patch-2.4.21 linux-2.4.21/drivers/ide/hd.c
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- Lines: 919
- Date:
1969-12-31 16:00:00.000000000 -0800
- Orig file:
linux-2.4.20/drivers/ide/hd.c
- Orig date:
2001-10-15 13:27:42.000000000 -0700
diff -urN linux-2.4.20/drivers/ide/hd.c linux-2.4.21/drivers/ide/hd.c
@@ -1,918 +0,0 @@
-/*
- * 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);
-
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)