patch-2.4.21 linux-2.4.21/drivers/ide/legacy/hd.c
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- Lines: 926
- Date:
2003-06-13 07:51:33.000000000 -0700
- Orig file:
linux-2.4.20/drivers/ide/legacy/hd.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.20/drivers/ide/legacy/hd.c linux-2.4.21/drivers/ide/legacy/hd.c
@@ -0,0 +1,925 @@
+/*
+ * linux/drivers/ide/legacy/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;
+
+ spin_lock_irqsave(&io_request_lock, flags);
+ t = jiffies * 11932;
+ outb_p(0, 0x43);
+ i = inb_p(0x40);
+ i |= inb(0x40) << 8;
+ spin_unlock_irqrestore(&io_request_lock, 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();
+}
+
+void do_reset_hd(void)
+{
+ DEVICE_INTR = NULL;
+ reset = 1;
+ reset_hd();
+}
+
+/*
+ * 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;
+
+ spin_lock_irqsave(&io_request_lock, flags);
+ if (DEVICE_BUSY || USAGE > maxusage) {
+ spin_unlock_irqrestore(&io_request_lock, flags);
+ return -EBUSY;
+ }
+ DEVICE_BUSY = 1;
+ spin_unlock_irqrestore(&io_request_lock, 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);
+
+module_init(hd_init);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)