[PATCH v4 20/21] memblock: add memblock_reserved_hugetlb_size()

[Pratyush Yadav <pratyush@kernel.org>]

From: "Pratyush Yadav (Google)" <pratyush@kernel.org>

Similar to memblock_reserved_kern_size(), but calculates only the memory
reserved for hugetlb pages. This is needed in an upcoming commit that
subtracts hugetlb reservation size when computing the size of KHO
scratch areas.

Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
---
 include/linux/memblock.h |  1 +
 mm/memblock.c            | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 678fe466529a..d62db9e776cf 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -487,6 +487,7 @@ static inline __init_memblock bool memblock_bottom_up(void)
 phys_addr_t memblock_phys_mem_size(void);
 phys_addr_t memblock_reserved_size(void);
 phys_addr_t memblock_reserved_kern_size(phys_addr_t limit, int nid);
+phys_addr_t memblock_reserved_hugetlb_size(phys_addr_t limit, int nid);
 unsigned long memblock_estimated_nr_free_pages(void);
 phys_addr_t memblock_start_of_DRAM(void);
 phys_addr_t memblock_end_of_DRAM(void);
diff --git a/mm/memblock.c b/mm/memblock.c
index ff470fd0fd10..78112b3f00d0 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1891,6 +1891,28 @@ phys_addr_t __init_memblock memblock_reserved_size(void)
 	return memblock.reserved.total_size;
 }
 
+phys_addr_t __init_memblock memblock_reserved_hugetlb_size(phys_addr_t limit, int nid)
+{
+	struct memblock_region *r;
+	phys_addr_t total = 0;
+
+	for_each_reserved_mem_region(r) {
+		phys_addr_t size = r->size;
+
+		if (r->base > limit)
+			break;
+
+		if (r->base + r->size > limit)
+			size = limit - r->base;
+
+		if (nid == memblock_get_region_node(r) || !numa_valid_node(nid))
+			if (r->flags & MEMBLOCK_RSRV_HUGETLB)
+				total += size;
+	}
+
+	return total;
+}
+
 phys_addr_t __init_memblock memblock_reserved_kern_size(phys_addr_t limit, int nid)
 {
 	struct memblock_region *r;
-- 
2.55.0.229.g6434b31f56-goog