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: Dan Williams <dan.j.williams@xxxxxxxxx> --- kernel/memremap.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index b981a7b023f0..4c7d08339f62 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -270,9 +270,10 @@ 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; + resource_size_t align_start = res->start & ~(SECTION_SIZE - 1); + resource_size_t align_size = ALIGN(resource_size(res), SECTION_SIZE); + int is_ram = region_intersects(align_start, align_size, "System RAM"); + resource_size_t key, align_end; struct dev_pagemap *pgmap; struct page_map *page_map; unsigned long pfn; @@ -314,8 +315,6 @@ 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; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>