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 <linux/memblock.h>
  12 #include <asm/pgtable.h>
  13 #include <linux/of_fdt.h>
  14 #include <asm/pgalloc.h>
  15 #include <asm/mmu_context.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/fncpy.h>
  18 #include <asm/mach-types.h>
  19 #include <asm/system_misc.h>
  20
  21 extern void relocate_new_kernel(void);
  22 extern const unsigned int relocate_new_kernel_size;
  23
  24 extern unsigned long kexec_start_address;
  25 extern unsigned long kexec_indirection_page;
  26 extern unsigned long kexec_mach_type;
  27 extern unsigned long kexec_boot_atags;
  28
  29 static atomic_t waiting_for_crash_ipi;
  30
  31 /*
  32  * Provide a dummy crash_notes definition while crash dump arrives to arm.
  33  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  34  */
  35
  36 int machine_kexec_prepare(struct kimage *image)
  37 {
  38         struct kexec_segment *current_segment;
  39         __be32 header;
  40         int i, err;
  41
  42         /*
  43          * No segment at default ATAGs address. try to locate
  44          * a dtb using magic.
  45          */
  46         for (i = 0; i < image->nr_segments; i++) {
  47                 current_segment = &image->segment[i];
  48
  49                 if (!memblock_is_region_memory(current_segment->mem,
  50                                                current_segment->memsz))
  51                         return -EINVAL;
  52
  53                 err = get_user(header, (__be32*)current_segment->buf);
  54                 if (err)
  55                         return err;
  56
  57                 if (be32_to_cpu(header) == OF_DT_HEADER)
  58                         kexec_boot_atags = current_segment->mem;
  59         }
  60         return 0;
  61 }
  62
  63 void machine_kexec_cleanup(struct kimage *image)
  64 {
  65 }
  66
  67 void machine_crash_nonpanic_core(void *unused)
  68 {
  69         struct pt_regs regs;
  70
  71         crash_setup_regs(&regs, NULL);
  72         printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  73                smp_processor_id());
  74         crash_save_cpu(&regs, smp_processor_id());
  75         flush_cache_all();
  76
  77         set_cpu_online(smp_processor_id(), false);
  78         atomic_dec(&waiting_for_crash_ipi);
  79         while (1)
  80                 cpu_relax();
  81 }
  82
  83 static void machine_kexec_mask_interrupts(void)
  84 {
  85         unsigned int i;
  86         struct irq_desc *desc;
  87
  88         for_each_irq_desc(i, desc) {
  89                 struct irq_chip *chip;
  90
  91                 chip = irq_desc_get_chip(desc);
  92                 if (!chip)
  93                         continue;
  94
  95                 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  96                         chip->irq_eoi(&desc->irq_data);
  97
  98                 if (chip->irq_mask)
  99                         chip->irq_mask(&desc->irq_data);
 100
 101                 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
 102                         chip->irq_disable(&desc->irq_data);
 103         }
 104 }
 105
 106 void machine_crash_shutdown(struct pt_regs *regs)
 107 {
 108         unsigned long msecs;
 109
 110         local_irq_disable();
 111
 112         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 113         smp_call_function(machine_crash_nonpanic_core, NULL, false);
 114         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 115         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 116                 mdelay(1);
 117                 msecs--;
 118         }
 119         if (atomic_read(&waiting_for_crash_ipi) > 0)
 120                 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
 121
 122         crash_save_cpu(regs, smp_processor_id());
 123         machine_kexec_mask_interrupts();
 124
 125         printk(KERN_INFO "Loading crashdump kernel...\n");
 126 }
 127
 128 /*
 129  * Function pointer to optional machine-specific reinitialization
 130  */
 131 void (*kexec_reinit)(void);
 132
 133 void machine_kexec(struct kimage *image)
 134 {
 135         unsigned long page_list;
 136         unsigned long reboot_code_buffer_phys;
 137         unsigned long reboot_entry = (unsigned long)relocate_new_kernel;
 138         unsigned long reboot_entry_phys;
 139         void *reboot_code_buffer;
 140
 141         if (num_online_cpus() > 1) {
 142                 pr_err("kexec: error: multiple CPUs still online\n");
 143                 return;
 144         }
 145
 146         page_list = image->head & PAGE_MASK;
 147
 148         /* we need both effective and real address here */
 149         reboot_code_buffer_phys =
 150             page_to_pfn(image->control_code_page) << PAGE_SHIFT;
 151         reboot_code_buffer = page_address(image->control_code_page);
 152
 153         /* Prepare parameters for reboot_code_buffer*/
 154         kexec_start_address = image->start;
 155         kexec_indirection_page = page_list;
 156         kexec_mach_type = machine_arch_type;
 157         if (!kexec_boot_atags)
 158                 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
 159
 160
 161         /* copy our kernel relocation code to the control code page */
 162         reboot_entry = fncpy(reboot_code_buffer,
 163                              reboot_entry,
 164                              relocate_new_kernel_size);
 165         reboot_entry_phys = (unsigned long)reboot_entry +
 166                 (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer);
 167
 168         printk(KERN_INFO "Bye!\n");
 169
 170         if (kexec_reinit)
 171                 kexec_reinit();
 172
 173         soft_restart(reboot_entry_phys);
 174 }
 175
 176 void arch_crash_save_vmcoreinfo(void)
 177 {
 178 #ifdef CONFIG_ARM_LPAE
 179         VMCOREINFO_CONFIG(ARM_LPAE);
 180 #endif
 181 }