blob: fc4bd933808002296b9b7127588e9f57dbabda21 [file] [log] [blame]
/*
* sd.c Copyright (C) 1992 Drew Eckhardt
* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
*
* Linux scsi disk driver
* Initial versions: Drew Eckhardt
* Subsequent revisions: Eric Youngdale
* Modification history:
* - Drew Eckhardt <drew@colorado.edu> original
* - Eric Youngdale <eric@andante.org> add scatter-gather, multiple
* outstanding request, and other enhancements.
* Support loadable low-level scsi drivers.
* - Jirka Hanika <geo@ff.cuni.cz> support more scsi disks using
* eight major numbers.
* - Richard Gooch <rgooch@atnf.csiro.au> support devfs.
* - Torben Mathiasen <tmm@image.dk> Resource allocation fixes in
* sd_init and cleanups.
* - Alex Davis <letmein@erols.com> Fix problem where partition info
* not being read in sd_open. Fix problem where removable media
* could be ejected after sd_open.
* - Douglas Gilbert <dgilbert@interlog.com> cleanup for lk 2.5.x
*
* Logging policy (needs CONFIG_SCSI_LOGGING defined):
* - setting up transfer: SCSI_LOG_HLQUEUE levels 1 and 2
* - end of transfer (bh + scsi_lib): SCSI_LOG_HLCOMPLETE level 1
* - entering sd_ioctl: SCSI_LOG_IOCTL level 1
* - entering other commands: SCSI_LOG_HLQUEUE level 3
* Note: when the logging level is set by the user, it must be greater
* than the level indicated above to trigger output.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/genhd.h>
#include <linux/hdreg.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/reboot.h>
#include <linux/vmalloc.h>
#include <linux/blk.h>
#include <linux/blkpg.h>
#include <asm/uaccess.h>
#include "scsi.h"
#include "hosts.h"
#include <scsi/scsi_ioctl.h>
#include <scsi/scsicam.h>
/*
* Remaining dev_t-handling stuff
*/
#define SD_MAJORS 16
#define SD_DISKS (SD_MAJORS << 4)
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
#define SD_TIMEOUT (30 * HZ)
#define SD_MOD_TIMEOUT (75 * HZ)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
struct scsi_disk {
struct list_head list; /* list of all scsi_disks */
struct Scsi_Device_Template *driver; /* always &sd_template */
struct scsi_device *device;
struct gendisk *disk;
sector_t capacity; /* size in 512-byte sectors */
u32 index;
u8 media_present;
u8 write_prot;
unsigned WCE : 1; /* state of disk WCE bit */
unsigned RCD : 1; /* state of disk RCD bit, unused */
};
static LIST_HEAD(sd_devlist);
static spinlock_t sd_devlist_lock = SPIN_LOCK_UNLOCKED;
static unsigned long sd_index_bits[SD_DISKS / BITS_PER_LONG];
static spinlock_t sd_index_lock = SPIN_LOCK_UNLOCKED;
static void sd_init_onedisk(struct scsi_disk * sdkp, struct gendisk *disk);
static void sd_rw_intr(struct scsi_cmnd * SCpnt);
static int sd_attach(struct scsi_device *);
static void sd_detach(struct scsi_device *);
static void sd_rescan(struct scsi_device *);
static int sd_init_command(struct scsi_cmnd *);
static int sd_synchronize_cache(struct scsi_disk *, int);
static int sd_notifier(struct notifier_block *, unsigned long, void *);
static void sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
struct scsi_request *SRpnt, unsigned char *buffer);
static struct notifier_block sd_notifier_block = {sd_notifier, NULL, 0};
static struct Scsi_Device_Template sd_template = {
.module = THIS_MODULE,
.list = LIST_HEAD_INIT(sd_template.list),
.name = "disk",
.scsi_type = TYPE_DISK,
.attach = sd_attach,
.detach = sd_detach,
.rescan = sd_rescan,
.init_command = sd_init_command,
.scsi_driverfs_driver = {
.name = "sd",
},
};
static int sd_major(int major_idx)
{
switch (major_idx) {
case 0:
return SCSI_DISK0_MAJOR;
case 1 ... 7:
return SCSI_DISK1_MAJOR + major_idx - 1;
case 8 ... 15:
return SCSI_DISK8_MAJOR + major_idx - 8;
default:
BUG();
return 0; /* shut up gcc */
}
}
static struct scsi_disk *sd_find_by_sdev(Scsi_Device *sd)
{
struct scsi_disk *sdkp;
spin_lock(&sd_devlist_lock);
list_for_each_entry(sdkp, &sd_devlist, list) {
if (sdkp->device == sd) {
spin_unlock(&sd_devlist_lock);
return sdkp;
}
}
spin_unlock(&sd_devlist_lock);
return NULL;
}
static inline void sd_devlist_insert(struct scsi_disk *sdkp)
{
spin_lock(&sd_devlist_lock);
list_add(&sdkp->list, &sd_devlist);
spin_unlock(&sd_devlist_lock);
}
static inline void sd_devlist_remove(struct scsi_disk *sdkp)
{
spin_lock(&sd_devlist_lock);
list_del(&sdkp->list);
spin_unlock(&sd_devlist_lock);
}
static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_disk, driver);
}
/**
* sd_init_command - build a scsi (read or write) command from
* information in the request structure.
* @SCpnt: pointer to mid-level's per scsi command structure that
* contains request and into which the scsi command is written
*
* Returns 1 if successful and 0 if error (or cannot be done now).
