mm/cma: add cma_pages_valid to determine if pages are in CMA

Add new interface cma_pages_valid() which indicates if the specified
pages are part of a CMA region.  This interface will be used in a
subsequent patch by hugetlb code.

In order to keep the same amount of DEBUG information, a pr_debug() call
was added to cma_pages_valid().  In the case where the page passed to
cma_release is not in cma region, the debug message will be printed from
cma_pages_valid as opposed to cma_release.

Link: https://lkml.kernel.org/r/20211007181918.136982-3-mike.kravetz@oracle.com


Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Nghia Le <nghialm78@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>