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>

2 files changed, 3 insertions, 3 deletions

diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 7e9c275ea148..344f64eca7a9 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -218,7 +218,7 @@ find_memory (void)
 
         /* Free all available memory, then mark bootmem-map as being in use. */
         efi_memmap_walk(filter_rsvd_memory, free_bootmem);
-        reserve_bootmem(bootmap_start, bootmap_size);
+        reserve_bootmem(bootmap_start, bootmap_size, BOOTMEM_DEFAULT);
 
         find_initrd();
 
diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index 0b567398f38e..ee5e68b2af94 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -299,12 +299,12 @@ static void __init reserve_pernode_space(void)
                 pages = bdp->node_low_pfn - (bdp->node_boot_start>>PAGE_SHIFT);
                 size = bootmem_bootmap_pages(pages) << PAGE_SHIFT;
                 base = __pa(bdp->node_bootmem_map);
-                reserve_bootmem_node(pdp, base, size);
+                reserve_bootmem_node(pdp, base, size, BOOTMEM_DEFAULT);
 
                 /* Now the per-node space */
                 size = mem_data[node].pernode_size;
                 base = __pa(mem_data[node].pernode_addr);
-                reserve_bootmem_node(pdp, base, size);
+                reserve_bootmem_node(pdp, base, size, BOOTMEM_DEFAULT);
         }
 }