kernel_optimize_test/arch/mips/lib/strnlen_user.S
Markos Chandras 4968db4b9c MIPS: lib: strnlen_user: Add EVA support
In non-EVA mode, a strlen_user* alias is used for the
strlen_kernel* symbols since the code is identical. In EVA
mode, a new strlen_user* symbol is used which uses the EVA
specific instructions to load values from userspace.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-03-26 23:09:13 +01:00

71 lines
1.6 KiB
ArmAsm

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle
* Copyright (c) 1999 Silicon Graphics, Inc.
*/
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
#define EX(insn,reg,addr,handler) \
9: insn reg, addr; \
.section __ex_table,"a"; \
PTR 9b, handler; \
.previous
/*
* Return the size of a string including the ending NUL character up to a
* maximum of a1 or 0 in case of error.
*
* Note: for performance reasons we deliberately accept that a user may
* make strlen_user and strnlen_user access the first few KSEG0
* bytes. There's nothing secret there. On 64-bit accessing beyond
* the maximum is a tad hairier ...
*/
.macro __BUILD_STRNLEN_ASM func
LEAF(__strnlen_\func\()_asm)
LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
and v0, a0
bnez v0, .Lfault\@
FEXPORT(__strnlen_\func\()_nocheck_asm)
move v0, a0
PTR_ADDU a1, a0 # stop pointer
1: beq v0, a1, 1f # limit reached?
.ifeqs "\func", "kernel"
EX(lb, t0, (v0), .Lfault\@)
.else
EX(lbe, t0, (v0), .Lfault\@)
.endif
PTR_ADDIU v0, 1
bnez t0, 1b
1: PTR_SUBU v0, a0
jr ra
END(__strnlen_\func\()_asm)
.Lfault\@:
move v0, zero
jr ra
.endm
#ifndef CONFIG_EVA
/* Set aliases */
.global __strnlen_user_asm
.global __strnlen_user_nocheck_asm
.set __strnlen_user_asm, __strnlen_kernel_asm
.set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm
#endif
__BUILD_STRNLEN_ASM kernel
#ifdef CONFIG_EVA
.set push
.set eva
__BUILD_STRNLEN_ASM user
.set pop
#endif