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 void (*_crash_smp_send_stop)(void) = NULL;
  29 #endif
  30
  31 static void kexec_image_info(const struct kimage *kimage)
  32 {
  33         unsigned long i;
  34
  35         pr_debug("kexec kimage info:\n");
  36         pr_debug("  type:        %d\n", kimage->type);
  37         pr_debug("  start:       %lx\n", kimage->start);
  38         pr_debug("  head:        %lx\n", kimage->head);
  39         pr_debug("  nr_segments: %lu\n", kimage->nr_segments);
  40
  41         for (i = 0; i < kimage->nr_segments; i++) {
  42                 pr_debug("    segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
  43                         i,
  44                         kimage->segment[i].mem,
  45                         kimage->segment[i].mem + kimage->segment[i].memsz,
  46                         (unsigned long)kimage->segment[i].memsz,
  47                         (unsigned long)kimage->segment[i].memsz /  PAGE_SIZE);
  48         }
  49 }
  50
  51 int
  52 machine_kexec_prepare(struct kimage *kimage)
  53 {
  54         kexec_image_info(kimage);
  55
  56         if (_machine_kexec_prepare)
  57                 return _machine_kexec_prepare(kimage);
  58         return 0;
  59 }
  60
  61 void
  62 machine_kexec_cleanup(struct kimage *kimage)
  63 {
  64 }
  65
  66 void
  67 machine_shutdown(void)
  68 {
  69         if (_machine_kexec_shutdown)
  70                 _machine_kexec_shutdown();
  71 }
  72
  73 void
  74 machine_crash_shutdown(struct pt_regs *regs)
  75 {
  76         if (_machine_crash_shutdown)
  77                 _machine_crash_shutdown(regs);
  78         else
  79                 default_machine_crash_shutdown(regs);
  80 }
  81
  82 typedef void (*noretfun_t)(void) __noreturn;
  83
  84 void
  85 machine_kexec(struct kimage *image)
  86 {
  87         unsigned long reboot_code_buffer;
  88         unsigned long entry;
  89         unsigned long *ptr;
  90
  91         reboot_code_buffer =
  92           (unsigned long)page_address(image->control_code_page);
  93
  94         kexec_start_address =
  95                 (unsigned long) phys_to_virt(image->start);
  96
  97         if (image->type == KEXEC_TYPE_DEFAULT) {
  98                 kexec_indirection_page =
  99                         (unsigned long) phys_to_virt(image->head & PAGE_MASK);
 100         } else {
 101                 kexec_indirection_page = (unsigned long)&image->head;
 102         }
 103
 104         memcpy((void*)reboot_code_buffer, relocate_new_kernel,
 105                relocate_new_kernel_size);
 106
 107         /*
 108          * The generic kexec code builds a page list with physical
 109          * addresses. they are directly accessible through KSEG0 (or
 110          * CKSEG0 or XPHYS if on 64bit system), hence the
 111          * phys_to_virt() call.
 112          */
 113         for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
 114              ptr = (entry & IND_INDIRECTION) ?
 115                phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
 116                 if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
 117                     *ptr & IND_DESTINATION)
 118                         *ptr = (unsigned long) phys_to_virt(*ptr);
 119         }
 120
 121         /*
 122          * we do not want to be bothered.
 123          */
 124         local_irq_disable();
 125
 126         printk("Will call new kernel at %08lx\n", image->start);
 127         printk("Bye ...\n");
 128         __flush_cache_all();
 129 #ifdef CONFIG_SMP
 130         /* All secondary cpus now may jump to kexec_wait cycle */
 131         relocated_kexec_smp_wait = reboot_code_buffer +
 132                 (void *)(kexec_smp_wait - relocate_new_kernel);
 133         smp_wmb();
 134         atomic_set(&kexec_ready_to_reboot, 1);
 135 #endif
 136         ((noretfun_t) reboot_code_buffer)();
 137 }