From c9ca78415ac1cbb0e9846111d5f01376266cf6f3 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 17 Apr 2014 14:16:03 +0200 Subject: [PATCH] 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 Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/uaccess.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) 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. -- 2.20.1