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
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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_frmr_depth;
74 unsigned int ri_max_inline_write;
75 unsigned int ri_max_inline_read;
76 struct ib_qp_attr ri_qp_attr;
77 struct ib_qp_init_attr ri_qp_init_attr;
81 * RDMA Endpoint -- one per transport instance
88 struct ib_qp_init_attr rep_attr;
89 wait_queue_head_t rep_connect_wait;
90 struct rdma_conn_param rep_remote_cma;
91 struct sockaddr_storage rep_remote_addr;
92 struct delayed_work rep_connect_worker;
95 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
96 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
98 /* Pre-allocate extra Work Requests for handling backward receives
99 * and sends. This is a fixed value because the Work Queues are
100 * allocated when the forward channel is set up.
102 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
103 #define RPCRDMA_BACKWARD_WRS (8)
105 #define RPCRDMA_BACKWARD_WRS (0)
108 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
110 * The below structure appears at the front of a large region of kmalloc'd
111 * memory, which always starts on a good alignment boundary.
114 struct rpcrdma_regbuf {
115 struct ib_sge rg_iov;
116 __be32 rg_base[0] __attribute__ ((aligned(256)));
120 rdmab_addr(struct rpcrdma_regbuf *rb)
122 return rb->rg_iov.addr;
126 rdmab_length(struct rpcrdma_regbuf *rb)
128 return rb->rg_iov.length;
132 rdmab_lkey(struct rpcrdma_regbuf *rb)
134 return rb->rg_iov.lkey;
137 static inline struct rpcrdma_msg *
138 rdmab_to_msg(struct rpcrdma_regbuf *rb)
140 return (struct rpcrdma_msg *)rb->rg_base;
143 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
145 /* To ensure a transport can always make forward progress,
146 * the number of RDMA segments allowed in header chunk lists
147 * is capped at 8. This prevents less-capable devices and
148 * memory registrations from overrunning the Send buffer
149 * while building chunk lists.
151 * Elements of the Read list take up more room than the
152 * Write list or Reply chunk. 8 read segments means the Read
153 * list (or Write list or Reply chunk) cannot consume more
156 * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
158 * And the fixed part of the header is another 24 bytes.
160 * The smallest inline threshold is 1024 bytes, ensuring that
161 * at least 750 bytes are available for RPC messages.
164 RPCRDMA_MAX_HDR_SEGS = 8,
165 RPCRDMA_HDRBUF_SIZE = 256,
169 * struct rpcrdma_rep -- this structure encapsulates state required to recv
170 * and complete a reply, asychronously. It needs several pieces of
172 * o recv buffer (posted to provider)
173 * o ib_sge (also donated to provider)
174 * o status of reply (length, success or not)
175 * o bookkeeping state to get run by reply handler (list, etc)
177 * These are allocated during initialization, per-transport instance.
179 * N of these are associated with a transport instance, and stored in
180 * struct rpcrdma_buffer. N is the max number of outstanding requests.
184 struct ib_cqe rr_cqe;
186 struct ib_device *rr_device;
187 struct rpcrdma_xprt *rr_rxprt;
188 struct work_struct rr_work;
189 struct list_head rr_list;
190 struct rpcrdma_regbuf *rr_rdmabuf;
193 #define RPCRDMA_BAD_LEN (~0U)
196 * struct rpcrdma_mw - external memory region metadata
198 * An external memory region is any buffer or page that is registered
199 * on the fly (ie, not pre-registered).
201 * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
202 * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
203 * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
204 * track of registration metadata while each RPC is pending.
205 * rpcrdma_deregister_external() uses this metadata to unmap and
206 * release these resources when an RPC is complete.
208 enum rpcrdma_frmr_state {
209 FRMR_IS_INVALID, /* ready to be used */
210 FRMR_IS_VALID, /* in use */
211 FRMR_IS_STALE, /* failed completion */
214 struct rpcrdma_frmr {
216 struct ib_cqe fr_cqe;
217 enum rpcrdma_frmr_state fr_state;
218 struct completion fr_linv_done;
220 struct ib_reg_wr fr_regwr;
221 struct ib_send_wr fr_invwr;
226 struct ib_fmr *fm_mr;
231 struct list_head mw_list;
232 struct scatterlist *mw_sg;
234 enum dma_data_direction mw_dir;
236 struct rpcrdma_fmr fmr;
237 struct rpcrdma_frmr frmr;
239 struct rpcrdma_xprt *mw_xprt;
243 struct list_head mw_all;
247 * struct rpcrdma_req -- structure central to the request/reply sequence.
