ide-disk.c

ep9315平台下硬盘驱动的源码

/*
 *  linux/drivers/ide/ide-disk.c	Version 1.18	Mar 05, 2003
 *
 *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
 *  Copyright (C) 1998-2002  Linux ATA Developemt
 *				Andre Hedrick <[e-mail]>
 *  Copyright (C) 2003	     Red Hat <[e-mail]>
 *
 *
 */

/*
 *  Mostly written by Mark Lord <[e-mail]>
 *                and Gadi Oxman <[e-mail]>
 *                and Andre Hedrick <[e-mail]>
 *
 * This is the IDE/ATA disk driver, as evolved from hd.c and ide.c.
 *
 * Version 1.00		move disk only code from ide.c to ide-disk.c
 *			support optional byte-swapping of all data
 * Version 1.01		fix previous byte-swapping code
 * Version 1.02		remove ", LBA" from drive identification msgs
 * Version 1.03		fix display of id->buf_size for big-endian
 * Version 1.04		add /proc configurable settings and S.M.A.R.T support
 * Version 1.05		add capacity support for ATA3 >= 8GB
 * Version 1.06		get boot-up messages to show full cyl count
 * Version 1.07		disable door-locking if it fails
 * Version 1.08		fixed CHS/LBA translations for ATA4 > 8GB,
 *			process of adding new ATA4 compliance.
 *			fixed problems in allowing fdisk to see
 *			the entire disk.
 * Version 1.09		added increment of rq->sector in ide_multwrite
 *			added UDMA 3/4 reporting
 * Version 1.10		request queue changes, Ultra DMA 100
 * Version 1.11		added 48-bit lba
 * Version 1.12		adding taskfile io access method
 * Version 1.13		added standby and flush-cache for notifier
 * Version 1.14		added acoustic-wcache
 * Version 1.15		convert all calls to ide_raw_taskfile
 *				since args will return register content.
 * Version 1.16		added suspend-resume-checkpower
 * Version 1.17		do flush on standy, do flush on ATA < ATA6
 *			fix wcache setup.
 */

#define IDEDISK_VERSION	"1.17"

#undef REALLY_SLOW_IO		/* most systems can safely undef this */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/delay.h>

#define _IDE_DISK

#include <linux/ide.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/* FIXME: some day we shouldnt need to look in here! */

#include "legacy/pdc4030.h"

static int driver_blocked;

static inline u32 idedisk_read_24 (ide_drive_t *drive)
{
#if 0
	return	(HWIF(drive)->INB(IDE_HCYL_REG)<<16) |
		(HWIF(drive)->INB(IDE_LCYL_REG)<<8) |
		 HWIF(drive)->INB(IDE_SECTOR_REG);
#else
	u8 hcyl = HWIF(drive)->INB(IDE_HCYL_REG);
	u8 lcyl = HWIF(drive)->INB(IDE_LCYL_REG);
	u8 sect = HWIF(drive)->INB(IDE_SECTOR_REG);
	return (hcyl<<16)|(lcyl<<8)|sect;
#endif
}

static int idedisk_end_request(ide_drive_t *drive, int uptodate);

/*
 * lba_capacity_is_ok() performs a sanity check on the claimed "lba_capacity"
 * value for this drive (from its reported identification information).
 *
 * Returns:	1 if lba_capacity looks sensible
 *		0 otherwise
 *
 * It is called only once for each drive.
 */
static int lba_capacity_is_ok (struct hd_driveid *id)
{
	unsigned long lba_sects, chs_sects, head, tail;

	if ((id->command_set_2 & 0x0400) && (id->cfs_enable_2 & 0x0400)) {
		printk("48-bit Drive: %llu \n", id->lba_capacity_2);
		return 1;
	}

	/*
	 * The ATA spec tells large drives to return
	 * C/H/S = 16383/16/63 independent of their size.
	 * Some drives can be jumpered to use 15 heads instead of 16.
	 * Some drives can be jumpered to use 4092 cyls instead of 16383.
	 */
	if ((id->cyls == 16383
	     || (id->cyls == 4092 && id->cur_cyls == 16383)) &&
	    id->sectors == 63 &&
	    (id->heads == 15 || id->heads == 16) &&
	    (id->lba_capacity >= 16383*63*id->heads))
		return 1;

	lba_sects   = id->lba_capacity;
	chs_sects   = id->cyls * id->heads * id->sectors;

	/* perform a rough sanity check on lba_sects:  within 10% is OK */
	if ((lba_sects - chs_sects) < chs_sects/10)
		return 1;

