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/memblock.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 */ 28 int num_node_memblks; 29 struct node_memblk_s node_memblk[NR_NODE_MEMBLKS]; 30 struct 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 */ 37 u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES]; 38 39 int __node_distance(int from, int to) 40 { 41 return slit_distance(from, to); 42 } 43 EXPORT_SYMBOL(__node_distance); 44 45 /* Identify which cnode a physical address resides on */ 46 int 47 paddr_to_nid(unsigned long paddr) 48 { 49 int i; 50 51 for (i = 0; i < num_node_memblks; i++) 52 if (paddr >= node_memblk[i].start_paddr && 53 paddr < node_memblk[i].start_paddr + node_memblk[i].size) 54 break; 55 56 return (i < num_node_memblks) ? node_memblk[i].nid : (num_node_memblks ? -1 : 0); 57 } 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 */ 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 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 */ 100 101 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