ide.c

基于组件方式开发操作系统的OSKIT源代码

/*
 *  linux/drivers/block/ide.c	Version 6.18  August 16, 1998
 *
 *  Copyright (C) 1994-1998  Linus Torvalds & authors (see below)
 */

/*
 *  Mostly written by Mark Lord  <[e-mail]>
 *                and Gadi Oxman <[e-mail]>
 *
 *  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.
 *
 * Primary:    ide0, port 0x1f0; major=3;  hda is minor=0; hdb is minor=64
 * Secondary:  ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
 * Tertiary:   ide2, port 0x???; major=33; hde is minor=0; hdf is minor=64
 * Quaternary: ide3, port 0x???; major=34; hdg is minor=0; hdh is minor=64
 * ...
 *
 *  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, [e-mail], who found a bug
 *  | in the early extended-partition checks and added DM partitions.
 *  |
 *  | Early work on error handling by Mika Liljeberg ([e-mail]).
 *  |
 *  | IRQ-unmask, drive-id, multiple-mode, support for ">16 heads",
 *  | and general streamlining by Mark Lord ([e-mail]).
 *
 *  October, 1994 -- Complete line-by-line overhaul for linux 1.1.x, by:
 *
 *	Mark Lord	([e-mail])		(IDE Perf.Pkg)
 *	Delman Lee	([e-mail])		("Mr. atdisk2")
 *	Scott Snyder	([e-mail])	(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.  [e-mail]
 *
 *  Version 1.0 ALPHA	initial code, primary i/f working okay
 *  Version 1.3 BETA	dual i/f on shared irq tested & working!
 *  Version 1.4 BETA	added auto probing for irq(s)
 *  Version 1.5 BETA	added ALPHA (untested) support for IDE cd-roms,
 *  ...
 * Version 5.50		allow values as small as 20 for idebus=
 * Version 5.51		force non io_32bit in drive_cmd_intr()
 *			change delay_10ms() to delay_50ms() to fix problems
 * Version 5.52		fix incorrect invalidation of removable devices
 *			add "hdx=slow" command line option
 * Version 5.60		start to modularize the driver; the disk and ATAPI
 *			 drivers can be compiled as loadable modules.
 *			move IDE probe code to ide-probe.c
 *			move IDE disk code to ide-disk.c
 *			add support for generic IDE device subdrivers
 *			add m68k code from Geert Uytterhoeven
 *			probe all interfaces by default
 *			add ioctl to (re)probe an interface
 * Version 6.00		use per device request queues
 *			attempt to optimize shared hwgroup performance
 *			add ioctl to manually adjust bandwidth algorithms
 *			add kerneld support for the probe module
 *			fix bug in ide_error()
 *			fix bug in the first ide_get_lock() call for Atari
 *			don't flush leftover data for ATAPI devices
 * Version 6.01		clear hwgroup->active while the hwgroup sleeps
 *			support HDIO_GETGEO for floppies
 * Version 6.02		fix ide_ack_intr() call
 *			check partition table on floppies
 * Version 6.03		handle bad status bit sequencing in ide_wait_stat()
 * Version 6.10		deleted old entries from this list of updates
 *			replaced triton.c with ide-dma.c generic PCI DMA
 *			added support for BIOS-enabled UltraDMA
 *			rename all "promise" things to "pdc4030"
 *			fix EZ-DRIVE handling on small disks
 * Version 6.11		fix probe error in ide_scan_devices()
 *			fix ancient "jiffies" polling bugs
 *			mask all hwgroup interrupts on each irq entry
 * Version 6.12		integrate ioctl and proc interfaces
 *			fix parsing of "idex=" command line parameter
 * Version 6.13		add support for ide4/ide5 courtesy [e-mail]
 * Version 6.14		fixed IRQ sharing among PCI devices
 * Version 6.15		added SMP awareness to IDE drivers
 * Version 6.16		fixed various bugs; even more SMP friendly
 * Version 6.17		fix for newest EZ-Drive problem
 * Version 6.18		default unpartitioned-disk translation now "BIOS LBA"
 *
 *  Some additional driver compile-time options are in ide.h
 *
 *  To do, in likely order of completion:
 *	- modify kernel to obtain BIOS geometry for drives on 2nd/3rd/4th i/f
*/

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

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

#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/malloc.h>
#include <linux/pci.h>
#include <linux/delay.h>

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

#include "ide.h"
#include "ide_modes.h"

#ifdef CONFIG_KMOD
#include <linux/kmod.h>
#endif /* CONFIG_KMOD */

static const byte	ide_hwif_to_major[] = {IDE0_MAJOR, IDE1_MAJOR, IDE2_MAJOR, IDE3_MAJOR, IDE4_MAJOR, IDE5_MAJOR };

static int	idebus_parameter; /* holds the "idebus=" parameter */
static int	system_bus_speed; /* holds what we think is VESA/PCI bus speed */
static int	initializing;     /* set while initializing built-in drivers */

/*
 * ide_lock is used by the Atari code to obtain access to the IDE interrupt,
 * which is shared between several drivers.
 */
static int	ide_lock = 0;

