Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 950 insertions, 0 deletions

diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
new file mode 100644
index 0000000..202a5a7
--- /dev/null
+++ b/drivers/block/paride/pd.c
@@ -0,0 +1,950 @@
+/* 
+        pd.c    (c) 1997-8  Grant R. Guenther <grant@torque.net>
+                            Under the terms of the GNU General Public License.
+
+        This is the high-level driver for parallel port IDE hard
+        drives based on chips supported by the paride module.
+
+	By default, the driver will autoprobe for a single parallel
+	port IDE drive, but if their individual parameters are
+        specified, the driver can handle up to 4 drives.
+
+        The behaviour of the pd driver can be altered by setting
+        some parameters from the insmod command line.  The following
+        parameters are adjustable:
+ 
+	    drive0  	These four arguments can be arrays of	    
+	    drive1	1-8 integers as follows:
+	    drive2
+	    drive3	<prt>,<pro>,<uni>,<mod>,<geo>,<sby>,<dly>,<slv>
+
+			Where,
+
+		<prt>	is the base of the parallel port address for
+			the corresponding drive.  (required)
+
+		<pro>   is the protocol number for the adapter that
+			supports this drive.  These numbers are
+                        logged by 'paride' when the protocol modules
+			are initialised.  (0 if not given)
+
+		<uni>   for those adapters that support chained
+			devices, this is the unit selector for the
+		        chain of devices on the given port.  It should
+			be zero for devices that don't support chaining.
+			(0 if not given)
+
+		<mod>   this can be -1 to choose the best mode, or one
+		        of the mode numbers supported by the adapter.
+			(-1 if not given)
+
+		<geo>   this defaults to 0 to indicate that the driver
+			should use the CHS geometry provided by the drive
+			itself.  If set to 1, the driver will provide
+			a logical geometry with 64 heads and 32 sectors
+			per track, to be consistent with most SCSI
+		        drivers.  (0 if not given)
+
+		<sby>   set this to zero to disable the power saving
+			standby mode, if needed.  (1 if not given)
+
+		<dly>   some parallel ports require the driver to 
+			go more slowly.  -1 sets a default value that
+			should work with the chosen protocol.  Otherwise,
+			set this to a small integer, the larger it is
+			the slower the port i/o.  In some cases, setting
+			this to zero will speed up the device. (default -1)
+
+		<slv>   IDE disks can be jumpered to master or slave.
+                        Set this to 0 to choose the master drive, 1 to
+                        choose the slave, -1 (the default) to choose the
+                        first drive found.
+			
+
+            major       You may use this parameter to overide the
+                        default major number (45) that this driver
+                        will use.  Be sure to change the device
+                        name as well.
+
+            name        This parameter is a character string that
+                        contains the name the kernel will use for this
+                        device (in /proc output, for instance).
+			(default "pd")
+
+	    cluster	The driver will attempt to aggregate requests
+			for adjacent blocks into larger multi-block
+			clusters.  The maximum cluster size (in 512
+			byte sectors) is set with this parameter.
+			(default 64)
+
+	    verbose	This parameter controls the amount of logging
+			that the driver will do.  Set it to 0 for 
+			normal operation, 1 to see autoprobe progress
+			messages, or 2 to see additional debugging
+			output.  (default 0)
+
+            nice        This parameter controls the driver's use of
+                        idle CPU time, at the expense of some speed.
+
+        If this driver is built into the kernel, you can use kernel
+        the following command line parameters, with the same values
+        as the corresponding module parameters listed above:
+
+            pd.drive0
+            pd.drive1
+            pd.drive2
+            pd.drive3
+            pd.cluster
+            pd.nice
+
+        In addition, you can use the parameter pd.disable to disable
+        the driver entirely.
+ 
+*/
+
+/* Changes:
+
+	1.01	GRG 1997.01.24	Restored pd_reset()
+				Added eject ioctl
+	1.02    GRG 1998.05.06  SMP spinlock changes, 
+				Added slave support
+	1.03    GRG 1998.06.16  Eliminate an Ugh.
