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         const struct rpcrdma_memreg_ops *ri_ops;
  64         rwlock_t                ri_qplock;
  65         struct rdma_cm_id       *ri_id;
  66         struct ib_pd            *ri_pd;
  67         struct ib_mr            *ri_bind_mem;
  68         u32                     ri_dma_lkey;
  69         int                     ri_have_dma_lkey;
  70         struct completion       ri_done;
  71         int                     ri_async_rc;
  72         enum rpcrdma_memreg     ri_memreg_strategy;
  73         unsigned int            ri_max_frmr_depth;
  74         struct ib_device_attr   ri_devattr;
  75         struct ib_qp_attr       ri_qp_attr;
  76         struct ib_qp_init_attr  ri_qp_init_attr;
  77 };
  78
  79 /*
  80  * RDMA Endpoint -- one per transport instance
  81  */
  82
  83 #define RPCRDMA_WC_BUDGET       (128)
  84 #define RPCRDMA_POLLSIZE        (16)
  85
  86 struct rpcrdma_ep {
  87         atomic_t                rep_cqcount;
  88         int                     rep_cqinit;
  89         int                     rep_connected;
  90         struct ib_qp_init_attr  rep_attr;
  91         wait_queue_head_t       rep_connect_wait;
  92         struct rpcrdma_regbuf   *rep_padbuf;
  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 /*
 101  * Force a signaled SEND Work Request every so often,
 102  * in case the provider needs to do some housekeeping.
 103  */
 104 #define RPCRDMA_MAX_UNSIGNALED_SENDS    (32)
 105
 106 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 107 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 108
 109 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
 110  *
 111  * The below structure appears at the front of a large region of kmalloc'd
 112  * memory, which always starts on a good alignment boundary.
 113  */
 114
 115 struct rpcrdma_regbuf {
 116         size_t                  rg_size;
 117         struct rpcrdma_req      *rg_owner;
 118         struct ib_mr            *rg_mr;
 119         struct ib_sge           rg_iov;
 120         __be32                  rg_base[0] __attribute__ ((aligned(256)));
 121 };
 122
 123 static inline u64
 124 rdmab_addr(struct rpcrdma_regbuf *rb)
 125 {
 126         return rb->rg_iov.addr;
 127 }
 128
 129 static inline u32
 130 rdmab_length(struct rpcrdma_regbuf *rb)
 131 {
 132         return rb->rg_iov.length;
 133 }
 134
 135 static inline u32
 136 rdmab_lkey(struct rpcrdma_regbuf *rb)
 137 {
 138         return rb->rg_iov.lkey;
 139 }
 140
 141 static inline struct rpcrdma_msg *
 142 rdmab_to_msg(struct rpcrdma_regbuf *rb)
 143 {
 144         return (struct rpcrdma_msg *)rb->rg_base;
 145 }
 146
 147 /*
 148  * struct rpcrdma_rep -- this structure encapsulates state required to recv
 149  * and complete a reply, asychronously. It needs several pieces of
 150  * state:
 151  *   o recv buffer (posted to provider)
 152  *   o ib_sge (also donated to provider)
 153  *   o status of reply (length, success or not)
 154  *   o bookkeeping state to get run by tasklet (list, etc)
 155  *
 156  * These are allocated during initialization, per-transport instance;
 157  * however, the tasklet execution list itself is global, as it should
 158  * always be pretty short.
 159  *
 160  * N of these are associated with a transport instance, and stored in
 161  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 162  */
 163
 164 /* temporary static scatter/gather max */
 165 #define RPCRDMA_MAX_DATA_SEGS   (64)    /* max scatter/gather */
 166 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 167
 168 struct rpcrdma_buffer;
 169
 170 struct rpcrdma_rep {
 171         unsigned int            rr_len;
 172         struct rpcrdma_buffer   *rr_buffer;
 173         struct rpc_xprt         *rr_xprt;
 174         void                    (*rr_func)(struct rpcrdma_rep *);
 175         struct list_head        rr_list;
 176         struct rpcrdma_regbuf   *rr_rdmabuf;
 177 };
 178
 179 /*
 180  * struct rpcrdma_mw - external memory region metadata
 181  *
 182  * An external memory region is any buffer or page that is registered
 183  * on the fly (ie, not pre-registered).
