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* Copy to/from userspace with optional address space checking.
* Copyright 2004-2006 Atmel Corporation
* 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 <asm/page.h>
#include <asm/thread_info.h>
#include <asm/asm.h>
* __kernel_size_t
* __copy_user(void *to, const void *from, __kernel_size_t n)
* Returns the number of bytes not copied. Might be off by
* max 3 bytes if we get a fault in the main loop.
* The address-space checking functions simply fall through to
* the non-checking version.
.align 1
.global copy_from_user
.type copy_from_user, @function
branch_if_kernel r8, __copy_user
ret_if_privileged r8, r11, r10, r10
rjmp __copy_user
.size ___copy_from_user, . - ___copy_from_user
.global copy_to_user
.type copy_to_user, @function
branch_if_kernel r8, __copy_user
ret_if_privileged r8, r12, r10, r10
.size copy_to_user, . - copy_to_user
.global __copy_user
.type __copy_user, @function
mov r9, r11
andl r9, 3, COH
brne 6f
/* At this point, from is word-aligned */
1: sub r10, 4
brlt 3f
10: ld.w r8, r11++
11: st.w r12++, r8
sub r10, 4
brge 2b
3: sub r10, -4
reteq 0
* Handle unaligned count. Need to be careful with r10 here so
* that we return the correct value even if we get a fault
20: ld.ub r8, r11++
21: st.b r12++, r8
sub r10, 1
reteq 0
22: ld.ub r8, r11++
23: st.b r12++, r8
sub r10, 1
reteq 0
24: ld.ub r8, r11++
25: st.b r12++, r8
retal 0
/* Handle unaligned from-pointer */
6: cp.w r10, 4
brlt 4b
rsub r9, r9, 4
30: ld.ub r8, r11++
31: st.b r12++, r8
sub r10, 1
sub r9, 1
breq 1b
32: ld.ub r8, r11++
33: st.b r12++, r8
sub r10, 1
sub r9, 1
breq 1b
34: ld.ub r8, r11++
35: st.b r12++, r8
sub r10, 1
rjmp 1b
.size __copy_user, . - __copy_user
.section .fixup,"ax"
.align 1
19: sub r10, -4
29: retal r10
.section __ex_table,"a"
.align 2
.long 10b, 19b
.long 11b, 19b
.long 20b, 29b
.long 21b, 29b
.long 22b, 29b
.long 23b, 29b
.long 24b, 29b
.long 25b, 29b
.long 30b, 29b
.long 31b, 29b
.long 32b, 29b
.long 33b, 29b
.long 34b, 29b
.long 35b, 29b