[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/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 465b75c..22612ed 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1013,7 +1013,7 @@
 	unsigned int instr;
 
 	addr &= ~3;
-	if (addr < KERNELBASE) {
+	if (!is_kernel_addr(addr)) {
 		printf("Breakpoints may only be placed at kernel addresses\n");
 		return 0;
 	}
@@ -1064,7 +1064,7 @@
 		dabr.address = 0;
 		dabr.enabled = 0;
 		if (scanhex(&dabr.address)) {
-			if (dabr.address < KERNELBASE) {
+			if (!is_kernel_addr(dabr.address)) {
 				printf(badaddr);
 				break;
 			}