arch/s390/kernel/machine_kexec.c

   1 /*
   2  * arch/s390/kernel/machine_kexec.c
   3  *
   4  * (C) Copyright IBM Corp. 2005
   5  *
   6  * Author(s): Rolf Adelsberger <adelsberger@de.ibm.com>
   7  *
   8  */
   9
  10 /*
  11  * s390_machine_kexec.c - handle the transition of Linux booting another kernel
  12  * on the S390 architecture.
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/mm.h>
  17 #include <linux/kexec.h>
  18 #include <linux/delay.h>
  19 #include <asm/cio.h>
  20 #include <asm/setup.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/system.h>
  24 #include <asm/smp.h>
  25 #include <asm/reset.h>
  26
  27 static void kexec_halt_all_cpus(void *);
  28
  29 typedef void (*relocate_kernel_t) (kimage_entry_t *, unsigned long);
  30
  31 extern const unsigned char relocate_kernel[];
  32 extern const unsigned long long relocate_kernel_len;
  33
  34 int
  35 machine_kexec_prepare(struct kimage *image)
  36 {
  37         unsigned long reboot_code_buffer;
  38
  39         /* We don't support anything but the default image type for now. */
  40         if (image->type != KEXEC_TYPE_DEFAULT)
  41                 return -EINVAL;
  42
  43         /* Get the destination where the assembler code should be copied to.*/
  44         reboot_code_buffer = page_to_pfn(image->control_code_page)<<PAGE_SHIFT;
  45
  46         /* Then copy it */
  47         memcpy((void *) reboot_code_buffer, relocate_kernel,
  48                relocate_kernel_len);
  49         return 0;
  50 }
  51
  52 void
  53 machine_kexec_cleanup(struct kimage *image)
  54 {
  55 }
  56
  57 void
  58 machine_shutdown(void)
  59 {
  60         printk(KERN_INFO "kexec: machine_shutdown called\n");
  61 }
  62
  63 NORET_TYPE void
  64 machine_kexec(struct kimage *image)
  65 {
  66         on_each_cpu(kexec_halt_all_cpus, image, 0, 0);
  67         for (;;);
  68 }
  69
  70 extern void pfault_fini(void);
  71
  72 static void
  73 kexec_halt_all_cpus(void *kernel_image)
  74 {
  75         static atomic_t cpuid = ATOMIC_INIT(-1);
  76         int cpu;
  77         struct kimage *image;
  78         relocate_kernel_t data_mover;
  79
  80 #ifdef CONFIG_PFAULT
  81         if (MACHINE_IS_VM)
  82                 pfault_fini();
  83 #endif
  84
  85         if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
  86                 signal_processor(smp_processor_id(), sigp_stop);
  87
  88         /* Wait for all other cpus to enter stopped state */
  89         for_each_online_cpu(cpu) {
  90                 if (cpu == smp_processor_id())
  91                         continue;
  92                 while (!smp_cpu_not_running(cpu))
  93                         cpu_relax();
  94         }
  95
  96         s390_reset_system();
  97
  98         image = (struct kimage *) kernel_image;
  99         data_mover = (relocate_kernel_t)
 100                 (page_to_pfn(image->control_code_page) << PAGE_SHIFT);
 101
 102         /* Call the moving routine */
 103         (*data_mover) (&image->head, image->start);
 104 }