2 * machine_kexec.c - handle transition of Linux booting another kernel
6 #include <linux/kexec.h>
7 #include <linux/delay.h>
8 #include <linux/reboot.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/smp_plat.h>
19 #include <asm/system_misc.h>
21 extern const unsigned char relocate_new_kernel[];
22 extern const unsigned int relocate_new_kernel_size;
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;
29 static atomic_t waiting_for_crash_ipi;
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.
36 int machine_kexec_prepare(struct kimage *image)
38 struct kexec_segment *current_segment;
43 * Validate that if the current HW supports SMP, then the SW supports
44 * and implements CPU hotplug for the current HW. If not, we won't be
45 * able to kexec reliably, so fail the prepare operation.
47 if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug())
51 * No segment at default ATAGs address. try to locate
54 for (i = 0; i < image->nr_segments; i++) {
55 current_segment = &image->segment[i];
57 if (!memblock_is_region_memory(current_segment->mem,
58 current_segment->memsz))
61 err = get_user(header, (__be32*)current_segment->buf);
65 if (be32_to_cpu(header) == OF_DT_HEADER)
66 kexec_boot_atags = current_segment->mem;
71 void machine_kexec_cleanup(struct kimage *image)
75 void machine_crash_nonpanic_core(void *unused)
79 crash_setup_regs(®s, NULL);
80 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
82 crash_save_cpu(®s, smp_processor_id());
85 atomic_dec(&waiting_for_crash_ipi);
90 static void machine_kexec_mask_interrupts(void)
93 struct irq_desc *desc;
95 for_each_irq_desc(i, desc) {
96 struct irq_chip *chip;
98 chip = irq_desc_get_chip(desc);
102 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
103 chip->irq_eoi(&desc->irq_data);
106 chip->irq_mask(&desc->irq_data);
108 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
109 chip->irq_disable(&desc->irq_data);
113 void machine_crash_shutdown(struct pt_regs *regs)
119 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
120 smp_call_function(machine_crash_nonpanic_core, NULL, false);
121 msecs = 1000; /* Wait at most a second for the other cpus to stop */
122 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
126 if (atomic_read(&waiting_for_crash_ipi) > 0)
127 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
129 crash_save_cpu(regs, smp_processor_id());
130 machine_kexec_mask_interrupts();
132 printk(KERN_INFO "Loading crashdump kernel...\n");
136 * Function pointer to optional machine-specific reinitialization
138 void (*kexec_reinit)(void);
140 void machine_kexec(struct kimage *image)
142 unsigned long page_list;
143 unsigned long reboot_code_buffer_phys;
144 void *reboot_code_buffer;
147 * This can only happen if machine_shutdown() failed to disable some
148 * CPU, and that can only happen if the checks in
149 * machine_kexec_prepare() were not correct. If this fails, we can't
150 * reliably kexec anyway, so BUG_ON is appropriate.
152 BUG_ON(num_online_cpus() > 1);
154 page_list = image->head & PAGE_MASK;
156 /* we need both effective and real address here */
157 reboot_code_buffer_phys =
158 page_to_pfn(image->control_code_page) << PAGE_SHIFT;
159 reboot_code_buffer = page_address(image->control_code_page);
161 /* Prepare parameters for reboot_code_buffer*/
162 kexec_start_address = image->start;
163 kexec_indirection_page = page_list;
164 kexec_mach_type = machine_arch_type;
165 if (!kexec_boot_atags)
166 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
169 /* copy our kernel relocation code to the control code page */
170 memcpy(reboot_code_buffer,
171 relocate_new_kernel, relocate_new_kernel_size);
174 flush_icache_range((unsigned long) reboot_code_buffer,
175 (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
176 printk(KERN_INFO "Bye!\n");
181 soft_restart(reboot_code_buffer_phys);