qemu

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/*
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 * SPDX-License-Identifier: GPL-2.0-or-later
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 * Host specific cpu identification for AArch64.
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 */
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#include "qemu/osdep.h"
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#include "host/cpuinfo.h"
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#ifdef CONFIG_LINUX
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# ifdef CONFIG_GETAUXVAL
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#  include <sys/auxv.h>
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# else
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#  include <asm/hwcap.h>
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#  include "elf.h"
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# endif
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# ifndef HWCAP2_BTI
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#  define HWCAP2_BTI 0  /* added in glibc 2.32 */
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# endif
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#endif
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#ifdef CONFIG_ELF_AUX_INFO
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#include <sys/auxv.h>
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#endif
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#ifdef CONFIG_DARWIN
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# include <sys/sysctl.h>
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#endif
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#if defined(__OpenBSD__) && !defined(CONFIG_ELF_AUX_INFO)
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# include <machine/armreg.h>
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# include <machine/cpu.h>
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# include <sys/types.h>
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# include <sys/sysctl.h>
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#endif
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unsigned cpuinfo;
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#ifdef CONFIG_DARWIN
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static bool sysctl_for_bool(const char *name)
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{
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    int val = 0;
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    size_t len = sizeof(val);
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    if (sysctlbyname(name, &val, &len, NULL, 0) == 0) {
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        return val != 0;
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    }
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    /*
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     * We might in the future ask for properties not present in older kernels,
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     * but we're only asking about static properties, all of which should be
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     * 'int'.  So we shouldn't see ENOMEM (val too small), or any of the other
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     * more exotic errors.
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     */
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    assert(errno == ENOENT);
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    return false;
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}
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#endif
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/* Called both as constructor and (possibly) via other constructors. */
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unsigned __attribute__((constructor)) cpuinfo_init(void)
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{
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    unsigned info = cpuinfo;
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    if (info) {
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        return info;
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    }
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    info = CPUINFO_ALWAYS;
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#if defined(CONFIG_LINUX) || defined(CONFIG_ELF_AUX_INFO)
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    unsigned long hwcap = qemu_getauxval(AT_HWCAP);
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    info |= (hwcap & HWCAP_ATOMICS ? CPUINFO_LSE : 0);
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    info |= (hwcap & HWCAP_USCAT ? CPUINFO_LSE2 : 0);
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    info |= (hwcap & HWCAP_AES ? CPUINFO_AES : 0);
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    info |= (hwcap & HWCAP_PMULL ? CPUINFO_PMULL : 0);
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    unsigned long hwcap2 = qemu_getauxval(AT_HWCAP2);
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    info |= (hwcap2 & HWCAP2_BTI ? CPUINFO_BTI : 0);
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#endif
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#ifdef CONFIG_DARWIN
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    info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE") * CPUINFO_LSE;
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    info |= sysctl_for_bool("hw.optional.arm.FEAT_LSE2") * CPUINFO_LSE2;
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    info |= sysctl_for_bool("hw.optional.arm.FEAT_AES") * CPUINFO_AES;
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    info |= sysctl_for_bool("hw.optional.arm.FEAT_PMULL") * CPUINFO_PMULL;
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    info |= sysctl_for_bool("hw.optional.arm.FEAT_BTI") * CPUINFO_BTI;
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#endif
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#if defined(__OpenBSD__) && !defined(CONFIG_ELF_AUX_INFO)
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    int mib[2];
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    uint64_t isar0;
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    uint64_t pfr1;
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    size_t len;
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    mib[0] = CTL_MACHDEP;
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    mib[1] = CPU_ID_AA64ISAR0;
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    len = sizeof(isar0);
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    if (sysctl(mib, 2, &isar0, &len, NULL, 0) != -1) {
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        if (ID_AA64ISAR0_ATOMIC(isar0) >= ID_AA64ISAR0_ATOMIC_IMPL) {
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            info |= CPUINFO_LSE;
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        }
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        if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_BASE) {
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            info |= CPUINFO_AES;
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        }
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        if (ID_AA64ISAR0_AES(isar0) >= ID_AA64ISAR0_AES_PMULL) {
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            info |= CPUINFO_PMULL;
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        }
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    }
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    mib[0] = CTL_MACHDEP;
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    mib[1] = CPU_ID_AA64PFR1;
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    len = sizeof(pfr1);
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    if (sysctl(mib, 2, &pfr1, &len, NULL, 0) != -1) {
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        if (ID_AA64PFR1_BT(pfr1) >= ID_AA64PFR1_BT_IMPL) {
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            info |= CPUINFO_BTI;
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        }
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    }
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#endif
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    cpuinfo = info;
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    return info;
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}
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