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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>
This commit is contained in:
Heiko Carstens 2014-04-17 14:16:03 +02:00 committed by Martin Schwidefsky
parent ac4995b9d5
commit c9ca78415a
1 changed files with 30 additions and 0 deletions
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30
arch/s390/include/asm/uaccess.h
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@ -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.