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 ib_device        *ri_device;
  66         struct rdma_cm_id       *ri_id;
  67         struct ib_pd            *ri_pd;
  68         struct ib_mr            *ri_bind_mem;
  69         u32                     ri_dma_lkey;
  70         int                     ri_have_dma_lkey;
  71         struct completion       ri_done;
  72         int                     ri_async_rc;
  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 /* Force completion handler to ignore the signal
 110  */
 111 #define RPCRDMA_IGNORE_COMPLETION       (0ULL)
 112
 113 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
 114  *
 115  * The below structure appears at the front of a large region of kmalloc'd
 116  * memory, which always starts on a good alignment boundary.
 117  */
 118
 119 struct rpcrdma_regbuf {
 120         size_t                  rg_size;
 121         struct rpcrdma_req      *rg_owner;
 122         struct ib_mr            *rg_mr;
 123         struct ib_sge           rg_iov;
 124         __be32                  rg_base[0] __attribute__ ((aligned(256)));
 125 };
 126
 127 static inline u64
 128 rdmab_addr(struct rpcrdma_regbuf *rb)
 129 {
 130         return rb->rg_iov.addr;
 131 }
 132
 133 static inline u32
 134 rdmab_length(struct rpcrdma_regbuf *rb)
 135 {
 136         return rb->rg_iov.length;
 137 }
 138
 139 static inline u32
 140 rdmab_lkey(struct rpcrdma_regbuf *rb)
 141 {
 142         return rb->rg_iov.lkey;
 143 }
 144
 145 static inline struct rpcrdma_msg *
 146 rdmab_to_msg(struct rpcrdma_regbuf *rb)
 147 {
 148         return (struct rpcrdma_msg *)rb->rg_base;
 149 }
 150
 151 /*
 152  * struct rpcrdma_rep -- this structure encapsulates state required to recv
 153  * and complete a reply, asychronously. It needs several pieces of
 154  * state:
 155  *   o recv buffer (posted to provider)
 156  *   o ib_sge (also donated to provider)
 157  *   o status of reply (length, success or not)
 158  *   o bookkeeping state to get run by tasklet (list, etc)
 159  *
 160  * These are allocated during initialization, per-transport instance;
 161  * however, the tasklet execution list itself is global, as it should
 162  * always be pretty short.
 163  *
 164  * N of these are associated with a transport instance, and stored in
 165  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 166  */
 167
 168 /* temporary static scatter/gather max */
 169 #define RPCRDMA_MAX_DATA_SEGS   (64)    /* max scatter/gather */
 170 #define RPCRDMA_MAX_SEGS        (RPCRDMA_MAX_DATA_SEGS + 2) /* head+tail = 2 */
 171
 172 struct rpcrdma_buffer;
 173
 174 struct rpcrdma_rep {
 175         unsigned int            rr_len;
 176         struct ib_device        *rr_device;
 177         struct rpcrdma_xprt     *rr_rxprt;
 178         struct list_head        rr_list;
 179         struct rpcrdma_regbuf   *rr_rdmabuf;
 180 };
 181
 182 /*
 183  * struct rpcrdma_mw - external memory region metadata
 184  *
 185  * An external memory region is any buffer or page that is registered
 186  * on the fly (ie, not pre-registered).
 187  *
 188  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
 189  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
 190  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
 191  * track of registration metadata while each RPC is pending.
 192  * rpcrdma_deregister_external() uses this metadata to unmap and
 193  * release these resources when an RPC is complete.
