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
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