aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/ide/legacy/hd.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/ide/legacy/hd.c')
-rw-r--r--drivers/ide/legacy/hd.c864
1 files changed, 864 insertions, 0 deletions
diff --git a/drivers/ide/legacy/hd.c b/drivers/ide/legacy/hd.c
new file mode 100644
index 0000000..c409055
--- /dev/null
+++ b/drivers/ide/legacy/hd.c
@@ -0,0 +1,864 @@
+/*
+ * 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/blkdev.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/interrupt.h>
+#include <linux/timer.h>
+#include <linux/fs.h>
+#include <linux/kernel.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>
+#include <linux/hdreg.h>
+
+#define REALLY_SLOW_IO
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#ifdef __arm__
+#undef HD_IRQ
+#endif
+#include <asm/irq.h>
+#ifdef __arm__
+#define HD_IRQ IRQ_HARDDISK
+#endif
+
+/* Hd controller regster ports */
+
+#define HD_DATA 0x1f0 /* _CTL when writing */
+#define HD_ERROR 0x1f1 /* see err-bits */
+#define HD_NSECTOR 0x1f2 /* nr of sectors to read/write */
+#define HD_SECTOR 0x1f3 /* starting sector */
+#define HD_LCYL 0x1f4 /* starting cylinder */
+#define HD_HCYL 0x1f5 /* high byte of starting cyl */
+#define HD_CURRENT 0x1f6 /* 101dhhhh , d=drive, hhhh=head */
+#define HD_STATUS 0x1f7 /* see status-bits */
+#define HD_FEATURE HD_ERROR /* same io address, read=error, write=feature */
+#define HD_PRECOMP HD_FEATURE /* obsolete use of this port - predates IDE */
+#define HD_COMMAND HD_STATUS /* same io address, read=status, write=cmd */
+
+#define HD_CMD 0x3f6 /* used for resets */
+#define HD_ALTSTATUS 0x3f6 /* same as HD_STATUS but doesn't clear irq */
+
+/* Bits of HD_STATUS */
+#define ERR_STAT 0x01
+#define INDEX_STAT 0x02
+#define ECC_STAT 0x04 /* Corrected error */
+#define DRQ_STAT 0x08
+#define SEEK_STAT 0x10
+#define SERVICE_STAT SEEK_STAT
+#define WRERR_STAT 0x20
+#define READY_STAT 0x40
+#define BUSY_STAT 0x80
+
+/* Bits for HD_ERROR */
+#define MARK_ERR 0x01 /* Bad address mark */
+#define TRK0_ERR 0x02 /* couldn't find track 0 */
+#define ABRT_ERR 0x04 /* Command aborted */
+#define MCR_ERR 0x08 /* media change request */
+#define ID_ERR 0x10 /* ID field not found */
+#define MC_ERR 0x20 /* media changed */
+#define ECC_ERR 0x40 /* Uncorrectable ECC error */
+#define BBD_ERR 0x80 /* pre-EIDE meaning: block marked bad */
+#define ICRC_ERR 0x80 /* new meaning: CRC error during transfer */
+
+static DEFINE_SPINLOCK(hd_lock);
+static struct request_queue *hd_queue;
+
+#define MAJOR_NR HD_MAJOR
+#define QUEUE (hd_queue)
+#define CURRENT elv_next_request(hd_queue)
+
+#define TIMEOUT_VALUE (6*HZ)
+#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 int reset;
+static int hd_error;
+
+/*
+ * This struct defines the HD's and their types.
+ */
+struct hd_i_struct {
+ unsigned int head,sect,cyl,wpcom,lzone,ctl;
+ int unit;
+ int recalibrate;
+ int special_op;
+};
+
+#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 gendisk *hd_gendisk[MAX_HD];
+
+static struct timer_list device_timer;
+
+#define TIMEOUT_VALUE (6*HZ)
+
+#define SET_TIMER \
+ do { \
+ mod_timer(&device_timer, jiffies + TIMEOUT_VALUE); \
+ } while (0)
+
+static void (*do_hd)(void) = NULL;
+#define SET_HANDLER(x) \
+if ((do_hd = (x)) != NULL) \
+ SET_TIMER; \
+else \
+ del_timer(&device_timer);
+
+
+#if (HD_DELAY > 0)
+unsigned long last_req;
+
+unsigned long read_timer(void)
+{
+ extern spinlock_t i8253_lock;
+ unsigned long t, flags;
+ int i;
+
+ spin_lock_irqsave(&i8253_lock, flags);
+ t = jiffies * 11932;
+ outb_p(0, 0x43);
+ i = inb_p(0x40);
+ i |= inb(0x40) << 8;
+ spin_unlock_irqrestore(&i8253_lock, flags);
+ return(t - i);
+}
+#endif
+
+static 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)
+{
+ char *name = "hd?";
+ if (CURRENT)
+ name = CURRENT->rq_disk->disk_name;
+
+#ifdef VERBOSE_ERRORS
+ printk("%s: %s: status=0x%02x { ", name, 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("%s: %s: error=0x%02x { ", name, 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 (CURRENT)
+ printk(", sector=%ld", CURRENT->sector);
+ }
+ printk("\n");
+ }
+#else
+ printk("%s: %s: status=0x%02x.\n", name, msg, stat & 0xff);
+ if ((stat & ERR_STAT) == 0) {
+ hd_error = 0;
+ } else {
+ hd_error = inb(HD_ERROR);
+ printk("%s: %s: error=0x%02x.\n", name, msg, hd_error & 0xff);
+ }
+#endif
+}
+
+static 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(struct hd_i_struct *disk,
+ 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(disk->unit, head)) {
+ reset = 1;
+ return;
+ }
+ SET_HANDLER(intr_addr);
+ outb_p(disk->ctl,HD_CMD);
+ port=HD_DATA;
+ outb_p(disk->wpcom>>2,++port);
+ outb_p(nsect,++port);
+ outb_p(sect,++port);
+ outb_p(cyl,++port);
+ outb_p(cyl>>8,++port);
+ outb_p(0xA0|(disk->unit<<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) {
+ struct hd_i_struct *disk = &hd_info[i];
+ disk->special_op = disk->recalibrate = 1;
+ hd_out(disk,disk->sect,disk->sect,disk->head-1,
+ disk->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.