 194  */
 195 enum rpcrdma_frmr_state {
 196         FRMR_IS_INVALID,        /* ready to be used */
 197         FRMR_IS_VALID,          /* in use */
 198         FRMR_IS_STALE,          /* failed completion */
 199 };
 200
 201 struct rpcrdma_frmr {
 202         struct ib_fast_reg_page_list    *fr_pgl;
 203         struct ib_mr                    *fr_mr;
 204         enum rpcrdma_frmr_state         fr_state;
 205         struct work_struct              fr_work;
 206         struct rpcrdma_xprt             *fr_xprt;
 207 };
 208
 209 struct rpcrdma_mw {
 210         union {
 211                 struct ib_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 struct rpcrdma_req {
 257         unsigned int    rl_niovs;       /* 0, 2 or 4 */
 258         unsigned int    rl_nchunks;     /* non-zero if chunks */
 259         unsigned int    rl_connect_cookie;      /* retry detection */
 260         struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
 261         struct rpcrdma_rep      *rl_reply;/* holder for reply buffer */
 262         struct ib_sge   rl_send_iov[4]; /* for active requests */
 263         struct rpcrdma_regbuf *rl_rdmabuf;
 264         struct rpcrdma_regbuf *rl_sendbuf;
 265         struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
 266 };
 267
 268 static inline struct rpcrdma_req *
 269 rpcr_to_rdmar(struct rpc_rqst *rqst)
 270 {
 271         void *buffer = rqst->rq_buffer;
 272         struct rpcrdma_regbuf *rb;
 273
 274         rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
 275         return rb->rg_owner;
 276 }
 277
 278 /*
 279  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 280  * inline requests/replies, and client/server credits.
 281  *
 282  * One of these is associated with a transport instance
 283  */
 284 struct rpcrdma_buffer {
 285         spinlock_t      rb_lock;        /* protects indexes */
 286         u32             rb_max_requests;/* client max requests */
 287         struct list_head rb_mws;        /* optional memory windows/fmrs/frmrs */
 288         struct list_head rb_all;
 289         int             rb_send_index;
 290         struct rpcrdma_req      **rb_send_bufs;
 291         int             rb_recv_index;
 292         struct rpcrdma_rep      **rb_recv_bufs;
 293         char            *rb_pool;
 294 };
 295 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
 296
 297 /*
 298  * Internal structure for transport instance creation. This
 299  * exists primarily for modularity.
 300  *
 301  * This data should be set with mount options
 302  */
 303 struct rpcrdma_create_data_internal {
 304         struct sockaddr_storage addr;   /* RDMA server address */
 305         unsigned int    max_requests;   /* max requests (slots) in flight */
 306         unsigned int    rsize;          /* mount rsize - max read hdr+data */
 307         unsigned int    wsize;          /* mount wsize - max write hdr+data */
 308         unsigned int    inline_rsize;   /* max non-rdma read data payload */
 309         unsigned int    inline_wsize;   /* max non-rdma write data payload */
 310         unsigned int    padding;        /* non-rdma write header padding */
 311 };
 312
 313 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
 314         (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
 315
 316 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
 317         (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
 318
 319 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
 320         rpcx_to_rdmad(rq->rq_xprt).padding
 321
 322 /*
 323  * Statistics for RPCRDMA
 324  */
 325 struct rpcrdma_stats {
 326         unsigned long           read_chunk_count;
 327         unsigned long           write_chunk_count;
 328         unsigned long           reply_chunk_count;
 329
 330         unsigned long long      total_rdma_request;
 331         unsigned long long      total_rdma_reply;
 332
 333         unsigned long long      pullup_copy_count;
 334         unsigned long long      fixup_copy_count;
 335         unsigned long           hardway_register_count;
 336         unsigned long           failed_marshal_count;
 337         unsigned long           bad_reply_count;
 338 };
 339
 340 /*
 341  * Per-registration mode operations
 342  */
 343 struct rpcrdma_xprt;
 344 struct rpcrdma_memreg_ops {
 345         int             (*ro_map)(struct rpcrdma_xprt *,
 346                                   struct rpcrdma_mr_seg *, int, bool);
 347         int             (*ro_unmap)(struct rpcrdma_xprt *,
 348                                     struct rpcrdma_mr_seg *);
 349         int             (*ro_open)(struct rpcrdma_ia *,
 350                                    struct rpcrdma_ep *,
 351                                    struct rpcrdma_create_data_internal *);
 352         size_t          (*ro_maxpages)(struct rpcrdma_xprt *);
 353         int             (*ro_init)(struct rpcrdma_xprt *);
 354         void            (*ro_destroy)(struct rpcrdma_buffer *);
 355         const char      *ro_displayname;
 356 };
 357
 358 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
 359 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
 360 extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
 361
 362 /*
 363  * RPCRDMA transport -- encapsulates the structures above for
 364  * integration with RPC.
 365  *
 366  * The contained structures are embedded, not pointers,
 367  * for convenience. This structure need not be visible externally.
