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author | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2004-02-20 11:15:03 +0000 |
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committer | kaf24@scramble.cl.cam.ac.uk <kaf24@scramble.cl.cam.ac.uk> | 2004-02-20 11:15:03 +0000 |
commit | 92207c117ac7c3b4f3304fb6855575844da73980 (patch) | |
tree | 3e9d4af5dbfb9619d7288c0f84d22643a5cd1b71 /xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c | |
parent | b39cfce3243dfbfa5d877425adad77a108fb1094 (diff) | |
download | xen-92207c117ac7c3b4f3304fb6855575844da73980.tar.gz xen-92207c117ac7c3b4f3304fb6855575844da73980.tar.bz2 xen-92207c117ac7c3b4f3304fb6855575844da73980.zip |
bitkeeper revision 1.735 (4035ec37QrObBVUp0-0jtnp646Qg3g)
xenolinux-sparse:
new file
Many files:
Port to linux-2.4.25
.del-xenolinux-sparse~6c1e6e8b9138ffe9:
Delete: xenolinux-sparse
Many files:
mvdir
Diffstat (limited to 'xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c')
-rw-r--r-- | xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c b/xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c new file mode 100644 index 0000000000..0677096b84 --- /dev/null +++ b/xenolinux-2.4.25-sparse/arch/xeno/drivers/block/xl_vbd.c @@ -0,0 +1,551 @@ +/****************************************************************************** + * xl_vbd.c + * + * Xenolinux virtual block-device driver (xvd). + * + * Copyright (c) 2003-2004, Keir Fraser & Steve Hand + * Modifications by Mark A. Williamson are (c) Intel Research Cambridge + */ + +#include "xl_block.h" +#include <linux/blk.h> + +/* + * For convenience we distinguish between ide, scsi and 'other' (i.e. + * potentially combinations of the two) in the naming scheme and in a few + * other places (like default readahead, etc). + */ +#define XLIDE_MAJOR_NAME "hd" +#define XLSCSI_MAJOR_NAME "sd" +#define XLVBD_MAJOR_NAME "xvd" + +#define XLIDE_DEVS_PER_MAJOR 2 +#define XLSCSI_DEVS_PER_MAJOR 16 +#define XLVBD_DEVS_PER_MAJOR 16 + +#define XLIDE_PARTN_SHIFT 6 /* amount to shift minor to get 'real' minor */ +#define XLIDE_MAX_PART (1 << XLIDE_PARTN_SHIFT) /* minors per ide vbd */ + +#define XLSCSI_PARTN_SHIFT 4 /* amount to shift minor to get 'real' minor */ +#define XLSCSI_MAX_PART (1 << XLSCSI_PARTN_SHIFT) /* minors per scsi vbd */ + +#define XLVBD_PARTN_SHIFT 4 /* amount to shift minor to get 'real' minor */ +#define XLVBD_MAX_PART (1 << XLVBD_PARTN_SHIFT) /* minors per 'other' vbd */ + +/* The below are for the generic drivers/block/ll_rw_block.c code. */ +static int xlide_blksize_size[256]; +static int xlide_hardsect_size[256]; +static int xlide_max_sectors[256]; +static int xlscsi_blksize_size[256]; +static int xlscsi_hardsect_size[256]; +static int xlscsi_max_sectors[256]; +static int xlvbd_blksize_size[256]; +static int xlvbd_hardsect_size[256]; +static int xlvbd_max_sectors[256]; + +/* Information from Xen about our VBDs. */ +#define MAX_VBDS 64 +static int nr_vbds; +static xen_disk_t *vbd_info; + +static struct block_device_operations xlvbd_block_fops = +{ + open: xenolinux_block_open, + release: xenolinux_block_release, + ioctl: xenolinux_block_ioctl, + check_media_change: xenolinux_block_check, + revalidate: xenolinux_block_revalidate, +}; + +static int xlvbd_get_vbd_info(xen_disk_t *disk_info) +{ + int