**/
static int sd_init_command(struct scsi_cmnd * SCpnt)
{
unsigned int this_count, timeout;
struct gendisk *disk;
sector_t block;
struct scsi_device *sdp = SCpnt->device;
timeout = SD_TIMEOUT;
if (SCpnt->device->type != TYPE_DISK)
timeout = SD_MOD_TIMEOUT;
/*
* these are already setup, just copy cdb basically
*/
if (SCpnt->request->flags & REQ_BLOCK_PC) {
struct request *rq = SCpnt->request;
if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
return 0;
memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
if (rq_data_dir(rq) == WRITE)
SCpnt->sc_data_direction = SCSI_DATA_WRITE;
else if (rq->data_len)
SCpnt->sc_data_direction = SCSI_DATA_READ;
else
SCpnt->sc_data_direction = SCSI_DATA_NONE;
this_count = rq->data_len;
if (rq->timeout)
timeout = rq->timeout;
SCpnt->transfersize = rq->data_len;
SCpnt->underflow = rq->data_len;
goto queue;
}
/*
* we only do REQ_CMD and REQ_BLOCK_PC
*/
if (!(SCpnt->request->flags & REQ_CMD))
return 0;
disk = SCpnt->request->rq_disk;
block = SCpnt->request->sector;
this_count = SCpnt->request_bufflen >> 9;
SCSI_LOG_HLQUEUE(1, printk("sd_init_command: disk=%s, block=%llu, "
"count=%d\n", disk->disk_name, (unsigned long long)block, this_count));
if (!sdp || !sdp->online ||
block + SCpnt->request->nr_sectors > get_capacity(disk)) {
SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
SCpnt->request->nr_sectors));
SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
return 0;
}
if (sdp->changed) {
/*
* quietly refuse to do anything to a changed disc until
* the changed bit has been reset
*/
/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : block=%llu\n",
disk->disk_name, (unsigned long long)block));
/*
* If we have a 1K hardware sectorsize, prevent access to single
* 512 byte sectors. In theory we could handle this - in fact
* the scsi cdrom driver must be able to handle this because
* we typically use 1K blocksizes, and cdroms typically have
* 2K hardware sectorsizes. Of course, things are simpler
* with the cdrom, since it is read-only. For performance
* reasons, the filesystems should be able to handle this
* and not force the scsi disk driver to use bounce buffers
* for this.
*/
if (sdp->sector_size == 1024) {
if ((block & 1) || (SCpnt->request->nr_sectors & 1)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 1;
this_count = this_count >> 1;
}
}
if (sdp->sector_size == 2048) {
if ((block & 3) || (SCpnt->request->nr_sectors & 3)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 2;
this_count = this_count >> 2;
}
}
if (sdp->sector_size == 4096) {
if ((block & 7) || (SCpnt->request->nr_sectors & 7)) {
printk(KERN_ERR "sd: Bad block number requested");
return 0;
} else {
block = block >> 3;
this_count = this_count >> 3;
}
}
if (rq_data_dir(SCpnt->request) == WRITE) {
if (!sdp->writeable) {
return 0;
}
SCpnt->cmnd[0] = WRITE_6;
SCpnt->sc_data_direction = SCSI_DATA_WRITE;
} else if (rq_data_dir(SCpnt->request) == READ) {
SCpnt->cmnd[0] = READ_6;
SCpnt->sc_data_direction = SCSI_DATA_READ;
} else {
printk(KERN_ERR "sd: Unknown command %lx\n",
SCpnt->request->flags);
/* overkill panic("Unknown sd command %lx\n", SCpnt->request->flags); */
return 0;
}
SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
disk->disk_name, (rq_data_dir(SCpnt->request) == WRITE) ?
"writing" : "reading", this_count, SCpnt->request->nr_sectors));
SCpnt->cmnd[1] = 0;
if (block > 0xffffffff) {
SCpnt->cmnd[0] += READ_16 - READ_6;
SCpnt->cmnd[2] = sizeof(block) > 4 ? (unsigned char) (block >> 56) & 0xff : 0;
SCpnt->cmnd[3] = sizeof(block) > 4 ? (unsigned char) (block >> 48) & 0xff : 0;
SCpnt->cmnd[4] = sizeof(block) > 4 ? (unsigned char) (block >> 40) & 0xff : 0;
SCpnt->cmnd[5] = sizeof(block) > 4 ? (unsigned char) (block >> 32) & 0xff : 0;
SCpnt->cmnd[6] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[7] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[8] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[9] = (unsigned char) block & 0xff;
SCpnt->cmnd[10] = (unsigned char) (this_count >> 24) & 0xff;
SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
} else if (((this_count > 0xff) || (block > 0x1fffff)) || SCpnt->device->ten) {
if (this_count > 0xffff)
this_count = 0xffff;
SCpnt->cmnd[0] += READ_10 - READ_6;
SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[5] = (unsigned char) block & 0xff;
SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
} else {
if (this_count > 0xff)
this_count = 0xff;
SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
SCpnt->cmnd[2] = (unsigned char) ((block >> 8) & 0xff);
SCpnt->cmnd[3] = (unsigned char) block & 0xff;
SCpnt->cmnd[4] = (unsigned char) this_count;
SCpnt->cmnd[5] = 0;
}
/*
* We shouldn't disconnect in the middle of a sector, so with a dumb
* host adapter, it's safe to assume that we can at least transfer
* this many bytes between each connect / disconnect.
*/
SCpnt->transfersize = sdp->sector_size;
SCpnt->underflow = this_count << 9;
queue:
SCpnt->allowed = SD_MAX_RETRIES;
SCpnt->timeout_per_command = timeout;
/*
* This is the completion routine we use. This is matched in terms
* of capability to this function.
*/
SCpnt->done = sd_rw_intr;
/*
* This indicates that the command is ready from our end to be
* queued.
*/
return 1;
}
/**
* sd_open - open a scsi disk device
* @inode: only i_rdev member may be used
* @filp: only f_mode and f_flags may be used
*
* Returns 0 if successful. Returns a negated errno value in case
* of error.
*
* Note: This can be called from a user context (e.g. fsck(1) )
* or from within the kernel (e.g. as a result of a mount(1) ).
* In the latter case @inode and @filp carry an abridged amount
* of information as noted above.
