kernel/arch/c6x/include/asm/uaccess.h

   1 /*
   2  *  Copyright (C) 2011 Texas Instruments Incorporated
   3  *  Author: Mark Salter <msalter@redhat.com>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License version 2 as
   7  *  published by the Free Software Foundation.
   8  */
   9 #ifndef _ASM_C6X_UACCESS_H
  10 #define _ASM_C6X_UACCESS_H
  11
  12 #include <linux/types.h>
  13 #include <linux/compiler.h>
  14 #include <linux/string.h>
  15
  16 #ifdef CONFIG_ACCESS_CHECK
  17 #define __access_ok _access_ok
  18 #endif
  19
  20 /*
  21  * __copy_from_user/copy_to_user are based on ones in asm-generic/uaccess.h
  22  *
  23  * C6X supports unaligned 32 and 64 bit loads and stores.
  24  */
  25 static inline __must_check long __copy_from_user(void *to,
  26                 const void __user *from, unsigned long n)
  27 {
  28         u32 tmp32;
  29         u64 tmp64;
  30
  31         if (__builtin_constant_p(n)) {
  32                 switch (n) {
  33                 case 1:
  34                         *(u8 *)to = *(u8 __force *)from;
  35                         return 0;
  36                 case 4:
  37                         asm volatile ("ldnw .d1t1 *%2,%0\n"
  38                                       "nop  4\n"
  39                                       "stnw .d1t1 %0,*%1\n"
  40                                       : "=&a"(tmp32)
  41                                       : "A"(to), "a"(from)
  42                                       : "memory");
  43                         return 0;
  44                 case 8:
  45                         asm volatile ("ldndw .d1t1 *%2,%0\n"
  46                                       "nop   4\n"
  47                                       "stndw .d1t1 %0,*%1\n"
  48                                       : "=&a"(tmp64)
  49                                       : "a"(to), "a"(from)
  50                                       : "memory");
  51                         return 0;
  52                 default:
  53                         break;
  54                 }
  55         }
  56
  57         memcpy(to, (const void __force *)from, n);
  58         return 0;
  59 }
  60
  61 static inline __must_check long __copy_to_user(void __user *to,
  62                 const void *from, unsigned long n)
  63 {
  64         u32 tmp32;
  65         u64 tmp64;
  66
  67         if (__builtin_constant_p(n)) {
  68                 switch (n) {
  69                 case 1:
  70                         *(u8 __force *)to = *(u8 *)from;
  71                         return 0;
  72                 case 4:
  73                         asm volatile ("ldnw .d1t1 *%2,%0\n"
  74                                       "nop  4\n"
  75                                       "stnw .d1t1 %0,*%1\n"
  76                                       : "=&a"(tmp32)
  77                                       : "a"(to), "a"(from)
  78                                       : "memory");
  79                         return 0;
  80                 case 8:
  81                         asm volatile ("ldndw .d1t1 *%2,%0\n"
  82                                       "nop   4\n"
  83                                       "stndw .d1t1 %0,*%1\n"
  84                                       : "=&a"(tmp64)
  85                                       : "a"(to), "a"(from)
  86                                       : "memory");
  87                         return 0;
  88                 default:
  89                         break;
  90                 }
  91         }
  92
  93         memcpy((void __force *)to, from, n);
  94         return 0;
  95 }
  96
  97 #define __copy_to_user   __copy_to_user
  98 #define __copy_from_user __copy_from_user
  99
 100 extern int _access_ok(unsigned long addr, unsigned long size);
 101 #ifdef CONFIG_ACCESS_CHECK
 102 #define __access_ok _access_ok
 103 #endif
 104
 105 #include <asm-generic/uaccess.h>
 106
 107 #endif /* _ASM_C6X_UACCESS_H */