#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/mutex.h>
#include <linux/ide.h>
#include <linux/hdreg.h>

#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
#define IDE_DISK_MINORS		(1 << PARTN_BITS)
#else
#define IDE_DISK_MINORS		0
#endif

#include "ide-disk.h"
#include "ide-floppy.h"

#define IDE_GD_VERSION	"1.18"

/* module parameters */
static unsigned long debug_mask;
module_param(debug_mask, ulong, 0644);

static DEFINE_MUTEX(ide_disk_ref_mutex);

static void ide_disk_release(struct kref *);

static struct ide_disk_obj *ide_disk_get(struct gendisk *disk)
{
	struct ide_disk_obj *idkp = NULL;

	mutex_lock(&ide_disk_ref_mutex);
	idkp = ide_drv_g(disk, ide_disk_obj);
	if (idkp) {
		if (ide_device_get(idkp->drive))
			idkp = NULL;
		else
			kref_get(&idkp->kref);
	}
	mutex_unlock(&ide_disk_ref_mutex);
	return idkp;
}

static void ide_disk_put(struct ide_disk_obj *idkp)
{
	ide_drive_t *drive = idkp->drive;

	mutex_lock(&ide_disk_ref_mutex);
	kref_put(&idkp->kref, ide_disk_release);
	ide_device_put(drive);
	mutex_unlock(&ide_disk_ref_mutex);
}

sector_t ide_gd_capacity(ide_drive_t *drive)
{
	return drive->capacity64;
}

static int ide_gd_probe(ide_drive_t *);

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

	ide_proc_unregister_driver(drive, idkp->driver);

	del_gendisk(g);

	drive->disk_ops->flush(drive);

	ide_disk_put(idkp);
}

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

	drive->disk_ops = NULL;
	drive->driver_data = NULL;
	g->private_data = NULL;
	put_disk(g);
	kfree(idkp);
}

/*
 * On HPA drives the capacity needs to be
 * reinitilized on resume otherwise the disk
 * can not be used and a hard reset is required
 */
static void ide_gd_resume(ide_drive_t *drive)
{
	if (ata_id_hpa_enabled(drive->id))
		(void)drive->disk_ops->get_capacity(drive);
}

static void ide_gd_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
		drive->disk_ops->flush(drive);
		return;
	}

	printk(KERN_INFO "Shutdown: %s\n", drive->name);

	drive->gendev.bus->suspend(&drive->gendev, PMSG_SUSPEND);
}

#ifdef CONFIG_IDE_PROC_FS
static ide_proc_entry_t *ide_disk_proc_entries(ide_drive_t *drive)
{
	return (drive->media == ide_disk) ? ide_disk_proc : ide_floppy_proc;
}

static const struct ide_proc_devset *ide_disk_proc_devsets(ide_drive_t *drive)
{
	return (drive->media == ide_disk) ? ide_disk_settings
					  : ide_floppy_settings;
}
#endif

static ide_startstop_t ide_gd_do_request(ide_drive_t *drive,
					 struct request *rq, sector_t sector)
{
	return drive->disk_ops->do_request(drive, rq, sector);
}

static int ide_gd_end_request(ide_drive_t *drive, int uptodate, int nrsecs)
{
	return drive->disk_ops->end_request(drive, uptodate, nrsecs);
}

static ide_driver_t ide_gd_driver = {
	.gen_driver = {
		.owner		= THIS_MODULE,
		.name		= "ide-gd",
		.bus		= &ide_bus_type,
	},
	.probe			= ide_gd_probe,
	.remove			= ide_gd_remove,
	.resume			= ide_gd_resume,
	.shutdown		= ide_gd_shutdown,
	.version		= IDE_GD_VERSION,
	.do_request		= ide_gd_do_request,
	.end_request		= ide_gd_end_request,
	.error			= __ide_error,
#ifdef CONFIG_IDE_PROC_FS
	.proc_entries		= ide_disk_proc_entries,
	.proc_devsets		= ide_disk_proc_devsets,
#endif
};

static int ide_gd_open(struct block_device *bdev, fmode_t mode)
{
	struct gendisk *disk = bdev->bd_disk;
	struct ide_disk_obj *idkp;
	ide_drive_t *drive;
	int ret = 0;

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

	drive = idkp->drive;

	ide_debug_log(IDE_DBG_FUNC, "Call %s\n", __func__);

	idkp->openers++;

	if ((drive->dev_flags & IDE_DFLAG_REMOVABLE) && idkp->openers == 1) {
		drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
		/* Just in case */

		ret = drive->disk_ops->init_media(drive, disk);

		/*
		 * Allow O_NDELAY to open a drive without a disk, or with an
		 * unreadable disk, so that we can get the format capacity
		 * of the drive or begin the format - Sam
		 */
		if (ret && (mode & FMODE_NDELAY) == 0) {
			ret = -EIO;
			goto out_put_idkp;
		}

		if ((drive->dev_flags & IDE_DFLAG_WP) && (mode & FMODE_WRITE)) {
			ret = -EROFS;
			goto out_put_idkp;
		}