+ */
+static 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)
+{
+ struct request *req = CURRENT;
+ if (req != NULL) {
+ struct hd_i_struct *disk = req->rq_disk->private_data;
+ if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) {
+ end_request(req, 0);
+ disk->special_op = disk->recalibrate = 1;
+ } else if (req->errors % RESET_FREQ == 0)
+ reset = 1;
+ else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0)
+ disk->special_op = disk->recalibrate = 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)
+{
+ struct request *req;
+ 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:
+ req = CURRENT;
+ insw(HD_DATA,req->buffer,256);
+ req->sector++;
+ req->buffer += 512;
+ req->errors = 0;
+ i = --req->nr_sectors;
+ --req->current_nr_sectors;
+#ifdef DEBUG
+ printk("%s: read: sector %ld, remaining = %ld, buffer=%p\n",
+ req->rq_disk->disk_name, req->sector, req->nr_sectors,
+ req->buffer+512));
+#endif
+ if (req->current_nr_sectors <= 0)
+ end_request(req, 1);
+ if (i > 0) {
+ SET_HANDLER(&read_intr);
+ return;
+ }
+ (void) inb_p(HD_STATUS);
+#if (HD_DELAY > 0)
+ last_req = read_timer();
+#endif
+ if (elv_next_request(QUEUE))
+ hd_request();
+ return;
+}
+
+static void write_intr(void)
+{
+ struct request *req = CURRENT;
+ int i;
+ int retries = 100000;
+
+ do {
+ i = (unsigned) inb_p(HD_STATUS);
+ if (i & BUSY_STAT)
+ continue;
+ if (!OK_STATUS(i))
+ break;
+ if ((req->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:
+ req->sector++;
+ i = --req->nr_sectors;
+ --req->current_nr_sectors;
+ req->buffer += 512;
+ if (!i || (req->bio && req->current_nr_sectors <= 0))
+ end_request(req, 1);
+ if (i > 0) {
+ SET_HANDLER(&write_intr);
+ outsw(HD_DATA,req->buffer,256);
+ local_irq_enable();
+ } 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)
+{
+ char *name;
+
+ do_hd = NULL;
+
+ if (!CURRENT)
+ return;
+
+ disable_irq(HD_IRQ);
+ local_irq_enable();
+ reset = 1;
+ name = CURRENT->rq_disk->disk_name;
+ printk("%s: timeout\n", name);
+ if (++CURRENT->errors >= MAX_ERRORS) {
+#ifdef DEBUG
+ printk("%s: too many errors\n", name);
+#endif
+ end_request(CURRENT, 0);
+ }
+ local_irq_disable();
+ hd_request();
+ enable_irq(HD_IRQ);
+}
+
+static int do_special_op(struct hd_i_struct *disk, struct request *req)
+{
+ if (disk->recalibrate) {
+ disk->recalibrate = 0;
+ hd_out(disk,disk->sect,0,0,0,WIN_RESTORE,&recal_intr);
+ return reset;
+ }
+ if (disk->head > 16) {
+ printk ("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
+ end_request(req, 0);
+ }
+ disk->special_op = 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 block, nsect, sec, track, head, cyl;
+ struct hd_i_struct *disk;
+ struct request *req;
+
+ if (do_hd)
+ return;
+repeat:
+ del_timer(&device_timer);
+ local_irq_enable();
+
+ req = CURRENT;
+ if (!req) {
+ do_hd = NULL;
+ return;
+ }
+
+ if (reset) {
+ local_irq_disable();
+ reset_hd();
+ return;
+ }
+ disk = req->rq_disk->private_data;
+ block = req->sector;
+ nsect = req->nr_sectors;
+ if (block >= get_capacity(req->rq_disk) ||
+ ((block+nsect) > get_capacity(req->rq_disk))) {
+ printk("%s: bad access: block=%d, count=%d\n",
+ req->rq_disk->disk_name, block, nsect);
+ end_request(req, 0);
+ goto repeat;
+ }
+
+ if (disk->special_op) {
+ if (do_special_op(disk, req))
+ goto repeat;
+ return;
+ }
+ sec = block % disk->sect + 1;
+ track = block / disk->sect;
+ head = track % disk->head;
+ cyl = track / disk->head;
+#ifdef DEBUG
+ printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
+ req->rq_disk->disk_name, (req->cmd == READ)?"read":"writ",
+ cyl, head, sec, nsect, req->buffer);
+#endif
+ if (req->flags & REQ_CMD) {
+ switch (rq_data_dir(req)) {
+ case READ:
+ hd_out(disk,nsect,sec,head,cyl,WIN_READ,&read_intr);
+ if (reset)
+ goto repeat;
+ break;
+ case WRITE:
+ hd_out(disk,nsect,sec,head,cyl,WIN_WRITE,&write_intr);
+ if (reset)
+ goto repeat;
+ if (wait_DRQ()) {
+ bad_rw_intr();
+ goto repeat;
+ }
+ outsw(HD_DATA,req->buffer,256);
+ break;
+ default:
+ printk("unknown hd-command\n");
+ end_request(req, 0);
+ break;
+ }
+ }
+}
+
+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_i_struct *disk = inode->i_bdev->bd_disk->private_data;
+ struct hd_geometry __user *loc = (struct hd_geometry __user *) arg;
+ struct hd_geometry g;
+
+ if (cmd != HDIO_GETGEO)
+ return -EINVAL;
+ if (!loc)
+ return -EINVAL;
+ g.heads = disk->head;
+ g.sectors = disk->sect;
+ g.cylinders = disk->cyl;
+ g.start = get_start_sect(inode->i_bdev);
+ return copy_to_user(loc, &g, sizeof g) ? -EFAULT : 0;
+}
+
+/*
+ * Releasing a block device means we sync() it, so that it can safely
+ * be forgotten about...
+ */
+
+static irqreturn_t hd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ void (*handler)(void) = do_hd;
+
+ do_hd = NULL;
+ del_timer(&device_timer);
+ if (!handler)
+ handler = unexpected_hd_interrupt;
+ handler();
+ local_irq_enable();
+ return IRQ_HANDLED;
+}
+
+static struct block_device_operations hd_fops = {
+ .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 int __init hd_init(void)
+{
+ int drive;
+
+ if (register_blkdev(MAJOR_NR,"hd"))
+ return -1;
+
+ hd_queue = blk_init_queue(do_hd_request, &hd_lock);
+ if (!hd_queue) {
+ unregister_blkdev(MAJOR_NR,"hd");
+ return -ENOMEM;
+ }
+
+ blk_queue_max_sectors(hd_queue, 255);
+ init_timer(&device_timer);
+ device_timer.function = hd_times_out;
+ blk_queue_hardsect_size(hd_queue, 512);
+
+#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
+ if (!NR_HD)
+ goto out;
+
+ for (drive=0 ; drive < NR_HD ; drive++) {
+ struct gendisk *disk = alloc_disk(64);
+ struct hd_i_struct *p = &hd_info[drive];
+ if (!disk)
+ goto Enomem;
+ disk->major = MAJOR_NR;
+ disk->first_minor = drive << 6;
+ disk->fops = &hd_fops;
+ sprintf(disk->disk_name, "hd%c", 'a'+drive);
+ disk->private_data = p;
+ set_capacity(disk, p->head * p->sect * p->cyl);
+ disk->queue = hd_queue;
+ p->unit = drive;
+ hd_gendisk[drive] = disk;
+ printk ("%s: %luMB, CHS=%d/%d/%d\n",
+ disk->disk_name, (unsigned long)get_capacity(disk)/2048,
+ p->cyl, p->head, p->sect);
+ }
+
+ 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);
+ goto out1;
+ }
+ if (!request_region(HD_DATA, 8, "hd")) {
+ printk(KERN_WARNING "hd: port 0x%x busy\n", HD_DATA);
+ goto out2;
+ }
+ if (!request_region(HD_CMD, 1, "hd(cmd)")) {
+ printk(KERN_WARNING "hd: port 0x%x busy\n", HD_CMD);
+ goto out3;
+ }
+
+ /* Let them fly */
+ for(drive=0; drive < NR_HD; drive++)
+ add_disk(hd_gendisk[drive]);
+
+ return 0;
+
+out3:
+ release_region(HD_DATA, 8);
+out2:
+ free_irq(HD_IRQ, NULL);
+out1:
+ for (drive = 0; drive < NR_HD; drive++)
+ put_disk(hd_gendisk[drive]);
+ NR_HD = 0;
+out:
+ del_timer(&device_timer);
+ unregister_blkdev(MAJOR_NR,"hd");
+ blk_cleanup_queue(hd_queue);
+ return -1;
+Enomem:
+ while (drive--)
+ put_disk(hd_gendisk[drive]);
+ goto out;
+}
+
+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);