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	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