arch/openrisc/include/asm/futex.h

   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
  33 static inline int
  34 arch_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
  68 static inline int
  69 futex_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 */