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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2005, 2011
4 *
5 * Author(s): Rolf Adelsberger,
6 * Heiko Carstens <heiko.carstens@de.ibm.com>
7 * Michael Holzheu <holzheu@linux.vnet.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 <linux/debug_locks.h>
17#include <linux/suspend.h>
18#include <asm/cio.h>
19#include <asm/setup.h>
20#include <asm/pgtable.h>
21#include <asm/pgalloc.h>
22#include <asm/smp.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/cacheflush.h>
28#include <asm/os_info.h>
29#include <asm/set_memory.h>
30#include <asm/switch_to.h>
31#include <asm/nmi.h>
32
33typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
34
35extern const unsigned char relocate_kernel[];
36extern const unsigned long long relocate_kernel_len;
37
38#ifdef CONFIG_CRASH_DUMP
39
40/*
41 * PM notifier callback for kdump
42 */
43static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
44 void *ptr)
45{
46 switch (action) {
47 case PM_SUSPEND_PREPARE:
48 case PM_HIBERNATION_PREPARE:
49 if (kexec_crash_image)
50 arch_kexec_unprotect_crashkres();
51 break;
52 case PM_POST_SUSPEND:
53 case PM_POST_HIBERNATION:
54 if (kexec_crash_image)
55 arch_kexec_protect_crashkres();
56 break;
57 default:
58 return NOTIFY_DONE;
59 }
60 return NOTIFY_OK;
61}
62
63static int __init machine_kdump_pm_init(void)
64{
65 pm_notifier(machine_kdump_pm_cb, 0);
66 return 0;
67}
68arch_initcall(machine_kdump_pm_init);
69
70/*
71 * Reset the system, copy boot CPU registers to absolute zero,
72 * and jump to the kdump image
73 */
74static void __do_machine_kdump(void *image)
75{
76 int (*start_kdump)(int);
77 unsigned long prefix;
78
79 /* store_status() saved the prefix register to lowcore */
80 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
81
82 /* Now do the reset */
83 s390_reset_system();
84
85 /*
86 * Copy dump CPU store status info to absolute zero.
87 * This need to be done *after* s390_reset_system set the
88 * prefix register of this CPU to zero
89 */
90 memcpy((void *) __LC_FPREGS_SAVE_AREA,
91 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
92
93 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
94 start_kdump = (void *)((struct kimage *) image)->start;
95 start_kdump(1);
96
97 /* Die if start_kdump returns */
98 disabled_wait((unsigned long) __builtin_return_address(0));
99}
100
101/*
102 * Start kdump: create a LGR log entry, store status of all CPUs and
103 * branch to __do_machine_kdump.
104 */
105static noinline void __machine_kdump(void *image)
106{
107 struct mcesa *mcesa;
108 union ctlreg2 cr2_old, cr2_new;
109 int this_cpu, cpu;
110
111 lgr_info_log();
112 /* Get status of the other CPUs */
113 this_cpu = smp_find_processor_id(stap());
114 for_each_online_cpu(cpu) {
115 if (cpu == this_cpu)
116 continue;
117 if (smp_store_status(cpu))
118 continue;
119 }
120 /* Store status of the boot CPU */
121 mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
122 if (MACHINE_HAS_VX)
123 save_vx_regs((__vector128 *) mcesa->vector_save_area);
124 if (MACHINE_HAS_GS) {
125 __ctl_store(cr2_old.val, 2, 2);
126 cr2_new = cr2_old;
127 cr2_new.gse = 1;
128 __ctl_load(cr2_new.val, 2, 2);
129 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
130 __ctl_load(cr2_old.val, 2, 2);
131 }
132 /*
133 * To create a good backchain for this CPU in the dump store_status
134 * is passed the address of a function. The address is saved into
135 * the PSW save area of the boot CPU and the function is invoked as
136 * a tail call of store_status. The backchain in the dump will look
137 * like this:
138 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
139 * The call to store_status() will not return.
