arch/s390/kernel/machine_kexec.c

   1 /*
   2  * arch/s390/kernel/machine_kexec.c
   3  *
   4  * Copyright IBM Corp. 2005,2006
   5  *
   6  * Author(s): Rolf Adelsberger,
   7  *            Heiko Carstens <heiko.carstens@de.ibm.com>
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/mm.h>
  12 #include <linux/kexec.h>
  13 #include <linux/delay.h>
  14 #include <linux/reboot.h>
  15 #include <linux/ftrace.h>
  16 #include <asm/cio.h>
  17 #include <asm/setup.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/pgalloc.h>
  20 #include <asm/system.h>
  21 #include <asm/smp.h>
  22 #include <asm/reset.h>
  23 #include <asm/ipl.h>
  24
  25 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
  26
  27 extern const unsigned char relocate_kernel[];
  28 extern const unsigned long long relocate_kernel_len;
  29
  30 int machine_kexec_prepare(struct kimage *image)
  31 {
  32         void *reboot_code_buffer;
  33
  34         /* Can't replace kernel image since it is read-only. */
  35         if (ipl_flags & IPL_NSS_VALID)
  36                 return -ENOSYS;
  37
  38         /* We don't support anything but the default image type for now. */
  39         if (image->type != KEXEC_TYPE_DEFAULT)
  40                 return -EINVAL;
  41
  42         /* Get the destination where the assembler code should be copied to.*/
  43         reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
  44
  45         /* Then copy it */
  46         memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
  47         return 0;
  48 }
  49
  50 void machine_kexec_cleanup(struct kimage *image)
  51 {
  52 }
  53
  54 void machine_shutdown(void)
  55 {
  56 }
  57
  58 static void __machine_kexec(void *data)
  59 {
  60         relocate_kernel_t data_mover;
  61         struct kimage *image = data;
  62
  63         pfault_fini();
  64         s390_reset_system();
  65
  66         data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
  67
  68         /* Call the moving routine */
  69         (*data_mover)(&image->head, image->start);
  70         for (;;);
  71 }
  72
  73 void machine_kexec(struct kimage *image)
  74 {
  75         tracer_disable();
  76         smp_send_stop();
  77         smp_switch_to_ipl_cpu(__machine_kexec, image);
  78 }