Linux-2.6.12-rc2v2.6.12-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, 982 insertions, 0 deletions

diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
new file mode 100644
index 000000000000..060b1f2a91dd
--- /dev/null
+++ b/drivers/block/paride/pf.c
@@ -0,0 +1,982 @@
+/* 
+        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 overide 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
+
+/* 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 = 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/blkdev.h>
+#include <linux/blkpg.h>
+#include <asm/uaccess.h>
+
+static spinlock_t 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 inode *inode, struct file *file);
+static void do_pf_request(request_queue_t * q);
+static int pf_ioctl(struct inode *inode, struct file *file,
+                    unsigned int cmd, unsigned long arg);
+
+static int pf_release(struct inode *inode, struct file *file);
+
+static int pf_detect(void);
+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;
+};
+
+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 int pf_check_media(struct gendisk *disk);
+
+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 */
+
+/* kernel glue structures */
+
+static struct block_device_operations pf_fops = {
+        .owner          = THIS_MODULE,
+        .open           = pf_open,
+        .release        = pf_release,
+        .ioctl          = pf_ioctl,
+        .media_changed  = pf_check_media,
+};
+
+static void __init pf_init_units(void)
+{
+        struct pf_unit *pf;
+        int unit;
+
+        pf_drive_count = 0;
+        for (unit = 0, pf = units; unit < PF_UNITS; unit++, pf++) {
+                struct gendisk *disk = alloc_disk(1);
+                if (!disk)
+                        continue;
+                pf->disk = disk;
+                pf->pi = &pf->pia;
+                pf->media_status = PF_NM;
+                pf->drive = (*drives[unit])[D_SLV];
+                pf->lun = (*drives[unit])[D_LUN];
+                snprintf(pf->name, PF_NAMELEN, "%s%d", name, unit);
+                disk->major = major;
+                disk->first_minor = unit;
+                strcpy(disk->disk_name, pf->name);
+                disk->fops = &pf_fops;
+                if (!(*drives[unit])[D_PRT])
+                        pf_drive_count++;
+        }
+}
+
+static int pf_open(struct inode *inode, struct file *file)
+{
+        struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;
+
+        pf_identify(pf);
+
+        if (pf->media_status == PF_NM)
+                return -ENODEV;
+
+        if ((pf->media_status == PF_RO) && (file->f_mode & 2))
+                return -EROFS;
+
+        pf->access++;
+        if (pf->removable)
+                pf_lock(pf, 1);
+
+        return 0;
+}
+
+static int pf_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+        struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;
+        struct hd_geometry __user *geo = (struct hd_geometry __user *) arg;
+        struct hd_geometry g;
+        sector_t capacity;
+
+        if (cmd == CDROMEJECT) {
+                if (pf->access == 1) {
+                        pf_eject(pf);
+                        return 0;
+                }
+                return -EBUSY;
+        }
+        if (cmd != HDIO_GETGEO)
+                return -EINVAL;
+        capacity = get_capacity(pf->disk);
+        if (capacity < PF_FD_MAX) {
+                g.cylinders = sector_div(capacity, PF_FD_HDS * PF_FD_SPT);
+                g.heads = PF_FD_HDS;
+                g.sectors = PF_FD_SPT;
+        } else {
+                g.cylinders = sector_div(capacity, PF_HD_HDS * PF_HD_SPT);
+                g.heads = PF_HD_HDS;
+                g.sectors = PF_HD_SPT;
+        }
+        if (copy_to_user(geo, &g, sizeof(g)))
+                return -EFAULT;
+        return 0;
+}
+
+static int pf_release(struct inode *inode, struct file *file)
+{
+        struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;
+
+        if (pf->access <= 0)
+                return -EINVAL;
+
+        pf->access--;
+
+        if (!pf->access && pf->removable)
+                pf_lock(pf, 0);
+
+        return 0;
+
+}
+
+static int pf_check_media(struct gendisk *disk)
+{
+        return 1;
+}
+
+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;
+}
+
+#define DBMSG(msg)      ((verbose>1)?(msg):NULL)
+
+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 ? "unlock" : "lock");
+}
+
+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)
+{
+        current->state = TASK_INTERRUPTIBLE;
+        schedule_timeout(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, DBMSG("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, DBMSG("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
+                -1, if drive detection failed
+*/
+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 -1;
+}
+
+static int pf_detect(void)
+{
+        struct pf_unit *pf = units;
+        int k, unit;
+
+        printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
+               name, name, PF_VERSION, major, cluster, nice);
+
+        k = 0;
+        if (pf_drive_count == 0) {
+                if (pi_init(pf->pi, 1, -1, -1, -1, -1, -1, pf_scratch, PI_PF,
+                            verbose, pf->name)) {
+                        if (!pf_probe(pf) && pf->disk) {
+                                pf->present = 1;
+                                k++;
+                        } else
+                                pi_release(pf->pi);
+                }
+
+        } else
+                for (unit = 0; unit < PF_UNITS; unit++, pf++) {
+                        int *conf = *drives[unit];
+                        if (!conf[D_PRT])
+                                continue;
+                        if (pi_init(pf->pi, 0, conf[D_PRT], conf[D_MOD],
+                                    conf[D_UNI], conf[D_PRO], conf[D_DLY],
+                                    pf_scratch, PI_PF, verbose, pf->name)) {
+                                if (!pf_probe(pf) && pf->disk) {
+                                        pf->present = 1;
+                                        k++;
+                                } else
+                                        pi_release(pf->pi);
+                        }
+                }
+        if (k)
+                return 0;
+
+        printk("%s: No ATAPI disk detected\n", name);
+        for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
+                put_disk(pf->disk);
+        return -1;
+}
+
+/* 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 struct request_queue *pf_queue;
+
+static void do_pf_request(request_queue_t * q)
+{
+        if (pf_busy)
+                return;
+repeat:
+        pf_req = elv_next_request(q);
+        if (!pf_req)
+                return;
+
+        pf_current = pf_req->rq_disk->private_data;
+        pf_block = pf_req->sector;
+        pf_run = pf_req->nr_sectors;
+        pf_count = pf_req->current_nr_sectors;
+
+        if (pf_block + pf_count > get_capacity(pf_req->rq_disk)) {
+                end_request(pf_req, 0);
+                goto repeat;
+        }
+
+        pf_cmd = rq_data_dir(pf_req);
+        pf_buf = pf_req->buffer;
+        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;
+                end_request(pf_req, 0);
+                goto repeat;
+        }
+}
+
+static int pf_next_buf(void)
+{
+        unsigned long saved_flags;
+
+        pf_count--;
+        pf_run--;
+        pf_buf += 512;
+        pf_block++;
+        if (!pf_run)
+                return 0;
+        if (!pf_count)
+                return 1;
+        spin_lock_irqsave(&pf_spin_lock, saved_flags);
+        end_request(pf_req, 1);
+        pf_count = pf_req->current_nr_sectors;
+        pf_buf = pf_req->buffer;
+        spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
+        return 1;
+}
+
+static inline void next_request(int success)
+{
+        unsigned long saved_flags;
+
+        spin_lock_irqsave(&pf_spin_lock, saved_flags);
+        end_request(pf_req, success);
+        pf_busy = 0;
+        do_pf_request(pf_queue);
+        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(0);
+                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(0);
+                        return;
+                }
+                pi_read_block(pf_current->pi, pf_buf, 512);
+                if (pf_next_buf())
+                        break;
+        }
+        pi_disconnect(pf_current->pi);
+        next_request(1);
+}
+
+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(0);
+                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(0);
+                        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(0);
+                return;
+        }
+        pi_disconnect(pf_current->pi);
+        next_request(1);
+}
+
+static int __init pf_init(void)
+{                               /* preliminary initialisation */
+        struct pf_unit *pf;
+        int unit;
+
+        if (disable)
+                return -1;
+
+        pf_init_units();
+
+        if (pf_detect())
+                return -1;
+        pf_busy = 0;
+
+        if (register_blkdev(major, name)) {
+                for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
+                        put_disk(pf->disk);
+                return -1;
+        }
+        pf_queue = blk_init_queue(do_pf_request, &pf_spin_lock);
+        if (!pf_queue) {
+                unregister_blkdev(major, name);
+                for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
+                        put_disk(pf->disk);
+                return -1;
+        }
+
+        blk_queue_max_phys_segments(pf_queue, cluster);
+        blk_queue_max_hw_segments(pf_queue, cluster);
+
+        for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
+                struct gendisk *disk = pf->disk;
+
+                if (!pf->present)
+                        continue;
+                disk->private_data = pf;
+                disk->queue = pf_queue;
+                add_disk(disk);
+        }
+        return 0;
+}
+
+static void __exit pf_exit(void)
+{
+        struct pf_unit *pf;
+        int unit;
+        unregister_blkdev(major, name);
+        for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
+                if (!pf->present)
+                        continue;
+                del_gendisk(pf->disk);
+                put_disk(pf->disk);
+                pi_release(pf->pi);
+        }
+        blk_cleanup_queue(pf_queue);
+}
+
+MODULE_LICENSE("GPL");
+module_init(pf_init)
+module_exit(pf_exit)