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 #include <linux/sunrpc/svc.h>           /* RPCSVC_MAXPAYLOAD */
  55
  56 #define RDMA_RESOLVE_TIMEOUT    (5000)  /* 5 seconds */
  57 #define RDMA_CONNECT_RETRY_MAX  (2)     /* retries if no listener backlog */
  58
  59 /*
  60  * Interface Adapter -- one per transport instance
  61  */
  62 struct rpcrdma_ia {
  63         rwlock_t                ri_qplock;
  64         struct rdma_cm_id       *ri_id;
  65         struct ib_pd            *ri_pd;
  66         struct ib_mr            *ri_bind_mem;
  67         u32                     ri_dma_lkey;
  68         int                     ri_have_dma_lkey;
  69         struct completion       ri_done;
  70         int                     ri_async_rc;
  71         enum rpcrdma_memreg     ri_memreg_strategy;
  72         unsigned int            ri_max_frmr_depth;
  73 };
  74
  75 /*
  76  * RDMA Endpoint -- one per transport instance
  77  */
  78
  79 #define RPCRDMA_WC_BUDGET       (128)
  80 #define RPCRDMA_POLLSIZE        (16)
  81
  82 struct rpcrdma_ep {
  83         atomic_t                rep_cqcount;
  84         int                     rep_cqinit;
  85         int                     rep_connected;
  86         struct rpcrdma_ia       *rep_ia;
  87         struct ib_qp_init_attr  rep_attr;
  88         wait_queue_head_t       rep_connect_wait;
  89         struct ib_sge           rep_pad;        /* holds zeroed pad */
  90         struct ib_mr            *rep_pad_mr;    /* holds zeroed pad */
  91         void                    (*rep_func)(struct rpcrdma_ep *);
  92         struct rpc_xprt         *rep_xprt;      /* for rep_func */
  93         struct rdma_conn_param  rep_remote_cma;
  94         struct sockaddr_storage rep_remote_addr;
  95         struct delayed_work     rep_connect_worker;
  96         struct ib_wc            rep_send_wcs[RPCRDMA_POLLSIZE];
  97         struct ib_wc            rep_recv_wcs[RPCRDMA_POLLSIZE];
  98 };
  99
 100 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 101 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 102
 103 enum rpcrdma_chunktype {
 104         rpcrdma_noch = 0,
 105         rpcrdma_readch,
 106         rpcrdma_areadch,
 107         rpcrdma_writech,
 108         rpcrdma_replych
 109 };
 110
 111 /*
 112  * struct rpcrdma_rep -- this structure encapsulates state required to recv
 113  * and complete a reply, asychronously. It needs several pieces of
 114  * state:
 115  *   o recv buffer (posted to provider)
 116  *   o ib_sge (also donated to provider)
 117  *   o status of reply (length, success or not)
 118  *   o bookkeeping state to get run by tasklet (list, etc)
 119  *
 120  * These are allocated during initialization, per-transport instance;
 121  * however, the tasklet execution list itself is global, as it should
 122  * always be pretty short.
 123  *
 124  * N of these are associated with a transport instance, and stored in
 125  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 126  */
 127
 128 /* temporary static scatter/gather max */
 129 #define RPCRDMA_MAX_DATA_SEGS   (64)    /* max scatter/gather */
 130 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 131 #define MAX_RPCRDMAHDR  (\
 132         /* max supported RPC/RDMA header */ \
 133         sizeof(struct rpcrdma_msg) + (2 * sizeof(u32)) + \
 134         (sizeof(struct rpcrdma_read_chunk) * RPCRDMA_MAX_SEGS) + sizeof(u32))
 135
 136 struct rpcrdma_buffer;
 137
 138 struct rpcrdma_rep {
 139         unsigned int    rr_len;         /* actual received reply length */
 140         struct rpcrdma_buffer *rr_buffer; /* home base for this structure */
 141         struct rpc_xprt *rr_xprt;       /* needed for request/reply matching */
 142         void (*rr_func)(struct rpcrdma_rep *);/* called by tasklet in softint */
 143         struct list_head rr_list;       /* tasklet list */
 144         struct ib_sge   rr_iov;         /* for posting */
 145         struct ib_mr    *rr_handle;     /* handle for mem in rr_iov */
 146         char    rr_base[MAX_RPCRDMAHDR]; /* minimal inline receive buffer */
 147 };
 148
 149 /*
 150  * struct rpcrdma_mw - external memory region metadata
 151  *
 152  * An external memory region is any buffer or page that is registered
 153  * on the fly (ie, not pre-registered).
