xref: /linux/include/linux/sunrpc/svc_rdma.h (revision 2c26b68cd5c51689b8cee9cb6a21abb5d2ab2d0f)
1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2 /*
3  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the BSD-type
9  * license below:
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  *
15  *      Redistributions of source code must retain the above copyright
16  *      notice, this list of conditions and the following disclaimer.
17  *
18  *      Redistributions in binary form must reproduce the above
19  *      copyright notice, this list of conditions and the following
20  *      disclaimer in the documentation and/or other materials provided
21  *      with the distribution.
22  *
23  *      Neither the name of the Network Appliance, Inc. nor the names of
24  *      its contributors may be used to endorse or promote products
25  *      derived from this software without specific prior written
26  *      permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39  *
40  * Author: Tom Tucker <tom@opengridcomputing.com>
41  */
42 
43 #ifndef SVC_RDMA_H
44 #define SVC_RDMA_H
45 #include <linux/llist.h>
46 #include <linux/sunrpc/xdr.h>
47 #include <linux/sunrpc/svcsock.h>
48 #include <linux/sunrpc/rpc_rdma.h>
49 #include <linux/sunrpc/rpc_rdma_cid.h>
50 #include <linux/sunrpc/svc_rdma_pcl.h>
51 #include <linux/sunrpc/rdma_rn.h>
52 
53 #include <linux/percpu_counter.h>
54 #include <rdma/ib_verbs.h>
55 #include <rdma/rdma_cm.h>
56 
57 /* Default and maximum inline threshold sizes */
58 enum {
59 	RPCRDMA_PULLUP_THRESH = RPCRDMA_V1_DEF_INLINE_SIZE >> 1,
60 	RPCRDMA_DEF_INLINE_THRESH = 4096,
61 	RPCRDMA_MAX_INLINE_THRESH = 65536
62 };
63 
64 /* RPC/RDMA parameters and stats */
65 extern unsigned int svcrdma_ord;
66 extern unsigned int svcrdma_max_requests;
67 extern unsigned int svcrdma_max_bc_requests;
68 extern unsigned int svcrdma_max_req_size;
69 extern struct workqueue_struct *svcrdma_wq;
70 
71 extern struct percpu_counter svcrdma_stat_read;
72 extern struct percpu_counter svcrdma_stat_recv;
73 extern struct percpu_counter svcrdma_stat_sq_starve;
74 extern struct percpu_counter svcrdma_stat_write;
75 
76 struct svcxprt_rdma {
77 	struct svc_xprt      sc_xprt;		/* SVC transport structure */
78 	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
79 	struct list_head     sc_accept_q;	/* Conn. waiting accept */
80 	struct rpcrdma_notification sc_rn;	/* removal notification */
81 	int		     sc_ord;		/* RDMA read limit */
82 	int                  sc_max_send_sges;
83 	bool		     sc_snd_w_inv;	/* OK to use Send With Invalidate */
84 
85 	atomic_t             sc_sq_avail;	/* SQEs ready to be consumed */
86 	unsigned int	     sc_sq_depth;	/* Depth of SQ */
87 	__be32		     sc_fc_credits;	/* Forward credits */
88 	u32		     sc_max_requests;	/* Max requests */
89 	u32		     sc_max_bc_requests;/* Backward credits */
90 	int                  sc_max_req_size;	/* Size of each RQ WR buf */
91 	u8		     sc_port_num;
92 
93 	struct ib_pd         *sc_pd;
94 
95 	spinlock_t	     sc_send_lock;
96 	struct llist_head    sc_send_ctxts;
97 	spinlock_t	     sc_rw_ctxt_lock;
98 	struct llist_head    sc_rw_ctxts;
99 
100 	u32		     sc_pending_recvs;
101 	u32		     sc_recv_batch;
102 	struct list_head     sc_rq_dto_q;
103 	struct list_head     sc_read_complete_q;
104 	spinlock_t	     sc_rq_dto_lock;
105 	struct ib_qp         *sc_qp;
106 	struct ib_cq         *sc_rq_cq;
107 	struct ib_cq         *sc_sq_cq;
108 
109 	spinlock_t	     sc_lock;		/* transport lock */
110 
111 	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
112 	unsigned long	     sc_flags;
113 	struct work_struct   sc_work;
114 
115 	struct llist_head    sc_recv_ctxts;
116 
117 	atomic_t	     sc_completion_ids;
118 };
119 /* sc_flags */
120 #define RDMAXPRT_CONN_PENDING	3
121 
122 static inline struct svcxprt_rdma *svc_rdma_rqst_rdma(struct svc_rqst *rqstp)
123 {
124 	struct svc_xprt *xprt = rqstp->rq_xprt;
125 
126 	return container_of(xprt, struct svcxprt_rdma, sc_xprt);
127 }
128 
129 /*
130  * Default connection parameters
131  */
132 enum {
133 	RPCRDMA_LISTEN_BACKLOG	= 10,
134 	RPCRDMA_MAX_REQUESTS	= 64,
135 	RPCRDMA_MAX_BC_REQUESTS	= 2,
136 };
137 
138 #define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
139 
140 /**
141  * svc_rdma_send_cid_init - Initialize a Receive Queue completion ID
142  * @rdma: controlling transport
143  * @cid: completion ID to initialize
144  */
145 static inline void svc_rdma_recv_cid_init(struct svcxprt_rdma *rdma,
146 					  struct rpc_rdma_cid *cid)
147 {
148 	cid->ci_queue_id = rdma->sc_rq_cq->res.id;
149 	cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids);
150 }
151 
152 /**
153  * svc_rdma_send_cid_init - Initialize a Send Queue completion ID
154  * @rdma: controlling transport
155  * @cid: completion ID to initialize
156  */
157 static inline void svc_rdma_send_cid_init(struct svcxprt_rdma *rdma,
158 					  struct rpc_rdma_cid *cid)
159 {
160 	cid->ci_queue_id = rdma->sc_sq_cq->res.id;
161 	cid->ci_completion_id = atomic_inc_return(&rdma->sc_completion_ids);
162 }
163 
164 /*
165  * A chunk context tracks all I/O for moving one Read or Write
166  * chunk. This is a set of rdma_rw's that handle data movement
167  * for all segments of one chunk.
168  */
169 struct svc_rdma_chunk_ctxt {
170 	struct rpc_rdma_cid	cc_cid;
171 	struct ib_cqe		cc_cqe;
172 	struct list_head	cc_rwctxts;
173 	ktime_t			cc_posttime;
174 	int			cc_sqecount;
175 };
176 
177 struct svc_rdma_recv_ctxt {
178 	struct llist_node	rc_node;
179 	struct list_head	rc_list;
180 	struct ib_recv_wr	rc_recv_wr;
181 	struct ib_cqe		rc_cqe;
182 	struct rpc_rdma_cid	rc_cid;
183 	struct ib_sge		rc_recv_sge;
184 	void			*rc_recv_buf;
185 	struct xdr_stream	rc_stream;
186 	u32			rc_byte_len;
187 	u32			rc_inv_rkey;
188 	__be32			rc_msgtype;
189 
190 	/* State for pulling a Read chunk */
191 	unsigned int		rc_pageoff;
192 	unsigned int		rc_curpage;
193 	unsigned int		rc_readbytes;
194 	struct xdr_buf		rc_saved_arg;
195 	struct svc_rdma_chunk_ctxt	rc_cc;
196 
197 	struct svc_rdma_pcl	rc_call_pcl;
198 
199 	struct svc_rdma_pcl	rc_read_pcl;
200 	struct svc_rdma_chunk	*rc_cur_result_payload;
201 	struct svc_rdma_pcl	rc_write_pcl;
202 	struct svc_rdma_pcl	rc_reply_pcl;
203 
204 	unsigned int		rc_page_count;
205 	unsigned long		rc_maxpages;
206 	struct page		*rc_pages[] __counted_by(rc_maxpages);
207 };
208 
209 /*
210  * State for sending a Write chunk.
211  *  - Tracks progress of writing one chunk over all its segments
212  *  - Stores arguments for the SGL constructor functions
213  */
214 struct svc_rdma_write_info {
215 	struct svcxprt_rdma	*wi_rdma;
216 
217 	const struct svc_rdma_chunk	*wi_chunk;
218 
219 	/* write state of this chunk */
220 	unsigned int		wi_seg_off;
221 	unsigned int		wi_seg_no;
222 
223 	/* SGL constructor arguments */
224 	const struct xdr_buf	*wi_xdr;
225 	unsigned char		*wi_base;
226 	unsigned int		wi_next_off;
227 
228 	struct svc_rdma_chunk_ctxt	wi_cc;
229 	struct work_struct	wi_work;
230 };
231 
232 struct svc_rdma_send_ctxt {
233 	struct llist_node	sc_node;
234 	struct rpc_rdma_cid	sc_cid;
235 	struct work_struct	sc_work;
236 
237 	struct svcxprt_rdma	*sc_rdma;
238 	struct ib_send_wr	sc_send_wr;
239 	struct ib_send_wr	*sc_wr_chain;
240 	int			sc_sqecount;
241 	struct ib_cqe		sc_cqe;
242 	struct xdr_buf		sc_hdrbuf;
243 	struct xdr_stream	sc_stream;
244 	struct svc_rdma_write_info sc_reply_info;
245 	void			*sc_xprt_buf;
246 	int			sc_page_count;
247 	int			sc_cur_sge_no;
248 	unsigned long		sc_maxpages;
249 	struct page		**sc_pages;
250 	struct ib_sge		sc_sges[];
251 };
252 
253 /* svc_rdma_backchannel.c */
254 extern void svc_rdma_handle_bc_reply(struct svc_rqst *rqstp,
255 				     struct svc_rdma_recv_ctxt *rctxt);
256 
257 /* svc_rdma_recvfrom.c */
258 extern void svc_rdma_recv_ctxts_destroy(struct svcxprt_rdma *rdma);
259 extern bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma);
260 extern struct svc_rdma_recv_ctxt *
261 		svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma);
262 extern void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma,
263 				   struct svc_rdma_recv_ctxt *ctxt);
264 extern void svc_rdma_flush_recv_queues(struct svcxprt_rdma *rdma);
265 extern void svc_rdma_release_ctxt(struct svc_xprt *xprt, void *ctxt);
266 extern int svc_rdma_recvfrom(struct svc_rqst *);
267 
268 /* svc_rdma_rw.c */
269 extern void svc_rdma_cc_init(struct svcxprt_rdma *rdma,
270 			     struct svc_rdma_chunk_ctxt *cc);
271 extern void svc_rdma_destroy_rw_ctxts(struct svcxprt_rdma *rdma);
272 extern void svc_rdma_cc_init(struct svcxprt_rdma *rdma,
273 			     struct svc_rdma_chunk_ctxt *cc);
274 extern void svc_rdma_cc_release(struct svcxprt_rdma *rdma,
275 				struct svc_rdma_chunk_ctxt *cc,
276 				enum dma_data_direction dir);
277 extern void svc_rdma_reply_chunk_release(struct svcxprt_rdma *rdma,
278 					 struct svc_rdma_send_ctxt *ctxt);
279 extern int svc_rdma_send_write_list(struct svcxprt_rdma *rdma,
280 				    const struct svc_rdma_recv_ctxt *rctxt,
281 				    const struct xdr_buf *xdr);
282 extern int svc_rdma_prepare_reply_chunk(struct svcxprt_rdma *rdma,
283 					const struct svc_rdma_pcl *write_pcl,
284 					const struct svc_rdma_pcl *reply_pcl,
285 					struct svc_rdma_send_ctxt *sctxt,
286 					const struct xdr_buf *xdr);
287 extern int svc_rdma_process_read_list(struct svcxprt_rdma *rdma,
288 				      struct svc_rqst *rqstp,
289 				      struct svc_rdma_recv_ctxt *head);
290 
291 /* svc_rdma_sendto.c */
292 extern void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma);
293 extern struct svc_rdma_send_ctxt *
294 		svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma);
295 extern void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma,
296 				   struct svc_rdma_send_ctxt *ctxt);
297 extern int svc_rdma_post_send(struct svcxprt_rdma *rdma,
298 			      struct svc_rdma_send_ctxt *ctxt);
299 extern int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
300 				  struct svc_rdma_send_ctxt *sctxt,
301 				  const struct svc_rdma_pcl *write_pcl,
302 				  const struct svc_rdma_pcl *reply_pcl,
303 				  const struct xdr_buf *xdr);
304 extern void svc_rdma_send_error_msg(struct svcxprt_rdma *rdma,
305 				    struct svc_rdma_send_ctxt *sctxt,
306 				    struct svc_rdma_recv_ctxt *rctxt,
307 				    int status);
308 extern void svc_rdma_wake_send_waiters(struct svcxprt_rdma *rdma, int avail);
309 extern int svc_rdma_sendto(struct svc_rqst *);
310 extern int svc_rdma_result_payload(struct svc_rqst *rqstp, unsigned int offset,
311 				   unsigned int length);
312 
313 /* svc_rdma_transport.c */
314 extern struct svc_xprt_class svc_rdma_class;
315 #ifdef CONFIG_SUNRPC_BACKCHANNEL
316 extern struct svc_xprt_class svc_rdma_bc_class;
317 #endif
318 
319 /* svc_rdma.c */
320 extern int svc_rdma_init(void);
321 extern void svc_rdma_cleanup(void);
322 
323 #endif
324