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/******************************************************************************
 * blkif.h
 *
 * Unified block-device I/O interface for Xen guest OSes.
 *
 * 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.
 *
 * Copyright (c) 2003-2004, Keir Fraser
 */

#ifndef __XEN_PUBLIC_IO_BLKIF_H__
#define __XEN_PUBLIC_IO_BLKIF_H__

#include "ring.h"
#include "../grant_table.h"

/*
 * Front->back notifications: When enqueuing a new request, sending a
 * notification can be made conditional on req_event (i.e., the generic
 * hold-off mechanism provided by the ring macros). Backends must set
 * req_event appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()).
 *
 * Back->front notifications: When enqueuing a new response, sending a
 * notification can be made conditional on rsp_event (i.e., the generic
 * hold-off mechanism provided by the ring macros). Frontends must set
 * rsp_event appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
 */

#ifndef blkif_vdev_t
#define blkif_vdev_t   uint16_t
#endif
#define blkif_sector_t uint64_t

/*
 * REQUEST CODES.
 */
#define BLKIF_OP_READ              0
#define BLKIF_OP_WRITE             1
/*
 * Recognised only if "feature-barrier" is present in backend xenbus info.
 * The "feature-barrier" node contains a boolean indicating whether barrier
 * requests are likely to succeed or fail. Either way, a barrier request
 * may fail at any time with BLKIF_RSP_EOPNOTSUPP if it is unsupported by
 * the underlying block-device hardware. The boolean simply indicates whether
 * or not it is worthwhile for the frontend to attempt barrier requests.
 * If a backend does not recognise BLKIF_OP_WRITE_BARRIER, it should *not*
 * create the "feature-barrier" node!
 */
#define BLKIF_OP_WRITE_BARRIER     2
/*
 * Recognised if "feature-flush-cache" is present in backend xenbus
 * info.  A flush will ask the underlying storage hardware to flush its
 * non-volatile caches as appropriate.  The "feature-flush-cache" node
 * contains a boolean indicating whether flush requests are likely to
 * succeed or fail. Either way, a flush request may fail at any time
 * with BLKIF_RSP_EOPNOTSUPP if it is unsupported by the underlying
 * block-device hardware. The boolean simply indicates whether or not it
 * is worthwhile for the frontend to attempt flushes.  If a backend does
 * not recognise BLKIF_OP_WRITE_FLUSH_CACHE, it should *not* create the
 * "feature-flush-cache" node!
 */
#define BLKIF_OP_FLUSH_DISKCACHE   3

/*
 * Maximum scatter/gather segments per request.
 * This is carefully chosen so that sizeof(blkif_ring_t) <= PAGE_SIZE.
 * NB. This could be 12 if the ring indexes weren't stored in the same page.
 */
#define BLKIF_MAX_SEGMENTS_PER_REQUEST 11

/*
 * NB. first_sect and last_sect in blkif_request_segment, as well as
 * sector_number in blkif_request, are always expressed in 512-byte units.
 * However they must be properly aligned to the real sector size of the
 * physical disk, which is reported in the "sector-size" node in the backend
 * xenbus info. Also the xenbus "sectors" node is expressed in 512-byte units.
 */
struct blkif_request_segment {
    grant_ref_t gref;        /* reference to I/O buffer frame        */
    /* @first_sect: first sector in frame to transfer (inclusive).   */
    /* @last_sect: last sector in frame to transfer (inclusive).     */
    uint8_t     first_sect, last_sect;
};

struct blkif_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];
};
typedef struct blkif_request blkif_request_t;

struct blkif_response {
    uint64_t        id;              /* copied from request */
    uint8_t         operation;       /* copied from request */
    int16_t         status;          /* BLKIF_RSP_???       */
};
typedef struct blkif_response blkif_response_t;

/*
 * STATUS RETURN CODES.
 */
 /* Operation not supported (only happens on barrier writes). */
#define BLKIF_RSP_EOPNOTSUPP  -2
 /* Operation failed for some unspecified reason (-EIO). */
#define BLKIF_RSP_ERROR       -1
 /* Operation completed successfully. */
#define BLKIF_RSP_OKAY         0

/*
 * Generate blkif ring structures and types.
 */

DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response);

