net/sunrpc/xprtrdma/xprt_rdma.h

   1 /*
   2  * Copyright (c) 2003-2007 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
  40 #ifndef _LINUX_SUNRPC_XPRT_RDMA_H
  41 #define _LINUX_SUNRPC_XPRT_RDMA_H
  42
  43 #include <linux/wait.h>                 /* wait_queue_head_t, etc */
  44 #include <linux/spinlock.h>             /* spinlock_t, etc */
  45 #include <asm/atomic.h>                 /* atomic_t, etc */
  46
  47 #include <rdma/rdma_cm.h>               /* RDMA connection api */
  48 #include <rdma/ib_verbs.h>              /* RDMA verbs api */
  49
  50 #include <linux/sunrpc/clnt.h>          /* rpc_xprt */
  51 #include <linux/sunrpc/rpc_rdma.h>      /* RPC/RDMA protocol */
  52 #include <linux/sunrpc/xprtrdma.h>      /* xprt parameters */
  53
  54 /*
  55  * Interface Adapter -- one per transport instance
  56  */
  57 struct rpcrdma_ia {
  58         struct rdma_cm_id       *ri_id;
  59         struct ib_pd            *ri_pd;
  60         struct ib_mr            *ri_bind_mem;
  61         struct completion       ri_done;
  62         int                     ri_async_rc;
  63         enum rpcrdma_memreg     ri_memreg_strategy;
  64 };
  65
  66 /*
  67  * RDMA Endpoint -- one per transport instance
  68  */
  69
  70 struct rpcrdma_ep {
  71         atomic_t                rep_cqcount;
  72         int                     rep_cqinit;
  73         int                     rep_connected;
  74         struct rpcrdma_ia       *rep_ia;
  75         struct ib_cq            *rep_cq;
  76         struct ib_qp_init_attr  rep_attr;
  77         wait_queue_head_t       rep_connect_wait;
  78         struct ib_sge           rep_pad;        /* holds zeroed pad */
  79         struct ib_mr            *rep_pad_mr;    /* holds zeroed pad */
  80         void                    (*rep_func)(struct rpcrdma_ep *);
  81         struct rpc_xprt         *rep_xprt;      /* for rep_func */
  82         struct rdma_conn_param  rep_remote_cma;
  83         struct sockaddr_storage rep_remote_addr;
  84 };
  85
  86 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
  87 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
  88
  89 /*
  90  * struct rpcrdma_rep -- this structure encapsulates state required to recv
  91  * and complete a reply, asychronously. It needs several pieces of
  92  * state:
  93  *   o recv buffer (posted to provider)
  94  *   o ib_sge (also donated to provider)
  95  *   o status of reply (length, success or not)
  96  *   o bookkeeping state to get run by tasklet (list, etc)
  97  *
  98  * These are allocated during initialization, per-transport instance;
  99  * however, the tasklet execution list itself is global, as it should
 100  * always be pretty short.
 101  *
 102  * N of these are associated with a transport instance, and stored in
 103  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 104  */
 105
 106 /* temporary static scatter/gather max */
 107 #define RPCRDMA_MAX_DATA_SEGS   (8)     /* max scatter/gather */
 108 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 109 #define MAX_RPCRDMAHDR  (\
 110         /* max supported RPC/RDMA header */ \
 111         sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
 112         (sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
 113
 114 struct rpcrdma_buffer;
 115
 116 struct rpcrdma_rep {
 117         unsigned int    rr_len;         /* actual received reply length */
 118         struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
 119         struct rpc_xprt *rr_xprt;       /* needed for request/reply matching */
 120         void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
 121         struct list_head rr_list;       /* tasklet list */
 122         wait_queue_head_t rr_unbind;    /* optional unbind wait */
 123         struct ib_sge   rr_iov;         /* for posting */
 124         struct ib_mr    *rr_handle;     /* handle for mem in rr_iov */
 125         char    rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
 126 };
 127
 128 /*
 129  * struct rpcrdma_req -- structure central to the request/reply sequence.
 130  *
 131  * N of these are associated with a transport instance, and stored in
 132  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 133  *
 134  * It includes pre-registered buffer memory for send AND recv.
 135  * The recv buffer, however, is not owned by this structure, and
 136  * is "donated" to the hardware when a recv is posted. When a
 137  * reply is handled, the recv buffer used is given back to the
 138  * struct rpcrdma_req associated with the request.
 139  *
 140  * In addition to the basic memory, this structure includes an array
 141  * of iovs for send operations. The reason is that the iovs passed to
 142  * ib_post_{send,recv} must not be modified until the work request
 143  * completes.
 144  *
 145  * NOTES:
 146  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 147  *     marshal. The number needed varies depending on the iov lists that
 148  *     are passed to us, the memory registration mode we are in, and if
 149  *     physical addressing is used, the layout.
