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 can
7 * be split away from DISCONTIGMEM and are used on NUMA machines with
8 * contiguous memory.
9 *
10 *                         2002/08/07 Erich Focht <efocht@ess.nec.de>
11 */
12
13#include <linux/cpu.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/node.h>
17#include <linux/init.h>
18#include <linux/bootmem.h>
19#include <linux/module.h>
20#include <asm/mmzone.h>
21#include <asm/numa.h>
22
23
24/*
25 * The following structures are usually initialized by ACPI or
26 * similar mechanisms and describe the NUMA characteristics of the machine.
27 */
28int num_node_memblks;
29struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
30struct node_cpuid_s node_cpuid[NR_CPUS];
31/*
32 * This is a matrix with "distances" between nodes, they should be
33 * proportional to the memory access latency ratios.
34 */
35u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
36
37/* Identify which cnode a physical address resides on */
38int
39paddr_to_nid(unsigned long paddr)
40{
41	int	i;
42
43	for (i = 0; i < num_node_memblks; i++)
44		if (paddr >= node_memblk[i].start_paddr &&
45		    paddr < node_memblk[i].start_paddr + node_memblk[i].size)
46			break;
47
48	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
49}
50
51#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
52/*
53 * Because of holes evaluate on section limits.
54 * If the section of memory exists, then return the node where the section
55 * resides.  Otherwise return node 0 as the default.  This is used by
56 * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
57 * the section resides.
58 */
59int early_pfn_to_nid(unsigned long pfn)
60{
61	int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
62
63	for (i = 0; i < num_node_memblks; i++) {
64		ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
65		esec = (node_memblk[i].start_paddr + node_memblk[i].size +
66			((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
67		if (section >= ssec && section < esec)
68			return node_memblk[i].nid;
69	}
70
71	return 0;
72}
73
74#ifdef CONFIG_MEMORY_HOTPLUG
75/*
76 *  SRAT information is stored in node_memblk[], then we can use SRAT
77 *  information at memory-hot-add if necessary.
78 */
79
80int memory_add_physaddr_to_nid(u64 addr)
81{
82	int nid = paddr_to_nid(addr);
83	if (nid < 0)
84		return 0;
85	return nid;
86}
87
88EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
89#endif
90#endif
91