diff options
Diffstat (limited to 'include/linux/cache.h')
| -rw-r--r-- | include/linux/cache.h | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/include/linux/cache.h b/include/linux/cache.h index 0ecb17bb6883..ca2a05682a54 100644 --- a/include/linux/cache.h +++ b/include/linux/cache.h @@ -13,6 +13,32 @@ #define SMP_CACHE_BYTES L1_CACHE_BYTES #endif +/** + * SMP_CACHE_ALIGN - align a value to the L2 cacheline size + * @x: value to align + * + * On some architectures, L2 ("SMP") CL size is bigger than L1, and sometimes, + * this needs to be accounted. + * + * Return: aligned value. + */ +#ifndef SMP_CACHE_ALIGN +#define SMP_CACHE_ALIGN(x) ALIGN(x, SMP_CACHE_BYTES) +#endif + +/* + * ``__aligned_largest`` aligns a field to the value most optimal for the + * target architecture to perform memory operations. Get the actual value + * to be able to use it anywhere else. + */ +#ifndef __LARGEST_ALIGN +#define __LARGEST_ALIGN sizeof(struct { long x; } __aligned_largest) +#endif + +#ifndef LARGEST_ALIGN +#define LARGEST_ALIGN(x) ALIGN(x, __LARGEST_ALIGN) +#endif + /* * __read_mostly is used to keep rarely changing variables out of frequently * updated cachelines. Its use should be reserved for data that is used @@ -95,6 +121,39 @@ __u8 __cacheline_group_end__##GROUP[0] #endif +/** + * __cacheline_group_begin_aligned - declare an aligned group start + * @GROUP: name of the group + * @...: optional group alignment + * + * The following block inside a struct: + * + * __cacheline_group_begin_aligned(grp); + * field a; + * field b; + * __cacheline_group_end_aligned(grp); + * + * will always be aligned to either the specified alignment or + * ``SMP_CACHE_BYTES``. + */ +#define __cacheline_group_begin_aligned(GROUP, ...) \ + __cacheline_group_begin(GROUP) \ + __aligned((__VA_ARGS__ + 0) ? : SMP_CACHE_BYTES) + +/** + * __cacheline_group_end_aligned - declare an aligned group end + * @GROUP: name of the group + * @...: optional alignment (same as was in __cacheline_group_begin_aligned()) + * + * Note that the end marker is aligned to sizeof(long) to allow more precise + * size assertion. It also declares a padding at the end to avoid next field + * falling into this cacheline. + */ +#define __cacheline_group_end_aligned(GROUP, ...) \ + __cacheline_group_end(GROUP) __aligned(sizeof(long)); \ + struct { } __cacheline_group_pad__##GROUP \ + __aligned((__VA_ARGS__ + 0) ? : SMP_CACHE_BYTES) + #ifndef CACHELINE_ASSERT_GROUP_MEMBER #define CACHELINE_ASSERT_GROUP_MEMBER(TYPE, GROUP, MEMBER) \ BUILD_BUG_ON(!(offsetof(TYPE, MEMBER) >= \ |