[PATCH] powerpc: Add a is_kernel_addr() macro

There's a bunch of code that compares an address with KERNELBASE to see if
it's a "kernel address", ie. >= KERNELBASE. The proper test is actually to
compare with PAGE_OFFSET, since we're going to change KERNELBASE soon.

So replace all of them with an is_kernel_addr() macro that does that.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h
index 18c1e5e..94905ba 100644
--- a/include/asm-powerpc/page.h
+++ b/include/asm-powerpc/page.h
@@ -86,6 +86,12 @@
 /* to align the pointer to the (next) page boundary */
 #define PAGE_ALIGN(addr)	_ALIGN(addr, PAGE_SIZE)
 
+/*
+ * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
+ * "kernelness", use is_kernel_addr() - it should do what you want.
+ */
+#define is_kernel_addr(x)	((x) >= PAGE_OFFSET)
+
 #ifndef __ASSEMBLY__
 
 #undef STRICT_MM_TYPECHECKS