libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment (41fce90f) · Commits · 戴 / test

The following namespace configuration attempt: # ndctl create-namespace -e namespace0.0 -m devdax -a 1G -f libndctl: ndctl_dax_enable: dax0.1: failed to enable Error: namespace0.0: failed to enable failed to reconfigure namespace: No such device or address ...fails when the backing memory range is not physically aligned to 1G: # cat /proc/iomem | grep Persistent 210000000-30fffffff : Persistent Memory (legacy) In the above example the 4G persistent memory range starts and ends on a 256MB boundary. We handle this case correctly when needing to handle cases that violate section alignment (128MB) collisions against "System RAM", and we simply need to extend that padding/truncation for the 1GB alignment use case. Cc: <stable@vger.kernel.org> Fixes: ("libnvdimm, pfn: add 'align' attribute...") Reported-and-tested-by:

Jane Chu <jane.chu@oracle.com> Signed-off-by:

Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/pfn_devs.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -583,6 +583,12 @@ static struct vmem_altmap __nvdimm_setup_pfn(struct nd_pfn nd_pfn,
		return altmap;
		}

		static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys)
		{
		return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys),
		ALIGN_DOWN(phys, nd_pfn->align));
		}

		static int nd_pfn_init(struct nd_pfn *nd_pfn)
		{
		u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
		@@ -638,13 +644,16 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
		start = nsio->res.start;
		size = PHYS_SECTION_ALIGN_UP(start + size) - start;
		if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
		IORES_DESC_NONE) == REGION_MIXED) {
		IORES_DESC_NONE) == REGION_MIXED
		\|\| !IS_ALIGNED(start + resource_size(&nsio->res),
		nd_pfn->align)) {
		size = resource_size(&nsio->res);
		end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
		end_trunc = start + size - phys_pmem_align_down(nd_pfn,
		start + size);
		}

		if (start_pad + end_trunc)
		dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
		dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n",
		dev_name(&ndns->dev), start_pad + end_trunc);

		/*

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