This is a driver-breaking update to the netdriver library, which is
used by all network drivers. The aim of this change is to make the
library more compatible with NetBSD, and in particular with various
features that are expected to be supported by the NetBSD userland.
The main changes made by this patch are the following:
- each network driver now has a NetBSD-style short device name;
- drivers are not expected to receive packets right after startup;
- extended support for receipt modes, including multicast lists;
- support for multiple parallel send, receive requests;
- embedding of I/O vectors in send and receive requests;
- support for capabilities, including checksum offloading;
- support for reporting link status updates to the TCP/IP stack;
- support for setting and retrieving media status;
- support for changing the hardware (MAC) address;
- support for NetBSD interface flags IFF_DEBUG, IFF_LINK[0-2];
- support for NetBSD error statistics;
- support for regular time-based ("tick") callbacks.
IMPORTANT: this patch applies a minimal update to the existing drivers
in order to make them work at all with the new netdriver library. It
however does *not* change all drivers to make use of the new features.
In fact, strictly speaking, all drivers are now violating requirements
imposed by the new library in one way or another, most notably by
enabling packet receipt when starting the driver. Changing all the
drivers to be compliant, and to support the newly added options, is
left to future patches. The existing drivers should currently *not*
be taken as examples of how to implement a new network driver!
With that said, a few drivers have already been changed to make use of
some of the new features: fxp, e1000, rtl8139, and rtl8169 now report
link and media status, and the last three of those now support setting
the hardware MAC address on the fly. In addition, dp8390 has been
changed to default to PCI autoconfiguration if no configuration is
specified through environment variables.
Change-Id: I4b3ea9c0b9bc25d5b0609c6ff256fb0db71cdc42
The new implementation of this library provides abstractions for
network drivers, and should be used for all network drivers from now
on. It provides the following functionality:
- a function call table abstraction, hiding the details of the
datalink protocol with simple parameters;
- a state machine for sending and receiving packets, freeing the
actual driver from keeping track of pending requests;
- an abstraction for copying data from and to the network driver,
freeing the actual driver from dealing with I/O vectors while at
the same time providing a copy implementation which is more
efficient than most current driver implementations;
- a generalized implementation of zero-copy port-based I/O;
- a clearer set of policies and defaults.
While the concept is very similar to lib{block,char,fs,input}driver,
one main difference is that libnetdriver now also takes care of SEF
initialization, mainly so that aspects such as recovery policies and
live-update aspects can be changed for all network drivers in a
single place. As always, for the case that the provided message loop
is too restrictive, a set of more low-level message processing
functions is provided.
The netdriver API has been designed so as to allow alleviation of one
current protocol bottleneck: the fact that at most one send request
and one receive request may be pending at any time. Changing this
aspect will however require a significant rewrite of libnetdriver,
and possibly debugging of drivers that are not able to cope with (in
particular) queuing multiple packets for transmission at once.
Beyond that, the design of the new API is based on the current
protocol, and may be changed/extended later to allow for non-ethernet
network drivers, exposure of link status, multicast address
configuration, suspend and resume, and any other features that are in
fact long overdue.
Change-Id: I47ec47e05852c42f92af04549d41524f928efec2
