1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
3 * Copyright (c) 2014-2017 Oracle. All rights reserved.
4 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
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42 #ifndef _LINUX_SUNRPC_XPRT_RDMA_H
43 #define _LINUX_SUNRPC_XPRT_RDMA_H
45 #include <linux/wait.h> /* wait_queue_head_t, etc */
46 #include <linux/spinlock.h> /* spinlock_t, etc */
47 #include <linux/atomic.h> /* atomic_t, etc */
48 #include <linux/kref.h> /* struct kref */
49 #include <linux/workqueue.h> /* struct work_struct */
50 #include <linux/llist.h>
52 #include <rdma/rdma_cm.h> /* RDMA connection api */
53 #include <rdma/ib_verbs.h> /* RDMA verbs api */
55 #include <linux/sunrpc/clnt.h> /* rpc_xprt */
56 #include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */
57 #include <linux/sunrpc/xprtrdma.h> /* xprt parameters */
59 #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
60 #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
62 #define RPCRDMA_BIND_TO (60U * HZ)
63 #define RPCRDMA_INIT_REEST_TO (5U * HZ)
64 #define RPCRDMA_MAX_REEST_TO (30U * HZ)
65 #define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ)
68 * Interface Adapter -- one per transport instance
71 struct rdma_cm_id *ri_id;
74 unsigned int ri_max_segs;
75 unsigned int ri_max_frwr_depth;
76 unsigned int ri_max_send_sges;
77 bool ri_implicit_roundup;
78 enum ib_mr_type ri_mrtype;
79 unsigned long ri_flags;
80 struct completion ri_done;
81 struct completion ri_remove_done;
85 RPCRDMA_IAF_REMOVING = 0,
89 * RDMA Endpoint -- one per transport instance
93 unsigned int rep_send_count;
94 unsigned int rep_send_batch;
95 unsigned int rep_max_inline_send;
96 unsigned int rep_max_inline_recv;
98 struct ib_qp_init_attr rep_attr;
99 wait_queue_head_t rep_connect_wait;
100 struct rpcrdma_connect_private rep_cm_private;
101 struct rdma_conn_param rep_remote_cma;
102 unsigned int rep_max_requests; /* set by /proc */
103 unsigned int rep_inline_send; /* negotiated */
104 unsigned int rep_inline_recv; /* negotiated */
105 int rep_receive_count;
108 /* Pre-allocate extra Work Requests for handling backward receives
109 * and sends. This is a fixed value because the Work Queues are
110 * allocated when the forward channel is set up, long before the
111 * backchannel is provisioned. This value is two times
112 * NFS4_DEF_CB_SLOT_TABLE_SIZE.
114 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
115 #define RPCRDMA_BACKWARD_WRS (32)
117 #define RPCRDMA_BACKWARD_WRS (0)
120 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
123 struct rpcrdma_regbuf {
124 struct ib_sge rg_iov;
125 struct ib_device *rg_device;
126 enum dma_data_direction rg_direction;
130 static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
132 return rb->rg_iov.addr;
135 static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
137 return rb->rg_iov.length;
140 static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
142 return rb->rg_iov.lkey;
145 static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
147 return rb->rg_device;
150 static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
155 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
157 /* To ensure a transport can always make forward progress,
158 * the number of RDMA segments allowed in header chunk lists
159 * is capped at 16. This prevents less-capable devices from
160 * overrunning the Send buffer while building chunk lists.
162 * Elements of the Read list take up more room than the
163 * Write list or Reply chunk. 16 read segments means the
164 * chunk lists cannot consume more than
166 * ((16 + 2) * read segment size) + 1 XDR words,
168 * or about 400 bytes. The fixed part of the header is
169 * another 24 bytes. Thus when the inline threshold is
170 * 1024 bytes, at least 600 bytes are available for RPC
174 RPCRDMA_MAX_HDR_SEGS = 16,
178 * struct rpcrdma_rep -- this structure encapsulates state required
179 * to receive and complete an RPC Reply, asychronously. It needs
180 * several pieces of state:
182 * o receive buffer and ib_sge (donated to provider)
183 * o status of receive (success or not, length, inv rkey)
184 * o bookkeeping state to get run by reply handler (XDR stream)
186 * These structures are allocated during transport initialization.
187 * N of these are associated with a transport instance, managed by
188 * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
192 struct ib_cqe rr_cqe;
199 struct rpcrdma_regbuf *rr_rdmabuf;
200 struct rpcrdma_xprt *rr_rxprt;
201 struct rpc_rqst *rr_rqst;
202 struct xdr_buf rr_hdrbuf;
203 struct xdr_stream rr_stream;
204 struct llist_node rr_node;
205 struct ib_recv_wr rr_recv_wr;
206 struct list_head rr_all;
209 /* To reduce the rate at which a transport invokes ib_post_recv
210 * (and thus the hardware doorbell rate), xprtrdma posts Receive
213 * Setting this to zero disables Receive post batching.
