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v4.6
  1#ifndef _RDS_RDS_H
  2#define _RDS_RDS_H
  3
  4#include <net/sock.h>
  5#include <linux/scatterlist.h>
  6#include <linux/highmem.h>
  7#include <rdma/rdma_cm.h>
  8#include <linux/mutex.h>
  9#include <linux/rds.h>
 10#include <linux/rhashtable.h>
 11
 12#include "info.h"
 13
 14/*
 15 * RDS Network protocol version
 16 */
 17#define RDS_PROTOCOL_3_0	0x0300
 18#define RDS_PROTOCOL_3_1	0x0301
 19#define RDS_PROTOCOL_VERSION	RDS_PROTOCOL_3_1
 20#define RDS_PROTOCOL_MAJOR(v)	((v) >> 8)
 21#define RDS_PROTOCOL_MINOR(v)	((v) & 255)
 22#define RDS_PROTOCOL(maj, min)	(((maj) << 8) | min)
 23
 24/*
 25 * XXX randomly chosen, but at least seems to be unused:
 26 * #               18464-18768 Unassigned
 27 * We should do better.  We want a reserved port to discourage unpriv'ed
 28 * userspace from listening.
 29 */
 30#define RDS_PORT	18634
 31
 32#ifdef ATOMIC64_INIT
 33#define KERNEL_HAS_ATOMIC64
 34#endif
 35
 36#ifdef DEBUG
 37#define rdsdebug(fmt, args...) pr_debug("%s(): " fmt, __func__ , ##args)
 38#else
 39/* sigh, pr_debug() causes unused variable warnings */
 40static inline __printf(1, 2)
 41void rdsdebug(char *fmt, ...)
 42{
 43}
 44#endif
 45
 46/* XXX is there one of these somewhere? */
 47#define ceil(x, y) \
 48	({ unsigned long __x = (x), __y = (y); (__x + __y - 1) / __y; })
 49
 50#define RDS_FRAG_SHIFT	12
 51#define RDS_FRAG_SIZE	((unsigned int)(1 << RDS_FRAG_SHIFT))
 52
 53#define RDS_CONG_MAP_BYTES	(65536 / 8)
 54#define RDS_CONG_MAP_PAGES	(PAGE_ALIGN(RDS_CONG_MAP_BYTES) / PAGE_SIZE)
 55#define RDS_CONG_MAP_PAGE_BITS	(PAGE_SIZE * 8)
 56
 57struct rds_cong_map {
 58	struct rb_node		m_rb_node;
 59	__be32			m_addr;
 60	wait_queue_head_t	m_waitq;
 61	struct list_head	m_conn_list;
 62	unsigned long		m_page_addrs[RDS_CONG_MAP_PAGES];
 63};
 64
 65
 66/*
 67 * This is how we will track the connection state:
 68 * A connection is always in one of the following
 69 * states. Updates to the state are atomic and imply
 70 * a memory barrier.
 71 */
 72enum {
 73	RDS_CONN_DOWN = 0,
 74	RDS_CONN_CONNECTING,
 75	RDS_CONN_DISCONNECTING,
 76	RDS_CONN_UP,
 
 77	RDS_CONN_ERROR,
 78};
 79
 80/* Bits for c_flags */
 81#define RDS_LL_SEND_FULL	0
 82#define RDS_RECONNECT_PENDING	1
 83#define RDS_IN_XMIT		2
 84#define RDS_RECV_REFILL		3
 85
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 86struct rds_connection {
 87	struct hlist_node	c_hash_node;
 88	__be32			c_laddr;
 89	__be32			c_faddr;
 90	unsigned int		c_loopback:1,
 91				c_outgoing:1,
 92				c_pad_to_32:30;
 
 93	struct rds_connection	*c_passive;
 
 94
 95	struct rds_cong_map	*c_lcong;
 96	struct rds_cong_map	*c_fcong;
 97
 98	struct rds_message	*c_xmit_rm;
 99	unsigned long		c_xmit_sg;
100	unsigned int		c_xmit_hdr_off;
101	unsigned int		c_xmit_data_off;
102	unsigned int		c_xmit_atomic_sent;
103	unsigned int		c_xmit_rdma_sent;
104	unsigned int		c_xmit_data_sent;
105
106	spinlock_t		c_lock;		/* protect msg queues */
107	u64			c_next_tx_seq;
108	struct list_head	c_send_queue;
109	struct list_head	c_retrans;
110
111	u64			c_next_rx_seq;
112
113	struct rds_transport	*c_trans;
114	void			*c_transport_data;
115
116	atomic_t		c_state;
117	unsigned long		c_send_gen;
118	unsigned long		c_flags;
119	unsigned long		c_reconnect_jiffies;
120	struct delayed_work	c_send_w;
121	struct delayed_work	c_recv_w;
122	struct delayed_work	c_conn_w;
123	struct work_struct	c_down_w;
124	struct mutex		c_cm_lock;	/* protect conn state & cm */
125	wait_queue_head_t	c_waitq;
126
127	struct list_head	c_map_item;
128	unsigned long		c_map_queued;
129
130	unsigned int		c_unacked_packets;
131	unsigned int		c_unacked_bytes;
132
133	/* Protocol version */
134	unsigned int		c_version;
135	possible_net_t		c_net;
136};
137
138static inline
139struct net *rds_conn_net(struct rds_connection *conn)
140{
141	return read_pnet(&conn->c_net);
142}
143
144static inline
145void rds_conn_net_set(struct rds_connection *conn, struct net *net)
146{
147	write_pnet(&conn->c_net, net);
148}
149
150#define RDS_FLAG_CONG_BITMAP	0x01
151#define RDS_FLAG_ACK_REQUIRED	0x02
152#define RDS_FLAG_RETRANSMITTED	0x04
153#define RDS_MAX_ADV_CREDIT	255
154
 
 
 
 
 
 
 
 
 
 
 
155/*
156 * Maximum space available for extension headers.
157 */
158#define RDS_HEADER_EXT_SPACE	16
159
160struct rds_header {
161	__be64	h_sequence;
162	__be64	h_ack;
163	__be32	h_len;
164	__be16	h_sport;
165	__be16	h_dport;
166	u8	h_flags;
167	u8	h_credit;
168	u8	h_padding[4];
169	__sum16	h_csum;
170
171	u8	h_exthdr[RDS_HEADER_EXT_SPACE];
172};
173
174/*
175 * Reserved - indicates end of extensions
176 */
177#define RDS_EXTHDR_NONE		0
178
179/*
180 * This extension header is included in the very
181 * first message that is sent on a new connection,
182 * and identifies the protocol level. This will help
183 * rolling updates if a future change requires breaking
184 * the protocol.
185 * NB: This is no longer true for IB, where we do a version
186 * negotiation during the connection setup phase (protocol
187 * version information is included in the RDMA CM private data).
188 */
189#define RDS_EXTHDR_VERSION	1
190struct rds_ext_header_version {
191	__be32			h_version;
192};
193
194/*
195 * This extension header is included in the RDS message
196 * chasing an RDMA operation.
197 */
198#define RDS_EXTHDR_RDMA		2
199struct rds_ext_header_rdma {
200	__be32			h_rdma_rkey;
201};
202
203/*
204 * This extension header tells the peer about the
205 * destination <R_Key,offset> of the requested RDMA
206 * operation.
207 */
208#define RDS_EXTHDR_RDMA_DEST	3
209struct rds_ext_header_rdma_dest {
210	__be32			h_rdma_rkey;
211	__be32			h_rdma_offset;
212};
213
 
 
 
 
 
 
214#define __RDS_EXTHDR_MAX	16 /* for now */
215
216struct rds_incoming {
217	atomic_t		i_refcount;
218	struct list_head	i_item;
219	struct rds_connection	*i_conn;
 
