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, 846 insertions, 0 deletions

diff --git a/drivers/block/viodasd.c b/drivers/block/viodasd.c
new file mode 100644
index 000000000000..46e56a25d2c8
--- /dev/null
+++ b/drivers/block/viodasd.c
@@ -0,0 +1,846 @@
+/* -*- linux-c -*-
+ * viodasd.c
+ *  Authors: Dave Boutcher <boutcher@us.ibm.com>
+ *           Ryan Arnold <ryanarn@us.ibm.com>
+ *           Colin Devilbiss <devilbis@us.ibm.com>
+ *           Stephen Rothwell <sfr@au1.ibm.com>
+ *
+ * (C) Copyright 2000-2004 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * This routine provides access to disk space (termed "DASD" in historical
+ * IBM terms) owned and managed by an OS/400 partition running on the
+ * same box as this Linux partition.
+ *
+ * All disk operations are performed by sending messages back and forth to
+ * the OS/400 partition.
+ */
+#include <linux/major.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/genhd.h>
+#include <linux/hdreg.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/dma-mapping.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+
+#include <asm/uaccess.h>
+#include <asm/vio.h>
+#include <asm/iSeries/HvTypes.h>
+#include <asm/iSeries/HvLpEvent.h>
+#include <asm/iSeries/HvLpConfig.h>
+#include <asm/iSeries/vio.h>
+
+MODULE_DESCRIPTION("iSeries Virtual DASD");
+MODULE_AUTHOR("Dave Boutcher");
+MODULE_LICENSE("GPL");
+
+/*
+ * We only support 7 partitions per physical disk....so with minor
+ * numbers 0-255 we get a maximum of 32 disks.
+ */
+#define VIOD_GENHD_NAME         "iseries/vd"
+#define VIOD_GENHD_DEVFS_NAME   "iseries/disc"
+
+#define VIOD_VERS               "1.64"
+
+#define VIOD_KERN_WARNING       KERN_WARNING "viod: "
+#define VIOD_KERN_INFO          KERN_INFO "viod: "
+
+enum {
+        PARTITION_SHIFT = 3,
+        MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS,
+        MAX_DISK_NAME = sizeof(((struct gendisk *)0)->disk_name)
+};
+
+static DEFINE_SPINLOCK(viodasd_spinlock);
+
+#define VIOMAXREQ               16
+#define VIOMAXBLOCKDMA          12
+
+#define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0])
+
+struct open_data {
+        u64     disk_size;
+        u16     max_disk;
+        u16     cylinders;
+        u16     tracks;
+        u16     sectors;
+        u16     bytes_per_sector;
+};
+
+struct rw_data {
+        u64     offset;
+        struct {
+                u32     token;
+                u32     reserved;
+                u64     len;
+        } dma_info[VIOMAXBLOCKDMA];
+};
+
+struct vioblocklpevent {
+        struct HvLpEvent        event;
+        u32                     reserved;
+        u16                     version;
+        u16                     sub_result;
+        u16                     disk;
+        u16                     flags;
+        union {
+                struct open_data        open_data;
+                struct rw_data          rw_data;
+                u64                     changed;
+        } u;
+};
+
+#define vioblockflags_ro   0x0001
+
+enum vioblocksubtype {
+        vioblockopen = 0x0001,
+        vioblockclose = 0x0002,
+        vioblockread = 0x0003,
+        vioblockwrite = 0x0004,
+        vioblockflush = 0x0005,
+        vioblockcheck = 0x0007
+};
+
+struct viodasd_waitevent {
+        struct completion       com;
+        int                     rc;
+        u16                     sub_result;
+        int                     max_disk;       /* open */
+};
+
+static const struct vio_error_entry viodasd_err_table[] = {
+        { 0x0201, EINVAL, "Invalid Range" },
+        { 0x0202, EINVAL, "Invalid Token" },
+        { 0x0203, EIO, "DMA Error" },
+        { 0x0204, EIO, "Use Error" },
+        { 0x0205, EIO, "Release Error" },
+        { 0x0206, EINVAL, "Invalid Disk" },
+        { 0x0207, EBUSY, "Cant Lock" },
+        { 0x0208, EIO, "Already Locked" },
+        { 0x0209, EIO, "Already Unlocked" },
+        { 0x020A, EIO, "Invalid Arg" },
+        { 0x020B, EIO, "Bad IFS File" },
+        { 0x020C, EROFS, "Read Only Device" },
+        { 0x02FF, EIO, "Internal Error" },
+        { 0x0000, 0, NULL },
+};
+
+/*
+ * Figure out the biggest I/O request (in sectors) we can accept
+ */
+#define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA)
+
+/*
+ * Number of disk I/O requests we've sent to OS/400
+ */
+static int num_req_outstanding;
+
+/*
+ * This is our internal structure for keeping track of disk devices
+ */
+struct viodasd_device {
+        u16             cylinders;
+        u16             tracks;
+        u16             sectors;
+        u16             bytes_per_sector;
+        u64             size;
+        int             read_only;
+        spinlock_t      q_lock;
+        struct gendisk  *disk;
+        struct device   *dev;
+} viodasd_devices[MAX_DISKNO];
+
+/*
+ * External open entry point.
