[linux-block.git] / drivers / block / xen-blkback / common.h

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef __XEN_BLKIF__BACKEND__COMMON_H__
#define __XEN_BLKIF__BACKEND__COMMON_H__

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/io.h>
#include <linux/rbtree.h>
#include <asm/setup.h>
#include <asm/pgalloc.h>
#include <asm/hypervisor.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <xen/interface/io/ring.h>
#include <xen/interface/io/blkif.h>
#include <xen/interface/io/protocols.h>

#define DRV_PFX "xen-blkback:"
#define DPRINTK(fmt, args...)				\
	pr_debug(DRV_PFX "(%s:%d) " fmt ".\n",		\
		 __func__, __LINE__, ##args)


/* Not a real protocol.  Used to generate ring structs which contain
 * the elements common to all protocols only.  This way we get a
 * compiler-checkable way to use common struct elements, so we can
 * avoid using switch(protocol) in a number of places.  */
struct blkif_common_request {
	char dummy;
};
struct blkif_common_response {
	char dummy;
};

struct blkif_x86_32_request_rw {
	uint8_t        nr_segments;  /* number of segments                   */
	blkif_vdev_t   handle;       /* only for read/write requests         */
	uint64_t       id;           /* private guest value, echoed in resp  */
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
} __attribute__((__packed__));

struct blkif_x86_32_request_discard {
	uint8_t        flag;         /* BLKIF_DISCARD_SECURE or zero         */
	blkif_vdev_t   _pad1;        /* was "handle" for read/write requests */
	uint64_t       id;           /* private guest value, echoed in resp  */
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	uint64_t       nr_sectors;
} __attribute__((__packed__));

struct blkif_x86_32_request_other {
	uint8_t        _pad1;
	blkif_vdev_t   _pad2;
	uint64_t       id;           /* private guest value, echoed in resp  */
} __attribute__((__packed__));

struct blkif_x86_32_request {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	union {
		struct blkif_x86_32_request_rw rw;
		struct blkif_x86_32_request_discard discard;
		struct blkif_x86_32_request_other other;
	} u;
} __attribute__((__packed__));

/* i386 protocol version */
#pragma pack(push, 4)
struct blkif_x86_32_response {
	uint64_t        id;              /* copied from request */
	uint8_t         operation;       /* copied from request */
	int16_t         status;          /* BLKIF_RSP_???       */
};
#pragma pack(pop)
/* x86_64 protocol version */

struct blkif_x86_64_request_rw {
	uint8_t        nr_segments;  /* number of segments                   */
	blkif_vdev_t   handle;       /* only for read/write requests         */
	uint32_t       _pad1;        /* offsetof(blkif_reqest..,u.rw.id)==8  */
	uint64_t       id;
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
} __attribute__((__packed__));

struct blkif_x86_64_request_discard {
	uint8_t        flag;         /* BLKIF_DISCARD_SECURE or zero         */
	blkif_vdev_t   _pad1;        /* was "handle" for read/write requests */
        uint32_t       _pad2;        /* offsetof(blkif_..,u.discard.id)==8   */
	uint64_t       id;
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	uint64_t       nr_sectors;
} __attribute__((__packed__));

struct blkif_x86_64_request_other {
	uint8_t        _pad1;
	blkif_vdev_t   _pad2;
	uint32_t       _pad3;        /* offsetof(blkif_..,u.discard.id)==8   */
	uint64_t       id;           /* private guest value, echoed in resp  */
} __attribute__((__packed__));

struct blkif_x86_64_request {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	union {
		struct blkif_x86_64_request_rw rw;
		struct blkif_x86_64_request_discard discard;
		struct blkif_x86_64_request_other other;
	} u;
} __attribute__((__packed__));

struct blkif_x86_64_response {
	uint64_t       __attribute__((__aligned__(8))) id;
	uint8_t         operation;       /* copied from request */
	int16_t         status;          /* BLKIF_RSP_???       */
};

DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
		  struct blkif_common_response);
DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
		  struct blkif_x86_32_response);
DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
		  struct blkif_x86_64_response);

union blkif_back_rings {
	struct blkif_back_ring        native;
	struct blkif_common_back_ring common;
	struct blkif_x86_32_back_ring x86_32;
	struct blkif_x86_64_back_ring x86_64;
};

enum blkif_protocol {
	BLKIF_PROTOCOL_NATIVE = 1,
	BLKIF_PROTOCOL_X86_32 = 2,
	BLKIF_PROTOCOL_X86_64 = 3,
};

struct xen_vbd {
	/* What the domain refers to this vbd as. */
	blkif_vdev_t		handle;
	/* Non-zero -> read-only */
	unsigned char		readonly;
	/* VDISK_xxx */
	unsigned char		type;
	/* phys device that this vbd maps to. */
	u32			pdevice;
	struct block_device	*bdev;
	/* Cached size parameter. */
	sector_t		size;
	unsigned int		flush_support:1;
	unsigned int		discard_secure:1;
	unsigned int		feature_gnt_persistent:1;
	unsigned int		overflow_max_grants:1;
};

struct backend_info;


struct persistent_gnt {
	struct page *page;
	grant_ref_t gnt;
	grant_handle_t handle;
	struct rb_node node;
};

struct xen_blkif {
	/* Unique identifier for this interface. */
	domid_t			domid;
	unsigned int		handle;
	/* Physical parameters of the comms window. */
	unsigned int		irq;
	/* Comms information. */
	enum blkif_protocol	blk_protocol;
	union blkif_back_rings	blk_rings;
	void			*blk_ring;
	/* The VBD attached to this interface. */
	struct xen_vbd		vbd;
	/* Back pointer to the backend_info. */
	struct backend_info	*be;
	/* Private fields. */
	spinlock_t		blk_ring_lock;
	atomic_t		refcnt;

	wait_queue_head_t	wq;
	/* for barrier (drain) requests */
	struct completion	drain_complete;
	atomic_t		drain;
	/* One thread per one blkif. */
	struct task_struct	*xenblkd;
	unsigned int		waiting_reqs;

	/* tree to store persistent grants */
	struct rb_root		persistent_gnts;
	unsigned int		persistent_gnt_c;

	/* statistics */
	unsigned long		st_print;
	unsigned long long			st_rd_req;
	unsigned long long			st_wr_req;
	unsigned long long			st_oo_req;
	unsigned long long			st_f_req;
	unsigned long long			st_ds_req;
	unsigned long long			st_rd_sect;
	unsigned long long			st_wr_sect;

	wait_queue_head_t	waiting_to_free;
};


#define vbd_sz(_v)	((_v)->bdev->bd_part ? \
			 (_v)->bdev->bd_part->nr_sects : \
			  get_capacity((_v)->bdev->bd_disk))

#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
#define xen_blkif_put(_b)				\
	do {						\
		if (atomic_dec_and_test(&(_b)->refcnt))	\
			wake_up(&(_b)->waiting_to_free);\
	} while (0)

struct phys_req {
	unsigned short		dev;
	blkif_sector_t		nr_sects;
	struct block_device	*bdev;
	blkif_sector_t		sector_number;
};
int xen_blkif_interface_init(void);

int xen_blkif_xenbus_init(void);

irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
int xen_blkif_schedule(void *arg);

int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
			      struct backend_info *be, int state);

int xen_blkbk_barrier(struct xenbus_transaction xbt,
		      struct backend_info *be, int state);
struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);

static inline void blkif_get_x86_32_req(struct blkif_request *dst,
					struct blkif_x86_32_request *src)
{
	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	dst->operation = src->operation;
	switch (src->operation) {
	case BLKIF_OP_READ:
	case BLKIF_OP_WRITE:
	case BLKIF_OP_WRITE_BARRIER:
	case BLKIF_OP_FLUSH_DISKCACHE:
		dst->u.rw.nr_segments = src->u.rw.nr_segments;
		dst->u.rw.handle = src->u.rw.handle;
		dst->u.rw.id = src->u.rw.id;
		dst->u.rw.sector_number = src->u.rw.sector_number;
		barrier();
		if (n > dst->u.rw.nr_segments)
			n = dst->u.rw.nr_segments;
		for (i = 0; i < n; i++)
			dst->u.rw.seg[i] = src->u.rw.seg[i];
		break;
	case BLKIF_OP_DISCARD:
		dst->u.discard.flag = src->u.discard.flag;
		dst->u.discard.id = src->u.discard.id;
		dst->u.discard.sector_number = src->u.discard.sector_number;
		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
		break;
	default:
		/*
		 * Don't know how to translate this op. Only get the
		 * ID so failure can be reported to the frontend.
		 */
		dst->u.other.id = src->u.other.id;
		break;
	}
}

static inline void blkif_get_x86_64_req(struct blkif_request *dst,
					struct blkif_x86_64_request *src)
{
	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	dst->operation = src->operation;
	switch (src->operation) {
	case BLKIF_OP_READ:
	case BLKIF_OP_WRITE:
	case BLKIF_OP_WRITE_BARRIER:
	case BLKIF_OP_FLUSH_DISKCACHE:
		dst->u.rw.nr_segments = src->u.rw.nr_segments;
		dst->u.rw.handle = src->u.rw.handle;
		dst->u.rw.id = src->u.rw.id;
		dst->u.rw.sector_number = src->u.rw.sector_number;
		barrier();
		if (n > dst->u.rw.nr_segments)
			n = dst->u.rw.nr_segments;
		for (i = 0; i < n; i++)
			dst->u.rw.seg[i] = src->u.rw.seg[i];
		break;
	case BLKIF_OP_DISCARD:
		dst->u.discard.flag = src->u.discard.flag;
		dst->u.discard.id = src->u.discard.id;
		dst->u.discard.sector_number = src->u.discard.sector_number;
		dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
		break;
	default:
		/*
		 * Don't know how to translate this op. Only get the
		 * ID so failure can be reported to the frontend.
		 */
		dst->u.other.id = src->u.other.id;
		break;
	}
}

