Re: [PATCH 2/3] libnvdimm: Add a device-tree interface

[Michael Ellerman]

Rob Herring  writes:
> On Thu, Nov 16, 2017 at 04:51:30AM +1100, Oliver O'Halloran wrote:
...
>> diff --git a/drivers/nvdimm/of_nvdimm.c b/drivers/nvdimm/of_nvdimm.c
>> new file mode 100644
>> index ..765cbbae8bcb
>> --- /dev/null
>> +++ b/drivers/nvdimm/of_nvdimm.c
>> @@ -0,0 +1,202 @@
>> +/*
>> + * 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.
>
> This can be SPDX tag.

Specifically:

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2017, IBM Corporation
 */

...

cheers

Re: [PATCH 2/3] libnvdimm: Add a device-tree interface

[Rob Herring]

On Thu, Nov 16, 2017 at 04:51:30AM +1100, Oliver O'Halloran wrote:
> A fairly bare-bones set of device-tree bindings so libnvdimm can be used
> on powerpc and other device-tree based platforms.
> 
> Cc: devicet...@vger.kernel.org
> Signed-off-by: Oliver O'Halloran 
> ---
>  .../devicetree/bindings/nvdimm/nvdimm-bus.txt  |  69 +++

Also, please split bindings to a separate patch.

>  MAINTAINERS|   8 +
>  drivers/nvdimm/Kconfig |  10 +
>  drivers/nvdimm/Makefile|   1 +
>  drivers/nvdimm/of_nvdimm.c | 202 
> +
>  5 files changed, 290 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
>  create mode 100644 drivers/nvdimm/of_nvdimm.c

Re: [PATCH 2/3] libnvdimm: Add a device-tree interface

[Rob Herring]

On Thu, Nov 16, 2017 at 04:51:30AM +1100, Oliver O'Halloran wrote:
> A fairly bare-bones set of device-tree bindings so libnvdimm can be used
> on powerpc and other device-tree based platforms.
> 
> Cc: devicet...@vger.kernel.org
> Signed-off-by: Oliver O'Halloran 
> ---
>  .../devicetree/bindings/nvdimm/nvdimm-bus.txt  |  69 +++
>  MAINTAINERS|   8 +
>  drivers/nvdimm/Kconfig |  10 +
>  drivers/nvdimm/Makefile|   1 +
>  drivers/nvdimm/of_nvdimm.c | 202 
> +
>  5 files changed, 290 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
>  create mode 100644 drivers/nvdimm/of_nvdimm.c
> 
> diff --git a/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt 
> b/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
> new file mode 100644
> index ..491e7c4900ed
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
> @@ -0,0 +1,69 @@
> +Device-tree bindings for nonvolatile-memory / NVDIMMs
> +-
> +
> +Non-volatile DIMMs are memory modules used to provide (cacheable) main 
> memory that
> +retains its contents across power cycles. In more practical terms, they are 
> kind
> +of storage device where the contents can be accessed by the CPU directly,
> +rather than indirectly via a storage controller or similar. This can provide
> +substantial performance improvements for applications designed to take
> +advantage of in-memory storage.
> +
> +This binding provides a way to describe memory regions that should be managed
> +by an NVDIMM storage driver (libNVDIMM in Linux) and some of the associated
> +metadata. The binding itself is split into two main parts: A container bus 
> and
> +its sub-nodes which describe which memory address ranges corresponding to
> +NVDIMM backed memory.
> +
> +Bindings for the container bus:
> +--
> +
> +Required properties:
> + - compatible = "nvdimm-bus";
> + - ranges;
> + A blank ranges property is required because the sub-nodes have
> + addresses in the system's physical address space.
> +
> +The use of a container bus is mainly to handle future expansion of the 
> binding. For
> +comparison the ACPI equivalent of this binding (NFIT) describes: Memory 
> regions, DIMM
> +control structures, Block mode DIMM control structures, interleave sets, and 
> more. Some
> +of these structures cross reference each other so everyone should be happier 
> if we keep
> +it relatively self contained.

Will adding any of these things need unit addresses and colide with the 
existing nodes below? IOW, at one level there's only 1 number space.

