machine_kexec.c 4.8 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * machine_kexec.c - handle transition of Linux booting another kernel
  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 <linux/of_fdt.h>
  13. #include <asm/mmu_context.h>
  14. #include <asm/cacheflush.h>
  15. #include <asm/kexec-internal.h>
  16. #include <asm/fncpy.h>
  17. #include <asm/mach-types.h>
  18. #include <asm/smp_plat.h>
  19. #include <asm/system_misc.h>
  20. #include <asm/set_memory.h>
  21. extern void relocate_new_kernel(void);
  22. extern const unsigned int relocate_new_kernel_size;
  23. static atomic_t waiting_for_crash_ipi;
  24. /*
  25. * Provide a dummy crash_notes definition while crash dump arrives to arm.
  26. * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
  27. */
  28. int machine_kexec_prepare(struct kimage *image)
  29. {
  30. struct kexec_segment *current_segment;
  31. __be32 header;
  32. int i, err;
  33. image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
  34. + KEXEC_ARM_ATAGS_OFFSET;
  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_secondary_boot() &&
  41. !platform_can_cpu_hotplug())
  42. return -EINVAL;
  43. /*
  44. * No segment at default ATAGs address. try to locate
  45. * a dtb using magic.
  46. */
  47. for (i = 0; i < image->nr_segments; i++) {
  48. current_segment = &image->segment[i];
  49. if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
  50. current_segment->memsz))
  51. return -EINVAL;
  52. err = get_user(header, (__be32*)current_segment->buf);
  53. if (err)
  54. return err;
  55. if (header == cpu_to_be32(OF_DT_HEADER))
  56. image->arch.kernel_r2 = current_segment->mem;
  57. }
  58. return 0;
  59. }
  60. void machine_kexec_cleanup(struct kimage *image)
  61. {
  62. }
  63. void machine_crash_nonpanic_core(void *unused)
  64. {
  65. struct pt_regs regs;
  66. crash_setup_regs(&regs, get_irq_regs());
  67. printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
  68. smp_processor_id());
  69. crash_save_cpu(&regs, smp_processor_id());
  70. flush_cache_all();
  71. set_cpu_online(smp_processor_id(), false);
  72. atomic_dec(&waiting_for_crash_ipi);
  73. while (1) {
  74. cpu_relax();
  75. wfe();
  76. }
  77. }
  78. void crash_smp_send_stop(void)
  79. {
  80. static int cpus_stopped;
  81. unsigned long msecs;
  82. if (cpus_stopped)
  83. return;
  84. atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
  85. smp_call_function(machine_crash_nonpanic_core, NULL, false);
  86. msecs = 1000; /* Wait at most a second for the other cpus to stop */
  87. while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
  88. mdelay(1);
  89. msecs--;
  90. }
  91. if (atomic_read(&waiting_for_crash_ipi) > 0)
  92. pr_warn("Non-crashing CPUs did not react to IPI\n");
  93. cpus_stopped = 1;
  94. }
  95. static void machine_kexec_mask_interrupts(void)
  96. {
  97. unsigned int i;
  98. struct irq_desc *desc;
  99. for_each_irq_desc(i, desc) {
  100. struct irq_chip *chip;
  101. chip = irq_desc_get_chip(desc);
  102. if (!chip)
  103. continue;
  104. if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
  105. chip->irq_eoi(&desc->irq_data);
  106. if (chip->irq_mask)
  107. chip->irq_mask(&desc->irq_data);
  108. if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
  109. chip->irq_disable(&desc->irq_data);
  110. }
  111. }
  112. void machine_crash_shutdown(struct pt_regs *regs)
  113. {
  114. local_irq_disable();
  115. crash_smp_send_stop();
  116. crash_save_cpu(regs, smp_processor_id());
  117. machine_kexec_mask_interrupts();
  118. pr_info("Loading crashdump kernel...\n");
  119. }
  120. /*
  121. * Function pointer to optional machine-specific reinitialization
  122. */
  123. void (*kexec_reinit)(void);
  124. void machine_kexec(struct kimage *image)
  125. {
  126. unsigned long page_list, reboot_entry_phys;
  127. struct kexec_relocate_data *data;
  128. void (*reboot_entry)(void);
  129. void *reboot_code_buffer;
  130. /*
  131. * This can only happen if machine_shutdown() failed to disable some
  132. * CPU, and that can only happen if the checks in
  133. * machine_kexec_prepare() were not correct. If this fails, we can't
  134. * reliably kexec anyway, so BUG_ON is appropriate.
  135. */
  136. BUG_ON(num_online_cpus() > 1);
  137. page_list = image->head & PAGE_MASK;
  138. reboot_code_buffer = page_address(image->control_code_page);
  139. /* copy our kernel relocation code to the control code page */
  140. reboot_entry = fncpy(reboot_code_buffer,
  141. &relocate_new_kernel,
  142. relocate_new_kernel_size);
  143. data = reboot_code_buffer + relocate_new_kernel_size;
  144. data->kexec_start_address = image->start;
  145. data->kexec_indirection_page = page_list;
  146. data->kexec_mach_type = machine_arch_type;
  147. data->kexec_r2 = image->arch.kernel_r2;
  148. /* get the identity mapping physical address for the reboot code */
  149. reboot_entry_phys = virt_to_idmap(reboot_entry);
  150. pr_info("Bye!\n");
  151. if (kexec_reinit)
  152. kexec_reinit();
  153. soft_restart(reboot_entry_phys);
  154. }
  155. void arch_crash_save_vmcoreinfo(void)
  156. {
  157. #ifdef CONFIG_ARM_LPAE
  158. VMCOREINFO_CONFIG(ARM_LPAE);
  159. #endif
  160. }