diff options
| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-04-17 14:16:03 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-05-20 08:58:50 +0200 |
| commit | c9ca78415ac1cbb0e9846111d5f01376266cf6f3 (patch) | |
| tree | e664bb4d8bdabcc0dd65732b6741d21260760dba /arch/s390 | |
| parent | ac4995b9d5705f10a69ea74d440e3943db41f2ca (diff) | |
s390/uaccess: provide inline variants of get_user/put_user
This shortens the code by ~17k (performace_defconfig, march=z196).
The number of exception table entries however increases from 164
entries to 2500 entries (+~18k).
However the executed code is shorter and also faster since we save
the branches to the out-of-line copy_to/from_user implementations.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/uaccess.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index 1be64a1506d0..cd4c68e0398d 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -132,6 +132,34 @@ unsigned long __must_check __copy_to_user(void __user *to, const void *from, #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user +#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES + +#define __put_get_user_asm(to, from, size, spec) \ +({ \ + register unsigned long __reg0 asm("0") = spec; \ + int __rc; \ + \ + asm volatile( \ + "0: mvcos %1,%3,%2\n" \ + "1: xr %0,%0\n" \ + "2:\n" \ + ".pushsection .fixup, \"ax\"\n" \ + "3: lhi %0,%5\n" \ + " jg 2b\n" \ + ".popsection\n" \ + EX_TABLE(0b,3b) EX_TABLE(1b,3b) \ + : "=d" (__rc), "=Q" (*(to)) \ + : "d" (size), "Q" (*(from)), \ + "d" (__reg0), "K" (-EFAULT) \ + : "cc"); \ + __rc; \ +}) + +#define __put_user_fn(x, ptr, size) __put_get_user_asm(ptr, x, size, 0x810000UL) +#define __get_user_fn(x, ptr, size) __put_get_user_asm(x, ptr, size, 0x81UL) + +#else /* CONFIG_HAVE_MARCH_Z10_FEATURES */ + static inline int __put_user_fn(void *x, void __user *ptr, unsigned long size) { size = __copy_to_user(ptr, x, size); @@ -144,6 +172,8 @@ static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long s return size ? -EFAULT : 0; } +#endif /* CONFIG_HAVE_MARCH_Z10_FEATURES */ + /* * These are the main single-value transfer routines. They automatically * use the right size if we just have the right pointer type. |