arch/m68k/include/asm/futex.h

   1 #ifndef _ASM_M68K_FUTEX_H
   2 #define _ASM_M68K_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5 #if !defined(CONFIG_MMU)
   6 #include <asm-generic/futex.h>
   7 #else   /* CONFIG_MMU */
   8
   9 #include <linux/futex.h>
  10 #include <linux/uaccess.h>
  11 #include <asm/errno.h>
  12
  13 static inline int
  14 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  15                               u32 oldval, u32 newval)
  16 {
  17         u32 val;
  18
  19         if (unlikely(get_user(val, uaddr) != 0))
  20                 return -EFAULT;
  21
  22         if (val == oldval && unlikely(put_user(newval, uaddr) != 0))
  23                 return -EFAULT;
  24
  25         *uval = val;
  26
  27         return 0;
  28 }
  29
  30 static inline int
  31 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
  32 {
  33         int op = (encoded_op >> 28) & 7;
  34         int cmp = (encoded_op >> 24) & 15;
  35         int oparg = (encoded_op << 8) >> 20;
  36         int cmparg = (encoded_op << 20) >> 20;
  37         int oldval, ret;
  38         u32 tmp;
  39
  40         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  41                 oparg = 1 << oparg;
  42
  43         pagefault_disable();    /* implies preempt_disable() */
  44
  45         ret = -EFAULT;
  46         if (unlikely(get_user(oldval, uaddr) != 0))
  47                 goto out_pagefault_enable;
  48
  49         ret = 0;
  50         tmp = oldval;
  51
  52         switch (op) {
  53         case FUTEX_OP_SET:
  54                 tmp = oparg;
  55                 break;
  56         case FUTEX_OP_ADD:
  57                 tmp += oparg;
  58                 break;
  59         case FUTEX_OP_OR:
  60                 tmp |= oparg;
  61                 break;
  62         case FUTEX_OP_ANDN:
  63                 tmp &= ~oparg;
  64                 break;
  65         case FUTEX_OP_XOR:
  66                 tmp ^= oparg;
  67                 break;
  68         default:
  69                 ret = -ENOSYS;
  70         }
  71
  72         if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
  73                 ret = -EFAULT;
  74
  75 out_pagefault_enable:
  76         pagefault_enable();     /* subsumes preempt_enable() */
  77
  78         if (ret == 0) {
  79                 switch (cmp) {
  80                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  81                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  82                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  83                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  84                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  85                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  86                 default: ret = -ENOSYS;
  87                 }
  88         }
  89         return ret;
  90 }
  91
  92 #endif /* CONFIG_MMU */
  93 #endif /* __KERNEL__ */
  94 #endif /* _ASM_M68K_FUTEX_H */