xref: /linux/arch/sh/kernel/machine_kexec.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * machine_kexec.c - handle transition of Linux booting another kernel
4  * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
5  *
6  * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
7  * LANDISK/sh4 supported by kogiidena
8  */
9 #include <linux/mm.h>
10 #include <linux/kexec.h>
11 #include <linux/delay.h>
12 #include <linux/reboot.h>
13 #include <linux/numa.h>
14 #include <linux/ftrace.h>
15 #include <linux/suspend.h>
16 #include <linux/memblock.h>
17 #include <asm/mmu_context.h>
18 #include <asm/io.h>
19 #include <asm/cacheflush.h>
20 #include <asm/sh_bios.h>
21 #include <asm/reboot.h>
22 
23 typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
24 				      unsigned long reboot_code_buffer,
25 				      unsigned long start_address);
26 
27 extern const unsigned char relocate_new_kernel[];
28 extern const unsigned int relocate_new_kernel_size;
29 extern void *vbr_base;
30 
native_machine_crash_shutdown(struct pt_regs * regs)31 void native_machine_crash_shutdown(struct pt_regs *regs)
32 {
33 	/* Nothing to do for UP, but definitely broken for SMP.. */
34 }
35 
36 /*
37  * Do what every setup is needed on image and the
38  * reboot code buffer to allow us to avoid allocations
39  * later.
40  */
machine_kexec_prepare(struct kimage * image)41 int machine_kexec_prepare(struct kimage *image)
42 {
43 	return 0;
44 }
45 
machine_kexec_cleanup(struct kimage * image)46 void machine_kexec_cleanup(struct kimage *image)
47 {
48 }
49 
kexec_info(struct kimage * image)50 static void kexec_info(struct kimage *image)
51 {
52         int i;
53 	printk("kexec information\n");
54 	for (i = 0; i < image->nr_segments; i++) {
55 	        printk("  segment[%d]: 0x%08x - 0x%08x (0x%08x)\n",
56 		       i,
57 		       (unsigned int)image->segment[i].mem,
58 		       (unsigned int)image->segment[i].mem +
59 				     image->segment[i].memsz,
60 		       (unsigned int)image->segment[i].memsz);
61 	}
62 	printk("  start     : 0x%08x\n\n", (unsigned int)image->start);
63 }
64 
65 /*
66  * Do not allocate memory (or fail in any way) in machine_kexec().
67  * We are past the point of no return, committed to rebooting now.
68  */
machine_kexec(struct kimage * image)69 void machine_kexec(struct kimage *image)
70 {
71 	unsigned long page_list;
72 	unsigned long reboot_code_buffer;
73 	relocate_new_kernel_t rnk;
74 	unsigned long entry;
75 	unsigned long *ptr;
76 	int save_ftrace_enabled;
77 
78 	/*
79 	 * Nicked from the mips version of machine_kexec():
80 	 * The generic kexec code builds a page list with physical
81 	 * addresses. Use phys_to_virt() to convert them to virtual.
82 	 */
83 	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
84 	     ptr = (entry & IND_INDIRECTION) ?
85 	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
86 		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
87 		    *ptr & IND_DESTINATION)
88 			*ptr = (unsigned long) phys_to_virt(*ptr);
89 	}
90 
91 #ifdef CONFIG_KEXEC_JUMP
92 	if (image->preserve_context)
93 		save_processor_state();
94 #endif
95 
96 	save_ftrace_enabled = __ftrace_enabled_save();
97 
98 	/* Interrupts aren't acceptable while we reboot */
99 	local_irq_disable();
100 
101 	page_list = image->head;
102 
103 	/* we need both effective and real address here */
104 	reboot_code_buffer =
105 			(unsigned long)page_address(image->control_code_page);
106 
107 	/* copy our kernel relocation code to the control code page */
108 	memcpy((void *)reboot_code_buffer, relocate_new_kernel,
109 						relocate_new_kernel_size);
110 
111 	kexec_info(image);
112 	flush_cache_all();
113 
114 	sh_bios_vbr_reload();
115 
116 	/* now call it */
117 	rnk = (relocate_new_kernel_t) reboot_code_buffer;
118 	(*rnk)(page_list, reboot_code_buffer,
119 	       (unsigned long)phys_to_virt(image->start));
120 
121 #ifdef CONFIG_KEXEC_JUMP
122 	asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory");
123 
124 	if (image->preserve_context)
125 		restore_processor_state();
126 
127 	/* Convert page list back to physical addresses, what a mess. */
128 	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
129 	     ptr = (*ptr & IND_INDIRECTION) ?
130 	       phys_to_virt(*ptr & PAGE_MASK) : ptr + 1) {
131 		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
132 		    *ptr & IND_DESTINATION)
133 			*ptr = virt_to_phys(*ptr);
134 	}
135 #endif
136 
137 	__ftrace_enabled_restore(save_ftrace_enabled);
138 }
139 
reserve_crashkernel(void)140 void __init reserve_crashkernel(void)
141 {
142 	unsigned long long crash_size, crash_base;
143 	int ret;
144 
145 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
146 		return;
147 
148 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
149 			&crash_size, &crash_base, NULL, NULL);
150 	if (ret == 0 && crash_size > 0) {
151 		crashk_res.start = crash_base;
152 		crashk_res.end = crash_base + crash_size - 1;
153 	}
154 
155 	if (crashk_res.end == crashk_res.start)
156 		goto disable;
157 
158 	crash_size = PAGE_ALIGN(resource_size(&crashk_res));
159 	if (!crashk_res.start) {
160 		unsigned long max = memblock_end_of_DRAM() - memory_limit;
161 		crashk_res.start = memblock_phys_alloc_range(crash_size,
162 							     PAGE_SIZE, 0, max);
163 		if (!crashk_res.start) {
164 			pr_err("crashkernel allocation failed\n");
165 			goto disable;
166 		}
167 	} else {
168 		ret = memblock_reserve(crashk_res.start, crash_size);
169 		if (unlikely(ret < 0)) {
170 			pr_err("crashkernel reservation failed - "
171 			       "memory is in use\n");
172 			goto disable;
173 		}
174 	}
175 
176 	crashk_res.end = crashk_res.start + crash_size - 1;
177 
178 	/*
179 	 * Crash kernel trumps memory limit
180 	 */
181 	if ((memblock_end_of_DRAM() - memory_limit) <= crashk_res.end) {
182 		memory_limit = 0;
183 		pr_info("Disabled memory limit for crashkernel\n");
184 	}
185 
186 	pr_info("Reserving %ldMB of memory at 0x%08lx "
187 		"for crashkernel (System RAM: %ldMB)\n",
188 		(unsigned long)(crash_size >> 20),
189 		(unsigned long)(crashk_res.start),
190 		(unsigned long)(memblock_phys_mem_size() >> 20));
191 
192 	return;
193 
194 disable:
195 	crashk_res.start = crashk_res.end = 0;
196 }
197