xref: /linux/arch/arm/kernel/machine_kexec.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * machine_kexec.c - handle transition of Linux booting another kernel
3  */
4 
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 <asm/pgtable.h>
11 #include <asm/pgalloc.h>
12 #include <asm/mmu_context.h>
13 #include <asm/cacheflush.h>
14 #include <asm/mach-types.h>
15 
16 extern const unsigned char relocate_new_kernel[];
17 extern const unsigned int relocate_new_kernel_size;
18 
19 extern void setup_mm_for_reboot(char mode);
20 
21 extern unsigned long kexec_start_address;
22 extern unsigned long kexec_indirection_page;
23 extern unsigned long kexec_mach_type;
24 extern unsigned long kexec_boot_atags;
25 
26 static atomic_t waiting_for_crash_ipi;
27 
28 /*
29  * Provide a dummy crash_notes definition while crash dump arrives to arm.
30  * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
31  */
32 
33 int machine_kexec_prepare(struct kimage *image)
34 {
35 	unsigned long page_list;
36 	void *reboot_code_buffer;
37 	page_list = image->head & PAGE_MASK;
38 
39 	reboot_code_buffer = page_address(image->control_code_page);
40 
41 	/* Prepare parameters for reboot_code_buffer*/
42 	kexec_start_address = image->start;
43 	kexec_indirection_page = page_list;
44 	kexec_mach_type = machine_arch_type;
45 	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
46 
47 	/* copy our kernel relocation code to the control code page */
48 	memcpy(reboot_code_buffer,
49 	       relocate_new_kernel, relocate_new_kernel_size);
50 
51 	flush_icache_range((unsigned long) reboot_code_buffer,
52 			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
53 	return 0;
54 }
55 
56 void machine_kexec_cleanup(struct kimage *image)
57 {
58 }
59 
60 void machine_crash_nonpanic_core(void *unused)
61 {
62 	struct pt_regs regs;
63 
64 	crash_setup_regs(&regs, NULL);
65 	printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
66 	       smp_processor_id());
67 	crash_save_cpu(&regs, smp_processor_id());
68 	flush_cache_all();
69 
70 	atomic_dec(&waiting_for_crash_ipi);
71 	while (1)
72 		cpu_relax();
73 }
74 
75 void machine_crash_shutdown(struct pt_regs *regs)
76 {
77 	unsigned long msecs;
78 
79 	local_irq_disable();
80 
81 	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
82 	smp_call_function(machine_crash_nonpanic_core, NULL, false);
83 	msecs = 1000; /* Wait at most a second for the other cpus to stop */
84 	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
85 		mdelay(1);
86 		msecs--;
87 	}
88 	if (atomic_read(&waiting_for_crash_ipi) > 0)
89 		printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
90 
91 	crash_save_cpu(regs, smp_processor_id());
92 
93 	printk(KERN_INFO "Loading crashdump kernel...\n");
94 }
95 
96 /*
97  * Function pointer to optional machine-specific reinitialization
98  */
99 void (*kexec_reinit)(void);
100 
101 void machine_kexec(struct kimage *image)
102 {
103 	unsigned long reboot_code_buffer_phys;
104 	void *reboot_code_buffer;
105 
106 	/* we need both effective and real address here */
107 	reboot_code_buffer_phys =
108 	    page_to_pfn(image->control_code_page) << PAGE_SHIFT;
109 	reboot_code_buffer = page_address(image->control_code_page);
110 
111 	printk(KERN_INFO "Bye!\n");
112 
113 	if (kexec_reinit)
114 		kexec_reinit();
115 	local_irq_disable();
116 	local_fiq_disable();
117 	setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
118 	flush_cache_all();
119 	outer_flush_all();
120 	outer_disable();
121 	cpu_proc_fin();
122 	outer_inv_all();
123 	flush_cache_all();
124 	cpu_reset(reboot_code_buffer_phys);
125 }
126