#define VDISK_CDROM        0x1
#define VDISK_REMOVABLE    0x2
#define VDISK_READONLY     0x4

#endif /* __XEN_PUBLIC_IO_BLKIF_H__ */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
/******************************************************************************
 * console.h
 *
 * Console I/O interface for Xen guest OSes.
 *
 * 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.
 *
 * Copyright (c) 2005, Keir Fraser
 */

#ifndef __XEN_PUBLIC_IO_CONSOLE_H__
#define __XEN_PUBLIC_IO_CONSOLE_H__

typedef uint32_t XENCONS_RING_IDX;

#define MASK_XENCONS_IDX(idx, ring) ((idx) & (sizeof(ring)-1))

struct xencons_interface {
    char in[1024];
    char out[2048];
    XENCONS_RING_IDX in_cons, in_prod;
    XENCONS_RING_IDX out_cons, out_prod;
};

#endif /* __XEN_PUBLIC_IO_CONSOLE_H__ */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
/******************************************************************************
 * netif.h
 *
 * Unified network-device I/O interface for Xen guest OSes.
 *
 * 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.
 *
 * Copyright (c) 2003-2004, Keir Fraser
 */

#ifndef __XEN_PUBLIC_IO_NETIF_H__
#define __XEN_PUBLIC_IO_NETIF_H__

#include "ring.h"
#include "../grant_table.h"

/*
 * Notifications after enqueuing any type of message should be conditional on
 * the appropriate req_event or rsp_event field in the shared ring.
 * If the client sends notification for rx requests then it should specify
 * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
 * that it cannot safely queue packets (as it may not be kicked to send them).
 */

/*
 * This is the 'wire' format for packets:
 *  Request 1: netif_tx_request -- NETTXF_* (any flags)
 * [Request 2: netif_tx_extra]  (only if request 1 has NETTXF_extra_info)
 * [Request 3: netif_tx_extra]  (only if request 2 has XEN_NETIF_EXTRA_MORE)
 *  Request 4: netif_tx_request -- NETTXF_more_data
 *  Request 5: netif_tx_request -- NETTXF_more_data
 *  ...
 *  Request N: netif_tx_request -- 0
 */

/* Protocol checksum field is blank in the packet (hardware offload)? */
#define _NETTXF_csum_blank     (0)
#define  NETTXF_csum_blank     (1U<<_NETTXF_csum_blank)

/* Packet data has been validated against protocol checksum. */
#define _NETTXF_data_validated (1)
#define  NETTXF_data_validated (1U<<_NETTXF_data_validated)

/* Packet continues in the next request descriptor. */
#define _NETTXF_more_data      (2)
#define  NETTXF_more_data      (1U<<_NETTXF_more_data)

/* Packet to be followed by extra descriptor(s). */
#define _NETTXF_extra_info     (3)
#define  NETTXF_extra_info     (1U<<_NETTXF_extra_info)

struct netif_tx_request {
    grant_ref_t gref;      /* Reference to buffer page */
    uint16_t offset;       /* Offset within buffer page */
    uint16_t flags;        /* NETTXF_* */
    uint16_t id;           /* Echoed in response message. */
    uint16_t size;         /* Packet size in bytes.       */
};
typedef struct netif_tx_request netif_tx_request_t;

/* Types of netif_extra_info descriptors. */
#define XEN_NETIF_EXTRA_TYPE_NONE      (0)  /* Never used - invalid */
#define XEN_NETIF_EXTRA_TYPE_GSO       (1)  /* u.gso */
#define XEN_NETIF_EXTRA_TYPE_MCAST_ADD (2)  /* u.mcast */
#define XEN_NETIF_EXTRA_TYPE_MCAST_DEL (3)  /* u.mcast */
#define XEN_NETIF_EXTRA_TYPE_MAX       (4)

/* netif_extra_info flags. */
#define _XEN_NETIF_EXTRA_FLAG_MORE (0)
#define XEN_NETIF_EXTRA_FLAG_MORE  (1U<<_XEN_NETIF_EXTRA_FLAG_MORE)

/* GSO types - only TCPv4 currently supported. */
#define XEN_NETIF_GSO_TYPE_TCPV4        (1)

/*
 * This structure needs to fit within both netif_tx_request and
 * netif_rx_response for compatibility.
 */
struct netif_extra_info {
    uint8_t type;  /* XEN_NETIF_EXTRA_TYPE_* */
    uint8_t flags; /* XEN_NETIF_EXTRA_FLAG_* */

    union {
        /*
         * XEN_NETIF_EXTRA_TYPE_GSO:
         */
        struct {
            /*
             * Maximum payload size of each segment. For example, for TCP this
             * is just the path MSS.
             */
            uint16_t size;

            /*
             * GSO type. This determines the protocol of the packet and any
             * extra features required to segment the packet properly.
             */
            uint8_t type; /* XEN_NETIF_GSO_TYPE_* */

            /* Future expansion. */
            uint8_t pad;

            /*
             * GSO features. This specifies any extra GSO features required
             * to process this packet, such as ECN support for TCPv4.
             */
            uint16_t features; /* XEN_NETIF_GSO_FEAT_* */
        } gso;

        /*
         * XEN_NETIF_EXTRA_TYPE_MCAST_{ADD,DEL}:
         * Backend advertises availability via 'feature-multicast-control'
         * xenbus node containing value '1'.
         * Frontend requests this feature by advertising
         * 'request-multicast-control' xenbus node containing value '1'.
         * If multicast control is requested then multicast flooding is
         * disabled and the frontend must explicitly register its interest
         * in multicast groups using dummy transmit requests containing
         * MCAST_{ADD,DEL} extra-info fragments.
         */
        struct {
            uint8_t addr[6]; /* Address to add/remove. */
        } mcast;

        uint16_t pad[3];
    } u;
};
typedef struct netif_extra_info netif_extra_info_t;

struct netif_tx_response {
    uint16_t id;
    int16_t  status;       /* NETIF_RSP_* */
};
typedef struct netif_tx_response netif_tx_response_t;

struct netif_rx_request {
    uint16_t    id;        /* Echoed in response message.        */
    grant_ref_t gref;      /* Reference to incoming granted frame */
};
typedef struct netif_rx_request netif_rx_request_t;

/* Packet data has been validated against protocol checksum. */
#define _NETRXF_data_validated (0)
#define  NETRXF_data_validated (1U<<_NETRXF_data_validated)

/* Protocol checksum field is blank in the packet (hardware offload)? */
#define _NETRXF_csum_blank     (1)
#define  NETRXF_csum_blank     (1U<<_NETRXF_csum_blank)

/* Packet continues in the next request descriptor. */
#define _NETRXF_more_data      (2)
#define  NETRXF_more_data      (1U<<_NETRXF_more_data)

/* Packet to be followed by extra descriptor(s). */
#define _NETRXF_extra_info     (3)
#define  NETRXF_extra_info     (1U<<_NETRXF_extra_info)

struct netif_rx_response {
    uint16_t id;
    uint16_t offset;       /* Offset in page of start of received packet  */
    uint16_t flags;        /* NETRXF_* */
    int16_t  status;       /* -ve: BLKIF_RSP_* ; +ve: Rx'ed pkt size. */
};
typedef struct netif_rx_response netif_rx_response_t;

/*
 * Generate netif ring structures and types.
 */

DEFINE_RING_TYPES(netif_tx, struct netif_tx_request, struct netif_tx_response);
DEFINE_RING_TYPES(netif_rx, struct netif_rx_request, struct netif_rx_response);

#define NETIF_RSP_DROPPED         -2
#define NETIF_RSP_ERROR           -1
#define NETIF_RSP_OKAY             0
/* No response: used for auxiliary requests (e.g., netif_tx_extra). */
#define NETIF_RSP_NULL             1

#endif

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
/******************************************************************************
 * protocols.h
 *
 * 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.
 */

#ifndef __XEN_PROTOCOLS_H__
#define __XEN_PROTOCOLS_H__

#define XEN_IO_PROTO_ABI_X86_32     "x86_32-abi"
#define XEN_IO_PROTO_ABI_X86_64     "x86_64-abi"
#define XEN_IO_PROTO_ABI_IA64       "ia64-abi"

#if defined(__i386__)
# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_32
#elif defined(__x86_64__)
# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_X86_64
#elif defined(__ia64__)
# define XEN_IO_PROTO_ABI_NATIVE XEN_IO_PROTO_ABI_IA64
#else
# error arch fixup needed here
#endif

#endif
/******************************************************************************
 * ring.h
 *
 * Shared producer-consumer ring macros.
 *
 * 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.
 *
 * Tim Deegan and Andrew Warfield November 2004.
 */

#ifndef __XEN_PUBLIC_IO_RING_H__
#define __XEN_PUBLIC_IO_RING_H__

#include "../xen-compat.h"

#if __XEN_INTERFACE_VERSION__ < 0x00030208
#define xen_mb()  mb()
#define xen_rmb() rmb()
#define xen_wmb() wmb()
#endif

typedef unsigned int RING_IDX;

/* Round a 32-bit unsigned constant down to the nearest power of two. */
#define __RD2(_x)  (((_x) & 0x00000002) ? 0x2                  : ((_x) & 0x1))
#define __RD4(_x)  (((_x) & 0x0000000c) ? __RD2((_x)>>2)<<2    : __RD2(_x))
#define __RD8(_x)  (((_x) & 0x000000f0) ? __RD4((_x)>>4)<<4    : __RD4(_x))
#define __RD16(_x) (((_x) & 0x0000ff00) ? __RD8((_x)>>8)<<8    : __RD8(_x))
#define __RD32(_x) (((_x) & 0xffff0000) ? __RD16((_x)>>16)<<16 : __RD16(_x))

/*
 * Calculate size of a shared ring, given the total available space for the
 * ring and indexes (_sz), and the name tag of the request/response structure.
 * A ring contains as many entries as will fit, rounded down to the nearest
 * power of two (so we can mask with (size-1) to loop around).
 */
#define __CONST_RING_SIZE(_s, _sz) \
    (__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \
       sizeof(((struct _s##_sring *)0)->ring[0])))
/*
 * The same for passing in an actual pointer instead of a name tag.
 */
#define __RING_SIZE(_s, _sz) \
    (__RD32(((_sz) - (long)(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0])))

/*
 * Macros to make the correct C datatypes for a new kind of ring.
 *
 * To make a new ring datatype, you need to have two message structures,
 * let's say request_t, and response_t already defined.
 *
 * In a header where you want the ring datatype declared, you then do:
 *
 *     DEFINE_RING_TYPES(mytag, request_t, response_t);
 *
 * These expand out to give you a set of types, as you can see below.
 * The most important of these are:
 *
 *     mytag_sring_t      - The shared ring.
 *     mytag_front_ring_t - The 'front' half of the ring.
 *     mytag_back_ring_t  - The 'back' half of the ring.
 *
 * To initialize a ring in your code you need to know the location and size
 * of the shared memory area (PAGE_SIZE, for instance). To initialise
 * the front half:
 *
 *     mytag_front_ring_t front_ring;
 *     SHARED_RING_INIT((mytag_sring_t *)shared_page);
 *     FRONT_RING_INIT(&front_ring, (mytag_sring_t *)shared_page, PAGE_SIZE);
 *
 * Initializing the back follows similarly (note that only the front
 * initializes the shared ring):
 *
 *     mytag_back_ring_t back_ring;
 *     BACK_RING_INIT(&back_ring, (mytag_sring_t *)shared_page, PAGE_SIZE);
 */

#define DEFINE_RING_TYPES(__name, __req_t, __rsp_t)                     \
                                                                        \
/* Shared ring entry */                                                 \
union __name##_sring_entry {                                            \
    __req_t req;                                                        \
    __rsp_t rsp;                                                        \
};                                                                      \
                                                                        \
/* Shared ring page */                                                  \
struct __name##_sring {                                                 \
    RING_IDX req_prod, req_event;                                       \
    RING_IDX rsp_prod, rsp_event;                                       \
    uint8_t  pad[48];                                                   \
    union __name##_sring_entry ring[1]; /* variable-length */           \
};                                                                      \
                                                                        \
/* "Front" end's private variables */                                   \
struct __name##_front_ring {                                            \
    RING_IDX req_prod_pvt;                                              \
    RING_IDX rsp_cons;                                                  \
    unsigned int nr_ents;                                               \
    struct __name##_sring *sring;                                       \
};                                                                      \
                                                                        \
/* "Back" end's private variables */                                    \
struct __name##_back_ring {                                             \
    RING_IDX rsp_prod_pvt;                                              \
    RING_IDX req_cons;                                                  \
    unsigned int nr_ents;                                               \
    struct __name##_sring *sring;                                       \
};                                                                      \
                                                                        \
/* Syntactic sugar */                                                   \
typedef struct __name##_sring __name##_sring_t;                         \
typedef struct __name##_front_ring __name##_front_ring_t;               \
typedef struct __name##_back_ring __name##_back_ring_t

/*
 * Macros for manipulating rings.
 *
 * FRONT_RING_whatever works on the "front end" of a ring: here
 * requests are pushed on to the ring and responses taken off it.
 *
 * BACK_RING_whatever works on the "back end" of a ring: here
 * requests are taken off the ring and responses put on.
 *
 * N.B. these macros do NO INTERLOCKS OR FLOW CONTROL.
 * This is OK in 1-for-1 request-response situations where the
 * requestor (front end) never has more than RING_SIZE()-1
 * outstanding requests.
 */

/* Initialising empty rings */
#define SHARED_RING_INIT(_s) do {                                       \
    (_s)->req_prod  = (_s)->rsp_prod  = 0;                              \
    (_s)->req_event = (_s)->rsp_event = 1;                              \
    (void)memset((_s)->pad, 0, sizeof((_s)->pad));                      \
} while(0)

#define FRONT_RING_INIT(_r, _s, __size) do {                            \
    (_r)->req_prod_pvt = 0;                                             \
    (_r)->rsp_cons = 0;                                                 \
    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
    (_r)->sring = (_s);                                                 \
} while (0)

#define BACK_RING_INIT(_r, _s, __size) do {                             \
    (_r)->rsp_prod_pvt = 0;                                             \
    (_r)->req_cons = 0;                                                 \
    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
    (_r)->sring = (_s);                                                 \
} while (0)

/* Initialize to existing shared indexes -- for recovery */
#define FRONT_RING_ATTACH(_r, _s, __size) do {                          \
    (_r)->sring = (_s);                                                 \
    (_r)->req_prod_pvt = (_s)->req_prod;                                \
    (_r)->rsp_cons = (_s)->rsp_prod;                                    \
    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
} while (0)

#define BACK_RING_ATTACH(_r, _s, __size) do {                           \
    (_r)->sring = (_s);                                                 \
    (_r)->rsp_prod_pvt = (_s)->rsp_prod;                                \
    (_r)->req_cons = (_s)->req_prod;                                    \
    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
} while (0)

/* How big is this ring? */
#define RING_SIZE(_r)                                                   \
    ((_r)->nr_ents)

/* Number of free requests (for use on front side only). */
#define RING_FREE_REQUESTS(_r)                                          \
    (RING_SIZE(_r) - ((_r)->req_prod_pvt - (_r)->rsp_cons))

/* Test if there is an empty slot available on the front ring.
 * (This is only meaningful from the front. )
 */
#define RING_FULL(_r)                                                   \
    (RING_FREE_REQUESTS(_r) == 0)

/* Test if there are outstanding messages to be processed on a ring. */
#define RING_HAS_UNCONSUMED_RESPONSES(_r)                               \
    ((_r)->sring->rsp_prod - (_r)->rsp_cons)

#ifdef __GNUC__
#define RING_HAS_UNCONSUMED_REQUESTS(_r) ({                             \
    unsigned int req = (_r)->sring->req_prod - (_r)->req_cons;          \
    unsigned int rsp = RING_SIZE(_r) -                                  \
        ((_r)->req_cons - (_r)->rsp_prod_pvt);                          \
    req < rsp ? req : rsp;                                              \
})
#else
/* Same as above, but without the nice GCC ({ ... }) syntax. */
#define RING_HAS_UNCONSUMED_REQUESTS(_r)                                \
    ((((_r)->sring->req_prod - (_r)->req_cons) <                        \
      (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) ?        \
     ((_r)->sring->req_prod - (_r)->req_cons) :                         \
     (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt)))
#endif

/* Direct access to individual ring elements, by index. */
#define RING_GET_REQUEST(_r, _idx)                                      \
    (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req))

#define RING_GET_RESPONSE(_r, _idx)                                     \
    (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp))

/* Loop termination condition: Would the specified index overflow the ring? */
#define RING_REQUEST_CONS_OVERFLOW(_r, _cons)                           \
    (((_cons) - (_r)->rsp_prod_pvt) >= RING_SIZE(_r))

#define RING_PUSH_REQUESTS(_r) do {                                     \
    xen_wmb(); /* back sees requests /before/ updated producer index */ \
    (_r)->sring->req_prod = (_r)->req_prod_pvt;                         \
} while (0)

#define RING_PUSH_RESPONSES(_r) do {                                    \
    xen_wmb(); /* front sees resps /before/ updated producer index */   \
    (_r)->sring->rsp_prod = (_r)->rsp_prod_pvt;                         \
} while (0)

/*
 * Notification hold-off (req_event and rsp_event):
 *
 * When queueing requests or responses on a shared ring, it may not always be
 * necessary to notify the remote end. For example, if requests are in flight
 * in a backend, the front may be able to queue further requests without
 * notifying the back (if the back checks for new requests when it queues
 * responses).
 *
 * When enqueuing requests or responses:
 *
 *  Use RING_PUSH_{REQUESTS,RESPONSES}_AND_CHECK_NOTIFY(). The second argument
 *  is a boolean return value. True indicates that the receiver requires an
 *  asynchronous notification.
 *
 * After dequeuing requests or responses (before sleeping the connection):
 *
 *  Use RING_FINAL_CHECK_FOR_REQUESTS() or RING_FINAL_CHECK_FOR_RESPONSES().
 *  The second argument is a boolean return value. True indicates that there
 *  are pending messages on the ring (i.e., the connection should not be put
 *  to sleep).
 *
 *  These macros will set the req_event/rsp_event field to trigger a
 *  notification on the very next message that is enqueued. If you want to
 *  create batches of work (i.e., only receive a notification after several
 *  messages have been enqueued) then you will need to create a customised
 *  version of the FINAL_CHECK macro in your own code, which sets the event
 *  field appropriately.
 */

#define RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(_r, _notify) do {           \
    RING_IDX __old = (_r)->sring->req_prod;                             \
    RING_IDX __new = (_r)->req_prod_pvt;                                \
    xen_wmb(); /* back sees requests /before/ updated producer index */ \
    (_r)->sring->req_prod = __new;                                      \
    xen_mb(); /* back sees new requests /before/ we check req_event */  \
    (_notify) = ((RING_IDX)(__new - (_r)->sring->req_event) <           \
                 (RING_IDX)(__new - __old));                            \
} while (0)

#define RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(_r, _notify) do {          \
    RING_IDX __old = (_r)->sring->rsp_prod;                             \
    RING_IDX __new = (_r)->rsp_prod_pvt;                                \
    xen_wmb(); /* front sees resps /before/ updated producer index */   \
    (_r)->sring->rsp_prod = __new;                                      \
    xen_mb(); /* front sees new resps /before/ we check rsp_event */    \
    (_notify) = ((RING_IDX)(__new - (_r)->sring->rsp_event) <           \
                 (RING_IDX)(__new - __old));                            \
} while (0)

#define RING_FINAL_CHECK_FOR_REQUESTS(_r, _work_to_do) do {             \
    (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r);                   \
    if (_work_to_do) break;                                             \
    (_r)->sring->req_event = (_r)->req_cons + 1;                        \
    xen_mb();                                                           \
    (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r);                   \
} while (0)

#define RING_FINAL_CHECK_FOR_RESPONSES(_r, _work_to_do) do {            \
    (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r);                  \
    if (_work_to_do) break;                                             \
    (_r)->sring->rsp_event = (_r)->rsp_cons + 1;                        \
    xen_mb();                                                           \
    (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r);                  \
} while (0)

#endif /* __XEN_PUBLIC_IO_RING_H__ */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
/*****************************************************************************
 * xenbus.h
 *
 * Xenbus protocol details.
 *
 * 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.
 *
 * Copyright (C) 2005 XenSource Ltd.
 */

