[mirror_qemu.git] / hw / block / xen_blkif.h

#ifndef __XEN_BLKIF_H__
#define __XEN_BLKIF_H__

#include <xen/io/ring.h>
#include <xen/io/blkif.h>
#include <xen/io/protocols.h>

/* 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;
};

/* i386 protocol version */
#pragma pack(push, 4)
struct blkif_x86_32_request {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	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];
};
struct blkif_x86_32_response {
	uint64_t        id;              /* copied from request */
	uint8_t         operation;       /* copied from request */
	int16_t         status;          /* BLKIF_RSP_???       */
};
typedef struct blkif_x86_32_request blkif_x86_32_request_t;
typedef struct blkif_x86_32_response blkif_x86_32_response_t;
#pragma pack(pop)

/* x86_64 protocol version */
struct blkif_x86_64_request {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	uint8_t        nr_segments;  /* number of segments                   */
	blkif_vdev_t   handle;       /* only for read/write requests         */
	uint64_t       __attribute__((__aligned__(8))) id;
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
};
struct blkif_x86_64_response {
	uint64_t       __attribute__((__aligned__(8))) id;
	uint8_t         operation;       /* copied from request */
	int16_t         status;          /* BLKIF_RSP_???       */
};
typedef struct blkif_x86_64_request blkif_x86_64_request_t;
typedef struct blkif_x86_64_response blkif_x86_64_response_t;

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 {
	blkif_back_ring_t        native;
	blkif_common_back_ring_t common;
        blkif_x86_32_back_ring_t x86_32_part;
        blkif_x86_64_back_ring_t x86_64_part;
};
typedef union blkif_back_rings blkif_back_rings_t;

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

static inline void blkif_get_x86_32_req(blkif_request_t *dst, blkif_x86_32_request_t *src)
{
	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;

	dst->operation = src->operation;
	dst->nr_segments = src->nr_segments;
	dst->handle = src->handle;
	dst->id = src->id;
	dst->sector_number = src->sector_number;
	if (src->operation == BLKIF_OP_DISCARD) {
		struct blkif_request_discard *s = (void *)src;
		struct blkif_request_discard *d = (void *)dst;
		d->nr_sectors = s->nr_sectors;
		return;
	}
	/* prevent the compiler from optimizing the code and using src->nr_segments instead */
	barrier();
	if (n > dst->nr_segments)
		n = dst->nr_segments;
	for (i = 0; i < n; i++)
		dst->seg[i] = src->seg[i];
}

static inline void blkif_get_x86_64_req(blkif_request_t *dst, blkif_x86_64_request_t *src)
{
	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;

	dst->operation = src->operation;
	dst->nr_segments = src->nr_segments;
	dst->handle = src->handle;
	dst->id = src->id;
	dst->sector_number = src->sector_number;
	if (src->operation == BLKIF_OP_DISCARD) {
		struct blkif_request_discard *s = (void *)src;
		struct blkif_request_discard *d = (void *)dst;
		d->nr_sectors = s->nr_sectors;
		return;
	}
	/* prevent the compiler from optimizing the code and using src->nr_segments instead */
	barrier();
	if (n > dst->nr_segments)
		n = dst->nr_segments;
	for (i = 0; i < n; i++)
		dst->seg[i] = src->seg[i];
}

