xref: /openbmc/linux/net/rds/rds.h (revision f20c7d91)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _RDS_RDS_H
3 #define _RDS_RDS_H
4 
5 #include <net/sock.h>
6 #include <linux/scatterlist.h>
7 #include <linux/highmem.h>
8 #include <rdma/rdma_cm.h>
9 #include <linux/mutex.h>
10 #include <linux/rds.h>
11 #include <linux/rhashtable.h>
12 #include <linux/refcount.h>
13 #include <linux/in6.h>
14 
15 #include "info.h"
16 
17 /*
18  * RDS Network protocol version
19  */
20 #define RDS_PROTOCOL_3_0	0x0300
21 #define RDS_PROTOCOL_3_1	0x0301
22 #define RDS_PROTOCOL_4_0	0x0400
23 #define RDS_PROTOCOL_4_1	0x0401
24 #define RDS_PROTOCOL_VERSION	RDS_PROTOCOL_3_1
25 #define RDS_PROTOCOL_MAJOR(v)	((v) >> 8)
26 #define RDS_PROTOCOL_MINOR(v)	((v) & 255)
27 #define RDS_PROTOCOL(maj, min)	(((maj) << 8) | min)
28 #define RDS_PROTOCOL_COMPAT_VERSION	RDS_PROTOCOL_3_1
29 
30 /* The following ports, 16385, 18634, 18635, are registered with IANA as
31  * the ports to be used for RDS over TCP and UDP.  Currently, only RDS over
32  * TCP and RDS over IB/RDMA are implemented.  18634 is the historical value
33  * used for the RDMA_CM listener port.  RDS/TCP uses port 16385.  After
34  * IPv6 work, RDMA_CM also uses 16385 as the listener port.  18634 is kept
35  * to ensure compatibility with older RDS modules.  Those ports are defined
36  * in each transport's header file.
37  */
38 #define RDS_PORT	18634
39 
40 #ifdef ATOMIC64_INIT
41 #define KERNEL_HAS_ATOMIC64
42 #endif
43 #ifdef RDS_DEBUG
44 #define rdsdebug(fmt, args...) pr_debug("%s(): " fmt, __func__ , ##args)
45 #else
46 /* sigh, pr_debug() causes unused variable warnings */
47 static inline __printf(1, 2)
48 void rdsdebug(char *fmt, ...)
49 {
50 }
51 #endif
52 
53 #define RDS_FRAG_SHIFT	12
54 #define RDS_FRAG_SIZE	((unsigned int)(1 << RDS_FRAG_SHIFT))
55 
56 /* Used to limit both RDMA and non-RDMA RDS message to 1MB */
57 #define RDS_MAX_MSG_SIZE	((unsigned int)(1 << 20))
58 
59 #define RDS_CONG_MAP_BYTES	(65536 / 8)
60 #define RDS_CONG_MAP_PAGES	(PAGE_ALIGN(RDS_CONG_MAP_BYTES) / PAGE_SIZE)
61 #define RDS_CONG_MAP_PAGE_BITS	(PAGE_SIZE * 8)
62 
63 struct rds_cong_map {
64 	struct rb_node		m_rb_node;
65 	struct in6_addr		m_addr;
66 	wait_queue_head_t	m_waitq;
67 	struct list_head	m_conn_list;
68 	unsigned long		m_page_addrs[RDS_CONG_MAP_PAGES];
69 };
70 
71 
72 /*
73  * This is how we will track the connection state:
74  * A connection is always in one of the following
75  * states. Updates to the state are atomic and imply
76  * a memory barrier.
77  */
78 enum {
79 	RDS_CONN_DOWN = 0,
80 	RDS_CONN_CONNECTING,
81 	RDS_CONN_DISCONNECTING,
82 	RDS_CONN_UP,
83 	RDS_CONN_RESETTING,
84 	RDS_CONN_ERROR,
85 };
86 
87 /* Bits for c_flags */
88 #define RDS_LL_SEND_FULL	0
89 #define RDS_RECONNECT_PENDING	1
90 #define RDS_IN_XMIT		2
91 #define RDS_RECV_REFILL		3
92 #define	RDS_DESTROY_PENDING	4
93 
94 /* Max number of multipaths per RDS connection. Must be a power of 2 */
95 #define	RDS_MPATH_WORKERS	8
96 #define	RDS_MPATH_HASH(rs, n) (jhash_1word((rs)->rs_bound_port, \
97 			       (rs)->rs_hash_initval) & ((n) - 1))
98 
99 #define IS_CANONICAL(laddr, faddr) (htonl(laddr) < htonl(faddr))
100 
101 /* Per mpath connection state */
102 struct rds_conn_path {
103 	struct rds_connection	*cp_conn;
104 	struct rds_message	*cp_xmit_rm;
105 	unsigned long		cp_xmit_sg;
106 	unsigned int		cp_xmit_hdr_off;
107 	unsigned int		cp_xmit_data_off;
108 	unsigned int		cp_xmit_atomic_sent;
109 	unsigned int		cp_xmit_rdma_sent;
110 	unsigned int		cp_xmit_data_sent;
111 
112 	spinlock_t		cp_lock;		/* protect msg queues */
113 	u64			cp_next_tx_seq;
114 	struct list_head	cp_send_queue;
115 	struct list_head	cp_retrans;
116 
117 	u64			cp_next_rx_seq;
118 
119 	void			*cp_transport_data;
120 
121 	atomic_t		cp_state;
122 	unsigned long		cp_send_gen;
