dpen(7) DG/UX R4.11MU05 dpen(7)
NAME
dpen - DEC PCI Ethernet Network Interface
SYNOPSIS
dpen(parent-bus[,pci-device-num[,pci-function-num[,alt-ether-
addr[,media]]]])
DESCRIPTION
The dpen device driver allows a DG/UX system that includes one or
more Model 7445 PCI LAN Controller/10, Model 7446 PCI LAN
Controller/100, Model 7463 PCI LAN Controller/100, Model 7458 and
Model 7467 PCI Multi-Channel/100 Ethernet adapters with a DEC
21040/21140/21143 local area network (LAN) controller to access an
Ethernet network. To configure such devices, you must add to the
DG/UX system configuration file a device name entry of the form
described in the synopsis above. The parameters in a device name
have the following meanings:
· The parent-bus parameter is itself a device name, representing
the PCI bus device to which the controller is attached (pci(0),
for example). There is no default value for this parameter; it
must always be specified explicitly.
· The pci-device-num parameter is a hexadecimal number in the range
0 through 1F; it represents the PCI device number ("slot number")
used by the device. The default value for pci-device-num is 0.
· The pci-function-num parameter is a hexadecimal number in the
range 0 through 7; it represents the PCI function number used by
the controller within pci-device-num. The default value for pci-
device-num is 0; non-zero values will be used only if the
controller lies on a multi-function card.
· The alt-ether-addr parameter can be used to override the
adapter's default Ethernet address with a user-specified value.
The alternate address must be expressed in one of two ways:
either as a string of exactly 12 hexadecimal digits, or as a
sequence of six pairs of two hexadecimal digits with each pair
separated by a colon (:) character. If no alt-ether-addr
parameter is specified, the adapter-resident default Ethernet
address is used.
· The media parameter can be used to override the adapter's default
media type. The following media types and options are supported:
10B: cable running 10BaseT
FD: cable running 10BaseT or 100BaseTx full duplex
10FD: 10BaseT cable running full duplex
100: cable running 100BaseTX
100FD: 100BaseTX cable running full duplex
AUI: cable running 10Base5
BNC: cable running 10Base2
Some adapters with both TP and AUI/BNC connectors can detect and
autoconfigure the correct TP or AUI/BNC interface; other adapters
require specification of the appropriate media parameter. Check
the hardware manual for the adapter to determine if a media
parameter and/or jumper changes on the adapter are required. If
it is not clear whether or not the adapter will
autosense/autoconfigure to the correct mode, the dpen driver's
media parameters can be used to set the appropriate default mode.
The Model 7463 PCI LAN Controller/100 supports ANSI/IEEE Std
802.3. For the 7463 controller, the driver negotiates the
network media type regardless of the specified default media type
and attempts re-negotiation of the network media type if a
connection change is detected.
Autoconfiguration of the full-duplex mode is only supported for
the Model 7463 PCI LAN Controller/100. For all other dpen
controllers, the full-duplex mode must be defined as a media
parameter. The full-duplex mode is only supported on 10BaseT and
100BaseTX Full-Duplex Ethernet networks that are generally
connected to an Ethernet Switch that supports Full-Duplex
connectivity.
In conjunction with the dpen system file entries, the following
tunable kernel parameters are used by all dpen devices configured
into the system:
· DPENPAD specifies the number of empty transmit descriptors that
should be inserted between back-to-back transmissions to reduce
the occurrence of the Ethernet "capture effect". The allowable
range is 0 - 10, but care should be taken when choosing values
greater than 5. Good results have been achieved with a value of
1 so that has been chosen as the default value. However, the
value for this variable should be based on the network
configuration and larger values may be appropriate if there is a
large propagation delay in the network. If a value larger than
10 is used, it will default to the maximum value of 10.
· DPEN_CA enables the DECchip 21040/21140/21143 based non-standard
method for resolution of the "capture effect" on the network. A
value of 1 enables the optional feature. The default value is 0,
which disables this feature.
· DPEN_BP when set enables the the transmit back pressure logic.
When receive data buffers are exhausted, the DEC
21040/21140/21143 Ethernet Controllers will assert the transmit
carrier for a maximum period of 500 milliseconds. Upon back
pressure, if a receive buffer descriptor becomes available, the
back pressure is stopped and controller fetches the descriptor.
By default the feature is disabled.
· DPEN_SF when set enables the DEC 21140 Store and Forward option.
When this is set the transmission starts when a full packet
resides in the on-chip FIFO. When this occurs, the Transmit
Threshold Control bits are ignored. By Default, the Store and
Forward option is enabled.
