Commit 8f4b01fc authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Dan Williams
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libnvdimm/namespace: Differentiate between probe mapping and runtime mapping 



The nvdimm core currently maps the full namespace to an ioremap range
while probing the namespace mode. This can result in probe failures on
architectures that have limited ioremap space.

For example, with a large btt namespace that consumes most of I/O remap
range, depending on the sequence of namespace initialization, the user
can find a pfn namespace initialization failure due to unavailable I/O
remap space which nvdimm core uses for temporary mapping.

nvdimm core can avoid this failure by only mapping the reserved info
block area to check for pfn superblock type and map the full namespace
resource only before using the namespace.

Given that personalities like BTT can be layered on top of any namespace
type create a generic form of devm_nsio_enable (devm_namespace_enable)
and use it inside the per-personality attach routines. Now
devm_namespace_enable() is always paired with disable unless the mapping
is going to be used for long term runtime access.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20191017073308.32645-1-aneesh.kumar@linux.ibm.com


[djbw: reworks to move devm_namespace_{en,dis}able into *attach helpers]
Reported-by: default avatarkbuild test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20191031105741.102793-2-aneesh.kumar@linux.ibm.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent c1f45d86

drivers/dax/pmem/core.c

+3 −3
Original line number Diff line number Diff line
@@ -25,20 +25,20 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) 
	ndns = nvdimm_namespace_common_probe(dev);

	if (IS_ERR(ndns))

		return ERR_CAST(ndns);

	nsio = to_nd_namespace_io(&ndns->dev);



	/* parse the 'pfn' info block via ->rw_bytes */

	rc = devm_nsio_enable(dev, nsio);

	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());

	if (rc)

		return ERR_PTR(rc);

	rc = nvdimm_setup_pfn(nd_pfn, &pgmap);

	if (rc)

		return ERR_PTR(rc);

	devm_nsio_disable(dev, nsio);

	devm_namespace_disable(dev, ndns);



	/* reserve the metadata area, device-dax will reserve the data */

	pfn_sb = nd_pfn->pfn_sb;

	offset = le64_to_cpu(pfn_sb->dataoff);

	nsio = to_nd_namespace_io(&ndns->dev);

	if (!devm_request_mem_region(dev, nsio->res.start, offset,

				dev_name(&ndns->dev))) {

		dev_warn(dev, "could not reserve metadata\n");

drivers/nvdimm/btt.c

+8 −2
Original line number Diff line number Diff line
@@ -1674,7 +1674,8 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns) 
	struct nd_region *nd_region;

	struct btt_sb *btt_sb;

	struct btt *btt;

	size_t rawsize;

	size_t size, rawsize;

	int rc;



	if (!nd_btt->uuid || !nd_btt->ndns || !nd_btt->lbasize) {

		dev_dbg(&nd_btt->dev, "incomplete btt configuration\n");
@@ -1685,6 +1686,11 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns) 
	if (!btt_sb)

		return -ENOMEM;



	size = nvdimm_namespace_capacity(ndns);

	rc = devm_namespace_enable(&nd_btt->dev, ndns, size);

	if (rc)

		return rc;



	/*

	 * If this returns < 0, that is ok as it just means there wasn't

	 * an existing BTT, and we're creating a new one. We still need to
@@ -1693,7 +1699,7 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns) 
	 */

	nd_btt_version(nd_btt, ndns, btt_sb);



	rawsize = nvdimm_namespace_capacity(ndns) - nd_btt->initial_offset;

	rawsize = size - nd_btt->initial_offset;

	if (rawsize < ARENA_MIN_SIZE) {

		dev_dbg(&nd_btt->dev, "%s must be at least %ld bytes\n",

				dev_name(&ndns->dev),

drivers/nvdimm/claim.c

+6 −8
Original line number Diff line number Diff line
@@ -300,13 +300,14 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns, 
	return rc;

}



int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)

int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,

		resource_size_t size)

{

	struct resource *res = &nsio->res;

	struct nd_namespace_common *ndns = &nsio->common;



	nsio->size = resource_size(res);

	if (!devm_request_mem_region(dev, res->start, resource_size(res),

	nsio->size = size;

	if (!devm_request_mem_region(dev, res->start, size,

				dev_name(&ndns->dev))) {

		dev_warn(dev, "could not reserve region %pR\n", res);

		return -EBUSY;
@@ -318,12 +319,10 @@ int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio) 
	nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,

			&nsio->res);



	nsio->addr = devm_memremap(dev, res->start, resource_size(res),

			ARCH_MEMREMAP_PMEM);

	nsio->addr = devm_memremap(dev, res->start, size, ARCH_MEMREMAP_PMEM);



	return PTR_ERR_OR_ZERO(nsio->addr);

}

EXPORT_SYMBOL_GPL(devm_nsio_enable);



void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)

{
@@ -331,6 +330,5 @@ void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio) 


	devm_memunmap(dev, nsio->addr);

	devm_exit_badblocks(dev, &nsio->bb);

	devm_release_mem_region(dev, res->start, resource_size(res));

	devm_release_mem_region(dev, res->start, nsio->size);

}
 
EXPORT_SYMBOL_GPL(devm_nsio_disable);

drivers/nvdimm/namespace_devs.c

+17 −0
Original line number Diff line number Diff line
@@ -1759,6 +1759,23 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev) 
}

EXPORT_SYMBOL(nvdimm_namespace_common_probe);



int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,

		resource_size_t size)

{

	if (is_namespace_blk(&ndns->dev))

		return 0;

	return devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev), size);

}

EXPORT_SYMBOL_GPL(devm_namespace_enable);



void devm_namespace_disable(struct device *dev, struct nd_namespace_common *ndns)

{

	if (is_namespace_blk(&ndns->dev))

		return;

	devm_nsio_disable(dev, to_nd_namespace_io(&ndns->dev));

}

EXPORT_SYMBOL_GPL(devm_namespace_disable);



static struct device **create_namespace_io(struct nd_region *nd_region)

{

	struct nd_namespace_io *nsio;

drivers/nvdimm/nd-core.h

+17 −0
Original line number Diff line number Diff line
@@ -171,6 +171,23 @@ ssize_t nd_namespace_store(struct device *dev, 
struct nd_pfn *to_nd_pfn_safe(struct device *dev);

bool is_nvdimm_bus(struct device *dev);



#if IS_ENABLED(CONFIG_ND_CLAIM)

int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio,

		resource_size_t size);

void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);

#else

static inline int devm_nsio_enable(struct device *dev,

		struct nd_namespace_io *nsio, resource_size_t size)

{

	return -ENXIO;

}



static inline void devm_nsio_disable(struct device *dev,

		struct nd_namespace_io *nsio)

{

}

#endif



#ifdef CONFIG_PROVE_LOCKING

extern struct class *nd_class;

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