1/*
2 * AMD K8 NUMA support.
3 * Discover the memory map and associated nodes.
4 *
5 * This version reads it directly from the K8 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 <asm/io.h>
15#include <linux/pci_ids.h>
16#include <asm/types.h>
17#include <asm/mmzone.h>
18#include <asm/proto.h>
19#include <asm/e820.h>
20#include <asm/pci-direct.h>
21#include <asm/numa.h>
22
23static __init int find_northbridge(void)
24{
25	int num;
26
27	for (num = 0; num < 32; num++) {
28		u32 header;
29
30		header = read_pci_config(0, num, 0, 0x00);
31		if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)))
32			continue;
33
34		header = read_pci_config(0, num, 1, 0x00);
35		if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)))
36			continue;
37		return num;
38	}
39
40	return -1;
41}
42
43int __init k8_scan_nodes(unsigned long start, unsigned long end)
44{
45	unsigned long prevbase;
46	struct bootnode nodes[8];
47	int nodeid, i, nb;
48	unsigned char nodeids[8];
49	int found = 0;
50	u32 reg;
51	unsigned numnodes;
52	unsigned dualcore = 0;
53
54	if (!early_pci_allowed())
55		return -1;
56
57	nb = find_northbridge();
58	if (nb < 0)
59		return nb;
60
61	printk(KERN_INFO "Scanning NUMA topology in Northbridge %d\n", nb);
62
63	reg = read_pci_config(0, nb, 0, 0x60);
64	numnodes = ((reg >> 4) & 0xF) + 1;
65	if (numnodes <= 1)
66		return -1;
67
68	printk(KERN_INFO "Number of nodes %d\n", numnodes);
69
70	memset(&nodes,0,sizeof(nodes));
71	prevbase = 0;
72	for (i = 0; i < 8; i++) {
73		unsigned long base,limit;
74		u32 nodeid;
75
76		/* Undefined before E stepping, but hopefully 0 */
77		dualcore |= ((read_pci_config(0, nb, 3, 0xe8) >> 12) & 3) == 1;
78		base = read_pci_config(0, nb, 1, 0x40 + i*8);
79		limit = read_pci_config(0, nb, 1, 0x44 + i*8);
80
81		nodeid = limit & 7;
82		nodeids[i] = nodeid;
83		if ((base & 3) == 0) {
84			if (i < numnodes)
85				printk("Skipping disabled node %d\n", i);
86			continue;
87		}
88		if (nodeid >= numnodes) {
89			printk("Ignoring excess node %d (%lx:%lx)\n", nodeid,
90			       base, limit);
91			continue;
92		}
93
94		if (!limit) {
95			printk(KERN_INFO "Skipping node entry %d (base %lx)\n", i,
96			       base);
97			continue;
98		}
99		if ((base >> 8) & 3 || (limit >> 8) & 3) {
100			printk(KERN_ERR "Node %d using interleaving mode %lx/%lx\n",
101			       nodeid, (base>>8)&3, (limit>>8) & 3);
102			return -1;
103		}
104		if (node_isset(nodeid, node_possible_map)) {
105			printk(KERN_INFO "Node %d already present. Skipping\n",
106			       nodeid);
107			continue;
108		}
109
110		limit >>= 16;
111		limit <<= 24;
112		limit |= (1<<24)-1;
113		limit++;
114
115		if (limit > end_pfn << PAGE_SHIFT)
116			limit = end_pfn << PAGE_SHIFT;
117		if (limit <= base)
118			continue;
119
120		base >>= 16;
121		base <<= 24;
122
123		if (base < start)
124			base = start;
125		if (limit > end)
126			limit = end;
127		if (limit == base) {
128			printk(KERN_ERR "Empty node %d\n", nodeid);
129			continue;
130		}
131		if (limit < base) {
132			printk(KERN_ERR "Node %d bogus settings %lx-%lx.\n",
133			       nodeid, base, limit);
134			continue;
135		}
136
137		/* Could sort here, but pun for now. Should not happen anyroads. */
138		if (prevbase > base) {
139			printk(KERN_ERR "Node map not sorted %lx,%lx\n",
140			       prevbase,base);
141			return -1;
142		}
143
144		printk(KERN_INFO "Node %d MemBase %016lx Limit %016lx\n",
145		       nodeid, base, limit);
146
147		found++;
148
149		nodes[nodeid].start = base;
150		nodes[nodeid].end = limit;
151		e820_register_active_regions(nodeid,
152				nodes[nodeid].start >> PAGE_SHIFT,
153				nodes[nodeid].end >> PAGE_SHIFT);
154
155		prevbase = base;
156
157		node_set(nodeid, node_possible_map);
158	}
159
160	if (!found)
161		return -1;
162
163	memnode_shift = compute_hash_shift(nodes, 8);
164	if (memnode_shift < 0) {
165		printk(KERN_ERR "No NUMA node hash function found. Contact maintainer\n");
166		return -1;
167	}
168	printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift);
169
170	for (i = 0; i < 8; i++) {
171		if (nodes[i].start != nodes[i].end) {
172			nodeid = nodeids[i];
173			apicid_to_node[nodeid << dualcore] = i;
174			apicid_to_node[(nodeid << dualcore) + dualcore] = i;
175			setup_node_bootmem(i, nodes[i].start, nodes[i].end);
176		}
177	}
178
179	numa_init_array();
180	return 0;
181}
182