Reminder 1: Device Tree documentation discussion for Cell/B.E. binding DRAFT - see Digest Vol 6, Issue 1
Christian Rund
Christian.Rund at de.ibm.com
Wed Dec 17 01:03:44 EST 2008
Dear Subscribers and Readers,
this is a reminder for review. Feedback appreciated!
For convenience I removed the disclaimer etc.
On dec 5th I posted our (complete) draft version of the Cell/B.E. device
tree documentation.
See also in devicetree-discuss Digest, Vol 6, Issue 1.
Goal of these review should be to finally establish the document as
Power.org
PAPR Binding for the Cell/B.E. processor.
Please review and give us feedback.
Thanks.
_________________________________
DRAFT Power.org Standard for the Cell Broadband Engine architecture device
tree
Table of Contents
1 Overview 5
1.1 Scope 5
1.2 Purpose 5
2 Terminology 5
2.1 Definitions 5
2.2 Abbreviations 5
2.3 Acronyms 5
3 Introduction 6
4 The Cell Broadband Engine architecture processor representation
in
the device tree 7
4.1 "be" node 7
4.1.1 ioc node 10
4.1.2 "bic0" node 11
4.1.3 "bic1" node 11
4.1.4 "mic-tm" node 12
4.1.5 "pervasive" node 12
4.1.6 "ppe-mmio" node 14
4.1.7 "interrupt-controller" node 15
4.1.8 "spe" nodes 16
DRAFT Power.org Standard for the Cell Broadband Engine architecture device
tree
Overview
1 Scope
This document is intended to apply the Power.org Standard for Power
Architecture Platform Requirements (Workstation, Server) PAPR on
Cell Broadband Engine architecture compliant processors. This
encompasses requirements therein and additional requirements for
device tree nodes and properties pertaining to Cell Broadband
Engine
architecture compliant processors.
2 Purpose
This document is intended to indicate the architectural option and
feature set of Cell Broadband Engine architecture processors to
software via Open Firmware (OF).
Terminology
This document uses definitions, abbreviations and acronyms as
indicated below or in the PAPR specification [3].
1 Definitions
Device Tree: Open Firmware data structure representing the set of
devices attached to a system. See [1] for details.
2 Abbreviations
Define key abbreviations here (use "paragraph" plus tab), such as
l.t.s.f.l.r. Leaving this section for later revisions of this
document - to be removed if not used !!!!!!!!!!!!
3 Acronyms
Define key acronyms here (use "paragraph" style with tabs"), such
as
EIB Element Interconnect Bus
IIC Internal Interrupt Controller
IOC Input Output Controller
MMIO Memory Mapped Input Output
OF Open Firmware (see [1]).
PPE PowerPC Processing Element
SPE Synergistic Processing Element
Introduction
The specific goals of this specification are as follows:
. To provide the address map for the components in a Cell
Broadband Engine Architecture processor. Subcomponent address
information is detected by the OF and passed to the OS in the
device tree.
. To build upon the OF boot environment defined in IEEE 1275,
IEEE Standard for Boot (Initialization Configuration)
Firmware:
Core Requirements and Practices.
. To provide device tree nodes and property values necessary
for
access to and configuration of the Cell Broadband Engine
Architecture processor subcomponents.
The Cell Broadband Engine architecture processors are implemented as
systems on a chip. Besides a PowerPC processor it contains eight
Synergistic Processing Elements (SPEs) in addition. Each SPE has access to
256kB of associated local store. All logic of the non-processor part is
accessed via MMIO. Mapping and structure of the MMIO space are described
with the "be" node. A nodes' unit address is the MMIO address of that
particular BE. The "be" node is located in the device tree as child of the
root node '/'.
The Cell Broadband Engine architecture processor representation in the
device tree
The following contents are outlined according to the hierarchy of the
components in the sub-tree containing the components of the Cell Broadband
Engine processor.
All device tree nodes detailed below contain a "name" property in addition
to the mentioned properties as follows
. Specifies the name of the node
. Encoded as with encode-string
. Default is the name of the node
Throughout the description below the notation
phandle(<expression>) is used to retrieve the phandle of a
node. A phandle of a device tree node is the cell-sized datum
identifying the particular device tree node.
