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>
21 #include <asm/set_memory.h>
23 extern void relocate_new_kernel(void);
24 extern const unsigned int relocate_new_kernel_size;
26 extern unsigned long kexec_start_address;
27 extern unsigned long kexec_indirection_page;
28 extern unsigned long kexec_mach_type;
29 extern unsigned long kexec_boot_atags;
31 static atomic_t waiting_for_crash_ipi;
33 static unsigned long dt_mem;
35 * Provide a dummy crash_notes definition while crash dump arrives to arm.
36 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
39 int machine_kexec_prepare(struct kimage *image)
41 struct kexec_segment *current_segment;
46 * Validate that if the current HW supports SMP, then the SW supports
47 * and implements CPU hotplug for the current HW. If not, we won't be
48 * able to kexec reliably, so fail the prepare operation.
50 if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
51 !platform_can_cpu_hotplug())
55 * No segment at default ATAGs address. try to locate
58 for (i = 0; i < image->nr_segments; i++) {
59 current_segment = &image->segment[i];
61 if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
62 current_segment->memsz))
65 err = get_user(header, (__be32*)current_segment->buf);
69 if (be32_to_cpu(header) == OF_DT_HEADER)
70 dt_mem = current_segment->mem;
75 void machine_kexec_cleanup(struct kimage *image)
79 void machine_crash_nonpanic_core(void *unused)
83 crash_setup_regs(®s, NULL);
84 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
86 crash_save_cpu(®s, smp_processor_id());
89 set_cpu_online(smp_processor_id(), false);
90 atomic_dec(&waiting_for_crash_ipi);
95 static void machine_kexec_mask_interrupts(void)
98 struct irq_desc *desc;
100 for_each_irq_desc(i, desc) {
101 struct irq_chip *chip;
103 chip = irq_desc_get_chip(desc);
107 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
108 chip->irq_eoi(&desc->irq_data);
111 chip->irq_mask(&desc->irq_data);
113 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
114 chip->irq_disable(&desc->irq_data);
118 void machine_crash_shutdown(struct pt_regs *regs)
124 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
125 smp_call_function(machine_crash_nonpanic_core, NULL, false);
126 msecs = 1000; /* Wait at most a second for the other cpus to stop */
127 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
131 if (atomic_read(&waiting_for_crash_ipi) > 0)
132 pr_warn("Non-crashing CPUs did not react to IPI\n");
134 crash_save_cpu(regs, smp_processor_id());
135 machine_kexec_mask_interrupts();
137 pr_info("Loading crashdump kernel...\n");
141 * Function pointer to optional machine-specific reinitialization
143 void (*kexec_reinit)(void);
145 void machine_kexec(struct kimage *image)
147 unsigned long page_list, reboot_entry_phys;
148 void (*reboot_entry)(void);
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 reboot_code_buffer = page_address(image->control_code_page);
163 /* Prepare parameters for reboot_code_buffer*/
164 set_kernel_text_rw();
165 kexec_start_address = image->start;
166 kexec_indirection_page = page_list;
167 kexec_mach_type = machine_arch_type;
168 kexec_boot_atags = dt_mem ?: image->start - KEXEC_ARM_ZIMAGE_OFFSET
169 + KEXEC_ARM_ATAGS_OFFSET;
171 /* copy our kernel relocation code to the control code page */
172 reboot_entry = fncpy(reboot_code_buffer,
173 &relocate_new_kernel,
174 relocate_new_kernel_size);
176 /* get the identity mapping physical address for the reboot code */
177 reboot_entry_phys = virt_to_idmap(reboot_entry);
184 soft_restart(reboot_entry_phys);
187 void arch_crash_save_vmcoreinfo(void)
189 #ifdef CONFIG_ARM_LPAE
190 VMCOREINFO_CONFIG(ARM_LPAE);