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
find_northbridge(void)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
amd_numa_init(void)55 int __init amd_numa_init(void)
56 {
57 u64 start = PFN_PHYS(0);
58 u64 end = PFN_PHYS(max_pfn);
59 unsigned numnodes;
60 u64 prevbase;
61 int i, j, nb;
62 u32 nodeid, reg;
63 unsigned int bits, cores, apicid_base;
64
65 if (!early_pci_allowed())
66 return -EINVAL;
67
68 nb = find_northbridge();
69 if (nb < 0)
70 return nb;
71
72 pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
73
74 reg = read_pci_config(0, nb, 0, 0x60);
75 numnodes = ((reg >> 4) & 0xF) + 1;
76 if (numnodes <= 1)
77 return -ENOENT;
78
79 pr_info("Number of physical nodes %d\n", numnodes);
80
81 prevbase = 0;
82 for (i = 0; i < 8; i++) {
83 u64 base, limit;
84
85 base = read_pci_config(0, nb, 1, 0x40 + i*8);
86 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
87
88 nodeids[i] = nodeid = limit & 7;
89 if ((base & 3) == 0) {
90 if (i < numnodes)
91 pr_info("Skipping disabled node %d\n", i);
92 continue;
93 }
94 if (nodeid >= numnodes) {
95 pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
96 base, limit);
97 continue;
98 }
99
100 if (!limit) {
101 pr_info("Skipping node entry %d (base %Lx)\n",
102 i, base);
103 continue;
104 }
105 if ((base >> 8) & 3 || (limit >> 8) & 3) {
106 pr_err("Node %d using interleaving mode %Lx/%Lx\n",
107 nodeid, (base >> 8) & 3, (limit >> 8) & 3);
108 return -EINVAL;
109 }
110 if (node_isset(nodeid, numa_nodes_parsed)) {
111 pr_info("Node %d already present, skipping\n",
112 nodeid);
113 continue;
114 }
115
116 limit >>= 16;
117 limit++;
118 limit <<= 24;
119
120 if (limit > end)
121 limit = end;
122 if (limit <= base)
123 continue;
124
125 base >>= 16;
126 base <<= 24;
127
128 if (base < start)
129 base = start;
130 if (limit > end)
131 limit = end;
132 if (limit == base) {
133 pr_err("Empty node %d\n", nodeid);
134 continue;
135 }
136 if (limit < base) {
137 pr_err("Node %d bogus settings %Lx-%Lx.\n",
138 nodeid, base, limit);
139 continue;
140 }
141
142 /* Could sort here, but pun for now. Should not happen anyroads. */
143 if (prevbase > base) {
144 pr_err("Node map not sorted %Lx,%Lx\n",
145 prevbase, base);
146 return -EINVAL;
147 }
148
149 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
150 nodeid, base, limit);
151
152 prevbase = base;
153 numa_add_memblk(nodeid, base, limit);
154 node_set(nodeid, numa_nodes_parsed);
155 }
156
157 if (!nodes_weight(numa_nodes_parsed))
158 return -ENOENT;
159
160 /*
161 * We seem to have valid NUMA configuration. Map apicids to nodes
162 * using the coreid bits from early_identify_cpu.
163 */
164 bits = boot_cpu_data.x86_coreid_bits;
165 cores = 1 << bits;
166 apicid_base = 0;
167
168 /*
169 * get boot-time SMP configuration:
170 */
171 early_get_smp_config();
172
173 if (boot_cpu_physical_apicid > 0) {
174 pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
175 apicid_base = boot_cpu_physical_apicid;
176 }
177
178 for_each_node_mask(i, numa_nodes_parsed)
179 for (j = apicid_base; j < cores + apicid_base; j++)
180 set_apicid_to_node((i << bits) + j, i);
181
182 return 0;
183 }
184
