338f6dac85
Currently, kernel shows the below values "persistence_domain":"cpu_cache" "persistence_domain":"memory_controller" "persistence_domain":"unknown" "cpu_cache" indicates no extra instructions is needed to ensure the persistence of data in the pmem media on power failure. "memory_controller" indicates cpu cache flush instructions are required to flush the data. Platform provides mechanisms to automatically flush outstanding write data from memory controler to pmem on system power loss. Based on the above use memory_controller for non volatile regions on ppc64. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Link: https://lore.kernel.org/r/20200324034821.60869-1-aneesh.kumar@linux.ibm.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
109 lines
2.6 KiB
C
109 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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#define pr_fmt(fmt) "of_pmem: " fmt
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#include <linux/of_platform.h>
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#include <linux/of_address.h>
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#include <linux/libnvdimm.h>
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#include <linux/module.h>
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#include <linux/ioport.h>
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#include <linux/slab.h>
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struct of_pmem_private {
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struct nvdimm_bus_descriptor bus_desc;
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struct nvdimm_bus *bus;
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};
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static int of_pmem_region_probe(struct platform_device *pdev)
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{
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struct of_pmem_private *priv;
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struct device_node *np;
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struct nvdimm_bus *bus;
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bool is_volatile;
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int i;
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np = dev_of_node(&pdev->dev);
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if (!np)
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return -ENXIO;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->bus_desc.provider_name = kstrdup(pdev->name, GFP_KERNEL);
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priv->bus_desc.module = THIS_MODULE;
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priv->bus_desc.of_node = np;
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priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
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if (!bus) {
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kfree(priv);
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return -ENODEV;
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}
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platform_set_drvdata(pdev, priv);
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is_volatile = !!of_find_property(np, "volatile", NULL);
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dev_dbg(&pdev->dev, "Registering %s regions from %pOF\n",
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is_volatile ? "volatile" : "non-volatile", np);
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for (i = 0; i < pdev->num_resources; i++) {
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struct nd_region_desc ndr_desc;
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struct nd_region *region;
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/*
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* NB: libnvdimm copies the data from ndr_desc into it's own
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* structures so passing a stack pointer is fine.
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*/
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memset(&ndr_desc, 0, sizeof(ndr_desc));
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ndr_desc.numa_node = dev_to_node(&pdev->dev);
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ndr_desc.target_node = ndr_desc.numa_node;
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ndr_desc.res = &pdev->resource[i];
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ndr_desc.of_node = np;
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set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
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if (is_volatile)
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region = nvdimm_volatile_region_create(bus, &ndr_desc);
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else {
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set_bit(ND_REGION_PERSIST_MEMCTRL, &ndr_desc.flags);
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region = nvdimm_pmem_region_create(bus, &ndr_desc);
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}
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if (!region)
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dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",
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ndr_desc.res, np);
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else
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dev_dbg(&pdev->dev, "Registered region %pR from %pOF\n",
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ndr_desc.res, np);
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}
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return 0;
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}
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static int of_pmem_region_remove(struct platform_device *pdev)
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{
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struct of_pmem_private *priv = platform_get_drvdata(pdev);
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nvdimm_bus_unregister(priv->bus);
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kfree(priv);
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return 0;
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}
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static const struct of_device_id of_pmem_region_match[] = {
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{ .compatible = "pmem-region" },
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{ },
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};
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static struct platform_driver of_pmem_region_driver = {
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.probe = of_pmem_region_probe,
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.remove = of_pmem_region_remove,
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.driver = {
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.name = "of_pmem",
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.of_match_table = of_pmem_region_match,
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},
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};
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module_platform_driver(of_pmem_region_driver);
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MODULE_DEVICE_TABLE(of, of_pmem_region_match);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("IBM Corporation");
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