util: move qemu_real_host_page_size/mask to osdep.h

These only depend on the host and therefore belong in the common
osdep, not in a target-dependent object.

While at it, query the host during an init constructor, which guarantees
the page size will be well-defined throughout the execution of the program.

Suggested-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/util/pagesize.c b/util/pagesize.c
new file mode 100644
index 0000000000..998632cf6e
--- /dev/null
+++ b/util/pagesize.c
@@ -0,0 +1,18 @@
+/*
+ * pagesize.c - query the host about its page size
+ *
+ * Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+
+uintptr_t qemu_real_host_page_size;
+intptr_t qemu_real_host_page_mask;
+
+static void __attribute__((constructor)) init_real_host_page_size(void)
+{
+    qemu_real_host_page_size = getpagesize();
+    qemu_real_host_page_mask = -(intptr_t)qemu_real_host_page_size;
+}