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, 3 insertions, 2 deletions

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 5a02bf4c91ec..1aecc658cd7d 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -238,9 +238,10 @@ void __init setup_node_bootmem(int nodeid, unsigned long start,
 
         free_bootmem_with_active_regions(nodeid, end);
 
-        reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size);
+        reserve_bootmem_node(NODE_DATA(nodeid), nodedata_phys, pgdat_size,
+                        BOOTMEM_DEFAULT);
         reserve_bootmem_node(NODE_DATA(nodeid), bootmap_start,
-                             bootmap_pages<<PAGE_SHIFT);
+                        bootmap_pages<<PAGE_SHIFT, BOOTMEM_DEFAULT);
 #ifdef CONFIG_ACPI_NUMA
         srat_reserve_add_area(nodeid);
 #endif