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Subject[PATCH 42/49] x86, memblock: Add memblock_x86_free_memory_in_range()
Date
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: Yinghai Lu <yinghai@kernel.org>
---
arch/x86/include/asm/memblock.h | 1 +
arch/x86/mm/memblock.c | 48 +++++++++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/memblock.h b/arch/x86/include/asm/memblock.h
index 3a86b10..fc3c230 100644
--- a/arch/x86/include/asm/memblock.h
+++ b/arch/x86/include/asm/memblock.h
@@ -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
diff --git a/arch/x86/mm/memblock.c b/arch/x86/mm/memblock.c
index 2b69820..b04b43b 100644
--- a/arch/x86/mm/memblock.c
+++ b/arch/x86/mm/memblock.c
@@ -217,6 +217,54 @@ 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)
--
1.6.4.2


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