error; + block_io_op_t op; + + /* Probe for disk information. */ + memset(&op, 0, sizeof(op)); + op.cmd = BLOCK_IO_OP_VBD_PROBE; + op.u.probe_params.domain = 0; + op.u.probe_params.xdi.max = MAX_VBDS; + op.u.probe_params.xdi.disks = disk_info; + op.u.probe_params.xdi.count = 0; + + if ( (error = HYPERVISOR_block_io_op(&op)) != 0 ) + { + printk(KERN_ALERT "Could not probe disks (%d)\n", error); + return -1; + } + + return op.u.probe_params.xdi.count; +} + +/* + * xlvbd_init_device - initialise a VBD device + * @disk: a xen_disk_t describing the VBD + * + * Takes a xen_disk_t * that describes a VBD the domain has access to. + * Performs appropriate initialisation and registration of the device. + * + * Care needs to be taken when making re-entrant calls to ensure that + * corruption does not occur. Also, devices that are in use should not have + * their details updated. This is the caller's responsibility. + */ +static int xlvbd_init_device(xen_disk_t *xd) +{ + int device = xd->device; + int major = MAJOR(device); + int minor = MINOR(device); + int is_ide = IDE_DISK_MAJOR(major); /* is this an ide device? */ + int is_scsi= SCSI_BLK_MAJOR(major); /* is this a scsi device? */ + char *major_name; + struct gendisk *gd; + struct block_device *bd; + xl_disk_t *disk; + int i, rc = 0, max_part, partno; + unsigned long capacity; + + unsigned char buf[64]; + + if ( (bd = bdget(device)) == NULL ) + return -1; + + /* + * Update of partition info, and check of usage count, is protected + * by the per-block-device semaphore. + */ + down(&bd->bd_sem); + + if ( ((disk = xldev_to_xldisk(device)) != NULL) && (disk->usage != 0) ) + { + printk(KERN_ALERT "VBD update failed - in use [dev=%x]\n", device); + rc = -1; + goto out; + } + + if ( is_ide ) + { + major_name = XLIDE_MAJOR_NAME; + max_part = XLIDE_MAX_PART; + } + else if ( is_scsi ) + { + major_name = XLSCSI_MAJOR_NAME; + max_part = XLSCSI_MAX_PART; + } + else + { + major_name = XLVBD_MAJOR_NAME; + max_part = XLVBD_MAX_PART; + } + + partno = minor & (max_part - 1); + + if ( (gd = get_gendisk(device)) == NULL ) + { + rc = register_blkdev(major, major_name, &xlvbd_block_fops); + if ( rc < 0 ) + { + printk(KERN_ALERT "XL VBD: can't get major %d\n", major); + goto out; + } + + if ( is_ide ) + { + blksize_size[major] = xlide_blksize_size; + hardsect_size[major] = xlide_hardsect_size; + max_sectors[major] = xlide_max_sectors; + read_ahead[major] = 8; /* from drivers/ide/ide-probe.c */ + } + else if ( is_scsi ) + { + blksize_size[major] = xlscsi_blksize_size; + hardsect_size[major] = xlscsi_hardsect_size; + max_sectors[major] = xlscsi_max_sectors; + read_ahead[major] = 0; /* XXX 8; -- guessing */ + } + else + { + blksize_size[major] = xlvbd_blksize_size; + hardsect_size[major] = xlvbd_hardsect_size; + max_sectors[major] = xlvbd_max_sectors; + read_ahead[major] = 8; + } + + blk_init_queue(BLK_DEFAULT_QUEUE(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(major), 0); + + /* Construct an appropriate gendisk structure. */ + gd = kmalloc(sizeof(struct gendisk), GFP_KERNEL); + gd->major = major; + gd->major_name = major_name; + + gd->max_p = max_part; + if ( is_ide ) + { + gd->minor_shift = XLIDE_PARTN_SHIFT; + gd->nr_real = XLIDE_DEVS_PER_MAJOR; + } + else if ( is_scsi ) + { + gd->minor_shift = XLSCSI_PARTN_SHIFT; + gd->nr_real = XLSCSI_DEVS_PER_MAJOR; + } + else + { + gd->minor_shift = XLVBD_PARTN_SHIFT; + gd->nr_real = XLVBD_DEVS_PER_MAJOR; + } + + /* + ** The sizes[] and part[] arrays hold the sizes and other + ** information about every partition with this 'major' (i.e. + ** every disk sharing the 8 bit prefix * max partns per disk) + */ + gd->sizes = kmalloc(max_part*gd->nr_real*sizeof(int), GFP_KERNEL); + gd->part = kmalloc(max_part*gd->nr_real*sizeof(struct hd_struct), + GFP_KERNEL); + memset(gd->sizes, 0, max_part * gd->nr_real * sizeof(int)); + memset(gd->part, 0, max_part * gd->nr_real + * sizeof(struct hd_struct)); + + + gd->real_devices = kmalloc(gd->nr_real * sizeof(xl_disk_t), + GFP_KERNEL); + memset(gd->real_devices, 0, gd->nr_real * sizeof(xl_disk_t)); + + gd->next = NULL; + gd->fops = &xlvbd_block_fops; + + gd->de_arr = kmalloc(gd->nr_real * sizeof(*gd->de_arr), + GFP_KERNEL); + gd->flags = kmalloc(gd->nr_real * sizeof(*gd->flags), GFP_KERNEL); + + memset(gd->de_arr, 0, gd->nr_real * sizeof(*gd->de_arr)); + memset(gd->flags, 0, gd->nr_real * sizeof(*gd->flags)); + + add_gendisk(gd); + + blk_size[major] = gd->sizes; + } + + if ( XD_READONLY(xd->info) ) + set_device_ro(device, 1); + + gd->flags[minor >> gd->minor_shift] |= GENHD_FL_XENO; + + /* NB. Linux 2.4 only handles 32-bit sector offsets and capacities. */ + capacity = (unsigned long)xd->capacity; + + if ( partno != 0 ) + { + /* + * If this was previously set up as a real disc we will have set + * up partition-table information. Virtual partitions override + * 'real' partitions, and the two cannot coexist on a device. + */ + if ( !(gd->flags[minor >> gd->minor_shift] & GENHD_FL_VIRT_PARTNS) && + (gd->sizes[minor & ~(max_part-1)] != 0) ) + { + /* + * Any non-zero sub-partition entries must be cleaned out before + * installing 'virtual' partition entries. The two types cannot + * coexist, and virtual partitions are favoured. + */ + kdev_t dev = device & ~(max_part-1); + for ( i = max_part - 1; i > 0; i-- ) + { + invalidate_device(dev+i, 1); + gd->part[MINOR(dev+i)].start_sect = 0; + gd->part[MINOR(dev+i)].nr_sects = 0; + gd->sizes[MINOR(dev+i)] = 0; + } + printk(KERN_ALERT + "Virtual partitions found for /dev/%s - ignoring any " + "real partition information we may have found.\n", + disk_name(gd, MINOR(device), buf)); + } + + /* Need to skankily setup 'partition' information */ + gd->part[minor].start_sect = 0; + gd->part[minor].nr_sects = capacity; + gd->sizes[minor] = capacity; + + gd->flags[minor >> gd->minor_shift] |= GENHD_FL_VIRT_PARTNS; + } + else + { + gd->part[minor].nr_sects = capacity; + gd->sizes[minor] = capacity>>(BLOCK_SIZE_BITS-9); + + /* Some final fix-ups depending on the device type */ + switch ( XD_TYPE(xd->info) ) + { + case XD_TYPE_CDROM: + case XD_TYPE_FLOPPY: + case XD_TYPE_TAPE: + gd->flags[minor >> gd->minor_shift] |= GENHD_FL_REMOVABLE; + printk(KERN_ALERT + "Skipping partition check on %s /dev/%s\n", + XD_TYPE(xd->info)==XD_TYPE_CDROM ? "cdrom" : + (XD_TYPE(xd->info)==XD_TYPE_TAPE ? "tape" : + "floppy"), disk_name(gd, MINOR(device), buf)); + break; + + case XD_TYPE_DISK: + /* Only check partitions on real discs (not virtual!). */ + if ( gd->flags[minor>>gd->minor_shift] & GENHD_FL_VIRT_PARTNS ) + { + printk(KERN_ALERT + "Skipping partition check on