Commit b52c17ce authored by Yinghai Lu's avatar Yinghai Lu Committed by H. Peter Anvin
Browse files

x86, memblock: Add memblock_x86_free_memory_in_range() 



It will return free memory size in specified range.

We can not use memory_size - reserved_size here, because some reserved area
may not be in the scope of memblock.memory.region.

Use memblock.memory.region subtracting memblock.reserved.region to get free range array.
then count size of all free ranges.

-v2: Ben insist on using _in_range

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 6bcc8176

arch/x86/include/asm/memblock.h

+1 −0
Original line number Diff line number Diff line
@@ -15,5 +15,6 @@ void memblock_x86_register_active_regions(int nid, unsigned long start_pfn, 
					 unsigned long last_pfn);

u64 memblock_x86_hole_size(u64 start, u64 end);

u64 memblock_x86_find_in_range_node(int nid, u64 start, u64 end, u64 size, u64 align);

u64 memblock_x86_free_memory_in_range(u64 addr, u64 limit);



#endif

arch/x86/mm/memblock.c

+48 −0
Original line number Diff line number Diff line
@@ -211,6 +211,54 @@ void __init memblock_x86_to_bootmem(u64 start, u64 end) 
}

#endif



u64 __init memblock_x86_free_memory_in_range(u64 addr, u64 limit)

{

	int i, count;

	struct range *range;

	int nr_range;

	u64 final_start, final_end;

	u64 free_size;

	struct memblock_region *r;



	count = (memblock.reserved.cnt + memblock.memory.cnt) * 2;



	range = find_range_array(count);

	nr_range = 0;



	addr = PFN_UP(addr);

	limit = PFN_DOWN(limit);



	for_each_memblock(memory, r) {

		final_start = PFN_UP(r->base);

		final_end = PFN_DOWN(r->base + r->size);

		if (final_start >= final_end)

			continue;

		if (final_start >= limit || final_end <= addr)

			continue;



		nr_range = add_range(range, count, nr_range, final_start, final_end);

	}

	subtract_range(range, count, 0, addr);

	subtract_range(range, count, limit, -1ULL);

	for_each_memblock(reserved, r) {

		final_start = PFN_DOWN(r->base);

		final_end = PFN_UP(r->base + r->size);

		if (final_start >= final_end)

			continue;

		if (final_start >= limit || final_end <= addr)

			continue;



		subtract_range(range, count, final_start, final_end);

	}

	nr_range = clean_sort_range(range, count);



	free_size = 0;

	for (i = 0; i < nr_range; i++)

		free_size += range[i].end - range[i].start;



	return free_size << PAGE_SHIFT;

}



void __init memblock_x86_reserve_range(u64 start, u64 end, char *name)

{

	if (start == end)

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