ide-disk.c

linux设备驱动开发详解（书代码）

	memset(&args, 0, sizeof(ide_task_t));
	args.tfRegister[IDE_FEATURE_OFFSET]	= (arg) ? SETFEATURES_EN_AAM :
							  SETFEATURES_DIS_AAM;
	args.tfRegister[IDE_NSECTOR_OFFSET]	= arg;
	args.tfRegister[IDE_COMMAND_OFFSET]	= WIN_SETFEATURES;
	args.command_type = IDE_DRIVE_TASK_NO_DATA;
	args.handler	  = &task_no_data_intr;
	ide_raw_taskfile(drive, &args, NULL);
	drive->acoustic = arg;
	return 0;
}

/*
 * drive->addressing:
 *	0: 28-bit
 *	1: 48-bit
 *	2: 48-bit capable doing 28-bit
 */
static int set_lba_addressing(ide_drive_t *drive, int arg)
{
	drive->addressing =  0;

	if (HWIF(drive)->no_lba48)
		return 0;

	if (!idedisk_supports_lba48(drive->id))
                return -EIO;
	drive->addressing = arg;
	return 0;
}

static void idedisk_add_settings(ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;

	ide_add_setting(drive,	"bios_cyl",		SETTING_RW,					-1,			-1,			TYPE_INT,	0,	65535,				1,	1,	&drive->bios_cyl,		NULL);
	ide_add_setting(drive,	"bios_head",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	255,				1,	1,	&drive->bios_head,		NULL);
	ide_add_setting(drive,	"bios_sect",		SETTING_RW,					-1,			-1,			TYPE_BYTE,	0,	63,				1,	1,	&drive->bios_sect,		NULL);
	ide_add_setting(drive,	"address",		SETTING_RW,					HDIO_GET_ADDRESS,	HDIO_SET_ADDRESS,	TYPE_INTA,	0,	2,				1,	1,	&drive->addressing,	set_lba_addressing);
	ide_add_setting(drive,	"bswap",		SETTING_READ,					-1,			-1,			TYPE_BYTE,	0,	1,				1,	1,	&drive->bswap,			NULL);
	ide_add_setting(drive,	"multcount",		id ? SETTING_RW : SETTING_READ,			HDIO_GET_MULTCOUNT,	HDIO_SET_MULTCOUNT,	TYPE_BYTE,	0,	id ? id->max_multsect : 0,	1,	1,	&drive->mult_count,		set_multcount);
	ide_add_setting(drive,	"nowerr",		SETTING_RW,					HDIO_GET_NOWERR,	HDIO_SET_NOWERR,	TYPE_BYTE,	0,	1,				1,	1,	&drive->nowerr,			set_nowerr);
	ide_add_setting(drive,	"lun",			SETTING_RW,					-1,			-1,			TYPE_INT,	0,	7,				1,	1,	&drive->lun,			NULL);
	ide_add_setting(drive,	"wcache",		SETTING_RW,					HDIO_GET_WCACHE,	HDIO_SET_WCACHE,	TYPE_BYTE,	0,	1,				1,	1,	&drive->wcache,			write_cache);
	ide_add_setting(drive,	"acoustic",		SETTING_RW,					HDIO_GET_ACOUSTIC,	HDIO_SET_ACOUSTIC,	TYPE_BYTE,	0,	254,				1,	1,	&drive->acoustic,		set_acoustic);
 	ide_add_setting(drive,	"failures",		SETTING_RW,					-1,			-1,			TYPE_INT,	0,	65535,				1,	1,	&drive->failures,		NULL);
 	ide_add_setting(drive,	"max_failures",		SETTING_RW,					-1,			-1,			TYPE_INT,	0,	65535,				1,	1,	&drive->max_failures,		NULL);
}

static void idedisk_setup (ide_drive_t *drive)
{
	struct hd_driveid *id = drive->id;
	unsigned long long capacity;

	idedisk_add_settings(drive);

	if (drive->id_read == 0)
		return;

	if (drive->removable) {
		/*
		 * Removable disks (eg. SYQUEST); ignore 'WD' drives 
		 */
		if (id->model[0] != 'W' || id->model[1] != 'D') {
			drive->doorlocking = 1;
		}
	}

	(void)set_lba_addressing(drive, 1);

	if (drive->addressing == 1) {
		ide_hwif_t *hwif = HWIF(drive);
		int max_s = 2048;

		if (max_s > hwif->rqsize)
			max_s = hwif->rqsize;

		blk_queue_max_sectors(drive->queue, max_s);
	}

	printk(KERN_INFO "%s: max request size: %dKiB\n", drive->name, drive->queue->max_sectors / 2);

	/* calculate drive capacity, and select LBA if possible */
	init_idedisk_capacity (drive);

