include/asm-s390/futex.h

   1 #ifndef _ASM_S390_FUTEX_H
   2 #define _ASM_S390_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <asm/errno.h>
   8 #include <asm/uaccess.h>
   9
  10 #ifndef __s390x__
  11 #define __futex_atomic_fixup \
  12                      ".section __ex_table,\"a\"\n"                      \
  13                      "   .align 4\n"                                    \
  14                      "   .long  0b,2b,1b,2b\n"                          \
  15                      ".previous"
  16 #else /* __s390x__ */
  17 #define __futex_atomic_fixup \
  18                      ".section __ex_table,\"a\"\n"                      \
  19                      "   .align 8\n"                                    \
  20                      "   .quad  0b,2b,1b,2b\n"                          \
  21                      ".previous"
  22 #endif /* __s390x__ */
  23
  24 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)      \
  25         asm volatile("   l   %1,0(%6)\n"                                \
  26                      "0: " insn                                         \
  27                      "   cs  %1,%2,0(%6)\n"                             \
  28                      "1: jl  0b\n"                                      \
  29                      "   lhi %0,0\n"                                    \
  30                      "2:\n"                                             \
  31                      __futex_atomic_fixup                               \
  32                      : "=d" (ret), "=&d" (oldval), "=&d" (newval),      \
  33                        "=m" (*uaddr)                                    \
  34                      : "0" (-EFAULT), "d" (oparg), "a" (uaddr),         \
  35                        "m" (*uaddr) : "cc" );
  36
  37 static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
  38 {
  39         int op = (encoded_op >> 28) & 7;
  40         int cmp = (encoded_op >> 24) & 15;
  41         int oparg = (encoded_op << 8) >> 20;
  42         int cmparg = (encoded_op << 20) >> 20;
  43         int oldval = 0, newval, ret;
  44         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  45                 oparg = 1 << oparg;
  46
  47         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
  48                 return -EFAULT;
  49
  50         inc_preempt_count();
  51
  52         switch (op) {
  53         case FUTEX_OP_SET:
  54                 __futex_atomic_op("lr %2,%5\n",
  55                                   ret, oldval, newval, uaddr, oparg);
  56                 break;
  57         case FUTEX_OP_ADD:
  58                 __futex_atomic_op("lr %2,%1\nar %2,%5\n",
  59                                   ret, oldval, newval, uaddr, oparg);
  60                 break;
  61         case FUTEX_OP_OR:
  62                 __futex_atomic_op("lr %2,%1\nor %2,%5\n",
  63                                   ret, oldval, newval, uaddr, oparg);
  64                 break;
  65         case FUTEX_OP_ANDN:
  66                 __futex_atomic_op("lr %2,%1\nnr %2,%5\n",
  67                                   ret, oldval, newval, uaddr, oparg);
  68                 break;
  69         case FUTEX_OP_XOR:
  70                 __futex_atomic_op("lr %2,%1\nxr %2,%5\n",
  71                                   ret, oldval, newval, uaddr, oparg);
  72                 break;
  73         default:
  74                 ret = -ENOSYS;
  75         }
  76
  77         dec_preempt_count();
  78
  79         if (!ret) {
  80                 switch (cmp) {
  81                 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
  82                 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
  83                 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
  84                 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
  85                 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
  86                 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
  87                 default: ret = -ENOSYS;
  88                 }
  89         }
  90         return ret;
  91 }
  92
  93 static inline int
  94 futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
  95 {
  96         int ret;
  97
  98         if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
  99                 return -EFAULT;
 100         asm volatile("   cs   %1,%4,0(%5)\n"
 101                      "0: lr   %0,%1\n"
 102                      "1:\n"
 103 #ifndef __s390x__
 104                      ".section __ex_table,\"a\"\n"
 105                      "   .align 4\n"
 106                      "   .long  0b,1b\n"
 107                      ".previous"
 108 #else /* __s390x__ */
 109                      ".section __ex_table,\"a\"\n"
 110                      "   .align 8\n"
 111                      "   .quad  0b,1b\n"
 112                      ".previous"
 113 #endif /* __s390x__ */
 114                      : "=d" (ret), "+d" (oldval), "=m" (*uaddr)
 115                      : "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
 116                      : "cc", "memory" );
 117         return oldval;
 118 }
 119
 120 #endif /* __KERNEL__ */
 121 #endif /* _ASM_S390_FUTEX_H */