123 	unsigned long		cp_flags;
124 	unsigned long		cp_reconnect_jiffies;
125 	struct delayed_work	cp_send_w;
126 	struct delayed_work	cp_recv_w;
127 	struct delayed_work	cp_conn_w;
128 	struct work_struct	cp_down_w;
129 	struct mutex		cp_cm_lock;	/* protect cp_state & cm */
130 	wait_queue_head_t	cp_waitq;
131 
132 	unsigned int		cp_unacked_packets;
133 	unsigned int		cp_unacked_bytes;
134 	unsigned int		cp_index;
135 };
136 
137 /* One rds_connection per RDS address pair */
138 struct rds_connection {
139 	struct hlist_node	c_hash_node;
140 	struct in6_addr		c_laddr;
141 	struct in6_addr		c_faddr;
142 	int			c_dev_if; /* ifindex used for this conn */
143 	int			c_bound_if; /* ifindex of c_laddr */
144 	unsigned int		c_loopback:1,
145 				c_isv6:1,
146 				c_ping_triggered:1,
147 				c_pad_to_32:29;
148 	int			c_npaths;
149 	struct rds_connection	*c_passive;
150 	struct rds_transport	*c_trans;
151 
152 	struct rds_cong_map	*c_lcong;
153 	struct rds_cong_map	*c_fcong;
154 
155 	/* Protocol version */
156 	unsigned int		c_proposed_version;
157 	unsigned int		c_version;
158 	possible_net_t		c_net;
159 
160 	/* TOS */
161 	u8			c_tos;
162 
163 	struct list_head	c_map_item;
164 	unsigned long		c_map_queued;
165 
166 	struct rds_conn_path	*c_path;
167 	wait_queue_head_t	c_hs_waitq; /* handshake waitq */
168 
169 	u32			c_my_gen_num;
170 	u32			c_peer_gen_num;
171 };
172 
173 static inline
174 struct net *rds_conn_net(struct rds_connection *conn)
175 {
176 	return read_pnet(&conn->c_net);
177 }
178 
179 static inline
180 void rds_conn_net_set(struct rds_connection *conn, struct net *net)
181 {
182 	write_pnet(&conn->c_net, net);
183 }
184 
185 #define RDS_FLAG_CONG_BITMAP	0x01
186 #define RDS_FLAG_ACK_REQUIRED	0x02
187 #define RDS_FLAG_RETRANSMITTED	0x04
188 #define RDS_MAX_ADV_CREDIT	255
189 
190 /* RDS_FLAG_PROBE_PORT is the reserved sport used for sending a ping
191  * probe to exchange control information before establishing a connection.
192  * Currently the control information that is exchanged is the number of
193  * supported paths. If the peer is a legacy (older kernel revision) peer,
194  * it would return a pong message without additional control information
195  * that would then alert the sender that the peer was an older rev.
196  */
197 #define RDS_FLAG_PROBE_PORT	1
198 #define	RDS_HS_PROBE(sport, dport) \
199 		((sport == RDS_FLAG_PROBE_PORT && dport == 0) || \
200 		 (sport == 0 && dport == RDS_FLAG_PROBE_PORT))
201 /*
202  * Maximum space available for extension headers.
203  */
204 #define RDS_HEADER_EXT_SPACE	16
205 
206 struct rds_header {
207 	__be64	h_sequence;
208 	__be64	h_ack;
209 	__be32	h_len;
210 	__be16	h_sport;
211 	__be16	h_dport;
212 	u8	h_flags;
213 	u8	h_credit;
214 	u8	h_padding[4];
215 	__sum16	h_csum;
216 
217 	u8	h_exthdr[RDS_HEADER_EXT_SPACE];
218 };
219 
220 /*
221  * Reserved - indicates end of extensions
222  */
223 #define RDS_EXTHDR_NONE		0
224 
225 /*
226  * This extension header is included in the very
227  * first message that is sent on a new connection,
228  * and identifies the protocol level. This will help
229  * rolling updates if a future change requires breaking
230  * the protocol.
231  * NB: This is no longer true for IB, where we do a version
232  * negotiation during the connection setup phase (protocol
233  * version information is included in the RDMA CM private data).
234  */
235 #define RDS_EXTHDR_VERSION	1
236 struct rds_ext_header_version {
237 	__be32			h_version;
238 };
239 
240 /*
241  * This extension header is included in the RDS message
242  * chasing an RDMA operation.
243  */
244 #define RDS_EXTHDR_RDMA		2
245 struct rds_ext_header_rdma {
246 	__be32			h_rdma_rkey;
247 };
248 
249 /*
250  * This extension header tells the peer about the
251  * destination <R_Key,offset> of the requested RDMA
252  * operation.
