { .owner = THIS_MODULE, .open = idetape_open, .release = idetape_release, .ioctl = idetape_ioctl, }; static int ide_tape_probe(ide_drive_t *drive) { idetape_tape_t *tape; struct gendisk *g; int minor; if (!strstr("ide-tape", drive->driver_req)) goto failed; if (!drive->present) goto failed; if (drive->media != ide_tape) goto failed; if (!idetape_identify_device(drive)) { printk(KERN_ERR "ide-tape: %s: not supported by this version of" " the driver\n", drive->name); goto failed; } if (drive->scsi) { printk(KERN_INFO "ide-tape: passing drive %s to ide-scsi" " emulation.\n", drive->name); goto failed; } tape = kzalloc(sizeof(idetape_tape_t), GFP_KERNEL); if (tape == NULL) { printk(KERN_ERR "ide-tape: %s: Can't allocate a tape struct\n", drive->name); goto failed; } g = alloc_disk(1 << PARTN_BITS); if (!g) goto out_free_tape; ide_init_disk(g, drive); ide_proc_register_driver(drive, &idetape_driver); kref_init(&tape->kref); tape->drive = drive; tape->driver = &idetape_driver; tape->disk = g; g->private_data = &tape->driver; drive->driver_data = tape; mutex_lock(&idetape_ref_mutex); for (minor = 0; idetape_devs[minor]; minor++) ; idetape_devs[minor] = tape; mutex_unlock(&idetape_ref_mutex); idetape_setup(drive, tape, minor); device_create(idetape_sysfs_class, &drive->gendev, MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name); device_create(idetape_sysfs_class, &drive->gendev, MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name); g->fops = &idetape_block_ops; ide_register_region(g); return 0; out_free_tape: kfree(tape); failed: return -ENODEV; } static void __exit idetape_exit(void) { driver_unregister(&idetape_driver.gen_driver); class_destroy(idetape_sysfs_class); unregister_chrdev(IDETAPE_MAJOR, "ht"); } static int __init idetape_init(void) { int error = 1; idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape"); if (IS_ERR(idetape_sysfs_class)) { idetape_sysfs_class = NULL; printk(KERN_ERR "Unable to create sysfs class for ide tapes\n"); error = -EBUSY; goto out; } if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) { printk(KERN_ERR "ide-tape: Failed to register chrdev" " interface\n"); error = -EBUSY; goto out_free_class; } error = driver_register(&idetape_driver.gen_driver); if (error) goto out_free_driver; return 0; out_free_driver: driver_unregister(&idetape_driver.gen_driver); out_free_class: class_destroy(idetape_sysfs_class); out: return error; } MODULE_ALIAS("ide:*m-tape*"); module_init(idetape_init); module_exit(idetape_exit); MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR); MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver"); MODULE_LICENSE("GPL");