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Commit 71936180 authored by Tejun Heo's avatar Tejun Heo
Browse files

memblock: Reimplement __memblock_remove() using memblock_isolate_range() 



__memblock_remove()'s open coded region manipulation can be trivially
replaced with memblock_islate_range().  This increases code sharing
and eases improving region tracking.

This pulls memblock_isolate_range() out of HAVE_MEMBLOCK_NODE_MAP.
Make it use memblock_get_region_node() instead of assuming rgn->nid is
available.

-v2: Fixed build failure on !HAVE_MEMBLOCK_NODE_MAP caused by direct
     rgn->nid access.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>
parent 6a9ceb31

mm/memblock.c

+9 −47
Original line number Diff line number Diff line
@@ -400,7 +400,6 @@ int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size) 
	return memblock_add_region(&memblock.memory, base, size);

}



#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP

/**

 * memblock_isolate_range - isolate given range into disjoint memblocks

 * @type: memblock type to isolate range for
@@ -449,7 +448,7 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, 
			rgn->base = base;

			rgn->size = rend - rgn->base;

			memblock_insert_region(type, i, rbase, base - rbase,

					       rgn->nid);

					       memblock_get_region_node(rgn));

		} else if (rend > end) {

			/*

			 * @rgn intersects from above.  Split and redo the
@@ -458,7 +457,7 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, 
			rgn->base = end;

			rgn->size = rend - rgn->base;

			memblock_insert_region(type, i--, rbase, end - rbase,

					       rgn->nid);

					       memblock_get_region_node(rgn));

		} else {

			/* @rgn is fully contained, record it */

			if (!*end_rgn)
@@ -469,56 +468,19 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, 


	return 0;

}

#endif



static int __init_memblock __memblock_remove(struct memblock_type *type,

					     phys_addr_t base, phys_addr_t size)

{

	phys_addr_t end = base + size;

	int i;



	/* Walk through the array for collisions */

	for (i = 0; i < type->cnt; i++) {

		struct memblock_region *rgn = &type->regions[i];

		phys_addr_t rend = rgn->base + rgn->size;



		/* Nothing more to do, exit */

		if (rgn->base > end || rgn->size == 0)

			break;



		/* If we fully enclose the block, drop it */

		if (base <= rgn->base && end >= rend) {

			memblock_remove_region(type, i--);

			continue;

		}



		/* If we are fully enclosed within a block

		 * then we need to split it and we are done

		 */

		if (base > rgn->base && end < rend) {

			rgn->size = base - rgn->base;

			if (!memblock_add_region(type, end, rend - end))

				return 0;

			/* Failure to split is bad, we at least

			 * restore the block before erroring

			 */

			rgn->size = rend - rgn->base;

			WARN_ON(1);

			return -1;

		}



		/* Check if we need to trim the bottom of a block */

		if (rgn->base < end && rend > end) {

			rgn->size -= end - rgn->base;

			rgn->base = end;

			break;

		}

	int start_rgn, end_rgn;

	int i, ret;



		/* And check if we need to trim the top of a block */

		if (base < rend)

			rgn->size -= rend - base;

	ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);

	if (ret)

		return ret;



	}

	for (i = end_rgn - 1; i >= start_rgn; i--)

		memblock_remove_region(type, i);

	return 0;

}