220	struct rds_header	i_hdr;
221	unsigned long		i_rx_jiffies;
222	__be32			i_saddr;
223
224	rds_rdma_cookie_t	i_rdma_cookie;
225	struct timeval		i_rx_tstamp;
226};
227
228struct rds_mr {
229	struct rb_node		r_rb_node;
230	atomic_t		r_refcount;
231	u32			r_key;
232
233	/* A copy of the creation flags */
234	unsigned int		r_use_once:1;
235	unsigned int		r_invalidate:1;
236	unsigned int		r_write:1;
237
238	/* This is for RDS_MR_DEAD.
239	 * It would be nice & consistent to make this part of the above
240	 * bit field here, but we need to use test_and_set_bit.
241	 */
242	unsigned long		r_state;
243	struct rds_sock		*r_sock; /* back pointer to the socket that owns us */
244	struct rds_transport	*r_trans;
245	void			*r_trans_private;
246};
247
248/* Flags for mr->r_state */
249#define RDS_MR_DEAD		0
250
251static inline rds_rdma_cookie_t rds_rdma_make_cookie(u32 r_key, u32 offset)
252{
253	return r_key | (((u64) offset) << 32);
254}
255
256static inline u32 rds_rdma_cookie_key(rds_rdma_cookie_t cookie)
257{
258	return cookie;
259}
260
261static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
262{
263	return cookie >> 32;
264}
265
266/* atomic operation types */
267#define RDS_ATOMIC_TYPE_CSWP		0
268#define RDS_ATOMIC_TYPE_FADD		1
269
270/*
271 * m_sock_item and m_conn_item are on lists that are serialized under
272 * conn->c_lock.  m_sock_item has additional meaning in that once it is empty
273 * the message will not be put back on the retransmit list after being sent.
274 * messages that are canceled while being sent rely on this.
275 *
276 * m_inc is used by loopback so that it can pass an incoming message straight
277 * back up into the rx path.  It embeds a wire header which is also used by
278 * the send path, which is kind of awkward.
279 *
280 * m_sock_item indicates the message's presence on a socket's send or receive
281 * queue.  m_rs will point to that socket.
282 *
283 * m_daddr is used by cancellation to prune messages to a given destination.
284 *
285 * The RDS_MSG_ON_SOCK and RDS_MSG_ON_CONN flags are used to avoid lock
286 * nesting.  As paths iterate over messages on a sock, or conn, they must
287 * also lock the conn, or sock, to remove the message from those lists too.
288 * Testing the flag to determine if the message is still on the lists lets
289 * us avoid testing the list_head directly.  That means each path can use
290 * the message's list_head to keep it on a local list while juggling locks
291 * without confusing the other path.
292 *
293 * m_ack_seq is an optional field set by transports who need a different
294 * sequence number range to invalidate.  They can use this in a callback
295 * that they pass to rds_send_drop_acked() to see if each message has been
296 * acked.  The HAS_ACK_SEQ flag can be used to detect messages which haven't
297 * had ack_seq set yet.
298 */
299#define RDS_MSG_ON_SOCK		1
300#define RDS_MSG_ON_CONN		2
301#define RDS_MSG_HAS_ACK_SEQ	3
302#define RDS_MSG_ACK_REQUIRED	4
303#define RDS_MSG_RETRANSMITTED	5
304#define RDS_MSG_MAPPED		6
305#define RDS_MSG_PAGEVEC		7
 
306
307struct rds_message {
308	atomic_t		m_refcount;
309	struct list_head	m_sock_item;
310	struct list_head	m_conn_item;
311	struct rds_incoming	m_inc;
312	u64			m_ack_seq;
313	__be32			m_daddr;
314	unsigned long		m_flags;
315
316	/* Never access m_rs without holding m_rs_lock.
317	 * Lock nesting is
318	 *  rm->m_rs_lock
319	 *   -> rs->rs_lock
320	 */
321	spinlock_t		m_rs_lock;
322	wait_queue_head_t	m_flush_wait;
323
324	struct rds_sock		*m_rs;
325
326	/* cookie to send to remote, in rds header */
327	rds_rdma_cookie_t	m_rdma_cookie;
328
329	unsigned int		m_used_sgs;
330	unsigned int		m_total_sgs;
331
332	void			*m_final_op;
333
334	struct {
335		struct rm_atomic_op {
336			int			op_type;
337			union {
338				struct {
339					uint64_t	compare;
340					uint64_t	swap;
341					uint64_t	compare_mask;
342					uint64_t	swap_mask;
343				} op_m_cswp;
344				struct {
345					uint64_t	add;
346					uint64_t	nocarry_mask;
347				} op_m_fadd;
348			};
349
350			u32			op_rkey;
351			u64			op_remote_addr;
352			unsigned int		op_notify:1;
353			unsigned int		op_recverr:1;
354			unsigned int		op_mapped:1;
355			unsigned int		op_silent:1;
356			unsigned int		op_active:1;
357			struct scatterlist	*op_sg;
358			struct rds_notifier	*op_notifier;
359
360			struct rds_mr		*op_rdma_mr;
361		} atomic;
362		struct rm_rdma_op {
363			u32			op_rkey;
364			u64			op_remote_addr;
365			unsigned int		op_write:1;
366			unsigned int		op_fence:1;
367			unsigned int		op_notify:1;
368			unsigned int		op_recverr:1;
369			unsigned int		op_mapped:1;
370			unsigned int		op_silent:1;
371			unsigned int		op_active:1;
372			unsigned int		op_bytes;
373			unsigned int		op_nents;
374			unsigned int		op_count;
375			struct scatterlist	*op_sg;
376			struct rds_notifier	*op_notifier;
377
378			struct rds_mr		*op_rdma_mr;
379		} rdma;
380		struct rm_data_op {
381			unsigned int		op_active:1;
382			unsigned int		op_nents;
383			unsigned int		op_count;
384			unsigned int		op_dmasg;
385			unsigned int		op_dmaoff;
386			struct scatterlist	*op_sg;
387		} data;
388	};
389};
390
391/*
392 * The RDS notifier is used (optionally) to tell the application about
393 * completed RDMA operations. Rather than keeping the whole rds message
394 * around on the queue, we allocate a small notifier that is put on the
395 * socket's notifier_list. Notifications are delivered to the application
396 * through control messages.
397 */
398struct rds_notifier {
399	struct list_head	n_list;
400	uint64_t		n_user_token;
401	int			n_status;
402};
403
404/**
405 * struct rds_transport -  transport specific behavioural hooks
406 *
407 * @xmit: .xmit is called by rds_send_xmit() to tell the transport to send
408 *        part of a message.  The caller serializes on the send_sem so this
409 *        doesn't need to be reentrant for a given conn.  The header must be
410 *        sent before the data payload.  .xmit must be prepared to send a
411 *        message with no data payload.  .xmit should return the number of
412 *        bytes that were sent down the connection, including header bytes.
413 *        Returning 0 tells the caller that it doesn't need to perform any
414 *        additional work now.  This is usually the case when the transport has
415 *        filled the sending queue for its connection and will handle
416 *        triggering the rds thread to continue the send when space becomes
417 *        available.  Returning -EAGAIN tells the caller to retry the send
418 *        immediately.  Returning -ENOMEM tells the caller to retry the send at
419 *        some point in the future.
420 *
421 * @conn_shutdown: conn_shutdown stops traffic on the given connection.  Once
422 *                 it returns the connection can not call rds_recv_incoming().
423 *                 This will only be called once after conn_connect returns
424 *                 non-zero success and will The caller serializes this with
425 *                 the send and connecting paths (xmit_* and conn_*).  The
426 *                 transport is responsible for other serialization, including
427 *                 rds_recv_incoming().  This is called in process context but
428 *                 should try hard not to block.
429 */
430
431struct rds_transport {
432	char			t_name[TRANSNAMSIZ];
433	struct list_head	t_item;
434	struct module		*t_owner;
435	unsigned int		t_prefer_loopback:1;
 
436	unsigned int		t_type;
437
438	int (*laddr_check)(struct net *net, __be32 addr);
439	int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
440	void (*conn_free)(void *data);
441	int (*conn_connect)(struct rds_connection *conn);
442	void (*conn_shutdown)(struct rds_connection *conn);
443	void (*xmit_prepare)(struct rds_connection *conn);
444	void (*xmit_complete)(struct rds_connection *conn);
445	int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
446		    unsigned int hdr_off, unsigned int sg, unsigned int off);
447	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
448	int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
449	int (*recv)(struct rds_connection *conn);
450	int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
451	void (*inc_free)(struct rds_incoming *inc);
452
453	int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
454				 struct rdma_cm_event *event);
455	int (*cm_initiate_connect)(struct rdma_cm_id *cm_id);
456	void (*cm_connect_complete)(struct rds_connection *conn,
457				    struct rdma_cm_event *event);
458
459	unsigned int (*stats_info_copy)(struct rds_info_iterator *iter,
460					unsigned int avail);
461	void (*exit)(void);
462	void *(*get_mr)(struct scatterlist *sg, unsigned long nr_sg,
463			struct rds_sock *rs, u32 *key_ret);
464	void (*sync_mr)(void *trans_private, int direction);
465	void (*free_mr)(void *trans_private, int invalidate);
466	void (*flush_mrs)(void);
467};
468
469struct rds_sock {
470	struct sock		rs_sk;
471
472	u64			rs_user_addr;
473	u64			rs_user_bytes;
474
475	/*
476	 * bound_addr used for both incoming and outgoing, no INADDR_ANY
477	 * support.
478	 */
479	struct rhash_head	rs_bound_node;
480	u64			rs_bound_key;
481	__be32			rs_bound_addr;
482	__be32			rs_conn_addr;
483	__be16			rs_bound_port;
484	__be16			rs_conn_port;
485	struct rds_transport    *rs_transport;
486
487	/*
488	 * rds_sendmsg caches the conn it used the last time around.
489	 * This helps avoid costly lookups.
490	 */
491	struct rds_connection	*rs_conn;
492
493	/* flag indicating we were congested or not */
494	int			rs_congested;
495	/* seen congestion (ENOBUFS) when sending? */
496	int			rs_seen_congestion;
497
498	/* rs_lock protects all these adjacent members before the newline */
499	spinlock_t		rs_lock;
500	struct list_head	rs_send_queue;
501	u32			rs_snd_bytes;
502	int			rs_rcv_bytes;
503	struct list_head	rs_notify_queue;	/* currently used for failed RDMAs */
504
505	/* Congestion wake_up. If rs_cong_monitor is set, we use cong_mask
506	 * to decide whether the application should be woken up.
507	 * If not set, we use rs_cong_track to find out whether a cong map
508	 * update arrived.
509	 */
510	uint64_t		rs_cong_mask;
511	uint64_t		rs_cong_notify;
512	struct list_head	rs_cong_list;
513	unsigned long		rs_cong_track;
514
515	/*
516	 * rs_recv_lock protects the receive queue, and is
517	 * used to serialize with rds_release.
518	 */
519	rwlock_t		rs_recv_lock;
520	struct list_head	rs_recv_queue;
521
522	/* just for stats reporting */
523	struct list_head	rs_item;
524
525	/* these have their own lock */
526	spinlock_t		rs_rdma_lock;
527	struct rb_root		rs_rdma_keys;
528
529	/* Socket options - in case there will be more */
530	unsigned char		rs_recverr,
531				rs_cong_monitor;
 
532};
533
534static inline struct rds_sock *rds_sk_to_rs(const struct sock *sk)
535{
536	return container_of(sk, struct rds_sock, rs_sk);
537}
538static inline struct sock *rds_rs_to_sk(struct rds_sock *rs)
539{
540	return &rs->rs_sk;
541}
542
543/*
544 * The stack assigns sk_sndbuf and sk_rcvbuf to twice the specified value
545 * to account for overhead.  We don't account for overhead, we just apply
546 * the number of payload bytes to the specified value.
547 */
548static inline int rds_sk_sndbuf(struct rds_sock *rs)
549{
550	return rds_rs_to_sk(rs)->sk_sndbuf / 2;
551}
552static inline int rds_sk_rcvbuf(struct rds_sock *rs)
553{
554	return rds_rs_to_sk(rs)->sk_rcvbuf / 2;
555}
556
557struct rds_statistics {
558	uint64_t	s_conn_reset;
559	uint64_t	s_recv_drop_bad_checksum;
560	uint64_t	s_recv_drop_old_seq;
561	uint64_t	s_recv_drop_no_sock;
562	uint64_t	s_recv_drop_dead_sock;
563	uint64_t	s_recv_deliver_raced;
564	uint64_t	s_recv_delivered;
565	uint64_t	s_recv_queued;
566	uint64_t	s_recv_immediate_retry;
567	uint64_t	s_recv_delayed_retry;
568	uint64_t	s_recv_ack_required;
569	uint64_t	s_recv_rdma_bytes;
570	uint64_t	s_recv_ping;
571	uint64_t	s_send_queue_empty;
572	uint64_t	s_send_queue_full;
573	uint64_t	s_send_lock_contention;
574	uint64_t	s_send_lock_queue_raced;
575	uint64_t	s_send_immediate_retry;
576	uint64_t	s_send_delayed_retry;
577	uint64_t	s_send_drop_acked;
578	uint64_t	s_send_ack_required;
579	uint64_t	s_send_queued;
580	uint64_t	s_send_rdma;
581	uint64_t	s_send_rdma_bytes;
582	uint64_t	s_send_pong;
583	uint64_t	s_page_remainder_hit;
584	uint64_t	s_page_remainder_miss;
585	uint64_t	s_copy_to_user;
586	uint64_t	s_copy_from_user;
587	uint64_t	s_cong_update_queued;
588	uint64_t	s_cong_update_received;
589	uint64_t	s_cong_send_error;
590	uint64_t	s_cong_send_blocked;
591};
592
593/* af_rds.c */
594void rds_sock_addref(struct rds_sock *rs);
595void rds_sock_put(struct rds_sock *rs);
596void rds_wake_sk_sleep(struct rds_sock *rs);
597static inline void __rds_wake_sk_sleep(struct sock *sk)
598{
599	wait_queue_head_t *waitq = sk_sleep(sk);
600
601	if (!sock_flag(sk, SOCK_DEAD) && waitq)
602		wake_up(waitq);
603}
604extern wait_queue_head_t rds_poll_waitq;
605
606
607/* bind.c */
608int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
609void rds_remove_bound(struct rds_sock *rs);
610struct rds_sock *rds_find_bound(__be32 addr, __be16 port);
611int rds_bind_lock_init(void);
612void rds_bind_lock_destroy(void);
613
614/* cong.c */
615int rds_cong_get_maps(struct rds_connection *conn);
616void rds_cong_add_conn(struct rds_connection *conn);
617void rds_cong_remove_conn(struct rds_connection *conn);
618void rds_cong_set_bit(struct rds_cong_map *map, __be16 port);
619void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port);
620int rds_cong_wait(struct rds_cong_map *map, __be16 port, int nonblock, struct rds_sock *rs);
621void rds_cong_queue_updates(struct rds_cong_map *map);
622void rds_cong_map_updated(struct rds_cong_map *map, uint64_t);
623int rds_cong_updated_since(unsigned long *recent);
624void rds_cong_add_socket(struct rds_sock *);
625void rds_cong_remove_socket(struct rds_sock *);
626void rds_cong_exit(void);
627struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
628
629/* conn.c */
 
630int rds_conn_init(void);
631void rds_conn_exit(void);
632struct rds_connection *rds_conn_create(struct net *net,
633				       __be32 laddr, __be32 faddr,
634				       struct rds_transport *trans, gfp_t gfp);
635struct rds_connection *rds_conn_create_outgoing(struct net *net,
636						__be32 laddr, __be32 faddr,
637			       struct rds_transport *trans, gfp_t gfp);
638void rds_conn_shutdown(struct rds_connection *conn);
639void rds_conn_destroy(struct rds_connection *conn);
640void rds_conn_drop(struct rds_connection *conn);
 
641void rds_conn_connect_if_down(struct rds_connection *conn);
 
642void rds_for_each_conn_info(struct socket *sock, unsigned int len,
643			  struct rds_info_iterator *iter,
644			  struct rds_info_lengths *lens,
645			  int (*visitor)(struct rds_connection *, void *),
646			  size_t item_len);
 
647__printf(2, 3)
648void __rds_conn_error(struct rds_connection *conn, const char *, ...);
649#define rds_conn_error(conn, fmt...) \
650	__rds_conn_error(conn, KERN_WARNING "RDS: " fmt)
 
 
 
 
 
 
651
652static inline int
653rds_conn_transition(struct rds_connection *conn, int old, int new)
654{
655	return atomic_cmpxchg(&conn->c_state, old, new) == old;
 
 
 
 
 
 
 
656}
657
658static inline int
659rds_conn_state(struct rds_connection *conn)
660{
661	return atomic_read(&conn->c_state);
 
 
 
 
 
 
 
662}
663
664static inline int
665rds_conn_up(struct rds_connection *conn)
666{
667	return atomic_read(&conn->c_state) == RDS_CONN_UP;
 
 
 
 
 
 
 
668}
669
670static inline int
671rds_conn_connecting(struct rds_connection *conn)
672{
673	return atomic_read(&conn->c_state) == RDS_CONN_CONNECTING;
 
674}
675
676/* message.c */
677struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
678struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
679int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from);
680struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
681void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
682				 __be16 dport, u64 seq);
683int rds_message_add_extension(struct rds_header *hdr,
684			      unsigned int type, const void *data, unsigned int len);
685int rds_message_next_extension(struct rds_header *hdr,
686			       unsigned int *pos, void *buf, unsigned int *buflen);
687int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
688int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
689void rds_message_inc_free(struct rds_incoming *inc);
690void rds_message_addref(struct rds_message *rm);
691void rds_message_put(struct rds_message *rm);
692void rds_message_wait(struct rds_message *rm);
693void rds_message_unmapped(struct rds_message *rm);
694
695static inline void rds_message_make_checksum(struct rds_header *hdr)
696{
697	hdr->h_csum = 0;
698	hdr->h_csum = ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2);
699}
700
701static inline int rds_message_verify_checksum(const struct rds_header *hdr)
702{
703	return !hdr->h_csum || ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2) == 0;
704}
705
706
707/* page.c */
708int rds_page_remainder_alloc(struct scatterlist *scat, unsigned long bytes,
709			     gfp_t gfp);
710int rds_page_copy_user(struct page *page, unsigned long offset,
711		       void __user *ptr, unsigned long bytes,
712		       int to_user);
713#define rds_page_copy_to_user(page, offset, ptr, bytes) \
714	rds_page_copy_user(page, offset, ptr, bytes, 1)
715#define rds_page_copy_from_user(page, offset, ptr, bytes) \
716	rds_page_copy_user(page, offset, ptr, bytes, 0)
717void rds_page_exit(void);
718
719/* recv.c */
720void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
721		  __be32 saddr);
 
 
722void rds_inc_put(struct rds_incoming *inc);
723void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
724		       struct rds_incoming *inc, gfp_t gfp);
725int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
726		int msg_flags);
727void rds_clear_recv_queue(struct rds_sock *rs);
728int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msg);
729void rds_inc_info_copy(struct rds_incoming *inc,
730		       struct rds_info_iterator *iter,
731		       __be32 saddr, __be32 daddr, int flip);
732
733/* send.c */
734int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len);
735void rds_send_reset(struct rds_connection *conn);
736int rds_send_xmit(struct rds_connection *conn);
737struct sockaddr_in;
738void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest);
739typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
740void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
741			 is_acked_func is_acked);
742int rds_send_pong(struct rds_connection *conn, __be16 dport);
743struct rds_message *rds_send_get_message(struct rds_connection *,
744					 struct rm_rdma_op *);
745
746/* rdma.c */
747void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force);
748int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen);
749int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen);
750int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen);
751void rds_rdma_drop_keys(struct rds_sock *rs);
752int rds_rdma_extra_size(struct rds_rdma_args *args);
753int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
754			  struct cmsghdr *cmsg);
755int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
756			  struct cmsghdr *cmsg);
757int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
758			  struct cmsghdr *cmsg);
759int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
760			  struct cmsghdr *cmsg);
761void rds_rdma_free_op(struct rm_rdma_op *ro);
762void rds_atomic_free_op(struct rm_atomic_op *ao);
763void rds_rdma_send_complete(struct rds_message *rm, int wc_status);
764void rds_atomic_send_complete(struct rds_message *rm, int wc_status);
765int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
766		    struct cmsghdr *cmsg);
767
768void __rds_put_mr_final(struct rds_mr *mr);
769static inline void rds_mr_put(struct rds_mr *mr)
770{
771	if (atomic_dec_and_test(&mr->r_refcount))
772		__rds_put_mr_final(mr);
773}
774
775/* stats.c */
776DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
777#define rds_stats_inc_which(which, member) do {		\
778	per_cpu(which, get_cpu()).member++;		\
779	put_cpu();					\
780} while (0)
781#define rds_stats_inc(member) rds_stats_inc_which(rds_stats, member)
782#define rds_stats_add_which(which, member, count) do {		\
783	per_cpu(which, get_cpu()).member += count;	\
784	put_cpu();					\
785} while (0)
786#define rds_stats_add(member, count) rds_stats_add_which(rds_stats, member, count)
787int rds_stats_init(void);
788void rds_stats_exit(void);
789void rds_stats_info_copy(struct rds_info_iterator *iter,
790			 uint64_t *values, const char *const *names,
791			 size_t nr);
792
793/* sysctl.c */
794int rds_sysctl_init(void);
795void rds_sysctl_exit(void);
796extern unsigned long rds_sysctl_sndbuf_min;
797extern unsigned long rds_sysctl_sndbuf_default;
798extern unsigned long rds_sysctl_sndbuf_max;
799extern unsigned long rds_sysctl_reconnect_min_jiffies;
800extern unsigned long rds_sysctl_reconnect_max_jiffies;
801extern unsigned int  rds_sysctl_max_unacked_packets;
802extern unsigned int  rds_sysctl_max_unacked_bytes;
803extern unsigned int  rds_sysctl_ping_enable;
804extern unsigned long rds_sysctl_trace_flags;
805extern unsigned int  rds_sysctl_trace_level;
806
807/* threads.c */
808int rds_threads_init(void);
809void rds_threads_exit(void);
810extern struct workqueue_struct *rds_wq;
811void rds_queue_reconnect(struct rds_connection *conn);
812void rds_connect_worker(struct work_struct *);
813void rds_shutdown_worker(struct work_struct *);
814void rds_send_worker(struct work_struct *);
815void rds_recv_worker(struct work_struct *);
 
