/*-
 * Copyright (c) 2016 Microsoft Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _VMBUS_H_
#define _VMBUS_H_

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/_iovec.h>

/*
 * VMBUS version is 32 bit, upper 16 bit for major_number and lower
 * 16 bit for minor_number.
 *
 * 0.13  --  Windows Server 2008
 * 1.1   --  Windows 7
 * 2.4   --  Windows 8
 * 3.0   --  Windows 8.1
 * 4.0   --  Windows 10
 * 5.0   --  Newer Windows 10
 */
#define VMBUS_VERSION_WS2008            ((0 << 16) | (13))
#define VMBUS_VERSION_WIN7              ((1 << 16) | (1))
#define VMBUS_VERSION_WIN8              ((2 << 16) | (4))
#define VMBUS_VERSION_WIN8_1            ((3 << 16) | (0))
#define VMBUS_VERSION_WIN10             ((4 << 16) | (0))
#define VMBUS_VERSION_WIN10_V5          ((5 << 16) | (0))

#define VMBUS_VERSION_MAJOR(ver)        (((uint32_t)(ver)) >> 16)
#define VMBUS_VERSION_MINOR(ver)        (((uint32_t)(ver)) & 0xffff)

#define VMBUS_CHAN_POLLHZ_MIN           100     /* 10ms interval */
#define VMBUS_CHAN_POLLHZ_MAX           1000000 /* 1us interval */

/*
 * GPA stuffs.
 */
struct vmbus_gpa_range {
        uint32_t        gpa_len;
        uint32_t        gpa_ofs;
        uint64_t        gpa_page[0];
} __packed;

/* This is actually vmbus_gpa_range.gpa_page[1] */
struct vmbus_gpa {
        uint32_t        gpa_len;
        uint32_t        gpa_ofs;
        uint64_t        gpa_page;
} __packed;

#define VMBUS_CHANPKT_SIZE_SHIFT        3

#define VMBUS_CHANPKT_GETLEN(pktlen)    \
        (((int)(pktlen)) << VMBUS_CHANPKT_SIZE_SHIFT)

struct vmbus_chanpkt_hdr {
        uint16_t        cph_type;       /* VMBUS_CHANPKT_TYPE_ */
        uint16_t        cph_hlen;       /* header len, in 8 bytes */
        uint16_t        cph_tlen;       /* total len, in 8 bytes */
        uint16_t        cph_flags;      /* VMBUS_CHANPKT_FLAG_ */
        uint64_t        cph_xactid;
} __packed;

#define VMBUS_CHANPKT_TYPE_INBAND       0x0006
#define VMBUS_CHANPKT_TYPE_RXBUF        0x0007
#define VMBUS_CHANPKT_TYPE_GPA          0x0009
#define VMBUS_CHANPKT_TYPE_COMP         0x000b

#define VMBUS_CHANPKT_FLAG_NONE         0
#define VMBUS_CHANPKT_FLAG_RC           0x0001  /* report completion */

#define VMBUS_CHANPKT_CONST_DATA(pkt)           \
        (const void *)((const uint8_t *)(pkt) + \
        VMBUS_CHANPKT_GETLEN((pkt)->cph_hlen))

/* Include padding */
#define VMBUS_CHANPKT_DATALEN(pkt)              \
        (VMBUS_CHANPKT_GETLEN((pkt)->cph_tlen) -\
         VMBUS_CHANPKT_GETLEN((pkt)->cph_hlen))

struct vmbus_rxbuf_desc {
        uint32_t        rb_len;
        uint32_t        rb_ofs;
} __packed;

struct vmbus_chanpkt_rxbuf {
        struct vmbus_chanpkt_hdr cp_hdr;
        uint16_t        cp_rxbuf_id;
        uint16_t        cp_rsvd;
        uint32_t        cp_rxbuf_cnt;
        struct vmbus_rxbuf_desc cp_rxbuf[];
} __packed;

struct vmbus_chan_br {
        void            *cbr;
        bus_addr_t      cbr_paddr;
        int             cbr_txsz;
        int             cbr_rxsz;
};

struct vmbus_channel;
struct vmbus_xact;
struct vmbus_xact_ctx;
struct hyperv_guid;
struct task;
struct taskqueue;

typedef void    (*vmbus_chan_callback_t)(struct vmbus_channel *, void *);
typedef int     (*vmbus_br_copy_callback_t)(void *, int, void *);

static __inline struct vmbus_channel *
vmbus_get_channel(device_t dev)
{
        return device_get_ivars(dev);
}

