From d76401ade0bb6ab0a70dea317ec115d5425880cf Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 2 Jun 2018 11:43:39 -0700 Subject: [PATCH] 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 Signed-off-by: Dan Williams --- drivers/nvdimm/e820.c | 41 ++++++++++++++++++++++------------------- kernel/resource.c | 1 + 2 files changed, 23 insertions(+), 19 deletions(-) diff --git a/drivers/nvdimm/e820.c b/drivers/nvdimm/e820.c index 6f9a6ffd7cde..521eaf53a52a 100644 --- a/drivers/nvdimm/e820.c +++ b/drivers/nvdimm/e820.c @@ -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)) - goto err; - } - + 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: +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 = { diff --git a/kernel/resource.c b/kernel/resource.c index 2af6c03858b9..b85f59e8a4b8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -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