xref: /openbmc/linux/arch/arm/lib/csumpartialcopyuser.S (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1/*
2 *  linux/arch/arm/lib/csumpartialcopyuser.S
3 *
4 *  Copyright (C) 1995-1998 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * 27/03/03 Ian Molton Clean up CONFIG_CPU
11 *
12 */
13#include <linux/linkage.h>
14#include <asm/assembler.h>
15#include <asm/errno.h>
16#include <asm/asm-offsets.h>
17
18		.text
19
20		.macro	save_regs
21		stmfd	sp!, {r1, r2, r4 - r8, lr}
22		.endm
23
24		.macro	load_regs
25		ldmfd	sp!, {r1, r2, r4 - r8, pc}
26		.endm
27
28		.macro	load1b,	reg1
299999:		ldrbt	\reg1, [r0], $1
30		.section __ex_table, "a"
31		.align	3
32		.long	9999b, 6001f
33		.previous
34		.endm
35
36		.macro	load2b, reg1, reg2
379999:		ldrbt	\reg1, [r0], $1
389998:		ldrbt	\reg2, [r0], $1
39		.section __ex_table, "a"
40		.long	9999b, 6001f
41		.long	9998b, 6001f
42		.previous
43		.endm
44
45		.macro	load1l, reg1
469999:		ldrt	\reg1, [r0], $4
47		.section __ex_table, "a"
48		.align	3
49		.long	9999b, 6001f
50		.previous
51		.endm
52
53		.macro	load2l, reg1, reg2
549999:		ldrt	\reg1, [r0], $4
559998:		ldrt	\reg2, [r0], $4
56		.section __ex_table, "a"
57		.long	9999b, 6001f
58		.long	9998b, 6001f
59		.previous
60		.endm
61
62		.macro	load4l, reg1, reg2, reg3, reg4
639999:		ldrt	\reg1, [r0], $4
649998:		ldrt	\reg2, [r0], $4
659997:		ldrt	\reg3, [r0], $4
669996:		ldrt	\reg4, [r0], $4
67		.section __ex_table, "a"
68		.long	9999b, 6001f
69		.long	9998b, 6001f
70		.long	9997b, 6001f
71		.long	9996b, 6001f
72		.previous
73		.endm
74
75/*
76 * unsigned int
77 * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
78 *  r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
79 *  Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
80 */
81
82#define FN_ENTRY	ENTRY(csum_partial_copy_from_user)
83#define FN_EXIT		ENDPROC(csum_partial_copy_from_user)
84
85#include "csumpartialcopygeneric.S"
86
87/*
88 * FIXME: minor buglet here
89 * We don't return the checksum for the data present in the buffer.  To do
90 * so properly, we would have to add in whatever registers were loaded before
91 * the fault, which, with the current asm above is not predictable.
92 */
93		.section .fixup,"ax"
94		.align	4
956001:		mov	r4, #-EFAULT
96		ldr	r5, [fp, #4]		@ *err_ptr
97		str	r4, [r5]
98		ldmia	sp, {r1, r2}		@ retrieve dst, len
99		add	r2, r2, r1
100		mov	r0, #0			@ zero the buffer
1016002:		teq	r2, r1
102		strneb	r0, [r1], #1
103		bne	6002b
104		load_regs
105		.previous
106