	/* some drives have the word order reversed */
	head = ((lba_sects >> 16) & 0xffff);
	tail = (lba_sects & 0xffff);
	lba_sects = (head | (tail << 16));
	if ((lba_sects - chs_sects) < chs_sects/10) {
		id->lba_capacity = lba_sects;
		return 1;	/* lba_capacity is (now) good */
	}

	return 0;	/* lba_capacity value may be bad */
}

#ifndef CONFIG_IDE_TASKFILE_IO

/*
 * read_intr() is the handler for disk read/multread interrupts
 */
static ide_startstop_t read_intr (ide_drive_t *drive)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u32 i = 0, nsect	= 0, msect = drive->mult_count;
	struct request *rq;
	unsigned long flags;
	u8 stat;
	char *to;

	/* new way for dealing with premature shared PCI interrupts */
	if (!OK_STAT(stat=hwif->INB(IDE_STATUS_REG),DATA_READY,BAD_R_STAT)) {
		if (stat & (ERR_STAT|DRQ_STAT)) {
			return DRIVER(drive)->error(drive, "read_intr", stat);
		}
		/* no data yet, so wait for another interrupt */
		ide_set_handler(drive, &read_intr, WAIT_CMD, NULL);
		return ide_started;
	}
	
read_next:
	rq = HWGROUP(drive)->rq;
	if (msect) {
		if ((nsect = rq->current_nr_sectors) > msect)
			nsect = msect;
		msect -= nsect;
	} else
		nsect = 1;
	to = ide_map_buffer(rq, &flags);
	taskfile_input_data(drive, to, nsect * SECTOR_WORDS);

#ifdef DEBUG
	printk("%s:  read: sectors(%ld-%ld), buffer=0x%08lx, remaining=%ld\n",
		drive->name, rq->sector, rq->sector+nsect-1,
		(unsigned long) rq->buffer+(nsect<<9), rq->nr_sectors-nsect);
#endif

	ide_unmap_buffer(to, &flags);
	rq->sector += nsect;
	rq->errors = 0;
	i = (rq->nr_sectors -= nsect);
	if (((long)(rq->current_nr_sectors -= nsect)) <= 0)
		idedisk_end_request(drive, 1);
	/*
	 * Another BH Page walker and DATA INTERGRITY Questioned on ERROR.
	 * If passed back up on multimode read, BAD DATA could be ACKED
	 * to FILE SYSTEMS above ...
	 */
	if (i > 0) {
		if (msect)
			goto read_next;
		ide_set_handler(drive, &read_intr, WAIT_CMD, NULL);
                return ide_started;
	}
        return ide_stopped;
}

/*
 * write_intr() is the handler for disk write interrupts
 */
static ide_startstop_t write_intr (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	struct request *rq	= hwgroup->rq;
	u32 i = 0;
	u8 stat;

	if (!OK_STAT(stat = hwif->INB(IDE_STATUS_REG),
			DRIVE_READY, drive->bad_wstat)) {
		printk("%s: write_intr error1: nr_sectors=%ld, stat=0x%02x\n",
			drive->name, rq->nr_sectors, stat);
        } else {
#ifdef DEBUG
		printk("%s: write: sector %ld, buffer=0x%08lx, remaining=%ld\n",
			drive->name, rq->sector, (unsigned long) rq->buffer,
			rq->nr_sectors-1);
#endif
		if ((rq->nr_sectors == 1) ^ ((stat & DRQ_STAT) != 0)) {
			rq->sector++;
			rq->errors = 0;
			i = --rq->nr_sectors;
			--rq->current_nr_sectors;
			if (((long)rq->current_nr_sectors) <= 0)
				idedisk_end_request(drive, 1);
			if (i > 0) {
				unsigned long flags;
				char *to = ide_map_buffer(rq, &flags);
				taskfile_output_data(drive, to, SECTOR_WORDS);
				ide_unmap_buffer(to, &flags);
				ide_set_handler(drive, &write_intr, WAIT_CMD, NULL);
                                return ide_started;
			}
                        return ide_stopped;
		}
		/* the original code did this here (?) */
		return ide_stopped;
	}
	return DRIVER(drive)->error(drive, "write_intr", stat);
}

