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author | Dan Williams <dan.j.williams@intel.com> | 2015-08-19 00:34:34 -0400 |
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committer | Dan Williams <dan.j.williams@intel.com> | 2015-08-19 00:34:34 -0400 |
commit | 7a67832c7e44c20935c5d6f2264035a0f7bf0d8f (patch) | |
tree | 1ace57d407ece741401f7b8878f1b2d85e990004 /drivers/nvdimm/e820.c | |
parent | 6ec689542b5bc516187917d49b112847dfb75b0b (diff) | |
download | linux-7a67832c7e44c20935c5d6f2264035a0f7bf0d8f.tar.bz2 |
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.c | 86 |
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); |