WSL2-Linux-Kernel/arch/arm26/lib/csumpartialcopyuser.S

115 строки
2.6 KiB
ArmAsm

/*
* linux/arch/arm26/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.
*/
#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 - r9, fp, ip, lr, pc}
mov r9, sp, lsr #13
mov r9, r9, lsl #13
ldr r9, [r9, #TSK_ADDR_LIMIT]
mov r9, r9, lsr #24
.endm
.macro load_regs,flags
ldm\flags fp, {r1, r2, r4-r9, fp, sp, pc}^
.endm
.macro load1b, reg1
tst r9, #0x01
9999: ldreqbt \reg1, [r0], #1
ldrneb \reg1, [r0], #1
.section __ex_table, "a"
.align 3
.long 9999b, 6001f
.previous
.endm
.macro load2b, reg1, reg2
tst r9, #0x01
9999: ldreqbt \reg1, [r0], #1
ldrneb \reg1, [r0], #1
9998: ldreqbt \reg2, [r0], #1
ldrneb \reg2, [r0], #1
.section __ex_table, "a"
.long 9999b, 6001f
.long 9998b, 6001f
.previous
.endm
.macro load1l, reg1
tst r9, #0x01
9999: ldreqt \reg1, [r0], #4
ldrne \reg1, [r0], #4
.section __ex_table, "a"
.align 3
.long 9999b, 6001f
.previous
.endm
.macro load2l, reg1, reg2
tst r9, #0x01
ldmneia r0!, {\reg1, \reg2}
9999: ldreqt \reg1, [r0], #4
9998: ldreqt \reg2, [r0], #4
.section __ex_table, "a"
.long 9999b, 6001f
.long 9998b, 6001f
.previous
.endm
.macro load4l, reg1, reg2, reg3, reg4
tst r9, #0x01
ldmneia r0!, {\reg1, \reg2, \reg3, \reg4}
9999: ldreqt \reg1, [r0], #4
9998: ldreqt \reg2, [r0], #4
9997: ldreqt \reg3, [r0], #4
9996: ldreqt \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)
#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.
*/
.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 ea