linux/arch/openrisc/include/asm/futex.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_OPENRISC_FUTEX_H
   3#define __ASM_OPENRISC_FUTEX_H
   4
   5#ifdef __KERNEL__
   6
   7#include <linux/futex.h>
   8#include <linux/uaccess.h>
   9#include <asm/errno.h>
  10
  11#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  12({                                                              \
  13        __asm__ __volatile__ (                                  \
  14                "1:     l.lwa   %0, %2                  \n"     \
  15                        insn                            "\n"    \
  16                "2:     l.swa   %2, %1                  \n"     \
  17                "       l.bnf   1b                      \n"     \
  18                "        l.ori  %1, r0, 0               \n"     \
  19                "3:                                     \n"     \
  20                ".section .fixup,\"ax\"                 \n"     \
  21                "4:     l.j     3b                      \n"     \
  22                "        l.addi %1, r0, %3              \n"     \
  23                ".previous                              \n"     \
  24                ".section __ex_table,\"a\"              \n"     \
  25                ".word  1b,4b,2b,4b                     \n"     \
  26                ".previous                              \n"     \
  27                : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr)    \
  28                : "i" (-EFAULT), "r" (oparg)                    \
  29                : "cc", "memory"                                \
  30                );                                              \
  31})
  32
  33static inline int
  34arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
  35{
  36        int oldval = 0, ret;
  37
  38        pagefault_disable();
  39
  40        switch (op) {
  41        case FUTEX_OP_SET:
  42                __futex_atomic_op("l.or %1,%4,%4", ret, oldval, uaddr, oparg);
  43                break;
  44        case FUTEX_OP_ADD:
  45                __futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);
  46                break;
  47        case FUTEX_OP_OR:
  48                __futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);
  49                break;
  50        case FUTEX_OP_ANDN:
  51                __futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);
  52                break;
  53        case FUTEX_OP_XOR:
  54                __futex_atomic_op("l.xor %1,%0,%4", ret, oldval, uaddr, oparg);
  55                break;
  56        default:
  57                ret = -ENOSYS;
  58        }
  59
  60        pagefault_enable();
  61
  62        if (!ret)
  63                *oval = oldval;
  64
  65        return ret;
  66}
  67
  68static inline int
  69futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  70                              u32 oldval, u32 newval)
  71{
  72        int ret = 0;
  73        u32 prev;
  74
  75        if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  76                return -EFAULT;
  77
  78        __asm__ __volatile__ (                          \
  79                "1:     l.lwa   %1, %2          \n"     \
  80                "       l.sfeq  %1, %3          \n"     \
  81                "       l.bnf   3f              \n"     \
  82                "        l.nop                  \n"     \
  83                "2:     l.swa   %2, %4          \n"     \
  84                "       l.bnf   1b              \n"     \
  85                "        l.nop                  \n"     \
  86                "3:                             \n"     \
  87                ".section .fixup,\"ax\"         \n"     \
  88                "4:     l.j     3b              \n"     \
  89                "        l.addi %0, r0, %5      \n"     \
  90                ".previous                      \n"     \
  91                ".section __ex_table,\"a\"      \n"     \
  92                ".word  1b,4b,2b,4b             \n"     \
  93                ".previous                      \n"     \
  94                : "+r" (ret), "=&r" (prev), "+m" (*uaddr) \
  95                : "r" (oldval), "r" (newval), "i" (-EFAULT) \
  96                : "cc", "memory"                        \
  97                );
  98
  99        *uval = prev;
 100        return ret;
 101}
 102
 103#endif /* __KERNEL__ */
 104
 105#endif /* __ASM_OPENRISC_FUTEX_H */
 106