From c9ca9b4e2198a4dbeb83739460d4a7ff9ffed24f Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Mon, 3 Apr 2017 11:23:55 +0900 Subject: memblock: add memblock_cap_memory_range() Add memblock_cap_memory_range() which will remove all the memblock regions except the memory range specified in the arguments. In addition, rework is done on memblock_mem_limit_remove_map() to re-implement it using memblock_cap_memory_range(). This function, like memblock_mem_limit_remove_map(), will not remove memblocks with MEMMAP_NOMAP attribute as they may be mapped and accessed later as "device memory." See the commit a571d4eb55d8 ("mm/memblock.c: add new infrastructure to address the mem limit issue"). This function is used, in a succeeding patch in the series of arm64 kdump suuport, to limit the range of usable memory, or System RAM, on crash dump kernel. (Please note that "mem=" parameter is of little use for this purpose.) Signed-off-by: AKASHI Takahiro Reviewed-by: Will Deacon Acked-by: Catalin Marinas Acked-by: Dennis Chen Cc: linux-mm@kvack.org Cc: Andrew Morton Reviewed-by: Ard Biesheuvel Signed-off-by: Catalin Marinas --- include/linux/memblock.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/memblock.h') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index e82daffcfc44..4ce24a376262 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -336,6 +336,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); +void memblock_cap_memory_range(phys_addr_t base, phys_addr_t size); void memblock_mem_limit_remove_map(phys_addr_t limit); bool memblock_is_memory(phys_addr_t addr); int memblock_is_map_memory(phys_addr_t addr); -- cgit