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/arm/mm/init.c b/arch/arm/mm/init.c
index c0ad7c0fbae0..ec00f26bffa4 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -239,7 +239,7 @@ bootmem_init_node(int node, int initrd_node, struct meminfo *mi)
          * Reserve the bootmem bitmap for this node.
          */
         reserve_bootmem_node(pgdat, boot_pfn << PAGE_SHIFT,
-                             boot_pages << PAGE_SHIFT);
+                             boot_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);
 
 #ifdef CONFIG_BLK_DEV_INITRD
         /*
@@ -247,7 +247,7 @@ bootmem_init_node(int node, int initrd_node, struct meminfo *mi)
          */
         if (node == initrd_node) {
                 reserve_bootmem_node(pgdat, phys_initrd_start,
-                                     phys_initrd_size);
+                                     phys_initrd_size, BOOTMEM_DEFAULT);
                 initrd_start = __phys_to_virt(phys_initrd_start);
                 initrd_end = initrd_start + phys_initrd_size;
         }