1 // SPDX-License-Identifier: GPL-2.0
4 * Discover the memory map and associated nodes.
6 * This version reads it directly from the AMD northbridge.
8 * Copyright 2002,2003 Andi Kleen, SuSE Labs.
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>
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>
25 #include <asm/mpspec.h>
27 #include <asm/amd_nb.h>
29 static unsigned char __initdata nodeids[8];
31 static __init int find_northbridge(void)
35 for (num = 0; num < 32; num++) {
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)))
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)))
55 int __init amd_numa_init(void)
57 u64 start = PFN_PHYS(0);
58 u64 end = PFN_PHYS(max_pfn);
63 unsigned int bits, cores, apicid_base;
65 if (!early_pci_allowed())
68 nb = find_northbridge();
72 pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
74 reg = read_pci_config(0, nb, 0, 0x60);
75 numnodes = ((reg >> 4) & 0xF) + 1;
79 pr_info("Number of physical nodes %d\n", numnodes);
82 for (i = 0; i < 8; i++) {
85 base = read_pci_config(0, nb, 1, 0x40 + i*8);
86 limit = read_pci_config(0, nb, 1, 0x44 + i*8);
88 nodeids[i] = nodeid = limit & 7;
89 if ((base & 3) == 0) {
91 pr_info("Skipping disabled node %d\n", i);
94 if (nodeid >= numnodes) {
95 pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
101 pr_info("Skipping node entry %d (base %Lx)\n",
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);
110 if (node_isset(nodeid, numa_nodes_parsed)) {
111 pr_info("Node %d already present, skipping\n",
133 pr_err("Empty node %d\n", nodeid);
137 pr_err("Node %d bogus settings %Lx-%Lx.\n",
138 nodeid, base, limit);
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",
149 pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
150 nodeid, base, limit);
153 numa_add_memblk(nodeid, base, limit);
154 node_set(nodeid, numa_nodes_parsed);
157 if (!nodes_weight(numa_nodes_parsed))
161 * We seem to have valid NUMA configuration. Map apicids to nodes
162 * using the coreid bits from early_identify_cpu.
164 bits = boot_cpu_data.x86_coreid_bits;
169 * get boot-time SMP configuration:
171 early_get_smp_config();
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;
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);