xref: /openbmc/linux/arch/arm64/kernel/acpi_numa.c (revision 2e7c04aec86758e0adfcad4a24c86593b45807a3) 
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/bootmem.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 = { NUMA_NO_NODE };
32 
33 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_gicc_pxm(struct acpi_subtable_header *header,
50 				      const unsigned long end)
51 {
52 	struct acpi_srat_gicc_affinity *pa;
53 	int cpu, pxm, node;
54 
55 	if (srat_disabled())
56 		return -EINVAL;
57 
58 	pa = (struct acpi_srat_gicc_affinity *)header;
59 	if (!pa)
60 		return -EINVAL;
61 
62 	if (!(pa->flags & ACPI_SRAT_GICC_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 -> MPIDR 0x%llx -> Node %d\n", pxm,
80 		cpu_logical_map(cpu), node);
81 
82 	return 0;
83 }
84 
85 void __init acpi_map_cpus_to_nodes(void)
86 {
87 	acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat),
88 					    ACPI_SRAT_TYPE_GICC_AFFINITY,
89 					    acpi_parse_gicc_pxm, 0);
90 }
91 
92 /* Callback for Proximity Domain -> ACPI processor UID mapping */
93 void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa)
94 {
95 	int pxm, node;
96 
97 	if (srat_disabled())
98 		return;
99 
100 	if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
101 		pr_err("SRAT: Invalid SRAT header length: %d\n",
102 			pa->header.length);
103 		bad_srat();
104 		return;
105 	}
106 
107 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
108 		return;
109 
110 	pxm = pa->proximity_domain;
111 	node = acpi_map_pxm_to_node(pxm);
112 
113 	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
114 		pr_err("SRAT: Too many proximity domains %d\n", pxm);
115 		bad_srat();
116 		return;
117 	}
118 
119 	node_set(node, numa_nodes_parsed);
120 }
121 
122 int __init arm64_acpi_numa_init(void)
123 {
124 	int ret;
125 
126 	ret = acpi_numa_init();
127 	if (ret) {
128 		pr_info("Failed to initialise from firmware\n");
129 		return ret;
130 	}
131 
132 	return srat_disabled() ? -EINVAL : 0;
133 }
134