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 <linux/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 #define RDMA_RESOLVE_TIMEOUT    (5000)  /* 5 seconds */
  55 #define RDMA_CONNECT_RETRY_MAX  (2)     /* retries if no listener backlog */
  56
  57 /*
  58  * Interface Adapter -- one per transport instance
  59  */
  60 struct rpcrdma_ia {
  61         struct rdma_cm_id       *ri_id;
  62         struct ib_pd            *ri_pd;
  63         struct ib_mr            *ri_bind_mem;
  64         u32                     ri_dma_lkey;
  65         int                     ri_have_dma_lkey;
  66         struct completion       ri_done;
  67         int                     ri_async_rc;
  68         enum rpcrdma_memreg     ri_memreg_strategy;
  69 };
  70
  71 /*
  72  * RDMA Endpoint -- one per transport instance
  73  */
  74
  75 struct rpcrdma_ep {
  76         atomic_t                rep_cqcount;
  77         int                     rep_cqinit;
  78         int                     rep_connected;
  79         struct rpcrdma_ia       *rep_ia;
  80         struct ib_cq            *rep_cq;
  81         struct ib_qp_init_attr  rep_attr;
  82         wait_queue_head_t       rep_connect_wait;
  83         struct ib_sge           rep_pad;        /* holds zeroed pad */
  84         struct ib_mr            *rep_pad_mr;    /* holds zeroed pad */
  85         void                    (*rep_func)(struct rpcrdma_ep *);
  86         struct rpc_xprt         *rep_xprt;      /* for rep_func */
  87         struct rdma_conn_param  rep_remote_cma;
  88         struct sockaddr_storage rep_remote_addr;
  89 };
  90
  91 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
  92 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
  93
  94 /*
  95  * struct rpcrdma_rep -- this structure encapsulates state required to recv
  96  * and complete a reply, asychronously. It needs several pieces of
  97  * state:
  98  *   o recv buffer (posted to provider)
  99  *   o ib_sge (also donated to provider)
 100  *   o status of reply (length, success or not)
 101  *   o bookkeeping state to get run by tasklet (list, etc)
 102  *
 103  * These are allocated during initialization, per-transport instance;
 104  * however, the tasklet execution list itself is global, as it should
 105  * always be pretty short.
 106  *
 107  * N of these are associated with a transport instance, and stored in
 108  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 109  */
 110
 111 /* temporary static scatter/gather max */
 112 #define RPCRDMA_MAX_DATA_SEGS   (8)     /* max scatter/gather */
 113 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 114 #define MAX_RPCRDMAHDR  (\
 115         /* max supported RPC/RDMA header */ \
 116         sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
 117         (sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
 118
 119 struct rpcrdma_buffer;
 120
 121 struct rpcrdma_rep {
 122         unsigned int    rr_len;         /* actual received reply length */
 123         struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
 124         struct rpc_xprt *rr_xprt;       /* needed for request/reply matching */
 125         void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
 126         struct list_head rr_list;       /* tasklet list */
 127         wait_queue_head_t rr_unbind;    /* optional unbind wait */
 128         struct ib_sge   rr_iov;         /* for posting */
 129         struct ib_mr    *rr_handle;     /* handle for mem in rr_iov */
 130         char    rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
 131 };
 132
 133 /*
 134  * struct rpcrdma_req -- structure central to the request/reply sequence.
 135  *
 136  * N of these are associated with a transport instance, and stored in
 137  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 138  *
 139  * It includes pre-registered buffer memory for send AND recv.
 140  * The recv buffer, however, is not owned by this structure, and
 141  * is "donated" to the hardware when a recv is posted. When a
 142  * reply is handled, the recv buffer used is given back to the
 143  * struct rpcrdma_req associated with the request.
 144  *
 145  * In addition to the basic memory, this structure includes an array
 146  * of iovs for send operations. The reason is that the iovs passed to
 147  * ib_post_{send,recv} must not be modified until the work request
 148  * completes.
 149  *
 150  * NOTES:
 151  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 152  *     marshal. The number needed varies depending on the iov lists that
 153  *     are passed to us, the memory registration mode we are in, and if
 154  *     physical addressing is used, the layout.
 155  */
 156
 157 struct rpcrdma_mr_seg {         /* chunk descriptors */
 158         union {                         /* chunk memory handles */
 159                 struct ib_mr    *rl_mr;         /* if registered directly */
 160                 struct rpcrdma_mw {             /* if registered from region */
 161                         union {
 162                                 struct ib_mw    *mw;
 163                                 struct ib_fmr   *fmr;
 164                                 struct {
 165                                         struct ib_fast_reg_page_list *fr_pgl;
 166                                         struct ib_mr *fr_mr;
 167                                         enum { FRMR_IS_INVALID, FRMR_IS_VALID  } state;
 168                                 } frmr;
 169                         } r;
 170                         struct list_head mw_list;
 171                 } *rl_mw;
 172         } mr_chunk;
 173         u64             mr_base;        /* registration result */
 174         u32             mr_rkey;        /* registration result */
 175         u32             mr_len;         /* length of chunk or segment */
 176         int             mr_nsegs;       /* number of segments in chunk or 0 */
 177         enum dma_data_direction mr_dir; /* segment mapping direction */
 178         dma_addr_t      mr_dma;         /* segment mapping address */
 179         size_t          mr_dmalen;      /* segment mapping length */
 180         struct page     *mr_page;       /* owning page, if any */
 181         char            *mr_offset;     /* kva if no page, else offset */
 182 };
 183
 184 struct rpcrdma_req {
 185         size_t          rl_size;        /* actual length of buffer */
 186         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 187         unsigned int    rl_nchunks;     /* non-zero if chunks */
 188         unsigned int    rl_connect_cookie;      /* retry detection */
 189         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 190         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 191         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
 192         struct ib_sge   rl_send_iov[4]; /* for active requests */
 193         struct ib_sge   rl_iov;         /* for posting */
 194         struct ib_mr    *rl_handle;     /* handle for mem in rl_iov */
 195         char            rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
 196         __u32           rl_xdr_buf[0];  /* start of returned rpc rq_buffer */
 197 };
 198 #define rpcr_to_rdmar(r) \
 199         container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
 200
 201 /*
 202  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 203  * inline requests/replies, and client/server credits.
 204  *
 205  * One of these is associated with a transport instance
 206  */
 207 struct rpcrdma_buffer {
 208         spinlock_t      rb_lock;        /* protects indexes */
 209         atomic_t        rb_credits;     /* most recent server credits */
 210         unsigned long   rb_cwndscale;   /* cached framework rpc_cwndscale */
 211         int             rb_max_requests;/* client max requests */
 212         struct list_head rb_mws;        /* optional memory windows/fmrs/frmrs */
 213         int             rb_send_index;
 214         struct rpcrdma_req      **rb_send_bufs;
 215         int             rb_recv_index;
 216         struct rpcrdma_rep      **rb_recv_bufs;
 217         char            *rb_pool;
 218 };
 219 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 220
 221 /*
 222  * Internal structure for transport instance creation. This
 223  * exists primarily for modularity.
 224  *
 225  * This data should be set with mount options
 226  */
 227 struct rpcrdma_create_data_internal {
 228         struct sockaddr_storage addr;   /* RDMA server address */
 229         unsigned int    max_requests;   /* max requests (slots) in flight */
 230         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 231         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 232         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 233         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 234         unsigned int    padding;        /* non-rdma write header padding */
 235 };
 236
 237 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 238         (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_rsize)
 239
 240 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 241         (rpcx_to_rdmad(rq->rq_task->tk_xprt).inline_wsize)
 242
 243 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 244         rpcx_to_rdmad(rq->rq_task->tk_xprt).padding
 245
 246 /*
 247  * Statistics for RPCRDMA
 248  */
 249 struct rpcrdma_stats {
 250         unsigned long           read_chunk_count;
 251         unsigned long           write_chunk_count;
 252         unsigned long           reply_chunk_count;
 253
 254         unsigned long long      total_rdma_request;
 255         unsigned long long      total_rdma_reply;
 256
 257         unsigned long long      pullup_copy_count;
 258         unsigned long long      fixup_copy_count;
 259         unsigned long           hardway_register_count;
 260         unsigned long           failed_marshal_count;
 261         unsigned long           bad_reply_count;
 262 };
 263
 264 /*
 265  * RPCRDMA transport -- encapsulates the structures above for
 266  * integration with RPC.
 267  *
 268  * The contained structures are embedded, not pointers,
 269  * for convenience. This structure need not be visible externally.
 270  *
 271  * It is allocated and initialized during mount, and released
 272  * during unmount.
 273  */
 274 struct rpcrdma_xprt {
 275         struct rpc_xprt         xprt;
 276         struct rpcrdma_ia       rx_ia;
 277         struct rpcrdma_ep       rx_ep;
 278         struct rpcrdma_buffer   rx_buf;
 279         struct rpcrdma_create_data_internal rx_data;
 280         struct delayed_work     rdma_connect;
 281         struct rpcrdma_stats    rx_stats;
 282 };
 283
 284 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
 285 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 286
 287 /* Setting this to 0 ensures interoperability with early servers.
 288  * Setting this to 1 enhances certain unaligned read/write performance.
 289  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 290 extern int xprt_rdma_pad_optimize;
 291
 292 /*
 293  * Interface Adapter calls - xprtrdma/verbs.c
 294  */
 295 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 296 void rpcrdma_ia_close(struct rpcrdma_ia *);
 297
 298 /*
 299  * Endpoint calls - xprtrdma/verbs.c
 300  */
 301 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 302                                 struct rpcrdma_create_data_internal *);
 303 int rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 304 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 305 int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 306
 307 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 308                                 struct rpcrdma_req *);
 309 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 310                                 struct rpcrdma_rep *);
 311
 312 /*
 313  * Buffer calls - xprtrdma/verbs.c
 314  */
 315 int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
 316                                 struct rpcrdma_ia *,
 317                                 struct rpcrdma_create_data_internal *);
 318 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 319
 320 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 321 void rpcrdma_buffer_put(struct rpcrdma_req *);
 322 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 323 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 324
 325 int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
 326                                 struct ib_mr **, struct ib_sge *);
 327 int rpcrdma_deregister_internal(struct rpcrdma_ia *,
 328                                 struct ib_mr *, struct ib_sge *);
 329
 330 int rpcrdma_register_external(struct rpcrdma_mr_seg *,
 331                                 int, int, struct rpcrdma_xprt *);
 332 int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
 333                                 struct rpcrdma_xprt *, void *);
 334
 335 /*
 336  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 337  */
 338 void rpcrdma_conn_func(struct rpcrdma_ep *);
 339 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 340
 341 /*
 342  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 343  */
 344 int rpcrdma_marshal_req(struct rpc_rqst *);
 345
 346 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */