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