net: documentation: build a directory structure for drivers

Documentation/networking/ is full of cryptically named files with
driver documentation.  This makes finding interesting information
at a glance really hard.  Move all those files into a directory
called device_drivers (since not all drivers are for device) and
fix up references.

RFC v0.1 -> RFC v1:
 - also add .txt suffix to the files which are missing it (Quentin)

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Henrik Austad <henrik@austad.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 260 deletions

diff --git a/Documentation/networking/dpaa.txt b/Documentation/networking/dpaa.txt
deleted file mode 100644
index f88194f71c54..000000000000
--- a/Documentation/networking/dpaa.txt
+++ /dev/null
@@ -1,260 +0,0 @@
-The QorIQ DPAA Ethernet Driver
-==============================
-
-Authors:
-Madalin Bucur <madalin.bucur@nxp.com>
-Camelia Groza <camelia.groza@nxp.com>
-
-Contents
-========
-
-	- DPAA Ethernet Overview
-	- DPAA Ethernet Supported SoCs
-	- Configuring DPAA Ethernet in your kernel
-	- DPAA Ethernet Frame Processing
-	- DPAA Ethernet Features
-	- DPAA IRQ Affinity and Receive Side Scaling
-	- Debugging
-
-DPAA Ethernet Overview
-======================
-
-DPAA stands for Data Path Acceleration Architecture and it is a
-set of networking acceleration IPs that are available on several
-generations of SoCs, both on PowerPC and ARM64.
-
-The Freescale DPAA architecture consists of a series of hardware blocks
-that support Ethernet connectivity. The Ethernet driver depends upon the
-following drivers in the Linux kernel:
-
- - Peripheral Access Memory Unit (PAMU) (* needed only for PPC platforms)
-    drivers/iommu/fsl_*
- - Frame Manager (FMan)
-    drivers/net/ethernet/freescale/fman
- - Queue Manager (QMan), Buffer Manager (BMan)
-    drivers/soc/fsl/qbman
-
-A simplified view of the dpaa_eth interfaces mapped to FMan MACs:
-
-  dpaa_eth       /eth0\     ...       /ethN\
-  driver        |      |             |      |
-  -------------   ----   -----------   ----   -------------
-       -Ports  / Tx  Rx \    ...    / Tx  Rx \
-  FMan        |          |         |          |
-       -MACs  |   MAC0   |         |   MACN   |
-             /   dtsec0   \  ...  /   dtsecN   \ (or tgec)
-            /              \     /              \(or memac)
-  ---------  --------------  ---  --------------  ---------
-      FMan, FMan Port, FMan SP, FMan MURAM drivers
-  ---------------------------------------------------------
-      FMan HW blocks: MURAM, MACs, Ports, SP
-  ---------------------------------------------------------
-
-The dpaa_eth relation to the QMan, BMan and FMan:
-              ________________________________
-  dpaa_eth   /            eth0                \
-  driver    /                                  \
-  ---------   -^-   -^-   -^-   ---    ---------
-  QMan driver / \   / \   / \  \   /  | BMan    |
-             |Rx | |Rx | |Tx | |Tx |  | driver  |
-  ---------  |Dfl| |Err| |Cnf| |FQs|  |         |
-  QMan HW    |FQ | |FQ | |FQs| |   |  |         |
-             /   \ /   \ /   \  \ /   |         |
-  ---------   ---   ---   ---   -v-    ---------
-            |        FMan QMI         |         |
-            | FMan HW       FMan BMI  | BMan HW |
-              -----------------------   --------
-
-where the acronyms used above (and in the code) are:
-DPAA = Data Path Acceleration Architecture
-FMan = DPAA Frame Manager
-QMan = DPAA Queue Manager
-BMan = DPAA Buffers Manager
-QMI = QMan interface in FMan
-BMI = BMan interface in FMan
-FMan SP = FMan Storage Profiles
-MURAM = Multi-user RAM in FMan
-FQ = QMan Frame Queue
-Rx Dfl FQ = default reception FQ
-Rx Err FQ = Rx error frames FQ
-Tx Cnf FQ = Tx confirmation FQs
-Tx FQs = transmission frame queues
-dtsec = datapath three speed Ethernet controller (10/100/1000 Mbps)
-tgec = ten gigabit Ethernet controller (10 Gbps)
-memac = multirate Ethernet MAC (10/100/1000/10000)
-
-DPAA Ethernet Supported SoCs
-============================
-
-The DPAA drivers enable the Ethernet controllers present on the following SoCs:
-
-# PPC
-P1023
-P2041
-P3041
-P4080
-P5020
-P5040
-T1023
-T1024
-T1040
-T1042
-T2080
-T4240
-B4860
-
-# ARM
-LS1043A
-LS1046A
-
-Configuring DPAA Ethernet in your kernel
-========================================
-
-To enable the DPAA Ethernet driver, the following Kconfig options are required:
-
-# common for arch/arm64 and arch/powerpc platforms
-CONFIG_FSL_DPAA=y
-CONFIG_FSL_FMAN=y
-CONFIG_FSL_DPAA_ETH=y
-CONFIG_FSL_XGMAC_MDIO=y
-
-# for arch/powerpc only
-CONFIG_FSL_PAMU=y
-
-# common options needed for the PHYs used on the RDBs
-CONFIG_VITESSE_PHY=y
-CONFIG_REALTEK_PHY=y
-CONFIG_AQUANTIA_PHY=y
-
-DPAA Ethernet Frame Processing
-==============================
-
-On Rx, buffers for the incoming frames are retrieved from one of the three
-existing buffers pools. The driver initializes and seeds these, each with
-buffers of different sizes: 1KB, 2KB and 4KB.
-
-On Tx, all transmitted frames are returned to the driver through Tx
-confirmation frame queues. The driver is then responsible for freeing the
-buffers. In order to do this properly, a backpointer is added to the buffer
-before transmission that points to the skb. When the buffer returns to the
