/*
* 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 = ARRAY_SIZE(hd_info);
#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)
#include <asm/i8253.h>
unsigned long last_req;
unsigned long read_timer(void)
{
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;
int stat;
for (retries = 0; retries < 100000; retries++) {
stat = inb_p(HD_STATUS);
if (stat & 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_data_dir(req) == READ ? "read" : "writ",
cyl, head, sec, nsect, req->buffer);
#endif
if (blk_fs_request(req)) {
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(struct request_queue *q)
{
disable_irq(HD_IRQ);
hd_request();
enable_irq(HD_IRQ);
}
static int hd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct hd_i_struct *disk = bdev->bd_disk->private_data;
geo->heads = disk->head;
geo->sectors = disk->sect;
geo->cylinders = disk->cyl;
return 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)
{
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 = {
.getgeo = hd_getgeo,
};
/*
* This is the hard disk IRQ description. The IRQF_DISABLED 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);
if (!NR_HD) {
/*
* We don't know anything about the drive. This means
* that you *MUST* specify the drive parameters to the
* kernel yourself.
*
* If we were on an i386, we used to read this info from
* the BIOS or CMOS. This doesn't work all that well,
* since this assumes that this is a primary or secondary
* drive, and if we're using this legacy driver, it's
* probably an auxilliary controller added to recover
* legacy data off an ST-506 drive. Either way, it's
* definitely safest to have the user explicitly specify
* the information.
*/
printk("hd: no drives specified - use hd=cyl,head,sectors"
" on kernel command line\n");
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, IRQF_DISABLED, "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 __init 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);
