path: root/include/linux/genhd.h

#ifndef _LINUX_GENHD_H
#define _LINUX_GENHD_H

/*
 * 	genhd.h Copyright (C) 1992 Drew Eckhardt
 *	Generic hard disk header file by  
 * 		Drew Eckhardt
 *
 *		<drew@colorado.edu>
 */

#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/rcupdate.h>

#ifdef CONFIG_BLOCK

#define kobj_to_dev(k)		container_of((k), struct device, kobj)
#define dev_to_disk(device)	container_of((device), struct gendisk, part0.__dev)
#define dev_to_part(device)	container_of((device), struct hd_struct, __dev)
#define disk_to_dev(disk)	(&(disk)->part0.__dev)
#define part_to_dev(part)	(&((part)->__dev))

extern struct device_type part_type;
extern struct kobject *block_depr;
extern struct class block_class;

extern const struct seq_operations diskstats_op;

enum {
/* These three have identical behaviour; use the second one if DOS FDISK gets
   confused about extended/logical partitions starting past cylinder 1023. */
	DOS_EXTENDED_PARTITION = 5,
	LINUX_EXTENDED_PARTITION = 0x85,
	WIN98_EXTENDED_PARTITION = 0x0f,

	SUN_WHOLE_DISK = DOS_EXTENDED_PARTITION,

	LINUX_SWAP_PARTITION = 0x82,
	LINUX_DATA_PARTITION = 0x83,
	LINUX_LVM_PARTITION = 0x8e,
	LINUX_RAID_PARTITION = 0xfd,	/* autodetect RAID partition */

	SOLARIS_X86_PARTITION =	LINUX_SWAP_PARTITION,
	NEW_SOLARIS_X86_PARTITION = 0xbf,

	DM6_AUX1PARTITION = 0x51,	/* no DDO:  use xlated geom */
	DM6_AUX3PARTITION = 0x53,	/* no DDO:  use xlated geom */
	DM6_PARTITION =	0x54,		/* has DDO: use xlated geom & offset */
	EZD_PARTITION =	0x55,		/* EZ-DRIVE */

	FREEBSD_PARTITION = 0xa5,	/* FreeBSD Partition ID */
	OPENBSD_PARTITION = 0xa6,	/* OpenBSD Partition ID */
	NETBSD_PARTITION = 0xa9,	/* NetBSD Partition ID */
	BSDI_PARTITION = 0xb7,		/* BSDI Partition ID */
	MINIX_PARTITION = 0x81,		/* Minix Partition ID */
	UNIXWARE_PARTITION = 0x63,	/* Same as GNU_HURD and SCO Unix */
};

#define DISK_MAX_PARTS			256
#define DISK_NAME_LEN			32

#include <linux/major.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/workqueue.h>

struct partition {
	unsigned char boot_ind;		/* 0x80 - active */
	unsigned char head;		/* starting head */
	unsigned char sector;		/* starting sector */
	unsigned char cyl;		/* starting cylinder */
	unsigned char sys_ind;		/* What partition type */
	unsigned char end_head;		/* end head */
	unsigned char end_sector;	/* end sector */
	unsigned char end_cyl;		/* end cylinder */
	__le32 start_sect;	/* starting sector counting from 0 */
	__le32 nr_sects;		/* nr of sectors in partition */
} __attribute__((packed));

struct disk_stats {
	unsigned long sectors[2];	/* READs and WRITEs */
	unsigned long ios[2];
	unsigned long merges[2];
	unsigned long ticks[2];
	unsigned long io_ticks;
	unsigned long time_in_queue;
};
	
struct hd_struct {
	sector_t start_sect;
	sector_t nr_sects;
	struct device __dev;
	struct kobject *holder_dir;
	int policy, partno;
#ifdef CONFIG_FAIL_MAKE_REQUEST
	int make_it_fail;
#endif
	unsigned long stamp;
	int in_flight;
#ifdef	CONFIG_SMP
	struct disk_stats *dkstats;
#else
	struct disk_stats dkstats;
#endif
	struct rcu_head rcu_head;
};

#define GENHD_FL_REMOVABLE			1
#define GENHD_FL_DRIVERFS			2
#define GENHD_FL_MEDIA_CHANGE_NOTIFY		4
#define GENHD_FL_CD				8
#define GENHD_FL_UP				16
#define GENHD_FL_SUPPRESS_PARTITION_INFO	32
#define GENHD_FL_EXT_DEVT			64 /* allow extended devt */

#define BLK_SCSI_MAX_CMDS	(256)
#define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))

struct blk_scsi_cmd_filter {
	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
	struct kobject kobj;
};

struct disk_part_tbl {
	struct rcu_head rcu_head;
	int len;
	struct hd_struct *part[];
};

struct gendisk {
	/* major, first_minor and minors are input parameters only,
	 * don't use directly.  Use disk_devt() and disk_max_parts().
	 */
	int major;			/* major number of driver */
	int first_minor;
	int minors;                     /* maximum number of minors, =1 for
                                         * disks that can't be partitioned. */

	char disk_name[DISK_NAME_LEN];	/* name of major driver */

	/* Array of pointers to partitions indexed by partno.
	 * Protected with matching bdev lock but stat and other
	 * non-critical accesses use RCU.  Always access through
	 * helpers.
	 */
	struct disk_part_tbl *part_tbl;
	struct hd_struct part0;

	struct block_device_operations *fops;
	struct request_queue *queue;
	void *private_data;

	int flags;
	struct device *driverfs_dev;  // FIXME: remove
	struct kobject *slave_dir;

	struct timer_rand_state *random;

	atomic_t sync_io;		/* RAID */
	struct work_struct async_notify;
#ifdef  CONFIG_BLK_DEV_INTEGRITY
	struct blk_integrity *integrity;
#endif
	int node_id;
};

