text: // SPDX-License-Identifier: GPL-2.0
  /*
   * pptt.c - parsing of Processor Properties Topology Table (PPTT)
   *
   * Copyright (C) 2018, ARM
   *
   * This file implements parsing of the Processor Properties Topology Table
   * which is optionally used to describe the processor and cache topology.
   * Due to the relative pointers used throughout the table, this doesn't
   * leverage the existing subtable parsing in the kernel.
   *
   * The PPTT structure is an inverted tree, with each node potentially
   * holding one or two inverted tree data structures describing
   * the caches available at that level. Each cache structure optionally
   * contains properties describing the cache at a given level which can be
   * used to override hardware probed values.
   */
  #define pr_fmt(fmt) "ACPI PPTT: " fmt
  
  #include <linux/acpi.h>
  #include <linux/cacheinfo.h>
  #include <acpi/processor.h>
  
  static struct acpi_subtable_header *fetch_pptt_subtable(struct acpi_table_header *table_hdr,
  							u32 pptt_ref)
  {
  	struct acpi_subtable_header *entry;
  
  	/* there isn't a subtable at reference 0 */
  	if (pptt_ref < sizeof(struct acpi_subtable_header))
  		return NULL;
  
  	if (pptt_ref + sizeof(struct acpi_subtable_header) > table_hdr->length)
  		return NULL;
  
  	entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, pptt_ref);
  
  	if (entry->length == 0)
  		return NULL;
  
  	if (pptt_ref + entry->length > table_hdr->length)
  		return NULL;
  
  	return entry;
  }
  
  static struct acpi_pptt_processor *fetch_pptt_node(struct acpi_table_header *table_hdr,
  						   u32 pptt_ref)
  {
  	return (struct acpi_pptt_processor *)fetch_pptt_subtable(table_hdr, pptt_ref);
  }
  
  static struct acpi_pptt_cache *fetch_pptt_cache(struct acpi_table_header *table_hdr,
  						u32 pptt_ref)
  {
  	return (struct acpi_pptt_cache *)fetch_pptt_subtable(table_hdr, pptt_ref);
  }
  
  static struct acpi_subtable_header *acpi_get_pptt_resource(struct acpi_table_header *table_hdr,
  							   struct acpi_pptt_processor *node,
  							   int resource)
  {
  	u32 *ref;
  
  	if (resource >= node->number_of_priv_resources)
  		return NULL;
  
  	ref = ACPI_ADD_PTR(u32, node, sizeof(struct acpi_pptt_processor));
  	ref += resource;
  
  	return fetch_pptt_subtable(table_hdr, *ref);
  }
  
  static inline bool acpi_pptt_match_type(int table_type, int type)
  {
  	return ((table_type & ACPI_PPTT_MASK_CACHE_TYPE) == type ||
  		table_type & ACPI_PPTT_CACHE_TYPE_UNIFIED & type);
  }
  
  /**
   * acpi_pptt_walk_cache() - Attempt to find the requested acpi_pptt_cache
   * @table_hdr: Pointer to the head of the PPTT table
   * @local_level: passed res reflects this cache level
   * @res: cache resource in the PPTT we want to walk
   * @found: returns a pointer to the requested level if found
   * @level: the requested cache level
   * @type: the requested cache type
   *
   * Attempt to find a given cache level, while counting the max number
   * of cache levels for the cache node.
   *
   * Given a pptt resource, verify that it is a cache node, then walk
   * down each level of caches, counting how many levels are found
   * as well as checking the cache type (icache, dcache, unified). If a
   * level & type match, then we set found, and continue the search.
   * Once the entire cache branch has been walked return its max
   * depth.
   *
   * Return: The cache structure and the level we terminated with.
   */
  static int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
  				int local_level,
  				struct acpi_subtable_header *res,
  				struct acpi_pptt_cache **found,
  				int level, int type)
  {
  	struct acpi_pptt_cache *cache;
  
  	if (res->type != ACPI_PPTT_TYPE_CACHE)
  		return 0;
  
  	cache = (struct acpi_pptt_cache *) res;
  	while (cache) {
  		local_level++;
  
  		if (local_level == level &&
  		    cache->flags & ACPI_PPTT_CACHE_TYPE_VALID &&
  		    acpi_pptt_match_type(cache->attributes, type)) {
  			if (*found != NULL && cache != *found)
  				pr_warn("Found duplicate cache level/type unable to determine uniqueness\n");
  
  			pr_debug("Found cache @ level %d\n", level);
  			*found = cache;
  			/*
  			 * continue looking at this node's resource list
  			 * to verify that we don't find a duplicate
  			 * cache node.
  			 */
  		}
  		cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);
  	}
  	return local_level;
  }
  
  static struct acpi_pptt_cache *acpi_find_cache_level(struct acpi_table_header *table_hdr,
  						     struct acpi_pptt_processor *cpu_node,
  						     int *starting_level, int level,
  						     int type)
  {
  	struct acpi_subtable_header *res;
  	int number_of_levels = *starting_level;
  	int resource = 0;
  	struct acpi_pptt_cache *ret = NULL;
  	int local_level;
  
