xref: /linux/arch/riscv/kernel/copy-unaligned.S (revision e7537735028c3ad4b0bfc02ff8fa2a1a28aa04fe)
1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (C) 2023 Rivos Inc. */
3
4#include <linux/cfi_types.h>
5#include <linux/linkage.h>
6#include <asm/asm.h>
7
8	.text
9
10/* void __riscv_copy_words_unaligned(void *, const void *, size_t) */
11/* Performs a memcpy without aligning buffers, using word loads and stores. */
12/* Note: The size is truncated to a multiple of 8 * SZREG */
13SYM_TYPED_FUNC_START(__riscv_copy_words_unaligned)
14	andi  a4, a2, ~((8*SZREG)-1)
15	beqz  a4, 2f
16	add   a3, a1, a4
171:
18	REG_L a4,       0(a1)
19	REG_L a5,   SZREG(a1)
20	REG_L a6, 2*SZREG(a1)
21	REG_L a7, 3*SZREG(a1)
22	REG_L t0, 4*SZREG(a1)
23	REG_L t1, 5*SZREG(a1)
24	REG_L t2, 6*SZREG(a1)
25	REG_L t3, 7*SZREG(a1)
26	REG_S a4,       0(a0)
27	REG_S a5,   SZREG(a0)
28	REG_S a6, 2*SZREG(a0)
29	REG_S a7, 3*SZREG(a0)
30	REG_S t0, 4*SZREG(a0)
31	REG_S t1, 5*SZREG(a0)
32	REG_S t2, 6*SZREG(a0)
33	REG_S t3, 7*SZREG(a0)
34	addi  a0, a0, 8*SZREG
35	addi  a1, a1, 8*SZREG
36	bltu  a1, a3, 1b
37
382:
39	ret
40SYM_FUNC_END(__riscv_copy_words_unaligned)
41
42/* void __riscv_copy_bytes_unaligned(void *, const void *, size_t) */
43/* Performs a memcpy without aligning buffers, using only byte accesses. */
44/* Note: The size is truncated to a multiple of 8 */
45SYM_TYPED_FUNC_START(__riscv_copy_bytes_unaligned)
46	andi a4, a2, ~(8-1)
47	beqz a4, 2f
48	add  a3, a1, a4
491:
50	lb   a4, 0(a1)
51	lb   a5, 1(a1)
52	lb   a6, 2(a1)
53	lb   a7, 3(a1)
54	lb   t0, 4(a1)
55	lb   t1, 5(a1)
56	lb   t2, 6(a1)
57	lb   t3, 7(a1)
58	sb   a4, 0(a0)
59	sb   a5, 1(a0)
60	sb   a6, 2(a0)
61	sb   a7, 3(a0)
62	sb   t0, 4(a0)
63	sb   t1, 5(a0)
64	sb   t2, 6(a0)
65	sb   t3, 7(a0)
66	addi a0, a0, 8
67	addi a1, a1, 8
68	bltu a1, a3, 1b
69
702:
71	ret
72SYM_FUNC_END(__riscv_copy_bytes_unaligned)
73