318 lines
8.5 KiB
C
318 lines
8.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Shared Memory Communications over RDMA (SMC-R) and RoCE
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*
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* Connection Data Control (CDC)
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*
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* Copyright IBM Corp. 2016
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*
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* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
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*/
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#ifndef SMC_CDC_H
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#define SMC_CDC_H
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#include <linux/kernel.h> /* max_t */
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#include <linux/atomic.h>
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#include <linux/in.h>
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#include <linux/compiler.h>
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#include "smc.h"
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#include "smc_core.h"
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#include "smc_wr.h"
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#define SMC_CDC_MSG_TYPE 0xFE
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/* in network byte order */
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union smc_cdc_cursor { /* SMC cursor */
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struct {
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__be16 reserved;
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__be16 wrap;
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__be32 count;
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};
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#ifdef KERNEL_HAS_ATOMIC64
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atomic64_t acurs; /* for atomic processing */
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#else
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u64 acurs; /* for atomic processing */
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#endif
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} __aligned(8);
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/* in network byte order */
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struct smc_cdc_msg {
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struct smc_wr_rx_hdr common; /* .type = 0xFE */
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u8 len; /* 44 */
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__be16 seqno;
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__be32 token;
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union smc_cdc_cursor prod;
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union smc_cdc_cursor cons; /* piggy backed "ack" */
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struct smc_cdc_producer_flags prod_flags;
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struct smc_cdc_conn_state_flags conn_state_flags;
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u8 reserved[18];
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};
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/* SMC-D cursor format */
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union smcd_cdc_cursor {
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struct {
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u16 wrap;
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u32 count;
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struct smc_cdc_producer_flags prod_flags;
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struct smc_cdc_conn_state_flags conn_state_flags;
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} __packed;
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#ifdef KERNEL_HAS_ATOMIC64
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atomic64_t acurs; /* for atomic processing */
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#else
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u64 acurs; /* for atomic processing */
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#endif
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} __aligned(8);
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/* CDC message for SMC-D */
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struct smcd_cdc_msg {
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struct smc_wr_rx_hdr common; /* Type = 0xFE */
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u8 res1[7];
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union smcd_cdc_cursor prod;
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union smcd_cdc_cursor cons;
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u8 res3[8];
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} __aligned(8);
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static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn)
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{
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return conn->local_rx_ctrl.conn_state_flags.peer_conn_abort ||
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conn->local_rx_ctrl.conn_state_flags.peer_conn_closed;
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}
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static inline bool smc_cdc_rxed_any_close_or_senddone(
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struct smc_connection *conn)
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{
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return smc_cdc_rxed_any_close(conn) ||
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conn->local_rx_ctrl.conn_state_flags.peer_done_writing;
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}
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static inline void smc_curs_add(int size, union smc_host_cursor *curs,
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int value)
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{
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curs->count += value;
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if (curs->count >= size) {
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curs->wrap++;
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curs->count -= size;
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}
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}
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/* SMC cursors are 8 bytes long and require atomic reading and writing */
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static inline u64 smc_curs_read(union smc_host_cursor *curs,
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struct smc_connection *conn)
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{
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#ifndef KERNEL_HAS_ATOMIC64
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unsigned long flags;
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u64 ret;
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spin_lock_irqsave(&conn->acurs_lock, flags);
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ret = curs->acurs;
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spin_unlock_irqrestore(&conn->acurs_lock, flags);
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return ret;
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#else
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return atomic64_read(&curs->acurs);
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#endif
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}
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/* Copy cursor src into tgt */
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static inline void smc_curs_copy(union smc_host_cursor *tgt,
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union smc_host_cursor *src,
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struct smc_connection *conn)
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{
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#ifndef KERNEL_HAS_ATOMIC64
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unsigned long flags;
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spin_lock_irqsave(&conn->acurs_lock, flags);
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tgt->acurs = src->acurs;
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spin_unlock_irqrestore(&conn->acurs_lock, flags);
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#else
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atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
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#endif
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}
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static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt,
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union smc_cdc_cursor *src,
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struct smc_connection *conn)
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{
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#ifndef KERNEL_HAS_ATOMIC64
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unsigned long flags;
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spin_lock_irqsave(&conn->acurs_lock, flags);
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tgt->acurs = src->acurs;
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spin_unlock_irqrestore(&conn->acurs_lock, flags);
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#else
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atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
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#endif
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}
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static inline void smcd_curs_copy(union smcd_cdc_cursor *tgt,
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union smcd_cdc_cursor *src,
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struct smc_connection *conn)
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{
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#ifndef KERNEL_HAS_ATOMIC64
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unsigned long flags;
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spin_lock_irqsave(&conn->acurs_lock, flags);
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tgt->acurs = src->acurs;
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spin_unlock_irqrestore(&conn->acurs_lock, flags);
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#else
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atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
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#endif
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}
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/* calculate cursor difference between old and new, where old <= new and
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* difference cannot exceed size
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*/
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static inline int smc_curs_diff(unsigned int size,
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union smc_host_cursor *old,
