Introduce flags for reserve_bootmem()

This patchset adds a flags variable to reserve_bootmem() and uses the
BOOTMEM_EXCLUSIVE flag in crashkernel reservation code to detect collisions
between crashkernel area and already used memory.

This patch:

Change the reserve_bootmem() function to accept a new flag BOOTMEM_EXCLUSIVE.
If that flag is set, the function returns with -EBUSY if the memory already
has been reserved in the past.  This is to avoid conflicts.

Because that code runs before SMP initialisation, there's no race condition
inside reserve_bootmem_core().

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: <linux-arch@vger.kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/sh/mm/numa.c b/arch/sh/mm/numa.c
index 8aff065dd307..2de7302724fc 100644
--- a/arch/sh/mm/numa.c
+++ b/arch/sh/mm/numa.c
@@ -80,9 +80,9 @@ void __init setup_bootmem_node(int nid, unsigned long start, unsigned long end)
 
         /* Reserve the pgdat and bootmap space with the bootmem allocator */
         reserve_bootmem_node(NODE_DATA(nid), start_pfn << PAGE_SHIFT,
-                             sizeof(struct pglist_data));
+                             sizeof(struct pglist_data), BOOTMEM_DEFAULT);
         reserve_bootmem_node(NODE_DATA(nid), free_pfn << PAGE_SHIFT,
-                             bootmap_pages << PAGE_SHIFT);
+                             bootmap_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
 
         /* It's up */
         node_set_online(nid);