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 #include <linux/workqueue.h>            /* struct work_struct */
  47
  48 #include <rdma/rdma_cm.h>               /* RDMA connection api */
  49 #include <rdma/ib_verbs.h>              /* RDMA verbs api */
  50
  51 #include <linux/sunrpc/clnt.h>          /* rpc_xprt */
  52 #include <linux/sunrpc/rpc_rdma.h>      /* RPC/RDMA protocol */
  53 #include <linux/sunrpc/xprtrdma.h>      /* xprt parameters */
  54
  55 #define RDMA_RESOLVE_TIMEOUT    (5000)  /* 5 seconds */
  56 #define RDMA_CONNECT_RETRY_MAX  (2)     /* retries if no listener backlog */
  57
  58 /*
  59  * Interface Adapter -- one per transport instance
  60  */
  61 struct rpcrdma_ia {
  62         struct rdma_cm_id       *ri_id;
  63         struct ib_pd            *ri_pd;
  64         struct ib_mr            *ri_bind_mem;
  65         u32                     ri_dma_lkey;
  66         int                     ri_have_dma_lkey;
  67         struct completion       ri_done;
  68         int                     ri_async_rc;
  69         enum rpcrdma_memreg     ri_memreg_strategy;
  70         unsigned int            ri_max_frmr_depth;
  71 };
  72
  73 /*
  74  * RDMA Endpoint -- one per transport instance
  75  */
  76
  77 #define RPCRDMA_WC_BUDGET       (128)
  78 #define RPCRDMA_POLLSIZE        (16)
  79
  80 struct rpcrdma_ep {
  81         atomic_t                rep_cqcount;
  82         int                     rep_cqinit;
  83         int                     rep_connected;
  84         struct rpcrdma_ia       *rep_ia;
  85         struct ib_qp_init_attr  rep_attr;
  86         wait_queue_head_t       rep_connect_wait;
  87         struct ib_sge           rep_pad;        /* holds zeroed pad */
  88         struct ib_mr            *rep_pad_mr;    /* holds zeroed pad */
  89         void                    (*rep_func)(struct rpcrdma_ep *);
  90         struct rpc_xprt         *rep_xprt;      /* for rep_func */
  91         struct rdma_conn_param  rep_remote_cma;
  92         struct sockaddr_storage rep_remote_addr;
  93         struct delayed_work     rep_connect_worker;
  94         struct ib_wc            rep_send_wcs[RPCRDMA_POLLSIZE];
  95         struct ib_wc            rep_recv_wcs[RPCRDMA_POLLSIZE];
  96 };
  97
  98 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
  99 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 100
 101 /*
 102  * struct rpcrdma_rep -- this structure encapsulates state required to recv
 103  * and complete a reply, asychronously. It needs several pieces of
 104  * state:
 105  *   o recv buffer (posted to provider)
 106  *   o ib_sge (also donated to provider)
 107  *   o status of reply (length, success or not)
 108  *   o bookkeeping state to get run by tasklet (list, etc)
 109  *
 110  * These are allocated during initialization, per-transport instance;
 111  * however, the tasklet execution list itself is global, as it should
 112  * always be pretty short.
 113  *
 114  * N of these are associated with a transport instance, and stored in
 115  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 116  */
 117
 118 /* temporary static scatter/gather max */
 119 #define RPCRDMA_MAX_DATA_SEGS   (64)    /* max scatter/gather */
 120 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 121 #define MAX_RPCRDMAHDR  (\
 122         /* max supported RPC/RDMA header */ \
 123         sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
 124         (sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
 125
 126 struct rpcrdma_buffer;
 127
 128 struct rpcrdma_rep {
 129         unsigned int    rr_len;         /* actual received reply length */
 130         struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
 131         struct rpc_xprt *rr_xprt;       /* needed for request/reply matching */
 132         void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
 133         struct list_head rr_list;       /* tasklet list */
 134         struct ib_sge   rr_iov;         /* for posting */
 135         struct ib_mr    *rr_handle;     /* handle for mem in rr_iov */
 136         char    rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
 137 };
 138
 139 /*
 140  * struct rpcrdma_req -- structure central to the request/reply sequence.
