2 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
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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;
73 unsigned int ri_max_segs;
74 unsigned int ri_max_frmr_depth;
75 unsigned int ri_max_inline_write;
76 unsigned int ri_max_inline_read;
77 unsigned int ri_max_send_sges;
78 bool ri_reminv_expected;
79 bool ri_implicit_roundup;
80 struct ib_qp_attr ri_qp_attr;
81 struct ib_qp_init_attr ri_qp_init_attr;
85 * RDMA Endpoint -- one per transport instance
92 struct ib_qp_init_attr rep_attr;
93 wait_queue_head_t rep_connect_wait;
94 struct rpcrdma_connect_private rep_cm_private;
95 struct rdma_conn_param rep_remote_cma;
96 struct sockaddr_storage rep_remote_addr;
97 struct delayed_work rep_connect_worker;
101 rpcrdma_init_cqcount(struct rpcrdma_ep *ep, int count)
103 atomic_set(&ep->rep_cqcount, ep->rep_cqinit - count);
106 /* To update send queue accounting, provider must take a
107 * send completion every now and then.
110 rpcrdma_set_signaled(struct rpcrdma_ep *ep, struct ib_send_wr *send_wr)
112 send_wr->send_flags = 0;
113 if (unlikely(atomic_sub_return(1, &ep->rep_cqcount) <= 0)) {
114 rpcrdma_init_cqcount(ep, 0);
115 send_wr->send_flags = IB_SEND_SIGNALED;
119 /* Pre-allocate extra Work Requests for handling backward receives
120 * and sends. This is a fixed value because the Work Queues are
121 * allocated when the forward channel is set up.
123 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
124 #define RPCRDMA_BACKWARD_WRS (8)
126 #define RPCRDMA_BACKWARD_WRS (0)
129 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
131 * The below structure appears at the front of a large region of kmalloc'd
132 * memory, which always starts on a good alignment boundary.
135 struct rpcrdma_regbuf {
136 struct ib_sge rg_iov;
137 struct ib_device *rg_device;
138 enum dma_data_direction rg_direction;
139 __be32 rg_base[0] __attribute__ ((aligned(256)));
143 rdmab_addr(struct rpcrdma_regbuf *rb)
145 return rb->rg_iov.addr;
149 rdmab_length(struct rpcrdma_regbuf *rb)
151 return rb->rg_iov.length;
155 rdmab_lkey(struct rpcrdma_regbuf *rb)
157 return rb->rg_iov.lkey;
160 static inline struct rpcrdma_msg *
161 rdmab_to_msg(struct rpcrdma_regbuf *rb)
163 return (struct rpcrdma_msg *)rb->rg_base;
166 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
168 /* To ensure a transport can always make forward progress,
169 * the number of RDMA segments allowed in header chunk lists
170 * is capped at 8. This prevents less-capable devices and
171 * memory registrations from overrunning the Send buffer
172 * while building chunk lists.
174 * Elements of the Read list take up more room than the
175 * Write list or Reply chunk. 8 read segments means the Read
176 * list (or Write list or Reply chunk) cannot consume more
179 * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
181 * And the fixed part of the header is another 24 bytes.
183 * The smallest inline threshold is 1024 bytes, ensuring that
184 * at least 750 bytes are available for RPC messages.
187 RPCRDMA_MAX_HDR_SEGS = 8,
188 RPCRDMA_HDRBUF_SIZE = 256,
192 * struct rpcrdma_rep -- this structure encapsulates state required to recv
193 * and complete a reply, asychronously. It needs several pieces of
195 * o recv buffer (posted to provider)
196 * o ib_sge (also donated to provider)
197 * o status of reply (length, success or not)
198 * o bookkeeping state to get run by reply handler (list, etc)
200 * These are allocated during initialization, per-transport instance.
202 * N of these are associated with a transport instance, and stored in
203 * struct rpcrdma_buffer. N is the max number of outstanding requests.
207 struct ib_cqe rr_cqe;
211 struct ib_device *rr_device;
212 struct rpcrdma_xprt *rr_rxprt;
213 struct work_struct rr_work;
214 struct list_head rr_list;
215 struct ib_recv_wr rr_recv_wr;
216 struct rpcrdma_regbuf *rr_rdmabuf;
219 #define RPCRDMA_BAD_LEN (~0U)
222 * struct rpcrdma_mw - external memory region metadata
224 * An external memory region is any buffer or page that is registered
225 * on the fly (ie, not pre-registered).
227 * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
228 * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
229 * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
230 * track of registration metadata while each RPC is pending.
231 * rpcrdma_deregister_external() uses this metadata to unmap and
232 * release these resources when an RPC is complete.
