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-rw-r--r--net/smc/smc_llc.c158
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;
+}