+	1.04	GRG 1998.08.15  Extra debugging, use HZ in loop timing
+	1.05    GRG 1998.09.24  Added jumbo support
+
+*/
+
+#define PD_VERSION      "1.05"
+#define PD_MAJOR	45
+#define PD_NAME		"pd"
+#define PD_UNITS	4
+
+/* Here are things one can override from the insmod command.
+   Most are autoprobed by paride unless set here.  Verbose is off
+   by default.
+
+*/
+
+static int verbose = 0;
+static int major = PD_MAJOR;
+static char *name = PD_NAME;
+static int cluster = 64;
+static int nice = 0;
+static int disable = 0;
+
+static int drive0[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
+static int drive1[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
+static int drive2[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
+static int drive3[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
+
+static int (*drives[4])[8] = {&drive0, &drive1, &drive2, &drive3};
+
+enum {D_PRT, D_PRO, D_UNI, D_MOD, D_GEO, D_SBY, D_DLY, D_SLV};
+
+/* end of parameters */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/hdreg.h>
+#include <linux/cdrom.h>	/* for the eject ioctl */
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <asm/uaccess.h>
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+
+static DEFINE_SPINLOCK(pd_lock);
+
+module_param(verbose, bool, 0);
+module_param(major, int, 0);
+module_param(name, charp, 0);
+module_param(cluster, int, 0);
+module_param(nice, int, 0);
+module_param_array(drive0, int, NULL, 0);
+module_param_array(drive1, int, NULL, 0);
+module_param_array(drive2, int, NULL, 0);
+module_param_array(drive3, int, NULL, 0);
+
+#include "paride.h"
+
+#define PD_BITS    4
+
+/* numbers for "SCSI" geometry */
+
+#define PD_LOG_HEADS    64
+#define PD_LOG_SECTS    32
+
+#define PD_ID_OFF       54
+#define PD_ID_LEN       14
+
+#define PD_MAX_RETRIES  5
+#define PD_TMO          800	/* interrupt timeout in jiffies */
+#define PD_SPIN_DEL     50	/* spin delay in micro-seconds  */
+
+#define PD_SPIN         (1000000*PD_TMO)/(HZ*PD_SPIN_DEL)
+
+#define STAT_ERR        0x00001
+#define STAT_INDEX      0x00002
+#define STAT_ECC        0x00004
+#define STAT_DRQ        0x00008
+#define STAT_SEEK       0x00010
+#define STAT_WRERR      0x00020
+#define STAT_READY      0x00040
+#define STAT_BUSY       0x00080
+
+#define ERR_AMNF        0x00100
+#define ERR_TK0NF       0x00200
+#define ERR_ABRT        0x00400
+#define ERR_MCR         0x00800
+#define ERR_IDNF        0x01000
+#define ERR_MC          0x02000
+#define ERR_UNC         0x04000
+#define ERR_TMO         0x10000
+
+#define IDE_READ        	0x20
+#define IDE_WRITE       	0x30
+#define IDE_READ_VRFY		0x40
+#define IDE_INIT_DEV_PARMS	0x91
+#define IDE_STANDBY     	0x96
+#define IDE_ACKCHANGE   	0xdb
+#define IDE_DOORLOCK    	0xde
+#define IDE_DOORUNLOCK  	0xdf
+#define IDE_IDENTIFY    	0xec
+#define IDE_EJECT		0xed
+
