[8/8] staging: fsl-mc: Convert documentation to rst format

Commit Message

Bogdan Purcareata Jan. 16, 2018, 1:19 p.m. UTC

From: Ioana Radulescu <[e-mail]>

Update the doc file to comply with the rst format.

It's not integrated into the documentation build structure yet,
since it's still located in drivers/staging.

Signed-off-by: Ioana Radulescu <[e-mail]>
Reviewed-by: Laurentiu Tudor <[e-mail]>
---
 drivers/staging/fsl-mc/README.txt   | 387 ----------------------------------
 drivers/staging/fsl-mc/overview.rst | 404 ++++++++++++++++++++++++++++++++++++
 2 files changed, 404 insertions(+), 387 deletions(-)
 delete mode 100644 drivers/staging/fsl-mc/README.txt
 create mode 100644 drivers/staging/fsl-mc/overview.rst

Comments

Greg KH Jan. 16, 2018, 3:14 p.m. UTC | #1

On Tue, Jan 16, 2018 at 03:19:10PM +0200, Bogdan Purcareata wrote:
> From: Ioana Radulescu <[e-mail]>
> 
> Update the doc file to comply with the rst format.
> 
> It's not integrated into the documentation build structure yet,
> since it's still located in drivers/staging.
> 
> Signed-off-by: Ioana Radulescu <[e-mail]>
> Reviewed-by: Laurentiu Tudor <[e-mail]>
> ---
>  drivers/staging/fsl-mc/README.txt   | 387 ----------------------------------
>  drivers/staging/fsl-mc/overview.rst | 404 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 404 insertions(+), 387 deletions(-)
>  delete mode 100644 drivers/staging/fsl-mc/README.txt
>  create mode 100644 drivers/staging/fsl-mc/overview.rst

Please generate patches with the -M option to git format-patch, so we
can see the file move, not just get removed and added as a brand new
one.

thanks,

greg k-h

Ioana Ciocoi Radulescu Jan. 16, 2018, 3:40 p.m. UTC | #2

> -----Original Message-----
> From: Greg KH [mailto:[e-mail]]
> Sent: Tuesday, January 16, 2018 5:14 PM
> To: Bogdan Purcareata <[e-mail]>
> Cc: Laurentiu Tudor <[e-mail]>; Ruxandra Ioana Ciocoi
> Radulescu <[e-mail]>; [e-mail];
> [e-mail]; [e-mail]; [e-mail];
> [e-mail]; Roy Pledge <[e-mail]>; Ioana Ciornei
> <[e-mail]>; [e-mail]; Horia Geantă
> <[e-mail]>; Nipun Gupta <[e-mail]>;
> [e-mail]; [e-mail];
> [e-mail]
> Subject: Re: [PATCH 8/8] staging: fsl-mc: Convert documentation to rst
> format
> 
> On Tue, Jan 16, 2018 at 03:19:10PM +0200, Bogdan Purcareata wrote:
> > From: Ioana Radulescu <[e-mail]>
> >
> > Update the doc file to comply with the rst format.
> >
> > It's not integrated into the documentation build structure yet,
> > since it's still located in drivers/staging.
> >
> > Signed-off-by: Ioana Radulescu <[e-mail]>
> > Reviewed-by: Laurentiu Tudor <[e-mail]>
> > ---
> >  drivers/staging/fsl-mc/README.txt   | 387 ----------------------------------
> >  drivers/staging/fsl-mc/overview.rst | 404
> ++++++++++++++++++++++++++++++++++++
> >  2 files changed, 404 insertions(+), 387 deletions(-)
> >  delete mode 100644 drivers/staging/fsl-mc/README.txt
> >  create mode 100644 drivers/staging/fsl-mc/overview.rst
> 
> Please generate patches with the -M option to git format-patch, so we
> can see the file move, not just get removed and added as a brand new
> one.

Sure, I can do this.

Even with -M, the diff is rather large since the indenting changes for most
of the lines in the file. Would it be better to make two patches, with
the first changing just line indenting and the second one, where the file is
moved, only updating rst specific markups?

