Viewing file:  hd.c (21.35 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* linux/drivers/ide/hd.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
/*
* This is the low-level hd interrupt support. It traverses the
* request-list, using interrupts to jump between functions. As
* all the functions are called within interrupts, we may not
* sleep. Special care is recommended.
*
* modified by Drew Eckhardt to check nr of hd's from the CMOS.
*
* Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug
* in the early extended-partition checks and added DM partitions
*
* IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
* and general streamlining by Mark Lord.
*
* Removed 99% of above. Use Mark's ide driver for those options.
* This is now a lightweight ST-506 driver. (Paul Gortmaker)
*
* Modified 1995 Russell King for ARM processor.
*
* Bugfix: max_sectors must be <= 255 or the wheels tend to come
* off in a hurry once you queue things up - Paul G. 02/2001
*/
/* Uncomment the following if you want verbose error reports. */
/* #define VERBOSE_ERRORS */
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/kernel.h>
#include <linux/hdreg.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/mc146818rtc.h> /* CMOS defines */
#include <linux/init.h>
#include <linux/blkpg.h>
#define REALLY_SLOW_IO
#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#define MAJOR_NR HD_MAJOR
#include <linux/blk.h>
#ifdef __arm__
#undef HD_IRQ
#endif
#include <asm/irq.h>
#ifdef __arm__
#define HD_IRQ IRQ_HARDDISK
#endif
static int revalidate_hddisk(kdev_t, int);
#define HD_DELAY 0
#define MAX_ERRORS 16 /* Max read/write errors/sector */
#define RESET_FREQ 8 /* Reset controller every 8th retry */
#define RECAL_FREQ 4 /* Recalibrate every 4th retry */
#define MAX_HD 2
#define STAT_OK (READY_STAT|SEEK_STAT)
#define OK_STATUS(s) (((s)&(STAT_OK|(BUSY_STAT|WRERR_STAT|ERR_STAT)))==STAT_OK)
static void recal_intr(void);
static void bad_rw_intr(void);
static char recalibrate[MAX_HD];
static char special_op[MAX_HD];
static int access_count[MAX_HD];
static char busy[MAX_HD];
static DECLARE_WAIT_QUEUE_HEAD(busy_wait);
static int reset;
static int hd_error;
#define SUBSECTOR(block) (CURRENT->current_nr_sectors > 0)
/*
* This struct defines the HD's and their types.
*/
struct hd_i_struct {
unsigned int head,sect,cyl,wpcom,lzone,ctl;
};
#ifdef HD_TYPE
static struct hd_i_struct hd_info[] = { HD_TYPE };
static int NR_HD = ((sizeof (hd_info))/(sizeof (struct hd_i_struct)));
#else
static struct hd_i_struct hd_info[MAX_HD];
static int NR_HD;
#endif
static struct hd_struct hd[MAX_HD<<6];
static int hd_sizes[MAX_HD<<6];
static int hd_blocksizes[MAX_HD<<6];
static int hd_hardsectsizes[MAX_HD<<6];
static int hd_maxsect[MAX_HD<<6];
static struct timer_list device_timer;
#define SET_TIMER \
do { \
mod_timer(&device_timer, jiffies + TIMEOUT_VALUE); \
} while (0)
#define CLEAR_TIMER del_timer(&device_timer);
#undef SET_INTR
#define SET_INTR(x) \
if ((DEVICE_INTR = (x)) != NULL) \
SET_TIMER; \
else \
CLEAR_TIMER;
#if (HD_DELAY > 0)
unsigned long last_req;
unsigned long read_timer(void)
{
unsigned long t, flags;
int i;
save_flags(flags);
cli();
t = jiffies * 11932;
outb_p(0, 0x43);
i = inb_p(0x40);
i |= inb(0x40) << 8;
restore_flags(flags);
return(t - i);
}
#endif
void __init hd_setup(char *str, int *ints)
{
int hdind = 0;
if (ints[0] != 3)
return;
if (hd_info[0].head != 0)
hdind=1;
hd_info[hdind].head = ints[2];
hd_info[hdind].sect = ints[3];
hd_info[hdind].cyl = ints[1];
hd_info[hdind].wpcom = 0;
hd_info[hdind].lzone = ints[1];
hd_info[hdind].ctl = (ints[2] > 8 ? 8 : 0);
NR_HD = hdind+1;
}
static void dump_status (const char *msg, unsigned int stat)
{
unsigned long flags;
char devc;
devc = !QUEUE_EMPTY ? 'a' + DEVICE_NR(CURRENT->rq_dev) : '?';
save_flags (flags);
sti();
#ifdef VERBOSE_ERRORS
printk("hd%c: %s: status=0x%02x { ", devc, msg, stat & 0xff);
if (stat & BUSY_STAT) printk("Busy ");
if (stat & READY_STAT) printk("DriveReady ");
if (stat & WRERR_STAT) printk("WriteFault ");
if (stat & SEEK_STAT) printk("SeekComplete ");
if (stat & DRQ_STAT) printk("DataRequest ");
if (stat & ECC_STAT) printk("CorrectedError ");
if (stat & INDEX_STAT) printk("Index ");
if (stat & ERR_STAT) printk("Error ");
printk("}\n");
if ((stat & ERR_STAT) == 0) {
hd_error = 0;
} else {
hd_error = inb(HD_ERROR);
printk("hd%c: %s: error=0x%02x { ", devc, msg, hd_error & 0xff);
if (hd_error & BBD_ERR) printk("BadSector ");
if (hd_error & ECC_ERR) printk("UncorrectableError ");
if (hd_error & ID_ERR) printk("SectorIdNotFound ");
if (hd_error & ABRT_ERR) printk("DriveStatusError ");
if (hd_error & TRK0_ERR) printk("TrackZeroNotFound ");
if (hd_error & MARK_ERR) printk("AddrMarkNotFound ");
printk("}");
if (hd_error & (BBD_ERR|ECC_ERR|ID_ERR|MARK_ERR)) {
printk(", CHS=%d/%d/%d", (inb(HD_HCYL)<<8) + inb(HD_LCYL),
inb(HD_CURRENT) & 0xf, inb(HD_SECTOR));
if (!QUEUE_EMPTY)
printk(", sector=%ld", CURRENT->sector);
}
printk("\n");
}
#else
printk("hd%c: %s: status=0x%02x.\n", devc, msg, stat & 0xff);
if ((stat & ERR_STAT) == 0) {
hd_error = 0;
} else {
hd_error = inb(HD_ERROR);
printk("hd%c: %s: error=0x%02x.\n", devc, msg, hd_error & 0xff);
}
#endif /* verbose errors */
restore_flags (flags);
}
void check_status(void)
{
int i = inb_p(HD_STATUS);
if (!OK_STATUS(i)) {
dump_status("check_status", i);
bad_rw_intr();
}
}
static int controller_busy(void)
{
int retries = 100000;
unsigned char status;
do {
status = inb_p(HD_STATUS);
} while ((status & BUSY_STAT) && --retries);
return status;
}
static int status_ok(void)
{
unsigned char status = inb_p(HD_STATUS);
if (status & BUSY_STAT)
return 1; /* Ancient, but does it make sense??? */
if (status & WRERR_STAT)
return 0;
if (!(status & READY_STAT))
return 0;
if (!(status & SEEK_STAT))
return 0;
return 1;
}
static int controller_ready(unsigned int drive, unsigned int head)
{
int retry = 100;
do {
if (controller_busy() & BUSY_STAT)
return 0;
outb_p(0xA0 | (drive<<4) | head, HD_CURRENT);
if (status_ok())
return 1;
} while (--retry);
return 0;
}
static void hd_out(unsigned int drive,unsigned int nsect,unsigned int sect,
unsigned int head,unsigned int cyl,unsigned int cmd,
void (*intr_addr)(void))
{
unsigned short port;
#if (HD_DELAY > 0)
while (read_timer() - last_req < HD_DELAY)
/* nothing */;
#endif
if (reset)
return;
if (!controller_ready(drive, head)) {
reset = 1;
return;
}
SET_INTR(intr_addr);
outb_p(hd_info[drive].ctl,HD_CMD);
port=HD_DATA;
outb_p(hd_info[drive].wpcom>>2,++port);
outb_p(nsect,++port);
outb_p(sect,++port);
outb_p(cyl,++port);
outb_p(cyl>>8,++port);
outb_p(0xA0|(drive<<4)|head,++port);
outb_p(cmd,++port);
}
static void hd_request (void);
static int drive_busy(void)
{
unsigned int i;
unsigned char c;
for (i = 0; i < 500000 ; i++) {
c = inb_p(HD_STATUS);
if ((c & (BUSY_STAT | READY_STAT | SEEK_STAT)) == STAT_OK)
return 0;
}
dump_status("reset timed out", c);
return 1;
}
static void reset_controller(void)
{
int i;
outb_p(4,HD_CMD);
for(i = 0; i < 1000; i++) barrier();
outb_p(hd_info[0].ctl & 0x0f,HD_CMD);
for(i = 0; i < 1000; i++) barrier();
if (drive_busy())
printk("hd: controller still busy\n");
else if ((hd_error = inb(HD_ERROR)) != 1)
printk("hd: controller reset failed: %02x\n",hd_error);
}
static void reset_hd(void)
{
static int i;
repeat:
if (reset) {
reset = 0;
i = -1;
reset_controller();
} else {
check_status();
if (reset)
goto repeat;
}
if (++i < NR_HD) {
special_op[i] = recalibrate[i] = 1;
hd_out(i,hd_info[i].sect,hd_info[i].sect,hd_info[i].head-1,
hd_info[i].cyl,WIN_SPECIFY,&reset_hd);
if (reset)
goto repeat;
} else
hd_request();
}
/*
* Ok, don't know what to do with the unexpected interrupts: on some machines
* doing a reset and a retry seems to result in an eternal loop. Right now I
* ignore it, and just set the timeout.
