From 72a7fe3967dbf86cb34e24fbf1d957fe24d2f246 Mon Sep 17 00:00:00 2001 From: Bernhard Walle Date: Thu, 7 Feb 2008 00:15:17 -0800 Subject: 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 Cc: Cc: "Eric W. Biederman" Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/bootmem.h | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'include/linux/bootmem.h') diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h index 0365ec9fc0c9..4e4e340592fb 100644 --- a/include/linux/bootmem.h +++ b/include/linux/bootmem.h @@ -60,8 +60,20 @@ extern void *__alloc_bootmem_core(struct bootmem_data *bdata, unsigned long goal, unsigned long limit); +/* + * flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE, + * the architecture-specific code should honor this) + */ +#define BOOTMEM_DEFAULT 0 +#define BOOTMEM_EXCLUSIVE (1<<0) + #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE -extern void reserve_bootmem(unsigned long addr, unsigned long size); +/* + * If flags is 0, then the return value is always 0 (success). If + * flags contains BOOTMEM_EXCLUSIVE, then -EBUSY is returned if the + * memory already was reserved. + */ +extern int reserve_bootmem(unsigned long addr, unsigned long size, int flags); #define alloc_bootmem(x) \ __alloc_bootmem(x, SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS)) #define alloc_bootmem_low(x) \ @@ -84,7 +96,8 @@ extern unsigned long init_bootmem_node(pg_data_t *pgdat, unsigned long endpfn); extern void reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, - unsigned long size); + unsigned long size, + int flags); extern void free_bootmem_node(pg_data_t *pgdat, unsigned long addr, unsigned long size); -- cgit v1.2.3