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Commit cfe30b87 authored by Dan Williams's avatar Dan Williams
Browse files

libnvdimm, pmem: adjust for section collisions with 'System RAM' 



On a platform where 'Persistent Memory' and 'System RAM' are mixed
within a given sparsemem section, trim the namespace and notify about the
sub-optimal alignment.

Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent d9cbe09d

drivers/nvdimm/namespace_devs.c

+7 −0
Original line number Diff line number Diff line
@@ -133,6 +133,7 @@ bool nd_is_uuid_unique(struct device *dev, u8 *uuid) 
bool pmem_should_map_pages(struct device *dev)

{

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

	struct nd_namespace_io *nsio;



	if (!IS_ENABLED(CONFIG_ZONE_DEVICE))

		return false;
@@ -143,6 +144,12 @@ bool pmem_should_map_pages(struct device *dev) 
	if (is_nd_pfn(dev) || is_nd_btt(dev))

		return false;



	nsio = to_nd_namespace_io(dev);

	if (region_intersects(nsio->res.start, resource_size(&nsio->res),

				IORESOURCE_SYSTEM_RAM,

				IORES_DESC_NONE) == REGION_MIXED)

		return false;



#ifdef ARCH_MEMREMAP_PMEM

	return ARCH_MEMREMAP_PMEM == MEMREMAP_WB;

#else

drivers/nvdimm/pfn.h

+8 −2
Original line number Diff line number Diff line
@@ -27,10 +27,13 @@ struct nd_pfn_sb { 
	__le32 flags;

	__le16 version_major;

	__le16 version_minor;

	__le64 dataoff;

	__le64 dataoff; /* relative to namespace_base + start_pad */

	__le64 npfns;

	__le32 mode;

	u8 padding[4012];

	/* minor-version-1 additions for section alignment */

	__le32 start_pad;

	__le32 end_trunc;

	u8 padding[4004];

	__le64 checksum;

};
@@ -45,4 +48,7 @@ struct nd_pfn_sb { 
#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

+5 −0
Original line number Diff line number Diff line
@@ -299,6 +299,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn) 
	if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)

		return -ENODEV;



	if (__le16_to_cpu(pfn_sb->version_minor) < 1) {

		pfn_sb->start_pad = 0;

		pfn_sb->end_trunc = 0;

	}



	switch (le32_to_cpu(pfn_sb->mode)) {

	case PFN_MODE_RAM:

	case PFN_MODE_PMEM:

drivers/nvdimm/pmem.c

+91 −34
Original line number Diff line number Diff line
@@ -43,7 +43,10 @@ struct pmem_device { 
	phys_addr_t		data_offset;

	u64			pfn_flags;

	void __pmem		*virt_addr;

	/* immutable base size of the namespace */

	size_t			size;

	/* trim size when namespace capacity has been section aligned */

	u32			pfn_pad;

	struct badblocks	bb;

};
@@ -145,7 +148,7 @@ static long pmem_direct_access(struct block_device *bdev, sector_t sector, 
	*kaddr = pmem->virt_addr + offset;

	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);



	return pmem->size - offset;

	return pmem->size - pmem->pfn_pad - offset;

}



static const struct block_device_operations pmem_fops = {
@@ -236,7 +239,8 @@ static int pmem_attach_disk(struct device *dev, 
	disk->flags		= GENHD_FL_EXT_DEVT;

	nvdimm_namespace_disk_name(ndns, disk->disk_name);

	disk->driverfs_dev = dev;

	set_capacity(disk, (pmem->size - pmem->data_offset) / 512);

	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)

			/ 512);

	pmem->pmem_disk = disk;

	devm_exit_badblocks(dev, &pmem->bb);

	if (devm_init_badblocks(dev, &pmem->bb))
@@ -279,6 +283,9 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) 
	struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);

	struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);

	struct nd_namespace_common *ndns = nd_pfn->ndns;

	u32 start_pad = 0, end_trunc = 0;

	resource_size_t start, size;

	struct nd_namespace_io *nsio;

	struct nd_region *nd_region;

	unsigned long npfns;

	phys_addr_t offset;
@@ -304,21 +311,56 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) 
	}



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

	npfns = (pmem->size - SZ_8K) / SZ_4K;



	/*

	 * Check if pmem collides with 'System RAM' when section aligned and

	 * trim it accordingly

	 */

	nsio = to_nd_namespace_io(&ndns->dev);

	start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);

	size = resource_size(&nsio->res);

	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,

				IORES_DESC_NONE) == REGION_MIXED) {



		start = nsio->res.start;

		start_pad = PHYS_SECTION_ALIGN_UP(start) - start;

	}



	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) {

		size = resource_size(&nsio->res);

		end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);

