/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lnet/klnds/o2iblnd/o2iblnd.h
 *
 * Author: Eric Barton <eric@bartonsoftware.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/uio.h>

#include <asm/uaccess.h>
#include <asm/io.h>

#include <linux/init.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/sysctl.h>
#include <linux/pci.h>

#include <net/sock.h>
#include <linux/in.h>

#define DEBUG_SUBSYSTEM S_LND

#include <linux/libcfs/libcfs.h>
#include <linux/lnet/lnet.h>
#include <linux/lnet/lib-lnet.h>
#include <linux/lnet/lnet-sysctl.h>

#include <rdma/rdma_cm.h>
#include <rdma/ib_cm.h>
#include <rdma/ib_verbs.h>
#include <rdma/ib_fmr_pool.h>

#define IBLND_PEER_HASH_SIZE		101	/* # peer lists */
/* # scheduler loops before reschedule */
#define IBLND_RESCHED			100

#define IBLND_N_SCHED			2
#define IBLND_N_SCHED_HIGH		4

typedef struct
{
	int	      *kib_dev_failover;     /* HCA failover */
	unsigned int     *kib_service;	  /* IB service number */
	int	      *kib_min_reconnect_interval; /* first failed connection retry... */
	int	      *kib_max_reconnect_interval; /* ...exponentially increasing to this */
	int	      *kib_cksum;	    /* checksum kib_msg_t? */
	int	      *kib_timeout;	  /* comms timeout (seconds) */
	int	      *kib_keepalive;	/* keepalive timeout (seconds) */
	int	      *kib_ntx;	      /* # tx descs */
	int	      *kib_credits;	  /* # concurrent sends */
	int	      *kib_peertxcredits;    /* # concurrent sends to 1 peer */
	int	      *kib_peerrtrcredits;   /* # per-peer router buffer credits */
	int	      *kib_peercredits_hiw;  /* # when eagerly to return credits */
	int	      *kib_peertimeout;      /* seconds to consider peer dead */
	char	    **kib_default_ipif;     /* default IPoIB interface */
	int	      *kib_retry_count;
	int	      *kib_rnr_retry_count;
	int	      *kib_concurrent_sends; /* send work queue sizing */
	int		 *kib_ib_mtu;		/* IB MTU */
	int	      *kib_map_on_demand;    /* map-on-demand if RD has more fragments
						 * than this value, 0 disable map-on-demand */
	int	      *kib_pmr_pool_size;    /* # physical MR in pool */
	int	      *kib_fmr_pool_size;    /* # FMRs in pool */
	int	      *kib_fmr_flush_trigger; /* When to trigger FMR flush */
	int	      *kib_fmr_cache;	/* enable FMR pool cache? */
#if defined(CONFIG_SYSCTL) && !CFS_SYSFS_MODULE_PARM
	ctl_table_header_t *kib_sysctl;  /* sysctl interface */
#endif
	int	      *kib_require_priv_port;/* accept only privileged ports */
	int	      *kib_use_priv_port;    /* use privileged port for active connect */
	/* # threads on each CPT */
	int		 *kib_nscheds;
} kib_tunables_t;

extern kib_tunables_t  kiblnd_tunables;

#define IBLND_MSG_QUEUE_SIZE_V1      8	  /* V1 only : # messages/RDMAs in-flight */
#define IBLND_CREDIT_HIGHWATER_V1    7	  /* V1 only : when eagerly to return credits */

#define IBLND_CREDITS_DEFAULT	8	  /* default # of peer credits */
#define IBLND_CREDITS_MAX	  ((typeof(((kib_msg_t*) 0)->ibm_credits)) - 1)  /* Max # of peer credits */

#define IBLND_MSG_QUEUE_SIZE(v)    ((v) == IBLND_MSG_VERSION_1 ? \
				     IBLND_MSG_QUEUE_SIZE_V1 :   \
				     *kiblnd_tunables.kib_peertxcredits) /* # messages/RDMAs in-flight */
#define IBLND_CREDITS_HIGHWATER(v) ((v) == IBLND_MSG_VERSION_1 ? \
				     IBLND_CREDIT_HIGHWATER_V1 : \
				     *kiblnd_tunables.kib_peercredits_hiw) /* when eagerly to return credits */

#define kiblnd_rdma_create_id(cb, dev, ps, qpt) rdma_create_id(cb, dev, ps, qpt)

static inline int
kiblnd_concurrent_sends_v1(void)
{
	if (*kiblnd_tunables.kib_concurrent_sends > IBLND_MSG_QUEUE_SIZE_V1 * 2)
		return IBLND_MSG_QUEUE_SIZE_V1 * 2;

	if (*kiblnd_tunables.kib_concurrent_sends < IBLND_MSG_QUEUE_SIZE_V1 / 2)
		return IBLND_MSG_QUEUE_SIZE_V1 / 2;

	return *kiblnd_tunables.kib_concurrent_sends;
}

#define IBLND_CONCURRENT_SENDS(v)  ((v) == IBLND_MSG_VERSION_1 ? \
				     kiblnd_concurrent_sends_v1() : \
				     *kiblnd_tunables.kib_concurrent_sends)
/* 2 OOB shall suffice for 1 keepalive and 1 returning credits */
#define IBLND_OOB_CAPABLE(v)       ((v) != IBLND_MSG_VERSION_1)
#define IBLND_OOB_MSGS(v)	   (IBLND_OOB_CAPABLE(v) ? 2 : 0)

