xref: /linux/arch/riscv/lib/uaccess_vector.S (revision 955abe0a1b41de5ba61fe4cd614ebc123084d499)
1/* SPDX-License-Identifier: GPL-2.0-only */
2
3#include <linux/linkage.h>
4#include <asm/asm.h>
5#include <asm/asm-extable.h>
6#include <asm/csr.h>
7
8#define pDst a0
9#define pSrc a1
10#define iNum a2
11
12#define iVL a3
13
14#define ELEM_LMUL_SETTING m8
15#define vData v0
16
17	.macro fixup op reg addr lbl
18100:
19	\op \reg, \addr
20	_asm_extable	100b, \lbl
21	.endm
22
23SYM_FUNC_START(__asm_vector_usercopy)
24	/* Enable access to user memory */
25	li	t6, SR_SUM
26	csrs	CSR_STATUS, t6
27
28loop:
29	vsetvli iVL, iNum, e8, ELEM_LMUL_SETTING, ta, ma
30	fixup vle8.v vData, (pSrc), 10f
31	sub iNum, iNum, iVL
32	add pSrc, pSrc, iVL
33	fixup vse8.v vData, (pDst), 11f
34	add pDst, pDst, iVL
35	bnez iNum, loop
36
37	/* Exception fixup for vector load is shared with normal exit */
3810:
39	/* Disable access to user memory */
40	csrc	CSR_STATUS, t6
41	mv	a0, iNum
42	ret
43
44	/* Exception fixup code for vector store. */
4511:
46	/* Undo the subtraction after vle8.v */
47	add	iNum, iNum, iVL
48	/* Make sure the scalar fallback skip already processed bytes */
49	csrr	t2, CSR_VSTART
50	sub	iNum, iNum, t2
51	j	10b
52SYM_FUNC_END(__asm_vector_usercopy)
53