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>
This commit is contained in:
Dan Williams 2016-03-09 14:08:13 -08:00 committed by Linus Torvalds
parent d77a117e68
commit 5f29a77cd9

View File

@ -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;