xref: /openbmc/linux/arch/arm64/kernel/acpi_numa.c (revision 0e6774ec)
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 = { [0 ... NR_CPUS - 1] = 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 int __init acpi_parse_gicc_pxm(union acpi_subtable_headers *header,
38 				      const unsigned long end)
39 {
40 	struct acpi_srat_gicc_affinity *pa;
41 	int cpu, pxm, node;
42 
43 	if (srat_disabled())
44 		return -EINVAL;
45 
46 	pa = (struct acpi_srat_gicc_affinity *)header;
47 	if (!pa)
48 		return -EINVAL;
49 
50 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
51 		return 0;
52 
53 	pxm = pa->proximity_domain;
54 	node = pxm_to_node(pxm);
55 
56 	/*
57 	 * If we can't map the UID to a logical cpu this
58 	 * means that the UID is not part of possible cpus
59 	 * so we do not need a NUMA mapping for it, skip
60 	 * the SRAT entry and keep parsing.
61 	 */
62 	cpu = get_cpu_for_acpi_id(pa->acpi_processor_uid);
63 	if (cpu < 0)
64 		return 0;
65 
66 	acpi_early_node_map[cpu] = node;
67 	pr_info("SRAT: PXM %d -> MPIDR 0x%llx -> Node %d\n", pxm,
68 		cpu_logical_map(cpu), node);
69 
70 	return 0;
71 }
72 
73 void __init acpi_map_cpus_to_nodes(void)
74 {
75 	acpi_table_parse_entries(ACPI_SIG_SRAT, sizeof(struct acpi_table_srat),
76 					    ACPI_SRAT_TYPE_GICC_AFFINITY,
77 					    acpi_parse_gicc_pxm, 0);
78 }
79 
80 /* Callback for Proximity Domain -> ACPI processor UID mapping */
81 void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa)
82 {
83 	int pxm, node;
84 
85 	if (srat_disabled())
86 		return;
87 
88 	if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
89 		pr_err("SRAT: Invalid SRAT header length: %d\n",
90 			pa->header.length);
91 		bad_srat();
92 		return;
93 	}
94 
95 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
96 		return;
97 
98 	pxm = pa->proximity_domain;
99 	node = acpi_map_pxm_to_node(pxm);
100 
101 	if (node == NUMA_NO_NODE) {
102 		pr_err("SRAT: Too many proximity domains %d\n", pxm);
103 		bad_srat();
104 		return;
105 	}
106 
107 	node_set(node, numa_nodes_parsed);
108 }
109 
110