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authorHeiko Carstens <heiko.carstens@de.ibm.com>2014-04-17 14:16:03 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-05-20 08:58:50 +0200
commitc9ca78415ac1cbb0e9846111d5f01376266cf6f3 (patch)
treee664bb4d8bdabcc0dd65732b6741d21260760dba /arch/s390/include
parentac4995b9d5705f10a69ea74d440e3943db41f2ca (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/include')
-rw-r--r--arch/s390/include/asm/uaccess.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 1be64a1506d..cd4c68e0398 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.