253  */
254 #define RDS_EXTHDR_RDMA_DEST	3
255 struct rds_ext_header_rdma_dest {
256 	__be32			h_rdma_rkey;
257 	__be32			h_rdma_offset;
258 };
259 
260 /* Extension header announcing number of paths.
261  * Implicit length = 2 bytes.
262  */
263 #define RDS_EXTHDR_NPATHS	5
264 #define RDS_EXTHDR_GEN_NUM	6
265 
266 #define __RDS_EXTHDR_MAX	16 /* for now */
267 #define RDS_RX_MAX_TRACES	(RDS_MSG_RX_DGRAM_TRACE_MAX + 1)
268 #define	RDS_MSG_RX_HDR		0
269 #define	RDS_MSG_RX_START	1
270 #define	RDS_MSG_RX_END		2
271 #define	RDS_MSG_RX_CMSG		3
272 
273 /* The following values are whitelisted for usercopy */
274 struct rds_inc_usercopy {
275 	rds_rdma_cookie_t	rdma_cookie;
276 	ktime_t			rx_tstamp;
277 };
278 
279 struct rds_incoming {
280 	refcount_t		i_refcount;
281 	struct list_head	i_item;
282 	struct rds_connection	*i_conn;
283 	struct rds_conn_path	*i_conn_path;
284 	struct rds_header	i_hdr;
285 	unsigned long		i_rx_jiffies;
286 	struct in6_addr		i_saddr;
287 
288 	struct rds_inc_usercopy i_usercopy;
289 	u64			i_rx_lat_trace[RDS_RX_MAX_TRACES];
290 };
291 
292 struct rds_mr {
293 	struct rb_node		r_rb_node;
294 	struct kref		r_kref;
295 	u32			r_key;
296 
297 	/* A copy of the creation flags */
298 	unsigned int		r_use_once:1;
299 	unsigned int		r_invalidate:1;
300 	unsigned int		r_write:1;
301 
302 	struct rds_sock		*r_sock; /* back pointer to the socket that owns us */
303 	struct rds_transport	*r_trans;
304 	void			*r_trans_private;
305 };
306 
307 static inline rds_rdma_cookie_t rds_rdma_make_cookie(u32 r_key, u32 offset)
308 {
309 	return r_key | (((u64) offset) << 32);
310 }
311 
312 static inline u32 rds_rdma_cookie_key(rds_rdma_cookie_t cookie)
313 {
314 	return cookie;
315 }
316 
317 static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
318 {
319 	return cookie >> 32;
320 }
321 
322 /* atomic operation types */
323 #define RDS_ATOMIC_TYPE_CSWP		0
324 #define RDS_ATOMIC_TYPE_FADD		1
325 
326 /*
327  * m_sock_item and m_conn_item are on lists that are serialized under
328  * conn->c_lock.  m_sock_item has additional meaning in that once it is empty
329  * the message will not be put back on the retransmit list after being sent.
330  * messages that are canceled while being sent rely on this.
331  *
332  * m_inc is used by loopback so that it can pass an incoming message straight
333  * back up into the rx path.  It embeds a wire header which is also used by
334  * the send path, which is kind of awkward.
335  *
336  * m_sock_item indicates the message's presence on a socket's send or receive
337  * queue.  m_rs will point to that socket.
338  *
339  * m_daddr is used by cancellation to prune messages to a given destination.
340  *
341  * The RDS_MSG_ON_SOCK and RDS_MSG_ON_CONN flags are used to avoid lock
342  * nesting.  As paths iterate over messages on a sock, or conn, they must
343  * also lock the conn, or sock, to remove the message from those lists too.
344  * Testing the flag to determine if the message is still on the lists lets
345  * us avoid testing the list_head directly.  That means each path can use
346  * the message's list_head to keep it on a local list while juggling locks
347  * without confusing the other path.
348  *
349  * m_ack_seq is an optional field set by transports who need a different
350  * sequence number range to invalidate.  They can use this in a callback
351  * that they pass to rds_send_drop_acked() to see if each message has been
352  * acked.  The HAS_ACK_SEQ flag can be used to detect messages which haven't
353  * had ack_seq set yet.
354  */
355 #define RDS_MSG_ON_SOCK		1
356 #define RDS_MSG_ON_CONN		2
357 #define RDS_MSG_HAS_ACK_SEQ	3
358 #define RDS_MSG_ACK_REQUIRED	4
359 #define RDS_MSG_RETRANSMITTED	5
360 #define RDS_MSG_MAPPED		6
361 #define RDS_MSG_PAGEVEC		7
362 #define RDS_MSG_FLUSH		8
363 
364 struct rds_znotifier {
365 	struct mmpin		z_mmp;
366 	u32			z_cookie;
367 };
368 
369 struct rds_msg_zcopy_info {
370 	struct list_head rs_zcookie_next;
371 	union {
372 		struct rds_znotifier znotif;
373 		struct rds_zcopy_cookies zcookies;
374 	};
375 };
376 
377 struct rds_msg_zcopy_queue {
378 	struct list_head zcookie_head;
379 	spinlock_t lock; /* protects zcookie_head queue */
380 };
381 
382 static inline void rds_message_zcopy_queue_init(struct rds_msg_zcopy_queue *q)
383 {
384 	spin_lock_init(&q->lock);
385 	INIT_LIST_HEAD(&q->zcookie_head);
386 }
387 
388 struct rds_iov_vector {
389 	struct rds_iovec *iov;
390 	int               len;
391 };
392 
393 struct rds_iov_vector_arr {
394 	struct rds_iov_vector *vec;
395 	int                    len;
396 	int                    indx;
397 	int                    incr;
398 };
399 
400 struct rds_message {
401 	refcount_t		m_refcount;
402 	struct list_head	m_sock_item;
403 	struct list_head	m_conn_item;
404 	struct rds_incoming	m_inc;
405 	u64			m_ack_seq;
406 	struct in6_addr		m_daddr;
407 	unsigned long		m_flags;
408 
409 	/* Never access m_rs without holding m_rs_lock.
