[mirror_ubuntu-artful-kernel.git] / net / smc / smc_cdc.h

/*
 * Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 * Connection Data Control (CDC)
 *
 * Copyright IBM Corp. 2016
 *
 * Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#ifndef SMC_CDC_H
#define SMC_CDC_H

#include <linux/kernel.h> /* max_t */
#include <linux/atomic.h>
#include <linux/in.h>
#include <linux/compiler.h>

#include "smc.h"
#include "smc_core.h"
#include "smc_wr.h"

#define	SMC_CDC_MSG_TYPE		0xFE

/* in network byte order */
union smc_cdc_cursor {		/* SMC cursor */
	struct {
		__be16	reserved;
		__be16	wrap;
		__be32	count;
	};
#ifdef KERNEL_HAS_ATOMIC64
	atomic64_t	acurs;		/* for atomic processing */
#else
	u64		acurs;		/* for atomic processing */
#endif
} __aligned(8);

/* in network byte order */
struct smc_cdc_msg {
	struct smc_wr_rx_hdr		common; /* .type = 0xFE */
	u8				len;	/* 44 */
	__be16				seqno;
	__be32				token;
	union smc_cdc_cursor		prod;
	union smc_cdc_cursor		cons;	/* piggy backed "ack" */
	struct smc_cdc_producer_flags	prod_flags;
	struct smc_cdc_conn_state_flags	conn_state_flags;
	u8				reserved[18];
} __aligned(8);

static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn)
{
	return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort ||
	       conn->local_rx_ctrl.conn_state_flags.peer_conn_closed;
}

static inline bool smc_cdc_rxed_any_close_or_senddone(
	struct smc_connection *conn)
{
	return smc_cdc_rxed_any_close(conn) ||
	       conn->local_rx_ctrl.conn_state_flags.peer_done_writing;
}

static inline void smc_curs_add(int size, union smc_host_cursor *curs,
				int value)
{
	curs->count += value;
	if (curs->count >= size) {
		curs->wrap++;
		curs->count -= size;
	}
}

/* SMC cursors are 8 bytes long and require atomic reading and writing */
static inline u64 smc_curs_read(union smc_host_cursor *curs,
				struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;
	u64 ret;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	ret = curs->acurs;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
	return ret;
#else
	return atomic64_read(&curs->acurs);
#endif
}

static inline u64 smc_curs_read_net(union smc_cdc_cursor *curs,
				    struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;
	u64 ret;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	ret = curs->acurs;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
	return ret;
#else
	return atomic64_read(&curs->acurs);
#endif
}

static inline void smc_curs_write(union smc_host_cursor *curs, u64 val,
				  struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	curs->acurs = val;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
#else
	atomic64_set(&curs->acurs, val);
#endif
}

static inline void smc_curs_write_net(union smc_cdc_cursor *curs, u64 val,
				      struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	curs->acurs = val;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
#else
	atomic64_set(&curs->acurs, val);
#endif
}

/* calculate cursor difference between old and new, where old <= new */
static inline int smc_curs_diff(unsigned int size,
				union smc_host_cursor *old,
				union smc_host_cursor *new)
{
	if (old->wrap != new->wrap)
		return max_t(int, 0,
			     ((size - old->count) + new->count));

	return max_t(int, 0, (new->count - old->count));
}

static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
					  union smc_host_cursor *local,
					  struct smc_connection *conn)
{
	union smc_host_cursor temp;

	smc_curs_write(&temp, smc_curs_read(local, conn), conn);
	peer->count = htonl(temp.count);
	peer->wrap = htons(temp.wrap);
	/* peer->reserved = htons(0); must be ensured by caller */
}

static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer,
				       struct smc_host_cdc_msg *local,
				       struct smc_connection *conn)
{
	peer->common.type = local->common.type;
	peer->len = local->len;
	peer->seqno = htons(local->seqno);
	peer->token = htonl(local->token);
	smc_host_cursor_to_cdc(&peer->prod, &local->prod, conn);
	smc_host_cursor_to_cdc(&peer->cons, &local->cons, conn);
	peer->prod_flags = local->prod_flags;
	peer->conn_state_flags = local->conn_state_flags;
}

static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local,
					  union smc_cdc_cursor *peer,
					  struct smc_connection *conn)
{
	union smc_host_cursor temp, old;
	union smc_cdc_cursor net;

	smc_curs_write(&old, smc_curs_read(local, conn), conn);
	smc_curs_write_net(&net, smc_curs_read_net(peer, conn), conn);
	temp.count = ntohl(net.count);
	temp.wrap = ntohs(net.wrap);
	if ((old.wrap > temp.wrap) && temp.wrap)
		return;
	if ((old.wrap == temp.wrap) &&
	    (old.count > temp.count))
		return;
	smc_curs_write(local, smc_curs_read(&temp, conn), conn);
}

static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
				       struct smc_cdc_msg *peer,
				       struct smc_connection *conn)
{
	local->common.type = peer->common.type;
	local->len = peer->len;
	local->seqno = ntohs(peer->seqno);
	local->token = ntohl(peer->token);
	smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn);
	smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn);
	local->prod_flags = peer->prod_flags;
	local->conn_state_flags = peer->conn_state_flags;
}

struct smc_cdc_tx_pend;

int smc_cdc_get_free_slot(struct smc_link *link, struct smc_wr_buf **wr_buf,
			  struct smc_cdc_tx_pend **pend);
void smc_cdc_tx_dismiss_slots(struct smc_connection *conn);
int smc_cdc_msg_send(struct smc_connection *conn, struct smc_wr_buf *wr_buf,
		     struct smc_cdc_tx_pend *pend);
int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn);
bool smc_cdc_tx_has_pending(struct smc_connection *conn);
int smc_cdc_init(void) __init;