**/
static int sd_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdev = sdkp->device;
int retval;
SCSI_LOG_HLQUEUE(3, printk("sd_open: disk=%s\n", disk->disk_name));
retval = scsi_device_get(sdev);
if (retval)
return retval;
/*
* If the device is in error recovery, wait until it is done.
* If the device is offline, then disallow any access to it.
*/
retval = -ENXIO;
if (!scsi_block_when_processing_errors(sdev))
goto error_out;
if (sdev->removable) {
check_disk_change(inode->i_bdev);
/*
* If the drive is empty, just let the open fail.
*/
retval = -ENOMEDIUM;
if ((!sdkp->media_present) && !(filp->f_flags & O_NDELAY))
goto error_out;
/*
* Similarly, if the device has the write protect tab set,
* have the open fail if the user expects to be able to write
* to the thing.
*/
retval = -EROFS;
if ((sdkp->write_prot) && (filp->f_mode & FMODE_WRITE))
goto error_out;
}
/*
* It is possible that the disk changing stuff resulted in
* the device being taken offline. If this is the case,
* report this to the user, and don't pretend that the
* open actually succeeded.
*/
retval = -ENXIO;
if (!sdev->online)
goto error_out;
if (sdev->removable && sdev->access_count == 1)
if (scsi_block_when_processing_errors(sdev))
scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
return 0;
error_out:
scsi_device_put(sdev);
return retval;
}
/**
* sd_release - invoked when the (last) close(2) is called on this
* scsi disk.
* @inode: only i_rdev member may be used
* @filp: only f_mode and f_flags may be used
*
* Returns 0.
*
* Note: may block (uninterruptible) if error recovery is underway
* on this disk.
**/
static int sd_release(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct scsi_device *sdev = scsi_disk(disk)->device;
SCSI_LOG_HLQUEUE(3, printk("sd_release: disk=%s\n", disk->disk_name));
if (sdev->removable && sdev->access_count == 1)
if (scsi_block_when_processing_errors(sdev))
scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
/*
* XXX and what if there are packets in flight and this close()
* XXX is followed by a "rmmod sd_mod"?
*/
scsi_device_put(sdev);
return 0;
}
static int sd_hdio_getgeo(struct block_device *bdev, struct hd_geometry *loc)
{
struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
struct scsi_device *sdp = sdkp->device;
struct Scsi_Host *host = sdp->host;
int diskinfo[4];
/* default to most commonly used values */
diskinfo[0] = 0x40; /* 1 << 6 */
diskinfo[1] = 0x20; /* 1 << 5 */
diskinfo[2] = sdkp->capacity >> 11;
/* override with calculated, extended default, or driver values */
if (host->hostt->bios_param)
host->hostt->bios_param(sdp, bdev, sdkp->capacity, diskinfo);
else
scsicam_bios_param(bdev, sdkp->capacity, diskinfo);
if (put_user(diskinfo[0], &loc->heads))
return -EFAULT;
if (put_user(diskinfo[1], &loc->sectors))
return -EFAULT;
if (put_user(diskinfo[2], &loc->cylinders))
return -EFAULT;
if (put_user((unsigned)get_start_sect(bdev),
(unsigned long *)&loc->start))
return -EFAULT;
return 0;
}
/**
* sd_ioctl - process an ioctl
* @inode: only i_rdev/i_bdev members may be used
* @filp: only f_mode and f_flags may be used
* @cmd: ioctl command number
* @arg: this is third argument given to ioctl(2) system call.
* Often contains a pointer.
*
* Returns 0 if successful (some ioctls return postive numbers on
* success as well). Returns a negated errno value in case of error.
*
* Note: most ioctls are forward onto the block subsystem or further
* down in the scsi subsytem.
**/
static int sd_ioctl(struct inode * inode, struct file * filp,
unsigned int cmd, unsigned long arg)
{
struct block_device *bdev = inode->i_bdev;
struct gendisk *disk = bdev->bd_disk;
struct scsi_device *sdp = scsi_disk(disk)->device;
int error;
SCSI_LOG_IOCTL(1, printk("sd_ioctl: disk=%s, cmd=0x%x\n",
disk->disk_name, cmd));
/*
* If we are in the middle of error recovery, don't let anyone
* else try and use this device. Also, if error recovery fails, it
* may try and take the device offline, in which case all further
* access to the device is prohibited.
*/
if (!scsi_block_when_processing_errors(sdp))
return -ENODEV;
if (cmd == HDIO_GETGEO) {
if (!arg)
return -EINVAL;
return sd_hdio_getgeo(bdev, (struct hd_geometry *)arg);
}
/*
* Send SCSI addressing ioctls directly to mid level, send other
* ioctls to block level and then onto mid level if they can't be
* resolved.
*/
switch (cmd) {
case SCSI_IOCTL_GET_IDLUN:
case SCSI_IOCTL_GET_BUS_NUMBER:
return scsi_ioctl(sdp, cmd, (void *)arg);
default:
error = scsi_cmd_ioctl(bdev, cmd, arg);
if (error != -ENOTTY)
return error;
}
return scsi_ioctl(sdp, cmd, (void *)arg);
}
static void set_media_not_present(struct scsi_disk *sdkp)
{
sdkp->media_present = 0;
sdkp->capacity = 0;
sdkp->device->changed = 1;
}
/**
* sd_media_changed - check if our medium changed
* @disk: kernel device descriptor
*
* Returns 0 if not applicable or no change; 1 if change
*
* Note: this function is invoked from the block subsystem.
**/
static int sd_media_changed(struct gendisk *disk)
{
struct scsi_disk *sdkp = scsi_disk(disk);
struct scsi_device *sdp = sdkp->device;
int retval;
SCSI_LOG_HLQUEUE(3, printk("sd_media_changed: disk=%s\n",
disk->disk_name));
if (!sdp->removable)
return 0;
/*
* If the device is offline, don't send any commands - just pretend as
* if the command failed. If the device ever comes back online, we
* can deal with it then. It is only because of unrecoverable errors
* that we would ever take a device offline in the first place.