410 	 * Lock nesting is
411 	 *  rm->m_rs_lock
412 	 *   -> rs->rs_lock
413 	 */
414 	spinlock_t		m_rs_lock;
415 	wait_queue_head_t	m_flush_wait;
416 
417 	struct rds_sock		*m_rs;
418 
419 	/* cookie to send to remote, in rds header */
420 	rds_rdma_cookie_t	m_rdma_cookie;
421 
422 	unsigned int		m_used_sgs;
423 	unsigned int		m_total_sgs;
424 
425 	void			*m_final_op;
426 
427 	struct {
428 		struct rm_atomic_op {
429 			int			op_type;
430 			union {
431 				struct {
432 					uint64_t	compare;
433 					uint64_t	swap;
434 					uint64_t	compare_mask;
435 					uint64_t	swap_mask;
436 				} op_m_cswp;
437 				struct {
438 					uint64_t	add;
439 					uint64_t	nocarry_mask;
440 				} op_m_fadd;
441 			};
442 
443 			u32			op_rkey;
444 			u64			op_remote_addr;
445 			unsigned int		op_notify:1;
446 			unsigned int		op_recverr:1;
447 			unsigned int		op_mapped:1;
448 			unsigned int		op_silent:1;
449 			unsigned int		op_active:1;
450 			struct scatterlist	*op_sg;
451 			struct rds_notifier	*op_notifier;
452 
453 			struct rds_mr		*op_rdma_mr;
454 		} atomic;
455 		struct rm_rdma_op {
456 			u32			op_rkey;
457 			u64			op_remote_addr;
458 			unsigned int		op_write:1;
459 			unsigned int		op_fence:1;
460 			unsigned int		op_notify:1;
461 			unsigned int		op_recverr:1;
462 			unsigned int		op_mapped:1;
463 			unsigned int		op_silent:1;
464 			unsigned int		op_active:1;
465 			unsigned int		op_bytes;
466 			unsigned int		op_nents;
467 			unsigned int		op_count;
468 			struct scatterlist	*op_sg;
469 			struct rds_notifier	*op_notifier;
470 
471 			struct rds_mr		*op_rdma_mr;
472 
473 			u64			op_odp_addr;
474 			struct rds_mr		*op_odp_mr;
475 		} rdma;
476 		struct rm_data_op {
477 			unsigned int		op_active:1;
478 			unsigned int		op_nents;
479 			unsigned int		op_count;
480 			unsigned int		op_dmasg;
481 			unsigned int		op_dmaoff;
482 			struct rds_znotifier	*op_mmp_znotifier;
483 			struct scatterlist	*op_sg;
484 		} data;
485 	};
486 
487 	struct rds_conn_path *m_conn_path;
488 };
489 
490 /*
491  * The RDS notifier is used (optionally) to tell the application about
492  * completed RDMA operations. Rather than keeping the whole rds message
493  * around on the queue, we allocate a small notifier that is put on the
494  * socket's notifier_list. Notifications are delivered to the application
495  * through control messages.
496  */
497 struct rds_notifier {
498 	struct list_head	n_list;
499 	uint64_t		n_user_token;
500 	int			n_status;
501 };
502 
503 /* Available as part of RDS core, so doesn't need to participate
504  * in get_preferred transport etc
505  */
506 #define	RDS_TRANS_LOOP	3
507 
508 /**
509  * struct rds_transport -  transport specific behavioural hooks
510  *
511  * @xmit: .xmit is called by rds_send_xmit() to tell the transport to send
512  *        part of a message.  The caller serializes on the send_sem so this
513  *        doesn't need to be reentrant for a given conn.  The header must be
514  *        sent before the data payload.  .xmit must be prepared to send a
515  *        message with no data payload.  .xmit should return the number of
516  *        bytes that were sent down the connection, including header bytes.
517  *        Returning 0 tells the caller that it doesn't need to perform any
518  *        additional work now.  This is usually the case when the transport has
519  *        filled the sending queue for its connection and will handle
520  *        triggering the rds thread to continue the send when space becomes
521  *        available.  Returning -EAGAIN tells the caller to retry the send
522  *        immediately.  Returning -ENOMEM tells the caller to retry the send at
523  *        some point in the future.
524  *
525  * @conn_shutdown: conn_shutdown stops traffic on the given connection.  Once
526  *                 it returns the connection can not call rds_recv_incoming().
527  *                 This will only be called once after conn_connect returns
528  *                 non-zero success and will The caller serializes this with
529  *                 the send and connecting paths (xmit_* and conn_*).  The
530  *                 transport is responsible for other serialization, including
531  *                 rds_recv_incoming().  This is called in process context but
532  *                 should try hard not to block.
533  */
534 
535 struct rds_transport {
536 	char			t_name[TRANSNAMSIZ];
537 	struct list_head	t_item;
538 	struct module		*t_owner;
539 	unsigned int		t_prefer_loopback:1,
540 				t_mp_capable:1;
541 	unsigned int		t_type;
542 
543 	int (*laddr_check)(struct net *net, const struct in6_addr *addr,
544 			   __u32 scope_id);
545 	int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
546 	void (*conn_free)(void *data);
547 	int (*conn_path_connect)(struct rds_conn_path *cp);
548 	void (*conn_path_shutdown)(struct rds_conn_path *conn);
549 	void (*xmit_path_prepare)(struct rds_conn_path *cp);
550 	void (*xmit_path_complete)(struct rds_conn_path *cp);
551 	int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
552 		    unsigned int hdr_off, unsigned int sg, unsigned int off);
553 	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
554 	int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
555 	int (*recv_path)(struct rds_conn_path *cp);
556 	int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
557 	void (*inc_free)(struct rds_incoming *inc);
558 
559 	int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
560 				 struct rdma_cm_event *event, bool isv6);
561 	int (*cm_initiate_connect)(struct rdma_cm_id *cm_id, bool isv6);
562 	void (*cm_connect_complete)(struct rds_connection *conn,
563 				    struct rdma_cm_event *event);
564 
565 	unsigned int (*stats_info_copy)(struct rds_info_iterator *iter,
566 					unsigned int avail);
567 	void (*exit)(void);
568 	void *(*get_mr)(struct scatterlist *sg, unsigned long nr_sg,
569 			struct rds_sock *rs, u32 *key_ret,
570 			struct rds_connection *conn,
571 			u64 start, u64 length, int need_odp);
572 	void (*sync_mr)(void *trans_private, int direction);
573 	void (*free_mr)(void *trans_private, int invalidate);
574 	void (*flush_mrs)(void);
575 	bool (*t_unloading)(struct rds_connection *conn);
576 	u8 (*get_tos_map)(u8 tos);
577 };
578 
579 /* Bind hash table key length.  It is the sum of the size of a struct
580  * in6_addr, a scope_id  and a port.
581  */
582 #define RDS_BOUND_KEY_LEN \
583 	(sizeof(struct in6_addr) + sizeof(__u32) + sizeof(__be16))
584 
585 struct rds_sock {
586 	struct sock		rs_sk;
587 
588 	u64			rs_user_addr;
589 	u64			rs_user_bytes;
590 
591 	/*
592 	 * bound_addr used for both incoming and outgoing, no INADDR_ANY
593 	 * support.
594 	 */
595 	struct rhash_head	rs_bound_node;
596 	u8			rs_bound_key[RDS_BOUND_KEY_LEN];
597 	struct sockaddr_in6	rs_bound_sin6;
598 #define rs_bound_addr		rs_bound_sin6.sin6_addr
599 #define rs_bound_addr_v4	rs_bound_sin6.sin6_addr.s6_addr32[3]
600 #define rs_bound_port		rs_bound_sin6.sin6_port
601 #define rs_bound_scope_id	rs_bound_sin6.sin6_scope_id
602 	struct in6_addr		rs_conn_addr;
603 #define rs_conn_addr_v4		rs_conn_addr.s6_addr32[3]
604 	__be16			rs_conn_port;
605 	struct rds_transport    *rs_transport;
606 
607 	/*
608 	 * rds_sendmsg caches the conn it used the last time around.
609 	 * This helps avoid costly lookups.
610 	 */
611 	struct rds_connection	*rs_conn;
612 
613 	/* flag indicating we were congested or not */
614 	int			rs_congested;
615 	/* seen congestion (ENOBUFS) when sending? */
616 	int			rs_seen_congestion;
617 
618 	/* rs_lock protects all these adjacent members before the newline */
619 	spinlock_t		rs_lock;
620 	struct list_head	rs_send_queue;
621 	u32			rs_snd_bytes;
622 	int			rs_rcv_bytes;
623 	struct list_head	rs_notify_queue;	/* currently used for failed RDMAs */
624 
625 	/* Congestion wake_up. If rs_cong_monitor is set, we use cong_mask
626 	 * to decide whether the application should be woken up.
627 	 * If not set, we use rs_cong_track to find out whether a cong map
628 	 * update arrived.
629 	 */
630 	uint64_t		rs_cong_mask;
631 	uint64_t		rs_cong_notify;
632 	struct list_head	rs_cong_list;
633 	unsigned long		rs_cong_track;
634 
635 	/*
636 	 * rs_recv_lock protects the receive queue, and is
637 	 * used to serialize with rds_release.