*
* On laptops (and "green" PCs), an unexpected interrupt occurs whenever the
* drive enters "idle", "standby", or "sleep" mode, so if the status looks
* "good", we just ignore the interrupt completely.
*/
void unexpected_hd_interrupt(void)
{
unsigned int stat = inb_p(HD_STATUS);
if (stat & (BUSY_STAT|DRQ_STAT|ECC_STAT|ERR_STAT)) {
dump_status ("unexpected interrupt", stat);
SET_TIMER;
}
}
/*
* bad_rw_intr() now tries to be a bit smarter and does things
* according to the error returned by the controller.
* -Mika Liljeberg (liljeber@cs.Helsinki.FI)
*/
static void bad_rw_intr(void)
{
int dev;
if (QUEUE_EMPTY)
return;
dev = DEVICE_NR(CURRENT->rq_dev);
if (++CURRENT->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
end_request(0);
special_op[dev] = recalibrate[dev] = 1;
} else if (CURRENT->errors % RESET_FREQ == 0)
reset = 1;
else if ((hd_error & TRK0_ERR) || CURRENT->errors % RECAL_FREQ == 0)
special_op[dev] = recalibrate[dev] = 1;
/* Otherwise just retry */
}
static inline int wait_DRQ(void)
{
int retries = 100000, stat;
while (--retries > 0)
if ((stat = inb_p(HD_STATUS)) & DRQ_STAT)
return 0;
dump_status("wait_DRQ", stat);
return -1;
}
static void read_intr(void)
{
int i, retries = 100000;
do {
i = (unsigned) inb_p(HD_STATUS);
if (i & BUSY_STAT)
continue;
if (!OK_STATUS(i))
break;
if (i & DRQ_STAT)
goto ok_to_read;
} while (--retries > 0);
dump_status("read_intr", i);
bad_rw_intr();
hd_request();
return;
ok_to_read:
insw(HD_DATA,CURRENT->buffer,256);
CURRENT->sector++;
CURRENT->buffer += 512;
CURRENT->errors = 0;
i = --CURRENT->nr_sectors;
--CURRENT->current_nr_sectors;
#ifdef DEBUG
printk("hd%c: read: sector %ld, remaining = %ld, buffer=0x%08lx\n",
dev+'a', CURRENT->sector, CURRENT->nr_sectors,
(unsigned long) CURRENT->buffer+512));
#endif
if (CURRENT->current_nr_sectors <= 0)
end_request(1);
if (i > 0) {
SET_INTR(&read_intr);
return;
}
(void) inb_p(HD_STATUS);
#if (HD_DELAY > 0)
last_req = read_timer();
#endif
if (!QUEUE_EMPTY)
hd_request();
return;
}
static void write_intr(void)
{
int i;
int retries = 100000;
do {
i = (unsigned) inb_p(HD_STATUS);
if (i & BUSY_STAT)
continue;
if (!OK_STATUS(i))
break;
if ((CURRENT->nr_sectors <= 1) || (i & DRQ_STAT))
goto ok_to_write;
} while (--retries > 0);
dump_status("write_intr", i);
bad_rw_intr();
hd_request();
return;
ok_to_write:
CURRENT->sector++;
i = --CURRENT->nr_sectors;
--CURRENT->current_nr_sectors;
CURRENT->buffer += 512;
if (!i || (CURRENT->bh && !SUBSECTOR(i)))
end_request(1);
if (i > 0) {
SET_INTR(&write_intr);
outsw(HD_DATA,CURRENT->buffer,256);
sti();
} else {
#if (HD_DELAY > 0)
last_req = read_timer();
#endif
hd_request();
}
return;
}
static void recal_intr(void)
{
check_status();
#if (HD_DELAY > 0)
last_req = read_timer();
#endif
hd_request();
}
/*
* This is another of the error-routines I don't know what to do with. The
* best idea seems to just set reset, and start all over again.
