2 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
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
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
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.
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
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.
40 #ifndef _LINUX_SUNRPC_XPRT_RDMA_H
41 #define _LINUX_SUNRPC_XPRT_RDMA_H
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 */
48 #include <rdma/rdma_cm.h> /* RDMA connection api */
49 #include <rdma/ib_verbs.h> /* RDMA verbs api */
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 */
55 #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
56 #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
58 #define RPCRDMA_BIND_TO (60U * HZ)
59 #define RPCRDMA_INIT_REEST_TO (5U * HZ)
60 #define RPCRDMA_MAX_REEST_TO (30U * HZ)
61 #define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ)
64 * Interface Adapter -- one per transport instance
67 const struct rpcrdma_memreg_ops *ri_ops;
68 struct ib_device *ri_device;
69 struct rdma_cm_id *ri_id;
71 struct completion ri_done;
72 struct completion ri_remove_done;
74 unsigned int ri_max_segs;
75 unsigned int ri_max_frmr_depth;
76 unsigned int ri_max_inline_write;
77 unsigned int ri_max_inline_read;
78 unsigned int ri_max_send_sges;
79 bool ri_reminv_expected;
80 bool ri_implicit_roundup;
81 enum ib_mr_type ri_mrtype;
82 unsigned long ri_flags;
83 struct ib_qp_attr ri_qp_attr;
84 struct ib_qp_init_attr ri_qp_init_attr;
88 RPCRDMA_IAF_REMOVING = 0,
92 * RDMA Endpoint -- one per transport instance
99 struct ib_qp_init_attr rep_attr;
100 wait_queue_head_t rep_connect_wait;
101 struct rpcrdma_connect_private rep_cm_private;
102 struct rdma_conn_param rep_remote_cma;
103 struct sockaddr_storage rep_remote_addr;
104 struct delayed_work rep_connect_worker;
108 rpcrdma_init_cqcount(struct rpcrdma_ep *ep, int count)
110 atomic_set(&ep->rep_cqcount, ep->rep_cqinit - count);
113 /* To update send queue accounting, provider must take a
114 * send completion every now and then.
117 rpcrdma_set_signaled(struct rpcrdma_ep *ep, struct ib_send_wr *send_wr)
119 send_wr->send_flags = 0;
120 if (unlikely(atomic_sub_return(1, &ep->rep_cqcount) <= 0)) {
121 rpcrdma_init_cqcount(ep, 0);
122 send_wr->send_flags = IB_SEND_SIGNALED;
126 /* Pre-allocate extra Work Requests for handling backward receives
127 * and sends. This is a fixed value because the Work Queues are
128 * allocated when the forward channel is set up.
130 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
131 #define RPCRDMA_BACKWARD_WRS (8)
133 #define RPCRDMA_BACKWARD_WRS (0)
136 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
138 * The below structure appears at the front of a large region of kmalloc'd
139 * memory, which always starts on a good alignment boundary.
142 struct rpcrdma_regbuf {
143 struct ib_sge rg_iov;
144 struct ib_device *rg_device;
145 enum dma_data_direction rg_direction;
146 __be32 rg_base[0] __attribute__ ((aligned(256)));
150 rdmab_addr(struct rpcrdma_regbuf *rb)
152 return rb->rg_iov.addr;
156 rdmab_length(struct rpcrdma_regbuf *rb)
158 return rb->rg_iov.length;
162 rdmab_lkey(struct rpcrdma_regbuf *rb)
164 return rb->rg_iov.lkey;
167 static inline struct rpcrdma_msg *
168 rdmab_to_msg(struct rpcrdma_regbuf *rb)
170 return (struct rpcrdma_msg *)rb->rg_base;
173 static inline struct ib_device *
174 rdmab_device(struct rpcrdma_regbuf *rb)
176 return rb->rg_device;
179 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
181 /* To ensure a transport can always make forward progress,
182 * the number of RDMA segments allowed in header chunk lists
183 * is capped at 8. This prevents less-capable devices and
184 * memory registrations from overrunning the Send buffer
185 * while building chunk lists.
187 * Elements of the Read list take up more room than the
188 * Write list or Reply chunk. 8 read segments means the Read
189 * list (or Write list or Reply chunk) cannot consume more
192 * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
194 * And the fixed part of the header is another 24 bytes.
