x86, nx: Mark the ACPI resume trampoline code as +x

We reserve lowmem for the things that need it, like the ACPI
wakeup code, way early to guarantee availability.  This happens
before we set up the proper pagetables, so set_memory_x() has no
effect.

Until we have a better solution, use an initcall to mark the
wakeup code executable.

Originally-by: Matthieu Castet <castet.matthieu@free.fr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Matthias Hopf <mhopf@suse.de>
Cc: rjw@sisk.pl
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <4D4F8019.2090104@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/acpi/sleep.c

@@ -12,10 +12,8 @@
 #include <linux/cpumask.h>
 #include <asm/segment.h>
 #include <asm/desc.h>
-
-#ifdef CONFIG_X86_32
 #include <asm/pgtable.h>
-#endif
+#include <asm/cacheflush.h>
 
 #include "realmode/wakeup.h"
 #include "sleep.h"
@@ -149,6 +147,15 @@ void __init acpi_reserve_wakeup_memory(void)
 	memblock_x86_reserve_range(mem, mem + WAKEUP_SIZE, "ACPI WAKEUP");
 }
 
+int __init acpi_configure_wakeup_memory(void)
+{
+	if (acpi_realmode)
+		set_memory_x(acpi_realmode, WAKEUP_SIZE >> PAGE_SHIFT);
+
+	return 0;
+}
+arch_initcall(acpi_configure_wakeup_memory);
+
 
 static int __init acpi_sleep_setup(char *str)
 {