[PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors

[PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors

[Oliver O'Halloran]

We want to be able to cross reference the region and bus devices
with the device tree node that they were spawned from. libNVDIMM
handles creating the actual devices for these internally, so we
need to pass in a pointer to the relevant node in the descriptor.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/bus.c         | 1 +
 drivers/nvdimm/region_devs.c | 1 +
 include/linux/libnvdimm.h    | 3 +++
 3 files changed, 5 insertions(+)

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 78eabc3a1ab1..c6106914f396 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -358,6 +358,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 	nvdimm_bus->dev.release = nvdimm_bus_release;
 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
+	nvdimm_bus->dev.of_node = nd_desc->of_node;
 	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 	rc = device_register(&nvdimm_bus->dev);
 	if (rc) {
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 1593e1806b16..30d5dc8b9bb2 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1014,6 +1014,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 	dev->parent = &nvdimm_bus->dev;
 	dev->type = dev_type;
 	dev->groups = ndr_desc->attr_groups;
+	dev->of_node = ndr_desc->of_node;
 	nd_region->ndr_size = resource_size(ndr_desc->res);
 	nd_region->ndr_start = ndr_desc->res->start;
 	nd_device_register(dev);
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index ff855ed965fb..f61cb5050297 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -76,12 +76,14 @@ typedef int (*ndctl_fn)(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd, void *buf,
 		unsigned int buf_len, int *cmd_rc);
 
+struct device_node;
 struct nvdimm_bus_descriptor {
 	const struct attribute_group **attr_groups;
 	unsigned long bus_dsm_mask;
 	unsigned long cmd_mask;
 	struct module *module;
 	char *provider_name;
+	struct device_node *of_node;
 	ndctl_fn ndctl;
 	int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc);
 	int (*clear_to_send)(struct nvdimm_bus_descriptor *nd_desc,
@@ -123,6 +125,7 @@ struct nd_region_desc {
 	int num_lanes;
 	int numa_node;
 	unsigned long flags;
+	struct device_node *of_node;
 };
 
 struct device;
-- 
2.9.5

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

[PATCH v3 2/4] libnvdimm: Add device-tree based driver

[Oliver O'Halloran]

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.
v3: Replaced of_nd_region_* prefix with of_pmem_region_* to make
    the driver specific parts more distinct from the libnvdimm
    parts.
---
 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 8133e97980f1..df240740ca78 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8014,6 +8014,13 @@ 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
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index a65f2e1d9f53..2d6862bf7436 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 70d5f3ad9909..e8847045dac0 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 000000000000..85013bad35de
--- /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 <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_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");
-- 
2.9.5

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

[PATCH v3 3/4] doc/devicetree: Persistent memory region bindings

[Oliver O'Halloran]

Add device-tree binding documentation for the nvdimm region driver.

Cc: devicetree@vger.kernel.org
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
v2: Changed name from nvdimm-region to pmem-region.
    Cleaned up the example binding and fixed the overlapping regions.
    Added support for multiple regions in a single reg.
v3: Removed platform bus boilerplate from the example.
    Changed description of the volatile and reg properties
    to make them more clear.
---
 .../devicetree/bindings/pmem/pmem-region.txt       | 65 ++++++++++++++++++++++
 MAINTAINERS                                        |  1 +
 2 files changed, 66 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pmem/pmem-region.txt

