4a8992271c
This patch introduces AArch64-specific memory functions (memcpy, memmove, memchr, memset). These functions are not optimised for any CPU implementation but can be used as a starting point once hardware is available. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
44 lines
1 KiB
ArmAsm
44 lines
1 KiB
ArmAsm
/*
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* Based on arch/arm/lib/memchr.S
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*
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* Copyright (C) 1995-2000 Russell King
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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/*
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* Find a character in an area of memory.
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*
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* Parameters:
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* x0 - buf
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* x1 - c
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* x2 - n
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* Returns:
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* x0 - address of first occurrence of 'c' or 0
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*/
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ENTRY(memchr)
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and w1, w1, #0xff
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1: subs x2, x2, #1
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b.mi 2f
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ldrb w3, [x0], #1
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cmp w3, w1
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b.ne 1b
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sub x0, x0, #1
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ret
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2: mov x0, #0
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ret
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ENDPROC(memchr)
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