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Commit c9ca7841 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent ac4995b9

arch/s390/include/asm/uaccess.h

+30 −0
Original line number Diff line number Diff line
@@ -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.