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