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/*
hptraid.c Copyright (C) 2001 Red Hat, Inc. All rights reserved.
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, or (at your option)
any later version.
You should have received a copy of the GNU General Public License
(for example /usr/src/linux/COPYING); if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Authors: Arjan van de Ven <arjanv@redhat.com>
Based on work
Copyleft (C) 2001 by Wilfried Weissmann <wweissmann@gmx.at>
Copyright (C) 1994-96 Marc ZYNGIER <zyngier@ufr-info-p7.ibp.fr>
Based on work done by Søren Schmidt for FreeBSD
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/genhd.h>
#include <linux/ioctl.h>
#include <linux/ide.h>
#include <asm/uaccess.h>
#include "ataraid.h"
static int hptraid_open(struct inode * inode, struct file * filp);
static int hptraid_release(struct inode * inode, struct file * filp);
static int hptraid_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
static int hptraid_make_request (request_queue_t *q, int rw, struct buffer_head * bh);
struct hptdisk {
kdev_t device;
unsigned long sectors;
struct block_device *bdev;
};
struct hptraid {
unsigned int stride;
unsigned int disks;
unsigned long sectors;
struct geom geom;
struct hptdisk disk[8];
unsigned long cutoff[8];
unsigned int cutoff_disks[8];
};
static struct raid_device_operations hptraid_ops = {
open: hptraid_open,
release: hptraid_release,
ioctl: hptraid_ioctl,
make_request: hptraid_make_request
};
static struct hptraid raid[16];
static int hptraid_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned int minor;
unsigned char val;
unsigned long sectors;
if (!inode || !inode->i_rdev)
return -EINVAL;
minor = MINOR(inode->i_rdev)>>SHIFT;
switch (cmd) {
case BLKGETSIZE: /* Return device size */
if (!arg) return -EINVAL;
sectors = ataraid_gendisk.part[MINOR(inode->i_rdev)].nr_sects;
if (MINOR(inode->i_rdev)&15)
return put_user(sectors, (unsigned long *) arg);
return put_user(raid[minor].sectors , (unsigned long *) arg);
break;
case HDIO_GETGEO:
{
struct hd_geometry *loc = (struct hd_geometry *) arg;
unsigned short bios_cyl;
if (!loc) return -EINVAL;
val = 255;
if (put_user(val, (byte *) &loc->heads)) return -EFAULT;
val=63;
if (put_user(val, (byte *) &loc->sectors)) return -EFAULT;
bios_cyl = raid[minor].sectors/63/255;
if (put_user(bios_cyl, (unsigned short *) &loc->cylinders)) return -EFAULT;
if (put_user((unsigned)ataraid_gendisk.part[MINOR(inode->i_rdev)].start_sect,
(unsigned long *) &loc->start)) return -EFAULT;
return 0;
}
case HDIO_GETGEO_BIG:
{
struct hd_big_geometry *loc = (struct hd_big_geometry *) arg;
unsigned int bios_cyl;
if (!loc) return -EINVAL;
val = 255;
if (put_user(val, (byte *) &loc->heads)) return -EFAULT;
val = 63;
if (put_user(val, (byte *) &loc->sectors)) return -EFAULT;
bios_cyl = raid[minor].sectors/63/255;
if (put_user(bios_cyl, (unsigned int *) &loc->cylinders)) return -EFAULT;
if (put_user((unsigned)ataraid_gendisk.part[MINOR(inode->i_rdev)].start_sect,
(unsigned long *) &loc->start)) return -EFAULT;
return 0;
}
case BLKROSET:
case BLKROGET:
case BLKSSZGET:
return blk_ioctl(inode->i_rdev, cmd, arg);
default:
return -EINVAL;
};
return 0;
}
static int hptraid_make_request (request_queue_t *q, int rw, struct buffer_head * bh)
{
unsigned long rsect;
unsigned long rsect_left,rsect_accum = 0;
unsigned long block;
unsigned int disk=0,real_disk=0;
int i;
int device;
struct hptraid *thisraid;
rsect = bh->b_rsector;
/* Ok. We need to modify this sector number to a new disk + new sector number.
* If there are disks of different sizes, this gets tricky.
* Example with 3 disks (1Gb, 4Gb and 5 GB):
* The first 3 Gb of the "RAID" are evenly spread over the 3 disks.
* Then things get interesting. The next 2Gb (RAID view) are spread across disk 2 and 3
* and the last 1Gb is disk 3 only.
*
* the way this is solved is like this: We have a list of "cutoff" points where everytime
* a disk falls out of the "higher" count, we mark the max sector. So once we pass a cutoff
* point, we have to divide by one less.
*/
device = (bh->b_rdev >> SHIFT)&MAJOR_MASK;
thisraid = &raid[device];
if (thisraid->stride==0)
thisraid->stride=1;
/* Partitions need adding of the start sector of the partition to the requested sector */
rsect += ataraid_gendisk.part[MINOR(bh->b_rdev)].start_sect;
/* Woops we need to split the request to avoid crossing a stride barrier */
if ((rsect/thisraid->stride) != ((rsect+(bh->b_size/512)-1)/thisraid->stride)) {
return -1;
}
rsect_left = rsect;
for (i=0;i<8;i++) {
if (thisraid->cutoff_disks[i]==0)
break;
if (rsect > thisraid->cutoff[i]) {
/* we're in the wrong area so far */
rsect_left -= thisraid->cutoff[i];
rsect_accum += thisraid->cutoff[i]/thisraid->cutoff_disks[i];
} else {
block = rsect_left / thisraid->stride;
disk = block % thisraid->cutoff_disks[i];
block = (block / thisraid->cutoff_disks[i]) * thisraid->stride;
rsect = rsect_accum + (rsect_left % thisraid->stride) + block;
break;
}
}
for (i=0;i<8;i++) {
if ((disk==0) && (thisraid->disk[i].sectors > rsect_accum)) {
real_disk = i;
break;
}
if ((disk>0) && (thisraid->disk[i].sectors >= rsect_accum)) {
disk--;
}
}
disk = real_disk;
/* All but the first disk have a 10 sector offset */
if (i>0)
rsect+=10;
/*
* The new BH_Lock semantics in ll_rw_blk.c guarantee that this
* is the only IO operation happening on this bh.
*/
bh->b_rdev = thisraid->disk[disk].device;
bh->b_rsector = rsect;
/*
* Let the main block layer submit the IO and resolve recursion:
*/
return 1;
}
#include "hptraid.h"
static int read_disk_sb (int major, int minor, unsigned char *buffer,int bufsize)
{
int ret = -EINVAL;
struct buffer_head *bh = NULL;
kdev_t dev = MKDEV(major,minor);
if (blksize_size[major]==NULL) /* device doesn't exist */
return -EINVAL;
/* Superblock is at 4096+412 bytes */
set_blocksize (dev, 4096);
bh = bread (dev, 1, 4096);
if (bh) {
memcpy (buffer, bh->b_data, bufsize);
} else {
printk(KERN_ERR "hptraid: Error reading superblock.\n");
goto abort;
}
ret = 0;
abort:
if (bh)
brelse (bh);
return ret;
}
static unsigned long maxsectors (int major,int minor)
{
unsigned long lba = 0;
kdev_t dev;
ide_drive_t *ideinfo;
dev = MKDEV(major,minor);
ideinfo = get_info_ptr (dev);
if (ideinfo==NULL)
return 0;
/* first sector of the last cluster */
if (ideinfo->head==0)
return 0;
if (ideinfo->sect==0)
return 0;
lba = (ideinfo->capacity);
return lba;
}
static void __init probedisk(int major, int minor,int device)
{
int i;
struct highpoint_raid_conf *prom;
static unsigned char block[4096];
struct block_device *bdev;
if (maxsectors(major,minor)==0)
return;
if (read_disk_sb(major,minor,(unsigned char*)&block,sizeof(block)))
return;
prom = (struct highpoint_raid_conf*)&block[512];
if (prom->magic!= 0x5a7816f0)
return;
if (prom->type) {
printk(KERN_INFO "hptraid: only RAID0 is supported currently\n");
return;
}
i = prom->disk_number;
if (i<0)
return;
if (i>8)
return;
bdev = bdget(MKDEV(major,minor));
if (bdev && blkdev_get(bdev,FMODE_READ|FMODE_WRITE,0,BDEV_RAW) == 0) {
int j=0;
struct gendisk *gd;
raid[device].disk[i].bdev = bdev;
/* This is supposed to prevent others from stealing our underlying disks */
/* now blank the /proc/partitions table for the wrong partition table,
so that scripts don't accidentally mount it and crash the kernel */
/* XXX: the 0 is an utter hack --hch */
gd=get_gendisk(MKDEV(major, 0));
if (gd!=NULL) {
for (j=1+(minor<<gd->minor_shift);j<((minor+1)<<gd->minor_shift);j++)
gd->part[j].nr_sects=0;
}
}
raid[device].disk[i].device = MKDEV(major,minor);
raid[device].disk[i].sectors = maxsectors(major,minor);
raid[device].stride = (1<<prom->raid0_shift);
raid[device].disks = prom->raid_disks;
raid[device].sectors = prom->total_secs;
}
static void __init fill_cutoff(int device)
{
int i,j;
unsigned long smallest;
unsigned long bar;
int count;
bar = 0;
for (i=0;i<8;i++) {
smallest = ~0;
for (j=0;j<8;j++)
if ((raid[device].disk[j].sectors < smallest) && (raid[device].disk[j].sectors>bar))
smallest = raid[device].disk[j].sectors;
count = 0;
for (j=0;j<8;j++)
if (raid[device].disk[j].sectors >= smallest)
count++;
smallest = smallest * count;
bar = smallest;
raid[device].cutoff[i] = smallest;
raid[device].cutoff_disks[i] = count;
}
}
static __init int hptraid_init_one(int device)
{
int i,count;
probedisk(IDE0_MAJOR, 0, device);
probedisk(IDE0_MAJOR, 64, device);
probedisk(IDE1_MAJOR, 0, device);
probedisk(IDE1_MAJOR, 64, device);
probedisk(IDE2_MAJOR, 0, device);
probedisk(IDE2_MAJOR, 64, device);
probedisk(IDE3_MAJOR, 0, device);
probedisk(IDE3_MAJOR, 64, device);
fill_cutoff(device);
/* Initialize the gendisk structure */
ataraid_register_disk(device,raid[device].sectors);
count=0;
printk(KERN_INFO "Highpoint HPT370 Softwareraid driver for linux version 0.01\n");
for (i=0;i<8;i++) {
if (raid[device].disk[i].device!=0) {
printk(KERN_INFO "Drive %i is %li Mb \n",
i,raid[device].disk[i].sectors/2048);
count++;
}
}
if (count) {
printk(KERN_INFO "Raid array consists of %i drives. \n",count);
return 0;
} else {
printk(KERN_INFO "No raid array found\n");
return -ENODEV;
}
}
static __init int hptraid_init(void)
{
int retval,device;
device=ataraid_get_device(&hptraid_ops);
if (device<0)
return -ENODEV;
retval = hptraid_init_one(device);
if (retval)
ataraid_release_device(device);
return retval;
}
static void __exit hptraid_exit (void)
{
int i,device;
for (device = 0; device<16; device++) {
for (i=0;i<8;i++) {
struct block_device *bdev = raid[device].disk[i].bdev;
raid[device].disk[i].bdev = NULL;
if (bdev)
blkdev_put(bdev, BDEV_RAW);
}
if (raid[device].sectors)
ataraid_release_device(device);
}
}
static int hptraid_open(struct inode * inode, struct file * filp)
{
MOD_INC_USE_COUNT;
return 0;
}
static int hptraid_release(struct inode * inode, struct file * filp)
{
MOD_DEC_USE_COUNT;
return 0;
}
module_init(hptraid_init);
module_exit(hptraid_exit);
MODULE_LICENSE("GPL");
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