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Commit 09433944 authored by Mark Rutland's avatar Mark Rutland Committed by Catalin Marinas
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arm64: percpu: kill off final ACCESS_ONCE() uses 



For several reasons it is preferable to use {READ,WRITE}_ONCE() rather than
ACCESS_ONCE(). For example, these handle aggregate types, result in shorter
source code, and better document the intended access (which may be useful for
instrumentation features such as the upcoming KTSAN).

Over a number of patches, most uses of ACCESS_ONCE() in arch/arm64 have been
migrated to {READ,WRITE}_ONCE(). For consistency, and the above reasons, this
patch migrates the final remaining uses.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 0c2f0afe

arch/arm64/include/asm/percpu.h

+8 −8
Original line number Diff line number Diff line
@@ -101,16 +101,16 @@ static inline unsigned long __percpu_read(void *ptr, int size) 


	switch (size) {

	case 1:

		ret = ACCESS_ONCE(*(u8 *)ptr);

		ret = READ_ONCE(*(u8 *)ptr);

		break;

	case 2:

		ret = ACCESS_ONCE(*(u16 *)ptr);

		ret = READ_ONCE(*(u16 *)ptr);

		break;

	case 4:

		ret = ACCESS_ONCE(*(u32 *)ptr);

		ret = READ_ONCE(*(u32 *)ptr);

		break;

	case 8:

		ret = ACCESS_ONCE(*(u64 *)ptr);

		ret = READ_ONCE(*(u64 *)ptr);

		break;

	default:

		BUILD_BUG();
@@ -123,16 +123,16 @@ static inline void __percpu_write(void *ptr, unsigned long val, int size) 
{

	switch (size) {

	case 1:

		ACCESS_ONCE(*(u8 *)ptr) = (u8)val;

		WRITE_ONCE(*(u8 *)ptr, (u8)val);

		break;

	case 2:

		ACCESS_ONCE(*(u16 *)ptr) = (u16)val;

		WRITE_ONCE(*(u16 *)ptr, (u16)val);

		break;

	case 4:

		ACCESS_ONCE(*(u32 *)ptr) = (u32)val;

		WRITE_ONCE(*(u32 *)ptr, (u32)val);

		break;

	case 8:

		ACCESS_ONCE(*(u64 *)ptr) = (u64)val;

		WRITE_ONCE(*(u64 *)ptr, (u64)val);

		break;

	default:

		BUILD_BUG();