qemu/roms/ipxe/src/drivers/linux/linux.c

   1 /*
   2  * Copyright (C) 2010 Piotr Jaroszyński <p.jaroszynski@gmail.com>
   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 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 St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 FILE_LICENCE(GPL2_OR_LATER);
  20
  21 /** @file
  22  *
  23  * Linux root_device and root_driver.
  24  */
  25
  26 #include <errno.h>
  27 #include <string.h>
  28 #include <stdio.h>
  29 #include <ipxe/linux.h>
  30 #include <ipxe/malloc.h>
  31 #include <ipxe/settings.h>
  32
  33 LIST_HEAD(linux_device_requests);
  34 LIST_HEAD(linux_global_settings);
  35
  36 /** Go over the device requests looking for a matching linux driver to handle them. */
  37 static int linux_probe(struct root_device *rootdev)
  38 {
  39         struct linux_device_request *request;
  40         struct linux_driver *driver;
  41         struct linux_device *device = NULL;
  42         int rc;
  43
  44         /* Apply global settings */
  45         linux_apply_settings(&linux_global_settings, NULL);
  46
  47         list_for_each_entry(request, &linux_device_requests, list) {
  48                 if (! device)
  49                         device = zalloc(sizeof(*device));
  50
  51                 if (! device)
  52                         return -ENOMEM;
  53
  54                 rc = 1;
  55
  56                 for_each_table_entry(driver, LINUX_DRIVERS) {
  57                         if ((rc = strcmp(driver->name, request->driver)) == 0)
  58                                 break;
  59                 }
  60
  61                 if (rc != 0) {
  62                         printf("Linux driver '%s' not found\n", request->driver);
  63                         continue;
  64                 }
  65
  66                 if (! driver->can_probe) {
  67                         printf("Driver '%s' cannot handle any more devices\n", driver->name);
  68                         continue;
  69                 }
  70
  71                 /* We found a matching driver so add the device to the hierarchy */
  72                 list_add(&device->dev.siblings, &rootdev->dev.children);
  73                 device->dev.parent = &rootdev->dev;
  74                 INIT_LIST_HEAD(&device->dev.children);
  75
  76                 if (driver->probe(device, request) == 0) {
  77                         device->driver = driver;
  78                         device->dev.driver_name = driver->name;
  79                         /* Driver handled the device so release ownership */
  80                         device = NULL;
  81                 } else {
  82                         /* Driver failed to handle the device so remove it from the hierarchy
  83                          * and reuse the object */
  84                         list_del(&device->dev.siblings);
  85                 }
  86         };
  87
  88         free(device);
  89
  90         return 0;
  91 }
  92
  93 /** Remove all the linux devices registered in probe() */
  94 static void linux_remove(struct root_device *rootdev)
  95 {
  96         struct linux_device *device;
  97         struct linux_device *tmp;
  98
  99         list_for_each_entry_safe(device, tmp, &rootdev->dev.children, dev.siblings) {
 100                 list_del(&device->dev.siblings);
 101                 device->driver->remove(device);
 102                 free(device);
 103         }
 104 }
 105
 106 /** Linux root driver */
 107 static struct root_driver linux_root_driver = {
 108         .probe = linux_probe,
 109         .remove = linux_remove,
 110 };
 111
 112 /** Linux root device */
 113 struct root_device linux_root_device __root_device = {
 114         .dev = { .name = "linux" },
 115         .driver = &linux_root_driver,
 116 };
 117
 118 struct linux_setting *linux_find_setting(char *name, struct list_head *settings)
 119 {
 120         struct linux_setting *setting;
 121         struct linux_setting *result = NULL;
 122
 123         /* Find the last occurrence of a setting with the specified name */
 124         list_for_each_entry(setting, settings, list) {
 125                 if (strcmp(setting->name, name) == 0) {
 126                         result = setting;
 127                 }
 128         }
 129
 130         return result;
 131 }
 132
 133 void linux_apply_settings(struct list_head *new_settings, struct settings *settings_block)
 134 {
 135         struct linux_setting *setting;
 136         int rc;
 137
 138         list_for_each_entry(setting, new_settings, list) {
 139                 /* Skip already applied settings */
 140                 if (setting->applied)
 141                         continue;
 142
 143                 struct setting *s = find_setting(setting->name);
 144                 if (s) {
 145                         rc = storef_setting(settings_block, find_setting(setting->name), setting->value);
 146                         if (rc != 0)
 147                                 DBG("linux storing setting '%s' = '%s' failed\n", setting->name, setting->value);
 148                         setting->applied = 1;
 149                 } else {
 150                         DBG("linux unknown setting '%s'\n", setting->name);
 151                 }
 152         }
 153 }