* [PATCH v3 2/4] libnvdimm: Add device-tree based driver
2018-04-06 5:21 [PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors Oliver O'Halloran
@ 2018-04-06 5:21 ` Oliver O'Halloran
2018-04-06 5:21 ` [PATCH v3 3/4] doc/devicetree: Persistent memory region bindings Oliver O'Halloran
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Oliver O'Halloran @ 2018-04-06 5:21 UTC (permalink / raw)
To: linuxppc-dev; +Cc: linux-nvdimm, 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
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 3/4] doc/devicetree: Persistent memory region bindings
2018-04-06 5:21 [PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors Oliver O'Halloran
2018-04-06 5:21 ` [PATCH v3 2/4] libnvdimm: Add device-tree based driver Oliver O'Halloran
@ 2018-04-06 5:21 ` Oliver O'Halloran
2018-04-07 10:58 ` Michael Ellerman
2018-04-06 5:21 ` [PATCH v3 4/4] powerpc/powernv: Create platform devs for nvdimm buses Oliver O'Halloran
2018-04-06 18:28 ` [PATCH v3 1/4] libnvdimm: Add of_node to region and bus descriptors Dan Williams
3 siblings, 1 reply; 7+ messages in thread
From: Oliver O'Halloran @ 2018-04-06 5:21 UTC (permalink / raw)
To: linuxppc-dev; +Cc: linux-nvdimm, Oliver O'Halloran, devicetree
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
^ permalink raw reply related [flat|nested] 7+ messages in thread