+ */
+static int viodasd_open(struct inode *ino, struct file *fil)
+{
+        struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
+        HvLpEvent_Rc hvrc;
+        struct viodasd_waitevent we;
+        u16 flags = 0;
+
+        if (d->read_only) {
+                if ((fil != NULL) && (fil->f_mode & FMODE_WRITE))
+                        return -EROFS;
+                flags = vioblockflags_ro;
+        }
+
+        init_completion(&we.com);
+
+        /* Send the open event to OS/400 */
+        hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+                        HvLpEvent_Type_VirtualIo,
+                        viomajorsubtype_blockio | vioblockopen,
+                        HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
+                        viopath_sourceinst(viopath_hostLp),
+                        viopath_targetinst(viopath_hostLp),
+                        (u64)(unsigned long)&we, VIOVERSION << 16,
+                        ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32),
+                        0, 0, 0);
+        if (hvrc != 0) {
+                printk(VIOD_KERN_WARNING "HV open failed %d\n", (int)hvrc);
+                return -EIO;
+        }
+
+        wait_for_completion(&we.com);
+
+        /* Check the return code */
+        if (we.rc != 0) {
+                const struct vio_error_entry *err =
+                        vio_lookup_rc(viodasd_err_table, we.sub_result);
+
+                printk(VIOD_KERN_WARNING
+                                "bad rc opening disk: %d:0x%04x (%s)\n",
+                                (int)we.rc, we.sub_result, err->msg);
+                return -EIO;
+        }
+
+        return 0;
+}
+
+/*
+ * External release entry point.
+ */
+static int viodasd_release(struct inode *ino, struct file *fil)
+{
+        struct viodasd_device *d = ino->i_bdev->bd_disk->private_data;
+        HvLpEvent_Rc hvrc;
+
+        /* Send the event to OS/400.  We DON'T expect a response */
+        hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+                        HvLpEvent_Type_VirtualIo,
+                        viomajorsubtype_blockio | vioblockclose,
+                        HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
+                        viopath_sourceinst(viopath_hostLp),
+                        viopath_targetinst(viopath_hostLp),
+                        0, VIOVERSION << 16,
+                        ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */,
+                        0, 0, 0);
+        if (hvrc != 0)
+                printk(VIOD_KERN_WARNING "HV close call failed %d\n",
+                                (int)hvrc);
+        return 0;
+}
+
+
+/* External ioctl entry point.
+ */
+static int viodasd_ioctl(struct inode *ino, struct file *fil,
+                         unsigned int cmd, unsigned long arg)
+{
+        unsigned char sectors;
+        unsigned char heads;
+        unsigned short cylinders;
+        struct hd_geometry *geo;
+        struct gendisk *gendisk;
+        struct viodasd_device *d;
+
+        switch (cmd) {
+        case HDIO_GETGEO:
+                geo = (struct hd_geometry *)arg;
+                if (geo == NULL)
+                        return -EINVAL;
+                if (!access_ok(VERIFY_WRITE, geo, sizeof(*geo)))
+                        return -EFAULT;
+                gendisk = ino->i_bdev->bd_disk;
+                d = gendisk->private_data;
+                sectors = d->sectors;
+                if (sectors == 0)
+                        sectors = 32;
+                heads = d->tracks;
+                if (heads == 0)
+                        heads = 64;
+                cylinders = d->cylinders;
+                if (cylinders == 0)
+                        cylinders = get_capacity(gendisk) / (sectors * heads);
+                if (__put_user(sectors, &geo->sectors) ||
+                    __put_user(heads, &geo->heads) ||
+                    __put_user(cylinders, &geo->cylinders) ||
+                    __put_user(get_start_sect(ino->i_bdev), &geo->start))
+                        return -EFAULT;
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+/*
+ * Our file operations table
+ */
+static struct block_device_operations viodasd_fops = {
+        .owner = THIS_MODULE,
+        .open = viodasd_open,
+        .release = viodasd_release,
+        .ioctl = viodasd_ioctl,
+};
+
+/*
+ * End a request
+ */
+static void viodasd_end_request(struct request *req, int uptodate,
+                int num_sectors)
+{
+        if (end_that_request_first(req, uptodate, num_sectors))
+                return;
+        add_disk_randomness(req->rq_disk);
+        end_that_request_last(req);
+}
+
+/*
+ * Send an actual I/O request to OS/400
+ */
+static int send_request(struct request *req)
+{
+        u64 start;
+        int direction;
+        int nsg;
+        u16 viocmd;
+        HvLpEvent_Rc hvrc;
+        struct vioblocklpevent *bevent;
+        struct scatterlist sg[VIOMAXBLOCKDMA];
+        int sgindex;
+        int statindex;
+        struct viodasd_device *d;
+        unsigned long flags;
+
+        start = (u64)req->sector << 9;
+
+        if (rq_data_dir(req) == READ) {
+                direction = DMA_FROM_DEVICE;
+                viocmd = viomajorsubtype_blockio | vioblockread;
+                statindex = 0;
+        } else {
+                direction = DMA_TO_DEVICE;
+                viocmd = viomajorsubtype_blockio | vioblockwrite;
+                statindex = 1;
+        }
+
+        d = req->rq_disk->private_data;
+
+        /* Now build the scatter-gather list */
+        nsg = blk_rq_map_sg(req->q, req, sg);
+        nsg = dma_map_sg(d->dev, sg, nsg, direction);
+
+        spin_lock_irqsave(&viodasd_spinlock, flags);
+        num_req_outstanding++;
+
+        /* This optimization handles a single DMA block */
+        if (nsg == 1)
+                hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+                                HvLpEvent_Type_VirtualIo, viocmd,
+                                HvLpEvent_AckInd_DoAck,
+                                HvLpEvent_AckType_ImmediateAck,
+                                viopath_sourceinst(viopath_hostLp),
+                                viopath_targetinst(viopath_hostLp),
+                                (u64)(unsigned long)req, VIOVERSION << 16,
+                                ((u64)DEVICE_NO(d) << 48), start,
+                                ((u64)sg_dma_address(&sg[0])) << 32,
+                                sg_dma_len(&sg[0]));
+        else {
+                bevent = (struct vioblocklpevent *)
+                        vio_get_event_buffer(viomajorsubtype_blockio);
+                if (bevent == NULL) {
+                        printk(VIOD_KERN_WARNING
+                               "error allocating disk event buffer\n");
+                        goto error_ret;
+                }
+
+                /*
+                 * Now build up the actual request.  Note that we store
+                 * the pointer to the request in the correlation
+                 * token so we can match the response up later
+                 */
+                memset(bevent, 0, sizeof(struct vioblocklpevent));
+                bevent->event.xFlags.xValid = 1;
