WSL2-Linux-Kernel/arch/arm/lib/csumpartialcopyuser.S

106 строки
2.3 KiB
ArmAsm

/*
* linux/arch/arm/lib/csumpartialcopyuser.S
*
* Copyright (C) 1995-1998 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 27/03/03 Ian Molton Clean up CONFIG_CPU
*
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/asm-offsets.h>
.text
.macro save_regs
stmfd sp!, {r1, r2, r4 - r8, lr}
.endm
.macro load_regs
ldmfd sp!, {r1, r2, r4 - r8, pc}
.endm
.macro load1b, reg1
9999: ldrbt \reg1, [r0], $1
.section __ex_table, "a"
.align 3
.long 9999b, 6001f
.previous
.endm
.macro load2b, reg1, reg2
9999: ldrbt \reg1, [r0], $1
9998: ldrbt \reg2, [r0], $1
.section __ex_table, "a"
.long 9999b, 6001f
.long 9998b, 6001f
.previous
.endm
.macro load1l, reg1
9999: ldrt \reg1, [r0], $4
.section __ex_table, "a"
.align 3
.long 9999b, 6001f
.previous
.endm
.macro load2l, reg1, reg2
9999: ldrt \reg1, [r0], $4
9998: ldrt \reg2, [r0], $4
.section __ex_table, "a"
.long 9999b, 6001f
.long 9998b, 6001f
.previous
.endm
.macro load4l, reg1, reg2, reg3, reg4
9999: ldrt \reg1, [r0], $4
9998: ldrt \reg2, [r0], $4
9997: ldrt \reg3, [r0], $4
9996: ldrt \reg4, [r0], $4
.section __ex_table, "a"
.long 9999b, 6001f
.long 9998b, 6001f
.long 9997b, 6001f
.long 9996b, 6001f
.previous
.endm
/*
* unsigned int
* csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
* r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
* Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
*/
#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
#define FN_EXIT ENDPROC(csum_partial_copy_from_user)
#include "csumpartialcopygeneric.S"
/*
* FIXME: minor buglet here
* We don't return the checksum for the data present in the buffer. To do
* so properly, we would have to add in whatever registers were loaded before
* the fault, which, with the current asm above is not predictable.
*/
.section .fixup,"ax"
.align 4
6001: mov r4, #-EFAULT
ldr r5, [fp, #4] @ *err_ptr
str r4, [r5]
ldmia sp, {r1, r2} @ retrieve dst, len
add r2, r2, r1
mov r0, #0 @ zero the buffer
6002: teq r2, r1
strneb r0, [r1], #1
bne 6002b
load_regs
.previous