#define IBLND_MSG_SIZE	      (4<<10)		 /* max size of queued messages (inc hdr) */
#define IBLND_MAX_RDMA_FRAGS	 LNET_MAX_IOV	   /* max # of fragments supported */
#define IBLND_CFG_RDMA_FRAGS       (*kiblnd_tunables.kib_map_on_demand != 0 ? \
				    *kiblnd_tunables.kib_map_on_demand :      \
				     IBLND_MAX_RDMA_FRAGS)  /* max # of fragments configured by user */
#define IBLND_RDMA_FRAGS(v)	((v) == IBLND_MSG_VERSION_1 ? \
				     IBLND_MAX_RDMA_FRAGS : IBLND_CFG_RDMA_FRAGS)

/************************/
/* derived constants... */
/* Pools (shared by connections on each CPT) */
/* These pools can grow at runtime, so don't need give a very large value */
#define IBLND_TX_POOL			256
#define IBLND_PMR_POOL			256
#define IBLND_FMR_POOL			256
#define IBLND_FMR_POOL_FLUSH		192

/* TX messages (shared by all connections) */
#define IBLND_TX_MSGS()	    (*kiblnd_tunables.kib_ntx)

/* RX messages (per connection) */
#define IBLND_RX_MSGS(v)	    (IBLND_MSG_QUEUE_SIZE(v) * 2 + IBLND_OOB_MSGS(v))
#define IBLND_RX_MSG_BYTES(v)       (IBLND_RX_MSGS(v) * IBLND_MSG_SIZE)
#define IBLND_RX_MSG_PAGES(v)      ((IBLND_RX_MSG_BYTES(v) + PAGE_SIZE - 1) / PAGE_SIZE)

/* WRs and CQEs (per connection) */
#define IBLND_RECV_WRS(v)	    IBLND_RX_MSGS(v)
#define IBLND_SEND_WRS(v)	  ((IBLND_RDMA_FRAGS(v) + 1) * IBLND_CONCURRENT_SENDS(v))
#define IBLND_CQ_ENTRIES(v)	 (IBLND_RECV_WRS(v) + IBLND_SEND_WRS(v))

struct kib_hca_dev;

/* o2iblnd can run over aliased interface */
#ifdef IFALIASZ
#define KIB_IFNAME_SIZE	      IFALIASZ
#else
#define KIB_IFNAME_SIZE	      256
#endif

typedef struct
{
	struct list_head	   ibd_list;	  /* chain on kib_devs */
	struct list_head	   ibd_fail_list;     /* chain on kib_failed_devs */
	__u32		ibd_ifip;	  /* IPoIB interface IP */
	/** IPoIB interface name */
	char		 ibd_ifname[KIB_IFNAME_SIZE];
	int		  ibd_nnets;	 /* # nets extant */

	cfs_time_t	   ibd_next_failover;
	int		  ibd_failed_failover; /* # failover failures */
	unsigned int	 ibd_failover;      /* failover in progress */
	unsigned int	 ibd_can_failover;  /* IPoIB interface is a bonding master */
	struct list_head	   ibd_nets;
	struct kib_hca_dev  *ibd_hdev;
} kib_dev_t;

typedef struct kib_hca_dev
{
	struct rdma_cm_id   *ibh_cmid;	  /* listener cmid */
	struct ib_device    *ibh_ibdev;	 /* IB device */
	int		  ibh_page_shift;    /* page shift of current HCA */
	int		  ibh_page_size;     /* page size of current HCA */
	__u64		ibh_page_mask;     /* page mask of current HCA */
	int		  ibh_mr_shift;      /* bits shift of max MR size */
	__u64		ibh_mr_size;       /* size of MR */
	int		  ibh_nmrs;	  /* # of global MRs */
	struct ib_mr       **ibh_mrs;	   /* global MR */
	struct ib_pd	*ibh_pd;	    /* PD */
	kib_dev_t	   *ibh_dev;	   /* owner */
	atomic_t	 ibh_ref;	   /* refcount */
} kib_hca_dev_t;

/** # of seconds to keep pool alive */
#define IBLND_POOL_DEADLINE     300
/** # of seconds to retry if allocation failed */
#define IBLND_POOL_RETRY	1

typedef struct
{
	int		     ibp_npages;	     /* # pages */
	struct page	    *ibp_pages[0];	   /* page array */
} kib_pages_t;

struct kib_pmr_pool;

typedef struct {
	struct list_head	      pmr_list;	       /* chain node */
	struct ib_phys_buf     *pmr_ipb;		/* physical buffer */
	struct ib_mr	   *pmr_mr;		 /* IB MR */
	struct kib_pmr_pool    *pmr_pool;	       /* owner of this MR */
	__u64		   pmr_iova;	       /* Virtual I/O address */
	int		     pmr_refcount;	   /* reference count */
} kib_phys_mr_t;

struct kib_pool;
struct kib_poolset;

typedef int  (*kib_ps_pool_create_t)(struct kib_poolset *ps,
				     int inc, struct kib_pool **pp_po);
typedef void (*kib_ps_pool_destroy_t)(struct kib_pool *po);
typedef void (*kib_ps_node_init_t)(struct kib_pool *po, struct list_head *node);
typedef void (*kib_ps_node_fini_t)(struct kib_pool *po, struct list_head *node);

struct kib_net;

#define IBLND_POOL_NAME_LEN     32

typedef struct kib_poolset
{
	spinlock_t		ps_lock;		/* serialize */
	struct kib_net	 *ps_net;		 /* network it belongs to */
	char		    ps_name[IBLND_POOL_NAME_LEN]; /* pool set name */
	struct list_head	      ps_pool_list;	   /* list of pools */
	struct list_head	      ps_failed_pool_list;    /* failed pool list */
	cfs_time_t	      ps_next_retry;	  /* time stamp for retry if failed to allocate */
	int		     ps_increasing;	  /* is allocating new pool */
	int		     ps_pool_size;	   /* new pool size */
	int			ps_cpt;			/* CPT id */

	kib_ps_pool_create_t    ps_pool_create;	 /* create a new pool */
	kib_ps_pool_destroy_t   ps_pool_destroy;	/* destroy a pool */
	kib_ps_node_init_t      ps_node_init;	   /* initialize new allocated node */
	kib_ps_node_fini_t      ps_node_fini;	   /* finalize node */
} kib_poolset_t;

typedef struct kib_pool
{
	struct list_head	      po_list;		/* chain on pool list */
	struct list_head	      po_free_list;	   /* pre-allocated node */
	kib_poolset_t	  *po_owner;	       /* pool_set of this pool */
	cfs_time_t	      po_deadline;	    /* deadline of this pool */
	int		     po_allocated;	   /* # of elements in use */
	int		     po_failed;	      /* pool is created on failed HCA */
	int		     po_size;		/* # of pre-allocated elements */
} kib_pool_t;

typedef struct {
	kib_poolset_t	   tps_poolset;	    /* pool-set */
	__u64		   tps_next_tx_cookie;     /* cookie of TX */
} kib_tx_poolset_t;

typedef struct {
	kib_pool_t	      tpo_pool;	       /* pool */
	struct kib_hca_dev     *tpo_hdev;	       /* device for this pool */
	struct kib_tx	  *tpo_tx_descs;	   /* all the tx descriptors */
	kib_pages_t	    *tpo_tx_pages;	   /* premapped tx msg pages */
} kib_tx_pool_t;

typedef struct {
	kib_poolset_t	   pps_poolset;	    /* pool-set */
} kib_pmr_poolset_t;

typedef struct kib_pmr_pool {
	struct kib_hca_dev     *ppo_hdev;	       /* device for this pool */
	kib_pool_t	      ppo_pool;	       /* pool */
} kib_pmr_pool_t;

typedef struct
{
	spinlock_t		fps_lock;		/* serialize */
	struct kib_net	 *fps_net;		/* IB network */
	struct list_head	      fps_pool_list;	  /* FMR pool list */
	struct list_head	      fps_failed_pool_list;   /* FMR pool list */
	__u64		   fps_version;	    /* validity stamp */
	int			fps_cpt;		/* CPT id */
	int			fps_pool_size;
	int			fps_flush_trigger;
	/* is allocating new pool */
	int			fps_increasing;
	/* time stamp for retry if failed to allocate */
	cfs_time_t		fps_next_retry;
} kib_fmr_poolset_t;

typedef struct
{
	struct list_head	      fpo_list;	       /* chain on pool list */
	struct kib_hca_dev     *fpo_hdev;	       /* device for this pool */
	kib_fmr_poolset_t      *fpo_owner;	      /* owner of this pool */
	struct ib_fmr_pool     *fpo_fmr_pool;	   /* IB FMR pool */
	cfs_time_t	      fpo_deadline;	   /* deadline of this pool */
	int		     fpo_failed;	     /* fmr pool is failed */
	int		     fpo_map_count;	  /* # of mapped FMR */
} kib_fmr_pool_t;

typedef struct {
	struct ib_pool_fmr     *fmr_pfmr;	       /* IB pool fmr */
	kib_fmr_pool_t	 *fmr_pool;	       /* pool of FMR */
} kib_fmr_t;

typedef struct kib_net
{
	struct list_head	   ibn_list;	  /* chain on kib_dev_t::ibd_nets */
	__u64		ibn_incarnation;   /* my epoch */
	int		  ibn_init;	  /* initialisation state */
	int		  ibn_shutdown;      /* shutting down? */

	atomic_t		ibn_npeers;	/* # peers extant */
	atomic_t		ibn_nconns;	/* # connections extant */

	kib_tx_poolset_t	**ibn_tx_ps;	/* tx pool-set */
	kib_fmr_poolset_t	**ibn_fmr_ps;	/* fmr pool-set */
	kib_pmr_poolset_t	**ibn_pmr_ps;	/* pmr pool-set */

	kib_dev_t		*ibn_dev;	/* underlying IB device */
} kib_net_t;

#define KIB_THREAD_SHIFT		16
#define KIB_THREAD_ID(cpt, tid)		((cpt) << KIB_THREAD_SHIFT | (tid))
#define KIB_THREAD_CPT(id)		((id) >> KIB_THREAD_SHIFT)
#define KIB_THREAD_TID(id)		((id) & ((1UL << KIB_THREAD_SHIFT) - 1))

struct kib_sched_info {
	/* serialise */
	spinlock_t		ibs_lock;
	/* schedulers sleep here */
	wait_queue_head_t		ibs_waitq;
	/* conns to check for rx completions */
	struct list_head		ibs_conns;
	/* number of scheduler threads */
	int			ibs_nthreads;
	/* max allowed scheduler threads */
	int			ibs_nthreads_max;
	int			ibs_cpt;	/* CPT id */
};

typedef struct
{
	int			kib_init;	/* initialisation state */
	int			kib_shutdown;	/* shut down? */
	struct list_head		kib_devs;	/* IB devices extant */
	/* list head of failed devices */
	struct list_head		kib_failed_devs;
	/* schedulers sleep here */
	wait_queue_head_t		kib_failover_waitq;
	atomic_t		kib_nthreads;	/* # live threads */
	/* stabilize net/dev/peer/conn ops */
	rwlock_t		kib_global_lock;
	/* hash table of all my known peers */
	struct list_head		*kib_peers;
	/* size of kib_peers */
	int			kib_peer_hash_size;
	/* the connd task (serialisation assertions) */
	void			*kib_connd;
	/* connections to setup/teardown */
	struct list_head		kib_connd_conns;
	/* connections with zero refcount */
	struct list_head		kib_connd_zombies;
	/* connection daemon sleeps here */
	wait_queue_head_t		kib_connd_waitq;
	spinlock_t		kib_connd_lock;	/* serialise */
	struct ib_qp_attr	kib_error_qpa;	/* QP->ERROR */
	/* percpt data for schedulers */
	struct kib_sched_info	**kib_scheds;
} kib_data_t;