diff --git a/Documentation/devicetree/bindings/pmem/pmem-region.txt b/Documentation/devicetree/bindings/pmem/pmem-region.txt
new file mode 100644
index 000000000000..5cfa4f016a00
--- /dev/null
+++ b/Documentation/devicetree/bindings/pmem/pmem-region.txt
@@ -0,0 +1,65 @@
+Device-tree bindings for persistent memory regions
+-----------------------------------------------------
+
+Persistent memory refers to a class of memory devices that are:
+
+	a) Usable as main system memory (i.e. cacheable), and
+	b) Retain their contents across power failure.
+
+Given b) it is best to think of persistent memory as a kind of memory mapped
+storage device. To ensure data integrity the operating system needs to manage
+persistent regions separately to the normal memory pool. To aid with that this
+binding provides a standardised interface for discovering where persistent
+memory regions exist inside the physical address space.
+
+Bindings for the region nodes:
+-----------------------------
+
+Required properties:
+	- compatible = "pmem-region"
+
+	- reg = <base, size>;
+		The reg property should specificy an address range that is
+		translatable to a system physical address range. This address
+		range should be mappable as normal system memory would be
+		(i.e cacheable).
+
+		If the reg property contains multiple address ranges
+		each address range will be treated as though it was specified
+		in a separate device node. Having multiple address ranges in a
+		node implies no special relationship between the two ranges.
+
+Optional properties:
+	- Any relevant NUMA assocativity properties for the target platform.
+
+	- volatile; This property indicates that this region is actually
+	  backed by non-persistent memory. This lets the OS know that it
+	  may skip the cache flushes required to ensure data is made
+	  persistent after a write.
+
+	  If this property is absent then the OS must assume that the region
+	  is backed by non-volatile memory.
+
+Examples:
+--------------------
+
+	/*
+	 * This node specifies one 4KB region spanning from
+	 * 0x5000 to 0x5fff that is backed by non-volatile memory.
+	 */
+	pmem@5000 {
+		compatible = "pmem-region";
+		reg = <0x00005000 0x00001000>;
+	};
+
+	/*
+	 * This node specifies two 4KB regions that are backed by
+	 * volatile (normal) memory.
+	 */
+	pmem@6000 {
+		compatible = "pmem-region";
+		reg = < 0x00006000 0x00001000
+			0x00008000 0x00001000 >;
+		volatile;
+	};
+
diff --git a/MAINTAINERS b/MAINTAINERS
index df240740ca78..cbd289d58644 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8020,6 +8020,7 @@ L:	linux-nvdimm@lists.01.org
 Q:	https://patchwork.kernel.org/project/linux-nvdimm/list/
 S:	Supported
 F:	drivers/nvdimm/of_pmem.c
+F:	Documentation/devicetree/bindings/pmem/pmem-region.txt
 
 LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
 M:	Dan Williams <dan.j.williams@intel.com>
-- 
2.9.5

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

[PATCH v3 4/4] powerpc/powernv: Create platform devs for nvdimm buses

[Oliver O'Halloran]

Scan the devicetree for an nvdimm-bus compatible and create
a platform device for them.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
 arch/powerpc/platforms/powernv/opal.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index c15182765ff5..c37485a3c5c9 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -821,6 +821,9 @@ static int __init opal_init(void)
 	/* Create i2c platform devices */
 	opal_pdev_init("ibm,opal-i2c");
 
+	/* Handle non-volatile memory devices */
+	opal_pdev_init("pmem-region");
+
 	/* Setup a heatbeat thread if requested by OPAL */
 	opal_init_heartbeat();
 
-- 
2.9.5

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

Re: [PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors

[Dan Williams]

On Thu, Apr 5, 2018 at 10:21 PM, Oliver O'Halloran <oohall@gmail.com> wrote:
> We want to be able to cross reference the region and bus devices
> with the device tree node that they were spawned from. libNVDIMM
> handles creating the actual devices for these internally, so we
> need to pass in a pointer to the relevant node in the descriptor.
>
> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
> Acked-by: Dan Williams <dan.j.williams@intel.com>

These look good to me. I'll get them applied today and let them soak
over the weekend for a pull request on Monday.

If anyone wants to add Acks or Reviews I can append them to the merge
tag. If there are any NAKs please speak up now, but as far as I know
there are no pending device-tree design concerns.
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

Re: [PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors

[Balbir Singh]

On Sat, Apr 7, 2018 at 4:28 AM, Dan Williams <dan.j.williams@intel.com> wrote:
> On Thu, Apr 5, 2018 at 10:21 PM, Oliver O'Halloran <oohall@gmail.com> wrote:
>> We want to be able to cross reference the region and bus devices
>> with the device tree node that they were spawned from. libNVDIMM
>> handles creating the actual devices for these internally, so we
>> need to pass in a pointer to the relevant node in the descriptor.
>>
>> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
>> Acked-by: Dan Williams <dan.j.williams@intel.com>
>
> These look good to me. I'll get them applied today and let them soak
> over the weekend for a pull request on Monday.
>
> If anyone wants to add Acks or Reviews I can append them to the merge
> tag. If there are any NAKs please speak up now, but as far as I know
> there are no pending device-tree design concerns.

Hi, Dan

I can ack Oliver's work, will do so in each patch

Overall

Acked-by: Balbir Singh <bsingharora@gmail.com>

Balbir Singh
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

Re: [PATCH v3 3/4] doc/devicetree: Persistent memory region bindings

[Michael Ellerman]

Oliver O'Halloran <oohall@gmail.com> writes:
> Add device-tree binding documentation for the nvdimm region driver.
>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
> ---
> v2: Changed name from nvdimm-region to pmem-region.
>     Cleaned up the example binding and fixed the overlapping regions.
>     Added support for multiple regions in a single reg.
> v3: Removed platform bus boilerplate from the example.
>     Changed description of the volatile and reg properties
>     to make them more clear.

Thanks.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

cheers
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm