arch/s390/include/asm/futex.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_S390_FUTEX_H
   3 #define _ASM_S390_FUTEX_H
   4
   5 #include <linux/uaccess.h>
   6 #include <linux/futex.h>
   7 #include <asm/mmu_context.h>
   8 #include <asm/errno.h>
   9
  10 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)      \
  11         asm volatile(                                                   \
  12                 "   sacf  256\n"                                        \
  13                 "0: l     %1,0(%6)\n"                                   \
  14                 "1:"insn                                                \
  15                 "2: cs    %1,%2,0(%6)\n"                                \
  16                 "3: jl    1b\n"                                         \
  17                 "   lhi   %0,0\n"                                       \
  18                 "4: sacf  768\n"                                        \
  19                 EX_TABLE(0b,4b) EX_TABLE(1b,4b)                         \
  20                 EX_TABLE(2b,4b) EX_TABLE(3b,4b)                         \
  21                 : "=d" (ret), "=&d" (oldval), "=&d" (newval),           \
  22                   "=m" (*uaddr)                                         \
  23                 : "0" (-EFAULT), "d" (oparg), "a" (uaddr),              \
  24                   "m" (*uaddr) : "cc");
  25
  26 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
  27                 u32 __user *uaddr)
  28 {
  29         int oldval = 0, newval, ret;
  30         mm_segment_t old_fs;
  31
  32         old_fs = enable_sacf_uaccess();
  33         pagefault_disable();
  34         switch (op) {
  35         case FUTEX_OP_SET:
  36                 __futex_atomic_op("lr %2,%5\n",
  37                                   ret, oldval, newval, uaddr, oparg);
  38                 break;
  39         case FUTEX_OP_ADD:
  40                 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
  41                                   ret, oldval, newval, uaddr, oparg);
  42                 break;
  43         case FUTEX_OP_OR:
  44                 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
  45                                   ret, oldval, newval, uaddr, oparg);
  46                 break;
  47         case FUTEX_OP_ANDN:
  48                 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
  49                                   ret, oldval, newval, uaddr, oparg);
  50                 break;
  51         case FUTEX_OP_XOR:
  52                 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
  53                                   ret, oldval, newval, uaddr, oparg);
  54                 break;
  55         default:
  56                 ret = -ENOSYS;
  57         }
  58         pagefault_enable();
  59         disable_sacf_uaccess(old_fs);
  60
  61         if (!ret)
  62                 *oval = oldval;
  63
  64         return ret;
  65 }
  66
  67 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  68                                                 u32 oldval, u32 newval)
  69 {
  70         mm_segment_t old_fs;
  71         int ret;
  72
  73         old_fs = enable_sacf_uaccess();
  74         asm volatile(
  75                 "   sacf 256\n"
  76                 "0: cs   %1,%4,0(%5)\n"
  77                 "1: la   %0,0\n"
  78                 "2: sacf 768\n"
  79                 EX_TABLE(0b,2b) EX_TABLE(1b,2b)
  80                 : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
  81                 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
  82                 : "cc", "memory");
  83         disable_sacf_uaccess(old_fs);
  84         *uval = oldval;
  85         return ret;
  86 }
  87
  88 #endif /* _ASM_S390_FUTEX_H */