linux/arch/csky/lib/usercopy.c
Arnd Bergmann 0cd1151886 csky: use generic strncpy/strnlen from_user
Remove the csky implemenation of strncpy/strnlen and instead use the
generic versions.  The csky version is fairly slow because it always does
byte accesses even for aligned data, and it lacks a checks for
user_addr_max().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-07-23 14:40:01 +02:00

215 lines
6.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/uaccess.h>
#include <linux/types.h>
unsigned long raw_copy_from_user(void *to, const void *from,
unsigned long n)
{
int tmp, nsave;
__asm__ __volatile__(
"0: cmpnei %1, 0 \n"
" bf 7f \n"
" mov %3, %1 \n"
" or %3, %2 \n"
" andi %3, 3 \n"
" cmpnei %3, 0 \n"
" bf 1f \n"
" br 5f \n"
"1: cmplti %0, 16 \n"
" bt 3f \n"
"2: ldw %3, (%2, 0) \n"
"10: ldw %4, (%2, 4) \n"
" stw %3, (%1, 0) \n"
" stw %4, (%1, 4) \n"
"11: ldw %3, (%2, 8) \n"
"12: ldw %4, (%2, 12) \n"
" stw %3, (%1, 8) \n"
" stw %4, (%1, 12) \n"
" addi %2, 16 \n"
" addi %1, 16 \n"
" subi %0, 16 \n"
" br 1b \n"
"3: cmplti %0, 4 \n"
" bt 5f \n"
"4: ldw %3, (%2, 0) \n"
" stw %3, (%1, 0) \n"
" addi %2, 4 \n"
" addi %1, 4 \n"
" subi %0, 4 \n"
" br 3b \n"
"5: cmpnei %0, 0 \n"
" bf 7f \n"
"6: ldb %3, (%2, 0) \n"
" stb %3, (%1, 0) \n"
" addi %2, 1 \n"
" addi %1, 1 \n"
" subi %0, 1 \n"
" br 5b \n"
"8: stw %3, (%1, 0) \n"
" subi %0, 4 \n"
" bf 7f \n"
"9: subi %0, 8 \n"
" bf 7f \n"
"13: stw %3, (%1, 8) \n"
" subi %0, 12 \n"
" bf 7f \n"
".section __ex_table, \"a\" \n"
".align 2 \n"
".long 2b, 7f \n"
".long 4b, 7f \n"
".long 6b, 7f \n"
".long 10b, 8b \n"
".long 11b, 9b \n"
".long 12b,13b \n"
".previous \n"
"7: \n"
: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),
"=r"(tmp)
: "0"(n), "1"(to), "2"(from)
: "memory");
return n;
}
EXPORT_SYMBOL(raw_copy_from_user);
unsigned long raw_copy_to_user(void *to, const void *from,
unsigned long n)
{
int w0, w1, w2, w3;
__asm__ __volatile__(
"0: cmpnei %1, 0 \n"
" bf 8f \n"
" mov %3, %1 \n"
" or %3, %2 \n"
" andi %3, 3 \n"
" cmpnei %3, 0 \n"
" bf 1f \n"
" br 5f \n"
"1: cmplti %0, 16 \n" /* 4W */
" bt 3f \n"
" ldw %3, (%2, 0) \n"
" ldw %4, (%2, 4) \n"
" ldw %5, (%2, 8) \n"
" ldw %6, (%2, 12) \n"
"2: stw %3, (%1, 0) \n"
"9: stw %4, (%1, 4) \n"
"10: stw %5, (%1, 8) \n"
"11: stw %6, (%1, 12) \n"
" addi %2, 16 \n"
" addi %1, 16 \n"
" subi %0, 16 \n"
" br 1b \n"
"3: cmplti %0, 4 \n" /* 1W */
" bt 5f \n"
" ldw %3, (%2, 0) \n"
"4: stw %3, (%1, 0) \n"
" addi %2, 4 \n"
" addi %1, 4 \n"
" subi %0, 4 \n"
" br 3b \n"
"5: cmpnei %0, 0 \n" /* 1B */
" bf 13f \n"
" ldb %3, (%2, 0) \n"
"6: stb %3, (%1, 0) \n"
" addi %2, 1 \n"
" addi %1, 1 \n"
" subi %0, 1 \n"
" br 5b \n"
"7: subi %0, 4 \n"
"8: subi %0, 4 \n"
"12: subi %0, 4 \n"
" br 13f \n"
".section __ex_table, \"a\" \n"
".align 2 \n"
".long 2b, 13f \n"
".long 4b, 13f \n"
".long 6b, 13f \n"
".long 9b, 12b \n"
".long 10b, 8b \n"
".long 11b, 7b \n"
".previous \n"
"13: \n"
: "=r"(n), "=r"(to), "=r"(from), "=r"(w0),
"=r"(w1), "=r"(w2), "=r"(w3)
: "0"(n), "1"(to), "2"(from)
: "memory");
return n;
}
EXPORT_SYMBOL(raw_copy_to_user);
/*
* __clear_user: - Zero a block of memory in user space, with less checking.
* @to: Destination address, in user space.
* @n: Number of bytes to zero.
*
* Zero a block of memory in user space. Caller must check
* the specified block with access_ok() before calling this function.
*
* Returns number of bytes that could not be cleared.
* On success, this will be zero.
*/
unsigned long
__clear_user(void __user *to, unsigned long n)
{
int data, value, tmp;
__asm__ __volatile__(
"0: cmpnei %1, 0 \n"
" bf 7f \n"
" mov %3, %1 \n"
" andi %3, 3 \n"
" cmpnei %3, 0 \n"
" bf 1f \n"
" br 5f \n"
"1: cmplti %0, 32 \n" /* 4W */
" bt 3f \n"
"8: stw %2, (%1, 0) \n"
"10: stw %2, (%1, 4) \n"
"11: stw %2, (%1, 8) \n"
"12: stw %2, (%1, 12) \n"
"13: stw %2, (%1, 16) \n"
"14: stw %2, (%1, 20) \n"
"15: stw %2, (%1, 24) \n"
"16: stw %2, (%1, 28) \n"
" addi %1, 32 \n"
" subi %0, 32 \n"
" br 1b \n"
"3: cmplti %0, 4 \n" /* 1W */
" bt 5f \n"
"4: stw %2, (%1, 0) \n"
" addi %1, 4 \n"
" subi %0, 4 \n"
" br 3b \n"
"5: cmpnei %0, 0 \n" /* 1B */
"9: bf 7f \n"
"6: stb %2, (%1, 0) \n"
" addi %1, 1 \n"
" subi %0, 1 \n"
" br 5b \n"
".section __ex_table,\"a\" \n"
".align 2 \n"
".long 8b, 9b \n"
".long 10b, 9b \n"
".long 11b, 9b \n"
".long 12b, 9b \n"
".long 13b, 9b \n"
".long 14b, 9b \n"
".long 15b, 9b \n"
".long 16b, 9b \n"
".long 4b, 9b \n"
".long 6b, 9b \n"
".previous \n"
"7: \n"
: "=r"(n), "=r" (data), "=r"(value), "=r"(tmp)
: "0"(n), "1"(to), "2"(0)
: "memory");
return n;
}
EXPORT_SYMBOL(__clear_user);