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 */
27 int num_node_memblks;
28 struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
29 struct 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 */
36 u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
37
__node_distance(int from,int to)38 int __node_distance(int from, int to)
39 {
40 return slit_distance(from, to);
41 }
42 EXPORT_SYMBOL(__node_distance);
43
44 /* Identify which cnode a physical address resides on */
45 int
paddr_to_nid(unsigned long paddr)46 paddr_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 }
57 EXPORT_SYMBOL(paddr_to_nid);
58
59 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
60 /*
61 * Because of holes evaluate on section limits.
62 * If the section of memory exists, then return the node where the section
63 * resides. Otherwise return node 0 as the default. This is used by
64 * SPARSEMEM to allocate the SPARSEMEM sectionmap on the NUMA node where
65 * the section resides.
66 */
__early_pfn_to_nid(unsigned long pfn,struct mminit_pfnnid_cache * state)67 int __meminit __early_pfn_to_nid(unsigned long pfn,
68 struct mminit_pfnnid_cache *state)
69 {
70 int i, section = pfn >> PFN_SECTION_SHIFT, ssec, esec;
71
72 if (section >= state->last_start && section < state->last_end)
73 return state->last_nid;
74
75 for (i = 0; i < num_node_memblks; i++) {
76 ssec = node_memblk[i].start_paddr >> PA_SECTION_SHIFT;
77 esec = (node_memblk[i].start_paddr + node_memblk[i].size +
78 ((1L << PA_SECTION_SHIFT) - 1)) >> PA_SECTION_SHIFT;
79 if (section >= ssec && section < esec) {
80 state->last_start = ssec;
81 state->last_end = esec;
82 state->last_nid = node_memblk[i].nid;
83 return node_memblk[i].nid;
84 }
85 }
86
87 return -1;
88 }
89
numa_clear_node(int cpu)90 void numa_clear_node(int cpu)
91 {
92 unmap_cpu_from_node(cpu, NUMA_NO_NODE);
93 }
94
95 #ifdef CONFIG_MEMORY_HOTPLUG
96 /*
97 * SRAT information is stored in node_memblk[], then we can use SRAT
98 * information at memory-hot-add if necessary.
99 */
100
memory_add_physaddr_to_nid(u64 addr)101 int memory_add_physaddr_to_nid(u64 addr)
102 {
103 int nid = paddr_to_nid(addr);
104 if (nid < 0)
105 return 0;
106 return nid;
107 }
108
109 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
110 #endif
111 #endif
112