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  */
  28 int num_node_memblks;
  29 struct node_memblk_s node_memblk[NR_NODE_MEMBLKS];
  30 struct 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  */
  37 u8 numa_slit[MAX_NUMNODES * MAX_NUMNODES];
  38
  39 int __node_distance(int from, int to)
  40 {
  41         return slit_distance(from, to);
  42 }
  43 EXPORT_SYMBOL(__node_distance);
  44
  45 /* Identify which cnode a physical address resides on */
  46 int
  47 paddr_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 EXPORT_SYMBOL(paddr_to_nid);
  59
  60 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_NUMA)
  61 void numa_clear_node(int cpu)
  62 {
  63         unmap_cpu_from_node(cpu, NUMA_NO_NODE);
  64 }
  65
  66 #ifdef CONFIG_MEMORY_HOTPLUG
  67 /*
  68  *  SRAT information is stored in node_memblk[], then we can use SRAT
  69  *  information at memory-hot-add if necessary.
  70  */
  71
  72 int memory_add_physaddr_to_nid(u64 addr)
  73 {
  74         int nid = paddr_to_nid(addr);
  75         if (nid < 0)
  76                 return 0;
  77         return nid;
  78 }
  79 #endif
  80 #endif