atomic_t: Cast to volatile when accessing atomic variables

In preparation for removing volatile from the atomic_t definition, this
patch adds a volatile cast to all the atomic read functions.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
index 610dff4..e756d04 100644
--- a/arch/alpha/include/asm/atomic.h
+++ b/arch/alpha/include/asm/atomic.h
@@ -17,8 +17,8 @@
 #define ATOMIC_INIT(i)		( (atomic_t) { (i) } )
 #define ATOMIC64_INIT(i)	( (atomic64_t) { (i) } )
 
-#define atomic_read(v)		((v)->counter + 0)
-#define atomic64_read(v)	((v)->counter + 0)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
+#define atomic64_read(v)	(*(volatile long *)&(v)->counter)
 
 #define atomic_set(v,i)		((v)->counter = (i))
 #define atomic64_set(v,i)	((v)->counter = (i))
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index e8ddec2..a0162fa 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -24,7 +24,7 @@
  * strex/ldrex monitor on some implementations. The reason we can use it for
  * atomic_set() is the clrex or dummy strex done on every exception return.
  */
-#define atomic_read(v)	((v)->counter)
+#define atomic_read(v)	(*(volatile int *)&(v)->counter)
 #define atomic_set(v,i)	(((v)->counter) = (i))
 
 #if __LINUX_ARM_ARCH__ >= 6
diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h
index b131c27..bbce6a1 100644
--- a/arch/avr32/include/asm/atomic.h
+++ b/arch/avr32/include/asm/atomic.h
@@ -19,7 +19,7 @@
 
 #define ATOMIC_INIT(i)  { (i) }
 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v, i)	(((v)->counter) = i)
 
 /*
diff --git a/arch/cris/include/asm/atomic.h b/arch/cris/include/asm/atomic.h
index a6aca81..88dc9b9 100644
--- a/arch/cris/include/asm/atomic.h
+++ b/arch/cris/include/asm/atomic.h
@@ -15,7 +15,7 @@
 
 #define ATOMIC_INIT(i)  { (i) }
 
-#define atomic_read(v) ((v)->counter)
+#define atomic_read(v) (*(volatile int *)&(v)->counter)
 #define atomic_set(v,i) (((v)->counter) = (i))
 
 /* These should be written in asm but we do it in C for now. */
diff --git a/arch/frv/include/asm/atomic.h b/arch/frv/include/asm/atomic.h
index 00a57af..fae32c7 100644
--- a/arch/frv/include/asm/atomic.h
+++ b/arch/frv/include/asm/atomic.h
@@ -36,7 +36,7 @@
 #define smp_mb__after_atomic_inc()	barrier()
 
 #define ATOMIC_INIT(i)		{ (i) }
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v, i)	(((v)->counter) = (i))
 
 #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
diff --git a/arch/h8300/include/asm/atomic.h b/arch/h8300/include/asm/atomic.h
index 33c8c0f..e936804 100644
--- a/arch/h8300/include/asm/atomic.h
+++ b/arch/h8300/include/asm/atomic.h
@@ -10,7 +10,7 @@
 
 #define ATOMIC_INIT(i)	{ (i) }
 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v, i)	(((v)->counter) = i)
 
 #include <asm/system.h>
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h
index 88405cb..4e19484 100644
--- a/arch/ia64/include/asm/atomic.h
+++ b/arch/ia64/include/asm/atomic.h
@@ -21,8 +21,8 @@
 #define ATOMIC_INIT(i)		((atomic_t) { (i) })
 #define ATOMIC64_INIT(i)	((atomic64_t) { (i) })
 
-#define atomic_read(v)		((v)->counter)
-#define atomic64_read(v)	((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
+#define atomic64_read(v)	(*(volatile long *)&(v)->counter)
 
 #define atomic_set(v,i)		(((v)->counter) = (i))
 #define atomic64_set(v,i)	(((v)->counter) = (i))
diff --git a/arch/m32r/include/asm/atomic.h b/arch/m32r/include/asm/atomic.h
index 63f0cf0..d44a51e 100644
--- a/arch/m32r/include/asm/atomic.h
+++ b/arch/m32r/include/asm/atomic.h
@@ -26,7 +26,7 @@
  *
  * Atomically reads the value of @v.
  */
-#define atomic_read(v)	((v)->counter)
+#define atomic_read(v)	(*(volatile int *)&(v)->counter)
 
 /**
  * atomic_set - set atomic variable
diff --git a/arch/m68k/include/asm/atomic_mm.h b/arch/m68k/include/asm/atomic_mm.h
index d9d2ed6..6a223b3 100644
--- a/arch/m68k/include/asm/atomic_mm.h
+++ b/arch/m68k/include/asm/atomic_mm.h
@@ -15,7 +15,7 @@
 
