@@ -8035,6 +8035,13 @@ Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
S: Supported
F: drivers/nvdimm/pmem*
+LIBNVDIMM: DEVICETREE BINDINGS
+M: Oliver O'Halloran <oohall@gmail.com>
+L: linux-nvdimm@lists.01.org
+Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
+S: Supported
+F: drivers/nvdimm/of_pmem.c
+
LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
M: Dan Williams <dan.j.williams@intel.com>
L: linux-nvdimm@lists.01.org
@@ -102,4 +102,14 @@ config NVDIMM_DAX
Select Y if unsure
+config OF_PMEM
+ tristate "Device-tree support for persistent memory regions"
+ depends on OF
+ default LIBNVDIMM
+ help
+ Allows regions of persistent memory to be described in the
+ device-tree.
+
+ Select Y if unsure.
+
endif
@@ -4,6 +4,7 @@ obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o
obj-$(CONFIG_ND_BTT) += nd_btt.o
obj-$(CONFIG_ND_BLK) += nd_blk.o
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
+obj-$(CONFIG_OF_PMEM) += of_pmem.o
nd_pmem-y := pmem.o
new file mode 100644
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#define pr_fmt(fmt) "of_pmem: " fmt
+
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+
+static const struct attribute_group *region_attr_groups[] = {
+ &nd_region_attribute_group,
+ &nd_device_attribute_group,
+ NULL,
+};
+
+static const struct attribute_group *bus_attr_groups[] = {
+ &nvdimm_bus_attribute_group,
+ NULL,
+};
+
+struct of_nd_private {
+ struct nvdimm_bus_descriptor bus_desc;
+ struct nvdimm_bus *bus;
+};
+
+static int of_nd_region_probe(struct platform_device *pdev)
+{
+ struct of_nd_private *priv;
+ struct device_node *np;
+ struct nvdimm_bus *bus;
+ bool is_volatile;
+ int i;
+
+ np = dev_of_node(&pdev->dev);
+ if (!np)
+ return -ENXIO;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->bus_desc.attr_groups = bus_attr_groups;
+ priv->bus_desc.provider_name = "of_pmem";
+ priv->bus_desc.module = THIS_MODULE;
+ priv->bus_desc.of_node = np;
+
+ priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
+ if (!bus) {
+ kfree(priv);
+ return -ENODEV;
+ }
+ platform_set_drvdata(pdev, priv);
+
+ is_volatile = !!of_find_property(np, "volatile", NULL);
+ dev_dbg(&pdev->dev, "Registering %s regions from %pOF\n",
+ is_volatile ? "volatile" : "non-volatile", np);
+
+ for (i = 0; i < pdev->num_resources; i++) {
+ struct nd_region_desc ndr_desc;
+ struct nd_region *region;
+
+ /*
+ * NB: libnvdimm copies the data from ndr_desc into it's own
+ * structures so passing a stack pointer is fine.
+ */
+ memset(&ndr_desc, 0, sizeof(ndr_desc));
+ ndr_desc.attr_groups = region_attr_groups;
+ ndr_desc.numa_node = of_node_to_nid(np);
+ ndr_desc.res = &pdev->resource[i];
+ ndr_desc.of_node = np;
+ set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+
+ if (is_volatile)
+ region = nvdimm_volatile_region_create(bus, &ndr_desc);
+ else
+ region = nvdimm_pmem_region_create(bus, &ndr_desc);
+
+ if (!region)
+ dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",
+ ndr_desc.res, np);
+ else
+ dev_dbg(&pdev->dev, "Registered region %pR from %pOF\n",
+ ndr_desc.res, np);
+ }
+
+ return 0;
+}
+
+static int of_nd_region_remove(struct platform_device *pdev)
+{
+ struct of_nd_private *priv = platform_get_drvdata(pdev);
+
+ nvdimm_bus_unregister(priv->bus);
+ kfree(priv);
+
+ return 0;
+}
+
+static const struct of_device_id of_nd_region_match[] = {
+ { .compatible = "pmem-region" },
+ { },
+};
+
+static struct platform_driver of_nd_region_driver = {
+ .probe = of_nd_region_probe,
+ .remove = of_nd_region_remove,
+ .driver = {
+ .name = "of_pmem",
+ .owner = THIS_MODULE,
+ .of_match_table = of_nd_region_match,
+ },
+};
+
+module_platform_driver(of_nd_region_driver);
+MODULE_DEVICE_TABLE(of, of_nd_region_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("IBM Corporation");
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> --- v2: Made each bus have a separate node rather having a shared bus. Renamed to of_pmem rather than of_nvdimm. Changed log level of happy-path messages to debug. --- MAINTAINERS | 7 +++ drivers/nvdimm/Kconfig | 10 ++++ drivers/nvdimm/Makefile | 1 + drivers/nvdimm/of_pmem.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 137 insertions(+) create mode 100644 drivers/nvdimm/of_pmem.c