xref: /linux/arch/x86/mm/amdtopology.c (revision 30e48a75df9c6ead93866bdf1511ca6ecfe17fbe)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AMD NUMA support.
4  * Discover the memory map and associated nodes.
5  *
6  * This version reads it directly from the AMD northbridge.
7  *
8  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
9  */
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/string.h>
13 #include <linux/nodemask.h>
14 #include <linux/memblock.h>
15 
16 #include <asm/io.h>
17 #include <linux/pci_ids.h>
18 #include <linux/acpi.h>
19 #include <asm/types.h>
20 #include <asm/mmzone.h>
21 #include <asm/proto.h>
22 #include <asm/e820/api.h>
23 #include <asm/pci-direct.h>
24 #include <asm/numa.h>
25 #include <asm/mpspec.h>
26 #include <asm/apic.h>
27 #include <asm/amd_nb.h>
28 
29 static unsigned char __initdata nodeids[8];
30 
31 static __init int find_northbridge(void)
32 {
33 	int num;
34 
35 	for (num = 0; num < 32; num++) {
36 		u32 header;
37 
38 		header = read_pci_config(0, num, 0, 0x00);
39 		if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
40 			header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
41 			header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
42 			continue;
43 
44 		header = read_pci_config(0, num, 1, 0x00);
45 		if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
46 			header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
47 			header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
48 			continue;
49 		return num;
50 	}
51 
52 	return -ENOENT;
53 }
54 
55 int __init amd_numa_init(void)
56 {
57 	unsigned int numnodes, cores, apicid;
58 	u64 prevbase, start = PFN_PHYS(0);
59 	u64 end = PFN_PHYS(max_pfn);
60 	u32 nodeid, reg;
61 	int i, j, nb;
62 
63 	if (!early_pci_allowed())
64 		return -EINVAL;
65 
66 	nb = find_northbridge();
67 	if (nb < 0)
68 		return nb;
69 
70 	pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
71 
72 	reg = read_pci_config(0, nb, 0, 0x60);
73 	numnodes = ((reg >> 4) & 0xF) + 1;
74 	if (numnodes <= 1)
75 		return -ENOENT;
76 
77 	pr_info("Number of physical nodes %d\n", numnodes);
78 
79 	prevbase = 0;
80 	for (i = 0; i < 8; i++) {
81 		u64 base, limit;
82 
83 		base = read_pci_config(0, nb, 1, 0x40 + i*8);
84 		limit = read_pci_config(0, nb, 1, 0x44 + i*8);
85 
86 		nodeids[i] = nodeid = limit & 7;
87 		if ((base & 3) == 0) {
88 			if (i < numnodes)
89 				pr_info("Skipping disabled node %d\n", i);
90 			continue;
91 		}
92 		if (nodeid >= numnodes) {
93 			pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
94 				base, limit);
95 			continue;
96 		}
97 
98 		if (!limit) {
99 			pr_info("Skipping node entry %d (base %Lx)\n",
100 				i, base);
101 			continue;
102 		}
103 		if ((base >> 8) & 3 || (limit >> 8) & 3) {
104 			pr_err("Node %d using interleaving mode %Lx/%Lx\n",
105 			       nodeid, (base >> 8) & 3, (limit >> 8) & 3);
106 			return -EINVAL;
107 		}
108 		if (node_isset(nodeid, numa_nodes_parsed)) {
109 			pr_info("Node %d already present, skipping\n",
110 				nodeid);
111 			continue;
112 		}
113 
114 		limit >>= 16;
115 		limit++;
116 		limit <<= 24;
117 
118 		if (limit > end)
119 			limit = end;
120 		if (limit <= base)
121 			continue;
122 
123 		base >>= 16;
124 		base <<= 24;
125 
126 		if (base < start)
127 			base = start;
128 		if (limit > end)
129 			limit = end;
130 		if (limit == base) {
131 			pr_err("Empty node %d\n", nodeid);
132 			continue;
133 		}
134 		if (limit < base) {
135 			pr_err("Node %d bogus settings %Lx-%Lx.\n",
136 			       nodeid, base, limit);
137 			continue;
138 		}
139 
140 		/* Could sort here, but pun for now. Should not happen anyroads. */
141 		if (prevbase > base) {
142 			pr_err("Node map not sorted %Lx,%Lx\n",
143 			       prevbase, base);
144 			return -EINVAL;
145 		}
146 
147 		pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
148 			nodeid, base, limit);
149 
150 		prevbase = base;
151 		numa_add_memblk(nodeid, base, limit);
152 		node_set(nodeid, numa_nodes_parsed);
153 	}
154 
155 	if (nodes_empty(numa_nodes_parsed))
156 		return -ENOENT;
157 
158 	/*
159 	 * We seem to have valid NUMA configuration. Map apicids to nodes
160 	 * using the size of the core domain in the APIC space.
161 	 */
162 	cores = topology_get_domain_size(TOPO_CORE_DOMAIN);
163 
164 	apicid = boot_cpu_physical_apicid;
165 	if (apicid > 0)
166 		pr_info("BSP APIC ID: %02x\n", apicid);
167 
168 	for_each_node_mask(i, numa_nodes_parsed) {
169 		for (j = 0; j < cores; j++, apicid++)
170 			set_apicid_to_node(apicid, i);
171 	}
172 	return 0;
173 }
174