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