xref: /illumos-gate/usr/src/uts/common/io/e1000api/README.illumos (revision 42b53e0fbc5c05289c3d334bb864b784fafe5ce4)
1#
2# This file and its contents are supplied under the terms of the
3# Common Development and Distribution License ("CDDL"), version 1.0.
4# You may only use this file in accordance with the terms of version
5# 1.0 of the CDDL.
6#
7# A full copy of the text of the CDDL should have accompanied this
8# source.  A copy of the CDDL is also available via the Internet at
9# http://www.illumos.org/license/CDDL.
10#
11
12#
13# Copyright (c) 2013 Joyent, Inc.  All rights reserved.
14#
15
16Historically e1000g and igb were maintained by two different teams at Sun and
17thus while they used identical common code from Intel, they each only ever used
18portions of it and were not kept in sync with one another. To help make
19maintenance and the adding of new devices easier in illumos, we have gone
20through and made it so that igb and e1000g rely on the same set of common code;
21however, this code is not in its own module, each has its own copy of the code
22compiled into it for various reasons which will be laid out below.
23
24As part of the interface with the common code, the driver is required to define
25an e1000_osdep.h. Currently each version of the driver defines its *own* version
26of this header file in their own driver specific directory. However, the code
27that implements this is different in each directory, specifically e1000g_osdep.c
28and igb_osdep.c. It's important that they have different names and not be called
29the same thing due to how the uts makefiles work.
30
31Deviations from the common FreeBSD code:
32
33We have a few differences from the common version of the FreeBSD code that exist
34so that we can both gather firmware information and that have workarounds for
35older chipsets. While, we would like to get that to be synced up and common, it
36is not currently.
37
38Energy Efficient Ethernet (EEE) is not enabled by default. This technology was
39introduced with the I350 family of parts in the igb driver. However, there have
40been issues seen with it in the wild and thus we opt to disable it by default
41until tests have proven that there are no longer problems.
42
43To help make that easier, we've documented here what these extra definitions
44are. DO NOT just blindly copy over new common code. There is more work that
45needs to be done in terms of changed interfaces and expectations for the
46drivers.
47
48# Support for Ice Lake, Cannon Lake, Tiger Lake, and the more recent I219 LM/V
49
50Due to several changes that have been made to the core e1000 code in
51FreeBSD that's specific to changes for iflib, a whole sale update was
52not done and instead support was manually merged based on information from
53Intel.
54
55# e1000_defines.h
56
57In e1000_defines.h we add the following three definitions which are not
58currently present. These definitions allow us to attach firware revisions and
59other information to the devinfo tree.
60
61#define		NVM_VERSION			0x0005
62#define		NVM_OEM_OFFSET_0		6
63#define		NVM_OEM_OFFSET_1		7
64
65# Workarounds for the 82541 and 82547
66
67There are various workarounds in place for the 82541 and 82547 due to errata
68that exist for these devices. This has traditionally been a part of the common
69code. Until this can get merged into the common code completely, we've spearted
70out the changes that are the actual C functions into
71uts/common/io/e1000g/e1000g_workarounds.c. However, this alone is not
72sufficient. You must make sure that in e1000_hw.h that the struc
73e1000_dev_spec_82541 actually looks like the following:
74
75struct e1000_dev_spec_82541 {
76	enum e1000_dsp_config dsp_config;
77	enum e1000_ffe_config ffe_config;
78	u32 tx_fifo_head;
79	u32 tx_fifo_start;
80	u32 tx_fifo_size;
81	u16 spd_default;
82	bool phy_init_script;
83	bool ttl_workaround;
84};
85
86# EEE
87
88By default we disable all support for EEE. To cause this to happen you must
89make the following change in e1000_82575.c's init_mac_params.
90
91From:
92 394         /* Enable EEE default settings for EEE supported devices */
93 395         if (mac->type >= e1000_i350)
94 396                 dev_spec->eee_disable = FALSE;
95To:
96 394         /* Enable EEE default settings for EEE supported devices */
97 395         if (mac->type >= e1000_i350)
98 396                 dev_spec->eee_disable = TRUE;
99
100Future work:
101
102The next step here is to take the osdep portions and merge them. That would
103allow us to build one common misc module e1000api that both igb and e1000g
104depend on rather than building separate copies of the common code into each
105driver. Another potential option which may prove to have less value is to take
106all of the gld and ddi logic and have one driver export that leaving e1000g and
107igb as small stubs which depend on that. Note however, that the latter is not
108how our upstream is currently structuring their igb and em (FreeBSD's e1000g)
109drivers.
110
111# illumos specific files
112
113The files e1000_illumos.[ch] introduce code that is shared between the two
114drivers so we can avoid copying and pasting some logic in multiple places. Any
115updates should not touch these unless the other definitions have changed as a
116result of the update.
117