Thanks,
Ioana

Greg KH Jan. 16, 2018, 4:54 p.m. UTC | #3

On Tue, Jan 16, 2018 at 03:40:18PM +0000, Ruxandra Ioana Ciocoi Radulescu wrote:
> > -----Original Message-----
> > From: Greg KH [mailto:[e-mail]]
> > Sent: Tuesday, January 16, 2018 5:14 PM
> > To: Bogdan Purcareata <[e-mail]>
> > Cc: Laurentiu Tudor <[e-mail]>; Ruxandra Ioana Ciocoi
> > Radulescu <[e-mail]>; [e-mail];
> > [e-mail]; [e-mail]; [e-mail];
> > [e-mail]; Roy Pledge <[e-mail]>; Ioana Ciornei
> > <[e-mail]>; [e-mail]; Horia Geantă
> > <[e-mail]>; Nipun Gupta <[e-mail]>;
> > [e-mail]; [e-mail];
> > [e-mail]
> > Subject: Re: [PATCH 8/8] staging: fsl-mc: Convert documentation to rst
> > format
> > 
> > On Tue, Jan 16, 2018 at 03:19:10PM +0200, Bogdan Purcareata wrote:
> > > From: Ioana Radulescu <[e-mail]>
> > >
> > > Update the doc file to comply with the rst format.
> > >
> > > It's not integrated into the documentation build structure yet,
> > > since it's still located in drivers/staging.
> > >
> > > Signed-off-by: Ioana Radulescu <[e-mail]>
> > > Reviewed-by: Laurentiu Tudor <[e-mail]>
> > > ---
> > >  drivers/staging/fsl-mc/README.txt   | 387 ----------------------------------
> > >  drivers/staging/fsl-mc/overview.rst | 404
> > ++++++++++++++++++++++++++++++++++++
> > >  2 files changed, 404 insertions(+), 387 deletions(-)
> > >  delete mode 100644 drivers/staging/fsl-mc/README.txt
> > >  create mode 100644 drivers/staging/fsl-mc/overview.rst
> > 
> > Please generate patches with the -M option to git format-patch, so we
> > can see the file move, not just get removed and added as a brand new
> > one.
> 
> Sure, I can do this.
> 
> Even with -M, the diff is rather large since the indenting changes for most
> of the lines in the file. Would it be better to make two patches, with
> the first changing just line indenting and the second one, where the file is
> moved, only updating rst specific markups?

Nah, just use -M and we can take it from there.