+#define PD_NAMELEN	8
+
+struct pd_unit {
+	struct pi_adapter pia;	/* interface to paride layer */
+	struct pi_adapter *pi;
+	int access;		/* count of active opens ... */
+	int capacity;		/* Size of this volume in sectors */
+	int heads;		/* physical geometry */
+	int sectors;
+	int cylinders;
+	int can_lba;
+	int drive;		/* master=0 slave=1 */
+	int changed;		/* Have we seen a disk change ? */
+	int removable;		/* removable media device  ?  */
+	int standby;
+	int alt_geom;
+	char name[PD_NAMELEN];	/* pda, pdb, etc ... */
+	struct gendisk *gd;
+};
+
+static struct pd_unit pd[PD_UNITS];
+
+static char pd_scratch[512];	/* scratch block buffer */
+
+static char *pd_errs[17] = { "ERR", "INDEX", "ECC", "DRQ", "SEEK", "WRERR",
+	"READY", "BUSY", "AMNF", "TK0NF", "ABRT", "MCR",
+	"IDNF", "MC", "UNC", "???", "TMO"
+};
+
+static inline int status_reg(struct pd_unit *disk)
+{
+	return pi_read_regr(disk->pi, 1, 6);
+}
+
+static inline int read_reg(struct pd_unit *disk, int reg)
+{
+	return pi_read_regr(disk->pi, 0, reg);
+}
+
+static inline void write_status(struct pd_unit *disk, int val)
+{
+	pi_write_regr(disk->pi, 1, 6, val);
+}
+
+static inline void write_reg(struct pd_unit *disk, int reg, int val)
+{
+	pi_write_regr(disk->pi, 0, reg, val);
+}
+
+static inline u8 DRIVE(struct pd_unit *disk)
+{
+	return 0xa0+0x10*disk->drive;
+}
+
+/*  ide command interface */
+
+static void pd_print_error(struct pd_unit *disk, char *msg, int status)
+{
+	int i;
+
+	printk("%s: %s: status = 0x%x =", disk->name, msg, status);
+	for (i = 0; i < 18; i++)
+		if (status & (1 << i))
+			printk(" %s", pd_errs[i]);
+	printk("\n");
+}
+
+static void pd_reset(struct pd_unit *disk)
+{				/* called only for MASTER drive */
+	write_status(disk, 4);
+	udelay(50);
+	write_status(disk, 0);
+	udelay(250);
+}
+
+#define DBMSG(msg)	((verbose>1)?(msg):NULL)
+
+static int pd_wait_for(struct pd_unit *disk, int w, char *msg)
+{				/* polled wait */
+	int k, r, e;
+
+	k = 0;
+	while (k < PD_SPIN) {
+		r = status_reg(disk);
+		k++;
+		if (((r & w) == w) && !(r & STAT_BUSY))
+			break;
+		udelay(PD_SPIN_DEL);
+	}
+	e = (read_reg(disk, 1) << 8) + read_reg(disk, 7);
+	if (k >= PD_SPIN)
+		e |= ERR_TMO;
+	if ((e & (STAT_ERR | ERR_TMO)) && (msg != NULL))
+		pd_print_error(disk, msg, e);
+	return e;
+}
+
+static void pd_send_command(struct pd_unit *disk, int n, int s, int h, int c0, int c1, int func)
+{
+	write_reg(disk, 6, DRIVE(disk) + h);
+	write_reg(disk, 1, 0);		/* the IDE task file */
+	write_reg(disk, 2, n);
+	write_reg(disk, 3, s);
+	write_reg(disk, 4, c0);
+	write_reg(disk, 5, c1);
+	write_reg(disk, 7, func);
+
+	udelay(1);
+}
+
+static void pd_ide_command(struct pd_unit *disk, int func, int block, int count)
+{
+	int c1, c0, h, s;
+
+	if (disk->can_lba) {
+		s = block & 255;
+		c0 = (block >>= 8) & 255;
+		c1 = (block >>= 8) & 255;
