diff options
Diffstat (limited to 'net/smc/smc_cdc.h')
| -rw-r--r-- | net/smc/smc_cdc.h | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h new file mode 100644 index 000000000..696cc11f2 --- /dev/null +++ b/net/smc/smc_cdc.h @@ -0,0 +1,305 @@ +/* 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; + } +} + +/* 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_wait_pend_tx_wr(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 */ |