216 RPCRDMA_MAX_RECV_BATCH = 7,
219 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
222 struct rpcrdma_sendctx {
223 struct ib_cqe sc_cqe;
224 struct rpcrdma_req *sc_req;
225 unsigned int sc_unmap_count;
226 struct ib_sge sc_sges[];
230 * struct rpcrdma_mr - external memory region metadata
232 * An external memory region is any buffer or page that is registered
233 * on the fly (ie, not pre-registered).
235 struct rpcrdma_frwr {
237 struct ib_cqe fr_cqe;
238 struct completion fr_linv_done;
240 struct ib_reg_wr fr_regwr;
241 struct ib_send_wr fr_invwr;
247 struct list_head mr_list;
248 struct rpcrdma_req *mr_req;
249 struct scatterlist *mr_sg;
251 enum dma_data_direction mr_dir;
252 struct rpcrdma_frwr frwr;
253 struct rpcrdma_xprt *mr_xprt;
257 struct list_head mr_all;
261 * struct rpcrdma_req -- structure central to the request/reply sequence.
263 * N of these are associated with a transport instance, and stored in
264 * struct rpcrdma_buffer. N is the max number of outstanding requests.
266 * It includes pre-registered buffer memory for send AND recv.
267 * The recv buffer, however, is not owned by this structure, and
268 * is "donated" to the hardware when a recv is posted. When a
269 * reply is handled, the recv buffer used is given back to the
270 * struct rpcrdma_req associated with the request.
272 * In addition to the basic memory, this structure includes an array
273 * of iovs for send operations. The reason is that the iovs passed to
274 * ib_post_{send,recv} must not be modified until the work request
278 /* Maximum number of page-sized "segments" per chunk list to be
279 * registered or invalidated. Must handle a Reply chunk:
282 RPCRDMA_MAX_IOV_SEGS = 3,
283 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
284 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
285 RPCRDMA_MAX_IOV_SEGS,
288 struct rpcrdma_mr_seg { /* chunk descriptors */
289 u32 mr_len; /* length of chunk or segment */
290 struct page *mr_page; /* owning page, if any */
291 char *mr_offset; /* kva if no page, else offset */
294 /* The Send SGE array is provisioned to send a maximum size
296 * - RPC-over-RDMA header
297 * - xdr_buf head iovec
298 * - RPCRDMA_MAX_INLINE bytes, in pages
299 * - xdr_buf tail iovec
301 * The actual number of array elements consumed by each RPC
302 * depends on the device's max_sge limit.
305 RPCRDMA_MIN_SEND_SGES = 3,
306 RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
307 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
310 struct rpcrdma_buffer;
312 struct list_head rl_list;
313 struct rpc_rqst rl_slot;
314 struct rpcrdma_rep *rl_reply;
315 struct xdr_stream rl_stream;
316 struct xdr_buf rl_hdrbuf;
317 struct ib_send_wr rl_wr;
318 struct rpcrdma_sendctx *rl_sendctx;
319 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */
320 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */
321 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */
323 struct list_head rl_all;
326 struct list_head rl_free_mrs;
327 struct list_head rl_registered;
328 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
331 static inline struct rpcrdma_req *
332 rpcr_to_rdmar(const struct rpc_rqst *rqst)
334 return container_of(rqst, struct rpcrdma_req, rl_slot);
338 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
340 list_add(&mr->mr_list, list);
343 static inline struct rpcrdma_mr *
344 rpcrdma_mr_pop(struct list_head *list)
346 struct rpcrdma_mr *mr;
348 mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
350 list_del_init(&mr->mr_list);
355 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
356 * inline requests/replies, and client/server credits.
358 * One of these is associated with a transport instance
360 struct rpcrdma_buffer {
362 struct list_head rb_send_bufs;
363 struct list_head rb_mrs;
365 unsigned long rb_sc_head;
366 unsigned long rb_sc_tail;
367 unsigned long rb_sc_last;
368 struct rpcrdma_sendctx **rb_sc_ctxs;
370 struct list_head rb_allreqs;
371 struct list_head rb_all_mrs;
372 struct list_head rb_all_reps;
374 struct llist_head rb_free_reps;
377 u32 rb_credits; /* most recent credit grant */
379 u32 rb_bc_srv_max_requests;
380 u32 rb_bc_max_requests;
382 struct work_struct rb_refresh_worker;
386 * Statistics for RPCRDMA
388 struct rpcrdma_stats {
389 /* accessed when sending a call */
390 unsigned long read_chunk_count;
391 unsigned long write_chunk_count;
392 unsigned long reply_chunk_count;
393 unsigned long long total_rdma_request;
395 /* rarely accessed error counters */
396 unsigned long long pullup_copy_count;
397 unsigned long hardway_register_count;
398 unsigned long failed_marshal_count;
399 unsigned long bad_reply_count;
400 unsigned long mrs_recycled;
401 unsigned long mrs_orphaned;
402 unsigned long mrs_allocated;
403 unsigned long empty_sendctx_q;
405 /* accessed when receiving a reply */
406 unsigned long long total_rdma_reply;
407 unsigned long long fixup_copy_count;
408 unsigned long reply_waits_for_send;
409 unsigned long local_inv_needed;
410 unsigned long nomsg_call_count;
411 unsigned long bcall_count;
415 * RPCRDMA transport -- encapsulates the structures above for
416 * integration with RPC.
