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authorDan Williams <dan.j.williams@intel.com>2015-08-19 00:34:34 -0400
committerDan Williams <dan.j.williams@intel.com>2015-08-19 00:34:34 -0400
commit7a67832c7e44c20935c5d6f2264035a0f7bf0d8f (patch)
tree1ace57d407ece741401f7b8878f1b2d85e990004 /drivers/nvdimm/e820.c
parent6ec689542b5bc516187917d49b112847dfb75b0b (diff)
libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
We currently register a platform device for e820 type-12 memory and register a nvdimm bus beneath it. Registering the platform device triggers the device-core machinery to probe for a driver, but that search currently comes up empty. Building the nvdimm-bus registration into the e820_pmem platform device registration in this way forces libnvdimm to be built-in. Instead, convert the built-in portion of CONFIG_X86_PMEM_LEGACY to simply register a platform device and move the rest of the logic to the driver for e820_pmem, for the following reasons: 1/ Letting e820_pmem support be a module allows building and testing libnvdimm.ko changes without rebooting 2/ All the normal policy around modules can be applied to e820_pmem (unbind to disable and/or blacklisting the module from loading by default) 3/ Moving the driver to a generic location and converting it to scan "iomem_resource" rather than "e820.map" means any other architecture can take advantage of this simple nvdimm resource discovery mechanism by registering a resource named "Persistent Memory (legacy)" Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm/e820.c')
-rw-r--r--drivers/nvdimm/e820.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/nvdimm/e820.c b/drivers/nvdimm/e820.c
new file mode 100644
index 000000000000..1b5743ad92db
--- /dev/null
+++ b/drivers/nvdimm/e820.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2015, Christoph Hellwig.
+ * Copyright (c) 2015, Intel Corporation.
+ */
+#include <linux/platform_device.h>
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
+
+static const struct attribute_group *e820_pmem_attribute_groups[] = {
+ &nvdimm_bus_attribute_group,
+ NULL,
+};
+
+static const struct attribute_group *e820_pmem_region_attribute_groups[] = {
+ &nd_region_attribute_group,
+ &nd_device_attribute_group,
+ NULL,
+};
+
+static int e820_pmem_remove(struct platform_device *pdev)
+{
+ struct nvdimm_bus *nvdimm_bus = platform_get_drvdata(pdev);
+
+ nvdimm_bus_unregister(nvdimm_bus);
+ 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;
+
+ nd_desc.attr_groups = e820_pmem_attribute_groups;
+ nd_desc.provider_name = "e820";
+ nvdimm_bus = nvdimm_bus_register(dev, &nd_desc);
+ if (!nvdimm_bus)
+ goto err;
+ platform_set_drvdata(pdev, nvdimm_bus);
+
+ for (p = iomem_resource.child; p ; p = p->sibling) {
+ struct nd_region_desc ndr_desc;
+
+ if (strncmp(p->name, "Persistent Memory (legacy)", 26) != 0)
+ 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 = NUMA_NO_NODE;
+ if (!nvdimm_pmem_region_create(nvdimm_bus, &ndr_desc))
+ goto err;
+ }
+
+ return 0;
+
+ err:
+ nvdimm_bus_unregister(nvdimm_bus);
+ dev_err(dev, "failed to register legacy persistent memory ranges\n");
+ return -ENXIO;
+}
+
+static struct platform_driver e820_pmem_driver = {
+ .probe = e820_pmem_probe,
+ .remove = e820_pmem_remove,
+ .driver = {
+ .name = "e820_pmem",
+ },
+};
+
+static __init int e820_pmem_init(void)
+{
+ return platform_driver_register(&e820_pmem_driver);
+}
+
+static __exit void e820_pmem_exit(void)
+{
+ platform_driver_unregister(&e820_pmem_driver);
+}
+
+MODULE_ALIAS("platform:e820_pmem*");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Intel Corporation");
+module_init(e820_pmem_init);
+module_exit(e820_pmem_exit);