xref: /linux-6.15/include/linux/sunrpc/svc_rdma.h (revision 564f7dfd)
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 <[email protected]>
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_bc_requests;
55 extern unsigned int svcrdma_max_req_size;
56 
57 extern atomic_t rdma_stat_recv;
58 extern atomic_t rdma_stat_read;
59 extern atomic_t rdma_stat_write;
60 extern atomic_t rdma_stat_sq_starve;
61 extern atomic_t rdma_stat_rq_starve;
62 extern atomic_t rdma_stat_rq_poll;
63 extern atomic_t rdma_stat_rq_prod;
64 extern atomic_t rdma_stat_sq_poll;
65 extern atomic_t rdma_stat_sq_prod;
66 
67 /*
68  * Contexts are built when an RDMA request is created and are a
69  * record of the resources that can be recovered when the request
70  * completes.
71  */
72 struct svc_rdma_op_ctxt {
73 	struct list_head list;
74 	struct svc_rdma_op_ctxt *read_hdr;
75 	struct svc_rdma_fastreg_mr *frmr;
76 	int hdr_count;
77 	struct xdr_buf arg;
78 	struct ib_cqe cqe;
79 	struct ib_cqe reg_cqe;
80 	struct ib_cqe inv_cqe;
81 	u32 byte_len;
82 	u32 position;
83 	struct svcxprt_rdma *xprt;
84 	unsigned long flags;
85 	enum dma_data_direction direction;
86 	int count;
87 	unsigned int mapped_sges;
88 	struct ib_sge sge[RPCSVC_MAXPAGES];
89 	struct page *pages[RPCSVC_MAXPAGES];
90 };
91 
92 /*
93  * NFS_ requests are mapped on the client side by the chunk lists in
94  * the RPCRDMA header. During the fetching of the RPC from the client
95  * and the writing of the reply to the client, the memory in the
96  * client and the memory in the server must be mapped as contiguous
97  * vaddr/len for access by the hardware. These data strucures keep
98  * these mappings.
99  *
100  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
101  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
102  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
103  * mapping of the reply.
104  */
105 struct svc_rdma_chunk_sge {
106 	int start;		/* sge no for this chunk */
107 	int count;		/* sge count for this chunk */
108 };
109 struct svc_rdma_fastreg_mr {
110 	struct ib_mr *mr;
111 	struct scatterlist *sg;
112 	int sg_nents;
113 	unsigned long access_flags;
114 	enum dma_data_direction direction;
115 	struct list_head frmr_list;
116 };
117 struct svc_rdma_req_map {
118 	struct list_head free;
119 	unsigned long count;
120 	union {
121 		struct kvec sge[RPCSVC_MAXPAGES];
122 		struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
123 		unsigned long lkey[RPCSVC_MAXPAGES];
124 	};
125 };
126 #define RDMACTXT_F_LAST_CTXT	2
127 
128 #define	SVCRDMA_DEVCAP_FAST_REG		1	/* fast mr registration */
129 #define	SVCRDMA_DEVCAP_READ_W_INV	2	/* read w/ invalidate */
130 
131 struct svcxprt_rdma {
132 	struct svc_xprt      sc_xprt;		/* SVC transport structure */
133 	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
134 	struct list_head     sc_accept_q;	/* Conn. waiting accept */
135 	int		     sc_ord;		/* RDMA read limit */
136 	int                  sc_max_sge;
137 	int                  sc_max_sge_rd;	/* max sge for read target */
138 	bool		     sc_snd_w_inv;	/* OK to use Send With Invalidate */
139 
140 	atomic_t             sc_sq_avail;	/* SQEs ready to be consumed */
141 	unsigned int	     sc_sq_depth;	/* Depth of SQ */
142 	unsigned int	     sc_rq_depth;	/* Depth of RQ */
143 	__be32		     sc_fc_credits;	/* Forward credits */
144 	u32		     sc_max_requests;	/* Max requests */
145 	u32		     sc_max_bc_requests;/* Backward credits */
146 	int                  sc_max_req_size;	/* Size of each RQ WR buf */
147 
148 	struct ib_pd         *sc_pd;
149 
150 	spinlock_t	     sc_ctxt_lock;
151 	struct list_head     sc_ctxts;
152 	int		     sc_ctxt_used;
153 	spinlock_t	     sc_map_lock;
154 	struct list_head     sc_maps;
155 
156 	struct list_head     sc_rq_dto_q;
157 	spinlock_t	     sc_rq_dto_lock;
158 	struct ib_qp         *sc_qp;
159 	struct ib_cq         *sc_rq_cq;
160 	struct ib_cq         *sc_sq_cq;
161 	int		     (*sc_reader)(struct svcxprt_rdma *,
162 					  struct svc_rqst *,
163 					  struct svc_rdma_op_ctxt *,
164 					  int *, u32 *, u32, u32, u64, bool);
165 	u32		     sc_dev_caps;	/* distilled device caps */
166 	unsigned int	     sc_frmr_pg_list_len;
167 	struct list_head     sc_frmr_q;
168 	spinlock_t	     sc_frmr_q_lock;
169 
170 	spinlock_t	     sc_lock;		/* transport lock */
171 
172 	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
173 	unsigned long	     sc_flags;
174 	struct list_head     sc_read_complete_q;
175 	struct work_struct   sc_work;
176 };
177 /* sc_flags */
178 #define RDMAXPRT_CONN_PENDING	3
179 
180 #define RPCRDMA_LISTEN_BACKLOG  10
181 /* The default ORD value is based on two outstanding full-size writes with a
182  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
183 #define RPCRDMA_ORD             (64/4)
184 #define RPCRDMA_SQ_DEPTH_MULT   8
185 #define RPCRDMA_MAX_REQUESTS    32
186 #define RPCRDMA_MAX_REQ_SIZE    4096
187 
188 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
189  * current NFSv4.1 implementation supports one backchannel slot.
190  */
191 #define RPCRDMA_MAX_BC_REQUESTS	2
192 
193 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
194 
195 /* Track DMA maps for this transport and context */
196 static inline void svc_rdma_count_mappings(struct svcxprt_rdma *rdma,
197 					   struct svc_rdma_op_ctxt *ctxt)
198 {
199 	ctxt->mapped_sges++;
200 }
201 
202 /* svc_rdma_backchannel.c */
203 extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
204 				    struct rpcrdma_msg *rmsgp,
205 				    struct xdr_buf *rcvbuf);
206 
207 /* svc_rdma_marshal.c */
208 extern int svc_rdma_xdr_decode_req(struct xdr_buf *);
209 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
210 				     struct rpcrdma_msg *,
211 				     enum rpcrdma_errcode, __be32 *);
212 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
213 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
214 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
215 					    __be32, __be64, u32);
216 extern unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp);
217 
218 /* svc_rdma_recvfrom.c */
219 extern int svc_rdma_recvfrom(struct svc_rqst *);
220 extern int rdma_read_chunk_lcl(struct svcxprt_rdma *, struct svc_rqst *,
221 			       struct svc_rdma_op_ctxt *, int *, u32 *,
222 			       u32, u32, u64, bool);
223 extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *,
224 				struct svc_rdma_op_ctxt *, int *, u32 *,
225 				u32, u32, u64, bool);
226 
227 /* svc_rdma_sendto.c */
228 extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *,
229 			    struct svc_rdma_req_map *, bool);
230 extern int svc_rdma_sendto(struct svc_rqst *);
231 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
232 				int);
233 
234 /* svc_rdma_transport.c */
235 extern void svc_rdma_wc_send(struct ib_cq *, struct ib_wc *);
236 extern void svc_rdma_wc_write(struct ib_cq *, struct ib_wc *);
237 extern void svc_rdma_wc_reg(struct ib_cq *, struct ib_wc *);
238 extern void svc_rdma_wc_read(struct ib_cq *, struct ib_wc *);
239 extern void svc_rdma_wc_inv(struct ib_cq *, struct ib_wc *);
240 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
241 extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t);
242 extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t);
243 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
244 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
245 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
246 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
247 extern struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *);
248 extern void svc_rdma_put_req_map(struct svcxprt_rdma *,
249 				 struct svc_rdma_req_map *);
250 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
251 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
252 			      struct svc_rdma_fastreg_mr *);
253 extern void svc_sq_reap(struct svcxprt_rdma *);
254 extern void svc_rq_reap(struct svcxprt_rdma *);
255 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
256 
257 extern struct svc_xprt_class svc_rdma_class;
258 #ifdef CONFIG_SUNRPC_BACKCHANNEL
259 extern struct svc_xprt_class svc_rdma_bc_class;
260 #endif
261 
262 /* svc_rdma.c */
263 extern struct workqueue_struct *svc_rdma_wq;
264 extern int svc_rdma_init(void);
265 extern void svc_rdma_cleanup(void);
266 
267 #endif
268