196 * The smallest inline threshold is 1024 bytes, ensuring that
197 * at least 750 bytes are available for RPC messages.
200 RPCRDMA_MAX_HDR_SEGS = 8,
201 RPCRDMA_HDRBUF_SIZE = 256,
205 * struct rpcrdma_rep -- this structure encapsulates state required
206 * to receive and complete an RPC Reply, asychronously. It needs
207 * several pieces of state:
209 * o receive buffer and ib_sge (donated to provider)
210 * o status of receive (success or not, length, inv rkey)
211 * o bookkeeping state to get run by reply handler (XDR stream)
213 * These structures are allocated during transport initialization.
214 * N of these are associated with a transport instance, managed by
215 * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
219 struct ib_cqe rr_cqe;
225 struct rpcrdma_regbuf *rr_rdmabuf;
226 struct rpcrdma_xprt *rr_rxprt;
227 struct work_struct rr_work;
228 struct xdr_buf rr_hdrbuf;
229 struct xdr_stream rr_stream;
230 struct rpc_rqst *rr_rqst;
231 struct list_head rr_list;
232 struct ib_recv_wr rr_recv_wr;
236 * struct rpcrdma_mw - external memory region metadata
238 * An external memory region is any buffer or page that is registered
239 * on the fly (ie, not pre-registered).
241 * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
242 * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
243 * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
244 * track of registration metadata while each RPC is pending.
245 * rpcrdma_deregister_external() uses this metadata to unmap and
246 * release these resources when an RPC is complete.
248 enum rpcrdma_frmr_state {
249 FRMR_IS_INVALID, /* ready to be used */
250 FRMR_IS_VALID, /* in use */
251 FRMR_FLUSHED_FR, /* flushed FASTREG WR */
252 FRMR_FLUSHED_LI, /* flushed LOCALINV WR */
255 struct rpcrdma_frmr {
257 struct ib_cqe fr_cqe;
258 enum rpcrdma_frmr_state fr_state;
259 struct completion fr_linv_done;
261 struct ib_reg_wr fr_regwr;
262 struct ib_send_wr fr_invwr;
267 struct ib_fmr *fm_mr;
272 struct list_head mw_list;
273 struct scatterlist *mw_sg;
275 enum dma_data_direction mw_dir;
276 unsigned long mw_flags;
278 struct rpcrdma_fmr fmr;
279 struct rpcrdma_frmr frmr;
281 struct rpcrdma_xprt *mw_xprt;
285 struct list_head mw_all;
294 * struct rpcrdma_req -- structure central to the request/reply sequence.
296 * N of these are associated with a transport instance, and stored in
297 * struct rpcrdma_buffer. N is the max number of outstanding requests.
299 * It includes pre-registered buffer memory for send AND recv.
300 * The recv buffer, however, is not owned by this structure, and
301 * is "donated" to the hardware when a recv is posted. When a
302 * reply is handled, the recv buffer used is given back to the
303 * struct rpcrdma_req associated with the request.
305 * In addition to the basic memory, this structure includes an array
306 * of iovs for send operations. The reason is that the iovs passed to
307 * ib_post_{send,recv} must not be modified until the work request
311 /* Maximum number of page-sized "segments" per chunk list to be
312 * registered or invalidated. Must handle a Reply chunk:
315 RPCRDMA_MAX_IOV_SEGS = 3,
316 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
317 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
318 RPCRDMA_MAX_IOV_SEGS,
321 struct rpcrdma_mr_seg { /* chunk descriptors */
322 u32 mr_len; /* length of chunk or segment */
323 struct page *mr_page; /* owning page, if any */
324 char *mr_offset; /* kva if no page, else offset */
327 /* The Send SGE array is provisioned to send a maximum size
329 * - RPC-over-RDMA header
330 * - xdr_buf head iovec
331 * - RPCRDMA_MAX_INLINE bytes, in pages
332 * - xdr_buf tail iovec
334 * The actual number of array elements consumed by each RPC
335 * depends on the device's max_sge limit.
