| Message ID | 20180122171534.7681-1-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 22/01/18 17:15, Lorenzo Pieralisi wrote: > The current ARM DT topology description provides the operating system > with a topological view of the system that is based on leaf nodes > representing either cores or threads (in an SMT system) and a > hierarchical set of cluster nodes that creates a hierarchical topology > view of how those cores and threads are grouped. > > As opposed to the ACPI topology description ([1], PPTT table), this > hierarchical representation of clusters does not allow to describe what > topology level actually represents the physical package boundary, which > is a key piece of information to be used by an operating system to > optimize resource allocation and scheduling. > > Define an optional, backward compatible boolean property for cluster > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > topological description a binding to define what cluster level > represents a physical package boundary. > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Sudeep Holla <sudeep.holla@arm.com> > Cc: Jeremy Linton <jeremy.linton@arm.com> > Cc: Morten Rasmussen <morten.rasmussen@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > --- > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > index de9eb0486630..8e78d76b0671 100644 > --- a/Documentation/devicetree/bindings/arm/topology.txt > +++ b/Documentation/devicetree/bindings/arm/topology.txt > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > The cluster node name must be "clusterN" as described in 2.1 above. > A cluster node can not be a leaf node. > > + Properties for cluster nodes: > + > + - physical-package > + Usage: optional > + Value type: <empty> IIUC, value type must be specified as boolean in this case. > + Definition: if present the cluster node represents the > + boundary of a physical package, whether socketed > + or surface mounted. > + > A cluster node's child nodes must be: > > - one or more cluster nodes; or > Otherwise looks good to me.
Hi, On 01/22/2018 11:15 AM, Lorenzo Pieralisi wrote: > The current ARM DT topology description provides the operating system > with a topological view of the system that is based on leaf nodes > representing either cores or threads (in an SMT system) and a > hierarchical set of cluster nodes that creates a hierarchical topology > view of how those cores and threads are grouped. > > As opposed to the ACPI topology description ([1], PPTT table), this > hierarchical representation of clusters does not allow to describe what > topology level actually represents the physical package boundary, which > is a key piece of information to be used by an operating system to > optimize resource allocation and scheduling. > > Define an optional, backward compatible boolean property for cluster > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > topological description a binding to define what cluster level > represents a physical package boundary. > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Sudeep Holla <sudeep.holla@arm.com> > Cc: Jeremy Linton <jeremy.linton@arm.com> > Cc: Morten Rasmussen <morten.rasmussen@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > --- > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > index de9eb0486630..8e78d76b0671 100644 > --- a/Documentation/devicetree/bindings/arm/topology.txt > +++ b/Documentation/devicetree/bindings/arm/topology.txt > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > The cluster node name must be "clusterN" as described in 2.1 above. > A cluster node can not be a leaf node. > > + Properties for cluster nodes: > + > + - physical-package > + Usage: optional > + Value type: <empty> > + Definition: if present the cluster node represents the > + boundary of a physical package, whether socketed > + or surface mounted. > + > A cluster node's child nodes must be: > > - one or more cluster nodes; or > Looks good so far, but I would worry about it being optional. That seemed like a mistake on the ACPI side. Assuming it is optional, it might be worth a sentence explaining what the fallback behavior is if the property is missing.
On 01/22/18 09:15, Lorenzo Pieralisi wrote: > The current ARM DT topology description provides the operating system > with a topological view of the system that is based on leaf nodes > representing either cores or threads (in an SMT system) and a > hierarchical set of cluster nodes that creates a hierarchical topology > view of how those cores and threads are grouped. > > As opposed to the ACPI topology description ([1], PPTT table), this > hierarchical representation of clusters does not allow to describe what > topology level actually represents the physical package boundary, which > is a key piece of information to be used by an operating system to > optimize resource allocation and scheduling. > > Define an optional, backward compatible boolean property for cluster > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > topological description a binding to define what cluster level > represents a physical package boundary. > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Sudeep Holla <sudeep.holla@arm.com> > Cc: Jeremy Linton <jeremy.linton@arm.com> > Cc: Morten Rasmussen <morten.rasmussen@arm.com> > Cc: Mark Rutland <mark.rutland@arm.com> > --- > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > index de9eb0486630..8e78d76b0671 100644 > --- a/Documentation/devicetree/bindings/arm/topology.txt > +++ b/Documentation/devicetree/bindings/arm/topology.txt > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > The cluster node name must be "clusterN" as described in 2.1 above. > A cluster node can not be a leaf node. > > + Properties for cluster nodes: > + > + - physical-package > + Usage: optional > + Value type: <empty> > + Definition: if present the cluster node represents the > + boundary of a physical package, whether socketed > + or surface mounted. I don't know how to interpret this. Is the node with this property inside or outside the boundary? If I had to guess, I would guess inside. A few extra words to clarify this please. > + > A cluster node's child nodes must be: > > - one or more cluster nodes; or >
On 22/01/18 23:25, Jeremy Linton wrote: > Hi, > > On 01/22/2018 11:15 AM, Lorenzo Pieralisi wrote: >> The current ARM DT topology description provides the operating system >> with a topological view of the system that is based on leaf nodes >> representing either cores or threads (in an SMT system) and a >> hierarchical set of cluster nodes that creates a hierarchical topology >> view of how those cores and threads are grouped. >> >> As opposed to the ACPI topology description ([1], PPTT table), this >> hierarchical representation of clusters does not allow to describe what >> topology level actually represents the physical package boundary, which >> is a key piece of information to be used by an operating system to >> optimize resource allocation and scheduling. >> >> Define an optional, backward compatible boolean property for cluster >> nodes that, by reusing the ACPI nomenclature, add to the ARM DT >> topological description a binding to define what cluster level >> represents a physical package boundary. >> >> [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf >> >> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >> Cc: Rob Herring <robh+dt@kernel.org> >> Cc: Sudeep Holla <sudeep.holla@arm.com> >> Cc: Jeremy Linton <jeremy.linton@arm.com> >> Cc: Morten Rasmussen <morten.rasmussen@arm.com> >> Cc: Mark Rutland <mark.rutland@arm.com> >> --- >> Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/arm/topology.txt >> b/Documentation/devicetree/bindings/arm/topology.txt >> index de9eb0486630..8e78d76b0671 100644 >> --- a/Documentation/devicetree/bindings/arm/topology.txt >> +++ b/Documentation/devicetree/bindings/arm/topology.txt >> @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined >> as follows: >> The cluster node name must be "clusterN" as described in 2.1 above. >> A cluster node can not be a leaf node. >> + Properties for cluster nodes: >> + >> + - physical-package >> + Usage: optional >> + Value type: <empty> >> + Definition: if present the cluster node represents the >> + boundary of a physical package, whether socketed >> + or surface mounted. >> + >> A cluster node's child nodes must be: >> - one or more cluster nodes; or >> > > Looks good so far, but I would worry about it being optional. We have no choice, it has to be optional for compatibility reasons as stated in the commit message. > That seemed like a mistake on the ACPI side. Not necessarily. It's firmware choice as long as it knows how to deal with the default(absence in case of DT) > > Assuming it is optional, it might be worth a sentence explaining what > the fallback behavior is if the property is missing. That would be helpful.
On Mon, Jan 22, 2018 at 08:45:26PM -0800, Frank Rowand wrote: > On 01/22/18 09:15, Lorenzo Pieralisi wrote: > > The current ARM DT topology description provides the operating system > > with a topological view of the system that is based on leaf nodes > > representing either cores or threads (in an SMT system) and a > > hierarchical set of cluster nodes that creates a hierarchical topology > > view of how those cores and threads are grouped. > > > > As opposed to the ACPI topology description ([1], PPTT table), this > > hierarchical representation of clusters does not allow to describe what > > topology level actually represents the physical package boundary, which > > is a key piece of information to be used by an operating system to > > optimize resource allocation and scheduling. > > > > Define an optional, backward compatible boolean property for cluster > > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > > topological description a binding to define what cluster level > > represents a physical package boundary. > > > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Cc: Rob Herring <robh+dt@kernel.org> > > Cc: Sudeep Holla <sudeep.holla@arm.com> > > Cc: Jeremy Linton <jeremy.linton@arm.com> > > Cc: Morten Rasmussen <morten.rasmussen@arm.com> > > Cc: Mark Rutland <mark.rutland@arm.com> > > --- > > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > > index de9eb0486630..8e78d76b0671 100644 > > --- a/Documentation/devicetree/bindings/arm/topology.txt > > +++ b/Documentation/devicetree/bindings/arm/topology.txt > > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > > The cluster node name must be "clusterN" as described in 2.1 above. > > A cluster node can not be a leaf node. > > > > + Properties for cluster nodes: > > + > > + - physical-package > > + Usage: optional > > + Value type: <empty> > > + Definition: if present the cluster node represents the > > + boundary of a physical package, whether socketed > > + or surface mounted. > > I don't know how to interpret this. Is the node with this property inside > or outside the boundary? If I had to guess, I would guess inside. A few > extra words to clarify this please. The node is neither inside nor outside, it _is_ the boundary. Every node defines a topology level - the property is there to define which one corresponds to a package, please let me know if it makes things clearer. Thanks, Lorenzo > > + > > A cluster node's child nodes must be: > > > > - one or more cluster nodes; or > > >
On Mon, Jan 22, 2018 at 05:29:20PM +0000, Sudeep Holla wrote: > > > On 22/01/18 17:15, Lorenzo Pieralisi wrote: > > The current ARM DT topology description provides the operating system > > with a topological view of the system that is based on leaf nodes > > representing either cores or threads (in an SMT system) and a > > hierarchical set of cluster nodes that creates a hierarchical topology > > view of how those cores and threads are grouped. > > > > As opposed to the ACPI topology description ([1], PPTT table), this > > hierarchical representation of clusters does not allow to describe what > > topology level actually represents the physical package boundary, which > > is a key piece of information to be used by an operating system to > > optimize resource allocation and scheduling. > > > > Define an optional, backward compatible boolean property for cluster > > nodes that, by reusing the ACPI nomenclature, add to the ARM DT > > topological description a binding to define what cluster level > > represents a physical package boundary. > > > > [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Cc: Rob Herring <robh+dt@kernel.org> > > Cc: Sudeep Holla <sudeep.holla@arm.com> > > Cc: Jeremy Linton <jeremy.linton@arm.com> > > Cc: Morten Rasmussen <morten.rasmussen@arm.com> > > Cc: Mark Rutland <mark.rutland@arm.com> > > --- > > Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > > index de9eb0486630..8e78d76b0671 100644 > > --- a/Documentation/devicetree/bindings/arm/topology.txt > > +++ b/Documentation/devicetree/bindings/arm/topology.txt > > @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > > The cluster node name must be "clusterN" as described in 2.1 above. > > A cluster node can not be a leaf node. > > > > + Properties for cluster nodes: > > + > > + - physical-package > > + Usage: optional > > + Value type: <empty> > > IIUC, value type must be specified as boolean in this case. That's what I thought too but according to DT specs v0.2, table 2.3 the property value type is <empty>. I do not mind changing it - whatever DT maintainers think is more appropriate. Thanks, Lorenzo
On 02/08/18 02:57, Lorenzo Pieralisi wrote: > On Mon, Jan 22, 2018 at 08:45:26PM -0800, Frank Rowand wrote: >> On 01/22/18 09:15, Lorenzo Pieralisi wrote: >>> The current ARM DT topology description provides the operating system >>> with a topological view of the system that is based on leaf nodes >>> representing either cores or threads (in an SMT system) and a >>> hierarchical set of cluster nodes that creates a hierarchical topology >>> view of how those cores and threads are grouped. >>> >>> As opposed to the ACPI topology description ([1], PPTT table), this >>> hierarchical representation of clusters does not allow to describe what >>> topology level actually represents the physical package boundary, which >>> is a key piece of information to be used by an operating system to >>> optimize resource allocation and scheduling. >>> >>> Define an optional, backward compatible boolean property for cluster >>> nodes that, by reusing the ACPI nomenclature, add to the ARM DT >>> topological description a binding to define what cluster level >>> represents a physical package boundary. >>> >>> [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf >>> >>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >>> Cc: Rob Herring <robh+dt@kernel.org> >>> Cc: Sudeep Holla <sudeep.holla@arm.com> >>> Cc: Jeremy Linton <jeremy.linton@arm.com> >>> Cc: Morten Rasmussen <morten.rasmussen@arm.com> >>> Cc: Mark Rutland <mark.rutland@arm.com> >>> --- >>> Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt >>> index de9eb0486630..8e78d76b0671 100644 >>> --- a/Documentation/devicetree/bindings/arm/topology.txt >>> +++ b/Documentation/devicetree/bindings/arm/topology.txt >>> @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: >>> The cluster node name must be "clusterN" as described in 2.1 above. >>> A cluster node can not be a leaf node. >>> >>> + Properties for cluster nodes: >>> + >>> + - physical-package >>> + Usage: optional >>> + Value type: <empty> >>> + Definition: if present the cluster node represents the >>> + boundary of a physical package, whether socketed >>> + or surface mounted. >> >> I don't know how to interpret this. Is the node with this property inside >> or outside the boundary? If I had to guess, I would guess inside. A few >> extra words to clarify this please. > > The node is neither inside nor outside, it _is_ the boundary. Every node > defines a topology level - the property is there to define which one > corresponds to a package, please let me know if it makes things clearer. Not at all clear. Using Example 1, from section "4 - Example dts" of topology.txt: cpu-map { cluster0 { cluster0 { core0 { thread0 { cpu = <&CPU0>; }; thread1 { cpu = <&CPU1>; }; }; core1 { thread0 { cpu = <&CPU2>; }; thread1 { cpu = <&CPU3>; }; }; }; cluster1 { core0 { thread0 { cpu = <&CPU4>; }; thread1 { cpu = <&CPU5>; }; }; core1 { thread0 { cpu = <&CPU6>; }; thread1 { cpu = <&CPU7>; }; }; }; }; Pretend that cpu-map/cluster0/cluster0 is a physical package that contains two cores, and cpu-map/cluster0/cluster1 is another physical package that contains two cores. My guess as to how to use the property "physical-package" would be to place it in nodes cpu-map/cluster0/cluster0 and cpu-map/cluster0/cluster1. In that case, those two nodes are on the "inside" of two different packages. The alternate way to use the property "physical-package" would be to place it in node cpu-map/cluster0. In this case, the node is "outside" of the packages. Again, I suspect that the intended use is the first of my two examples, but the proposed binding wording does not make that clear to me. My use of "inside" and "outside" may not be the proper words or concept, but the binding somehow needs to say which of my two above example locations is the correct place to use the "physical-package" property. -Frank > > Thanks, > Lorenzo > >>> + >>> A cluster node's child nodes must be: >>> >>> - one or more cluster nodes; or >>> >> > . >
On Thu, Feb 08, 2018 at 02:22:00PM -0800, Frank Rowand wrote: > On 02/08/18 02:57, Lorenzo Pieralisi wrote: > > On Mon, Jan 22, 2018 at 08:45:26PM -0800, Frank Rowand wrote: > >> On 01/22/18 09:15, Lorenzo Pieralisi wrote: > >>> The current ARM DT topology description provides the operating system > >>> with a topological view of the system that is based on leaf nodes > >>> representing either cores or threads (in an SMT system) and a > >>> hierarchical set of cluster nodes that creates a hierarchical topology > >>> view of how those cores and threads are grouped. > >>> > >>> As opposed to the ACPI topology description ([1], PPTT table), this > >>> hierarchical representation of clusters does not allow to describe what > >>> topology level actually represents the physical package boundary, which > >>> is a key piece of information to be used by an operating system to > >>> optimize resource allocation and scheduling. > >>> > >>> Define an optional, backward compatible boolean property for cluster > >>> nodes that, by reusing the ACPI nomenclature, add to the ARM DT > >>> topological description a binding to define what cluster level > >>> represents a physical package boundary. > >>> > >>> [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf > >>> > >>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > >>> Cc: Rob Herring <robh+dt@kernel.org> > >>> Cc: Sudeep Holla <sudeep.holla@arm.com> > >>> Cc: Jeremy Linton <jeremy.linton@arm.com> > >>> Cc: Morten Rasmussen <morten.rasmussen@arm.com> > >>> Cc: Mark Rutland <mark.rutland@arm.com> > >>> --- > >>> Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ > >>> 1 file changed, 9 insertions(+) > >>> > >>> diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt > >>> index de9eb0486630..8e78d76b0671 100644 > >>> --- a/Documentation/devicetree/bindings/arm/topology.txt > >>> +++ b/Documentation/devicetree/bindings/arm/topology.txt > >>> @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: > >>> The cluster node name must be "clusterN" as described in 2.1 above. > >>> A cluster node can not be a leaf node. > >>> > >>> + Properties for cluster nodes: > >>> + > >>> + - physical-package > >>> + Usage: optional > >>> + Value type: <empty> > >>> + Definition: if present the cluster node represents the > >>> + boundary of a physical package, whether socketed > >>> + or surface mounted. > >> > >> I don't know how to interpret this. Is the node with this property inside > >> or outside the boundary? If I had to guess, I would guess inside. A few > >> extra words to clarify this please. > > > > The node is neither inside nor outside, it _is_ the boundary. Every node > > defines a topology level - the property is there to define which one > > corresponds to a package, please let me know if it makes things clearer. > > Not at all clear. > > Using Example 1, from section "4 - Example dts" of topology.txt: > > > cpu-map { > cluster0 { > cluster0 { > core0 { > thread0 { > cpu = <&CPU0>; > }; > thread1 { > cpu = <&CPU1>; > }; > }; > > core1 { > thread0 { > cpu = <&CPU2>; > }; > thread1 { > cpu = <&CPU3>; > }; > }; > }; > > cluster1 { > core0 { > thread0 { > cpu = <&CPU4>; > }; > thread1 { > cpu = <&CPU5>; > }; > }; > > core1 { > thread0 { > cpu = <&CPU6>; > }; > thread1 { > cpu = <&CPU7>; > }; > }; > }; > }; > > Pretend that cpu-map/cluster0/cluster0 is a physical package that > contains two cores, and cpu-map/cluster0/cluster1 is another > physical package that contains two cores. My guess as to how > to use the property "physical-package" would be to place it > in nodes cpu-map/cluster0/cluster0 and cpu-map/cluster0/cluster1. > In that case, those two nodes are on the "inside" of two different > packages. > > The alternate way to use the property "physical-package" would be > to place it in node cpu-map/cluster0. In this case, the node is > "outside" of the packages. > > Again, I suspect that the intended use is the first of my two > examples, but the proposed binding wording does not make that > clear to me. My use of "inside" and "outside" may not be the > proper words or concept, but the binding somehow needs to > say which of my two above example locations is the correct place > to use the "physical-package" property. Ok, I see, I will update the description accordingly to make it clearer. Thank you, Lorenzo
diff --git a/Documentation/devicetree/bindings/arm/topology.txt b/Documentation/devicetree/bindings/arm/topology.txt index de9eb0486630..8e78d76b0671 100644 --- a/Documentation/devicetree/bindings/arm/topology.txt +++ b/Documentation/devicetree/bindings/arm/topology.txt @@ -109,6 +109,15 @@ Bindings for cluster/cpu/thread nodes are defined as follows: The cluster node name must be "clusterN" as described in 2.1 above. A cluster node can not be a leaf node. + Properties for cluster nodes: + + - physical-package + Usage: optional + Value type: <empty> + Definition: if present the cluster node represents the + boundary of a physical package, whether socketed + or surface mounted. + A cluster node's child nodes must be: - one or more cluster nodes; or
The current ARM DT topology description provides the operating system with a topological view of the system that is based on leaf nodes representing either cores or threads (in an SMT system) and a hierarchical set of cluster nodes that creates a hierarchical topology view of how those cores and threads are grouped. As opposed to the ACPI topology description ([1], PPTT table), this hierarchical representation of clusters does not allow to describe what topology level actually represents the physical package boundary, which is a key piece of information to be used by an operating system to optimize resource allocation and scheduling. Define an optional, backward compatible boolean property for cluster nodes that, by reusing the ACPI nomenclature, add to the ARM DT topological description a binding to define what cluster level represents a physical package boundary. [1] http://www.uefi.org/sites/default/files/resources/ACPI_6_2.pdf Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> --- Documentation/devicetree/bindings/arm/topology.txt | 9 +++++++++ 1 file changed, 9 insertions(+)