x86: move page_is_ram() function
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index f4a2082..d3026e1 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -31,6 +31,30 @@
#endif
+int page_is_ram(unsigned long pagenr)
+{
+ unsigned long addr, end;
+ int i;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ /*
+ * Not usable memory:
+ */
+ if (e820.map[i].type != E820_RAM)
+ continue;
+ /*
+ * !!!FIXME!!! Some BIOSen report areas as RAM that
+ * are not. Notably the 640->1Mb area. We need a sanity
+ * check here.
+ */
+ addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
+ end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
+ if ((pagenr >= addr) && (pagenr < end))
+ return 1;
+ }
+ return 0;
+}
+
/*
* Fix up the linear direct mapping of the kernel to avoid cache attribute
* conflicts.
