[PATCH] atomic_read: Use ACCESS_ONCE() instead of cast to volatile
From: Pranith Kumar <hidden>
Date: 2014-09-23 14:29:50
Also in:
linux-mips
Subsystem:
alpha port, arm port, arm64 port (aarch64 architecture), atomic infrastructure, generic include/asm header files, m68k architecture, mips, parisc architecture, sparc + ultrasparc (sparc/sparc64), superh, tensilica xtensa port (xtensa), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Russell King, Catalin Marinas, Will Deacon, Peter Zijlstra, Boqun Feng, Arnd Bergmann, Geert Uytterhoeven, Thomas Bogendoerfer, "James E.J. Bottomley", Helge Deller, "David S. Miller", Andreas Larsson, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Chris Zankel, Max Filippov, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Use the much reader friendly ACCESS_ONCE() instead of the cast to volatile. This is purely a style change. Signed-off-by: Pranith Kumar <redacted> --- arch/alpha/include/asm/atomic.h | 4 ++-- arch/arm/include/asm/atomic.h | 2 +- arch/arm64/include/asm/atomic.h | 4 ++-- arch/avr32/include/asm/atomic.h | 2 +- arch/cris/include/asm/atomic.h | 2 +- arch/frv/include/asm/atomic.h | 2 +- arch/ia64/include/asm/atomic.h | 4 ++-- arch/m32r/include/asm/atomic.h | 2 +- arch/m68k/include/asm/atomic.h | 2 +- arch/mips/include/asm/atomic.h | 4 ++-- arch/parisc/include/asm/atomic.h | 4 ++-- arch/sh/include/asm/atomic.h | 2 +- arch/sparc/include/asm/atomic_32.h | 2 +- arch/sparc/include/asm/atomic_64.h | 4 ++-- arch/x86/include/asm/atomic.h | 2 +- arch/x86/include/asm/atomic64_64.h | 2 +- arch/xtensa/include/asm/atomic.h | 2 +- include/asm-generic/atomic.h | 2 +- 18 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
index 6fbb53a..8f8eafb 100644
--- a/arch/alpha/include/asm/atomic.h
+++ b/arch/alpha/include/asm/atomic.h@@ -17,8 +17,8 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) -#define atomic64_read(v) (*(volatile long *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic64_read(v) ACCESS_ONCE((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 832f1cd..e22c119 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h@@ -27,7 +27,7 @@ * 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) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) #if __LINUX_ARM_ARCH__ >= 6
diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h
index b83c325..7047051 100644
--- a/arch/arm64/include/asm/atomic.h
+++ b/arch/arm64/include/asm/atomic.h@@ -35,7 +35,7 @@ * 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) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) /*
@@ -139,7 +139,7 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) */ #define ATOMIC64_INIT(i) { (i) } -#define atomic64_read(v) (*(volatile long *)&(v)->counter) +#define atomic64_read(v) ACCESS_ONCE((v)->counter) #define atomic64_set(v,i) (((v)->counter) = (i)) #define ATOMIC64_OP(op, asm_op) \
diff --git a/arch/avr32/include/asm/atomic.h b/arch/avr32/include/asm/atomic.h
index 83e980a..2d07ce1 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) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v, i) (((v)->counter) = i) #define ATOMIC_OP_RETURN(op, asm_op, asm_con) \
diff --git a/arch/cris/include/asm/atomic.h b/arch/cris/include/asm/atomic.h
index 0033f9d..279766a 100644
--- a/arch/cris/include/asm/atomic.h
+++ b/arch/cris/include/asm/atomic.h@@ -17,7 +17,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((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 f6c3a16..102190a 100644
--- a/arch/frv/include/asm/atomic.h
+++ b/arch/frv/include/asm/atomic.h@@ -31,7 +31,7 @@ */ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v, i) (((v)->counter) = (i)) #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h
index 42919a8..0bf0350 100644
--- a/arch/ia64/include/asm/atomic.h
+++ b/arch/ia64/include/asm/atomic.h@@ -21,8 +21,8 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) -#define atomic64_read(v) (*(volatile long *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic64_read(v) ACCESS_ONCE((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 3946b2c..31bb74a 100644
