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, 4 insertions, 3 deletions

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index c032409cba9b..39f3dfe134fb 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -232,7 +232,7 @@ static void __init finalize_initrd(void)
                 goto disable;
         }
 
-        reserve_bootmem(__pa(initrd_start), size);
+        reserve_bootmem(__pa(initrd_start), size, BOOTMEM_DEFAULT);
         initrd_below_start_ok = 1;
 
         printk(KERN_INFO "Initial ramdisk at: 0x%lx (%lu bytes)\n",
@@ -413,7 +413,7 @@ static void __init bootmem_init(void)
         /*
          * Reserve the bootmap memory.
          */
-        reserve_bootmem(PFN_PHYS(mapstart), bootmap_size);
+        reserve_bootmem(PFN_PHYS(mapstart), bootmap_size, BOOTMEM_DEFAULT);
 
         /*
          * Reserve initrd memory if needed.
diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
index e5e023f50a07..bf438d02366e 100644
--- a/arch/mips/sgi-ip27/ip27-memory.c
+++ b/arch/mips/sgi-ip27/ip27-memory.c
@@ -465,7 +465,8 @@ static void __init node_mem_init(cnodeid_t node)
         free_bootmem_node(NODE_DATA(node), slot_firstpfn << PAGE_SHIFT,
                         (slot_lastpfn - slot_firstpfn) << PAGE_SHIFT);
         reserve_bootmem_node(NODE_DATA(node), slot_firstpfn << PAGE_SHIFT,
-                ((slot_freepfn - slot_firstpfn) << PAGE_SHIFT) + bootmap_size);
+                ((slot_freepfn - slot_firstpfn) << PAGE_SHIFT) + bootmap_size,
+                BOOTMEM_DEFAULT);
 }
 
 /*