xref: /openbmc/linux/arch/arm64/kernel/acpi_numa.c (revision 8730046c)
1 /*
2  * ACPI 5.1 based NUMA setup for ARM64
3  * Lots of code was borrowed from arch/x86/mm/srat.c
4  *
5  * Copyright 2004 Andi Kleen, SuSE Labs.
6  * Copyright (C) 2013-2016, Linaro Ltd.
7  *		Author: Hanjun Guo <hanjun.guo@linaro.org>
8  *
9  * Reads the ACPI SRAT table to figure out what memory belongs to which CPUs.
10  *
11  * Called from acpi_numa_init while reading the SRAT and SLIT tables.
12  * Assumes all memory regions belonging to a single proximity domain
13  * are in one chunk. Holes between them will be included in the node.
14  */
15 
16 #define pr_fmt(fmt) "ACPI: NUMA: " fmt
17 
18 #include <linux/acpi.h>
19 #include <linux/bitmap.h>
20 #include <linux/bootmem.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 <acpi/processor.h>
29 #include <asm/numa.h>
30 
31 static int cpus_in_srat;
32 
33 struct __node_cpu_hwid {
34 	u32 node_id;    /* logical node containing this CPU */
35 	u64 cpu_hwid;   /* MPIDR for this CPU */
36 };
37 
38 static struct __node_cpu_hwid early_node_cpu_hwid[NR_CPUS] = {
39 [0 ... NR_CPUS - 1] = {NUMA_NO_NODE, PHYS_CPUID_INVALID} };
40 
41 int acpi_numa_get_nid(unsigned int cpu, u64 hwid)
42 {
43 	int i;
44 
45 	for (i = 0; i < cpus_in_srat; i++) {
46 		if (hwid == early_node_cpu_hwid[i].cpu_hwid)
47 			return early_node_cpu_hwid[i].node_id;
48 	}
49 
50 	return NUMA_NO_NODE;
51 }
52 
53 /* Callback for Proximity Domain -> ACPI processor UID mapping */
54 void __init acpi_numa_gicc_affinity_init(struct acpi_srat_gicc_affinity *pa)
55 {
56 	int pxm, node;
57 	phys_cpuid_t mpidr;
58 
59 	if (srat_disabled())
60 		return;
61 
62 	if (pa->header.length < sizeof(struct acpi_srat_gicc_affinity)) {
63 		pr_err("SRAT: Invalid SRAT header length: %d\n",
64 			pa->header.length);
65 		bad_srat();
66 		return;
67 	}
68 
69 	if (!(pa->flags & ACPI_SRAT_GICC_ENABLED))
70 		return;
71 
72 	if (cpus_in_srat >= NR_CPUS) {
73 		pr_warn_once("SRAT: cpu_to_node_map[%d] is too small, may not be able to use all cpus\n",
74 			     NR_CPUS);
75 		return;
76 	}
77 
78 	pxm = pa->proximity_domain;
79 	node = acpi_map_pxm_to_node(pxm);
80 
81 	if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
82 		pr_err("SRAT: Too many proximity domains %d\n", pxm);
83 		bad_srat();
84 		return;
85 	}
86 
87 	mpidr = acpi_map_madt_entry(pa->acpi_processor_uid);
88 	if (mpidr == PHYS_CPUID_INVALID) {
89 		pr_err("SRAT: PXM %d with ACPI ID %d has no valid MPIDR in MADT\n",
90 			pxm, pa->acpi_processor_uid);
91 		bad_srat();
92 		return;
93 	}
94 
95 	early_node_cpu_hwid[cpus_in_srat].node_id = node;
96 	early_node_cpu_hwid[cpus_in_srat].cpu_hwid =  mpidr;
97 	node_set(node, numa_nodes_parsed);
98 	cpus_in_srat++;
99 	pr_info("SRAT: PXM %d -> MPIDR 0x%Lx -> Node %d\n",
100 		pxm, mpidr, node);
101 }
102 
103 int __init arm64_acpi_numa_init(void)
104 {
105 	int ret;
106 
107 	ret = acpi_numa_init();
108 	if (ret) {
109 		pr_info("Failed to initialise from firmware\n");
110 		return ret;
111 	}
112 
113 	return srat_disabled() ? -EINVAL : 0;
114 }
115