diff options
Diffstat (limited to 'drivers/ide/ide-tape.c')
| -rw-r--r-- | drivers/ide/ide-tape.c | 2489 |
1 files changed, 2489 insertions, 0 deletions
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c new file mode 100644 index 0000000..a2d470e --- /dev/null +++ b/drivers/ide/ide-tape.c @@ -0,0 +1,2489 @@ +/* + * IDE ATAPI streaming tape driver. + * + * Copyright (C) 1995-1999 Gadi Oxman <gadio@netvision.net.il> + * 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 DRV_NAME "ide-tape" + +#define IDETAPE_VERSION "1.20" + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/jiffies.h> +#include <linux/major.h> +#include <linux/errno.h> +#include <linux/genhd.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/ide.h> +#include <linux/smp_lock.h> +#include <linux/completion.h> +#include <linux/bitops.h> +#include <linux/mutex.h> +#include <scsi/scsi.h> + +#include <asm/byteorder.h> +#include <linux/irq.h> +#include <linux/uaccess.h> +#include <linux/io.h> +#include <asm/unaligned.h> +#include <linux/mtio.h> + +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), +}; + +/* 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 *****************************/ +/* + * 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 + +/* + * 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 ***********************/ + +/* 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; +}; + +/* Tape door status */ +#define DOOR_UNLOCKED 0 +#define DOOR_LOCKED 1 +#define DOOR_EXPLICITLY_LOCKED 2 + +/* 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 + +/* 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 + +/* + * 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; + + /* + * 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. + */ + /* Last failed packet command */ + struct ide_atapi_pc *failed_pc; + /* used by REQ_IDETAPE_{READ,WRITE} requests */ + struct ide_atapi_pc queued_pc; + + /* + * 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. + */ + 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. + */ + + /* Data buffer size chosen based on the tape's recommendation */ + int buffer_size; + /* merge buffer */ + struct idetape_bh *merge_bh; + /* size of the merge buffer */ + int merge_bh_size; + /* pointer to current buffer head within the merge buffer */ + struct idetape_bh *bh; + char *b_data; + int b_count; + + int pages_per_buffer; + /* Wasted space in each stage */ + int excess_bh_size; + + /* 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; + + u32 debug_mask; +} idetape_tape_t; + +static DEFINE_MUTEX(idetape_ref_mutex); + +static struct class *idetape_sysfs_class; + +static void ide_tape_release(struct kref *); + +static struct ide_tape_obj *ide_tape_get(struct gendisk *disk) +{ + struct ide_tape_obj *tape = NULL; + + mutex_lock(&idetape_ref_mutex); + tape = ide_drv_g(disk, ide_tape_obj); + if (tape) { + if (ide_device_get(tape->drive)) + tape = NULL; + else + kref_get(&tape->kref); + } + mutex_unlock(&idetape_ref_mutex); + return tape; +} + +static void ide_tape_put(struct ide_tape_obj *tape) +{ + ide_drive_t *drive = tape->drive; + + mutex_lock(&idetape_ref_mutex); + kref_put(&tape->kref, ide_tape_release); + ide_device_put(drive); + mutex_unlock(&idetape_ref_mutex); +} + +/* + * 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]; + +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, struct ide_atapi_pc *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_pad_transfer(drive, 0, bcount); + return; + } + count = min( + (unsigned int)(bh->b_size - atomic_read(&bh->b_count)), + bcount); + drive->hwif->tp_ops->input_data(drive, NULL, 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, struct ide_atapi_pc *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); + drive->hwif->tp_ops->output_data(drive, NULL, 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(ide_drive_t *drive, struct ide_atapi_pc *pc) +{ + struct idetape_bh *bh = pc->bh; + int count; + unsigned int bcount = pc->xferred; + + if (pc->flags & PC_FLAG_WRITING) + 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; +} + +/* + * 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; + struct ide_atapi_pc *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->xferred by asking the tape. */ + if (pc->flags & PC_FLAG_DMA_ERROR) { + pc->xferred = pc->req_xfer - + tape->blk_size * + get_unaligned_be32(&sense[3]); + idetape_update_buffers(drive, 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 */ + pc->flags |= PC_FLAG_ABORT; + } + } + if (pc->c[0] == READ_6 && (sense[2] & 0x80)) { + pc->error = IDETAPE_ERROR_FILEMARK; + pc->flags |= PC_FLAG_ABORT; + } + 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; + pc->flags |= PC_FLAG_ABORT; + } + } + if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) { + if (tape->sense_key == 8) { + pc->error = IDETAPE_ERROR_EOD; + pc->flags |= PC_FLAG_ABORT; + } + if (!