diff options
Diffstat (limited to 'net/smc/smc_cdc.h')
| -rw-r--r-- | net/smc/smc_cdc.h | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h new file mode 100644 index 000000000000..8e1d76f26007 --- /dev/null +++ b/net/smc/smc_cdc.h @@ -0,0 +1,218 @@ +/* + * 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 */ |