	/* limit drive capacity to 137GB if LBA48 cannot be used */
	if (drive->addressing == 0 && drive->capacity64 > 1ULL << 28) {
		printk(KERN_WARNING "%s: cannot use LBA48 - full capacity "
		       "%llu sectors (%llu MB)\n",
		       drive->name, (unsigned long long)drive->capacity64,
		       sectors_to_MB(drive->capacity64));
		drive->capacity64 = 1ULL << 28;
	}

	if (drive->hwif->no_lba48_dma && drive->addressing) {
		if (drive->capacity64 > 1ULL << 28) {
			printk(KERN_INFO "%s: cannot use LBA48 DMA - PIO mode will"
					 " be used for accessing sectors > %u\n",
					 drive->name, 1 << 28);
		} else
			drive->addressing = 0;
	}

	/*
	 * if possible, give fdisk access to more of the drive,
	 * by correcting bios_cyls:
	 */
	capacity = idedisk_capacity (drive);
	if (!drive->forced_geom) {

		if (idedisk_supports_lba48(drive->id)) {
			/* compatibility */
			drive->bios_sect = 63;
			drive->bios_head = 255;
		}

		if (drive->bios_sect && drive->bios_head) {
			unsigned int cap0 = capacity; /* truncate to 32 bits */
			unsigned int cylsz, cyl;

			if (cap0 != capacity)
				drive->bios_cyl = 65535;
			else {
				cylsz = drive->bios_sect * drive->bios_head;
				cyl = cap0 / cylsz;
				if (cyl > 65535)
					cyl = 65535;
				if (cyl > drive->bios_cyl)
					drive->bios_cyl = cyl;
			}
		}
	}
	printk(KERN_INFO "%s: %llu sectors (%llu MB)",
			 drive->name, capacity, sectors_to_MB(capacity));

	/* Only print cache size when it was specified */
	if (id->buf_size)
		printk (" w/%dKiB Cache", id->buf_size/2);

	printk(", CHS=%d/%d/%d", 
	       drive->bios_cyl, drive->bios_head, drive->bios_sect);
	if (drive->using_dma)
		ide_dma_verbose(drive);
	printk("\n");

	drive->no_io_32bit = id->dword_io ? 1 : 0;

	/* write cache enabled? */
	if ((id->csfo & 1) || (id->cfs_enable_1 & (1 << 5)))
		drive->wcache = 1;

	write_cache(drive, 1);
}

static void ide_cacheflush_p(ide_drive_t *drive)
{
	if (!drive->wcache || !ide_id_has_flush_cache(drive->id))
		return;

	if (do_idedisk_flushcache(drive))
		printk(KERN_INFO "%s: wcache flush failed!\n", drive->name);
}

static void ide_disk_remove(ide_drive_t *drive)
{
	struct ide_disk_obj *idkp = drive->driver_data;
	struct gendisk *g = idkp->disk;

	ide_unregister_subdriver(drive, idkp->driver);

	del_gendisk(g);

	ide_cacheflush_p(drive);

	ide_disk_put(idkp);
}

static void ide_disk_release(struct kref *kref)
{
	struct ide_disk_obj *idkp = to_ide_disk(kref);
	ide_drive_t *drive = idkp->drive;
	struct gendisk *g = idkp->disk;

	drive->driver_data = NULL;
	drive->devfs_name[0] = '\0';
	g->private_data = NULL;
	put_disk(g);
	kfree(idkp);
}

static int ide_disk_probe(ide_drive_t *drive);

static void ide_device_shutdown(ide_drive_t *drive)
{
#ifdef	CONFIG_ALPHA
	/* On Alpha, halt(8) doesn't actually turn the machine off,
	   it puts you into the sort of firmware monitor. Typically,
	   it's used to boot another kernel image, so it's not much
	   different from reboot(8). Therefore, we don't need to
	   spin down the disk in this case, especially since Alpha
	   firmware doesn't handle disks in standby mode properly.
	   On the other hand, it's reasonably safe to turn the power
	   off when the shutdown process reaches the firmware prompt,
	   as the firmware initialization takes rather long time -
	   at least 10 seconds, which should be sufficient for
	   the disk to expire its write cache. */
	if (system_state != SYSTEM_POWER_OFF) {
#else
	if (system_state == SYSTEM_RESTART) {
#endif
		ide_cacheflush_p(drive);
		return;
	}

	printk("Shutdown: %s\n", drive->name);
	drive->gendev.bus->suspend(&drive->gendev, PMSG_SUSPEND);
}

static ide_driver_t idedisk_driver = {
	.gen_driver = {
		.owner		= THIS_MODULE,
		.name		= "ide-disk",
		.bus		= &ide_bus_type,
	},
	.probe			= ide_disk_probe,
	.remove			= ide_disk_remove,
	.shutdown		= ide_device_shutdown,
	.version		= IDEDISK_VERSION,
	.media			= ide_disk,
	.supports_dsc_overlap	= 0,
	.do_request		= ide_do_rw_disk,
	.end_request		= ide_end_request,
	.error			= __ide_error,
	.abort			= __ide_abort,
	.proc			= idedisk_proc,
};

static int idedisk_open(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_disk_obj *idkp;
	ide_drive_t *drive;

	if (!(idkp = ide_disk_get(disk)))
		return -ENXIO;

	drive = idkp->drive;

