[PATCH 30/38] Create asm-generic/barrier.h [ver #3]

From: David Howells
Date: Thu Mar 15 2012 - 17:00:09 EST


Create asm-generic/barrier.h and move the barrier definitions from
asm-generic/system.h to it.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
---

include/asm-generic/barrier.h | 50 +++++++++++++++++++++++++++++++++++++++++
include/asm-generic/system.h | 34 +---------------------------
2 files changed, 51 insertions(+), 33 deletions(-)
create mode 100644 include/asm-generic/barrier.h

diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
new file mode 100644
index 0000000..639d7a4
--- /dev/null
+++ b/include/asm-generic/barrier.h
@@ -0,0 +1,50 @@
+/* Generic barrier definitions, based on MN10300 definitions.
+ *
+ * It should be possible to use these on really simple architectures,
+ * but it serves more as a starting point for new ports.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef __ASM_GENERIC_BARRIER_H
+#define __ASM_GENERIC_BARRIER_H
+
+#ifndef __ASSEMBLY__
+
+#define nop() asm volatile ("nop")
+
+/*
+ * Force strict CPU ordering.
+ * And yes, this is required on UP too when we're talking
+ * to devices.
+ *
+ * This implementation only contains a compiler barrier.
+ */
+
+#define mb() asm volatile ("": : :"memory")
+#define rmb() mb()
+#define wmb() asm volatile ("": : :"memory")
+
+#ifdef CONFIG_SMP
+#define smp_mb() mb()
+#define smp_rmb() rmb()
+#define smp_wmb() wmb()
+#else
+#define smp_mb() barrier()
+#define smp_rmb() barrier()
+#define smp_wmb() barrier()
+#endif
+
+#define set_mb(var, value) do { var = value; mb(); } while (0)
+#define set_wmb(var, value) do { var = value; wmb(); } while (0)
+
+#define read_barrier_depends() do {} while (0)
+#define smp_read_barrier_depends() do {} while (0)
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __ASM_GENERIC_BARRIER_H */
diff --git a/include/asm-generic/system.h b/include/asm-generic/system.h
index 82cb53a..f98f693 100644
--- a/include/asm-generic/system.h
+++ b/include/asm-generic/system.h
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <linux/irqflags.h>

+#include <asm/barrier.h>
#include <asm/cmpxchg.h>

struct task_struct;
@@ -33,42 +34,9 @@ extern struct task_struct *__switch_to(struct task_struct *,

#define arch_align_stack(x) (x)

-#define nop() asm volatile ("nop")
-
-#endif /* !__ASSEMBLY__ */
-
-/*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
- *
- * This implementation only contains a compiler barrier.
- */
-
-#define mb() asm volatile ("": : :"memory")
-#define rmb() mb()
-#define wmb() asm volatile ("": : :"memory")
-
-#ifdef CONFIG_SMP
-#define smp_mb() mb()
-#define smp_rmb() rmb()
-#define smp_wmb() wmb()
-#else
-#define smp_mb() barrier()
-#define smp_rmb() barrier()
-#define smp_wmb() barrier()
-#endif
-
-#define set_mb(var, value) do { var = value; mb(); } while (0)
-#define set_wmb(var, value) do { var = value; wmb(); } while (0)
-
-#define read_barrier_depends() do {} while (0)
-#define smp_read_barrier_depends() do {} while (0)
-
/*
* we make sure local_irq_enable() doesn't cause priority inversion
*/
-#ifndef __ASSEMBLY__

/* This function doesn't exist, so you'll get a linker error
* if something tries to do an invalid xchg(). */

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