#endif /* SMC_CDC_H */
Commit	Line	Data
5f08318f UB	1	/*
	2	* Shared Memory Communications over RDMA (SMC-R) and RoCE
	3	*
	4	* Connection Data Control (CDC)
	5	*
	6	* Copyright IBM Corp. 2016
	7	*
	8	* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
	9	*/
	10
	11	#ifndef SMC_CDC_H
	12	#define SMC_CDC_H
	13
	14	#include <linux/kernel.h> /* max_t */
	15	#include <linux/atomic.h>
	16	#include <linux/in.h>
	17	#include <linux/compiler.h>
	18
	19	#include "smc.h"
	20	#include "smc_core.h"
	21	#include "smc_wr.h"
	22
	23	#define SMC_CDC_MSG_TYPE 0xFE
	24
	25	/* in network byte order */
	26	union smc_cdc_cursor { /* SMC cursor */
	27	struct {
	28	__be16 reserved;
	29	__be16 wrap;
	30	__be32 count;
	31	};
	32	#ifdef KERNEL_HAS_ATOMIC64
	33	atomic64_t acurs; /* for atomic processing */
	34	#else
	35	u64 acurs; /* for atomic processing */
	36	#endif
	37	} __aligned(8);
	38
	39	/* in network byte order */
	40	struct smc_cdc_msg {
	41	struct smc_wr_rx_hdr common; /* .type = 0xFE */
	42	u8 len; /* 44 */
	43	__be16 seqno;
	44	__be32 token;
	45	union smc_cdc_cursor prod;
	46	union smc_cdc_cursor cons; /* piggy backed "ack" */
	47	struct smc_cdc_producer_flags prod_flags;
	48	struct smc_cdc_conn_state_flags conn_state_flags;
	49	u8 reserved[18];
	50	} __aligned(8);
	51
	52	static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn)
	53	{
	54	return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort \|\|
	55	conn->local_rx_ctrl.conn_state_flags.peer_conn_closed;
	56	}
	57
	58	static inline bool smc_cdc_rxed_any_close_or_senddone(
	59	struct smc_connection *conn)
	60	{
	61	return smc_cdc_rxed_any_close(conn) \|\|
	62	conn->local_rx_ctrl.conn_state_flags.peer_done_writing;
	63	}
	64
65	static inline void smc_curs_add(int size, union smc_host_cursor *curs,
66	int value)
67	{
68	curs->count += value;
69	if (curs->count >= size) {
70	curs->wrap++;
71	curs->count -= size;
72	}
73	}
74
75	/* SMC cursors are 8 bytes long and require atomic reading and writing */
76	static inline u64 smc_curs_read(union smc_host_cursor *curs,
77	struct smc_connection *conn)
78	{
79	#ifndef KERNEL_HAS_ATOMIC64
80	unsigned long flags;
81	u64 ret;
82
83	spin_lock_irqsave(&conn->acurs_lock, flags);
84	ret = curs->acurs;
85	spin_unlock_irqrestore(&conn->acurs_lock, flags);
86	return ret;
87	#else
88	return atomic64_read(&curs->acurs);
89	#endif
90	}
91
92	static inline u64 smc_curs_read_net(union smc_cdc_cursor *curs,
93	struct smc_connection *conn)
94	{
95	#ifndef KERNEL_HAS_ATOMIC64
96	unsigned long flags;
97	u64 ret;
98
99	spin_lock_irqsave(&conn->acurs_lock, flags);
100	ret = curs->acurs;
101	spin_unlock_irqrestore(&conn->acurs_lock, flags);
102	return ret;
103	#else
104	return atomic64_read(&curs->acurs);
105	#endif
106	}
107
108	static inline void smc_curs_write(union smc_host_cursor *curs, u64 val,
109	struct smc_connection *conn)
110	{
111	#ifndef KERNEL_HAS_ATOMIC64
112	unsigned long flags;
113
114	spin_lock_irqsave(&conn->acurs_lock, flags);
115	curs->acurs = val;
116	spin_unlock_irqrestore(&conn->acurs_lock, flags);
117	#else
118	atomic64_set(&curs->acurs, val);
119	#endif
120	}
121
122	static inline void smc_curs_write_net(union smc_cdc_cursor *curs, u64 val,
123	struct smc_connection *conn)
124	{
125	#ifndef KERNEL_HAS_ATOMIC64
126	unsigned long flags;
127
128	spin_lock_irqsave(&conn->acurs_lock, flags);
129	curs->acurs = val;
130	spin_unlock_irqrestore(&conn->acurs_lock, flags);
131	#else
132	atomic64_set(&curs->acurs, val);
133	#endif
134	}
135
136	/* calculate cursor difference between old and new, where old <= new */
137	static inline int smc_curs_diff(unsigned int size,
138	union smc_host_cursor *old,
139	union smc_host_cursor *new)
140	{
141	if (old->wrap != new->wrap)
142	return max_t(int, 0,
143	((size - old->count) + new->count));
144
145	return max_t(int, 0, (new->count - old->count));
146	}
147
148	static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
149	union smc_host_cursor *local,
150	struct smc_connection *conn)
151	{
152	union smc_host_cursor temp;
153
154	smc_curs_write(&temp, smc_curs_read(local, conn), conn);
155	peer->count = htonl(temp.count);
156	peer->wrap = htons(temp.wrap);
157	/* peer->reserved = htons(0); must be ensured by caller */
158	}
159
160	static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer,
161	struct smc_host_cdc_msg *local,
162	struct smc_connection *conn)
163	{
164	peer->common.type = local->common.type;
165	peer->len = local->len;
166	peer->seqno = htons(local->seqno);
167	peer->token = htonl(local->token);
168	smc_host_cursor_to_cdc(&peer->prod, &local->prod, conn);
169	smc_host_cursor_to_cdc(&peer->cons, &local->cons, conn);
170	peer->prod_flags = local->prod_flags;
171	peer->conn_state_flags = local->conn_state_flags;
172	}
173
174	static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local,
175	union smc_cdc_cursor *peer,
176	struct smc_connection *conn)
177	{
178	union smc_host_cursor temp, old;
179	union smc_cdc_cursor net;
180
181	smc_curs_write(&old, smc_curs_read(local, conn), conn);
182	smc_curs_write_net(&net, smc_curs_read_net(peer, conn), conn);
183	temp.count = ntohl(net.count);
184	temp.wrap = ntohs(net.wrap);
185	if ((old.wrap > temp.wrap) && temp.wrap)
186	return;
187	if ((old.wrap == temp.wrap) &&
188	(old.count > temp.count))
189	return;
190	smc_curs_write(local, smc_curs_read(&temp, conn), conn);
191	}
192
193	static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
194	struct smc_cdc_msg *peer,
195	struct smc_connection *conn)
196	{
197	local->common.type = peer->common.type;
198	local->len = peer->len;
199	local->seqno = ntohs(peer->seqno);
200	local->token = ntohl(peer->token);
201	smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn);
202	smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn);
203	local->prod_flags = peer->prod_flags;
204	local->conn_state_flags = peer->conn_state_flags;
205	}
206
207	struct smc_cdc_tx_pend;
208
209	int smc_cdc_get_free_slot(struct smc_link link, struct smc_wr_buf *wr_buf,
210	struct smc_cdc_tx_pend **pend);
211	void smc_cdc_tx_dismiss_slots(struct smc_connection *conn);
212	int smc_cdc_msg_send(struct smc_connection conn, struct smc_wr_buf wr_buf,
213	struct smc_cdc_tx_pend *pend);
214	int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn);
b38d7324	215	bool smc_cdc_tx_has_pending(struct smc_connection *conn);
5f08318f UB	216	int smc_cdc_init(void) __init;
	217
	218	#endif /* SMC_CDC_H */