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 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
  31 {
  32         int op = (encoded_op >> 28) & 7;
  33         int cmp = (encoded_op >> 24) & 15;
  34         u32 oparg = (encoded_op << 8) >> 20;
  35         u32 cmparg = (encoded_op << 20) >> 20;
  36         u32 oldval, newval, prev;
  37         int ret;
  38
  39         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  40                 oparg = 1 << oparg;
  41
  42         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  43                 return -EFAULT;
  44
  45         pagefault_disable();
  46
  47         do {
  48                 if (op == FUTEX_OP_SET)
  49                         ret = oldval = 0;
  50                 else
  51                         ret = get_user(oldval, uaddr);
  52
  53                 if (ret) break;
  54
  55                 switch (op) {
  56                 case FUTEX_OP_SET:
  57                         newval = oparg;
  58                         break;
  59                 case FUTEX_OP_ADD:
  60                         newval = oldval + oparg;
  61                         break;
  62                 case FUTEX_OP_OR:
  63                         newval = oldval | oparg;
  64                         break;
  65                 case FUTEX_OP_ANDN:
  66                         newval = oldval & ~oparg;
  67                         break;
  68                 case FUTEX_OP_XOR:
  69                         newval = oldval ^ oparg;
  70                         break;
  71                 default:
  72                         ret = -ENOSYS;
  73                         break;
  74                 }
  75
  76                 if (ret) break;
  77
  78                 ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
  79         } while (!ret && prev != oldval);
  80
  81         pagefault_enable();
  82
  83         if (!ret) {
  84                 switch (cmp) {
  85                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  86                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  87                 case FUTEX_OP_CMP_LT: ret = ((int)oldval < (int)cmparg); break;
  88                 case FUTEX_OP_CMP_GE: ret = ((int)oldval >= (int)cmparg); break;
  89                 case FUTEX_OP_CMP_LE: ret = ((int)oldval <= (int)cmparg); break;
  90                 case FUTEX_OP_CMP_GT: ret = ((int)oldval > (int)cmparg); break;
  91                 default: ret = -ENOSYS;
  92                 }
  93         }
  94
  95         return ret;
  96 }
  97
  98 #endif /* __KERNEL__ */
  99 #endif /* __ASM_SH_FUTEX_H */