From: Mike Rapoport <rppt@xxxxxxxxxxxxx> Subject: memblock: update initialization of reserved pages The struct pages representing a reserved memory region are initialized using reserve_bootmem_range() function. This function is called for each reserved region just before the memory is freed from memblock to the buddy page allocator. The struct pages for MEMBLOCK_NOMAP regions are kept with the default values set by the memory map initialization which makes it necessary to have a special treatment for such pages in pfn_valid() and pfn_valid_within(). Split out initialization of the reserved pages to a function with a meaningful name and treat the MEMBLOCK_NOMAP regions the same way as the reserved regions and mark struct pages for the NOMAP regions as PageReserved. Link: https://lkml.kernel.org/r/20210511100550.28178-3-rppt@xxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Marc Zyngier <maz@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memblock.h | 4 +++- mm/memblock.c | 28 ++++++++++++++++++++++++++-- 2 files changed, 29 insertions(+), 3 deletions(-) --- a/include/linux/memblock.h~memblock-update-initialization-of-reserved-pages +++ a/include/linux/memblock.h @@ -30,7 +30,9 @@ extern unsigned long long max_possible_p * @MEMBLOCK_NONE: no special request * @MEMBLOCK_HOTPLUG: hotpluggable region * @MEMBLOCK_MIRROR: mirrored region - * @MEMBLOCK_NOMAP: don't add to kernel direct mapping + * @MEMBLOCK_NOMAP: don't add to kernel direct mapping and treat as + * reserved in the memory map; refer to memblock_mark_nomap() description + * for further details */ enum memblock_flags { MEMBLOCK_NONE = 0x0, /* No special request */ --- a/mm/memblock.c~memblock-update-initialization-of-reserved-pages +++ a/mm/memblock.c @@ -906,6 +906,11 @@ int __init_memblock memblock_mark_mirror * @base: the base phys addr of the region * @size: the size of the region * + * The memory regions marked with %MEMBLOCK_NOMAP will not be added to the + * direct mapping of the physical memory. These regions will still be + * covered by the memory map. The struct page representing NOMAP memory + * frames in the memory map will be PageReserved() + * * Return: 0 on success, -errno on failure. */ int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size) @@ -2002,6 +2007,26 @@ static unsigned long __init __free_memor return end_pfn - start_pfn; } +static void __init memmap_init_reserved_pages(void) +{ + struct memblock_region *region; + phys_addr_t start, end; + u64 i; + + /* initialize struct pages for the reserved regions */ + for_each_reserved_mem_range(i, &start, &end) + reserve_bootmem_region(start, end); + + /* and also treat struct pages for the NOMAP regions as PageReserved */ + for_each_mem_region(region) { + if (memblock_is_nomap(region)) { + start = region->base; + end = start + region->size; + reserve_bootmem_region(start, end); + } + } +} + static unsigned long __init free_low_memory_core_early(void) { unsigned long count = 0; @@ -2010,8 +2035,7 @@ static unsigned long __init free_low_mem memblock_clear_hotplug(0, -1); - for_each_reserved_mem_range(i, &start, &end) - reserve_bootmem_region(start, end); + memmap_init_reserved_pages(); /* * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id _