#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */
Commit	Line	Data
4d05a28d KRW	1	/*
	2	* This program is free software; you can redistribute it and/or
	3	* modify it under the terms of the GNU General Public License version 2
	4	* as published by the Free Software Foundation; or, when distributed
	5	* separately from the Linux kernel or incorporated into other
	6	* software packages, subject to the following license:
	7	*
	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this source file (the "Software"), to deal in the Software without
	10	* restriction, including without limitation the rights to use, copy, modify,
	11	* merge, publish, distribute, sublicense, and/or sell copies of the Software,
	12	* and to permit persons to whom the Software is furnished to do so, subject to
	13	* the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be included in
	16	* all copies or substantial portions of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	21	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	22	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	23	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	24	* IN THE SOFTWARE.
	25	*/
	26
5a577e38 KRW	27	#ifndef __XEN_BLKIF__BACKEND__COMMON_H__
5a577e38 KRW	28	#define __XEN_BLKIF__BACKEND__COMMON_H__
4d05a28d	29
4d05a28d KRW	30	#include <linux/module.h>
	31	#include <linux/interrupt.h>
	32	#include <linux/slab.h>
	33	#include <linux/blkdev.h>
	34	#include <linux/vmalloc.h>
	35	#include <linux/wait.h>
5489377c	36	#include <linux/io.h>
0a8704a5	37	#include <linux/rbtree.h>
4d05a28d KRW	38	#include <asm/setup.h>
4d05a28d KRW	39	#include <asm/pgalloc.h>
4d05a28d	40	#include <asm/hypervisor.h>
88122933	41	#include <xen/grant_table.h>
4d05a28d	42	#include <xen/xenbus.h>
452a6b2b KRW	43	#include <xen/interface/io/ring.h>
	44	#include <xen/interface/io/blkif.h>
	45	#include <xen/interface/io/protocols.h>
4d05a28d	46
22b20f2d	47	#define DRV_PFX "xen-blkback:"
1afbd730	48	#define DPRINTK(fmt, args...) \
1bc05b0a	49	pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
1afbd730	50	__func__, __LINE__, ##args)
4d05a28d	51
452a6b2b KRW	52
	53	/* Not a real protocol. Used to generate ring structs which contain
	54	* the elements common to all protocols only. This way we get a
	55	* compiler-checkable way to use common struct elements, so we can
	56	* avoid using switch(protocol) in a number of places. */
	57	struct blkif_common_request {
	58	char dummy;
	59	};
	60	struct blkif_common_response {
	61	char dummy;
	62	};
	63
b3cb0d6a	64	struct blkif_x86_32_request_rw {
97e36834 KRW	65	uint8_t nr_segments; /* number of segments */
	66	blkif_vdev_t handle; /* only for read/write requests */
	67	uint64_t id; /* private guest value, echoed in resp */
b3cb0d6a LD	68	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
b3cb0d6a LD	69	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
97e36834	70	} __attribute__((__packed__));
b3cb0d6a LD	71
b3cb0d6a LD	72	struct blkif_x86_32_request_discard {
5ea42986	73	uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
97e36834 KRW	74	blkif_vdev_t _pad1; /* was "handle" for read/write requests */
97e36834 KRW	75	uint64_t id; /* private guest value, echoed in resp */
b3cb0d6a	76	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
97e36834 KRW	77	uint64_t nr_sectors;
97e36834 KRW	78	} __attribute__((__packed__));
b3cb0d6a	79
0e367ae4 DV	80	struct blkif_x86_32_request_other {
	81	uint8_t _pad1;
	82	blkif_vdev_t _pad2;
	83	uint64_t id; /* private guest value, echoed in resp */
	84	} __attribute__((__packed__));
	85
452a6b2b KRW	86	struct blkif_x86_32_request {
452a6b2b KRW	87	uint8_t operation; /* BLKIF_OP_??? */
b3cb0d6a LD	88	union {
	89	struct blkif_x86_32_request_rw rw;
	90	struct blkif_x86_32_request_discard discard;
0e367ae4	91	struct blkif_x86_32_request_other other;
b3cb0d6a	92	} u;
97e36834 KRW	93	} __attribute__((__packed__));
	94
	95	/* i386 protocol version */
	96	#pragma pack(push, 4)
452a6b2b KRW	97	struct blkif_x86_32_response {
	98	uint64_t id; /* copied from request */
	99	uint8_t operation; /* copied from request */
	100	int16_t status; /* BLKIF_RSP_??? */
	101	};
452a6b2b	102	#pragma pack(pop)
452a6b2b	103	/* x86_64 protocol version */
b3cb0d6a LD	104
b3cb0d6a LD	105	struct blkif_x86_64_request_rw {
97e36834 KRW	106	uint8_t nr_segments; /* number of segments */
