arch/s390/include/asm/futex.h

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