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/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/completion.h>
#include <linux/device.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 };

DEFINE_MUTEX(ide_cfg_mtx);

__cacheline_aligned_in_smp DEFINE_SPINLOCK(ide_lock);
EXPORT_SYMBOL(ide_lock);

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[0]	= 'i';
	hwif->name[1]	= 'd';
	hwif->name[2]	= 'e';
	hwif->name[3]	= '0' + index;

	hwif->bus_state	= BUSSTATE_ON;

	init_completion(&hwif->gendev_rel_comp);

	default_hwif_iops(hwif);
	default_hwif_transport(hwif);

	ide_port_init_devices_data(hwif);
}

static void ide_port_init_devices_data(ide_hwif_t *hwif)
{
	int unit;

	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];
		u8 j = (hwif->index * MAX_DRIVES) + unit;

		memset(drive, 0, sizeof(*drive));

		drive->media			= ide_disk;
		drive->select.all		= (unit<<4)|0xa0;
		drive->hwif			= hwif;
		drive->ready_stat		= READY_STAT;
		drive->bad_wstat		= BAD_W_STAT;
		drive->special.b.recalibrate	= 1;
		drive->special.b.set_geometry	= 1;
		drive->name[0]			= 'h';
		drive->name[1]			= 'd';
		drive->name[2]			= 'a' + j;
		drive->max_failures		= IDE_DEFAULT_MAX_FAILURES;

		INIT_LIST_HEAD(&drive->list);
		init_completion(&drive->gendev_rel_comp);
	}
}

void ide_remove_port_from_hwgroup(ide_hwif_t *hwif)
{
	ide_hwgroup_t *hwgroup = hwif->hwgroup;

	spin_lock_irq(&ide_lock);
	/*
	 * Remove us from the hwgroup, and free
	 * the hwgroup if we were the only member
	 */
	if (hwif->next == hwif) {
		BUG_ON(hwgroup->hwif != hwif);
		kfree(hwgroup);
	} else {
		/* There is another interface in hwgroup.
		 * Unlink us, and set hwgroup->drive and ->hwif to
		 * something sane.
		 */
		ide_hwif_t *g = hwgroup->hwif;

		while (g->next != hwif)
			g = g->next;
		g->next = hwif->next;
		if (hwgroup->hwif == hwif) {
			/* Chose a random hwif for hwgroup->hwif.
			 * It's guaranteed that there are no drives
			 * left in the hwgroup.
			 */
			BUG_ON(hwgroup->drive != NULL);
			hwgroup->hwif = g;
		}
		BUG_ON(hwgroup->hwif == hwif);
	}
	spin_unlock_irq(&ide_lock);
}

/* Called with ide_lock held. */
static void __ide_port_unregister_devices(ide_hwif_t *hwif)
{
	int i;

	for (i = 0; i < MAX_DRIVES; i++) {
		ide_drive_t