338 RPCRDMA_MIN_SEND_SGES = 3,
339 RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
340 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
343 struct rpcrdma_buffer;
345 struct list_head rl_list;
346 unsigned int rl_mapped_sges;
347 unsigned int rl_connect_cookie;
348 struct rpcrdma_buffer *rl_buffer;
349 struct rpcrdma_rep *rl_reply;
350 struct xdr_stream rl_stream;
351 struct xdr_buf rl_hdrbuf;
352 struct ib_send_wr rl_send_wr;
353 struct ib_sge rl_send_sge[RPCRDMA_MAX_SEND_SGES];
354 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */
355 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */
356 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */
358 struct ib_cqe rl_cqe;
359 struct list_head rl_all;
362 struct list_head rl_registered; /* registered segments */
363 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
367 rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req)
369 rqst->rq_xprtdata = req;
372 static inline struct rpcrdma_req *
373 rpcr_to_rdmar(struct rpc_rqst *rqst)
375 return rqst->rq_xprtdata;
379 rpcrdma_push_mw(struct rpcrdma_mw *mw, struct list_head *list)
381 list_add_tail(&mw->mw_list, list);
384 static inline struct rpcrdma_mw *
385 rpcrdma_pop_mw(struct list_head *list)
387 struct rpcrdma_mw *mw;
389 mw = list_first_entry(list, struct rpcrdma_mw, mw_list);
390 list_del(&mw->mw_list);
395 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
396 * inline requests/replies, and client/server credits.
398 * One of these is associated with a transport instance
400 struct rpcrdma_buffer {
401 spinlock_t rb_mwlock; /* protect rb_mws list */
402 struct list_head rb_mws;
403 struct list_head rb_all;
405 spinlock_t rb_lock; /* protect buf lists */
406 int rb_send_count, rb_recv_count;
407 struct list_head rb_send_bufs;
408 struct list_head rb_recv_bufs;
410 atomic_t rb_credits; /* most recent credit grant */
412 u32 rb_bc_srv_max_requests;
413 spinlock_t rb_reqslock; /* protect rb_allreqs */
414 struct list_head rb_allreqs;
416 u32 rb_bc_max_requests;
418 spinlock_t rb_recovery_lock; /* protect rb_stale_mrs */
419 struct list_head rb_stale_mrs;
420 struct delayed_work rb_recovery_worker;
421 struct delayed_work rb_refresh_worker;
423 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
426 * Internal structure for transport instance creation. This
427 * exists primarily for modularity.
429 * This data should be set with mount options
431 struct rpcrdma_create_data_internal {
432 struct sockaddr_storage addr; /* RDMA server address */
433 unsigned int max_requests; /* max requests (slots) in flight */
434 unsigned int rsize; /* mount rsize - max read hdr+data */
435 unsigned int wsize; /* mount wsize - max write hdr+data */
436 unsigned int inline_rsize; /* max non-rdma read data payload */
437 unsigned int inline_wsize; /* max non-rdma write data payload */
438 unsigned int padding; /* non-rdma write header padding */
442 * Statistics for RPCRDMA
444 struct rpcrdma_stats {
445 /* accessed when sending a call */
446 unsigned long read_chunk_count;
447 unsigned long write_chunk_count;
448 unsigned long reply_chunk_count;
449 unsigned long long total_rdma_request;
451 /* rarely accessed error counters */
452 unsigned long long pullup_copy_count;
453 unsigned long hardway_register_count;
454 unsigned long failed_marshal_count;
455 unsigned long bad_reply_count;
456 unsigned long mrs_recovered;
457 unsigned long mrs_orphaned;
458 unsigned long mrs_allocated;
460 /* accessed when receiving a reply */
461 unsigned long long total_rdma_reply;
462 unsigned long long fixup_copy_count;
463 unsigned long local_inv_needed;
464 unsigned long nomsg_call_count;
465 unsigned long bcall_count;
469 * Per-registration mode operations
472 struct rpcrdma_memreg_ops {
473 struct rpcrdma_mr_seg *
474 (*ro_map)(struct rpcrdma_xprt *,
475 struct rpcrdma_mr_seg *, int, bool,
476 struct rpcrdma_mw **);
477 void (*ro_unmap_sync)(struct rpcrdma_xprt *,
479 void (*ro_recover_mr)(struct rpcrdma_mw *);
480 int (*ro_open)(struct rpcrdma_ia *,
482 struct rpcrdma_create_data_internal *);
483 size_t (*ro_maxpages)(struct rpcrdma_xprt *);
484 int (*ro_init_mr)(struct rpcrdma_ia *,
485 struct rpcrdma_mw *);
486 void (*ro_release_mr)(struct rpcrdma_mw *);
487 const char *ro_displayname;
488 const int ro_send_w_inv_ok;
491 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
492 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
495 * RPCRDMA transport -- encapsulates the structures above for
496 * integration with RPC.
