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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/stacktrace.h>
31#include <asm/switch_to.h>
32#include <asm/nmi.h>
33
34typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
35
36extern const unsigned char relocate_kernel[];
37extern const unsigned long long relocate_kernel_len;
38
39#ifdef CONFIG_CRASH_DUMP
40
41/*
42 * PM notifier callback for kdump
43 */
44static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
45 void *ptr)
46{
47 switch (action) {
48 case PM_SUSPEND_PREPARE:
49 case PM_HIBERNATION_PREPARE:
50 if (kexec_crash_image)
51 arch_kexec_unprotect_crashkres();
52 break;
53 case PM_POST_SUSPEND:
54 case PM_POST_HIBERNATION:
55 if (kexec_crash_image)
56 arch_kexec_protect_crashkres();
57 break;
58 default:
59 return NOTIFY_DONE;
60 }
61 return NOTIFY_OK;
62}
63
64static int __init machine_kdump_pm_init(void)
65{
66 pm_notifier(machine_kdump_pm_cb, 0);
67 return 0;
68}
69arch_initcall(machine_kdump_pm_init);
70
71/*
72 * Reset the system, copy boot CPU registers to absolute zero,
73 * and jump to the kdump image
74 */
75static void __do_machine_kdump(void *image)
76{
77 int (*start_kdump)(int);
78 unsigned long prefix;
79
80 /* store_status() saved the prefix register to lowcore */
81 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
82
83 /* Now do the reset */
84 s390_reset_system();
85
86 /*
87 * Copy dump CPU store status info to absolute zero.
88 * This need to be done *after* s390_reset_system set the
89 * prefix register of this CPU to zero
90 */
91 memcpy((void *) __LC_FPREGS_SAVE_AREA,
92 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
93
94 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
95 start_kdump = (void *)((struct kimage *) image)->start;
96 start_kdump(1);
97
98 /* Die if start_kdump returns */
99 disabled_wait();
100}
101
102/*
103 * Start kdump: create a LGR log entry, store status of all CPUs and
104 * branch to __do_machine_kdump.
105 */
106static noinline void __machine_kdump(void *image)
107{
108 struct mcesa *mcesa;
109 union ctlreg2 cr2_old, cr2_new;
110 int this_cpu, cpu;
111
112 lgr_info_log();
113 /* Get status of the other CPUs */
114 this_cpu = smp_find_processor_id(stap());
115 for_each_online_cpu(cpu) {
116 if (cpu == this_cpu)
117 continue;
118 if (smp_store_status(cpu))
119 continue;
120 }
121 /* Store status of the boot CPU */
122 mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
123 if (MACHINE_HAS_VX)
124 save_vx_regs((__vector128 *) mcesa->vector_save_area);
125 if (MACHINE_HAS_GS) {
126 __ctl_store(cr2_old.val, 2, 2);
127 cr2_new = cr2_old;
128 cr2_new.gse = 1;
129 __ctl_load(cr2_new.val, 2, 2);
130 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
131 __ctl_load(cr2_old.val, 2, 2);
132 }
133 /*
134 * To create a good backchain for this CPU in the dump store_status
135 * is passed the address of a function. The address is saved into
136 * the PSW save area of the boot CPU and the function is invoked as
137 * a tail call of store_status. The backchain in the dump will look
138 * like this:
139 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
140 * The call to store_status() will not return.
141 */
142 store_status(__do_machine_kdump, image);
143}
144
145static unsigned long do_start_kdump(unsigned long addr)
146{
147 struct kimage *image = (struct kimage *) addr;
148 int (*start_kdump)(int) = (void *)image->start;
149 int rc;
150
151 __arch_local_irq_stnsm(0xfb); /* disable DAT */
152 rc = start_kdump(0);
153 __arch_local_irq_stosm(0x04); /* enable DAT */
154 return rc;
155}
156
157#endif /* CONFIG_CRASH_DUMP */
158
159/*
160 * Check if kdump checksums are valid: We call purgatory with parameter "0"
161 */
162static bool kdump_csum_valid(struct kimage *image)
163{
164#ifdef CONFIG_CRASH_DUMP
165 int rc;
166
167 rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image);
168 return rc == 0;
169#else
170 return false;
171#endif
172}
173
174#ifdef CONFIG_CRASH_DUMP
175
176void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
177{
178 unsigned long addr, size;
179
180 for (addr = begin; addr < end; addr += PAGE_SIZE)
181 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
182 size = begin - crashk_res.start;
183 if (size)
184 os_info_crashkernel_add(crashk_res.start, size);
185 else
186 os_info_crashkernel_add(0, 0);
187}
188
189static void crash_protect_pages(int protect)
190{
191 unsigned long size;
192
193 if (!crashk_res.end)
194 return;
195 size = resource_size(&crashk_res);
196 if (protect)
197 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
198 else
199 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
200}
201
202void arch_kexec_protect_crashkres(void)
203{
204 crash_protect_pages(1);
205}
206
207void arch_kexec_unprotect_crashkres(void)
208{
209 crash_protect_pages(0);
210}
211
212#endif
213
214/*
215 * Give back memory to hypervisor before new kdump is loaded
216 */
217static int machine_kexec_prepare_kdump(void)
218{
219#ifdef CONFIG_CRASH_DUMP
220 if (MACHINE_IS_VM)
221 diag10_range(PFN_DOWN(crashk_res.start),
222 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
223 return 0;
224#else
225 return -EINVAL;
226#endif
227}
228
229int machine_kexec_prepare(struct kimage *image)
230{
231 void *reboot_code_buffer;
232
233 if (image->type == KEXEC_TYPE_CRASH)
234 return machine_kexec_prepare_kdump();
235
236 /* We don't support anything but the default image type for now. */
237 if (image->type != KEXEC_TYPE_DEFAULT)
238 return -EINVAL;
239
240 /* Get the destination where the assembler code should be copied to.*/
241 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
242
243 /* Then copy it */
244 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
245 return 0;
246}
247
248void machine_kexec_cleanup(struct kimage *image)
249{
250}
251
252void arch_crash_save_vmcoreinfo(void)
253{
254 VMCOREINFO_SYMBOL(lowcore_ptr);
255 VMCOREINFO_SYMBOL(high_memory);
256 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
257 mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
258 vmcoreinfo_append_str("SDMA=%lx\n", __sdma);
259 vmcoreinfo_append_str("EDMA=%lx\n", __edma);
260 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
261}
262
263void machine_shutdown(void)
264{
265}
266
267void machine_crash_shutdown(struct pt_regs *regs)
268{
269 set_os_info_reipl_block();
270}
271
272/*
273 * Do normal kexec
274 */
275static void __do_machine_kexec(void *data)
276{
277 relocate_kernel_t data_mover;
278 struct kimage *image = data;
279
280 s390_reset_system();
281 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
282
283 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
284 /* Call the moving routine */
285 (*data_mover)(&image->head, image->start);
286
287 /* Die if kexec returns */
288 disabled_wait();
289}
290
291/*
292 * Reset system and call either kdump or normal kexec
293 */
294static void __machine_kexec(void *data)
295{
296 __arch_local_irq_stosm(0x04); /* enable DAT */
297 pfault_fini();
298 tracing_off();
299 debug_locks_off();
300#ifdef CONFIG_CRASH_DUMP
301 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
302 __machine_kdump(data);
303#endif
304 __do_machine_kexec(data);
305}
306
307/*
308 * Do either kdump or normal kexec. In case of kdump we first ask
309 * purgatory, if kdump checksums are valid.
310 */
311void machine_kexec(struct kimage *image)
312{
313 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
314 return;
315 tracer_disable();
316 smp_send_stop();
317 smp_call_ipl_cpu(__machine_kexec, image);
318}
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/cacheflush.h>
28#include <asm/os_info.h>
29#include <asm/switch_to.h>
30
31typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
32
33extern const unsigned char relocate_kernel[];
34extern const unsigned long long relocate_kernel_len;
35
36#ifdef CONFIG_CRASH_DUMP
37
38/*
39 * PM notifier callback for kdump
40 */
41static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
42 void *ptr)
43{
44 switch (action) {
45 case PM_SUSPEND_PREPARE:
46 case PM_HIBERNATION_PREPARE:
47 if (kexec_crash_image)
48 arch_kexec_unprotect_crashkres();
49 break;
50 case PM_POST_SUSPEND:
51 case PM_POST_HIBERNATION:
52 if (kexec_crash_image)
53 arch_kexec_protect_crashkres();
54 break;
55 default:
56 return NOTIFY_DONE;
57 }
58 return NOTIFY_OK;
59}
60
61static int __init machine_kdump_pm_init(void)
62{
63 pm_notifier(machine_kdump_pm_cb, 0);
64 return 0;
65}
66arch_initcall(machine_kdump_pm_init);
67
68/*
69 * Reset the system, copy boot CPU registers to absolute zero,
70 * and jump to the kdump image
71 */
72static void __do_machine_kdump(void *image)
73{
74 int (*start_kdump)(int);
75 unsigned long prefix;
76
77 /* store_status() saved the prefix register to lowcore */
78 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
79
80 /* Now do the reset */
81 s390_reset_system();
82
83 /*
84 * Copy dump CPU store status info to absolute zero.
85 * This need to be done *after* s390_reset_system set the
86 * prefix register of this CPU to zero
87 */
88 memcpy((void *) __LC_FPREGS_SAVE_AREA,
89 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
90
91 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
92 start_kdump = (void *)((struct kimage *) image)->start;
93 start_kdump(1);
94
95 /* Die if start_kdump returns */
96 disabled_wait((unsigned long) __builtin_return_address(0));
97}
98
99/*
100 * Start kdump: create a LGR log entry, store status of all CPUs and
101 * branch to __do_machine_kdump.
102 */
103static noinline void __machine_kdump(void *image)
104{
105 int this_cpu, cpu;
106
107 lgr_info_log();
108 /* Get status of the other CPUs */
109 this_cpu = smp_find_processor_id(stap());
110 for_each_online_cpu(cpu) {
111 if (cpu == this_cpu)
112 continue;
113 if (smp_store_status(cpu))
114 continue;
115 }
116 /* Store status of the boot CPU */
117 if (MACHINE_HAS_VX)
118 save_vx_regs((void *) &S390_lowcore.vector_save_area);
119 /*
120 * To create a good backchain for this CPU in the dump store_status
121 * is passed the address of a function. The address is saved into
122 * the PSW save area of the boot CPU and the function is invoked as
123 * a tail call of store_status. The backchain in the dump will look
124 * like this:
125 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
126 * The call to store_status() will not return.
127 */
128 store_status(__do_machine_kdump, image);
129}
130#endif
131
132/*
133 * Check if kdump checksums are valid: We call purgatory with parameter "0"
134 */
135static int kdump_csum_valid(struct kimage *image)
136{
137#ifdef CONFIG_CRASH_DUMP
138 int (*start_kdump)(int) = (void *)image->start;
139 int rc;
140
141 __arch_local_irq_stnsm(0xfb); /* disable DAT */
142 rc = start_kdump(0);
143 __arch_local_irq_stosm(0x04); /* enable DAT */
144 return rc ? 0 : -EINVAL;
145#else
146 return -EINVAL;
147#endif
148}
149
150#ifdef CONFIG_CRASH_DUMP
151
152void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
153{
154 unsigned long addr, size;
155
156 for (addr = begin; addr < end; addr += PAGE_SIZE)
157 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
158 size = begin - crashk_res.start;
159 if (size)
160 os_info_crashkernel_add(crashk_res.start, size);
161 else
162 os_info_crashkernel_add(0, 0);
163}
164
165static void crash_protect_pages(int protect)
166{
167 unsigned long size;
168
169 if (!crashk_res.end)
170 return;
171 size = resource_size(&crashk_res);
172 if (protect)
173 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
174 else
175 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
176}
177
178void arch_kexec_protect_crashkres(void)
179{
180 crash_protect_pages(1);
181}
182
183void arch_kexec_unprotect_crashkres(void)
184{
185 crash_protect_pages(0);
186}
187
188#endif
189
190/*
191 * Give back memory to hypervisor before new kdump is loaded
192 */
193static int machine_kexec_prepare_kdump(void)
194{
195#ifdef CONFIG_CRASH_DUMP
196 if (MACHINE_IS_VM)
197 diag10_range(PFN_DOWN(crashk_res.start),
198 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
199 return 0;
200#else
201 return -EINVAL;
202#endif
203}
204
205int machine_kexec_prepare(struct kimage *image)
206{
207 void *reboot_code_buffer;
208
209 /* Can't replace kernel image since it is read-only. */
210 if (ipl_flags & IPL_NSS_VALID)
211 return -EOPNOTSUPP;
212
213 if (image->type == KEXEC_TYPE_CRASH)
214 return machine_kexec_prepare_kdump();
215
216 /* We don't support anything but the default image type for now. */
217 if (image->type != KEXEC_TYPE_DEFAULT)
218 return -EINVAL;
219
220 /* Get the destination where the assembler code should be copied to.*/
221 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
222
223 /* Then copy it */
224 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
225 return 0;
226}
227
228void machine_kexec_cleanup(struct kimage *image)
229{
230}
231
232void arch_crash_save_vmcoreinfo(void)
233{
234 VMCOREINFO_SYMBOL(lowcore_ptr);
235 VMCOREINFO_SYMBOL(high_memory);
236 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
237}
238
239void machine_shutdown(void)
240{
241}
242
243void machine_crash_shutdown(struct pt_regs *regs)
244{
245}
246
247/*
248 * Do normal kexec
249 */
250static void __do_machine_kexec(void *data)
251{
252 relocate_kernel_t data_mover;
253 struct kimage *image = data;
254
255 s390_reset_system();
256 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
257
258 /* Call the moving routine */
259 (*data_mover)(&image->head, image->start);
260
261 /* Die if kexec returns */
262 disabled_wait((unsigned long) __builtin_return_address(0));
263}
264
265/*
266 * Reset system and call either kdump or normal kexec
267 */
268static void __machine_kexec(void *data)
269{
270 __arch_local_irq_stosm(0x04); /* enable DAT */
271 pfault_fini();
272 tracing_off();
273 debug_locks_off();
274#ifdef CONFIG_CRASH_DUMP
275 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
276 __machine_kdump(data);
277#endif
278 __do_machine_kexec(data);
279}
280
281/*
282 * Do either kdump or normal kexec. In case of kdump we first ask
283 * purgatory, if kdump checksums are valid.
284 */
285void machine_kexec(struct kimage *image)
286{
287 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
288 return;
289 tracer_disable();
290 smp_send_stop();
291 smp_call_ipl_cpu(__machine_kexec, image);
292}