PCI/P2PDMA: track pgmap references per resource, not globally
In preparation for fixing a race between devm_memremap_pages_release()
and the final put of a page from the device-page-map, allocate a
percpu-ref per p2pdma resource mapping.
Link: http://lkml.kernel.org/r/155727338646.292046.9922678317501435597.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams at intel.com>
Reviewed-by: Ira Weiny <ira.weiny at intel.com>
Reviewed-by: Logan Gunthorpe <logang at deltatee.com>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: Christoph Hellwig <hch at lst.de>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: "Jérôme Glisse" <jglisse at redhat.com>
Cc: "Rafael J. Wysocki" <rafael at kernel.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
UnifiedSplitRaw
