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, 8 insertions, 4 deletions

diff --git a/arch/v850/kernel/setup.c b/arch/v850/kernel/setup.c
index a914f244f494..a0a8456a8430 100644
--- a/arch/v850/kernel/setup.c
+++ b/arch/v850/kernel/setup.c
@@ -241,15 +241,18 @@ init_bootmem_alloc (unsigned long ram_start, unsigned long ram_len)
         if (kram_end > kram_start)
                 /* Reserve the RAM part of the kernel's address space, so it
                    doesn't get allocated.  */
-                reserve_bootmem (kram_start, kram_end - kram_start);
+                reserve_bootmem(kram_start, kram_end - kram_start,
+                                BOOTMEM_DEFAULT);
         
         if (intv_in_ram && !intv_in_kram)
                 /* Reserve the interrupt vector space.  */
-                reserve_bootmem (intv_start, intv_end - intv_start);
+                reserve_bootmem(intv_start, intv_end - intv_start,
+                                BOOTMEM_DEFAULT);
 
         if (bootmap >= ram_start && bootmap < ram_end)
                 /* Reserve the bootmap space.  */
-                reserve_bootmem (bootmap, bootmap_len);
+                reserve_bootmem(bootmap, bootmap_len,
+                                BOOTMEM_DEFAULT);
 
         /* Reserve the memory used by the root filesystem image if it's
            in RAM.  */
@@ -257,7 +260,8 @@ init_bootmem_alloc (unsigned long ram_start, unsigned long ram_len)
             && (unsigned long)&_root_fs_image_start >= ram_start
             && (unsigned long)&_root_fs_image_start < ram_end)
                 reserve_bootmem ((unsigned long)&_root_fs_image_start,
-                                 &_root_fs_image_end - &_root_fs_image_start);
+                                 &_root_fs_image_end - &_root_fs_image_start,
+                                 BOOTMEM_DEFAULT);
 
         /* Let the platform-dependent code reserve some too.  */
         if (mrb)