aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/machine_kexec.c
blob: 76300f3813e89bc48a76d83dc3076d9f7b79ee84 (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
// SPDX-License-Identifier: GPL-2.0
/*
 * machine_kexec.c - handle transition of Linux booting another kernel
 */

#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/memblock.h>
#include <asm/pgtable.h>
#include <linux/of_fdt.h>
#include <asm/pgalloc.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
#include <asm/fncpy.h>
#include <asm/mach-types.h>
#include <asm/smp_plat.h>
#include <asm/system_misc.h>
#include <asm/set_memory.h>

extern void relocate_new_kernel(void);
extern const unsigned int relocate_new_kernel_size;

extern unsigned long kexec_start_address;
extern unsigned long kexec_indirection_page;
extern unsigned long kexec_mach_type;
extern unsigned long kexec_boot_atags;

static atomic_t waiting_for_crash_ipi;

/*
 * Provide a dummy crash_notes definition while crash dump arrives to arm.
 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
 */

int machine_kexec_prepare(struct kimage *image)
{
	struct kexec_segment *current_segment;
	__be32 header;
	int i, err;

	image->arch.kernel_r2 = image->start - KEXEC_ARM_ZIMAGE_OFFSET
				     + KEXEC_ARM_ATAGS_OFFSET;

	/*
	 * Validate that if the current HW supports SMP, then the SW supports
	 * and implements CPU hotplug for the current HW. If not, we won't be
	 * able to kexec reliably, so fail the prepare operation.
	 */
	if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
	    !platform_can_cpu_hotplug())
		return -EINVAL;

	/*
	 * No segment at default ATAGs address. try to locate
	 * a dtb using magic.
	 */
	for (i = 0; i < image->nr_segments; i++) {
		current_segment = &image->segment[i];

		if (!memblock_is_region_memory(idmap_to_phys(current_segment->mem),
					       current_segment->memsz))
			return -EINVAL;

		err = get_user(header, (__be32*)current_segment->buf);
		if (err)
			return err;

		if (header == cpu_to_be32(OF_DT_HEADER))
			image->arch.kernel_r2 = current_segment->mem;
	}
	return 0;
}

void machine_kexec_cleanup(struct kimage *image)
{
}

void machine_crash_nonpanic_core(void *unused)
{
	struct pt_regs regs;

	crash_setup_regs(&regs, get_irq_regs());
	printk(KERN_DEBUG "CPU %u will stop doing anything useful since another CPU has crashed\n",
	       smp_processor_id());
	crash_save_cpu(&regs, smp_processor_id());
	flush_cache_all();

	set_cpu_online(smp_processor_id(), false);
	atomic_dec(&waiting_for_crash_ipi);

	while (1) {
		cpu_relax();
		wfe();
	}
}

void crash_smp_send_stop(void)
{
	static int cpus_stopped;
	unsigned long msecs;

	if (cpus_stopped)
		return;

	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
	smp_call_function(machine_crash_nonpanic_core, NULL, false);
	msecs = 1000; /* Wait at most a second for the other cpus to stop */
	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
		mdelay(1);
		msecs--;
	}
	if (atomic_read(&waiting_for_crash_ipi) > 0)
		pr_warn("Non-crashing CPUs did not react to IPI\n");

	cpus_stopped = 1;
}

static void machine_kexec_mask_interrupts(void)
{
	unsigned int i;
	struct irq_desc *desc;

	for_each_irq_desc(i, desc) {
		struct irq_chip *chip;

		chip = irq_desc_get_chip(desc);
		if (!chip)
			continue;

		if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
			chip->irq_eoi(&desc->irq_data);

		if (chip->irq_mask)
			chip->irq_mask(&desc->irq_data);

		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
			chip->irq_disable(&desc->irq_data);
	}
}

void machine_crash_shutdown(struct pt_regs *regs)
{
	local_irq_disable();
	crash_smp_send_stop();

	crash_save_cpu(regs, smp_processor_id());
	machine_kexec_mask_interrupts();

	pr_info("Loading crashdump kernel...\n");
}

/*
 * Function pointer to optional machine-specific reinitialization
 */
void (*kexec_reinit)(void);

void machine_kexec(struct kimage *image)
{
	unsigned long page_list, reboot_entry_phys;
	void (*reboot_entry)(void);
	void *reboot_code_buffer;

	/*
	 * This can only happen if machine_shutdown() failed to disable some
	 * CPU, and that can only happen if the checks in
	 * machine_kexec_prepare() were not correct. If this fails, we can't
	 * reliably kexec anyway, so BUG_ON is appropriate.
	 */
	BUG_ON(num_online_cpus() > 1);

	page_list = image->head & PAGE_MASK;

	reboot_code_buffer = page_address(image->control_code_page);

	/* Prepare parameters for reboot_code_buffer*/
	set_kernel_text_rw();
	kexec_start_address = image->start;
	kexec_indirection_page = page_list;
	kexec_mach_type = machine_arch_type;
	kexec_boot_atags = image->arch.kernel_r2;

	/* copy our kernel relocation code to the control code page */
	reboot_entry = fncpy(reboot_code_buffer,
			     &relocate_new_kernel,
			     relocate_new_kernel_size);

	/* get the identity mapping physical address for the reboot code */
	reboot_entry_phys = virt_to_idmap(reboot_entry);

	pr_info("Bye!\n");

	if (kexec_reinit)
		kexec_reinit();

	soft_restart(reboot_entry_phys);
}

void arch_crash_save_vmcoreinfo(void)
{
#ifdef CONFIG_ARM_LPAE
	VMCOREINFO_CONFIG(ARM_LPAE);
#endif
}

Privacy Policy