From 7171976089528cb3d057a6fb288e7f8f89ab7f68 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Fri, 6 Apr 2018 15:21:14 +1000 Subject: [PATCH] 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 Signed-off-by: Dan Williams --- 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 diff --git a/MAINTAINERS b/MAINTAINERS index 4623caf..06230c0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -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 +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 L: linux-nvdimm@lists.01.org diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig index a65f2e1..2d6862b 100644 --- a/drivers/nvdimm/Kconfig +++ b/drivers/nvdimm/Kconfig @@ -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 diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index 70d5f3a..e884704 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -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 diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c new file mode 100644 index 0000000..85013ba --- /dev/null +++ b/drivers/nvdimm/of_pmem.c @@ -0,0 +1,119 @@ +// SPDX-License-Identifier: GPL-2.0+ + +#define pr_fmt(fmt) "of_pmem: " fmt + +#include +#include +#include +#include +#include +#include + +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_pmem_private { + struct nvdimm_bus_descriptor bus_desc; + struct nvdimm_bus *bus; +}; + +static int of_pmem_region_probe(struct platform_device *pdev) +{ + struct of_pmem_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_pmem_region_remove(struct platform_device *pdev) +{ + struct of_pmem_private *priv = platform_get_drvdata(pdev); + + nvdimm_bus_unregister(priv->bus); + kfree(priv); + + return 0; +} + +static const struct of_device_id of_pmem_region_match[] = { + { .compatible = "pmem-region" }, + { }, +}; + +static struct platform_driver of_pmem_region_driver = { + .probe = of_pmem_region_probe, + .remove = of_pmem_region_remove, + .driver = { + .name = "of_pmem", + .owner = THIS_MODULE, + .of_match_table = of_pmem_region_match, + }, +}; + +module_platform_driver(of_pmem_region_driver); +MODULE_DEVICE_TABLE(of, of_pmem_region_match); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("IBM Corporation"); -- 2.7.4