Merge commit 'v2.6.39' into 20110526
[linux-2.6.git] / arch / arm / kernel / machine_kexec.c
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         return 0;
36 }
37
38 void machine_kexec_cleanup(struct kimage *image)
39 {
40 }
41
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
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
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 }