mm/cma: introduce cma_intersects function

mm/cma: introduce cma_intersects function

Now that CMA areas can have multiple physical ranges, code can't assume a
CMA struct represents a base_pfn plus a size, as returned from
cma_get_base.

Most cases are ok though, since they all explicitly refer to CMA areas
that were created using existing interfaces (cma_declare_contiguous_nid or
cma_init_reserved_mem), which guarantees they have just one physical
range.

An exception is the s390 code, which walks all CMA ranges to see if they
intersect with a range of memory that is about to be hotremoved.  So, in
the future, it might run in to multi-range areas.  To keep this check
working, define a cma_intersects function.  This just checks if a physaddr
range intersects any of the ranges.  Use it in the s390 check.

Link: https://lkml.kernel.org/r/20250228182928.2645936-4-fvdl@google.com
Signed-off-by: Frank van der Linden <fvdl@google.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>