 154  *
 155  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
 156  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
 157  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
 158  * track of registration metadata while each RPC is pending.
 159  * rpcrdma_deregister_external() uses this metadata to unmap and
 160  * release these resources when an RPC is complete.
 161  */
 162 enum rpcrdma_frmr_state {
 163         FRMR_IS_INVALID,        /* ready to be used */
 164         FRMR_IS_VALID,          /* in use */
 165         FRMR_IS_STALE,          /* failed completion */
 166 };
 167
 168 struct rpcrdma_frmr {
 169         struct ib_fast_reg_page_list    *fr_pgl;
 170         struct ib_mr                    *fr_mr;
 171         enum rpcrdma_frmr_state         fr_state;
 172 };
 173
 174 struct rpcrdma_mw {
 175         union {
 176                 struct ib_fmr           *fmr;
 177                 struct rpcrdma_frmr     frmr;
 178         } r;
 179         struct list_head        mw_list;
 180         struct list_head        mw_all;
 181 };
 182
 183 /*
 184  * struct rpcrdma_req -- structure central to the request/reply sequence.
 185  *
 186  * N of these are associated with a transport instance, and stored in
 187  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 188  *
 189  * It includes pre-registered buffer memory for send AND recv.
 190  * The recv buffer, however, is not owned by this structure, and
 191  * is "donated" to the hardware when a recv is posted. When a
 192  * reply is handled, the recv buffer used is given back to the
 193  * struct rpcrdma_req associated with the request.
 194  *
 195  * In addition to the basic memory, this structure includes an array
 196  * of iovs for send operations. The reason is that the iovs passed to
 197  * ib_post_{send,recv} must not be modified until the work request
 198  * completes.
 199  *
 200  * NOTES:
 201  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 202  *     marshal. The number needed varies depending on the iov lists that
 203  *     are passed to us, the memory registration mode we are in, and if
 204  *     physical addressing is used, the layout.
 205  */
 206
 207 struct rpcrdma_mr_seg {         /* chunk descriptors */
 208         union {                         /* chunk memory handles */
 209                 struct ib_mr    *rl_mr;         /* if registered directly */
 210                 struct rpcrdma_mw *rl_mw;       /* if registered from region */
 211         } mr_chunk;
 212         u64             mr_base;        /* registration result */
 213         u32             mr_rkey;        /* registration result */
 214         u32             mr_len;         /* length of chunk or segment */
 215         int             mr_nsegs;       /* number of segments in chunk or 0 */
 216         enum dma_data_direction mr_dir; /* segment mapping direction */
 217         dma_addr_t      mr_dma;         /* segment mapping address */
 218         size_t          mr_dmalen;      /* segment mapping length */
 219         struct page     *mr_page;       /* owning page, if any */
 220         char            *mr_offset;     /* kva if no page, else offset */
 221 };
 222
 223 struct rpcrdma_req {
 224         size_t          rl_size;        /* actual length of buffer */
 225         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 226         unsigned int    rl_nchunks;     /* non-zero if chunks */
 227         unsigned int    rl_connect_cookie;      /* retry detection */
 228         enum rpcrdma_chunktype  rl_rtype, rl_wtype;
 229         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 230         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 231         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
 232         struct ib_sge   rl_send_iov[4]; /* for active requests */
 233         struct ib_sge   rl_iov;         /* for posting */
 234         struct ib_mr    *rl_handle;     /* handle for mem in rl_iov */
 235         char            rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
 236         __u32           rl_xdr_buf[0];  /* start of returned rpc rq_buffer */
 237 };
 238 #define rpcr_to_rdmar(r) \
 239         container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
 240
 241 /*
 242  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 243  * inline requests/replies, and client/server credits.
 244  *
 245  * One of these is associated with a transport instance
 246  */
 247 struct rpcrdma_buffer {
 248         spinlock_t      rb_lock;        /* protects indexes */
 249         atomic_t        rb_credits;     /* most recent server credits */
 250         int             rb_max_requests;/* client max requests */
 251         struct list_head rb_mws;        /* optional memory windows/fmrs/frmrs */
 252         struct list_head rb_all;
 253         int             rb_send_index;
 254         struct rpcrdma_req      **rb_send_bufs;
 255         int             rb_recv_index;
 256         struct rpcrdma_rep      **rb_recv_bufs;
 257         char            *rb_pool;
 258 };
 259 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 260
 261 /*
 262  * Internal structure for transport instance creation. This
 263  * exists primarily for modularity.