	107	blkif_vdev_t handle; /* only for read/write requests */
	108	uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */
	109	uint64_t id;
b3cb0d6a LD	110	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
b3cb0d6a LD	111	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
97e36834	112	} __attribute__((__packed__));
b3cb0d6a LD	113
b3cb0d6a LD	114	struct blkif_x86_64_request_discard {
5ea42986	115	uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
97e36834 KRW	116	blkif_vdev_t _pad1; /* was "handle" for read/write requests */
	117	uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
	118	uint64_t id;
b3cb0d6a	119	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
97e36834 KRW	120	uint64_t nr_sectors;
97e36834 KRW	121	} __attribute__((__packed__));
b3cb0d6a	122
0e367ae4 DV	123	struct blkif_x86_64_request_other {
	124	uint8_t _pad1;
	125	blkif_vdev_t _pad2;
	126	uint32_t _pad3; /* offsetof(blkif_..,u.discard.id)==8 */
	127	uint64_t id; /* private guest value, echoed in resp */
	128	} __attribute__((__packed__));
	129
452a6b2b KRW	130	struct blkif_x86_64_request {
452a6b2b KRW	131	uint8_t operation; /* BLKIF_OP_??? */
b3cb0d6a LD	132	union {
	133	struct blkif_x86_64_request_rw rw;
	134	struct blkif_x86_64_request_discard discard;
0e367ae4	135	struct blkif_x86_64_request_other other;
b3cb0d6a	136	} u;
97e36834 KRW	137	} __attribute__((__packed__));
97e36834 KRW	138
452a6b2b KRW	139	struct blkif_x86_64_response {
	140	uint64_t __attribute__((__aligned__(8))) id;
	141	uint8_t operation; /* copied from request */
	142	int16_t status; /* BLKIF_RSP_??? */
	143	};
452a6b2b KRW	144
	145	DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
	146	struct blkif_common_response);
	147	DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
	148	struct blkif_x86_32_response);
	149	DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
	150	struct blkif_x86_64_response);
	151
	152	union blkif_back_rings {
	153	struct blkif_back_ring native;
	154	struct blkif_common_back_ring common;
	155	struct blkif_x86_32_back_ring x86_32;
	156	struct blkif_x86_64_back_ring x86_64;
	157	};
	158
	159	enum blkif_protocol {
	160	BLKIF_PROTOCOL_NATIVE = 1,
	161	BLKIF_PROTOCOL_X86_32 = 2,
	162	BLKIF_PROTOCOL_X86_64 = 3,
	163	};
	164
3d814731	165	struct xen_vbd {
01f37f2d KRW	166	/* What the domain refers to this vbd as. */
	167	blkif_vdev_t handle;
	168	/* Non-zero -> read-only */
	169	unsigned char readonly;
	170	/* VDISK_xxx */
	171	unsigned char type;
	172	/* phys device that this vbd maps to. */
	173	u32 pdevice;
	174	struct block_device *bdev;
	175	/* Cached size parameter. */
	176	sector_t size;
1f999572 OC	177	unsigned int flush_support:1;
1f999572 OC	178	unsigned int discard_secure:1;
0a8704a5 RPM	179	unsigned int feature_gnt_persistent:1;
0a8704a5 RPM	180	unsigned int overflow_max_grants:1;
4d05a28d KRW	181	};
	182
	183	struct backend_info;
	184
0a8704a5 RPM	185
	186	struct persistent_gnt {
	187	struct page *page;
	188	grant_ref_t gnt;
	189	grant_handle_t handle;
0a8704a5 RPM	190	struct rb_node node;
	191	};
	192
30fd1502	193	struct xen_blkif {
4d05a28d	194	/* Unique identifier for this interface. */
01f37f2d KRW	195	domid_t domid;
01f37f2d KRW	196	unsigned int handle;
4d05a28d	197	/* Physical parameters of the comms window. */
01f37f2d	198	unsigned int irq;
4d05a28d	199	/* Comms information. */
01f37f2d KRW	200	enum blkif_protocol blk_protocol;
01f37f2d KRW	201	union blkif_back_rings blk_rings;
2d073846	202	void *blk_ring;
4d05a28d	203	/* The VBD attached to this interface. */
3d814731	204	struct xen_vbd vbd;
4d05a28d	205	/* Back pointer to the backend_info. */
01f37f2d	206	struct backend_info *be;
4d05a28d	207	/* Private fields. */
01f37f2d KRW	208	spinlock_t blk_ring_lock;
01f37f2d KRW	209	atomic_t refcnt;
4d05a28d	210
01f37f2d	211	wait_queue_head_t wq;
29bde093 KRW	212	/* for barrier (drain) requests */
	213	struct completion drain_complete;
	214	atomic_t drain;
a1397fa3	215	/* One thread per one blkif. */
01f37f2d KRW	216	struct task_struct *xenblkd;
01f37f2d KRW	217	unsigned int waiting_reqs;
4d05a28d	218
0a8704a5 RPM	219	/* tree to store persistent grants */
	220	struct rb_root persistent_gnts;
	221	unsigned int persistent_gnt_c;
	222
4d05a28d	223	/* statistics */
01f37f2d	224	unsigned long st_print;
986cacbd ZK	225	unsigned long long st_rd_req;