249 * N of these are associated with a transport instance, and stored in
250 * struct rpcrdma_buffer. N is the max number of outstanding requests.
252 * It includes pre-registered buffer memory for send AND recv.
253 * The recv buffer, however, is not owned by this structure, and
254 * is "donated" to the hardware when a recv is posted. When a
255 * reply is handled, the recv buffer used is given back to the
256 * struct rpcrdma_req associated with the request.
258 * In addition to the basic memory, this structure includes an array
259 * of iovs for send operations. The reason is that the iovs passed to
260 * ib_post_{send,recv} must not be modified until the work request
264 /* Maximum number of page-sized "segments" per chunk list to be
265 * registered or invalidated. Must handle a Reply chunk:
268 RPCRDMA_MAX_IOV_SEGS = 3,
269 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
270 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
271 RPCRDMA_MAX_IOV_SEGS,
274 struct rpcrdma_mr_seg { /* chunk descriptors */
275 u32 mr_len; /* length of chunk or segment */
276 struct page *mr_page; /* owning page, if any */
277 char *mr_offset; /* kva if no page, else offset */
280 #define RPCRDMA_MAX_IOVS (2)
282 struct rpcrdma_buffer;
284 struct list_head rl_free;
285 unsigned int rl_niovs;
286 unsigned int rl_connect_cookie;
287 struct rpcrdma_buffer *rl_buffer;
288 struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
289 struct ib_sge rl_send_iov[RPCRDMA_MAX_IOVS];
290 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */
291 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */
292 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */
294 struct ib_cqe rl_cqe;
295 struct list_head rl_all;
298 struct list_head rl_registered; /* registered segments */
299 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
303 rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req)
305 rqst->rq_xprtdata = req;
308 static inline struct rpcrdma_req *
309 rpcr_to_rdmar(struct rpc_rqst *rqst)
311 return rqst->rq_xprtdata;
315 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
316 * inline requests/replies, and client/server credits.
318 * One of these is associated with a transport instance
320 struct rpcrdma_buffer {
321 spinlock_t rb_mwlock; /* protect rb_mws list */
322 struct list_head rb_mws;
323 struct list_head rb_all;
326 spinlock_t rb_lock; /* protect buf lists */
327 int rb_send_count, rb_recv_count;
328 struct list_head rb_send_bufs;
329 struct list_head rb_recv_bufs;
331 atomic_t rb_credits; /* most recent credit grant */
333 u32 rb_bc_srv_max_requests;
334 spinlock_t rb_reqslock; /* protect rb_allreqs */
335 struct list_head rb_allreqs;
337 u32 rb_bc_max_requests;
339 spinlock_t rb_recovery_lock; /* protect rb_stale_mrs */
340 struct list_head rb_stale_mrs;
341 struct delayed_work rb_recovery_worker;
342 struct delayed_work rb_refresh_worker;
344 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
347 * Internal structure for transport instance creation. This
348 * exists primarily for modularity.
