1/*
 2 * This file is subject to the terms and conditions of the GNU General Public
 3 * License.  See the file "COPYING" in the main directory of this archive
 4 * for more details.
 5 *
 6 * This file contains NUMA specific variables and functions which are used on
 7 * NUMA machines with contiguous memory.
 8 * 
 9 *                         2002/08/07 Erich Focht <efocht@ess.nec.de>
10 */
11
12#include <linux/cpu.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/node.h>
16#include <linux/init.h>
17#include <linux/memblock.h>
18#include <linux/module.h>
19#include <asm/mmzone.h>
20#include <asm/numa.h>
21
22
23/*
24 * The following structures are usually initialized by ACPI or
25 * similar mechanisms and describe the NUMA characteristics of the machine.
26 */
27int num_node_memblks;
28struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
29struct node_cpuid_s node_cpuid[NR_CPUS] =
30	{ [0 ... NR_CPUS-1] = { .phys_id = 0, .nid = NUMA_NO_NODE } };
31
32/*
33 * This is a matrix with "distances" between nodes, they should be
34 * proportional to the memory access latency ratios.
35 */
36u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
37
38int __node_distance(int from, int to)
39{
40	return slit_distance(from, to);
41}
42EXPORT_SYMBOL(__node_distance);
43
44/* Identify which cnode a physical address resides on */
45int
46paddr_to_nid(unsigned long paddr)
47{
48	int	i;
49
50	for (i = 0; i < num_node_memblks; i++)
51		if (paddr >= node_memblk[i].start_paddr &&
52		    paddr < node_memblk[i].start_paddr + node_memblk[i].size)
53			break;
54
55	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
56}
57EXPORT_SYMBOL(paddr_to_nid);
58
59#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
60void numa_clear_node(int cpu)
61{
62	unmap_cpu_from_node(cpu, NUMA_NO_NODE);
63}
64
65#ifdef CONFIG_MEMORY_HOTPLUG
66/*
67 *  SRAT information is stored in node_memblk[], then we can use SRAT
68 *  information at memory-hot-add if necessary.
69 */
70
71int memory_add_physaddr_to_nid(u64 addr)
72{
73	int nid = paddr_to_nid(addr);
74	if (nid < 0)
75		return 0;
76	return nid;
77}
78EXPORT_SYMBOL(memory_add_physaddr_to_nid);
79#endif
80#endif