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 };