acpi_numa.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ACPI 6.6 based NUMA setup for RISCV
  4 * Lots of code was borrowed from arch/arm64/kernel/acpi_numa.c
  5 *
  6 * Copyright 2004 Andi Kleen, SuSE Labs.
  7 * Copyright (C) 2013-2016, Linaro Ltd.
  8 *		Author: Hanjun Guo <hanjun.guo@linaro.org>
  9 * Copyright (C) 2024 Intel Corporation.
 10 *
 11 * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
 12 *
 13 * Called from acpi_numa_init while reading the SRAT and SLIT tables.
 14 * Assumes all memory regions belonging to a single proximity domain
 15 * are in one chunk. Holes between them will be included in the node.
 16 */
 17
 18#define pr_fmt(fmt) "ACPI: NUMA: " fmt
 19
 20#include <linux/acpi.h>
 21#include <linux/bitmap.h>
 22#include <linux/kernel.h>
 23#include <linux/mm.h>
 24#include <linux/memblock.h>
 25#include <linux/mmzone.h>
 26#include <linux/module.h>
 27#include <linux/topology.h>
 28
 29#include <asm/numa.h>
 30
 31static int acpi_early_node_map[NR_CPUS] __initdata = { [0 ... NR_CPUS - 1] = NUMA_NO_NODE };
 32
 33static int __init acpi_numa_get_nid(unsigned int cpu)
 34{
 35	return acpi_early_node_map[cpu];
 36}
 37
 38static inline int get_cpu_for_acpi_id(u32 uid)
 39{
 40	int cpu;
 41
 42	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
 43		if (uid == get_acpi_id_for_cpu(cpu))
 44			return cpu;
 45
 46	return -EINVAL;
 47}
 48
 49static int __init acpi_parse_rintc_pxm(union acpi_subtable_headers *header,
 50				       const unsigned long end)
 51{
 52	struct acpi_srat_rintc_affinity *pa;
 53	int cpu, pxm, node;
 54
 55	if (srat_disabled())
 56		return -EINVAL;
 57
 58	pa = (struct acpi_srat_rintc_affinity *)header;
 59	if (!pa)
 60		return -EINVAL;
 61
 62	if (!(pa->flags & ACPI_SRAT_RINTC_ENABLED))
 63		return 0;
 64
 65	pxm = pa->proximity_domain;
 66	node = pxm_to_node(pxm);
 67
 68	/*
 69	 * If we can't map the UID to a logical cpu this
 70	 * means that the UID is not part of possible cpus
 71	 * so we do not need a NUMA mapping for it, skip
 72	 * the SRAT entry and keep parsing.
 73	 */
 74	cpu = get_cpu_for_acpi_id(pa->acpi_processor_uid);
 75	if (cpu < 0)
 76		return 0;
 77
 78	acpi_early_node_map[cpu] = node;
 79	pr_info("SRAT: PXM %d -> HARTID 0x%lx -> Node %d\n", pxm,
 80		cpuid_to_hartid_map(cpu), node);
 81
 82	return 0;
 83}
 84
 85void __init acpi_map_cpus_to_nodes(void)
 86{
 87	int i;
 88
 89	/*
 90	 * In ACPI, SMP and CPU NUMA information is provided in separate
 91	 * static tables, namely the MADT and the SRAT.
 92	 *
 93	 * Thus, it is simpler to first create the cpu logical map through
 94	 * an MADT walk and then map the logical cpus to their node ids
 95	 * as separate steps.
 96	 */
 97	acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat),
 98				 ACPI_SRAT_TYPE_RINTC_AFFINITY, acpi_parse_rintc_pxm, 0);
 99
100	for (i = 0; i < nr_cpu_ids; i++)
101		early_map_cpu_to_node(i, acpi_numa_get_nid(i));
102}
103
104/* Callback for Proximity Domain -> logical node ID mapping */
105void __init acpi_numa_rintc_affinity_init(struct acpi_srat_rintc_affinity *pa)
106{
107	int pxm, node;
108
109	if (srat_disabled())
110		return;
111
112	if (pa->header.length < sizeof(struct acpi_srat_rintc_affinity)) {
113		pr_err("SRAT: Invalid SRAT header length: %d\n", pa->header.length);
114		bad_srat();
115		return;
116	}
117
118	if (!(pa->flags & ACPI_SRAT_RINTC_ENABLED))
119		return;
120
121	pxm = pa->proximity_domain;
122	node = acpi_map_pxm_to_node(pxm);
123
124	if (node == NUMA_NO_NODE) {
125		pr_err("SRAT: Too many proximity domains %d\n", pxm);
126		bad_srat();
127		return;
128	}
129
130	node_set(node, numa_nodes_parsed);
131}