+		h = ((block >>= 8) & 15) + 0x40;
+	} else {
+		s = (block % disk->sectors) + 1;
+		h = (block /= disk->sectors) % disk->heads;
+		c0 = (block /= disk->heads) % 256;
+		c1 = (block >>= 8);
+	}
+	pd_send_command(disk, count, s, h, c0, c1, func);
+}
+
+/* The i/o request engine */
+
+enum action {Fail = 0, Ok = 1, Hold, Wait};
+
+static struct request *pd_req;	/* current request */
+static enum action (*phase)(void);
+
+static void run_fsm(void);
+
+static void ps_tq_int( void *data);
+
+static DECLARE_WORK(fsm_tq, ps_tq_int, NULL);
+
+static void schedule_fsm(void)
+{
+	if (!nice)
+		schedule_work(&fsm_tq);
+	else
+		schedule_delayed_work(&fsm_tq, nice-1);
+}
+
+static void ps_tq_int(void *data)
+{
+	run_fsm();
+}
+
+static enum action do_pd_io_start(void);
+static enum action pd_special(void);
+static enum action do_pd_read_start(void);
+static enum action do_pd_write_start(void);
+static enum action do_pd_read_drq(void);
+static enum action do_pd_write_done(void);
+
+static struct request_queue *pd_queue;
+static int pd_claimed;
+
+static struct pd_unit *pd_current; /* current request's drive */
+static PIA *pi_current; /* current request's PIA */
+
+static void run_fsm(void)
+{
+	while (1) {
+		enum action res;
+		unsigned long saved_flags;
+		int stop = 0;
+
+		if (!phase) {
+			pd_current = pd_req->rq_disk->private_data;
+			pi_current = pd_current->pi;
+			phase = do_pd_io_start;
+		}
+
+		switch (pd_claimed) {
+			case 0:
+				pd_claimed = 1;
+				if (!pi_schedule_claimed(pi_current, run_fsm))
+					return;
+			case 1:
+				pd_claimed = 2;
+				pi_current->proto->connect(pi_current);
+		}
+
+		switch(res = phase()) {
+			case Ok: case Fail:
+				pi_disconnect(pi_current);
+				pd_claimed = 0;
+				phase = NULL;
+				spin_lock_irqsave(&pd_lock, saved_flags);
+				end_request(pd_req, res);
+				pd_req = elv_next_request(pd_queue);
+				if (!pd_req)
+					stop = 1;
+				spin_unlock_irqrestore(&pd_lock, saved_flags);
+				if (stop)
+					return;
+			case Hold:
+				schedule_fsm();
+				return;
+			case Wait:
+				pi_disconnect(pi_current);
+				pd_claimed = 0;
+		}
+	}
+}
+
+static int pd_retries = 0;	/* i/o error retry count */
+static int pd_block;		/* address of next requested block */
+static int pd_count;		/* number of blocks still to do */
+static int pd_run;		/* sectors in current cluster */
+static int pd_cmd;		/* current command READ/WRITE */
+static char *pd_buf;		/* buffer for request in progress */
+
+static enum action do_pd_io_start(void)
+{
+	if (pd_req->flags & REQ_SPECIAL) {
+		phase = pd_special;
+		return pd_special();
+	}
+
+	pd_cmd = rq_data_dir(pd_req);
+	if (pd_cmd == READ || pd_cmd == WRITE) {
+		pd_block = pd_req->sector;
+		pd_count = pd_req->current_nr_sectors;
+		if (pd_block + pd_count > get_capacity(pd_req->rq_disk))
+			return Fail;
+		pd_run = pd_req->nr_sectors;
+		pd_buf = pd_req->buffer;
+		pd_retries = 0;
+		if (pd_cmd == READ)
+			return do_pd_read_start();
+		else
+			return do_pd_write_start();
+	}
+	return Fail;
+}
+
+static enum action pd_special(void)
+{
+	enum action (*func)(struct pd_unit *) = pd_req->special;
+	return func(pd_current);
+}
+
+static int pd_next_buf(void)
+{
+	unsigned long saved_flags;
+
+	pd_count--;
+	pd_run--;
+	pd_buf += 512;
+	pd_block++;
+	if (!pd_run)
+		return 1;
+	if (pd_count)
+		return 0;
+	spin_lock_irqsave(&pd_lock, saved_flags);
+	end_request(pd_req, 1);
+	pd_count = pd_req->current_nr_sectors;
+	pd_buf = pd_req->buffer;
+	spin_unlock_irqrestore(&pd_lock, saved_flags);
+	return 0;
+}
+
+static unsigned long pd_timeout;
+
+static enum action do_pd_read_start(void)
+{
+	if (pd_wait_for(pd_current, STAT_READY, "do_pd_read") & STAT_ERR) {
+		if (pd_retries < PD_MAX_RETRIES) {
+			pd_retries++;
+			return Wait;
+		}
+		return Fail;
+	}
+	pd_ide_command(pd_current, IDE_READ, pd_block, pd_run);
+	phase = do_pd_read_drq;
+	pd_timeout = jiffies + PD_TMO;
+	return Hold;
+}
+
+static enum action do_pd_write_start(void)
+{
+	if (pd_wait_for(pd_current, STAT_READY, "do_pd_write") & STAT_ERR) {
+		if (pd_retries < PD_MAX_RETRIES) {
+			pd_retries++;
+			return Wait;
+		}
+		return Fail;
+	}
+	pd_ide_command(pd_current, IDE_WRITE, pd_block, pd_run);
+	while (1) {
+		if (pd_wait_for(pd_current, STAT_DRQ, "do_pd_write_drq") & STAT_ERR) {
+			if (pd_retries < PD_MAX_RETRIES) {
+				pd_retries++;
+				return Wait;
+			}
+			return Fail;
+		}
+		pi_write_block(pd_current->pi, pd_buf, 512);
+		if (pd_next_buf())
+			break;
+	}
+	phase = do_pd_write_done;
+	pd_timeout = jiffies + PD_TMO;
+	return Hold;
+}
+
+static inline int pd_ready(void)
+{
+	return !(status_reg(pd_current) & STAT_BUSY);
+}
+
+static enum action do_pd_read_drq(void)
+{
+	if (!pd_ready() && !time_after_eq(jiffies, pd_timeout))
+		return Hold;
+
+	while (1) {
+		if (pd_wait_for(pd_current, STAT_DRQ, "do_pd_read_drq") & STAT_ERR) {
+			if (pd_retries < PD_MAX_RETRIES) {
+				pd_retries++;
+				phase = do_pd_read_start;
+				return Wait;
+			}
+			return Fail;
+		}
+		pi_read_block(pd_current->pi, pd_buf, 512);
+		if (pd_next_buf())
+			break;
+	}
+	return Ok;
+}
+
+static enum action do_pd_write_done(void)
+{
+	if (!pd_ready() && !time_after_eq(jiffies, pd_timeout))
+		return Hold;
+
+	if (pd_wait_for(pd_current, STAT_READY, "do_pd_write_done") & STAT_ERR) {
+		if (pd_retries < PD_MAX_RETRIES) {
+			pd_retries++;
+			phase = do_pd_write_start;
+			return Wait;
+		}
+		return Fail;
+	}
+	return Ok;
+}
+
+/* special io requests */
+
+/* According to the ATA standard, the default CHS geometry should be
+   available following a reset.  Some Western Digital drives come up
+   in a mode where only LBA addresses are accepted until the device
+   parameters are initialised.
