Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1057 insertions, 0 deletions

diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
new file mode 100644
index 000000000..eec1b9fde
--- /dev/null
+++ b/drivers/block/paride/pf.c
@@ -0,0 +1,1057 @@
+/* 
+        pf.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 ATAPI disk
+        drives based on chips supported by the paride module.
+
+        By default, the driver will autoprobe for a single parallel
+        port ATAPI disk drive, but if their individual parameters are
+        specified, the driver can handle up to 4 drives.
+
+        The behaviour of the pf 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      1-7 integers as follows:
+            drive2
+            drive3      <prt>,<pro>,<uni>,<mod>,<slv>,<lun>,<dly>
+
+                        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)
+
+                <slv>   ATAPI CDroms 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.
+
+		<lun>   Some ATAPI devices support multiple LUNs.
+                        One example is the ATAPI PD/CD drive from
+                        Matshita/Panasonic.  This device has a 
+                        CD drive on LUN 0 and a PD drive on LUN 1.
+                        By default, the driver will search for the
+                        first LUN with a supported device.  Set 
+                        this parameter to force it to use a specific
+                        LUN.  (default -1)
+
+                <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)
+
+	    major	You may use this parameter to override the
+			default major number (47) 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 "pf").
+
+            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 the
+        following command line parameters, with the same values
+        as the corresponding module parameters listed above:
+
+            pf.drive0
+            pf.drive1
+            pf.drive2
+            pf.drive3
+	    pf.cluster
+            pf.nice
+
+        In addition, you can use the parameter pf.disable to disable
+        the driver entirely.
+
+*/
+
+/* Changes:
+
+	1.01	GRG 1998.05.03  Changes for SMP.  Eliminate sti().
+				Fix for drives that don't clear STAT_ERR
+			        until after next CDB delivered.
+				Small change in pf_completion to round
+				up transfer size.
+	1.02    GRG 1998.06.16  Eliminated an Ugh
+	1.03    GRG 1998.08.16  Use HZ in loop timings, extra debugging
+	1.04    GRG 1998.09.24  Added jumbo support
+
+*/
+
+#define PF_VERSION      "1.04"
+#define PF_MAJOR	47
+#define PF_NAME		"pf"
+#define PF_UNITS	4
+
+#include <linux/types.h>
+
+/* Here are things one can override from the insmod command.
+   Most are autoprobed by paride unless set here.  Verbose is off
+   by default.
+
+*/
+
+static bool verbose = 0;
+static int major = PF_MAJOR;
+static char *name = PF_NAME;
+static int cluster = 64;
+static int nice = 0;
+static int disable = 0;
+
+static int drive0[7] = { 0, 0, 0, -1, -1, -1, -1 };
+static int drive1[7] = { 0, 0, 0, -1, -1, -1, -1 };
