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 */
54 #include <linux/sunrpc/svc.h> /* RPCSVC_MAXPAYLOAD */
56 #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
57 #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
60 * Interface Adapter -- one per transport instance
63 const struct rpcrdma_memreg_ops *ri_ops;
65 struct ib_device *ri_device;
66 struct rdma_cm_id *ri_id;
68 struct ib_mr *ri_bind_mem;
71 struct completion ri_done;
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;
80 * RDMA Endpoint -- one per transport instance
83 #define RPCRDMA_WC_BUDGET (128)
84 #define RPCRDMA_POLLSIZE (16)
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];
101 * Force a signaled SEND Work Request every so often,
102 * in case the provider needs to do some housekeeping.
104 #define RPCRDMA_MAX_UNSIGNALED_SENDS (32)
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)
109 /* Force completion handler to ignore the signal
111 #define RPCRDMA_IGNORE_COMPLETION (0ULL)
113 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
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.
119 struct rpcrdma_regbuf {
121 struct rpcrdma_req *rg_owner;
123 struct ib_sge rg_iov;
124 __be32 rg_base[0] __attribute__ ((aligned(256)));
128 rdmab_addr(struct rpcrdma_regbuf *rb)
130 return rb->rg_iov.addr;
134 rdmab_length(struct rpcrdma_regbuf *rb)
136 return rb->rg_iov.length;
140 rdmab_lkey(struct rpcrdma_regbuf *rb)
142 return rb->rg_iov.lkey;
145 static inline struct rpcrdma_msg *
146 rdmab_to_msg(struct rpcrdma_regbuf *rb)
148 return (struct rpcrdma_msg *)rb->rg_base;
152 * struct rpcrdma_rep -- this structure encapsulates state required to recv
153 * and complete a reply, asychronously. It needs several pieces of
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)
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.
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.
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 */
172 struct rpcrdma_buffer;
176 struct ib_device *rr_device;
177 struct rpcrdma_xprt *rr_rxprt;
178 struct list_head rr_list;
179 struct rpcrdma_regbuf *rr_rdmabuf;
183 * struct rpcrdma_mw - external memory region metadata
185 * An external memory region is any buffer or page that is registered
186 * on the fly (ie, not pre-registered).
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.
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 */
201 struct rpcrdma_frmr {
202 struct ib_fast_reg_page_list *fr_pgl;
204 enum rpcrdma_frmr_state fr_state;
205 struct work_struct fr_work;
206 struct rpcrdma_xprt *fr_xprt;
216 struct rpcrdma_fmr fmr;
217 struct rpcrdma_frmr frmr;
219 void (*mw_sendcompletion)(struct ib_wc *);
220 struct list_head mw_list;
221 struct list_head mw_all;
225 * struct rpcrdma_req -- structure central to the request/reply sequence.
227 * N of these are associated with a transport instance, and stored in
228 * struct rpcrdma_buffer. N is the max number of outstanding requests.
230 * It includes pre-registered buffer memory for send AND recv.
231 * The recv buffer, however, is not owned by this structure, and
232 * is "donated" to the hardware when a recv is posted. When a
233 * reply is handled, the recv buffer used is given back to the
234 * struct rpcrdma_req associated with the request.
236 * In addition to the basic memory, this structure includes an array
237 * of iovs for send operations. The reason is that the iovs passed to
238 * ib_post_{send,recv} must not be modified until the work request
242 * o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
243 * marshal. The number needed varies depending on the iov lists that
244 * are passed to us, the memory registration mode we are in, and if
245 * physical addressing is used, the layout.
248 struct rpcrdma_mr_seg { /* chunk descriptors */
249 struct rpcrdma_mw *rl_mw; /* registered MR */
250 u64 mr_base; /* registration result */
251 u32 mr_rkey; /* registration result */
252 u32 mr_len; /* length of chunk or segment */
253 int mr_nsegs; /* number of segments in chunk or 0 */
254 enum dma_data_direction mr_dir; /* segment mapping direction */
255 dma_addr_t mr_dma; /* segment mapping address */
256 size_t mr_dmalen; /* segment mapping length */
257 struct page *mr_page; /* owning page, if any */
258 char *mr_offset; /* kva if no page, else offset */
262 unsigned int rl_niovs; /* 0, 2 or 4 */
263 unsigned int rl_nchunks; /* non-zero if chunks */
264 unsigned int rl_connect_cookie; /* retry detection */
265 struct rpcrdma_buffer *rl_buffer; /* home base for this structure */
266 struct rpcrdma_rep *rl_reply;/* holder for reply buffer */
267 struct ib_sge rl_send_iov[4]; /* for active requests */
268 struct rpcrdma_regbuf *rl_rdmabuf;
269 struct rpcrdma_regbuf *rl_sendbuf;
270 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
273 static inline struct rpcrdma_req *
274 rpcr_to_rdmar(struct rpc_rqst *rqst)
276 void *buffer = rqst->rq_buffer;
277 struct rpcrdma_regbuf *rb;
279 rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
284 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
285 * inline requests/replies, and client/server credits.
287 * One of these is associated with a transport instance
289 struct rpcrdma_buffer {
290 spinlock_t rb_mwlock; /* protect rb_mws list */
291 struct list_head rb_mws;
292 struct list_head rb_all;
295 spinlock_t rb_lock; /* protect buf arrays */
299 struct rpcrdma_req **rb_send_bufs;
300 struct rpcrdma_rep **rb_recv_bufs;
302 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
305 * Internal structure for transport instance creation. This
306 * exists primarily for modularity.
308 * This data should be set with mount options
310 struct rpcrdma_create_data_internal {
311 struct sockaddr_storage addr; /* RDMA server address */
312 unsigned int max_requests; /* max requests (slots) in flight */
313 unsigned int rsize; /* mount rsize - max read hdr+data */
314 unsigned int wsize; /* mount wsize - max write hdr+data */
315 unsigned int inline_rsize; /* max non-rdma read data payload */
316 unsigned int inline_wsize; /* max non-rdma write data payload */
317 unsigned int padding; /* non-rdma write header padding */
320 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
321 (rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
323 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
324 (rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
326 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
327 rpcx_to_rdmad(rq->rq_xprt).padding
330 * Statistics for RPCRDMA
332 struct rpcrdma_stats {
333 unsigned long read_chunk_count;
334 unsigned long write_chunk_count;
335 unsigned long reply_chunk_count;
337 unsigned long long total_rdma_request;
338 unsigned long long total_rdma_reply;
340 unsigned long long pullup_copy_count;
341 unsigned long long fixup_copy_count;
342 unsigned long hardway_register_count;
343 unsigned long failed_marshal_count;
344 unsigned long bad_reply_count;
348 * Per-registration mode operations
351 struct rpcrdma_memreg_ops {
352 int (*ro_map)(struct rpcrdma_xprt *,
353 struct rpcrdma_mr_seg *, int, bool);
354 int (*ro_unmap)(struct rpcrdma_xprt *,
355 struct rpcrdma_mr_seg *);
356 int (*ro_open)(struct rpcrdma_ia *,
358 struct rpcrdma_create_data_internal *);
359 size_t (*ro_maxpages)(struct rpcrdma_xprt *);
360 int (*ro_init)(struct rpcrdma_xprt *);
361 void (*ro_destroy)(struct rpcrdma_buffer *);
362 const char *ro_displayname;
365 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
366 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
367 extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
370 * RPCRDMA transport -- encapsulates the structures above for
371 * integration with RPC.
373 * The contained structures are embedded, not pointers,
374 * for convenience. This structure need not be visible externally.
376 * It is allocated and initialized during mount, and released
379 struct rpcrdma_xprt {
380 struct rpc_xprt rx_xprt;
381 struct rpcrdma_ia rx_ia;
382 struct rpcrdma_ep rx_ep;
383 struct rpcrdma_buffer rx_buf;
384 struct rpcrdma_create_data_internal rx_data;
385 struct delayed_work rx_connect_worker;
386 struct rpcrdma_stats rx_stats;
389 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
390 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
392 /* Setting this to 0 ensures interoperability with early servers.
393 * Setting this to 1 enhances certain unaligned read/write performance.
394 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
395 extern int xprt_rdma_pad_optimize;
398 * Interface Adapter calls - xprtrdma/verbs.c
400 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
401 void rpcrdma_ia_close(struct rpcrdma_ia *);
404 * Endpoint calls - xprtrdma/verbs.c
406 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
407 struct rpcrdma_create_data_internal *);
408 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
409 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
410 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
412 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
413 struct rpcrdma_req *);
414 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
415 struct rpcrdma_rep *);
418 * Buffer calls - xprtrdma/verbs.c
420 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
421 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
423 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
424 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
425 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
426 void rpcrdma_buffer_put(struct rpcrdma_req *);
427 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
428 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
430 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
432 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
433 struct rpcrdma_regbuf *);
435 unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
437 int frwr_alloc_recovery_wq(void);
438 void frwr_destroy_recovery_wq(void);
441 * Wrappers for chunk registration, shared by read/write chunk code.
444 void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
446 static inline enum dma_data_direction
447 rpcrdma_data_dir(bool writing)
449 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
453 rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
454 enum dma_data_direction direction)
456 seg->mr_dir = direction;
457 seg->mr_dmalen = seg->mr_len;
460 seg->mr_dma = ib_dma_map_page(device,
461 seg->mr_page, offset_in_page(seg->mr_offset),
462 seg->mr_dmalen, seg->mr_dir);
464 seg->mr_dma = ib_dma_map_single(device,
466 seg->mr_dmalen, seg->mr_dir);
468 if (ib_dma_mapping_error(device, seg->mr_dma))
469 rpcrdma_mapping_error(seg);
473 rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
476 ib_dma_unmap_page(device,
477 seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
479 ib_dma_unmap_single(device,
480 seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
484 * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
486 void rpcrdma_connect_worker(struct work_struct *);
487 void rpcrdma_conn_func(struct rpcrdma_ep *);
488 void rpcrdma_reply_handler(struct rpcrdma_rep *);
491 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
493 int rpcrdma_marshal_req(struct rpc_rqst *);
495 /* RPC/RDMA module init - xprtrdma/transport.c
497 int xprt_rdma_init(void);
498 void xprt_rdma_cleanup(void);
500 /* Temporary NFS request map cache. Created in svc_rdma.c */
501 extern struct kmem_cache *svc_rdma_map_cachep;
502 /* WR context cache. Created in svc_rdma.c */
503 extern struct kmem_cache *svc_rdma_ctxt_cachep;
504 /* Workqueue created in svc_rdma.c */
505 extern struct workqueue_struct *svc_rdma_wq;
507 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */