Import QEMU upstream snapshot d2e570c

Upstream: https://gitlab.com/qemu-project/qemu.git

Upstream-Commit: d2e570cc0f97b936902a5b1b86b73c0f5998b475

page-vary-common.c

@@ -0,0 +1,67 @@
+/*
+ * Variable page size handling -- target independent part.
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define IN_PAGE_VARY 1
+
+#include "qemu/osdep.h"
+#include "qemu/target-info-impl.h"
+#include "exec/page-vary.h"
+
+/* WARNING: This file must *not* be complied with -flto. */
+
+TargetPageBits target_page;
+
+bool set_preferred_target_page_bits(int bits)
+{
+    const TargetInfo *ti = target_info();
+
+    assert(bits >= TARGET_PAGE_BITS_MIN);
+    if (ti->page_bits_vary) {
+
+        /*
+         * The target page size is the lowest common denominator for all
+         * the CPUs in the system, so we can only make it smaller, never
+         * larger. And we can't make it smaller once we've committed to
+         * a particular size.
+         */
+        if (target_page.bits == 0 || target_page.bits > bits) {
+            if (target_page.decided) {
+                return false;
+            }
+            target_page.bits = bits;
+        }
+    }
+    return true;
+}
+
+void finalize_target_page_bits(void)
+{
+    int bits = target_page.bits;
+
+    if (bits == 0) {
+        const TargetInfo *ti = target_info();
+
+        bits = ti->page_bits_init;
+        assert(bits != 0);
+        target_page.bits = bits;
+    }
+
+    target_page.mask = -1ull << bits;
+    target_page.decided = true;
+}