 #define ATOMIC_INIT(i)	{ (i) }
 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v, i)	(((v)->counter) = i)
 
 static inline void atomic_add(int i, atomic_t *v)
diff --git a/arch/m68k/include/asm/atomic_no.h b/arch/m68k/include/asm/atomic_no.h
index 5674cb9..289310c 100644
--- a/arch/m68k/include/asm/atomic_no.h
+++ b/arch/m68k/include/asm/atomic_no.h
@@ -15,7 +15,7 @@
 
 #define ATOMIC_INIT(i)	{ (i) }
 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v, i)	(((v)->counter) = i)
 
 static __inline__ void atomic_add(int i, atomic_t *v)
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index 519197e..59dc0c7 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -29,7 +29,7 @@
  *
  * Atomically reads the value of @v.
  */
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 
 /*
  * atomic_set - set atomic variable
@@ -410,7 +410,7 @@
  * @v: pointer of type atomic64_t
  *
  */
-#define atomic64_read(v)	((v)->counter)
+#define atomic64_read(v)	(*(volatile long *)&(v)->counter)
 
 /*
  * atomic64_set - set atomic variable
diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h
index 5bf5be9..e41222d 100644
--- a/arch/mn10300/include/asm/atomic.h
+++ b/arch/mn10300/include/asm/atomic.h
@@ -31,7 +31,7 @@
  * Atomically reads the value of @v.  Note that the guaranteed
  * useful range of an atomic_t is only 24 bits.
  */
-#define atomic_read(v)	((v)->counter)
+#define atomic_read(v)	(*(volatile int *)&(v)->counter)
 
 /**
  * atomic_set - set atomic variable
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
index 716634d..f819559 100644
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h
@@ -189,7 +189,7 @@
 
 static __inline__ int atomic_read(const atomic_t *v)
 {
-	return v->counter;
+	return (*(volatile int *)&(v)->counter);
 }
 
 /* exported interface */
@@ -286,7 +286,7 @@
 static __inline__ s64
 atomic64_read(const atomic64_t *v)
 {
-	return v->counter;
+	return (*(volatile long *)&(v)->counter);
 }
 
 #define atomic64_add(i,v)	((void)(__atomic64_add_return( ((s64)(i)),(v))))
diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h
index 275a448..c798312 100644
--- a/arch/sh/include/asm/atomic.h
+++ b/arch/sh/include/asm/atomic.h
@@ -13,7 +13,7 @@
 
 #define ATOMIC_INIT(i)	( (atomic_t) { (i) } )
 
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 #define atomic_set(v,i)		((v)->counter = (i))
 
 #if defined(CONFIG_GUSA_RB)
diff --git a/arch/sparc/include/asm/atomic_32.h b/arch/sparc/include/asm/atomic_32.h
index f0d343c..7ae128b 100644
--- a/arch/sparc/include/asm/atomic_32.h
+++ b/arch/sparc/include/asm/atomic_32.h
@@ -25,7 +25,7 @@
 extern int atomic_add_unless(atomic_t *, int, int);
 extern void atomic_set(atomic_t *, int);
 
-#define atomic_read(v)          ((v)->counter)
+#define atomic_read(v)          (*(volatile int *)&(v)->counter)
 
 #define atomic_add(i, v)	((void)__atomic_add_return( (int)(i), (v)))
 #define atomic_sub(i, v)	((void)__atomic_add_return(-(int)(i), (v)))
diff --git a/arch/sparc/include/asm/atomic_64.h b/arch/sparc/include/asm/atomic_64.h
index f2e4800..2050ca0 100644
--- a/arch/sparc/include/asm/atomic_64.h
+++ b/arch/sparc/include/asm/atomic_64.h
@@ -13,8 +13,8 @@
 #define ATOMIC_INIT(i)		{ (i) }
 #define ATOMIC64_INIT(i)	{ (i) }
 
-#define atomic_read(v)		((v)->counter)
-#define atomic64_read(v)	((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
+#define atomic64_read(v)	(*(volatile long *)&(v)->counter)
 
 #define atomic_set(v, i)	(((v)->counter) = i)
 #define atomic64_set(v, i)	(((v)->counter) = i)
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index 8f8217b..37b39d2 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -22,7 +22,7 @@
  */
 static inline int atomic_read(const atomic_t *v)
 {
-	return v->counter;
+	return (*(volatile int *)&(v)->counter);
 }
 
 /**
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 51c5b40..b014e23 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -18,7 +18,7 @@
  */
 static inline long atomic64_read(const atomic64_t *v)
 {
-	return v->counter;
+	return (*(volatile long *)&(v)->counter);
 }
 
 /**
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
index 22d6dde..a96a061 100644
--- a/arch/xtensa/include/asm/atomic.h
+++ b/arch/xtensa/include/asm/atomic.h
@@ -46,7 +46,7 @@
  *
  * Atomically reads the value of @v.
  */
-#define atomic_read(v)		((v)->counter)
+#define atomic_read(v)		(*(volatile int *)&(v)->counter)
 
 /**
  * atomic_set - set atomic variable