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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 <linux/acpi.h>
17 #include <asm/types.h>
18 #include <asm/mmzone.h>
19 #include <asm/proto.h>
20 #include <asm/e820.h>
21 #include <asm/pci-direct.h>
22 #include <asm/numa.h>
23 #include <asm/mpspec.h>
24 #include <asm/apic.h>
25 #include <asm/k8.h>
26 
find_northbridge(void)27 static __init int find_northbridge(void)
28 {
29 	int num;
30 
31 	for (num = 0; num < 32; num++) {
32 		u32 header;
33 
34 		header = read_pci_config(0, num, 0, 0x00);
35 		if (header != (PCI_VENDOR_ID_AMD | (0x1100<<16)) &&
36 			header != (PCI_VENDOR_ID_AMD | (0x1200<<16)) &&
37 			header != (PCI_VENDOR_ID_AMD | (0x1300<<16)))
38 			continue;
39 
40 		header = read_pci_config(0, num, 1, 0x00);
41 		if (header != (PCI_VENDOR_ID_AMD | (0x1101<<16)) &&
42 			header != (PCI_VENDOR_ID_AMD | (0x1201<<16)) &&
43 			header != (PCI_VENDOR_ID_AMD | (0x1301<<16)))
44 			continue;
45 		return num;
46 	}
47 
48 	return -1;
49 }
50 
early_get_boot_cpu_id(void)51 static __init void early_get_boot_cpu_id(void)
52 {
53 	/*
54 	 * need to get boot_cpu_id so can use that to create apicid_to_node
55 	 * in k8_scan_nodes()
56 	 */
57 	/*
58 	 * Find possible boot-time SMP configuration:
59 	 */
60 #ifdef CONFIG_X86_MPPARSE
61 	early_find_smp_config();
62 #endif
63 #ifdef CONFIG_ACPI
64 	/*
65 	 * Read APIC information from ACPI tables.
66 	 */
67 	early_acpi_boot_init();
68 #endif
69 #ifdef CONFIG_X86_MPPARSE
70 	/*
71 	 * get boot-time SMP configuration:
72 	 */
73 	if (smp_found_config)
74 		early_get_smp_config();
75 #endif
76 	early_init_lapic_mapping();
77 }
78 
k8_scan_nodes(unsigned long start,unsigned long end)79 int __init k8_scan_nodes(unsigned long start, unsigned long end)
80 {
81 	unsigned numnodes, cores, bits, apicid_base;
82 	unsigned long prevbase;
83 	struct bootnode nodes[8];
84 	int i, j, nb, found = 0;
85 	u32 nodeid, reg;
86 
87 	if (!early_pci_allowed())
88 		return -1;
89 
90 	nb = find_northbridge();
91 	if (nb < 0)
92 		return nb;
93 
94 	printk(KERN_INFO "Scanning NUMA topology in Northbridge %d\n", nb);
95 
96 	reg = read_pci_config(0, nb, 0, 0x60);
97 	numnodes = ((reg >> 4) & 0xF) + 1;
98 	if (numnodes <= 1)
99 		return -1;
100 
101 	printk(KERN_INFO "Number of nodes %d\n", numnodes);
102 
103 	memset(&nodes, 0, sizeof(nodes));
104 	prevbase = 0;
105 	for (i = 0; i < 8; i++) {
106 		unsigned long base, limit;
107 
108 		base = read_pci_config(0, nb, 1, 0x40 + i*8);
109 		limit = read_pci_config(0, nb, 1, 0x44 + i*8);
110 
111 		nodeid = limit & 7;
112 		if ((base & 3) == 0) {
113 			if (i < numnodes)
114 				printk("Skipping disabled node %d\n", i);
115 			continue;
116 		}
117 		if (nodeid >= numnodes) {
118 			printk("Ignoring excess node %d (%lx:%lx)\n", nodeid,
119 			       base, limit);
120 			continue;
121 		}
122 
123 		if (!limit) {
124 			printk(KERN_INFO "Skipping node entry %d (base %lx)\n",
125 			       i, base);
126 			continue;
127 		}
128 		if ((base >> 8) & 3 || (limit >> 8) & 3) {
129 			printk(KERN_ERR "Node %d using interleaving mode %lx/%lx\n",
130 			       nodeid, (base>>8)&3, (limit>>8) & 3);
131 			return -1;
132 		}
133 		if (node_isset(nodeid, node_possible_map)) {
134 			printk(KERN_INFO "Node %d already present. Skipping\n",
135 			       nodeid);
136 			continue;
137 		}
138 
139 		limit >>= 16;
140 		limit <<= 24;
141 		limit |= (1<<24)-1;
142 		limit++;
143 
144 		if (limit > max_pfn << PAGE_SHIFT)
145 			limit = max_pfn << PAGE_SHIFT;
146 		if (limit <= base)
147 			continue;
148 
149 		base >>= 16;
150 		base <<= 24;
151 
152 		if (base < start)
153 			base = start;
154 		if (limit > end)
155 			limit = end;
156 		if (limit == base) {
157 			printk(KERN_ERR "Empty node %d\n", nodeid);
158 			continue;
159 		}
160 		if (limit < base) {
161 			printk(KERN_ERR "Node %d bogus settings %lx-%lx.\n",
162 			       nodeid, base, limit);
163 			continue;
164 		}
165 
166 		/* Could sort here, but pun for now. Should not happen anyroads. */
167 		if (prevbase > base) {
168 			printk(KERN_ERR "Node map not sorted %lx,%lx\n",
169 			       prevbase, base);
170 			return -1;
171 		}
172 
173 		printk(KERN_INFO "Node %d MemBase %016lx Limit %016lx\n",
174 		       nodeid, base, limit);
175 
176 		found++;
177 
178 		nodes[nodeid].start = base;
179 		nodes[nodeid].end = limit;
180 
181 		prevbase = base;
182 
183 		node_set(nodeid, node_possible_map);
184 	}
185 
186 	if (!found)
187 		return -1;
188 
189 	memnode_shift = compute_hash_shift(nodes, 8, NULL);
190 	if (memnode_shift < 0) {
191 		printk(KERN_ERR "No NUMA node hash function found. Contact maintainer\n");
192 		return -1;
193 	}
194 	printk(KERN_INFO "Using node hash shift of %d\n", memnode_shift);
195 
196 	/* use the coreid bits from early_identify_cpu */
197 	bits = boot_cpu_data.x86_coreid_bits;
198 	cores = (1<<bits);
199 	apicid_base = 0;
200 	/* need to get boot_cpu_id early for system with apicid lifting */
201 	early_get_boot_cpu_id();
202 	if (boot_cpu_physical_apicid > 0) {
203 		printk(KERN_INFO "BSP APIC ID: %02x\n",
204 				 boot_cpu_physical_apicid);
205 		apicid_base = boot_cpu_physical_apicid;
206 	}
207 
208 	for (i = 0; i < 8; i++) {
209 		if (nodes[i].start == nodes[i].end)
210 			continue;
211 
212 		e820_register_active_regions(i,
213 				nodes[i].start >> PAGE_SHIFT,
214 				nodes[i].end >> PAGE_SHIFT);
215 		for (j = apicid_base; j < cores + apicid_base; j++)
216 			apicid_to_node[(i << bits) + j] = i;
217 		setup_node_bootmem(i, nodes[i].start, nodes[i].end);
218 	}
219 
220 	numa_init_array();
221 	return 0;
222 }
223