thanks,

greg k-h

Patch

diff --git a/drivers/staging/fsl-mc/README.txt b/drivers/staging/fsl-mc/README.txt
deleted file mode 100644
index 0ea5cd7..0000000
--- a/drivers/staging/fsl-mc/README.txt
+++ /dev/null
@@ -1,387 +0,0 @@ 
-Copyright (C) 2015 Freescale Semiconductor Inc.
-
-DPAA2 (Data Path Acceleration Architecture Gen2) Overview
----------------------------------------------------------
-
-This document provides an overview of the Freescale DPAA2 architecture
-and how it is integrated into the Linux kernel.
-
-Contents summary
-   -DPAA2 overview
-   -Overview of DPAA2 objects
-   -DPAA2 Linux driver architecture overview
-        -bus driver
-        -DPRC driver
-        -allocator
-        -DPIO driver
-        -Ethernet
-        -MAC
-
-Introduction
-------------
-
-DPAA2 is a hardware architecture designed for high-speeed network
-packet processing.  DPAA2 consists of sophisticated mechanisms for
-processing Ethernet packets, queue management, buffer management,
-autonomous L2 switching, virtual Ethernet bridging, and accelerator
-(e.g. crypto) sharing.
-
-A DPAA2 hardware component called the Management Complex (or MC) manages the
-DPAA2 hardware resources.  The MC provides an object-based abstraction for
-software drivers to use the DPAA2 hardware.
-
-The MC uses DPAA2 hardware resources such as queues, buffer pools, and
-network ports to create functional objects/devices such as network
-interfaces, an L2 switch, or accelerator instances.
-
-The MC provides memory-mapped I/O command interfaces (MC portals)
-which DPAA2 software drivers use to operate on DPAA2 objects.
-
-The diagram below shows an overview of the DPAA2 resource management
-architecture:
-
-         +--------------------------------------+
-         |                  OS                  |
-         |                        DPAA2 drivers |
-         |                             |        |
-         +-----------------------------|--------+
-                                       |
-                                       | (create,discover,connect
-                                       |  config,use,destroy)
-                                       |
-                         DPAA2         |
-         +------------------------| mc portal |-+
-         |                             |        |
-         |   +- - - - - - - - - - - - -V- - -+  |
-         |   |                               |  |
-         |   |   Management Complex (MC)     |  |
-         |   |                               |  |
-         |   +- - - - - - - - - - - - - - - -+  |
-         |                                      |
-         | Hardware                  Hardware   |
-         | Resources                 Objects    |
-         | ---------                 -------    |
-         | -queues                   -DPRC      |
-         | -buffer pools             -DPMCP     |
-         | -Eth MACs/ports           -DPIO      |
-         | -network interface        -DPNI      |
-         |  profiles                 -DPMAC     |
-         | -queue portals            -DPBP      |
-         | -MC portals                ...       |
-         |  ...                                 |
-         |                                      |
-         +--------------------------------------+
-
-The MC mediates operations such as create, discover,
-connect, configuration, and destroy.  Fast-path operations
-on data, such as packet transmit/receive, are not mediated by
-the MC and are done directly using memory mapped regions in
-DPIO objects.
-
-Overview of DPAA2 Objects
--------------------------
-The section provides a brief overview of some key DPAA2 objects.
-A simple scenario is described illustrating the objects involved
-in creating a network interfaces.
-
--DPRC (Datapath Resource Container)
-
-    A DPRC is a container object that holds all the other
-    types of DPAA2 objects.  In the example diagram below there
-    are 8 objects of 5 types (DPMCP, DPIO, DPBP, DPNI, and DPMAC)
-    in the container.
-
-    +---------------------------------------------------------+
-    | DPRC                                                    |
-    |                                                         |
-    |  +-------+  +-------+  +-------+  +-------+  +-------+  |
-    |  | DPMCP |  | DPIO  |  | DPBP  |  | DPNI  |  | DPMAC |  |
-    |  +-------+  +-------+  +-------+  +---+---+  +---+---+  |
-    |  | DPMCP |  | DPIO  |                                   |
-    |  +-------+  +-------+                                   |
-    |  | DPMCP |                                              |
-    |  +-------+                                              |
-    |                                                         |
-    +---------------------------------------------------------+
-
-    From the point of view of an OS, a DPRC behaves similar to a plug and
-    play bus, like PCI.  DPRC commands can be used to enumerate the contents
-    of the DPRC, discover the hardware objects present (including mappable
-    regions and interrupts).
-
-     DPRC.1 (bus)
-       |
-       +--+--------+-------+-------+-------+
-          |        |       |       |       |
-        DPMCP.1  DPIO.1  DPBP.1  DPNI.1  DPMAC.1
-        DPMCP.2  DPIO.2
-        DPMCP.3
-
-    Hardware objects can be created and destroyed dynamically, providing
-    the ability to hot plug/unplug objects in and out of the DPRC.
-
-    A DPRC has a mappable MMIO region (an MC portal) that can be used
-    to send MC commands.  It has an interrupt for status events (like
-    hotplug).
-
