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/******************************************************************************
* xl_segment.c
*
* Xenolinux virtual block-device driver (vhd).
*
*/
#include "xl_block.h"
#define MAJOR_NR XLVIRT_MAJOR
#include <linux/blk.h>
/* Copied from linux/ide.h */
typedef unsigned char byte;
/* We support up to 16 devices of up to 16 partitions each. */
#define XLVIRT_MAX 256
#define XLVIRT_MAJOR_NAME "xvd"
#define VIRT_PARTN_BITS 4
static int xlseg_blksize_size[XLVIRT_MAX];
static int xlseg_hardsect_size[XLVIRT_MAX];
static int xlseg_max_sectors[XLVIRT_MAX];
struct gendisk *xlsegment_gendisk = NULL;
static xen_disk_info_t xlseg_disk_info;
static struct block_device_operations xlsegment_block_fops =
{
open: xenolinux_block_open,
release: xenolinux_block_release,
ioctl: xenolinux_block_ioctl,
check_media_change: xenolinux_block_check,
revalidate: xenolinux_block_revalidate,
};
int xlsegment_hwsect(int minor)
{
return xlseg_hardsect_size[minor];
}
int __init xlseg_init(void)
{
int i, result, units, minors, disk;
xen_disk_info_t *xdi = &xlseg_disk_info;
struct gendisk *gd;
SET_MODULE_OWNER(&xlsegment_block_fops);
/* Probe for disk information. */
memset(xdi, 0, sizeof(*xdi));
xenolinux_control_msg(XEN_BLOCK_PROBE_SEG, (char *)xdi, sizeof(*xdi));
DPRINTK("vhd block device probe:\n");
for ( i = 0; i < xdi->count; i++ )
{
DPRINTK(" %2d: type: %d, capacity: %ld\n",
i, xdi->disks[i].type, xdi->disks[i].capacity);
}
result = register_blkdev(XLVIRT_MAJOR, XLVIRT_MAJOR_NAME,
&xlsegment_block_fops);
if ( result < 0 )
{
printk(KERN_ALERT "XL Segment: can't get major %d\n", XLVIRT_MAJOR);
return result;
}
/* Initialize global arrays. */
for (i = 0; i < XLVIRT_MAX; i++)
{
xlseg_blksize_size[i] = 512;
xlseg_hardsect_size[i] = 512;
xlseg_max_sectors[i] = 128;
}
blk_size[XLVIRT_MAJOR] = NULL;
blksize_size[XLVIRT_MAJOR] = xlseg_blksize_size;
hardsect_size[XLVIRT_MAJOR] = xlseg_hardsect_size;
max_sectors[XLVIRT_MAJOR] = xlseg_max_sectors;
read_ahead[XLVIRT_MAJOR] = 8;
blk_init_queue(BLK_DEFAULT_QUEUE(XLVIRT_MAJOR), do_xlblk_request);
/*
* Turn off barking 'headactive' mode. We dequeue buffer heads as
* soon as we pass them down to Xen.
*/
blk_queue_headactive(BLK_DEFAULT_QUEUE(XLVIRT_MAJOR), 0);
/*
* We may register up to 16 devices in a sparse identifier space.
* Unlike with IDE and SCSI, we always register a gendisk, as new
* virtual devices may get allocate dto us later on.
*/
units = 16;
/* Construct an appropriate gendisk structure. */
minors = units * (1<<VIRT_PARTN_BITS);
gd = kmalloc(sizeof(struct gendisk), GFP_KERNEL);
gd->sizes = kmalloc(minors * sizeof(int), GFP_KERNEL);
gd->part = kmalloc(minors * sizeof(struct hd_struct), GFP_KERNEL);
gd->major = XLVIRT_MAJOR;
gd->major_name = XLVIRT_MAJOR_NAME;
gd->minor_shift = VIRT_PARTN_BITS;
gd->max_p = 1<<VIRT_PARTN_BITS;
gd->nr_real = units;
gd->real_devices = kmalloc(units * sizeof(xl_disk_t), GFP_KERNEL);
gd->next = NULL;
gd->fops = &xlsegment_block_fops;
gd->de_arr = kmalloc(sizeof(*gd->de_arr) * units, GFP_KERNEL);
gd->flags = kmalloc(sizeof(*gd->flags) * units, GFP_KERNEL);
memset(gd->sizes, 0, minors * sizeof(int));
memset(gd->part, 0, minors * sizeof(struct hd_struct));
memset(gd->de_arr, 0, sizeof(*gd->de_arr) * units);
memset(gd->flags, 0, sizeof(*gd->flags) * units);
memset(gd->real_devices, 0, sizeof(xl_disk_t) * units);
xlsegment_gendisk = gd;
add_gendisk(gd);
/* Now register each disk in turn. */
for ( i = 0; i < xdi->count; i++ )
{
disk = xdi->disks[i].device & XENDEV_IDX_MASK;
/* We can use the first 16 IDE devices. */
if ( !IS_VIRTUAL_XENDEV(xdi->disks[i].device) || (disk >= 16) )
continue;
((xl_disk_t *)gd->real_devices)[disk].capacity =
xdi->disks[i].capacity;
register_disk(gd,
MKDEV(XLVIRT_MAJOR, disk<<VIRT_PARTN_BITS),
1<<VIRT_PARTN_BITS,
&xlsegment_block_fops,
xdi->disks[i].capacity);
}
printk(KERN_ALERT
"XenoLinux Virtual Segment Device Driver installed [device: %d]\n",
XLVIRT_MAJOR);
return 0;
}
static void __exit xlseg_cleanup(void)
{
if ( xlsegment_gendisk == NULL ) return;
blk_cleanup_queue(BLK_DEFAULT_QUEUE(XLVIRT_MAJOR));
xlsegment_gendisk = NULL;
read_ahead[XLVIRT_MAJOR] = 0;
if ( blksize_size[XLVIRT_MAJOR] != NULL )
{
kfree(blksize_size[XLVIRT_MAJOR]);
blksize_size[XLVIRT_MAJOR] = NULL;
}
if ( hardsect_size[XLVIRT_MAJOR] != NULL )
{
kfree(hardsect_size[XLVIRT_MAJOR]);
hardsect_size[XLVIRT_MAJOR] = NULL;
}
if ( max_sectors[XLVIRT_MAJOR] != NULL )
{
kfree(max_sectors[XLVIRT_MAJOR]);
max_sectors[XLVIRT_MAJOR] = NULL;
}
if ( unregister_blkdev(XLVIRT_MAJOR, XLVIRT_MAJOR_NAME) != 0 )
{
printk(KERN_ALERT
"XenoLinux Virtual Segment Device Driver"
" uninstalled w/ errs\n");
}
}
#ifdef MODULE
module_init(xlseg_init);
module_exit(xlseg_cleanup);
#endif
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