/*
   *  copyright (c) 2006 IBM Corporation
   *  Authored by: Mike D. Day <ncmike@us.ibm.com>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2 as
   *  published by the Free Software Foundation.
   */

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/kobject.h>

  #include <linux/err.h>

  
  #include <asm/xen/hypervisor.h>
  #include <asm/xen/hypercall.h>

  #include <xen/xen.h>

  #include <xen/xenbus.h>
  #include <xen/interface/xen.h>
  #include <xen/interface/version.h>
  
  #define HYPERVISOR_ATTR_RO(_name) \
  static struct hyp_sysfs_attr  _name##_attr = __ATTR_RO(_name)
  
  #define HYPERVISOR_ATTR_RW(_name) \
  static struct hyp_sysfs_attr _name##_attr = \
  	__ATTR(_name, 0644, _name##_show, _name##_store)
  
  struct hyp_sysfs_attr {
  	struct attribute attr;
  	ssize_t (*show)(struct hyp_sysfs_attr *, char *);
  	ssize_t (*store)(struct hyp_sysfs_attr *, const char *, size_t);
  	void *hyp_attr_data;
  };
  
  static ssize_t type_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	return sprintf(buffer, "xen
  ");
  }
  
  HYPERVISOR_ATTR_RO(type);
  
  static int __init xen_sysfs_type_init(void)
  {
  	return sysfs_create_file(hypervisor_kobj, &type_attr.attr);
  }
  
  static void xen_sysfs_type_destroy(void)
  {
  	sysfs_remove_file(hypervisor_kobj, &type_attr.attr);
  }
  
  /* xen version attributes */
  static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int version = HYPERVISOR_xen_version(XENVER_version, NULL);
  	if (version)
  		return sprintf(buffer, "%d
  ", version >> 16);
  	return -ENODEV;
  }
  
  HYPERVISOR_ATTR_RO(major);
  
  static ssize_t minor_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int version = HYPERVISOR_xen_version(XENVER_version, NULL);
  	if (version)
  		return sprintf(buffer, "%d
  ", version & 0xff);
  	return -ENODEV;
  }
  
  HYPERVISOR_ATTR_RO(minor);
  
  static ssize_t extra_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	char *extra;
  
  	extra = kmalloc(XEN_EXTRAVERSION_LEN, GFP_KERNEL);
  	if (extra) {
  		ret = HYPERVISOR_xen_version(XENVER_extraversion, extra);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", extra);
  		kfree(extra);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(extra);
  
  static struct attribute *version_attrs[] = {
  	&major_attr.attr,
  	&minor_attr.attr,
  	&extra_attr.attr,
  	NULL
  };

  static const struct attribute_group version_group = {

  	.name = "version",
  	.attrs = version_attrs,
  };
  
  static int __init xen_sysfs_version_init(void)
  {
  	return sysfs_create_group(hypervisor_kobj, &version_group);
  }
  
  static void xen_sysfs_version_destroy(void)
  {
  	sysfs_remove_group(hypervisor_kobj, &version_group);
  }
  
  /* UUID */

  static ssize_t uuid_show_fallback(struct hyp_sysfs_attr *attr, char *buffer)

  {
  	char *vm, *val;
  	int ret;
  	extern int xenstored_ready;
  
  	if (!xenstored_ready)
  		return -EBUSY;
  
  	vm = xenbus_read(XBT_NIL, "vm", "", NULL);
  	if (IS_ERR(vm))
  		return PTR_ERR(vm);
  	val = xenbus_read(XBT_NIL, vm, "uuid", NULL);
  	kfree(vm);
  	if (IS_ERR(val))
  		return PTR_ERR(val);
  	ret = sprintf(buffer, "%s
  ", val);
  	kfree(val);
  	return ret;
  }

  static ssize_t uuid_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	xen_domain_handle_t uuid;
  	int ret;
  	ret = HYPERVISOR_xen_version(XENVER_guest_handle, uuid);
  	if (ret)
  		return uuid_show_fallback(attr, buffer);
  	ret = sprintf(buffer, "%pU
  ", uuid);
  	return ret;
  }

  HYPERVISOR_ATTR_RO(uuid);
  
  static int __init xen_sysfs_uuid_init(void)
  {
  	return sysfs_create_file(hypervisor_kobj, &uuid_attr.attr);
  }
  
  static void xen_sysfs_uuid_destroy(void)
  {
  	sysfs_remove_file(hypervisor_kobj, &uuid_attr.attr);
  }
  
  /* xen compilation attributes */
  
  static ssize_t compiler_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	struct xen_compile_info *info;
  
  	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
  	if (info) {
  		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", info->compiler);
  		kfree(info);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(compiler);
  
  static ssize_t compiled_by_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	struct xen_compile_info *info;
  
  	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
  	if (info) {
  		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", info->compile_by);
  		kfree(info);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(compiled_by);
  
  static ssize_t compile_date_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	struct xen_compile_info *info;
  
  	info = kmalloc(sizeof(struct xen_compile_info), GFP_KERNEL);
  	if (info) {
  		ret = HYPERVISOR_xen_version(XENVER_compile_info, info);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", info->compile_date);
  		kfree(info);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(compile_date);
  
  static struct attribute *xen_compile_attrs[] = {
  	&compiler_attr.attr,
  	&compiled_by_attr.attr,
  	&compile_date_attr.attr,
  	NULL
  };

  static const struct attribute_group xen_compilation_group = {

  	.name = "compilation",
  	.attrs = xen_compile_attrs,
  };

  static int __init xen_compilation_init(void)

  {
  	return sysfs_create_group(hypervisor_kobj, &xen_compilation_group);
  }
  
  static void xen_compilation_destroy(void)
  {
  	sysfs_remove_group(hypervisor_kobj, &xen_compilation_group);
  }
  
  /* xen properties info */
  
  static ssize_t capabilities_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	char *caps;
  
  	caps = kmalloc(XEN_CAPABILITIES_INFO_LEN, GFP_KERNEL);
  	if (caps) {
  		ret = HYPERVISOR_xen_version(XENVER_capabilities, caps);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", caps);
  		kfree(caps);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(capabilities);
  
  static ssize_t changeset_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	char *cset;
  
  	cset = kmalloc(XEN_CHANGESET_INFO_LEN, GFP_KERNEL);
  	if (cset) {
  		ret = HYPERVISOR_xen_version(XENVER_changeset, cset);
  		if (!ret)
  			ret = sprintf(buffer, "%s
  ", cset);
  		kfree(cset);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(changeset);
  
  static ssize_t virtual_start_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret = -ENOMEM;
  	struct xen_platform_parameters *parms;
  
  	parms = kmalloc(sizeof(struct xen_platform_parameters), GFP_KERNEL);
  	if (parms) {
  		ret = HYPERVISOR_xen_version(XENVER_platform_parameters,
  					     parms);
  		if (!ret)

  			ret = sprintf(buffer, "%"PRI_xen_ulong"
  ",
  				      parms->virt_start);

  		kfree(parms);
  	}
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(virtual_start);
  
  static ssize_t pagesize_show(struct hyp_sysfs_attr *attr, char *buffer)
  {
  	int ret;
  
  	ret = HYPERVISOR_xen_version(XENVER_pagesize, NULL);
  	if (ret > 0)
  		ret = sprintf(buffer, "%x
  ", ret);
  
  	return ret;
  }
  
  HYPERVISOR_ATTR_RO(pagesize);

  static ssize_t xen_feature_show(int index, char *buffer)
  {

  	ssize_t ret;
  	struct xen_feature_info info;

  	info.submap_idx = index;
  	ret = HYPERVISOR_xen_version(XENVER_get_features, &info);
  	if (!ret)
  		ret = sprintf(buffer, "%08x", info.submap);

  
  	return ret;
  }

  static ssize_t features_show(struct hyp_sysfs_attr *attr, char *buffer)

