diff options
Diffstat (limited to 'net/smc/smc_llc.c')
| -rw-r--r-- | net/smc/smc_llc.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c new file mode 100644 index 000000000000..c2f9165d13ef --- /dev/null +++ b/net/smc/smc_llc.c @@ -0,0 +1,158 @@ +/* + * 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 <Klaus.Wacker@de.ibm.com> + * Ursula Braun <ubraun@linux.vnet.ibm.com> + */ + +#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 */ +} + +/** + * 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; +} + +/* 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; +} + +/********************************* 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); + } + } +} + +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); +} + +/***************************** 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; +} |