816void rds_connect_complete(struct rds_connection *conn);
817
818/* transport.c */
819int rds_trans_register(struct rds_transport *trans);
820void rds_trans_unregister(struct rds_transport *trans);
821struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr);
822void rds_trans_put(struct rds_transport *trans);
823unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
824				       unsigned int avail);
825struct rds_transport *rds_trans_get(int t_type);
826int rds_trans_init(void);
827void rds_trans_exit(void);
828
829#endif
v4.10.11
  1#ifndef _RDS_RDS_H
  2#define _RDS_RDS_H
  3
  4#include <net/sock.h>
  5#include <linux/scatterlist.h>
  6#include <linux/highmem.h>
  7#include <rdma/rdma_cm.h>
  8#include <linux/mutex.h>
  9#include <linux/rds.h>
 10#include <linux/rhashtable.h>
 11
 12#include "info.h"
 13
 14/*
 15 * RDS Network protocol version
 16 */
 17#define RDS_PROTOCOL_3_0	0x0300
 18#define RDS_PROTOCOL_3_1	0x0301
 19#define RDS_PROTOCOL_VERSION	RDS_PROTOCOL_3_1
 20#define RDS_PROTOCOL_MAJOR(v)	((v) >> 8)
 21#define RDS_PROTOCOL_MINOR(v)	((v) & 255)
 22#define RDS_PROTOCOL(maj, min)	(((maj) << 8) | min)
 23
 24/*
 25 * XXX randomly chosen, but at least seems to be unused:
 26 * #               18464-18768 Unassigned
 27 * We should do better.  We want a reserved port to discourage unpriv'ed
 28 * userspace from listening.
 29 */
 30#define RDS_PORT	18634
 31
 32#ifdef ATOMIC64_INIT
 33#define KERNEL_HAS_ATOMIC64
 34#endif
 35
 36#ifdef RDS_DEBUG
 37#define rdsdebug(fmt, args...) pr_debug("%s(): " fmt, __func__ , ##args)
 38#else
 39/* sigh, pr_debug() causes unused variable warnings */
 40static inline __printf(1, 2)
 41void rdsdebug(char *fmt, ...)
 42{
 43}
 44#endif
 45
 46/* XXX is there one of these somewhere? */
 47#define ceil(x, y) \
 48	({ unsigned long __x = (x), __y = (y); (__x + __y - 1) / __y; })
 49
 50#define RDS_FRAG_SHIFT	12
 51#define RDS_FRAG_SIZE	((unsigned int)(1 << RDS_FRAG_SHIFT))
 52
 53#define RDS_CONG_MAP_BYTES	(65536 / 8)
 54#define RDS_CONG_MAP_PAGES	(PAGE_ALIGN(RDS_CONG_MAP_BYTES) / PAGE_SIZE)
 55#define RDS_CONG_MAP_PAGE_BITS	(PAGE_SIZE * 8)
 56
 57struct rds_cong_map {
 58	struct rb_node		m_rb_node;
 59	__be32			m_addr;
 60	wait_queue_head_t	m_waitq;
 61	struct list_head	m_conn_list;
 62	unsigned long		m_page_addrs[RDS_CONG_MAP_PAGES];
 63};
 64
 65
 66/*
 67 * This is how we will track the connection state:
 68 * A connection is always in one of the following
 69 * states. Updates to the state are atomic and imply
 70 * a memory barrier.
 71 */
 72enum {
 73	RDS_CONN_DOWN = 0,
 74	RDS_CONN_CONNECTING,
 75	RDS_CONN_DISCONNECTING,
 76	RDS_CONN_UP,
 77	RDS_CONN_RESETTING,
 78	RDS_CONN_ERROR,
 79};
 80
 81/* Bits for c_flags */
 82#define RDS_LL_SEND_FULL	0
 83#define RDS_RECONNECT_PENDING	1
 84#define RDS_IN_XMIT		2
 85#define RDS_RECV_REFILL		3
 86
 87/* Max number of multipaths per RDS connection. Must be a power of 2 */
 88#define	RDS_MPATH_WORKERS	8
 89#define	RDS_MPATH_HASH(rs, n) (jhash_1word((rs)->rs_bound_port, \
 90			       (rs)->rs_hash_initval) & ((n) - 1))
 91
 92/* Per mpath connection state */
 93struct rds_conn_path {
 94	struct rds_connection	*cp_conn;
 95	struct rds_message	*cp_xmit_rm;
 96	unsigned long		cp_xmit_sg;
 97	unsigned int		cp_xmit_hdr_off;
 98	unsigned int		cp_xmit_data_off;
 99	unsigned int		cp_xmit_atomic_sent;
100	unsigned int		cp_xmit_rdma_sent;
101	unsigned int		cp_xmit_data_sent;
102
103	spinlock_t		cp_lock;		/* protect msg queues */
104	u64			cp_next_tx_seq;
105	struct list_head	cp_send_queue;
106	struct list_head	cp_retrans;
107
108	u64			cp_next_rx_seq;
109
110	void			*cp_transport_data;
111
112	atomic_t		cp_state;
113	unsigned long		cp_send_gen;
114	unsigned long		cp_flags;
115	unsigned long		cp_reconnect_jiffies;
116	struct delayed_work	cp_send_w;
117	struct delayed_work	cp_recv_w;
118	struct delayed_work	cp_conn_w;
119	struct work_struct	cp_down_w;
120	struct mutex		cp_cm_lock;	/* protect cp_state & cm */
121	wait_queue_head_t	cp_waitq;
122
123	unsigned int		cp_unacked_packets;
124	unsigned int		cp_unacked_bytes;
125	unsigned int		cp_outgoing:1,
126				cp_pad_to_32:31;
127	unsigned int		cp_index;
128};
129
130/* One rds_connection per RDS address pair */
131struct rds_connection {
132	struct hlist_node	c_hash_node;
133	__be32			c_laddr;
134	__be32			c_faddr;
135	unsigned int		c_loopback:1,
136				c_ping_triggered:1,
137				c_pad_to_32:30;
138	int			c_npaths;
139	struct rds_connection	*c_passive;
140	struct rds_transport	*c_trans;
141
142	struct rds_cong_map	*c_lcong;
143	struct rds_cong_map	*c_fcong;
144
145	/* Protocol version */
146	unsigned int		c_version;
147	possible_net_t		c_net;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
148
149	struct list_head	c_map_item;
150	unsigned long		c_map_queued;
151
152	struct rds_conn_path	c_path[RDS_MPATH_WORKERS];
153	wait_queue_head_t	c_hs_waitq; /* handshake waitq */
154
155	u32			c_my_gen_num;
156	u32			c_peer_gen_num;
 