-    All objects in a container share the same hardware "isolation context".
-    This means that with respect to an IOMMU the isolation granularity
-    is at the DPRC (container) level, not at the individual object
-    level.
-
-    DPRCs can be defined statically and populated with objects
-    via a config file passed to the MC when firmware starts it.
-
--DPAA2 Objects for an Ethernet Network Interface
-
-    A typical Ethernet NIC is monolithic-- the NIC device contains TX/RX
-    queuing mechanisms, configuration mechanisms, buffer management,
-    physical ports, and interrupts.  DPAA2 uses a more granular approach
-    utilizing multiple hardware objects.  Each object provides specialized
-    functions. Groups of these objects are used by software to provide
-    Ethernet network interface functionality.  This approach provides
-    efficient use of finite hardware resources, flexibility, and
-    performance advantages.
-
-    The diagram below shows the objects needed for a simple
-    network interface configuration on a system with 2 CPUs.
-
-              +---+---+ +---+---+
-                 CPU0     CPU1
-              +---+---+ +---+---+
-                  |         |
-              +---+---+ +---+---+
-                 DPIO     DPIO
-              +---+---+ +---+---+
-                    \     /
-                     \   /
-                      \ /
-                   +---+---+
-                      DPNI  --- DPBP,DPMCP
-                   +---+---+
-                       |
-                       |
-                   +---+---+
-                     DPMAC
-                   +---+---+
-                       |
-                    port/PHY
-
-    Below the objects are described.  For each object a brief description
-    is provided along with a summary of the kinds of operations the object
-    supports and a summary of key resources of the object (MMIO regions
-    and IRQs).
-
-       -DPMAC (Datapath Ethernet MAC): represents an Ethernet MAC, a
-        hardware device that connects to an Ethernet PHY and allows
-        physical transmission and reception of Ethernet frames.
-           -MMIO regions: none
-           -IRQs: DPNI link change
-           -commands: set link up/down, link config, get stats,
-            IRQ config, enable, reset
-
-       -DPNI (Datapath Network Interface): contains TX/RX queues,
-        network interface configuration, and RX buffer pool configuration
-        mechanisms.  The TX/RX queues are in memory and are identified by
-        queue number.
-           -MMIO regions: none
-           -IRQs: link state
-           -commands: port config, offload config, queue config,
-            parse/classify config, IRQ config, enable, reset
-
-       -DPIO (Datapath I/O): provides interfaces to enqueue and dequeue
-        packets and do hardware buffer pool management operations.  The DPAA2
-        architecture separates the mechanism to access queues (the DPIO object)
-        from the queues themselves.  The DPIO provides an MMIO interface to
-        enqueue/dequeue packets.  To enqueue something a descriptor is written
-        to the DPIO MMIO region, which includes the target queue number.
-        There will typically be one DPIO assigned to each CPU.  This allows all
-        CPUs to simultaneously perform enqueue/dequeued operations.  DPIOs are
-        expected to be shared by different DPAA2 drivers.
-           -MMIO regions: queue operations, buffer management
-           -IRQs: data availability, congestion notification, buffer
-                  pool depletion
-           -commands: IRQ config, enable, reset
-
-       -DPBP (Datapath Buffer Pool): represents a hardware buffer
-        pool.
-           -MMIO regions: none
-           -IRQs: none
-           -commands: enable, reset
-
-       -DPMCP (Datapath MC Portal): provides an MC command portal.
-        Used by drivers to send commands to the MC to manage
-        objects.
-           -MMIO regions: MC command portal
-           -IRQs: command completion
-           -commands: IRQ config, enable, reset
-
-Object Connections
-------------------
-    Some objects have explicit relationships that must
-    be configured:
-
-       -DPNI <--> DPMAC
-       -DPNI <--> DPNI
-       -DPNI <--> L2-switch-port
-          A DPNI must be connected to something such as a DPMAC,
-          another DPNI, or L2 switch port.  The DPNI connection
-          is made via a DPRC command.
-
-              +-------+  +-------+
-              | DPNI  |  | DPMAC |
-              +---+---+  +---+---+
-                  |          |
-                  +==========+
-
-       -DPNI <--> DPBP
-          A network interface requires a 'buffer pool' (DPBP
-          object) which provides a list of pointers to memory
-          where received Ethernet data is to be copied.  The
-          Ethernet driver configures the DPBPs associated with
-          the network interface.
-
-Interrupts
-----------
-    All interrupts generated by DPAA2 objects are message
-    interrupts.  At the hardware level message interrupts
-    generated by devices will normally have 3 components--
-    1) a non-spoofable 'device-id' expressed on the hardware
-    bus, 2) an address, 3) a data value.
-
-    In the case of DPAA2 devices/objects, all objects in the
-    same container/DPRC share the same 'device-id'.
-    For ARM-based SoC this is the same as the stream ID.
-
-
-DPAA2 Linux Drivers Overview
-----------------------------
-
-This section provides an overview of the Linux kernel drivers for
-DPAA2-- 1) the bus driver and associated "DPAA2 infrastructure"
-drivers and 2) functional object drivers (such as Ethernet).
-
-As described previously, a DPRC is a container that holds the other
-types of DPAA2 objects.  It is functionally similar to a plug-and-play
-bus controller.
-
-Each object in the DPRC is a Linux "device" and is bound to a driver.
-The diagram below shows the Linux drivers involved in a networking
-scenario and the objects bound to each driver.  A brief description
-of each driver follows.
-
-                                             +------------+
-                                             | OS Network |
-                                             |   Stack    |
-                 +------------+              +------------+
-                 | Allocator  |. . . . . . . |  Ethernet  |
-                 |(DPMCP,DPBP)|              |   (DPNI)   |
-                 +-.----------+              +---+---+----+
-                  .          .                   ^   |
-                 .            .     <data avail, |   |<enqueue,
-                .              .     tx confirm> |   | dequeue>
-    +-------------+             .                |   |
-    | DPRC driver |              .           +---+---V----+     +---------+
-    |   (DPRC)    |               . . . . . .| DPIO driver|     |   MAC   |
-    +----------+--+                          |  (DPIO)    |     | (DPMAC) |
-               |                             +------+-----+     +-----+---+
-               |<dev add/remove>                    |                 |
-               |                                    |                 |
-          +----+--------------+                     |              +--+---+
-          |   MC-bus driver   |                     |              | PHY  |
-          |                   |                     |              |driver|
-          | /bus/fsl-mc       |                     |              +--+---+
-          +-------------------+                     |                 |
-                                                    |                 |
- ================================ HARDWARE =========|=================|======
-                                                  DPIO                |
-                                                    |                 |
-                                                  DPNI---DPBP         |
-                                                    |                 |
-                                                  DPMAC               |
-                                                    |                 |
-                                                   PHY ---------------+
- ===================================================|========================
-
-A brief description of each driver is provided below.
-
-    MC-bus driver
-    -------------
-    The MC-bus driver is a platform driver and is probed from a
-    node in the device tree (compatible "fsl,qoriq-mc") passed in by boot
-    firmware.  It is responsible for bootstrapping the DPAA2 kernel
-    infrastructure.
-    Key functions include:
-       -registering a new bus type named "fsl-mc" with the kernel,
-        and implementing bus call-backs (e.g. match/uevent/dev_groups)
-       -implementing APIs for DPAA2 driver registration and for device
-        add/remove
-       -creates an MSI IRQ domain
-       -doing a 'device add' to expose the 'root' DPRC, in turn triggering
-        a bind of the root DPRC to the DPRC driver
-    The binding for the MC-bus device-tree node can be consulted here:
-        Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
-    The sysfs bind/unbind interfaces for the MC-bus can be consulted here:
-        Documentation/ABI/testing/sysfs-bus-fsl-mc*
-
-    DPRC driver
-    -----------
-    The DPRC driver is bound to DPRC objects and does runtime management
-    of a bus instance.  It performs the initial bus scan of the DPRC
-    and handles interrupts for container events such as hot plug by
-    re-scanning the DPRC.
-
-    Allocator
-    ----------
-    Certain objects such as DPMCP and DPBP are generic and fungible,
-    and are intended to be used by other drivers.  For example,
-    the DPAA2 Ethernet driver needs:
-       -DPMCPs to send MC commands, to configure network interfaces
-       -DPBPs for network buffer pools
-
-    The allocator driver registers for these allocatable object types
-    and those objects are bound to the allocator when the bus is probed.
-    The allocator maintains a pool of objects that are available for
-    allocation by other DPAA2 drivers.
-
-    DPIO driver
-    -----------
-    The DPIO driver is bound to DPIO objects and provides services that allow
-    other drivers such as the Ethernet driver to enqueue and dequeue data for
-    their respective objects.
-    Key services include:
-        -data availability notifications
-        -hardware queuing operations (enqueue and dequeue of data)
-        -hardware buffer pool management
-
-    To transmit a packet the Ethernet driver puts data on a queue and
-    invokes a DPIO API.  For receive, the Ethernet driver registers
-    a data availability notification callback.  To dequeue a packet
-    a DPIO API is used.
-
-    There is typically one DPIO object per physical CPU for optimum
-    performance, allowing different CPUs to simultaneously enqueue
-    and dequeue data.
-
-    The DPIO driver operates on behalf of all DPAA2 drivers
-    active in the kernel--  Ethernet, crypto, compression,
-    etc.
-
-    Ethernet driver
-    ---------------
-    The Ethernet driver is bound to a DPNI and implements the kernel
-    interfaces needed to connect the DPAA2 network interface to
-    the network stack.
-
-    Each DPNI corresponds to a Linux network interface.
-
-    MAC driver
-    ----------
-    An Ethernet PHY is an off-chip, board specific component and is managed
-    by the appropriate PHY driver via an mdio bus.  The MAC driver
-    plays a role of being a proxy between the PHY driver and the
-    MC.  It does this proxy via the MC commands to a DPMAC object.
-    If the PHY driver signals a link change, the MAC driver notifies
-    the MC via a DPMAC command.  If a network interface is brought
-    up or down, the MC notifies the DPMAC driver via an interrupt and
-    the driver can take appropriate action.
diff --git a/drivers/staging/fsl-mc/overview.rst b/drivers/staging/fsl-mc/overview.rst
new file mode 100644
index 0000000..79fede4
--- /dev/null
+++ b/drivers/staging/fsl-mc/overview.rst
@@ -0,0 +1,404 @@ 
+.. include:: <isonum.txt>
+
+DPAA2 (Data Path Acceleration Architecture Gen2) Overview
+=========================================================
+
+:Copyright: |copy| 2015 Freescale Semiconductor Inc.
+:Copyright: |copy| 2018 NXP
+
+This document provides an overview of the Freescale DPAA2 architecture
+and how it is integrated into the Linux kernel.
+
+Introduction
+============
+
+DPAA2 is a hardware architecture designed for high-speeed network
+packet processing.  DPAA2 consists of sophisticated mechanisms for
+processing Ethernet packets, queue management, buffer management,
+autonomous L2 switching, virtual Ethernet bridging, and accelerator
+(e.g. crypto) sharing.
+
+A DPAA2 hardware component called the Management Complex (or MC) manages the
+DPAA2 hardware resources.  The MC provides an object-based abstraction for
+software drivers to use the DPAA2 hardware.
+The MC uses DPAA2 hardware resources such as queues, buffer pools, and
+network ports to create functional objects/devices such as network
+interfaces, an L2 switch, or accelerator instances.
+The MC provides memory-mapped I/O command interfaces (MC portals)
+which DPAA2 software drivers use to operate on DPAA2 objects.
+
+The diagram below shows an overview of the DPAA2 resource management
+architecture::
+
+	+--------------------------------------+
+	|                  OS                  |
+	|                        DPAA2 drivers |
+	|                             |        |
+	+-----------------------------|--------+
+	                              |
+	                              | (create,discover,connect
+	                              |  config,use,destroy)
+	                              |
+	                 DPAA2        |
+	+------------------------| mc portal |-+
+	|                             |        |
+	|   +- - - - - - - - - - - - -V- - -+  |
+	|   |                               |  |
+	|   |   Management Complex (MC)     |  |
+	|   |                               |  |
+	|   +- - - - - - - - - - - - - - - -+  |
+	|                                      |
+	| Hardware                  Hardware   |
+	| Resources                 Objects    |
+	| ---------                 -------    |
+	| -queues                   -DPRC      |
+	| -buffer pools             -DPMCP     |
+	| -Eth MACs/ports           -DPIO      |
+	| -network interface        -DPNI      |
+	|  profiles                 -DPMAC     |
+	| -queue portals            -DPBP      |
+	| -MC portals                ...       |
+	|  ...                                 |
+	|                                      |
+	+--------------------------------------+
+
+
+The MC mediates operations such as create, discover,
+connect, configuration, and destroy.  Fast-path operations
+on data, such as packet transmit/receive, are not mediated by
+the MC and are done directly using memory mapped regions in
+DPIO objects.
+
+Overview of DPAA2 Objects
+=========================
+
+The section provides a brief overview of some key DPAA2 objects.
+A simple scenario is described illustrating the objects involved
+in creating a network interfaces.
+
+DPRC (Datapath Resource Container)
+----------------------------------
+
+A DPRC is a container object that holds all the other
+types of DPAA2 objects.  In the example diagram below there
+are 8 objects of 5 types (DPMCP, DPIO, DPBP, DPNI, and DPMAC)
+in the container.
+
+::
+
+	+---------------------------------------------------------+
+	| DPRC                                                    |
+	|                                                         |
+	|  +-------+  +-------+  +-------+  +-------+  +-------+  |
+	|  | DPMCP |  | DPIO  |  | DPBP  |  | DPNI  |  | DPMAC |  |
+	|  +-------+  +-------+  +-------+  +---+---+  +---+---+  |
+	|  | DPMCP |  | DPIO  |                                   |
+	|  +-------+  +-------+                                   |
+	|  | DPMCP |                                              |
+	|  +-------+                                              |
+	|                                                         |
+	+---------------------------------------------------------+
+
+From the point of view of an OS, a DPRC behaves similar to a plug and
+play bus, like PCI.  DPRC commands can be used to enumerate the contents
+of the DPRC, discover the hardware objects present (including mappable
+regions and interrupts).
+
+::
+
+	DPRC.1 (bus)
+	   |
+	   +--+--------+-------+-------+-------+
+	      |        |       |       |       |
+	    DPMCP.1  DPIO.1  DPBP.1  DPNI.1  DPMAC.1
+	    DPMCP.2  DPIO.2
+	    DPMCP.3
+
+Hardware objects can be created and destroyed dynamically, providing
+the ability to hot plug/unplug objects in and out of the DPRC.
+
+A DPRC has a mappable MMIO region (an MC portal) that can be used
+to send MC commands.  It has an interrupt for status events (like
+hotplug).
+All objects in a container share the same hardware "isolation context".
+This means that with respect to an IOMMU the isolation granularity
+is at the DPRC (container) level, not at the individual object
+level.
+
+DPRCs can be defined statically and populated with objects
+via a config file passed to the MC when firmware starts it.
+
+DPAA2 Objects for an Ethernet Network Interface
+-----------------------------------------------
+
+A typical Ethernet NIC is monolithic-- the NIC device contains TX/RX
+queuing mechanisms, configuration mechanisms, buffer management,
+physical ports, and interrupts.  DPAA2 uses a more granular approach
+utilizing multiple hardware objects.  Each object provides specialized
+functions. Groups of these objects are used by software to provide
+Ethernet network interface functionality.  This approach provides
+efficient use of finite hardware resources, flexibility, and
+performance advantages.
+
+The diagram below shows the objects needed for a simple
+network interface configuration on a system with 2 CPUs.
+
+::
+
+	+---+---+ +---+---+
+	   CPU0     CPU1
+	+---+---+ +---+---+
+	    |         |
+	+---+---+ +---+---+
+	   DPIO     DPIO
+	+---+---+ +---+---+
+	    \     /
+	     \   /
+	      \ /
+	   +---+---+
+	      DPNI  --- DPBP,DPMCP
+	   +---+---+
+	       |
+	       |
+	   +---+---+
+	     DPMAC
+	   +---+---+
+	       |
+	   port/PHY
+
+Below the objects are described.  For each object a brief description
+is provided along with a summary of the kinds of operations the object
+supports and a summary of key resources of the object (MMIO regions
+and IRQs).
+
+DPMAC (Datapath Ethernet MAC)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Represents an Ethernet MAC, a hardware device that connects to an Ethernet
+PHY and allows physical transmission and reception of Ethernet frames.
+
+- MMIO regions: none
+- IRQs: DPNI link change
+- commands: set link up/down, link config, get stats,
+  IRQ config, enable, reset
+
+DPNI (Datapath Network Interface)
+Contains TX/RX queues, network interface configuration, and RX buffer pool
+configuration mechanisms.  The TX/RX queues are in memory and are identified
+by queue number.
+
+- MMIO regions: none
+- IRQs: link state
+- commands: port config, offload config, queue config,
+  parse/classify config, IRQ config, enable, reset
+
+DPIO (Datapath I/O)
+~~~~~~~~~~~~~~~~~~~
+Provides interfaces to enqueue and dequeue
+packets and do hardware buffer pool management operations.  The DPAA2
+architecture separates the mechanism to access queues (the DPIO object)
+from the queues themselves.  The DPIO provides an MMIO interface to
+enqueue/dequeue packets.  To enqueue something a descriptor is written
+to the DPIO MMIO region, which includes the target queue number.
+There will typically be one DPIO assigned to each CPU.  This allows all
+CPUs to simultaneously perform enqueue/dequeued operations.  DPIOs are
+expected to be shared by different DPAA2 drivers.
+
+- MMIO regions: queue operations, buffer management
+- IRQs: data availability, congestion notification, buffer
+  pool depletion
+- commands: IRQ config, enable, reset
+
+DPBP (Datapath Buffer Pool)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Represents a hardware buffer pool.
+
+- MMIO regions: none
+- IRQs: none
+- commands: enable, reset
+
+DPMCP (Datapath MC Portal)
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+Provides an MC command portal.
+Used by drivers to send commands to the MC to manage
+objects.
+
+- MMIO regions: MC command portal
+- IRQs: command completion
+- commands: IRQ config, enable, reset
+
+Object Connections
+==================
+Some objects have explicit relationships that must
+be configured:
+
+- DPNI <--> DPMAC
+- DPNI <--> DPNI
+- DPNI <--> L2-switch-port
+
+    A DPNI must be connected to something such as a DPMAC,
+    another DPNI, or L2 switch port.  The DPNI connection
+    is made via a DPRC command.
+
+::
+
+              +-------+  +-------+
+              | DPNI  |  | DPMAC |
+              +---+---+  +---+---+
+                  |          |
+                  +==========+
+
+- DPNI <--> DPBP
+
+    A network interface requires a 'buffer pool' (DPBP
+    object) which provides a list of pointers to memory
+    where received Ethernet data is to be copied.  The
+    Ethernet driver configures the DPBPs associated with
+    the network interface.
+
+Interrupts
+==========
+All interrupts generated by DPAA2 objects are message
+interrupts.  At the hardware level message interrupts
+generated by devices will normally have 3 components--
+1) a non-spoofable 'device-id' expressed on the hardware
+bus, 2) an address, 3) a data value.
+
+In the case of DPAA2 devices/objects, all objects in the
+same container/DPRC share the same 'device-id'.
+For ARM-based SoC this is the same as the stream ID.
+
+
+DPAA2 Linux Drivers Overview
+============================
+
+This section provides an overview of the Linux kernel drivers for
+DPAA2-- 1) the bus driver and associated "DPAA2 infrastructure"
+drivers and 2) functional object drivers (such as Ethernet).
+
+As described previously, a DPRC is a container that holds the other
+types of DPAA2 objects.  It is functionally similar to a plug-and-play
+bus controller.