638 	 */
639 	rwlock_t		rs_recv_lock;
640 	struct list_head	rs_recv_queue;
641 
642 	/* just for stats reporting */
643 	struct list_head	rs_item;
644 
645 	/* these have their own lock */
646 	spinlock_t		rs_rdma_lock;
647 	struct rb_root		rs_rdma_keys;
648 
649 	/* Socket options - in case there will be more */
650 	unsigned char		rs_recverr,
651 				rs_cong_monitor;
652 	u32			rs_hash_initval;
653 
654 	/* Socket receive path trace points*/
655 	u8			rs_rx_traces;
656 	u8			rs_rx_trace[RDS_MSG_RX_DGRAM_TRACE_MAX];
657 	struct rds_msg_zcopy_queue rs_zcookie_queue;
658 	u8			rs_tos;
659 };
660 
661 static inline struct rds_sock *rds_sk_to_rs(const struct sock *sk)
662 {
663 	return container_of(sk, struct rds_sock, rs_sk);
664 }
665 static inline struct sock *rds_rs_to_sk(struct rds_sock *rs)
666 {
667 	return &rs->rs_sk;
668 }
669 
670 /*
671  * The stack assigns sk_sndbuf and sk_rcvbuf to twice the specified value
672  * to account for overhead.  We don't account for overhead, we just apply
673  * the number of payload bytes to the specified value.
674  */
675 static inline int rds_sk_sndbuf(struct rds_sock *rs)
676 {
677 	return rds_rs_to_sk(rs)->sk_sndbuf / 2;
678 }
679 static inline int rds_sk_rcvbuf(struct rds_sock *rs)
680 {
681 	return rds_rs_to_sk(rs)->sk_rcvbuf / 2;
682 }
683 
684 struct rds_statistics {
685 	uint64_t	s_conn_reset;
686 	uint64_t	s_recv_drop_bad_checksum;
687 	uint64_t	s_recv_drop_old_seq;
688 	uint64_t	s_recv_drop_no_sock;
689 	uint64_t	s_recv_drop_dead_sock;
690 	uint64_t	s_recv_deliver_raced;
691 	uint64_t	s_recv_delivered;
692 	uint64_t	s_recv_queued;
693 	uint64_t	s_recv_immediate_retry;
694 	uint64_t	s_recv_delayed_retry;
695 	uint64_t	s_recv_ack_required;
696 	uint64_t	s_recv_rdma_bytes;
697 	uint64_t	s_recv_ping;
698 	uint64_t	s_send_queue_empty;
699 	uint64_t	s_send_queue_full;
700 	uint64_t	s_send_lock_contention;
701 	uint64_t	s_send_lock_queue_raced;
702 	uint64_t	s_send_immediate_retry;
703 	uint64_t	s_send_delayed_retry;
704 	uint64_t	s_send_drop_acked;
705 	uint64_t	s_send_ack_required;
706 	uint64_t	s_send_queued;
707 	uint64_t	s_send_rdma;
708 	uint64_t	s_send_rdma_bytes;
709 	uint64_t	s_send_pong;
710 	uint64_t	s_page_remainder_hit;
711 	uint64_t	s_page_remainder_miss;
712 	uint64_t	s_copy_to_user;
713 	uint64_t	s_copy_from_user;
714 	uint64_t	s_cong_update_queued;
715 	uint64_t	s_cong_update_received;
716 	uint64_t	s_cong_send_error;
717 	uint64_t	s_cong_send_blocked;
718 	uint64_t	s_recv_bytes_added_to_socket;
719 	uint64_t	s_recv_bytes_removed_from_socket;
720 	uint64_t	s_send_stuck_rm;
721 };
722 
723 /* af_rds.c */
724 void rds_sock_addref(struct rds_sock *rs);
725 void rds_sock_put(struct rds_sock *rs);
726 void rds_wake_sk_sleep(struct rds_sock *rs);
727 static inline void __rds_wake_sk_sleep(struct sock *sk)
728 {
729 	wait_queue_head_t *waitq = sk_sleep(sk);
730 
731 	if (!sock_flag(sk, SOCK_DEAD) && waitq)
732 		wake_up(waitq);
733 }
734 extern wait_queue_head_t rds_poll_waitq;
735 
736 
737 /* bind.c */
738 int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
739 void rds_remove_bound(struct rds_sock *rs);
740 struct rds_sock *rds_find_bound(const struct in6_addr *addr, __be16 port,
741 				__u32 scope_id);
742 int rds_bind_lock_init(void);
743 void rds_bind_lock_destroy(void);
744 
745 /* cong.c */
746 int rds_cong_get_maps(struct rds_connection *conn);
747 void rds_cong_add_conn(struct rds_connection *conn);
748 void rds_cong_remove_conn(struct rds_connection *conn);
749 void rds_cong_set_bit(struct rds_cong_map *map, __be16 port);
750 void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port);
751 int rds_cong_wait(struct rds_cong_map *map, __be16 port, int nonblock, struct rds_sock *rs);
752 void rds_cong_queue_updates(struct rds_cong_map *map);
753 void rds_cong_map_updated(struct rds_cong_map *map, uint64_t);
754 int rds_cong_updated_since(unsigned long *recent);
755 void rds_cong_add_socket(struct rds_sock *);
756 void rds_cong_remove_socket(struct rds_sock *);
757 void rds_cong_exit(void);
758 struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
759 
760 /* connection.c */
761 extern u32 rds_gen_num;
762 int rds_conn_init(void);
763 void rds_conn_exit(void);
764 struct rds_connection *rds_conn_create(struct net *net,
765 				       const struct in6_addr *laddr,
766 				       const struct in6_addr *faddr,
767 				       struct rds_transport *trans,
768 				       u8 tos, gfp_t gfp,
769 				       int dev_if);
770 struct rds_connection *rds_conn_create_outgoing(struct net *net,
771 						const struct in6_addr *laddr,
772 						const struct in6_addr *faddr,
773 						struct rds_transport *trans,
774 						u8 tos, gfp_t gfp, int dev_if);
