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1/*
2 * arch/s390/kernel/machine_kexec.c
3 *
4 * Copyright IBM Corp. 2005,2006
5 *
6 * Author(s): Rolf Adelsberger,
7 * Heiko Carstens <heiko.carstens@de.ibm.com>
8 */
9
10#include <linux/device.h>
11#include <linux/mm.h>
12#include <linux/kexec.h>
13#include <linux/delay.h>
14#include <linux/reboot.h>
15#include <linux/ftrace.h>
16#include <asm/cio.h>
17#include <asm/setup.h>
18#include <asm/pgtable.h>
19#include <asm/pgalloc.h>
20#include <asm/system.h>
21#include <asm/smp.h>
22#include <asm/reset.h>
23#include <asm/ipl.h>
24
25typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
26
27extern const unsigned char relocate_kernel[];
28extern const unsigned long long relocate_kernel_len;
29
30int machine_kexec_prepare(struct kimage *image)
31{
32 void *reboot_code_buffer;
33
34 /* Can't replace kernel image since it is read-only. */
35 if (ipl_flags & IPL_NSS_VALID)
36 return -ENOSYS;
37
38 /* We don't support anything but the default image type for now. */
39 if (image->type != KEXEC_TYPE_DEFAULT)
40 return -EINVAL;
41
42 /* Get the destination where the assembler code should be copied to.*/
43 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
44
45 /* Then copy it */
46 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
47 return 0;
48}
49
50void machine_kexec_cleanup(struct kimage *image)
51{
52}
53
54void machine_shutdown(void)
55{
56}
57
58static void __machine_kexec(void *data)
59{
60 relocate_kernel_t data_mover;
61 struct kimage *image = data;
62
63 pfault_fini();
64 s390_reset_system();
65
66 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
67
68 /* Call the moving routine */
69 (*data_mover)(&image->head, image->start);
70 for (;;);
71}
72
73void machine_kexec(struct kimage *image)
74{
75 tracer_disable();
76 smp_send_stop();
77 smp_switch_to_ipl_cpu(__machine_kexec, image);
78}
1/*
2 * Copyright IBM Corp. 2005, 2011
3 *
4 * Author(s): Rolf Adelsberger,
5 * Heiko Carstens <heiko.carstens@de.ibm.com>
6 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
7 */
8
9#include <linux/device.h>
10#include <linux/mm.h>
11#include <linux/kexec.h>
12#include <linux/delay.h>
13#include <linux/reboot.h>
14#include <linux/ftrace.h>
15#include <linux/debug_locks.h>
16#include <linux/suspend.h>
17#include <asm/cio.h>
18#include <asm/setup.h>
19#include <asm/pgtable.h>
20#include <asm/pgalloc.h>
21#include <asm/smp.h>
22#include <asm/reset.h>
23#include <asm/ipl.h>
24#include <asm/diag.h>
25#include <asm/elf.h>
26#include <asm/asm-offsets.h>
27#include <asm/os_info.h>
28#include <asm/switch_to.h>
29
30typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
31
32extern const unsigned char relocate_kernel[];
33extern const unsigned long long relocate_kernel_len;
34
35#ifdef CONFIG_CRASH_DUMP
36
37/*
38 * PM notifier callback for kdump
39 */
40static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
41 void *ptr)
42{
43 switch (action) {
44 case PM_SUSPEND_PREPARE:
45 case PM_HIBERNATION_PREPARE:
46 if (crashk_res.start)
47 crash_map_reserved_pages();
48 break;
49 case PM_POST_SUSPEND:
50 case PM_POST_HIBERNATION:
51 if (crashk_res.start)
52 crash_unmap_reserved_pages();
53 break;
54 default:
55 return NOTIFY_DONE;
56 }
57 return NOTIFY_OK;
58}
59
60static int __init machine_kdump_pm_init(void)
61{
62 pm_notifier(machine_kdump_pm_cb, 0);
63 return 0;
64}
65arch_initcall(machine_kdump_pm_init);
66
67/*
68 * Reset the system, copy boot CPU registers to absolute zero,
69 * and jump to the kdump image
70 */
71static void __do_machine_kdump(void *image)
72{
73 int (*start_kdump)(int);
74 unsigned long prefix;
75
76 /* store_status() saved the prefix register to lowcore */
77 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
78
79 /* Now do the reset */
80 s390_reset_system();
81
82 /*
83 * Copy dump CPU store status info to absolute zero.
84 * This need to be done *after* s390_reset_system set the
85 * prefix register of this CPU to zero
86 */
87 memcpy((void *) __LC_FPREGS_SAVE_AREA,
88 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
89
90 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
91 start_kdump = (void *)((struct kimage *) image)->start;
92 start_kdump(1);
93
94 /* Die if start_kdump returns */
95 disabled_wait((unsigned long) __builtin_return_address(0));
96}
97
98/*
99 * Start kdump: create a LGR log entry, store status of all CPUs and
100 * branch to __do_machine_kdump.