*/
if (!sdp->online)
goto not_present;
/*
* Using TEST_UNIT_READY enables differentiation between drive with
* no cartridge loaded - NOT READY, drive with changed cartridge -
* UNIT ATTENTION, or with same cartridge - GOOD STATUS.
*
* Drives that auto spin down. eg iomega jaz 1G, will be started
* by sd_spinup_disk() from sd_init_onedisk(), which happens whenever
* sd_revalidate() is called.
*/
retval = -ENODEV;
if (scsi_block_when_processing_errors(sdp))
retval = scsi_ioctl(sdp, SCSI_IOCTL_TEST_UNIT_READY, NULL);
/*
* Unable to test, unit probably not ready. This usually
* means there is no disc in the drive. Mark as changed,
* and we will figure it out later once the drive is
* available again.
*/
if (retval)
goto not_present;
/*
* For removable scsi disk we have to recognise the presence
* of a disk in the drive. This is kept in the struct scsi_disk
* struct and tested at open ! Daniel Roche (dan@lectra.fr)
*/
sdkp->media_present = 1;
retval = sdp->changed;
sdp->changed = 0;
return retval;
not_present:
set_media_not_present(sdkp);
return 1;
}
static void sd_rescan(struct scsi_device * sdp)
{
unsigned char *buffer;
struct scsi_disk *sdkp = sd_find_by_sdev(sdp);
struct gendisk *gd;
struct scsi_request *SRpnt;
if (!sdkp || sdp->online == FALSE || !sdkp->media_present)
return;
gd = sdkp->disk;
SCSI_LOG_HLQUEUE(3, printk("sd_rescan: disk=%s\n", gd->disk_name));
SRpnt = scsi_allocate_request(sdp);
if (!SRpnt) {
printk(KERN_WARNING "(sd_rescan:) Request allocation "
"failure.\n");
return;
}
if (sdkp->device->host->unchecked_isa_dma)
buffer = kmalloc(512, GFP_DMA);
else
buffer = kmalloc(512, GFP_KERNEL);
sd_read_capacity(sdkp, gd->disk_name, SRpnt, buffer);
set_capacity(gd, sdkp->capacity);
scsi_release_request(SRpnt);
kfree(buffer);
}
static int sd_revalidate_disk(struct gendisk *disk)
{
struct scsi_disk *sdkp = scsi_disk(disk);
sd_init_onedisk(sdkp, disk);
set_capacity(disk, sdkp->capacity);
return 0;
}
static struct block_device_operations sd_fops = {
.owner = THIS_MODULE,
.open = sd_open,
.release = sd_release,
.ioctl = sd_ioctl,
.media_changed = sd_media_changed,
.revalidate_disk = sd_revalidate_disk,
};
/**
* sd_rw_intr - bottom half handler: called when the lower level
* driver has completed (successfully or otherwise) a scsi command.
* @SCpnt: mid-level's per command structure.
*
* Note: potentially run from within an ISR. Must not block.
**/
static void sd_rw_intr(struct scsi_cmnd * SCpnt)
{
int result = SCpnt->result;
int this_count = SCpnt->bufflen >> 9;
int good_sectors = (result == 0 ? this_count : 0);
sector_t block_sectors = 1;
sector_t error_sector;
#if CONFIG_SCSI_LOGGING
SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: %s: res=0x%x\n",
SCpnt->request->rq_disk->disk_name, result));
if (0 != result) {
SCSI_LOG_HLCOMPLETE(1, printk("sd_rw_intr: sb[0,2,asc,ascq]"
"=%x,%x,%x,%x\n", SCpnt->sense_buffer[0],
SCpnt->sense_buffer[2], SCpnt->sense_buffer[12],
SCpnt->sense_buffer[13]));
}
#endif
/*
Handle MEDIUM ERRORs that indicate partial success. Since this is a
relatively rare error condition, no care is taken to avoid
unnecessary additional work such as memcpy's that could be avoided.
*/
/* An error occurred */
if (driver_byte(result) != 0 && /* An error occurred */
SCpnt->sense_buffer[0] == 0xF0) { /* Sense data is valid */
switch (SCpnt->sense_buffer[2]) {
case MEDIUM_ERROR:
error_sector = (SCpnt->sense_buffer[3] << 24) |
(SCpnt->sense_buffer[4] << 16) |
(SCpnt->sense_buffer[5] << 8) |
SCpnt->sense_buffer[6];
if (SCpnt->request->bio != NULL)
block_sectors = bio_sectors(SCpnt->request->bio);
switch (SCpnt->device->sector_size) {
case 1024:
error_sector <<= 1;
if (block_sectors < 2)
block_sectors = 2;
break;
case 2048:
error_sector <<= 2;
if (block_sectors < 4)
block_sectors = 4;
break;
case 4096:
error_sector <<=3;
if (block_sectors < 8)
block_sectors = 8;
break;
case 256:
error_sector >>= 1;
break;
default:
break;
}
error_sector &= ~(block_sectors - 1);
good_sectors = error_sector - SCpnt->request->sector;
if (good_sectors < 0 || good_sectors >= this_count)
good_sectors = 0;
break;
case RECOVERED_ERROR:
/*
* An error occurred, but it recovered. Inform the
* user, but make sure that it's not treated as a
* hard error.
*/
print_sense("sd", SCpnt);
result = 0;
SCpnt->sense_buffer[0] = 0x0;
good_sectors = this_count;
break;
case ILLEGAL_REQUEST:
if (SCpnt->device->ten == 1) {
if (SCpnt->cmnd[0] == READ_10 ||
SCpnt->cmnd[0] == WRITE_10)
SCpnt->device->ten = 0;
}
break;
default:
break;
}
}
/*
* This calls the generic completion function, now that we know
* how many actual sectors finished, and how many sectors we need
* to say have failed.