  	/* walk down from processor node */
  	while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, resource))) {
  		resource++;
  
  		local_level = acpi_pptt_walk_cache(table_hdr, *starting_level,
  						   res, &ret, level, type);
  		/*
  		 * we are looking for the max depth. Since its potentially
  		 * possible for a given node to have resources with differing
  		 * depths verify that the depth we have found is the largest.
  		 */
  		if (number_of_levels < local_level)
  			number_of_levels = local_level;
  	}
  	if (number_of_levels > *starting_level)
  		*starting_level = number_of_levels;
  
  	return ret;
  }
  
  /**
   * acpi_count_levels() - Given a PPTT table, and a cpu node, count the caches
   * @table_hdr: Pointer to the head of the PPTT table
   * @cpu_node: processor node we wish to count caches for
   *
   * Given a processor node containing a processing unit, walk into it and count
   * how many levels exist solely for it, and then walk up each level until we hit
   * the root node (ignore the package level because it may be possible to have
   * caches that exist across packages). Count the number of cache levels that
   * exist at each level on the way up.
   *
   * Return: Total number of levels found.
   */
  static int acpi_count_levels(struct acpi_table_header *table_hdr,
  			     struct acpi_pptt_processor *cpu_node)
  {
  	int total_levels = 0;
  
  	do {
  		acpi_find_cache_level(table_hdr, cpu_node, &total_levels, 0, 0);
  		cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
  	} while (cpu_node);
  
  	return total_levels;
  }
  
  /**
   * acpi_pptt_leaf_node() - Given a processor node, determine if its a leaf
   * @table_hdr: Pointer to the head of the PPTT table
   * @node: passed node is checked to see if its a leaf
   *
   * Determine if the *node parameter is a leaf node by iterating the
   * PPTT table, looking for nodes which reference it.
   *
   * Return: 0 if we find a node referencing the passed node (or table error),
   * or 1 if we don't.
   */
  static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr,
  			       struct acpi_pptt_processor *node)
  {
  	struct acpi_subtable_header *entry;
  	unsigned long table_end;
  	u32 node_entry;
  	struct acpi_pptt_processor *cpu_node;
  	u32 proc_sz;
  
  	table_end = (unsigned long)table_hdr + table_hdr->length;
  	node_entry = ACPI_PTR_DIFF(node, table_hdr);
  	entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
  			     sizeof(struct acpi_table_pptt));
  	proc_sz = sizeof(struct acpi_pptt_processor *);
  
  	while ((unsigned long)entry + proc_sz < table_end) {
  		cpu_node = (struct acpi_pptt_processor *)entry;
  		if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
  		    cpu_node->parent == node_entry)
  			return 0;
  		if (entry->length == 0)
  			return 0;
  		entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
  				     entry->length);
  
  	}
  	return 1;
  }
  
  /**
   * acpi_find_processor_node() - Given a PPTT table find the requested processor
   * @table_hdr:  Pointer to the head of the PPTT table
   * @acpi_cpu_id: cpu we are searching for
   *
   * Find the subtable entry describing the provided processor.
   * This is done by iterating the PPTT table looking for processor nodes
   * which have an acpi_processor_id that matches the acpi_cpu_id parameter
   * passed into the function. If we find a node that matches this criteria
   * we verify that its a leaf node in the topology rather than depending
   * on the valid flag, which doesn't need to be set for leaf nodes.
   *
   * Return: NULL, or the processors acpi_pptt_processor*
   */
  static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr,
  							    u32 acpi_cpu_id)
  {
  	struct acpi_subtable_header *entry;
  	unsigned long table_end;
  	struct acpi_pptt_processor *cpu_node;
  	u32 proc_sz;
  
  	table_end = (unsigned long)table_hdr + table_hdr->length;
  	entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
  			     sizeof(struct acpi_table_pptt));
  	proc_sz = sizeof(struct acpi_pptt_processor *);
  
  	/* find the processor structure associated with this cpuid */
  	while ((unsigned long)entry + proc_sz < table_end) {
  		cpu_node = (struct acpi_pptt_processor *)entry;
  
  		if (entry->length == 0) {
  			pr_warn("Invalid zero length subtable\n");
  			break;
  		}
  		if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
  		    acpi_cpu_id == cpu_node->acpi_processor_id &&
  		     acpi_pptt_leaf_node(table_hdr, cpu_node)) {
  			return (struct acpi_pptt_processor *)entry;
  		}
  
  		entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
  				     entry->length);
  	}
  
  	return NULL;
  }
  
  static int acpi_find_cache_levels(struct acpi_table_header *table_hdr,
  				  u32 acpi_cpu_id)
  {
  	int number_of_levels = 0;
  	struct acpi_pptt_processor *cpu;
  
  	cpu = acpi_find_processor_node(table_hdr, acpi_cpu_id);
  	if (cpu)
  		number_of_levels = acpi_count_levels(table_hdr, cpu);
  
  	return number_of_levels;
  }
  
  static u8 acpi_cache_type(enum cache_type type)
  {
  	switch (type) {
  	case CACHE_TYPE_DATA:
  		pr_debug("Looking for data cache\n");
  		return ACPI_PPTT_CACHE_TYPE_DATA;
  	case CACHE_TYPE_INST:
  		pr_debug("Looking for instruction cache\n");
  		return ACPI_PPTT_CACHE_TYPE_INSTR;
  	default:
  	case CACHE_TYPE_UNIFIED:
  		pr_debug("Looking for unified cache\n");
  		/*
  		 * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED
  		 * contains the bit pattern that will match both
  		 * ACPI unified bit patterns because we use it later
  		 * to match both cases.
  		 */
  		return ACPI_PPTT_CACHE_TYPE_UNIFIED;
  	}
  }
  
  static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr,
  						    u32 acpi_cpu_id,
  						    enum cache_type type,
  						    unsigned int level,
  						    struct acpi_pptt_processor **node)
  {
  	int total_levels = 0;
  	struct acpi_pptt_cache *found = NULL;
  	struct acpi_pptt_processor *cpu_node;
  	u8 acpi_type = acpi_cache_type(type);
  
  	pr_debug("Looking for CPU %d's level %d cache type %d\n",
  		 acpi_cpu_id, level, acpi_type);
  
  	cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id);
  
  	while (cpu_node && !found) {
  		found = acpi_find_cache_level(table_hdr, cpu_node,
  					      &total_levels, level, acpi_type);
  		*node = cpu_node;
  		cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
  	}
  
  	return found;
  }
  
  /* total number of attributes checked by the properties code */
  #define PPTT_CHECKED_ATTRIBUTES 4
  
  /**
   * update_cache_properties() - Update cacheinfo for the given processor
   * @this_leaf: Kernel cache info structure being updated
   * @found_cache: The PPTT node describing this cache instance
   * @cpu_node: A unique reference to describe this cache instance
   *
   * The ACPI spec implies that the fields in the cache structures are used to
   * extend and correct the information probed from the hardware. Lets only
   * set fields that we determine are VALID.
   *
   * Return: nothing. Side effect of updating the global cacheinfo
   */
  static void update_cache_properties(struct cacheinfo *this_leaf,
  				    struct acpi_pptt_cache *found_cache,
  				    struct acpi_pptt_processor *cpu_node)
  {
  	int valid_flags = 0;
  
  	this_leaf->fw_token = cpu_node;
  	if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) {
  		this_leaf->size = found_cache->size;
  		valid_flags++;
  	}
  	if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID) {
  		this_leaf->coherency_line_size = found_cache->line_size;
  		valid_flags++;
  	}
  	if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID) {
  		this_leaf->number_of_sets = found_cache->number_of_sets;
  		valid_flags++;
  	}
  	if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID) {
  		this_leaf->ways_of_associativity = found_cache->associativity;
  		valid_flags++;
  	}
  	if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) {
  		switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) {
  		case ACPI_PPTT_CACHE_POLICY_WT:
  			this_leaf->attributes = CACHE_WRITE_THROUGH;
  			break;
  		case ACPI_PPTT_CACHE_POLICY_WB:
  			this_leaf->attributes = CACHE_WRITE_BACK;
  			break;
  		}
  	}
  	if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) {
  		switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) {
  		case ACPI_PPTT_CACHE_READ_ALLOCATE:
  			this_leaf->attributes |= CACHE_READ_ALLOCATE;
  			break;
  		case ACPI_PPTT_CACHE_WRITE_ALLOCATE:
  			this_leaf->attributes |= CACHE_WRITE_ALLOCATE;
  			break;
  		case ACPI_PPTT_CACHE_RW_ALLOCATE:
  		case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT:
  			this_leaf->attributes |=
  				CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE;
  			break;
  		}
  	}
  	/*
  	 * If the above flags are valid, and the cache type is NOCACHE
  	 * update the cache type as well.
  	 */
  	if (this_leaf->type == CACHE_TYPE_NOCACHE &&
  	    valid_flags == PPTT_CHECKED_ATTRIBUTES)
  		this_leaf->type = CACHE_TYPE_UNIFIED;
  }
  
  static void cache_setup_acpi_cpu(struct acpi_table_header *table,
  				 unsigned int cpu)
  {
  	struct acpi_pptt_cache *found_cache;
  	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
  	u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
  	struct cacheinfo *this_leaf;
  	unsigned int index = 0;
  	struct acpi_pptt_processor *cpu_node = NULL;
  
  	while (index < get_cpu_cacheinfo(cpu)->num_leaves) {
  		this_leaf = this_cpu_ci->info_list + index;
  		found_cache = acpi_find_cache_node(table, acpi_cpu_id,
  						   this_leaf->type,
  						   this_leaf->level,
  						   &cpu_node);
  		pr_debug("found = %p %p\n", found_cache, cpu_node);
  		if (found_cache)
  			update_cache_properties(this_leaf,
  						found_cache,
  						cpu_node);
  
  		index++;
  	}
  }
  
  /* Passing level values greater than this will result in search termination */
  #define PPTT_ABORT_PACKAGE 0xFF
  
  static struct acpi_pptt_processor *acpi_find_processor_package_id(struct acpi_table_header *table_hdr,
  								  struct acpi_pptt_processor *cpu,
  								  int level, int flag)
  {
  	struct acpi_pptt_processor *prev_node;
  
  	while (cpu && level) {
  		if (cpu->flags & flag)
  			break;
  		pr_debug("level %d\n", level);
  		prev_node = fetch_pptt_node(table_hdr, cpu->parent);
  		if (prev_node == NULL)
  			break;
  		cpu = prev_node;
  		level--;
  	}
  	return cpu;
  }
  
  /**
   * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature
   * @table: Pointer to the head of the PPTT table
   * @cpu: Kernel logical cpu number
   * @level: A level that terminates the search
   * @flag: A flag which terminates the search
   *
   * Get a unique value given a cpu, and a topology level, that can be
   * matched to determine which cpus share common topological features
   * at that level.
   *
   * Return: Unique value, or -ENOENT if unable to locate cpu
   */
  static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,
  				     unsigned int cpu, int level, int flag)
  {
  	struct acpi_pptt_processor *cpu_node;
  	u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
  
  	cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
  	if (cpu_node) {
  		cpu_node = acpi_find_processor_package_id(table, cpu_node,
  							  level, flag);
  		/*
  		 * As per specification if the processor structure represents
  		 * an actual processor, then ACPI processor ID must be valid.
  		 * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID
  		 * should be set if the UID is valid
  		 */
  		if (level == 0 ||
  		    cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID)
  			return cpu_node->acpi_processor_id;
  		return ACPI_PTR_DIFF(cpu_node, table);
  	}
  	pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n",
  		    cpu, acpi_cpu_id);
  	return -ENOENT;
  }
  
  static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
  {
  	struct acpi_table_header *table;
  	acpi_status status;
  	int retval;
  
  	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
  	if (ACPI_FAILURE(status)) {
  		pr_warn_once("No PPTT table found, cpu topology may be inaccurate\n");
  		return -ENOENT;
  	}
  	retval = topology_get_acpi_cpu_tag(table, cpu, level, flag);
  	pr_debug("Topology Setup ACPI cpu %d, level %d ret = %d\n",
  		 cpu, level, retval);
  	acpi_put_table(table);
  
  	return retval;
  }
  
  /**
   * acpi_find_last_cache_level() - Determines the number of cache levels for a PE
   * @cpu: Kernel logical cpu number
   *
   * Given a logical cpu number, returns the number of levels of cache represented
   * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0
   * indicating we didn't find any cache levels.
   *
   * Return: Cache levels visible to this core.
   */
  int acpi_find_last_cache_level(unsigned int cpu)
  {
  	u32 acpi_cpu_id;
  	struct acpi_table_header *table;
  	int number_of_levels = 0;
  	acpi_status status;
  
