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
);