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 <linux/irq.h>
  11 #include <asm/pgtable.h>
  12 #include <asm/pgalloc.h>
  13 #include <asm/mmu_context.h>
  14 #include <asm/cacheflush.h>
  15 #include <asm/mach-types.h>
  16 #include <asm/system_misc.h>
  17
  18 extern const unsigned char relocate_new_kernel[];
  19 extern const unsigned int relocate_new_kernel_size;
  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 static void machine_kexec_mask_interrupts(void)
  58 {
  59         unsigned int i;
  60         struct irq_desc *desc;
  61
  62         for_each_irq_desc(i, desc) {
  63                 struct irq_chip *chip;
  64
  65                 chip = irq_desc_get_chip(desc);
  66                 if (!chip)
  67                         continue;
  68
  69                 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  70                         chip->irq_eoi(&desc->irq_data);
  71
  72                 if (chip->irq_mask)
  73                         chip->irq_mask(&desc->irq_data);
  74
  75                 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  76                         chip->irq_disable(&desc->irq_data);
  77         }
  78 }
  79
  80 void machine_crash_shutdown(struct pt_regs *regs)
  81 {
  82         unsigned long msecs;
  83
  84         local_irq_disable();
  85
  86         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  87         smp_call_function(machine_crash_nonpanic_core, NULL, false);
  88         msecs = 1000; /* Wait at most a second for the other cpus to stop */
  89         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  90                 mdelay(1);
  91                 msecs--;
  92         }
  93         if (atomic_read(&waiting_for_crash_ipi) > 0)
  94                 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
  95
  96         crash_save_cpu(regs, smp_processor_id());
  97         machine_kexec_mask_interrupts();
  98
  99         printk(KERN_INFO "Loading crashdump kernel...\n");
 100 }
 101
 102 /*
 103  * Function pointer to optional machine-specific reinitialization
 104  */
 105 void (*kexec_reinit)(void);
 106
 107 void machine_kexec(struct kimage *image)
 108 {
 109         unsigned long page_list;
 110         unsigned long reboot_code_buffer_phys;
 111         void *reboot_code_buffer;
 112
 113
 114         page_list = image->head & PAGE_MASK;
 115
 116         /* we need both effective and real address here */
 117         reboot_code_buffer_phys =
 118             page_to_pfn(image->control_code_page) << PAGE_SHIFT;
 119         reboot_code_buffer = page_address(image->control_code_page);
 120
 121         /* Prepare parameters for reboot_code_buffer*/
 122         kexec_start_address = image->start;
 123         kexec_indirection_page = page_list;
 124         kexec_mach_type = machine_arch_type;
 125         kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
 126
 127         /* copy our kernel relocation code to the control code page */
 128         memcpy(reboot_code_buffer,
 129                relocate_new_kernel, relocate_new_kernel_size);
 130
 131
 132         flush_icache_range((unsigned long) reboot_code_buffer,
 133                            (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
 134         printk(KERN_INFO "Bye!\n");
 135
 136         if (kexec_reinit)
 137                 kexec_reinit();
 138
 139         soft_restart(reboot_code_buffer_phys);
 140 }