aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/kernel/machine_kexec.c
blob: 03d2027d656a13b8c3f4607aa830e822a9aa51e3 (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
/*
 * arch/s390/kernel/machine_kexec.c
 *
 * Copyright IBM Corp. 2005,2011
 *
 * Author(s): Rolf Adelsberger,
 *	      Heiko Carstens <heiko.carstens@de.ibm.com>
 *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
 */

#include <linux/device.h>
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
#include <linux/debug_locks.h>
#include <asm/cio.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/smp.h>
#include <asm/reset.h>
#include <asm/ipl.h>
#include <asm/diag.h>
#include <asm/asm-offsets.h>
#include <asm/os_info.h>

typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);

extern const unsigned char relocate_kernel[];
extern const unsigned long long relocate_kernel_len;

#ifdef CONFIG_CRASH_DUMP

void *fill_cpu_elf_notes(void *ptr, struct save_area *sa);

/*
 * Create ELF notes for one CPU
 */
static void add_elf_notes(int cpu)
{
	struct save_area *sa = (void *) 4608 + store_prefix();
	void *ptr;

	memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
	ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
	ptr = fill_cpu_elf_notes(ptr, sa);
	memset(ptr, 0, sizeof(struct elf_note));
}

/*
 * Initialize CPU ELF notes
 */
void setup_regs(void)
{
	unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
	int cpu, this_cpu;

	this_cpu = smp_find_processor_id(stap());
	add_elf_notes(this_cpu);
	for_each_online_cpu(cpu) {
		if (cpu == this_cpu)
			continue;
		if (smp_store_status(cpu))
			continue;
		add_elf_notes(cpu);
	}
	/* Copy dump CPU store status info to absolute zero */
	memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
}

#endif

/*
 * Start kdump: We expect here that a store status has been done on our CPU
 */
static void __do_machine_kdump(void *image)
{
#ifdef CONFIG_CRASH_DUMP
	int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;

	__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
	setup_regs();
	start_kdump(1);
#endif
}

/*
 * Check if kdump checksums are valid: We call purgatory with parameter "0"
 */
static int kdump_csum_valid(struct kimage *image)
{
#ifdef CONFIG_CRASH_DUMP
	int (*start_kdump)(int) = (void *)image->start;
	int rc;

	__arch_local_irq_stnsm(0xfb); /* disable DAT */
	rc = start_kdump(0);
	__arch_local_irq_stosm(0x04); /* enable DAT */
	return rc ? 0 : -EINVAL;
#else
	return -EINVAL;
#endif
}

/*
 * Map or unmap crashkernel memory
 */
static void crash_map_pages(int enable)
{
	unsigned long size = resource_size(&crashk_res);

	BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
	       size % KEXEC_CRASH_MEM_ALIGN);
	if (enable)
		vmem_add_mapping(crashk_res.start, size);
	else {
		vmem_remove_mapping(crashk_res.start, size);
		if (size)
			os_info_crashkernel_add(crashk_res.start, size);
		else
			os_info_crashkernel_add(0, 0);
	}
}

/*
 * Map crashkernel memory
 */
void crash_map_reserved_pages(void)
{
	crash_map_pages(1);
}

/*
 * Unmap crashkernel memory
 */
void crash_unmap_reserved_pages(void)
{
	crash_map_pages(0);
}

/*
 * Give back memory to hypervisor before new kdump is loaded
 */
static int machine_kexec_prepare_kdump(void)
{
#ifdef CONFIG_CRASH_DUMP
	if (MACHINE_IS_VM)
		diag10_range(PFN_DOWN(crashk_res.start),
			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
	return 0;
#else
	return -EINVAL;
#endif
}

int machine_kexec_prepare(struct kimage *image)
{
	void *reboot_code_buffer;

	/* Can't replace kernel image since it is read-only. */
	if (ipl_flags & IPL_NSS_VALID)
		return -ENOSYS;

	if (image->type == KEXEC_TYPE_CRASH)
		return machine_kexec_prepare_kdump();

	/* We don't support anything but the default image type for now. */
	if (image->type != KEXEC_TYPE_DEFAULT)
		return -EINVAL;

	/* Get the destination where the assembler code should be copied to.*/
	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);

	/* Then copy it */
	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
	return 0;
}

void machine_kexec_cleanup(struct kimage *image)
{
}

void arch_crash_save_vmcoreinfo(void)
{
	VMCOREINFO_SYMBOL(lowcore_ptr);
	VMCOREINFO_SYMBOL(high_memory);
	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
}

void machine_shutdown(void)
{
}

/*
 * Do normal kexec
 */
static void __do_machine_kexec(void *data)
{
	relocate_kernel_t data_mover;
	struct kimage *image = data;

	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);

	/* Call the moving routine */
	(*data_mover)(&image->head, image->start);
}

/*
 * Reset system and call either kdump or normal kexec
 */
static void __machine_kexec(void *data)
{
	struct kimage *image = data;

	pfault_fini();
	tracing_off();
	debug_locks_off();
	if (image->type == KEXEC_TYPE_CRASH) {
		lgr_info_log();
		s390_reset_system(__do_machine_kdump, data);
	} else {
		s390_reset_system(__do_machine_kexec, data);
	}
	disabled_wait((unsigned long) __builtin_return_address(0));
}

/*
 * Do either kdump or normal kexec. In case of kdump we first ask
 * purgatory, if kdump checksums are valid.
 */
void machine_kexec(struct kimage *image)
{
	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
		return;
	tracer_disable();
	smp_send_stop();
	smp_call_ipl_cpu(__machine_kexec, image);
}