xref: /openbmc/qemu/util/cpuinfo-aarch64.c (revision b9c0a2e0)
1 /*
2  * SPDX-License-Identifier: GPL-2.0-or-later
3  * Host specific cpu identification for AArch64.
4  */
5 
6 #include "qemu/osdep.h"
7 #include "host/cpuinfo.h"
8 
9 #ifdef CONFIG_LINUX
10 # ifdef CONFIG_GETAUXVAL
11 #  include <sys/auxv.h>
12 # else
13 #  include <asm/hwcap.h>
14 #  include "elf.h"
15 # endif
16 # ifndef HWCAP2_BTI
17 #  define HWCAP2_BTI 0  /* added in glibc 2.32 */
18 # endif
19 #endif
20 #ifdef CONFIG_DARWIN
21 # include <sys/sysctl.h>
22 #endif
23 #ifdef __OpenBSD__
24 # include <machine/armreg.h>
25 # include <machine/cpu.h>
26 # include <sys/types.h>
27 # include <sys/sysctl.h>
28 #endif
29 
30 unsigned cpuinfo;
31 
32 #ifdef CONFIG_DARWIN
33 static bool sysctl_for_bool(const char *name)
34 {
35     int val = 0;
36     size_t len = sizeof(val);
37 
38     if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
39         return val != 0;
40     }
41 
42     /*
43      * We might in the future ask for properties not present in older kernels,
44      * but we're only asking about static properties, all of which should be
45      * 'int'.  So we shouldn't see ENOMEM (val too small), or any of the other
46      * more exotic errors.
47      */
48     assert(errno == ENOENT);
49     return false;
50 }
51 #endif
52 
53 /* Called both as constructor and (possibly) via other constructors. */
54 unsigned __attribute__((constructor)) cpuinfo_init(void)
55 {
56     unsigned info = cpuinfo;
57 
58     if (info) {
59         return info;
60     }
61 
62     info = CPUINFO_ALWAYS;
63 
64 #ifdef CONFIG_LINUX
65     unsigned long hwcap = qemu_getauxval(AT_HWCAP);
66     info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
67     info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
68     info |= (hwcap & HWCAP_AES ? CPUINFO_AES : 0);
69     info |= (hwcap & HWCAP_PMULL ? CPUINFO_PMULL : 0);
70 
71     unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
72     info |= (hwcap2 & HWCAP2_BTI ? CPUINFO_BTI : 0);
73 #endif
74 #ifdef CONFIG_DARWIN
75     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
76     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
77     info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
78     info |= sysctl_for_bool("hw.optional.arm.FEAT_PMULL") * CPUINFO_PMULL;
79     info |= sysctl_for_bool("hw.optional.arm.FEAT_BTI") * CPUINFO_BTI;
80 #endif
81 #ifdef __OpenBSD__
82     int mib[2];
83     uint64_t isar0;
84     uint64_t pfr1;
85     size_t len;
86 
87     mib[0] = CTL_MACHDEP;
88     mib[1] = CPU_ID_AA64ISAR0;
89     len = sizeof(isar0);
90     if (sysctl(mib, 2, &isar0, &len, NULL, 0) != -1) {
91         if (ID_AA64ISAR0_ATOMIC(isar0) >= ID_AA64ISAR0_ATOMIC_IMPL) {
92             info |= CPUINFO_LSE;
93         }
94         if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_BASE) {
95             info |= CPUINFO_AES;
96         }
97         if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_PMULL) {
98             info |= CPUINFO_PMULL;
99         }
100     }
101 
102     mib[0] = CTL_MACHDEP;
103     mib[1] = CPU_ID_AA64PFR1;
104     len = sizeof(pfr1);
105     if (sysctl(mib, 2, &pfr1, &len, NULL, 0) != -1) {
106         if (ID_AA64PFR1_BT(pfr1) >= ID_AA64PFR1_BT_IMPL) {
107             info |= CPUINFO_BTI;
108         }
109     }
110 #endif
111 
112     cpuinfo = info;
113     return info;
114 }
115