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: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 778191e..60baf4d3 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -270,13 +270,16 @@
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 @@
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;