	226	unsigned long long st_wr_req;
	227	unsigned long long st_oo_req;
	228	unsigned long long st_f_req;
	229	unsigned long long st_ds_req;
	230	unsigned long long st_rd_sect;
	231	unsigned long long st_wr_sect;
01f37f2d KRW	232
01f37f2d KRW	233	wait_queue_head_t waiting_to_free;
5489377c	234	};
4d05a28d	235
42c7841d KRW	236
	237	#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
	238	(_v)->bdev->bd_part->nr_sects : \
	239	get_capacity((_v)->bdev->bd_disk))
4d05a28d	240
8b6bf747 KRW	241	#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
8b6bf747 KRW	242	#define xen_blkif_put(_b) \
4d05a28d KRW	243	do { \
	244	if (atomic_dec_and_test(&(_b)->refcnt)) \
	245	wake_up(&(_b)->waiting_to_free);\
	246	} while (0)
	247
4d05a28d	248	struct phys_req {
01f37f2d	249	unsigned short dev;
b3cb0d6a	250	blkif_sector_t nr_sects;
01f37f2d KRW	251	struct block_device *bdev;
01f37f2d KRW	252	blkif_sector_t sector_number;
4d05a28d	253	};
8b6bf747	254	int xen_blkif_interface_init(void);
4d05a28d	255
8b6bf747	256	int xen_blkif_xenbus_init(void);
4d05a28d	257
8b6bf747 KRW	258	irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
8b6bf747 KRW	259	int xen_blkif_schedule(void *arg);
4d05a28d	260
24f567f9 KRW	261	int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
24f567f9 KRW	262	struct backend_info *be, int state);
4d05a28d	263
29bde093 KRW	264	int xen_blkbk_barrier(struct xenbus_transaction xbt,
29bde093 KRW	265	struct backend_info *be, int state);
8b6bf747	266	struct xenbus_device xen_blkbk_xenbus(struct backend_info be);
98e036a3	267
b0f80127	268	static inline void blkif_get_x86_32_req(struct blkif_request *dst,
68c88dd7 KRW	269	struct blkif_x86_32_request *src)
	270	{
	271	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	272	dst->operation = src->operation;
b3cb0d6a LD	273	switch (src->operation) {
	274	case BLKIF_OP_READ:
	275	case BLKIF_OP_WRITE:
	276	case BLKIF_OP_WRITE_BARRIER:
	277	case BLKIF_OP_FLUSH_DISKCACHE:
97e36834 KRW	278	dst->u.rw.nr_segments = src->u.rw.nr_segments;
	279	dst->u.rw.handle = src->u.rw.handle;
	280	dst->u.rw.id = src->u.rw.id;
b3cb0d6a LD	281	dst->u.rw.sector_number = src->u.rw.sector_number;
b3cb0d6a LD	282	barrier();
97e36834 KRW	283	if (n > dst->u.rw.nr_segments)
97e36834 KRW	284	n = dst->u.rw.nr_segments;
b3cb0d6a LD	285	for (i = 0; i < n; i++)
	286	dst->u.rw.seg[i] = src->u.rw.seg[i];
	287	break;
	288	case BLKIF_OP_DISCARD:
5ea42986	289	dst->u.discard.flag = src->u.discard.flag;
8c9ce606	290	dst->u.discard.id = src->u.discard.id;
b3cb0d6a LD	291	dst->u.discard.sector_number = src->u.discard.sector_number;
	292	dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
	293	break;
	294	default:
0e367ae4 DV	295	/*
	296	* Don't know how to translate this op. Only get the
	297	* ID so failure can be reported to the frontend.
	298	*/
	299	dst->u.other.id = src->u.other.id;
b3cb0d6a LD	300	break;
b3cb0d6a LD	301	}
68c88dd7 KRW	302	}
68c88dd7 KRW	303
b0f80127	304	static inline void blkif_get_x86_64_req(struct blkif_request *dst,
68c88dd7 KRW	305	struct blkif_x86_64_request *src)
	306	{
	307	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	308	dst->operation = src->operation;
b3cb0d6a LD	309	switch (src->operation) {
	310	case BLKIF_OP_READ:
	311	case BLKIF_OP_WRITE:
	312	case BLKIF_OP_WRITE_BARRIER:
	313	case BLKIF_OP_FLUSH_DISKCACHE:
97e36834 KRW	314	dst->u.rw.nr_segments = src->u.rw.nr_segments;
	315	dst->u.rw.handle = src->u.rw.handle;
	316	dst->u.rw.id = src->u.rw.id;
b3cb0d6a LD	317	dst->u.rw.sector_number = src->u.rw.sector_number;
b3cb0d6a LD	318	barrier();
97e36834 KRW	319	if (n > dst->u.rw.nr_segments)
97e36834 KRW	320	n = dst->u.rw.nr_segments;
b3cb0d6a LD	321	for (i = 0; i < n; i++)
	322	dst->u.rw.seg[i] = src->u.rw.seg[i];
	323	break;
	324	case BLKIF_OP_DISCARD:
5ea42986	325	dst->u.discard.flag = src->u.discard.flag;
8c9ce606	326	dst->u.discard.id = src->u.discard.id;
b3cb0d6a LD	327	dst->u.discard.sector_number = src->u.discard.sector_number;
	328	dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
	329	break;
	330	default:
0e367ae4 DV	331	/*
	332	* Don't know how to translate this op. Only get the
	333	* ID so failure can be reported to the frontend.
	334	*/
	335	dst->u.other.id = src->u.other.id;
b3cb0d6a LD	336	break;
b3cb0d6a LD	337	}
68c88dd7 KRW	338	}
68c88dd7 KRW	339
5a577e38	340	#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */