drivers/acpi/numa.c - linux - Git at Google

 /*
  *  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.
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  */

 #define pr_fmt(fmt) "ACPI: " fmt

 #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/bootmem.h>
 #include <linux/memblock.h>
 #include <linux/numa.h>
 #include <linux/nodemask.h>
 #include <linux/topology.h>

 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 acpi_numa __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 || numa_off)
 		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, min_node;

 	node = acpi_map_pxm_to_node(pxm);

 	if (node == NUMA_NO_NODE)
 		node = 0;

 	min_node = node;
 	if (!node_online(node)) {
 		int min_dist = INT_MAX, dist, n;

 		for_each_online_node(n) {
 			dist = node_distance(node, n);
 			if (dist < min_dist) {
 				min_dist = dist;
 				min_node = n;
 			}
 		}
 	}

 	return min_node;
 }
 EXPORT_SYMBOL(acpi_map_pxm_to_online_node);

 static void __init
 acpi_table_print_srat_entry(struct acpi_subtable_header *header)
 {
 	switch (header->type) {
 	case ACPI_SRAT_TYPE_CPU_AFFINITY:
 		{
 			struct acpi_srat_cpu_affinity *p =
 			    (struct acpi_srat_cpu_affinity *)header;
 			pr_debug("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");
 		}
 		break;

 	case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
 		{
 			struct acpi_srat_mem_affinity *p =
 			    (struct acpi_srat_mem_affinity *)header;
 			pr_debug("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" : "");
 		}
 		break;

 	case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
 		{
 			struct acpi_srat_x2apic_cpu_affinity *p =
 			    (struct acpi_srat_x2apic_cpu_affinity *)header;
 			pr_debug("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");
 		}
 		break;

 	case ACPI_SRAT_TYPE_GICC_AFFINITY:
 		{
 			struct acpi_srat_gicc_affinity *p =
 			    (struct acpi_srat_gicc_affinity *)header;
 			pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
 				 p->acpi_processor_uid,
 				 p->proximity_domain,
 				 (p->flags & ACPI_SRAT_GICC_ENABLED) ?
 				 "enabled" : "disabled");
 		}
 		break;

 	default:
 		pr_warn("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;
 }

 void __init bad_srat(void)
 {
 	pr_err("SRAT: SRAT not used.\n");
 	acpi_numa = -1;
 }

 int __init srat_disabled(void)
 {
 	return acpi_numa < 0;
 }

 #if defined(CONFIG_X86) || defined(CONFIG_ARM64)
 /*
  * Callback for SLIT parsing.  pxm_to_node() returns NUMA_NO_NODE for
  * I/O localities since SRAT does not list them.  I/O localities are
  * not supported at this point.
  */
 void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
 {
 	int i, j;

 	for (i = 0; i < slit->locality_count; i++) {
 		const int from_node = pxm_to_node(i);

 		if (from_node == NUMA_NO_NODE)
 			continue;

 		for (j = 0; j < slit->locality_count; j++) {
 			const int to_node = pxm_to_node(j);

 			if (to_node == NUMA_NO_NODE)
 				continue;

 			numa_set_distance(from_node, to_node,
 				slit->entry[slit->locality_count * i + j]);
 		}
 	}
 }

 /*
  * Default callback for parsing of the Proximity Domain <-> Memory
  * Area mappings
  */
 int __init
 acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
 {
 	u64 start, end;
 	u32 hotpluggable;
 	int node, pxm;

 	if (srat_disabled())
 		goto out_err;
 	if (ma->header.length < sizeof(struct acpi_srat_mem_affinity)) {
 		pr_err("SRAT: Unexpected header length: %d\n",
 		       ma->header.length);
 		goto out_err_bad_srat;
 	}
 	if ((ma->flags & ACPI_SRAT_MEM_ENABLED) == 0)
 		goto out_err;
 	hotpluggable = ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE;
 	if (hotpluggable && !IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
 		goto out_err;

 	start = ma->base_address;
 	end = start + ma->length;
 	pxm = ma->proximity_domain;
 	if (acpi_srat_revision <= 1)
 		pxm &= 0xff;

 	node = acpi_map_pxm_to_node(pxm);
 	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
 		pr_err("SRAT: Too many proximity domains.\n");
 		goto out_err_bad_srat;
 	}

 	if (numa_add_memblk(node, start, end) < 0) {
 		pr_err("SRAT: Failed to add memblk to node %u [mem %#010Lx-%#010Lx]\n",
 		       node, (unsigned long long) start,
 		       (unsigned long long) end - 1);
 		goto out_err_bad_srat;
 	}

 	node_set(node, numa_nodes_parsed);

 	pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
 		node, pxm,
 		(unsigned long long) start, (unsigned long long) end - 1,
 		hotpluggable ? " hotplug" : "",
 		ma->flags & ACPI_SRAT_MEM_NON_VOLATILE ? " non-volatile" : "");

 	/* Mark hotplug range in memblock. */
 	if (hotpluggable && memblock_mark_hotplug(start, ma->length))
 		pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
 			(unsigned long long)start, (unsigned long long)end - 1);

 	max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));

 	return 0;
 out_err_bad_srat:
 	bad_srat();
 out_err:
 	return -EINVAL;
 }
 #endif /* defined(CONFIG_X86) || defined (CONFIG_ARM64) */

 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)) {
 		pr_info("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)
 {
 	pr_warn("Found unsupported x2apic [0x%08x] SRAT entry\n", pa->apic_id);
 }

 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 __init
 acpi_parse_gicc_affinity(struct acpi_subtable_header *header,
 			 const unsigned long end)
 {
 	struct acpi_srat_gicc_affinity *processor_affinity;

 	processor_affinity = (struct acpi_srat_gicc_affinity *)header;
 	if (!processor_affinity)
 		return -EINVAL;

 	acpi_table_print_srat_entry(header);

 	/* let architecture-dependent part to do it */
 	acpi_numa_gicc_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;

 	if (acpi_disabled)
 		return -EINVAL;

 	/*
 	 * 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: System Resource Affinity Table */
 	if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
 		struct acpi_subtable_proc srat_proc[3];

 		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;
 		srat_proc[2].id = ACPI_SRAT_TYPE_GICC_AFFINITY;
 		srat_proc[2].handler = acpi_parse_gicc_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, 0);
 	}

 	/* SLIT: System Locality Information Table */
 	acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);

 	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);
	/*
	* 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.
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*
	*/

	#define pr_fmt(fmt) "ACPI: " fmt

	#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/bootmem.h>
	#include <linux/memblock.h>
	#include <linux/numa.h>
	#include <linux/nodemask.h>
	#include <linux/topology.h>

	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 acpi_numa __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 \|\| numa_off)
	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, min_node;

	node = acpi_map_pxm_to_node(pxm);

	if (node == NUMA_NO_NODE)
	node = 0;

	min_node = node;
	if (!node_online(node)) {
	int min_dist = INT_MAX, dist, n;

	for_each_online_node(n) {
	dist = node_distance(node, n);
	if (dist < min_dist) {
	min_dist = dist;
	min_node = n;
	}
	}
	}

	return min_node;
	}
	EXPORT_SYMBOL(acpi_map_pxm_to_online_node);

	static void __init
	acpi_table_print_srat_entry(struct acpi_subtable_header *header)
	{
	switch (header->type) {
	case ACPI_SRAT_TYPE_CPU_AFFINITY:
	{
	struct acpi_srat_cpu_affinity *p =
	(struct acpi_srat_cpu_affinity *)header;
	pr_debug("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");
	}
	break;

	case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
	{
	struct acpi_srat_mem_affinity *p =
	(struct acpi_srat_mem_affinity *)header;
	pr_debug("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" : "");
	}
	break;

	case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
	{
	struct acpi_srat_x2apic_cpu_affinity *p =
	(struct acpi_srat_x2apic_cpu_affinity *)header;
	pr_debug("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");
	}
	break;

	case ACPI_SRAT_TYPE_GICC_AFFINITY:
	{
	struct acpi_srat_gicc_affinity *p =
	(struct acpi_srat_gicc_affinity *)header;
	pr_debug("SRAT Processor (acpi id[0x%04x]) in proximity domain %d %s\n",
	p->acpi_processor_uid,
	p->proximity_domain,
	(p->flags & ACPI_SRAT_GICC_ENABLED) ?
	"enabled" : "disabled");
	}
	break;

	default:
	pr_warn("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;
	}

	void __init bad_srat(void)
	{
	pr_err("SRAT: SRAT not used.\n");
	acpi_numa = -1;
	}

	int __init srat_disabled(void)
	{
	return acpi_numa < 0;
	}

	#if defined(CONFIG_X86) \|\| defined(CONFIG_ARM64)
	/*
	* Callback for SLIT parsing. pxm_to_node() returns NUMA_NO_NODE for
	* I/O localities since SRAT does not list them. I/O localities are
	* not supported at this point.
	*/
	void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
	{
	int i, j;

	for (i = 0; i < slit->locality_count; i++) {
	const int from_node = pxm_to_node(i);

	if (from_node == NUMA_NO_NODE)
	continue;

	for (j = 0; j < slit->locality_count; j++) {
	const int to_node = pxm_to_node(j);

	if (to_node == NUMA_NO_NODE)
	continue;

	numa_set_distance(from_node, to_node,
	slit->entry[slit->locality_count * i + j]);
	}
	}
	}

	/*
	* Default callback for parsing of the Proximity Domain <-> Memory
	* Area mappings
	*/
	int __init
	acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
	{
	u64 start, end;
	u32 hotpluggable;
	int node, pxm;

	if (srat_disabled())
	goto out_err;
	if (ma->header.length < sizeof(struct acpi_srat_mem_affinity)) {
	pr_err("SRAT: Unexpected header length: %d\n",
	ma->header.length);
	goto out_err_bad_srat;
	}
	if ((ma->flags & ACPI_SRAT_MEM_ENABLED) == 0)
	goto out_err;
	hotpluggable = ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE;
	if (hotpluggable && !IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
	goto out_err;

	start = ma->base_address;
	end = start + ma->length;
	pxm = ma->proximity_domain;
	if (acpi_srat_revision <= 1)
	pxm &= 0xff;

	node = acpi_map_pxm_to_node(pxm);
	if (node == NUMA_NO_NODE \|\| node >= MAX_NUMNODES) {
	pr_err("SRAT: Too many proximity domains.\n");
	goto out_err_bad_srat;
	}

	if (numa_add_memblk(node, start, end) < 0) {
	pr_err("SRAT: Failed to add memblk to node %u [mem %#010Lx-%#010Lx]\n",
	node, (unsigned long long) start,
	(unsigned long long) end - 1);
	goto out_err_bad_srat;
	}

	node_set(node, numa_nodes_parsed);

	pr_info("SRAT: Node %u PXM %u [mem %#010Lx-%#010Lx]%s%s\n",
	node, pxm,
	(unsigned long long) start, (unsigned long long) end - 1,
	hotpluggable ? " hotplug" : "",
	ma->flags & ACPI_SRAT_MEM_NON_VOLATILE ? " non-volatile" : "");

	/* Mark hotplug range in memblock. */
	if (hotpluggable && memblock_mark_hotplug(start, ma->length))
	pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n",
	(unsigned long long)start, (unsigned long long)end - 1);

	max_possible_pfn = max(max_possible_pfn, PFN_UP(end - 1));

	return 0;
	out_err_bad_srat:
	bad_srat();
	out_err:
	return -EINVAL;
	}
	#endif /* defined(CONFIG_X86) \|\| defined (CONFIG_ARM64) */

	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)) {
	pr_info("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)
	{
	pr_warn("Found unsupported x2apic [0x%08x] SRAT entry\n", pa->apic_id);
	}

	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 __init
	acpi_parse_gicc_affinity(struct acpi_subtable_header *header,
	const unsigned long end)
	{
	struct acpi_srat_gicc_affinity *processor_affinity;

	processor_affinity = (struct acpi_srat_gicc_affinity *)header;
	if (!processor_affinity)
	return -EINVAL;

	acpi_table_print_srat_entry(header);

	/* let architecture-dependent part to do it */
	acpi_numa_gicc_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;

	if (acpi_disabled)
	return -EINVAL;

	/*
	* 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: System Resource Affinity Table */
	if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
	struct acpi_subtable_proc srat_proc[3];

	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;
	srat_proc[2].id = ACPI_SRAT_TYPE_GICC_AFFINITY;
	srat_proc[2].handler = acpi_parse_gicc_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, 0);
	}

	/* SLIT: System Locality Information Table */
	acpi_table_parse(ACPI_SIG_SLIT, acpi_parse_slit);

	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);