	}



	if (start_pad + end_trunc)

		dev_info(&nd_pfn->dev, "%s section 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 += start_pad;

	npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;

	if (nd_pfn->mode == PFN_MODE_PMEM)

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

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

			- start;

	else if (nd_pfn->mode == PFN_MODE_RAM)

		offset = ALIGN(SZ_8K, nd_pfn->align);

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

	else

		goto err;



	npfns = (pmem->size - offset) / SZ_4K;

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

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

				dev_name(&ndns->dev));

		goto err;

	}



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

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

	pfn_sb->dataoff = cpu_to_le64(offset);

	pfn_sb->npfns = cpu_to_le64(npfns);
@@ -326,6 +368,9 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) 
	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);

	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(1);

	pfn_sb->start_pad = cpu_to_le32(start_pad);

	pfn_sb->end_trunc = cpu_to_le32(end_trunc);

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

	pfn_sb->checksum = cpu_to_le64(checksum);
@@ -376,41 +421,36 @@ static unsigned long init_altmap_reserve(resource_size_t base) 
	return reserve;

}



static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)

static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)

{

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

	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);

	struct device *dev = &nd_pfn->dev;

	struct nd_region *nd_region;

	struct vmem_altmap *altmap;

	struct nd_pfn_sb *pfn_sb;

	struct pmem_device *pmem;

	struct request_queue *q;

	phys_addr_t offset;

	int rc;

	struct resource res;

	struct request_queue *q;

	struct pmem_device *pmem;

	struct vmem_altmap *altmap;

	struct device *dev = &nd_pfn->dev;

	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;

	struct nd_namespace_common *ndns = nd_pfn->ndns;

	u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);

	u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);

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

	resource_size_t base = nsio->res.start + start_pad;

	struct vmem_altmap __altmap = {

		.base_pfn = init_altmap_base(nsio->res.start),

		.reserve = init_altmap_reserve(nsio->res.start),

		.base_pfn = init_altmap_base(base),

		.reserve = init_altmap_reserve(base),

	};



	if (!nd_pfn->uuid || !nd_pfn->ndns)

		return -ENODEV;



	nd_region = to_nd_region(dev->parent);

	rc = nd_pfn_init(nd_pfn);

	if (rc)

		return rc;



	pfn_sb = nd_pfn->pfn_sb;

	offset = le64_to_cpu(pfn_sb->dataoff);

	pmem = dev_get_drvdata(dev);

	pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);

	pmem->pfn_pad = start_pad + end_trunc;

	nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);

	if (nd_pfn->mode == PFN_MODE_RAM) {

		if (offset < SZ_8K)

		if (pmem->data_offset < SZ_8K)

			return -EINVAL;

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

		altmap = NULL;

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

		nd_pfn->npfns = (resource_size(&nsio->res) - offset)

		nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)

			/ PAGE_SIZE;

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

			dev_info(&nd_pfn->dev,
@@ -418,7 +458,7 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns) 
					le64_to_cpu(nd_pfn->pfn_sb->npfns),

					nd_pfn->npfns);

		altmap = & __altmap;

		altmap->free = __phys_to_pfn(offset - SZ_8K);

		altmap->free = __phys_to_pfn(pmem->data_offset - SZ_8K);

		altmap->alloc = 0;

	} else {

		rc = -ENXIO;
@@ -426,10 +466,12 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns) 
	}



	/* establish pfn range for lookup, and switch to direct map */

	pmem = dev_get_drvdata(dev);

	q = pmem->pmem_queue;

	memcpy(&res, &nsio->res, sizeof(res));

	res.start += start_pad;

	res.end -= end_trunc;

	devm_memunmap(dev, (void __force *) pmem->virt_addr);

	pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &nsio->res,

	pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,

			&q->q_usage_counter, altmap);

	pmem->pfn_flags |= PFN_MAP;

	if (IS_ERR(pmem->virt_addr)) {
@@ -438,7 +480,6 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns) 
	}



	/* attach pmem disk in "pfn-mode" */

	pmem->data_offset = offset;

	rc = pmem_attach_disk(dev, ndns, pmem);

	if (rc)

		goto err;
@@ -447,6 +488,22 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns) 
 err:

	nvdimm_namespace_detach_pfn(ndns);

	return rc;



}



static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)

{

	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);

	int rc;



	if (!nd_pfn->uuid || !nd_pfn->ndns)

		return -ENODEV;



	rc = nd_pfn_init(nd_pfn);

	if (rc)

		return rc;

	/* we need a valid pfn_sb before we can init a vmem_altmap */

	return __nvdimm_namespace_attach_pfn(nd_pfn);

}



static int nd_pmem_probe(struct device *dev)