[mirror_ubuntu-artful-kernel.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 {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	union {
		struct blkif_x86_32_request_rw rw;
		struct blkif_x86_32_request_discard discard;
	} 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 {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	union {
		struct blkif_x86_64_request_rw rw;
		struct blkif_x86_64_request_discard discard;
	} 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;
	uint64_t dev_bus_addr;
	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;
	int			st_rd_req;
	int			st_wr_req;
	int			st_oo_req;
	int			st_f_req;
	int			st_ds_req;
	int			st_rd_sect;
	int			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:
		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:
		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
452a6b2b KRW	80	struct blkif_x86_32_request {
452a6b2b KRW	81	uint8_t operation; /* BLKIF_OP_??? */
b3cb0d6a LD	82	union {
	83	struct blkif_x86_32_request_rw rw;
	84	struct blkif_x86_32_request_discard discard;
	85	} u;
97e36834 KRW	86	} __attribute__((__packed__));
	87
	88	/* i386 protocol version */
	89	#pragma pack(push, 4)
452a6b2b KRW	90	struct blkif_x86_32_response {
	91	uint64_t id; /* copied from request */
	92	uint8_t operation; /* copied from request */
	93	int16_t status; /* BLKIF_RSP_??? */
	94	};
452a6b2b	95	#pragma pack(pop)
452a6b2b	96	/* x86_64 protocol version */
b3cb0d6a LD	97
b3cb0d6a LD	98	struct blkif_x86_64_request_rw {
97e36834 KRW	99	uint8_t nr_segments; /* number of segments */
	100	blkif_vdev_t handle; /* only for read/write requests */
	101	uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */
	102	uint64_t id;
b3cb0d6a LD	103	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
b3cb0d6a LD	104	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
97e36834	105	} __attribute__((__packed__));
b3cb0d6a LD	106
b3cb0d6a LD	107	struct blkif_x86_64_request_discard {
5ea42986	108	uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
97e36834 KRW	109	blkif_vdev_t _pad1; /* was "handle" for read/write requests */
	110	uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
	111	uint64_t id;
b3cb0d6a	112	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
97e36834 KRW	113	uint64_t nr_sectors;
97e36834 KRW	114	} __attribute__((__packed__));
b3cb0d6a	115
452a6b2b KRW	116	struct blkif_x86_64_request {
452a6b2b KRW	117	uint8_t operation; /* BLKIF_OP_??? */
b3cb0d6a LD	118	union {
	119	struct blkif_x86_64_request_rw rw;
	120	struct blkif_x86_64_request_discard discard;
	121	} u;
97e36834 KRW	122	} __attribute__((__packed__));
97e36834 KRW	123
452a6b2b KRW	124	struct blkif_x86_64_response {
	125	uint64_t __attribute__((__aligned__(8))) id;
	126	uint8_t operation; /* copied from request */
	127	int16_t status; /* BLKIF_RSP_??? */
	128	};
452a6b2b KRW	129
	130	DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
	131	struct blkif_common_response);
	132	DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
	133	struct blkif_x86_32_response);
	134	DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
	135	struct blkif_x86_64_response);
	136
	137	union blkif_back_rings {
	138	struct blkif_back_ring native;
	139	struct blkif_common_back_ring common;
	140	struct blkif_x86_32_back_ring x86_32;
	141	struct blkif_x86_64_back_ring x86_64;
	142	};
	143
	144	enum blkif_protocol {
	145	BLKIF_PROTOCOL_NATIVE = 1,
	146	BLKIF_PROTOCOL_X86_32 = 2,
	147	BLKIF_PROTOCOL_X86_64 = 3,
	148	};
	149
3d814731	150	struct xen_vbd {
01f37f2d KRW	151	/* What the domain refers to this vbd as. */
	152	blkif_vdev_t handle;
	153	/* Non-zero -> read-only */
	154	unsigned char readonly;
	155	/* VDISK_xxx */
	156	unsigned char type;
	157	/* phys device that this vbd maps to. */
	158	u32 pdevice;
	159	struct block_device *bdev;
	160	/* Cached size parameter. */
	161	sector_t size;
1f999572 OC	162	unsigned int flush_support:1;
1f999572 OC	163	unsigned int discard_secure:1;
0a8704a5 RPM	164	unsigned int feature_gnt_persistent:1;
0a8704a5 RPM	165	unsigned int overflow_max_grants:1;
4d05a28d KRW	166	};
	167
	168	struct backend_info;
	169
0a8704a5 RPM	170
	171	struct persistent_gnt {
	172	struct page *page;
	173	grant_ref_t gnt;
	174	grant_handle_t handle;
	175	uint64_t dev_bus_addr;
	176	struct rb_node node;
	177	};
	178
30fd1502	179	struct xen_blkif {
4d05a28d	180	/* Unique identifier for this interface. */
01f37f2d KRW	181	domid_t domid;
01f37f2d KRW	182	unsigned int handle;
4d05a28d	183	/* Physical parameters of the comms window. */
01f37f2d	184	unsigned int irq;
4d05a28d	185	/* Comms information. */
01f37f2d KRW	186	enum blkif_protocol blk_protocol;
01f37f2d KRW	187	union blkif_back_rings blk_rings;
2d073846	188	void *blk_ring;
4d05a28d	189	/* The VBD attached to this interface. */
3d814731	190	struct xen_vbd vbd;
4d05a28d	191	/* Back pointer to the backend_info. */
01f37f2d	192	struct backend_info *be;
4d05a28d	193	/* Private fields. */
01f37f2d KRW	194	spinlock_t blk_ring_lock;
01f37f2d KRW	195	atomic_t refcnt;
4d05a28d	196
01f37f2d	197	wait_queue_head_t wq;
29bde093 KRW	198	/* for barrier (drain) requests */
	199	struct completion drain_complete;
	200	atomic_t drain;
a1397fa3	201	/* One thread per one blkif. */
01f37f2d KRW	202	struct task_struct *xenblkd;
01f37f2d KRW	203	unsigned int waiting_reqs;
4d05a28d	204
0a8704a5 RPM	205	/* tree to store persistent grants */
	206	struct rb_root persistent_gnts;
	207	unsigned int persistent_gnt_c;
	208
4d05a28d	209	/* statistics */
01f37f2d KRW	210	unsigned long st_print;
	211	int st_rd_req;
	212	int st_wr_req;
	213	int st_oo_req;
	214	int st_f_req;
b3cb0d6a	215	int st_ds_req;
01f37f2d KRW	216	int st_rd_sect;
	217	int st_wr_sect;
	218
	219	wait_queue_head_t waiting_to_free;
5489377c	220	};
4d05a28d	221
42c7841d KRW	222
	223	#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
	224	(_v)->bdev->bd_part->nr_sects : \
	225	get_capacity((_v)->bdev->bd_disk))
4d05a28d	226
8b6bf747 KRW	227	#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
8b6bf747 KRW	228	#define xen_blkif_put(_b) \
4d05a28d KRW	229	do { \
	230	if (atomic_dec_and_test(&(_b)->refcnt)) \
	231	wake_up(&(_b)->waiting_to_free);\
	232	} while (0)
	233
4d05a28d	234	struct phys_req {
01f37f2d	235	unsigned short dev;
b3cb0d6a	236	blkif_sector_t nr_sects;
01f37f2d KRW	237	struct block_device *bdev;
01f37f2d KRW	238	blkif_sector_t sector_number;
4d05a28d	239	};
8b6bf747	240	int xen_blkif_interface_init(void);
4d05a28d	241
8b6bf747	242	int xen_blkif_xenbus_init(void);
4d05a28d	243
8b6bf747 KRW	244	irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
8b6bf747 KRW	245	int xen_blkif_schedule(void *arg);
4d05a28d	246
24f567f9 KRW	247	int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
24f567f9 KRW	248	struct backend_info *be, int state);
4d05a28d	249
29bde093 KRW	250	int xen_blkbk_barrier(struct xenbus_transaction xbt,
29bde093 KRW	251	struct backend_info *be, int state);
8b6bf747	252	struct xenbus_device xen_blkbk_xenbus(struct backend_info be);
98e036a3	253
b0f80127	254	static inline void blkif_get_x86_32_req(struct blkif_request *dst,
68c88dd7 KRW	255	struct blkif_x86_32_request *src)
	256	{
	257	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	258	dst->operation = src->operation;
b3cb0d6a LD	259	switch (src->operation) {
	260	case BLKIF_OP_READ:
	261	case BLKIF_OP_WRITE:
	262	case BLKIF_OP_WRITE_BARRIER:
	263	case BLKIF_OP_FLUSH_DISKCACHE:
97e36834 KRW	264	dst->u.rw.nr_segments = src->u.rw.nr_segments;
	265	dst->u.rw.handle = src->u.rw.handle;
	266	dst->u.rw.id = src->u.rw.id;
b3cb0d6a LD	267	dst->u.rw.sector_number = src->u.rw.sector_number;
b3cb0d6a LD	268	barrier();
97e36834 KRW	269	if (n > dst->u.rw.nr_segments)
97e36834 KRW	270	n = dst->u.rw.nr_segments;
b3cb0d6a LD	271	for (i = 0; i < n; i++)
	272	dst->u.rw.seg[i] = src->u.rw.seg[i];
	273	break;
	274	case BLKIF_OP_DISCARD:
5ea42986	275	dst->u.discard.flag = src->u.discard.flag;
8c9ce606	276	dst->u.discard.id = src->u.discard.id;
b3cb0d6a LD	277	dst->u.discard.sector_number = src->u.discard.sector_number;
	278	dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
	279	break;
	280	default:
	281	break;
	282	}
68c88dd7 KRW	283	}
68c88dd7 KRW	284
b0f80127	285	static inline void blkif_get_x86_64_req(struct blkif_request *dst,
68c88dd7 KRW	286	struct blkif_x86_64_request *src)
	287	{
	288	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	289	dst->operation = src->operation;
b3cb0d6a LD	290	switch (src->operation) {
	291	case BLKIF_OP_READ:
	292	case BLKIF_OP_WRITE:
	293	case BLKIF_OP_WRITE_BARRIER:
	294	case BLKIF_OP_FLUSH_DISKCACHE:
97e36834 KRW	295	dst->u.rw.nr_segments = src->u.rw.nr_segments;
	296	dst->u.rw.handle = src->u.rw.handle;
	297	dst->u.rw.id = src->u.rw.id;
b3cb0d6a LD	298	dst->u.rw.sector_number = src->u.rw.sector_number;
b3cb0d6a LD	299	barrier();
97e36834 KRW	300	if (n > dst->u.rw.nr_segments)
97e36834 KRW	301	n = dst->u.rw.nr_segments;
b3cb0d6a LD	302	for (i = 0; i < n; i++)
	303	dst->u.rw.seg[i] = src->u.rw.seg[i];
	304	break;
	305	case BLKIF_OP_DISCARD:
5ea42986	306	dst->u.discard.flag = src->u.discard.flag;
8c9ce606	307	dst->u.discard.id = src->u.discard.id;
b3cb0d6a LD	308	dst->u.discard.sector_number = src->u.discard.sector_number;
	309	dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
	310	break;
	311	default:
	312	break;
	313	}
68c88dd7 KRW	314	}
68c88dd7 KRW	315
5a577e38	316	#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */