Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / arch / arm / kernel / machine_kexec.c
blob8cf0996aa1a8d795bfdb65add498aa1552829382
1 /*
2 * machine_kexec.c - handle transition of Linux booting another kernel
3 */
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/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;
33 * Provide a dummy crash_notes definition while crash dump arrives to arm.
34 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
37 int machine_kexec_prepare(struct kimage *image)
39 struct kexec_segment *current_segment;
40 __be32 header;
41 int i, err;
44 * Validate that if the current HW supports SMP, then the SW supports
45 * and implements CPU hotplug for the current HW. If not, we won't be
46 * able to kexec reliably, so fail the prepare operation.
48 if (num_possible_cpus() > 1 && !platform_can_cpu_hotplug())
49 return -EINVAL;
52 * No segment at default ATAGs address. try to locate
53 * a dtb using magic.
55 for (i = 0; i < image->nr_segments; i++) {
56 current_segment = &image->segment[i];
58 if (!memblock_is_region_memory(current_segment->mem,
59 current_segment->memsz))
60 return -EINVAL;
62 err = get_user(header, (__be32*)current_segment->buf);
63 if (err)
64 return err;
66 if (be32_to_cpu(header) == OF_DT_HEADER)
67 kexec_boot_atags = current_segment->mem;
69 return 0;
72 void machine_kexec_cleanup(struct kimage *image)
76 void machine_crash_nonpanic_core(void *unused)
78 struct pt_regs regs;
80 crash_setup_regs(&regs, NULL);
81 printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
82 smp_processor_id());
83 crash_save_cpu(&regs, smp_processor_id());
84 flush_cache_all();
86 set_cpu_online(smp_processor_id(), false);
87 atomic_dec(&waiting_for_crash_ipi);
88 while (1)
89 cpu_relax();
92 static void machine_kexec_mask_interrupts(void)
94 unsigned int i;
95 struct irq_desc *desc;
97 for_each_irq_desc(i, desc) {
98 struct irq_chip *chip;
100 chip = irq_desc_get_chip(desc);
101 if (!chip)
102 continue;
104 if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
105 chip->irq_eoi(&desc->irq_data);
107 if (chip->irq_mask)
108 chip->irq_mask(&desc->irq_data);
110 if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
111 chip->irq_disable(&desc->irq_data);
115 void machine_crash_shutdown(struct pt_regs *regs)
117 unsigned long msecs;
119 local_irq_disable();
121 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
122 smp_call_function(machine_crash_nonpanic_core, NULL, false);
123 msecs = 1000; /* Wait at most a second for the other cpus to stop */
124 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
125 mdelay(1);
126 msecs--;
128 if (atomic_read(&waiting_for_crash_ipi) > 0)
129 printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
131 crash_save_cpu(regs, smp_processor_id());
132 machine_kexec_mask_interrupts();
134 printk(KERN_INFO "Loading crashdump kernel...\n");
138 * Function pointer to optional machine-specific reinitialization
140 void (*kexec_reinit)(void);
142 void machine_kexec(struct kimage *image)
144 unsigned long page_list;
145 unsigned long reboot_code_buffer_phys;
146 unsigned long reboot_entry = (unsigned long)relocate_new_kernel;
147 unsigned long reboot_entry_phys;
148 void *reboot_code_buffer;
151 * This can only happen if machine_shutdown() failed to disable some
152 * CPU, and that can only happen if the checks in
153 * machine_kexec_prepare() were not correct. If this fails, we can't
154 * reliably kexec anyway, so BUG_ON is appropriate.
156 BUG_ON(num_online_cpus() > 1);
158 page_list = image->head & PAGE_MASK;
160 /* we need both effective and real address here */
161 reboot_code_buffer_phys =
162 page_to_pfn(image->control_code_page) << PAGE_SHIFT;
163 reboot_code_buffer = page_address(image->control_code_page);
165 /* Prepare parameters for reboot_code_buffer*/
166 kexec_start_address = image->start;
167 kexec_indirection_page = page_list;
168 kexec_mach_type = machine_arch_type;
169 if (!kexec_boot_atags)
170 kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
173 /* copy our kernel relocation code to the control code page */
174 reboot_entry = fncpy(reboot_code_buffer,
175 reboot_entry,
176 relocate_new_kernel_size);
177 reboot_entry_phys = (unsigned long)reboot_entry +
178 (reboot_code_buffer_phys - (unsigned long)reboot_code_buffer);
180 printk(KERN_INFO "Bye!\n");
182 if (kexec_reinit)
183 kexec_reinit();
185 soft_restart(reboot_entry_phys);
188 void arch_crash_save_vmcoreinfo(void)
190 #ifdef CONFIG_ARM_LPAE
191 VMCOREINFO_CONFIG(ARM_LPAE);
192 #endif