[tcpip] Allow supported address families to be detected at runtime
[ipxe.git] / src / drivers / bus / pci_settings.c
1 /*
2 * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 #include <stdio.h>
27 #include <errno.h>
28 #include <ipxe/pci.h>
29 #include <ipxe/settings.h>
30 #include <ipxe/init.h>
31
32 /** @file
33 *
34 * PCI device settings
35 *
36 */
37
38 /** PCI device settings scope */
39 static const struct settings_scope pci_settings_scope;
40
41 /**
42 * Check applicability of PCI device setting
43 *
44 * @v settings Settings block
45 * @v setting Setting
46 * @ret applies Setting applies within this settings block
47 */
48 static int pci_settings_applies ( struct settings *settings __unused,
49 const struct setting *setting ) {
50
51 return ( setting->scope == &pci_settings_scope );
52 }
53
54 /**
55 * Fetch value of PCI device setting
56 *
57 * @v settings Settings block
58 * @v setting Setting to fetch
59 * @v data Buffer to fill with setting data
60 * @v len Length of buffer
61 * @ret len Length of setting data, or negative error
62 */
63 static int pci_settings_fetch ( struct settings *settings __unused,
64 struct setting *setting,
65 void *data, size_t len ) {
66 struct pci_device pci;
67 unsigned int tag_busdevfn;
68 unsigned int tag_offset;
69 unsigned int tag_len;
70 unsigned int i;
71
72 /* Extract busdevfn, offset, and length from tag */
73 tag_busdevfn = ( ( setting->tag >> 16 ) & 0xffff );
74 tag_offset = ( ( setting->tag >> 8 ) & 0xff );
75 tag_len = ( ( setting->tag >> 0 ) & 0xff );
76
77 /* Locate PCI device */
78 memset ( &pci, 0, sizeof ( pci ) );
79 pci_init ( &pci, tag_busdevfn );
80 DBG ( PCI_FMT " reading %#02x+%#x\n", PCI_ARGS ( &pci ),
81 tag_offset, tag_len );
82
83 /* Read data one byte at a time, in reverse order (since PCI
84 * is little-endian and iPXE settings are essentially
85 * big-endian).
86 */
87 tag_offset += tag_len;
88 for ( i = 0 ; ( ( i < tag_len ) && ( i < len ) ); i++ ) {
89 pci_read_config_byte ( &pci, --tag_offset, data++ );
90 }
91
92 /* Set type to ":hexraw" if not already specified */
93 if ( ! setting->type )
94 setting->type = &setting_type_hexraw;
95
96 return tag_len;
97 }
98
99 /** PCI device settings operations */
100 static struct settings_operations pci_settings_operations = {
101 .applies = pci_settings_applies,
102 .fetch = pci_settings_fetch,
103 };
104
105 /** PCI device settings */
106 static struct settings pci_settings = {
107 .refcnt = NULL,
108 .siblings = LIST_HEAD_INIT ( pci_settings.siblings ),
109 .children = LIST_HEAD_INIT ( pci_settings.children ),
110 .op = &pci_settings_operations,
111 .default_scope = &pci_settings_scope,
112 };
113
114 /** Initialise PCI device settings */
115 static void pci_settings_init ( void ) {
116 int rc;
117
118 if ( ( rc = register_settings ( &pci_settings, NULL, "pci" ) ) != 0 ) {
119 DBG ( "PCI could not register settings: %s\n",
120 strerror ( rc ) );
121 return;
122 }
123 }
124
125 /** PCI device settings initialiser */
126 struct init_fn pci_settings_init_fn __init_fn ( INIT_NORMAL ) = {
127 .initialise = pci_settings_init,
128 };