diff options
Diffstat (limited to 'drivers/block/hd.c')
| -rw-r--r-- | drivers/block/hd.c | 815 |
1 files changed, 815 insertions, 0 deletions
diff --git a/drivers/block/hd.c b/drivers/block/hd.c new file mode 100644 index 0000000..00b6956 --- /dev/null +++ b/drivers/block/hd.c @@ -0,0 +1,815 @@ +/* + * 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); + +late_initcall(hd_init); |