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union smc_host_cursor *new)
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{
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if (old->wrap != new->wrap)
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return max_t(int, 0,
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((size - old->count) + new->count));
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return max_t(int, 0, (new->count - old->count));
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}
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/* calculate cursor difference between old and new - returns negative
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* value in case old > new
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*/
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static inline int smc_curs_comp(unsigned int size,
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union smc_host_cursor *old,
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union smc_host_cursor *new)
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{
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if (old->wrap > new->wrap ||
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(old->wrap == new->wrap && old->count > new->count))
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return -smc_curs_diff(size, new, old);
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return smc_curs_diff(size, old, new);
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}
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/* calculate cursor difference between old and new, where old <= new and
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* difference may exceed size
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*/
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static inline int smc_curs_diff_large(unsigned int size,
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union smc_host_cursor *old,
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union smc_host_cursor *new)
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{
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if (old->wrap < new->wrap)
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return min_t(int,
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(size - old->count) + new->count +
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(new->wrap - old->wrap - 1) * size,
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size);
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if (old->wrap > new->wrap) /* wrap has switched from 0xffff to 0x0000 */
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return min_t(int,
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(size - old->count) + new->count +
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(new->wrap + 0xffff - old->wrap) * size,
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size);
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return max_t(int, 0, (new->count - old->count));
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}
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static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
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union smc_host_cursor *local,
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union smc_host_cursor *save,
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struct smc_connection *conn)
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{
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smc_curs_copy(save, local, conn);
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peer->count = htonl(save->count);
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peer->wrap = htons(save->wrap);
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/* peer->reserved = htons(0); must be ensured by caller */
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}
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static inline void smc_host_msg_to_cdc(struct smc_cdc_msg *peer,
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struct smc_connection *conn,
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union smc_host_cursor *save)
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{
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struct smc_host_cdc_msg *local = &conn->local_tx_ctrl;
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peer->common.type = local->common.type;
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peer->len = local->len;
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peer->seqno = htons(local->seqno);
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peer->token = htonl(local->token);
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smc_host_cursor_to_cdc(&peer->prod, &local->prod, save, conn);
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smc_host_cursor_to_cdc(&peer->cons, &local->cons, save, conn);
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peer->prod_flags = local->prod_flags;
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peer->conn_state_flags = local->conn_state_flags;
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}
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static inline void smc_cdc_cursor_to_host(union smc_host_cursor *local,
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union smc_cdc_cursor *peer,
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struct smc_connection *conn)
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{
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union smc_host_cursor temp, old;
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union smc_cdc_cursor net;
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smc_curs_copy(&old, local, conn);
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smc_curs_copy_net(&net, peer, conn);
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temp.count = ntohl(net.count);
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temp.wrap = ntohs(net.wrap);
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if ((old.wrap > temp.wrap) && temp.wrap)
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return;
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if ((old.wrap == temp.wrap) &&
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(old.count > temp.count))
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return;
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smc_curs_copy(local, &temp, conn);
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}
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static inline void smcr_cdc_msg_to_host(struct smc_host_cdc_msg *local,
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struct smc_cdc_msg *peer,
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struct smc_connection *conn)
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{
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local->common.type = peer->common.type;
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local->len = peer->len;
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local->seqno = ntohs(peer->seqno);
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local->token = ntohl(peer->token);
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smc_cdc_cursor_to_host(&local->prod, &peer->prod, conn);
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smc_cdc_cursor_to_host(&local->cons, &peer->cons, conn);
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local->prod_flags = peer->prod_flags;
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local->conn_state_flags = peer->conn_state_flags;
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}
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static inline void smcd_cdc_msg_to_host(struct smc_host_cdc_msg *local,
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struct smcd_cdc_msg *peer)
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{
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union smc_host_cursor temp;
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temp.wrap = peer->prod.wrap;
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temp.count = peer->prod.count;
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atomic64_set(&local->prod.acurs, atomic64_read(&temp.acurs));
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temp.wrap = peer->cons.wrap;
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temp.count = peer->cons.count;
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atomic64_set(&local->cons.acurs, atomic64_read(&temp.acurs));
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local->prod_flags = peer->cons.prod_flags;
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local->conn_state_flags = peer->cons.conn_state_flags;
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}
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static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
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struct smc_cdc_msg *peer,
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struct smc_connection *conn)
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{
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if (conn->lgr->is_smcd)
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smcd_cdc_msg_to_host(local, (struct smcd_cdc_msg *)peer);
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else
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smcr_cdc_msg_to_host(local, peer, conn);
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}
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struct smc_cdc_tx_pend {
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struct smc_connection *conn; /* socket connection */
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union smc_host_cursor cursor; /* tx sndbuf cursor sent */
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union smc_host_cursor p_cursor; /* rx RMBE cursor produced */
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u16 ctrl_seq; /* conn. tx sequence # */
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};
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int smc_cdc_get_free_slot(struct smc_connection *conn,
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struct smc_wr_buf **wr_buf,
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struct smc_rdma_wr **wr_rdma_buf,
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struct smc_cdc_tx_pend **pend);
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void smc_cdc_tx_dismiss_slots(struct smc_connection *conn);
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int smc_cdc_msg_send(struct smc_connection *conn, struct smc_wr_buf *wr_buf,
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struct smc_cdc_tx_pend *pend);
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int smc_cdc_get_slot_and_msg_send(struct smc_connection *conn);
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int smcd_cdc_msg_send(struct smc_connection *conn);
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int smc_cdc_init(void) __init;
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void smcd_cdc_rx_init(struct smc_connection *conn);
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#endif /* SMC_CDC_H */
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