 184  *
 185  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
 186  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
 187  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
 188  * track of registration metadata while each RPC is pending.
 189  * rpcrdma_deregister_external() uses this metadata to unmap and
 190  * release these resources when an RPC is complete.
 191  */
 192 enum rpcrdma_frmr_state {
 193         FRMR_IS_INVALID,        /* ready to be used */
 194         FRMR_IS_VALID,          /* in use */
 195         FRMR_IS_STALE,          /* failed completion */
 196 };
 197
 198 struct rpcrdma_frmr {
 199         struct ib_fast_reg_page_list    *fr_pgl;
 200         struct ib_mr                    *fr_mr;
 201         enum rpcrdma_frmr_state         fr_state;
 202 };
 203
 204 struct rpcrdma_mw {
 205         union {
 206                 struct ib_fmr           *fmr;
 207                 struct rpcrdma_frmr     frmr;
 208         } r;
 209         struct list_head        mw_list;
 210         struct list_head        mw_all;
 211 };
 212
 213 /*
 214  * struct rpcrdma_req -- structure central to the request/reply sequence.
 215  *
 216  * N of these are associated with a transport instance, and stored in
 217  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 218  *
 219  * It includes pre-registered buffer memory for send AND recv.
 220  * The recv buffer, however, is not owned by this structure, and
 221  * is "donated" to the hardware when a recv is posted. When a
 222  * reply is handled, the recv buffer used is given back to the
 223  * struct rpcrdma_req associated with the request.
 224  *
 225  * In addition to the basic memory, this structure includes an array
 226  * of iovs for send operations. The reason is that the iovs passed to
 227  * ib_post_{send,recv} must not be modified until the work request
 228  * completes.
 229  *
 230  * NOTES:
 231  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 232  *     marshal. The number needed varies depending on the iov lists that
 233  *     are passed to us, the memory registration mode we are in, and if
 234  *     physical addressing is used, the layout.
 235  */
 236
 237 struct rpcrdma_mr_seg {         /* chunk descriptors */
 238         struct rpcrdma_mw *rl_mw;       /* registered MR */
 239         u64             mr_base;        /* registration result */
 240         u32             mr_rkey;        /* registration result */
 241         u32             mr_len;         /* length of chunk or segment */
 242         int             mr_nsegs;       /* number of segments in chunk or 0 */
 243         enum dma_data_direction mr_dir; /* segment mapping direction */
 244         dma_addr_t      mr_dma;         /* segment mapping address */
 245         size_t          mr_dmalen;      /* segment mapping length */
 246         struct page     *mr_page;       /* owning page, if any */
 247         char            *mr_offset;     /* kva if no page, else offset */
 248 };
 249
 250 struct rpcrdma_req {
 251         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 252         unsigned int    rl_nchunks;     /* non-zero if chunks */
 253         unsigned int    rl_connect_cookie;      /* retry detection */
 254         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 255         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 256         struct ib_sge   rl_send_iov[4]; /* for active requests */
 257         struct rpcrdma_regbuf *rl_rdmabuf;
 258         struct rpcrdma_regbuf *rl_sendbuf;
 259         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
 260 };
 261
 262 static inline struct rpcrdma_req *
 263 rpcr_to_rdmar(struct rpc_rqst *rqst)
 264 {
 265         void *buffer = rqst->rq_buffer;
 266         struct rpcrdma_regbuf *rb;
 267
 268         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
 269         return rb->rg_owner;
 270 }
 271
 272 /*
 273  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 274  * inline requests/replies, and client/server credits.
 275  *
 276  * One of these is associated with a transport instance
 277  */
 278 struct rpcrdma_buffer {
 279         spinlock_t      rb_lock;        /* protects indexes */
 280         u32             rb_max_requests;/* client max requests */
 281         struct list_head rb_mws;        /* optional memory windows/fmrs/frmrs */
 282         struct list_head rb_all;
 283         int             rb_send_index;
 284         struct rpcrdma_req      **rb_send_bufs;
 285         int             rb_recv_index;
 286         struct rpcrdma_rep      **rb_recv_bufs;
 287         char            *rb_pool;
 288 };
 289 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 290
 291 /*
 292  * Internal structure for transport instance creation. This
 293  * exists primarily for modularity.