418 * The contained structures are embedded, not pointers,
419 * for convenience. This structure need not be visible externally.
421 * It is allocated and initialized during mount, and released
424 struct rpcrdma_xprt {
425 struct rpc_xprt rx_xprt;
426 struct rpcrdma_ia rx_ia;
427 struct rpcrdma_ep rx_ep;
428 struct rpcrdma_buffer rx_buf;
429 struct delayed_work rx_connect_worker;
430 struct rpc_timeout rx_timeout;
431 struct rpcrdma_stats rx_stats;
434 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
436 static inline const char *
437 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
439 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
442 static inline const char *
443 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
445 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
448 /* Setting this to 0 ensures interoperability with early servers.
449 * Setting this to 1 enhances certain unaligned read/write performance.
450 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
451 extern int xprt_rdma_pad_optimize;
453 /* This setting controls the hunt for a supported memory
454 * registration strategy.
456 extern unsigned int xprt_rdma_memreg_strategy;
459 * Interface Adapter calls - xprtrdma/verbs.c
461 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt);
462 void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
463 void rpcrdma_ia_close(struct rpcrdma_ia *);
466 * Endpoint calls - xprtrdma/verbs.c
468 int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt);
469 void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt);
470 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
471 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
473 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
474 struct rpcrdma_req *);
475 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
478 * Buffer calls - xprtrdma/verbs.c
480 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
482 void rpcrdma_req_destroy(struct rpcrdma_req *req);
483 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
484 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
485 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
487 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
488 void rpcrdma_mr_put(struct rpcrdma_mr *mr);
489 void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
491 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
492 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
493 struct rpcrdma_req *req);
494 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
496 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
498 bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
499 struct rpcrdma_regbuf *rb);
502 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
504 * Returns true if the buffer is now mapped to rb->rg_device.
506 static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
508 return rb->rg_device != NULL;
512 * rpcrdma_regbuf_dma_map - DMA-map a regbuf
513 * @r_xprt: controlling transport instance
514 * @rb: regbuf to be mapped
516 * Returns true if the buffer is currently DMA mapped.
518 static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
519 struct rpcrdma_regbuf *rb)
521 if (likely(rpcrdma_regbuf_is_mapped(rb)))
523 return __rpcrdma_regbuf_dma_map(r_xprt, rb);
527 * Wrappers for chunk registration, shared by read/write chunk code.
530 static inline enum dma_data_direction
531 rpcrdma_data_dir(bool writing)
533 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
536 /* Memory registration calls xprtrdma/frwr_ops.c
538 bool frwr_is_supported(struct ib_device *device);
539 void frwr_reset(struct rpcrdma_req *req);
540 int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep);
541 int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr);
542 void frwr_release_mr(struct rpcrdma_mr *mr);
543 size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt);
544 struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
545 struct rpcrdma_mr_seg *seg,
546 int nsegs, bool writing, __be32 xid,
547 struct rpcrdma_mr *mr);
548 int frwr_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req);
549 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
550 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
551 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
554 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
557 enum rpcrdma_chunktype {
567 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
568 struct rpcrdma_req *req, u32 hdrlen,
570 enum rpcrdma_chunktype rtype);
571 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
572 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
573 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
574 void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
575 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
576 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
578 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
580 xdr->head[0].iov_len = len;
584 /* RPC/RDMA module init - xprtrdma/transport.c
586 extern unsigned int xprt_rdma_slot_table_entries;
587 extern unsigned int xprt_rdma_max_inline_read;
588 extern unsigned int xprt_rdma_max_inline_write;
589 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
590 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
591 void xprt_rdma_close(struct rpc_xprt *xprt);
592 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
593 int xprt_rdma_init(void);
594 void xprt_rdma_cleanup(void);
596 /* Backchannel calls - xprtrdma/backchannel.c
598 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
599 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
600 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
601 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
602 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
603 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
604 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
605 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
606 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
607 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
609 extern struct xprt_class xprt_rdma_bc;
611 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */