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 <asm/cio.h>
  16 #include <asm/setup.h>
  17 #include <linux/device.h>
  18 #include <linux/mm.h>
  19 #include <linux/kexec.h>
  20 #include <linux/delay.h>
  21 #include <asm/pgtable.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/system.h>
  24
  25 static void kexec_halt_all_cpus(void *);
  26
  27 typedef void (*relocate_kernel_t) (kimage_entry_t *, unsigned long);
  28
  29 const extern unsigned char relocate_kernel[];
  30 const extern unsigned long long relocate_kernel_len;
  31
  32 int
  33 machine_kexec_prepare(struct kimage *image)
  34 {
  35         unsigned long reboot_code_buffer;
  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 = page_to_pfn(image->control_code_page)<<PAGE_SHIFT;
  43
  44         /* Then copy it */
  45         memcpy((void *) reboot_code_buffer, relocate_kernel,
  46                relocate_kernel_len);
  47         return 0;
  48 }
  49
  50 void
  51 machine_kexec_cleanup(struct kimage *image)
  52 {
  53 }
  54
  55 void
  56 machine_shutdown(void)
  57 {
  58         printk(KERN_INFO "kexec: machine_shutdown called\n");
  59 }
  60
  61 NORET_TYPE void
  62 machine_kexec(struct kimage *image)
  63 {
  64         clear_all_subchannels();
  65
  66         /* Disable lowcore protection */
  67         ctl_clear_bit(0,28);
  68
  69         on_each_cpu(kexec_halt_all_cpus, image, 0, 0);
  70         for (;;);
  71 }
  72
  73 extern void pfault_fini(void);
  74
  75 static void
  76 kexec_halt_all_cpus(void *kernel_image)
  77 {
  78         static atomic_t cpuid = ATOMIC_INIT(-1);
  79         int cpu;
  80         struct kimage *image;
  81         relocate_kernel_t data_mover;
  82
  83 #ifdef CONFIG_PFAULT
  84         if (MACHINE_IS_VM)
  85                 pfault_fini();
  86 #endif
  87
  88         if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid))
  89                 signal_processor(smp_processor_id(), sigp_stop);
  90
  91         /* Wait for all other cpus to enter stopped state */
  92         for_each_online_cpu(cpu) {
  93                 if (cpu == smp_processor_id())
  94                         continue;
  95                 while (!smp_cpu_not_running(cpu))
  96                         cpu_relax();
  97         }
  98
  99         image = (struct kimage *) kernel_image;
 100         data_mover = (relocate_kernel_t)
 101                 (page_to_pfn(image->control_code_page) << PAGE_SHIFT);
 102
 103         /* Call the moving routine */
 104         (*data_mover) (&image->head, image->start);
 105 }