Aneesh reports that PowerPC requires 16MiB alignment for the address range passed to devm_memremap_pages(), and Jeff reports that it is possible to create a misaligned namespace which blocks future namespace creation in that region. Both of these issues require namespace alignment to be managed at the region level rather than padding at the namespace level which has been a broken approach to date.
Introduce memremap_compat_align() to indicate the hard requirements of an arch's memremap_pages() implementation. Use the maximum known memremap_compat_align() to set the default namespace alignment for libnvdimm. Consult that alignment when allocating free space. Finally, allow the default region alignment to be overridden to maintain the same namespace creation capability as previous kernels. The ndctl unit tests, which have some misaligned namespace assumptions, are updated to use the alignment override where necessary. Thanks to Aneesh for early feedback and testing on this improved alignment handling. --- Dan Williams (5): mm/memremap_pages: Kill unused __devm_memremap_pages() mm/memremap_pages: Introduce memremap_compat_align() libnvdimm/namespace: Enforce memremap_compat_align() libnvdimm/region: Introduce NDD_LABELING libnvdimm/region: Introduce an 'align' attribute arch/powerpc/include/asm/io.h | 10 ++ arch/powerpc/platforms/pseries/papr_scm.c | 2 drivers/acpi/nfit/core.c | 4 + drivers/nvdimm/dimm.c | 2 drivers/nvdimm/dimm_devs.c | 95 +++++++++++++++++---- drivers/nvdimm/namespace_devs.c | 21 ++++- drivers/nvdimm/nd.h | 3 - drivers/nvdimm/pfn_devs.c | 2 drivers/nvdimm/region_devs.c | 132 ++++++++++++++++++++++++++--- include/linux/io.h | 23 +++++ include/linux/libnvdimm.h | 2 include/linux/mmzone.h | 1 12 files changed, 255 insertions(+), 42 deletions(-) _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-le...@lists.01.org