arch/x86/kernel/setup.c

   1 #include <linux/kernel.h>
   2 #include <linux/module.h>
   3 #include <linux/init.h>
   4 #include <linux/bootmem.h>
   5 #include <linux/percpu.h>
   6 #include <asm/smp.h>
   7 #include <asm/percpu.h>
   8 #include <asm/sections.h>
   9 #include <asm/processor.h>
  10 #include <asm/setup.h>
  11 #include <asm/topology.h>
  12 #include <asm/apicdef.h>
  13
  14 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
  15 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
  16
  17 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
  18 /*
  19  * Copy data used in early init routines from the initial arrays to the
  20  * per cpu data areas.  These arrays then become expendable and the
  21  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  22  */
  23 static void __init setup_per_cpu_maps(void)
  24 {
  25         int cpu;
  26
  27         for_each_possible_cpu(cpu) {
  28                 per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu];
  29                 per_cpu(x86_bios_cpu_apicid, cpu) =
  30                                                 x86_bios_cpu_apicid_init[cpu];
  31 #ifdef CONFIG_NUMA
  32                 per_cpu(x86_cpu_to_node_map, cpu) =
  33                                                 x86_cpu_to_node_map_init[cpu];
  34 #endif
  35         }
  36
  37         /* indicate the early static arrays will soon be gone */
  38         x86_cpu_to_apicid_early_ptr = NULL;
  39         x86_bios_cpu_apicid_early_ptr = NULL;
  40 #ifdef CONFIG_NUMA
  41         x86_cpu_to_node_map_early_ptr = NULL;
  42 #endif
  43 }
  44
  45 #ifdef CONFIG_X86_32
  46 /*
  47  * Great future not-so-futuristic plan: make i386 and x86_64 do it
  48  * the same way
  49  */
  50 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  51 EXPORT_SYMBOL(__per_cpu_offset);
  52 #endif
  53
  54 /*
  55  * Great future plan:
  56  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  57  * Always point %gs to its beginning
  58  */
  59 void __init setup_per_cpu_areas(void)
  60 {
  61         int i;
  62         unsigned long size;
  63
  64 #ifdef CONFIG_HOTPLUG_CPU
  65         prefill_possible_map();
  66 #endif
  67
  68         /* Copy section for each CPU (we discard the original) */
  69         size = PERCPU_ENOUGH_ROOM;
  70         printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
  71                           size);
  72
  73         for_each_possible_cpu(i) {
  74                 char *ptr;
  75 #ifndef CONFIG_NEED_MULTIPLE_NODES
  76                 ptr = alloc_bootmem_pages(size);
  77 #else
  78                 int node = early_cpu_to_node(i);
  79                 if (!node_online(node) || !NODE_DATA(node)) {
  80                         ptr = alloc_bootmem_pages(size);
  81                         printk(KERN_INFO
  82                                "cpu %d has no node or node-local memory\n", i);
  83                 }
  84                 else
  85                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  86 #endif
  87                 if (!ptr)
  88                         panic("Cannot allocate cpu data for CPU %d\n", i);
  89 #ifdef CONFIG_X86_64
  90                 cpu_pda(i)->data_offset = ptr - __per_cpu_start;
  91 #else
  92                 __per_cpu_offset[i] = ptr - __per_cpu_start;
  93 #endif
  94                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
  95         }
  96
  97         /* Setup percpu data maps */
  98         setup_per_cpu_maps();
  99 }
 100
 101 #endif