/*
 * vmbus_chan_open_br()
 *
 * Return values:
 * 0                    Succeeded.
 * EISCONN              Failed, and the memory passed through 'br' is still
 *                      connected.  Callers must _not_ free the memory
 *                      passed through 'br', if this error happens.
 * other values         Failed.  The memory passed through 'br' is no longer
 *                      connected.  Callers are free to do anything with the
 *                      memory passed through 'br'.
 *
 *
 *
 * vmbus_chan_close_direct()
 *
 * NOTE:
 * Callers of this function _must_ make sure to close all sub-channels before
 * closing the primary channel.
 *
 * Return values:
 * 0                    Succeeded.
 * EISCONN              Failed, and the memory associated with the bufring
 *                      is still connected.  Callers must _not_ free the the
 *                      memory associated with the bufring, if this error
 *                      happens.
 * other values         Failed.  The memory associated with the bufring is
 *                      no longer connected.  Callers are free to do anything
 *                      with the memory associated with the bufring.
 */
int             vmbus_chan_open(struct vmbus_channel *chan,
                    int txbr_size, int rxbr_size, const void *udata, int udlen,
                    vmbus_chan_callback_t cb, void *cbarg);
int             vmbus_chan_open_br(struct vmbus_channel *chan,
                    const struct vmbus_chan_br *cbr, const void *udata,
                    int udlen, vmbus_chan_callback_t cb, void *cbarg);
void            vmbus_chan_close(struct vmbus_channel *chan);
int             vmbus_chan_close_direct(struct vmbus_channel *chan);
void            vmbus_chan_intr_drain(struct vmbus_channel *chan);
void            vmbus_chan_run_task(struct vmbus_channel *chan,
                    struct task *task);
void            vmbus_chan_set_orphan(struct vmbus_channel *chan,
                    struct vmbus_xact_ctx *);
void            vmbus_chan_unset_orphan(struct vmbus_channel *chan);
const void      *vmbus_chan_xact_wait(const struct vmbus_channel *chan,
                    struct vmbus_xact *xact, size_t *resp_len, bool can_sleep);

int             vmbus_chan_gpadl_connect(struct vmbus_channel *chan,
                    bus_addr_t paddr, int size, uint32_t *gpadl);
int             vmbus_chan_gpadl_disconnect(struct vmbus_channel *chan,
                    uint32_t gpadl);

void            vmbus_chan_cpu_set(struct vmbus_channel *chan, int cpu);
void            vmbus_chan_cpu_rr(struct vmbus_channel *chan);
void            vmbus_chan_set_readbatch(struct vmbus_channel *chan, bool on);

struct vmbus_channel **
                vmbus_subchan_get(struct vmbus_channel *pri_chan,
                    int subchan_cnt);
void            vmbus_subchan_rel(struct vmbus_channel **subchan,
                    int subchan_cnt);
void            vmbus_subchan_drain(struct vmbus_channel *pri_chan);

int             vmbus_chan_recv(struct vmbus_channel *chan, void *data, int *dlen,
                    uint64_t *xactid);
int             vmbus_chan_recv_pkt(struct vmbus_channel *chan,
                    struct vmbus_chanpkt_hdr *pkt, int *pktlen);

int             vmbus_chan_recv_idxadv(struct vmbus_channel *chan,
                    uint32_t advance);
int             vmbus_chan_recv_peek(struct vmbus_channel *chan,
                    void *data, int data_len, uint32_t advance);
int             vmbus_chan_recv_peek_call(struct vmbus_channel *chan,
                    int data_len, uint32_t skip,
                    vmbus_br_copy_callback_t cb, void *cbarg);

int             vmbus_chan_send(struct vmbus_channel *chan, uint16_t type,
                    uint16_t flags, void *data, int dlen, uint64_t xactid);
int             vmbus_chan_send_sglist(struct vmbus_channel *chan,
                    struct vmbus_gpa sg[], int sglen, void *data, int dlen,
                    uint64_t xactid);
int             vmbus_chan_send_prplist(struct vmbus_channel *chan,
                    struct vmbus_gpa_range *prp, int prp_cnt, void *data,
                    int dlen, uint64_t xactid);
int             vmbus_chan_iov_send(struct vmbus_channel *chan,
                    const struct iovec iov[], int iovlen,
                    vmbus_br_copy_callback_t cb, void *cbarg);
uint32_t        vmbus_chan_write_available(struct vmbus_channel *chan);
uint32_t        vmbus_chan_read_available(struct vmbus_channel *chan);
bool            vmbus_chan_write_signal(struct vmbus_channel *chan,
                    int32_t min_signal_size);
void            vmbus_chan_set_pending_send_size(struct vmbus_channel *chan,
                    uint32_t size);

uint32_t        vmbus_chan_id(const struct vmbus_channel *chan);
uint32_t        vmbus_chan_subidx(const struct vmbus_channel *chan);
bool            vmbus_chan_is_primary(const struct vmbus_channel *chan);
bool            vmbus_chan_is_revoked(const struct vmbus_channel *chan);
bool            vmbus_chan_is_hvs(const struct vmbus_channel *chan);
bool            vmbus_chan_is_hvs_conn_from_host(
                    const struct vmbus_channel *chan);
int             vmbus_req_tl_connect(struct hyperv_guid *,
                    struct hyperv_guid *);

struct hyperv_guid *
                vmbus_chan_guid_type(struct vmbus_channel *chan);
struct hyperv_guid *
                vmbus_chan_guid_inst(struct vmbus_channel *chan);
int             vmbus_chan_prplist_nelem(int br_size, int prpcnt_max,
                    int dlen_max);
bool            vmbus_chan_rx_empty(const struct vmbus_channel *chan);
bool            vmbus_chan_tx_empty(const struct vmbus_channel *chan);
struct taskqueue *
                vmbus_chan_mgmt_tq(const struct vmbus_channel *chan);

void            vmbus_chan_poll_enable(struct vmbus_channel *chan,
                    u_int pollhz);
void            vmbus_chan_poll_disable(struct vmbus_channel *chan);

#endif  /* !_VMBUS_H_ */