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/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index beff6297f788..74c346625658 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -428,7 +428,8 @@ setup_memory(void *kernel_end)
         }
 
         /* Reserve the bootmap memory.  */
-        reserve_bootmem(PFN_PHYS(bootmap_start), bootmap_size);
+        reserve_bootmem(PFN_PHYS(bootmap_start), bootmap_size,
+                        BOOTMEM_DEFAULT);
         printk("reserving pages %ld:%ld\n", bootmap_start, bootmap_start+PFN_UP(bootmap_size));
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -446,7 +447,7 @@ setup_memory(void *kernel_end)
                                        phys_to_virt(PFN_PHYS(max_low_pfn)));
                 } else {
                         reserve_bootmem(virt_to_phys((void *)initrd_start),
-                                        INITRD_SIZE);
+                                        INITRD_SIZE, BOOTMEM_DEFAULT);
                 }
         }
 #endif /* CONFIG_BLK_DEV_INITRD */