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 /*
  12  * Initialize the CPU's GDT.  This is either the boot CPU doing itself
  13  * (still using the master per-cpu area), or a CPU doing it for a
  14  * secondary which will soon come up.
  15  */
  16 __cpuinit void init_gdt(int cpu)
  17 {
  18         struct desc_struct gdt;
  19
  20         pack_descriptor(&gdt, __per_cpu_offset[cpu], 0xFFFFF,
  21                         0x2 | DESCTYPE_S, 0x8);
  22         gdt.s = 1;
  23
  24         write_gdt_entry(get_cpu_gdt_table(cpu),
  25                         GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
  26
  27         per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
  28         per_cpu(cpu_number, cpu) = cpu;
  29 }
  30 #endif