LXR linux/arch/ia64/mm/numa.c

   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 */
  27int num_node_memblks;
  28struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
  29struct 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 */
  36u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
  37
  38int __node_distance(int from, int to)
  39{
  40        return slit_distance(from, to);
  41}
  42EXPORT_SYMBOL(__node_distance);
  43
  44/* Identify which cnode a physical address resides on */
  45int
  46paddr_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}
  57EXPORT_SYMBOL(paddr_to_nid);
  58
  59#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
  60void 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
  71int 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#endif
  79#endif
  80