498 * The contained structures are embedded, not pointers,
499 * for convenience. This structure need not be visible externally.
501 * It is allocated and initialized during mount, and released
504 struct rpcrdma_xprt {
505 struct rpc_xprt rx_xprt;
506 struct rpcrdma_ia rx_ia;
507 struct rpcrdma_ep rx_ep;
508 struct rpcrdma_buffer rx_buf;
509 struct rpcrdma_create_data_internal rx_data;
510 struct delayed_work rx_connect_worker;
511 struct rpcrdma_stats rx_stats;
514 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
515 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
517 /* Setting this to 0 ensures interoperability with early servers.
518 * Setting this to 1 enhances certain unaligned read/write performance.
519 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
520 extern int xprt_rdma_pad_optimize;
522 /* This setting controls the hunt for a supported memory
523 * registration strategy.
525 extern unsigned int xprt_rdma_memreg_strategy;
528 * Interface Adapter calls - xprtrdma/verbs.c
530 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr);
531 void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
532 void rpcrdma_ia_close(struct rpcrdma_ia *);
533 bool frwr_is_supported(struct rpcrdma_ia *);
534 bool fmr_is_supported(struct rpcrdma_ia *);
537 * Endpoint calls - xprtrdma/verbs.c
539 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
540 struct rpcrdma_create_data_internal *);
541 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
542 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
543 void rpcrdma_conn_func(struct rpcrdma_ep *ep);
544 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
546 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
547 struct rpcrdma_req *);
548 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_rep *);
551 * Buffer calls - xprtrdma/verbs.c
553 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
554 struct rpcrdma_rep *rpcrdma_create_rep(struct rpcrdma_xprt *);
555 void rpcrdma_destroy_req(struct rpcrdma_req *);
556 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
557 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
559 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
560 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
561 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
562 void rpcrdma_buffer_put(struct rpcrdma_req *);
563 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
564 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
566 void rpcrdma_defer_mr_recovery(struct rpcrdma_mw *);
568 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(size_t, enum dma_data_direction,
570 bool __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *, struct rpcrdma_regbuf *);
571 void rpcrdma_free_regbuf(struct rpcrdma_regbuf *);
574 rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
576 return rb->rg_device != NULL;
580 rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
582 if (likely(rpcrdma_regbuf_is_mapped(rb)))
584 return __rpcrdma_dma_map_regbuf(ia, rb);
587 int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
589 int rpcrdma_alloc_wq(void);
590 void rpcrdma_destroy_wq(void);
593 * Wrappers for chunk registration, shared by read/write chunk code.
596 static inline enum dma_data_direction
597 rpcrdma_data_dir(bool writing)
599 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
603 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
606 enum rpcrdma_chunktype {
614 bool rpcrdma_prepare_send_sges(struct rpcrdma_ia *, struct rpcrdma_req *,
615 u32, struct xdr_buf *, enum rpcrdma_chunktype);
616 void rpcrdma_unmap_sges(struct rpcrdma_ia *, struct rpcrdma_req *);
617 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
618 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
619 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
620 void rpcrdma_reply_handler(struct work_struct *work);
622 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
624 xdr->head[0].iov_len = len;
628 /* RPC/RDMA module init - xprtrdma/transport.c
630 extern unsigned int xprt_rdma_max_inline_read;
631 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
632 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
633 void rpcrdma_connect_worker(struct work_struct *work);
634 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
635 int xprt_rdma_init(void);
636 void xprt_rdma_cleanup(void);
638 /* Backchannel calls - xprtrdma/backchannel.c
640 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
641 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
642 int xprt_rdma_bc_up(struct svc_serv *, struct net *);
643 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
644 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
645 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
646 int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
647 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
648 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
649 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
651 extern struct xprt_class xprt_rdma_bc;
653 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */