Re: [PATCH v3 3/3] dt-bindings: pmem-region: Document memory-region
From: Rob Herring <robh@kernel.org>
Date: 2020-02-27 23:23:00
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On Sun, Feb 23, 2020 at 06:10:29PM -0800, Alistair Delva wrote:
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From: Kenny Root <redacted> Add documentation and example for memory-region in pmem. Signed-off-by: Kenny Root <redacted> Signed-off-by: Alistair Delva <redacted> Cc: "Oliver O'Halloran" <oohall@gmail.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Dan Williams <redacted> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ira Weiny <redacted> Cc: devicetree@vger.kernel.org Cc: linux-nvdimm@lists.01.org Cc: kernel-team@android.com --- [v3: adelva: remove duplicate "From:"] .../devicetree/bindings/pmem/pmem-region.txt | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+)diff --git a/Documentation/devicetree/bindings/pmem/pmem-region.txt b/Documentation/devicetree/bindings/pmem/pmem-region.txt index 5cfa4f016a00..0ec87bd034e0 100644 --- a/Documentation/devicetree/bindings/pmem/pmem-region.txt +++ b/Documentation/devicetree/bindings/pmem/pmem-region.txt@@ -29,6 +29,18 @@ Required properties: in a separate device node. Having multiple address ranges in a node implies no special relationship between the two ranges. + This property may be replaced or supplemented with a + memory-region property. Only one of reg or memory-region + properties is required. + + - memory-region: + Reference to the reserved memory node. The reserved memory + node should be defined as per the bindings in + reserved-memory.txt
Though we've never enforced it, but /reserved-memory should be within the bounds of /memory node(s). Is that the intent here? If so, how does that work? Wouldn't all the memory be persistent then? Or some other system processor is preserving the contents?
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+ + This property may be replaced or supplemented with a reg + property. Only one of reg or memory-region is required. + Optional properties: - Any relevant NUMA assocativity properties for the target platform.@@ -63,3 +75,20 @@ Examples: volatile; }; + + /* + * This example uses a reserved-memory entry instead of + * specifying the memory region directly in the node. + */ + + reserved-memory { + pmem_1: pmem@5000 { + no-map;
Just add 'compatible = "pmem-region";' here and be done with it. Why add a layer of indirection?
+ reg = <0x00005000 0x00001000>;
+ };
+ };
+
+ pmem@1 {No 'reg', so shouldn't have a unit-address here.
+ compatible = "pmem-region"; + memory-region = <&pmem_1>; + }; -- 2.25.0.265.gbab2e86ba0-goog