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/mpspec.h>
  13 #include <asm/apicdef.h>
  14
  15 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
  16 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
  17
  18 /* Bitmask of physically existing CPUs */
  19 physid_mask_t phys_cpu_present_map;
  20
  21 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
  22 /*
  23  * Copy data used in early init routines from the initial arrays to the
  24  * per cpu data areas.  These arrays then become expendable and the
  25  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  26  */
  27 static void __init setup_per_cpu_maps(void)
  28 {
  29         int cpu;
  30
  31         for_each_possible_cpu(cpu) {
  32                 per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu];
  33                 per_cpu(x86_bios_cpu_apicid, cpu) =
  34                                                 x86_bios_cpu_apicid_init[cpu];
  35 #ifdef CONFIG_NUMA
  36                 per_cpu(x86_cpu_to_node_map, cpu) =
  37                                                 x86_cpu_to_node_map_init[cpu];
  38 #endif
  39         }
  40
  41         /* indicate the early static arrays will soon be gone */
  42         x86_cpu_to_apicid_early_ptr = NULL;
  43         x86_bios_cpu_apicid_early_ptr = NULL;
  44 #ifdef CONFIG_NUMA
  45         x86_cpu_to_node_map_early_ptr = NULL;
  46 #endif
  47 }
  48
  49 #ifdef CONFIG_X86_32
  50 /*
  51  * Great future not-so-futuristic plan: make i386 and x86_64 do it
  52  * the same way
  53  */
  54 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  55 EXPORT_SYMBOL(__per_cpu_offset);
  56 #endif
  57
  58 /*
  59  * Great future plan:
  60  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  61  * Always point %gs to its beginning
  62  */
  63 void __init setup_per_cpu_areas(void)
  64 {
  65         int i;
  66         unsigned long size;
  67
  68 #ifdef CONFIG_HOTPLUG_CPU
  69         prefill_possible_map();
  70 #endif
  71
  72         /* Copy section for each CPU (we discard the original) */
  73         size = PERCPU_ENOUGH_ROOM;
  74         printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
  75                           size);
  76
  77         for_each_possible_cpu(i) {
  78                 char *ptr;
  79 #ifndef CONFIG_NEED_MULTIPLE_NODES
  80                 ptr = alloc_bootmem_pages(size);
  81 #else
  82                 int node = early_cpu_to_node(i);
  83                 if (!node_online(node) || !NODE_DATA(node)) {
  84                         ptr = alloc_bootmem_pages(size);
  85                         printk(KERN_INFO
  86                                "cpu %d has no node or node-local memory\n", i);
  87                 }
  88                 else
  89                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  90 #endif
  91                 if (!ptr)
  92                         panic("Cannot allocate cpu data for CPU %d\n", i);
  93 #ifdef CONFIG_X86_64
  94                 cpu_pda(i)->data_offset = ptr - __per_cpu_start;
  95 #else
  96                 __per_cpu_offset[i] = ptr - __per_cpu_start;
  97 #endif
  98                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
  99         }
 100
 101         /* Setup percpu data maps */
 102         setup_per_cpu_maps();
 103 }
 104
 105 #endif