*/
scsi_io_completion(SCpnt, good_sectors, block_sectors);
}
static int media_not_present(struct scsi_disk *sdkp, struct scsi_request *srp)
{
if (!srp->sr_result)
return 0;
if (!(driver_byte(srp->sr_result) & DRIVER_SENSE))
return 0;
if (srp->sr_sense_buffer[2] != NOT_READY &&
srp->sr_sense_buffer[2] != UNIT_ATTENTION)
return 0;
if (srp->sr_sense_buffer[12] != 0x3A) /* medium not present */
return 0;
set_media_not_present(sdkp);
return 1;
}
/*
* spinup disk - called only in sd_init_onedisk()
*/
static void
sd_spinup_disk(struct scsi_disk *sdkp, char *diskname,
struct scsi_request *SRpnt, unsigned char *buffer) {
unsigned char cmd[10];
unsigned long spintime_value = 0;
int the_result, retries, spintime;
spintime = 0;
/* Spin up drives, as required. Only do this at boot time */
/* Spinup needs to be done for module loads too. */
do {
retries = 0;
while (retries < 3) {
cmd[0] = TEST_UNIT_READY;
memset((void *) &cmd[1], 0, 9);
SRpnt->sr_cmd_len = 0;
SRpnt->sr_sense_buffer[0] = 0;
SRpnt->sr_sense_buffer[2] = 0;
SRpnt->sr_data_direction = SCSI_DATA_NONE;
scsi_wait_req (SRpnt, (void *) cmd, (void *) buffer,
0/*512*/, SD_TIMEOUT, SD_MAX_RETRIES);
the_result = SRpnt->sr_result;
retries++;
if (the_result == 0
|| SRpnt->sr_sense_buffer[2] != UNIT_ATTENTION)
break;
}
/*
* If the drive has indicated to us that it doesn't have
* any media in it, don't bother with any of the rest of
* this crap.
*/
if (media_not_present(sdkp, SRpnt))
return;
if (the_result == 0)
break; /* all is well now */
/*
* If manual intervention is required, or this is an
* absent USB storage device, a spinup is meaningless.
*/
if (SRpnt->sr_sense_buffer[2] == NOT_READY &&
SRpnt->sr_sense_buffer[12] == 4 /* not ready */ &&
SRpnt->sr_sense_buffer[13] == 3)
break; /* manual intervention required */
/*
* Issue command to spin up drive when not ready
*/
if (SRpnt->sr_sense_buffer[2] == NOT_READY) {
unsigned long time1;
if (!spintime) {
printk(KERN_NOTICE "%s: Spinning up disk...",
diskname);
cmd[0] = START_STOP;
cmd[1] = 1; /* Return immediately */
memset((void *) &cmd[2], 0, 8);
cmd[4] = 1; /* Start spin cycle */
SRpnt->sr_cmd_len = 0;
SRpnt->sr_sense_buffer[0] = 0;
SRpnt->sr_sense_buffer[2] = 0;
SRpnt->sr_data_direction = SCSI_DATA_READ;
scsi_wait_req(SRpnt, (void *)cmd,
(void *) buffer, 0/*512*/,
SD_TIMEOUT, SD_MAX_RETRIES);
spintime_value = jiffies;
}
spintime = 1;
time1 = HZ;
/* Wait 1 second for next try */
do {
current->state = TASK_UNINTERRUPTIBLE;
time1 = schedule_timeout(time1);
} while(time1);
printk(".");
}
} while (spintime &&
time_after(spintime_value + 100 * HZ, jiffies));
if (spintime) {
if (the_result)
printk("not responding...\n");
else
printk("ready\n");
}
}
/*
* read disk capacity - called only in sd_init_onedisk()
*/
static void
sd_read_capacity(struct scsi_disk *sdkp, char *diskname,
struct scsi_request *SRpnt, unsigned char *buffer) {
unsigned char cmd[16];
struct scsi_device *sdp = sdkp->device;
int the_result, retries;
int sector_size = 0;
int longrc = 0;
repeat:
retries = 3;
do {
if (longrc) {
memset((void *) cmd, 0, 16);
cmd[0] = SERVICE_ACTION_IN;
cmd[1] = SAI_READ_CAPACITY_16;
cmd[13] = 12;
memset((void *) buffer, 0, 12);
} else {
cmd[0] = READ_CAPACITY;
memset((void *) &cmd[1], 0, 9);
memset((void *) buffer, 0, 8);
}
SRpnt->sr_cmd_len = 0;
SRpnt->sr_sense_buffer[0] = 0;
SRpnt->sr_sense_buffer[2] = 0;
SRpnt->sr_data_direction = SCSI_DATA_READ;
scsi_wait_req(SRpnt, (void *) cmd, (void *) buffer,
longrc ? 12 : 8, SD_TIMEOUT, SD_MAX_RETRIES);
if (media_not_present(sdkp, SRpnt))
return;
the_result = SRpnt->sr_result;
retries--;
} while (the_result && retries);
if (the_result && !longrc) {
printk(KERN_NOTICE "%s : READ CAPACITY failed.\n"
"%s : status=%x, message=%02x, host=%d, driver=%02x \n",
diskname, diskname,
status_byte(the_result),
msg_byte(the_result),
host_byte(the_result),
driver_byte(the_result));
if (driver_byte(the_result) & DRIVER_SENSE)
print_req_sense("sd", SRpnt);
else
printk("%s : sense not available. \n", diskname);
/* Set dirty bit for removable devices if not ready -
* sometimes drives will not report this properly. */
if (sdp->removable &&
SRpnt->sr_sense_buffer[2] == NOT_READY)
sdp->changed = 1;
/* Either no media are present but the drive didn't tell us,
