Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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 */
 52 extern unsigned int svcrdma_ord;
 53 extern unsigned int svcrdma_max_requests;
 54 extern unsigned int svcrdma_max_req_size;
 55 
 56 extern atomic_t rdma_stat_recv;
 57 extern atomic_t rdma_stat_read;
 58 extern atomic_t rdma_stat_write;
 59 extern atomic_t rdma_stat_sq_starve;
 60 extern atomic_t rdma_stat_rq_starve;
 61 extern atomic_t rdma_stat_rq_poll;
 62 extern atomic_t rdma_stat_rq_prod;
 63 extern atomic_t rdma_stat_sq_poll;
 64 extern atomic_t rdma_stat_sq_prod;
 65 
 66 #define RPCRDMA_VERSION 1
 67 
 68 /*
 69  * Contexts are built when an RDMA request is created and are a
 70  * record of the resources that can be recovered when the request
 71  * completes.
 72  */
 73 struct svc_rdma_op_ctxt {
 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 list_head dto_q;
 79         enum ib_wr_opcode wr_op;
 80         enum ib_wc_status wc_status;
 81         u32 byte_len;
 82         struct svcxprt_rdma *xprt;
 83         unsigned long flags;
 84         enum dma_data_direction direction;
 85         int count;
 86         struct ib_sge sge[RPCSVC_MAXPAGES];
 87         struct page *pages[RPCSVC_MAXPAGES];
 88 };
 89 
 90 /*
 91  * NFS_ requests are mapped on the client side by the chunk lists in
 92  * the RPCRDMA header. During the fetching of the RPC from the client
 93  * and the writing of the reply to the client, the memory in the
 94  * client and the memory in the server must be mapped as contiguous
 95  * vaddr/len for access by the hardware. These data strucures keep
 96  * these mappings.
 97  *
 98  * For an RDMA_WRITE, the 'sge' maps the RPC REPLY. For RDMA_READ, the
 99  * 'sge' in the svc_rdma_req_map maps the server side RPC reply and the
100  * 'ch' field maps the read-list of the RPCRDMA header to the 'sge'
101  * mapping of the reply.
102  */
103 struct svc_rdma_chunk_sge {
104         int start;              /* sge no for this chunk */
105         int count;              /* sge count for this chunk */
106 };
107 struct svc_rdma_fastreg_mr {
108         struct ib_mr *mr;
109         void *kva;
110         struct ib_fast_reg_page_list *page_list;
111         int page_list_len;
112         unsigned long access_flags;
113         unsigned long map_len;
114         enum dma_data_direction direction;
115         struct list_head frmr_list;
116 };
117 struct svc_rdma_req_map {
118         struct svc_rdma_fastreg_mr *frmr;
119         unsigned long count;
120         union {
121                 struct kvec sge[RPCSVC_MAXPAGES];
122                 struct svc_rdma_chunk_sge ch[RPCSVC_MAXPAGES];
123         };
124 };
125 #define RDMACTXT_F_FAST_UNREG   1
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 
138         int                  sc_sq_depth;       /* Depth of SQ */
139         atomic_t             sc_sq_count;       /* Number of SQ WR on queue */
140 
141         int                  sc_max_requests;   /* Depth of RQ */
142         int                  sc_max_req_size;   /* Size of each RQ WR buf */
143 
144         struct ib_pd         *sc_pd;
145 
146         atomic_t             sc_dma_used;
147         atomic_t             sc_ctxt_used;
148         struct list_head     sc_rq_dto_q;
149         spinlock_t           sc_rq_dto_lock;
150         struct ib_qp         *sc_qp;
151         struct ib_cq         *sc_rq_cq;
152         struct ib_cq         *sc_sq_cq;
153         struct ib_mr         *sc_phys_mr;       /* MR for server memory */
154         u32                  sc_dev_caps;       /* distilled device caps */
155         u32                  sc_dma_lkey;       /* local dma key */
156         unsigned int         sc_frmr_pg_list_len;
157         struct list_head     sc_frmr_q;
158         spinlock_t           sc_frmr_q_lock;
159 
160         spinlock_t           sc_lock;           /* transport lock */
161 
162         wait_queue_head_t    sc_send_wait;      /* SQ exhaustion waitlist */
163         unsigned long        sc_flags;
164         struct list_head     sc_dto_q;          /* DTO tasklet I/O pending Q */
165         struct list_head     sc_read_complete_q;
166         struct work_struct   sc_work;
167 };
168 /* sc_flags */
169 #define RDMAXPRT_RQ_PENDING     1
170 #define RDMAXPRT_SQ_PENDING     2
171 #define RDMAXPRT_CONN_PENDING   3
172 
173 #define RPCRDMA_LISTEN_BACKLOG  10
174 /* The default ORD value is based on two outstanding full-size writes with a
175  * page size of 4k, or 32k * 2 ops / 4k = 16 outstanding RDMA_READ.  */
176 #define RPCRDMA_ORD             (64/4)
177 #define RPCRDMA_SQ_DEPTH_MULT   8
178 #define RPCRDMA_MAX_THREADS     16
179 #define RPCRDMA_MAX_REQUESTS    16
180 #define RPCRDMA_MAX_REQ_SIZE    4096
181 
182 /* svc_rdma_marshal.c */
183 extern void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *,
184                                       int *, int *);
185 extern int svc_rdma_xdr_decode_req(struct rpcrdma_msg **, struct svc_rqst *);
