| Date | Tue, 05 May 2020 15:16:08 +0200 | From | Thomas Gleixner <> | Subject | [patch V4 part 1 06/36] compiler: Simple READ/WRITE_ONCE() implementations |
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READ/WRITE_ONCE_NOCHECK() is required for atomics in code which cannot be instrumented like the x86 int3 text poke code. As READ/WRITE_ONCE() is undergoing a rewrite, provide __{READ,WRITE}_ONCE_SCALAR().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- include/linux/compiler.h | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -313,6 +313,14 @@ unsigned long read_word_at_a_time(const __u.__val; \ }) +#define __READ_ONCE_SCALAR(x) \ + (*(const volatile typeof(x) *)&(x)) + +#define __WRITE_ONCE_SCALAR(x, val) \ +do { \ + *(volatile typeof(x) *)&(x) = val; \ +} while (0) + /** * data_race - mark an expression as containing intentional data races *
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