[linux.git] / net / smc / smc_cdc.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 * Connection Data Control (CDC)
 *
 * Copyright IBM Corp. 2016
 *
 * Author(s):  Ursula Braun <[email protected]>
 */

#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];
};

/* SMC-D cursor format */
union smcd_cdc_cursor {
	struct {
		u16	wrap;
		u32	count;
		struct smc_cdc_producer_flags	prod_flags;
		struct smc_cdc_conn_state_flags	conn_state_flags;
	} __packed;
#ifdef KERNEL_HAS_ATOMIC64
	atomic64_t		acurs;		/* for atomic processing */
#else
	u64			acurs;		/* for atomic processing */
#endif
} __aligned(8);

/* CDC message for SMC-D */
struct smcd_cdc_msg {
	struct smc_wr_rx_hdr common;	/* Type = 0xFE */
	u8 res1[7];
	union smcd_cdc_cursor	prod;
	union smcd_cdc_cursor	cons;
	u8 res3[8];
} __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;
	}
}

/* Copy cursor src into tgt */
static inline void smc_curs_copy(union smc_host_cursor *tgt,
				 union smc_host_cursor *src,
				 struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	tgt->acurs = src->acurs;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
#else
	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
#endif
}

static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt,
				     union smc_cdc_cursor *src,
				     struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	tgt->acurs = src->acurs;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
#else
	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
#endif
}

static inline void smcd_curs_copy(union smcd_cdc_cursor *tgt,
				  union smcd_cdc_cursor *src,
				  struct smc_connection *conn)
{
#ifndef KERNEL_HAS_ATOMIC64
	unsigned long flags;

	spin_lock_irqsave(&conn->acurs_lock, flags);
	tgt->acurs = src->acurs;
	spin_unlock_irqrestore(&conn->acurs_lock, flags);
#else
	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
#endif
}

/* calculate cursor difference between old and new, where old <= new and
 * difference cannot exceed size
 */
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));
}

/* calculate cursor difference between old and new - returns negative
 * value in case old > new
 */
static inline int smc_curs_comp(unsigned int size,
				union smc_host_cursor *old,
				union smc_host_cursor *new)
{
	if (old->wrap > new->wrap ||
	    (old->wrap == new->wrap && old->count > new->count))
		return -smc_curs_diff(size, new, old);
	return smc_curs_diff(size, old, new);
}

/* calculate cursor difference between old and new, where old <= new and
 * difference may exceed size
 */
static inline int smc_curs_diff_large(unsigned int size,
				      union smc_host_cursor *old,
				      union smc_host_cursor *new)
{
	if (old->wrap < new->wrap)
		return min_t(int,
			     (size - old->count) + new->count +
			     (new->wrap - old->wrap - 1) * size,
			     size);

	if (old->wrap > new->wrap) /* wrap has switched from 0xffff to 0x0000 */
		return min_t(int,
			     (size - old->count) + new->count +
			     (new->wrap + 0xffff - old->wrap) * size,
			     size);

	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,
					  union smc_host_cursor *save,
					  struct smc_connection *conn)
{
	smc_curs_copy(save, local, conn);
	peer->count = htonl(save->count);
	peer->wrap = htons(save->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_connection *conn,
				       union smc_host_cursor *save)
{
	struct smc_host_cdc_msg *local = &conn->local_tx_ctrl;

	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, save, conn);
	smc_host_cursor_to_cdc(&peer->cons, &local->cons, save, 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_copy(&old, local, conn);
	smc_curs_copy_net(&net, peer, 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_copy(local, &temp, conn);
}

static inline void smcr_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;
}

static inline void smcd_cdc_msg_to_host(struct smc_host_cdc_msg *local,
					struct smcd_cdc_msg *peer,
					struct smc_connection *conn)
{
	union smc_host_cursor temp;

	temp.wrap = peer->prod.wrap;
	temp.count = peer->prod.count;
	smc_curs_copy(&local->prod, &temp, conn);

	temp.wrap = peer->cons.wrap;
	temp.count = peer->cons.count;
	smc_curs_copy(&local->cons, &temp, conn);
	local->prod_flags = peer->cons.prod_flags;
	local->conn_state_flags = peer->cons.conn_state_flags;
}

static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
				       struct smc_cdc_msg *peer,
				       struct smc_connection *conn)
{
	if (conn->lgr->is_smcd)
		smcd_cdc_msg_to_host(local, (struct smcd_cdc_msg *)peer, conn);
	else
		smcr_cdc_msg_to_host(local, peer, conn);
}

struct smc_cdc_tx_pend {
	struct smc_connection	*conn;		/* socket connection */
	union smc_host_cursor	cursor;		/* tx sndbuf cursor sent */
	union smc_host_cursor	p_cursor;	/* rx RMBE cursor produced */
	u16			ctrl_seq;	/* conn. tx sequence # */
};

int smc_cdc_get_free_slot(struct smc_connection *conn,
			  struct smc_link *link,
			  struct smc_wr_buf **wr_buf,
			  struct smc_rdma_wr **wr_rdma_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);
int smcd_cdc_msg_send(struct smc_connection *conn);
int smcr_cdc_msg_send_validation(struct smc_connection *conn,
				 struct smc_cdc_tx_pend *pend,
				 struct smc_wr_buf *wr_buf);
int smc_cdc_init(void) __init;
void smcd_cdc_rx_init(struct smc_connection *conn);

#endif /* SMC_CDC_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
5f08318f UB	2	/*
	3	* Shared Memory Communications over RDMA (SMC-R) and RoCE
	4	*
	5	* Connection Data Control (CDC)
	6	*
	7	* Copyright IBM Corp. 2016
	8	*
	9	* Author(s): Ursula Braun <[email protected]>
	10	*/
	11
	12	#ifndef SMC_CDC_H
	13	#define SMC_CDC_H
	14
	15	#include <linux/kernel.h> /* max_t */
	16	#include <linux/atomic.h>
	17	#include <linux/in.h>
	18	#include <linux/compiler.h>
	19
	20	#include "smc.h"
	21	#include "smc_core.h"
	22	#include "smc_wr.h"
	23
	24	#define SMC_CDC_MSG_TYPE 0xFE
	25
	26	/* in network byte order */
	27	union smc_cdc_cursor { /* SMC cursor */
	28	struct {
	29	__be16 reserved;
	30	__be16 wrap;
	31	__be32 count;
	32	};
	33	#ifdef KERNEL_HAS_ATOMIC64
	34	atomic64_t acurs; /* for atomic processing */
	35	#else
	36	u64 acurs; /* for atomic processing */
	37	#endif
	38	} __aligned(8);
	39
	40	/* in network byte order */
	41	struct smc_cdc_msg {
	42	struct smc_wr_rx_hdr common; /* .type = 0xFE */
	43	u8 len; /* 44 */
	44	__be16 seqno;
	45	__be32 token;
	46	union smc_cdc_cursor prod;
	47	union smc_cdc_cursor cons; /* piggy backed "ack" */
	48	struct smc_cdc_producer_flags prod_flags;
	49	struct smc_cdc_conn_state_flags conn_state_flags;
	50	u8 reserved[18];
b9a22dd9 UB	51	};
	52
	53	/* SMC-D cursor format */
	54	union smcd_cdc_cursor {
	55	struct {
	56	u16 wrap;
	57	u32 count;
	58	struct smc_cdc_producer_flags prod_flags;
	59	struct smc_cdc_conn_state_flags conn_state_flags;
	60	} __packed;
	61	#ifdef KERNEL_HAS_ATOMIC64
	62	atomic64_t acurs; /* for atomic processing */
	63	#else
	64	u64 acurs; /* for atomic processing */
	65	#endif
	66	} __aligned(8);
5f08318f	67
be244f28 HW	68	/* CDC message for SMC-D */
	69	struct smcd_cdc_msg {
	70	struct smc_wr_rx_hdr common; /* Type = 0xFE */
	71	u8 res1[7];
b9a22dd9 UB	72	union smcd_cdc_cursor prod;
b9a22dd9 UB	73	union smcd_cdc_cursor cons;
be244f28	74	u8 res3[8];
b9a22dd9	75	} __aligned(8);
be244f28	76
5f08318f UB	77	static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn)
	78	{
	79	return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort \|\|
	80	conn->local_rx_ctrl.conn_state_flags.peer_conn_closed;
	81	}
	82
	83	static inline bool smc_cdc_rxed_any_close_or_senddone(
	84	struct smc_connection *conn)
	85	{
	86	return smc_cdc_rxed_any_close(conn) \|\|
	87	conn->local_rx_ctrl.conn_state_flags.peer_done_writing;
	88	}
	89
	90	static inline void smc_curs_add(int size, union smc_host_cursor *curs,
	91	int value)
	92	{
	93	curs->count += value;
	94	if (curs->count >= size) {
	95	curs->wrap++;
	96	curs->count -= size;
	97	}
	98	}
	99
bac6de7b SR	100	/* Copy cursor src into tgt */
	101	static inline void smc_curs_copy(union smc_host_cursor *tgt,
	102	union smc_host_cursor *src,
	103	struct smc_connection *conn)
5f08318f UB	104	{
	105	#ifndef KERNEL_HAS_ATOMIC64
	106	unsigned long flags;
	107