 141  *
 142  * N of these are associated with a transport instance, and stored in
 143  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 144  *
 145  * It includes pre-registered buffer memory for send AND recv.
 146  * The recv buffer, however, is not owned by this structure, and
 147  * is "donated" to the hardware when a recv is posted. When a
 148  * reply is handled, the recv buffer used is given back to the
 149  * struct rpcrdma_req associated with the request.
 150  *
 151  * In addition to the basic memory, this structure includes an array
 152  * of iovs for send operations. The reason is that the iovs passed to
 153  * ib_post_{send,recv} must not be modified until the work request
 154  * completes.
 155  *
 156  * NOTES:
 157  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 158  *     marshal. The number needed varies depending on the iov lists that
 159  *     are passed to us, the memory registration mode we are in, and if
 160  *     physical addressing is used, the layout.
 161  */
 162
 163 struct rpcrdma_mr_seg {         /* chunk descriptors */
 164         union {                         /* chunk memory handles */
 165                 struct ib_mr    *rl_mr;         /* if registered directly */
 166                 struct rpcrdma_mw {             /* if registered from region */
 167                         union {
 168                                 struct ib_fmr   *fmr;
 169                                 struct {
 170                                         struct ib_fast_reg_page_list *fr_pgl;
 171                                         struct ib_mr *fr_mr;
 172                                         enum { FRMR_IS_INVALID, FRMR_IS_VALID  } state;
 173                                 } frmr;
 174                         } r;
 175                         struct list_head mw_list;
 176                 } *rl_mw;
 177         } mr_chunk;
 178         u64             mr_base;        /* registration result */
 179         u32             mr_rkey;        /* registration result */
 180         u32             mr_len;         /* length of chunk or segment */
 181         int             mr_nsegs;       /* number of segments in chunk or 0 */
 182         enum dma_data_direction mr_dir; /* segment mapping direction */
 183         dma_addr_t      mr_dma;         /* segment mapping address */
 184         size_t          mr_dmalen;      /* segment mapping length */
 185         struct page     *mr_page;       /* owning page, if any */
 186         char            *mr_offset;     /* kva if no page, else offset */
 187 };
 188
 189 struct rpcrdma_req {
 190         size_t          rl_size;        /* actual length of buffer */
 191         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 192         unsigned int    rl_nchunks;     /* non-zero if chunks */
 193         unsigned int    rl_connect_cookie;      /* retry detection */
 194         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 195         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 196         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
 197         struct ib_sge   rl_send_iov[4]; /* for active requests */
 198         struct ib_sge   rl_iov;         /* for posting */
 199         struct ib_mr    *rl_handle;     /* handle for mem in rl_iov */
 200         char            rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
 201         __u32           rl_xdr_buf[0];  /* start of returned rpc rq_buffer */
 202 };
 203 #define rpcr_to_rdmar(r) \
 204         container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
 205
 206 /*
 207  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 208  * inline requests/replies, and client/server credits.
 209  *
 210  * One of these is associated with a transport instance
 211  */
 212 struct rpcrdma_buffer {
 213         spinlock_t      rb_lock;        /* protects indexes */
 214         atomic_t        rb_credits;     /* most recent server credits */
 215         int             rb_max_requests;/* client max requests */
 216         struct list_head rb_mws;        /* optional memory windows/fmrs/frmrs */
 217         int             rb_send_index;
 218         struct rpcrdma_req      **rb_send_bufs;
 219         int             rb_recv_index;
 220         struct rpcrdma_rep      **rb_recv_bufs;
 221         char            *rb_pool;
 222 };
 223 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 224
 225 /*
 226  * Internal structure for transport instance creation. This
 227  * exists primarily for modularity.
 228  *
 229  * This data should be set with mount options
 230  */
 231 struct rpcrdma_create_data_internal {
 232         struct sockaddr_storage addr;   /* RDMA server address */
 233         unsigned int    max_requests;   /* max requests (slots) in flight */
 234         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 235         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 236         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 237         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 238         unsigned int    padding;        /* non-rdma write header padding */
 239 };
 240
 241 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 242         (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 243
 244 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 245         (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 246
 247 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 248         rpcx_to_rdmad(rq->rq_xprt).padding
 249
 250 /*
 251  * Statistics for RPCRDMA
 252  */
 253 struct rpcrdma_stats {
 254         unsigned long           read_chunk_count;
 255         unsigned long           write_chunk_count;
 256         unsigned long           reply_chunk_count;
 257
 258         unsigned long long      total_rdma_request;
 259         unsigned long long      total_rdma_reply;
 260
 261         unsigned long long      pullup_copy_count;
 262         unsigned long long      fixup_copy_count;
 263         unsigned long           hardway_register_count;
 264         unsigned long           failed_marshal_count;
 265         unsigned long           bad_reply_count;
 266 };
 267
 268 /*
 269  * RPCRDMA transport -- encapsulates the structures above for
 270  * integration with RPC.
 271  *
 272  * The contained structures are embedded, not pointers,
 273  * for convenience. This structure need not be visible externally.
 274  *
 275  * It is allocated and initialized during mount, and released
 276  * during unmount.
 277  */
 278 struct rpcrdma_xprt {
 279         struct rpc_xprt         xprt;
 280         struct rpcrdma_ia       rx_ia;
 281         struct rpcrdma_ep       rx_ep;
 282         struct rpcrdma_buffer   rx_buf;
 283         struct rpcrdma_create_data_internal rx_data;
 284         struct delayed_work     rdma_connect;
 285         struct rpcrdma_stats    rx_stats;
 286 };
 287
 288 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
 289 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 290
 291 /* Setting this to 0 ensures interoperability with early servers.
 292  * Setting this to 1 enhances certain unaligned read/write performance.
 293  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 294 extern int xprt_rdma_pad_optimize;
 295
 296 /*
 297  * Interface Adapter calls - xprtrdma/verbs.c
 298  */
 299 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 300 void rpcrdma_ia_close(struct rpcrdma_ia *);
 301
 302 /*
 303  * Endpoint calls - xprtrdma/verbs.c
 304  */
 305 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 306                                 struct rpcrdma_create_data_internal *);
 307 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 308 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 309 int rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 310
 311 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 312                                 struct rpcrdma_req *);
 313 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 314                                 struct rpcrdma_rep *);
 315
 316 /*
 317  * Buffer calls - xprtrdma/verbs.c
 318  */
 319 int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
 320                                 struct rpcrdma_ia *,
 321                                 struct rpcrdma_create_data_internal *);
 322 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 323
 324 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 325 void rpcrdma_buffer_put(struct rpcrdma_req *);
 326 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 327 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 328
 329 int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
 330                                 struct ib_mr **, struct ib_sge *);
 331 int rpcrdma_deregister_internal(struct rpcrdma_ia *,
 332                                 struct ib_mr *, struct ib_sge *);
 333
 334 int rpcrdma_register_external(struct rpcrdma_mr_seg *,
 335                                 int, int, struct rpcrdma_xprt *);
 336 int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
 337                                 struct rpcrdma_xprt *);
 338
 339 /*
 340  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 341  */
 342 void rpcrdma_connect_worker(struct work_struct *);
 343 void rpcrdma_conn_func(struct rpcrdma_ep *);
 344 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 345
 346 /*
 347  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 348  */
 349 int rpcrdma_marshal_req(struct rpc_rqst *);
 350
 351 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 352 extern struct kmem_cache *svc_rdma_map_cachep;
 353 /* WR context cache. Created in svc_rdma.c  */
 354 extern struct kmem_cache *svc_rdma_ctxt_cachep;
 355 /* Workqueue created in svc_rdma.c */
 356 extern struct workqueue_struct *svc_rdma_wq;
 357
 358 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */