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 */
52extern unsigned int svcrdma_ord;
53extern unsigned int svcrdma_max_requests;
54extern unsigned int svcrdma_max_req_size;
55
56extern atomic_t rdma_stat_recv;
57extern atomic_t rdma_stat_read;
58extern atomic_t rdma_stat_write;
59extern atomic_t rdma_stat_sq_starve;
60extern atomic_t rdma_stat_rq_starve;
61extern atomic_t rdma_stat_rq_poll;
62extern atomic_t rdma_stat_rq_prod;
63extern atomic_t rdma_stat_sq_poll;
64extern 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 */
71struct 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 */
102struct svc_rdma_chunk_sge {
103	int start;		/* sge no for this chunk */
104	int count;		/* sge count for this chunk */
105};
106struct svc_rdma_fastreg_mr {
107	struct ib_mr *mr;
108	void *kva;
109	struct ib_fast_reg_page_list *page_list;
110	int page_list_len;
111	unsigned long access_flags;
112	unsigned long map_len;
113	enum dma_data_direction direction;
114	struct list_head frmr_list;
115};
116struct svc_rdma_req_map {
117	unsigned long count;
118	union {
119		struct kvec sge[RPCSVC_MAXPAGES];
120		struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
121		unsigned long lkey[RPCSVC_MAXPAGES];
122	};
123};
124#define RDMACTXT_F_LAST_CTXT	2
125
126#define	SVCRDMA_DEVCAP_FAST_REG		1	/* fast mr registration */
127#define	SVCRDMA_DEVCAP_READ_W_INV	2	/* read w/ invalidate */
128
129struct svcxprt_rdma {
130	struct svc_xprt      sc_xprt;		/* SVC transport structure */
131	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
132	struct list_head     sc_accept_q;	/* Conn. waiting accept */
133	int		     sc_ord;		/* RDMA read limit */
134	int                  sc_max_sge;
135
136	int                  sc_sq_depth;	/* Depth of SQ */
137	atomic_t             sc_sq_count;	/* Number of SQ WR on queue */
138
139	int                  sc_max_requests;	/* Depth of RQ */
140	int                  sc_max_req_size;	/* Size of each RQ WR buf */
141
142	struct ib_pd         *sc_pd;
143
144	atomic_t	     sc_dma_used;
145	atomic_t	     sc_ctxt_used;
146	struct list_head     sc_rq_dto_q;
147	spinlock_t	     sc_rq_dto_lock;
148	struct ib_qp         *sc_qp;
149	struct ib_cq         *sc_rq_cq;
150	struct ib_cq         *sc_sq_cq;
151	struct ib_mr         *sc_phys_mr;	/* MR for server memory */
152	int		     (*sc_reader)(struct svcxprt_rdma *,
153					  struct svc_rqst *,
154					  struct svc_rdma_op_ctxt *,
155					  int *, u32 *, u32, u32, u64, bool);
156	u32		     sc_dev_caps;	/* distilled device caps */
157	u32		     sc_dma_lkey;	/* local dma key */
158	unsigned int	     sc_frmr_pg_list_len;
159	struct list_head     sc_frmr_q;
160	spinlock_t	     sc_frmr_q_lock;
161
162	spinlock_t	     sc_lock;		/* transport lock */
163
164	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
165	unsigned long	     sc_flags;
166	struct list_head     sc_dto_q;		/* DTO tasklet I/O pending Q */
167	struct list_head     sc_read_complete_q;
168	struct work_struct   sc_work;
169};
170/* sc_flags */
171#define RDMAXPRT_RQ_PENDING	1
172#define RDMAXPRT_SQ_PENDING	2
173#define RDMAXPRT_CONN_PENDING	3
174
175#define RPCRDMA_LISTEN_BACKLOG  10
176/* The default ORD value is based on two outstanding full-size writes with a
177 * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
178#define RPCRDMA_ORD             (64/4)
179#define RPCRDMA_SQ_DEPTH_MULT   8
180#define RPCRDMA_MAX_REQUESTS    32
181#define RPCRDMA_MAX_REQ_SIZE    4096
182
183/* svc_rdma_marshal.c */
184extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
185extern int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *);
186extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
187				     struct rpcrdma_msg *,
188				     enum rpcrdma_errcode, u32 *);
189extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
190extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
191extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
192					    __be32, __be64, u32);
193extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
194					     struct rpcrdma_msg *,
195					     struct rpcrdma_msg *,
196					     enum rpcrdma_proc);
197extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
198
199/* svc_rdma_recvfrom.c */
200extern int svc_rdma_recvfrom(struct svc_rqst *);
201extern int rdma_read_chunk_lcl(struct svcxprt_rdma *, struct svc_rqst *,
202			       struct svc_rdma_op_ctxt *, int *, u32 *,
203			       u32, u32, u64, bool);
204extern 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 */
209extern int svc_rdma_sendto(struct svc_rqst *);
210
211/* svc_rdma_transport.c */
212extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
213extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
214				enum rpcrdma_errcode);
215struct page *svc_rdma_get_page(void);
216extern int svc_rdma_post_recv(struct svcxprt_rdma *);
217extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
218extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
219extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
220extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
221extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
222extern void svc_rdma_put_req_map(struct svc_rdma_req_map *);
223extern int svc_rdma_fastreg(struct svcxprt_rdma *, struct svc_rdma_fastreg_mr *);
224extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
225extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
226			      struct svc_rdma_fastreg_mr *);
227extern void svc_sq_reap(struct svcxprt_rdma *);
228extern void svc_rq_reap(struct svcxprt_rdma *);
229extern struct svc_xprt_class svc_rdma_class;
230extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
231
232/* svc_rdma.c */
233extern int svc_rdma_init(void);
234extern void svc_rdma_cleanup(void);
235
236/*
237 * Returns the address of the first read chunk or <nul> if no read chunk is
238 * present
239 */
240static inline struct rpcrdma_read_chunk *
241svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)
242{
243	struct rpcrdma_read_chunk *ch =
244		(struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
245
246	if (ch->rc_discrim == 0)
247		return NULL;
248
249	return ch;
250}
251
252/*
253 * Returns the address of the first read write array element or <nul> if no
254 * write array list is present
255 */
256static inline struct rpcrdma_write_array *
257svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)
258{
259	if (rmsgp->rm_body.rm_chunks[0] != 0
260	    || rmsgp->rm_body.rm_chunks[1] == 0)
261		return NULL;
262
263	return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];
264}
265
266/*
267 * Returns the address of the first reply array element or <nul> if no
268 * reply array is present
269 */
270static inline struct rpcrdma_write_array *
271svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)
272{
273	struct rpcrdma_read_chunk *rch;
274	struct rpcrdma_write_array *wr_ary;
275	struct rpcrdma_write_array *rp_ary;
276
277	/* XXX: Need to fix when reply list may occur with read-list and/or
278	 * write list */
279	if (rmsgp->rm_body.rm_chunks[0] != 0 ||
280	    rmsgp->rm_body.rm_chunks[1] != 0)
281		return NULL;
282
283	rch = svc_rdma_get_read_chunk(rmsgp);
284	if (rch) {
285		while (rch->rc_discrim)
286			rch++;
287
288		/* The reply list follows an empty write array located
289		 * at 'rc_position' here. The reply array is at rc_target.
290		 */
291		rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;
292
293		goto found_it;
294	}
295
296	wr_ary = svc_rdma_get_write_array(rmsgp);
297	if (wr_ary) {
298		rp_ary = (struct rpcrdma_write_array *)
299			&wr_ary->
300			wc_array[ntohl(wr_ary->wc_nchunks)].wc_target.rs_length;
301
302		goto found_it;
303	}
304
305	/* No read list, no write list */
306	rp_ary = (struct rpcrdma_write_array *)
307		&rmsgp->rm_body.rm_chunks[2];
308
309 found_it:
310	if (rp_ary->wc_discrim == 0)
311		return NULL;
312
313	return rp_ary;
314}
315#endif
316