#endif /* __XEN_BLKIF_H__ */
Commit	Line	Data
62d23efa AL	1	#ifndef __XEN_BLKIF_H__
	2	#define __XEN_BLKIF_H__
	3
	4	#include <xen/io/ring.h>
	5	#include <xen/io/blkif.h>
	6	#include <xen/io/protocols.h>
	7
	8	/* Not a real protocol. Used to generate ring structs which contain
	9	* the elements common to all protocols only. This way we get a
	10	* compiler-checkable way to use common struct elements, so we can
	11	* avoid using switch(protocol) in a number of places. */
	12	struct blkif_common_request {
	13	char dummy;
	14	};
	15	struct blkif_common_response {
	16	char dummy;
	17	};
	18
	19	/* i386 protocol version */
	20	#pragma pack(push, 4)
	21	struct blkif_x86_32_request {
	22	uint8_t operation; /* BLKIF_OP_??? */
	23	uint8_t nr_segments; /* number of segments */
	24	blkif_vdev_t handle; /* only for read/write requests */
	25	uint64_t id; /* private guest value, echoed in resp */
	26	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
	27	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
	28	};
	29	struct blkif_x86_32_response {
	30	uint64_t id; /* copied from request */
	31	uint8_t operation; /* copied from request */
	32	int16_t status; /* BLKIF_RSP_??? */
	33	};
	34	typedef struct blkif_x86_32_request blkif_x86_32_request_t;
	35	typedef struct blkif_x86_32_response blkif_x86_32_response_t;
	36	#pragma pack(pop)
	37
	38	/* x86_64 protocol version */
	39	struct blkif_x86_64_request {
	40	uint8_t operation; /* BLKIF_OP_??? */
	41	uint8_t nr_segments; /* number of segments */
	42	blkif_vdev_t handle; /* only for read/write requests */
	43	uint64_t __attribute__((__aligned__(8))) id;
	44	blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
	45	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
	46	};
	47	struct blkif_x86_64_response {
	48	uint64_t __attribute__((__aligned__(8))) id;
	49	uint8_t operation; /* copied from request */
	50	int16_t status; /* BLKIF_RSP_??? */
	51	};
	52	typedef struct blkif_x86_64_request blkif_x86_64_request_t;
	53	typedef struct blkif_x86_64_response blkif_x86_64_response_t;
	54
	55	DEFINE_RING_TYPES(blkif_common, struct blkif_common_request, struct blkif_common_response);
	56	DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request, struct blkif_x86_32_response);
	57	DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request, struct blkif_x86_64_response);
	58
	59	union blkif_back_rings {
	60	blkif_back_ring_t native;
	61	blkif_common_back_ring_t common;
6fcfeff9 BS	62	blkif_x86_32_back_ring_t x86_32_part;
6fcfeff9 BS	63	blkif_x86_64_back_ring_t x86_64_part;
62d23efa AL	64	};
	65	typedef union blkif_back_rings blkif_back_rings_t;
	66
	67	enum blkif_protocol {
	68	BLKIF_PROTOCOL_NATIVE = 1,
	69	BLKIF_PROTOCOL_X86_32 = 2,
	70	BLKIF_PROTOCOL_X86_64 = 3,
	71	};
	72
86178a57	73	static inline void blkif_get_x86_32_req(blkif_request_t dst, blkif_x86_32_request_t src)
62d23efa AL	74	{
	75	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	76
	77	dst->operation = src->operation;
	78	dst->nr_segments = src->nr_segments;
	79	dst->handle = src->handle;
	80	dst->id = src->id;
	81	dst->sector_number = src->sector_number;
f3135204 OH	82	if (src->operation == BLKIF_OP_DISCARD) {
	83	struct blkif_request_discard s = (void )src;
	84	struct blkif_request_discard d = (void )dst;
	85	d->nr_sectors = s->nr_sectors;
	86	return;
	87	}
f9e98e5d SS	88	/* prevent the compiler from optimizing the code and using src->nr_segments instead */
	89	barrier();
	90	if (n > dst->nr_segments)
	91	n = dst->nr_segments;
62d23efa AL	92	for (i = 0; i < n; i++)
	93	dst->seg[i] = src->seg[i];
	94	}
	95
86178a57	96	static inline void blkif_get_x86_64_req(blkif_request_t dst, blkif_x86_64_request_t src)
62d23efa AL	97	{
	98	int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
	99
	100	dst->operation = src->operation;
	101	dst->nr_segments = src->nr_segments;
	102	dst->handle = src->handle;
	103	dst->id = src->id;
	104	dst->sector_number = src->sector_number;
f3135204 OH	105	if (src->operation == BLKIF_OP_DISCARD) {
	106	struct blkif_request_discard s = (void )src;
	107	struct blkif_request_discard d = (void )dst;
	108	d->nr_sectors = s->nr_sectors;
	109	return;
	110	}
f9e98e5d SS	111	/* prevent the compiler from optimizing the code and using src->nr_segments instead */
	112	barrier();
	113	if (n > dst->nr_segments)
	114	n = dst->nr_segments;
62d23efa AL	115	for (i = 0; i < n; i++)
	116	dst->seg[i] = src->seg[i];
	117	}
	118
	119	#endif /* __XEN_BLKIF_H__ */