157};
158
159static inline
160struct net *rds_conn_net(struct rds_connection *conn)
161{
162	return read_pnet(&conn->c_net);
163}
164
165static inline
166void rds_conn_net_set(struct rds_connection *conn, struct net *net)
167{
168	write_pnet(&conn->c_net, net);
169}
170
171#define RDS_FLAG_CONG_BITMAP	0x01
172#define RDS_FLAG_ACK_REQUIRED	0x02
173#define RDS_FLAG_RETRANSMITTED	0x04
174#define RDS_MAX_ADV_CREDIT	255
175
176/* RDS_FLAG_PROBE_PORT is the reserved sport used for sending a ping
177 * probe to exchange control information before establishing a connection.
178 * Currently the control information that is exchanged is the number of
179 * supported paths. If the peer is a legacy (older kernel revision) peer,
180 * it would return a pong message without additional control information
181 * that would then alert the sender that the peer was an older rev.
182 */
183#define RDS_FLAG_PROBE_PORT	1
184#define	RDS_HS_PROBE(sport, dport) \
185		((sport == RDS_FLAG_PROBE_PORT && dport == 0) || \
186		 (sport == 0 && dport == RDS_FLAG_PROBE_PORT))
187/*
188 * Maximum space available for extension headers.
189 */
190#define RDS_HEADER_EXT_SPACE	16
191
192struct rds_header {
193	__be64	h_sequence;
194	__be64	h_ack;
195	__be32	h_len;
196	__be16	h_sport;
197	__be16	h_dport;
198	u8	h_flags;
199	u8	h_credit;
200	u8	h_padding[4];
201	__sum16	h_csum;
202
203	u8	h_exthdr[RDS_HEADER_EXT_SPACE];
204};
205
206/*
207 * Reserved - indicates end of extensions
208 */
209#define RDS_EXTHDR_NONE		0
210
211/*
212 * This extension header is included in the very
213 * first message that is sent on a new connection,
214 * and identifies the protocol level. This will help
215 * rolling updates if a future change requires breaking
216 * the protocol.
217 * NB: This is no longer true for IB, where we do a version
218 * negotiation during the connection setup phase (protocol
219 * version information is included in the RDMA CM private data).
220 */
221#define RDS_EXTHDR_VERSION	1
222struct rds_ext_header_version {
223	__be32			h_version;
224};
225
226/*
227 * This extension header is included in the RDS message
228 * chasing an RDMA operation.
229 */
230#define RDS_EXTHDR_RDMA		2
231struct rds_ext_header_rdma {
232	__be32			h_rdma_rkey;
233};
234
235/*
236 * This extension header tells the peer about the
237 * destination <R_Key,offset> of the requested RDMA
238 * operation.
239 */
240#define RDS_EXTHDR_RDMA_DEST	3
241struct rds_ext_header_rdma_dest {
242	__be32			h_rdma_rkey;
243	__be32			h_rdma_offset;
244};
245
246/* Extension header announcing number of paths.
247 * Implicit length = 2 bytes.
248 */
249#define RDS_EXTHDR_NPATHS	5
250#define RDS_EXTHDR_GEN_NUM	6
251
252#define __RDS_EXTHDR_MAX	16 /* for now */
253
254struct rds_incoming {
255	atomic_t		i_refcount;
256	struct list_head	i_item;
257	struct rds_connection	*i_conn;
258	struct rds_conn_path	*i_conn_path;
259	struct rds_header	i_hdr;
260	unsigned long		i_rx_jiffies;
261	__be32			i_saddr;
262
263	rds_rdma_cookie_t	i_rdma_cookie;
264	struct timeval		i_rx_tstamp;
265};
266
267struct rds_mr {
268	struct rb_node		r_rb_node;
269	atomic_t		r_refcount;
270	u32			r_key;
271
272	/* A copy of the creation flags */
273	unsigned int		r_use_once:1;
274	unsigned int		r_invalidate:1;
275	unsigned int		r_write:1;
276
277	/* This is for RDS_MR_DEAD.
278	 * It would be nice & consistent to make this part of the above
279	 * bit field here, but we need to use test_and_set_bit.
280	 */
281	unsigned long		r_state;
282	struct rds_sock		*r_sock; /* back pointer to the socket that owns us */
283	struct rds_transport	*r_trans;
284	void			*r_trans_private;
285};
286
287/* Flags for mr->r_state */
288#define RDS_MR_DEAD		0
289
290static inline rds_rdma_cookie_t rds_rdma_make_cookie(u32 r_key, u32 offset)
291{
292	return r_key | (((u64) offset) << 32);
293}
294
295static inline u32 rds_rdma_cookie_key(rds_rdma_cookie_t cookie)
296{
297	return cookie;
298}
299
300static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
301{
302	return cookie >> 32;
303}
304
305/* atomic operation types */
306#define RDS_ATOMIC_TYPE_CSWP		0
307#define RDS_ATOMIC_TYPE_FADD		1
308
309/*
310 * m_sock_item and m_conn_item are on lists that are serialized under
311 * conn->c_lock.  m_sock_item has additional meaning in that once it is empty
312 * the message will not be put back on the retransmit list after being sent.
313 * messages that are canceled while being sent rely on this.
314 *
315 * m_inc is used by loopback so that it can pass an incoming message straight
316 * back up into the rx path.  It embeds a wire header which is also used by
317 * the send path, which is kind of awkward.
318 *
319 * m_sock_item indicates the message's presence on a socket's send or receive
320 * queue.  m_rs will point to that socket.
321 *
322 * m_daddr is used by cancellation to prune messages to a given destination.
323 *
324 * The RDS_MSG_ON_SOCK and RDS_MSG_ON_CONN flags are used to avoid lock
325 * nesting.  As paths iterate over messages on a sock, or conn, they must
326 * also lock the conn, or sock, to remove the message from those lists too.
327 * Testing the flag to determine if the message is still on the lists lets
328 * us avoid testing the list_head directly.  That means each path can use
329 * the message's list_head to keep it on a local list while juggling locks
330 * without confusing the other path.
331 *
332 * m_ack_seq is an optional field set by transports who need a different
333 * sequence number range to invalidate.  They can use this in a callback
334 * that they pass to rds_send_drop_acked() to see if each message has been
335 * acked.  The HAS_ACK_SEQ flag can be used to detect messages which haven't
336 * had ack_seq set yet.
337 */
338#define RDS_MSG_ON_SOCK		1
339#define RDS_MSG_ON_CONN		2
340#define RDS_MSG_HAS_ACK_SEQ	3
341#define RDS_MSG_ACK_REQUIRED	4
342#define RDS_MSG_RETRANSMITTED	5
343#define RDS_MSG_MAPPED		6
344#define RDS_MSG_PAGEVEC		7
345#define RDS_MSG_FLUSH		8
346
347struct rds_message {
348	atomic_t		m_refcount;
349	struct list_head	m_sock_item;
350	struct list_head	m_conn_item;
351	struct rds_incoming	m_inc;
352	u64			m_ack_seq;
353	__be32			m_daddr;
354	unsigned long		m_flags;
355
356	/* Never access m_rs without holding m_rs_lock.
357	 * Lock nesting is
358	 *  rm->m_rs_lock
359	 *   -> rs->rs_lock
360	 */
361	spinlock_t		m_rs_lock;
362	wait_queue_head_t	m_flush_wait;
363
364	struct rds_sock		*m_rs;
365
366	/* cookie to send to remote, in rds header */
367	rds_rdma_cookie_t	m_rdma_cookie;
368
369	unsigned int		m_used_sgs;
370	unsigned int		m_total_sgs;
371
372	void			*m_final_op;
373
374	struct {
375		struct rm_atomic_op {
376			int			op_type;
377			union {
378				struct {
379					uint64_t	compare;
380					uint64_t	swap;
381					uint64_t	compare_mask;
382					uint64_t	swap_mask;
383				} op_m_cswp;
384				struct {
385					uint64_t	add;
386					uint64_t	nocarry_mask;
387				} op_m_fadd;
388			};
389
390			u32			op_rkey;
391			u64			op_remote_addr;
392			unsigned int		op_notify:1;
393			unsigned int		op_recverr:1;
394			unsigned int		op_mapped:1;
395			unsigned int		op_silent:1;
396			unsigned int		op_active:1;
397			struct scatterlist	*op_sg;
398			struct rds_notifier	*op_notifier;
399
400			struct rds_mr		*op_rdma_mr;
401		} atomic;
402		struct rm_rdma_op {
403			u32			op_rkey;
404			u64			op_remote_addr;
405			unsigned int		op_write:1;
406			unsigned int		op_fence:1;
407			unsigned int		op_notify:1;
408			unsigned int		op_recverr:1;
409			unsigned int		op_mapped:1;
410			unsigned int		op_silent:1;
411			unsigned int		op_active:1;
412			unsigned int		op_bytes;
413			unsigned int		op_nents;
414			unsigned int		op_count;
415			struct scatterlist	*op_sg;
416			struct rds_notifier	*op_notifier;
417
418			struct rds_mr		*op_rdma_mr;
419		} rdma;
420		struct rm_data_op {
421			unsigned int		op_active:1;
422			unsigned int		op_nents;
423			unsigned int		op_count;
424			unsigned int		op_dmasg;
425			unsigned int		op_dmaoff;
426			struct scatterlist	*op_sg;
427		} data;
428	};
429};
430
431/*
432 * The RDS notifier is used (optionally) to tell the application about
433 * completed RDMA operations. Rather than keeping the whole rds message
434 * around on the queue, we allocate a small notifier that is put on the
435 * socket's notifier_list. Notifications are delivered to the application
436 * through control messages.
437 */
438struct rds_notifier {
439	struct list_head	n_list;
440	uint64_t		n_user_token;
441	int			n_status;
442};
443
444/**
445 * struct rds_transport -  transport specific behavioural hooks
446 *
447 * @xmit: .xmit is called by rds_send_xmit() to tell the transport to send
448 *        part of a message.  The caller serializes on the send_sem so this
449 *        doesn't need to be reentrant for a given conn.  The header must be