+*/
+
+static void pd_init_dev_parms(struct pd_unit *disk)
+{
+	pd_wait_for(disk, 0, DBMSG("before init_dev_parms"));
+	pd_send_command(disk, disk->sectors, 0, disk->heads - 1, 0, 0,
+			IDE_INIT_DEV_PARMS);
+	udelay(300);
+	pd_wait_for(disk, 0, "Initialise device parameters");
+}
+
+static enum action pd_door_lock(struct pd_unit *disk)
+{
+	if (!(pd_wait_for(disk, STAT_READY, "Lock") & STAT_ERR)) {
+		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORLOCK);
+		pd_wait_for(disk, STAT_READY, "Lock done");
+	}
+	return Ok;
+}
+
+static enum action pd_door_unlock(struct pd_unit *disk)
+{
+	if (!(pd_wait_for(disk, STAT_READY, "Lock") & STAT_ERR)) {
+		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORUNLOCK);
+		pd_wait_for(disk, STAT_READY, "Lock done");
+	}
+	return Ok;
+}
+
+static enum action pd_eject(struct pd_unit *disk)
+{
+	pd_wait_for(disk, 0, DBMSG("before unlock on eject"));
+	pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORUNLOCK);
+	pd_wait_for(disk, 0, DBMSG("after unlock on eject"));
+	pd_wait_for(disk, 0, DBMSG("before eject"));
+	pd_send_command(disk, 0, 0, 0, 0, 0, IDE_EJECT);
+	pd_wait_for(disk, 0, DBMSG("after eject"));
+	return Ok;
+}
+
+static enum action pd_media_check(struct pd_unit *disk)
+{
+	int r = pd_wait_for(disk, STAT_READY, DBMSG("before media_check"));
+	if (!(r & STAT_ERR)) {
+		pd_send_command(disk, 1, 1, 0, 0, 0, IDE_READ_VRFY);
+		r = pd_wait_for(disk, STAT_READY, DBMSG("RDY after READ_VRFY"));
+	} else
+		disk->changed = 1;	/* say changed if other error */
+	if (r & ERR_MC) {
+		disk->changed = 1;
+		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_ACKCHANGE);
+		pd_wait_for(disk, STAT_READY, DBMSG("RDY after ACKCHANGE"));
+		pd_send_command(disk, 1, 1, 0, 0, 0, IDE_READ_VRFY);
+		r = pd_wait_for(disk, STAT_READY, DBMSG("RDY after VRFY"));
+	}
+	return Ok;
+}
+
+static void pd_standby_off(struct pd_unit *disk)
+{
+	pd_wait_for(disk, 0, DBMSG("before STANDBY"));
+	pd_send_command(disk, 0, 0, 0, 0, 0, IDE_STANDBY);
+	pd_wait_for(disk, 0, DBMSG("after STANDBY"));
+}
+
+static enum action pd_identify(struct pd_unit *disk)
+{
+	int j;
+	char id[PD_ID_LEN + 1];
+
+/* WARNING:  here there may be dragons.  reset() applies to both drives,
+   but we call it only on probing the MASTER. This should allow most
+   common configurations to work, but be warned that a reset can clear
+   settings on the SLAVE drive.
+*/
+
+	if (disk->drive == 0)
+		pd_reset(disk);
+
+	write_reg(disk, 6, DRIVE(disk));
+	pd_wait_for(disk, 0, DBMSG("before IDENT"));
+	pd_send_command(disk, 1, 0, 0, 0, 0, IDE_IDENTIFY);
+
+	if (pd_wait_for(disk, STAT_DRQ, DBMSG("IDENT DRQ")) & STAT_ERR)
+		return Fail;
+	pi_read_block(disk->pi, pd_scratch, 512);
+	disk->can_lba = pd_scratch[99] & 2;
+	disk->sectors = le16_to_cpu(*(u16 *) (pd_scratch + 12));
+	disk->heads = le16_to_cpu(*(u16 *) (pd_scratch + 6));
+	disk->cylinders = le16_to_cpu(*(u16 *) (pd_scratch + 2));
+	if (disk->can_lba)
+		disk->capacity = le32_to_cpu(*(u32 *) (pd_scratch + 120));
+	else
+		disk->capacity = disk->sectors * disk->heads * disk->cylinders;
+
+	for (j = 0; j < PD_ID_LEN; j++)
+		id[j ^ 1] = pd_scratch[j + PD_ID_OFF];
+	j = PD_ID_LEN - 1;
+	while ((j >= 0) && (id[j] <= 0x20))
+		j--;
+	j++;
+	id[j] = 0;
+
+	disk->removable = pd_scratch[0] & 0x80;
+
+	printk("%s: %s, %s, %d blocks [%dM], (%d/%d/%d), %s media\n",
+	       disk->name, id,
+	       disk->drive ? "slave" : "master",
+	       disk->capacity, disk->capacity / 2048,
+	       disk->cylinders, disk->heads, disk->sectors,
+	       disk->removable ? "removable" : "fixed");
+
+	if (disk->capacity)
+		pd_init_dev_parms(disk);
+	if (!disk->standby)
+		pd_standby_off(disk);
+
+	return Ok;
+}
+
+/* end of io request engine */
+
+static void do_pd_request(request_queue_t * q)
+{
+	if (pd_req)
+		return;
+	pd_req = elv_next_request(q);
+	if (!pd_req)
+		return;
+
+	schedule_fsm();
+}
+
+static int pd_special_command(struct pd_unit *disk,
+		      enum action (*func)(struct pd_unit *disk))
+{
+	DECLARE_COMPLETION(wait);
+	struct request rq;
+	int err = 0;
+
+	memset(&rq, 0, sizeof(rq));
+	rq.errors = 0;
+	rq.rq_status = RQ_ACTIVE;
+	rq.rq_disk = disk->gd;
+	rq.ref_count = 1;
+	rq.waiting = &wait;
+	rq.end_io = blk_end_sync_rq;
+	blk_insert_request(disk->gd->queue, &rq, 0, func, 0);
+	wait_for_completion(&wait);
+	rq.waiting = NULL;
+	if (rq.errors)
+		err = -EIO;
+	blk_put_request(&rq);
+	return err;
+}
+
+/* kernel glue structures */
+
+static int pd_open(struct inode *inode, struct file *file)
+{
+	struct pd_unit *disk = inode->i_bdev->bd_disk->private_data;
+
+	disk->access++;
+
+	if (disk->removable) {
+		pd_special_command(disk, pd_media_check);
+		pd_special_command(disk, pd_door_lock);
+	}
+	return 0;
+}
+
+static int pd_ioctl(struct inode *inode, struct file *file,
+	 unsigned int cmd, unsigned long arg)
+{
+	struct pd_unit *disk = inode->i_bdev->bd_disk->private_data;
+	struct hd_geometry __user *geo = (struct hd_geometry __user *) arg;
+	struct hd_geometry g;
+
+	switch (cmd) {
+	case CDROMEJECT:
+		if (disk->access == 1)
+			pd_special_command(disk, pd_eject);
+		return 0;
+	case HDIO_GETGEO:
+		if (disk->alt_geom) {
+			g.heads = PD_LOG_HEADS;
+			g.sectors = PD_LOG_SECTS;
+			g.cylinders = disk->capacity / (g.heads * g.sectors);
+		} else {
+			g.heads = disk->heads;
+			g.sectors = disk->sectors;
+			g.cylinders = disk->cylinders;
+		}
+		g.start = get_start_sect(inode->i_bdev);
+		if (copy_to_user(geo, &g, sizeof(struct hd_geometry)))
+			return -EFAULT;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int pd_release(struct inode *inode, struct file *file)
+{
+	struct pd_unit *disk = inode->i_bdev->bd_disk->private_data;
+
+	if (!--disk->access && disk->removable)
+		pd_special_command(disk, pd_door_unlock);
+
+	return 0;
+}
+
+static int pd_check_media(struct gendisk *p)
+{
+	struct pd_unit *disk = p->private_data;
+	int r;
+	if (!disk->removable)
+		return 0;
+	pd_special_command(disk, pd_media_check);
+	r = disk->changed;
+	disk->changed = 0;
+	return r;
+}
+
+static int pd_revalidate(struct gendisk *p)
+{
+	struct pd_unit *disk = p->private_data;
+	if (pd_special_command(disk, pd_identify) == 0)
+		set_capacity(p, disk->capacity);
+	else
+		set_capacity(p, 0);
+	return 0;
+}
+
+static struct block_device_operations pd_fops = {
+	.owner		= THIS_MODULE,
+	.open		= pd_open,
+	.release	= pd_release,
+	.ioctl		= pd_ioctl,
+	.media_changed	= pd_check_media,
+	.revalidate_disk= pd_revalidate
+};
+
+/* probing */
+
+static void pd_probe_drive(struct pd_unit *disk)
+{
+	struct gendisk *p = alloc_disk(1 << PD_BITS);
+	if (!p)
+		return;
+	strcpy(p->disk_name, disk->name);
+	p->fops = &pd_fops;
+	p->major = major;
+	p->first_minor = (disk - pd) << PD_BITS;
+	disk->gd = p;
+	p->private_data = disk;
+	p->queue = pd_queue;
+
+	if (disk->drive == -1) {
+		for (disk->drive = 0; disk->drive <= 1; disk->drive++)
+			if (pd_special_command(disk, pd_identify) == 0)
+				return;
+	} else if (pd_special_command(disk, pd_identify) == 0)
+		return;
+	disk->gd = NULL;
+	put_disk(p);
+}
+
+static int pd_detect(void)
+{
+	int found = 0, unit, pd_drive_count = 0;
+	struct pd_unit *disk;
+
+	for (unit = 0; unit < PD_UNITS; unit++) {
+		int *parm = *drives[unit];
+		struct pd_unit *disk = pd + unit;
+		disk->pi = &disk->pia;
+		disk->access = 0;
+		disk->changed = 1;
+		disk->capacity = 0;
+		disk->drive = parm[D_SLV];
+		snprintf(disk->name, PD_NAMELEN, "%s%c", name, 'a'+unit);
+		disk->alt_geom = parm[D_GEO];
+		disk->standby = parm[D_SBY];
+		if (parm[D_PRT])
+			pd_drive_count++;
+	}
+
+	if (pd_drive_count == 0) { /* nothing spec'd - so autoprobe for 1 */
+		disk = pd;
+		if (pi_init(disk->pi, 1, -1, -1, -1, -1, -1, pd_scratch,
+			    PI_PD, verbose, disk->name)) {
+			pd_probe_drive(disk);
+			if (!disk->gd)
+				pi_release(disk->pi);
+		}
+
+	} else {
+		for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
+			int *parm = *drives[unit];
+			if (!parm[D_PRT])
+				continue;
+			if (pi_init(disk->pi, 0, parm[D_PRT], parm[D_MOD],
+				     parm[D_UNI], parm[D_PRO], parm[D_DLY],
+				     pd_scratch, PI_PD, verbose, disk->name)) {
+				pd_probe_drive(disk);
+				if (!disk->gd)
+					pi_release(disk->pi);
+			}
+		}
+	}
+	for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
+		if (disk->gd) {
+			set_capacity(disk->gd, disk->capacity);
+			add_disk(disk->gd);
+			found = 1;
+		}
+	}
+	if (!found)
+		printk("%s: no valid drive found\n", name);
+	return found;
+}
+
+static int __init pd_init(void)
+{
+	if (disable)
+		goto out1;
+
+	pd_queue = blk_init_queue(do_pd_request, &pd_lock);
+	if (!pd_queue)
+		goto out1;
+
+	blk_queue_max_sectors(pd_queue, cluster);
+
+	if (register_blkdev(major, name))
+		goto out2;
+
+	printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
+	       name, name, PD_VERSION, major, cluster, nice);
+	if (!pd_detect())
+		goto out3;
+
+	return 0;
+
+out3:
+	unregister_blkdev(major, name);
+out2:
+	blk_cleanup_queue(pd_queue);
+out1:
+	return -ENODEV;
+}
+
+static void __exit pd_exit(void)
+{
+	struct pd_unit *disk;
+	int unit;
+	unregister_blkdev(major, name);
+	for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
+		struct gendisk *p = disk->gd;
+		if (p) {
+			disk->gd = NULL;
+			del_gendisk(p);
+			put_disk(p);
+			pi_release(disk->pi);
+		}
+	}
+	blk_cleanup_queue(pd_queue);
+}
+
+MODULE_LICENSE("GPL");
+module_init(pd_init)
+module_exit(pd_exit)