release/src-rt-6.x.4708/linux/linux-2.6.36/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 <asm/cio.h>
  16 #include <asm/setup.h>
  17 #include <asm/pgtable.h>
  18 #include <asm/pgalloc.h>
  19 #include <asm/system.h>
  20 #include <asm/smp.h>
  21 #include <asm/reset.h>
  22 #include <asm/ipl.h>
  23
  24 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
  25
  26 extern const unsigned char relocate_kernel[];
  27 extern const unsigned long long relocate_kernel_len;
  28
  29 int machine_kexec_prepare(struct kimage *image)
  30 {
  31         void *reboot_code_buffer;
  32
  33         /* Can't replace kernel image since it is read-only. */
  34         if (ipl_flags & IPL_NSS_VALID)
  35                 return -ENOSYS;
  36
  37         /* We don't support anything but the default image type for now. */
  38         if (image->type != KEXEC_TYPE_DEFAULT)
  39                 return -EINVAL;
  40
  41         /* Get the destination where the assembler code should be copied to.*/
  42         reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
  43
  44         /* Then copy it */
  45         memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
  46         return 0;
  47 }
  48
  49 void machine_kexec_cleanup(struct kimage *image)
  50 {
  51 }
  52
  53 void machine_shutdown(void)
  54 {
  55 }
  56
  57 static void __machine_kexec(void *data)
  58 {
  59         relocate_kernel_t data_mover;
  60         struct kimage *image = data;
  61
  62         pfault_fini();
  63         s390_reset_system();
  64
  65         data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
  66
  67         /* Call the moving routine */
  68         (*data_mover)(&image->head, image->start);
  69         for (;;);
  70 }
  71
  72 void machine_kexec(struct kimage *image)
  73 {
  74         smp_send_stop();
  75         smp_switch_to_ipl_cpu(__machine_kexec, image);
  76 }