		/*
		 * Ignore the return code from door_lock,
		 * since the open() has already succeeded,
		 * and the door_lock is irrelevant at this point.
		 */
		drive->disk_ops->set_doorlock(drive, disk, 1);
		drive->dev_flags |= IDE_DFLAG_MEDIA_CHANGED;
		check_disk_change(bdev);
	} else if (drive->dev_flags & IDE_DFLAG_FORMAT_IN_PROGRESS) {
		ret = -EBUSY;
		goto out_put_idkp;
	}
	return 0;

out_put_idkp:
	idkp->openers--;
	ide_disk_put(idkp);
	return ret;
}

static int ide_gd_release(struct gendisk *disk, fmode_t mode)
{
	struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj);
	ide_drive_t *drive = idkp->drive;

	ide_debug_log(IDE_DBG_FUNC, "Call %s\n", __func__);

	if (idkp->openers == 1)
		drive->disk_ops->flush(drive);

	if ((drive->dev_flags & IDE_DFLAG_REMOVABLE) && idkp->openers == 1) {
		drive->disk_ops->set_doorlock(drive, disk, 0);
		drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
	}

	idkp->openers--;

	ide_disk_put(idkp);

	return 0;
}

static int ide_gd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct ide_disk_obj *idkp = ide_drv_g(bdev->bd_disk, ide_disk_obj);
	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 ide_gd_media_changed(struct gendisk *disk)
{
	struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj);
	ide_drive_t *drive = idkp->drive;
	int ret;

	/* do not scan partitions twice if this is a removable device */
	if (drive->dev_flags & IDE_DFLAG_ATTACH) {
		drive->dev_flags &= ~IDE_DFLAG_ATTACH;
		return 0;
	}

	ret = !!(drive->dev_flags & IDE_DFLAG_MEDIA_CHANGED);
	drive->dev_flags &= ~IDE_DFLAG_MEDIA_CHANGED;

	return ret;
}

static int ide_gd_revalidate_disk(struct gendisk *disk)
{
	struct ide_disk_obj *idkp = ide_drv_g(disk, ide_disk_obj);
	ide_drive_t *drive = idkp->drive;

	if (ide_gd_media_changed(disk))
		drive->disk_ops->get_capacity(drive);

	set_capacity(disk, ide_gd_capacity(drive));
	return 0;
}

static int ide_gd_ioctl(struct block_device *bdev, fmode_t mode,
			     unsigned int cmd, unsigned long arg)
{
	struct ide_disk_obj *idkp = ide_drv_g(bdev->bd_disk, ide_disk_obj);
	ide_drive_t *drive = idkp->drive;

	return drive->disk_ops->ioctl(drive, bdev, mode, cmd, arg);
}

static struct block_device_operations ide_gd_ops = {
	.owner			= THIS_MODULE,
	.open			= ide_gd_open,
	.release		= ide_gd_release,
	.locked_ioctl		= ide_gd_ioctl,
	.getgeo			= ide_gd_getgeo,
	.media_changed		= ide_gd_media_changed,
	.revalidate_disk	= ide_gd_revalidate_disk
};

static int ide_gd_probe(ide_drive_t *drive)
{
	const struct ide_disk_ops *disk_ops = NULL;
	struct ide_disk_obj *idkp;
	struct gendisk *g;

	/* strstr("foo", "") is non-NULL */
	if (!strstr("ide-gd", drive->driver_req))
		goto failed;

#ifdef CONFIG_IDE_GD_ATA
	if (drive->media == ide_disk)
		disk_ops = &ide_ata_disk_ops;
#endif
#ifdef CONFIG_IDE_GD_ATAPI
	if (drive->media == ide_floppy)
		disk_ops = &ide_atapi_disk_ops;
#endif
	if (disk_ops == NULL)
		goto failed;

	if (disk_ops->check(drive, DRV_NAME) == 0) {
		printk(KERN_ERR PFX "%s: not supported by this driver\n",
			drive->name);
		goto failed;
	}

	idkp = kzalloc(sizeof(*idkp), GFP_KERNEL);
	if (!idkp) {
		printk(KERN_ERR PFX "%s: can't allocate a disk structure\n",
			drive->name);
		goto failed;
	}

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

	ide_init_disk(g, drive);

	kref_init(&idkp->kref);

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

	g->private_data = &idkp->driver;

	drive->driver_data = idkp;
	drive->debug_mask = debug_mask;
	drive->disk_ops = disk_ops;

	disk_ops->setup(drive);

	set_capacity(g, ide_gd_capacity(drive));

	g->minors = IDE_DISK_MINORS;
	g->driverfs_dev = &drive->gendev;
	g->flags |= GENHD_FL_EXT_DEVT;
	if (drive->dev_flags & IDE_DFLAG_REMOVABLE)
		g->flags = GENHD_FL_REMOVABLE;
	g->fops = &ide_gd_ops;
	add_disk(g);
	return 0;

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

static int __init ide_gd_init(void)
{
	printk(KERN_INFO DRV_NAME " driver " IDE_GD_VERSION "\n");
	return driver_register(&ide_gd_driver.gen_driver);
}

static void __exit ide_gd_exit(void)
{
	driver_unregister(&ide_gd_driver.gen_driver);
}

MODULE_ALIAS("ide:*m-disk*");
MODULE_ALIAS("ide-disk");
MODULE_ALIAS("ide:*m-floppy*");
MODULE_ALIAS("ide-floppy");
module_init(ide_gd_init);
module_exit(ide_gd_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("generic ATA/ATAPI disk driver");