> +
> +Bindings for the region nodes:
> +-
> +
> +Required properties:
> + - compatible = "nvdimm-persistent" or "nvdimm-volatile"
> +
> + The "nvdimm-persistent" region type indicates that this memory 
> region
> + is actually a persistent region. The volatile type is mainly 
> useful
> + for testing and RAM disks that can persist across kexec.
> +
> + - reg = ;
> + The reg property should only contain one address range.
> +
> +Optional properties:
> + - Any relevant NUMA assocativity properties for the target platform.
> +
> +A complete example:
> +
> +
> +/ {
> + #size-cells = <1>;
> + #address-cells = <1>;
> +
> + nonvolatile-memory {
> + compatible = "nonvolatile-memory";
> + ranges;
> +
> + region@5000 {
> + compatible = "nvdimm-persistent";
> + reg = <0x5000 0x1000>;
> + };
> +
> + region@6000 {
> + compatible = "nvdimm-volatile";
> + reg = <0x6000 0x1000>;
> + };
> + };
> +};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 65eff7857ec3..0350bf5a94d2 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7875,6 +7875,14 @@ Q: 
> https://patchwork.kernel.org/project/linux-nvdimm/list/
>  S:   Supported
>  F:   drivers/nvdimm/pmem*
>  
> +LIBNVDIMM: DEVICETREE BINDINGS
> +M:   Oliver O'Halloran 
> +L:   linux-nvd...@lists.01.org
> +Q:   https://patchwork.kernel.org/project/linux-nvdimm/list/
> +S:   Supported
> +F:   drivers/nvdimm/of_nvdimm.c
> +F:   Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
> +
>  LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
>  M:   Dan Williams 
>  L:   linux-nvd...@lists.01.org
> 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 

[PATCH 2/3] libnvdimm: Add a device-tree interface

[Oliver O'Halloran]

A fairly bare-bones set of device-tree bindings so libnvdimm can be used
on powerpc and other device-tree based platforms.

Cc: devicet...@vger.kernel.org
Signed-off-by: Oliver O'Halloran 
---
 .../devicetree/bindings/nvdimm/nvdimm-bus.txt  |  69 +++
 MAINTAINERS|   8 +
 drivers/nvdimm/Kconfig |  10 +
 drivers/nvdimm/Makefile|   1 +
 drivers/nvdimm/of_nvdimm.c | 202 +
 5 files changed, 290 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
 create mode 100644 drivers/nvdimm/of_nvdimm.c

diff --git a/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt 
b/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
new file mode 100644
index ..491e7c4900ed
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
@@ -0,0 +1,69 @@
+Device-tree bindings for nonvolatile-memory / NVDIMMs
+-
+
+Non-volatile DIMMs are memory modules used to provide (cacheable) main memory 
that
+retains its contents across power cycles. In more practical terms, they are 
kind
+of storage device where the contents can be accessed by the CPU directly,
+rather than indirectly via a storage controller or similar. This can provide
+substantial performance improvements for applications designed to take
+advantage of in-memory storage.
+
+This binding provides a way to describe memory regions that should be managed
+by an NVDIMM storage driver (libNVDIMM in Linux) and some of the associated
+metadata. The binding itself is split into two main parts: A container bus and
+its sub-nodes which describe which memory address ranges corresponding to
+NVDIMM backed memory.
+
+Bindings for the container bus:
+--
+
+Required properties:
+ - compatible = "nvdimm-bus";
+ - ranges;
+   A blank ranges property is required because the sub-nodes have
+   addresses in the system's physical address space.
+
+The use of a container bus is mainly to handle future expansion of the 
binding. For
+comparison the ACPI equivalent of this binding (NFIT) describes: Memory 
regions, DIMM
+control structures, Block mode DIMM control structures, interleave sets, and 
more. Some
+of these structures cross reference each other so everyone should be happier 
if we keep
+it relatively self contained.
+
+Bindings for the region nodes:
+-
+
+Required properties:
+   - compatible = "nvdimm-persistent" or "nvdimm-volatile"
+
+   The "nvdimm-persistent" region type indicates that this memory 
region
+   is actually a persistent region. The volatile type is mainly 
useful
+   for testing and RAM disks that can persist across kexec.
+
+   - reg = ;
+   The reg property should only contain one address range.
+
+Optional properties:
+   - Any relevant NUMA assocativity properties for the target platform.
+
+A complete example:
+
+
+/ {
+   #size-cells = <1>;
+   #address-cells = <1>;
+
+   nonvolatile-memory {
+   compatible = "nonvolatile-memory";
+   ranges;
+
+   region@5000 {
+   compatible = "nvdimm-persistent";
+   reg = <0x5000 0x1000>;
+   };
+
+   region@6000 {
+   compatible = "nvdimm-volatile";
+   reg = <0x6000 0x1000>;
+   };
+   };
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index 65eff7857ec3..0350bf5a94d2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7875,6 +7875,14 @@ Q:   
https://patchwork.kernel.org/project/linux-nvdimm/list/
 S: Supported
 F: drivers/nvdimm/pmem*
 
+LIBNVDIMM: DEVICETREE BINDINGS
+M: Oliver O'Halloran 
+L: linux-nvd...@lists.01.org
+Q: https://patchwork.kernel.org/project/linux-nvdimm/list/
+S: Supported
+F: drivers/nvdimm/of_nvdimm.c
+F: Documentation/devicetree/bindings/nvdimm/nvdimm-bus.txt
+
 LIBNVDIMM: NON-VOLATILE MEMORY DEVICE SUBSYSTEM
 M: Dan Williams 
 L: linux-nvd...@lists.01.org
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 ca6d325438a3..9029511a8486 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -3,6