+static int drive2[7] = { 0, 0, 0, -1, -1, -1, -1 };
+static int drive3[7] = { 0, 0, 0, -1, -1, -1, -1 };
+
+static int (*drives[4])[7] = {&drive0, &drive1, &drive2, &drive3};
+static int pf_drive_count;
+
+enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_LUN, D_DLY};
+
+/* end of parameters */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/hdreg.h>
+#include <linux/cdrom.h>
+#include <linux/spinlock.h>
+#include <linux/blk-mq.h>
+#include <linux/blkpg.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+
+static DEFINE_MUTEX(pf_mutex);
+static DEFINE_SPINLOCK(pf_spin_lock);
+
+module_param(verbose, bool, 0644);
+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"
+#include "pseudo.h"
+
+/* constants for faking geometry numbers */
+
+#define PF_FD_MAX	8192	/* use FD geometry under this size */
+#define PF_FD_HDS	2
+#define PF_FD_SPT	18
+#define PF_HD_HDS	64
+#define PF_HD_SPT	32
+
+#define PF_MAX_RETRIES  5
+#define PF_TMO          800	/* interrupt timeout in jiffies */
+#define PF_SPIN_DEL     50	/* spin delay in micro-seconds  */
+
+#define PF_SPIN         (1000000*PF_TMO)/(HZ*PF_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 ATAPI_REQ_SENSE		0x03
+#define ATAPI_LOCK		0x1e
+#define ATAPI_DOOR		0x1b
+#define ATAPI_MODE_SENSE	0x5a
+#define ATAPI_CAPACITY		0x25
+#define ATAPI_IDENTIFY		0x12
+#define ATAPI_READ_10		0x28
+#define ATAPI_WRITE_10		0x2a
+
+static int pf_open(struct block_device *bdev, fmode_t mode);
+static blk_status_t pf_queue_rq(struct blk_mq_hw_ctx *hctx,
+				const struct blk_mq_queue_data *bd);
+static int pf_ioctl(struct block_device *bdev, fmode_t mode,
+		    unsigned int cmd, unsigned long arg);
+static int pf_getgeo(struct block_device *bdev, struct hd_geometry *geo);
+
+static void pf_release(struct gendisk *disk, fmode_t mode);
+
+static void do_pf_read(void);
+static void do_pf_read_start(void);
+static void do_pf_write(void);
+static void do_pf_write_start(void);
+static void do_pf_read_drq(void);
+static void do_pf_write_done(void);
+
+#define PF_NM           0
+#define PF_RO           1
+#define PF_RW           2
+
+#define PF_NAMELEN      8
+
+struct pf_unit {
+	struct pi_adapter pia;	/* interface to paride layer */
+	struct pi_adapter *pi;
+	int removable;		/* removable media device  ?  */
+	int media_status;	/* media present ?  WP ? */
+	int drive;		/* drive */
+	int lun;
+	int access;		/* count of active opens ... */
+	int present;		/* device present ? */
+	char name[PF_NAMELEN];	/* pf0, pf1, ... */
+	struct gendisk *disk;
+	struct blk_mq_tag_set tag_set;
+	struct list_head rq_list;
+};
+
+static struct pf_unit units[PF_UNITS];
+
+static int pf_identify(struct pf_unit *pf);
+static void pf_lock(struct pf_unit *pf, int func);
+static void pf_eject(struct pf_unit *pf);
+static unsigned int pf_check_events(struct gendisk *disk,
+				    unsigned int clearing);
+
+static char pf_scratch[512];	/* scratch block buffer */
+
+/* the variables below are used mainly in the I/O request engine, which
+   processes only one request at a time.
+*/
+
+static int pf_retries = 0;	/* i/o error retry count */
+static int pf_busy = 0;		/* request being processed ? */
+static struct request *pf_req;	/* current request */
+static int pf_block;		/* address of next requested block */
+static int pf_count;		/* number of blocks still to do */
+static int pf_run;		/* sectors in current cluster */
+static int pf_cmd;		/* current command READ/WRITE */
+static struct pf_unit *pf_current;/* unit of current request */
+static int pf_mask;		/* stopper for pseudo-int */
+static char *pf_buf;		/* buffer for request in progress */
+static void *par_drv;		/* reference of parport driver */
+
+/* kernel glue structures */
+
+static const struct block_device_operations pf_fops = {
+	.owner		= THIS_MODULE,
+	.open		= pf_open,
+	.release	= pf_release,
+	.ioctl		= pf_ioctl,
+	.compat_ioctl	= pf_ioctl,
+	.getgeo		= pf_getgeo,
+	.check_events	= pf_check_events,
+};
+
+static const struct blk_mq_ops pf_mq_ops = {
+	.queue_rq	= pf_queue_rq,
+};
+
+static int pf_open(struct block_device *bdev, fmode_t mode)
+{
+	struct pf_unit *pf = bdev->bd_disk->private_data;
+	int ret;
+
+	mutex_lock(&pf_mutex);
+	pf_identify(pf);
+
+	ret = -ENODEV;
+	if (pf->media_status == PF_NM)
+		goto out;
+
+	ret = -EROFS;
+	if ((pf->media_status == PF_RO) && (mode & FMODE_WRITE))
+		goto out;
+
+	ret = 0;
+	pf->access++;
+	if (pf->removable)
+		pf_lock(pf, 1);
+out:
+	mutex_unlock(&pf_mutex);
+	return ret;
+}
+
+static int pf_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+	struct pf_unit *pf = bdev->bd_disk->private_data;
+	sector_t capacity = get_capacity(pf->disk);
+
+	if (capacity < PF_FD_MAX) {
+		geo->cylinders = sector_div(capacity, PF_FD_HDS * PF_FD_SPT);
+		geo->heads = PF_FD_HDS;
+		geo->sectors = PF_FD_SPT;
+	} else {
+		geo->cylinders = sector_div(capacity, PF_HD_HDS * PF_HD_SPT);
+		geo->heads = PF_HD_HDS;
+		geo->sectors = PF_HD_SPT;
+	}
+
+	return 0;
+}
+
+static int pf_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
+{
+	struct pf_unit *pf = bdev->bd_disk->private_data;
+
+	if (cmd != CDROMEJECT)
+		return -EINVAL;
+
+	if (pf->access != 1)
+		return -EBUSY;
+	mutex_lock(&pf_mutex);
+	pf_eject(pf);
+	mutex_unlock(&pf_mutex);
+
+	return 0;
+}
+
+static void pf_release(struct gendisk *disk, fmode_t mode)
+{
+	struct pf_unit *pf = disk->private_data;
+
+	mutex_lock(&pf_mutex);
+	if (pf->access <= 0) {
+		mutex_unlock(&pf_mutex);
+		WARN_ON(1);
+		return;
+	}
+
+	pf->access--;
+
+	if (!pf->access && pf->removable)
+		pf_lock(pf, 0);
+
+	mutex_unlock(&pf_mutex);
+}
+
+static unsigned int pf_check_events(struct gendisk *disk, unsigned int clearing)
+{
+	return DISK_EVENT_MEDIA_CHANGE;
+}
+
+static inline int status_reg(struct pf_unit *pf)
+{
+	return pi_read_regr(pf->pi, 1, 6);
+}
+
+static inline int read_reg(struct pf_unit *pf, int reg)
+{
+	return pi_read_regr(pf->pi, 0, reg);
+}
+
+static inline void write_reg(struct pf_unit *pf, int reg, int val)
+{
+	pi_write_regr(pf->pi, 0, reg, val);
+}
+
+static int pf_wait(struct pf_unit *pf, int go, int stop, char *fun, char *msg)
+{
+	int j, r, e, s, p;
+
+	j = 0;
+	while ((((r = status_reg(pf)) & go) || (stop && (!(r & stop))))
