arch/arm/kernel/machine_kexec.c

   1 /*
   2  * machine_kexec.c - handle transition of Linux booting another kernel
   3  */
   4
   5 #include <linux/mm.h>
   6 #include <linux/kexec.h>
   7 #include <linux/delay.h>
   8 #include <linux/reboot.h>
   9 #include <linux/io.h>
  10 #include <asm/pgtable.h>
  11 #include <asm/pgalloc.h>
  12 #include <asm/mmu_context.h>
  13 #include <asm/cacheflush.h>
  14 #include <asm/mach-types.h>
  15 #include <asm/system.h>
  16
  17 extern const unsigned char relocate_new_kernel[];
  18 extern const unsigned int relocate_new_kernel_size;
  19
  20 extern unsigned long kexec_start_address;
  21 extern unsigned long kexec_indirection_page;
  22 extern unsigned long kexec_mach_type;
  23 extern unsigned long kexec_boot_atags;
  24
  25 static atomic_t waiting_for_crash_ipi;
  26
  27 /*
  28  * Provide a dummy crash_notes definition while crash dump arrives to arm.
  29  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  30  */
  31
  32 int machine_kexec_prepare(struct kimage *image)
  33 {
  34         return 0;
  35 }
  36
  37 void machine_kexec_cleanup(struct kimage *image)
  38 {
  39 }
  40
  41 void machine_crash_nonpanic_core(void *unused)
  42 {
  43         struct pt_regs regs;
  44
  45         crash_setup_regs(&regs, NULL);
  46         printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  47                smp_processor_id());
  48         crash_save_cpu(&regs, smp_processor_id());
  49         flush_cache_all();
  50
  51         atomic_dec(&waiting_for_crash_ipi);
  52         while (1)
  53                 cpu_relax();
  54 }
  55
  56 void machine_crash_shutdown(struct pt_regs *regs)
  57 {
  58         unsigned long msecs;
  59
  60         local_irq_disable();
  61
  62         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  63         smp_call_function(machine_crash_nonpanic_core, NULL, false);
  64         msecs = 1000; /* Wait at most a second for the other cpus to stop */
  65         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  66                 mdelay(1);
  67                 msecs--;
  68         }
  69         if (atomic_read(&waiting_for_crash_ipi) > 0)
  70                 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
  71
  72         crash_save_cpu(regs, smp_processor_id());
  73
  74         printk(KERN_INFO "Loading crashdump kernel...\n");
  75 }
  76
  77 /*
  78  * Function pointer to optional machine-specific reinitialization
  79  */
  80 void (*kexec_reinit)(void);
  81
  82 void machine_kexec(struct kimage *image)
  83 {
  84         unsigned long page_list;
  85         unsigned long reboot_code_buffer_phys;
  86         void *reboot_code_buffer;
  87
  88
  89         page_list = image->head & PAGE_MASK;
  90
  91         /* we need both effective and real address here */
  92         reboot_code_buffer_phys =
  93             page_to_pfn(image->control_code_page) << PAGE_SHIFT;
  94         reboot_code_buffer = page_address(image->control_code_page);
  95
  96         /* Prepare parameters for reboot_code_buffer*/
  97         kexec_start_address = image->start;
  98         kexec_indirection_page = page_list;
  99         kexec_mach_type = machine_arch_type;
 100         kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
 101
 102         /* copy our kernel relocation code to the control code page */
 103         memcpy(reboot_code_buffer,
 104                relocate_new_kernel, relocate_new_kernel_size);
 105
 106
 107         flush_icache_range((unsigned long) reboot_code_buffer,
 108                            (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 109         printk(KERN_INFO "Bye!\n");
 110
 111         if (kexec_reinit)
 112                 kexec_reinit();
 113
 114         soft_restart(reboot_code_buffer_phys);
 115 }