*/
static void hd_times_out(unsigned long dummy)
{
unsigned int dev;
DEVICE_INTR = NULL;
if (QUEUE_EMPTY)
return;
disable_irq(HD_IRQ);
sti();
reset = 1;
dev = DEVICE_NR(CURRENT->rq_dev);
printk("hd%c: timeout\n", dev+'a');
if (++CURRENT->errors >= MAX_ERRORS) {
#ifdef DEBUG
printk("hd%c: too many errors\n", dev+'a');
#endif
end_request(0);
}
cli();
hd_request();
enable_irq(HD_IRQ);
}
int do_special_op (unsigned int dev)
{
if (recalibrate[dev]) {
recalibrate[dev] = 0;
hd_out(dev,hd_info[dev].sect,0,0,0,WIN_RESTORE,&recal_intr);
return reset;
}
if (hd_info[dev].head > 16) {
printk ("hd%c: cannot handle device with more than 16 heads - giving up\n", dev+'a');
end_request(0);
}
special_op[dev] = 0;
return 1;
}
/*
* The driver enables interrupts as much as possible. In order to do this,
* (a) the device-interrupt is disabled before entering hd_request(),
* and (b) the timeout-interrupt is disabled before the sti().
*
* Interrupts are still masked (by default) whenever we are exchanging
* data/cmds with a drive, because some drives seem to have very poor
* tolerance for latency during I/O. The IDE driver has support to unmask
* interrupts for non-broken hardware, so use that driver if required.
*/
static void hd_request(void)
{
unsigned int dev, block, nsect, sec, track, head, cyl;
if (!QUEUE_EMPTY && CURRENT->rq_status == RQ_INACTIVE) return;
if (DEVICE_INTR)
return;
repeat:
del_timer(&device_timer);
sti();
INIT_REQUEST;
if (reset) {
cli();
reset_hd();
return;
}
dev = MINOR(CURRENT->rq_dev);
block = CURRENT->sector;
nsect = CURRENT->nr_sectors;
if (dev >= (NR_HD<<6) || block >= hd[dev].nr_sects || ((block+nsect) > hd[dev].nr_sects)) {
#ifdef DEBUG
if (dev >= (NR_HD<<6))
printk("hd: bad minor number: device=%s\n",
kdevname(CURRENT->rq_dev));
else
printk("hd%c: bad access: block=%d, count=%d\n",
(MINOR(CURRENT->rq_dev)>>6)+'a', block, nsect);
#endif
end_request(0);
goto repeat;
}
block += hd[dev].start_sect;
dev >>= 6;
if (special_op[dev]) {
if (do_special_op(dev))
goto repeat;
return;
}
sec = block % hd_info[dev].sect + 1;
track = block / hd_info[dev].sect;
head = track % hd_info[dev].head;
cyl = track / hd_info[dev].head;
#ifdef DEBUG
printk("hd%c: %sing: CHS=%d/%d/%d, sectors=%d, buffer=0x%08lx\n",
dev+'a', (CURRENT->cmd == READ)?"read":"writ",
cyl, head, sec, nsect, (unsigned long) CURRENT->buffer);
#endif
if (CURRENT->cmd == READ) {
hd_out(dev,nsect,sec,head,cyl,WIN_READ,&read_intr);
if (reset)
goto repeat;
return;
}
if (CURRENT->cmd == WRITE) {
hd_out(dev,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
if (reset)
goto repeat;
if (wait_DRQ()) {
bad_rw_intr();
goto repeat;
}
outsw(HD_DATA,CURRENT->buffer,256);
return;
}
panic("unknown hd-command");
}
static void do_hd_request (request_queue_t * q)
{
disable_irq(HD_IRQ);
hd_request();
enable_irq(HD_IRQ);
}
static int hd_ioctl(struct inode * inode, struct file * file,
unsigned int cmd, unsigned long arg)
{
struct hd_geometry *loc = (struct hd_geometry *) arg;
int dev;
if ((!inode) || !(inode->i_rdev))
return -EINVAL;
dev = DEVICE_NR(inode->i_rdev);
if (dev >= NR_HD)
return -EINVAL;
switch (cmd) {
case HDIO_GETGEO:
{
struct hd_geometry g;
if (!loc) return -EINVAL;
g.heads = hd_info[dev].head;
g.sectors = hd_info[dev].sect;
g.cylinders = hd_info[dev].cyl;
g.start = hd[MINOR(inode->i_rdev)].start_sect;
