xref: /kernel/linux/linux-6.6/arch/x86/mm/amdtopology.c (revision 62306a36)
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
29static unsigned char __initdata nodeids[8];
30
31static __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
55int __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