osst.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,984 行 · 第 1/5 页

/*
  SCSI Tape Driver for Linux version 1.1 and newer. See the accompanying
  file Documentation/scsi/st.txt for more information.

  History:

  OnStream SCSI Tape support (osst) cloned from st.c by
  Willem Riede ([e-mail]) Feb 2000
  Fixes ... Kurt Garloff <[e-mail]> Mar 2000

  Rewritten from Dwayne Forsyth's SCSI tape driver by Kai Makisara.
  Contribution and ideas from several people including (in alphabetical
  order) Klaus Ehrenfried, Wolfgang Denk, Steve Hirsch, Andreas Koppenh"ofer,
  Michael Leodolter, Eyal Lebedinsky, J"org Weule, and Eric Youngdale.

  Copyright 1992 - 2002 Kai Makisara / Willem Riede
	 email [e-mail] / [e-mail]

  $Header: /cvsroot/osst/Driver/osst.c,v 1.70 2003/12/23 14:22:12 wriede Exp $

  Microscopic alterations - Rik Ling, 2000/12/21
  Last st.c sync: Tue Oct 15 22:01:04 2002 by makisara
  Some small formal changes - aeb, 950809
*/

static const char * cvsid = "$Id: osst.c,v 1.70 2003/12/23 14:22:12 wriede Exp $";
const char * osst_version = "0.99.1";

/* The "failure to reconnect" firmware bug */
#define OSST_FW_NEED_POLL_MIN 10601 /*(107A)*/
#define OSST_FW_NEED_POLL_MAX 10704 /*(108D)*/
#define OSST_FW_NEED_POLL(x,d) ((x) >= OSST_FW_NEED_POLL_MIN && (x) <= OSST_FW_NEED_POLL_MAX && d->host->this_id != 7)

#include <linux/module.h>

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/mtio.h>
#include <linux/ioctl.h>
#include <linux/fcntl.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/blkdev.h>
#include <linux/devfs_fs_kernel.h>
#include <asm/uaccess.h>
#include <asm/dma.h>
#include <asm/system.h>

/* The driver prints some debugging information on the console if DEBUG
   is defined and non-zero. */
#define DEBUG 0

/* The message level for the debug messages is currently set to KERN_NOTICE
   so that people can easily see the messages. Later when the debugging messages
   in the drivers are more widely classified, this may be changed to KERN_DEBUG. */
#define OSST_DEB_MSG  KERN_NOTICE

#include "scsi.h"
#include <scsi/scsi_host.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_ioctl.h>

#define ST_KILOBYTE 1024

#include "st.h"
#include "osst.h"
#include "osst_options.h"
#include "osst_detect.h"

static int max_dev = 0;
static int write_threshold_kbs = 0;
static int max_sg_segs = 0;

#ifdef MODULE
MODULE_AUTHOR("Willem Riede");
MODULE_DESCRIPTION("OnStream {DI-|FW-|SC-|USB}{30|50} Tape Driver");
MODULE_LICENSE("GPL");

MODULE_PARM(max_dev, "i");
MODULE_PARM_DESC(max_dev, "Maximum number of OnStream Tape Drives to attach (4)");

MODULE_PARM(write_threshold_kbs, "i");
MODULE_PARM_DESC(write_threshold_kbs, "Asynchronous write threshold (KB; 32)");

MODULE_PARM(max_sg_segs, "i");
MODULE_PARM_DESC(max_sg_segs, "Maximum number of scatter/gather segments to use (9)");
#else
static struct osst_dev_parm {
       char   *name;
       int    *val;
} parms[] __initdata = {
       { "max_dev",             &max_dev             },
       { "write_threshold_kbs", &write_threshold_kbs },
       { "max_sg_segs",         &max_sg_segs         }
};
#endif

static char *osst_formats[ST_NBR_MODES] ={"", "l", "m", "a"};

/* Some default definitions have been moved to osst_options.h */
#define OSST_BUFFER_SIZE (OSST_BUFFER_BLOCKS * ST_KILOBYTE)
#define OSST_WRITE_THRESHOLD (OSST_WRITE_THRESHOLD_BLOCKS * ST_KILOBYTE)

/* The buffer size should fit into the 24 bits for length in the
   6-byte SCSI read and write commands. */
#if OSST_BUFFER_SIZE >= (2 << 24 - 1)
#error "Buffer size should not exceed (2 << 24 - 1) bytes!"
#endif

#if DEBUG
static int debugging = 1;
/* uncomment define below to test error recovery */
// #define OSST_INJECT_ERRORS 1 
#endif

#define MAX_RETRIES 2
#define MAX_READ_RETRIES 0
#define MAX_WRITE_RETRIES 0
#define MAX_READY_RETRIES 0
#define NO_TAPE  NOT_READY

#define OSST_WAIT_POSITION_COMPLETE   (HZ > 200 ? HZ / 200 : 1)
#define OSST_WAIT_WRITE_COMPLETE      (HZ / 12)
#define OSST_WAIT_LONG_WRITE_COMPLETE (HZ / 2)
	
#define OSST_TIMEOUT (200 * HZ)
#define OSST_LONG_TIMEOUT (1800 * HZ)

#define TAPE_NR(x) (iminor(x) & ~(-1 << ST_MODE_SHIFT))
#define TAPE_MODE(x) ((iminor(x) & ST_MODE_MASK) >> ST_MODE_SHIFT)
#define TAPE_REWIND(x) ((iminor(x) & 0x80) == 0)
#define TAPE_IS_RAW(x) (TAPE_MODE(x) & (ST_NBR_MODES >> 1))

/* Internal ioctl to set both density (uppermost 8 bits) and blocksize (lower
   24 bits) */
#define SET_DENS_AND_BLK 0x10001

static int osst_buffer_size       = OSST_BUFFER_SIZE;
static int osst_write_threshold   = OSST_WRITE_THRESHOLD;
static int osst_max_sg_segs       = OSST_MAX_SG;
static int osst_max_dev           = OSST_MAX_TAPES;
static int osst_nr_dev;

static OS_Scsi_Tape **os_scsi_tapes = NULL;
static rwlock_t  os_scsi_tapes_lock = RW_LOCK_UNLOCKED;

static int modes_defined = FALSE;

static OSST_buffer *new_tape_buffer(int, int, int);
static int enlarge_buffer(OSST_buffer *, int);
static void normalize_buffer(OSST_buffer *);
static int append_to_buffer(const char __user *, OSST_buffer *, int);
static int from_buffer(OSST_buffer *, char __user *, int);
static int osst_zero_buffer_tail(OSST_buffer *);
static int osst_copy_to_buffer(OSST_buffer *, unsigned char *);
static int osst_copy_from_buffer(OSST_buffer *, unsigned char *);

static int osst_probe(struct device *);
static int osst_remove(struct device *);

struct scsi_driver osst_template = {
	.owner			= THIS_MODULE,
	.gendrv = {
		.name		=  "osst",
		.probe		= osst_probe,
		.remove		= osst_remove,
	}
};

static int osst_int_ioctl(OS_Scsi_Tape *STp, Scsi_Request ** aSRpnt, unsigned int cmd_in,unsigned long arg);

static int osst_set_frame_position(OS_Scsi_Tape *STp, Scsi_Request ** aSRpnt, int frame, int skip);

static int osst_get_frame_position(OS_Scsi_Tape *STp, Scsi_Request ** aSRpnt);

static int osst_flush_write_buffer(OS_Scsi_Tape *STp, Scsi_Request ** aSRpnt);

static int osst_write_error_recovery(OS_Scsi_Tape * STp, Scsi_Request ** aSRpnt, int pending);

static inline char *tape_name(OS_Scsi_Tape *tape)
{
	return tape->drive->disk_name;
}

