1 /*
2  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the BSD-type
8  * license below:
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  *      Redistributions of source code must retain the above copyright
15  *      notice, this list of conditions and the following disclaimer.
16  *
17  *      Redistributions in binary form must reproduce the above
18  *      copyright notice, this list of conditions and the following
19  *      disclaimer in the documentation and/or other materials provided
20  *      with the distribution.
21  *
22  *      Neither the name of the Network Appliance, Inc. nor the names of
23  *      its contributors may be used to endorse or promote products
24  *      derived from this software without specific prior written
25  *      permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  *
39  * Author: Tom Tucker <tom@opengridcomputing.com>
40  */
41 
42 #ifndef SVC_RDMA_H
43 #define SVC_RDMA_H
44 #include <linux/sunrpc/xdr.h>
45 #include <linux/sunrpc/svcsock.h>
46 #include <linux/sunrpc/rpc_rdma.h>
47 #include <rdma/ib_verbs.h>
48 #include <rdma/rdma_cm.h>
49 #define SVCRDMA_DEBUG
50 
51 /* RPC/RDMA parameters and stats */
52 extern unsigned int svcrdma_ord;
53 extern unsigned int svcrdma_max_requests;
54 extern unsigned int svcrdma_max_req_size;
55 
56 extern atomic_t rdma_stat_recv;
57 extern atomic_t rdma_stat_read;
58 extern atomic_t rdma_stat_write;
59 extern atomic_t rdma_stat_sq_starve;
60 extern atomic_t rdma_stat_rq_starve;
61 extern atomic_t rdma_stat_rq_poll;
62 extern atomic_t rdma_stat_rq_prod;
63 extern atomic_t rdma_stat_sq_poll;
64 extern atomic_t rdma_stat_sq_prod;
65 
66 /*
67  * Contexts are built when an RDMA request is created and are a
68  * record of the resources that can be recovered when the request
69  * completes.
70  */
71 struct svc_rdma_op_ctxt {
72 	struct svc_rdma_op_ctxt *read_hdr;
73 	struct svc_rdma_fastreg_mr *frmr;
74 	int hdr_count;
75 	struct xdr_buf arg;
76 	struct list_head dto_q;
77 	enum ib_wr_opcode wr_op;
78 	enum ib_wc_status wc_status;
79 	u32 byte_len;
80 	u32 position;
81 	struct svcxprt_rdma *xprt;
82 	unsigned long flags;
83 	enum dma_data_direction direction;
84 	int count;
85 	struct ib_sge sge[RPCSVC_MAXPAGES];
86 	struct page *pages[RPCSVC_MAXPAGES];
87 };
88 
89 /*
90  * NFS_ requests are mapped on the client side by the chunk lists in
91  * the RPCRDMA header. During the fetching of the RPC from the client
92  * and the writing of the reply to the client, the memory in the
93  * client and the memory in the server must be mapped as contiguous
94  * vaddr/len for access by the hardware. These data strucures keep
95  * these mappings.
96  *
97  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
98  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
99  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
100  * mapping of the reply.
101  */
102 struct svc_rdma_chunk_sge {
103 	int start;		/* sge no for this chunk */
104 	int count;		/* sge count for this chunk */
105 };
106 struct svc_rdma_fastreg_mr {
107 	struct ib_mr *mr;
108 	struct scatterlist *sg;
109 	int sg_nents;
110 	unsigned long access_flags;
111 	enum dma_data_direction direction;
112 	struct list_head frmr_list;
113 };
114 struct svc_rdma_req_map {
115 	unsigned long count;
116 	union {
117 		struct kvec sge[RPCSVC_MAXPAGES];
118 		struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
119 		unsigned long lkey[RPCSVC_MAXPAGES];
120 	};
121 };
122 #define RDMACTXT_F_LAST_CTXT	2
123 
124 #define	SVCRDMA_DEVCAP_FAST_REG		1	/* fast mr registration */
125 #define	SVCRDMA_DEVCAP_READ_W_INV	2	/* read w/ invalidate */
126 
127 struct svcxprt_rdma {
128 	struct svc_xprt      sc_xprt;		/* SVC transport structure */
129 	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
130 	struct list_head     sc_accept_q;	/* Conn. waiting accept */
131 	int		     sc_ord;		/* RDMA read limit */
132 	int                  sc_max_sge;
133 	int                  sc_max_sge_rd;	/* max sge for read target */
134 
135 	int                  sc_sq_depth;	/* Depth of SQ */
136 	atomic_t             sc_sq_count;	/* Number of SQ WR on queue */
137 
138 	int                  sc_max_requests;	/* Depth of RQ */
139 	int                  sc_max_req_size;	/* Size of each RQ WR buf */
140 
141 	struct ib_pd         *sc_pd;
142 
143 	atomic_t	     sc_dma_used;
144 	atomic_t	     sc_ctxt_used;
145 	struct list_head     sc_rq_dto_q;
146 	spinlock_t	     sc_rq_dto_lock;
147 	struct ib_qp         *sc_qp;
148 	struct ib_cq         *sc_rq_cq;
149 	struct ib_cq         *sc_sq_cq;
150 	struct ib_mr         *sc_phys_mr;	/* MR for server memory */
151 	int		     (*sc_reader)(struct svcxprt_rdma *,
152 					  struct svc_rqst *,
153 					  struct svc_rdma_op_ctxt *,
154 					  int *, u32 *, u32, u32, u64, bool);
155 	u32		     sc_dev_caps;	/* distilled device caps */
156 	u32		     sc_dma_lkey;	/* local dma key */
157 	unsigned int	     sc_frmr_pg_list_len;
158 	struct list_head     sc_frmr_q;
159 	spinlock_t	     sc_frmr_q_lock;
160 
161 	spinlock_t	     sc_lock;		/* transport lock */
162 
163 	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
164 	unsigned long	     sc_flags;
165 	struct list_head     sc_dto_q;		/* DTO tasklet I/O pending Q */
166 	struct list_head     sc_read_complete_q;
167 	struct work_struct   sc_work;
168 };
169 /* sc_flags */
170 #define RDMAXPRT_RQ_PENDING	1
171 #define RDMAXPRT_SQ_PENDING	2
172 #define RDMAXPRT_CONN_PENDING	3
173 
174 #define RPCRDMA_LISTEN_BACKLOG  10
175 /* The default ORD value is based on two outstanding full-size writes with a
176  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
177 #define RPCRDMA_ORD             (64/4)
178 #define RPCRDMA_SQ_DEPTH_MULT   8
179 #define RPCRDMA_MAX_REQUESTS    32
180 #define RPCRDMA_MAX_REQ_SIZE    4096
181 
182 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
183 
184 /* svc_rdma_marshal.c */
185 extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
186 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
187 				     struct rpcrdma_msg *,
188 				     enum rpcrdma_errcode, __be32 *);
189 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
190 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
191 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
192 					    __be32, __be64, u32);
193 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
194 					     struct rpcrdma_msg *,
195 					     struct rpcrdma_msg *,
196 					     enum rpcrdma_proc);
197 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
198 
199 /* svc_rdma_recvfrom.c */
200 extern int svc_rdma_recvfrom(struct svc_rqst *);
201 extern int rdma_read_chunk_lcl(struct svcxprt_rdma *, struct svc_rqst *,
202 			       struct svc_rdma_op_ctxt *, int *, u32 *,
203 			       u32, u32, u64, bool);
204 extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *,
205 				struct svc_rdma_op_ctxt *, int *, u32 *,
206 				u32, u32, u64, bool);
207 
208 /* svc_rdma_sendto.c */
209 extern int svc_rdma_sendto(struct svc_rqst *);
210 extern struct rpcrdma_read_chunk *
211 	svc_rdma_get_read_chunk(struct rpcrdma_msg *);
212 
213 /* svc_rdma_transport.c */
214 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
215 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
216 				enum rpcrdma_errcode);
217 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
218 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
219 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
220 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
221 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
222 extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
223 extern void svc_rdma_put_req_map(struct svc_rdma_req_map *);
224 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
225 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
226 			      struct svc_rdma_fastreg_mr *);
227 extern void svc_sq_reap(struct svcxprt_rdma *);
228 extern void svc_rq_reap(struct svcxprt_rdma *);
229 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
230 
231 extern struct svc_xprt_class svc_rdma_class;
232 #ifdef CONFIG_SUNRPC_BACKCHANNEL
233 extern struct svc_xprt_class svc_rdma_bc_class;
234 #endif
235 
236 /* svc_rdma.c */
237 extern int svc_rdma_init(void);
238 extern void svc_rdma_cleanup(void);
239 
240 #endif
241