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ide-tape.c
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/*
* 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/seq_file.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/completion.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <scsi/scsi.h>
#include <asm/byteorder.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <asm/unaligned.h>
#include <linux/mtio.h>
/* define to see debug info */
#undef IDETAPE_DEBUG_LOG
#ifdef IDETAPE_DEBUG_LOG
#define ide_debug_log(lvl, fmt, args...) __ide_debug_log(lvl, fmt, ## args)
#else
#define ide_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),
};
/* 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
/* 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;
struct ide_driver *driver;
struct gendisk *disk;
struct device dev;
/* 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.
*/
bool 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;
/* Staging buffer of buffer_size bytes */
void *buf;
/* The read/write cursor */
void *cur;
/* The number of valid bytes in buf */
size_t valid;
/* 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;
} idetape_tape_t;
static DEFINE_MUTEX(ide_tape_mutex);
static DEFINE_MUTEX(idetape_ref_mutex);
static DEFINE_MUTEX(idetape_chrdev_mutex);
static struct class *idetape_sysfs_class;
static void ide_tape_release(struct device *);
static struct ide_tape_obj *idetape_devs[MAX_HWIFS * MAX_DRIVES];
static struct ide_tape_obj *ide_tape_get(struct gendisk *disk, bool cdev,
unsigned int i)
{
struct ide_tape_obj *tape = NULL;
mutex_lock(&idetape_ref_mutex);
if (cdev)
tape = idetape_devs[i];
else
tape = ide_drv_g(disk, ide_tape_obj);
if (tape) {
if (ide_device_get(tape->drive))
tape = NULL;
else
get_device(&tape->dev);
}
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);
put_device(&tape->dev);
ide_device_put(drive);
mutex_unlock(&idetape_ref_mutex);
}
/*
* 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)
{
idetape_tape_t *tape = drive->driver_data;
struct ide_atapi_pc *pc = drive->failed_pc;
struct request *rq = drive->hwif->rq;
u8 *sense = bio_data(rq->bio);
tape->sense_key = sense[2] & 0xF;
tape->asc = sense[12];
tape->ascq = sense[13];
ide_debug_log(IDE_DBG_FUNC,
"cmd: 0x%x, sense key = %x, asc = %x, ascq = %x",
rq->cmd[0], tape->sense_key, tape->asc, tape->ascq);
/* correct remaining bytes to transfer */
if (pc->flags & PC_FLAG_DMA_ERROR)
scsi_req(rq)->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
/*
* 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 = IDE_DRV_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 = IDE_DRV_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 = IDE_DRV_ERROR_EOD;
pc->flags |= PC_FLAG_ABORT;
}
if (!(pc->flags & PC_FLAG_ABORT) &&
(blk_rq_bytes(rq) - scsi_req(rq)->resid_len))
pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
}
}
static void ide_tape_handle_dsc(ide_drive_t *);
static int ide_tape_callback(ide_drive_t *drive, int dsc)
{
idetape_tape_t *tape = drive->driver_data;
struct ide_atapi_pc *pc = drive->pc;
struct request *rq = drive->hwif->rq;
int uptodate = pc->error ? 0 : 1;
int err = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc: %d, err: %d", rq->cmd[0],
dsc, err);
if (dsc)
ide_tape_handle_dsc(drive);
if (drive->failed_pc == pc)
drive->failed_pc = NULL;
if (pc->c[0] == REQUEST_SENSE) {
if (uptodate)
idetape_analyze_error(drive);
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) {
unsigned int blocks =
(blk_rq_bytes(rq) - scsi_req(rq)->resid_len) / 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;
if (pc->error) {
uptodate = 0;
err = pc->error;
}
}
scsi_req(rq)->result = err;
return uptodate;
}
/*
* Postpone the current request so that ide.c will be able to service requests
* from another device on the same port while we are polling for DSC.