350 * This data should be set with mount options
352 struct rpcrdma_create_data_internal {
353 struct sockaddr_storage addr; /* RDMA server address */
354 unsigned int max_requests; /* max requests (slots) in flight */
355 unsigned int rsize; /* mount rsize - max read hdr+data */
356 unsigned int wsize; /* mount wsize - max write hdr+data */
357 unsigned int inline_rsize; /* max non-rdma read data payload */
358 unsigned int inline_wsize; /* max non-rdma write data payload */
359 unsigned int padding; /* non-rdma write header padding */
363 * Statistics for RPCRDMA
365 struct rpcrdma_stats {
366 unsigned long read_chunk_count;
367 unsigned long write_chunk_count;
368 unsigned long reply_chunk_count;
370 unsigned long long total_rdma_request;
371 unsigned long long total_rdma_reply;
373 unsigned long long pullup_copy_count;
374 unsigned long long fixup_copy_count;
375 unsigned long hardway_register_count;
376 unsigned long failed_marshal_count;
377 unsigned long bad_reply_count;
378 unsigned long nomsg_call_count;
379 unsigned long bcall_count;
380 unsigned long mrs_recovered;
381 unsigned long mrs_orphaned;
382 unsigned long mrs_allocated;
386 * Per-registration mode operations
389 struct rpcrdma_memreg_ops {
390 int (*ro_map)(struct rpcrdma_xprt *,
391 struct rpcrdma_mr_seg *, int, bool,
392 struct rpcrdma_mw **);
393 void (*ro_unmap_sync)(struct rpcrdma_xprt *,
394 struct rpcrdma_req *);
395 void (*ro_unmap_safe)(struct rpcrdma_xprt *,
396 struct rpcrdma_req *, bool);
397 void (*ro_recover_mr)(struct rpcrdma_mw *);
398 int (*ro_open)(struct rpcrdma_ia *,
400 struct rpcrdma_create_data_internal *);
401 size_t (*ro_maxpages)(struct rpcrdma_xprt *);
402 int (*ro_init_mr)(struct rpcrdma_ia *,
403 struct rpcrdma_mw *);
404 void (*ro_release_mr)(struct rpcrdma_mw *);
405 const char *ro_displayname;
408 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
409 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
412 * RPCRDMA transport -- encapsulates the structures above for
413 * integration with RPC.
415 * The contained structures are embedded, not pointers,
416 * for convenience. This structure need not be visible externally.
418 * It is allocated and initialized during mount, and released
421 struct rpcrdma_xprt {
422 struct rpc_xprt rx_xprt;
423 struct rpcrdma_ia rx_ia;
424 struct rpcrdma_ep rx_ep;
425 struct rpcrdma_buffer rx_buf;
426 struct rpcrdma_create_data_internal rx_data;
427 struct delayed_work rx_connect_worker;
428 struct rpcrdma_stats rx_stats;
431 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
432 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
434 /* Setting this to 0 ensures interoperability with early servers.
435 * Setting this to 1 enhances certain unaligned read/write performance.
436 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
437 extern int xprt_rdma_pad_optimize;
440 * Interface Adapter calls - xprtrdma/verbs.c
442 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
443 void rpcrdma_ia_close(struct rpcrdma_ia *);
444 bool frwr_is_supported(struct rpcrdma_ia *);
445 bool fmr_is_supported(struct rpcrdma_ia *);
448 * Endpoint calls - xprtrdma/verbs.c
450 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
451 struct rpcrdma_create_data_internal *);
452 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
453 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
454 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
456 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
457 struct rpcrdma_req *);
458 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
459 struct rpcrdma_rep *);
462 * Buffer calls - xprtrdma/verbs.c
464 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
465 struct rpcrdma_rep *rpcrdma_create_rep(struct rpcrdma_xprt *);
466 void rpcrdma_destroy_req(struct rpcrdma_ia *, struct rpcrdma_req *);
467 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
468 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
470 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
471 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
472 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
473 void rpcrdma_buffer_put(struct rpcrdma_req *);
474 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
475 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
477 void rpcrdma_defer_mr_recovery(struct rpcrdma_mw *);
479 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
481 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
482 struct rpcrdma_regbuf *);
484 int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
486 int rpcrdma_alloc_wq(void);
487 void rpcrdma_destroy_wq(void);
490 * Wrappers for chunk registration, shared by read/write chunk code.
493 static inline enum dma_data_direction
494 rpcrdma_data_dir(bool writing)
496 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
500 * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
502 void rpcrdma_connect_worker(struct work_struct *);
503 void rpcrdma_conn_func(struct rpcrdma_ep *);
504 void rpcrdma_reply_handler(struct rpcrdma_rep *);
507 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
509 int rpcrdma_marshal_req(struct rpc_rqst *);
510 void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *,
511 struct rpcrdma_create_data_internal *,
514 /* RPC/RDMA module init - xprtrdma/transport.c
516 extern unsigned int xprt_rdma_max_inline_read;
517 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
518 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
519 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
520 int xprt_rdma_init(void);
521 void xprt_rdma_cleanup(void);
523 /* Backchannel calls - xprtrdma/backchannel.c
525 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
526 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
527 int xprt_rdma_bc_up(struct svc_serv *, struct net *);
528 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
529 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
530 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
531 int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
532 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
533 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
534 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
536 extern struct xprt_class xprt_rdma_bc;
538 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */