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61a6fccc0b
Loongson-2 series (Loongson-2K500, Loongson-2K1000) don't support unaligned access in hardware, while Loongson-3 series (Loongson-3A5000, Loongson-3C5000) are configurable whether support unaligned access in hardware. This patch add unaligned access emulation for those LoongArch processors without hardware support. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
85 lines
1.4 KiB
ArmAsm
85 lines
1.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#include <linux/linkage.h>
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#include <asm/asm.h>
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#include <asm/asmmacro.h>
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#include <asm/asm-extable.h>
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#include <asm/errno.h>
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#include <asm/export.h>
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#include <asm/regdef.h>
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.L_fixup_handle_unaligned:
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li.w a0, -EFAULT
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jr ra
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/*
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* unsigned long unaligned_read(void *addr, void *value, unsigned long n, bool sign)
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*
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* a0: addr
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* a1: value
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* a2: n
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* a3: sign
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*/
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SYM_FUNC_START(unaligned_read)
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beqz a2, 5f
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li.w t2, 0
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addi.d t0, a2, -1
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slli.d t1, t0, 3
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add.d a0, a0, t0
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beqz a3, 2f
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1: ld.b t3, a0, 0
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b 3f
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2: ld.bu t3, a0, 0
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3: sll.d t3, t3, t1
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or t2, t2, t3
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addi.d t1, t1, -8
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addi.d a0, a0, -1
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addi.d a2, a2, -1
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bgtz a2, 2b
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4: st.d t2, a1, 0
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move a0, a2
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jr ra
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5: li.w a0, -EFAULT
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jr ra
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_asm_extable 1b, .L_fixup_handle_unaligned
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_asm_extable 2b, .L_fixup_handle_unaligned
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_asm_extable 4b, .L_fixup_handle_unaligned
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SYM_FUNC_END(unaligned_read)
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/*
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* unsigned long unaligned_write(void *addr, unsigned long value, unsigned long n)
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*
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* a0: addr
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* a1: value
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* a2: n
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*/
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SYM_FUNC_START(unaligned_write)
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beqz a2, 3f
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li.w t0, 0
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1: srl.d t1, a1, t0
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2: st.b t1, a0, 0
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addi.d t0, t0, 8
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addi.d a2, a2, -1
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addi.d a0, a0, 1
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bgtz a2, 1b
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move a0, a2
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jr ra
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3: li.w a0, -EFAULT
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jr ra
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_asm_extable 2b, .L_fixup_handle_unaligned
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SYM_FUNC_END(unaligned_write)
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