/*
 * ide_multwrite() transfers a block of up to mcount sectors of data
 * to a drive as part of a disk multiple-sector write operation.
 *
 * Returns 0 on success.
 *
 * Note that we may be called from two contexts - the do_rw_disk context
 * and IRQ context. The IRQ can happen any time after we've output the
 * full "mcount" number of sectors, so we must make sure we update the
 * state _before_ we output the final part of the data!
 *
 * The update and return to BH is a BLOCK Layer Fakey to get more data
 * to satisfy the hardware atomic segment.  If the hardware atomic segment
 * is shorter or smaller than the BH segment then we should be OKAY.
 * This is only valid if we can rewind the rq->current_nr_sectors counter.
 */
int ide_multwrite (ide_drive_t *drive, unsigned int mcount)
{
 	ide_hwgroup_t *hwgroup	= HWGROUP(drive);
 	struct request *rq	= &hwgroup->wrq;
 
  	do {
  		char *buffer;
  		int nsect = rq->current_nr_sectors;
		unsigned long flags;
 
		if (nsect > mcount)
			nsect = mcount;
		mcount -= nsect;
		buffer = ide_map_buffer(rq, &flags);

		rq->sector += nsect;
		rq->nr_sectors -= nsect;
		rq->current_nr_sectors -= nsect;

		/* Do we move to the next bh after this? */
		if (!rq->current_nr_sectors) {
			struct buffer_head *bh = rq->bh->b_reqnext;

			/* end early early we ran out of requests */
			if (!bh) {
				mcount = 0;
			} else {
				rq->bh = bh;
				rq->current_nr_sectors = bh->b_size >> 9;
				rq->hard_cur_sectors = rq->current_nr_sectors;
				rq->buffer             = bh->b_data;
			}
		}

		/*
		 * Ok, we're all setup for the interrupt
		 * re-entering us on the last transfer.
		 */
		taskfile_output_data(drive, buffer, nsect<<7);
		ide_unmap_buffer(buffer, &flags);
	} while (mcount);

        return 0;
}

/*
 * multwrite_intr() is the handler for disk multwrite interrupts
 */
static ide_startstop_t multwrite_intr (ide_drive_t *drive)
{
	ide_hwgroup_t *hwgroup	= HWGROUP(drive);
	ide_hwif_t *hwif	= HWIF(drive);
	struct request *rq	= &hwgroup->wrq;
	u32 i = 0;
	u8 stat;

	if (OK_STAT(stat = hwif->INB(IDE_STATUS_REG),
			DRIVE_READY, drive->bad_wstat)) {
		if (stat & DRQ_STAT) {
			/*
			 *	The drive wants data. Remember rq is the copy
			 *	of the request
			 */
			if (rq->nr_sectors) {
				if (ide_multwrite(drive, drive->mult_count))
					return ide_stopped;
				ide_set_handler(drive, &multwrite_intr, WAIT_CMD, NULL);
				return ide_started;
			}
		} else {
			/*
			 *	If the copy has all the blocks completed then
			 *	we can end the original request.
			 */
			if (!rq->nr_sectors) {	/* all done? */
				rq = hwgroup->rq;
				for (i = rq->nr_sectors; i > 0;) {
					i -= rq->current_nr_sectors;
					idedisk_end_request(drive, 1);
				}
				return ide_stopped;
			}
		}
		/* the original code did this here (?) */
		return ide_stopped;
	}
	return DRIVER(drive)->error(drive, "multwrite_intr", stat);
}


/*
 * __ide_do_rw_disk() issues READ and WRITE commands to a disk,
 * using LBA if supported, or CHS otherwise, to address sectors.
 * It also takes care of issuing special DRIVE_CMDs.
 */

ide_startstop_t __ide_do_rw_disk (ide_drive_t *drive, struct request *rq, unsigned long block)
{
	ide_hwif_t *hwif	= HWIF(drive);
	u8 lba48		= (drive->addressing == 1) ? 1 : 0;
	task_ioreg_t command	= WIN_NOP;
	ata_nsector_t		nsectors;

	nsectors.all		= (u16) rq->nr_sectors;

	if (driver_blocked)
		panic("Request while ide driver is blocked?");

	if (IDE_CONTROL_REG)
		hwif->OUTB(drive->ctl, IDE_CONTROL_REG);

	if (drive->select.b.lba) {
		if (drive->addressing == 1) {
			task_ioreg_t tasklets[10];