	108	spin_lock_irqsave(&conn->acurs_lock, flags);
bac6de7b	109	tgt->acurs = src->acurs;
5f08318f UB	110	spin_unlock_irqrestore(&conn->acurs_lock, flags);
5f08318f UB	111	#else
bac6de7b	112	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
5f08318f UB	113	#endif
	114	}
	115
bac6de7b SR	116	static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt,
	117	union smc_cdc_cursor *src,
	118	struct smc_connection *conn)
5f08318f UB	119	{
	120	#ifndef KERNEL_HAS_ATOMIC64
	121	unsigned long flags;
	122
	123	spin_lock_irqsave(&conn->acurs_lock, flags);
bac6de7b	124	tgt->acurs = src->acurs;
5f08318f UB	125	spin_unlock_irqrestore(&conn->acurs_lock, flags);
5f08318f UB	126	#else
bac6de7b	127	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
5f08318f UB	128	#endif
	129	}
	130
b9a22dd9 UB	131	static inline void smcd_curs_copy(union smcd_cdc_cursor *tgt,
	132	union smcd_cdc_cursor *src,
	133	struct smc_connection *conn)
	134	{
	135	#ifndef KERNEL_HAS_ATOMIC64
	136	unsigned long flags;
	137
	138	spin_lock_irqsave(&conn->acurs_lock, flags);
	139	tgt->acurs = src->acurs;
	140	spin_unlock_irqrestore(&conn->acurs_lock, flags);
	141	#else
	142	atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
	143	#endif
	144	}
	145
b8649efa UB	146	/* calculate cursor difference between old and new, where old <= new and
	147	* difference cannot exceed size
	148	*/
5f08318f UB	149	static inline int smc_curs_diff(unsigned int size,
	150	union smc_host_cursor *old,
	151	union smc_host_cursor *new)
	152	{
	153	if (old->wrap != new->wrap)
	154	return max_t(int, 0,
	155	((size - old->count) + new->count));
	156
	157	return max_t(int, 0, (new->count - old->count));
	158	}
	159
de8474eb SR	160	/* calculate cursor difference between old and new - returns negative
	161	* value in case old > new
	162	*/
	163	static inline int smc_curs_comp(unsigned int size,
	164	union smc_host_cursor *old,
	165	union smc_host_cursor *new)
	166	{
	167	if (old->wrap > new->wrap \|\|
	168	(old->wrap == new->wrap && old->count > new->count))
	169	return -smc_curs_diff(size, new, old);
	170	return smc_curs_diff(size, old, new);
	171	}
	172
b8649efa UB	173	/* calculate cursor difference between old and new, where old <= new and
	174	* difference may exceed size
	175	*/
	176	static inline int smc_curs_diff_large(unsigned int size,
	177	union smc_host_cursor *old,
	178	union smc_host_cursor *new)
	179	{
	180	if (old->wrap < new->wrap)
	181	return min_t(int,
	182	(size - old->count) + new->count +
	183	(new->wrap - old->wrap - 1) * size,
	184	size);
	185
	186	if (old->wrap > new->wrap) /* wrap has switched from 0xffff to 0x0000 */
	187	return min_t(int,
	188	(size - old->count) + new->count +
	189	(new->wrap + 0xffff - old->wrap) * size,
	190	size);
	191
	192	return max_t(int, 0, (new->count - old->count));
	193	}
	194
5f08318f UB	195	static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
5f08318f UB	196	union smc_host_cursor *local,
ccc8ca9b	197	union smc_host_cursor *save,
5f08318f UB	198	struct smc_connection *conn)
5f08318f UB	199	{
ccc8ca9b UB	200	smc_curs_copy(save, local, conn);
	201	peer->count = htonl(save->count);
	202	peer->wrap = htons(save->wrap);
5f08318f UB	203	/* peer->reserved = htons(0); must be ensured by caller */
	204	}
	205
	206	static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer,
ccc8ca9b UB	207	struct smc_connection *conn,
ccc8ca9b UB	208	union smc_host_cursor *save)
5f08318f	209	{
ccc8ca9b UB	210	struct smc_host_cdc_msg *local = &conn->local_tx_ctrl;
ccc8ca9b UB	211
5f08318f UB	212	peer->common.type = local->common.type;
	213	peer->len = local->len;
	214	peer->seqno = htons(local->seqno);
	215	peer->token = htonl(local->token);
ccc8ca9b UB	216	smc_host_cursor_to_cdc(&peer->prod, &local->prod, save, conn);
ccc8ca9b UB	217	smc_host_cursor_to_cdc(&peer->cons, &local->cons, save, conn);
5f08318f UB	218	peer->prod_flags = local->prod_flags;
	219	peer->conn_state_flags = local->conn_state_flags;
	220	}
	221
	222	static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local,
	223	union smc_cdc_cursor *peer,
	224	struct smc_connection *conn)
	225	{
	226	union smc_host_cursor temp, old;
	227	union smc_cdc_cursor net;
	228
bac6de7b SR	229	smc_curs_copy(&old, local, conn);
bac6de7b SR	230	smc_curs_copy_net(&net, peer, conn);
5f08318f UB	231	temp.count = ntohl(net.count);
	232	temp.wrap = ntohs(net.wrap);
	233	if ((old.wrap > temp.wrap) && temp.wrap)
	234	return;
	235	if ((old.wrap == temp.wrap) &&
	236	(old.count > temp.count))
	237	return;
bac6de7b	238	smc_curs_copy(local, &temp, conn);
5f08318f UB	239	}
5f08318f UB	240
be244f28 HW	241	static inline void smcr_cdc_msg_to_host(struct smc_host_cdc_msg *local,
	242	struct smc_cdc_msg *peer,
	243	struct smc_connection *conn)
5f08318f UB	244	{
	245	local->common.type = peer->common.type;
	246	local->len = peer->len;
	247	local->seqno = ntohs(peer->seqno);
	248	local->token = ntohl(peer->token);
	249	smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn);
	250	smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn);
	251	local->prod_flags = peer->prod_flags;
	252	local->conn_state_flags = peer->conn_state_flags;
	253	}
	254
be244f28	255	static inline void smcd_cdc_msg_to_host(struct smc_host_cdc_msg *local,
a225d2cd UB	256	struct smcd_cdc_msg *peer,
a225d2cd UB	257	struct smc_connection *conn)
be244f28	258	{
b9a22dd9 UB	259	union smc_host_cursor temp;
	260
	261	temp.wrap = peer->prod.wrap;
	262	temp.count = peer->prod.count;
a225d2cd	263	smc_curs_copy(&local->prod, &temp, conn);
b9a22dd9 UB	264
	265	temp.wrap = peer->cons.wrap;
	266	temp.count = peer->cons.count;
a225d2cd	267	smc_curs_copy(&local->cons, &temp, conn);
b9a22dd9 UB	268	local->prod_flags = peer->cons.prod_flags;
b9a22dd9 UB	269	local->conn_state_flags = peer->cons.conn_state_flags;
be244f28 HW	270	}
	271
	272	static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
	273	struct smc_cdc_msg *peer,
	274	struct smc_connection *conn)
	275	{
	276	if (conn->lgr->is_smcd)
a225d2cd	277	smcd_cdc_msg_to_host(local, (struct smcd_cdc_msg *)peer, conn);
be244f28 HW	278	else
	279	smcr_cdc_msg_to_host(local, peer, conn);
	280	}
	281
ad6f317f UB	282	struct smc_cdc_tx_pend {
	283	struct smc_connection conn; / socket connection */
	284	union smc_host_cursor cursor; /* tx sndbuf cursor sent */
	285	union smc_host_cursor p_cursor; /* rx RMBE cursor produced */
	286	u16 ctrl_seq; /* conn. tx sequence # */
	287	};
5f08318f	288
51957bc5	289	int smc_cdc_get_free_slot(struct smc_connection *conn,
c6f02ebe	290	struct smc_link *link,
51957bc5	291	struct smc_wr_buf **wr_buf,
ad6f317f	292	struct smc_rdma_wr **wr_rdma_buf,
5f08318f UB	293	struct smc_cdc_tx_pend **pend);
	294	void smc_cdc_tx_dismiss_slots(struct smc_connection *conn);
	295	int smc_cdc_msg_send(struct smc_connection conn, struct smc_wr_buf wr_buf,
	296	struct smc_cdc_tx_pend *pend);
	297	int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn);
be244f28	298	int smcd_cdc_msg_send(struct smc_connection *conn);
b8ded9de KG	299	int smcr_cdc_msg_send_validation(struct smc_connection *conn,
	300	struct smc_cdc_tx_pend *pend,
	301	struct smc_wr_buf *wr_buf);
5f08318f	302	int smc_cdc_init(void) __init;
be244f28	303	void smcd_cdc_rx_init(struct smc_connection *conn);
5f08318f UB	304
5f08318f UB	305	#endif /* SMC_CDC_H */