net/smc: atomic SMCD cursor handling

[sfrench/cifs-2.6.git] / net / smc / smc_cdc.h

diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h
index 934df4473a7cebc4f2cb4fa654d7189201745ac2..b5bfe38c7f9b6a87258adc0aecce58c31c2a164a 100644 (file)
--- a/net/smc/smc_cdc.h
+++ b/net/smc/smc_cdc.h
@@ -48,21 +48,31 @@ struct smc_cdc_msg {
        struct smc_cdc_producer_flags   prod_flags;
        struct smc_cdc_conn_state_flags conn_state_flags;
        u8                              reserved[18];
-} __packed;                                    /* format defined in RFC7609 */
+};
+
+/* SMC-D cursor format */
+union smcd_cdc_cursor {
+       struct {
+               u16     wrap;
+               u32     count;
+               struct smc_cdc_producer_flags   prod_flags;
+               struct smc_cdc_conn_state_flags conn_state_flags;
+       } __packed;
+#ifdef KERNEL_HAS_ATOMIC64
+       atomic64_t              acurs;          /* for atomic processing */
+#else
+       u64                     acurs;          /* for atomic processing */
+#endif
+} __aligned(8);
 
 /* 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;
+       union smcd_cdc_cursor   prod;
+       union smcd_cdc_cursor   cons;
        u8 res3[8];
-} __packed;
+} __aligned(8);
 
 static inline bool smc_cdc_rxed_any_close(struct smc_connection *conn)
 {
@@ -135,6 +145,21 @@ static inline void smc_curs_copy_net(union smc_cdc_cursor *tgt,
 #endif
 }
 
+static inline void smcd_curs_copy(union smcd_cdc_cursor *tgt,
+                                 union smcd_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 */
 static inline int smc_curs_diff(unsigned int size,
                                union smc_host_cursor *old,
@@ -222,12 +247,17 @@ static inline void smcr_cdc_msg_to_host(struct smc_host_cdc_msg *local,
 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;
+       union smc_host_cursor temp;
+
+       temp.wrap = peer->prod.wrap;
+       temp.count = peer->prod.count;
+       atomic64_set(&local->prod.acurs, atomic64_read(&temp.acurs));
+
+       temp.wrap = peer->cons.wrap;
+       temp.count = peer->cons.count;
+       atomic64_set(&local->cons.acurs, atomic64_read(&temp.acurs));
+       local->prod_flags = peer->cons.prod_flags;
+       local->conn_state_flags = peer->cons.conn_state_flags;
 }
 
 static inline void smc_cdc_msg_to_host(struct smc_host_cdc_msg *local,