			tasklets[0] = 0;
			tasklets[1] = 0;
			tasklets[2] = nsectors.b.low;
			tasklets[3] = nsectors.b.high;
			tasklets[4] = (task_ioreg_t) block;
			tasklets[5] = (task_ioreg_t) (block>>8);
			tasklets[6] = (task_ioreg_t) (block>>16);
			tasklets[7] = (task_ioreg_t) (block>>24);
			tasklets[8] = (task_ioreg_t) 0;
			tasklets[9] = (task_ioreg_t) 0;
//			tasklets[8] = (task_ioreg_t) (block>>32);
//			tasklets[9] = (task_ioreg_t) (block>>40);
#ifdef DEBUG
			printk("%s: %sing: LBAsect=%lu, sectors=%ld, "
				"buffer=0x%08lx, LBAsect=0x%012lx\n",
				drive->name,
				(rq->cmd==READ)?"read":"writ",
				block,
				rq->nr_sectors,
				(unsigned long) rq->buffer,
				block);
			printk("%s: 0x%02x%02x 0x%02x%02x%02x%02x%02x%02x\n",
				drive->name, tasklets[3], tasklets[2],
				tasklets[9], tasklets[8], tasklets[7],
				tasklets[6], tasklets[5], tasklets[4]);
#endif
			hwif->OUTB(tasklets[1], IDE_FEATURE_REG);
			hwif->OUTB(tasklets[3], IDE_NSECTOR_REG);
			hwif->OUTB(tasklets[7], IDE_SECTOR_REG);
			hwif->OUTB(tasklets[8], IDE_LCYL_REG);
			hwif->OUTB(tasklets[9], IDE_HCYL_REG);

			hwif->OUTB(tasklets[0], IDE_FEATURE_REG);
			hwif->OUTB(tasklets[2], IDE_NSECTOR_REG);
			hwif->OUTB(tasklets[4], IDE_SECTOR_REG);
			hwif->OUTB(tasklets[5], IDE_LCYL_REG);
			hwif->OUTB(tasklets[6], IDE_HCYL_REG);
			hwif->OUTB(0x00|drive->select.all,IDE_SELECT_REG);
		} else {
#ifdef DEBUG
			printk("%s: %sing: LBAsect=%ld, sectors=%ld, "
				"buffer=0x%08lx\n",
				drive->name, (rq->cmd==READ)?"read":"writ",
				block, rq->nr_sectors,
				(unsigned long) rq->buffer);
#endif
			hwif->OUTB(0x00, IDE_FEATURE_REG);
			hwif->OUTB(nsectors.b.low, IDE_NSECTOR_REG);
			hwif->OUTB(block, IDE_SECTOR_REG);
			hwif->OUTB(block>>=8, IDE_LCYL_REG);
			hwif->OUTB(block>>=8, IDE_HCYL_REG);
			hwif->OUTB(((block>>8)&0x0f)|drive->select.all,IDE_SELECT_REG);
		}
	} else {
		unsigned int sect,head,cyl,track;
		track = block / drive->sect;
		sect  = block % drive->sect + 1;
		hwif->OUTB(sect, IDE_SECTOR_REG);
		head  = track % drive->head;
		cyl   = track / drive->head;

		hwif->OUTB(0x00, IDE_FEATURE_REG);
		hwif->OUTB(nsectors.b.low, IDE_NSECTOR_REG);
		hwif->OUTB(cyl, IDE_LCYL_REG);
		hwif->OUTB(cyl>>8, IDE_HCYL_REG);
		hwif->OUTB(head|drive->select.all,IDE_SELECT_REG);
#ifdef DEBUG
		printk("%s: %sing: CHS=%d/%d/%d, sectors=%ld, buffer=0x%08lx\n",
			drive->name, (rq->cmd==READ)?"read":"writ", cyl,
			head, sect, rq->nr_sectors, (unsigned long) rq->buffer);
#endif
	}

	if (rq_data_dir(rq) == READ) {
#ifdef CONFIG_BLK_DEV_IDEDMA
		if (drive->using_dma && !hwif->ide_dma_read(drive))
			return ide_started;
#endif /* CONFIG_BLK_DEV_IDEDMA */
		if (HWGROUP(drive)->handler != NULL)
			BUG();

		command = ((drive->mult_count) ?
			   ((lba48) ? WIN_MULTREAD_EXT : WIN_MULTREAD) :
			   ((lba48) ? WIN_READ_EXT : WIN_READ));
	
		ide_execute_command(drive, command, &read_intr, WAIT_CMD, NULL);
		return ide_started;
	} else if (rq_data_dir(rq) == WRITE) {
		ide_startstop_t startstop;
#ifdef CONFIG_BLK_DEV_IDEDMA
		if (drive->using_dma && !(HWIF(drive)->ide_dma_write(drive)))
			return ide_started;
#endif /* CONFIG_BLK_DEV_IDEDMA */

		command = ((drive->mult_count) ?
			   ((lba48) ? WIN_MULTWRITE_EXT : WIN_MULTWRITE) :
			   ((lba48) ? WIN_WRITE_EXT : WIN_WRITE));
		hwif->OUTB(command, IDE_COMMAND_REG);

		if (ide_wait_stat(&startstop, drive, DATA_READY,
				drive->bad_wstat, WAIT_DRQ)) {
			printk(KERN_ERR "%s: no DRQ after issuing %s\n",
				drive->name,
				drive->mult_count ? "MULTWRITE" : "WRITE");