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-rw-r--r--net/smc/smc_cdc.h281
1 files changed, 281 insertions, 0 deletions
diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h
new file mode 100644
index 000000000..34d2e1450
--- /dev/null
+++ b/net/smc/smc_cdc.h
@@ -0,0 +1,281 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * 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];
+} __packed; /* format defined in RFC7609 */
+
+/* CDC message for SMC-D */
+struct smcd_cdc_msg {
+ struct smc_wr_rx_hdr common; /* Type = 0xFE */
+ u8 res1[7];
+ u16 prod_wrap;
+ u32 prod_count;
+ u8 res2[2];
+ u16 cons_wrap;
+ u32 cons_count;
+ struct smc_cdc_producer_flags prod_flags;
+ struct smc_cdc_conn_state_flags conn_state_flags;
+ u8 res3[8];
+} __packed;
+
+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
+}
+
+/* Copy cursor src into tgt */
+static inline void smc_curs_copy(union smc_host_cursor *tgt,
+ union smc_host_cursor *src,
+ struct smc_connection *conn)
+{
+#ifndef KERNEL_HAS_ATOMIC64
+ unsigned long flags;
+
+ spin_lock_irqsave(&conn->acurs_lock, flags);
+ tgt->acurs = src->acurs;
+ spin_unlock_irqrestore(&conn->acurs_lock, flags);
+#else
+ atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
+#endif
+}
+
+static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt,
+ union smc_cdc_cursor *src,
+ struct smc_connection *conn)
+{
+#ifndef KERNEL_HAS_ATOMIC64
+ unsigned long flags;
+
+ spin_lock_irqsave(&conn->acurs_lock, flags);
+ tgt->acurs = src->acurs;
+ spin_unlock_irqrestore(&conn->acurs_lock, flags);
+#else
+ atomic64_set(&tgt->acurs, atomic64_read(&src->acurs));
+#endif
+}
+
+/* calculate cursor difference between old and new, where old <= new and
+ * difference cannot exceed size
+ */
+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));
+}
+
+/* calculate cursor difference between old and new - returns negative
+ * value in case old > new
+ */
+static inline int smc_curs_comp(unsigned int size,
+ union smc_host_cursor *old,
+ union smc_host_cursor *new)
+{
+ if (old->wrap > new->wrap ||
+ (old->wrap == new->wrap && old->count > new->count))
+ return -smc_curs_diff(size, new, old);
+ return smc_curs_diff(size, old, new);
+}
+
+/* calculate cursor difference between old and new, where old <= new and
+ * difference may exceed size
+ */
+static inline int smc_curs_diff_large(unsigned int size,
+ union smc_host_cursor *old,
+ union smc_host_cursor *new)
+{
+ if (old->wrap < new->wrap)
+ return min_t(int,
+ (size - old->count) + new->count +
+ (new->wrap - old->wrap - 1) * size,
+ size);
+
+ if (old->wrap > new->wrap) /* wrap has switched from 0xffff to 0x0000 */
+ return min_t(int,
+ (size - old->count) + new->count +
+ (new->wrap + 0xffff - old->wrap) * size,
+ size);
+
+ 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,
+ union smc_host_cursor *save,
+ struct smc_connection *conn)
+{
+ smc_curs_copy(save, local, conn);
+ peer->count = htonl(save->count);
+ peer->wrap = htons(save->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_connection *conn,
+ union smc_host_cursor *save)
+{
+ struct smc_host_cdc_msg *local = &conn->local_tx_ctrl;
+
+ 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, save, conn);
+ smc_host_cursor_to_cdc(&peer->cons, &local->cons, save, 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_copy(&old, local, conn);
+ smc_curs_copy_net(&net, peer, 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_copy(local, &temp, conn);
+}
+
+static inline void smcr_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;
+}
+
+static inline void smcd_cdc_msg_to_host(struct smc_host_cdc_msg *local,
+ struct smcd_cdc_msg *peer)
+{
+ local->prod.wrap = peer->prod_wrap;
+ local->prod.count = peer->prod_count;
+ local->cons.wrap = peer->cons_wrap;
+ local->cons.count = peer->cons_count;
+ local->prod_flags = peer->prod_flags;
+ local->conn_state_flags = peer->conn_state_flags;
+}
+
+static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,
+ struct smc_cdc_msg *peer,
+ struct smc_connection *conn)
+{
+ if (conn->lgr->is_smcd)
+ smcd_cdc_msg_to_host(local, (struct smcd_cdc_msg *)peer);
+ else
+ smcr_cdc_msg_to_host(local, peer, conn);
+}
+
+struct smc_cdc_tx_pend;
+
+int smc_cdc_get_free_slot(struct smc_connection *conn,
+ 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 smcd_cdc_msg_send(struct smc_connection *conn);
+int smc_cdc_init(void) __init;
+void smcd_cdc_rx_init(struct smc_connection *conn);
+
+#endif /* SMC_CDC_H */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 15:45:57 +0000