1 "be" node
The "be" node contains a set of properties and sub-nodes, which describe
the structure of a Cell Broadband Engine Architecture processor. All the
devices are contained, except the Power PC processor core nodes, which are
located under the "/cpus" path according to the PowerPC Processor binding
to the IEEE 1275 standard.
"reg" property
Standard property name specifying the < address, size > pair
of
the Cell Broadband Engine processor's MMIO mapped registers.
Prop-encoded array: Encoded as with encode-phys for the
address. The size part is encoded with two encode-ints.
The array consists of four 32-bit values. Value one and two
in
this array correspond to the 64-bit address value the the
Cell
Broadband Engine Architecture processor is mapped into. Value
three and four correspond to the 64-bit size. Both pairs
represent the < address, size > pair of MMIO mapped registers
in the Cell Broadband Engine processor's MMIO mapped register
space.
Default value is { 0x00000iii 0x00000000 0x00000000
0x000800000
}, where iii is the offset defined by the hardware settings.
"ranges" property
Standard property name which specifies the mapping of the
child
of the "be" node within the "be" nodes' parent address space
using the < child, parent, size > triple.
Prop-encoded array: Encoded as with encode-int for the childs
range, encode-phys for the parents range and encode-int for
the
size.
The array consists of four 32-bit values. Value one in this
array corresponds to the 32-bit child address encoded as with
encode-int. Value two and three correspond to the 64-bit
parent
address encoded as with encode-phys. Value three in this
array
corresponds to the 32-bit size.
Default value is { 0x00000000 0x00000iii 0x00000000
0x00080000
}, mapping address 0 of child to 0x00000iii 00000000.
"device-type" property
Standard property name which specifies the type of the node.
Encoded as with encode-string.
Default value is { "be" }.
"model" property
property name: Specifies model of node.
Encoded as with encode-string.
Default value is { "IBM,CBEA" }.
"ibm,dt-version" property
property name: Specifies the current device tree version number. The
version number format is major.minor.
Whenever the device tree is changed or extended in a way that OS changes
are required the major version is changed.
The minor version is changed when at least one new property is added or
removed.
Encoded as with encode-string
The default value is { 1.1 }
"#address-cells" property
property name which specifies the number of address cells for child nodes
to the current node.
Encoded as with encode-int.
Default value is { 1 }
"#size-cells" property
Standard property name which specifies the number of size cells for child
nodes to the current node.
Encoded as with encode-int.
Default value is { 1 }
"ibm,associativity" property
property name: Property to define the associativity domains for this
resource.
See Power Architecture Platform Requirements (PAPR) [3], Sections
14.11.2.2, 15.2, 15.3, 18.3 and C.6.2.2 for details on this property.
Set values to { 4 0x00000000, 0x00000000, 0x0000000i, 0x0000000i }; i = 0
for associativity to Cell Broadband Engine processor 0, i = 1 for
associativity to Cell Broadband Engine processor 1.
"interrupt-parent" property
property name: Property that specifies the interrupt handler responsible
for this node.
The value represents a phandle of the interrupt handler node, encoded as
with encode-int.
Default value is { phandle( my-self/interrupt-controller) }
"cpus" property
property name: Porperty to specify the PPE component of the Cell Broadband
Engine architecture processor chip.
phandle of the cpu node, encoded as with encode-int.
Default value is { phandle(/cpus/PowerPC,BE at i) }; i = 0 for Cell Broadband
Engine Architecture processor 0, i = 1 for Cell Broadband Engine
Architecture processor 1.
1 ioc node
The Input/Output Controller (IOC) node contains among others the
properties
specifying the address range of MMIO register space controlling the IOC.
"reg" property
Default property name: Property to specify the MMIO offset of the IOC,
which are two sets of registers each represented by an < offset, size >
pair.
prop-encoded-array: Encoded as with encode-phys for the offset values,
encode-int for the size values.
The array consists of four 32-bit values to represent two < offset, size >
pairs. Value one in this array corresponds to the first offset value
within
the child address space, encoded as with encode-phys. Value two
corresponds
to the size, encoded as with encode-int. Value three in this array
corresponds to the second offset value, value four to the second size.
Default value is { 0x00510000 0x00001000 0x00511000 0x00001000 }.
