arch/sh/include/asm/futex.h

   1 #ifndef __ASM_SH_FUTEX_H
   2 #define __ASM_SH_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9
  10 #if !defined(CONFIG_SMP)
  11 #include <asm/futex-irq.h>
  12 #elif defined(CONFIG_CPU_J2)
  13 #include <asm/futex-cas.h>
  14 #elif defined(CONFIG_CPU_SH4A)
  15 #include <asm/futex-llsc.h>
  16 #else
  17 #error SMP not supported on this configuration.
  18 #endif
  19
  20 static inline int
  21 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  22                               u32 oldval, u32 newval)
  23 {
  24         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  25                 return -EFAULT;
  26
  27         return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
  28 }
  29
  30 static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
  31                 u32 __user *uaddr)
  32 {
  33         u32 oldval, newval, prev;
  34         int ret;
  35
  36         pagefault_disable();
  37
  38         do {
  39                 if (op == FUTEX_OP_SET)
  40                         ret = oldval = 0;
  41                 else
  42                         ret = get_user(oldval, uaddr);
  43
  44                 if (ret) break;
  45
  46                 switch (op) {
  47                 case FUTEX_OP_SET:
  48                         newval = oparg;
  49                         break;
  50                 case FUTEX_OP_ADD:
  51                         newval = oldval + oparg;
  52                         break;
  53                 case FUTEX_OP_OR:
  54                         newval = oldval | oparg;
  55                         break;
  56                 case FUTEX_OP_ANDN:
  57                         newval = oldval & ~oparg;
  58                         break;
  59                 case FUTEX_OP_XOR:
  60                         newval = oldval ^ oparg;
  61                         break;
  62                 default:
  63                         ret = -ENOSYS;
  64                         break;
  65                 }
  66
  67                 if (ret) break;
  68
  69                 ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
  70         } while (!ret && prev != oldval);
  71
  72         pagefault_enable();
  73
  74         if (!ret)
  75                 *oval = oldval;
  76
  77         return ret;
  78 }
  79
  80 #endif /* __KERNEL__ */
  81 #endif /* __ASM_SH_FUTEX_H */