xref: /openbmc/linux/arch/arm64/kernel/acpi_numa.c (revision 55fd7e02) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * ACPI 5.1 based NUMA setup for ARM64
4  * Lots of code was borrowed from arch/x86/mm/srat.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  *
10  * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
11  *
12  * Called from acpi_numa_init while reading the SRAT and SLIT tables.
13  * Assumes all memory regions belonging to a single proximity domain
14  * are in one chunk. Holes between them will be included in the node.
15  */
16 
17 #define pr_fmt(fmt) "ACPI: NUMA: " fmt
18 
19 #include <linux/acpi.h>
20 #include <linux/bitmap.h>
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/memblock.h>
24 #include <linux/mmzone.h>
25 #include <linux/module.h>
26 #include <linux/topology.h>
27 
28 #include <asm/numa.h>
29 
30 static int acpi_early_node_map[NR_CPUS] __initdata = { NUMA_NO_NODE };
31 
32 int __init acpi_numa_get_nid(unsigned int cpu)
33 {
34 	return acpi_early_node_map[cpu];
35 }
36 
37 static inline int get_cpu_for_acpi_id(u32 uid)
38 {
39 	int cpu;
40 
41 	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
42 		if (uid == get_acpi_id_for_cpu(cpu))
43 			return cpu;
44 
45 	return -EINVAL;
46 }
47 
48 static int __init acpi_parse_gicc_pxm(union acpi_subtable_headers *header,
49 				      const unsigned long end)
50 {
51 	struct acpi_srat_gicc_affinity *pa;
52 	int cpu, pxm, node;
53 
54 	if (srat_disabled())
55 		return -EINVAL;
56 
57 	pa = (struct acpi_srat_gicc_affinity *)header;
58 	if (!pa)
59 		return -EINVAL;
60 
61 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
62 		return 0;
63 
64 	pxm = pa->proximity_domain;
65 	node = pxm_to_node(pxm);
66 
67 	/*
68 	 * If we can't map the UID to a logical cpu this
69 	 * means that the UID is not part of possible cpus
70 	 * so we do not need a NUMA mapping for it, skip
71 	 * the SRAT entry and keep parsing.
72 	 */
73 	cpu = get_cpu_for_acpi_id(pa->acpi_processor_uid);
74 	if (cpu < 0)
75 		return 0;
76 
77 	acpi_early_node_map[cpu] = node;
78 	pr_info("SRAT: PXM %d -> MPIDR 0x%llx -> Node %d\n", pxm,
79 		cpu_logical_map(cpu), node);
80 
81 	return 0;
82 }
83 
84 void __init acpi_map_cpus_to_nodes(void)
85 {
86 	acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat),
87 					    ACPI_SRAT_TYPE_GICC_AFFINITY,
88 					    acpi_parse_gicc_pxm, 0);
89 }
90 
91 /* Callback for Proximity Domain -> ACPI processor UID mapping */
92 void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa)
93 {
94 	int pxm, node;
95 
96 	if (srat_disabled())
97 		return;
98 
99 	if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
100 		pr_err("SRAT: Invalid SRAT header length: %d\n",
101 			pa->header.length);
102 		bad_srat();
103 		return;
104 	}
105 
106 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
107 		return;
108 
109 	pxm = pa->proximity_domain;
110 	node = acpi_map_pxm_to_node(pxm);
111 
112 	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
113 		pr_err("SRAT: Too many proximity domains %d\n", pxm);
114 		bad_srat();
115 		return;
116 	}
117 
118 	node_set(node, numa_nodes_parsed);
119 }
120 
121 int __init arm64_acpi_numa_init(void)
122 {
123 	int ret;
124 
125 	ret = acpi_numa_init();
126 	if (ret) {
127 		pr_info("Failed to initialise from firmware\n");
128 		return ret;
129 	}
130 
131 	return srat_disabled() ? -EINVAL : 0;
132 }
133