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
  26 static void kexec_halt_all_cpus(void *);
  27
  28 typedef void (*relocate_kernel_t) (kimage_entry_t *, unsigned long);
  29
  30 extern const unsigned char relocate_kernel[];
  31 extern const unsigned long long relocate_kernel_len;
  32
  33 int
  34 machine_kexec_prepare(struct kimage *image)
  35 {
  36         unsigned long reboot_code_buffer;
  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 = page_to_pfn(image->control_code_page)<<PAGE_SHIFT;
  44
  45         /* Then copy it */
  46         memcpy((void *) reboot_code_buffer, relocate_kernel,
  47                relocate_kernel_len);
  48         return 0;
  49 }
  50
  51 void
  52 machine_kexec_cleanup(struct kimage *image)
  53 {
  54 }
  55
  56 void
  57 machine_shutdown(void)
  58 {
  59         printk(KERN_INFO "kexec: machine_shutdown called\n");
  60 }
  61
  62 NORET_TYPE void
  63 machine_kexec(struct kimage *image)
  64 {
  65         clear_all_subchannels();
  66
  67         /* Disable lowcore protection */
  68         ctl_clear_bit(0,28);
  69
  70         on_each_cpu(kexec_halt_all_cpus, image, 0, 0);
  71         for (;;);
  72 }
  73
  74 extern void pfault_fini(void);
  75
  76 static void
  77 kexec_halt_all_cpus(void *kernel_image)
  78 {
  79         static atomic_t cpuid = ATOMIC_INIT(-1);
  80         int cpu;
  81         struct kimage *image;
  82         relocate_kernel_t data_mover;
  83
  84 #ifdef CONFIG_PFAULT
  85         if (MACHINE_IS_VM)
  86                 pfault_fini();
  87 #endif
  88
  89         if (atomic_cmpxchg(&cpuid, -1, smp_processor_id()) != -1)
  90                 signal_processor(smp_processor_id(), sigp_stop);
  91
  92         /* Wait for all other cpus to enter stopped state */
  93         for_each_online_cpu(cpu) {
  94                 if (cpu == smp_processor_id())
  95                         continue;
  96                 while (!smp_cpu_not_running(cpu))
  97                         cpu_relax();
  98         }
  99
 100         image = (struct kimage *) kernel_image;
 101         data_mover = (relocate_kernel_t)
 102                 (page_to_pfn(image->control_code_page) << PAGE_SHIFT);
 103
 104         /* Call the moving routine */
 105         (*data_mover) (&image->head, image->start);
 106 }