[PATCH 9/9] util: Add cpuinfo-aarch64.c

[Richard Henderson <richard.henderson@linaro.org>]

Move the code from tcg/.  The only use of these bits so far
is with respect to the atomicity of tcg operations.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/host/aarch64/cpuinfo.h | 22 +++++++++++
 tcg/aarch64/tcg-target.h       |  4 +-
 util/cpuinfo-aarch64.c         | 67 ++++++++++++++++++++++++++++++++++
 tcg/aarch64/tcg-target.c.inc   | 41 +--------------------
 util/meson.build               |  4 +-
 5 files changed, 95 insertions(+), 43 deletions(-)
 create mode 100644 include/host/aarch64/cpuinfo.h
 create mode 100644 util/cpuinfo-aarch64.c

diff --git a/include/host/aarch64/cpuinfo.h b/include/host/aarch64/cpuinfo.h
new file mode 100644
index 0000000000..82227890b4
--- /dev/null
+++ b/include/host/aarch64/cpuinfo.h
@@ -0,0 +1,22 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Host specific cpu indentification for AArch64.
+ */
+
+#ifndef HOST_CPUINFO_H
+#define HOST_CPUINFO_H
+
+#define CPUINFO_ALWAYS          (1u << 0)  /* so cpuinfo is nonzero */
+#define CPUINFO_LSE             (1u << 1)
+#define CPUINFO_LSE2            (1u << 2)
+
+/* Initialized with a constructor. */
+extern unsigned cpuinfo;
+
+/*
+ * We cannot rely on constructor ordering, so other constructors must
+ * use the function interface rather than the variable above.
+ */
+unsigned cpuinfo_init(void);
+
+#endif /* HOST_CPUINFO_H */
diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index 74ee2ed255..b6ff440e15 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -57,8 +57,8 @@ typedef enum {
 #define TCG_TARGET_CALL_ARG_I128        TCG_CALL_ARG_EVEN
 #define TCG_TARGET_CALL_RET_I128        TCG_CALL_RET_NORMAL
 
-extern bool have_lse;
-extern bool have_lse2;
+#define have_lse    (cpuinfo & CPUINFO_LSE)
+#define have_lse2   (cpuinfo & CPUINFO_LSE2)
 
 /* optional instructions */
 #define TCG_TARGET_HAS_div_i32          1
diff --git a/util/cpuinfo-aarch64.c b/util/cpuinfo-aarch64.c
new file mode 100644
index 0000000000..a774fb170f
--- /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 "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;
+}
diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
index bc6b99a1bd..1e5ffb7a49 100644
--- a/tcg/aarch64/tcg-target.c.inc
+++ b/tcg/aarch64/tcg-target.c.inc
@@ -13,12 +13,7 @@
 #include "../tcg-ldst.c.inc"
 #include "../tcg-pool.c.inc"
 #include "qemu/bitops.h"
-#ifdef __linux__
-#include <asm/hwcap.h>
-#endif
-#ifdef CONFIG_DARWIN
-#include <sys/sysctl.h>
-#endif
+#include "cpuinfo.h"
 
 /* We're going to re-use TCGType in setting of the SF bit, which controls
    the size of the operation performed.  If we know the values match, it
@@ -77,9 +72,6 @@ static TCGReg tcg_target_call_oarg_reg(TCGCallReturnKind kind, int slot)
     return TCG_REG_X0 + slot;
 }
 
-bool have_lse;
-bool have_lse2;
-
 #define TCG_REG_TMP TCG_REG_X30
 #define TCG_VEC_TMP TCG_REG_V31
 
@@ -2878,39 +2870,8 @@ static TCGConstraintSetIndex tcg_target_op_def(TCGOpcode op)
     }
 }
 
-#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
-
 static void tcg_target_init(TCGContext *s)
 {
-#ifdef __linux__
-    unsigned long hwcap = qemu_getauxval(AT_HWCAP);
-    have_lse = hwcap & HWCAP_ATOMICS;
-    have_lse2 = hwcap & HWCAP_USCAT;
-#endif
-#ifdef CONFIG_DARWIN
-    have_lse = sysctl_for_bool("hw.optional.arm.FEAT_LSE");
-    have_lse2 = sysctl_for_bool("hw.optional.arm.FEAT_LSE2");
-#endif
-
     tcg_target_available_regs[TCG_TYPE_I32] = 0xffffffffu;
     tcg_target_available_regs[TCG_TYPE_I64] = 0xffffffffu;
     tcg_target_available_regs[TCG_TYPE_V64] = 0xffffffff00000000ull;
diff --git a/util/meson.build b/util/meson.build
index 714c783b4c..c43b910aa7 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -107,6 +107,8 @@ if have_block
   util_ss.add(when: 'CONFIG_LINUX', if_true: files('vfio-helpers.c'))
 endif
 
-if cpu in ['x86', 'x86_64']
+if cpu == 'aarch64'
+  util_ss.add(files('cpuinfo-aarch64.c'))
+elif cpu in ['x86', 'x86_64']
   util_ss.add(files('cpuinfo-i386.c'))
 endif
-- 
2.34.1