return copy_to_user(loc, &g, sizeof g) ? -EFAULT : 0;
}
case BLKGETSIZE: /* Return device size */
return put_user(hd[MINOR(inode->i_rdev)].nr_sects,
(unsigned long *) arg);
case BLKGETSIZE64:
return put_user((u64)hd[MINOR(inode->i_rdev)].nr_sects << 9,
(u64 *) arg);
case BLKRRPART: /* Re-read partition tables */
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
return revalidate_hddisk(inode->i_rdev, 1);
case BLKROSET:
case BLKROGET:
case BLKRASET:
case BLKRAGET:
case BLKFLSBUF:
case BLKPG:
return blk_ioctl(inode->i_rdev, cmd, arg);
default:
return -EINVAL;
}
}
static int hd_open(struct inode * inode, struct file * filp)
{
int target;
target = DEVICE_NR(inode->i_rdev);
if (target >= NR_HD)
return -ENODEV;
while (busy[target])
sleep_on(&busy_wait);
access_count[target]++;
return 0;
}
/*
* Releasing a block device means we sync() it, so that it can safely
* be forgotten about...
*/
static int hd_release(struct inode * inode, struct file * file)
{
int target = DEVICE_NR(inode->i_rdev);
access_count[target]--;
return 0;
}
extern struct block_device_operations hd_fops;
static struct gendisk hd_gendisk = {
major: MAJOR_NR,
major_name: "hd",
minor_shift: 6,
max_p: 1 << 6,
part: hd,
sizes: hd_sizes,
fops: &hd_fops,
};
static void hd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
void (*handler)(void) = DEVICE_INTR;
DEVICE_INTR = NULL;
del_timer(&device_timer);
if (!handler)
handler = unexpected_hd_interrupt;
handler();
sti();
}
static struct block_device_operations hd_fops = {
open: hd_open,
release: hd_release,
ioctl: hd_ioctl,
};
/*
* This is the hard disk IRQ description. The SA_INTERRUPT in sa_flags
* means we run the IRQ-handler with interrupts disabled: this is bad for
* interrupt latency, but anything else has led to problems on some
* machines.
*
* We enable interrupts in some of the routines after making sure it's
* safe.
*/
static void __init hd_geninit(void)
{
int drive;
for(drive=0; drive < (MAX_HD << 6); drive++) {
hd_blocksizes[drive] = 1024;
hd_hardsectsizes[drive] = 512;
hd_maxsect[drive]=255;
}
blksize_size[MAJOR_NR] = hd_blocksizes;
hardsect_size[MAJOR_NR] = hd_hardsectsizes;
max_sectors[MAJOR_NR] = hd_maxsect;
#ifdef __i386__
if (!NR_HD) {
extern struct drive_info drive_info;
unsigned char *BIOS = (unsigned char *) &drive_info;
unsigned long flags;
int cmos_disks;
for (drive=0 ; drive<2 ; drive++) {
hd_info[drive].cyl = *(unsigned short *) BIOS;
hd_info[drive].head = *(2+BIOS);
hd_info[drive].wpcom = *(unsigned short *) (5+BIOS);
hd_info[drive].ctl = *(8+BIOS);
hd_info[drive].lzone = *(unsigned short *) (12+BIOS);
hd_info[drive].sect = *(14+BIOS);
#ifdef does_not_work_for_everybody_with_scsi_but_helps_ibm_vp
if (hd_info[drive].cyl && NR_HD == drive)
NR_HD++;
#endif
BIOS += 16;
}
/*
We query CMOS about hard disks : it could be that
we have a SCSI/ESDI/etc controller that is BIOS
compatible with ST-506, and thus showing up in our
BIOS table, but not register compatible, and therefore
not present in CMOS.
Furthermore, we will assume that our ST-506 drives
<if any> are the primary drives in the system, and
the ones reflected as drive 1 or 2.
The first drive is stored in the high nibble of CMOS
byte 0x12, the second in the low nibble. This will be
either a 4 bit drive type or 0xf indicating use byte 0x19
for an 8 bit type, drive 1, 0x1a for drive 2 in CMOS.
Needless to say, a non-zero value means we have
an AT controller hard disk for that drive.
Currently the rtc_lock is a bit academic since this
driver is non-modular, but someday... ? Paul G.
*/
spin_lock_irqsave(&rtc_lock, flags);
cmos_disks = CMOS_READ(0x12);
spin_unlock_irqrestore(&rtc_lock, flags);
if (cmos_disks & 0xf0) {
if (cmos_disks & 0x0f)
NR_HD = 2;
else
NR_HD = 1;
}
}
#endif /* __i386__ */
#ifdef __arm__
if (!NR_HD) {
/* We don't know anything about the drive. This means
* that you *MUST* specify the drive parameters to the
* kernel yourself.
*/
printk("hd: no drives specified - use hd=cyl,head,sectors"
" on kernel command line\n");
}
#endif
for (drive=0 ; drive < NR_HD ; drive++) {
hd[drive<<6].nr_sects = hd_info[drive].head *
hd_info[drive].sect * hd_info[drive].cyl;
printk ("hd%c: %ldMB, CHS=%d/%d/%d\n", drive+'a',
hd[drive<<6].nr_sects / 2048, hd_info[drive].cyl,
hd_info[drive].head, hd_info[drive].sect);
}
if (!NR_HD)
return;
if (request_irq(HD_IRQ, hd_interrupt, SA_INTERRUPT, "hd", NULL)) {
printk("hd: unable to get IRQ%d for the hard disk driver\n",
HD_IRQ);
NR_HD = 0;
return;
}
request_region(HD_DATA, 8, "hd");
request_region(HD_CMD, 1, "hd(cmd)");
hd_gendisk.nr_real = NR_HD;
for(drive=0; drive < NR_HD; drive++)
register_disk(&hd_gendisk, MKDEV(MAJOR_NR,drive<<6), 1<<6,
&hd_fops, hd_info[drive].head * hd_info[drive].sect *
hd_info[drive].cyl);
}
int __init hd_init(void)
{
if (devfs_register_blkdev(MAJOR_NR,"hd",&hd_fops)) {
printk("hd: unable to get major %d for hard disk\n",MAJOR_NR);
return -1;
}
blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), DEVICE_REQUEST);
read_ahead[MAJOR_NR] = 8; /* 8 sector (4kB) read-ahead */
add_gendisk(&hd_gendisk);
init_timer(&device_timer);
device_timer.function = hd_times_out;
hd_geninit();
return 0;
}
#define DEVICE_BUSY busy[target]
#define USAGE access_count[target]
#define CAPACITY (hd_info[target].head*hd_info[target].sect*hd_info[target].cyl)
/* We assume that the BIOS parameters do not change, so the disk capacity
will not change */
#undef MAYBE_REINIT
#define GENDISK_STRUCT hd_gendisk
/*
* This routine is called to flush all partitions and partition tables
* for a changed disk, and then re-read the new partition table.
* If we are revalidating a disk because of a media change, then we
* enter with usage == 0. If we are using an ioctl, we automatically have
* usage == 1 (we need an open channel to use an ioctl :-), so this
* is our limit.
*/
static int revalidate_hddisk(kdev_t dev, int maxusage)
{
int target;
struct gendisk * gdev;
int max_p;
int start;
int i;
long flags;
target = DEVICE_NR(dev);
gdev = &GENDISK_STRUCT;
save_flags(flags);
cli();
if (DEVICE_BUSY || USAGE > maxusage) {
restore_flags(flags);
return -EBUSY;
}
DEVICE_BUSY = 1;
restore_flags(flags);
max_p = gdev->max_p;
start = target << gdev->minor_shift;
for (i=max_p - 1; i >=0 ; i--) {
int minor = start + i;
invalidate_device(MKDEV(MAJOR_NR, minor), 1);
gdev->part[minor].start_sect = 0;
gdev->part[minor].nr_sects = 0;
}
#ifdef MAYBE_REINIT
MAYBE_REINIT;
#endif
grok_partitions(gdev, target, 1<<6, CAPACITY);
DEVICE_BUSY = 0;
wake_up(&busy_wait);
return 0;
}
static int parse_hd_setup (char *line) {
int ints[6];
(void) get_options(line, ARRAY_SIZE(ints), ints);
hd_setup(NULL, ints);
return 1;
}
__setup("hd=", parse_hd_setup);
|