--- a/arch/m32r/include/asm/atomic.h
+++ b/arch/m32r/include/asm/atomic.h@@ -28,7 +28,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) /** * atomic_set - set atomic variable
diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h
index 663d4ba..e85f047 100644
--- a/arch/m68k/include/asm/atomic.h
+++ b/arch/m68k/include/asm/atomic.h@@ -17,7 +17,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v, i) (((v)->counter) = i) /*
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index f3ee721..6dd6bfc 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) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) /* * atomic_set - set atomic variable
@@ -306,7 +306,7 @@ static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u) * @v: pointer of type atomic64_t * */ -#define atomic64_read(v) (*(volatile long *)&(v)->counter) +#define atomic64_read(v) ACCESS_ONCE((v)->counter) /* * atomic64_set - set atomic variable
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
index 219750b..226f8ca 100644
--- a/arch/parisc/include/asm/atomic.h
+++ b/arch/parisc/include/asm/atomic.h@@ -67,7 +67,7 @@ static __inline__ void atomic_set(atomic_t *v, int i) static __inline__ int atomic_read(const atomic_t *v) { - return (*(volatile int *)&(v)->counter); + return ACCESS_ONCE((v)->counter); } /* exported interface */
@@ -204,7 +204,7 @@ atomic64_set(atomic64_t *v, s64 i) static __inline__ s64 atomic64_read(const atomic64_t *v) { - return (*(volatile long *)&(v)->counter); + return ACCESS_ONCE((v)->counter); } #define atomic64_inc(v) (atomic64_add( 1,(v)))
diff --git a/arch/sh/include/asm/atomic.h b/arch/sh/include/asm/atomic.h
index f57b8a6..05b9f74 100644
--- a/arch/sh/include/asm/atomic.h
+++ b/arch/sh/include/asm/atomic.h@@ -14,7 +14,7 @@ #define ATOMIC_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((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 7b024f0..765c177 100644
--- a/arch/sparc/include/asm/atomic_32.h
+++ b/arch/sparc/include/asm/atomic_32.h@@ -26,7 +26,7 @@ int atomic_cmpxchg(atomic_t *, int, int); int __atomic_add_unless(atomic_t *, int, int); void atomic_set(atomic_t *, int); -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((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 7e4ca1e..4082749 100644
--- a/arch/sparc/include/asm/atomic_64.h
+++ b/arch/sparc/include/asm/atomic_64.h@@ -14,8 +14,8 @@ #define ATOMIC_INIT(i) { (i) } #define ATOMIC64_INIT(i) { (i) } -#define atomic_read(v) (*(volatile int *)&(v)->counter) -#define atomic64_read(v) (*(volatile long *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) +#define atomic64_read(v) ACCESS_ONCE((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 bf20c81..5e5cd12 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h@@ -24,7 +24,7 @@ */ static inline int atomic_read(const atomic_t *v) { - return (*(volatile int *)&(v)->counter); + return ACCESS_ONCE((v)->counter); } /**
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 46e9052..f8d273e 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 (*(volatile long *)&(v)->counter); + return ACCESS_ONCE((v)->counter); } /**
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
index 6266766..00b7d46 100644
--- a/arch/xtensa/include/asm/atomic.h
+++ b/arch/xtensa/include/asm/atomic.h@@ -47,7 +47,7 @@ * * Atomically reads the value of @v. */ -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) /** * atomic_set - set atomic variable
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index 56d4d36..1973ad2 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h@@ -126,7 +126,7 @@ ATOMIC_OP(or, |) * Atomically reads the value of @v. */ #ifndef atomic_read -#define atomic_read(v) (*(volatile int *)&(v)->counter) +#define atomic_read(v) ACCESS_ONCE((v)->counter) #endif /**
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2.1.0