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oohaldjbw
oohal
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libnvdimm: Add device-tree based driver
This patch adds peliminary device-tree bindings for persistent memory regions. The driver registers a libnvdimm bus for each pmem-region node and each address range under the node is converted to a region within that bus. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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‎MAINTAINERS

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@@ -8035,6 +8035,13 @@ Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
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S: Supported
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F: drivers/nvdimm/pmem*
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LIBNVDIMM: DEVICETREE BINDINGS
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M: Oliver O'Halloran <oohall@gmail.com>
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L: linux-nvdimm@lists.01.org
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Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
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S: Supported
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F: drivers/nvdimm/of_pmem.c
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LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
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M: Dan Williams <dan.j.williams@intel.com>
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L: linux-nvdimm@lists.01.org

‎drivers/nvdimm/Kconfig

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@@ -102,4 +102,14 @@ config NVDIMM_DAX
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Select Y if unsure
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config OF_PMEM
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tristate "Device-tree support for persistent memory regions"
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depends on OF
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default LIBNVDIMM
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help
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Allows regions of persistent memory to be described in the
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device-tree.
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Select Y if unsure.
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endif

‎drivers/nvdimm/Makefile

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@@ -4,6 +4,7 @@ obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o
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obj-$(CONFIG_ND_BTT) += nd_btt.o
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obj-$(CONFIG_ND_BLK) += nd_blk.o
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obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
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obj-$(CONFIG_OF_PMEM) += of_pmem.o
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nd_pmem-y := pmem.o
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‎drivers/nvdimm/of_pmem.c

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// 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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static const struct attribute_group *region_attr_groups[] = {
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&nd_region_attribute_group,
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&nd_device_attribute_group,
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NULL,
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};
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static const struct attribute_group *bus_attr_groups[] = {
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&nvdimm_bus_attribute_group,
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NULL,
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};
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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.attr_groups = bus_attr_groups;
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priv->bus_desc.provider_name = "of_pmem";
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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.attr_groups = region_attr_groups;
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ndr_desc.numa_node = of_node_to_nid(np);
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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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region = nvdimm_pmem_region_create(bus, &ndr_desc);
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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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.owner = THIS_MODULE,
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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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