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 
machine_kexec_prepare(struct kimage * image)33 int machine_kexec_prepare(struct kimage *image)
34 {
35 	return 0;
36 }
37 
machine_kexec_cleanup(struct kimage * image)38 void machine_kexec_cleanup(struct kimage *image)
39 {
40 }
41 
machine_crash_nonpanic_core(void * unused)42 void machine_crash_nonpanic_core(void *unused)
43 {
44 	struct pt_regs regs;
45 
46 	crash_setup_regs(&regs, NULL);
47 	printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
48 	       smp_processor_id());
49 	crash_save_cpu(&regs, smp_processor_id());
50 	flush_cache_all();
51 
52 	atomic_dec(&waiting_for_crash_ipi);
53 	while (1)
54 		cpu_relax();
55 }
56 
machine_crash_shutdown(struct pt_regs * regs)57 void machine_crash_shutdown(struct pt_regs *regs)
58 {
59 	unsigned long msecs;
60 
61 	local_irq_disable();
62 
63 	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
64 	smp_call_function(machine_crash_nonpanic_core, NULL, false);
65 	msecs = 1000; /* Wait at most a second for the other cpus to stop */
66 	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
67 		mdelay(1);
68 		msecs--;
69 	}
70 	if (atomic_read(&waiting_for_crash_ipi) > 0)
71 		printk(KERN_WARNING "Non-crashing CPUs did not react to IPI\n");
72 
73 	crash_save_cpu(regs, smp_processor_id());
74 
75 	printk(KERN_INFO "Loading crashdump kernel...\n");
76 }
77 
78 /*
79  * Function pointer to optional machine-specific reinitialization
80  */
81 void (*kexec_reinit)(void);
82 
machine_kexec(struct kimage * image)83 void machine_kexec(struct kimage *image)
84 {
85 	unsigned long page_list;
86 	unsigned long reboot_code_buffer_phys;
87 	void *reboot_code_buffer;
88 
89 
90 	page_list = image->head & PAGE_MASK;
91 
92 	/* we need both effective and real address here */
93 	reboot_code_buffer_phys =
94 	    page_to_pfn(image->control_code_page) << PAGE_SHIFT;
95 	reboot_code_buffer = page_address(image->control_code_page);
96 
97 	/* Prepare parameters for reboot_code_buffer*/
98 	kexec_start_address = image->start;
99 	kexec_indirection_page = page_list;
100 	kexec_mach_type = machine_arch_type;
101 	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
102 
103 	/* copy our kernel relocation code to the control code page */
104 	memcpy(reboot_code_buffer,
105 	       relocate_new_kernel, relocate_new_kernel_size);
106 
107 
108 	flush_icache_range((unsigned long) reboot_code_buffer,
109 			   (unsigned long) reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
110 	printk(KERN_INFO "Bye!\n");
111 
112 	if (kexec_reinit)
113 		kexec_reinit();
114 	local_irq_disable();
115 	local_fiq_disable();
116 	setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
117 	flush_cache_all();
118 	outer_flush_all();
119 	outer_disable();
120 	cpu_proc_fin();
121 	outer_inv_all();
122 	flush_cache_all();
123 	cpu_reset(reboot_code_buffer_phys);
124 }
125