path: root/drivers/ide/ide.c

/*
 *  Copyright (C) 1994-1998	    Linus Torvalds & authors (see below)
 *  Copyrifht (C) 2003-2005, 2007   Bartlomiej Zolnierkiewicz
 */

/*
 *  Mostly written by Mark Lord  <mlord@pobox.com>
 *                and Gadi Oxman <gadio@netvision.net.il>
 *                and Andre Hedrick <andre@linux-ide.org>
 *
 *  See linux/MAINTAINERS for address of current maintainer.
 *
 * This is the multiple IDE interface driver, as evolved from hd.c.
 * It supports up to MAX_HWIFS IDE interfaces, on one or more IRQs
 *   (usually 14 & 15).
 * There can be up to two drives per interface, as per the ATA-2 spec.
 *
 * ...
 *
 *  From hd.c:
 *  |
 *  | It traverses the request-list, using interrupts to jump between functions.
 *  | As nearly all functions can be called within interrupts, we may not sleep.
 *  | Special care is recommended.  Have Fun!
 *  |
 *  | 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.
 *  |
 *  | Early work on error handling by Mika Liljeberg (liljeber@cs.Helsinki.FI).
 *  |
 *  | IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
 *  | and general streamlining by Mark Lord (mlord@pobox.com).
 *
 *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
 *
 *	Mark Lord	(mlord@pobox.com)		(IDE Perf.Pkg)
 *	Delman Lee	(delman@ieee.org)		("Mr. atdisk2")
 *	Scott Snyder	(snyder@fnald0.fnal.gov)	(ATAPI IDE cd-rom)
 *
 *  This was a rewrite of just about everything from hd.c, though some original
 *  code is still sprinkled about.  Think of it as a major evolution, with
 *  inspiration from lots of linux users, esp.  hamish@zot.apana.org.au
 */

#define _IDE_C			/* Tell ide.h it's really us */

#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/blkpg.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/completion.h>
#include <linux/reboot.h>
#include <linux/cdrom.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/bitops.h>

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


/* default maximum number of failures */
#define IDE_DEFAULT_MAX_FAILURES 	1

struct class *ide_port_class;

static const u8 ide_hwif_to_major[] = { IDE0_MAJOR, IDE1_MAJOR,
					IDE2_MAJOR, IDE3_MAJOR,
					IDE4_MAJOR, IDE5_MAJOR,
					IDE6_MAJOR, IDE7_MAJOR,
					IDE8_MAJOR, IDE9_MAJOR };

static int idebus_parameter;	/* holds the "idebus=" parameter */
static int system_bus_speed;	/* holds what we think is VESA/PCI bus speed */

DEFINE_MUTEX(ide_cfg_mtx);
 __cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);

int noautodma = 0;

#ifdef CONFIG_BLK_DEV_IDEACPI
int ide_noacpi = 0;
int ide_noacpitfs = 1;
int ide_noacpionboot = 1;
#endif

ide_hwif_t ide_hwifs[MAX_HWIFS];	/* master data repository */

static void ide_port_init_devices_data(ide_hwif_t *);

/*
 * Do not even *think* about calling this!
 */
void ide_init_port_data(ide_hwif_t *hwif, unsigned int index)
{
	/* bulk initialize hwif & drive info with zeros */
	memset(hwif, 0, sizeof(ide_hwif_t));

	/* fill in any non-zero initial values */
	hwif->index	= index;
	hwif->major	= ide_hwif_to_major[index];

	hwif->name[