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
  16 extern const unsigned char relocate_new_kernel[];
  17 extern const unsigned int relocate_new_kernel_size;
  18
  19 extern void setup_mm_for_reboot(char mode);
  20
  21 extern unsigned long kexec_start_address;
  22 extern unsigned long kexec_indirection_page;
  23 extern unsigned long kexec_mach_type;
  24 extern unsigned long kexec_boot_atags;
  25
  26 static atomic_t waiting_for_crash_ipi;
  27
  28 /*
  29  * Provide a dummy crash_notes definition while crash dump arrives to arm.
  30  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  31  */
  32
  33 int machine_kexec_prepare(struct kimage *image)
  34 {
  35         return 0;
  36 }
  37
  38 void machine_kexec_cleanup(struct kimage *image)
  39 {
  40 }
  41
  42 void machine_crash_nonpanic_core(void *unused)
  43 {
  44         struct pt_regs regs;
  45
  46         crash_setup_regs(&regs, NULL);
  47         printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  48                smp_processor_id());
  49         crash_save_cpu(&regs, smp_processor_id());
  50         flush_cache_all();
  51
  52         atomic_dec(&waiting_for_crash_ipi);
  53         while (1)
  54                 cpu_relax();
  55 }
  56
  57 void machine_crash_shutdown(struct pt_regs *regs)
  58 {
  59         unsigned long msecs;
  60
  61         local_irq_disable();
  62
  63         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  64         smp_call_function(machine_crash_nonpanic_core, NULL, false);
  65         msecs = 1000; /* Wait at most a second for the other cpus to stop */
  66         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  67                 mdelay(1);
  68                 msecs--;
  69         }
  70         if (atomic_read(&waiting_for_crash_ipi) > 0)
  71                 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
  72
  73         crash_save_cpu(regs, smp_processor_id());
  74
  75         printk(KERN_INFO "Loading crashdump kernel...\n");
  76 }
  77
  78 void machine_kexec(struct kimage *image)
  79 {
  80         unsigned long page_list;
  81         unsigned long reboot_code_buffer_phys;
  82         void *reboot_code_buffer;
  83
  84
  85         page_list = image->head & PAGE_MASK;
  86
  87         /* we need both effective and real address here */
  88         reboot_code_buffer_phys =
  89             page_to_pfn(image->control_code_page) << PAGE_SHIFT;
  90         reboot_code_buffer = page_address(image->control_code_page);
  91
  92         /* Prepare parameters for reboot_code_buffer*/
  93         kexec_start_address = image->start;
  94         kexec_indirection_page = page_list;
  95         kexec_mach_type = machine_arch_type;
  96         kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
  97
  98         /* copy our kernel relocation code to the control code page */
  99         memcpy(reboot_code_buffer,
 100                relocate_new_kernel, relocate_new_kernel_size);
 101
 102
 103         flush_icache_range((unsigned long) reboot_code_buffer,
 104                            (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 105         printk(KERN_INFO "Bye!\n");
 106
 107         local_irq_disable();
 108         local_fiq_disable();
 109         setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
 110         flush_cache_all();
 111         outer_flush_all();
 112         outer_disable();
 113         cpu_proc_fin();
 114         outer_inv_all();
 115         flush_cache_all();
 116         cpu_reset(reboot_code_buffer_phys);
 117 }