xref: /openbmc/linux/arch/x86/mm/amdtopology.c (revision 2a598d0b)
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 	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_empty(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