or they are present but the read capacity command fails */
/* sdkp->media_present = 0; -- not always correct */
sdkp->capacity = 0x200000; /* 1 GB - random */
return;
} else if (the_result && longrc) {
/* READ CAPACITY(16) has been failed */
printk(KERN_NOTICE "%s : READ CAPACITY(16) failed.\n"
"%s : status=%x, message=%02x, host=%d, driver=%02x \n",
diskname, diskname,
status_byte(the_result),
msg_byte(the_result),
host_byte(the_result),
driver_byte(the_result));
printk(KERN_NOTICE "%s : use 0xffffffff as device size\n",
diskname);
sdkp->capacity = 1 + (sector_t) 0xffffffff;
goto got_data;
}
if (!longrc) {
sector_size = (buffer[4] << 24) |
(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
if (buffer[0] == 0xff && buffer[1] == 0xff &&
buffer[2] == 0xff && buffer[3] == 0xff) {
if(sizeof(sdkp->capacity) > 4) {
printk(KERN_NOTICE "%s : very big device. try to use"
" READ CAPACITY(16).\n", diskname);
longrc = 1;
goto repeat;
} else {
printk(KERN_ERR "%s: too big for kernel. Assuming maximum 2Tb\n", diskname);
}
}
sdkp->capacity = 1 + (((sector_t)buffer[0] << 24) |
(buffer[1] << 16) |
(buffer[2] << 8) |
buffer[3]);
} else {
sdkp->capacity = 1 + (((u64)buffer[0] << 56) |
((u64)buffer[1] << 48) |
((u64)buffer[2] << 40) |
((u64)buffer[3] << 32) |
((sector_t)buffer[4] << 24) |
((sector_t)buffer[5] << 16) |
((sector_t)buffer[6] << 8) |
(sector_t)buffer[7]);
sector_size = (buffer[8] << 24) |
(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];
}
got_data:
if (sector_size == 0) {
sector_size = 512;
printk(KERN_NOTICE "%s : sector size 0 reported, "
"assuming 512.\n", diskname);
}
if (sector_size != 512 &&
sector_size != 1024 &&
sector_size != 2048 &&
sector_size != 4096 &&
sector_size != 256) {
printk(KERN_NOTICE "%s : unsupported sector size "
"%d.\n", diskname, sector_size);
/*
* The user might want to re-format the drive with
* a supported sectorsize. Once this happens, it
* would be relatively trivial to set the thing up.
* For this reason, we leave the thing in the table.
*/
sdkp->capacity = 0;
}
{
/*
* The msdos fs needs to know the hardware sector size
* So I have created this table. See ll_rw_blk.c
* Jacques Gelinas (Jacques@solucorp.qc.ca)
*/
int hard_sector = sector_size;
sector_t sz = sdkp->capacity * (hard_sector/256);
request_queue_t *queue = sdp->request_queue;
sector_t mb;
blk_queue_hardsect_size(queue, hard_sector);
/* avoid 64-bit division on 32-bit platforms */
mb = sz >> 1;
sector_div(sz, 1250);
mb -= sz - 974;
sector_div(mb, 1950);
printk(KERN_NOTICE "SCSI device %s: "
"%llu %d-byte hdwr sectors (%llu MB)\n",
diskname, (unsigned long long)sdkp->capacity,
hard_sector, (unsigned long long)mb);
}
/* Rescale capacity to 512-byte units */
if (sector_size == 4096)
sdkp->capacity <<= 3;
else if (sector_size == 2048)
sdkp->capacity <<= 2;
else if (sector_size == 1024)
sdkp->capacity <<= 1;
else if (sector_size == 256)
sdkp->capacity >>= 1;
sdkp->device->sector_size = sector_size;
}
static int
sd_do_mode_sense6(struct scsi_device *sdp, struct scsi_request *SRpnt,
int dbd, int modepage, unsigned char *buffer, int len) {
unsigned char cmd[8];
memset((void *) &cmd[0], 0, 8);
cmd[0] = MODE_SENSE;
cmd[1] = dbd;
cmd[2] = modepage;
cmd[4] = len;
SRpnt->sr_cmd_len = 0;
SRpnt->sr_sense_buffer[0] = 0;
SRpnt->sr_sense_buffer[2] = 0;
SRpnt->sr_data_direction = SCSI_DATA_READ;
memset((void *) buffer, 0, len);
scsi_wait_req(SRpnt, (void *) cmd, (void *) buffer,
len, SD_TIMEOUT, SD_MAX_RETRIES);
return SRpnt->sr_result;
}
/*
* read write protect setting, if possible - called only in sd_init_onedisk()
*/
static void
sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname,
struct scsi_request *SRpnt, unsigned char *buffer) {
struct scsi_device *sdp = sdkp->device;
int res;
/*
* First attempt: ask for all pages (0x3F), but only 4 bytes.
* We have to start carefully: some devices hang if we ask
* for more than is available.
*/
res = sd_do_mode_sense6(sdp, SRpnt, 0, 0x3F, buffer, 4);
/*
* Second attempt: ask for page 0
* When only page 0 is implemented, a request for page 3F may return
* Sense Key 5: Illegal Request, Sense Code 24: Invalid field in CDB.
*/
if (res)
res = sd_do_mode_sense6(sdp, SRpnt, 0, 0, buffer, 4);
/*
* Third attempt: ask 255 bytes, as we did earlier.
