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
23typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
24				      unsigned long reboot_code_buffer,
25				      unsigned long start_address);
26
27extern const unsigned char relocate_new_kernel[];
28extern const unsigned int relocate_new_kernel_size;
29extern void *vbr_base;
30
31void 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 */
41int machine_kexec_prepare(struct kimage *image)
42{
43	return 0;
44}
45
46void machine_kexec_cleanup(struct kimage *image)
47{
48}
49
50static 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 */
69void 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
140void __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
194disable:
195	crashk_res.start = crashk_res.end = 0;
196}
197