/* Routines that handle the interaction with mid-layer SCSI routines */

/* Convert the result to success code */
static int osst_chk_result(OS_Scsi_Tape * STp, Scsi_Request * SRpnt)
{
	char *name = tape_name(STp);
	int result = SRpnt->sr_result;
	unsigned char * sense = SRpnt->sr_sense_buffer, scode;
#if DEBUG
	const char *stp;
#endif

	if (!result) {
		sense[0] = 0;    /* We don't have sense data if this byte is zero */
		return 0;
	}
	if ((driver_byte(result) & DRIVER_MASK) == DRIVER_SENSE)
		scode = sense[2] & 0x0f;
	else {
		sense[0] = 0;    /* We don't have sense data if this byte is zero */
		scode = 0;
	}
#if DEBUG
	if (debugging) {
		printk(OSST_DEB_MSG "%s:D: Error: %x, cmd: %x %x %x %x %x %x Len: %d\n",
		   name, result,
		   SRpnt->sr_cmnd[0], SRpnt->sr_cmnd[1], SRpnt->sr_cmnd[2],
		   SRpnt->sr_cmnd[3], SRpnt->sr_cmnd[4], SRpnt->sr_cmnd[5],
		   SRpnt->sr_bufflen);
		if (scode) printk(OSST_DEB_MSG "%s:D: Sense: %02x, ASC: %02x, ASCQ: %02x\n",
			       	name, scode, sense[12], sense[13]);
		if (driver_byte(result) & DRIVER_SENSE)
			print_req_sense("osst ", SRpnt);
	}
//	else
#endif
	if (!(driver_byte(result) & DRIVER_SENSE) ||
		((sense[0] & 0x70) == 0x70 &&
		 scode != NO_SENSE &&
		 scode != RECOVERED_ERROR &&
/*      	 scode != UNIT_ATTENTION && */
		 scode != BLANK_CHECK &&
		 scode != VOLUME_OVERFLOW &&
		 SRpnt->sr_cmnd[0] != MODE_SENSE &&
		 SRpnt->sr_cmnd[0] != TEST_UNIT_READY)) { /* Abnormal conditions for tape */
		if (driver_byte(result) & DRIVER_SENSE) {
			printk(KERN_WARNING "%s:W: Command with sense data: ", name);
			print_req_sense("osst:", SRpnt);
		}
		else {
			static	int	notyetprinted = 1;

			printk(KERN_WARNING
			     "%s:W: Warning %x (sugg. bt 0x%x, driver bt 0x%x, host bt 0x%x).\n",
			     name, result, suggestion(result), driver_byte(result) & DRIVER_MASK,
			     host_byte(result));
			if (notyetprinted) {
				notyetprinted = 0;
				printk(KERN_INFO
					"%s:I: This warning may be caused by your scsi controller,\n", name);
				printk(KERN_INFO
					"%s:I: it has been reported with some Buslogic cards.\n", name);
			}
		}
	}
	STp->pos_unknown |= STp->device->was_reset;

	if ((sense[0] & 0x70) == 0x70 &&
	     scode == RECOVERED_ERROR) {
		STp->recover_count++;
		STp->recover_erreg++;
#if DEBUG
		if (debugging) {
			if (SRpnt->sr_cmnd[0] == READ_6)
				stp = "read";
			else if (SRpnt->sr_cmnd[0] == WRITE_6)
				stp = "write";
			else
				stp = "ioctl";
			printk(OSST_DEB_MSG "%s:D: Recovered %s error (%d).\n", name, stp,
					     STp->recover_count);
		}
#endif
		if ((sense[2] & 0xe0) == 0)
			return 0;
	}
	return (-EIO);
}


/* Wakeup from interrupt */
static void osst_sleep_done (Scsi_Cmnd * SCpnt)
{
	OS_Scsi_Tape * STp = container_of(SCpnt->request->rq_disk->private_data, OS_Scsi_Tape, driver);

	if ((STp->buffer)->writing &&
	    (SCpnt->sense_buffer[0] & 0x70) == 0x70 &&
	    (SCpnt->sense_buffer[2] & 0x40)) {
		/* EOM at write-behind, has all been written? */
		if ((SCpnt->sense_buffer[2] & 0x0f) == VOLUME_OVERFLOW)
			STp->buffer->midlevel_result = SCpnt->result; /* Error */
		else
			STp->buffer->midlevel_result = INT_MAX;       /* OK */
	}
	else
		STp->buffer->midlevel_result = SCpnt->result;
	SCpnt->request->rq_status = RQ_SCSI_DONE;
	STp->buffer->last_SRpnt = SCpnt->sc_request;

