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	{ [0 ... NR_CPUS-1] = { .phys_id = 0, .nid = NUMA_NO_NODE } };
32
33/*
34 * This is a matrix with "distances" between nodes, they should be
35 * proportional to the memory access latency ratios.
36 */
37u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
38
39/* Identify which cnode a physical address resides on */
40int
41paddr_to_nid(unsigned long paddr)
42{
43	int	i;
44
45	for (i = 0; i < num_node_memblks; i++)
46		if (paddr >= node_memblk[i].start_paddr &&
47		    paddr < node_memblk[i].start_paddr + node_memblk[i].size)
48			break;
49
50	return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0);
51}
52
53#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
54/*
55 * Because of holes evaluate on section limits.
56 * If the section of memory exists, then return the node where the section
57 * resides.  Otherwise return node 0 as the default.  This is used by
58 * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
59 * the section resides.
60 */
61int __meminit __early_pfn_to_nid(unsigned long pfn)
62{
63	int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
64	/*
65	 * NOTE: The following SMP-unsafe globals are only used early in boot
66	 * when the kernel is running single-threaded.
67	 */
68	static int __meminitdata last_ssec, last_esec;
69	static int __meminitdata last_nid;
70
71	if (section >= last_ssec && section < last_esec)
72		return last_nid;
73
74	for (i = 0; i < num_node_memblks; i++) {
75		ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
76		esec = (node_memblk[i].start_paddr + node_memblk[i].size +
77			((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
78		if (section >= ssec && section < esec) {
79			last_ssec = ssec;
80			last_esec = esec;
81			last_nid = node_memblk[i].nid;
82			return node_memblk[i].nid;
83		}
84	}
85
86	return -1;
87}
88
89void numa_clear_node(int cpu)
90{
91	unmap_cpu_from_node(cpu, NUMA_NO_NODE);
92}
93
94#ifdef CONFIG_MEMORY_HOTPLUG
95/*
96 *  SRAT information is stored in node_memblk[], then we can use SRAT
97 *  information at memory-hot-add if necessary.
98 */
99
100int memory_add_physaddr_to_nid(u64 addr)
101{
102	int nid = paddr_to_nid(addr);
103	if (nid < 0)
104		return 0;
105	return nid;
106}
107
108EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
109#endif
110#endif
111