#ifndef _XEN_PUBLIC_IO_XENBUS_H
#define _XEN_PUBLIC_IO_XENBUS_H

/*
 * The state of either end of the Xenbus, i.e. the current communication
 * status of initialisation across the bus.  States here imply nothing about
 * the state of the connection between the driver and the kernel's device
 * layers.
 */
enum xenbus_state {
    XenbusStateUnknown       = 0,

    XenbusStateInitialising  = 1,

    /*
     * InitWait: Finished early initialisation but waiting for information
     * from the peer or hotplug scripts.
     */
    XenbusStateInitWait      = 2,

    /*
     * Initialised: Waiting for a connection from the peer.
     */
    XenbusStateInitialised   = 3,

    XenbusStateConnected     = 4,

    /*
     * Closing: The device is being closed due to an error or an unplug event.
     */
    XenbusStateClosing       = 5,

    XenbusStateClosed        = 6,

    /*
     * Reconfiguring: The device is being reconfigured.
     */
    XenbusStateReconfiguring = 7,

    XenbusStateReconfigured  = 8
};
typedef enum xenbus_state XenbusState;

#endif /* _XEN_PUBLIC_IO_XENBUS_H */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
/*
 * Details of the "wire" protocol between Xen Store Daemon and client
 * library or guest kernel.
 *
 * 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.
 *
 * Copyright (C) 2005 Rusty Russell IBM Corporation
 */

#ifndef _XS_WIRE_H
#define _XS_WIRE_H

enum xsd_sockmsg_type
{
    XS_DEBUG,
    XS_DIRECTORY,
    XS_READ,
    XS_GET_PERMS,
    XS_WATCH,
    XS_UNWATCH,
    XS_TRANSACTION_START,
    XS_TRANSACTION_END,
    XS_INTRODUCE,
    XS_RELEASE,
    XS_GET_DOMAIN_PATH,
    XS_WRITE,
    XS_MKDIR,
    XS_RM,
    XS_SET_PERMS,
    XS_WATCH_EVENT,
    XS_ERROR,
    XS_IS_DOMAIN_INTRODUCED,
    XS_RESUME,
    XS_SET_TARGET
};

#define XS_WRITE_NONE "NONE"
#define XS_WRITE_CREATE "CREATE"
#define XS_WRITE_CREATE_EXCL "CREATE|EXCL"

/* We hand errors as strings, for portability. */
struct xsd_errors
{
    int errnum;
    const char *errstring;
};
#define XSD_ERROR(x) { x, #x }
/* LINTED: static unused */
static struct xsd_errors xsd_errors[]
#if defined(__GNUC__)
__attribute__((unused))
#endif
    = {
    XSD_ERROR(EINVAL),
    XSD_ERROR(EACCES),
    XSD_ERROR(EEXIST),
    XSD_ERROR(EISDIR),
    XSD_ERROR(ENOENT),
    XSD_ERROR(ENOMEM),
    XSD_ERROR(ENOSPC),
    XSD_ERROR(EIO),
    XSD_ERROR(ENOTEMPTY),
    XSD_ERROR(ENOSYS),
    XSD_ERROR(EROFS),
    XSD_ERROR(EBUSY),
    XSD_ERROR(EAGAIN),
    XSD_ERROR(EISCONN)
};

struct xsd_sockmsg
{
    uint32_t type;  /* XS_??? */
    uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
    uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
    uint32_t len;   /* Length of data following this. */

    /* Generally followed by nul-terminated string(s). */
};

enum xs_watch_type
{
    XS_WATCH_PATH = 0,
    XS_WATCH_TOKEN
};

/* Inter-domain shared memory communications. */
#define XENSTORE_RING_SIZE 1024
typedef uint32_t XENSTORE_RING_IDX;
#define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
struct xenstore_domain_interface {
    char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
    char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
    XENSTORE_RING_IDX req_cons, req_prod;
    XENSTORE_RING_IDX rsp_cons, rsp_prod;
};

/* Violating this is very bad.  See docs/misc/xenstore.txt. */
#define XENSTORE_PAYLOAD_MAX 4096

/* Violating these just gets you an error back */
#define XENSTORE_ABS_PATH_MAX 3072
#define XENSTORE_REL_PATH_MAX 2048

#endif /* _XS_WIRE_H */

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */