xref: /openbmc/linux/arch/x86/mm/amdtopology.c (revision bc5aa3a0)
1 /*
2  * AMD NUMA support.
3  * Discover the memory map and associated nodes.
4  *
5  * This version reads it directly from the AMD northbridge.
6  *
7  * Copyright 2002,2003 Andi Kleen, SuSE Labs.
8  */
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/string.h>
12 #include <linux/nodemask.h>
13 #include <linux/memblock.h>
14 #include <linux/bootmem.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.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 static __init void early_get_boot_cpu_id(void)
56 {
57 	/*
58 	 * need to get the APIC ID of the BSP so can use that to
59 	 * create apicid_to_node in amd_scan_nodes()
60 	 */
61 #ifdef CONFIG_X86_MPPARSE
62 	/*
63 	 * get boot-time SMP configuration:
64 	 */
65 	if (smp_found_config)
66 		early_get_smp_config();
67 #endif
68 }
69 
70 int __init amd_numa_init(void)
71 {
72 	u64 start = PFN_PHYS(0);
73 	u64 end = PFN_PHYS(max_pfn);
74 	unsigned numnodes;
75 	u64 prevbase;
76 	int i, j, nb;
77 	u32 nodeid, reg;
78 	unsigned int bits, cores, apicid_base;
79 
80 	if (!early_pci_allowed())
81 		return -EINVAL;
82 
83 	nb = find_northbridge();
84 	if (nb < 0)
85 		return nb;
86 
87 	pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
88 
89 	reg = read_pci_config(0, nb, 0, 0x60);
90 	numnodes = ((reg >> 4) & 0xF) + 1;
91 	if (numnodes <= 1)
92 		return -ENOENT;
93 
94 	pr_info("Number of physical nodes %d\n", numnodes);
95 
96 	prevbase = 0;
97 	for (i = 0; i < 8; i++) {
98 		u64 base, limit;
99 
100 		base = read_pci_config(0, nb, 1, 0x40 + i*8);
101 		limit = read_pci_config(0, nb, 1, 0x44 + i*8);
102 
103 		nodeids[i] = nodeid = limit & 7;
104 		if ((base & 3) == 0) {
105 			if (i < numnodes)
106 				pr_info("Skipping disabled node %d\n", i);
107 			continue;
108 		}
109 		if (nodeid >= numnodes) {
110 			pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
111 				base, limit);
112 			continue;
113 		}
114 
115 		if (!limit) {
116 			pr_info("Skipping node entry %d (base %Lx)\n",
117 				i, base);
118 			continue;
119 		}
120 		if ((base >> 8) & 3 || (limit >> 8) & 3) {
121 			pr_err("Node %d using interleaving mode %Lx/%Lx\n",
122 			       nodeid, (base >> 8) & 3, (limit >> 8) & 3);
123 			return -EINVAL;
124 		}
125 		if (node_isset(nodeid, numa_nodes_parsed)) {
126 			pr_info("Node %d already present, skipping\n",
127 				nodeid);
128 			continue;
129 		}
130 
131 		limit >>= 16;
132 		limit++;
133 		limit <<= 24;
134 
135 		if (limit > end)
136 			limit = end;
137 		if (limit <= base)
138 			continue;
139 
140 		base >>= 16;
141 		base <<= 24;
142 
143 		if (base < start)
144 			base = start;
145 		if (limit > end)
146 			limit = end;
147 		if (limit == base) {
148 			pr_err("Empty node %d\n", nodeid);
149 			continue;
150 		}
151 		if (limit < base) {
152 			pr_err("Node %d bogus settings %Lx-%Lx.\n",
153 			       nodeid, base, limit);
154 			continue;
155 		}
156 
157 		/* Could sort here, but pun for now. Should not happen anyroads. */
158 		if (prevbase > base) {
159 			pr_err("Node map not sorted %Lx,%Lx\n",
160 			       prevbase, base);
161 			return -EINVAL;
162 		}
163 
164 		pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
165 			nodeid, base, limit);
166 
167 		prevbase = base;
168 		numa_add_memblk(nodeid, base, limit);
169 		node_set(nodeid, numa_nodes_parsed);
170 	}
171 
172 	if (!nodes_weight(numa_nodes_parsed))
173 		return -ENOENT;
174 
175 	/*
176 	 * We seem to have valid NUMA configuration.  Map apicids to nodes
177 	 * using the coreid bits from early_identify_cpu.
178 	 */
179 	bits = boot_cpu_data.x86_coreid_bits;
180 	cores = 1 << bits;
181 	apicid_base = 0;
182 
183 	/* get the APIC ID of the BSP early for systems with apicid lifting */
184 	early_get_boot_cpu_id();
185 	if (boot_cpu_physical_apicid > 0) {
186 		pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
187 		apicid_base = boot_cpu_physical_apicid;
188 	}
189 
190 	for_each_node_mask(i, numa_nodes_parsed)
191 		for (j = apicid_base; j < cores + apicid_base; j++)
192 			set_apicid_to_node((i << bits) + j, i);
193 
194 	return 0;
195 }
196