xref: /linux/include/linux/sunrpc/svc_rdma.h (revision e2be04c7f9958dde770eeb8b30e829ca969b37bb)
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 /* Default and maximum inline threshold sizes */
52 enum {
53 	RPCRDMA_DEF_INLINE_THRESH = 4096,
54 	RPCRDMA_MAX_INLINE_THRESH = 65536
55 };
56 
57 /* RPC/RDMA parameters and stats */
58 extern unsigned int svcrdma_ord;
59 extern unsigned int svcrdma_max_requests;
60 extern unsigned int svcrdma_max_bc_requests;
61 extern unsigned int svcrdma_max_req_size;
62 
63 extern atomic_t rdma_stat_recv;
64 extern atomic_t rdma_stat_read;
65 extern atomic_t rdma_stat_write;
66 extern atomic_t rdma_stat_sq_starve;
67 extern atomic_t rdma_stat_rq_starve;
68 extern atomic_t rdma_stat_rq_poll;
69 extern atomic_t rdma_stat_rq_prod;
70 extern atomic_t rdma_stat_sq_poll;
71 extern atomic_t rdma_stat_sq_prod;
72 
73 /*
74  * Contexts are built when an RDMA request is created and are a
75  * record of the resources that can be recovered when the request
76  * completes.
77  */
78 struct svc_rdma_op_ctxt {
79 	struct list_head list;
80 	struct xdr_buf arg;
81 	struct ib_cqe cqe;
82 	u32 byte_len;
83 	struct svcxprt_rdma *xprt;
84 	enum dma_data_direction direction;
85 	int count;
86 	unsigned int mapped_sges;
87 	int hdr_count;
88 	struct ib_send_wr send_wr;
89 	struct ib_sge sge[1 + RPCRDMA_MAX_INLINE_THRESH / PAGE_SIZE];
90 	struct page *pages[RPCSVC_MAXPAGES];
91 };
92 
93 struct svcxprt_rdma {
94 	struct svc_xprt      sc_xprt;		/* SVC transport structure */
95 	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
96 	struct list_head     sc_accept_q;	/* Conn. waiting accept */
97 	int		     sc_ord;		/* RDMA read limit */
98 	int                  sc_max_sge;
99 	bool		     sc_snd_w_inv;	/* OK to use Send With Invalidate */
100 
101 	atomic_t             sc_sq_avail;	/* SQEs ready to be consumed */
102 	unsigned int	     sc_sq_depth;	/* Depth of SQ */
103 	unsigned int	     sc_rq_depth;	/* Depth of RQ */
104 	__be32		     sc_fc_credits;	/* Forward credits */
105 	u32		     sc_max_requests;	/* Max requests */
106 	u32		     sc_max_bc_requests;/* Backward credits */
107 	int                  sc_max_req_size;	/* Size of each RQ WR buf */
108 	u8		     sc_port_num;
109 
110 	struct ib_pd         *sc_pd;
111 
112 	spinlock_t	     sc_ctxt_lock;
113 	struct list_head     sc_ctxts;
114 	int		     sc_ctxt_used;
115 	spinlock_t	     sc_rw_ctxt_lock;
116 	struct list_head     sc_rw_ctxts;
117 
118 	struct list_head     sc_rq_dto_q;
119 	spinlock_t	     sc_rq_dto_lock;
120 	struct ib_qp         *sc_qp;
121 	struct ib_cq         *sc_rq_cq;
122 	struct ib_cq         *sc_sq_cq;
123 
124 	spinlock_t	     sc_lock;		/* transport lock */
125 
126 	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
127 	unsigned long	     sc_flags;
128 	struct list_head     sc_read_complete_q;
129 	struct work_struct   sc_work;
130 };
131 /* sc_flags */
132 #define RDMAXPRT_CONN_PENDING	3
133 
134 #define RPCRDMA_LISTEN_BACKLOG  10
135 /* The default ORD value is based on two outstanding full-size writes with a
136  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
137 #define RPCRDMA_ORD             (64/4)
138 #define RPCRDMA_MAX_REQUESTS    32
139 
140 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
141  * current NFSv4.1 implementation supports one backchannel slot.
142  */
143 #define RPCRDMA_MAX_BC_REQUESTS	2
144 
145 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
146 
147 /* Track DMA maps for this transport and context */
148 static inline void svc_rdma_count_mappings(struct svcxprt_rdma *rdma,
149 					   struct svc_rdma_op_ctxt *ctxt)
150 {
151 	ctxt->mapped_sges++;
152 }
153 
154 /* svc_rdma_backchannel.c */
155 extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
156 				    __be32 *rdma_resp,
157 				    struct xdr_buf *rcvbuf);
158 
159 /* svc_rdma_recvfrom.c */
160 extern int svc_rdma_recvfrom(struct svc_rqst *);
161 
162 /* svc_rdma_rw.c */
163 extern void svc_rdma_destroy_rw_ctxts(struct svcxprt_rdma *rdma);
164 extern int svc_rdma_recv_read_chunk(struct svcxprt_rdma *rdma,
165 				    struct svc_rqst *rqstp,
166 				    struct svc_rdma_op_ctxt *head, __be32 *p);
167 extern int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma,
168 				     __be32 *wr_ch, struct xdr_buf *xdr);
169 extern int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma,
170 				     __be32 *rp_ch, bool writelist,
171 				     struct xdr_buf *xdr);
172 
173 /* svc_rdma_sendto.c */
174 extern int svc_rdma_map_reply_hdr(struct svcxprt_rdma *rdma,
175 				  struct svc_rdma_op_ctxt *ctxt,
176 				  __be32 *rdma_resp, unsigned int len);
177 extern int svc_rdma_post_send_wr(struct svcxprt_rdma *rdma,
178 				 struct svc_rdma_op_ctxt *ctxt,
179 				 int num_sge, u32 inv_rkey);
180 extern int svc_rdma_sendto(struct svc_rqst *);
181 
182 /* svc_rdma_transport.c */
183 extern void svc_rdma_wc_send(struct ib_cq *, struct ib_wc *);
184 extern void svc_rdma_wc_reg(struct ib_cq *, struct ib_wc *);
185 extern void svc_rdma_wc_read(struct ib_cq *, struct ib_wc *);
186 extern void svc_rdma_wc_inv(struct ib_cq *, struct ib_wc *);
187 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
188 extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t);
189 extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t);
190 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
191 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
192 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
193 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
194 extern void svc_sq_reap(struct svcxprt_rdma *);
195 extern void svc_rq_reap(struct svcxprt_rdma *);
196 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
197 
198 extern struct svc_xprt_class svc_rdma_class;
199 #ifdef CONFIG_SUNRPC_BACKCHANNEL
200 extern struct svc_xprt_class svc_rdma_bc_class;
201 #endif
202 
203 /* svc_rdma.c */
204 extern struct workqueue_struct *svc_rdma_wq;
205 extern int svc_rdma_init(void);
206 extern void svc_rdma_cleanup(void);
207 
208 #endif
209