140 */
141 store_status(__do_machine_kdump, image);
142}
143#endif
144
145/*
146 * Check if kdump checksums are valid: We call purgatory with parameter "0"
147 */
148static bool kdump_csum_valid(struct kimage *image)
149{
150#ifdef CONFIG_CRASH_DUMP
151 int (*start_kdump)(int) = (void *)image->start;
152 int rc;
153
154 __arch_local_irq_stnsm(0xfb); /* disable DAT */
155 rc = start_kdump(0);
156 __arch_local_irq_stosm(0x04); /* enable DAT */
157 return rc == 0;
158#else
159 return false;
160#endif
161}
162
163#ifdef CONFIG_CRASH_DUMP
164
165void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
166{
167 unsigned long addr, size;
168
169 for (addr = begin; addr < end; addr += PAGE_SIZE)
170 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
171 size = begin - crashk_res.start;
172 if (size)
173 os_info_crashkernel_add(crashk_res.start, size);
174 else
175 os_info_crashkernel_add(0, 0);
176}
177
178static void crash_protect_pages(int protect)
179{
180 unsigned long size;
181
182 if (!crashk_res.end)
183 return;
184 size = resource_size(&crashk_res);
185 if (protect)
186 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
187 else
188 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
189}
190
191void arch_kexec_protect_crashkres(void)
192{
193 crash_protect_pages(1);
194}
195
196void arch_kexec_unprotect_crashkres(void)
197{
198 crash_protect_pages(0);
199}
200
201#endif
202
203/*
204 * Give back memory to hypervisor before new kdump is loaded
205 */
206static int machine_kexec_prepare_kdump(void)
207{
208#ifdef CONFIG_CRASH_DUMP
209 if (MACHINE_IS_VM)
210 diag10_range(PFN_DOWN(crashk_res.start),
211 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
212 return 0;
213#else
214 return -EINVAL;
215#endif
216}
217
218int machine_kexec_prepare(struct kimage *image)
219{
220 void *reboot_code_buffer;
221
222 if (image->type == KEXEC_TYPE_CRASH)
223 return machine_kexec_prepare_kdump();
224
225 /* We don't support anything but the default image type for now. */
226 if (image->type != KEXEC_TYPE_DEFAULT)
227 return -EINVAL;
228
229 /* Get the destination where the assembler code should be copied to.*/
230 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
231
232 /* Then copy it */
233 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
234 return 0;
235}
236
237void machine_kexec_cleanup(struct kimage *image)
238{
239}
240
241void arch_crash_save_vmcoreinfo(void)
242{
243 VMCOREINFO_SYMBOL(lowcore_ptr);
244 VMCOREINFO_SYMBOL(high_memory);
245 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
246 mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
247}
248
249void machine_shutdown(void)
250{
251}
252
253void machine_crash_shutdown(struct pt_regs *regs)
254{
255 set_os_info_reipl_block();
256}
257
258/*
259 * Do normal kexec
260 */
261static void __do_machine_kexec(void *data)
262{
263 relocate_kernel_t data_mover;
264 struct kimage *image = data;
265
266 s390_reset_system();
267 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
268
269 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
270 /* Call the moving routine */
271 (*data_mover)(&image->head, image->start);
272
273 /* Die if kexec returns */
274 disabled_wait((unsigned long) __builtin_return_address(0));
275}
276
277/*
278 * Reset system and call either kdump or normal kexec
279 */
280static void __machine_kexec(void *data)
281{
282 __arch_local_irq_stosm(0x04); /* enable DAT */
283 pfault_fini();
284 tracing_off();
285 debug_locks_off();
286#ifdef CONFIG_CRASH_DUMP
287 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
288 __machine_kdump(data);
289#endif
290 __do_machine_kexec(data);
291}
292
293/*
294 * Do either kdump or normal kexec. In case of kdump we first ask
295 * purgatory, if kdump checksums are valid.
296 */
297void machine_kexec(struct kimage *image)
298{
299 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
300 return;
301 tracer_disable();
302 smp_send_stop();
303 smp_call_ipl_cpu(__machine_kexec, image);
304}