text: /*
   *  acpi_numa.c - ACPI NUMA support
   *
   *  Copyright (C) 2002 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   */
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/acpi.h>
  #include <linux/numa.h>
  #include <linux/nodemask.h>
  #include <linux/topology.h>
  
  #define PREFIX "ACPI: "
  
  #define ACPI_NUMA	0x80000000
  #define _COMPONENT	ACPI_NUMA
  ACPI_MODULE_NAME("numa");
  
  static nodemask_t nodes_found_map = NODE_MASK_NONE;
  
  /* maps to convert between proximity domain and logical node ID */
  static int pxm_to_node_map[MAX_PXM_DOMAINS]
  			= { [0 ... MAX_PXM_DOMAINS - 1] = NUMA_NO_NODE };
  static int node_to_pxm_map[MAX_NUMNODES]
  			= { [0 ... MAX_NUMNODES - 1] = PXM_INVAL };
  
  unsigned char acpi_srat_revision __initdata;
  
  int pxm_to_node(int pxm)
  {
  	if (pxm < 0)
  		return NUMA_NO_NODE;
  	return pxm_to_node_map[pxm];
  }
  
  int node_to_pxm(int node)
  {
  	if (node < 0)
  		return PXM_INVAL;
  	return node_to_pxm_map[node];
  }
  
  static void __acpi_map_pxm_to_node(int pxm, int node)
  {
  	if (pxm_to_node_map[pxm] == NUMA_NO_NODE || node < pxm_to_node_map[pxm])
  		pxm_to_node_map[pxm] = node;
  	if (node_to_pxm_map[node] == PXM_INVAL || pxm < node_to_pxm_map[node])
  		node_to_pxm_map[node] = pxm;
  }
  
  int acpi_map_pxm_to_node(int pxm)
  {
  	int node;
  
  	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS)
  		return NUMA_NO_NODE;
  
  	node = pxm_to_node_map[pxm];
  
  	if (node == NUMA_NO_NODE) {
  		if (nodes_weight(nodes_found_map) >= MAX_NUMNODES)
  			return NUMA_NO_NODE;
  		node = first_unset_node(nodes_found_map);
  		__acpi_map_pxm_to_node(pxm, node);
  		node_set(node, nodes_found_map);
  	}
  
  	return node;
  }
  
  /**
   * acpi_map_pxm_to_online_node - Map proximity ID to online node
   * @pxm: ACPI proximity ID
   *
   * This is similar to acpi_map_pxm_to_node(), but always returns an online
   * node.  When the mapped node from a given proximity ID is offline, it
   * looks up the node distance table and returns the nearest online node.
   *
   * ACPI device drivers, which are called after the NUMA initialization has
   * completed in the kernel, can call this interface to obtain their device
   * NUMA topology from ACPI tables.  Such drivers do not have to deal with
   * offline nodes.  A node may be offline when a device proximity ID is
   * unique, SRAT memory entry does not exist, or NUMA is disabled, ex.
   * "numa=off" on x86.
   */
  int acpi_map_pxm_to_online_node(int pxm)
  {
  	int node, n, dist, min_dist;
  
  	node = acpi_map_pxm_to_node(pxm);
  
  	if (node == NUMA_NO_NODE)
  		node = 0;
  
  	if (!node_online(node)) {
  		min_dist = INT_MAX;
  		for_each_online_node(n) {
  			dist = node_distance(node, n);
  			if (dist < min_dist) {
  				min_dist = dist;
  				node = n;
  			}
  		}
  	}
  
  	return node;
  }
  EXPORT_SYMBOL(acpi_map_pxm_to_online_node);
  
  static void __init
  acpi_table_print_srat_entry(struct acpi_subtable_header *header)
  {
  
  	ACPI_FUNCTION_NAME("acpi_table_print_srat_entry");
  
  	if (!header)
  		return;
  
  	switch (header->type) {
  
  	case ACPI_SRAT_TYPE_CPU_AFFINITY:
  #ifdef ACPI_DEBUG_OUTPUT
  		{
  			struct acpi_srat_cpu_affinity *p =
  			    (struct acpi_srat_cpu_affinity *)header;
  			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  					  "SRAT Processor (id[0x%02x] eid[0x%02x]) in proximity domain %d %s\n",
  					  p->apic_id, p->local_sapic_eid,
  					  p->proximity_domain_lo,
  					  (p->flags & ACPI_SRAT_CPU_ENABLED)?
  					  "enabled" : "disabled"));
  		}
  #endif				/* ACPI_DEBUG_OUTPUT */
  		break;
  
  	case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
  #ifdef ACPI_DEBUG_OUTPUT
  		{
  			struct acpi_srat_mem_affinity *p =
  			    (struct acpi_srat_mem_affinity *)header;
  			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  					  "SRAT Memory (0x%lx length 0x%lx) in proximity domain %d %s%s%s\n",
  					  (unsigned long)p->base_address,
  					  (unsigned long)p->length,
  					  p->proximity_domain,
  					  (p->flags & ACPI_SRAT_MEM_ENABLED)?
  					  "enabled" : "disabled",
  					  (p->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE)?
  					  " hot-pluggable" : "",
  					  (p->flags & ACPI_SRAT_MEM_NON_VOLATILE)?
  					  " non-volatile" : ""));
  		}
  #endif				/* ACPI_DEBUG_OUTPUT */
  		break;
  
  	case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
  #ifdef ACPI_DEBUG_OUTPUT
  		{
  			struct acpi_srat_x2apic_cpu_affinity *p =
  			    (struct acpi_srat_x2apic_cpu_affinity *)header;
  			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  					  "SRAT Processor (x2apicid[0x%08x]) in"
  					  " proximity domain %d %s\n",
  					  p->apic_id,
  					  p->proximity_domain,
  					  (p->flags & ACPI_SRAT_CPU_ENABLED) ?
  					  "enabled" : "disabled"));
  		}
  #endif				/* ACPI_DEBUG_OUTPUT */
  		break;
  	default:
  		printk(KERN_WARNING PREFIX
  		       "Found unsupported SRAT entry (type = 0x%x)\n",
  		       header->type);
  		break;
  	}
  }
  
  /*
   * A lot of BIOS fill in 10 (= no distance) everywhere. This messes
   * up the NUMA heuristics which wants the local node to have a smaller
   * distance than the others.
   * Do some quick checks here and only use the SLIT if it passes.
   */
  static int __init slit_valid(struct acpi_table_slit *slit)
  {
  	int i, j;
  	int d = slit->locality_count;
  	for (i = 0; i < d; i++) {
  		for (j = 0; j < d; j++)  {
  			u8 val = slit->entry[d*i + j];
  			if (i == j) {
  				if (val != LOCAL_DISTANCE)
  					return 0;
  			} else if (val <= LOCAL_DISTANCE)
  				return 0;
  		}
  	}
  	return 1;
  }
  
  static int __init acpi_parse_slit(struct acpi_table_header *table)
  {
  	struct acpi_table_slit *slit = (struct acpi_table_slit *)table;
  
  	if (!slit_valid(slit)) {
  		printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
  		return -EINVAL;
  	}
  	acpi_numa_slit_init(slit);
  
  	return 0;
  }
  
  void __init __weak
  acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
  {
  	printk(KERN_WARNING PREFIX
  	       "Found unsupported x2apic [0x%08x] SRAT entry\n", pa->apic_id);
  	return;
  }
  
  
  static int __init
  acpi_parse_x2apic_affinity(struct acpi_subtable_header *header,
  			   const unsigned long end)
  {
  	struct acpi_srat_x2apic_cpu_affinity *processor_affinity;
  
  	processor_affinity = (struct acpi_srat_x2apic_cpu_affinity *)header;
  	if (!processor_affinity)
  		return -EINVAL;
  
  	acpi_table_print_srat_entry(header);
  
  	/* let architecture-dependent part to do it */
  	acpi_numa_x2apic_affinity_init(processor_affinity);
  
  	return 0;
  }
  
  static int __init
  acpi_parse_processor_affinity(struct acpi_subtable_header *header,
  			      const unsigned long end)
  {
  	struct acpi_srat_cpu_affinity *processor_affinity;
  
  	processor_affinity = (struct acpi_srat_cpu_affinity *)header;
  	if (!processor_affinity)
  		return -EINVAL;
  
  	acpi_table_print_srat_entry(header);
  
  	/* let architecture-dependent part to do it */
  	acpi_numa_processor_affinity_init(processor_affinity);
  
  	return 0;
  }
  
  static int __initdata parsed_numa_memblks;
  
  static int __init
  acpi_parse_memory_affinity(struct acpi_subtable_header * header,
  			   const unsigned long end)
  {
  	struct acpi_srat_mem_affinity *memory_affinity;
  
  	memory_affinity = (struct acpi_srat_mem_affinity *)header;
  	if (!memory_affinity)
  		return -EINVAL;
  
  	acpi_table_print_srat_entry(header);
  
  	/* let architecture-dependent part to do it */
  	if (!acpi_numa_memory_affinity_init(memory_affinity))
  		parsed_numa_memblks++;
  	return 0;
  }
  
  static int __init acpi_parse_srat(struct acpi_table_header *table)
  {
  	struct acpi_table_srat *srat = (struct acpi_table_srat *)table;
  
  	acpi_srat_revision = srat->header.revision;
  
  	/* Real work done in acpi_table_parse_srat below. */
  
  	return 0;
  }
  
  static int __init
  acpi_table_parse_srat(enum acpi_srat_type id,
  		      acpi_tbl_entry_handler handler, unsigned int max_entries)
  {
  	return acpi_table_parse_entries(ACPI_SIG_SRAT,
  					    sizeof(struct acpi_table_srat), id,
  					    handler, max_entries);
  }
  
  int __init acpi_numa_init(void)
  {
  	int cnt = 0;
  
  	/*
  	 * Should not limit number with cpu num that is from NR_CPUS or nr_cpus=
  	 * SRAT cpu entries could have different order with that in MADT.
  	 * So go over all cpu entries in SRAT to get apicid to node mapping.
  	 */
  
  	/* SRAT: Static Resource Affinity Table */
  	if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
  		struct acpi_subtable_proc srat_proc[2];
  
  		memset(srat_proc, 0, sizeof(srat_proc));
  		srat_proc[0].id = ACPI_SRAT_TYPE_CPU_AFFINITY;
  		srat_proc[0].handler = acpi_parse_processor_affinity;
  		srat_proc[1].id = ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY;
  		srat_proc[1].handler = acpi_parse_x2apic_affinity;
  
  		acpi_table_parse_entries_array(ACPI_SIG_SRAT,
  					sizeof(struct acpi_table_srat),
  					srat_proc, ARRAY_SIZE(srat_proc), 0);
  
  		cnt = acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
  					    acpi_parse_memory_affinity,
  					    NR_NODE_MEMBLKS);
  	}
  
  	/* SLIT: System Locality Information Table */
  	acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);
  
  	acpi_numa_arch_fixup();
  
  	if (cnt < 0)
  		return cnt;
  	else if (!parsed_numa_memblks)
  		return -ENOENT;
  	return 0;
  }
  
  static int acpi_get_pxm(acpi_handle h)
  {
  	unsigned long long pxm;
  	acpi_status status;
  	acpi_handle handle;
  	acpi_handle phandle = h;
  
  	do {
  		handle = phandle;
  		status = acpi_evaluate_integer(handle, "_PXM", NULL, &pxm);
  		if (ACPI_SUCCESS(status))
  			return pxm;
  		status = acpi_get_parent(handle, &phandle);
  	} while (ACPI_SUCCESS(status));
  	return -1;
  }
  
  int acpi_get_node(acpi_handle handle)
  {
  	int pxm;
  
  	pxm = acpi_get_pxm(handle);
  
  	return acpi_map_pxm_to_node(pxm);
  }
  EXPORT_SYMBOL(acpi_get_node);
  