+                bevent->event.xFlags.xFunction = HvLpEvent_Function_Int;
+                bevent->event.xFlags.xAckInd = HvLpEvent_AckInd_DoAck;
+                bevent->event.xFlags.xAckType = HvLpEvent_AckType_ImmediateAck;
+                bevent->event.xType = HvLpEvent_Type_VirtualIo;
+                bevent->event.xSubtype = viocmd;
+                bevent->event.xSourceLp = HvLpConfig_getLpIndex();
+                bevent->event.xTargetLp = viopath_hostLp;
+                bevent->event.xSizeMinus1 =
+                        offsetof(struct vioblocklpevent, u.rw_data.dma_info) +
+                        (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1;
+                bevent->event.xSourceInstanceId =
+                        viopath_sourceinst(viopath_hostLp);
+                bevent->event.xTargetInstanceId =
+                        viopath_targetinst(viopath_hostLp);
+                bevent->event.xCorrelationToken = (u64)req;
+                bevent->version = VIOVERSION;
+                bevent->disk = DEVICE_NO(d);
+                bevent->u.rw_data.offset = start;
+
+                /*
+                 * Copy just the dma information from the sg list
+                 * into the request
+                 */
+                for (sgindex = 0; sgindex < nsg; sgindex++) {
+                        bevent->u.rw_data.dma_info[sgindex].token =
+                                sg_dma_address(&sg[sgindex]);
+                        bevent->u.rw_data.dma_info[sgindex].len =
+                                sg_dma_len(&sg[sgindex]);
+                }
+
+                /* Send the request */
+                hvrc = HvCallEvent_signalLpEvent(&bevent->event);
+                vio_free_event_buffer(viomajorsubtype_blockio, bevent);
+        }
+
+        if (hvrc != HvLpEvent_Rc_Good) {
+                printk(VIOD_KERN_WARNING
+                       "error sending disk event to OS/400 (rc %d)\n",
+                       (int)hvrc);
+                goto error_ret;
+        }
+        spin_unlock_irqrestore(&viodasd_spinlock, flags);
+        return 0;
+
+error_ret:
+        num_req_outstanding--;
+        spin_unlock_irqrestore(&viodasd_spinlock, flags);
+        dma_unmap_sg(d->dev, sg, nsg, direction);
+        return -1;
+}
+
+/*
+ * This is the external request processing routine
+ */
+static void do_viodasd_request(request_queue_t *q)
+{
+        struct request *req;
+
+        /*
+         * If we already have the maximum number of requests
+         * outstanding to OS/400 just bail out. We'll come
+         * back later.
+         */
+        while (num_req_outstanding < VIOMAXREQ) {
+                req = elv_next_request(q);
+                if (req == NULL)
+                        return;
+                /* dequeue the current request from the queue */
+                blkdev_dequeue_request(req);
+                /* check that request contains a valid command */
+                if (!blk_fs_request(req)) {
+                        viodasd_end_request(req, 0, req->hard_nr_sectors);
+                        continue;
+                }
+                /* Try sending the request */
+                if (send_request(req) != 0)
+                        viodasd_end_request(req, 0, req->hard_nr_sectors);
+        }
+}
+
+/*
+ * Probe a single disk and fill in the viodasd_device structure
+ * for it.
+ */
+static void probe_disk(struct viodasd_device *d)
+{
+        HvLpEvent_Rc hvrc;
+        struct viodasd_waitevent we;
+        int dev_no = DEVICE_NO(d);
+        struct gendisk *g;
+        struct request_queue *q;
+        u16 flags = 0;
+
+retry:
+        init_completion(&we.com);
+
+        /* Send the open event to OS/400 */
+        hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+                        HvLpEvent_Type_VirtualIo,
+                        viomajorsubtype_blockio | vioblockopen,
+                        HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
+                        viopath_sourceinst(viopath_hostLp),
+                        viopath_targetinst(viopath_hostLp),
+                        (u64)(unsigned long)&we, VIOVERSION << 16,
+                        ((u64)dev_no << 48) | ((u64)flags<< 32),
+                        0, 0, 0);
+        if (hvrc != 0) {
+                printk(VIOD_KERN_WARNING "bad rc on HV open %d\n", (int)hvrc);
+                return;
+        }
+
+        wait_for_completion(&we.com);
+
+        if (we.rc != 0) {
+                if (flags != 0)
+                        return;
+                /* try again with read only flag set */
