• Dave Hansen's avatar
    mm/resource: Move HMM pr_debug() deeper into resource code · b926b7f3
    Dave Hansen authored
    HMM consumes physical address space for its own use, even
    though nothing is mapped or accessible there.  It uses a
    special resource description (IORES_DESC_DEVICE_PRIVATE_MEMORY)
    to uniquely identify these areas.
    When HMM consumes address space, it makes a best guess about
    what to consume.  However, it is possible that a future memory
    or device hotplug can collide with the reserved area.  In the
    case of these conflicts, there is an error message in
    Later patches in this series move register_memory_resource()
    from using request_resource_conflict() to __request_region().
    Unfortunately, __request_region() does not return the conflict
    like the previous function did, which makes it impossible to
    check for IORES_DESC_DEVICE_PRIVATE_MEMORY in a conflicting
    Instead of warning in register_memory_resource(), move the
    check into the core resource code itself (__request_region())
    where the conflicting resource _is_ available.  This has the
    added bonus of producing a warning in case of HMM conflicts
    with devices *or* RAM address space, as opposed to the RAM-
    only warnings that were there previously.
    Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
    Reviewed-by: default avatarJerome Glisse <jglisse@redhat.com>
    Cc: Dan Williams <dan.j.williams@intel.com>
    Cc: Dave Jiang <dave.jiang@intel.com>
    Cc: Ross Zwisler <zwisler@kernel.org>
    Cc: Vishal Verma <vishal.l.verma@intel.com>
    Cc: Tom Lendacky <thomas.lendacky@amd.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Michal Hocko <mhocko@suse.com>
    Cc: linux-nvdimm@lists.01.org
    Cc: linux-kernel@vger.kernel.org
    Cc: linux-mm@kvack.org
    Cc: Huang Ying <ying.huang@intel.com>
    Cc: Fengguang Wu <fengguang.wu@intel.com>
    Cc: Keith Busch <keith.busch@intel.com>
    Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
memory_hotplug.c 48 KB