(pc->flags & PC_FLAG_ABORT) && + pc->xferred) + pc->retries = IDETAPE_MAX_PC_RETRIES + 1; + } +} + +/* Free data buffers completely. */ +static void ide_tape_kfree_buffer(idetape_tape_t *tape) +{ + struct idetape_bh *prev_bh, *bh = tape->merge_bh; + + while (bh) { + u32 size = bh->b_size; + + while (size) { + unsigned int order = fls(size >> PAGE_SHIFT)-1; + + if (bh->b_data) + free_pages((unsigned long)bh->b_data, order); + + size &= (order-1); + bh->b_data += (1 << order) * PAGE_SIZE; + } + prev_bh = bh; + bh = bh->b_reqnext; + kfree(prev_bh); + } +} + +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; + + 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); + + ide_end_drive_cmd(drive, 0, 0); + + spin_unlock_irqrestore(&tape->lock, flags); + return 0; +} + +static void ide_tape_handle_dsc(ide_drive_t *); + +static void ide_tape_callback(ide_drive_t *drive, int dsc) +{ + idetape_tape_t *tape = drive->driver_data; + struct ide_atapi_pc *pc = drive->pc; + int uptodate = pc->error ? 0 : 1; + + debug_log(DBG_PROCS, "Enter %s\n", __func__); + + if (dsc) + ide_tape_handle_dsc(drive); + + if (tape->failed_pc == pc) + tape->failed_pc = NULL; + + if (pc->c[0] == REQUEST_SENSE) { + if (uptodate) + idetape_analyze_error(drive, pc->buf); + else + printk(KERN_ERR "ide-tape: Error in REQUEST SENSE " + "itself - Aborting request!\n"); + } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) { + struct request *rq = drive->hwif->hwgroup->rq; + int blocks = pc->xferred / tape->blk_size; + + tape->avg_size += blocks * tape->blk_size; + + 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; + } + + tape->first_frame += blocks; + rq->current_nr_sectors -= blocks; + + if (pc->error) + uptodate = pc->error; + } else if (pc->c[0] == READ_POSITION && uptodate) { + u8 *readpos = pc->buf; + + 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(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags); + uptodate = 0; + } else { + debug_log(DBG_SENSE, "Block Location - %u\n", + be32_to_cpup((__be32 *)&readpos[4])); + + tape->partition = readpos[1]; + tape->first_frame = be32_to_cpup((__be32 *)&readpos[4]); + set_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags); + } + } + + idetape_end_request(drive, uptodate, 0); +} + +/* + * 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); +} + +static void ide_tape_handle_dsc(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + + /* 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); +} + +static int ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, + unsigned int bcount, int write) +{ + if (write) + idetape_output_buffers(drive, pc, bcount); + else + idetape_input_buffers(drive, pc, bcount); + + return bcount; +} + +/* + * Packet Command Interface + * + * The current Packet Command is available in drive->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 ide_pc_intr. + * + * 2. On each interrupt, ide_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_issue_pc(ide_drive_t *drive, + struct ide_atapi_pc *pc) +{ + idetape_tape_t *tape = drive->driver_data; + + if (drive->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 */ + drive->pc = pc; + + if (pc->retries > IDETAPE_MAX_PC_RETRIES || + (pc->flags & PC_FLAG_ABORT)) { + /* + * 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 (!(pc->flags & PC_FLAG_ABORT)) { + 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; + drive->pc_callback(drive, 0); + return ide_stopped; + } + debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]); + + pc->retries++; + + return ide_issue_pc(drive, WAIT_TAPE_CMD, NULL); +} + +/* A mode sense command is used to "sense" tape parameters. */ +static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code) +{ + ide_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->req_xfer = 12; + else if (page_code == IDETAPE_CAPABILITIES_PAGE) + pc->req_xfer = 24; + else + pc->req_xfer = 50; +} + +static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + idetape_tape_t *tape = drive->driver_data; + struct ide_atapi_pc *pc = drive->pc; + u8 stat; + + stat = hwif->tp_ops->read_status(hwif); + + if (stat & ATA_DSC) { + if (stat & ATA_ERR) { + /* Error detected */ + if (pc->c[0] != TEST_UNIT_READY) + printk(KERN_ERR "ide-tape: %s: I/O error, ", + tape->name); + /* Retry operation */ + ide_retry_pc(drive, tape->disk); + return ide_stopped; + } + pc->error = 0; + } else { + pc->error = IDETAPE_ERROR_GENERAL; + tape->failed_pc = NULL; + } + drive->pc_callback(drive, 0); + return ide_stopped; +} + +static void ide_tape_create_rw_cmd(idetape_tape_t *tape, + struct ide_atapi_pc *pc, struct request *rq, + u8 opcode) +{ + struct idetape_bh *bh = (struct idetape_bh *)rq->special; + unsigned int length = rq->current_nr_sectors; + + ide_init_pc(pc); + put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]); + pc->c[1] = 1; + pc->bh = bh; + pc->buf = NULL; + pc->buf_size = length * tape->blk_size; + pc->req_xfer = pc->buf_size; + if (pc->req_xfer == tape->buffer_size) + pc->flags |= PC_FLAG_DMA_OK; + + if (opcode == READ_6) { + pc->c[0] = READ_6; + atomic_set(&bh->b_count, 0); + } else if (opcode == WRITE_6) { + pc->c[0] = WRITE_6; + pc->flags |= PC_FLAG_WRITING; + pc->b_data = bh->b_data; + pc->b_count = atomic_read(&bh->b_count); + } + + memcpy(rq->cmd, pc->c, 12); +} + +static ide_startstop_t idetape_do_request(ide_drive_t *drive, + struct request *rq, sector_t block) +{ + ide_hwif_t *hwif = drive->hwif; + idetape_tape_t *tape = drive->driver_data; + struct ide_atapi_pc *pc = NULL; + struct request *postponed_rq = tape->postponed_rq; + u8 stat; + + debug_log(DBG_SENSE, "sector: %llu, nr_sectors: %lu," + " current_nr_sectors: %u\n", + (unsigned long long)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 && drive->pc->c[0] == REQUEST_SENSE) { + pc = tape->failed_pc; + goto out; + } + + 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 = hwif->tp_ops->read_status(hwif); + + if ((drive->dev_flags & IDE_DFLAG_DSC_OVERLAP) == 0 && + (rq->cmd[13] & REQ_IDETAPE_PC2) == 0) + set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags); + + if (drive->dev_flags & IDE_DFLAG_POST_RESET) { + set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags); + drive->dev_flags &= ~IDE_DFLAG_POST_RESET; + } + + if (!test_and_clear_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags) && + (stat & ATA_DSC) == 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[13] & 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[13] & REQ_IDETAPE_READ) { + pc = &tape->queued_pc; + ide_tape_create_rw_cmd(tape, pc, rq, READ_6); + goto out; + } + if (rq->cmd[13] & REQ_IDETAPE_WRITE) { + pc = &tape->queued_pc; + ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6); + goto out; + } + if (rq->cmd[13] & REQ_IDETAPE_PC1) { + pc = (struct ide_atapi_pc *) rq->buffer; + rq->cmd[13] &= ~(REQ_IDETAPE_PC1); + rq->cmd[13] |= REQ_IDETAPE_PC2; + goto out; + } + if (rq->cmd[13] & REQ_IDETAPE_PC2) { + idetape_media_access_finished(drive); + return ide_stopped; + } + BUG(); + +out: + return idetape_issue_pc(drive, pc); +} + +/* + * The function below uses __get_free_pages to allocate a data buffer of size + * tape->buffer_size (or a bit more). We attempt to combine sequential pages as + * much as possible. + * + * It returns a pointer to the newly allocated buffer, or NULL in case of + * failure. + */ +static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape, + int full, int clear) +{ + struct idetape_bh *prev_bh, *bh, *merge_bh; + int pages = tape->pages_per_buffer; + unsigned int order, b_allocd; + char *b_data = NULL; + + merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); + bh = merge_bh; + if (bh == NULL) + goto abort; + + order = fls(pages) - 1; + bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order); + if (!bh->b_data) + goto abort; + b_allocd = (1 << order) * PAGE_SIZE; + pages &= (order-1); + + if (clear) + memset(bh->b_data, 0, b_allocd); + bh->b_reqnext = NULL; + bh->b_size = b_allocd; + atomic_set(&bh->b_count, full ? bh->b_size : 0); + + while (pages) { + order = fls(pages) - 1; + b_data = (char *) __get_free_pages(GFP_KERNEL, order); + if (!b_data) + goto abort; + b_allocd = (1 << order) * PAGE_SIZE; + + if (clear) + memset(b_data, 0, b_allocd); + + /* newly allocated page frames below buffer header or ...*/ + if (bh->b_data == b_data + b_allocd) { + bh->b_size += b_allocd; + bh->b_data -= b_allocd; + if (full) + atomic_add(b_allocd, &bh->b_count); + continue; + } + /* they are above the header */ + if (b_data == bh->b_data + bh->b_size) { + bh->b_size += b_allocd; + if (full) + atomic_add(b_allocd, &bh->b_count); + continue; + } + prev_bh = bh; + bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); + if (!bh) { + free_pages((unsigned long) b_data, order); + goto abort; + } + bh->b_reqnext = NULL; + bh->b_data = b_data; + bh->b_size = b_allocd; + atomic_set(&bh->b_count, full ? bh->b_size : 0); + prev_bh->b_reqnext = bh; + + pages &= (order-1); + } + + bh->b_size -= tape->excess_bh_size; + if (full) + atomic_sub(tape->excess_bh_size, &bh->b_count); + return merge_bh; +abort: + ide_tape_kfree_buffer(tape); + return NULL; +} + +static int idetape_copy_stage_from_user(idetape_tape_t *tape, + 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, + 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_buffer(idetape_tape_t *tape) +{ + struct idetape_bh *bh = tape->merge_bh; + tape->bh = tape->merge_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); + } +} + +/* + * 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, + struct ide_atapi_pc *pc, int write_filemark) +{ + ide_init_pc(pc); + pc->c[0] = WRITE_FILEMARKS; + pc->c[4] = write_filemark; + pc->flags |= PC_FLAG_WAIT_FOR_DSC; +} + +static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout) +{ + idetape_tape_t *tape = drive->driver_data; + struct gendisk *disk = tape->disk; + int load_attempted = 0; + + /* Wait for the tape to become ready */ + set_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags); + timeout += jiffies; + while (time_before(jiffies, timeout)) { + if (ide_do_test_unit_ready(drive, disk) == 0) + return 0; + if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) + || (tape->asc == 0x3A)) { + /* no media */ + if (load_attempted) + return -ENOMEDIUM; + ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK); + 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_flush_tape_buffers(ide_drive_t *drive) +{ + struct ide_tape_obj *tape = drive->driver_data; + struct ide_atapi_pc pc; + int rc; + + idetape_create_write_filemark_cmd(drive, &pc, 0); + rc = ide_queue_pc_tail(drive, tape->disk, &pc); + if (rc) + return rc; + idetape_wait_ready(drive, 60 * 5 * HZ); + return 0; +} + +static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc) +{ + ide_init_pc(pc); + pc->c[0] = READ_POSITION; + pc->req_xfer = 20; +} + +static int idetape_read_position(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + struct ide_atapi_pc pc; + int position; + + debug_log(DBG_PROCS, "Enter %s\n", __func__); + + idetape_create_read_position_cmd(&pc); + if (ide_queue_pc_tail(drive, tape->disk, &pc)) + return -1; + position = tape->first_frame; + return position; +} + +static void idetape_create_locate_cmd(ide_drive_t *drive, + struct ide_atapi_pc *pc, + unsigned int block, u8 partition, int skip) +{ + ide_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; + pc->flags |= PC_FLAG_WAIT_FOR_DSC; +} + +static void __ide_tape_discard_merge_buffer(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + + if (tape->chrdev_dir != IDETAPE_DIR_READ) + return; + + clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags); + tape->merge_bh_size = 0; + if (tape->merge_bh != NULL) { + ide_tape_kfree_buffer(tape); + tape->merge_bh = NULL; + } + + tape->chrdev_dir = IDETAPE_DIR_NONE; +} + +/* + * 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; + struct gendisk *disk = tape->disk; + int retval; + struct ide_atapi_pc pc; + + if (tape->chrdev_dir == IDETAPE_DIR_READ) + __ide_tape_discard_merge_buffer(drive); + idetape_wait_ready(drive, 60 * 5 * HZ); + idetape_create_locate_cmd(drive, &pc, block, partition, skip); + retval = ide_queue_pc_tail(drive, disk, &pc); + if (retval) + return (retval); + + idetape_create_read_position_cmd(&pc); + return ide_queue_pc_tail(drive, disk, &pc); +} + +static void ide_tape_discard_merge_buffer(ide_drive_t *drive, + int restore_position) +{ + idetape_tape_t *tape = drive->driver_data; + int seek, position; + + __ide_tape_discard_merge_buffer(drive); + if (restore_position) { + position = idetape_read_position(drive); + seek = position > 0 ? position : 0; + if (idetape_position_tape(drive, seek, 0, 0)) { + printk(KERN_INFO "ide-tape: %s: position_tape failed in" + " %s\n", tape->name, __func__); + 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; + int ret, errors; + + debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd); + + rq = blk_get_request(drive->queue, READ, __GFP_WAIT); + rq->cmd_type = REQ_TYPE_SPECIAL; + rq->cmd[13] = cmd; + rq->rq_disk = tape->disk; + rq->special = (void *)bh; + rq->sector = tape->first_frame; + rq->nr_sectors = blocks; + rq->current_nr_sectors = blocks; + blk_execute_rq(drive->queue, tape->disk, rq, 0); + + errors = rq->errors; + ret = tape->blk_size * (blocks - rq->current_nr_sectors); + blk_put_request(rq); + + if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0) + return 0; + + if (tape->merge_bh) + idetape_init_merge_buffer(tape); + if (errors == IDETAPE_ERROR_GENERAL) + return -EIO; + return ret; +} + +static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc) +{ + ide_init_pc(pc); + pc->c[0] = INQUIRY; + pc->c[4] = 254; + pc->req_xfer = 254; +} + +static void idetape_create_rewind_cmd(ide_drive_t *drive, + struct ide_atapi_pc *pc) +{ + ide_init_pc(pc); + pc->c[0] = REZERO_UNIT; + pc->flags |= PC_FLAG_WAIT_FOR_DSC; +} + +static void idetape_create_erase_cmd(struct ide_atapi_pc *pc) +{ + ide_init_pc(pc); + pc->c[0] = ERASE; + pc->c[1] = 1; + pc->flags |= PC_FLAG_WAIT_FOR_DSC; +} + +static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd) +{ + ide_init_pc(pc); + pc->c[0] = SPACE; + put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]); + pc->c[1] = cmd; + pc->flags |= PC_FLAG_WAIT_FOR_DSC; +} + +/* Queue up a character device originated write request. */ +static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + + debug_log(DBG_CHRDEV, "Enter %s\n", __func__); + + return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, + blocks, tape->merge_bh); +} + +static void ide_tape_flush_merge_buffer(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 merge buffer" + " but we are not writing.\n"); + return; + } + if (tape->merge_bh_size > tape->buffer_size) { + printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n"); + tape->merge_bh_size = tape->buffer_size; + } + if (tape->merge_bh_size) { + blocks = tape->merge_bh_size / tape->blk_size; + if (tape->merge_bh_size % tape->blk_size) { + unsigned int i; + + blocks++; + i = tape->blk_size - tape->merge_bh_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_bh_size = 0; + } + if (tape->merge_bh != NULL) { + ide_tape_kfree_buffer(tape); + tape->merge_bh = NULL; + } + tape->chrdev_dir = IDETAPE_DIR_NONE; +} + +static int idetape_init_read(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int bytes_read; + + /* Initialize read operation */ + if (tape->chrdev_dir != IDETAPE_DIR_READ) { + if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { + ide_tape_flush_merge_buffer(drive); + idetape_flush_tape_buffers(drive); + } + if (tape->merge_bh || tape->merge_bh_size) { + printk(KERN_ERR "ide-tape: merge_bh_size should be" + " 0 now\n"); + tape->merge_bh_size = 0; + } + tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0); + if (!tape->merge_bh) + 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->dev_flags & IDE_DFLAG_DSC_OVERLAP) { + bytes_read = idetape_queue_rw_tail(drive, + REQ_IDETAPE_READ, 0, + tape->merge_bh); + if (bytes_read < 0) { + ide_tape_kfree_buffer(tape); + tape->merge_bh = NULL; + tape->chrdev_dir = IDETAPE_DIR_NONE; + return bytes_read; + } + } + } + + return 0; +} + +/* called from idetape_chrdev_read() to service a chrdev read request. */ +static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + + 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(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) + return 0; + + idetape_init_read(drive); + + return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, + tape->merge_bh); +} + +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_bh; + count = min(tape->buffer_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_bh); + } +} + +/* + * 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) +{ + struct ide_tape_obj *tape = drive->driver_data; + struct gendisk *disk = tape->disk; + int retval; + struct ide_atapi_pc pc; + + debug_log(DBG_SENSE, "Enter %s\n", __func__); + + idetape_create_rewind_cmd(drive, &pc); + retval = ide_queue_pc_tail(drive, disk, &pc); + if (retval) + return retval; + + idetape_create_read_position_cmd(&pc); + retval = ide_queue_pc_tail(drive, disk, &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; + break; + case 0x0350: + config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq; + config.nr_stages = 1; + if (copy_to_user(argp, &config, sizeof(config))) + return -EFAULT; + break; + default: + return -EIO; + } + return 0; +} + +static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op, + int mt_count) +{ + idetape_tape_t *tape = drive->driver_data; + struct gendisk *disk = tape->disk; + struct ide_atapi_pc pc; + 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) { + tape->merge_bh_size = 0; + if (test_and_clear_bit(IDE_AFLAG_FILEMARK, &drive->atapi_flags)) + ++count; + ide_tape_discard_merge_buffer(drive, 0); + } + + switch (mt_op) { + case MTFSF: + case MTBSF: + idetape_create_space_cmd(&pc, mt_count - count, + IDETAPE_SPACE_OVER_FILEMARK); + return ide_queue_pc_tail(drive, disk, &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 = file->private_data; + 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(IDE_AFLAG_DETECT_BS, &drive->atapi_flags)) + if (count > tape->blk_size && + (count % tape->blk_size) == 0) + tape->user_bs_factor = count / tape->blk_size; + } + rc = idetape_init_read(drive); + if (rc < 0) + return rc; + if (count == 0) + return (0); + if (tape->merge_bh_size) { + actually_read = min((unsigned int)(tape->merge_bh_size), + (unsigned int)count); + if (idetape_copy_stage_to_user(tape, buf, actually_read)) + ret = -EFAULT; + buf += actually_read; + tape->merge_bh_size -= actually_read; + count -= actually_read; + } + while (count >= tape->buffer_size) { + bytes_read = idetape_add_chrdev_read_request(drive, ctl); + if (bytes_read <= 0) + goto finish; + if (idetape_copy_stage_to_user(tape, buf, 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, temp)) + ret = -EFAULT; + actually_read += temp; + tape->merge_bh_size = bytes_read-temp; + } +finish: + if (!actually_read && test_bit(IDE_AFLAG_FILEMARK, &drive->atapi_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 = file->private_data; + 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) + ide_tape_discard_merge_buffer(drive, 1); + if (tape->merge_bh || tape->merge_bh_size) { + printk(KERN_ERR "ide-tape: merge_bh_size " + "should be 0 now\n"); + tape->merge_bh_size = 0; + } + tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0); + if (!tape->merge_bh) + return -ENOMEM; + tape->chrdev_dir = IDETAPE_DIR_WRITE; + idetape_init_merge_buffer(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->dev_flags & IDE_DFLAG_DSC_OVERLAP) { + ssize_t retval = idetape_queue_rw_tail(drive, + REQ_IDETAPE_WRITE, 0, + tape->merge_bh); + if (retval < 0) { + ide_tape_kfree_buffer(tape); + tape->merge_bh = NULL; + tape->chrdev_dir = IDETAPE_DIR_NONE; + return retval; + } + } + } + if (count == 0) + return (0); + if (tape->merge_bh_size) { + if (tape->merge_bh_size >= tape->buffer_size) { + printk(KERN_ERR "ide-tape: bug: merge buf too big\n"); + tape->merge_bh_size = 0; + } + actually_written = min((unsigned int) + (tape->buffer_size - tape->merge_bh_size), + (unsigned int)count); + if (idetape_copy_stage_from_user(tape, buf, actually_written)) + ret = -EFAULT; + buf += actually_written; + tape->merge_bh_size += actually_written; + count -= actually_written; + + if (tape->merge_bh_size == tape->buffer_size) { + ssize_t retval; + tape->merge_bh_size = 0; + retval = idetape_add_chrdev_write_request(drive, ctl); + if (retval <= 0) + return (retval); + } + } + while (count >= tape->buffer_size) { + ssize_t retval; + if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size)) + ret = -EFAULT; + buf += tape->buffer_size; + count -= tape->buffer_size; + retval = idetape_add_chrdev_write_request(drive, ctl); + actually_written += tape->buffer_size; + if (retval <= 0) + return (retval); + } + if (count) { + actually_written += count; + if (idetape_copy_stage_from_user(tape, buf, count)) + ret = -EFAULT; + tape->merge_bh_size += count; + } + return ret ? ret : actually_written; +} + +static int idetape_write_filemark(ide_drive_t *drive) +{ + struct ide_tape_obj *tape = drive->driver_data; + struct ide_atapi_pc pc; + + /* Write a filemark */ + idetape_create_write_filemark_cmd(drive, &pc, 1); + if (ide_queue_pc_tail(drive, tape->disk, &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. + * + * 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; + struct gendisk *disk = tape->disk; + struct ide_atapi_pc pc; + int i, retval; + + debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n", + mt_op, mt_count); + + 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; + ide_tape_discard_merge_buffer(drive, 1); + for (i = 0; i < mt_count; i++) { + retval = idetape_write_filemark(drive); + if (retval) + return retval; + } + return 0; + case MTREW: + ide_tape_discard_merge_buffer(drive, 0); + if (idetape_rewind_tape(drive)) + return -EIO; + return 0; + case MTLOAD: + ide_tape_discard_merge_buffer(drive, 0); + return ide_do_start_stop(drive, disk, IDETAPE_LU_LOAD_MASK); + case MTUNLOAD: + case MTOFFL: + /* + * If door is locked, attempt to unlock before + * attempting to eject. + */ + if (tape->door_locked) { + if (!ide_set_media_lock(drive, disk, 0)) + tape->door_locked = DOOR_UNLOCKED; + } + ide_tape_discard_merge_buffer(drive, 0); + retval = ide_do_start_stop(drive, disk, !IDETAPE_LU_LOAD_MASK); + if (!retval) + clear_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags); + return retval; + case MTNOP: + ide_tape_discard_merge_buffer(drive, 0); + return idetape_flush_tape_buffers(drive); + case MTRETEN: + ide_tape_discard_merge_buffer(drive, 0); + return ide_do_start_stop(drive, disk, + IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); + case MTEOM: + idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD); + return ide_queue_pc_tail(drive, disk, &pc); + case MTERASE: + (void)idetape_rewind_tape(drive); + idetape_create_erase_cmd(&pc); + return ide_queue_pc_tail(drive, disk, &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(IDE_AFLAG_DETECT_BS, &drive->atapi_flags); + } else + set_bit(IDE_AFLAG_DETECT_BS, &drive->atapi_flags); + return 0; + case MTSEEK: + ide_tape_discard_merge_buffer(drive, 0); + return idetape_position_tape(drive, + mt_count * tape->user_bs_factor, tape->partition, 0); + case MTSETPART: + ide_tape_discard_merge_buffer(drive, 0); + return idetape_position_tape(drive, 0, mt_count, 0); + case MTFSR: + case MTBSR: + case MTLOCK: + retval = ide_set_media_lock(drive, disk, 1); + if (retval) + return retval; + tape->door_locked = DOOR_EXPLICITLY_LOCKED; + return 0; + case MTUNLOCK: + retval = ide_set_media_lock(drive, disk, 0); + 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 = file->private_data; + 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); + + if (tape->chrdev_dir == IDETAPE_DIR_WRITE) { + ide_tape_flush_merge_buffer(drive); + idetape_flush_tape_buffers(drive); + } + if (cmd == MTIOCGET || cmd == MTIOCPOS) { + block_offset = tape->merge_bh_size / + (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) + ide_tape_discard_merge_buffer(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; + struct ide_atapi_pc pc; + + idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR); + if (ide_queue_pc_tail(drive, tape->disk, &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.buf[4 + 5] << 16) + + (pc.buf[4 + 6] << 8) + + pc.buf[4 + 7]; + tape->drv_write_prot = (pc.buf[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; + int retval; + + if (i >= MAX_HWIFS * MAX_DRIVES) + return -ENXIO; + + lock_kernel(); + tape = ide_tape_chrdev_get(i); + if (!tape) { + unlock_kernel(); + 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(IDE_AFLAG_BUSY, &drive->atapi_flags)) { + retval = -EBUSY; + goto out_put_tape; + } + + retval = idetape_wait_ready(drive, 60 * HZ); + if (retval) { + clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags); + printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name); + goto out_put_tape; + } + + idetape_read_position(drive); + if (!test_bit(IDE_AFLAG_ADDRESS_VALID, &drive->atapi_flags)) + (void)idetape_rewind_tape(drive); + + /* 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(IDE_AFLAG_BUSY, &drive->atapi_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 (!ide_set_media_lock(drive, tape->disk, 1)) { + if (tape->door_locked != DOOR_EXPLICITLY_LOCKED) + tape->door_locked = DOOR_LOCKED; + } + } + unlock_kernel(); + return 0; + +out_put_tape: + ide_tape_put(tape); + unlock_kernel(); + return retval; +} + +static void idetape_write_release(ide_drive_t *drive, unsigned int minor) +{ + idetape_tape_t *tape = drive->driver_data; + + ide_tape_flush_merge_buffer(drive); + tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0); + if (tape->merge_bh != NULL) { + idetape_pad_zeros(drive, tape->blk_size * + (tape->user_bs_factor - 1)); + ide_tape_kfree_buffer(tape); + tape->merge_bh = 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 = filp->private_data; + ide_drive_t *drive = tape->drive; + 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) + ide_tape_discard_merge_buffer(drive, 1); + } + + if (minor < 128 && test_bit(IDE_AFLAG_MEDIUM_PRESENT, &drive->atapi_flags)) + (void) idetape_rewind_tape(drive); + if (tape->chrdev_dir == IDETAPE_DIR_NONE) { + if (tape->door_locked == DOOR_LOCKED) { + if (!ide_set_media_lock(drive, tape->disk, 0)) + tape->door_locked = DOOR_UNLOCKED; + } + } + clear_bit(IDE_AFLAG_BUSY, &drive->atapi_flags); + ide_tape_put(tape); + unlock_kernel(); + return 0; +} + +static void idetape_get_inquiry_results(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + struct ide_atapi_pc pc; + char fw_rev[4], vendor_id[8], product_id[16]; + + idetape_create_inquiry_cmd(&pc); + if (ide_queue_pc_tail(drive, tape->disk, &pc)) { + printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", + tape->name); + return; + } + memcpy(vendor_id, &pc.buf[8], 8); + memcpy(product_id, &pc.buf[16], 16); + memcpy(fw_rev, &pc.buf[32], 4); + + ide_fixstring(vendor_id, 8, 0); + ide_fixstring(product_id, 16, 0); + ide_fixstring(fw_rev, 4, 0); + + printk(KERN_INFO "ide-tape: %s <-> %s: %.8s %.16s rev %.4s\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; + struct ide_atapi_pc pc; + u8 *caps; + u8 speed, max_speed; + + idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE); + if (ide_queue_pc_tail(drive, tape->disk, &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.buf + 4 + pc.buf[3]; + + /* convert to host order and save for later use */ + speed = be16_to_cpup((__be16 *)&caps[14]); + max_speed = be16_to_cpup((__be16 *)&caps[8]); + + *(u16 *)&caps[8] = max_speed; + *(u16 *)&caps[12] = be16_to_cpup((__be16 *)&caps[12]); + *(u16 *)&caps[14] = speed; + *(u16 *)&caps[16] = be16_to_cpup((__be16 *)&caps[16]); + + if (!speed) { + printk(KERN_INFO "ide-tape: %s: invalid tape speed " + "(assuming 650KB/sec)\n", drive->name); + *(u16 *)&caps[14] = 650; + } + if (!max_speed) { + printk(KERN_INFO "ide-tape: %s: invalid max_speed " + "(assuming 650KB/sec)\n", drive->name); + *(u16 *)&caps[8] = 650; + } + + memcpy(&tape->caps, caps, 20); + + /* device lacks locking support according to capabilities page */ + if ((caps[6] & 1) == 0) + drive->dev_flags &= ~IDE_DFLAG_DOORLOCKING; + + if (caps[7] & 0x02) + tape->blk_size = 512; + else if (caps[7] & 0x04) + tape->blk_size = 1024; +} + +#ifdef CONFIG_IDE_PROC_FS +#define ide_tape_devset_get(name, field) \ +static int get_##name(ide_drive_t *drive) \ +{ \ + idetape_tape_t *tape = drive->driver_data; \ + return tape->field; \ +} + +#define ide_tape_devset_set(name, field) \ +static int set_##name(ide_drive_t *drive, int arg) \ +{ \ + idetape_tape_t *tape = drive->driver_data; \ + tape->field = arg; \ + return 0; \ +} + +#define ide_tape_devset_rw_field(_name, _field) \ +ide_tape_devset_get(_name, _field) \ +ide_tape_devset_set(_name, _field) \ +IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name) + +#define ide_tape_devset_r_field(_name, _field) \ +ide_tape_devset_get(_name, _field) \ +IDE_DEVSET(_name, 0, get_##_name, NULL) + +static int mulf_tdsc(ide_drive_t *drive) { return 1000; } +static int divf_tdsc(ide_drive_t *drive) { return HZ; } +static int divf_buffer(ide_drive_t *drive) { return 2; } +static int divf_buffer_size(ide_drive_t *drive) { return 