arch/x86/include/asm/uaccess_32.h

   1 #ifndef _ASM_X86_UACCESS_32_H
   2 #define _ASM_X86_UACCESS_32_H
   3
   4 /*
   5  * User space memory access functions
   6  */
   7 #include <linux/string.h>
   8 #include <asm/asm.h>
   9 #include <asm/page.h>
  10
  11 unsigned long __must_check __copy_user_ll
  12                 (void *to, const void *from, unsigned long n);
  13 unsigned long __must_check __copy_from_user_ll_nocache_nozero
  14                 (void *to, const void __user *from, unsigned long n);
  15
  16 static __always_inline unsigned long __must_check
  17 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
  18 {
  19         return __copy_user_ll((__force void *)to, from, n);
  20 }
  21
  22 static __always_inline unsigned long
  23 raw_copy_from_user(void *to, const void __user *from, unsigned long n)
  24 {
  25         if (__builtin_constant_p(n)) {
  26                 unsigned long ret;
  27
  28                 switch (n) {
  29                 case 1:
  30                         ret = 0;
  31                         __uaccess_begin();
  32                         __get_user_asm_nozero(*(u8 *)to, from, ret,
  33                                               "b", "b", "=q", 1);
  34                         __uaccess_end();
  35                         return ret;
  36                 case 2:
  37                         ret = 0;
  38                         __uaccess_begin();
  39                         __get_user_asm_nozero(*(u16 *)to, from, ret,
  40                                               "w", "w", "=r", 2);
  41                         __uaccess_end();
  42                         return ret;
  43                 case 4:
  44                         ret = 0;
  45                         __uaccess_begin();
  46                         __get_user_asm_nozero(*(u32 *)to, from, ret,
  47                                               "l", "k", "=r", 4);
  48                         __uaccess_end();
  49                         return ret;
  50                 }
  51         }
  52         return __copy_user_ll(to, (__force const void *)from, n);
  53 }
  54
  55 static __always_inline unsigned long
  56 __copy_from_user_inatomic_nocache(void *to, const void __user *from,
  57                                   unsigned long n)
  58 {
  59        return __copy_from_user_ll_nocache_nozero(to, from, n);
  60 }
  61
  62 #endif /* _ASM_X86_UACCESS_32_H */