450 *        sent before the data payload.  .xmit must be prepared to send a
451 *        message with no data payload.  .xmit should return the number of
452 *        bytes that were sent down the connection, including header bytes.
453 *        Returning 0 tells the caller that it doesn't need to perform any
454 *        additional work now.  This is usually the case when the transport has
455 *        filled the sending queue for its connection and will handle
456 *        triggering the rds thread to continue the send when space becomes
457 *        available.  Returning -EAGAIN tells the caller to retry the send
458 *        immediately.  Returning -ENOMEM tells the caller to retry the send at
459 *        some point in the future.
460 *
461 * @conn_shutdown: conn_shutdown stops traffic on the given connection.  Once
462 *                 it returns the connection can not call rds_recv_incoming().
463 *                 This will only be called once after conn_connect returns
464 *                 non-zero success and will The caller serializes this with
465 *                 the send and connecting paths (xmit_* and conn_*).  The
466 *                 transport is responsible for other serialization, including
467 *                 rds_recv_incoming().  This is called in process context but
468 *                 should try hard not to block.
469 */
470
471struct rds_transport {
472	char			t_name[TRANSNAMSIZ];
473	struct list_head	t_item;
474	struct module		*t_owner;
475	unsigned int		t_prefer_loopback:1,
476				t_mp_capable:1;
477	unsigned int		t_type;
478
479	int (*laddr_check)(struct net *net, __be32 addr);
480	int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
481	void (*conn_free)(void *data);
482	int (*conn_path_connect)(struct rds_conn_path *cp);
483	void (*conn_path_shutdown)(struct rds_conn_path *conn);
484	void (*xmit_path_prepare)(struct rds_conn_path *cp);
485	void (*xmit_path_complete)(struct rds_conn_path *cp);
486	int (*xmit)(struct rds_connection *conn, struct rds_message *rm,
487		    unsigned int hdr_off, unsigned int sg, unsigned int off);
488	int (*xmit_rdma)(struct rds_connection *conn, struct rm_rdma_op *op);
489	int (*xmit_atomic)(struct rds_connection *conn, struct rm_atomic_op *op);
490	int (*recv_path)(struct rds_conn_path *cp);
491	int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
492	void (*inc_free)(struct rds_incoming *inc);
493
494	int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
495				 struct rdma_cm_event *event);
496	int (*cm_initiate_connect)(struct rdma_cm_id *cm_id);
497	void (*cm_connect_complete)(struct rds_connection *conn,
498				    struct rdma_cm_event *event);
499
500	unsigned int (*stats_info_copy)(struct rds_info_iterator *iter,
501					unsigned int avail);
502	void (*exit)(void);
503	void *(*get_mr)(struct scatterlist *sg, unsigned long nr_sg,
504			struct rds_sock *rs, u32 *key_ret);
505	void (*sync_mr)(void *trans_private, int direction);
506	void (*free_mr)(void *trans_private, int invalidate);
507	void (*flush_mrs)(void);
508};
509
510struct rds_sock {
511	struct sock		rs_sk;
512
513	u64			rs_user_addr;
514	u64			rs_user_bytes;
515
516	/*
517	 * bound_addr used for both incoming and outgoing, no INADDR_ANY
518	 * support.
519	 */
520	struct rhash_head	rs_bound_node;
521	u64			rs_bound_key;
522	__be32			rs_bound_addr;
523	__be32			rs_conn_addr;
524	__be16			rs_bound_port;
525	__be16			rs_conn_port;
526	struct rds_transport    *rs_transport;
527
528	/*
529	 * rds_sendmsg caches the conn it used the last time around.
530	 * This helps avoid costly lookups.
531	 */
532	struct rds_connection	*rs_conn;
533
534	/* flag indicating we were congested or not */
535	int			rs_congested;
536	/* seen congestion (ENOBUFS) when sending? */
537	int			rs_seen_congestion;
538
539	/* rs_lock protects all these adjacent members before the newline */
540	spinlock_t		rs_lock;
541	struct list_head	rs_send_queue;
542	u32			rs_snd_bytes;
543	int			rs_rcv_bytes;
544	struct list_head	rs_notify_queue;	/* currently used for failed RDMAs */
545
546	/* Congestion wake_up. If rs_cong_monitor is set, we use cong_mask
547	 * to decide whether the application should be woken up.
548	 * If not set, we use rs_cong_track to find out whether a cong map
549	 * update arrived.
550	 */
551	uint64_t		rs_cong_mask;
552	uint64_t		rs_cong_notify;
553	struct list_head	rs_cong_list;
554	unsigned long		rs_cong_track;
555
556	/*
557	 * rs_recv_lock protects the receive queue, and is
558	 * used to serialize with rds_release.
559	 */
560	rwlock_t		rs_recv_lock;
561	struct list_head	rs_recv_queue;
562
563	/* just for stats reporting */
564	struct list_head	rs_item;
565
566	/* these have their own lock */
567	spinlock_t		rs_rdma_lock;
568	struct rb_root		rs_rdma_keys;
569
570	/* Socket options - in case there will be more */
571	unsigned char		rs_recverr,
572				rs_cong_monitor;
573	u32			rs_hash_initval;
574};
575
576static inline struct rds_sock *rds_sk_to_rs(const struct sock *sk)
577{
578	return container_of(sk, struct rds_sock, rs_sk);
579}
580static inline struct sock *rds_rs_to_sk(struct rds_sock *rs)
581{
582	return &rs->rs_sk;
583}
584
585/*
586 * The stack assigns sk_sndbuf and sk_rcvbuf to twice the specified value
587 * to account for overhead.  We don't account for overhead, we just apply
588 * the number of payload bytes to the specified value.
589 */
590static inline int rds_sk_sndbuf(struct rds_sock *rs)
591{
592	return rds_rs_to_sk(rs)->sk_sndbuf / 2;
593}
594static inline int rds_sk_rcvbuf(struct rds_sock *rs)
595{
596	return rds_rs_to_sk(rs)->sk_rcvbuf / 2;
597}
598
599struct rds_statistics {
600	uint64_t	s_conn_reset;
601	uint64_t	s_recv_drop_bad_checksum;
602	uint64_t	s_recv_drop_old_seq;
603	uint64_t	s_recv_drop_no_sock;
604	uint64_t	s_recv_drop_dead_sock;
605	uint64_t	s_recv_deliver_raced;
606	uint64_t	s_recv_delivered;
607	uint64_t	s_recv_queued;
608	uint64_t	s_recv_immediate_retry;
609	uint64_t	s_recv_delayed_retry;
610	uint64_t	s_recv_ack_required;
611	uint64_t	s_recv_rdma_bytes;
612	uint64_t	s_recv_ping;
613	uint64_t	s_send_queue_empty;
614	uint64_t	s_send_queue_full;
615	uint64_t	s_send_lock_contention;
616	uint64_t	s_send_lock_queue_raced;
617	uint64_t	s_send_immediate_retry;
618	uint64_t	s_send_delayed_retry;
619	uint64_t	s_send_drop_acked;
620	uint64_t	s_send_ack_required;
621	uint64_t	s_send_queued;
622	uint64_t	s_send_rdma;
623	uint64_t	s_send_rdma_bytes;
624	uint64_t	s_send_pong;
625	uint64_t	s_page_remainder_hit;
626	uint64_t	s_page_remainder_miss;
627	uint64_t	s_copy_to_user;
628	uint64_t	s_copy_from_user;
629	uint64_t	s_cong_update_queued;
630	uint64_t	s_cong_update_received;
631	uint64_t	s_cong_send_error;
632	uint64_t	s_cong_send_blocked;
633};
634
635/* af_rds.c */
636void rds_sock_addref(struct rds_sock *rs);
637void rds_sock_put(struct rds_sock *rs);
638void rds_wake_sk_sleep(struct rds_sock *rs);
639static inline void __rds_wake_sk_sleep(struct sock *sk)
640{
641	wait_queue_head_t *waitq = sk_sleep(sk);
642
643	if (!sock_flag(sk, SOCK_DEAD) && waitq)
644		wake_up(waitq);
645}
646extern wait_queue_head_t rds_poll_waitq;
647
648
649/* bind.c */
650int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
651void rds_remove_bound(struct rds_sock *rs);
652struct rds_sock *rds_find_bound(__be32 addr, __be16 port);
653int rds_bind_lock_init(void);
654void rds_bind_lock_destroy(void);
655
656/* cong.c */
657int rds_cong_get_maps(struct rds_connection *conn);
658void rds_cong_add_conn(struct rds_connection *conn);
659void rds_cong_remove_conn(struct rds_connection *conn);
660void rds_cong_set_bit(struct rds_cong_map *map, __be16 port);
661void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port);
662int rds_cong_wait(struct rds_cong_map *map, __be16 port, int nonblock, struct rds_sock *rs);
663void rds_cong_queue_updates(struct rds_cong_map *map);
664void rds_cong_map_updated(struct rds_cong_map *map, uint64_t);
665int rds_cong_updated_since(unsigned long *recent);
666void rds_cong_add_socket(struct rds_sock *);
667void rds_cong_remove_socket(struct rds_sock *);
668void rds_cong_exit(void);
669struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
670
671/* conn.c */
672extern u32 rds_gen_num;
673int rds_conn_init(void);
674void rds_conn_exit(void);
675struct rds_connection *rds_conn_create(struct net *net,
676				       __be32 laddr, __be32 faddr,
677				       struct rds_transport *trans, gfp_t gfp);
678struct rds_connection *rds_conn_create_outgoing(struct net *net,
679						__be32 laddr, __be32 faddr,
680			       struct rds_transport *trans, gfp_t gfp);
681void rds_conn_shutdown(struct rds_conn_path *cpath);
682void rds_conn_destroy(struct rds_connection *conn);
683void rds_conn_drop(struct rds_connection *conn);
