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/*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (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.
*
* $FreeBSD$
*/
#ifndef __XEN_BLKIF_H__
#define __XEN_BLKIF_H__
#include <xen/interface/io/ring.h>
#include <xen/interface/io/blkif.h>
#include <xen/interface/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);
/*
* Maximum number of requests that can be active for a given instance
* regardless of the protocol in use, based on the ring size. This constant
* facilitates resource pre-allocation in backend drivers since the size is
* known well in advance of attaching to a front end.
*/
#define BLKIF_MAX_RING_REQUESTS(_sz) \
MAX(__RING_SIZE((blkif_x86_64_sring_t *)NULL, _sz), \
MAX(__RING_SIZE((blkif_x86_32_sring_t *)NULL, _sz), \
__RING_SIZE((blkif_sring_t *)NULL, _sz)))
/*
* The number of ring pages required to support a given number of requests
* for a given instance regardless of the protocol in use.
*/
#define BLKIF_RING_PAGES(_entries) \
MAX(__RING_PAGES((blkif_x86_64_sring_t *)NULL, _entries), \
MAX(__RING_PAGES((blkif_x86_32_sring_t *)NULL, _entries), \
__RING_PAGES((blkif_sring_t *)NULL, _entries)))
union blkif_back_rings {
blkif_back_ring_t native;
blkif_common_back_ring_t common;
blkif_x86_32_back_ring_t x86_32;
blkif_x86_64_back_ring_t x86_64;
};
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 void inline 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;
barrier();
if (n > dst->nr_segments)
n = dst->nr_segments;
for (i = 0; i < n; i++)
dst->seg[i] = src->seg[i];
}
static void inline 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;
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__ */
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