xref: /linux/arch/riscv/kernel/acpi_numa.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0) 
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 
31 static int acpi_early_node_map[NR_CPUS] __initdata = { [0 ... NR_CPUS - 1] = NUMA_NO_NODE };
32 
33 static int __init acpi_numa_get_nid(unsigned int cpu)
34 {
35 	return acpi_early_node_map[cpu];
36 }
37 
38 static 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 
49 static 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 
85 void __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 */
105 void __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 }
132