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Commit 3af044e0 authored by David Rientjes's avatar David Rientjes Committed by Linus Torvalds
Browse files

x86_64: extract helper function from e820_register_active_regions 



The logic in e820_find_active_regions() for determining the true active
regions for an e820 entry given a range of PFN's is needed for
e820_hole_size() as well.

e820_hole_size() is called from the NUMA emulation code to determine the
reserved area within an address range on a per-node basis.  Its logic should
duplicate that of finding active regions in an e820 entry because these are
the only true ranges we may register anyway.

[akpm@linux-foundation.org: cleanup]
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 34feb2c8

arch/x86_64/kernel/e820.c

+48 −34
Original line number Diff line number Diff line
@@ -289,47 +289,61 @@ void __init e820_mark_nosave_regions(void) 
	}

}



/* Walk the e820 map and register active regions within a node */

void __init

e820_register_active_regions(int nid, unsigned long start_pfn,

							unsigned long end_pfn)

/*

 * Finds an active region in the address range from start_pfn to end_pfn and

 * returns its range in ei_startpfn and ei_endpfn for the e820 entry.

 */

static int __init e820_find_active_region(const struct e820entry *ei,

					  unsigned long start_pfn,

					  unsigned long end_pfn,

					  unsigned long *ei_startpfn,

					  unsigned long *ei_endpfn)

{

	int i;

	unsigned long ei_startpfn, ei_endpfn;

	for (i = 0; i < e820.nr_map; i++) {

		struct e820entry *ei = &e820.map[i];

		ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;

		ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE)

								>> PAGE_SHIFT;

	*ei_startpfn = round_up(ei->addr, PAGE_SIZE) >> PAGE_SHIFT;

	*ei_endpfn = round_down(ei->addr + ei->size, PAGE_SIZE) >> PAGE_SHIFT;



	/* Skip map entries smaller than a page */

		if (ei_startpfn >= ei_endpfn)

			continue;

	if (*ei_startpfn >= *ei_endpfn)

		return 0;



	/* Check if end_pfn_map should be updated */

		if (ei->type != E820_RAM && ei_endpfn > end_pfn_map)

			end_pfn_map = ei_endpfn;

	if (ei->type != E820_RAM && *ei_endpfn > end_pfn_map)

		end_pfn_map = *ei_endpfn;



	/* Skip if map is outside the node */

		if (ei->type != E820_RAM ||

				ei_endpfn <= start_pfn ||

				ei_startpfn >= end_pfn)

			continue;

	if (ei->type != E820_RAM || *ei_endpfn <= start_pfn ||

				    *ei_startpfn >= end_pfn)

		return 0;



	/* Check for overlaps */

		if (ei_startpfn < start_pfn)

			ei_startpfn = start_pfn;

		if (ei_endpfn > end_pfn)

			ei_endpfn = end_pfn;

	if (*ei_startpfn < start_pfn)

		*ei_startpfn = start_pfn;

	if (*ei_endpfn > end_pfn)

		*ei_endpfn = end_pfn;



	/* Obey end_user_pfn to save on memmap */

		if (ei_startpfn >= end_user_pfn)

			continue;

		if (ei_endpfn > end_user_pfn)

			ei_endpfn = end_user_pfn;

	if (*ei_startpfn >= end_user_pfn)

		return 0;

	if (*ei_endpfn > end_user_pfn)

		*ei_endpfn = end_user_pfn;



		add_active_range(nid, ei_startpfn, ei_endpfn);

	return 1;

}



/* Walk the e820 map and register active regions within a node */

void __init

e820_register_active_regions(int nid, unsigned long start_pfn,

							unsigned long end_pfn)

{

	unsigned long ei_startpfn;

	unsigned long ei_endpfn;

	int i;



	for (i = 0; i < e820.nr_map; i++)

		if (e820_find_active_region(&e820.map[i],

					    start_pfn, end_pfn,

					    &ei_startpfn, &ei_endpfn))

			add_active_range(nid, ei_startpfn, ei_endpfn);

}



/*