  {

  	ssize_t len;
  	int i;
  
  	len = 0;
  	for (i = XENFEAT_NR_SUBMAPS-1; i >= 0; i--) {
  		int ret = xen_feature_show(i, buffer + len);
  		if (ret < 0) {
  			if (len == 0)
  				len = ret;
  			break;
  		}
  		len += ret;
  	}
  	if (len > 0)
  		buffer[len++] = '
  ';
  
  	return len;

  }

  HYPERVISOR_ATTR_RO(features);

  
  static struct attribute *xen_properties_attrs[] = {
  	&capabilities_attr.attr,
  	&changeset_attr.attr,
  	&virtual_start_attr.attr,
  	&pagesize_attr.attr,

  	&features_attr.attr,

  	NULL
  };

  static const struct attribute_group xen_properties_group = {

  	.name = "properties",
  	.attrs = xen_properties_attrs,
  };
  
  static int __init xen_properties_init(void)
  {
  	return sysfs_create_group(hypervisor_kobj, &xen_properties_group);
  }
  
  static void xen_properties_destroy(void)
  {
  	sysfs_remove_group(hypervisor_kobj, &xen_properties_group);
  }

  static int __init hyper_sysfs_init(void)
  {
  	int ret;
  
  	if (!xen_domain())
  		return -ENODEV;
  
  	ret = xen_sysfs_type_init();
  	if (ret)
  		goto out;
  	ret = xen_sysfs_version_init();
  	if (ret)
  		goto version_out;
  	ret = xen_compilation_init();
  	if (ret)
  		goto comp_out;
  	ret = xen_sysfs_uuid_init();
  	if (ret)
  		goto uuid_out;
  	ret = xen_properties_init();
  	if (ret)
  		goto prop_out;

  
  	goto out;

  prop_out:
  	xen_sysfs_uuid_destroy();
  uuid_out:
  	xen_compilation_destroy();
  comp_out:
  	xen_sysfs_version_destroy();
  version_out:
  	xen_sysfs_type_destroy();
  out:
  	return ret;
  }
  
  static void __exit hyper_sysfs_exit(void)
  {

  	xen_properties_destroy();
  	xen_compilation_destroy();
  	xen_sysfs_uuid_destroy();
  	xen_sysfs_version_destroy();
  	xen_sysfs_type_destroy();
  
  }
  module_init(hyper_sysfs_init);
  module_exit(hyper_sysfs_exit);
  
  static ssize_t hyp_sysfs_show(struct kobject *kobj,
  			      struct attribute *attr,
  			      char *buffer)
  {
  	struct hyp_sysfs_attr *hyp_attr;
  	hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
  	if (hyp_attr->show)
  		return hyp_attr->show(hyp_attr, buffer);
  	return 0;
  }
  
  static ssize_t hyp_sysfs_store(struct kobject *kobj,
  			       struct attribute *attr,
  			       const char *buffer,
  			       size_t len)
  {
  	struct hyp_sysfs_attr *hyp_attr;
  	hyp_attr = container_of(attr, struct hyp_sysfs_attr, attr);
  	if (hyp_attr->store)
  		return hyp_attr->store(hyp_attr, buffer, len);
  	return 0;
  }

  static const struct sysfs_ops hyp_sysfs_ops = {

  	.show = hyp_sysfs_show,
  	.store = hyp_sysfs_store,
  };
  
  static struct kobj_type hyp_sysfs_kobj_type = {
  	.sysfs_ops = &hyp_sysfs_ops,
  };
  
  static int __init hypervisor_subsys_init(void)
  {
  	if (!xen_domain())
  		return -ENODEV;
  
  	hypervisor_kobj->ktype = &hyp_sysfs_kobj_type;
  	return 0;
  }
  device_initcall(hypervisor_subsys_init);