Linux Kernel  3.7.1
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machine_kexec.c
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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/mach-types.h>
18 #include <asm/system_misc.h>
19 
20 extern const unsigned char relocate_new_kernel[];
21 extern const unsigned int relocate_new_kernel_size;
22 
23 extern unsigned long kexec_start_address;
24 extern unsigned long kexec_indirection_page;
25 extern unsigned long kexec_mach_type;
26 extern unsigned long kexec_boot_atags;
27 
28 static atomic_t waiting_for_crash_ipi;
29 
30 /*
31  * Provide a dummy crash_notes definition while crash dump arrives to arm.
32  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
33  */
34 
35 int machine_kexec_prepare(struct kimage *image)
36 {
37  struct kexec_segment *current_segment;
38  __be32 header;
39  int i, err;
40 
41  /*
42  * No segment at default ATAGs address. try to locate
43  * a dtb using magic.
44  */
45  for (i = 0; i < image->nr_segments; i++) {
46  current_segment = &image->segment[i];
47 
48  if (!memblock_is_region_memory(current_segment->mem,
49  current_segment->memsz))
50  return -EINVAL;
51 
52  err = get_user(header, (__be32*)current_segment->buf);
53  if (err)
54  return err;
55 
56  if (be32_to_cpu(header) == OF_DT_HEADER)
57  kexec_boot_atags = current_segment->mem;
58  }
59  return 0;
60 }
61 
62 void machine_kexec_cleanup(struct kimage *image)
63 {
64 }
65 
67 {
68  struct pt_regs regs;
69 
70  crash_setup_regs(&regs, NULL);
71  printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
75 
76  atomic_dec(&waiting_for_crash_ipi);
77  while (1)
78  cpu_relax();
79 }
80 
81 static void machine_kexec_mask_interrupts(void)
82 {
83  unsigned int i;
84  struct irq_desc *desc;
85 
86  for_each_irq_desc(i, desc) {
87  struct irq_chip *chip;
88 
89  chip = irq_desc_get_chip(desc);
90  if (!chip)
91  continue;
92 
93  if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
94  chip->irq_eoi(&desc->irq_data);
95 
96  if (chip->irq_mask)
97  chip->irq_mask(&desc->irq_data);
98 
99  if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
100  chip->irq_disable(&desc->irq_data);
101  }
102 }
103 
105 {
106  unsigned long msecs;
107 
109 
110  atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
112  msecs = 1000; /* Wait at most a second for the other cpus to stop */
113  while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
114  mdelay(1);
115  msecs--;
116  }
117  if (atomic_read(&waiting_for_crash_ipi) > 0)
118  printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
119 
122 
123  printk(KERN_INFO "Loading crashdump kernel...\n");
124 }
125 
126 /*
127  * Function pointer to optional machine-specific reinitialization
128  */
130 
131 void machine_kexec(struct kimage *image)
132 {
133  unsigned long page_list;
134  unsigned long reboot_code_buffer_phys;
135  void *reboot_code_buffer;
136 
137 
138  page_list = image->head & PAGE_MASK;
139 
140  /* we need both effective and real address here */
141  reboot_code_buffer_phys =
142  page_to_pfn(image->control_code_page) << PAGE_SHIFT;
143  reboot_code_buffer = page_address(image->control_code_page);
144 
145  /* Prepare parameters for reboot_code_buffer*/
146  kexec_start_address = image->start;
147  kexec_indirection_page = page_list;
148  kexec_mach_type = machine_arch_type;
149  if (!kexec_boot_atags)
150  kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
151 
152 
153  /* copy our kernel relocation code to the control code page */
154  memcpy(reboot_code_buffer,
156 
157 
158  flush_icache_range((unsigned long) reboot_code_buffer,
159  (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
160  printk(KERN_INFO "Bye!\n");
161 
162  if (kexec_reinit)
163  kexec_reinit();
164 
165  soft_restart(reboot_code_buffer_phys);
166 }