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, int sum, int *err_ptr)
66 *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
67 *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
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 * FIXME: minor buglet here
77 * We don't return the checksum for the data present in the buffer.  To do
78 * so properly, we would have to add in whatever registers were loaded before
79 * the fault, which, with the current asm above is not predictable.
80 */
81		.pushsection .text.fixup,"ax"
82		.align	4
839001:		mov	r4, #-EFAULT
84#ifdef CONFIG_CPU_SW_DOMAIN_PAN
85		ldr	r5, [sp, #9*4]		@ *err_ptr
86#else
87		ldr	r5, [sp, #8*4]		@ *err_ptr
88#endif
89		str	r4, [r5]
90		ldmia	sp, {r1, r2}		@ retrieve dst, len
91		add	r2, r2, r1
92		mov	r0, #0			@ zero the buffer
939002:		teq	r2, r1
94		strbne	r0, [r1], #1
95		bne	9002b
96		load_regs
97		.popsection
98