235 lines
6.2 KiB
C
235 lines
6.2 KiB
C
/*
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* User space memory access functions for Nios II
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*
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* Copyright (C) 2010-2011, Tobias Klauser <tklauser@distanz.ch>
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* Copyright (C) 2009, Wind River Systems Inc
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* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#ifndef _ASM_NIOS2_UACCESS_H
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#define _ASM_NIOS2_UACCESS_H
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#include <linux/errno.h>
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#include <linux/thread_info.h>
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#include <linux/string.h>
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#include <asm/page.h>
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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/*
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* The exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry {
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unsigned long insn;
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unsigned long fixup;
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};
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extern int fixup_exception(struct pt_regs *regs);
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/*
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* Segment stuff
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*/
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#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
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#define USER_DS MAKE_MM_SEG(0x80000000UL)
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#define KERNEL_DS MAKE_MM_SEG(0)
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#define get_ds() (KERNEL_DS)
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#define get_fs() (current_thread_info()->addr_limit)
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#define set_fs(seg) (current_thread_info()->addr_limit = (seg))
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#define segment_eq(a, b) ((a).seg == (b).seg)
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#define __access_ok(addr, len) \
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(((signed long)(((long)get_fs().seg) & \
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((long)(addr) | (((long)(addr)) + (len)) | (len)))) == 0)
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#define access_ok(type, addr, len) \
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likely(__access_ok((unsigned long)(addr), (unsigned long)(len)))
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# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
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/*
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* Zero Userspace
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*/
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static inline unsigned long __must_check __clear_user(void __user *to,
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unsigned long n)
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{
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__asm__ __volatile__ (
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"1: stb zero, 0(%1)\n"
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" addi %0, %0, -1\n"
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" addi %1, %1, 1\n"
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" bne %0, zero, 1b\n"
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"2:\n"
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__EX_TABLE_SECTION
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".word 1b, 2b\n"
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".previous\n"
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: "=r" (n), "=r" (to)
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: "0" (n), "1" (to)
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);
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return n;
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}
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static inline unsigned long __must_check clear_user(void __user *to,
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unsigned long n)
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{
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if (!access_ok(VERIFY_WRITE, to, n))
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return n;
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return __clear_user(to, n);
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}
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extern long __copy_from_user(void *to, const void __user *from,
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unsigned long n);
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extern long __copy_to_user(void __user *to, const void *from, unsigned long n);
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static inline long copy_from_user(void *to, const void __user *from,
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unsigned long n)
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{
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unsigned long res = n;
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if (access_ok(VERIFY_READ, from, n))
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res = __copy_from_user(to, from, n);
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if (unlikely(res))
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memset(to + (n - res), 0, res);
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return res;
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}
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static inline long copy_to_user(void __user *to, const void *from,
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unsigned long n)
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{
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if (!access_ok(VERIFY_WRITE, to, n))
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return n;
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return __copy_to_user(to, from, n);
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}
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extern long strncpy_from_user(char *__to, const char __user *__from,
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long __len);
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extern long strnlen_user(const char __user *s, long n);
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#define __copy_from_user_inatomic __copy_from_user
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#define __copy_to_user_inatomic __copy_to_user
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/* Optimized macros */
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#define __get_user_asm(val, insn, addr, err) \
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{ \
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__asm__ __volatile__( \
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" movi %0, %3\n" \
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"1: " insn " %1, 0(%2)\n" \
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" movi %0, 0\n" \
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"2:\n" \
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" .section __ex_table,\"a\"\n" \
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" .word 1b, 2b\n" \
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" .previous" \
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: "=&r" (err), "=r" (val) \
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: "r" (addr), "i" (-EFAULT)); \
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}
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#define __get_user_unknown(val, size, ptr, err) do { \
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err = 0; \
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if (__copy_from_user(&(val), ptr, size)) { \
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err = -EFAULT; \
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} \
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} while (0)
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#define __get_user_common(val, size, ptr, err) \
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do { \
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switch (size) { \
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case 1: \
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__get_user_asm(val, "ldbu", ptr, err); \
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break; \
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case 2: \
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__get_user_asm(val, "ldhu", ptr, err); \
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break; \
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case 4: \
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__get_user_asm(val, "ldw", ptr, err); \
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break; \
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default: \
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__get_user_unknown(val, size, ptr, err); \
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break; \
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} \
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} while (0)
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#define __get_user(x, ptr) \
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({ \
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long __gu_err = -EFAULT; \
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const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
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unsigned long __gu_val = 0; \
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__get_user_common(__gu_val, sizeof(*(ptr)), __gu_ptr, __gu_err);\
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(x) = (__force __typeof__(x))__gu_val; \
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__gu_err; \
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})
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#define get_user(x, ptr) \
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({ \
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long __gu_err = -EFAULT; \
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const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
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unsigned long __gu_val = 0; \
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if (access_ok(VERIFY_READ, __gu_ptr, sizeof(*__gu_ptr))) \
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__get_user_common(__gu_val, sizeof(*__gu_ptr), \
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__gu_ptr, __gu_err); \
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(x) = (__force __typeof__(x))__gu_val; \
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__gu_err; \
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})
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#define __put_user_asm(val, insn, ptr, err) \
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{ \
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__asm__ __volatile__( \
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" movi %0, %3\n" \
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"1: " insn " %1, 0(%2)\n" \
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" movi %0, 0\n" \
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"2:\n" \
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" .section __ex_table,\"a\"\n" \
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" .word 1b, 2b\n" \
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" .previous\n" \
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: "=&r" (err) \
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: "r" (val), "r" (ptr), "i" (-EFAULT)); \
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}
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#define put_user(x, ptr) \
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({ \
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long __pu_err = -EFAULT; \
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__typeof__(*(ptr)) __user *__pu_ptr = (ptr); \
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__typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \
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if (access_ok(VERIFY_WRITE, __pu_ptr, sizeof(*__pu_ptr))) { \
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switch (sizeof(*__pu_ptr)) { \
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case 1: \
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__put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \
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break; \
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case 2: \
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__put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \
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break; \
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case 4: \
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__put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \
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break; \
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default: \
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/* XXX: This looks wrong... */ \
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__pu_err = 0; \
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if (copy_to_user(__pu_ptr, &(__pu_val), \
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sizeof(*__pu_ptr))) \
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__pu_err = -EFAULT; \
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break; \
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} \
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} \
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__pu_err; \
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})
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#define __put_user(x, ptr) put_user(x, ptr)
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#endif /* _ASM_NIOS2_UACCESS_H */
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