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         const struct rpcrdma_memreg_ops *ri_ops;
  63         rwlock_t                ri_qplock;
  64         struct ib_device        *ri_device;
  65         struct rdma_cm_id       *ri_id;
  66         struct ib_pd            *ri_pd;
  67         struct ib_mr            *ri_dma_mr;
  68         struct completion       ri_done;
  69         int                     ri_async_rc;
  70         unsigned int            ri_max_frmr_depth;
  71         struct ib_device_attr   ri_devattr;
  72         struct ib_qp_attr       ri_qp_attr;
  73         struct ib_qp_init_attr  ri_qp_init_attr;
  74 };
  75
  76 /*
  77  * RDMA Endpoint -- one per transport instance
  78  */
  79
  80 #define RPCRDMA_WC_BUDGET       (128)
  81 #define RPCRDMA_POLLSIZE        (16)
  82
  83 struct rpcrdma_ep {
  84         atomic_t                rep_cqcount;
  85         int                     rep_cqinit;
  86         int                     rep_connected;
  87         struct ib_qp_init_attr  rep_attr;
  88         wait_queue_head_t       rep_connect_wait;
  89         struct rdma_conn_param  rep_remote_cma;
  90         struct sockaddr_storage rep_remote_addr;
  91         struct delayed_work     rep_connect_worker;
  92         struct ib_wc            rep_send_wcs[RPCRDMA_POLLSIZE];
  93         struct ib_wc            rep_recv_wcs[RPCRDMA_POLLSIZE];
  94 };
  95
  96 /*
  97  * Force a signaled SEND Work Request every so often,
  98  * in case the provider needs to do some housekeeping.
  99  */
 100 #define RPCRDMA_MAX_UNSIGNALED_SENDS    (32)
 101
 102 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
 103 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
 104
 105 /* Force completion handler to ignore the signal
 106  */
 107 #define RPCRDMA_IGNORE_COMPLETION       (0ULL)
 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_sge           rg_iov;
 119         __be32                  rg_base[0] __attribute__ ((aligned(256)));
 120 };
 121
 122 static inline u64
 123 rdmab_addr(struct rpcrdma_regbuf *rb)
 124 {
 125         return rb->rg_iov.addr;
 126 }
 127
 128 static inline u32
 129 rdmab_length(struct rpcrdma_regbuf *rb)
 130 {
 131         return rb->rg_iov.length;
 132 }
 133
 134 static inline u32
 135 rdmab_lkey(struct rpcrdma_regbuf *rb)
 136 {
 137         return rb->rg_iov.lkey;
 138 }
 139
 140 static inline struct rpcrdma_msg *
 141 rdmab_to_msg(struct rpcrdma_regbuf *rb)
 142 {
 143         return (struct rpcrdma_msg *)rb->rg_base;
 144 }
 145
 146 /*
 147  * struct rpcrdma_rep -- this structure encapsulates state required to recv
 148  * and complete a reply, asychronously. It needs several pieces of
 149  * state:
 150  *   o recv buffer (posted to provider)
 151  *   o ib_sge (also donated to provider)
 152  *   o status of reply (length, success or not)
 153  *   o bookkeeping state to get run by tasklet (list, etc)
 154  *
 155  * These are allocated during initialization, per-transport instance;
 156  * however, the tasklet execution list itself is global, as it should
 157  * always be pretty short.
 158  *
 159  * N of these are associated with a transport instance, and stored in
 160  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 161  */
 162
 163 #define RPCRDMA_MAX_DATA_SEGS   ((1 * 1024 * 1024) / PAGE_SIZE)
 164 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 165
 166 struct rpcrdma_buffer;
 167
 168 struct rpcrdma_rep {
 169         unsigned int            rr_len;
 170         struct ib_device        *rr_device;
 171         struct rpcrdma_xprt     *rr_rxprt;
 172         struct list_head        rr_list;
 173         struct rpcrdma_regbuf   *rr_rdmabuf;
 174 };
 175
 176 /*
 177  * struct rpcrdma_mw - external memory region metadata
 178  *
 179  * An external memory region is any buffer or page that is registered
 180  * on the fly (ie, not pre-registered).
 181  *
 182  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
 183  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
 184  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
 185  * track of registration metadata while each RPC is pending.
 186  * rpcrdma_deregister_external() uses this metadata to unmap and
 187  * release these resources when an RPC is complete.
 188  */
 189 enum rpcrdma_frmr_state {
 190         FRMR_IS_INVALID,        /* ready to be used */
 191         FRMR_IS_VALID,          /* in use */
 192         FRMR_IS_STALE,          /* failed completion */
 193 };
 194
 195 struct rpcrdma_frmr {
 196         struct scatterlist              *sg;
 197         int                             sg_nents;
 198         struct ib_mr                    *fr_mr;
 199         enum rpcrdma_frmr_state         fr_state;
 200         struct work_struct              fr_work;
 201         struct rpcrdma_xprt             *fr_xprt;
 202 };
 203
 204 struct rpcrdma_fmr {
 205         struct ib_fmr           *fmr;
 206         u64                     *physaddrs;
 207 };
 208
 209 struct rpcrdma_mw {
 210         union {
 211                 struct rpcrdma_fmr      fmr;
 212                 struct rpcrdma_frmr     frmr;
 213         } r;
 214         void                    (*mw_sendcompletion)(struct ib_wc *);
 215         struct list_head        mw_list;
 216         struct list_head        mw_all;
 217 };
 218
 219 /*
 220  * struct rpcrdma_req -- structure central to the request/reply sequence.