· DPEN_TT specifies the selected threshold level for the DEC
21040/21140/21143 transmit FIFO. The following values are
supported:
Value 100 Mb/s 10 Mb/s
Threshold Threshold
0 None None
1 128 72
2 256 96
3 512 128
4 1024 160
· DPEN_CACHE_ALIGN specifies the Programmable address boundaries
alignment (in 32-bit longwords) for the DEC 21040/21140 data
burst stop. If the buffer is not aligned, the DEC 21040/21140
controller executes the first transfer up to the address
boundary, then all transfers are aligned to the specified
boundary. For DEC 21140-AD/21140-AE/21143 based devices, this
parameter is ignored and the cache alignment is always set to the
system cache line size.
The following values are supported:
Value Alignment
0 Use Driver Default
1 8
2 16
3 32
· DPEN_RM when set enables the DEC 21140-A/21143 PCI Memory Read
Multiple (i.e. fetch multiple cachelines) feature. By Default,
this feature is enabled.
· DPEN_RL when set enables the DEC 21140-AD/21140-AE/21143 PCI
Memory Read Line (i.e. fetch a complete cacheline) feature. By
Default, this feature is enabled.
· DPEN_WI when set enables the DEC 21140-AD/21140-AE/21143 PCI
Memory Write and Invalidate feature. By Default, this feature is
enabled.
· DPEN_BURST_LENGTH specifies the maximum number of longwords to be
transferred in one DMA transaction. If DPEN_BURST_LENGTH = 0,
the DEC 21040/21140/21143 Ethernet Controllers burst is limited
only by the amount of data stored in the receive FIFO (at least
16 longwords), or by the amount of free space in the transmit
FIFO (at least 16 longwords) before issuing a bus request. The
following values are supported:
Value Burst size
0 FIFO-Limited
1 1
2 2
3 4
4 8
5 16
6 32
· DPEN_MAX_RX_BUF specifies the total number of receive buffers for
each adapter installed. The set of valid values = {12 .. 170}.
Entering a value of 0 or greater than 170 causes the driver to
use a default value of 164.
· DPEN_MAX_TX_BUF specifies the total number of transmit descriptor
ring entries for each adapter installed. The set of valid values
= {12 .. 170}. Entering a value of 0 or greater than 170 causes
the driver to use a default value of 128.
· DPEN_MAX_RX_10_BURST specifies the maximum number of consecutive
frames that the dpen Streams Read Service Routine will process
without relinquishing control and returning to Streams for
10BaseT Ethernets. The set of valid values = {1 .. 170}.
Entering a value of 0 causes the driver to use a default value of
64, a value greater than 170 causes the driver to use the maximum
value of 170.
· DPEN_MAX_RX_100_BURST specifies the maximum number of consecutive
frames that the dpen Streams Read Service Routine will process
without relinquishing control and returning to Streams for
100BaseTX interfaces using the dpen driver. The set of valid
values = {1 .. 512}. Entering a value of 0 causes the driver to
use a default value of 170, a value greater than 512 causes the
driver to use the maximum value of 512
FILES
Each dpen device creates a single character-special device node when
it is configured:
/dev/net/dpen(parent-bus,pci-device-num,pci-function-num)
The chk.devlink command is responsible for creating and maintaining
an additional link to each dpen device node, with a pathname of the
form /dev/net/dpen[0-9]*. See the chk.devlink(1M) and devlinktab(4M)
man pages for details.
The dpen device is implemented as a clonable Streams driver. This
means that you can open a single node, such as /dev/dpen0, to access
any unused minor device. Each subsequent access of the node via the
open(2) system call allocates a separate Stream (minor number) to the
device driver.
EXAMPLES
The following entries in a DG/UX configuration file configure two
dpen adapters at nodes /dev/net/dpen(cpci(0),4,0) and
/dev/net/dpen(cpci(1),2,0). The first card is connected to slot 4 of
the primary Corollary PCI host bridge, and the second card is
connected to slot 2 of the secondary Corollary PCI host bridge.
dpen(cpci(0),4,0)
dpen(cpci(1),2,0)
The following statement configures a dpen adapter with an alternate
Ethernet address:
dpen(pci(0),6,0,08001b123456)
The following statement configures the first channel of the Model
7548 Multi-Channel 10/100 PCI Ethernet adapter in the second PCI slot
of the first PCI bus of an AViiON 3000:
dpen(dppb(pci(0),D,0),4,0)
The following statement configures a PLC/100 Ethernet adapter in an
Expansion PCI Chassis with explicit definition of the media speed as
100BaseTX:
dpen(xpci(cpci(0),1,0),2,0,,100)
For more information about DG/UX device configuration, refer to
"Writing a Device Driver" in Programming in the DG/UX Kernel Environment.
FILES
/etc/devlinktab This file contains entries used to make short-named
links to device nodes.
DIAGNOSTICS
Use the -i option with netstat(1C).
Use the -o specify, -o configure, or -o deconfigure option with
admdevice(1M).
SEE ALSO
ifconfig(1M), netinit(1M), netstat(1M), admdevice(1M), system(4),
chk.devlink(1M), devlinktab(4M), arp(6P), inet(6F), pci_bus(7),
intro(7).
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