*/
if (res)
res = sd_do_mode_sense6(sdp, SRpnt, 0, 0x3F, buffer, 255);
if (res) {
printk(KERN_WARNING
"%s: test WP failed, assume Write Enabled\n", diskname);
} else {
sdkp->write_prot = ((buffer[2] & 0x80) != 0);
printk(KERN_NOTICE "%s: Write Protect is %s\n", diskname,
sdkp->write_prot ? "on" : "off");
printk(KERN_DEBUG "%s: Mode Sense: %02x %02x %02x %02x\n",
diskname, buffer[0], buffer[1], buffer[2], buffer[3]);
}
}
/*
* sd_read_cache_type - called only from sd_init_onedisk()
*/
static void
sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
struct scsi_request *SRpnt, unsigned char *buffer) {
struct scsi_device *sdp = sdkp->device;
int len = 0, res;
const int dbd = 0x08; /* DBD */
const int modepage = 0x08; /* current values, cache page */
/* cautiously ask */
res = sd_do_mode_sense6(sdp, SRpnt, dbd, modepage, buffer, 4);
if (res == 0) {
/* that went OK, now ask for the proper length */
len = buffer[0] + 1;
if (len > 128)
len = 128;
res = sd_do_mode_sense6(sdp, SRpnt, dbd, modepage, buffer, len);
}
if (res == 0 && buffer[3] + 6 < len) {
const char *types[] = {
"write through", "none", "write back",
"write back, no read (daft)"
};
int ct = 0;
int offset = buffer[3] + 4; /* start of mode page */
sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
ct = sdkp->RCD + 2*sdkp->WCE;
printk(KERN_NOTICE "SCSI device %s: drive cache: %s\n",
diskname, types[ct]);
} else {
if (res == 0 ||
(status_byte(res) == CHECK_CONDITION
&& (SRpnt->sr_sense_buffer[0] & 0x70) == 0x70
&& (SRpnt->sr_sense_buffer[2] & 0x0f) == ILLEGAL_REQUEST
/* ASC 0x24 ASCQ 0x00: Invalid field in CDB */
&& SRpnt->sr_sense_buffer[12] == 0x24
&& SRpnt->sr_sense_buffer[13] == 0x00)) {
printk(KERN_NOTICE "%s: cache data unavailable\n",
diskname);
} else {
printk(KERN_ERR "%s: asking for cache data failed\n",
diskname);
}
printk(KERN_ERR "%s: assuming drive cache: write through\n",
diskname);
sdkp->WCE = 0;
sdkp->RCD = 0;
}
}
/**
* sd_init_onedisk - called the first time a new disk is seen,
* performs disk spin up, read_capacity, etc.
* @sdkp: pointer to associated struct scsi_disk object
* @dsk_nr: disk number within this driver (e.g. 0->/dev/sda,
* 1->/dev/sdb, etc)
*
* Note: this function is local to this driver.
**/
static void
sd_init_onedisk(struct scsi_disk * sdkp, struct gendisk *disk)
{
unsigned char *buffer;
struct scsi_device *sdp;
struct scsi_request *SRpnt;
SCSI_LOG_HLQUEUE(3, printk("sd_init_onedisk: disk=%s\n", disk->disk_name));
/*
* If the device is offline, don't try and read capacity or any
* of the other niceties.
*/
sdp = sdkp->device;
if (sdp->online == FALSE)
return;
SRpnt = scsi_allocate_request(sdp);
if (!SRpnt) {
printk(KERN_WARNING "(sd_init_onedisk:) Request allocation "
"failure.\n");
return;
}
buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
if (!buffer) {
printk(KERN_WARNING "(sd_init_onedisk:) Memory allocation "
"failure.\n");
goto leave;
}
/* defaults, until the device tells us otherwise */
sdkp->capacity = 0;
sdkp->device->sector_size = 512;
sdkp->media_present = 1;
sdkp->write_prot = 0;
sdkp->WCE = 0;
sdkp->RCD = 0;
sd_spinup_disk(sdkp, disk->disk_name, SRpnt, buffer);
if (sdkp->media_present)
sd_read_capacity(sdkp, disk->disk_name, SRpnt, buffer);
if (sdp->removable && sdkp->media_present)
sd_read_write_protect_flag(sdkp, disk->disk_name, SRpnt, buffer);
/* without media there is no reason to ask;
moreover, some devices react badly if we do */
if (sdkp->media_present)
sd_read_cache_type(sdkp, disk->disk_name, SRpnt, buffer);
SRpnt->sr_device->ten = 1;
SRpnt->sr_device->remap = 1;
leave:
scsi_release_request(SRpnt);
kfree(buffer);
}
/**
* sd_attach - called during driver initialization and whenever a
* new scsi device is attached to the system. It is called once
* for each scsi device (not just disks) present.
* @sdp: pointer to mid level scsi device object
*
* Returns 0 if successful (or not interested in this scsi device
* (e.g. scanner)); 1 when there is an error.
*
* Note: this function is invoked from the scsi mid-level.
* This function sets up the mapping between a given
* <host,channel,id,lun> (found in sdp) and new device name
* (e.g. /dev/sda). More precisely it is the block device major
* and minor number that is chosen here.
*
* Assume sd_attach is not re-entrant (for time being)
* Also think about sd_attach() and sd_detach() running coincidentally.
**/
static int sd_attach(struct scsi_device * sdp)
{
struct scsi_disk *sdkp;
struct gendisk *gd;
u32 index;
int error;
if ((sdp->type != TYPE_DISK) && (sdp->type != TYPE_MOD))
return 1;
SCSI_LOG_HLQUEUE(3, printk("sd_attach: scsi device: <%d,%d,%d,%d>\n",
sdp->host->host_no, sdp->channel, sdp->id, sdp->lun));
error = scsi_slave_attach(sdp);
if (error)
goto out;
error = -ENOMEM;
sdkp = kmalloc(sizeof(*sdkp), GFP_KERNEL);
if (!sdkp)
goto out_detach;
gd = alloc_disk(16);
if (!gd)
goto out_free;
spin_lock(&sd_index_lock);
index = find_first_zero_bit(sd_index_bits, SD_DISKS);
if (index == SD_DISKS) {
spin_unlock(&sd_index_lock);
error = -EBUSY;
goto out_put;
}
__set_bit(index, sd_index_bits);
spin_unlock(&sd_index_lock);
sdkp->device = sdp;
sdkp->driver = &sd_template;
sdkp->disk = gd;
sdkp->index = index;
gd->major = sd_major(index >> 4);
gd->first_minor = (index & 15) << 4;
gd->minors = 16;
gd->fops = &sd_fops;
if (index >= 26) {
sprintf(gd->disk_name, "sd%c%c",
'a' + index/26-1,'a' + index % 26);
} else {
sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
}
strcpy(gd->devfs_name, sdp->devfs_name);
sd_init_onedisk(sdkp, gd);
gd->driverfs_dev = &sdp->sdev_driverfs_dev;
gd->flags = GENHD_FL_DRIVERFS;
if (sdp->removable)
gd->flags |= GENHD_FL_REMOVABLE;
gd->private_data = &sdkp->driver;
gd->queue = sdkp->device->request_queue;
sd_devlist_insert(sdkp);
set_capacity(gd, sdkp->capacity);
add_disk(gd);
printk(KERN_NOTICE "Attached scsi %sdisk %s at scsi%d, channel %d, "
"id %d, lun %d\n", sdp->removable ? "removable " : "",
gd->disk_name, sdp->host->host_no, sdp->channel,
sdp->id, sdp->lun);
return 0;
out_put:
put_disk(gd);
out_free:
kfree(sdkp);
out_detach:
scsi_slave_detach(sdp);
out:
return error;
}
/**
* sd_detach - called whenever a scsi disk (previously recognized by
* sd_attach) is detached from the system. It is called (potentially
* multiple times) during sd module unload.
