arch/x86/kernel/smpcommon.c

   1 /*
   2  * SMP stuff which is common to all sub-architectures.
   3  */
   4 #include <linux/module.h>
   5 #include <asm/smp.h>
   6
   7 #ifdef CONFIG_X86_32
   8 DEFINE_PER_CPU(unsigned long, this_cpu_off);
   9 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
  10
  11 /* Initialize the CPU's GDT.  This is either the boot CPU doing itself
  12    (still using the master per-cpu area), or a CPU doing it for a
  13    secondary which will soon come up. */
  14 __cpuinit void init_gdt(int cpu)
  15 {
  16         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
  17
  18         pack_descriptor(&gdt[GDT_ENTRY_PERCPU],
  19                         __per_cpu_offset[cpu], 0xFFFFF,
  20                         0x2 | DESCTYPE_S, 0x8);
  21
  22         gdt[GDT_ENTRY_PERCPU].s = 1;
  23
  24         per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
  25         per_cpu(cpu_number, cpu) = cpu;
  26 }
  27 #endif