Commit f6c6010a authored by Wei Yang's avatar Wei Yang Committed by Ingo Molnar
Browse files

mm/resource: Use resource_overlaps() to simplify region_intersects() 



The three checks in region_intersects() are basically an open-coded version
of resource_overlaps() - so use the real thing.

Also fix typos in comments while at it.

Signed-off-by: default avatarWei Yang <richardw.yang@linux.intel.com>
Reviewed-by: default avatarLike Xu <like.xu@linux.intel.com>
Reviewed-by: default avatarYuan Yao <yuan.yao@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: bhelgaas@google.com
Cc: bp@suse.de
Cc: dan.j.williams@intel.com
Cc: jack@suse.cz
Cc: rdunlap@infradead.org
Cc: tiwai@suse.de
Link: http://lkml.kernel.org/r/20190305083432.23675-1-richardw.yang@linux.intel.com


[ Rewrote the changelog. ]
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 64559598

kernel/iomem.c

+2 −2
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size, 
 *

 * MEMREMAP_WB - matches the default mapping for System RAM on

 * the architecture.  This is usually a read-allocate write-back cache.

 * Morever, if MEMREMAP_WB is specified and the requested remap region is RAM

 * Moreover, if MEMREMAP_WB is specified and the requested remap region is RAM

 * memremap() will bypass establishing a new mapping and instead return

 * a pointer into the direct map.

 *
@@ -86,7 +86,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags) 
	/* Try all mapping types requested until one returns non-NULL */

	if (flags & MEMREMAP_WB) {

		/*

		 * MEMREMAP_WB is special in that it can be satisifed

		 * MEMREMAP_WB is special in that it can be satisfied

		 * from the direct map.  Some archs depend on the

		 * capability of memremap() to autodetect cases where

		 * the requested range is potentially in System RAM.

kernel/resource.c

+5 −6
Original line number Diff line number Diff line
@@ -520,21 +520,20 @@ EXPORT_SYMBOL_GPL(page_is_ram); 
int region_intersects(resource_size_t start, size_t size, unsigned long flags,

		      unsigned long desc)

{

	resource_size_t end = start + size - 1;

	struct resource res;

	int type = 0; int other = 0;

	struct resource *p;



	res.start = start;

	res.end = start + size - 1;



	read_lock(&resource_lock);

	for (p = iomem_resource.child; p ; p = p->sibling) {

		bool is_type = (((p->flags & flags) == flags) &&

				((desc == IORES_DESC_NONE) ||

				 (desc == p->desc)));



		if (start >= p->start && start <= p->end)

			is_type ? type++ : other++;

		if (end >= p->start && end <= p->end)

			is_type ? type++ : other++;

		if (p->start >= start && p->end <= end)

		if (resource_overlaps(p, &res))

			is_type ? type++ : other++;

	}

	read_unlock(&resource_lock);

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