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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-01-14 11:54:12 +1300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-01-14 11:54:12 +1300 |
commit | 0c133dd00ed84aefc41af2cc70e6560a61c95c89 (patch) | |
tree | 542e5cdcc9b2adec9fcf182185e87dc556bfae7d | |
parent | e7a823be2adc2c8617bead1376194a399143e4ed (diff) | |
parent | 43239cbe79fc369f5d2160bd7f69e28b5c50a58c (diff) | |
download | linux-0c133dd00ed84aefc41af2cc70e6560a61c95c89.tar.bz2 |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux
Pull WRITE_ONCE argument order change from Christian Borntraeger:
"As discussed on LKML[1] it was agreed that WRITE_ONCE(x, val) is
better than ASSIGN_ONCE(val, x)
Lets change that for 3.19 as 3.19 has no user yet, but the first users
will hit linux-next soon"
[1] http://marc.info/?l=linux-kernel&m=142081181707596
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux:
kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)
-rw-r--r-- | include/linux/compiler.h | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index a1c81f80978e..33063f872ee3 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -215,7 +215,7 @@ static __always_inline void __read_once_size(volatile void *p, void *res, int si } } -static __always_inline void __assign_once_size(volatile void *p, void *res, int size) +static __always_inline void __write_once_size(volatile void *p, void *res, int size) { switch (size) { case 1: *(volatile __u8 *)p = *(__u8 *)res; break; @@ -235,15 +235,15 @@ static __always_inline void __assign_once_size(volatile void *p, void *res, int /* * Prevent the compiler from merging or refetching reads or writes. The * compiler is also forbidden from reordering successive instances of - * READ_ONCE, ASSIGN_ONCE and ACCESS_ONCE (see below), but only when the + * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the * compiler is aware of some particular ordering. One way to make the * compiler aware of ordering is to put the two invocations of READ_ONCE, - * ASSIGN_ONCE or ACCESS_ONCE() in different C statements. + * WRITE_ONCE or ACCESS_ONCE() in different C statements. * * In contrast to ACCESS_ONCE these two macros will also work on aggregate * data types like structs or unions. If the size of the accessed data * type exceeds the word size of the machine (e.g., 32 bits or 64 bits) - * READ_ONCE() and ASSIGN_ONCE() will fall back to memcpy and print a + * READ_ONCE() and WRITE_ONCE() will fall back to memcpy and print a * compile-time warning. * * Their two major use cases are: (1) Mediating communication between @@ -257,8 +257,8 @@ static __always_inline void __assign_once_size(volatile void *p, void *res, int #define READ_ONCE(x) \ ({ typeof(x) __val; __read_once_size(&x, &__val, sizeof(__val)); __val; }) -#define ASSIGN_ONCE(val, x) \ - ({ typeof(x) __val; __val = val; __assign_once_size(&x, &__val, sizeof(__val)); __val; }) +#define WRITE_ONCE(x, val) \ + ({ typeof(x) __val; __val = val; __write_once_size(&x, &__val, sizeof(__val)); __val; }) #endif /* __KERNEL__ */ |