/*
 * ide_modules keeps track of the available IDE chipset/probe/driver modules.
 */
ide_module_t *ide_modules = NULL;

/*
 * This is declared extern in ide.h, for access by other IDE modules:
 */
ide_hwif_t	ide_hwifs[MAX_HWIFS];	/* master data repository */

#if (DISK_RECOVERY_TIME > 0)
/*
 * For really screwy hardware (hey, at least it *can* be used with Linux)
 * we can enforce a minimum delay time between successive operations.
 */
static unsigned long read_timer(void)
{
	unsigned long t, flags;
	int i;

	__save_flags(flags);	/* local CPU only */
	__cli();		/* local CPU only */
	t = jiffies * 11932;
    	outb_p(0, 0x43);
	i = inb_p(0x40);
	i |= inb(0x40) << 8;
	__restore_flags(flags);	/* local CPU only */
	return (t - i);
}
#endif /* DISK_RECOVERY_TIME */

static inline void set_recovery_timer (ide_hwif_t *hwif)
{
#if (DISK_RECOVERY_TIME > 0)
	hwif->last_time = read_timer();
#endif /* DISK_RECOVERY_TIME */
}

/*
 * Do not even *think* about calling this!
 */
static void init_hwif_data (unsigned int index)
{
	unsigned int unit;
	ide_hwif_t *hwif = &ide_hwifs[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;
	ide_init_hwif_ports(hwif->io_ports, ide_default_io_base(index), &hwif->irq);
	hwif->noprobe	= !hwif->io_ports[IDE_DATA_OFFSET];
#ifdef CONFIG_BLK_DEV_HD
	if (hwif->io_ports[IDE_DATA_OFFSET] == HD_DATA)
		hwif->noprobe = 1; /* may be overridden by ide_setup() */
#endif /* CONFIG_BLK_DEV_HD */
	hwif->major	= ide_hwif_to_major[index];
	hwif->name[0]	= 'i';
	hwif->name[1]	= 'd';
	hwif->name[2]	= 'e';
	hwif->name[3]	= '0' + index;
	for (unit = 0; unit < MAX_DRIVES; ++unit) {
		ide_drive_t *drive = &hwif->drives[unit];

		drive->media			= ide_disk;
		drive->select.all		= (unit<<4)|0xa0;
		drive->hwif			= hwif;
		drive->ctl			= 0x08;
		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' + (index * MAX_DRIVES) + unit;
	}
}

/*
 * init_ide_data() sets reasonable default values into all fields
 * of all instances of the hwifs and drives, but only on the first call.
 * Subsequent calls have no effect (they don't wipe out anything).
 *
 * This routine is normally called at driver initialization time,
 * but may also be called MUCH earlier during kernel "command-line"
 * parameter processing.  As such, we cannot depend on any other parts
 * of the kernel (such as memory allocation) to be functioning yet.
 *
 * This is too bad, as otherwise we could dynamically allocate the
 * ide_drive_t structs as needed, rather than always consuming memory
 * for the max possible number (MAX_HWIFS * MAX_DRIVES) of them.
 */
#define MAGIC_COOKIE 0x12345678
static void init_ide_data (void)
{
	unsigned int index;
	static unsigned long magic_cookie = MAGIC_COOKIE;

	if (magic_cookie != MAGIC_COOKIE)
		return;		/* already initialized */
	magic_cookie = 0;

	for (index = 0; index < MAX_HWIFS; ++index)
		init_hwif_data(index);

	idebus_parameter = 0;
	system_bus_speed = 0;
}

/*
 * CompactFlash cards and their brethern pretend to be removable hard disks, except:
 *	(1) they never have a slave unit, and
 *	(2) they don't have doorlock mechanisms.
 * This test catches them, and is invoked elsewhere when setting appropriate config bits.
 *
 * FIXME: This treatment is probably applicable for *all* PCMCIA (PC CARD) devices,
 * so in linux 2.3.x we should change this to just treat all PCMCIA drives this way,
 * and get rid of the model-name tests below (too big of an interface change for 2.2.x).
 * At that time, we might also consider parameterizing the timeouts and retries,
 * since these are MUCH faster than mechanical drives.	-M.Lord
 */
int drive_is_flashcard (ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;

	if (drive->removable && id != NULL) {
		if (!strncmp(id->model, "KODAK ATA_FLASH", 15)	/* Kodak */
		 || !strncmp(id->model, "Hitachi CV", 10)		/* Hitachi */
		 || !strncmp(id->model, "SunDisk SDCFB", 13)	/* SunDisk */
		 || !strncmp(id->model, "HAGIWARA HPC", 12))	/* Hagiwara */
		{
			return 1;	/* yes, it is a flash memory card */
		}
	}
	return 0;	/* no, it is not a flash memory card */
}