 368  *
 369  * It is allocated and initialized during mount, and released
 370  * during unmount.
 371  */
 372 struct rpcrdma_xprt {
 373         struct rpc_xprt         rx_xprt;
 374         struct rpcrdma_ia       rx_ia;
 375         struct rpcrdma_ep       rx_ep;
 376         struct rpcrdma_buffer   rx_buf;
 377         struct rpcrdma_create_data_internal rx_data;
 378         struct delayed_work     rx_connect_worker;
 379         struct rpcrdma_stats    rx_stats;
 380 };
 381
 382 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
 383 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
 384
 385 /* Setting this to 0 ensures interoperability with early servers.
 386  * Setting this to 1 enhances certain unaligned read/write performance.
 387  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 388 extern int xprt_rdma_pad_optimize;
 389
 390 /*
 391  * Interface Adapter calls - xprtrdma/verbs.c
 392  */
 393 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
 394 void rpcrdma_ia_close(struct rpcrdma_ia *);
 395
 396 /*
 397  * Endpoint calls - xprtrdma/verbs.c
 398  */
 399 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
 400                                 struct rpcrdma_create_data_internal *);
 401 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
 402 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 403 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
 404
 405 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
 406                                 struct rpcrdma_req *);
 407 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
 408                                 struct rpcrdma_rep *);
 409
 410 /*
 411  * Buffer calls - xprtrdma/verbs.c
 412  */
 413 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
 414 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 415
 416 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
 417 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
 418 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 419 void rpcrdma_buffer_put(struct rpcrdma_req *);
 420 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
 421 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 422
 423 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
 424                                             size_t, gfp_t);
 425 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
 426                          struct rpcrdma_regbuf *);
 427
 428 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
 429
 430 int frwr_alloc_recovery_wq(void);
 431 void frwr_destroy_recovery_wq(void);
 432
 433 /*
 434  * Wrappers for chunk registration, shared by read/write chunk code.
 435  */
 436
 437 void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
 438
 439 static inline enum dma_data_direction
 440 rpcrdma_data_dir(bool writing)
 441 {
 442         return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 443 }
 444
 445 static inline void
 446 rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
 447                 enum dma_data_direction direction)
 448 {
 449         seg->mr_dir = direction;
 450         seg->mr_dmalen = seg->mr_len;
 451
 452         if (seg->mr_page)
 453                 seg->mr_dma = ib_dma_map_page(device,
 454                                 seg->mr_page, offset_in_page(seg->mr_offset),
 455                                 seg->mr_dmalen, seg->mr_dir);
 456         else
 457                 seg->mr_dma = ib_dma_map_single(device,
 458                                 seg->mr_offset,
 459                                 seg->mr_dmalen, seg->mr_dir);
 460
 461         if (ib_dma_mapping_error(device, seg->mr_dma))
 462                 rpcrdma_mapping_error(seg);
 463 }
 464
 465 static inline void
 466 rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
 467 {
 468         if (seg->mr_page)
 469                 ib_dma_unmap_page(device,
 470                                   seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
 471         else
 472                 ib_dma_unmap_single(device,
 473                                     seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
 474 }
 475
 476 /*
 477  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
 478  */
 479 void rpcrdma_connect_worker(struct work_struct *);
 480 void rpcrdma_conn_func(struct rpcrdma_ep *);
 481 void rpcrdma_reply_handler(struct rpcrdma_rep *);
 482
 483 /*
 484  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 485  */
 486 int rpcrdma_marshal_req(struct rpc_rqst *);
 487
 488 /* Temporary NFS request map cache. Created in svc_rdma.c  */
 489 extern struct kmem_cache *svc_rdma_map_cachep;
 490 /* WR context cache. Created in svc_rdma.c  */
 491 extern struct kmem_cache *svc_rdma_ctxt_cachep;
 492 /* Workqueue created in svc_rdma.c */
 493 extern struct workqueue_struct *svc_rdma_wq;
 494
 495 #if RPCSVC_MAXPAYLOAD < (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 496 #define RPCSVC_MAXPAYLOAD_RDMA RPCSVC_MAXPAYLOAD
 497 #else
 498 #define RPCSVC_MAXPAYLOAD_RDMA (RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT)
 499 #endif
 500
 501 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */