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/module.h>
13#include <linux/nodemask.h>
14#include <linux/memblock.h>
15#include <linux/bootmem.h>
16
17#include <asm/io.h>
18#include <linux/pci_ids.h>
19#include <linux/acpi.h>
20#include <asm/types.h>
21#include <asm/mmzone.h>
22#include <asm/proto.h>
23#include <asm/e820.h>
24#include <asm/pci-direct.h>
25#include <asm/numa.h>
26#include <asm/mpspec.h>
27#include <asm/apic.h>
28#include <asm/amd_nb.h>
29
30static unsigned char __initdata nodeids[8];
31
32static __init int find_northbridge(void)
33{
34	int num;
35
36	for (num = 0; num < 32; num++) {
37		u32 header;
38
39		header = read_pci_config(0, num, 0, 0x00);
40		if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
41			header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
42			header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
43			continue;
44
45		header = read_pci_config(0, num, 1, 0x00);
46		if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
47			header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
48			header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
49			continue;
50		return num;
51	}
52
53	return -ENOENT;
54}
55
56static __init void early_get_boot_cpu_id(void)
57{
58	/*
59	 * need to get the APIC ID of the BSP so can use that to
60	 * create apicid_to_node in amd_scan_nodes()
61	 */
62#ifdef CONFIG_X86_MPPARSE
63	/*
64	 * get boot-time SMP configuration:
65	 */
66	if (smp_found_config)
67		early_get_smp_config();
68#endif
69}
70
71int __init amd_numa_init(void)
72{
73	u64 start = PFN_PHYS(0);
74	u64 end = PFN_PHYS(max_pfn);
75	unsigned numnodes;
76	u64 prevbase;
77	int i, j, nb;
78	u32 nodeid, reg;
79	unsigned int bits, cores, apicid_base;
80
81	if (!early_pci_allowed())
82		return -EINVAL;
83
84	nb = find_northbridge();
85	if (nb < 0)
86		return nb;
87
88	pr_info("Scanning NUMA topology in Northbridge %d\n", nb);
89
90	reg = read_pci_config(0, nb, 0, 0x60);
91	numnodes = ((reg >> 4) & 0xF) + 1;
92	if (numnodes <= 1)
93		return -ENOENT;
94
95	pr_info("Number of physical nodes %d\n", numnodes);
96
97	prevbase = 0;
98	for (i = 0; i < 8; i++) {
99		u64 base, limit;
100
101		base = read_pci_config(0, nb, 1, 0x40 + i*8);
102		limit = read_pci_config(0, nb, 1, 0x44 + i*8);
103
104		nodeids[i] = nodeid = limit & 7;
105		if ((base & 3) == 0) {
106			if (i < numnodes)
107				pr_info("Skipping disabled node %d\n", i);
108			continue;
109		}
110		if (nodeid >= numnodes) {
111			pr_info("Ignoring excess node %d (%Lx:%Lx)\n", nodeid,
112				base, limit);
113			continue;
114		}
115
116		if (!limit) {
117			pr_info("Skipping node entry %d (base %Lx)\n",
118				i, base);
119			continue;
120		}
121		if ((base >> 8) & 3 || (limit >> 8) & 3) {
122			pr_err("Node %d using interleaving mode %Lx/%Lx\n",
123			       nodeid, (base >> 8) & 3, (limit >> 8) & 3);
124			return -EINVAL;
125		}
126		if (node_isset(nodeid, numa_nodes_parsed)) {
127			pr_info("Node %d already present, skipping\n",
128				nodeid);
129			continue;
130		}
131
132		limit >>= 16;
133		limit++;
134		limit <<= 24;
135
136		if (limit > end)
137			limit = end;
138		if (limit <= base)
139			continue;
140
141		base >>= 16;
142		base <<= 24;
143
144		if (base < start)
145			base = start;
146		if (limit > end)
147			limit = end;
148		if (limit == base) {
149			pr_err("Empty node %d\n", nodeid);
150			continue;
151		}
152		if (limit < base) {
153			pr_err("Node %d bogus settings %Lx-%Lx.\n",
154			       nodeid, base, limit);
155			continue;
156		}
157
158		/* Could sort here, but pun for now. Should not happen anyroads. */
159		if (prevbase > base) {
160			pr_err("Node map not sorted %Lx,%Lx\n",
161			       prevbase, base);
162			return -EINVAL;
163		}
164
165		pr_info("Node %d MemBase %016Lx Limit %016Lx\n",
166			nodeid, base, limit);
167
168		prevbase = base;
169		numa_add_memblk(nodeid, base, limit);
170		node_set(nodeid, numa_nodes_parsed);
171	}
172
173	if (!nodes_weight(numa_nodes_parsed))
174		return -ENOENT;
175
176	/*
177	 * We seem to have valid NUMA configuration.  Map apicids to nodes
178	 * using the coreid bits from early_identify_cpu.
179	 */
180	bits = boot_cpu_data.x86_coreid_bits;
181	cores = 1 << bits;
182	apicid_base = 0;
183
184	/* get the APIC ID of the BSP early for systems with apicid lifting */
185	early_get_boot_cpu_id();
186	if (boot_cpu_physical_apicid > 0) {
187		pr_info("BSP APIC ID: %02x\n", boot_cpu_physical_apicid);
188		apicid_base = boot_cpu_physical_apicid;
189	}
190
191	for_each_node_mask(i, numa_nodes_parsed)
192		for (j = apicid_base; j < cores + apicid_base; j++)
193			set_apicid_to_node((i << bits) + j, i);
194
195	return 0;
196}
197