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/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9b61c75a2355..5fe880fc305d 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -644,9 +644,9 @@ void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
 
         /* Should check here against the e820 map to avoid double free */
 #ifdef CONFIG_NUMA
-        reserve_bootmem_node(NODE_DATA(nid), phys, len);
+        reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
 #else
-        reserve_bootmem(phys, len);
+        reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
 #endif
         if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
                 dma_reserve += len / PAGE_SIZE;