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Commit a3619190 authored by Dan Williams's avatar Dan Williams Committed by Linus Torvalds
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libnvdimm/pfn: stop padding pmem namespaces to section alignment 

Now that the mm core supports section-unaligned hotplug of ZONE_DEVICE
memory, we no longer need to add padding at pfn/dax device creation
time.  The kernel will still honor padding established by older kernels.

Link: http://lkml.kernel.org/r/156092356588.979959.6793371748950931916.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Reported-by: default avatarJeff Moyer <jmoyer@redhat.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7e3e888d

drivers/nvdimm/pfn.h

+0 −14
Original line number Diff line number Diff line
@@ -33,18 +33,4 @@ struct nd_pfn_sb { 
	__le64 checksum;

};



#ifdef CONFIG_SPARSEMEM

#define PFN_SECTION_ALIGN_DOWN(x) SECTION_ALIGN_DOWN(x)

#define PFN_SECTION_ALIGN_UP(x) SECTION_ALIGN_UP(x)

#else

/*

 * In this case ZONE_DEVICE=n and we will disable 'pfn' device support,

 * but we still want pmem to compile.

 */

#define PFN_SECTION_ALIGN_DOWN(x) (x)

#define PFN_SECTION_ALIGN_UP(x) (x)

#endif



#define PHYS_SECTION_ALIGN_DOWN(x) PFN_PHYS(PFN_SECTION_ALIGN_DOWN(PHYS_PFN(x)))

#define PHYS_SECTION_ALIGN_UP(x) PFN_PHYS(PFN_SECTION_ALIGN_UP(PHYS_PFN(x)))

#endif /* __NVDIMM_PFN_H */

drivers/nvdimm/pfn_devs.c

+13 −64
Original line number Diff line number Diff line
@@ -587,14 +587,14 @@ static u32 info_block_reserve(void) 
}



/*

 * We hotplug memory at section granularity, pad the reserved area from

 * the previous section base to the namespace base address.

 * We hotplug memory at sub-section granularity, pad the reserved area

 * from the previous section base to the namespace base address.

 */

static unsigned long init_altmap_base(resource_size_t base)

{

	unsigned long base_pfn = PHYS_PFN(base);



	return PFN_SECTION_ALIGN_DOWN(base_pfn);

	return SUBSECTION_ALIGN_DOWN(base_pfn);

}



static unsigned long init_altmap_reserve(resource_size_t base)
@@ -602,7 +602,7 @@ static unsigned long init_altmap_reserve(resource_size_t base) 
	unsigned long reserve = info_block_reserve() >> PAGE_SHIFT;

	unsigned long base_pfn = PHYS_PFN(base);



	reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);

	reserve += base_pfn - SUBSECTION_ALIGN_DOWN(base_pfn);

	return reserve;

}
@@ -632,8 +632,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) 
			return -EINVAL;

		nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);

	} else if (nd_pfn->mode == PFN_MODE_PMEM) {

		nd_pfn->npfns = PFN_SECTION_ALIGN_UP((resource_size(res)

					- offset) / PAGE_SIZE);

		nd_pfn->npfns = PHYS_PFN((resource_size(res) - offset));

		if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)

			dev_info(&nd_pfn->dev,

					"number of pfns truncated from %lld to %ld\n",
@@ -649,54 +648,14 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) 
	return 0;

}



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));

}



/*

 * Check if pmem collides with 'System RAM', or other regions when

 * section aligned.  Trim it accordingly.

