util/cpuinfo-aarch64.c

   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 }