234 enum rpcrdma_frmr_state {
235 FRMR_IS_INVALID, /* ready to be used */
236 FRMR_IS_VALID, /* in use */
237 FRMR_FLUSHED_FR, /* flushed FASTREG WR */
238 FRMR_FLUSHED_LI, /* flushed LOCALINV WR */
241 struct rpcrdma_frmr {
243 struct ib_cqe fr_cqe;
244 enum rpcrdma_frmr_state fr_state;
245 struct completion fr_linv_done;
247 struct ib_reg_wr fr_regwr;
248 struct ib_send_wr fr_invwr;
253 struct ib_fmr *fm_mr;
258 struct list_head mw_list;
259 struct scatterlist *mw_sg;
261 enum dma_data_direction mw_dir;
263 struct rpcrdma_fmr fmr;
264 struct rpcrdma_frmr frmr;
266 struct rpcrdma_xprt *mw_xprt;
270 struct list_head mw_all;
274 * struct rpcrdma_req -- structure central to the request/reply sequence.
276 * N of these are associated with a transport instance, and stored in
277 * struct rpcrdma_buffer. N is the max number of outstanding requests.
279 * It includes pre-registered buffer memory for send AND recv.
280 * The recv buffer, however, is not owned by this structure, and
281 * is "donated" to the hardware when a recv is posted. When a
282 * reply is handled, the recv buffer used is given back to the
283 * struct rpcrdma_req associated with the request.
285 * In addition to the basic memory, this structure includes an array
286 * of iovs for send operations. The reason is that the iovs passed to
287 * ib_post_{send,recv} must not be modified until the work request
291 /* Maximum number of page-sized "segments" per chunk list to be
292 * registered or invalidated. Must handle a Reply chunk:
295 RPCRDMA_MAX_IOV_SEGS = 3,
296 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
297 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
298 RPCRDMA_MAX_IOV_SEGS,
301 struct rpcrdma_mr_seg { /* chunk descriptors */
302 u32 mr_len; /* length of chunk or segment */
303 struct page *mr_page; /* owning page, if any */
304 char *mr_offset; /* kva if no page, else offset */
307 /* Reserve enough Send SGEs to send a maximum size inline request:
308 * - RPC-over-RDMA header
309 * - xdr_buf head iovec
310 * - RPCRDMA_MAX_INLINE bytes, possibly unaligned, in pages
311 * - xdr_buf tail iovec
314 RPCRDMA_MIN_SEND_SGES = 3,
315 RPCRDMA_MAX_SEND_PAGES = PAGE_SIZE + RPCRDMA_MAX_INLINE - 1,
316 RPCRDMA_MAX_PAGE_SGES = (RPCRDMA_MAX_SEND_PAGES >> PAGE_SHIFT) + 1,
317 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
320 struct rpcrdma_buffer;
322 struct list_head rl_free;
323 unsigned int rl_mapped_sges;
324 unsigned int rl_connect_cookie;
325 struct rpcrdma_buffer *rl_buffer;
326 struct rpcrdma_rep *rl_reply;
327 struct ib_send_wr rl_send_wr;
328 struct ib_sge rl_send_sge[RPCRDMA_MAX_SEND_SGES];
329 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */
330 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */
331 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */
333 struct ib_cqe rl_cqe;
334 struct list_head rl_all;
337 struct list_head rl_registered; /* registered segments */
338 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
342 rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req)
344 rqst->rq_xprtdata = req;
347 static inline struct rpcrdma_req *
348 rpcr_to_rdmar(struct rpc_rqst *rqst)
350 return rqst->rq_xprtdata;
354 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
355 * inline requests/replies, and client/server credits.
357 * One of these is associated with a transport instance
359 struct rpcrdma_buffer {
360 spinlock_t rb_mwlock; /* protect rb_mws list */
361 struct list_head rb_mws;
362 struct list_head rb_all;
365 spinlock_t rb_lock; /* protect buf lists */
366 int rb_send_count, rb_recv_count;
367 struct list_head rb_send_bufs;
368 struct list_head rb_recv_bufs;
370 atomic_t rb_credits; /* most recent credit grant */
372 u32 rb_bc_srv_max_requests;
373 spinlock_t rb_reqslock; /* protect rb_allreqs */
374 struct list_head rb_allreqs;
376 u32 rb_bc_max_requests;
378 spinlock_t rb_recovery_lock; /* protect rb_stale_mrs */
379 struct list_head rb_stale_mrs;
380 struct delayed_work rb_recovery_worker;
381 struct delayed_work rb_refresh_worker;
383 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
386 * Internal structure for transport instance creation. This
387 * exists primarily for modularity.
389 * This data should be set with mount options
391 struct rpcrdma_create_data_internal {
392 struct sockaddr_storage addr; /* RDMA server address */
393 unsigned int max_requests; /* max requests (slots) in flight */
394 unsigned int rsize; /* mount rsize - max read hdr+data */
395 unsigned int wsize; /* mount wsize - max write hdr+data */
396 unsigned int inline_rsize; /* max non-rdma read data payload */
397 unsigned int inline_wsize; /* max non-rdma write data payload */
398 unsigned int padding; /* non-rdma write header padding */
402 * Statistics for RPCRDMA
404 struct rpcrdma_stats {
405 unsigned long read_chunk_count;
406 unsigned long write_chunk_count;
407 unsigned long reply_chunk_count;
409 unsigned long long total_rdma_request;
410 unsigned long long total_rdma_reply;
412 unsigned long long pullup_copy_count;
413 unsigned long long fixup_copy_count;
414 unsigned long hardway_register_count;
415 unsigned long failed_marshal_count;
416 unsigned long bad_reply_count;
417 unsigned long nomsg_call_count;
418 unsigned long bcall_count;
419 unsigned long mrs_recovered;
420 unsigned long mrs_orphaned;
421 unsigned long mrs_allocated;
422 unsigned long local_inv_needed;
426 * Per-registration mode operations
429 struct rpcrdma_memreg_ops {
430 int (*ro_map)(struct rpcrdma_xprt *,
431 struct rpcrdma_mr_seg *, int, bool,
432 struct rpcrdma_mw **);
433 void (*ro_unmap_sync)(struct rpcrdma_xprt *,
434 struct rpcrdma_req *);
435 void (*ro_unmap_safe)(struct rpcrdma_xprt *,
436 struct rpcrdma_req *, bool);
437 void (*ro_recover_mr)(struct rpcrdma_mw *);
438 int (*ro_open)(struct rpcrdma_ia *,
440 struct rpcrdma_create_data_internal *);
441 size_t (*ro_maxpages)(struct rpcrdma_xprt *);
442 int (*ro_init_mr)(struct rpcrdma_ia *,
443 struct rpcrdma_mw *);
444 void (*ro_release_mr)(struct rpcrdma_mw *);
445 const char *ro_displayname;
446 const int ro_send_w_inv_ok;
449 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
450 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
453 * RPCRDMA transport -- encapsulates the structures above for
454 * integration with RPC.
456 * The contained structures are embedded, not pointers,
457 * for convenience. This structure need not be visible externally.
459 * It is allocated and initialized during mount, and released
462 struct rpcrdma_xprt {
463 struct rpc_xprt rx_xprt;
464 struct rpcrdma_ia rx_ia;
465 struct rpcrdma_ep rx_ep;
466 struct rpcrdma_buffer rx_buf;
467 struct rpcrdma_create_data_internal rx_data;
468 struct delayed_work rx_connect_worker;
469 struct rpcrdma_stats rx_stats;
472 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
473 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
475 /* Setting this to 0 ensures interoperability with early servers.
476 * Setting this to 1 enhances certain unaligned read/write performance.
477 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
478 extern int xprt_rdma_pad_optimize;
481 * Interface Adapter calls - xprtrdma/verbs.c
483 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
484 void rpcrdma_ia_close(struct rpcrdma_ia *);
485 bool frwr_is_supported(struct rpcrdma_ia *);
486 bool fmr_is_supported(struct rpcrdma_ia *);
489 * Endpoint calls - xprtrdma/verbs.c
491 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
492 struct rpcrdma_create_data_internal *);
493 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
494 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
495 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
497 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
498 struct rpcrdma_req *);
499 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_rep *);
502 * Buffer calls - xprtrdma/verbs.c
504 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
505 void rpcrdma_destroy_req(struct rpcrdma_req *);
506 int rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt);
507 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
508 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
510 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
511 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
512 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
513 void rpcrdma_buffer_put(struct rpcrdma_req *);
514 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
515 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
517 void rpcrdma_defer_mr_recovery(struct rpcrdma_mw *);
519 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(size_t, enum dma_data_direction,
521 bool __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *, struct rpcrdma_regbuf *);
522 void rpcrdma_free_regbuf(struct rpcrdma_regbuf *);
525 rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
527 return rb->rg_device != NULL;
531 rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
533 if (likely(rpcrdma_regbuf_is_mapped(rb)))
535 return __rpcrdma_dma_map_regbuf(ia, rb);
538 int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
540 int rpcrdma_alloc_wq(void);
541 void rpcrdma_destroy_wq(void);
544 * Wrappers for chunk registration, shared by read/write chunk code.
547 static inline enum dma_data_direction
548 rpcrdma_data_dir(bool writing)
550 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
554 * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
556 void rpcrdma_connect_worker(struct work_struct *);
557 void rpcrdma_conn_func(struct rpcrdma_ep *);
558 void rpcrdma_reply_handler(struct work_struct *);
561 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
564 enum rpcrdma_chunktype {
572 bool rpcrdma_prepare_send_sges(struct rpcrdma_ia *, struct rpcrdma_req *,
573 u32, struct xdr_buf *, enum rpcrdma_chunktype);
574 void rpcrdma_unmap_sges(struct rpcrdma_ia *, struct rpcrdma_req *);
575 int rpcrdma_marshal_req(struct rpc_rqst *);
576 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
578 /* RPC/RDMA module init - xprtrdma/transport.c
580 extern unsigned int xprt_rdma_max_inline_read;
581 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
582 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
583 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
584 int xprt_rdma_init(void);
585 void xprt_rdma_cleanup(void);
587 /* Backchannel calls - xprtrdma/backchannel.c
589 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
590 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
591 int xprt_rdma_bc_up(struct svc_serv *, struct net *);
592 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
593 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
594 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
595 int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
596 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
597 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
598 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
600 extern struct xprt_class xprt_rdma_bc;
602 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */