xref: /linux-6.15/include/linux/sunrpc/svc_rdma.h (revision 094dbffe)
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 free;
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 	struct list_head dto_q;
82 	enum ib_wc_status wc_status;
83 	u32 byte_len;
84 	u32 position;
85 	struct svcxprt_rdma *xprt;
86 	unsigned long flags;
87 	enum dma_data_direction direction;
88 	int count;
89 	unsigned int mapped_sges;
90 	struct ib_sge sge[RPCSVC_MAXPAGES];
91 	struct page *pages[RPCSVC_MAXPAGES];
92 };
93 
94 /*
95  * NFS_ requests are mapped on the client side by the chunk lists in
96  * the RPCRDMA header. During the fetching of the RPC from the client
97  * and the writing of the reply to the client, the memory in the
98  * client and the memory in the server must be mapped as contiguous
99  * vaddr/len for access by the hardware. These data strucures keep
100  * these mappings.
101  *
102  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
103  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
104  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
105  * mapping of the reply.
106  */
107 struct svc_rdma_chunk_sge {
108 	int start;		/* sge no for this chunk */
109 	int count;		/* sge count for this chunk */
110 };
111 struct svc_rdma_fastreg_mr {
112 	struct ib_mr *mr;
113 	struct scatterlist *sg;
114 	int sg_nents;
115 	unsigned long access_flags;
116 	enum dma_data_direction direction;
117 	struct list_head frmr_list;
118 };
119 struct svc_rdma_req_map {
120 	struct list_head free;
121 	unsigned long count;
122 	union {
123 		struct kvec sge[RPCSVC_MAXPAGES];
124 		struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
125 		unsigned long lkey[RPCSVC_MAXPAGES];
126 	};
127 };
128 #define RDMACTXT_F_LAST_CTXT	2
129 
130 #define	SVCRDMA_DEVCAP_FAST_REG		1	/* fast mr registration */
131 #define	SVCRDMA_DEVCAP_READ_W_INV	2	/* read w/ invalidate */
132 
133 struct svcxprt_rdma {
134 	struct svc_xprt      sc_xprt;		/* SVC transport structure */
135 	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
136 	struct list_head     sc_accept_q;	/* Conn. waiting accept */
137 	int		     sc_ord;		/* RDMA read limit */
138 	int                  sc_max_sge;
139 	int                  sc_max_sge_rd;	/* max sge for read target */
140 	bool		     sc_snd_w_inv;	/* OK to use Send With Invalidate */
141 
142 	atomic_t             sc_sq_count;	/* Number of SQ WR on queue */
143 	unsigned int	     sc_sq_depth;	/* Depth of SQ */
144 	unsigned int	     sc_rq_depth;	/* Depth of RQ */
145 	u32		     sc_max_requests;	/* Forward credits */
146 	u32		     sc_max_bc_requests;/* Backward credits */
147 	int                  sc_max_req_size;	/* Size of each RQ WR buf */
148 
149 	struct ib_pd         *sc_pd;
150 
151 	atomic_t	     sc_dma_used;
152 	spinlock_t	     sc_ctxt_lock;
153 	struct list_head     sc_ctxts;
154 	int		     sc_ctxt_used;
155 	spinlock_t	     sc_map_lock;
156 	struct list_head     sc_maps;
157 
158 	struct list_head     sc_rq_dto_q;
159 	spinlock_t	     sc_rq_dto_lock;
160 	struct ib_qp         *sc_qp;
161 	struct ib_cq         *sc_rq_cq;
162 	struct ib_cq         *sc_sq_cq;
163 	int		     (*sc_reader)(struct svcxprt_rdma *,
164 					  struct svc_rqst *,
165 					  struct svc_rdma_op_ctxt *,
166 					  int *, u32 *, u32, u32, u64, bool);
167 	u32		     sc_dev_caps;	/* distilled device caps */
168 	unsigned int	     sc_frmr_pg_list_len;
169 	struct list_head     sc_frmr_q;
170 	spinlock_t	     sc_frmr_q_lock;
171 
172 	spinlock_t	     sc_lock;		/* transport lock */
173 
174 	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
175 	unsigned long	     sc_flags;
176 	struct list_head     sc_dto_q;		/* DTO tasklet I/O pending Q */
177 	struct list_head     sc_read_complete_q;
178 	struct work_struct   sc_work;
179 };
180 /* sc_flags */
181 #define RDMAXPRT_CONN_PENDING	3
182 
183 #define RPCRDMA_LISTEN_BACKLOG  10
184 /* The default ORD value is based on two outstanding full-size writes with a
185  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
186 #define RPCRDMA_ORD             (64/4)
187 #define RPCRDMA_SQ_DEPTH_MULT   8
188 #define RPCRDMA_MAX_REQUESTS    32
189 #define RPCRDMA_MAX_REQ_SIZE    4096
190 
191 /* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
192  * current NFSv4.1 implementation supports one backchannel slot.
193  */
194 #define RPCRDMA_MAX_BC_REQUESTS	2
195 
196 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
197 
198 /* Track DMA maps for this transport and context */
199 static inline void svc_rdma_count_mappings(struct svcxprt_rdma *rdma,
200 					   struct svc_rdma_op_ctxt *ctxt)
201 {
202 	ctxt->mapped_sges++;
203 	atomic_inc(&rdma->sc_dma_used);
204 }
205 
206 /* svc_rdma_backchannel.c */
207 extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
208 				    struct rpcrdma_msg *rmsgp,
209 				    struct xdr_buf *rcvbuf);
210 
211 /* svc_rdma_marshal.c */
212 extern int svc_rdma_xdr_decode_req(struct xdr_buf *);
213 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
214 				     struct rpcrdma_msg *,
215 				     enum rpcrdma_errcode, __be32 *);
216 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
217 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
218 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
219 					    __be32, __be64, u32);
220 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
221 					     struct rpcrdma_msg *,
222 					     struct rpcrdma_msg *,
223 					     enum rpcrdma_proc);
224 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
225 
226 /* svc_rdma_recvfrom.c */
227 extern int svc_rdma_recvfrom(struct svc_rqst *);
228 extern int rdma_read_chunk_lcl(struct svcxprt_rdma *, struct svc_rqst *,
229 			       struct svc_rdma_op_ctxt *, int *, u32 *,
230 			       u32, u32, u64, bool);
231 extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *,
232 				struct svc_rdma_op_ctxt *, int *, u32 *,
233 				u32, u32, u64, bool);
234 
235 /* svc_rdma_sendto.c */
236 extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *,
237 			    struct svc_rdma_req_map *, bool);
238 extern int svc_rdma_sendto(struct svc_rqst *);
239 extern struct rpcrdma_read_chunk *
240 	svc_rdma_get_read_chunk(struct rpcrdma_msg *);
241 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
242 				int);
243 
244 /* svc_rdma_transport.c */
245 extern void svc_rdma_wc_send(struct ib_cq *, struct ib_wc *);
246 extern void svc_rdma_wc_write(struct ib_cq *, struct ib_wc *);
247 extern void svc_rdma_wc_reg(struct ib_cq *, struct ib_wc *);
248 extern void svc_rdma_wc_read(struct ib_cq *, struct ib_wc *);
249 extern void svc_rdma_wc_inv(struct ib_cq *, struct ib_wc *);
250 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
251 extern int svc_rdma_post_recv(struct svcxprt_rdma *, gfp_t);
252 extern int svc_rdma_repost_recv(struct svcxprt_rdma *, gfp_t);
253 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
254 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
255 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
256 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
257 extern struct svc_rdma_req_map *svc_rdma_get_req_map(struct svcxprt_rdma *);
258 extern void svc_rdma_put_req_map(struct svcxprt_rdma *,
259 				 struct svc_rdma_req_map *);
260 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
261 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
262 			      struct svc_rdma_fastreg_mr *);
263 extern void svc_sq_reap(struct svcxprt_rdma *);
264 extern void svc_rq_reap(struct svcxprt_rdma *);
265 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
266 
267 extern struct svc_xprt_class svc_rdma_class;
268 #ifdef CONFIG_SUNRPC_BACKCHANNEL
269 extern struct svc_xprt_class svc_rdma_bc_class;
270 #endif
271 
272 /* svc_rdma.c */
273 extern struct workqueue_struct *svc_rdma_wq;
274 extern int svc_rdma_init(void);
275 extern void svc_rdma_cleanup(void);
276 
277 #endif
278