mm: Add alloc_bootmem_low_pages_nopanic()

We don't need to panic in some case, like for swiotlb preallocating.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-35-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 3f778c2..3cd16ba 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -99,6 +99,9 @@
 extern void *__alloc_bootmem_low(unsigned long size,
 				 unsigned long align,
 				 unsigned long goal);
+void *__alloc_bootmem_low_nopanic(unsigned long size,
+				 unsigned long align,
+				 unsigned long goal);
 extern void *__alloc_bootmem_low_node(pg_data_t *pgdat,
 				      unsigned long size,
 				      unsigned long align,
@@ -132,6 +135,8 @@
 
 #define alloc_bootmem_low(x) \
 	__alloc_bootmem_low(x, SMP_CACHE_BYTES, 0)
+#define alloc_bootmem_low_pages_nopanic(x) \
+	__alloc_bootmem_low_nopanic(x, PAGE_SIZE, 0)
 #define alloc_bootmem_low_pages(x) \
 	__alloc_bootmem_low(x, PAGE_SIZE, 0)
 #define alloc_bootmem_low_pages_node(pgdat, x) \
diff --git a/mm/bootmem.c b/mm/bootmem.c
index b93376c..2b0bcb0 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -833,6 +833,14 @@
 	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
 }
 
+void * __init __alloc_bootmem_low_nopanic(unsigned long size,
+					  unsigned long align,
+					  unsigned long goal)
+{
+	return ___alloc_bootmem_nopanic(size, align, goal,
+					ARCH_LOW_ADDRESS_LIMIT);
+}
+
 /**
  * __alloc_bootmem_low_node - allocate low boot memory from a specific node
  * @pgdat: node to allocate from
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 03d152a..5e07d36 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -391,6 +391,14 @@
 	return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
 }
 
+void * __init __alloc_bootmem_low_nopanic(unsigned long size,
+					  unsigned long align,
+					  unsigned long goal)
+{
+	return ___alloc_bootmem_nopanic(size, align, goal,
+					ARCH_LOW_ADDRESS_LIMIT);
+}
+
 /**
  * __alloc_bootmem_low_node - allocate low boot memory from a specific node
  * @pgdat: node to allocate from