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>
This commit is contained in:
Bernhard Walle 2008-02-07 00:15:17 -08:00 committed by Linus Torvalds
parent 25fad945a7
commit 72a7fe3967
43 changed files with 183 additions and 105 deletions

View file

@ -649,21 +649,24 @@ setup_memory(void)
/*
* Reserve memory used for lowcore/command line/kernel image.
*/
reserve_bootmem(0, (unsigned long)_ehead);
reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
reserve_bootmem((unsigned long)_stext,
PFN_PHYS(start_pfn) - (unsigned long)_stext);
PFN_PHYS(start_pfn) - (unsigned long)_stext,
BOOTMEM_DEFAULT);
/*
* Reserve the bootmem bitmap itself as well. We do this in two
* steps (first step was init_bootmem()) because this catches
* the (very unlikely) case of us accidentally initializing the
* bootmem allocator with an invalid RAM area.
*/
reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
BOOTMEM_DEFAULT);
#ifdef CONFIG_BLK_DEV_INITRD
if (INITRD_START && INITRD_SIZE) {
if (INITRD_START + INITRD_SIZE <= memory_end) {
reserve_bootmem(INITRD_START, INITRD_SIZE);
reserve_bootmem(INITRD_START, INITRD_SIZE,
BOOTMEM_DEFAULT);
initrd_start = INITRD_START;
initrd_end = initrd_start + INITRD_SIZE;
} else {