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 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
  25 {
  26         int op = (encoded_op >> 28) & 7;
  27         int cmp = (encoded_op >> 24) & 15;
  28         int oparg = (encoded_op << 8) >> 20;
  29         int cmparg = (encoded_op << 20) >> 20;
  30         int oldval = 0, newval, ret;
  31
  32         load_kernel_asce();
  33         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  34                 oparg = 1 << oparg;
  35
  36         pagefault_disable();
  37         switch (op) {
  38         case FUTEX_OP_SET:
  39                 __futex_atomic_op("lr %2,%5\n",
  40                                   ret, oldval, newval, uaddr, oparg);
  41                 break;
  42         case FUTEX_OP_ADD:
  43                 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
  44                                   ret, oldval, newval, uaddr, oparg);
  45                 break;
  46         case FUTEX_OP_OR:
  47                 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
  48                                   ret, oldval, newval, uaddr, oparg);
  49                 break;
  50         case FUTEX_OP_ANDN:
  51                 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
  52                                   ret, oldval, newval, uaddr, oparg);
  53                 break;
  54         case FUTEX_OP_XOR:
  55                 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
  56                                   ret, oldval, newval, uaddr, oparg);
  57                 break;
  58         default:
  59                 ret = -ENOSYS;
  60         }
  61         pagefault_enable();
  62
  63         if (!ret) {
  64                 switch (cmp) {
  65                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  66                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  67                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  68                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  69                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  70                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  71                 default: ret = -ENOSYS;
  72                 }
  73         }
  74         return ret;
  75 }
  76
  77 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
  78                                                 u32 oldval, u32 newval)
  79 {
  80         int ret;
  81
  82         load_kernel_asce();
  83         asm volatile(
  84                 "   sacf 256\n"
  85                 "0: cs   %1,%4,0(%5)\n"
  86                 "1: la   %0,0\n"
  87                 "2: sacf 768\n"
  88                 EX_TABLE(0b,2b) EX_TABLE(1b,2b)
  89                 : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
  90                 : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
  91                 : "cc", "memory");
  92         *uval = oldval;
  93         return ret;
  94 }
  95
  96 #endif /* _ASM_S390_FUTEX_H */