* @sdp: pointer to mid level scsi device object
*
* Note: this function is invoked from the scsi mid-level.
* This function potentially frees up a device name (e.g. /dev/sdc)
* that could be re-used by a subsequent sd_attach().
* This function is not called when the built-in sd driver is "exit-ed".
**/
static void sd_detach(struct scsi_device * sdp)
{
struct scsi_disk *sdkp;
SCSI_LOG_HLQUEUE(3, printk("sd_detach: <%d,%d,%d,%d>\n",
sdp->host->host_no, sdp->channel, sdp->id,
sdp->lun));
sdkp = sd_find_by_sdev(sdp);
if (!sdkp)
return;
/* check that we actually have a write back cache to synchronize */
if (sdkp->WCE) {
printk(KERN_NOTICE "Synchronizing SCSI cache: ");
sd_synchronize_cache(sdkp, 1);
printk("\n");
}
sd_devlist_remove(sdkp);
del_gendisk(sdkp->disk);
scsi_slave_detach(sdp);
spin_lock(&sd_index_lock);
clear_bit(sdkp->index, sd_index_bits);
spin_unlock(&sd_index_lock);
put_disk(sdkp->disk);
kfree(sdkp);
}
/**
* init_sd - entry point for this driver (both when built in or when
* a module).
*
* Note: this function registers this driver with the scsi mid-level.
**/
static int __init init_sd(void)
{
int majors = 0, rc = -ENODEV, i;
SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
for (i = 0; i < SD_MAJORS; i++)
if (register_blkdev(sd_major(i), "sd") == 0)
majors++;
if (!majors)
return -ENODEV;
rc = scsi_register_device(&sd_template);
if (rc)
return rc;
register_reboot_notifier(&sd_notifier_block);
return rc;
}
/**
* exit_sd - exit point for this driver (when it is a module).
*
* Note: this function unregisters this driver from the scsi mid-level.
**/
static void __exit exit_sd(void)
{
int i;
SCSI_LOG_HLQUEUE(3, printk("exit_sd: exiting sd driver\n"));
unregister_reboot_notifier(&sd_notifier_block);
scsi_unregister_device(&sd_template);
for (i = 0; i < SD_MAJORS; i++)
unregister_blkdev(sd_major(i), "sd");
}
/*
* XXX: this function does not take sd_devlist_lock to synchronize
* access to sd_devlist. This should be safe as no other reboot
* notifier can access it.
*/
static int sd_notifier(struct notifier_block *n, unsigned long event, void *p)
{
if (event != SYS_RESTART &&
event != SYS_HALT &&
event != SYS_POWER_OFF)
return NOTIFY_DONE;
if (!list_empty(&sd_devlist)) {
struct scsi_disk *sdkp;
printk(KERN_NOTICE "Synchronizing SCSI caches: ");
list_for_each_entry(sdkp, &sd_devlist, list)
if (sdkp->WCE)
sd_synchronize_cache(sdkp, 1);
printk("\n");
}
return NOTIFY_OK;
}
/* send a SYNCHRONIZE CACHE instruction down to the device through the
* normal SCSI command structure. Wait for the command to complete (must
* have user context) */
static int sd_synchronize_cache(struct scsi_disk *sdkp, int verbose)
{
struct scsi_request *SRpnt;
struct scsi_device *SDpnt = sdkp->device;
int retries, the_result;
if (!SDpnt->online)
return 0;
if (verbose)
printk("%s ", sdkp->disk->disk_name);
SRpnt = scsi_allocate_request(SDpnt);
if(!SRpnt) {
if(verbose)
printk("FAILED\n No memory for request\n");
return 0;
}
for(retries = 3; retries > 0; --retries) {
unsigned char cmd[10] = { 0 };
cmd[0] = SYNCHRONIZE_CACHE;
/* leave the rest of the command zero to indicate
* flush everything */
scsi_wait_req(SRpnt, (void *)cmd, NULL, 0,
SD_TIMEOUT, SD_MAX_RETRIES);
if(SRpnt->sr_result == 0)
break;
}
the_result = SRpnt->sr_result;
if(verbose) {
if(the_result != 0) {
printk("FAILED\n status = %x, message = %02x, host = %d, driver = %02x\n ",
status_byte(the_result),
msg_byte(the_result),
host_byte(the_result),
driver_byte(the_result));
if (driver_byte(the_result) & DRIVER_SENSE)
print_req_sense("sd", SRpnt);
}
}
scsi_release_request(SRpnt);
return (the_result == 0);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Eric Youngdale");
MODULE_DESCRIPTION("SCSI disk (sd) driver");
module_init(init_sd);
module_exit(exit_sd);