/*
   * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
   * 		     are not related to any other subsystem
   *
   * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   * 
   * This file is release under the GPLv2
   *
   */

  #include <linux/kobject.h>
  #include <linux/string.h>
  #include <linux/sysfs.h>
  #include <linux/module.h>
  #include <linux/init.h>

  #include <linux/kexec.h>

  
  #define KERNEL_ATTR_RO(_name) \
  static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
  
  #define KERNEL_ATTR_RW(_name) \
  static struct subsys_attribute _name##_attr = \
  	__ATTR(_name, 0644, _name##_show, _name##_store)

  #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)

  /* current uevent sequence number */

  static ssize_t uevent_seqnum_show(struct kset *kset, char *page)

  {

  	return sprintf(page, "%llu
  ", (unsigned long long)uevent_seqnum);

  }

  KERNEL_ATTR_RO(uevent_seqnum);
  
  /* uevent helper program, used during early boo */

  static ssize_t uevent_helper_show(struct kset *kset, char *page)

  {

  	return sprintf(page, "%s
  ", uevent_helper);

  }

  static ssize_t uevent_helper_store(struct kset *kset, const char *page, size_t count)

  {

  	if (count+1 > UEVENT_HELPER_PATH_LEN)

  		return -ENOENT;

  	memcpy(uevent_helper, page, count);
  	uevent_helper[count] = '\0';
  	if (count && uevent_helper[count-1] == '
  ')
  		uevent_helper[count-1] = '\0';

  	return count;
  }
  KERNEL_ATTR_RW(uevent_helper);

  #endif

  #ifdef CONFIG_KEXEC

  static ssize_t kexec_loaded_show(struct kset *kset, char *page)

  {
  	return sprintf(page, "%d
  ", !!kexec_image);
  }
  KERNEL_ATTR_RO(kexec_loaded);

  static ssize_t kexec_crash_loaded_show(struct kset *kset, char *page)

  {
  	return sprintf(page, "%d
  ", !!kexec_crash_image);
  }
  KERNEL_ATTR_RO(kexec_crash_loaded);
  #endif /* CONFIG_KEXEC */

  /*
   * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
   */

  extern const void __start_notes __attribute__((weak));
  extern const void __stop_notes __attribute__((weak));

  #define	notes_size (&__stop_notes - &__start_notes)
  
  static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr,
  			  char *buf, loff_t off, size_t count)
  {
  	memcpy(buf, &__start_notes + off, count);
  	return count;
  }
  
  static struct bin_attribute notes_attr = {
  	.attr = {
  		.name = "notes",
  		.mode = S_IRUGO,
  	},
  	.read = &notes_read,
  };

  decl_subsys(kernel, NULL, NULL);
  EXPORT_SYMBOL_GPL(kernel_subsys);
  
  static struct attribute * kernel_attrs[] = {

  #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)

  	&uevent_seqnum_attr.attr,
  	&uevent_helper_attr.attr,

  #endif

  #ifdef CONFIG_KEXEC
  	&kexec_loaded_attr.attr,
  	&kexec_crash_loaded_attr.attr,
  #endif

  	NULL
  };
  
  static struct attribute_group kernel_attr_group = {
  	.attrs = kernel_attrs,
  };
  
  static int __init ksysfs_init(void)
  {
  	int error = subsystem_register(&kernel_subsys);
  	if (!error)

  		error = sysfs_create_group(&kernel_subsys.kobj,

  					   &kernel_attr_group);

  	if (!error && notes_size > 0) {
  		notes_attr.size = notes_size;
  		error = sysfs_create_bin_file(&kernel_subsys.kobj,
  					      &notes_attr);
  	}

  	return error;
  }
  
  core_initcall(ksysfs_init);