	drive->usage++;
	if (drive->removable && drive->usage == 1) {
		ide_task_t args;
		memset(&args, 0, sizeof(ide_task_t));
		args.tfRegister[IDE_COMMAND_OFFSET] = WIN_DOORLOCK;
		args.command_type = IDE_DRIVE_TASK_NO_DATA;
		args.handler	  = &task_no_data_intr;
		check_disk_change(inode->i_bdev);
		/*
		 * Ignore the return code from door_lock,
		 * since the open() has already succeeded,
		 * and the door_lock is irrelevant at this point.
		 */
		if (drive->doorlocking && ide_raw_taskfile(drive, &args, NULL))
			drive->doorlocking = 0;
	}
	return 0;
}

static int idedisk_release(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_disk_obj *idkp = ide_disk_g(disk);
	ide_drive_t *drive = idkp->drive;

	if (drive->usage == 1)
		ide_cacheflush_p(drive);
	if (drive->removable && drive->usage == 1) {
		ide_task_t args;
		memset(&args, 0, sizeof(ide_task_t));
		args.tfRegister[IDE_COMMAND_OFFSET] = WIN_DOORUNLOCK;
		args.command_type = IDE_DRIVE_TASK_NO_DATA;
		args.handler	  = &task_no_data_intr;
		if (drive->doorlocking && ide_raw_taskfile(drive, &args, NULL))
			drive->doorlocking = 0;
	}
	drive->usage--;

	ide_disk_put(idkp);

	return 0;
}

static int idedisk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct ide_disk_obj *idkp = ide_disk_g(bdev->bd_disk);
	ide_drive_t *drive = idkp->drive;

	geo->heads = drive->bios_head;
	geo->sectors = drive->bios_sect;
	geo->cylinders = (u16)drive->bios_cyl; /* truncate */
	return 0;
}

static int idedisk_ioctl(struct inode *inode, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct block_device *bdev = inode->i_bdev;
	struct ide_disk_obj *idkp = ide_disk_g(bdev->bd_disk);
	return generic_ide_ioctl(idkp->drive, file, bdev, cmd, arg);
}

static int idedisk_media_changed(struct gendisk *disk)
{
	struct ide_disk_obj *idkp = ide_disk_g(disk);
	ide_drive_t *drive = idkp->drive;

	/* do not scan partitions twice if this is a removable device */
	if (drive->attach) {
		drive->attach = 0;
		return 0;
	}
	/* if removable, always assume it was changed */
	return drive->removable;
}

static int idedisk_revalidate_disk(struct gendisk *disk)
{
	struct ide_disk_obj *idkp = ide_disk_g(disk);
	set_capacity(disk, idedisk_capacity(idkp->drive));
	return 0;
}

static struct block_device_operations idedisk_ops = {
	.owner		= THIS_MODULE,
	.open		= idedisk_open,
	.release	= idedisk_release,
	.ioctl		= idedisk_ioctl,
	.getgeo		= idedisk_getgeo,
	.media_changed	= idedisk_media_changed,
	.revalidate_disk= idedisk_revalidate_disk
};

MODULE_DESCRIPTION("ATA DISK Driver");

static int ide_disk_probe(ide_drive_t *drive)
{
	struct ide_disk_obj *idkp;
	struct gendisk *g;

	/* strstr("foo", "") is non-NULL */
	if (!strstr("ide-disk", drive->driver_req))
		goto failed;
	if (!drive->present)
		goto failed;
	if (drive->media != ide_disk)
		goto failed;

	idkp = kzalloc(sizeof(*idkp), GFP_KERNEL);
	if (!idkp)
		goto failed;

	g = alloc_disk_node(1 << PARTN_BITS,
			hwif_to_node(drive->hwif));
	if (!g)
		goto out_free_idkp;

	ide_init_disk(g, drive);

	ide_register_subdriver(drive, &idedisk_driver);

	kref_init(&idkp->kref);

	idkp->drive = drive;
	idkp->driver = &idedisk_driver;
	idkp->disk = g;

	g->private_data = &idkp->driver;

	drive->driver_data = idkp;

	idedisk_setup(drive);
	if ((!drive->head || drive->head > 16) && !drive->select.b.lba) {
		printk(KERN_ERR "%s: INVALID GEOMETRY: %d PHYSICAL HEADS?\n",
			drive->name, drive->head);
		drive->attach = 0;
	} else
		drive->attach = 1;

	g->minors = 1 << PARTN_BITS;
	strcpy(g->devfs_name, drive->devfs_name);
	g->driverfs_dev = &drive->gendev;
	g->flags = drive->removable ? GENHD_FL_REMOVABLE : 0;
	set_capacity(g, idedisk_capacity(drive));
	g->fops = &idedisk_ops;
	add_disk(g);
	return 0;

out_free_idkp:
	kfree(idkp);
failed:
	return -ENODEV;
}

static void __exit idedisk_exit (void)
{
	driver_unregister(&idedisk_driver.gen_driver);
}

static int __init idedisk_init(void)
{
	return driver_register(&idedisk_driver.gen_driver);
}

MODULE_ALIAS("ide:*m-disk*");
module_init(idedisk_init);
module_exit(idedisk_exit);
MODULE_LICENSE("GPL");