arch/x86/kernel/trampoline.c

   1 #include <linux/io.h>
   2
   3 #include <asm/trampoline.h>
   4 #include <asm/e820.h>
   5
   6 #if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
   7 #define __trampinit
   8 #define __trampinitdata
   9 #else
  10 #define __trampinit __cpuinit
  11 #define __trampinitdata __cpuinitdata
  12 #endif
  13
  14 /* ready for x86_64 and x86 */
  15 unsigned char *__trampinitdata trampoline_base = __va(TRAMPOLINE_BASE);
  16
  17 void __init reserve_trampoline_memory(void)
  18 {
  19 #ifdef CONFIG_X86_32
  20         /*
  21          * But first pinch a few for the stack/trampoline stuff
  22          * FIXME: Don't need the extra page at 4K, but need to fix
  23          * trampoline before removing it. (see the GDT stuff)
  24          */
  25         reserve_early(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
  26 #endif
  27         /* Has to be in very low memory so we can execute real-mode AP code. */
  28         reserve_early(TRAMPOLINE_BASE, TRAMPOLINE_BASE + TRAMPOLINE_SIZE,
  29                         "TRAMPOLINE");
  30 }
  31
  32 /*
  33  * Currently trivial. Write the real->protected mode
  34  * bootstrap into the page concerned. The caller
  35  * has made sure it's suitably aligned.
  36  */
  37 unsigned long __trampinit setup_trampoline(void)
  38 {
  39         memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
  40         return virt_to_phys(trampoline_base);
  41 }