diff options
| author | Nylon Chen <nylon7@andestech.com> | 2020-11-30 17:13:19 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2020-12-10 17:27:54 -0800 |
| commit | 04091d6c0535f6dc82af864ab56425235c6581a4 (patch) | |
| tree | d66795c6f1eb1eb6fc98443b5a9209ee93069c74 /arch/riscv/lib | |
| parent | b5b11a8ac4b5a997a1b3ae388aea3879e26c857f (diff) | |
riscv: provide memmove implementation
The memmove used by the kernel feature like KASAN.
Signed-off-by: Nick Hu <nickhu@andestech.com>
Signed-off-by: Nick Hu <nick650823@gmail.com>
Signed-off-by: Nylon Chen <nylon7@andestech.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/lib')
| -rw-r--r-- | arch/riscv/lib/Makefile | 1 | ||||
| -rw-r--r-- | arch/riscv/lib/memmove.S | 64 |
2 files changed, 65 insertions, 0 deletions
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index 47e7a8204460..ac6171e9c19e 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -2,5 +2,6 @@ lib-y += delay.o lib-y += memcpy.o lib-y += memset.o +lib-y += memmove.o lib-$(CONFIG_MMU) += uaccess.o lib-$(CONFIG_64BIT) += tishift.o diff --git a/arch/riscv/lib/memmove.S b/arch/riscv/lib/memmove.S new file mode 100644 index 000000000000..07d1d2152ba5 --- /dev/null +++ b/arch/riscv/lib/memmove.S @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/linkage.h> +#include <asm/asm.h> + +ENTRY(__memmove) +WEAK(memmove) + move t0, a0 + move t1, a1 + + beq a0, a1, exit_memcpy + beqz a2, exit_memcpy + srli t2, a2, 0x2 + + slt t3, a0, a1 + beqz t3, do_reverse + + andi a2, a2, 0x3 + li t4, 1 + beqz t2, byte_copy + +word_copy: + lw t3, 0(a1) + addi t2, t2, -1 + addi a1, a1, 4 + sw t3, 0(a0) + addi a0, a0, 4 + bnez t2, word_copy + beqz a2, exit_memcpy + j byte_copy + +do_reverse: + add a0, a0, a2 + add a1, a1, a2 + andi a2, a2, 0x3 + li t4, -1 + beqz t2, reverse_byte_copy + +reverse_word_copy: + addi a1, a1, -4 + addi t2, t2, -1 + lw t3, 0(a1) + addi a0, a0, -4 + sw t3, 0(a0) + bnez t2, reverse_word_copy + beqz a2, exit_memcpy + +reverse_byte_copy: + addi a0, a0, -1 + addi a1, a1, -1 + +byte_copy: + lb t3, 0(a1) + addi a2, a2, -1 + sb t3, 0(a0) + add a1, a1, t4 + add a0, a0, t4 + bnez a2, byte_copy + +exit_memcpy: + move a0, t0 + move a1, t1 + ret +END(__memmove) |