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_DARWIN
  21 # include <sys/sysctl.h>
  22 #endif
  23
  24 unsigned cpuinfo;
  25
  26 #ifdef CONFIG_DARWIN
  27 static bool sysctl_for_bool(const char *name)
  28 {
  29     int val = 0;
  30     size_t len = sizeof(val);
  31
  32     if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
  33         return val != 0;
  34     }
  35
  36     /*
  37      * We might in the future ask for properties not present in older kernels,
  38      * but we're only asking about static properties, all of which should be
  39      * 'int'.  So we shouldn't see ENOMEM (val too small), or any of the other
  40      * more exotic errors.
  41      */
  42     assert(errno == ENOENT);
  43     return false;
  44 }
  45 #endif
  46
  47 /* Called both as constructor and (possibly) via other constructors. */
  48 unsigned __attribute__((constructor)) cpuinfo_init(void)
  49 {
  50     unsigned info = cpuinfo;
  51
  52     if (info) {
  53         return info;
  54     }
  55
  56     info = CPUINFO_ALWAYS;
  57
  58 #ifdef CONFIG_LINUX
  59     unsigned long hwcap = qemu_getauxval(AT_HWCAP);
  60     info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
  61     info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
  62     info |= (hwcap & HWCAP_AES ? CPUINFO_AES : 0);
  63     info |= (hwcap & HWCAP_PMULL ? CPUINFO_PMULL : 0);
  64
  65     unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
  66     info |= (hwcap2 & HWCAP2_BTI ? CPUINFO_BTI : 0);
  67 #endif
  68 #ifdef CONFIG_DARWIN
  69     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
  70     info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
  71     info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
  72     info |= sysctl_for_bool("hw.optional.arm.FEAT_PMULL") * CPUINFO_PMULL;
  73     info |= sysctl_for_bool("hw.optional.arm.FEAT_BTI") * CPUINFO_BTI;
  74 #endif
  75
  76     cpuinfo = info;
  77     return info;
  78 }