diff options
Diffstat (limited to 'arch/loongarch/lib/copy_user.S')
| -rw-r--r-- | arch/loongarch/lib/copy_user.S | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S new file mode 100644 index 000000000..55ac6020a --- /dev/null +++ b/arch/loongarch/lib/copy_user.S @@ -0,0 +1,123 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ + +#include <asm/alternative-asm.h> +#include <asm/asm.h> +#include <asm/asmmacro.h> +#include <asm/asm-extable.h> +#include <asm/cpu.h> +#include <asm/export.h> +#include <asm/regdef.h> + +.irp to, 0, 1, 2, 3, 4, 5, 6, 7 +.L_fixup_handle_\to\(): + addi.d a0, a2, (\to) * (-8) + jr ra +.endr + +SYM_FUNC_START(__copy_user) + /* + * Some CPUs support hardware unaligned access + */ + ALTERNATIVE "b __copy_user_generic", \ + "b __copy_user_fast", CPU_FEATURE_UAL +SYM_FUNC_END(__copy_user) + +EXPORT_SYMBOL(__copy_user) + +/* + * unsigned long __copy_user_generic(void *to, const void *from, size_t n) + * + * a0: to + * a1: from + * a2: n + */ +SYM_FUNC_START(__copy_user_generic) + beqz a2, 3f + +1: ld.b t0, a1, 0 +2: st.b t0, a0, 0 + addi.d a0, a0, 1 + addi.d a1, a1, 1 + addi.d a2, a2, -1 + bgtz a2, 1b + +3: move a0, a2 + jr ra + + _asm_extable 1b, .L_fixup_handle_0 + _asm_extable 2b, .L_fixup_handle_0 +SYM_FUNC_END(__copy_user_generic) + +/* + * unsigned long __copy_user_fast(void *to, const void *from, unsigned long n) + * + * a0: to + * a1: from + * a2: n + */ +SYM_FUNC_START(__copy_user_fast) + beqz a2, 19f + + ori a3, zero, 64 + blt a2, a3, 17f + + /* copy 64 bytes at a time */ +1: ld.d t0, a1, 0 +2: ld.d t1, a1, 8 +3: ld.d t2, a1, 16 +4: ld.d t3, a1, 24 +5: ld.d t4, a1, 32 +6: ld.d t5, a1, 40 +7: ld.d t6, a1, 48 +8: ld.d t7, a1, 56 +9: st.d t0, a0, 0 +10: st.d t1, a0, 8 +11: st.d t2, a0, 16 +12: st.d t3, a0, 24 +13: st.d t4, a0, 32 +14: st.d t5, a0, 40 +15: st.d t6, a0, 48 +16: st.d t7, a0, 56 + + addi.d a0, a0, 64 + addi.d a1, a1, 64 + addi.d a2, a2, -64 + bge a2, a3, 1b + + beqz a2, 19f + + /* copy the remaining bytes */ +17: ld.b t0, a1, 0 +18: st.b t0, a0, 0 + addi.d a0, a0, 1 + addi.d a1, a1, 1 + addi.d a2, a2, -1 + bgt a2, zero, 17b + + /* return */ +19: move a0, a2 + jr ra + + /* fixup and ex_table */ + _asm_extable 1b, .L_fixup_handle_0 + _asm_extable 2b, .L_fixup_handle_1 + _asm_extable 3b, .L_fixup_handle_2 + _asm_extable 4b, .L_fixup_handle_3 + _asm_extable 5b, .L_fixup_handle_4 + _asm_extable 6b, .L_fixup_handle_5 + _asm_extable 7b, .L_fixup_handle_6 + _asm_extable 8b, .L_fixup_handle_7 + _asm_extable 9b, .L_fixup_handle_0 + _asm_extable 10b, .L_fixup_handle_1 + _asm_extable 11b, .L_fixup_handle_2 + _asm_extable 12b, .L_fixup_handle_3 + _asm_extable 13b, .L_fixup_handle_4 + _asm_extable 14b, .L_fixup_handle_5 + _asm_extable 15b, .L_fixup_handle_6 + _asm_extable 16b, .L_fixup_handle_7 + _asm_extable 17b, .L_fixup_handle_0 + _asm_extable 18b, .L_fixup_handle_0 +SYM_FUNC_END(__copy_user_fast) |