blob: 4e5c8b36ad93ea91fa72674c3fe0fec44c593871 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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/config.h>
14#include <linux/cpu.h>
15#include <linux/kernel.h>
16#include <linux/mm.h>
17#include <linux/node.h>
18#include <linux/init.h>
19#include <linux/bootmem.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}
Bob Picco2d4b1fa2005-10-04 15:13:57 -040050
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#endif