rdma: SVCRMDA Header File

/*

 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.

 *

 * This software is available to you under a choice of one of two

 * licenses.  You may choose to be licensed under the terms of the GNU

 * General Public License (GPL) Version 2, available from the file

 * COPYING in the main directory of this source tree, or the BSD-type

 * license below:

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *      Redistributions of source code must retain the above copyright

 *      notice, this list of conditions and the following disclaimer.

 *

 *      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.

 *

 *      Neither the name of the Network Appliance, Inc. nor the names of

 *      its contributors may be used to endorse or promote products

 *      derived from this software without specific prior written

 *      permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "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 COPYRIGHT

 * OWNER OR CONTRIBUTORS 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.

 *

 * Author: Tom Tucker <tom@opengridcomputing.com>

 */

#ifndef SVC_RDMA_H

#define SVC_RDMA_H

#include <linux/sunrpc/xdr.h>

#include <linux/sunrpc/svcsock.h>

#include <linux/sunrpc/rpc_rdma.h>

#include <rdma/ib_verbs.h>

#include <rdma/rdma_cm.h>

#define SVCRDMA_DEBUG

/* RPC/RDMA parameters and stats */

extern unsigned int svcrdma_ord;

extern unsigned int svcrdma_max_requests;

extern unsigned int svcrdma_max_req_size;

extern atomic_t rdma_stat_recv;

extern atomic_t rdma_stat_read;

extern atomic_t rdma_stat_write;

extern atomic_t rdma_stat_sq_starve;

extern atomic_t rdma_stat_rq_starve;

extern atomic_t rdma_stat_rq_poll;

extern atomic_t rdma_stat_rq_prod;

extern atomic_t rdma_stat_sq_poll;

extern atomic_t rdma_stat_sq_prod;

#define RPCRDMA_VERSION 1

/*

 * Contexts are built when an RDMA request is created and are a

 * record of the resources that can be recovered when the request

 * completes.

 */

struct svc_rdma_op_ctxt {

	struct svc_rdma_op_ctxt *next;

	struct xdr_buf arg;

	struct list_head dto_q;

	enum ib_wr_opcode wr_op;

	enum ib_wc_status wc_status;

	u32 byte_len;

	struct svcxprt_rdma *xprt;

	unsigned long flags;

	enum dma_data_direction direction;

	int count;

	struct ib_sge sge[RPCSVC_MAXPAGES];

	struct page *pages[RPCSVC_MAXPAGES];

};

#define RDMACTXT_F_READ_DONE	1

#define RDMACTXT_F_LAST_CTXT	2

struct svcxprt_rdma {

	struct svc_xprt      sc_xprt;		/* SVC transport structure */

	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */

	struct list_head     sc_accept_q;	/* Conn. waiting accept */

	int		     sc_ord;		/* RDMA read limit */

	wait_queue_head_t    sc_read_wait;

	int                  sc_max_sge;

	int                  sc_sq_depth;	/* Depth of SQ */

	atomic_t             sc_sq_count;	/* Number of SQ WR on queue */

	int                  sc_max_requests;	/* Depth of RQ */

	int                  sc_max_req_size;	/* Size of each RQ WR buf */

	struct ib_pd         *sc_pd;

	struct svc_rdma_op_ctxt  *sc_ctxt_head;

	int		     sc_ctxt_cnt;

	int		     sc_ctxt_bump;

	int		     sc_ctxt_max;

	spinlock_t	     sc_ctxt_lock;

	struct list_head     sc_rq_dto_q;

	spinlock_t	     sc_rq_dto_lock;

	struct ib_qp         *sc_qp;

	struct ib_cq         *sc_rq_cq;

	struct ib_cq         *sc_sq_cq;

	struct ib_mr         *sc_phys_mr;	/* MR for server memory */

	spinlock_t	     sc_lock;		/* transport lock */

	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */

	unsigned long	     sc_flags;

	struct list_head     sc_dto_q;		/* DTO tasklet I/O pending Q */

	struct list_head     sc_read_complete_q;

	spinlock_t           sc_read_complete_lock;

};

/* sc_flags */

#define RDMAXPRT_RQ_PENDING	1

#define RDMAXPRT_SQ_PENDING	2

#define RDMAXPRT_CONN_PENDING	3

#define RPCRDMA_LISTEN_BACKLOG  10

/* The default ORD value is based on two outstanding full-size writes with a

 * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */

#define RPCRDMA_ORD             (64/4)

#define RPCRDMA_SQ_DEPTH_MULT   8

#define RPCRDMA_MAX_THREADS     16

#define RPCRDMA_MAX_REQUESTS    16

#define RPCRDMA_MAX_REQ_SIZE    4096

/* svc_rdma_marshal.c */

extern void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *,

				      int *, int *);

extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);

extern int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *);

extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,

				     struct rpcrdma_msg *,

				     enum rpcrdma_errcode, u32 *);

extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);

extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);

extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,

					    u32, u64, u32);

extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,

					     struct rpcrdma_msg *,

					     struct rpcrdma_msg *,

					     enum rpcrdma_proc);

extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);

/* svc_rdma_recvfrom.c */

extern int svc_rdma_recvfrom(struct svc_rqst *);

/* svc_rdma_sendto.c */

extern int svc_rdma_sendto(struct svc_rqst *);

/* svc_rdma_transport.c */

extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);

extern int svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,

			       enum rpcrdma_errcode);

struct page *svc_rdma_get_page(void);

extern int svc_rdma_post_recv(struct svcxprt_rdma *);

extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);

extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);

extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);

extern void svc_sq_reap(struct svcxprt_rdma *);

extern void svc_rq_reap(struct svcxprt_rdma *);

extern struct svc_xprt_class svc_rdma_class;

extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);

/* svc_rdma.c */

extern int svc_rdma_init(void);

extern void svc_rdma_cleanup(void);

/*

 * Returns the address of the first read chunk or <nul> if no read chunk is

 * present

 */

static inline struct rpcrdma_read_chunk *

svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)

{

	struct rpcrdma_read_chunk *ch =

		(struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];

	if (ch->rc_discrim == 0)

		return NULL;

	return ch;

}

/*

 * Returns the address of the first read write array element or <nul> if no

 * write array list is present

 */

static inline struct rpcrdma_write_array *

svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)

{

	if (rmsgp->rm_body.rm_chunks[0] != 0

	    || rmsgp->rm_body.rm_chunks[1] == 0)

		return NULL;

	return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];

}

/*

 * Returns the address of the first reply array element or <nul> if no

 * reply array is present

 */

static inline struct rpcrdma_write_array *

svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)

{

	struct rpcrdma_read_chunk *rch;

	struct rpcrdma_write_array *wr_ary;

	struct rpcrdma_write_array *rp_ary;

	/* XXX: Need to fix when reply list may occur with read-list and/or

	 * write list */

	if (rmsgp->rm_body.rm_chunks[0] != 0 ||

	    rmsgp->rm_body.rm_chunks[1] != 0)

		return NULL;

	rch = svc_rdma_get_read_chunk(rmsgp);

	if (rch) {

		while (rch->rc_discrim)

			rch++;

		/* The reply list follows an empty write array located

		 * at 'rc_position' here. The reply array is at rc_target.

		 */

		rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;

		goto found_it;

	}

	wr_ary = svc_rdma_get_write_array(rmsgp);

	if (wr_ary) {

		rp_ary = (struct rpcrdma_write_array *)

			&wr_ary->

			wc_array[wr_ary->wc_nchunks].wc_target.rs_length;

		goto found_it;

	}

	/* No read list, no write list */

	rp_ary = (struct rpcrdma_write_array *)

		&rmsgp->rm_body.rm_chunks[2];

 found_it:

	if (rp_ary->wc_discrim == 0)

		return NULL;

	return rp_ary;

}

#endif