 264  *
 265  * This data should be set with mount options
 266  */
 267 struct rpcrdma_create_data_internal {
 268         struct sockaddr_storage addr;   /* RDMA server address */
 269         unsigned int    max_requests;   /* max requests (slots) in flight */
 270         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 271         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 272         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 273         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 274         unsigned int    padding;        /* non-rdma write header padding */
 275 };
 276
 277 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 278         (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 279
 280 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 281         (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 282
 283 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 284         rpcx_to_rdmad(rq->rq_xprt).padding
 285
 286 /*
 287  * Statistics for RPCRDMA
 288  */
 289 struct rpcrdma_stats {
 290         unsigned long           read_chunk_count;
 291         unsigned long           write_chunk_count;
 292         unsigned long           reply_chunk_count;
 293
 294         unsigned long long      total_rdma_request;
 295         unsigned long long      total_rdma_reply;
 296
 297         unsigned long long      pullup_copy_count;
 298         unsigned long long      fixup_copy_count;
 299         unsigned long           hardway_register_count;
 300         unsigned long           failed_marshal_count;
 301         unsigned long           bad_reply_count;
 302 };
 303
 304 /*
 305  * RPCRDMA transport -- encapsulates the structures above for
 306  * integration with RPC.
 307  *
 308  * The contained structures are embedded, not pointers,
 309  * for convenience. This structure need not be visible externally.
 310  *
 311  * It is allocated and initialized during mount, and released
 312  * during unmount.
 313  */
 314 struct rpcrdma_xprt {
 315         struct rpc_xprt         xprt;
 316         struct rpcrdma_ia       rx_ia;
 317         struct rpcrdma_ep       rx_ep;
 318         struct rpcrdma_buffer   rx_buf;
 319         struct rpcrdma_create_data_internal rx_data;
 320         struct delayed_work     rdma_connect;
 321         struct rpcrdma_stats    rx_stats;
 322 };
 323
 324 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
 325 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 326
 327 /* Setting this to 0 ensures interoperability with early servers.
 328  * Setting this to 1 enhances certain unaligned read/write performance.
 329  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 330 extern int xprt_rdma_pad_optimize;
 331
 332 /*
 333  * Interface Adapter calls - xprtrdma/verbs.c
 334  */
 335 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 336 void rpcrdma_ia_close(struct rpcrdma_ia *);
 337
 338 /*
 339  * Endpoint calls - xprtrdma/verbs.c
 340  */
 341 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 342                                 struct rpcrdma_create_data_internal *);
 343 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 344 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 345 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 346
 347 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 348                                 struct rpcrdma_req *);
 349 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 350                                 struct rpcrdma_rep *);
 351
 352 /*
 353  * Buffer calls - xprtrdma/verbs.c
 354  */
 355 int rpcrdma_buffer_create(struct rpcrdma_buffer *, struct rpcrdma_ep *,
 356                                 struct rpcrdma_ia *,
 357                                 struct rpcrdma_create_data_internal *);
 358 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 359
 360 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 361 void rpcrdma_buffer_put(struct rpcrdma_req *);
 362 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 363 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 364
 365 int rpcrdma_register_internal(struct rpcrdma_ia *, void *, int,
 366                                 struct ib_mr **, struct ib_sge *);
 367 int rpcrdma_deregister_internal(struct rpcrdma_ia *,
 368                                 struct ib_mr *, struct ib_sge *);
 369
 370 int rpcrdma_register_external(struct rpcrdma_mr_seg *,
 371                                 int, int, struct rpcrdma_xprt *);
 372 int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
 373                                 struct rpcrdma_xprt *);
 374
 375 /*
 376  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 377  */
 378 void rpcrdma_connect_worker(struct work_struct *);
 379 void rpcrdma_conn_func(struct rpcrdma_ep *);
 380 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 381
 382 /*
 383  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 384  */
 385 ssize_t rpcrdma_marshal_chunks(struct rpc_rqst *, ssize_t);
 386 int rpcrdma_marshal_req(struct rpc_rqst *);
 387 size_t rpcrdma_max_payload(struct rpcrdma_xprt *);
 388
 389 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 390 extern struct kmem_cache *svc_rdma_map_cachep;
 391 /* WR context cache. Created in svc_rdma.c  */
 392 extern struct kmem_cache *svc_rdma_ctxt_cachep;
 393 /* Workqueue created in svc_rdma.c */
 394 extern struct workqueue_struct *svc_rdma_wq;
 395
 396 #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 397 #define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
 398 #else
 399 #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 400 #endif
 401
 402 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */