summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/machine_kexec.c
blob: 93936dce04d65d606accb838009a1d62ebb1169e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
/*
 * machine_kexec.c for kexec
 * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */
#include <linux/compiler.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/libfdt.h>

#include <asm/cacheflush.h>
#include <asm/page.h>

extern const unsigned char relocate_new_kernel[];
extern const size_t relocate_new_kernel_size;

extern unsigned long kexec_start_address;
extern unsigned long kexec_indirection_page;

static unsigned long reboot_code_buffer;

#ifdef CONFIG_SMP
static void (*relocated_kexec_smp_wait)(void *);

atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
void (*_crash_smp_send_stop)(void) = NULL;
#endif

void (*_machine_kexec_shutdown)(void) = NULL;
void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;

static void kexec_image_info(const struct kimage *kimage)
{
	unsigned long i;

	pr_debug("kexec kimage info:\n");
	pr_debug("  type:        %d\n", kimage->type);
	pr_debug("  start:       %lx\n", kimage->start);
	pr_debug("  head:        %lx\n", kimage->head);
	pr_debug("  nr_segments: %lu\n", kimage->nr_segments);

	for (i = 0; i < kimage->nr_segments; i++) {
		pr_debug("    segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
			i,
			kimage->segment[i].mem,
			kimage->segment[i].mem + kimage->segment[i].memsz,
			(unsigned long)kimage->segment[i].memsz,
			(unsigned long)kimage->segment[i].memsz /  PAGE_SIZE);
	}
}

#ifdef CONFIG_UHI_BOOT

static int uhi_machine_kexec_prepare(struct kimage *kimage)
{
	int i;

	/*
	 * In case DTB file is not passed to the new kernel, a flat device
	 * tree will be created by kexec tool. It holds modified command
	 * line for the new kernel.
	 */
	for (i = 0; i < kimage->nr_segments; i++) {
		struct fdt_header fdt;

		if (kimage->segment[i].memsz <= sizeof(fdt))
			continue;

		if (copy_from_user(&fdt, kimage->segment[i].buf, sizeof(fdt)))
			continue;

		if (fdt_check_header(&fdt))
			continue;

		kexec_args[0] = -2;
		kexec_args[1] = (unsigned long)
			phys_to_virt((unsigned long)kimage->segment[i].mem);
		break;
	}

	return 0;
}

int (*_machine_kexec_prepare)(struct kimage *) = uhi_machine_kexec_prepare;

#else

int (*_machine_kexec_prepare)(struct kimage *) = NULL;

#endif /* CONFIG_UHI_BOOT */

int
machine_kexec_prepare(struct kimage *kimage)
{
#ifdef CONFIG_SMP
	if (!kexec_nonboot_cpu_func())
		return -EINVAL;
#endif

	kexec_image_info(kimage);

	if (_machine_kexec_prepare)
		return _machine_kexec_prepare(kimage);

	return 0;
}

void
machine_kexec_cleanup(struct kimage *kimage)
{
}

#ifdef CONFIG_SMP
static void kexec_shutdown_secondary(void *param)
{
	int cpu = smp_processor_id();

	if (!cpu_online(cpu))
		return;

	/* We won't be sent IPIs any more. */
	set_cpu_online(cpu, false);

	local_irq_disable();
	while (!atomic_read(&kexec_ready_to_reboot))
		cpu_relax();

	kexec_reboot();

	/* NOTREACHED */
}
#endif

void
machine_shutdown(void)
{
	if (_machine_kexec_shutdown)
		_machine_kexec_shutdown();

#ifdef CONFIG_SMP
	smp_call_function(kexec_shutdown_secondary, NULL, 0);

	while (num_online_cpus() > 1) {
		cpu_relax();
		mdelay(1);
	}
#endif
}

void
machine_crash_shutdown(struct pt_regs *regs)
{
	if (_machine_crash_shutdown)
		_machine_crash_shutdown(regs);
	else
		default_machine_crash_shutdown(regs);
}

#ifdef CONFIG_SMP
void kexec_nonboot_cpu_jump(void)
{
	local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
				 reboot_code_buffer + relocate_new_kernel_size);

	relocated_kexec_smp_wait(NULL);
}
#endif

void kexec_reboot(void)
{
	void (*do_kexec)(void) __noreturn;

	/*
	 * We know we were online, and there will be no incoming IPIs at
	 * this point. Mark online again before rebooting so that the crash
	 * analysis tool will see us correctly.
	 */
	set_cpu_online(smp_processor_id(), true);

	/* Ensure remote CPUs observe that we're online before rebooting. */
	smp_mb__after_atomic();

#ifdef CONFIG_SMP
	if (smp_processor_id() > 0) {
		/*
		 * Instead of cpu_relax() or wait, this is needed for kexec
		 * smp reboot. Kdump usually doesn't require an smp new
		 * kernel, but kexec may do.
		 */
		kexec_nonboot_cpu();

		/* NOTREACHED */
	}
#endif

	/*
	 * Make sure we get correct instructions written by the
	 * machine_kexec() CPU.
	 */
	local_flush_icache_range(reboot_code_buffer,
				 reboot_code_buffer + relocate_new_kernel_size);

	do_kexec = (void *)reboot_code_buffer;
	do_kexec();
}

void
machine_kexec(struct kimage *image)
{
	unsigned long entry;
	unsigned long *ptr;

	reboot_code_buffer =
	  (unsigned long)page_address(image->control_code_page);

	kexec_start_address =
		(unsigned long) phys_to_virt(image->start);

	if (image->type == KEXEC_TYPE_DEFAULT) {
		kexec_indirection_page =
			(unsigned long) phys_to_virt(image->head & PAGE_MASK);
	} else {
		kexec_indirection_page = (unsigned long)&image->head;
	}

	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
	       relocate_new_kernel_size);

	/*
	 * The generic kexec code builds a page list with physical
	 * addresses. they are directly accessible through KSEG0 (or
	 * CKSEG0 or XPHYS if on 64bit system), hence the
	 * phys_to_virt() call.
	 */
	for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
	     ptr = (entry & IND_INDIRECTION) ?
	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
		    *ptr & IND_DESTINATION)
			*ptr = (unsigned long) phys_to_virt(*ptr);
	}

	/* Mark offline BEFORE disabling local irq. */
	set_cpu_online(smp_processor_id(), false);

	/*
	 * we do not want to be bothered.
	 */
	local_irq_disable();

	printk("Will call new kernel at %08lx\n", image->start);
	printk("Bye ...\n");
	/* Make reboot code buffer available to the boot CPU. */
	__flush_cache_all();
#ifdef CONFIG_SMP
	/* All secondary cpus now may jump to kexec_wait cycle */
	relocated_kexec_smp_wait = reboot_code_buffer +
		(void *)(kexec_smp_wait - relocate_new_kernel);
	smp_wmb();
	atomic_set(&kexec_ready_to_reboot, 1);
#endif
	kexec_reboot();
}