linux/net/smc/smc_cdc.h
Karsten Graul 29bd73dba4 net/smc: send failover validation message
When a connection is switched to a new link then a link validation
message must be sent to the peer over the new link, containing the
sequence number of the last CDC message that was sent over the old link.
The peer will validate if this sequence number is the same or lower then
the number he received, and abort the connection if messages were lost.
Add smcr_cdc_msg_send_validation() to send the message validation
message and call it when a connection was switched in
smc_switch_cursor().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00

321 lines
8.6 KiB
C

/* 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 <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];
};
/* 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;
}
}
/* 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
}
/* 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);
int smc_cdc_init(void) __init;
void smcd_cdc_rx_init(struct smc_connection *conn);
#endif /* SMC_CDC_H */