+	       && (j++ < PF_SPIN))
+		udelay(PF_SPIN_DEL);
+
+	if ((r & (STAT_ERR & stop)) || (j > PF_SPIN)) {
+		s = read_reg(pf, 7);
+		e = read_reg(pf, 1);
+		p = read_reg(pf, 2);
+		if (j > PF_SPIN)
+			e |= 0x100;
+		if (fun)
+			printk("%s: %s %s: alt=0x%x stat=0x%x err=0x%x"
+			       " loop=%d phase=%d\n",
+			       pf->name, fun, msg, r, s, e, j, p);
+		return (e << 8) + s;
+	}
+	return 0;
+}
+
+static int pf_command(struct pf_unit *pf, char *cmd, int dlen, char *fun)
+{
+	pi_connect(pf->pi);
+
+	write_reg(pf, 6, 0xa0+0x10*pf->drive);
+
+	if (pf_wait(pf, STAT_BUSY | STAT_DRQ, 0, fun, "before command")) {
+		pi_disconnect(pf->pi);
+		return -1;
+	}
+
+	write_reg(pf, 4, dlen % 256);
+	write_reg(pf, 5, dlen / 256);
+	write_reg(pf, 7, 0xa0);	/* ATAPI packet command */
+
+	if (pf_wait(pf, STAT_BUSY, STAT_DRQ, fun, "command DRQ")) {
+		pi_disconnect(pf->pi);
+		return -1;
+	}
+
+	if (read_reg(pf, 2) != 1) {
+		printk("%s: %s: command phase error\n", pf->name, fun);
+		pi_disconnect(pf->pi);
+		return -1;
+	}
+
+	pi_write_block(pf->pi, cmd, 12);
+
+	return 0;
+}
+
+static int pf_completion(struct pf_unit *pf, char *buf, char *fun)
+{
+	int r, s, n;
+
+	r = pf_wait(pf, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
+		    fun, "completion");
+
+	if ((read_reg(pf, 2) & 2) && (read_reg(pf, 7) & STAT_DRQ)) {
+		n = (((read_reg(pf, 4) + 256 * read_reg(pf, 5)) +
+		      3) & 0xfffc);
+		pi_read_block(pf->pi, buf, n);
+	}
+
+	s = pf_wait(pf, STAT_BUSY, STAT_READY | STAT_ERR, fun, "data done");
+
+	pi_disconnect(pf->pi);
+
+	return (r ? r : s);
+}
+
+static void pf_req_sense(struct pf_unit *pf, int quiet)
+{
+	char rs_cmd[12] =
+	    { ATAPI_REQ_SENSE, pf->lun << 5, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0 };
+	char buf[16];
+	int r;
+
+	r = pf_command(pf, rs_cmd, 16, "Request sense");
+	mdelay(1);
+	if (!r)
+		pf_completion(pf, buf, "Request sense");
+
+	if ((!r) && (!quiet))
+		printk("%s: Sense key: %x, ASC: %x, ASQ: %x\n",
+		       pf->name, buf[2] & 0xf, buf[12], buf[13]);
+}
+
+static int pf_atapi(struct pf_unit *pf, char *cmd, int dlen, char *buf, char *fun)
+{
+	int r;
+
+	r = pf_command(pf, cmd, dlen, fun);
+	mdelay(1);
+	if (!r)
+		r = pf_completion(pf, buf, fun);
+	if (r)
+		pf_req_sense(pf, !fun);
+
+	return r;
+}
+
+static void pf_lock(struct pf_unit *pf, int func)
+{
+	char lo_cmd[12] = { ATAPI_LOCK, pf->lun << 5, 0, 0, func, 0, 0, 0, 0, 0, 0, 0 };
+
+	pf_atapi(pf, lo_cmd, 0, pf_scratch, func ? "lock" : "unlock");
+}
+
+static void pf_eject(struct pf_unit *pf)
+{
+	char ej_cmd[12] = { ATAPI_DOOR, pf->lun << 5, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0 };
+
+	pf_lock(pf, 0);
+	pf_atapi(pf, ej_cmd, 0, pf_scratch, "eject");
+}
+
+#define PF_RESET_TMO   30	/* in tenths of a second */
+
+static void pf_sleep(int cs)
+{
+	schedule_timeout_interruptible(cs);
+}
+
+/* the ATAPI standard actually specifies the contents of all 7 registers
+   after a reset, but the specification is ambiguous concerning the last
+   two bytes, and different drives interpret the standard differently.
+ */
+
+static int pf_reset(struct pf_unit *pf)
+{
+	int i, k, flg;
+	int expect[5] = { 1, 1, 1, 0x14, 0xeb };
+
+	pi_connect(pf->pi);
+	write_reg(pf, 6, 0xa0+0x10*pf->drive);
+	write_reg(pf, 7, 8);
+
+	pf_sleep(20 * HZ / 1000);
+
+	k = 0;
+	while ((k++ < PF_RESET_TMO) && (status_reg(pf) & STAT_BUSY))
+		pf_sleep(HZ / 10);
+
+	flg = 1;
+	for (i = 0; i < 5; i++)
+		flg &= (read_reg(pf, i + 1) == expect[i]);
+
+	if (verbose) {
+		printk("%s: Reset (%d) signature = ", pf->name, k);
+		for (i = 0; i < 5; i++)
+			printk("%3x", read_reg(pf, i + 1));
+		if (!flg)
+			printk(" (incorrect)");
+		printk("\n");
+	}
+
+	pi_disconnect(pf->pi);
+	return flg - 1;
+}
+
+static void pf_mode_sense(struct pf_unit *pf)
+{
+	char ms_cmd[12] =
+	    { ATAPI_MODE_SENSE, pf->lun << 5, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0 };
+	char buf[8];
+
+	pf_atapi(pf, ms_cmd, 8, buf, "mode sense");
+	pf->media_status = PF_RW;
+	if (buf[3] & 0x80)
+		pf->media_status = PF_RO;
+}
+
+static void xs(char *buf, char *targ, int offs, int len)
+{
+	int j, k, l;
+
+	j = 0;
+	l = 0;
+	for (k = 0; k < len; k++)
+		if ((buf[k + offs] != 0x20) || (buf[k + offs] != l))
+			l = targ[j++] = buf[k + offs];
+	if (l == 0x20)
+		j--;
+	targ[j] = 0;
+}
+
+static int xl(char *buf, int offs)
+{
+	int v, k;
+
+	v = 0;
+	for (k = 0; k < 4; k++)
+		v = v * 256 + (buf[k + offs] & 0xff);
+	return v;
+}
+
+static void pf_get_capacity(struct pf_unit *pf)
+{
+	char rc_cmd[12] = { ATAPI_CAPACITY, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+	char buf[8];
+	int bs;
+
+	if (pf_atapi(pf, rc_cmd, 8, buf, "get capacity")) {
+		pf->media_status = PF_NM;
+		return;
+	}
+	set_capacity(pf->disk, xl(buf, 0) + 1);
+	bs = xl(buf, 4);
+	if (bs != 512) {
+		set_capacity(pf->disk, 0);
+		if (verbose)
+			printk("%s: Drive %d, LUN %d,"
+			       " unsupported block size %d\n",
+			       pf->name, pf->drive, pf->lun, bs);
+	}
+}
+
+static int pf_identify(struct pf_unit *pf)
+{
+	int dt, s;
+	char *ms[2] = { "master", "slave" };
+	char mf[10], id[18];
+	char id_cmd[12] =
+	    { ATAPI_IDENTIFY, pf->lun << 5, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
+	char buf[36];
+
+	s = pf_atapi(pf, id_cmd, 36, buf, "identify");
+	if (s)
+		return -1;
+
+	dt = buf[0] & 0x1f;
+	if ((dt != 0) && (dt != 7)) {
+		if (verbose)
+			printk("%s: Drive %d, LUN %d, unsupported type %d\n",
+			       pf->name, pf->drive, pf->lun, dt);
+		return -1;
+	}
+
+	xs(buf, mf, 8, 8);
+	xs(buf, id, 16, 16);
+
+	pf->removable = (buf[1] & 0x80);
+
+	pf_mode_sense(pf);
+	pf_mode_sense(pf);
+	pf_mode_sense(pf);
+
+	pf_get_capacity(pf);
+
+	printk("%s: %s %s, %s LUN %d, type %d",
+	       pf->name, mf, id, ms[pf->drive], pf->lun, dt);
+	if (pf->removable)
+		printk(", removable");
+	if (pf->media_status == PF_NM)
+		printk(", no media\n");
+	else {
+		if (pf->media_status == PF_RO)
+			printk(", RO");
+		printk(", %llu blocks\n",
+			(unsigned long long)get_capacity(pf->disk));
+	}
+	return 0;
+}
+
+/*
+ * returns 0, with id set if drive is detected, otherwise an error code.
