diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-01-23 11:18:36 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-02-21 08:50:14 +0100 |
| commit | 4f41c2b4567dbfb7ff93e5c552b869e2865bcd9d (patch) | |
| tree | 5845eccdb038c5e1bc90a0aaf8919f2a65fa8096 /arch/s390/include/asm/futex.h | |
| parent | cfa785e623577cdad2aa721acb23bd3a95eced9a (diff) | |
s390/uaccess: get rid of indirect function calls
There are only two uaccess variants on s390 left: the version that is used
if the mvcos instruction is available, and the page table walk variant.
So there is no need for expensive indirect function calls.
By default the mvcos variant will be called. If the mvcos instruction is not
available it will call the page table walk variant.
For minimal performance impact the "if (mvcos_is_available)" is implemented
with a jump label, which will be a six byte nop on machines with mvcos.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/futex.h')
| -rw-r--r-- | arch/s390/include/asm/futex.h | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h index 51bcaa0fdeef..fda46bd38c99 100644 --- a/arch/s390/include/asm/futex.h +++ b/arch/s390/include/asm/futex.h @@ -5,7 +5,10 @@ #include <linux/uaccess.h> #include <asm/errno.h> -static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) +int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval, u32 newval); +int __futex_atomic_op_inuser(int op, u32 __user *uaddr, int oparg, int *old); + +static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) { int op = (encoded_op >> 28) & 7; int cmp = (encoded_op >> 24) & 15; @@ -17,7 +20,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) oparg = 1 << oparg; pagefault_disable(); - ret = uaccess.futex_atomic_op(op, uaddr, oparg, &oldval); + ret = __futex_atomic_op_inuser(op, uaddr, oparg, &oldval); pagefault_enable(); if (!ret) { @@ -34,10 +37,4 @@ static inline int futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr) return ret; } -static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, - u32 oldval, u32 newval) -{ - return uaccess.futex_atomic_cmpxchg(uval, uaddr, oldval, newval); -} - #endif /* _ASM_S390_FUTEX_H */ |