[PATCH] ARM: cleanup vmalloc start/offset macros
VMALLOC_START and VMALLOC_OFFSET are common between all ARM
machine classes. Move them into include/asm-arm/pgtable.h,
but allow a machine class to override them if required.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
diff --git a/include/asm-arm/pgtable.h b/include/asm-arm/pgtable.h
index 2df4eac..a9892eb 100644
--- a/include/asm-arm/pgtable.h
+++ b/include/asm-arm/pgtable.h
@@ -17,6 +17,23 @@
#include <asm/arch/vmalloc.h>
/*
+ * Just any arbitrary offset to the start of the vmalloc VM area: the
+ * current 8MB value just means that there will be a 8MB "hole" after the
+ * physical memory until the kernel virtual memory starts. That means that
+ * any out-of-bounds memory accesses will hopefully be caught.
+ * The vmalloc() routines leaves a hole of 4kB between each vmalloced
+ * area for the same reason. ;)
+ *
+ * Note that platforms may override VMALLOC_START, but they must provide
+ * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
+ * which may not overlap IO space.
+ */
+#ifndef VMALLOC_START
+#define VMALLOC_OFFSET (8*1024*1024)
+#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
+#endif
+
+/*
* Hardware-wise, we have a two level page table structure, where the first
* level has 4096 entries, and the second level has 256 entries. Each entry
* is one 32-bit word. Most of the bits in the second level entry are used