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, 4 insertions, 2 deletions

diff --git a/arch/avr32/kernel/setup.c b/arch/avr32/kernel/setup.c
index 4b4c1884e1c5..e66a07a928cd 100644
--- a/arch/avr32/kernel/setup.c
+++ b/arch/avr32/kernel/setup.c
@@ -489,7 +489,8 @@ static void __init setup_bootmem(void)
                 /* Reserve space for the bootmem bitmap... */
                 reserve_bootmem_node(NODE_DATA(node),
                                      PFN_PHYS(bootmap_pfn),
-                                     bootmap_size);
+                                     bootmap_size,
+                                     BOOTMEM_DEFAULT);
 
                 /* ...and any other reserved regions. */
                 for (res = reserved; res; res = res->sibling) {
@@ -505,7 +506,8 @@ static void __init setup_bootmem(void)
                             && res->end < PFN_PHYS(max_pfn))
                                 reserve_bootmem_node(
                                         NODE_DATA(node), res->start,
-                                        res->end - res->start + 1);
+                                        res->end - res->start + 1,
+                                        BOOTMEM_DEFAULT);
                 }
 
                 node_set_online(node);