/*
 * ide_system_bus_speed() returns what we think is the system VESA/PCI
 * bus speed (in MHz).  This is used for calculating interface PIO timings.
 * The default is 40 for known PCI systems, 50 otherwise.
 * The "idebus=xx" parameter can be used to override this value.
 * The actual value to be used is computed/displayed the first time through.
 */
int ide_system_bus_speed (void)
{
	if (!system_bus_speed) {
		if (idebus_parameter)
			system_bus_speed = idebus_parameter;	/* user supplied value */
#ifdef CONFIG_PCI
		else if (pci_present())
			system_bus_speed = 40;	/* safe default value for PCI */
#endif /* CONFIG_PCI */
		else
			system_bus_speed = 50;	/* safe default value for VESA and PCI */
		printk("ide: Assuming %dMHz system bus speed for PIO modes%s\n", system_bus_speed,
			idebus_parameter ? "" : "; override with idebus=xx");
	}
	return system_bus_speed;
}

#if SUPPORT_VLB_SYNC
/*
 * Some localbus EIDE interfaces require a special access sequence
 * when using 32-bit I/O instructions to transfer data.  We call this
 * the "vlb_sync" sequence, which consists of three successive reads
 * of the sector count register location, with interrupts disabled
 * to ensure that the reads all happen together.
 */
static inline void do_vlb_sync (ide_ioreg_t port) {
	(void) inb (port);
	(void) inb (port);
	(void) inb (port);
}
#endif /* SUPPORT_VLB_SYNC */

/*
 * This is used for most PIO data transfers *from* the IDE interface
 */
void ide_input_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
	byte io_32bit = drive->io_32bit;

	if (io_32bit) {
#if SUPPORT_VLB_SYNC
		if (io_32bit & 2) {
			unsigned long flags;
			__save_flags(flags);	/* local CPU only */
			__cli();		/* local CPU only */
			do_vlb_sync(IDE_NSECTOR_REG);
			insl(IDE_DATA_REG, buffer, wcount);
			__restore_flags(flags);	/* local CPU only */
		} else
#endif /* SUPPORT_VLB_SYNC */
			insl(IDE_DATA_REG, buffer, wcount);
	} else {
#if SUPPORT_SLOW_DATA_PORTS
		if (drive->slow) {
			unsigned short *ptr = (unsigned short *) buffer;
			while (wcount--) {
				*ptr++ = inw_p(IDE_DATA_REG);
				*ptr++ = inw_p(IDE_DATA_REG);
			}
		} else
#endif /* SUPPORT_SLOW_DATA_PORTS */
			insw(IDE_DATA_REG, buffer, wcount<<1);
	}
}

/*
 * This is used for most PIO data transfers *to* the IDE interface
 */
void ide_output_data (ide_drive_t *drive, void *buffer, unsigned int wcount)
{
	byte io_32bit = drive->io_32bit;

	if (io_32bit) {
#if SUPPORT_VLB_SYNC
		if (io_32bit & 2) {
			unsigned long flags;
			__save_flags(flags);	/* local CPU only */
			__cli();		/* local CPU only */
			do_vlb_sync(IDE_NSECTOR_REG);
			outsl(IDE_DATA_REG, buffer, wcount);
			__restore_flags(flags);	/* local CPU only */
		} else
#endif /* SUPPORT_VLB_SYNC */
			outsl(IDE_DATA_REG, buffer, wcount);
	} else {
#if SUPPORT_SLOW_DATA_PORTS
		if (drive->slow) {
			unsigned short *ptr = (unsigned short *) buffer;
			while (wcount--) {
				outw_p(*ptr++, IDE_DATA_REG);
				outw_p(*ptr++, IDE_DATA_REG);
			}
		} else
#endif /* SUPPORT_SLOW_DATA_PORTS */
			outsw(IDE_DATA_REG, buffer, wcount<<1);
	}
}

/*
 * The following routines are mainly used by the ATAPI drivers.
 *
 * These routines will round up any request for an odd number of bytes,
 * so if an odd bytecount is specified, be sure that there's at least one
 * extra byte allocated for the buffer.
 */
void atapi_input_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
	++bytecount;
#ifdef CONFIG_ATARI
	if (MACH_IS_ATARI) {
		/* Atari has a byte-swapped IDE interface */
		insw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
		return;
	}
#endif /* CONFIG_ATARI */
	ide_input_data (drive, buffer, bytecount / 4);
	if ((bytecount & 0x03) >= 2)
		insw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

void atapi_output_bytes (ide_drive_t *drive, void *buffer, unsigned int bytecount)
{
	++bytecount;
#ifdef CONFIG_ATARI
	if (MACH_IS_ATARI) {
		/* Atari has a byte-swapped IDE interface */
		outsw_swapw(IDE_DATA_REG, buffer, bytecount / 2);
		return;
	}
#endif /* CONFIG_ATARI */
	ide_output_data (drive, buffer, bytecount / 4);
	if ((bytecount & 0x03) >= 2)
		outsw (IDE_DATA_REG, ((byte *)buffer) + (bytecount & ~0x03), 1);
}

/*
 * Needed for PCI irq sharing
 */
static inline int drive_is_ready (ide_drive_t *drive)
{
	if (drive->waiting_for_dma)
		return HWIF(drive)->dmaproc(ide_dma_test_irq, drive);
#if 0