#if DEBUG
	STp->write_pending = 0;
#endif
	complete(SCpnt->request->waiting);
}


/* Do the scsi command. Waits until command performed if do_wait is true.
   Otherwise osst_write_behind_check() is used to check that the command
   has finished. */
static	Scsi_Request * osst_do_scsi(Scsi_Request *SRpnt, OS_Scsi_Tape *STp, 
	unsigned char *cmd, int bytes, int direction, int timeout, int retries, int do_wait)
{
	unsigned char *bp;
#ifdef OSST_INJECT_ERRORS
	static   int   inject = 0;
	static   int   repeat = 0;
#endif
	if (SRpnt == NULL) {
		if ((SRpnt = scsi_allocate_request(STp->device, GFP_ATOMIC)) == NULL) {
			printk(KERN_ERR "%s:E: Can't get SCSI request.\n", tape_name(STp));
			if (signal_pending(current))
				(STp->buffer)->syscall_result = (-EINTR);
			else
				(STp->buffer)->syscall_result = (-EBUSY);
			return NULL;
		}
	}

        init_completion(&STp->wait);
	SRpnt->sr_use_sg = (bytes > (STp->buffer)->sg[0].length) ?
				    (STp->buffer)->use_sg : 0;
	if (SRpnt->sr_use_sg) {
		bp = (char *)&(STp->buffer->sg[0]);
		if (STp->buffer->sg_segs < SRpnt->sr_use_sg)
			SRpnt->sr_use_sg = STp->buffer->sg_segs;
	}
	else
		bp = (STp->buffer)->b_data;
	SRpnt->sr_data_direction = direction;
	SRpnt->sr_cmd_len = 0;
	SRpnt->sr_request->waiting = &(STp->wait);
	SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
	SRpnt->sr_request->rq_disk = STp->drive;

	scsi_do_req(SRpnt, (void *)cmd, bp, bytes, osst_sleep_done, timeout, retries);

	if (do_wait) {
		wait_for_completion(SRpnt->sr_request->waiting);
		SRpnt->sr_request->waiting = NULL;
		STp->buffer->syscall_result = osst_chk_result(STp, SRpnt);
#ifdef OSST_INJECT_ERRORS
		if (STp->buffer->syscall_result == 0 &&
		    cmd[0] == READ_6 &&
		    cmd[4] && 
		    ( (++ inject % 83) == 29  ||
		      (STp->first_frame_position == 240 
			         /* or STp->read_error_frame to fail again on the block calculated above */ &&
				 ++repeat < 3))) {
			printk(OSST_DEB_MSG "%s:D: Injecting read error\n", tape_name(STp));
			STp->buffer->last_result_fatal = 1;
		}
#endif
	}
	return SRpnt;
}


/* Handle the write-behind checking (downs the semaphore) */
static void osst_write_behind_check(OS_Scsi_Tape *STp)
{
	OSST_buffer * STbuffer;

	STbuffer = STp->buffer;

#if DEBUG
	if (STp->write_pending)
		STp->nbr_waits++;
	else
		STp->nbr_finished++;
#endif
	wait_for_completion(&(STp->wait));
	(STp->buffer)->last_SRpnt->sr_request->waiting = NULL;

	STp->buffer->syscall_result = osst_chk_result(STp, STp->buffer->last_SRpnt);

	if ((STp->buffer)->syscall_result)
		(STp->buffer)->syscall_result =
			osst_write_error_recovery(STp, &((STp->buffer)->last_SRpnt), 1);
	else
		STp->first_frame_position++;

	scsi_release_request((STp->buffer)->last_SRpnt);

	if (STbuffer->writing < STbuffer->buffer_bytes)
		printk(KERN_WARNING "osst :A: write_behind_check: something left in buffer!\n");

	STbuffer->buffer_bytes -= STbuffer->writing;
	STbuffer->writing = 0;