arch/mips/kernel/machine_kexec.c

   1 /*
   2  * machine_kexec.c for kexec
   3  * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
   4  *
   5  * This source code is licensed under the GNU General Public License,
   6  * Version 2.  See the file COPYING for more details.
   7  */
   8 #include <linux/compiler.h>
   9 #include <linux/kexec.h>
  10 #include <linux/mm.h>
  11 #include <linux/delay.h>
  12
  13 #include <asm/cacheflush.h>
  14 #include <asm/page.h>
  15
  16 extern const unsigned char relocate_new_kernel[];
  17 extern const size_t relocate_new_kernel_size;
  18
  19 extern unsigned long kexec_start_address;
  20 extern unsigned long kexec_indirection_page;
  21
  22 int (*_machine_kexec_prepare)(struct kimage *) = NULL;
  23 void (*_machine_kexec_shutdown)(void) = NULL;
  24 void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
  25 #ifdef CONFIG_SMP
  26 void (*relocated_kexec_smp_wait) (void *);
  27 atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
  28 #endif
  29
  30 int
  31 machine_kexec_prepare(struct kimage *kimage)
  32 {
  33         if (_machine_kexec_prepare)
  34                 return _machine_kexec_prepare(kimage);
  35         return 0;
  36 }
  37
  38 void
  39 machine_kexec_cleanup(struct kimage *kimage)
  40 {
  41 }
  42
  43 void
  44 machine_shutdown(void)
  45 {
  46         if (_machine_kexec_shutdown)
  47                 _machine_kexec_shutdown();
  48 }
  49
  50 void
  51 machine_crash_shutdown(struct pt_regs *regs)
  52 {
  53         if (_machine_crash_shutdown)
  54                 _machine_crash_shutdown(regs);
  55         else
  56                 default_machine_crash_shutdown(regs);
  57 }
  58
  59 typedef void (*noretfun_t)(void) __noreturn;
  60
  61 void
  62 machine_kexec(struct kimage *image)
  63 {
  64         unsigned long reboot_code_buffer;
  65         unsigned long entry;
  66         unsigned long *ptr;
  67
  68         reboot_code_buffer =
  69           (unsigned long)page_address(image->control_code_page);
  70
  71         kexec_start_address =
  72                 (unsigned long) phys_to_virt(image->start);
  73
  74         if (image->type == KEXEC_TYPE_DEFAULT) {
  75                 kexec_indirection_page =
  76                         (unsigned long) phys_to_virt(image->head & PAGE_MASK);
  77         } else {
  78                 kexec_indirection_page = (unsigned long)&image->head;
  79         }
  80
  81         memcpy((void*)reboot_code_buffer, relocate_new_kernel,
  82                relocate_new_kernel_size);
  83
  84         /*
  85          * The generic kexec code builds a page list with physical
  86          * addresses. they are directly accessible through KSEG0 (or
  87          * CKSEG0 or XPHYS if on 64bit system), hence the
  88          * phys_to_virt() call.
  89          */
  90         for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
  91              ptr = (entry & IND_INDIRECTION) ?
  92                phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
  93                 if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
  94                     *ptr & IND_DESTINATION)
  95                         *ptr = (unsigned long) phys_to_virt(*ptr);
  96         }
  97
  98         /*
  99          * we do not want to be bothered.
 100          */
 101         local_irq_disable();
 102
 103         printk("Will call new kernel at %08lx\n", image->start);
 104         printk("Bye ...\n");
 105         __flush_cache_all();
 106 #ifdef CONFIG_SMP
 107         /* All secondary cpus now may jump to kexec_wait cycle */
 108         relocated_kexec_smp_wait = reboot_code_buffer +
 109                 (void *)(kexec_smp_wait - relocate_new_kernel);
 110         smp_wmb();
 111         atomic_set(&kexec_ready_to_reboot, 1);
 112 #endif
 113         ((noretfun_t) reboot_code_buffer)();
 114 }