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Release 4.14 net/smc/smc_llc.c

Directory: net/smc
// SPDX-License-Identifier: GPL-2.0
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *  Link Layer Control (LLC)
 *  For now, we only support the necessary "confirm link" functionality
 *  which happens for the first RoCE link after successful CLC handshake.
 *  Copyright IBM Corp. 2016
 *  Author(s):  Klaus Wacker <>
 *              Ursula Braun <>

#include <net/tcp.h>
#include <rdma/ib_verbs.h>

#include "smc.h"
#include "smc_core.h"
#include "smc_clc.h"
#include "smc_llc.h"

/********************************** send *************************************/

struct smc_llc_tx_pend {

/* handler for send/transmission completion of an LLC msg */

static void smc_llc_tx_handler(struct smc_wr_tx_pend_priv *pend, struct smc_link *link, enum ib_wc_status wc_status) { /* future work: handle wc_status error for recovery and failover */ }


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/** * smc_llc_add_pending_send() - add LLC control message to pending WQE transmits * @link: Pointer to SMC link used for sending LLC control message. * @wr_buf: Out variable returning pointer to work request payload buffer. * @pend: Out variable returning pointer to private pending WR tracking. * It's the context the transmit complete handler will get. * * Reserves and pre-fills an entry for a pending work request send/tx. * Used by mid-level smc_llc_send_msg() to prepare for later actual send/tx. * Can sleep due to smc_get_ctrl_buf (if not in softirq context). * * Return: 0 on success, otherwise an error value. */
static int smc_llc_add_pending_send(struct smc_link *link, struct smc_wr_buf **wr_buf, struct smc_wr_tx_pend_priv **pend) { int rc; rc = smc_wr_tx_get_free_slot(link, smc_llc_tx_handler, wr_buf, pend); if (rc < 0) return rc; BUILD_BUG_ON_MSG( sizeof(union smc_llc_msg) > SMC_WR_BUF_SIZE, "must increase SMC_WR_BUF_SIZE to at least sizeof(struct smc_llc_msg)"); BUILD_BUG_ON_MSG( sizeof(union smc_llc_msg) != SMC_WR_TX_SIZE, "must adapt SMC_WR_TX_SIZE to sizeof(struct smc_llc_msg); if not all smc_wr upper layer protocols use the same message size any more, must start to set link->wr_tx_sges[i].length on each individual smc_wr_tx_send()"); BUILD_BUG_ON_MSG( sizeof(struct smc_llc_tx_pend) > SMC_WR_TX_PEND_PRIV_SIZE, "must increase SMC_WR_TX_PEND_PRIV_SIZE to at least sizeof(struct smc_llc_tx_pend)"); return 0; }


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/* high-level API to send LLC confirm link */
int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[], union ib_gid *gid, enum smc_llc_reqresp reqresp) { struct smc_link_group *lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]); struct smc_llc_msg_confirm_link *confllc; struct smc_wr_tx_pend_priv *pend; struct smc_wr_buf *wr_buf; int rc; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) return rc; confllc = (struct smc_llc_msg_confirm_link *)wr_buf; memset(confllc, 0, sizeof(*confllc)); confllc->hd.common.type = SMC_LLC_CONFIRM_LINK; confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link); if (reqresp == SMC_LLC_RESP) confllc->hd.flags |= SMC_LLC_FLAG_RESP; memcpy(confllc->sender_mac, mac, ETH_ALEN); memcpy(confllc->sender_gid, gid, SMC_GID_SIZE); hton24(confllc->sender_qp_num, link->roce_qp->qp_num); /* confllc->link_num = SMC_SINGLE_LINK; already done by memset above */ memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE); confllc->max_links = SMC_LINKS_PER_LGR_MAX; /* send llc message */ rc = smc_wr_tx_send(link, pend); return rc; }


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/********************************* receive ***********************************/
static void smc_llc_rx_confirm_link(struct smc_link *link, struct smc_llc_msg_confirm_link *llc) { struct smc_link_group *lgr; lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]); if (llc->hd.flags & SMC_LLC_FLAG_RESP) { if (lgr->role == SMC_SERV) complete(&link->llc_confirm_resp); } else { if (lgr->role == SMC_CLNT) { link->link_id = llc->link_num; complete(&link->llc_confirm); } } }


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static void smc_llc_rx_handler(struct ib_wc *wc, void *buf) { struct smc_link *link = (struct smc_link *)wc->qp->qp_context; union smc_llc_msg *llc = buf; if (wc->byte_len < sizeof(*llc)) return; /* short message */ if (llc->raw.hdr.length != sizeof(*llc)) return; /* invalid message */ if (llc->raw.hdr.common.type == SMC_LLC_CONFIRM_LINK) smc_llc_rx_confirm_link(link, &llc->confirm_link); }


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/***************************** init, exit, misc ******************************/ static struct smc_wr_rx_handler smc_llc_rx_handlers[] = { { .handler = smc_llc_rx_handler, .type = SMC_LLC_CONFIRM_LINK }, { .handler = NULL, } };
int __init smc_llc_init(void) { struct smc_wr_rx_handler *handler; int rc = 0; for (handler = smc_llc_rx_handlers; handler->handler; handler++) { INIT_HLIST_NODE(&handler->list); rc = smc_wr_rx_register_handler(handler); if (rc) break; } return rc; }


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Overall Contributors

Ursula Braun61599.84%150.00%
Greg Kroah-Hartman10.16%150.00%
Directory: net/smc
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