Commit d76401ad authored by Dan Williams's avatar Dan Williams
Browse files

libnvdimm, e820: Register all pmem resources 



There is currently a mismatch between the resources that will trigger
the e820_pmem driver to register/load and the resources that will
actually be surfaced as pmem ranges. register_e820_pmem() uses
walk_iomem_res_desc() which includes children and siblings. In contrast,
e820_pmem_probe() only considers top level resources. For example the
following resource tree results in the driver being loaded, but no
resources being registered:

    398000000000-39bfffffffff : PCI Bus 0000:ae
      39be00000000-39bf07ffffff : PCI Bus 0000:af
        39be00000000-39beffffffff : 0000:af:00.0
          39be10000000-39beffffffff : Persistent Memory (legacy)

Fix this up to allow definitions of "legacy" pmem ranges anywhere in
system-physical address space. Not that it is a recommended or safe to
define a pmem range in PCI space, but it is useful for debug /
experimentation, and the restriction on being a top-level resource was
arbitrary.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 3f46833d

drivers/nvdimm/e820.c

+22 −19
Original line number Diff line number Diff line
@@ -38,12 +38,27 @@ static int e820_range_to_nid(resource_size_t addr) 
}

#endif



static int e820_register_one(struct resource *res, void *data)

{

	struct nd_region_desc ndr_desc;

	struct nvdimm_bus *nvdimm_bus = data;



	memset(&ndr_desc, 0, sizeof(ndr_desc));

	ndr_desc.res = res;

	ndr_desc.attr_groups = e820_pmem_region_attribute_groups;

	ndr_desc.numa_node = e820_range_to_nid(res->start);

	set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);

	if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))

		return -ENXIO;

	return 0;

}



static int e820_pmem_probe(struct platform_device *pdev)

{

	static struct nvdimm_bus_descriptor nd_desc;

	struct device *dev = &pdev->dev;

	struct nvdimm_bus *nvdimm_bus;

	struct resource *p;

	int rc = -ENXIO;



	nd_desc.attr_groups = e820_pmem_attribute_groups;

	nd_desc.provider_name = "e820";
@@ -53,27 +68,15 @@ static int e820_pmem_probe(struct platform_device *pdev) 
		goto err;

	platform_set_drvdata(pdev, nvdimm_bus);



	for (p = iomem_resource.child; p ; p = p->sibling) {

		struct nd_region_desc ndr_desc;



		if (p->desc != IORES_DESC_PERSISTENT_MEMORY_LEGACY)

			continue;



		memset(&ndr_desc, 0, sizeof(ndr_desc));

		ndr_desc.res = p;

		ndr_desc.attr_groups = e820_pmem_region_attribute_groups;

		ndr_desc.numa_node = e820_range_to_nid(p->start);

		set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);

		if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))

	rc = walk_iomem_res_desc(IORES_DESC_PERSISTENT_MEMORY_LEGACY,

			IORESOURCE_MEM, 0, -1, nvdimm_bus, e820_register_one);

	if (rc)

		goto err;

	}



	return 0;



err:

	nvdimm_bus_unregister(nvdimm_bus);

	dev_err(dev, "failed to register legacy persistent memory ranges\n");

	return -ENXIO;

	return rc;

}



static struct platform_driver e820_pmem_driver = {

kernel/resource.c

+1 −0
Original line number Diff line number Diff line
@@ -448,6 +448,7 @@ int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, 


	return __walk_iomem_res_desc(&res, desc, false, arg, func);

}

EXPORT_SYMBOL_GPL(walk_iomem_res_desc);



/*

 * This function calls the @func callback against all memory ranges of type

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