"device_type" property
Standard property name: Specify the type of this node
Encoded as with encode-string
Default value is { "ioc" }
"interrupts" property
Standard property name: Property which specifies the interrupt number of
the interrupt issued by the IOC for IIC "IO Exceptions"
Encoded as with encode-int.
The property value consists of four bytes each representing a specific
value for a node, an Internal Interrupt Controller Interrupt Service
Routine bit mask, a class and a unit
0xNN3d010e (NN=node, bit 3d (61) in IIC_ISR, class=1, unit=E for IIC_ISR
interrupt)
Default value is { 0i3d010e }, i = 0 for Cell Broadband Engine processor
0,
i = 1 for Cell Broadband Engine processor 1.
2 "bic0" node
The Bus Interface Controller (BIC) 0 node describes the address range of
MMIO register space controlling the BIC0.
"reg" property
Default property name: Property to specify the MMIO offset of the BIC0,
which is one set of registers representing an < offset, size > pair.
prop-encoded-array: Encoded as with encode-phys for the offset value,
encode-int for the size.
Default value is { 0x00512000 0x00001000 }
"device_type" property
Standard property name: Property to specify the type of this node.
Encoded as with encode-string.
Default value is { "bic0" }.
3 "bic1" node
The Bus Interface Controller (BIC) 1 node describes the address range of
MMIO register space controlling the BIC1.
"reg" property
Default property name: Property to specify the MMIO offset of the BIC1,
which is one set of registers representing an < offset, size > pair.
prop-encoded-array: Encoded as with encode-phys for the offset value,
encode-int for the size.
Default value is { 0x00513000 0x00001000 }
"device_type" property
Standard property name: Property to pecify the type of this node.
Encoded as with encode-string.
Default value is { "bic1" }.
4 "mic-tm" node
The "mic-tm" node represents the Memory Interface Controller (MIC) in the
device tree. The main property value is the address range of MMIO register
space controlling the MIC.
"reg" property
Default property name: Property to specify the MMIO offset of the BIC1,
which is one set of registers representing an < offset, size > pair.
prop-encoded-array: Encoded as with encode-phys for the offset value,
encode-int for the size.
Default value is { 0x0050a000 0x00001000 }.
"device_type" property
Standard property name: Specify the type of this node.
Encoded as with encode-string.
Default value is { "mic-tm" }.
5 "pervasive" node
The pervasive node node represents the pervasive unit in the device tree.
T>he main property value is the address range of MMIO register space
controlling the pervasive unit.
"reg" property
Default property name: Property to specify the MMIO offset of the BIC1,
which is one set of registers representing an < offset, size > pair.
prop-encoded-array: Encoded as with encode-phys for the offset value,
encode-int for the size.
Default value is { 0x00509000 0x00001000 }.
"device_type" property
Standard property name: Property to specify the type of this node.
Encoded as with encode-string.
Default value is { "pervasive" }.
"ppe-throttle-temp" property
property name: Property to specify the minimum temperature the PPE is
throttled.
Temperature in °C, encoded as with encode-int.
Default value is { 0x65 } for 101°C
"ppe-end-throttle-temp" property
Standard property name: Property to specify the temperature below the PPE
throttling is exited.
Temperature in °C, encoded as with encode-int.
Default value is { 0x5b } for 91°C
"ppe-full-throttle-temp" property
property name: Property to specify the minimum temperature the PPE is
stopped.
Temperature in °C, encoded as with encode-int.
Default value is { 0x7f } for 127°C
"spe-throttle-temp" property
property name: : Property to specify the minimum temperature the SPEs are
throttled.
Temperature in °C, encoded as with encode-int.
Default value is { 0x65 } for 101°C
"spe-end-throttle-temp" property
property name: : Property to specify the temperature below the SPEs
throttling is exited.
Temperature in °C, encoded as with encode-int.
Default value is { 0x5b } for 91°C
"spe-full-throttle-temp" property
property name: Property to specify the minimum temperature the PPE is
stopped.
Temperature in °C, encoded as with encode-int.
Default value is { 0x6f } for 111°C
6 "ppe-mmio" node
The "ppe-mmio" node represents the PowerPC Processing Element (PPE) in the
device tree. The main property is the address range of MMIO register space
controlling the PPE part of the Cell Broadband Engine processor.
"reg" property
Standard property name: Property to specify the MMIO offset of the mic.
prop-encoded-array: Encoded as with encode-phys for the offset, encode-int
for the size.
Default value is { 0x00500000 0x00001000 }
"device_type" property
Standard property name: Property to specify the type of this node.
Encoded as with encode-string.
Default value is { "ppe-mmio" }.
7 "interrupt-controller" node
The Cell Broadband Engine Architecture processor contains an Internal
Interrupt Controller (IIC), which is handling all the interrupts from the
PPE, the SPE and the connected IO.
"reg" property
Standard property name: Property to specify the MMIO offset of the IIC,
one
range for each of the two threads contained in each PPE and one range for
the common MMIO.
prop-encoded-array: Consisting of six 32-bit values. The values form three
< offset,length > pairs of the denoted space encoded as with encode-phys
for the offsets and encode-int for the sizes
1. for MMIO space of thread one
2. for MMIO space of thread two
3. for MMIO space of the common PPE MMIO space.
Default value is
{ 0x00508400 0x00000020 0x00508420 0x00000020 0x00508000 0x00001000 }.
"device_type" property
Standard property name: Property to specify the type of this node.
Encoded as with encode-string.
Default value is { "CBEA-Internal-Interrupt-Controller" }.
"compatible" property
property name: Property to specify the compatiblity of this interrupt
controller.
Encoded as with encode-string.
Default values is { "IBM,CBEA-Internal-Interrupt-Controller" }.
"interrupt-controller" property
property name: Property to specify that this node is an interrupt
controller.
The mere presence of this property denotes the current node being an
interrupt controller.
Zero length property.
The value is {}.
"#interrupt-cells" property
Standard property name: Property to specify the number of interrupt cells.
Encoded as with encode-int.
Default value is { 0x1 }.
"ibm,interrupt-server-ranges" property
property name: Property to specify the threads handled by this interrupt
controller.
Array of threads, encoded as with encode-int.
Default values for
|Cell Broadband Engine |Property Value |
|Architecture processor # | |
|0 |{ 0x00000000 0x00000001 }|
|1 |{ 0x00000000 0x00000001 }|
8 "spe" nodes
The Cell Broadband Engine Architecture processor contains eight SPEs, each
consisting of an SPU, 256kB local store and a Memory Flow Controller
(MFC).
The SPEs are connected to the EIB (Element Interconnect Bus) ring. The
access to the internal devices is done via MMIO reads, with a fixed offset
to the Cell Broadband Engine processor base address.
"reg" property
Standard property name: Specifies the MMIO offset and size of the SPEs
Local Storage, Problem-State, Privilege 2 Area and Privilege 1 Area.
prop-encoded array: Encoded as four < offset, length > pairs per SPE
encoded as with encode-phys for the offsets, encode-int for the size. The
pairs define the following SPE units:
1. Local Store (LS)
2. Problem State MMIO Registers
3. Privilege State 2 MMIO Registers
4. Privilege State 1 MMIO Registers
The property exists once in each spe node.
Default values for SPE
|# |Property Value |
|spe at 0 |{ 0x00000000 0x00040000 0x00040000 |
| |0x00020000 |
| |0x00060000 0x00020000 0x00400000 |
| |0x00002000 } |
|spe at 80000 |{ 0x00080000 0x00040000 0x000c0000 |
| |0x00020000 |
| |0x000e0000 0x00020000 0x00402000 |
| |0x00002000 } |
|spe at 100000 |{ 0x00100000 0x00040000 0x00140000 |
| |0x00020000 |
| |0x00160000 0x00020000 0x00404000 |
| |0x00002000 } |
|spe at 180000 |{ 0x00180000 0x00040000 0x001c0000 |
| |0x00020000 |
| |0x001e0000 0x00020000 0x00406000 |
| |0x00002000 } |
|spe at 200000 |{ 0x00200000 0x00040000 0x00240000 |
| |0x00020000 |
| |0x00260000 0x00020000 0x00408000 |
| |0x00002000 } |
|spe at 280000 |{ 0x00280000 0x00040000 0x002c0000 |
| |0x00020000 |
| |0x002e0000 0x00020000 0x0040a000 |
| |0x00002000 } |
|spe at 300000 |{ 0x00280000 0x00040000 0x002c0000 |
| |0x00020000 |
| |0x002e0000 0x00020000 0x0040a000 |
| |0x00002000 } |
|spe at 380000 |{ 0x00380000 0x00040000 0x003c0000 |
| |0x00020000 |
| |0x003e0000 0x00020000 0x0040e000 |
| |0x00002000 } |
"device_type" property
Standard property name: Specifies the type of this node.
Encoded as with encode-string.
Default value is {"spe" }.
"interrupts" property
Standard property name: Property to specify the interrupt numbers of the
interrupts issued by SPE.
prop-encoded array: List of interrupt numbers issued by the SPE. Each
value
in the list is encoded as with encode-int.
The property exists once in each spe node.
Default values for SPEs are
|# |Property Value |
|spe at 0 |{ 0x4, 0x104, 0x204 } |
|spe at 80000 |{ 0x7, 0x107, 0x207 } |
|spe at 100000 |{ 0x3, 0x103, 0x203 } |
|spe at 180000 |{ 0x8, 0x108, 0x208 } |
|spe at 200000 |{ 0x2, 0x102, 0x202 } |
|spe at 280000 |{ 0x9, 0x109, 0x209 } |
|spe at 300000 |{0x1, 0x101, 0x201 } |
|spe at 380000 |{0xa, 0x10a, 0x20a } |
"vicinity" property
property name: Specifies the direct neighbouring componentes on the EIB
ring related to each SPE.
prop-encoded array: Pairs of phandles ( < phandle, phandle >) of the
neighbouring nodes, each phandle is encoded as with encode-int.
The property exists once in each spe node.
Default values for SPEs
|# |Property Value |
|spe at 0 |{ phandle(mic-tm, SPE 3) } |
|spe at 80000 |{ phandle(mic-tm, SPE 2) } |
|spe at 100000 |{ phandle(SPE 0, SPE 4) } |
|spe at 180000 |{ phandle(SPE 1, SPE 5) } |
|spe at 200000 |{ phandle(SPE 2, SPE 6) } |
|spe at 280000 |{ phandle(SPE 3, SPE 7) } |
|spe at 300000 |{ phandle(SPE 4, BIC0) } |
|spe at 380000 |{ phandle(SPE 5, BIC0) } |
"physical-id" property
property name: Property to specify the physical id of an SPE.
Default values for the physical id is encoded as with encode-int.
The property exists once in each spe node.
|# |Property Value |
|spe at 0 |{ 0 } |
|spe at 80000 |{ 1 } |
|spe at 100000 |{ 2 } |
|spe at 180000 |{ 3 } |
|spe at 200000 |{ 4 } |
|spe at 280000 |{ 5 } |
|spe at 300000 |{ 6 } |
|spe at 380000 |{ 7 } |
Appendix A - Bibliography
This section lists documents which were referenced in this specification
or
which provide additional information, and some useful information
for
obtaining these documents. Referenced documents are listed below. When
any
of the following standards are superseded by an approved revision,
the
revision shall apply.
1. IEEE 1275, IEEE Standard for Boot (Initialization Configuration)
Firmware: Core Requirements and Practices
IEEE part number DS02683, ISBN 1-55937-426-8
2. PowerPC Processor binding to: IEEE 1275, IEEE Standard for
Boot
(Initialization Configuration) Firmware: Core Requirements and
Practices
3. Power.org Standard for Power Architecture Platform
Requirements
(Workstation, Server) Version 2.2, 9th Oct 2007
Mit freundlichen Grüßen / Kind regards
Christian Rund
Engineer in Development, SLOF, directCell, Systems Management
IBM Systems & Technology Group, Integrated Systems Development
Open Systems Firmware Development
Phone:
+49-7031-16-3235
IBM Deutschland
E-Mail:
Christian.Rund at de.ibm.com
Schoenaicher Str. 220
71032 Boeblingen
Germany
IBM Deutschland Research & Development GmbH / Vorsitzender des
Aufsichtsrats: Martin Jetter
Geschaeftsfuehrung: Erich Baier
Sitz der Gesellschaft: Boeblingen / Registergericht: Amtsgericht
Stuttgart, HRB 243294
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