1024; } + +ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP); + +ide_tape_devset_rw_field(debug_mask, debug_mask); +ide_tape_devset_rw_field(tdsc, best_dsc_rw_freq); + +ide_tape_devset_r_field(avg_speed, avg_speed); +ide_tape_devset_r_field(speed, caps[14]); +ide_tape_devset_r_field(buffer, caps[16]); +ide_tape_devset_r_field(buffer_size, buffer_size); + +static const struct ide_proc_devset idetape_settings[] = { + __IDE_PROC_DEVSET(avg_speed, 0, 0xffff, NULL, NULL), + __IDE_PROC_DEVSET(buffer, 0, 0xffff, NULL, divf_buffer), + __IDE_PROC_DEVSET(buffer_size, 0, 0xffff, NULL, divf_buffer_size), + __IDE_PROC_DEVSET(debug_mask, 0, 0xffff, NULL, NULL), + __IDE_PROC_DEVSET(dsc_overlap, 0, 1, NULL, NULL), + __IDE_PROC_DEVSET(speed, 0, 0xffff, NULL, NULL), + __IDE_PROC_DEVSET(tdsc, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX, + mulf_tdsc, divf_tdsc), + { 0 }, +}; +#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 t; + int speed; + int buffer_size; + u16 *ctl = (u16 *)&tape->caps[12]; + + drive->pc_callback = ide_tape_callback; + drive->pc_update_buffers = idetape_update_buffers; + drive->pc_io_buffers = ide_tape_io_buffers; + + spin_lock_init(&tape->lock); + + drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP; + + if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) { + printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", + tape->name); + drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP; + } + + /* Seagate Travan drives do not support DSC overlap. */ + if (strstr((char *)&drive->id[ATA_ID_PROD], "Seagate STT3401")) + drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP; + + tape->minor = minor; + tape->name[0] = 'h'; + tape->name[1] = 't'; + tape->name[2] = '0' + minor; + tape->chrdev_dir = IDETAPE_DIR_NONE; + + idetape_get_inquiry_results(drive); + idetape_get_mode_sense_results(drive); + ide_tape_get_bsize_from_bdesc(drive); + tape->user_bs_factor = 1; + tape->buffer_size = *ctl * tape->blk_size; + while (tape->buffer_size > 0xffff) { + printk(KERN_NOTICE "ide-tape: decreasing stage size\n"); + *ctl /= 2; + tape->buffer_size = *ctl * tape->blk_size; + } + buffer_size = tape->buffer_size; + tape->pages_per_buffer = buffer_size / PAGE_SIZE; + if (buffer_size % PAGE_SIZE) { + tape->pages_per_buffer++; + tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE; + } + + /* select the "best" DSC read/write polling freq */ + speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]); + + t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000); + + /* + * 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 = clamp_t(unsigned long, t, IDETAPE_DSC_RW_MIN, + IDETAPE_DSC_RW_MAX); + printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, " + "%lums tDSC%s\n", + drive->name, tape->name, *(u16 *)&tape->caps[14], + (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size, + tape->buffer_size / 1024, + tape->best_dsc_rw_freq * 1000 / HZ, + (drive->dev_flags & IDE_DFLAG_USING_DMA) ? ", DMA" : ""); + + ide_proc_register_driver(drive, tape->driver); +} + +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_drv(kref, ide_tape_obj); + ide_drive_t *drive = tape->drive; + struct gendisk *g = tape->disk; + + BUG_ON(tape->merge_bh_size); + + drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP; + 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 } +}; + +static ide_proc_entry_t *ide_tape_proc_entries(ide_drive_t *drive) +{ + return idetape_proc; +} + +static const struct ide_proc_devset *ide_tape_proc_devsets(ide_drive_t *drive) +{ + return idetape_settings; +} +#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, + .do_request = idetape_do_request, + .end_request = idetape_end_request, + .error = __ide_error, +#ifdef CONFIG_IDE_PROC_FS + .proc_entries = ide_tape_proc_entries, + .proc_devsets = ide_tape_proc_devsets, +#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 block_device *bdev, fmode_t mode) +{ + struct ide_tape_obj *tape = ide_tape_get(bdev->bd_disk); + + if (!tape) + return -ENXIO; + + return 0; +} + +static int idetape_release(struct gendisk *disk, fmode_t mode) +{ + struct ide_tape_obj *tape = ide_drv_g(disk, ide_tape_obj); + + ide_tape_put(tape); + return 0; +} + +static int idetape_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + struct ide_tape_obj *tape = ide_drv_g(bdev->bd_disk, ide_tape_obj); + ide_drive_t *drive = tape->drive; + int err = generic_ide_ioctl(drive, 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, + .locked_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->media != ide_tape) + goto failed; + + if ((drive->dev_flags & IDE_DFLAG_ID_READ) && + ide_check_atapi_device(drive, DRV_NAME) == 0) { + printk(KERN_ERR "ide-tape: %s: not supported by this version of" + " the driver\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); + + 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), NULL, "%s", tape->name); + device_create(idetape_sysfs_class, &drive->gendev, + MKDEV(IDETAPE_MAJOR, minor + 128), NULL, + "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"); |