#define IBLND_INIT_NOTHING	 0
#define IBLND_INIT_DATA	    1
#define IBLND_INIT_ALL	     2

/************************************************************************
 * IB Wire message format.
 * These are sent in sender's byte order (i.e. receiver flips).
 */

typedef struct kib_connparams
{
	__u16	     ibcp_queue_depth;
	__u16	     ibcp_max_frags;
	__u32	     ibcp_max_msg_size;
} WIRE_ATTR kib_connparams_t;

typedef struct
{
	lnet_hdr_t	ibim_hdr;	     /* portals header */
	char	      ibim_payload[0];      /* piggy-backed payload */
} WIRE_ATTR kib_immediate_msg_t;

typedef struct
{
	__u32	     rf_nob;	       /* # bytes this frag */
	__u64	     rf_addr;	      /* CAVEAT EMPTOR: misaligned!! */
} WIRE_ATTR kib_rdma_frag_t;

typedef struct
{
	__u32	     rd_key;	       /* local/remote key */
	__u32	     rd_nfrags;	    /* # fragments */
	kib_rdma_frag_t   rd_frags[0];	  /* buffer frags */
} WIRE_ATTR kib_rdma_desc_t;

typedef struct
{
	lnet_hdr_t	ibprm_hdr;	    /* portals header */
	__u64	     ibprm_cookie;	 /* opaque completion cookie */
} WIRE_ATTR kib_putreq_msg_t;

typedef struct
{
	__u64	     ibpam_src_cookie;     /* reflected completion cookie */
	__u64	     ibpam_dst_cookie;     /* opaque completion cookie */
	kib_rdma_desc_t   ibpam_rd;	     /* sender's sink buffer */
} WIRE_ATTR kib_putack_msg_t;

typedef struct
{
	lnet_hdr_t	ibgm_hdr;	     /* portals header */
	__u64	     ibgm_cookie;	  /* opaque completion cookie */
	kib_rdma_desc_t   ibgm_rd;	      /* rdma descriptor */
} WIRE_ATTR kib_get_msg_t;

typedef struct
{
	__u64	     ibcm_cookie;	  /* opaque completion cookie */
	__s32	     ibcm_status;	  /* < 0 failure: >= 0 length */
} WIRE_ATTR kib_completion_msg_t;

typedef struct
{
	/* First 2 fields fixed FOR ALL TIME */
	__u32	     ibm_magic;	    /* I'm an ibnal message */
	__u16	     ibm_version;	  /* this is my version number */

	__u8	      ibm_type;	     /* msg type */
	__u8	      ibm_credits;	  /* returned credits */
	__u32	     ibm_nob;	      /* # bytes in whole message */
	__u32	     ibm_cksum;	    /* checksum (0 == no checksum) */
	__u64	     ibm_srcnid;	   /* sender's NID */
	__u64	     ibm_srcstamp;	 /* sender's incarnation */
	__u64	     ibm_dstnid;	   /* destination's NID */
	__u64	     ibm_dststamp;	 /* destination's incarnation */

	union {
		kib_connparams_t      connparams;
		kib_immediate_msg_t   immediate;
		kib_putreq_msg_t      putreq;
		kib_putack_msg_t      putack;
		kib_get_msg_t	 get;
		kib_completion_msg_t  completion;
	} WIRE_ATTR ibm_u;
} WIRE_ATTR kib_msg_t;

#define IBLND_MSG_MAGIC LNET_PROTO_IB_MAGIC	/* unique magic */

#define IBLND_MSG_VERSION_1	 0x11
#define IBLND_MSG_VERSION_2	 0x12
#define IBLND_MSG_VERSION	   IBLND_MSG_VERSION_2

#define IBLND_MSG_CONNREQ	   0xc0	/* connection request */
#define IBLND_MSG_CONNACK	   0xc1	/* connection acknowledge */
#define IBLND_MSG_NOOP	      0xd0	/* nothing (just credits) */
#define IBLND_MSG_IMMEDIATE	 0xd1	/* immediate */
#define IBLND_MSG_PUT_REQ	   0xd2	/* putreq (src->sink) */
#define IBLND_MSG_PUT_NAK	   0xd3	/* completion (sink->src) */
#define IBLND_MSG_PUT_ACK	   0xd4	/* putack (sink->src) */
#define IBLND_MSG_PUT_DONE	  0xd5	/* completion (src->sink) */
#define IBLND_MSG_GET_REQ	   0xd6	/* getreq (sink->src) */
#define IBLND_MSG_GET_DONE	  0xd7	/* completion (src->sink: all OK) */

typedef struct {
	__u32	    ibr_magic;	     /* sender's magic */
	__u16	    ibr_version;	   /* sender's version */
	__u8	     ibr_why;	       /* reject reason */
	__u8	     ibr_padding;	   /* padding */
	__u64	    ibr_incarnation;       /* incarnation of peer */
	kib_connparams_t ibr_cp;		/* connection parameters */
} WIRE_ATTR kib_rej_t;

/* connection rejection reasons */
#define IBLND_REJECT_CONN_RACE       1	  /* You lost connection race */
#define IBLND_REJECT_NO_RESOURCES    2	  /* Out of memory/conns etc */
#define IBLND_REJECT_FATAL	   3	  /* Anything else */

#define IBLND_REJECT_CONN_UNCOMPAT   4	  /* incompatible version peer */
#define IBLND_REJECT_CONN_STALE      5	  /* stale peer */

#define IBLND_REJECT_RDMA_FRAGS      6	  /* Fatal: peer's rdma frags can't match mine */
#define IBLND_REJECT_MSG_QUEUE_SIZE  7	  /* Fatal: peer's msg queue size can't match mine */

/***********************************************************************/

typedef struct kib_rx			   /* receive message */
{
	struct list_head		rx_list;      /* queue for attention */
	struct kib_conn	  *rx_conn;      /* owning conn */
	int		       rx_nob;       /* # bytes received (-1 while posted) */
	enum ib_wc_status	 rx_status;    /* completion status */
	kib_msg_t		*rx_msg;       /* message buffer (host vaddr) */
	__u64		     rx_msgaddr;   /* message buffer (I/O addr) */
	DECLARE_PCI_UNMAP_ADDR   (rx_msgunmap); /* for dma_unmap_single() */
	struct ib_recv_wr	 rx_wrq;       /* receive work item... */
	struct ib_sge	     rx_sge;       /* ...and its memory */
} kib_rx_t;

#define IBLND_POSTRX_DONT_POST    0	     /* don't post */
#define IBLND_POSTRX_NO_CREDIT    1	     /* post: no credits */
#define IBLND_POSTRX_PEER_CREDIT  2	     /* post: give peer back 1 credit */
#define IBLND_POSTRX_RSRVD_CREDIT 3	     /* post: give myself back 1 reserved credit */

typedef struct kib_tx			   /* transmit message */
{
	struct list_head		tx_list;      /* queue on idle_txs ibc_tx_queue etc. */
	kib_tx_pool_t	    *tx_pool;      /* pool I'm from */
	struct kib_conn	  *tx_conn;      /* owning conn */
	short		     tx_sending;   /* # tx callbacks outstanding */
	short		     tx_queued;    /* queued for sending */
	short		     tx_waiting;   /* waiting for peer */
	int		       tx_status;    /* LNET completion status */
	unsigned long	     tx_deadline;  /* completion deadline */
	__u64		     tx_cookie;    /* completion cookie */
	lnet_msg_t	       *tx_lntmsg[2]; /* lnet msgs to finalize on completion */
	kib_msg_t		*tx_msg;       /* message buffer (host vaddr) */
	__u64		     tx_msgaddr;   /* message buffer (I/O addr) */
	DECLARE_PCI_UNMAP_ADDR   (tx_msgunmap); /* for dma_unmap_single() */
	int		       tx_nwrq;      /* # send work items */
	struct ib_send_wr	*tx_wrq;       /* send work items... */
	struct ib_sge	    *tx_sge;       /* ...and their memory */
	kib_rdma_desc_t	  *tx_rd;	/* rdma descriptor */
	int		       tx_nfrags;    /* # entries in... */
	struct scatterlist       *tx_frags;     /* dma_map_sg descriptor */
	__u64		    *tx_pages;     /* rdma phys page addrs */
	union {
		kib_phys_mr_t      *pmr;	/* MR for physical buffer */
		kib_fmr_t	   fmr;	/* FMR */
	}			 tx_u;
	int		       tx_dmadir;    /* dma direction */
} kib_tx_t;

typedef struct kib_connvars
{
	/* connection-in-progress variables */
	kib_msg_t		 cv_msg;
} kib_connvars_t;

typedef struct kib_conn
{
	struct kib_sched_info *ibc_sched;	/* scheduler information */
	struct kib_peer     *ibc_peer;	  /* owning peer */
	kib_hca_dev_t       *ibc_hdev;	  /* HCA bound on */
	struct list_head	   ibc_list;	  /* stash on peer's conn list */
	struct list_head	   ibc_sched_list;    /* schedule for attention */
	__u16		ibc_version;       /* version of connection */
	__u64		ibc_incarnation;   /* which instance of the peer */
	atomic_t	 ibc_refcount;      /* # users */
	int		  ibc_state;	 /* what's happening */
	int		  ibc_nsends_posted; /* # uncompleted sends */
	int		  ibc_noops_posted;  /* # uncompleted NOOPs */
	int		  ibc_credits;       /* # credits I have */
	int		  ibc_outstanding_credits; /* # credits to return */
	int		  ibc_reserved_credits;/* # ACK/DONE msg credits */
	int		  ibc_comms_error;   /* set on comms error */
	unsigned int	     ibc_nrx:16;	/* receive buffers owned */
	unsigned int	     ibc_scheduled:1;   /* scheduled for attention */
	unsigned int	     ibc_ready:1;       /* CQ callback fired */
	/* time of last send */
	unsigned long	ibc_last_send;
	/** link chain for kiblnd_check_conns only */
	struct list_head	   ibc_connd_list;
	/** rxs completed before ESTABLISHED */
	struct list_head	   ibc_early_rxs;
	/** IBLND_MSG_NOOPs for IBLND_MSG_VERSION_1 */
	struct list_head	   ibc_tx_noops;
	struct list_head	   ibc_tx_queue;       /* sends that need a credit */
	struct list_head	   ibc_tx_queue_nocred;/* sends that don't need a credit */
	struct list_head	   ibc_tx_queue_rsrvd; /* sends that need to reserve an ACK/DONE msg */
	struct list_head	   ibc_active_txs;     /* active tx awaiting completion */
	spinlock_t	     ibc_lock;		 /* serialise */
	kib_rx_t	    *ibc_rxs;	    /* the rx descs */
	kib_pages_t	 *ibc_rx_pages;       /* premapped rx msg pages */

	struct rdma_cm_id   *ibc_cmid;	   /* CM id */
	struct ib_cq	*ibc_cq;	     /* completion queue */

	kib_connvars_t      *ibc_connvars;       /* in-progress connection state */
} kib_conn_t;

#define IBLND_CONN_INIT	       0	 /* being initialised */
#define IBLND_CONN_ACTIVE_CONNECT     1	 /* active sending req */
#define IBLND_CONN_PASSIVE_WAIT       2	 /* passive waiting for rtu */
#define IBLND_CONN_ESTABLISHED	3	 /* connection established */
#define IBLND_CONN_CLOSING	    4	 /* being closed */
#define IBLND_CONN_DISCONNECTED       5	 /* disconnected */

typedef struct kib_peer
{
	struct list_head	   ibp_list;	   /* stash on global peer list */
	lnet_nid_t	   ibp_nid;	    /* who's on the other end(s) */
	lnet_ni_t	   *ibp_ni;	     /* LNet interface */
	atomic_t	 ibp_refcount;       /* # users */
	struct list_head	   ibp_conns;	  /* all active connections */
	struct list_head	   ibp_tx_queue;       /* msgs waiting for a conn */
	__u16		ibp_version;	/* version of peer */
	__u64		ibp_incarnation;    /* incarnation of peer */
	int		  ibp_connecting;     /* current active connection attempts */
	int		  ibp_accepting;      /* current passive connection attempts */
	int		  ibp_error;	  /* errno on closing this peer */
	cfs_time_t	   ibp_last_alive;     /* when (in jiffies) I was last alive */
} kib_peer_t;

extern kib_data_t      kiblnd_data;

extern void kiblnd_hdev_destroy(kib_hca_dev_t *hdev);

static inline void
kiblnd_hdev_addref_locked(kib_hca_dev_t *hdev)
{
	LASSERT (atomic_read(&hdev->ibh_ref) > 0);
	atomic_inc(&hdev->ibh_ref);
}

static inline void
kiblnd_hdev_decref(kib_hca_dev_t *hdev)
{
	LASSERT (atomic_read(&hdev->ibh_ref) > 0);
	if (atomic_dec_and_test(&hdev->ibh_ref))
		kiblnd_hdev_destroy(hdev);
}

static inline int
kiblnd_dev_can_failover(kib_dev_t *dev)
{
	if (!list_empty(&dev->ibd_fail_list)) /* already scheduled */
		return 0;

	if (*kiblnd_tunables.kib_dev_failover == 0) /* disabled */
		return 0;

	if (*kiblnd_tunables.kib_dev_failover > 1) /* force failover */
		return 1;

	return dev->ibd_can_failover;
}

#define kiblnd_conn_addref(conn)				\
do {							    \
	CDEBUG(D_NET, "conn[%p] (%d)++\n",		      \
	       (conn), atomic_read(&(conn)->ibc_refcount)); \
	atomic_inc(&(conn)->ibc_refcount);		  \
} while (0)

#define kiblnd_conn_decref(conn)					\
do {									\
	unsigned long flags;						\
									\
	CDEBUG(D_NET, "conn[%p] (%d)--\n",				\
	       (conn), atomic_read(&(conn)->ibc_refcount));		\
	LASSERT_ATOMIC_POS(&(conn)->ibc_refcount);			\
	if (atomic_dec_and_test(&(conn)->ibc_refcount)) {		\
		spin_lock_irqsave(&kiblnd_data.kib_connd_lock, flags);	\
		list_add_tail(&(conn)->ibc_list,			\
				  &kiblnd_data.kib_connd_zombies);	\
		wake_up(&kiblnd_data.kib_connd_waitq);		\
		spin_unlock_irqrestore(&kiblnd_data.kib_connd_lock, flags);\
	}								\
} while (0)

#define kiblnd_peer_addref(peer)				\
do {							    \
	CDEBUG(D_NET, "peer[%p] -> %s (%d)++\n",		\
	       (peer), libcfs_nid2str((peer)->ibp_nid),	 \
	       atomic_read (&(peer)->ibp_refcount));	\
	atomic_inc(&(peer)->ibp_refcount);		  \
} while (0)

#define kiblnd_peer_decref(peer)				\
do {							    \
	CDEBUG(D_NET, "peer[%p] -> %s (%d)--\n",		\
	       (peer), libcfs_nid2str((peer)->ibp_nid),	 \
	       atomic_read (&(peer)->ibp_refcount));	\
	LASSERT_ATOMIC_POS(&(peer)->ibp_refcount);	      \
	if (atomic_dec_and_test(&(peer)->ibp_refcount))     \
		kiblnd_destroy_peer(peer);		      \
} while (0)

static inline struct list_head *
kiblnd_nid2peerlist (lnet_nid_t nid)
{
	unsigned int hash =
		((unsigned int)nid) % kiblnd_data.kib_peer_hash_size;

	return (&kiblnd_data.kib_peers [hash]);
}

static inline int
kiblnd_peer_active (kib_peer_t *peer)
{
	/* Am I in the peer hash table? */
	return (!list_empty(&peer->ibp_list));
}

static inline kib_conn_t *
kiblnd_get_conn_locked (kib_peer_t *peer)
{
	LASSERT (!list_empty(&peer->ibp_conns));

	/* just return the first connection */
	return list_entry(peer->ibp_conns.next, kib_conn_t, ibc_list);
}

static inline int
kiblnd_send_keepalive(kib_conn_t *conn)
{
	return (*kiblnd_tunables.kib_keepalive > 0) &&
		cfs_time_after(jiffies, conn->ibc_last_send +
			       *kiblnd_tunables.kib_keepalive*HZ);
}

static inline int
kiblnd_need_noop(kib_conn_t *conn)
{
	LASSERT (conn->ibc_state >= IBLND_CONN_ESTABLISHED);

	if (conn->ibc_outstanding_credits <
	    IBLND_CREDITS_HIGHWATER(conn->ibc_version) &&
	    !kiblnd_send_keepalive(conn))
		return 0; /* No need to send NOOP */

	if (IBLND_OOB_CAPABLE(conn->ibc_version)) {
		if (!list_empty(&conn->ibc_tx_queue_nocred))
			return 0; /* NOOP can be piggybacked */

		/* No tx to piggyback NOOP onto or no credit to send a tx */
		return (list_empty(&conn->ibc_tx_queue) ||
			conn->ibc_credits == 0);
	}

	if (!list_empty(&conn->ibc_tx_noops) || /* NOOP already queued */
	    !list_empty(&conn->ibc_tx_queue_nocred) || /* piggyback NOOP */
	    conn->ibc_credits == 0)		    /* no credit */
		return 0;

	if (conn->ibc_credits == 1 &&      /* last credit reserved for */
	    conn->ibc_outstanding_credits == 0) /* giving back credits */
		return 0;

	/* No tx to piggyback NOOP onto or no credit to send a tx */
	return (list_empty(&conn->ibc_tx_queue) || conn->ibc_credits == 1);
}

static inline void
kiblnd_abort_receives(kib_conn_t *conn)
{
	ib_modify_qp(conn->ibc_cmid->qp,
		     &kiblnd_data.kib_error_qpa, IB_QP_STATE);
}

static inline const char *
kiblnd_queue2str (kib_conn_t *conn, struct list_head *q)
{
	if (q == &conn->ibc_tx_queue)
		return "tx_queue";

	if (q == &conn->ibc_tx_queue_rsrvd)
		return "tx_queue_rsrvd";

	if (q == &conn->ibc_tx_queue_nocred)
		return "tx_queue_nocred";

	if (q == &conn->ibc_active_txs)
		return "active_txs";

	LBUG();
	return NULL;
}

/* CAVEAT EMPTOR: We rely on descriptor alignment to allow us to use the
 * lowest bits of the work request id to stash the work item type. */

#define IBLND_WID_TX    0
#define IBLND_WID_RDMA  1
#define IBLND_WID_RX    2
#define IBLND_WID_MASK  3UL

static inline __u64
kiblnd_ptr2wreqid (void *ptr, int type)
{
	unsigned long lptr = (unsigned long)ptr;

	LASSERT ((lptr & IBLND_WID_MASK) == 0);
	LASSERT ((type & ~IBLND_WID_MASK) == 0);
	return (__u64)(lptr | type);
}

static inline void *
kiblnd_wreqid2ptr (__u64 wreqid)
{
	return (void *)(((unsigned long)wreqid) & ~IBLND_WID_MASK);
}

static inline int
kiblnd_wreqid2type (__u64 wreqid)
{
	return (wreqid & IBLND_WID_MASK);
}

static inline void
kiblnd_set_conn_state (kib_conn_t *conn, int state)
{
	conn->ibc_state = state;
	mb();
}

static inline void
kiblnd_init_msg (kib_msg_t *msg, int type, int body_nob)
{
	msg->ibm_type = type;
	msg->ibm_nob  = offsetof(kib_msg_t, ibm_u) + body_nob;
}

static inline int
kiblnd_rd_size (kib_rdma_desc_t *rd)
{
	int   i;
	int   size;

	for (i = size = 0; i < rd->rd_nfrags; i++)
		size += rd->rd_frags[i].rf_nob;

	return size;
}

static inline __u64
kiblnd_rd_frag_addr(kib_rdma_desc_t *rd, int index)
{
	return rd->rd_frags[index].rf_addr;
}

static inline __u32
kiblnd_rd_frag_size(kib_rdma_desc_t *rd, int index)
{
	return rd->rd_frags[index].rf_nob;
}

static inline __u32
kiblnd_rd_frag_key(kib_rdma_desc_t *rd, int index)
{
	return rd->rd_key;
}

static inline int
kiblnd_rd_consume_frag(kib_rdma_desc_t *rd, int index, __u32 nob)
{
	if (nob < rd->rd_frags[index].rf_nob) {
		rd->rd_frags[index].rf_addr += nob;
		rd->rd_frags[index].rf_nob  -= nob;
	} else {
		index ++;
	}

	return index;
}

static inline int
kiblnd_rd_msg_size(kib_rdma_desc_t *rd, int msgtype, int n)
{
	LASSERT (msgtype == IBLND_MSG_GET_REQ ||
		 msgtype == IBLND_MSG_PUT_ACK);

	return msgtype == IBLND_MSG_GET_REQ ?
	       offsetof(kib_get_msg_t, ibgm_rd.rd_frags[n]) :
	       offsetof(kib_putack_msg_t, ibpam_rd.rd_frags[n]);
}


static inline __u64
kiblnd_dma_mapping_error(struct ib_device *dev, u64 dma_addr)
{
	return ib_dma_mapping_error(dev, dma_addr);
}

static inline __u64 kiblnd_dma_map_single(struct ib_device *dev,
					  void *msg, size_t size,
					  enum dma_data_direction direction)
{
	return ib_dma_map_single(dev, msg, size, direction);
}

static inline void kiblnd_dma_unmap_single(struct ib_device *dev,
					   __u64 addr, size_t size,
					  enum dma_data_direction direction)
{
	ib_dma_unmap_single(dev, addr, size, direction);
}

#define KIBLND_UNMAP_ADDR_SET(p, m, a)  do {} while (0)
#define KIBLND_UNMAP_ADDR(p, m, a)      (a)

static inline int kiblnd_dma_map_sg(struct ib_device *dev,
				    struct scatterlist *sg, int nents,
				    enum dma_data_direction direction)
{
	return ib_dma_map_sg(dev, sg, nents, direction);
}

static inline void kiblnd_dma_unmap_sg(struct ib_device *dev,
				       struct scatterlist *sg, int nents,
				       enum dma_data_direction direction)
{
	ib_dma_unmap_sg(dev, sg, nents, direction);
}

static inline __u64 kiblnd_sg_dma_address(struct ib_device *dev,
					  struct scatterlist *sg)
{
	return ib_sg_dma_address(dev, sg);
}

static inline unsigned int kiblnd_sg_dma_len(struct ib_device *dev,
					     struct scatterlist *sg)
{
	return ib_sg_dma_len(dev, sg);
}

/* XXX We use KIBLND_CONN_PARAM(e) as writable buffer, it's not strictly
 * right because OFED1.2 defines it as const, to use it we have to add
 * (void *) cast to overcome "const" */

#define KIBLND_CONN_PARAM(e)	    ((e)->param.conn.private_data)
#define KIBLND_CONN_PARAM_LEN(e)	((e)->param.conn.private_data_len)


struct ib_mr *kiblnd_find_rd_dma_mr(kib_hca_dev_t *hdev,
				    kib_rdma_desc_t *rd);
struct ib_mr *kiblnd_find_dma_mr(kib_hca_dev_t *hdev,
				 __u64 addr, __u64 size);
void kiblnd_map_rx_descs(kib_conn_t *conn);
void kiblnd_unmap_rx_descs(kib_conn_t *conn);
int kiblnd_map_tx(lnet_ni_t *ni, kib_tx_t *tx,
		  kib_rdma_desc_t *rd, int nfrags);
void kiblnd_unmap_tx(lnet_ni_t *ni, kib_tx_t *tx);
void kiblnd_pool_free_node(kib_pool_t *pool, struct list_head *node);
struct list_head *kiblnd_pool_alloc_node(kib_poolset_t *ps);

int  kiblnd_fmr_pool_map(kib_fmr_poolset_t *fps, __u64 *pages,
			 int npages, __u64 iov, kib_fmr_t *fmr);
void kiblnd_fmr_pool_unmap(kib_fmr_t *fmr, int status);

int  kiblnd_pmr_pool_map(kib_pmr_poolset_t *pps, kib_hca_dev_t *hdev,
			 kib_rdma_desc_t *rd, __u64 *iova, kib_phys_mr_t **pp_pmr);
void kiblnd_pmr_pool_unmap(kib_phys_mr_t *pmr);

int  kiblnd_startup (lnet_ni_t *ni);
void kiblnd_shutdown (lnet_ni_t *ni);
int  kiblnd_ctl (lnet_ni_t *ni, unsigned int cmd, void *arg);
void kiblnd_query (struct lnet_ni *ni, lnet_nid_t nid, cfs_time_t *when);

int  kiblnd_tunables_init(void);
void kiblnd_tunables_fini(void);

int  kiblnd_connd (void *arg);
int  kiblnd_scheduler(void *arg);
int  kiblnd_thread_start(int (*fn)(void *arg), void *arg, char *name);
int  kiblnd_failover_thread (void *arg);

int  kiblnd_alloc_pages(kib_pages_t **pp, int cpt, int npages);
void kiblnd_free_pages (kib_pages_t *p);

int  kiblnd_cm_callback(struct rdma_cm_id *cmid,
			struct rdma_cm_event *event);
int  kiblnd_translate_mtu(int value);

int  kiblnd_dev_failover(kib_dev_t *dev);
int  kiblnd_create_peer (lnet_ni_t *ni, kib_peer_t **peerp, lnet_nid_t nid);
void kiblnd_destroy_peer (kib_peer_t *peer);
void kiblnd_destroy_dev (kib_dev_t *dev);
void kiblnd_unlink_peer_locked (kib_peer_t *peer);
void kiblnd_peer_alive (kib_peer_t *peer);
kib_peer_t *kiblnd_find_peer_locked (lnet_nid_t nid);
void kiblnd_peer_connect_failed (kib_peer_t *peer, int active, int error);
int  kiblnd_close_stale_conns_locked (kib_peer_t *peer,
				      int version, __u64 incarnation);
int  kiblnd_close_peer_conns_locked (kib_peer_t *peer, int why);

void kiblnd_connreq_done(kib_conn_t *conn, int status);
kib_conn_t *kiblnd_create_conn (kib_peer_t *peer, struct rdma_cm_id *cmid,
				int state, int version);
void kiblnd_destroy_conn (kib_conn_t *conn);
void kiblnd_close_conn (kib_conn_t *conn, int error);
void kiblnd_close_conn_locked (kib_conn_t *conn, int error);

int  kiblnd_init_rdma (kib_conn_t *conn, kib_tx_t *tx, int type,
		       int nob, kib_rdma_desc_t *dstrd, __u64 dstcookie);

void kiblnd_launch_tx (lnet_ni_t *ni, kib_tx_t *tx, lnet_nid_t nid);
void kiblnd_queue_tx_locked (kib_tx_t *tx, kib_conn_t *conn);
void kiblnd_queue_tx (kib_tx_t *tx, kib_conn_t *conn);
void kiblnd_init_tx_msg (lnet_ni_t *ni, kib_tx_t *tx, int type, int body_nob);
void kiblnd_txlist_done (lnet_ni_t *ni, struct list_head *txlist,
			 int status);
void kiblnd_check_sends (kib_conn_t *conn);

void kiblnd_qp_event(struct ib_event *event, void *arg);
void kiblnd_cq_event(struct ib_event *event, void *arg);
void kiblnd_cq_completion(struct ib_cq *cq, void *arg);

void kiblnd_pack_msg (lnet_ni_t *ni, kib_msg_t *msg, int version,
		      int credits, lnet_nid_t dstnid, __u64 dststamp);
int  kiblnd_unpack_msg(kib_msg_t *msg, int nob);
int  kiblnd_post_rx (kib_rx_t *rx, int credit);

int  kiblnd_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg);
int  kiblnd_recv(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg, int delayed,
		 unsigned int niov, struct iovec *iov, lnet_kiov_t *kiov,
		 unsigned int offset, unsigned int mlen, unsigned int rlen);