xref: /openbmc/qemu/util/cpuinfo-aarch64.c (revision 7d87775f)
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_ELF_AUX_INFO
21 #include <sys/auxv.h>
22 #endif
23 #ifdef CONFIG_DARWIN
24 # include <sys/sysctl.h>
25 #endif
26 #if defined(__OpenBSD__) && !defined(CONFIG_ELF_AUX_INFO)
27 # include <machine/armreg.h>
28 # include <machine/cpu.h>
29 # include <sys/types.h>
30 # include <sys/sysctl.h>
31 #endif
32 
33 unsigned cpuinfo;
34 
35 #ifdef CONFIG_DARWIN
36 static bool sysctl_for_bool(const char *name)
37 {
38     int val = 0;
39     size_t len = sizeof(val);
40 
41     if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
42         return val != 0;
43     }
44 
45     /*
46      * We might in the future ask for properties not present in older kernels,
47      * but we're only asking about static properties, all of which should be
48      * 'int'.  So we shouldn't see ENOMEM (val too small), or any of the other
49      * more exotic errors.
50      */
51     assert(errno == ENOENT);
52     return false;
53 }
54 #endif
55 
56 /* Called both as constructor and (possibly) via other constructors. */
57 unsigned __attribute__((constructor)) cpuinfo_init(void)
58 {
59     unsigned info = cpuinfo;
60 
61     if (info) {
62         return info;
63     }
64 
65     info = CPUINFO_ALWAYS;
66 
67 #if defined(CONFIG_LINUX) || defined(CONFIG_ELF_AUX_INFO)
68     unsigned long hwcap = qemu_getauxval(AT_HWCAP);
69     info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
70     info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
71     info |= (hwcap & HWCAP_AES ? CPUINFO_AES : 0);
72     info |= (hwcap & HWCAP_PMULL ? CPUINFO_PMULL : 0);
73 
74     unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
75     info |= (hwcap2 & HWCAP2_BTI ? CPUINFO_BTI : 0);
76 #endif
77 #ifdef CONFIG_DARWIN
78     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
79     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
80     info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
81     info |= sysctl_for_bool("hw.optional.arm.FEAT_PMULL") * CPUINFO_PMULL;
82     info |= sysctl_for_bool("hw.optional.arm.FEAT_BTI") * CPUINFO_BTI;
83 #endif
84 #if defined(__OpenBSD__) && !defined(CONFIG_ELF_AUX_INFO)
85     int mib[2];
86     uint64_t isar0;
87     uint64_t pfr1;
88     size_t len;
89 
90     mib[0] = CTL_MACHDEP;
91     mib[1] = CPU_ID_AA64ISAR0;
92     len = sizeof(isar0);
93     if (sysctl(mib, 2, &isar0, &len, NULL, 0) != -1) {
94         if (ID_AA64ISAR0_ATOMIC(isar0) >= ID_AA64ISAR0_ATOMIC_IMPL) {
95             info |= CPUINFO_LSE;
96         }
97         if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_BASE) {
98             info |= CPUINFO_AES;
99         }
100         if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_PMULL) {
101             info |= CPUINFO_PMULL;
102         }
103     }
104 
105     mib[0] = CTL_MACHDEP;
106     mib[1] = CPU_ID_AA64PFR1;
107     len = sizeof(pfr1);
108     if (sysctl(mib, 2, &pfr1, &len, NULL, 0) != -1) {
109         if (ID_AA64PFR1_BT(pfr1) >= ID_AA64PFR1_BT_IMPL) {
110             info |= CPUINFO_BTI;
111         }
112     }
113 #endif
114 
115     cpuinfo = info;
116     return info;
117 }
118