sparc64: Document the shift counts used to validate linear kernel addresses.
This way we can see exactly what they are derived from, and in particular
how they would change if we were to use a different PAGE_OFFSET value.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
diff --git a/arch/sparc/mm/init_64.h b/arch/sparc/mm/init_64.h
index 0661aa6..5d3782de 100644
--- a/arch/sparc/mm/init_64.h
+++ b/arch/sparc/mm/init_64.h
@@ -1,11 +1,13 @@
#ifndef _SPARC64_MM_INIT_H
#define _SPARC64_MM_INIT_H
+#include <asm/page.h>
+
/* Most of the symbols in this file are defined in init.c and
* marked non-static so that assembler code can get at them.
*/
-#define MAX_PHYS_ADDRESS (1UL << 41UL)
+#define MAX_PHYS_ADDRESS (1UL << MAX_PHYS_ADDRESS_BITS)
#define KPTE_BITMAP_CHUNK_SZ (256UL * 1024UL * 1024UL)
#define KPTE_BITMAP_BYTES \
((MAX_PHYS_ADDRESS / KPTE_BITMAP_CHUNK_SZ) / 4)