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