xref: /linux/arch/arm/lib/csumpartialcopyuser.S (revision 9e56ff53b4115875667760445b028357848b4748)
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