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/fncpy.h>
18 #include <asm/mach-types.h>
19 #include <asm/smp_plat.h>
20 #include <asm/system_misc.h>
22 extern void relocate_new_kernel(void);
23 extern const unsigned int relocate_new_kernel_size;
25 extern unsigned long kexec_start_address;
26 extern unsigned long kexec_indirection_page;
27 extern unsigned long kexec_mach_type;
28 extern unsigned long kexec_boot_atags;
30 static atomic_t waiting_for_crash_ipi;
32 static unsigned long dt_mem;
34 * Provide a dummy crash_notes definition while crash dump arrives to arm.
35 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
38 int machine_kexec_prepare(struct kimage *image)
40 struct kexec_segment *current_segment;
45 * Validate that if the current HW supports SMP, then the SW supports
46 * and implements CPU hotplug for the current HW. If not, we won't be
47 * able to kexec reliably, so fail the prepare operation.
49 if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug())
53 * No segment at default ATAGs address. try to locate
56 for (i = 0; i < image->nr_segments; i++) {
57 current_segment = &image->segment[i];
59 if (!memblock_is_region_memory(current_segment->mem,
60 current_segment->memsz))
63 err = get_user(header, (__be32*)current_segment->buf);
67 if (be32_to_cpu(header) == OF_DT_HEADER)
68 dt_mem = current_segment->mem;
73 void machine_kexec_cleanup(struct kimage *image)
77 void machine_crash_nonpanic_core(void *unused)
81 crash_setup_regs(®s, NULL);
82 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
84 crash_save_cpu(®s, smp_processor_id());
87 set_cpu_online(smp_processor_id(), false);
88 atomic_dec(&waiting_for_crash_ipi);
93 static void machine_kexec_mask_interrupts(void)
96 struct irq_desc *desc;
98 for_each_irq_desc(i, desc) {
99 struct irq_chip *chip;
101 chip = irq_desc_get_chip(desc);
105 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
106 chip->irq_eoi(&desc->irq_data);
109 chip->irq_mask(&desc->irq_data);
111 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
112 chip->irq_disable(&desc->irq_data);
116 void machine_crash_shutdown(struct pt_regs *regs)
122 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
123 smp_call_function(machine_crash_nonpanic_core, NULL, false);
124 msecs = 1000; /* Wait at most a second for the other cpus to stop */
125 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
129 if (atomic_read(&waiting_for_crash_ipi) > 0)
130 pr_warn("Non-crashing CPUs did not react to IPI\n");
132 crash_save_cpu(regs, smp_processor_id());
133 machine_kexec_mask_interrupts();
135 pr_info("Loading crashdump kernel...\n");
139 * Function pointer to optional machine-specific reinitialization
141 void (*kexec_reinit)(void);
143 void machine_kexec(struct kimage *image)
145 unsigned long page_list;
146 unsigned long reboot_code_buffer_phys;
147 unsigned long reboot_entry = (unsigned long)relocate_new_kernel;
148 unsigned long reboot_entry_phys;
149 void *reboot_code_buffer;
152 * This can only happen if machine_shutdown() failed to disable some
153 * CPU, and that can only happen if the checks in
154 * machine_kexec_prepare() were not correct. If this fails, we can't
155 * reliably kexec anyway, so BUG_ON is appropriate.
157 BUG_ON(num_online_cpus() > 1);
159 page_list = image->head & PAGE_MASK;
161 /* we need both effective and real address here */
162 reboot_code_buffer_phys =
163 page_to_pfn(image->control_code_page) << PAGE_SHIFT;
164 reboot_code_buffer = page_address(image->control_code_page);
166 /* Prepare parameters for reboot_code_buffer*/
167 set_kernel_text_rw();
168 kexec_start_address = image->start;
169 kexec_indirection_page = page_list;
170 kexec_mach_type = machine_arch_type;
171 kexec_boot_atags = dt_mem ?: image->start - KEXEC_ARM_ZIMAGE_OFFSET
172 + KEXEC_ARM_ATAGS_OFFSET;
174 /* copy our kernel relocation code to the control code page */
175 reboot_entry = fncpy(reboot_code_buffer,
177 relocate_new_kernel_size);
178 reboot_entry_phys = (unsigned long)reboot_entry +
179 (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer);
186 soft_restart(reboot_entry_phys);
189 void arch_crash_save_vmcoreinfo(void)
191 #ifdef CONFIG_ARM_LPAE
192 VMCOREINFO_CONFIG(ARM_LPAE);