101 */
102static noinline void __machine_kdump(void *image)
103{
104 int this_cpu, cpu;
105
106 lgr_info_log();
107 /* Get status of the other CPUs */
108 this_cpu = smp_find_processor_id(stap());
109 for_each_online_cpu(cpu) {
110 if (cpu == this_cpu)
111 continue;
112 if (smp_store_status(cpu))
113 continue;
114 }
115 /* Store status of the boot CPU */
116 if (MACHINE_HAS_VX)
117 save_vx_regs((void *) &S390_lowcore.vector_save_area);
118 /*
119 * To create a good backchain for this CPU in the dump store_status
120 * is passed the address of a function. The address is saved into
121 * the PSW save area of the boot CPU and the function is invoked as
122 * a tail call of store_status. The backchain in the dump will look
123 * like this:
124 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
125 * The call to store_status() will not return.
126 */
127 store_status(__do_machine_kdump, image);
128}
129#endif
130
131/*
132 * Check if kdump checksums are valid: We call purgatory with parameter "0"
133 */
134static int kdump_csum_valid(struct kimage *image)
135{
136#ifdef CONFIG_CRASH_DUMP
137 int (*start_kdump)(int) = (void *)image->start;
138 int rc;
139
140 __arch_local_irq_stnsm(0xfb); /* disable DAT */
141 rc = start_kdump(0);
142 __arch_local_irq_stosm(0x04); /* enable DAT */
143 return rc ? 0 : -EINVAL;
144#else
145 return -EINVAL;
146#endif
147}
148
149/*
150 * Map or unmap crashkernel memory
151 */
152static void crash_map_pages(int enable)
153{
154 unsigned long size = resource_size(&crashk_res);
155
156 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
157 size % KEXEC_CRASH_MEM_ALIGN);
158 if (enable)
159 vmem_add_mapping(crashk_res.start, size);
160 else {
161 vmem_remove_mapping(crashk_res.start, size);
162 if (size)
163 os_info_crashkernel_add(crashk_res.start, size);
164 else
165 os_info_crashkernel_add(0, 0);
166 }
167}
168
169/*
170 * Map crashkernel memory
171 */
172void crash_map_reserved_pages(void)
173{
174 crash_map_pages(1);
175}
176
177/*
178 * Unmap crashkernel memory
179 */
180void crash_unmap_reserved_pages(void)
181{
182 crash_map_pages(0);
183}
184
185/*
186 * Give back memory to hypervisor before new kdump is loaded
187 */
188static int machine_kexec_prepare_kdump(void)
189{
190#ifdef CONFIG_CRASH_DUMP
191 if (MACHINE_IS_VM)
192 diag10_range(PFN_DOWN(crashk_res.start),
193 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
194 return 0;
195#else
196 return -EINVAL;
197#endif
198}
199
200int machine_kexec_prepare(struct kimage *image)
201{
202 void *reboot_code_buffer;
203
204 /* Can't replace kernel image since it is read-only. */
205 if (ipl_flags & IPL_NSS_VALID)
206 return -EOPNOTSUPP;
207
208 if (image->type == KEXEC_TYPE_CRASH)
209 return machine_kexec_prepare_kdump();
210
211 /* We don't support anything but the default image type for now. */
212 if (image->type != KEXEC_TYPE_DEFAULT)
213 return -EINVAL;
214
215 /* Get the destination where the assembler code should be copied to.*/
216 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
217
218 /* Then copy it */
219 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
220 return 0;
221}
222
223void machine_kexec_cleanup(struct kimage *image)
224{
225}
226
227void arch_crash_save_vmcoreinfo(void)
228{
229 VMCOREINFO_SYMBOL(lowcore_ptr);
230 VMCOREINFO_SYMBOL(high_memory);
231 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
232}
233
234void machine_shutdown(void)
235{
236}
237
238void machine_crash_shutdown(struct pt_regs *regs)
239{
240}
241
242/*
243 * Do normal kexec
244 */
245static void __do_machine_kexec(void *data)
246{
247 relocate_kernel_t data_mover;
248 struct kimage *image = data;
249
250 s390_reset_system();
251 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
252
253 /* Call the moving routine */
254 (*data_mover)(&image->head, image->start);
255
256 /* Die if kexec returns */
257 disabled_wait((unsigned long) __builtin_return_address(0));
258}
259
260/*
261 * Reset system and call either kdump or normal kexec
262 */
263static void __machine_kexec(void *data)
264{
265 __arch_local_irq_stosm(0x04); /* enable DAT */
266 pfault_fini();
267 tracing_off();
268 debug_locks_off();
269#ifdef CONFIG_CRASH_DUMP
270 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
271 __machine_kdump(data);
272#endif
273 __do_machine_kexec(data);
274}
275
276/*
277 * Do either kdump or normal kexec. In case of kdump we first ask
278 * purgatory, if kdump checksums are valid.
279 */
280void machine_kexec(struct kimage *image)
281{
282 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
283 return;
284 tracer_disable();
285 smp_send_stop();
286 smp_call_ipl_cpu(__machine_kexec, image);
287}