 294  *
 295  * This data should be set with mount options
 296  */
 297 struct rpcrdma_create_data_internal {
 298         struct sockaddr_storage addr;   /* RDMA server address */
 299         unsigned int    max_requests;   /* max requests (slots) in flight */
 300         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 301         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 302         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 303         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 304         unsigned int    padding;        /* non-rdma write header padding */
 305 };
 306
 307 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 308         (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 309
 310 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 311         (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 312
 313 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 314         rpcx_to_rdmad(rq->rq_xprt).padding
 315
 316 /*
 317  * Statistics for RPCRDMA
 318  */
 319 struct rpcrdma_stats {
 320         unsigned long           read_chunk_count;
 321         unsigned long           write_chunk_count;
 322         unsigned long           reply_chunk_count;
 323
 324         unsigned long long      total_rdma_request;
 325         unsigned long long      total_rdma_reply;
 326
 327         unsigned long long      pullup_copy_count;
 328         unsigned long long      fixup_copy_count;
 329         unsigned long           hardway_register_count;
 330         unsigned long           failed_marshal_count;
 331         unsigned long           bad_reply_count;
 332 };
 333
 334 /*
 335  * Per-registration mode operations
 336  */
 337 struct rpcrdma_memreg_ops {
 338         const char      *ro_displayname;
 339 };
 340
 341 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
 342 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
 343 extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
 344
 345 /*
 346  * RPCRDMA transport -- encapsulates the structures above for
 347  * integration with RPC.
 348  *
 349  * The contained structures are embedded, not pointers,
 350  * for convenience. This structure need not be visible externally.
 351  *
 352  * It is allocated and initialized during mount, and released
 353  * during unmount.
 354  */
 355 struct rpcrdma_xprt {
 356         struct rpc_xprt         rx_xprt;
 357         struct rpcrdma_ia       rx_ia;
 358         struct rpcrdma_ep       rx_ep;
 359         struct rpcrdma_buffer   rx_buf;
 360         struct rpcrdma_create_data_internal rx_data;
 361         struct delayed_work     rx_connect_worker;
 362         struct rpcrdma_stats    rx_stats;
 363 };
 364
 365 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
 366 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 367
 368 /* Setting this to 0 ensures interoperability with early servers.
 369  * Setting this to 1 enhances certain unaligned read/write performance.
 370  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 371 extern int xprt_rdma_pad_optimize;
 372
 373 /*
 374  * Interface Adapter calls - xprtrdma/verbs.c
 375  */
 376 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 377 void rpcrdma_ia_close(struct rpcrdma_ia *);
 378
 379 /*
 380  * Endpoint calls - xprtrdma/verbs.c
 381  */
 382 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 383                                 struct rpcrdma_create_data_internal *);
 384 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 385 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 386 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 387
 388 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 389                                 struct rpcrdma_req *);
 390 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 391                                 struct rpcrdma_rep *);
 392
 393 /*
 394  * Buffer calls - xprtrdma/verbs.c
 395  */
 396 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
 397 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 398
 399 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 400 void rpcrdma_buffer_put(struct rpcrdma_req *);
 401 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 402 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 403
 404 int rpcrdma_register_external(struct rpcrdma_mr_seg *,
 405                                 int, int, struct rpcrdma_xprt *);
 406 int rpcrdma_deregister_external(struct rpcrdma_mr_seg *,
 407                                 struct rpcrdma_xprt *);
 408
 409 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
 410                                             size_t, gfp_t);
 411 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 412                          struct rpcrdma_regbuf *);
 413
 414 /*
 415  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 416  */
 417 void rpcrdma_connect_worker(struct work_struct *);
 418 void rpcrdma_conn_func(struct rpcrdma_ep *);
 419 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 420
 421 /*
 422  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 423  */
 424 int rpcrdma_marshal_req(struct rpc_rqst *);
 425 size_t rpcrdma_max_payload(struct rpcrdma_xprt *);
 426
 427 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 428 extern struct kmem_cache *svc_rdma_map_cachep;
 429 /* WR context cache. Created in svc_rdma.c  */
 430 extern struct kmem_cache *svc_rdma_ctxt_cachep;
 431 /* Workqueue created in svc_rdma.c */
 432 extern struct workqueue_struct *svc_rdma_wq;
 433
 434 #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 435 #define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
 436 #else
 437 #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 438 #endif
 439
 440 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */