1 /*
   2  * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef CPU_ARM_VM_VERSION_ARM_HPP
  26 #define CPU_ARM_VM_VERSION_ARM_HPP
  27 
  28 #include "runtime/abstract_vm_version.hpp"
  29 #include "runtime/globals.hpp"
  30 
  31 class VM_Version: public Abstract_VM_Version {
  32   friend class JVMCIVMStructs;
  33 
  34   static bool _has_simd;
  35   static bool _has_mp_ext;
  36 
  37  protected:
  38   // Are we done with vm version initialization
  39   static bool _is_initialized;
  40 
  41  public:
  42   static void initialize();
  43   static bool is_initialized()      { return _is_initialized; }
  44 
  45 
  46  protected:
  47   enum Feature_Flag {
  48     vfp = 0,
  49     vfp3_32 = 1,
  50     simd = 2,
  51     mp_ext = 3
  52   };
  53 
  54   enum Feature_Flag_Set {
  55     unknown_m           = 0,
  56     all_features_m      = -1,
  57 
  58     vfp_m     = 1 << vfp,
  59     vfp3_32_m = 1 << vfp3_32,
  60     simd_m    = 1 << simd,
  61     mp_ext_m  = 1 << mp_ext
  62   };
  63 
  64   // The value stored by "STR PC, [addr]" instruction can be either
  65   // (address of this instruction + 8) or (address of this instruction + 12)
  66   // depending on hardware implementation.
  67   // This adjustment is calculated in runtime.
  68   static int _stored_pc_adjustment;
  69 
  70   // ARM architecture version: 5 = ARMv5, 6 = ARMv6, 7 = ARMv7 etc.
  71   static int _arm_arch;
  72 
  73   // linux kernel atomic helper function version info
  74   // __kuser_cmpxchg() if version >= 2
  75   // __kuser_cmpxchg64() if version >= 5
  76   static int _kuser_helper_version;
  77 
  78 #define KUSER_HELPER_VERSION_ADDR 0xffff0ffc
  79 #define KUSER_VERSION_CMPXCHG32 2
  80 #define KUSER_VERSION_CMPXCHG64 5
  81 
  82   // Read additional info using OS-specific interfaces
  83   static void get_os_cpu_info();
  84 
  85  public:
  86   static void early_initialize();
  87 
  88   static int arm_arch()             { return _arm_arch; }
  89   static int stored_pc_adjustment() { return _stored_pc_adjustment; }
  90   static bool supports_rev()        { return _arm_arch >= 6; }
  91   static bool supports_ldrex()      { return _arm_arch >= 6; }
  92   static bool supports_movw()       { return _arm_arch >= 7; }
  93   static bool supports_ldrexd()     { return _arm_arch >= 7; }
  94   static bool supports_compare_and_exchange() { return true; }
  95   static bool supports_kuser_cmpxchg32() { return _kuser_helper_version >= KUSER_VERSION_CMPXCHG32; }
  96   static bool supports_kuser_cmpxchg64() { return _kuser_helper_version >= KUSER_VERSION_CMPXCHG64; }
  97   // Override Abstract_VM_Version implementation
  98   static bool use_biased_locking();
  99 
 100   static bool has_vfp()             { return (_features & vfp_m) != 0; }
 101   static bool has_vfp3_32()         { return (_features & vfp3_32_m) != 0; }
 102   static bool has_simd()            { return (_features & simd_m) != 0; }
 103   static bool has_multiprocessing_extensions() { return (_features & mp_ext_m) != 0; }
 104 
 105   static bool simd_math_is_compliant() { return false; }
 106 
 107   static bool prefer_moves_over_load_literal() { return supports_movw(); }
 108 
 109   friend class VM_Version_StubGenerator;
 110 
 111 };
 112 
 113 #endif // CPU_ARM_VM_VERSION_ARM_HPP