1 files changed, 67 insertions, 0 deletions
diff --git a/util/cpuinfo-aarch64.c b/util/cpuinfo-aarch64.c
new file mode 100644
index 0000000..f99acb7
--- /dev/null
+++ b/util/cpuinfo-aarch64.c
@@ -0,0 +1,67 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Host specific cpu indentification 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 shouln'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);
+#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;
+#endif
+
+    cpuinfo = info;
+    return info;
+}