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         unsigned long page_list;
  36         void *reboot_code_buffer;
  37         page_list = image->head & PAGE_MASK;
  38
  39         reboot_code_buffer = page_address(image->control_code_page);
  40
  41         /* Prepare parameters for reboot_code_buffer*/
  42         kexec_start_address = image->start;
  43         kexec_indirection_page = page_list;
  44         kexec_mach_type = machine_arch_type;
  45         kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
  46
  47         /* copy our kernel relocation code to the control code page */
  48         memcpy(reboot_code_buffer,
  49                relocate_new_kernel, relocate_new_kernel_size);
  50
  51         flush_icache_range((unsigned long) reboot_code_buffer,
  52                            (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
  53         return 0;
  54 }
  55
  56 void machine_kexec_cleanup(struct kimage *image)
  57 {
  58 }
  59
  60 void machine_crash_nonpanic_core(void *unused)
  61 {
  62         struct pt_regs regs;
  63
  64         crash_setup_regs(&regs, NULL);
  65         printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  66                smp_processor_id());
  67         crash_save_cpu(&regs, smp_processor_id());
  68         flush_cache_all();
  69
  70         atomic_dec(&waiting_for_crash_ipi);
  71         while (1)
  72                 cpu_relax();
  73 }
  74
  75 void machine_crash_shutdown(struct pt_regs *regs)
  76 {
  77         unsigned long msecs;
  78
  79         local_irq_disable();
  80
  81         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  82         smp_call_function(machine_crash_nonpanic_core, NULL, false);
  83         msecs = 1000; /* Wait at most a second for the other cpus to stop */
  84         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  85                 mdelay(1);
  86                 msecs--;
  87         }
  88         if (atomic_read(&waiting_for_crash_ipi) > 0)
  89                 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
  90
  91         crash_save_cpu(regs, smp_processor_id());
  92
  93         printk(KERN_INFO "Loading crashdump kernel...\n");
  94 }
  95
  96 /*
  97  * Function pointer to optional machine-specific reinitialization
  98  */
  99 void (*kexec_reinit)(void);
 100
 101 void machine_kexec(struct kimage *image)
 102 {
 103         unsigned long reboot_code_buffer_phys;
 104         void *reboot_code_buffer;
 105
 106         /* we need both effective and real address here */
 107         reboot_code_buffer_phys =
 108             page_to_pfn(image->control_code_page) << PAGE_SHIFT;
 109         reboot_code_buffer = page_address(image->control_code_page);
 110
 111         printk(KERN_INFO "Bye!\n");
 112
 113         if (kexec_reinit)
 114                 kexec_reinit();
 115         local_irq_disable();
 116         local_fiq_disable();
 117         setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
 118         flush_cache_all();
 119         outer_flush_all();
 120         outer_disable();
 121         cpu_proc_fin();
 122         outer_inv_all();
 123         flush_cache_all();
 124         cpu_reset(reboot_code_buffer_phys);
 125 }