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 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 */
  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
  39int __node_distance(int from, int to)
  40{
  41        return slit_distance(from, to);
  42}
  43EXPORT_SYMBOL(__node_distance);
  44
  45/* Identify which cnode a physical address resides on */
  46int
  47paddr_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 */
  67int __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
  90void 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
 101int 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
 109EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 110#endif
 111#endif
 112