+                flags = vioblockflags_ro;
+                goto retry;
+        }
+        if (we.max_disk > (MAX_DISKNO - 1)) {
+                static int warned;
+
+                if (warned == 0) {
+                        warned++;
+                        printk(VIOD_KERN_INFO
+                                "Only examining the first %d "
+                                "of %d disks connected\n",
+                                MAX_DISKNO, we.max_disk + 1);
+                }
+        }
+
+        /* Send the close event to OS/400.  We DON'T expect a response */
+        hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
+                        HvLpEvent_Type_VirtualIo,
+                        viomajorsubtype_blockio | vioblockclose,
+                        HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
+                        viopath_sourceinst(viopath_hostLp),
+                        viopath_targetinst(viopath_hostLp),
+                        0, VIOVERSION << 16,
+                        ((u64)dev_no << 48) | ((u64)flags << 32),
+                        0, 0, 0);
+        if (hvrc != 0) {
+                printk(VIOD_KERN_WARNING
+                       "bad rc sending event to OS/400 %d\n", (int)hvrc);
+                return;
+        }
+        /* create the request queue for the disk */
+        spin_lock_init(&d->q_lock);
+        q = blk_init_queue(do_viodasd_request, &d->q_lock);
+        if (q == NULL) {
+                printk(VIOD_KERN_WARNING "cannot allocate queue for disk %d\n",
+                                dev_no);
+                return;
+        }
+        g = alloc_disk(1 << PARTITION_SHIFT);
+        if (g == NULL) {
+                printk(VIOD_KERN_WARNING
+                                "cannot allocate disk structure for disk %d\n",
+                                dev_no);
+                blk_cleanup_queue(q);
+                return;
+        }
+
+        d->disk = g;
+        blk_queue_max_hw_segments(q, VIOMAXBLOCKDMA);
+        blk_queue_max_phys_segments(q, VIOMAXBLOCKDMA);
+        blk_queue_max_sectors(q, VIODASD_MAXSECTORS);
+        g->major = VIODASD_MAJOR;
+        g->first_minor = dev_no << PARTITION_SHIFT;
+        if (dev_no >= 26)
+                snprintf(g->disk_name, sizeof(g->disk_name),
+                                VIOD_GENHD_NAME "%c%c",
+                                'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26));
+        else
+                snprintf(g->disk_name, sizeof(g->disk_name),
+                                VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26));
+        snprintf(g->devfs_name, sizeof(g->devfs_name),
+                        "%s%d", VIOD_GENHD_DEVFS_NAME, dev_no);
+        g->fops = &viodasd_fops;
+        g->queue = q;
+        g->private_data = d;
+        g->driverfs_dev = d->dev;
+        set_capacity(g, d->size >> 9);
+
+        printk(VIOD_KERN_INFO "disk %d: %lu sectors (%lu MB) "
+                        "CHS=%d/%d/%d sector size %d%s\n",
+                        dev_no, (unsigned long)(d->size >> 9),
+                        (unsigned long)(d->size >> 20),
+                        (int)d->cylinders, (int)d->tracks,
+                        (int)d->sectors, (int)d->bytes_per_sector,
+                        d->read_only ? " (RO)" : "");
+
+        /* register us in the global list */
+        add_disk(g);
+}
+
+/* returns the total number of scatterlist elements converted */
+static int block_event_to_scatterlist(const struct vioblocklpevent *bevent,
+                struct scatterlist *sg, int *total_len)
+{
+        int i, numsg;
+        const struct rw_data *rw_data = &bevent->u.rw_data;
+        static const int offset =
+                offsetof(struct vioblocklpevent, u.rw_data.dma_info);
+        static const int element_size = sizeof(rw_data->dma_info[0]);
+
+        numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size;
+        if (numsg > VIOMAXBLOCKDMA)
+                numsg = VIOMAXBLOCKDMA;
+
+        *total_len = 0;
+        memset(sg, 0, sizeof(sg[0]) * VIOMAXBLOCKDMA);
+
+        for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) {
+                sg_dma_address(&sg[i]) = rw_data->dma_info[i].token;
+                sg_dma_len(&sg[i]) = rw_data->dma_info[i].len;
+                *total_len += rw_data->dma_info[i].len;
+        }
+        return i;
+}
+
+/*
+ * Restart all queues, starting with the one _after_ the disk given,
+ * thus reducing the chance of starvation of higher numbered disks.
