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 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 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 void numa_clear_node(int cpu) 61 { 62 unmap_cpu_from_node(cpu, NUMA_NO_NODE); 63 } 64 65 #ifdef CONFIG_MEMORY_HOTPLUG 66 /* 67 * SRAT information is stored in node_memblk[], then we can use SRAT 68 * information at memory-hot-add if necessary. 69 */ 70 71 int memory_add_physaddr_to_nid(u64 addr) 72 { 73 int nid = paddr_to_nid(addr); 74 if (nid < 0) 75 return 0; 76 return nid; 77 } 78 EXPORT_SYMBOL(memory_add_physaddr_to_nid); 79 #endif 80 #endif 81