xref: /openbmc/linux/arch/sh/kernel/machine_kexec.c (revision b627b4ed)
1 /*
2  * machine_kexec.c - handle transition of Linux booting another kernel
3  * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
4  *
5  * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
6  * LANDISK/sh4 supported by kogiidena
7  *
8  * This source code is licensed under the GNU General Public License,
9  * Version 2.  See the file COPYING for more details.
10  */
11 
12 #include <linux/mm.h>
13 #include <linux/kexec.h>
14 #include <linux/delay.h>
15 #include <linux/reboot.h>
16 #include <linux/numa.h>
17 #include <linux/ftrace.h>
18 #include <linux/suspend.h>
19 #include <asm/pgtable.h>
20 #include <asm/pgalloc.h>
21 #include <asm/mmu_context.h>
22 #include <asm/io.h>
23 #include <asm/cacheflush.h>
24 
25 typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
26 				      unsigned long reboot_code_buffer,
27 				      unsigned long start_address);
28 
29 extern const unsigned char relocate_new_kernel[];
30 extern const unsigned int relocate_new_kernel_size;
31 extern void *gdb_vbr_vector;
32 extern void *vbr_base;
33 
34 void machine_shutdown(void)
35 {
36 }
37 
38 void machine_crash_shutdown(struct pt_regs *regs)
39 {
40 }
41 
42 /*
43  * Do what every setup is needed on image and the
44  * reboot code buffer to allow us to avoid allocations
45  * later.
46  */
47 int machine_kexec_prepare(struct kimage *image)
48 {
49 	/* older versions of kexec-tools are passing
50 	 * the zImage entry point as a virtual address.
51 	 */
52 	if (image->start != PHYSADDR(image->start))
53 		return -EINVAL; /* upgrade your kexec-tools */
54 
55 	return 0;
56 }
57 
58 void machine_kexec_cleanup(struct kimage *image)
59 {
60 }
61 
62 static void kexec_info(struct kimage *image)
63 {
64         int i;
65 	printk("kexec information\n");
66 	for (i = 0; i < image->nr_segments; i++) {
67 	        printk("  segment[%d]: 0x%08x - 0x%08x (0x%08x)\n",
68 		       i,
69 		       (unsigned int)image->segment[i].mem,
70 		       (unsigned int)image->segment[i].mem +
71 				     image->segment[i].memsz,
72 		       (unsigned int)image->segment[i].memsz);
73 	}
74 	printk("  start     : 0x%08x\n\n", (unsigned int)image->start);
75 }
76 
77 /*
78  * Do not allocate memory (or fail in any way) in machine_kexec().
79  * We are past the point of no return, committed to rebooting now.
80  */
81 void machine_kexec(struct kimage *image)
82 {
83 	unsigned long page_list;
84 	unsigned long reboot_code_buffer;
85 	relocate_new_kernel_t rnk;
86 	unsigned long entry;
87 	unsigned long *ptr;
88 	int save_ftrace_enabled;
89 
90 	/*
91 	 * Nicked from the mips version of machine_kexec():
92 	 * The generic kexec code builds a page list with physical
93 	 * addresses. Use phys_to_virt() to convert them to virtual.
94 	 */
95 	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
96 	     ptr = (entry & IND_INDIRECTION) ?
97 	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
98 		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
99 		    *ptr & IND_DESTINATION)
100 			*ptr = (unsigned long) phys_to_virt(*ptr);
101 	}
102 
103 #ifdef CONFIG_KEXEC_JUMP
104 	if (image->preserve_context)
105 		save_processor_state();
106 #endif
107 
108 	save_ftrace_enabled = __ftrace_enabled_save();
109 
110 	/* Interrupts aren't acceptable while we reboot */
111 	local_irq_disable();
112 
113 	page_list = image->head;
114 
115 	/* we need both effective and real address here */
116 	reboot_code_buffer =
117 			(unsigned long)page_address(image->control_code_page);
118 
119 	/* copy our kernel relocation code to the control code page */
120 	memcpy((void *)reboot_code_buffer, relocate_new_kernel,
121 						relocate_new_kernel_size);
122 
123 	kexec_info(image);
124 	flush_cache_all();
125 
126 #if defined(CONFIG_SH_STANDARD_BIOS)
127 	asm volatile("ldc %0, vbr" :
128 		     : "r" (((unsigned long) gdb_vbr_vector) - 0x100)
129 		     : "memory");
130 #endif
131 
132 	/* now call it */
133 	rnk = (relocate_new_kernel_t) reboot_code_buffer;
134 	(*rnk)(page_list, reboot_code_buffer,
135 	       (unsigned long)phys_to_virt(image->start));
136 
137 #ifdef CONFIG_KEXEC_JUMP
138 	asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory");
139 
140 	if (image->preserve_context)
141 		restore_processor_state();
142 
143 	/* Convert page list back to physical addresses, what a mess. */
144 	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
145 	     ptr = (*ptr & IND_INDIRECTION) ?
146 	       phys_to_virt(*ptr & PAGE_MASK) : ptr + 1) {
147 		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
148 		    *ptr & IND_DESTINATION)
149 			*ptr = virt_to_phys(*ptr);
150 	}
151 #endif
152 
153 	__ftrace_enabled_restore(save_ftrace_enabled);
154 }
155 
156 void arch_crash_save_vmcoreinfo(void)
157 {
158 #ifdef CONFIG_NUMA
159 	VMCOREINFO_SYMBOL(node_data);
160 	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
161 #endif
162 }
163