 221  *
 222  * N of these are associated with a transport instance, and stored in
 223  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 224  *
 225  * It includes pre-registered buffer memory for send AND recv.
 226  * The recv buffer, however, is not owned by this structure, and
 227  * is "donated" to the hardware when a recv is posted. When a
 228  * reply is handled, the recv buffer used is given back to the
 229  * struct rpcrdma_req associated with the request.
 230  *
 231  * In addition to the basic memory, this structure includes an array
 232  * of iovs for send operations. The reason is that the iovs passed to
 233  * ib_post_{send,recv} must not be modified until the work request
 234  * completes.
 235  *
 236  * NOTES:
 237  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
 238  *     marshal. The number needed varies depending on the iov lists that
 239  *     are passed to us, the memory registration mode we are in, and if
 240  *     physical addressing is used, the layout.
 241  */
 242
 243 struct rpcrdma_mr_seg {         /* chunk descriptors */
 244         struct rpcrdma_mw *rl_mw;       /* registered MR */
 245         u64             mr_base;        /* registration result */
 246         u32             mr_rkey;        /* registration result */
 247         u32             mr_len;         /* length of chunk or segment */
 248         int             mr_nsegs;       /* number of segments in chunk or 0 */
 249         enum dma_data_direction mr_dir; /* segment mapping direction */
 250         dma_addr_t      mr_dma;         /* segment mapping address */
 251         size_t          mr_dmalen;      /* segment mapping length */
 252         struct page     *mr_page;       /* owning page, if any */
 253         char            *mr_offset;     /* kva if no page, else offset */
 254 };
 255
 256 #define RPCRDMA_MAX_IOVS        (2)
 257
 258 struct rpcrdma_req {
 259         unsigned int            rl_niovs;
 260         unsigned int            rl_nchunks;
 261         unsigned int            rl_connect_cookie;
 262         struct rpcrdma_buffer   *rl_buffer;
 263         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 264         struct ib_sge           rl_send_iov[RPCRDMA_MAX_IOVS];
 265         struct rpcrdma_regbuf   *rl_rdmabuf;
 266         struct rpcrdma_regbuf   *rl_sendbuf;
 267         struct rpcrdma_mr_seg   rl_segments[RPCRDMA_MAX_SEGS];
 268 };
 269
 270 static inline struct rpcrdma_req *
 271 rpcr_to_rdmar(struct rpc_rqst *rqst)
 272 {
 273         void *buffer = rqst->rq_buffer;
 274         struct rpcrdma_regbuf *rb;
 275
 276         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
 277         return rb->rg_owner;
 278 }
 279
 280 /*
 281  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 282  * inline requests/replies, and client/server credits.
 283  *
 284  * One of these is associated with a transport instance
 285  */
 286 struct rpcrdma_buffer {
 287         spinlock_t              rb_mwlock;      /* protect rb_mws list */
 288         struct list_head        rb_mws;
 289         struct list_head        rb_all;
 290         char                    *rb_pool;
 291
 292         spinlock_t              rb_lock;        /* protect buf arrays */
 293         u32                     rb_max_requests;
 294         int                     rb_send_index;
 295         int                     rb_recv_index;
 296         struct rpcrdma_req      **rb_send_bufs;
 297         struct rpcrdma_rep      **rb_recv_bufs;
 298 };
 299 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 300
 301 /*
 302  * Internal structure for transport instance creation. This
 303  * exists primarily for modularity.
 304  *
 305  * This data should be set with mount options
 306  */
 307 struct rpcrdma_create_data_internal {
 308         struct sockaddr_storage addr;   /* RDMA server address */
 309         unsigned int    max_requests;   /* max requests (slots) in flight */
 310         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 311         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 312         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 313         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 314         unsigned int    padding;        /* non-rdma write header padding */
 315 };
 316
 317 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 318         (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 319
 320 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 321         (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 322
 323 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 324         rpcx_to_rdmad(rq->rq_xprt).padding
 325
 326 /*
 327  * Statistics for RPCRDMA
 328  */
 329 struct rpcrdma_stats {
 330         unsigned long           read_chunk_count;
 331         unsigned long           write_chunk_count;
 332         unsigned long           reply_chunk_count;
 333
 334         unsigned long long      total_rdma_request;
 335         unsigned long long      total_rdma_reply;
 336
 337         unsigned long long      pullup_copy_count;
 338         unsigned long long      fixup_copy_count;
 339         unsigned long           hardway_register_count;
 340         unsigned long           failed_marshal_count;
 341         unsigned long           bad_reply_count;
 342         unsigned long           nomsg_call_count;
 343 };
 344
 345 /*
 346  * Per-registration mode operations
 347  */
 348 struct rpcrdma_xprt;
 349 struct rpcrdma_memreg_ops {
 350         int             (*ro_map)(struct rpcrdma_xprt *,
 351                                   struct rpcrdma_mr_seg *, int, bool);
 352         int             (*ro_unmap)(struct rpcrdma_xprt *,
 353                                     struct rpcrdma_mr_seg *);
 354         int             (*ro_open)(struct rpcrdma_ia *,
 355                                    struct rpcrdma_ep *,
 356                                    struct rpcrdma_create_data_internal *);
 357         size_t          (*ro_maxpages)(struct rpcrdma_xprt *);
 358         int             (*ro_init)(struct rpcrdma_xprt *);
 359         void            (*ro_destroy)(struct rpcrdma_buffer *);
 360         const char      *ro_displayname;
 361 };
 362
 363 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
 364 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
 365 extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
 366
 367 /*
 368  * RPCRDMA transport -- encapsulates the structures above for
 369  * integration with RPC.
