RDS: Use spinlock to protect 64b value update on 32b archs
We have a 64bit value that needs to be set atomically.
This is easy and quick on all 64bit archs, and can also be done
on x86/32 with set_64bit() (uses cmpxchg8b). However other
32b archs don't have this.
I actually changed this to the current state in preparation for
mainline because the old way (using a spinlock on 32b) resulted in
unsightly #ifdefs in the code. But obviously, being correct takes
precedence.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/iw.h b/net/rds/iw.h
index 70eb948..b4fb272 100644
--- a/net/rds/iw.h
+++ b/net/rds/iw.h
@@ -131,7 +131,12 @@
/* sending acks */
unsigned long i_ack_flags;
+#ifdef KERNEL_HAS_ATOMIC64
+ atomic64_t i_ack_next; /* next ACK to send */
+#else
+ spinlock_t i_ack_lock; /* protect i_ack_next */
u64 i_ack_next; /* next ACK to send */
+#endif
struct rds_header *i_ack;
struct ib_send_wr i_ack_wr;
struct ib_sge i_ack_sge;
@@ -391,13 +396,4 @@
return &sge[1];
}
-static inline void rds_iw_set_64bit(u64 *ptr, u64 val)
-{
-#if BITS_PER_LONG == 64
- *ptr = val;
-#else
- set_64bit(ptr, val);
-#endif
-}
-
#endif