+ */
+static int pf_probe(struct pf_unit *pf)
+{
+	if (pf->drive == -1) {
+		for (pf->drive = 0; pf->drive <= 1; pf->drive++)
+			if (!pf_reset(pf)) {
+				if (pf->lun != -1)
+					return pf_identify(pf);
+				else
+					for (pf->lun = 0; pf->lun < 8; pf->lun++)
+						if (!pf_identify(pf))
+							return 0;
+			}
+	} else {
+		if (pf_reset(pf))
+			return -1;
+		if (pf->lun != -1)
+			return pf_identify(pf);
+		for (pf->lun = 0; pf->lun < 8; pf->lun++)
+			if (!pf_identify(pf))
+				return 0;
+	}
+	return -ENODEV;
+}
+
+/* The i/o request engine */
+
+static int pf_start(struct pf_unit *pf, int cmd, int b, int c)
+{
+	int i;
+	char io_cmd[12] = { cmd, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+	for (i = 0; i < 4; i++) {
+		io_cmd[5 - i] = b & 0xff;
+		b = b >> 8;
+	}
+
+	io_cmd[8] = c & 0xff;
+	io_cmd[7] = (c >> 8) & 0xff;
+
+	i = pf_command(pf, io_cmd, c * 512, "start i/o");
+
+	mdelay(1);
+
+	return i;
+}
+
+static int pf_ready(void)
+{
+	return (((status_reg(pf_current) & (STAT_BUSY | pf_mask)) == pf_mask));
+}
+
+static int pf_queue;
+
+static int set_next_request(void)
+{
+	struct pf_unit *pf;
+	int old_pos = pf_queue;
+
+	do {
+		pf = &units[pf_queue];
+		if (++pf_queue == PF_UNITS)
+			pf_queue = 0;
+		if (pf->present && !list_empty(&pf->rq_list)) {
+			pf_req = list_first_entry(&pf->rq_list, struct request,
+							queuelist);
+			list_del_init(&pf_req->queuelist);
+			blk_mq_start_request(pf_req);
+			break;
+		}
+	} while (pf_queue != old_pos);
+
+	return pf_req != NULL;
+}
+
+static void pf_end_request(blk_status_t err)
+{
+	if (!pf_req)
+		return;
+	if (!blk_update_request(pf_req, err, blk_rq_cur_bytes(pf_req))) {
+		__blk_mq_end_request(pf_req, err);
+		pf_req = NULL;
+	}
+}
+
+static void pf_request(void)
+{
+	if (pf_busy)
+		return;
+repeat:
+	if (!pf_req && !set_next_request())
+		return;
+
+	pf_current = pf_req->q->disk->private_data;
+	pf_block = blk_rq_pos(pf_req);
+	pf_run = blk_rq_sectors(pf_req);
+	pf_count = blk_rq_cur_sectors(pf_req);
+
+	if (pf_block + pf_count > get_capacity(pf_req->q->disk)) {
+		pf_end_request(BLK_STS_IOERR);
+		goto repeat;
+	}
+
+	pf_cmd = rq_data_dir(pf_req);
+	pf_buf = bio_data(pf_req->bio);
+	pf_retries = 0;
+
+	pf_busy = 1;
+	if (pf_cmd == READ)
+		pi_do_claimed(pf_current->pi, do_pf_read);
+	else if (pf_cmd == WRITE)
+		pi_do_claimed(pf_current->pi, do_pf_write);
+	else {
+		pf_busy = 0;
+		pf_end_request(BLK_STS_IOERR);
+		goto repeat;
+	}
+}
+
+static blk_status_t pf_queue_rq(struct blk_mq_hw_ctx *hctx,
+				const struct blk_mq_queue_data *bd)
+{
+	struct pf_unit *pf = hctx->queue->queuedata;
+
+	spin_lock_irq(&pf_spin_lock);
+	list_add_tail(&bd->rq->queuelist, &pf->rq_list);
+	pf_request();
+	spin_unlock_irq(&pf_spin_lock);
+
+	return BLK_STS_OK;
+}
+
+static int pf_next_buf(void)
+{
+	unsigned long saved_flags;
+
+	pf_count--;
+	pf_run--;
+	pf_buf += 512;
+	pf_block++;
+	if (!pf_run)
+		return 1;
+	if (!pf_count) {
+		spin_lock_irqsave(&pf_spin_lock, saved_flags);
+		pf_end_request(0);
+		spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
+		if (!pf_req)
+			return 1;
+		pf_count = blk_rq_cur_sectors(pf_req);
+		pf_buf = bio_data(pf_req->bio);
+	}
+	return 0;
+}
+
+static inline void next_request(blk_status_t err)
+{
+	unsigned long saved_flags;
+
+	spin_lock_irqsave(&pf_spin_lock, saved_flags);
+	pf_end_request(err);
+	pf_busy = 0;
+	pf_request();
+	spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
+}
+
+/* detach from the calling context - in case the spinlock is held */
+static void do_pf_read(void)
+{
+	ps_set_intr(do_pf_read_start, NULL, 0, nice);
+}
+
+static void do_pf_read_start(void)
+{
+	pf_busy = 1;
+
+	if (pf_start(pf_current, ATAPI_READ_10, pf_block, pf_run)) {
+		pi_disconnect(pf_current->pi);
+		if (pf_retries < PF_MAX_RETRIES) {
+			pf_retries++;
+			pi_do_claimed(pf_current->pi, do_pf_read_start);
+			return;
+		}
+		next_request(BLK_STS_IOERR);
+		return;
+	}
+	pf_mask = STAT_DRQ;
+	ps_set_intr(do_pf_read_drq, pf_ready, PF_TMO, nice);
+}
+
+static void do_pf_read_drq(void)
+{
+	while (1) {
+		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
+			    "read block", "completion") & STAT_ERR) {
+			pi_disconnect(pf_current->pi);
+			if (pf_retries < PF_MAX_RETRIES) {
+				pf_req_sense(pf_current, 0);
+				pf_retries++;
+				pi_do_claimed(pf_current->pi, do_pf_read_start);
+				return;
+			}
+			next_request(BLK_STS_IOERR);
+			return;
+		}
+		pi_read_block(pf_current->pi, pf_buf, 512);
+		if (pf_next_buf())
+			break;
+	}
+	pi_disconnect(pf_current->pi);
+	next_request(0);
+}
+
+static void do_pf_write(void)
+{
+	ps_set_intr(do_pf_write_start, NULL, 0, nice);
+}
+
+static void do_pf_write_start(void)
+{
+	pf_busy = 1;
+
+	if (pf_start(pf_current, ATAPI_WRITE_10, pf_block, pf_run)) {
+		pi_disconnect(pf_current->pi);
+		if (pf_retries < PF_MAX_RETRIES) {
+			pf_retries++;
+			pi_do_claimed(pf_current->pi, do_pf_write_start);
+			return;
+		}
+		next_request(BLK_STS_IOERR);
+		return;
+	}
+
+	while (1) {
+		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
+			    "write block", "data wait") & STAT_ERR) {
+			pi_disconnect(pf_current->pi);
+			if (pf_retries < PF_MAX_RETRIES) {
+				pf_retries++;
+				pi_do_claimed(pf_current->pi, do_pf_write_start);
+				return;
+			}
+			next_request(BLK_STS_IOERR);
+			return;
+		}
+		pi_write_block(pf_current->pi, pf_buf, 512);
+		if (pf_next_buf())
+			break;
+	}
+	pf_mask = 0;
+	ps_set_intr(do_pf_write_done, pf_ready, PF_TMO, nice);
+}
+
+static void do_pf_write_done(void)
+{
+	if (pf_wait(pf_current, STAT_BUSY, 0, "write block", "done") & STAT_ERR) {
+		pi_disconnect(pf_current->pi);
+		if (pf_retries < PF_MAX_RETRIES) {
+			pf_retries++;
+			pi_do_claimed(pf_current->pi, do_pf_write_start);
+			return;
+		}
+		next_request(BLK_STS_IOERR);
+		return;
+	}
+	pi_disconnect(pf_current->pi);
+	next_request(0);
+}
+
+static int __init pf_init_unit(struct pf_unit *pf, bool autoprobe, int port,
+		int mode, int unit, int protocol, int delay, int ms)
+{
+	struct gendisk *disk;
+	int ret;
+
+	ret = blk_mq_alloc_sq_tag_set(&pf->tag_set, &pf_mq_ops, 1,
+				      BLK_MQ_F_SHOULD_MERGE);
+	if (ret)
+		return ret;
+
+	disk = blk_mq_alloc_disk(&pf->tag_set, pf);
+	if (IS_ERR(disk)) {
+		ret = PTR_ERR(disk);
+		goto out_free_tag_set;
+	}
+	disk->major = major;
+	disk->first_minor = pf - units;
+	disk->minors = 1;
+	strcpy(disk->disk_name, pf->name);
+	disk->fops = &pf_fops;
+	disk->flags |= GENHD_FL_NO_PART;
+	disk->events = DISK_EVENT_MEDIA_CHANGE;
+	disk->private_data = pf;
+
+	blk_queue_max_segments(disk->queue, cluster);
+	blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
+
+	INIT_LIST_HEAD(&pf->rq_list);
+	pf->disk = disk;
+	pf->pi = &pf->pia;
+	pf->media_status = PF_NM;
+	pf->drive = (*drives[disk->first_minor])[D_SLV];
+	pf->lun = (*drives[disk->first_minor])[D_LUN];
+	snprintf(pf->name, PF_NAMELEN, "%s%d", name, disk->first_minor);
+
+	if (!pi_init(pf->pi, autoprobe, port, mode, unit, protocol, delay,
+			pf_scratch, PI_PF, verbose, pf->name)) {
+		ret = -ENODEV;
+		goto out_free_disk;
+	}
+	ret = pf_probe(pf);
+	if (ret)
+		goto out_pi_release;
+
+	ret = add_disk(disk);
+	if (ret)
+		goto out_pi_release;
+	pf->present = 1;
+	return 0;
+
+out_pi_release:
+	pi_release(pf->pi);
+out_free_disk:
+	put_disk(pf->disk);
+out_free_tag_set:
+	blk_mq_free_tag_set(&pf->tag_set);
+	return ret;
+}
+
+static int __init pf_init(void)
+{				/* preliminary initialisation */
+	struct pf_unit *pf;
+	int found = 0, unit;
+
+	if (disable)
+		return -EINVAL;
+
+	if (register_blkdev(major, name))
+		return -EBUSY;
+
+	printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
+	       name, name, PF_VERSION, major, cluster, nice);
+
+	par_drv = pi_register_driver(name);
+	if (!par_drv) {
+		pr_err("failed to register %s driver\n", name);
+		goto out_unregister_blkdev;
+	}
+
+	for (unit = 0; unit < PF_UNITS; unit++) {
+		if (!(*drives[unit])[D_PRT])
+			pf_drive_count++;
+	}
+
+	pf = units;
+	if (pf_drive_count == 0) {
+		if (pf_init_unit(pf, 1, -1, -1, -1, -1, -1, verbose))
+			found++;
+	} else {
+		for (unit = 0; unit < PF_UNITS; unit++, pf++) {
+			int *conf = *drives[unit];
+			if (!conf[D_PRT])
+				continue;
+			if (pf_init_unit(pf, 0, conf[D_PRT], conf[D_MOD],
+				    conf[D_UNI], conf[D_PRO], conf[D_DLY],
+				    verbose))
+				found++;
+		}
+	}
+	if (!found) {
+		printk("%s: No ATAPI disk detected\n", name);
+		goto out_unregister_pi_driver;
+	}
+	pf_busy = 0;
+	return 0;
+
+out_unregister_pi_driver:
+	pi_unregister_driver(par_drv);
+out_unregister_blkdev:
+	unregister_blkdev(major, name);
+	return -ENODEV;
+}
+
+static void __exit pf_exit(void)
+{
+	struct pf_unit *pf;
+	int unit;
+
+	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
+		if (!pf->present)
+			continue;
+		del_gendisk(pf->disk);
+		put_disk(pf->disk);
+		blk_mq_free_tag_set(&pf->tag_set);
+		pi_release(pf->pi);
+	}
+
+	unregister_blkdev(major, name);
+}
+
+MODULE_LICENSE("GPL");
+module_init(pf_init)
+module_exit(pf_exit)