[PATCH] bootmem: use MAX_DMA_ADDRESS instead of LOW32LIMIT

Introduce ARCH_LOW_ADDRESS_LIMIT which can be set per architecture to
override the 4GB default limit used by the bootmem allocater within
__alloc_bootmem_low() and __alloc_bootmem_low_node().  E.g.  s390 needs a
2GB limit instead of 4GB.

Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 10 insertions, 3 deletions

diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index a3a4e5fd30d7..578c2209fa76 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -337,6 +337,8 @@ struct notifier_block;
 int register_idle_notifier(struct notifier_block *nb);
 int unregister_idle_notifier(struct notifier_block *nb);
 
+#define ARCH_LOW_ADDRESS_LIMIT  0x7fffffffUL
+
 #endif
 
 /*
diff --git a/mm/bootmem.c b/mm/bootmem.c
index f0f85fa713ca..d53112fcb404 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -15,6 +15,7 @@
 
 #include <asm/bug.h>
 #include <asm/io.h>
+#include <asm/processor.h>
 
 #include "internal.h"
 
@@ -453,7 +454,9 @@ void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
         return __alloc_bootmem(size, align, goal);
 }
 
-#define LOW32LIMIT 0xffffffff
+#ifndef ARCH_LOW_ADDRESS_LIMIT
+#define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
+#endif
 
 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
                                   unsigned long goal)
@@ -462,7 +465,8 @@ void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
         void *ptr;
 
         list_for_each_entry(bdata, &bdata_list, list) {
-                ptr = __alloc_bootmem_core(bdata, size, align, goal, LOW32LIMIT);
+                ptr = __alloc_bootmem_core(bdata, size, align, goal,
+                                                ARCH_LOW_ADDRESS_LIMIT);
                 if (ptr)
                         return ptr;
         }
@@ -478,5 +482,6 @@ void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
                                        unsigned long align, unsigned long goal)
 {
-        return __alloc_bootmem_core(pgdat->bdata, size, align, goal, LOW32LIMIT);
+        return __alloc_bootmem_core(pgdat->bdata, size, align, goal,
+                                    ARCH_LOW_ADDRESS_LIMIT);
 }