775 void rds_conn_shutdown(struct rds_conn_path *cpath);
776 void rds_conn_destroy(struct rds_connection *conn);
777 void rds_conn_drop(struct rds_connection *conn);
778 void rds_conn_path_drop(struct rds_conn_path *cpath, bool destroy);
779 void rds_conn_connect_if_down(struct rds_connection *conn);
780 void rds_conn_path_connect_if_down(struct rds_conn_path *cp);
781 void rds_for_each_conn_info(struct socket *sock, unsigned int len,
782 			  struct rds_info_iterator *iter,
783 			  struct rds_info_lengths *lens,
784 			  int (*visitor)(struct rds_connection *, void *),
785 			  u64 *buffer,
786 			  size_t item_len);
787 
788 __printf(2, 3)
789 void __rds_conn_path_error(struct rds_conn_path *cp, const char *, ...);
790 #define rds_conn_path_error(cp, fmt...) \
791 	__rds_conn_path_error(cp, KERN_WARNING "RDS: " fmt)
792 
793 static inline int
794 rds_conn_path_transition(struct rds_conn_path *cp, int old, int new)
795 {
796 	return atomic_cmpxchg(&cp->cp_state, old, new) == old;
797 }
798 
799 static inline int
800 rds_conn_transition(struct rds_connection *conn, int old, int new)
801 {
802 	WARN_ON(conn->c_trans->t_mp_capable);
803 	return rds_conn_path_transition(&conn->c_path[0], old, new);
804 }
805 
806 static inline int
807 rds_conn_path_state(struct rds_conn_path *cp)
808 {
809 	return atomic_read(&cp->cp_state);
810 }
811 
812 static inline int
813 rds_conn_state(struct rds_connection *conn)
814 {
815 	WARN_ON(conn->c_trans->t_mp_capable);
816 	return rds_conn_path_state(&conn->c_path[0]);
817 }
818 
819 static inline int
820 rds_conn_path_up(struct rds_conn_path *cp)
821 {
822 	return atomic_read(&cp->cp_state) == RDS_CONN_UP;
823 }
824 
825 static inline int
826 rds_conn_up(struct rds_connection *conn)
827 {
828 	WARN_ON(conn->c_trans->t_mp_capable);
829 	return rds_conn_path_up(&conn->c_path[0]);
830 }
831 
832 static inline int
833 rds_conn_path_connecting(struct rds_conn_path *cp)
834 {
835 	return atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING;
836 }
837 
838 static inline int
839 rds_conn_connecting(struct rds_connection *conn)
840 {
841 	WARN_ON(conn->c_trans->t_mp_capable);
842 	return rds_conn_path_connecting(&conn->c_path[0]);
843 }
844 
845 /* message.c */
846 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
847 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
848 int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from,
849 			       bool zcopy);
850 struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
851 void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
852 				 __be16 dport, u64 seq);
853 int rds_message_add_extension(struct rds_header *hdr,
854 			      unsigned int type, const void *data, unsigned int len);
855 int rds_message_next_extension(struct rds_header *hdr,
856 			       unsigned int *pos, void *buf, unsigned int *buflen);
857 int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
858 int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
859 void rds_message_inc_free(struct rds_incoming *inc);
860 void rds_message_addref(struct rds_message *rm);
861 void rds_message_put(struct rds_message *rm);
862 void rds_message_wait(struct rds_message *rm);
863 void rds_message_unmapped(struct rds_message *rm);
864 void rds_notify_msg_zcopy_purge(struct rds_msg_zcopy_queue *info);
865 
866 static inline void rds_message_make_checksum(struct rds_header *hdr)
867 {
868 	hdr->h_csum = 0;
869 	hdr->h_csum = ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2);
870 }
871 
872 static inline int rds_message_verify_checksum(const struct rds_header *hdr)
873 {
874 	return !hdr->h_csum || ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2) == 0;
875 }
876 
877 
878 /* page.c */
879 int rds_page_remainder_alloc(struct scatterlist *scat, unsigned long bytes,
880 			     gfp_t gfp);
881 void rds_page_exit(void);
882 
883 /* recv.c */
884 void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
885 		  struct in6_addr *saddr);
886 void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *conn,
887 		       struct in6_addr *saddr);
888 void rds_inc_put(struct rds_incoming *inc);
889 void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
890 		       struct in6_addr *daddr,
891 		       struct rds_incoming *inc, gfp_t gfp);
892 int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
893 		int msg_flags);
894 void rds_clear_recv_queue(struct rds_sock *rs);
895 int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msg);
896 void rds_inc_info_copy(struct rds_incoming *inc,
897 		       struct rds_info_iterator *iter,
898 		       __be32 saddr, __be32 daddr, int flip);
899 void rds6_inc_info_copy(struct rds_incoming *inc,
900 			struct rds_info_iterator *iter,
