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, 6 insertions, 4 deletions

diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 855cdf9d85b1..af10db90a554 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -148,7 +148,8 @@ static void __init reserve_crashkernel(void)
                                         (unsigned long)(free_mem >> 20));
                         crashk_res.start = crash_base;
                         crashk_res.end   = crash_base + crash_size - 1;
-                        reserve_bootmem(crash_base, crash_size);
+                        reserve_bootmem(crash_base, crash_size,
+                                        BOOTMEM_DEFAULT);
                 } else
                         printk(KERN_INFO "crashkernel reservation failed - "
                                         "you have to specify a base address\n");
@@ -184,13 +185,14 @@ void __init setup_bootmem_allocator(unsigned long free_pfn)
          * an invalid RAM area.
          */
         reserve_bootmem(__MEMORY_START+PAGE_SIZE,
-                (PFN_PHYS(free_pfn)+bootmap_size+PAGE_SIZE-1)-__MEMORY_START);
+                (PFN_PHYS(free_pfn)+bootmap_size+PAGE_SIZE-1)-__MEMORY_START,
+                BOOTMEM_DEFAULT);
 
         /*
          * reserve physical page 0 - it's a special BIOS page on many boxes,
          * enabling clean reboots, SMP operation, laptop functions.
          */
-        reserve_bootmem(__MEMORY_START, PAGE_SIZE);
+        reserve_bootmem(__MEMORY_START, PAGE_SIZE, BOOTMEM_DEFAULT);
 
         sparse_memory_present_with_active_regions(0);
 
@@ -200,7 +202,7 @@ void __init setup_bootmem_allocator(unsigned long free_pfn)
         if (LOADER_TYPE && INITRD_START) {
                 if (INITRD_START + INITRD_SIZE <= (max_low_pfn << PAGE_SHIFT)) {
                         reserve_bootmem(INITRD_START + __MEMORY_START,
-                                        INITRD_SIZE);
+                                        INITRD_SIZE, BOOTMEM_DEFAULT);
                         initrd_start = INITRD_START + PAGE_OFFSET +
                                         __MEMORY_START;
                         initrd_end = initrd_start + INITRD_SIZE;