+Each object in the DPRC is a Linux "device" and is bound to a driver.
+The diagram below shows the Linux drivers involved in a networking
+scenario and the objects bound to each driver.  A brief description
+of each driver follows.
+
+::
+
+	                                     +------------+
+	                                     | OS Network |
+	                                     |   Stack    |
+	         +------------+              +------------+
+	         | Allocator  |. . . . . . . |  Ethernet  |
+	         |(DPMCP,DPBP)|              |   (DPNI)   |
+	         +-.----------+              +---+---+----+
+	          .          .                   ^   |
+	         .            .     <data avail, |   | <enqueue,
+	        .              .     tx confirm> |   | dequeue>
+	+-------------+         .                |   |
+	| DPRC driver |          .           +---+---V----+     +---------+
+	|   (DPRC)    |           . . . . . .| DPIO driver|     |   MAC   |
+	+----------+--+                      |  (DPIO)    |     | (DPMAC) |
+	           |                         +------+-----+     +-----+---+
+	           |<dev add/remove>                |                 |
+	           |                                |                 |
+	  +--------+----------+                     |              +--+---+
+	  |   MC-bus driver   |                     |              | PHY  |
+	  |                   |                     |              |driver|
+	  |   /bus/fsl-mc     |                     |              +--+---+
+	  +-------------------+                     |                 |
+	                                            |                 |
+	========================= HARDWARE =========|=================|======
+	                                          DPIO                |
+	                                            |                 |
+	                                          DPNI---DPBP         |
+	                                            |                 |
+	                                          DPMAC               |
+	                                            |                 |
+	                                           PHY ---------------+
+	============================================|========================
+
+A brief description of each driver is provided below.
+
+MC-bus driver
+-------------
+The MC-bus driver is a platform driver and is probed from a
+node in the device tree (compatible "fsl,qoriq-mc") passed in by boot
+firmware.  It is responsible for bootstrapping the DPAA2 kernel
+infrastructure.
+Key functions include:
+
+- registering a new bus type named "fsl-mc" with the kernel,
+  and implementing bus call-backs (e.g. match/uevent/dev_groups)
+- implementing APIs for DPAA2 driver registration and for device
+  add/remove
+- creates an MSI IRQ domain
+- doing a 'device add' to expose the 'root' DPRC, in turn triggering
+  a bind of the root DPRC to the DPRC driver
+
+The binding for the MC-bus device-tree node can be consulted at
+*Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt*.
+The sysfs bind/unbind interfaces for the MC-bus can be consulted at
+*Documentation/ABI/testing/sysfs-bus-fsl-mc*.
+
+DPRC driver
+-----------
+The DPRC driver is bound to DPRC objects and does runtime management
+of a bus instance.  It performs the initial bus scan of the DPRC
+and handles interrupts for container events such as hot plug by
+re-scanning the DPRC.
+
+Allocator
+---------
+Certain objects such as DPMCP and DPBP are generic and fungible,
+and are intended to be used by other drivers.  For example,
+the DPAA2 Ethernet driver needs:
+
+- DPMCPs to send MC commands, to configure network interfaces
+- DPBPs for network buffer pools
+
+The allocator driver registers for these allocatable object types
+and those objects are bound to the allocator when the bus is probed.
+The allocator maintains a pool of objects that are available for
+allocation by other DPAA2 drivers.
+
+DPIO driver
+-----------
+The DPIO driver is bound to DPIO objects and provides services that allow
+other drivers such as the Ethernet driver to enqueue and dequeue data for
+their respective objects.
+Key services include:
+
+- data availability notifications
+- hardware queuing operations (enqueue and dequeue of data)
+- hardware buffer pool management
+
+To transmit a packet the Ethernet driver puts data on a queue and
+invokes a DPIO API.  For receive, the Ethernet driver registers
+a data availability notification callback.  To dequeue a packet
+a DPIO API is used.
+There is typically one DPIO object per physical CPU for optimum
+performance, allowing different CPUs to simultaneously enqueue
+and dequeue data.
+
+The DPIO driver operates on behalf of all DPAA2 drivers
+active in the kernel--  Ethernet, crypto, compression,
+etc.
+
+Ethernet driver
+---------------
+The Ethernet driver is bound to a DPNI and implements the kernel
+interfaces needed to connect the DPAA2 network interface to
+the network stack.
+Each DPNI corresponds to a Linux network interface.
+
+MAC driver
+----------
+An Ethernet PHY is an off-chip, board specific component and is managed
+by the appropriate PHY driver via an mdio bus.  The MAC driver
+plays a role of being a proxy between the PHY driver and the
+MC.  It does this proxy via the MC commands to a DPMAC object.
+If the PHY driver signals a link change, the MAC driver notifies
+the MC via a DPMAC command.  If a network interface is brought
+up or down, the MC notifies the DPMAC driver via an interrupt and
+the driver can take appropriate action.