mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
0131f2b2c9
Optimise 'strncpy' to use microMIPS instructions and/or optimisations for binary size reduction. When the microMIPS ISA is not being used, the library function compiles to the original binary code. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
61 lines
1.4 KiB
ArmAsm
61 lines
1.4 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, 1999 by Ralf Baechle
|
|
* Copyright (C) 2011 MIPS Technologies, Inc.
|
|
*/
|
|
#include <linux/errno.h>
|
|
#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
|
|
|
|
/*
|
|
* Returns: -EFAULT if exception before terminator, N if the entire
|
|
* buffer filled, else strlen.
|
|
*/
|
|
|
|
/*
|
|
* Ugly special case have to check: we might get passed a user space
|
|
* pointer which wraps into the kernel space. We don't deal with that. If
|
|
* it happens at most some bytes of the exceptions handlers will be copied.
|
|
*/
|
|
|
|
LEAF(__strncpy_from_user_asm)
|
|
LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok?
|
|
and v0, a1
|
|
bnez v0, .Lfault
|
|
|
|
FEXPORT(__strncpy_from_user_nocheck_asm)
|
|
.set noreorder
|
|
move t0, zero
|
|
move v1, a1
|
|
1: EX(lbu, v0, (v1), .Lfault)
|
|
PTR_ADDIU v1, 1
|
|
R10KCBARRIER(0(ra))
|
|
beqz v0, 2f
|
|
sb v0, (a0)
|
|
PTR_ADDIU t0, 1
|
|
bne t0, a2, 1b
|
|
PTR_ADDIU a0, 1
|
|
2: PTR_ADDU v0, a1, t0
|
|
xor v0, a1
|
|
bltz v0, .Lfault
|
|
nop
|
|
jr ra # return n
|
|
move v0, t0
|
|
END(__strncpy_from_user_asm)
|
|
|
|
.Lfault: jr ra
|
|
li v0, -EFAULT
|
|
|
|
.section __ex_table,"a"
|
|
PTR 1b, .Lfault
|
|
.previous
|