1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * linux/arch/arm/lib/csumpartialcopyuser.S
4 *
5 * Copyright (C) 1995-1998 Russell King
6 *
7 * 27/03/03 Ian Molton Clean up CONFIG_CPU
8 */
9#include <linux/linkage.h>
10#include <asm/assembler.h>
11#include <asm/errno.h>
12#include <asm/asm-offsets.h>
13
14 .text
15
16#ifdef CONFIG_CPU_SW_DOMAIN_PAN
17 .macro save_regs
18 mrc p15, 0, ip, c3, c0, 0
19 stmfd sp!, {r1, r2, r4 - r8, ip, lr}
20 uaccess_enable ip
21 .endm
22
23 .macro load_regs
24 ldmfd sp!, {r1, r2, r4 - r8, ip, lr}
25 mcr p15, 0, ip, c3, c0, 0
26 ret lr
27 .endm
28#else
29 .macro save_regs
30 stmfd sp!, {r1, r2, r4 - r8, lr}
31 .endm
32
33 .macro load_regs
34 ldmfd sp!, {r1, r2, r4 - r8, pc}
35 .endm
36#endif
37
38 .macro load1b, reg1
39 ldrusr \reg1, r0, 1
40 .endm
41
42 .macro load2b, reg1, reg2
43 ldrusr \reg1, r0, 1
44 ldrusr \reg2, r0, 1
45 .endm
46
47 .macro load1l, reg1
48 ldrusr \reg1, r0, 4
49 .endm
50
51 .macro load2l, reg1, reg2
52 ldrusr \reg1, r0, 4
53 ldrusr \reg2, r0, 4
54 .endm
55
56 .macro load4l, reg1, reg2, reg3, reg4
57 ldrusr \reg1, r0, 4
58 ldrusr \reg2, r0, 4
59 ldrusr \reg3, r0, 4
60 ldrusr \reg4, r0, 4
61 .endm
62
63/*
64 * unsigned int
65 * csum_partial_copy_from_user(const char *src, char *dst, int len)
66 * r0 = src, r1 = dst, r2 = len
67 * Returns : r0 = checksum or 0
68 */
69
70#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
71#define FN_EXIT ENDPROC(csum_partial_copy_from_user)
72
73#include "csumpartialcopygeneric.S"
74
75/*
76 * We report fault by returning 0 csum - impossible in normal case, since
77 * we start with 0xffffffff for initial sum.
78 */
79 .pushsection .text.fixup,"ax"
80 .align 4
819001: mov r0, #0
82 load_regs
83 .popsection
84

source code of linux/arch/arm/lib/csumpartialcopyuser.S