static inline struct gendisk *part_to_disk(struct hd_struct *part)
{
	if (likely(part)) {
		if (part->partno)
			return dev_to_disk(part_to_dev(part)->parent);
		else
			return dev_to_disk(part_to_dev(part));
	}
	return NULL;
}

static inline int disk_max_parts(struct gendisk *disk)
{
	if (disk->flags & GENHD_FL_EXT_DEVT)
		return DISK_MAX_PARTS;
	return disk->minors;
}

static inline bool disk_partitionable(struct gendisk *disk)
{
	return disk_max_parts(disk) > 1;
}

static inline dev_t disk_devt(struct gendisk *disk)
{
	return disk_to_dev(disk)->devt;
}

static inline dev_t part_devt(struct hd_struct *part)
{
	return part_to_dev(part)->devt;
}

extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);

static inline void disk_put_part(struct hd_struct *part)
{
	if (likely(part))
		put_device(part_to_dev(part));
}

/*
 * Smarter partition iterator without context limits.
 */
#define DISK_PITER_REVERSE	(1 << 0) /* iterate in the reverse direction */
#define DISK_PITER_INCL_EMPTY	(1 << 1) /* include 0-sized parts */
#define DISK_PITER_INCL_PART0	(1 << 2) /* include partition 0 */

struct disk_part_iter {
	struct gendisk		*disk;
	struct hd_struct	*part;
	int			idx;
	unsigned int		flags;
};

extern void disk_part_iter_init(struct disk_part_iter *piter,
				 struct gendisk *disk, unsigned int flags);
extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
extern void disk_part_iter_exit(struct disk_part_iter *piter);

extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
					     sector_t sector);

/*
 * Macros to operate on percpu disk statistics:
 *
 * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
 * and should be called between disk_stat_lock() and
 * disk_stat_unlock().
 *
 * part_stat_read() can be called at any time.
 *
 * part_stat_{add|set_all}() and {init|free}_part_stats are for
 * internal use only.
 */
#ifdef	CONFIG_SMP
#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)

#define __part_stat_add(cpu, part, field, addnd)			\
	(per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))

#define part_stat_read(part, field)					\
({									\
	typeof((part)->dkstats->field) res = 0;				\
	int i;								\
	for_each_possible_cpu(i)					\
		res += per_cpu_ptr((part)->dkstats, i)->field;		\
	res;								\
})

static inline void part_stat_set_all(struct hd_struct *part, int value)
{
	int i;

	for_each_possible_cpu(i)
		memset(per_cpu_ptr(part->dkstats, i), value,
				sizeof(struct disk_stats));
}

static inline int init_part_stats(struct hd_struct *part)
{
	part->dkstats = alloc_percpu(struct disk_stats);
	if (!part->dkstats)
		return 0;
	return 1;
}

static inline void free_part_stats(struct hd_struct *part)
{
	free_percpu(part->dkstats);
}

#else /* !CONFIG_SMP */
#define part_stat_lock()	({ rcu_read_lock(); 0; })
#define part_stat_unlock()	rcu_read_unlock()

#define __part_stat_add(cpu, part, field, addnd)				\
	((part)->dkstats.field += addnd)

#define part_stat_read(part, field)	((part)->dkstats.field)

static inline void part_stat_set_all(struct hd_struct *part, int value)
{
	memset(&part->dkstats, value, sizeof(struct disk_stats));
}

static inline int init_part_stats(struct hd_struct *part)
{
	return 1;
}

static inline void free_part_stats(struct hd_struct *part)
{
}

#endif /* CONFIG_SMP */

#define part_stat_add(cpu, part, field, addnd)	do {			\
	__part_stat_add((cpu), (part), field, addnd);			\
	if ((part)->partno)						\
		__part_stat_add((cpu), &part_to_disk((part))->part0,	\
				field, addnd);				\
} while (0)

#define part_stat_dec(cpu, gendiskp, field)				\
	part_stat_add(cpu, gendiskp, field, -1)
#define part_stat_inc(cpu, gendiskp, field)				\
	part_stat_add(cpu, gendiskp, field, 1)
#define part_stat_sub(cpu, gendiskp, field, subnd)			\
	part_stat_add(cpu, gendiskp, field, -subnd)

static inline void part_inc_in_flight(struct hd_struct *part)
{
	part->in_flight++;
	if (part->partno)
		part_to_disk(part)->part0.in_flight++;
}

static inline void part_dec_in_flight(struct hd_struct *part)
{
	part->in_flight--;
	if (part->partno)
		part_to_disk(part)->part0.in_flight--;
}

/* drivers/block/ll_rw_blk.c */
extern void part_round_stats(int cpu, struct hd_struct *part);

/* drivers/block/genhd.c */
extern int get_blkdev_list(char *, int);
extern void add_disk(struct gendisk *disk);
extern void del_gendisk(struct gendisk *gp);
extern void unlink_gendisk(struct gendisk *gp);
extern struct gendisk *get_gendisk(dev_t dev, int *partno);
extern struct block_device *bdget_disk(struct gendisk *disk, int partno);

extern void set_device_ro(struct block_device *bdev, int flag);
extern void set_disk_ro(struct gendisk *disk, int flag);

static inline int get_disk_ro(struct gendisk *disk)
{
	return disk->part0.policy;
}

/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk);
extern void rand_initialize_disk(struct gendisk *disk);

static inline sector_t get_start_sect(struct block_device *bdev)
{
	return bdev->bd_part->start_sect;
}
static inline sector_t get_capacity(struct gendisk *disk)
{
	return disk->part0.nr_sects;
}
static inline void set_capacity(struct gendisk *disk, sector_t size)
{
	disk->part0.nr_sects = size;