LXR linux/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
  21static inline int
  22futex_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
  31static 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 */
  80