arch/sh/include/asm/futex.h

   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(VERIFY_WRITE, 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                 if (op == FUTEX_OP_SET)
  41                         ret = oldval = 0;
  42                 else
  43                         ret = get_user(oldval, uaddr);
  44
  45                 if (ret) break;
  46
  47                 switch (op) {
  48                 case FUTEX_OP_SET:
  49                         newval = oparg;
  50                         break;
  51                 case FUTEX_OP_ADD:
  52                         newval = oldval + oparg;
  53                         break;
  54                 case FUTEX_OP_OR:
  55                         newval = oldval | oparg;
  56                         break;
  57                 case FUTEX_OP_ANDN:
  58                         newval = oldval & ~oparg;
  59                         break;
  60                 case FUTEX_OP_XOR:
  61                         newval = oldval ^ oparg;
  62                         break;
  63                 default:
  64                         ret = -ENOSYS;
  65                         break;
  66                 }
  67
  68                 if (ret) break;
  69
  70                 ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
  71         } while (!ret && prev != oldval);
  72
  73         pagefault_enable();
  74
  75         if (!ret)
  76                 *oval = oldval;
  77
  78         return ret;
  79 }
  80
  81 #endif /* __KERNEL__ */
  82 #endif /* __ASM_SH_FUTEX_H */