root/arch/sh/include/asm/futex.h

INCLUDED FROM

DEFINITIONS

1. futex_atomic_cmpxchg_inatomic
2. arch_futex_atomic_op_inuser

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_SH_FUTEX_H
   3 #define __ASM_SH_FUTEX_H
   4 
   5 #ifdef __KERNEL__
   6 
   7 #include <linux/futex.h>
   8 #include <linux/uaccess.h>
   9 #include <asm/errno.h>
  10 
  11 #if !defined(CONFIG_SMP)
  12 #include <asm/futex-irq.h>
  13 #elif defined(CONFIG_CPU_J2)
  14 #include <asm/futex-cas.h>
  15 #elif defined(CONFIG_CPU_SH4A)
  16 #include <asm/futex-llsc.h>
  17 #else
  18 #error SMP not supported on this configuration.
  19 #endif
  20 
  21 static inline int
  22 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  23                               u32 oldval, u32 newval)
  24 {
  25         if (!access_ok(uaddr, sizeof(u32)))
  26                 return -EFAULT;
  27 
  28         return atomic_futex_op_cmpxchg_inatomic(uval, uaddr, oldval, newval);
  29 }
  30 
  31 static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
  32                 u32 __user *uaddr)
  33 {
  34         u32 oldval, newval, prev;
  35         int ret;
  36 
  37         pagefault_disable();
  38 
  39         do {
  40                 ret = get_user(oldval, uaddr);
  41 
  42                 if (ret) break;
  43 
  44                 switch (op) {
  45                 case FUTEX_OP_SET:
  46                         newval = oparg;
  47                         break;
  48                 case FUTEX_OP_ADD:
  49                         newval = oldval + oparg;
  50                         break;
  51                 case FUTEX_OP_OR:
  52                         newval = oldval | oparg;
  53                         break;
  54                 case FUTEX_OP_ANDN:
  55                         newval = oldval & ~oparg;
  56                         break;
  57                 case FUTEX_OP_XOR:
  58                         newval = oldval ^ oparg;
  59                         break;
  60                 default:
  61                         ret = -ENOSYS;
  62                         break;
  63                 }
  64 
  65                 if (ret) break;
  66 
  67                 ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
  68         } while (!ret && prev != oldval);
  69 
  70         pagefault_enable();
  71 
  72         if (!ret)
  73                 *oval = oldval;
  74 
  75         return ret;
  76 }
  77 
  78 #endif /* __KERNEL__ */
  79 #endif /* __ASM_SH_FUTEX_H */