+ */
+static void viodasd_restart_all_queues_starting_from(int first_index)
+{
+        int i;
+
+        for (i = first_index + 1; i < MAX_DISKNO; ++i)
+                if (viodasd_devices[i].disk)
+                        blk_run_queue(viodasd_devices[i].disk->queue);
+        for (i = 0; i <= first_index; ++i)
+                if (viodasd_devices[i].disk)
+                        blk_run_queue(viodasd_devices[i].disk->queue);
+}
+
+/*
+ * For read and write requests, decrement the number of outstanding requests,
+ * Free the DMA buffers we allocated.
+ */
+static int viodasd_handle_read_write(struct vioblocklpevent *bevent)
+{
+        int num_sg, num_sect, pci_direction, total_len;
+        struct request *req;
+        struct scatterlist sg[VIOMAXBLOCKDMA];
+        struct HvLpEvent *event = &bevent->event;
+        unsigned long irq_flags;
+        struct viodasd_device *d;
+        int error;
+        spinlock_t *qlock;
+
+        num_sg = block_event_to_scatterlist(bevent, sg, &total_len);
+        num_sect = total_len >> 9;
+        if (event->xSubtype == (viomajorsubtype_blockio | vioblockread))
+                pci_direction = DMA_FROM_DEVICE;
+        else
+                pci_direction = DMA_TO_DEVICE;
+        req = (struct request *)bevent->event.xCorrelationToken;
+        d = req->rq_disk->private_data;
+
+        dma_unmap_sg(d->dev, sg, num_sg, pci_direction);
+
+        /*
+         * Since this is running in interrupt mode, we need to make sure
+         * we're not stepping on any global I/O operations
+         */
+        spin_lock_irqsave(&viodasd_spinlock, irq_flags);
+        num_req_outstanding--;
+        spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
+
+        error = event->xRc != HvLpEvent_Rc_Good;
+        if (error) {
+                const struct vio_error_entry *err;
+                err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
+                printk(VIOD_KERN_WARNING "read/write error %d:0x%04x (%s)\n",
+                                event->xRc, bevent->sub_result, err->msg);
+                num_sect = req->hard_nr_sectors;
+        }
+        qlock = req->q->queue_lock;
+        spin_lock_irqsave(qlock, irq_flags);
+        viodasd_end_request(req, !error, num_sect);
+        spin_unlock_irqrestore(qlock, irq_flags);
+
+        /* Finally, try to get more requests off of this device's queue */
+        viodasd_restart_all_queues_starting_from(DEVICE_NO(d));
+
+        return 0;
+}
+
+/* This routine handles incoming block LP events */
+static void handle_block_event(struct HvLpEvent *event)
+{
+        struct vioblocklpevent *bevent = (struct vioblocklpevent *)event;
+        struct viodasd_waitevent *pwe;
+
+        if (event == NULL)
+                /* Notification that a partition went away! */
+                return;
+        /* First, we should NEVER get an int here...only acks */
+        if (event->xFlags.xFunction == HvLpEvent_Function_Int) {
+                printk(VIOD_KERN_WARNING
+                       "Yikes! got an int in viodasd event handler!\n");
+                if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
+                        event->xRc = HvLpEvent_Rc_InvalidSubtype;
+                        HvCallEvent_ackLpEvent(event);
+                }
+        }
+
+        switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
+        case vioblockopen:
+                /*
+                 * Handle a response to an open request.  We get all the
+                 * disk information in the response, so update it.  The
+                 * correlation token contains a pointer to a waitevent
+                 * structure that has a completion in it.  update the
+                 * return code in the waitevent structure and post the
+                 * completion to wake up the guy who sent the request
+                 */
+                pwe = (struct viodasd_waitevent *)event->xCorrelationToken;
+                pwe->rc = event->xRc;
+                pwe->sub_result = bevent->sub_result;
+                if (event->xRc == HvLpEvent_Rc_Good) {
+                        const struct open_data *data = &bevent->u.open_data;
+                        struct viodasd_device *device =
+                                &viodasd_devices[bevent->disk];
+                        device->read_only =
+                                bevent->flags & vioblockflags_ro;
+                        device->size = data->disk_size;
+                        device->cylinders = data->cylinders;
+                        device->tracks = data->tracks;
+                        device->sectors = data->sectors;
+                        device->bytes_per_sector = data->bytes_per_sector;
+                        pwe->max_disk = data->max_disk;
+                }
+                complete(&pwe->com);
+                break;
+        case vioblockclose:
+                break;
+        case vioblockread:
+        case vioblockwrite:
+                viodasd_handle_read_write(bevent);
+                break;
+
+        default:
+                printk(VIOD_KERN_WARNING "invalid subtype!");
+                if (event->xFlags.xAckInd == HvLpEvent_AckInd_DoAck) {
+                        event->xRc = HvLpEvent_Rc_InvalidSubtype;
+                        HvCallEvent_ackLpEvent(event);
+                }
+        }
+}
+
+/*
+ * Get the driver to reprobe for more disks.
