machine_kexec.c 4.7 KB

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  1. /*
  2. * machine_kexec.c - handle transition of Linux booting another kernel
  3. */
  4. #include <linux/mm.h>
  5. #include <linux/kexec.h>
  6. #include <linux/delay.h>
  7. #include <linux/reboot.h>
  8. #include <linux/io.h>
  9. #include <linux/irq.h>
  10. #include <linux/memblock.h>
  11. #include <asm/pgtable.h>
  12. #include <linux/of_fdt.h>
  13. #include <asm/pgalloc.h>
  14. #include <asm/mmu_context.h>
  15. #include <asm/cacheflush.h>
  16. #include <asm/mach-types.h>
  17. #include <asm/smp_plat.h>
  18. #include <asm/system_misc.h>
  19. extern const unsigned char relocate_new_kernel[];
  20. extern const unsigned int relocate_new_kernel_size;
  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. static atomic_t waiting_for_crash_ipi;
  26. /*
  27. * Provide a dummy crash_notes definition while crash dump arrives to arm.
  28. * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  29. */
  30. int machine_kexec_prepare(struct kimage *image)
  31. {
  32. struct kexec_segment *current_segment;
  33. __be32 header;
  34. int i, err;
  35. /*
  36. * Validate that if the current HW supports SMP, then the SW supports
  37. * and implements CPU hotplug for the current HW. If not, we won't be
  38. * able to kexec reliably, so fail the prepare operation.
  39. */
  40. if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug())
  41. return -EINVAL;
  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. if (!memblock_is_region_memory(current_segment->mem,
  49. current_segment->memsz))
  50. return -EINVAL;
  51. err = get_user(header, (__be32*)current_segment->buf);
  52. if (err)
  53. return err;
  54. if (be32_to_cpu(header) == OF_DT_HEADER)
  55. kexec_boot_atags = current_segment->mem;
  56. }
  57. return 0;
  58. }
  59. void machine_kexec_cleanup(struct kimage *image)
  60. {
  61. }
  62. void machine_crash_nonpanic_core(void *unused)
  63. {
  64. struct pt_regs regs;
  65. crash_setup_regs(&regs, NULL);
  66. printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  67. smp_processor_id());
  68. crash_save_cpu(&regs, smp_processor_id());
  69. flush_cache_all();
  70. set_cpu_online(smp_processor_id(), false);
  71. atomic_dec(&waiting_for_crash_ipi);
  72. while (1)
  73. cpu_relax();
  74. }
  75. static void machine_kexec_mask_interrupts(void)
  76. {
  77. unsigned int i;
  78. struct irq_desc *desc;
  79. for_each_irq_desc(i, desc) {
  80. struct irq_chip *chip;
  81. chip = irq_desc_get_chip(desc);
  82. if (!chip)
  83. continue;
  84. if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  85. chip->irq_eoi(&desc->irq_data);
  86. if (chip->irq_mask)
  87. chip->irq_mask(&desc->irq_data);
  88. if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  89. chip->irq_disable(&desc->irq_data);
  90. }
  91. }
  92. void machine_crash_shutdown(struct pt_regs *regs)
  93. {
  94. unsigned long msecs;
  95. local_irq_disable();
  96. atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  97. smp_call_function(machine_crash_nonpanic_core, NULL, false);
  98. msecs = 1000; /* Wait at most a second for the other cpus to stop */
  99. while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  100. mdelay(1);
  101. msecs--;
  102. }
  103. if (atomic_read(&waiting_for_crash_ipi) > 0)
  104. printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
  105. crash_save_cpu(regs, smp_processor_id());
  106. machine_kexec_mask_interrupts();
  107. printk(KERN_INFO "Loading crashdump kernel...\n");
  108. }
  109. /*
  110. * Function pointer to optional machine-specific reinitialization
  111. */
  112. void (*kexec_reinit)(void);
  113. void machine_kexec(struct kimage *image)
  114. {
  115. unsigned long page_list;
  116. unsigned long reboot_code_buffer_phys;
  117. void *reboot_code_buffer;
  118. /*
  119. * This can only happen if machine_shutdown() failed to disable some
  120. * CPU, and that can only happen if the checks in
  121. * machine_kexec_prepare() were not correct. If this fails, we can't
  122. * reliably kexec anyway, so BUG_ON is appropriate.
  123. */
  124. BUG_ON(num_online_cpus() > 1);
  125. page_list = image->head & PAGE_MASK;
  126. /* we need both effective and real address here */
  127. reboot_code_buffer_phys =
  128. page_to_pfn(image->control_code_page) << PAGE_SHIFT;
  129. reboot_code_buffer = page_address(image->control_code_page);
  130. /* Prepare parameters for reboot_code_buffer*/
  131. kexec_start_address = image->start;
  132. kexec_indirection_page = page_list;
  133. kexec_mach_type = machine_arch_type;
  134. if (!kexec_boot_atags)
  135. kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
  136. /* copy our kernel relocation code to the control code page */
  137. memcpy(reboot_code_buffer,
  138. relocate_new_kernel, relocate_new_kernel_size);
  139. flush_icache_range((unsigned long) reboot_code_buffer,
  140. (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
  141. printk(KERN_INFO "Bye!\n");
  142. if (kexec_reinit)
  143. kexec_reinit();
  144. soft_restart(reboot_code_buffer_phys);
  145. }