summaryrefslogtreecommitdiff
path: root/arch/ia64/mm/numa.c
blob: 4248492b9321b2eb5f7c3079d532982011a907ef (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * This file contains NUMA specific variables and functions which can
 * be split away from DISCONTIGMEM and are used on NUMA machines with
 * contiguous memory.
 * 
 *                         2002/08/07 Erich Focht <efocht@ess.nec.de>
 */

#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/node.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <asm/mmzone.h>
#include <asm/numa.h>


/*
 * The following structures are usually initialized by ACPI or
 * similar mechanisms and describe the NUMA characteristics of the machine.
 */
int num_node_memblks;
struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
struct node_cpuid_s node_cpuid[NR_CPUS] =
	{ [0 ... NR_CPUS-1] = { .phys_id = 0, .nid = NUMA_NO_NODE } };

/*
 * This is a matrix with "distances" between nodes, they should be
 * proportional to the memory access latency ratios.
 */
u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];

/* Identify which cnode a physical address resides on */
int
paddr_to_nid(unsigned long paddr)
{
	int	i;

	for (i = 0; i < num_node_memblks; i++)
		if (paddr >= node_memblk[i].start_paddr &&
		    paddr < node_memblk[i].start_paddr + node_memblk[i].size)
			break;

	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
}

#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
/*
 * Because of holes evaluate on section limits.
 * If the section of memory exists, then return the node where the section
 * resides.  Otherwise return node 0 as the default.  This is used by
 * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
 * the section resides.
 */
int __meminit __early_pfn_to_nid(unsigned long pfn)
{
	int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
	/*
	 * NOTE: The following SMP-unsafe globals are only used early in boot
	 * when the kernel is running single-threaded.
	 */
	static int __meminitdata last_ssec, last_esec;
	static int __meminitdata last_nid;

	if (section >= last_ssec && section < last_esec)
		return last_nid;

	for (i = 0; i < num_node_memblks; i++) {
		ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
		esec = (node_memblk[i].start_paddr + node_memblk[i].size +
			((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
		if (section >= ssec && section < esec) {
			last_ssec = ssec;
			last_esec = esec;
			last_nid = node_memblk[i].nid;
			return node_memblk[i].nid;
		}
	}

	return -1;
}

void __cpuinit numa_clear_node(int cpu)
{
	unmap_cpu_from_node(cpu, NUMA_NO_NODE);
}

#ifdef CONFIG_MEMORY_HOTPLUG
/*
 *  SRAT information is stored in node_memblk[], then we can use SRAT
 *  information at memory-hot-add if necessary.
 */

int memory_add_physaddr_to_nid(u64 addr)
{
	int nid = paddr_to_nid(addr);
	if (nid < 0)
		return 0;
	return nid;
}

EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
#endif