 */

static void trim_pfn_device(struct nd_pfn *nd_pfn, u32 *start_pad, u32 *end_trunc)

{

	struct nd_namespace_common *ndns = nd_pfn->ndns;

	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);

	struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);

	const resource_size_t start = nsio->res.start;

	const resource_size_t end = start + resource_size(&nsio->res);

	resource_size_t adjust, size;



	*start_pad = 0;

	*end_trunc = 0;



	adjust = start - PHYS_SECTION_ALIGN_DOWN(start);

	size = resource_size(&nsio->res) + adjust;

	if (region_intersects(start - adjust, size, IORESOURCE_SYSTEM_RAM,

				IORES_DESC_NONE) == REGION_MIXED

			|| nd_region_conflict(nd_region, start - adjust, size))

		*start_pad = PHYS_SECTION_ALIGN_UP(start) - start;



	/* Now check that end of the range does not collide. */

	adjust = PHYS_SECTION_ALIGN_UP(end) - end;

	size = resource_size(&nsio->res) + adjust;

	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,

				IORES_DESC_NONE) == REGION_MIXED

			|| !IS_ALIGNED(end, nd_pfn->align)

			|| nd_region_conflict(nd_region, start, size))

		*end_trunc = end - phys_pmem_align_down(nd_pfn, end);

}



static int nd_pfn_init(struct nd_pfn *nd_pfn)

{

	struct nd_namespace_common *ndns = nd_pfn->ndns;

	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);

	u32 start_pad, end_trunc, reserve = info_block_reserve();

	resource_size_t start, size;

	struct nd_region *nd_region;

	unsigned long npfns, align;

	struct nd_pfn_sb *pfn_sb;

	unsigned long npfns;

	phys_addr_t offset;

	const char *sig;

	u64 checksum;
@@ -727,43 +686,35 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) 
		return -ENXIO;

	}



	memset(pfn_sb, 0, sizeof(*pfn_sb));



	trim_pfn_device(nd_pfn, &start_pad, &end_trunc);

	if (start_pad + end_trunc)

		dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n",

				dev_name(&ndns->dev), start_pad + end_trunc);



	/*

	 * Note, we use 64 here for the standard size of struct page,

	 * debugging options may cause it to be larger in which case the

	 * implementation will limit the pfns advertised through

	 * ->direct_access() to those that are included in the memmap.

	 */

	start = nsio->res.start + start_pad;

	start = nsio->res.start;

	size = resource_size(&nsio->res);

	npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - reserve)

			/ PAGE_SIZE);

	npfns = PHYS_PFN(size - SZ_8K);

	align = max(nd_pfn->align, (1UL << SUBSECTION_SHIFT));

	if (nd_pfn->mode == PFN_MODE_PMEM) {

		/*

		 * The altmap should be padded out to the block size used

		 * when populating the vmemmap. This *should* be equal to

		 * PMD_SIZE for most architectures.

		 */

		offset = ALIGN(start + reserve + 64 * npfns,

				max(nd_pfn->align, PMD_SIZE)) - start;

		offset = ALIGN(start + SZ_8K + 64 * npfns, align) - start;

	} else if (nd_pfn->mode == PFN_MODE_RAM)

		offset = ALIGN(start + reserve, nd_pfn->align) - start;

		offset = ALIGN(start + SZ_8K, align) - start;

	else

		return -ENXIO;



	if (offset + start_pad + end_trunc >= size) {

	if (offset >= size) {

		dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",

				dev_name(&ndns->dev));

		return -ENXIO;

	}



	npfns = (size - offset - start_pad - end_trunc) / SZ_4K;

	npfns = PHYS_PFN(size - offset);

	pfn_sb->mode = cpu_to_le32(nd_pfn->mode);

	pfn_sb->dataoff = cpu_to_le64(offset);

	pfn_sb->npfns = cpu_to_le64(npfns);
@@ -772,8 +723,6 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) 
	memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);

	pfn_sb->version_major = cpu_to_le16(1);

	pfn_sb->version_minor = cpu_to_le16(3);

	pfn_sb->start_pad = cpu_to_le32(start_pad);

	pfn_sb->end_trunc = cpu_to_le32(end_trunc);

	pfn_sb->align = cpu_to_le32(nd_pfn->align);

	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);

	pfn_sb->checksum = cpu_to_le64(checksum);

include/linux/mmzone.h

+3 −0
Original line number Diff line number Diff line
@@ -1160,6 +1160,9 @@ static inline unsigned long section_nr_to_pfn(unsigned long sec) 
#define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))

#endif



#define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)

#define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)



struct mem_section_usage {

	DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);

	/* See declaration of similar field in struct zone */