exec: Split out variable page size support to exec-vary.c

The next patch will play a trick with "const" that will
confuse the compiler about the uses of target_page_bits
within exec.c.  Moving everything to a new file prevents
this confusion.

No functional change so far.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Makefile.target

@@ -107,7 +107,7 @@ obj-y += trace/
 
 #########################################################
 # cpu emulator library
-obj-y += exec.o
+obj-y += exec.o exec-vary.o
 obj-y += accel/
 obj-$(CONFIG_TCG) += tcg/tcg.o tcg/tcg-op.o tcg/tcg-op-vec.o tcg/tcg-op-gvec.o
 obj-$(CONFIG_TCG) += tcg/tcg-common.o tcg/optimize.o

exec-vary.c

@@ -0,0 +1,57 @@
+/*
+ * Variable page size handling
+ *
+ *  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 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "exec/exec-all.h"
+
+#ifdef TARGET_PAGE_BITS_VARY
+int target_page_bits;
+bool target_page_bits_decided;
+#endif
+
+bool set_preferred_target_page_bits(int bits)
+{
+    /*
+     * 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.
+     */
+#ifdef TARGET_PAGE_BITS_VARY
+    assert(bits >= TARGET_PAGE_BITS_MIN);
+    if (target_page_bits == 0 || target_page_bits > bits) {
+        if (target_page_bits_decided) {
+            return false;
+        }
+        target_page_bits = bits;
+    }
+#endif
+    return true;
+}
+
+void finalize_target_page_bits(void)
+{
+#ifdef TARGET_PAGE_BITS_VARY
+    if (target_page_bits == 0) {
+        target_page_bits = TARGET_PAGE_BITS_MIN;
+    }
+    target_page_bits_decided = true;
+#endif
+}

exec.c

@@ -91,11 +91,6 @@ AddressSpace address_space_memory;
 static MemoryRegion io_mem_unassigned;
 #endif
 
-#ifdef TARGET_PAGE_BITS_VARY
-int target_page_bits;
-bool target_page_bits_decided;
-#endif
-
 CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
 
 /* current CPU in the current thread. It is only valid inside
@@ -109,37 +104,8 @@ int use_icount;
 uintptr_t qemu_host_page_size;
 intptr_t qemu_host_page_mask;
 
-bool set_preferred_target_page_bits(int bits)
-{
-    /* 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.
-     */
-#ifdef TARGET_PAGE_BITS_VARY
-    assert(bits >= TARGET_PAGE_BITS_MIN);
-    if (target_page_bits == 0 || target_page_bits > bits) {
-        if (target_page_bits_decided) {
-            return false;
-        }
-        target_page_bits = bits;
-    }
-#endif
-    return true;
-}
-
 #if !defined(CONFIG_USER_ONLY)
 
-static void finalize_target_page_bits(void)
-{
-#ifdef TARGET_PAGE_BITS_VARY
-    if (target_page_bits == 0) {
-        target_page_bits = TARGET_PAGE_BITS_MIN;
-    }
-    target_page_bits_decided = true;
-#endif
-}
-
 typedef struct PhysPageEntry PhysPageEntry;
 
 struct PhysPageEntry {

include/qemu-common.h

@@ -74,6 +74,12 @@ void cpu_exec_step_atomic(CPUState *cpu);
  */
 bool set_preferred_target_page_bits(int bits);
 
+/**
+ * finalize_target_page_bits:
+ * Commit the final value set by set_preferred_target_page_bits.
+ */
+void finalize_target_page_bits(void);
+
 /**
  * Sends a (part of) iovec down a socket, yielding when the socket is full, or
  * Receives data into a (part of) iovec from a socket,