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| author |   Jiri Kosina <jkosina@suse.cz> | 2015-09-01 15:35:24 +0200 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2015-09-01 15:35:24 +0200 |
| commit | 067e2601d3c076abbf45db91261f9065eaa879b2 (patch) | |
| tree | 86c8d4b913873dbd3b4ff23562a3a8597984b4df /include/linux/compiler.h | |
| parent | Merge branches 'for-4.2/upstream-fixes-devm-fixed' and 'for-4.3/upstream' into for-linus (diff) | |
| parent | HID: gembird: add new driver to fix Gembird JPD-DualForce 2 (diff) | |
| download | wireguard-linux-067e2601d3c076abbf45db91261f9065eaa879b2.tar.xz wireguard-linux-067e2601d3c076abbf45db91261f9065eaa879b2.zip | |
Merge branch 'for-4.3/gembird' into for-linus
Diffstat (limited to '')
| -rw-r--r-- | include/linux/compiler.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 05be2352fef8..e08a6ae7c0a4 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -17,6 +17,7 @@ # define __release(x) __context__(x,-1) # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) # define __percpu __attribute__((noderef, address_space(3))) +# define __pmem __attribute__((noderef, address_space(5))) #ifdef CONFIG_SPARSE_RCU_POINTER # define __rcu __attribute__((noderef, address_space(4))) #else @@ -42,6 +43,7 @@ extern void __chk_io_ptr(const volatile void __iomem *); # define __cond_lock(x,c) (c) # define __percpu # define __rcu +# define __pmem #endif /* Indirect macros required for expanded argument pasting, eg. __LINE__. */ @@ -473,6 +475,21 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s (volatile typeof(x) *)&(x); }) #define ACCESS_ONCE(x) (*__ACCESS_ONCE(x)) +/** + * lockless_dereference() - safely load a pointer for later dereference + * @p: The pointer to load + * + * Similar to rcu_dereference(), but for situations where the pointed-to + * object's lifetime is managed by something other than RCU. That + * "something other" might be reference counting or simple immortality. + */ +#define lockless_dereference(p) \ +({ \ + typeof(p) _________p1 = READ_ONCE(p); \ + smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ + (_________p1); \ +}) + /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */ #ifdef CONFIG_KPROBES # define __kprobes __attribute__((__section__(".kprobes.text"))) |