*/
static void ide_tape_stall_queue(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, dsc_poll_freq: %lu",
drive->hwif->rq->cmd[0], tape->dsc_poll_freq);
tape->postponed_rq = true;
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 */
ide_tape_stall_queue(drive);
}
/*
* 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. ide_tape_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 ide_tape_issue_pc(ide_drive_t *drive,
struct ide_cmd *cmd,
struct ide_atapi_pc *pc)
{
idetape_tape_t *tape = drive->driver_data;
struct request *rq = drive->hwif->rq;
if (drive->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
drive->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 = IDE_DRV_ERROR_GENERAL;
}
drive->failed_pc = NULL;
drive->pc_callback(drive, 0);
ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
return ide_stopped;
}
ide_debug_log(IDE_DBG_SENSE, "retry #%d, cmd: 0x%02x", pc->retries,
pc->c[0]);
pc->retries++;
return ide_issue_pc(drive, cmd);
}
/* 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);
return ide_stopped;
}
pc->error = 0;
} else {
pc->error = IDE_DRV_ERROR_GENERAL;
drive->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)
{
unsigned int length = blk_rq_sectors(rq) / (tape->blk_size >> 9);
ide_init_pc(pc);
put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
pc->c[1] = 1;
if (blk_rq_bytes(rq) == tape->buffer_size)
pc->flags |= PC_FLAG_DMA_OK;
if (opcode == READ_6)
pc->c[0] = READ_6;
else if (opcode == WRITE_6) {
pc->c[0] = WRITE_6;
pc->flags |= PC_FLAG_WRITING;
}
memcpy(scsi_req(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 ide_cmd cmd;
struct scsi_request *req = scsi_req(rq);
u8 stat;
ide_debug_log(IDE_DBG_RQ, "cmd: 0x%x, sector: %llu, nr_sectors: %u",
req->cmd[0], (unsigned long long)blk_rq_pos(rq),
blk_rq_sectors(rq));
BUG_ON(!blk_rq_is_private(rq));
BUG_ON(ide_req(rq)->type != ATA_PRIV_MISC &&
ide_req(rq)->type != ATA_PRIV_SENSE);
/* Retry a failed packet command */
if (drive->failed_pc && drive->pc->c[0] == REQUEST_SENSE) {
pc = drive->failed_pc;
goto out;
}
/*
* 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 &&
(req->cmd[13] & REQ_IDETAPE_PC2) == 0)
drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
if (drive->dev_flags & IDE_DFLAG_POST_RESET) {
drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
drive->dev_flags &= ~IDE_DFLAG_POST_RESET;
}
if (!(drive->atapi_flags & IDE_AFLAG_IGNORE_DSC) &&
!(stat & ATA_DSC)) {
if (!tape->postponed_rq) {
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 (req->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;
ide_tape_stall_queue(drive);
return ide_stopped;
} else {
drive->atapi_flags &= ~IDE_AFLAG_IGNORE_DSC;
tape->postponed_rq = false;
}
if (req->cmd[13] & REQ_IDETAPE_READ) {
pc = &tape->queued_pc;
ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
goto out;
}
if (req->cmd[13] & REQ_IDETAPE_WRITE) {
pc = &tape->queued_pc;
ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
goto out;
}
if (req->cmd[13] & REQ_IDETAPE_PC1) {
pc = (struct ide_atapi_pc *)rq->special;
req->cmd[13] &= ~(REQ_IDETAPE_PC1);
req->cmd[13] |= REQ_IDETAPE_PC2;
goto out;
}
if (req->cmd[13] & REQ_IDETAPE_PC2) {
idetape_media_access_finished(drive);
return ide_stopped;
}
BUG();
out:
/* prepare sense request for this command */
ide_prep_sense(drive, rq);
memset(&cmd, 0, sizeof(cmd));
if (rq_data_dir(rq))
cmd.tf_flags |= IDE_TFLAG_WRITE;
cmd.rq = rq;
ide_init_sg_cmd(&cmd, blk_rq_bytes(rq));
ide_map_sg(drive, &cmd);
return ide_tape_issue_pc(drive, &cmd, pc);
}
/*
* 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(ilog2(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, NULL, 0);
if (rc)
return rc;
idetape_wait_ready(drive, 60 * 5 * HZ);
return 0;
}
static int ide_tape_read_position(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
struct ide_atapi_pc pc;
u8 buf[20];
ide_debug_log(IDE_DBG_FUNC, "enter");
/* prep cmd */
ide_init_pc(&pc);
