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, 2 deletions

diff --git a/arch/m68k/atari/stram.c b/arch/m68k/atari/stram.c
index 8dda6515887a..0055a6c06f75 100644
--- a/arch/m68k/atari/stram.c
+++ b/arch/m68k/atari/stram.c
@@ -154,7 +154,7 @@ void __init atari_stram_reserve_pages(void *start_mem)
         /* always reserve first page of ST-RAM, the first 2 kB are
          * supervisor-only! */
         if (!kernel_in_stram)
-                reserve_bootmem (0, PAGE_SIZE);
+                reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
 
 }
 
diff --git a/arch/m68k/kernel/setup.c b/arch/m68k/kernel/setup.c
index ed3a4caec620..9a06c48edcb3 100644
--- a/arch/m68k/kernel/setup.c
+++ b/arch/m68k/kernel/setup.c
@@ -323,7 +323,8 @@ void __init setup_arch(char **cmdline_p)
 #ifdef CONFIG_BLK_DEV_INITRD
         if (m68k_ramdisk.size) {
                 reserve_bootmem_node(__virt_to_node(phys_to_virt(m68k_ramdisk.addr)),
-                                     m68k_ramdisk.addr, m68k_ramdisk.size);
+                                     m68k_ramdisk.addr, m68k_ramdisk.size,
+                                     BOOTMEM_DEFAULT);
                 initrd_start = (unsigned long)phys_to_virt(m68k_ramdisk.addr);
                 initrd_end = initrd_start + m68k_ramdisk.size;
                 printk("initrd: %08lx - %08lx\n", initrd_start, initrd_end);