-driver on a confirmation FQ, the skb can be correctly consumed.
-
-DPAA Ethernet Features
-======================
-
-Currently the DPAA Ethernet driver enables the basic features required for
-a Linux Ethernet driver. The support for advanced features will be added
-gradually.
-
-The driver has Rx and Tx checksum offloading for UDP and TCP. Currently the Rx
-checksum offload feature is enabled by default and cannot be controlled through
-ethtool. Also, rx-flow-hash and rx-hashing was added. The addition of RSS
-provides a big performance boost for the forwarding scenarios, allowing
-different traffic flows received by one interface to be processed by different
-CPUs in parallel.
-
-The driver has support for multiple prioritized Tx traffic classes. Priorities
-range from 0 (lowest) to 3 (highest). These are mapped to HW workqueues with
-strict priority levels. Each traffic class contains NR_CPU TX queues. By
-default, only one traffic class is enabled and the lowest priority Tx queues
-are used. Higher priority traffic classes can be enabled with the mqprio
-qdisc. For example, all four traffic classes are enabled on an interface with
-the following command. Furthermore, skb priority levels are mapped to traffic
-classes as follows:
-
-	* priorities 0 to 3 - traffic class 0 (low priority)
-	* priorities 4 to 7 - traffic class 1 (medium-low priority)
-	* priorities 8 to 11 - traffic class 2 (medium-high priority)
-	* priorities 12 to 15 - traffic class 3 (high priority)
-
-tc qdisc add dev <int> root handle 1: \
-	 mqprio num_tc 4 map 0 0 0 0 1 1 1 1 2 2 2 2 3 3 3 3 hw 1
-
-DPAA IRQ Affinity and Receive Side Scaling
-==========================================
-
-Traffic coming on the DPAA Rx queues or on the DPAA Tx confirmation
-queues is seen by the CPU as ingress traffic on a certain portal.
-The DPAA QMan portal interrupts are affined each to a certain CPU.
-The same portal interrupt services all the QMan portal consumers.
-
-By default the DPAA Ethernet driver enables RSS, making use of the
-DPAA FMan Parser and Keygen blocks to distribute traffic on 128
-hardware frame queues using a hash on IP v4/v6 source and destination
-and L4 source and destination ports, in present in the received frame.
-When RSS is disabled, all traffic received by a certain interface is
-received on the default Rx frame queue. The default DPAA Rx frame
-queues are configured to put the received traffic into a pool channel
-that allows any available CPU portal to dequeue the ingress traffic.
-The default frame queues have the HOLDACTIVE option set, ensuring that
-traffic bursts from a certain queue are serviced by the same CPU.
-This ensures a very low rate of frame reordering. A drawback of this
-is that only one CPU at a time can service the traffic received by a
-certain interface when RSS is not enabled.
-
-To implement RSS, the DPAA Ethernet driver allocates an extra set of
-128 Rx frame queues that are configured to dedicated channels, in a
-round-robin manner. The mapping of the frame queues to CPUs is now
-hardcoded, there is no indirection table to move traffic for a certain
-FQ (hash result) to another CPU. The ingress traffic arriving on one
-of these frame queues will arrive at the same portal and will always
-be processed by the same CPU. This ensures intra-flow order preservation
-and workload distribution for multiple traffic flows.
-
-RSS can be turned off for a certain interface using ethtool, i.e.
-
-	# ethtool -N fm1-mac9 rx-flow-hash tcp4 ""
-
-To turn it back on, one needs to set rx-flow-hash for tcp4/6 or udp4/6:
-
-	# ethtool -N fm1-mac9 rx-flow-hash udp4 sfdn
-
-There is no independent control for individual protocols, any command
-run for one of tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 is
-going to control the rx-flow-hashing for all protocols on that interface.
-
-Besides using the FMan Keygen computed hash for spreading traffic on the
-128 Rx FQs, the DPAA Ethernet driver also sets the skb hash value when
-the NETIF_F_RXHASH feature is on (active by default). This can be turned
-on or off through ethtool, i.e.:
-
-	# ethtool -K fm1-mac9 rx-hashing off
-	# ethtool -k fm1-mac9 | grep hash
-	receive-hashing: off
-	# ethtool -K fm1-mac9 rx-hashing on
-	Actual changes:
-	receive-hashing: on
-	# ethtool -k fm1-mac9 | grep hash
-	receive-hashing: on
-
-Please note that Rx hashing depends upon the rx-flow-hashing being on
-for that interface - turning off rx-flow-hashing will also disable the
-rx-hashing (without ethtool reporting it as off as that depends on the
-NETIF_F_RXHASH feature flag).
-
-Debugging
-=========
-
-The following statistics are exported for each interface through ethtool:
-
-	- interrupt count per CPU
-	- Rx packets count per CPU
-	- Tx packets count per CPU
-	- Tx confirmed packets count per CPU
-	- Tx S/G frames count per CPU
-	- Tx error count per CPU
-	- Rx error count per CPU
-	- Rx error count per type
-	- congestion related statistics:
-		- congestion status
-		- time spent in congestion
-		- number of time the device entered congestion
-		- dropped packets count per cause
-
-The driver also exports the following information in sysfs:
-
-	- the FQ IDs for each FQ type
-	/sys/devices/platform/dpaa-ethernet.0/net/<int>/fqids
-
-	- the IDs of the buffer pools in use
-	/sys/devices/platform/dpaa-ethernet.0/net/<int>/bpids