pc.c[0] = READ_POSITION;
pc.req_xfer = 20;
if (ide_queue_pc_tail(drive, tape->disk, &pc, buf, pc.req_xfer))
return -1;
if (!pc.error) {
ide_debug_log(IDE_DBG_FUNC, "BOP - %s",
(buf[0] & 0x80) ? "Yes" : "No");
ide_debug_log(IDE_DBG_FUNC, "EOP - %s",
(buf[0] & 0x40) ? "Yes" : "No");
if (buf[0] & 0x4) {
printk(KERN_INFO "ide-tape: Block location is unknown"
"to the tape\n");
clear_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
&drive->atapi_flags);
return -1;
} else {
ide_debug_log(IDE_DBG_FUNC, "Block Location: %u",
be32_to_cpup((__be32 *)&buf[4]));
tape->partition = buf[1];
tape->first_frame = be32_to_cpup((__be32 *)&buf[4]);
set_bit(ilog2(IDE_AFLAG_ADDRESS_VALID),
&drive->atapi_flags);
}
}
return tape->first_frame;
}
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(ilog2(IDE_AFLAG_FILEMARK), &drive->atapi_flags);
tape->valid = 0;
if (tape->buf != NULL) {
kfree(tape->buf);
tape->buf = 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 ret;
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);
ret = ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
if (ret)
return ret;
ret = ide_tape_read_position(drive);
if (ret < 0)
return ret;
return 0;
}
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 = ide_tape_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 size)
{
idetape_tape_t *tape = drive->driver_data;
struct request *rq;
int ret;
ide_debug_log(IDE_DBG_FUNC, "cmd: 0x%x, size: %d", cmd, size);
BUG_ON(cmd != REQ_IDETAPE_READ && cmd != REQ_IDETAPE_WRITE);
BUG_ON(size < 0 || size % tape->blk_size);
rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
ide_req(rq)->type = ATA_PRIV_MISC;
scsi_req(rq)->cmd[13] = cmd;
rq->rq_disk = tape->disk;
rq->__sector = tape->first_frame;
if (size) {
ret = blk_rq_map_kern(drive->queue, rq, tape->buf, size,
__GFP_RECLAIM);
if (ret)
goto out_put;
}
blk_execute_rq(drive->queue, tape->disk, rq, 0);
/* calculate the number of transferred bytes and update buffer state */
size -= scsi_req(rq)->resid_len;
tape->cur = tape->buf;
if (cmd == REQ_IDETAPE_READ)
tape->valid = size;
else
tape->valid = 0;
ret = size;
if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
ret = -EIO;
out_put:
blk_put_request(rq);
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;
}
static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
{
idetape_tape_t *tape = drive->driver_data;
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->buf) {
size_t aligned = roundup(tape->valid, tape->blk_size);
memset(tape->cur, 0, aligned - tape->valid);
idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, aligned);
kfree(tape->buf);
tape->buf = NULL;
}
tape->chrdev_dir = IDETAPE_DIR_NONE;
}
static int idetape_init_rw(ide_drive_t *drive, int dir)
{
idetape_tape_t *tape = drive->driver_data;
int rc;
BUG_ON(dir != IDETAPE_DIR_READ && dir != IDETAPE_DIR_WRITE);
if (tape->chrdev_dir == dir)
return 0;
if (tape->chrdev_dir == IDETAPE_DIR_READ)
ide_tape_discard_merge_buffer(drive, 1);
else if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
ide_tape_flush_merge_buffer(drive);
idetape_flush_tape_buffers(drive);
}
if (tape->buf || tape->valid) {
printk(KERN_ERR "ide-tape: valid should be 0 now\n");
tape->valid = 0;
}
tape->buf = kmalloc(tape->buffer_size, GFP_KERNEL);
if (!tape->buf)
return -ENOMEM;
tape->chrdev_dir = dir;
tape->cur = tape->buf;
/*
* Issue a 0 rw 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) {
int cmd = dir == IDETAPE_DIR_READ ? REQ_IDETAPE_READ
: REQ_IDETAPE_WRITE;
rc = idetape_queue_rw_tail(drive, cmd, 0);
if (rc < 0) {
kfree(tape->buf);
tape->buf = NULL;
tape->chrdev_dir = IDETAPE_DIR_NONE;
return rc;
}
}
return 0;
}
static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
{
idetape_tape_t *tape = drive->driver_data;
memset(tape->buf, 0, tape->buffer_size);
while (bcount) {
unsigned int count = min(tape->buffer_size, bcount);
idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, count);