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_extension.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();
is_initialized()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 
arm_arch()88   static int arm_arch()             { return _arm_arch; }
stored_pc_adjustment()89   static int stored_pc_adjustment() { return _stored_pc_adjustment; }
supports_rev()90   static bool supports_rev()        { return _arm_arch >= 6; }
supports_ldrex()91   static bool supports_ldrex()      { return _arm_arch >= 6; }
supports_movw()92   static bool supports_movw()       { return _arm_arch >= 7; }
supports_ldrexd()93   static bool supports_ldrexd()     { return _arm_arch >= 7; }
supports_compare_and_exchange()94   static bool supports_compare_and_exchange() { return true; }
supports_kuser_cmpxchg32()95   static bool supports_kuser_cmpxchg32() { return _kuser_helper_version >= KUSER_VERSION_CMPXCHG32; }
supports_kuser_cmpxchg64()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 
has_vfp()100   static bool has_vfp()             { return (_features & vfp_m) != 0; }
has_vfp3_32()101   static bool has_vfp3_32()         { return (_features & vfp3_32_m) != 0; }
has_simd()102   static bool has_simd()            { return (_features & simd_m) != 0; }
has_multiprocessing_extensions()103   static bool has_multiprocessing_extensions() { return (_features & mp_ext_m) != 0; }
104 
simd_math_is_compliant()105   static bool simd_math_is_compliant() { return false; }
106 
prefer_moves_over_load_literal()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
114