virtual /dev/%s\n", + disk_name(gd, MINOR(device), buf)); + break; + } + register_disk(gd, device, gd->max_p, &xlvbd_block_fops, capacity); + break; + + default: + printk(KERN_ALERT "XenoLinux: unknown device type %d\n", + XD_TYPE(xd->info)); + break; + } + } + + out: + up(&bd->bd_sem); + bdput(bd); + return rc; +} + + +/* + * xlvbd_remove_device - remove a device node if possible + * @device: numeric device ID + * + * Updates the gendisk structure and invalidates devices. + * + * This is OK for now but in future, should perhaps consider where this should + * deallocate gendisks / unregister devices. + */ +static int xlvbd_remove_device(int device) +{ + int i, rc = 0, minor = MINOR(device); + struct gendisk *gd; + struct block_device *bd; + xl_disk_t *disk = NULL; + + if ( (bd = bdget(device)) == NULL ) + return -1; + + /* + * Update of partition info, and check of usage count, is protected + * by the per-block-device semaphore. + */ + down(&bd->bd_sem); + + if ( ((gd = get_gendisk(device)) == NULL) || + ((disk = xldev_to_xldisk(device)) == NULL) ) + BUG(); + + if ( disk->usage != 0 ) + { + printk(KERN_ALERT "VBD removal failed - in use [dev=%x]\n", device); + rc = -1; + goto out; + } + + if ( (minor & (gd->max_p-1)) != 0 ) + { + /* 1: The VBD is mapped to a partition rather than a whole unit. */ + invalidate_device(device, 1); + gd->part[minor].start_sect = 0; + gd->part[minor].nr_sects = 0; + gd->sizes[minor] = 0; + + /* Clear the consists-of-virtual-partitions flag if possible. */ + gd->flags[minor >> gd->minor_shift] &= ~GENHD_FL_VIRT_PARTNS; + for ( i = 1; i < gd->max_p; i++ ) + if ( gd->sizes[(minor & ~(gd->max_p-1)) + i] != 0 ) + gd->flags[minor >> gd->minor_shift] |= GENHD_FL_VIRT_PARTNS; + + /* + * If all virtual partitions are now gone, and a 'whole unit' VBD is + * present, then we can try to grok the unit's real partition table. + */ + if ( !(gd->flags[minor >> gd->minor_shift] & GENHD_FL_VIRT_PARTNS) && + (gd->sizes[minor & ~(gd->max_p-1)] != 0) && + !(gd->flags[minor >> gd->minor_shift] & GENHD_FL_REMOVABLE) ) + { + register_disk(gd, + device&~(gd->max_p-1), + gd->max_p, + &xlvbd_block_fops, + gd->part[minor&~(gd->max_p-1)].nr_sects); + } + } + else + { + /* + * 2: The VBD is mapped to an entire 'unit'. Clear all partitions. + * NB. The partition entries are only cleared if there are no VBDs + * mapped to individual partitions on this unit. + */ + i = gd->max_p - 1; /* Default: clear subpartitions as well. */ + if ( gd->flags[minor >> gd->minor_shift] & GENHD_FL_VIRT_PARTNS ) + i = 0; /* 'Virtual' mode: only clear the 'whole unit' entry. */ + while ( i >= 0 ) + { + invalidate_device(device+i, 1); + gd->part[minor+i].start_sect = 0; + gd->part[minor+i].nr_sects = 0; + gd->sizes[minor+i] = 0; + i--; + } + } + + out: + up(&bd->bd_sem); + bdput(bd); + return rc; +} + +/* + * xlvbd_update_vbds - reprobes the VBD status and performs updates driver + * state. The VBDs need to be updated in this way when the domain is + * initialised and also each time we receive an XLBLK_UPDATE event. + */ +void xlvbd_update_vbds(void) +{ + int i, j, k, old_nr, new_nr; + xen_disk_t *old_info, *new_info, *merged_info; + + old_info = vbd_info; + old_nr = nr_vbds; + + new_info = kmalloc(MAX_VBDS * sizeof(xen_disk_t), GFP_KERNEL); + if ( unlikely(new_nr = xlvbd_get_vbd_info(new_info)) < 0 ) + { + kfree(new_info); + return; + } + + /* + * Final list maximum size is old list + new list. This occurs only when + * old list and new list do not overlap at all, and we cannot yet destroy + * VBDs in the old list because the usage counts are busy. + */ + merged_info = kmalloc((old_nr + new_nr) * sizeof(xen_disk_t), GFP_KERNEL); + + /* @i tracks old list; @j tracks new list; @k tracks merged list. */ + i = j = k = 0; + + while ( (i < old_nr) && (j < new_nr) ) + { + if ( old_info[i].device < new_info[j].device ) + { + if ( xlvbd_remove_device(old_info[i].device) != 0 ) + memcpy(&merged_info[k++], &old_info[i], sizeof(xen_disk_t)); + i++; + } + else if ( old_info[i].device > new_info[j].device ) + { + if ( xlvbd_init_device(&new_info[j]) == 0 ) + memcpy(&merged_info[k++], &new_info[j], sizeof(xen_disk_t)); + j++; + } + else + { + if ( ((old_info[i].capacity == new_info[j].capacity) && + (old_info[i].info == new_info[j].info)) || + (xlvbd_remove_device(old_info[i].device) != 0) ) + memcpy(&merged_info[k++], &old_info[i], sizeof(xen_disk_t)); + else if ( xlvbd_init_device(&new_info[j]) == 0 ) + memcpy(&merged_info[k++], &new_info[j], sizeof(xen_disk_t)); + i++; j++; + } + } + + for ( ; i < old_nr; i++ ) + { + if ( xlvbd_remove_device(old_info[i].device) != 0 ) + memcpy(&merged_info[k++], &old_info[i], sizeof(xen_disk_t)); + } + + for ( ; j < new_nr; j++ ) + { + if ( xlvbd_init_device(&new_info[j]) == 0 ) + memcpy(&merged_info[k++], &new_info[j], sizeof(xen_disk_t)); + } + + vbd_info = merged_info; + nr_vbds = k; + + kfree(old_info); + kfree(new_info); +} + + +/* + * Set up all the linux device goop for the virtual block devices (vbd's) that + * xen tells us about. Note that although from xen's pov VBDs are addressed + * simply an opaque 16-bit device number, the domain creation tools + * conventionally allocate these numbers to correspond to those used by 'real' + * linux -- this is just for convenience as it means e.g. that the same + * /etc/fstab can be used when booting with or without xen. + */ +int __init xlvbd_init(void) +{ + int i; + + /* + * If compiled as a module, we don't support unloading yet. We therefore + * permanently increment the reference count to disallow it. + */ + SET_MODULE_OWNER(&xlvbd_block_fops); + MOD_INC_USE_COUNT; + + /* Initialize the global arrays. */ + for ( i = 0; i < 256; i++ ) + { + /* from the generic ide code (drivers/ide/ide-probe.c, etc) */ + xlide_blksize_size[i] = 1024; + xlide_hardsect_size[i] = 512; + xlide_max_sectors[i] = 128; /* 'hwif->rqsize' if we knew it */ + + /* from the generic scsi disk code (drivers/scsi/sd.c) */ + xlscsi_blksize_size[i] = 1024; /* XXX 512; */ + xlscsi_hardsect_size[i] = 512; + xlscsi_max_sectors[i] = 128*8; /* XXX 128; */ + + /* we don't really know what to set these too since it depends */ + xlvbd_blksize_size[i] = 512; + xlvbd_hardsect_size[i] = 512; + xlvbd_max_sectors[i] = 128; + } + + vbd_info = kmalloc(MAX_VBDS * sizeof(xen_disk_t), GFP_KERNEL); + nr_vbds = xlvbd_get_vbd_info(vbd_info); + + if ( nr_vbds < 0 ) + { + kfree(vbd_info); + vbd_info = NULL; + nr_vbds = 0; + } + else + { + for ( i = 0; i < nr_vbds; i++ ) + xlvbd_init_device(&vbd_info[i]); + } + + return 0; +} + + +#ifdef MODULE +module_init(xlvbd_init); +#endif |