linux/arch/arm/lib/csumpartialcopyuser.S

98 lines
2.0 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/lib/csumpartialcopyuser.S
*
* Copyright (C) 1995-1998 Russell King
*
* 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
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
.macro save_regs
mrc p15, 0, ip, c3, c0, 0
stmfd sp!, {r1, r2, r4 - r8, ip, lr}
uaccess_enable ip
.endm
.macro load_regs
ldmfd sp!, {r1, r2, r4 - r8, ip, lr}
mcr p15, 0, ip, c3, c0, 0
ret lr
.endm
#else
.macro save_regs
stmfd sp!, {r1, r2, r4 - r8, lr}
.endm
.macro load_regs
ldmfd sp!, {r1, r2, r4 - r8, pc}
.endm
#endif
.macro load1b, reg1
ldrusr \reg1, r0, 1
.endm
.macro load2b, reg1, reg2
ldrusr \reg1, r0, 1
ldrusr \reg2, r0, 1
.endm
.macro load1l, reg1
ldrusr \reg1, r0, 4
.endm
.macro load2l, reg1, reg2
ldrusr \reg1, r0, 4
ldrusr \reg2, r0, 4
.endm
.macro load4l, reg1, reg2, reg3, reg4
ldrusr \reg1, r0, 4
ldrusr \reg2, r0, 4
ldrusr \reg3, r0, 4
ldrusr \reg4, r0, 4
.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.
*/
.pushsection .text.fixup,"ax"
.align 4
9001: mov r4, #-EFAULT
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
ldr r5, [sp, #9*4] @ *err_ptr
#else
ldr r5, [sp, #8*4] @ *err_ptr
#endif
str r4, [r5]
ldmia sp, {r1, r2} @ retrieve dst, len
add r2, r2, r1
mov r0, #0 @ zero the buffer
9002: teq r2, r1
strbne r0, [r1], #1
bne 9002b
load_regs
.popsection