arch/x86/kernel/trampoline.c

   1 #include <linux/io.h>
   2 #include <linux/memblock.h>
   3
   4 #include <asm/trampoline.h>
   5 #include <asm/pgtable.h>
   6
   7 #if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
   8 #define __trampinit
   9 #define __trampinitdata
  10 #else
  11 #define __trampinit __cpuinit
  12 #define __trampinitdata __cpuinitdata
  13 #endif
  14
  15 /* ready for x86_64 and x86 */
  16 unsigned char *__trampinitdata trampoline_base;
  17
  18 void __init reserve_trampoline_memory(void)
  19 {
  20         phys_addr_t mem;
  21
  22         /* Has to be in very low memory so we can execute real-mode AP code. */
  23         mem = memblock_find_in_range(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE);
  24         if (mem == MEMBLOCK_ERROR)
  25                 panic("Cannot allocate trampoline\n");
  26
  27         trampoline_base = __va(mem);
  28         memblock_x86_reserve_range(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE");
  29 }
  30
  31 /*
  32  * Currently trivial. Write the real->protected mode
  33  * bootstrap into the page concerned. The caller
  34  * has made sure it's suitably aligned.
  35  */
  36 unsigned long __trampinit setup_trampoline(void)
  37 {
  38         memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
  39         return virt_to_phys(trampoline_base);
  40 }