 370  *
 371  * The contained structures are embedded, not pointers,
 372  * for convenience. This structure need not be visible externally.
 373  *
 374  * It is allocated and initialized during mount, and released
 375  * during unmount.
 376  */
 377 struct rpcrdma_xprt {
 378         struct rpc_xprt         rx_xprt;
 379         struct rpcrdma_ia       rx_ia;
 380         struct rpcrdma_ep       rx_ep;
 381         struct rpcrdma_buffer   rx_buf;
 382         struct rpcrdma_create_data_internal rx_data;
 383         struct delayed_work     rx_connect_worker;
 384         struct rpcrdma_stats    rx_stats;
 385 };
 386
 387 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
 388 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 389
 390 /* Setting this to 0 ensures interoperability with early servers.
 391  * Setting this to 1 enhances certain unaligned read/write performance.
 392  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 393 extern int xprt_rdma_pad_optimize;
 394
 395 /*
 396  * Interface Adapter calls - xprtrdma/verbs.c
 397  */
 398 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 399 void rpcrdma_ia_close(struct rpcrdma_ia *);
 400
 401 /*
 402  * Endpoint calls - xprtrdma/verbs.c
 403  */
 404 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 405                                 struct rpcrdma_create_data_internal *);
 406 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 407 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 408 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 409
 410 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 411                                 struct rpcrdma_req *);
 412 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 413                                 struct rpcrdma_rep *);
 414
 415 /*
 416  * Buffer calls - xprtrdma/verbs.c
 417  */
 418 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
 419 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 420
 421 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
 422 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
 423 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 424 void rpcrdma_buffer_put(struct rpcrdma_req *);
 425 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 426 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 427
 428 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
 429                                             size_t, gfp_t);
 430 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 431                          struct rpcrdma_regbuf *);
 432
 433 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
 434
 435 int frwr_alloc_recovery_wq(void);
 436 void frwr_destroy_recovery_wq(void);
 437
 438 /*
 439  * Wrappers for chunk registration, shared by read/write chunk code.
 440  */
 441
 442 void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
 443
 444 static inline enum dma_data_direction
 445 rpcrdma_data_dir(bool writing)
 446 {
 447         return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 448 }
 449
 450 static inline void
 451 rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
 452                 enum dma_data_direction direction)
 453 {
 454         seg->mr_dir = direction;
 455         seg->mr_dmalen = seg->mr_len;
 456
 457         if (seg->mr_page)
 458                 seg->mr_dma = ib_dma_map_page(device,
 459                                 seg->mr_page, offset_in_page(seg->mr_offset),
 460                                 seg->mr_dmalen, seg->mr_dir);
 461         else
 462                 seg->mr_dma = ib_dma_map_single(device,
 463                                 seg->mr_offset,
 464                                 seg->mr_dmalen, seg->mr_dir);
 465
 466         if (ib_dma_mapping_error(device, seg->mr_dma))
 467                 rpcrdma_mapping_error(seg);
 468 }
 469
 470 static inline void
 471 rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
 472 {
 473         if (seg->mr_page)
 474                 ib_dma_unmap_page(device,
 475                                   seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
 476         else
 477                 ib_dma_unmap_single(device,
 478                                     seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
 479 }
 480
 481 /*
 482  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 483  */
 484 void rpcrdma_connect_worker(struct work_struct *);
 485 void rpcrdma_conn_func(struct rpcrdma_ep *);
 486 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 487
 488 /*
 489  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 490  */
 491 int rpcrdma_marshal_req(struct rpc_rqst *);
 492
 493 /* RPC/RDMA module init - xprtrdma/transport.c
 494  */
 495 int xprt_rdma_init(void);
 496 void xprt_rdma_cleanup(void);
 497
 498 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 499 extern struct kmem_cache *svc_rdma_map_cachep;
 500 /* WR context cache. Created in svc_rdma.c  */
 501 extern struct kmem_cache *svc_rdma_ctxt_cachep;
 502 /* Workqueue created in svc_rdma.c */
 503 extern struct workqueue_struct *svc_rdma_wq;
 504
 505 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */