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
  13 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
  14 /*
  15  * Copy data used in early init routines from the initial arrays to the
  16  * per cpu data areas.  These arrays then become expendable and the
  17  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  18  */
  19 static void __init setup_per_cpu_maps(void)
  20 {
  21         int cpu;
  22
  23         for_each_possible_cpu(cpu) {
  24 #ifdef CONFIG_SMP
  25                 if (per_cpu_offset(cpu)) {
  26 #endif
  27                         per_cpu(x86_cpu_to_apicid, cpu) =
  28                                                 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 #ifdef CONFIG_SMP
  36                 } else
  37                         printk(KERN_NOTICE "per_cpu_offset zero for cpu %d\n",
  38                                                                         cpu);
  39 #endif
  40         }
  41
  42         /* indicate the early static arrays will soon be gone */
  43         x86_cpu_to_apicid_early_ptr = NULL;
  44         x86_bios_cpu_apicid_early_ptr = NULL;
  45 #ifdef CONFIG_NUMA
  46         x86_cpu_to_node_map_early_ptr = NULL;
  47 #endif
  48 }
  49
  50 #ifdef CONFIG_X86_32
  51 /*
  52  * Great future not-so-futuristic plan: make i386 and x86_64 do it
  53  * the same way
  54  */
  55 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  56 EXPORT_SYMBOL(__per_cpu_offset);
  57 #endif
  58
  59 /*
  60  * Great future plan:
  61  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  62  * Always point %gs to its beginning
  63  */
  64 void __init setup_per_cpu_areas(void)
  65 {
  66         int i;
  67         unsigned long size;
  68
  69 #ifdef CONFIG_HOTPLUG_CPU
  70         prefill_possible_map();
  71 #endif
  72
  73         /* Copy section for each CPU (we discard the original) */
  74         size = PERCPU_ENOUGH_ROOM;
  75
  76         printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
  77                           size);
  78         for_each_cpu_mask(i, cpu_possible_map) {
  79                 char *ptr;
  80 #ifndef CONFIG_NEED_MULTIPLE_NODES
  81                 ptr = alloc_bootmem_pages(size);
  82 #else
  83                 int node = early_cpu_to_node(i);
  84                 if (!node_online(node) || !NODE_DATA(node))
  85                         ptr = alloc_bootmem_pages(size);
  86                 else
  87                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  88 #endif
  89                 if (!ptr)
  90                         panic("Cannot allocate cpu data for CPU %d\n", i);
  91 #ifdef CONFIG_X86_64
  92                 cpu_pda(i)->data_offset = ptr - __per_cpu_start;
  93 #else
  94                 __per_cpu_offset[i] = ptr - __per_cpu_start;
  95 #endif
  96                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
  97         }
  98
  99         /* setup percpu data maps early */
 100         setup_per_cpu_maps();
 101 }
 102
 103 #endif