smc: connection data control (CDC)
send and receive CDC messages (via IB message send and CQE)
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h
new file mode 100644
index 0000000..135f613
--- /dev/null
+++ b/net/smc/smc_cdc.h
@@ -0,0 +1,217 @@
+/*
+ * 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);
+int smc_cdc_init(void) __init;
+
+#endif /* SMC_CDC_H */