901 			struct in6_addr *saddr, struct in6_addr *daddr,
902 			int flip);
903 
904 /* send.c */
905 int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len);
906 void rds_send_path_reset(struct rds_conn_path *conn);
907 int rds_send_xmit(struct rds_conn_path *cp);
908 struct sockaddr_in;
909 void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in6 *dest);
910 typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
911 void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
912 			 is_acked_func is_acked);
913 void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
914 			      is_acked_func is_acked);
915 void rds_send_ping(struct rds_connection *conn, int cp_index);
916 int rds_send_pong(struct rds_conn_path *cp, __be16 dport);
917 
918 /* rdma.c */
919 void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force);
920 int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen);
921 int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen);
922 int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen);
923 void rds_rdma_drop_keys(struct rds_sock *rs);
924 int rds_rdma_extra_size(struct rds_rdma_args *args,
925 			struct rds_iov_vector *iov);
926 int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
927 			  struct cmsghdr *cmsg);
928 int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
929 			  struct cmsghdr *cmsg,
930 			  struct rds_iov_vector *vec);
931 int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
932 			  struct cmsghdr *cmsg);
933 void rds_rdma_free_op(struct rm_rdma_op *ro);
934 void rds_atomic_free_op(struct rm_atomic_op *ao);
935 void rds_rdma_send_complete(struct rds_message *rm, int wc_status);
936 void rds_atomic_send_complete(struct rds_message *rm, int wc_status);
937 int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
938 		    struct cmsghdr *cmsg);
939 
940 void __rds_put_mr_final(struct kref *kref);
941 
942 static inline bool rds_destroy_pending(struct rds_connection *conn)
943 {
944 	return !check_net(rds_conn_net(conn)) ||
945 	       (conn->c_trans->t_unloading && conn->c_trans->t_unloading(conn));
946 }
947 
948 enum {
949 	ODP_NOT_NEEDED,
950 	ODP_ZEROBASED,
951 	ODP_VIRTUAL
952 };
953 
954 /* stats.c */
955 DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
956 #define rds_stats_inc_which(which, member) do {		\
957 	per_cpu(which, get_cpu()).member++;		\
958 	put_cpu();					\
959 } while (0)
960 #define rds_stats_inc(member) rds_stats_inc_which(rds_stats, member)
961 #define rds_stats_add_which(which, member, count) do {		\
962 	per_cpu(which, get_cpu()).member += count;	\
963 	put_cpu();					\
964 } while (0)
965 #define rds_stats_add(member, count) rds_stats_add_which(rds_stats, member, count)
966 int rds_stats_init(void);
967 void rds_stats_exit(void);
968 void rds_stats_info_copy(struct rds_info_iterator *iter,
969 			 uint64_t *values, const char *const *names,
970 			 size_t nr);
971 
972 /* sysctl.c */
973 int rds_sysctl_init(void);
974 void rds_sysctl_exit(void);
975 extern unsigned long rds_sysctl_sndbuf_min;
976 extern unsigned long rds_sysctl_sndbuf_default;
977 extern unsigned long rds_sysctl_sndbuf_max;
978 extern unsigned long rds_sysctl_reconnect_min_jiffies;
979 extern unsigned long rds_sysctl_reconnect_max_jiffies;
980 extern unsigned int  rds_sysctl_max_unacked_packets;
981 extern unsigned int  rds_sysctl_max_unacked_bytes;
982 extern unsigned int  rds_sysctl_ping_enable;
983 extern unsigned long rds_sysctl_trace_flags;
984 extern unsigned int  rds_sysctl_trace_level;
985 
986 /* threads.c */
987 int rds_threads_init(void);
988 void rds_threads_exit(void);
989 extern struct workqueue_struct *rds_wq;
990 void rds_queue_reconnect(struct rds_conn_path *cp);
991 void rds_connect_worker(struct work_struct *);
992 void rds_shutdown_worker(struct work_struct *);
993 void rds_send_worker(struct work_struct *);
994 void rds_recv_worker(struct work_struct *);
995 void rds_connect_path_complete(struct rds_conn_path *conn, int curr);
996 void rds_connect_complete(struct rds_connection *conn);
997 int rds_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2);
998 
999 /* transport.c */
1000 void rds_trans_register(struct rds_transport *trans);
1001 void rds_trans_unregister(struct rds_transport *trans);
1002 struct rds_transport *rds_trans_get_preferred(struct net *net,
1003 					      const struct in6_addr *addr,
1004 					      __u32 scope_id);
1005 void rds_trans_put(struct rds_transport *trans);
1006 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
1007 				       unsigned int avail);
1008 struct rds_transport *rds_trans_get(int t_type);
1009 int rds_trans_init(void);
1010 void rds_trans_exit(void);
1011 
1012 #endif
1013