qemu/util/cpuinfo-aarch64.c

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/*
* SPDX-License-Identifier: GPL-2.0-or-later
* Host specific cpu identification for AArch64.
*/
#include "qemu/osdep.h"
#include "host/cpuinfo.h"
#ifdef CONFIG_LINUX
# ifdef CONFIG_GETAUXVAL
# include <sys/auxv.h>
# else
# include <asm/hwcap.h>
# include "elf.h"
# endif
#endif
#ifdef CONFIG_DARWIN
# include <sys/sysctl.h>
#endif
unsigned cpuinfo;
#ifdef CONFIG_DARWIN
static bool sysctl_for_bool(const char *name)
{
int val = 0;
size_t len = sizeof(val);
if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
return val != 0;
}
/*
* We might in the future ask for properties not present in older kernels,
* but we're only asking about static properties, all of which should be
* 'int'. So we shouldn't see ENOMEM (val too small), or any of the other
* more exotic errors.
*/
assert(errno == ENOENT);
return false;
}
#endif
/* Called both as constructor and (possibly) via other constructors. */
unsigned __attribute__((constructor)) cpuinfo_init(void)
{
unsigned info = cpuinfo;
if (info) {
return info;
}
info = CPUINFO_ALWAYS;
#ifdef CONFIG_LINUX
unsigned long hwcap = qemu_getauxval(AT_HWCAP);
info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
info |= (hwcap & HWCAP_AES ? CPUINFO_AES: 0);
#endif
#ifdef CONFIG_DARWIN
info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
#endif
cpuinfo = info;
return info;
}