 150  */
 151
 152 struct rpcrdma_mr_seg {         /* chunk descriptors */
 153         union {                         /* chunk memory handles */
 154                 struct ib_mr    *rl_mr;         /* if registered directly */
 155                 struct rpcrdma_mw {             /* if registered from region */
 156                         union {
 157                                 struct ib_mw    *mw;
 158                                 struct ib_fmr   *fmr;
 159                         } r;
 160                         struct list_head mw_list;
 161                 } *rl_mw;
 162         } mr_chunk;
 163         u64             mr_base;        /* registration result */
 164         u32             mr_rkey;        /* registration result */
 165         u32             mr_len;         /* length of chunk or segment */
 166         int             mr_nsegs;       /* number of segments in chunk or 0 */
 167         enum dma_data_direction mr_dir; /* segment mapping direction */
 168         dma_addr_t      mr_dma;         /* segment mapping address */
 169         size_t          mr_dmalen;      /* segment mapping length */
 170         struct page     *mr_page;       /* owning page, if any */
 171         char            *mr_offset;     /* kva if no page, else offset */
 172 };
 173
 174 struct rpcrdma_req {
 175         size_t          rl_size;        /* actual length of buffer */
 176         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 177         unsigned int    rl_nchunks;     /* non-zero if chunks */
 178         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 179         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 180         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
 181         struct ib_sge   rl_send_iov[4]; /* for active requests */
 182         struct ib_sge   rl_iov;         /* for posting */
 183         struct ib_mr    *rl_handle;     /* handle for mem in rl_iov */
 184         char            rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
 185         __u32           rl_xdr_buf[0];  /* start of returned rpc rq_buffer */
 186 };
 187 #define rpcr_to_rdmar(r) \
 188         container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
 189
 190 /*
 191  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 192  * inline requests/replies, and client/server credits.
 193  *
 194  * One of these is associated with a transport instance
 195  */
 196 struct rpcrdma_buffer {
 197         spinlock_t      rb_lock;        /* protects indexes */
 198         atomic_t        rb_credits;     /* most recent server credits */
 199         unsigned long   rb_cwndscale;   /* cached framework rpc_cwndscale */
 200         int             rb_max_requests;/* client max requests */
 201         struct list_head rb_mws;        /* optional memory windows/fmrs */
 202         int             rb_send_index;
 203         struct rpcrdma_req      **rb_send_bufs;
 204         int             rb_recv_index;
 205         struct rpcrdma_rep      **rb_recv_bufs;
 206         char            *rb_pool;
 207 };
 208 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 209
 210 /*
 211  * Internal structure for transport instance creation. This
 212  * exists primarily for modularity.
 213  *
 214  * This data should be set with mount options
 215  */
 216 struct rpcrdma_create_data_internal {
 217         struct sockaddr_storage addr;   /* RDMA server address */
 218         unsigned int    max_requests;   /* max requests (slots) in flight */
 219         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 220         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 221         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 222         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 223         unsigned int    padding;        /* non-rdma write header padding */
 224 };
 225
 226 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 227         (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_rsize)
 228
 229 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 230         (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_wsize)
 231
 232 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 233         rpcx_to_rdmad(rq->rq_task->tk_xprt).padding
 234
 235 /*
 236  * Statistics for RPCRDMA
 237  */
 238 struct rpcrdma_stats {
 239         unsigned long           read_chunk_count;
 240         unsigned long           write_chunk_count;
 241         unsigned long           reply_chunk_count;
 242
 243         unsigned long long      total_rdma_request;
 244         unsigned long long      total_rdma_reply;
 245
 246         unsigned long long      pullup_copy_count;
 247         unsigned long long      fixup_copy_count;
 248         unsigned long           hardway_register_count;
 249         unsigned long           failed_marshal_count;
 250         unsigned long           bad_reply_count;
 251 };
 252
 253 /*
 254  * RPCRDMA transport -- encapsulates the structures above for
 255  * integration with RPC.
 256  *
 257  * The contained structures are embedded, not pointers,
 258  * for convenience. This structure need not be visible externally.
 259  *
 260  * It is allocated and initialized during mount, and released
 261  * during unmount.
 262  */
 263 struct rpcrdma_xprt {
 264         struct rpc_xprt         xprt;
 265         struct rpcrdma_ia       rx_ia;
 266         struct rpcrdma_ep       rx_ep;
 267         struct rpcrdma_buffer   rx_buf;
 268         struct rpcrdma_create_data_internal rx_data;
 269         struct delayed_work     rdma_connect;
 270         struct rpcrdma_stats    rx_stats;
 271 };
 272
 273 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
 274 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 275
 276 /*
 277  * Interface Adapter calls - xprtrdma/verbs.c
 278  */
 279 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 280 void rpcrdma_ia_close(struct rpcrdma_ia *);
 281
 282 /*
 283  * Endpoint calls - xprtrdma/verbs.c
 284  */
 285 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 286                                 struct rpcrdma_create_data_internal *);
 287 int rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 288 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 289 int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 290
 291 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 292                                 struct rpcrdma_req *);
 293 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 294                                 struct rpcrdma_rep *);
 295
 296 /*
 297  * Buffer calls - xprtrdma/verbs.c
 298  */
 299 int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
 300                                 struct rpcrdma_ia *,
 301                                 struct rpcrdma_create_data_internal *);
 302 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 303
 304 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 305 void rpcrdma_buffer_put(struct rpcrdma_req *);
 306 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 307 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 308
 309 int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
 310                                 struct ib_mr **, struct ib_sge *);
 311 int rpcrdma_deregister_internal(struct rpcrdma_ia *,
 312                                 struct ib_mr *, struct ib_sge *);
 313
 314 int rpcrdma_register_external(struct rpcrdma_mr_seg *,
 315                                 int, int, struct rpcrdma_xprt *);
 316 int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
 317                                 struct rpcrdma_xprt *, void *);
 318
 319 /*
 320  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 321  */
 322 void rpcrdma_conn_func(struct rpcrdma_ep *);
 323 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 324
 325 /*
 326  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 327  */
 328 int rpcrdma_marshal_req(struct rpc_rqst *);
 329
 330 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */