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, 10 insertions, 6 deletions

diff --git a/arch/frv/kernel/setup.c b/arch/frv/kernel/setup.c
index b38ae1fc15fd..6c01464db699 100644
--- a/arch/frv/kernel/setup.c
+++ b/arch/frv/kernel/setup.c
@@ -925,13 +925,15 @@ static void __init setup_linux_memory(void)
 #endif
 
         /* take back the memory occupied by the kernel image and the bootmem alloc map */
-        reserve_bootmem(kstart, kend - kstart + bootmap_size);
+        reserve_bootmem(kstart, kend - kstart + bootmap_size,
+                        BOOTMEM_DEFAULT);
 
         /* reserve the memory occupied by the initial ramdisk */
 #ifdef CONFIG_BLK_DEV_INITRD
         if (LOADER_TYPE && INITRD_START) {
                 if (INITRD_START + INITRD_SIZE <= (low_top_pfn << PAGE_SHIFT)) {
-                        reserve_bootmem(INITRD_START, INITRD_SIZE);
+                        reserve_bootmem(INITRD_START, INITRD_SIZE,
+                                        BOOTMEM_DEFAULT);
                         initrd_start = INITRD_START + PAGE_OFFSET;
                         initrd_end = initrd_start + INITRD_SIZE;
                 }
@@ -986,9 +988,10 @@ static void __init setup_uclinux_memory(void)
 
         /* now take back the bits the core kernel is occupying */
 #ifndef CONFIG_PROTECT_KERNEL
-        reserve_bootmem(kend, bootmap_size);
+        reserve_bootmem(kend, bootmap_size, BOOTMEM_DEFAULT);
         reserve_bootmem((unsigned long) &__kernel_image_start,
-                        kend - (unsigned long) &__kernel_image_start);
+                        kend - (unsigned long) &__kernel_image_start,
+                        BOOTMEM_DEFAULT);
 
 #else
         dampr = __get_DAMPR(0);
@@ -996,14 +999,15 @@ static void __init setup_uclinux_memory(void)
         dampr = (dampr >> 4) + 17;
         dampr = 1 << dampr;
 
-        reserve_bootmem(__get_DAMPR(0) & xAMPRx_PPFN, dampr);
+        reserve_bootmem(__get_DAMPR(0) & xAMPRx_PPFN, dampr, BOOTMEM_DEFAULT);
 #endif
 
         /* reserve some memory to do uncached DMA through if requested */
 #ifdef CONFIG_RESERVE_DMA_COHERENT
         if (dma_coherent_mem_start)
                 reserve_bootmem(dma_coherent_mem_start,
-                                dma_coherent_mem_end - dma_coherent_mem_start);
+                                dma_coherent_mem_end - dma_coherent_mem_start,
+                                BOOTMEM_DEFAULT);
 #endif
 
 } /* end setup_uclinux_memory() */