Merge tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dave Jiang:
 "Collection of misc libnvdimm patches for 4.19 submission:

   - Adding support to read locked nvdimm capacity.

   - Change test code to make DSM failure code injection an override.

   - Add support for calculate maximum contiguous area for namespace.

   - Add support for queueing a short ARS when there is on going ARS for
     nvdimm.

   - Allow NULL to be passed in to ->direct_access() for kaddr and pfn
     params.

   - Improve smart injection support for nvdimm emulation testing.

   - Fix test code that supports for emulating controller temperature.

   - Fix hang on error before devm_memremap_pages()

   - Fix a bug that causes user memory corruption when data returned to
     user for ars_status.

   - Maintainer updates for Ross Zwisler emails and adding Jan Kara to
     fsdax"

* tag 'libnvdimm-for-4.19_misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm: fix ars_status output length calculation
  device-dax: avoid hang on error before devm_memremap_pages()
  tools/testing/nvdimm: improve emulation of smart injection
  filesystem-dax: Do not request kaddr and pfn when not required
  md/dm-writecache: Don't request pointer dummy_addr when not required
  dax/super: Do not request a pointer kaddr when not required
  tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access()
  s390, dcssblk: kaddr and pfn can be NULL to ->direct_access()
  libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access()
  acpi/nfit: queue issuing of ars when an uc error notification comes in
  libnvdimm: Export max available extent
  libnvdimm: Use max contiguous area for namespace size
  MAINTAINERS: Add Jan Kara for filesystem DAX
  MAINTAINERS: update Ross Zwisler's email address
  tools/testing/nvdimm: Fix support for emulating controller temperature
  tools/testing/nvdimm: Make DSM failure code injection an override
  acpi, nfit: Prefer _DSM over _LSR for namespace label reads
  libnvdimm: Introduce locked DIMM capacity support

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index dd17acd8fe68..c23649867696 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -226,8 +226,11 @@ __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
 					PFN_PHYS(nr_pages))))
 		return -EIO;
-	*kaddr = pmem->virt_addr + offset;
-	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
+
+	if (kaddr)
+		*kaddr = pmem->virt_addr + offset;
+	if (pfn)
+		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 
 	/*
 	 * If badblocks are present, limit known good range to the