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, 8 deletions

diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 62adc5f20be5..d1d8c347cc0b 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -390,7 +390,7 @@ static void __init reserve_ebda_region(void)
         unsigned int addr;
         addr = get_bios_ebda();
         if (addr)
-                reserve_bootmem(addr, PAGE_SIZE);
+                reserve_bootmem(addr, PAGE_SIZE, BOOTMEM_DEFAULT);
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
@@ -484,7 +484,8 @@ static void __init reserve_crashkernel(void)
                                         (unsigned long)(total_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");
@@ -525,7 +526,7 @@ static void __init reserve_initrd(void)
         }
         if (ramdisk_end <= end_of_lowmem) {
                 /* All in lowmem, easy case */
-                reserve_bootmem(ramdisk_image, ramdisk_size);
+                reserve_bootmem(ramdisk_image, ramdisk_size, BOOTMEM_DEFAULT);
                 initrd_start = ramdisk_image + PAGE_OFFSET;
                 initrd_end = initrd_start+ramdisk_size;
                 return;
@@ -536,7 +537,7 @@ static void __init reserve_initrd(void)
 
         /* Note: this includes all the lowmem currently occupied by
            the initrd, we rely on that fact to keep the data intact. */
-        reserve_bootmem(ramdisk_here, ramdisk_size);
+        reserve_bootmem(ramdisk_here, ramdisk_size, BOOTMEM_DEFAULT);
         initrd_start = ramdisk_here + PAGE_OFFSET;
         initrd_end   = initrd_start + ramdisk_size;
 
@@ -606,13 +607,14 @@ void __init setup_bootmem_allocator(void)
          * bootmem allocator with an invalid RAM area.
          */
         reserve_bootmem(__pa_symbol(_text), (PFN_PHYS(min_low_pfn) +
-                         bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text));
+                         bootmap_size + PAGE_SIZE-1) - __pa_symbol(_text),
+                         BOOTMEM_DEFAULT);
 
         /*
          * reserve physical page 0 - it's a special BIOS page on many boxes,
          * enabling clean reboots, SMP operation, laptop functions.
          */
-        reserve_bootmem(0, PAGE_SIZE);
+        reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
 
         /* reserve EBDA region, it's a 4K region */
         reserve_ebda_region();
@@ -622,7 +624,7 @@ void __init setup_bootmem_allocator(void)
        unless you have no PS/2 mouse plugged in. */
         if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
             boot_cpu_data.x86 == 6)
-             reserve_bootmem(0xa0000 - 4096, 4096);
+             reserve_bootmem(0xa0000 - 4096, 4096, BOOTMEM_DEFAULT);
 
 #ifdef CONFIG_SMP
         /*
@@ -630,7 +632,7 @@ void __init setup_bootmem_allocator(void)
          * FIXME: Don't need the extra page at 4K, but need to fix
          * trampoline before removing it. (see the GDT stuff)
          */
-        reserve_bootmem(PAGE_SIZE, PAGE_SIZE);
+        reserve_bootmem(PAGE_SIZE, PAGE_SIZE, BOOTMEM_DEFAULT);
 #endif
 #ifdef CONFIG_ACPI_SLEEP
         /*