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Commit 5f29a77c authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
Browse files

mm: fix mixed zone detection in devm_memremap_pages 



The check for whether we overlap "System RAM" needs to be done at
section granularity.  For example a system with the following mapping:

    100000000-37bffffff : System RAM
    37c000000-837ffffff : Persistent Memory

...is unable to use devm_memremap_pages() as it would result in two
zones colliding within a given section.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: default avatarToshi Kani <toshi.kani@hpe.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d77a117e

kernel/memremap.c

+6 −5
Original line number Diff line number Diff line
@@ -270,13 +270,16 @@ struct dev_pagemap *find_dev_pagemap(resource_size_t phys) 
void *devm_memremap_pages(struct device *dev, struct resource *res,

		struct percpu_ref *ref, struct vmem_altmap *altmap)

{

	int is_ram = region_intersects(res->start, resource_size(res),

			"System RAM");

	resource_size_t key, align_start, align_size, align_end;

	struct dev_pagemap *pgmap;

	struct page_map *page_map;

	int error, nid, is_ram;

	unsigned long pfn;

	int error, nid;



	align_start = res->start & ~(SECTION_SIZE - 1);

	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)

		- align_start;

	is_ram = region_intersects(align_start, align_size, "System RAM");



	if (is_ram == REGION_MIXED) {

		WARN_ONCE(1, "%s attempted on mixed region %pr\n",
@@ -314,8 +317,6 @@ void *devm_memremap_pages(struct device *dev, struct resource *res, 


	mutex_lock(&pgmap_lock);

	error = 0;

	align_start = res->start & ~(SECTION_SIZE - 1);

	align_size = ALIGN(resource_size(res), SECTION_SIZE);

	align_end = align_start + align_size - 1;

	for (key = align_start; key <= align_end; key += SECTION_SIZE) {

		struct dev_pagemap *dup;