684void rds_conn_path_drop(struct rds_conn_path *cpath);
685void rds_conn_connect_if_down(struct rds_connection *conn);
686void rds_conn_path_connect_if_down(struct rds_conn_path *cp);
687void rds_for_each_conn_info(struct socket *sock, unsigned int len,
688			  struct rds_info_iterator *iter,
689			  struct rds_info_lengths *lens,
690			  int (*visitor)(struct rds_connection *, void *),
691			  size_t item_len);
692
693__printf(2, 3)
694void __rds_conn_path_error(struct rds_conn_path *cp, const char *, ...);
695#define rds_conn_path_error(cp, fmt...) \
696	__rds_conn_path_error(cp, KERN_WARNING "RDS: " fmt)
697
698static inline int
699rds_conn_path_transition(struct rds_conn_path *cp, int old, int new)
700{
701	return atomic_cmpxchg(&cp->cp_state, old, new) == old;
702}
703
704static inline int
705rds_conn_transition(struct rds_connection *conn, int old, int new)
706{
707	WARN_ON(conn->c_trans->t_mp_capable);
708	return rds_conn_path_transition(&conn->c_path[0], old, new);
709}
710
711static inline int
712rds_conn_path_state(struct rds_conn_path *cp)
713{
714	return atomic_read(&cp->cp_state);
715}
716
717static inline int
718rds_conn_state(struct rds_connection *conn)
719{
720	WARN_ON(conn->c_trans->t_mp_capable);
721	return rds_conn_path_state(&conn->c_path[0]);
722}
723
724static inline int
725rds_conn_path_up(struct rds_conn_path *cp)
726{
727	return atomic_read(&cp->cp_state) == RDS_CONN_UP;
728}
729
730static inline int
731rds_conn_up(struct rds_connection *conn)
732{
733	WARN_ON(conn->c_trans->t_mp_capable);
734	return rds_conn_path_up(&conn->c_path[0]);
735}
736
737static inline int
738rds_conn_path_connecting(struct rds_conn_path *cp)
739{
740	return atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING;
741}
742
743static inline int
744rds_conn_connecting(struct rds_connection *conn)
745{
746	WARN_ON(conn->c_trans->t_mp_capable);
747	return rds_conn_path_connecting(&conn->c_path[0]);
748}
749
750/* message.c */
751struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
752struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
753int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from);
754struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
755void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
756				 __be16 dport, u64 seq);
757int rds_message_add_extension(struct rds_header *hdr,
758			      unsigned int type, const void *data, unsigned int len);
759int rds_message_next_extension(struct rds_header *hdr,
760			       unsigned int *pos, void *buf, unsigned int *buflen);
761int rds_message_add_rdma_dest_extension(struct rds_header *hdr, u32 r_key, u32 offset);
762int rds_message_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
763void rds_message_inc_free(struct rds_incoming *inc);
764void rds_message_addref(struct rds_message *rm);
765void rds_message_put(struct rds_message *rm);
766void rds_message_wait(struct rds_message *rm);
767void rds_message_unmapped(struct rds_message *rm);
768
769static inline void rds_message_make_checksum(struct rds_header *hdr)
770{
771	hdr->h_csum = 0;
772	hdr->h_csum = ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2);
773}
774
775static inline int rds_message_verify_checksum(const struct rds_header *hdr)
776{
777	return !hdr->h_csum || ip_fast_csum((void *) hdr, sizeof(*hdr) >> 2) == 0;
778}
779
780
781/* page.c */
782int rds_page_remainder_alloc(struct scatterlist *scat, unsigned long bytes,
783			     gfp_t gfp);
784int rds_page_copy_user(struct page *page, unsigned long offset,
785		       void __user *ptr, unsigned long bytes,
786		       int to_user);
787#define rds_page_copy_to_user(page, offset, ptr, bytes) \
788	rds_page_copy_user(page, offset, ptr, bytes, 1)
789#define rds_page_copy_from_user(page, offset, ptr, bytes) \
790	rds_page_copy_user(page, offset, ptr, bytes, 0)
791void rds_page_exit(void);
792
793/* recv.c */
794void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
795		  __be32 saddr);
796void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *conn,
797		       __be32 saddr);
798void rds_inc_put(struct rds_incoming *inc);
799void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
800		       struct rds_incoming *inc, gfp_t gfp);
801int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
802		int msg_flags);
803void rds_clear_recv_queue(struct rds_sock *rs);
804int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msg);
805void rds_inc_info_copy(struct rds_incoming *inc,
806		       struct rds_info_iterator *iter,
807		       __be32 saddr, __be32 daddr, int flip);
808
809/* send.c */
810int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len);
811void rds_send_path_reset(struct rds_conn_path *conn);
812int rds_send_xmit(struct rds_conn_path *cp);
813struct sockaddr_in;
814void rds_send_drop_to(struct rds_sock *rs, struct sockaddr_in *dest);
815typedef int (*is_acked_func)(struct rds_message *rm, uint64_t ack);
816void rds_send_drop_acked(struct rds_connection *conn, u64 ack,
817			 is_acked_func is_acked);
818void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack,
819			      is_acked_func is_acked);
820int rds_send_pong(struct rds_conn_path *cp, __be16 dport);
821
822/* rdma.c */
823void rds_rdma_unuse(struct rds_sock *rs, u32 r_key, int force);
824int rds_get_mr(struct rds_sock *rs, char __user *optval, int optlen);
825int rds_get_mr_for_dest(struct rds_sock *rs, char __user *optval, int optlen);
826int rds_free_mr(struct rds_sock *rs, char __user *optval, int optlen);
827void rds_rdma_drop_keys(struct rds_sock *rs);
828int rds_rdma_extra_size(struct rds_rdma_args *args);
829int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
830			  struct cmsghdr *cmsg);
831int rds_cmsg_rdma_dest(struct rds_sock *rs, struct rds_message *rm,
832			  struct cmsghdr *cmsg);
833int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm,
834			  struct cmsghdr *cmsg);
835int rds_cmsg_rdma_map(struct rds_sock *rs, struct rds_message *rm,
836			  struct cmsghdr *cmsg);
837void rds_rdma_free_op(struct rm_rdma_op *ro);
838void rds_atomic_free_op(struct rm_atomic_op *ao);
839void rds_rdma_send_complete(struct rds_message *rm, int wc_status);
840void rds_atomic_send_complete(struct rds_message *rm, int wc_status);
841int rds_cmsg_atomic(struct rds_sock *rs, struct rds_message *rm,
842		    struct cmsghdr *cmsg);
843
844void __rds_put_mr_final(struct rds_mr *mr);
845static inline void rds_mr_put(struct rds_mr *mr)
846{
847	if (atomic_dec_and_test(&mr->r_refcount))
848		__rds_put_mr_final(mr);
849}
850
851/* stats.c */
852DECLARE_PER_CPU_SHARED_ALIGNED(struct rds_statistics, rds_stats);
853#define rds_stats_inc_which(which, member) do {		\
854	per_cpu(which, get_cpu()).member++;		\
855	put_cpu();					\
856} while (0)
857#define rds_stats_inc(member) rds_stats_inc_which(rds_stats, member)
858#define rds_stats_add_which(which, member, count) do {		\
859	per_cpu(which, get_cpu()).member += count;	\
860	put_cpu();					\
861} while (0)
862#define rds_stats_add(member, count) rds_stats_add_which(rds_stats, member, count)
863int rds_stats_init(void);
864void rds_stats_exit(void);
865void rds_stats_info_copy(struct rds_info_iterator *iter,
866			 uint64_t *values, const char *const *names,
867			 size_t nr);
868
869/* sysctl.c */
870int rds_sysctl_init(void);
871void rds_sysctl_exit(void);
872extern unsigned long rds_sysctl_sndbuf_min;
873extern unsigned long rds_sysctl_sndbuf_default;
874extern unsigned long rds_sysctl_sndbuf_max;
875extern unsigned long rds_sysctl_reconnect_min_jiffies;
876extern unsigned long rds_sysctl_reconnect_max_jiffies;
877extern unsigned int  rds_sysctl_max_unacked_packets;
878extern unsigned int  rds_sysctl_max_unacked_bytes;
879extern unsigned int  rds_sysctl_ping_enable;
880extern unsigned long rds_sysctl_trace_flags;
881extern unsigned int  rds_sysctl_trace_level;
882
883/* threads.c */
884int rds_threads_init(void);
885void rds_threads_exit(void);
886extern struct workqueue_struct *rds_wq;
887void rds_queue_reconnect(struct rds_conn_path *cp);
888void rds_connect_worker(struct work_struct *);
889void rds_shutdown_worker(struct work_struct *);
890void rds_send_worker(struct work_struct *);
891void rds_recv_worker(struct work_struct *);
892void rds_connect_path_complete(struct rds_conn_path *conn, int curr);
893void rds_connect_complete(struct rds_connection *conn);
894
895/* transport.c */
896int rds_trans_register(struct rds_transport *trans);
897void rds_trans_unregister(struct rds_transport *trans);
898struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr);
899void rds_trans_put(struct rds_transport *trans);
900unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
901				       unsigned int avail);
902struct rds_transport *rds_trans_get(int t_type);
903int rds_trans_init(void);
904void rds_trans_exit(void);
905
906#endif