  	pr_debug("Cache Setup find last level cpu=%d\n", cpu);
  
  	acpi_cpu_id = get_acpi_id_for_cpu(cpu);
  	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
  	if (ACPI_FAILURE(status)) {
  		pr_warn_once("No PPTT table found, cache topology may be inaccurate\n");
  	} else {
  		number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id);
  		acpi_put_table(table);
  	}
  	pr_debug("Cache Setup find last level level=%d\n", number_of_levels);
  
  	return number_of_levels;
  }
  
  /**
   * cache_setup_acpi() - Override CPU cache topology with data from the PPTT
   * @cpu: Kernel logical cpu number
   *
   * Updates the global cache info provided by cpu_get_cacheinfo()
   * when there are valid properties in the acpi_pptt_cache nodes. A
   * successful parse may not result in any updates if none of the
   * cache levels have any valid flags set.  Futher, a unique value is
   * associated with each known CPU cache entry. This unique value
   * can be used to determine whether caches are shared between cpus.
   *
   * Return: -ENOENT on failure to find table, or 0 on success
   */
  int cache_setup_acpi(unsigned int cpu)
  {
  	struct acpi_table_header *table;
  	acpi_status status;
  
  	pr_debug("Cache Setup ACPI cpu %d\n", cpu);
  
  	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
  	if (ACPI_FAILURE(status)) {
  		pr_warn_once("No PPTT table found, cache topology may be inaccurate\n");
  		return -ENOENT;
  	}
  
  	cache_setup_acpi_cpu(table, cpu);
  	acpi_put_table(table);
  
  	return status;
  }
  
  /**
   * find_acpi_cpu_topology() - Determine a unique topology value for a given cpu
   * @cpu: Kernel logical cpu number
   * @level: The topological level for which we would like a unique ID
   *
   * Determine a topology unique ID for each thread/core/cluster/mc_grouping
   * /socket/etc. This ID can then be used to group peers, which will have
   * matching ids.
   *
   * The search terminates when either the requested level is found or
   * we reach a root node. Levels beyond the termination point will return the
   * same unique ID. The unique id for level 0 is the acpi processor id. All
   * other levels beyond this use a generated value to uniquely identify
   * a topological feature.
   *
   * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
   * Otherwise returns a value which represents a unique topological feature.
   */
  int find_acpi_cpu_topology(unsigned int cpu, int level)
  {
  	return find_acpi_cpu_topology_tag(cpu, level, 0);
  }
  
  /**
   * find_acpi_cpu_cache_topology() - Determine a unique cache topology value
   * @cpu: Kernel logical cpu number
   * @level: The cache level for which we would like a unique ID
   *
   * Determine a unique ID for each unified cache in the system
   *
   * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
   * Otherwise returns a value which represents a unique topological feature.
   */
  int find_acpi_cpu_cache_topology(unsigned int cpu, int level)
  {
  	struct acpi_table_header *table;
  	struct acpi_pptt_cache *found_cache;
  	acpi_status status;
  	u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
  	struct acpi_pptt_processor *cpu_node = NULL;
  	int ret = -1;
  
  	status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
  	if (ACPI_FAILURE(status)) {
  		pr_warn_once("No PPTT table found, topology may be inaccurate\n");
  		return -ENOENT;
  	}
  
  	found_cache = acpi_find_cache_node(table, acpi_cpu_id,
  					   CACHE_TYPE_UNIFIED,
  					   level,
  					   &cpu_node);
  	if (found_cache)
  		ret = ACPI_PTR_DIFF(cpu_node, table);
  
  	acpi_put_table(table);
  
  	return ret;
  }
  
  
  /**
   * find_acpi_cpu_topology_package() - Determine a unique cpu package value
   * @cpu: Kernel logical cpu number
   *
   * Determine a topology unique package ID for the given cpu.
   * This ID can then be used to group peers, which will have matching ids.
   *
   * The search terminates when either a level is found with the PHYSICAL_PACKAGE
   * flag set or we reach a root node.
   *
   * Return: -ENOENT if the PPTT doesn't exist, or the cpu cannot be found.
   * Otherwise returns a value which represents the package for this cpu.
   */
  int find_acpi_cpu_topology_package(unsigned int cpu)
  {
  	return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
  					  ACPI_PPTT_PHYSICAL_PACKAGE);
  }
  