A fairly bare-bones set of device-tree bindings so libnvdimm can be used
on powerpc and other, less cool, device-tree based platforms.
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Oliver O'Halloran <oohall@xxxxxxxxx>
---
The current bindings are essentially this:
nonvolatile-memory {
compatible = "nonvolatile-memory", "special-memory";
ranges;
region@0 {
compatible = "nvdimm,byte-addressable";
reg = <0x0 0x1000>;
};
region@1000 {
compatible = "nvdimm,byte-addressable";
reg = <0x1000 0x1000>;
};
};
To handle interleave sets, etc the plan was the add an extra property with the
interleave stride and a "mapping" property with <&DIMM, dimm-start-offset>
tuples for each dimm in the interleave set. Block MMIO regions can be added
with a different compatible type, but I'm not too concerned with them for
now.
Does this sound reasonable? Is there anything this scheme would make difficult?
---
drivers/nvdimm/Kconfig | 10 +++
drivers/nvdimm/Makefile | 1 +
drivers/nvdimm/of_nvdimm.c | 209 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 220 insertions(+)
create mode 100644 drivers/nvdimm/of_nvdimm.c
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 5bdd499b5f4f..72d147b55596 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -102,4 +102,14 @@ config NVDIMM_DAX
Select Y if unsure
+config OF_NVDIMM
+ tristate "Device-tree support for NVDIMMs"
+ depends on OF
+ default LIBNVDIMM
+ help
+ Allows byte addressable persistent memory regions to be described in the
+ device-tree.
+
+ Select Y if unsure.
+
endif
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 909554c3f955..622961f4849d 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -3,6 +3,7 @@ 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_NVDIMM) += of_nvdimm.o
nd_pmem-y := pmem.o
diff --git a/drivers/nvdimm/of_nvdimm.c b/drivers/nvdimm/of_nvdimm.c
new file mode 100644
index 000000000000..359808200feb
--- /dev/null
+++ b/drivers/nvdimm/of_nvdimm.c
@@ -0,0 +1,209 @@
+/*
+ * Copyright 2017, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ */
+
+#define pr_fmt(fmt) "of_nvdimm: " 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 int of_nvdimm_add_byte(struct nvdimm_bus *bus, struct device_node *np)
+{
+ struct nd_region_desc ndr_desc;
+ struct resource temp_res;
+ struct nd_region *region;
+
+ /*
+ * byte regions should only have one address range
+ */
+ if (of_address_to_resource(np, 0, &temp_res)) {
+ pr_warn("Unable to parse reg[0] for %s\n", np->full_name);
+ return -ENXIO;
+ }
+
+ pr_debug("Found %pR for %s\n", &temp_res, np->full_name);
+
+ memset(&ndr_desc, 0, sizeof(ndr_desc));
+ ndr_desc.res = &temp_res;
+ ndr_desc.attr_groups = region_attr_groups;
+#ifdef CONFIG_NUMA
+ ndr_desc.numa_node = of_node_to_nid(np);
+#endif
+ set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+
+ region = nvdimm_pmem_region_create(bus, &ndr_desc);
+ if (!region)
+ return -ENXIO;
+
+ /*
+ * Bind the region to the OF node we spawned it from. We
+ * already bumped the node's refcount while walking the
+ * bus.
+ */
+ to_nd_region_dev(region)->of_node = np;
+
+ return 0;
+}
+
+/*
+ * 'data' is a pointer to the function that handles registering the device
+ * on the nvdimm bus.
+ */
+static struct of_device_id of_nvdimm_dev_types[] = {
+ { .compatible = "nvdimm,byte-addressable", .data = of_nvdimm_add_byte },
+ { },
+};
+
+static void of_nvdimm_parse_one(struct nvdimm_bus *bus,
+ struct device_node *node)
+{
+ int (*parse_node)(struct nvdimm_bus *, struct device_node *);
+ const struct of_device_id *match;
+ int rc;
+
+ if (of_node_test_and_set_flag(node, OF_POPULATED)) {
+ pr_debug("%s already parsed, skipping\n",
+ node->full_name);
+ return;
+ }
+
+ match = of_match_node(of_nvdimm_dev_types, node);
+ if (!match) {
+ pr_info("No compatible match for '%s'\n",
+ node->full_name);
+ of_node_clear_flag(node, OF_POPULATED);
+ return;
+ }
+
+ of_node_get(node);
+ parse_node = match->data;
+ rc = parse_node(bus, node);
+
+ if (rc) {
+ of_node_clear_flag(node, OF_POPULATED);
+ of_node_put(node);
+ }
+
+ pr_debug("Parsed %s, rc = %d\n", node->full_name, rc);
+
+ return;
+}
+
+/*
+ * The nvdimm core refers to the bus descriptor structure at runtime
+ * so we need to keep it around. Note that this is different to region
+ * descriptors which can be stack allocated.
+ */
+struct of_nd_bus {
+ struct nvdimm_bus_descriptor desc;
+ struct nvdimm_bus *bus;
+};
+
+static const struct attribute_group *bus_attr_groups[] = {
+ &nvdimm_bus_attribute_group,
+ NULL,
+};
+
+static int of_nvdimm_probe(struct platform_device *pdev)
+{
+ struct device_node *node, *child;
+ struct of_nd_bus *of_nd_bus;
+
+ node = dev_of_node(&pdev->dev);
+ if (!node)
+ return -ENXIO;
+
+ of_nd_bus = kzalloc(sizeof(*of_nd_bus), GFP_KERNEL);
+ if (!of_nd_bus)
+ return -ENOMEM;
+
+ of_nd_bus->desc.attr_groups = bus_attr_groups;
+ of_nd_bus->desc.provider_name = "of_nvdimm";
+ of_nd_bus->desc.module = THIS_MODULE;
+ of_nd_bus->bus = nvdimm_bus_register(&pdev->dev, &of_nd_bus->desc);
+ if (!of_nd_bus->bus)
+ goto err;
+
+ to_nvdimm_bus_dev(of_nd_bus->bus)->of_node = node;
+
+ /* now walk the node bus and setup regions, etc */
+ for_each_available_child_of_node(node, child)
+ of_nvdimm_parse_one(of_nd_bus->bus, child);
+
+ platform_set_drvdata(pdev, of_nd_bus);
+
+ return 0;
+
+err:
+ nvdimm_bus_unregister(of_nd_bus->bus);
+ kfree(of_nd_bus);
+ return -ENXIO;
+}
+
+static int of_nvdimm_remove(struct platform_device *pdev)
+{
+ struct of_nd_bus *bus = platform_get_drvdata(pdev);
+ struct device_node *node;
+
+ if (!bus)
+ return 0; /* possible? */
+
+ for_each_available_child_of_node(pdev->dev.of_node, node) {
+ if (!of_node_check_flag(node, OF_POPULATED))
+ continue;
+
+ of_node_clear_flag(node, OF_POPULATED);
+ of_node_put(node);
+ pr_debug("de-populating %s\n", node->full_name);
+ }
+
+ nvdimm_bus_unregister(bus->bus);
+ kfree(bus);
+
+ return 0;
+}
+
+static const struct of_device_id of_nvdimm_bus_match[] = {
+ { .compatible = "nonvolatile-memory" },
+ { .compatible = "special-memory" },
+ { },
+};
+
+static struct platform_driver of_nvdimm_driver = {
+ .probe = of_nvdimm_probe,
+ .remove = of_nvdimm_remove,
+ .driver = {
+ .name = "of_nvdimm",
+ .owner = THIS_MODULE,
+ .of_match_table = of_nvdimm_bus_match,
+ },
+};
+
+module_platform_driver(of_nvdimm_driver);
+MODULE_DEVICE_TABLE(of, of_nvdimm_bus_match);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("IBM Corporation");
--
2.9.4
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