186 extern int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *);
187 extern int svc_rdma_xdr_encode_error(struct svcxprt_rdma *,
188                                      struct rpcrdma_msg *,
189                                      enum rpcrdma_errcode, u32 *);
190 extern void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *, int);
191 extern void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *, int);
192 extern void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *, int,
193                                             u32, u64, u32);
194 extern void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *,
195                                              struct rpcrdma_msg *,
196                                              struct rpcrdma_msg *,
197                                              enum rpcrdma_proc);
198 extern int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *);
199 
200 /* svc_rdma_recvfrom.c */
201 extern int svc_rdma_recvfrom(struct svc_rqst *);
202 
203 /* svc_rdma_sendto.c */
204 extern int svc_rdma_sendto(struct svc_rqst *);
205 
206 /* svc_rdma_transport.c */
207 extern int svc_rdma_send(struct svcxprt_rdma *, struct ib_send_wr *);
208 extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
209                                 enum rpcrdma_errcode);
210 struct page *svc_rdma_get_page(void);
211 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
212 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
213 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
214 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
215 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
216 extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
217 extern void svc_rdma_put_req_map(struct svc_rdma_req_map *);
218 extern int svc_rdma_fastreg(struct svcxprt_rdma *, struct svc_rdma_fastreg_mr *);
219 extern struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *);
220 extern void svc_rdma_put_frmr(struct svcxprt_rdma *,
221                               struct svc_rdma_fastreg_mr *);
222 extern void svc_sq_reap(struct svcxprt_rdma *);
223 extern void svc_rq_reap(struct svcxprt_rdma *);
224 extern struct svc_xprt_class svc_rdma_class;
225 extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
226 
227 /* svc_rdma.c */
228 extern int svc_rdma_init(void);
229 extern void svc_rdma_cleanup(void);
230 
231 /*
232  * Returns the address of the first read chunk or <nul> if no read chunk is
233  * present
234  */
235 static inline struct rpcrdma_read_chunk *
236 svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp)
237 {
238         struct rpcrdma_read_chunk *ch =
239                 (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
240 
241         if (ch->rc_discrim == 0)
242                 return NULL;
243 
244         return ch;
245 }
246 
247 /*
248  * Returns the address of the first read write array element or <nul> if no
249  * write array list is present
250  */
251 static inline struct rpcrdma_write_array *
252 svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp)
253 {
254         if (rmsgp->rm_body.rm_chunks[0] != 0
255             || rmsgp->rm_body.rm_chunks[1] == 0)
256                 return NULL;
257 
258         return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1];
259 }
260 
261 /*
262  * Returns the address of the first reply array element or <nul> if no
263  * reply array is present
264  */
265 static inline struct rpcrdma_write_array *
266 svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp)
267 {
268         struct rpcrdma_read_chunk *rch;
269         struct rpcrdma_write_array *wr_ary;
270         struct rpcrdma_write_array *rp_ary;
271 
272         /* XXX: Need to fix when reply list may occur with read-list and/or
273          * write list */
274         if (rmsgp->rm_body.rm_chunks[0] != 0 ||
275             rmsgp->rm_body.rm_chunks[1] != 0)
276                 return NULL;
277 
278         rch = svc_rdma_get_read_chunk(rmsgp);
279         if (rch) {
280                 while (rch->rc_discrim)
281                         rch++;
282 
283                 /* The reply list follows an empty write array located
284                  * at 'rc_position' here. The reply array is at rc_target.
285                  */
286                 rp_ary = (struct rpcrdma_write_array *)&rch->rc_target;
287 
288                 goto found_it;
289         }
290 
291         wr_ary = svc_rdma_get_write_array(rmsgp);
292         if (wr_ary) {
293                 rp_ary = (struct rpcrdma_write_array *)
294                         &wr_ary->
295                         wc_array[wr_ary->wc_nchunks].wc_target.rs_length;
296 
297                 goto found_it;
298         }
299 
300         /* No read list, no write list */
301         rp_ary = (struct rpcrdma_write_array *)
302                 &rmsgp->rm_body.rm_chunks[2];
303 
304  found_it:
305         if (rp_ary->wc_discrim == 0)
306                 return NULL;
307 
308         return rp_ary;
309 }
310 #endif
311 
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