+ */
+static ssize_t probe_disks(struct device_driver *drv, const char *buf,
+                size_t count)
+{
+        struct viodasd_device *d;
+
+        for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) {
+                if (d->disk == NULL)
+                        probe_disk(d);
+        }
+        return count;
+}
+static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks);
+
+static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
+{
+        struct viodasd_device *d = &viodasd_devices[vdev->unit_address];
+
+        d->dev = &vdev->dev;
+        probe_disk(d);
+        if (d->disk == NULL)
+                return -ENODEV;
+        return 0;
+}
+
+static int viodasd_remove(struct vio_dev *vdev)
+{
+        struct viodasd_device *d;
+
+        d = &viodasd_devices[vdev->unit_address];
+        if (d->disk) {
+                del_gendisk(d->disk);
+                blk_cleanup_queue(d->disk->queue);
+                put_disk(d->disk);
+                d->disk = NULL;
+        }
+        d->dev = NULL;
+        return 0;
+}
+
+/**
+ * viodasd_device_table: Used by vio.c to match devices that we
+ * support.
+ */
+static struct vio_device_id viodasd_device_table[] __devinitdata = {
+        { "viodasd", "" },
+        { 0, }
+};
+
+MODULE_DEVICE_TABLE(vio, viodasd_device_table);
+static struct vio_driver viodasd_driver = {
+        .name = "viodasd",
+        .id_table = viodasd_device_table,
+        .probe = viodasd_probe,
+        .remove = viodasd_remove
+};
+
+/*
+ * Initialize the whole device driver.  Handle module and non-module
+ * versions
+ */
+static int __init viodasd_init(void)
+{
+        int rc;
+
+        /* Try to open to our host lp */
+        if (viopath_hostLp == HvLpIndexInvalid)
+                vio_set_hostlp();
+
+        if (viopath_hostLp == HvLpIndexInvalid) {
+                printk(VIOD_KERN_WARNING "invalid hosting partition\n");
+                return -EIO;
+        }
+
+        printk(VIOD_KERN_INFO "vers " VIOD_VERS ", hosting partition %d\n",
+                        viopath_hostLp);
+
+        /* register the block device */
+        if (register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME)) {
+                printk(VIOD_KERN_WARNING
+                                "Unable to get major number %d for %s\n",
+                                VIODASD_MAJOR, VIOD_GENHD_NAME);
+                return -EIO;
+        }
+        /* Actually open the path to the hosting partition */
+        if (viopath_open(viopath_hostLp, viomajorsubtype_blockio,
+                                VIOMAXREQ + 2)) {
+                printk(VIOD_KERN_WARNING
+                       "error opening path to host partition %d\n",
+                       viopath_hostLp);
+                unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
+                return -EIO;
+        }
+
+        /* Initialize our request handler */
+        vio_setHandler(viomajorsubtype_blockio, handle_block_event);
+
+        rc = vio_register_driver(&viodasd_driver);
+        if (rc == 0)
+                driver_create_file(&viodasd_driver.driver, &driver_attr_probe);
+        return rc;
+}
+module_init(viodasd_init);
+
+void viodasd_exit(void)
+{
+        driver_remove_file(&viodasd_driver.driver, &driver_attr_probe);
+        vio_unregister_driver(&viodasd_driver);
+        vio_clearHandler(viomajorsubtype_blockio);
+        unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME);
+        viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2);
+}
+
+module_exit(viodasd_exit);