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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 * 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 <asm/cio.h>
17#include <asm/setup.h>
18#include <asm/smp.h>
19#include <asm/ipl.h>
20#include <asm/diag.h>
21#include <asm/elf.h>
22#include <asm/asm-offsets.h>
23#include <asm/cacheflush.h>
24#include <asm/abs_lowcore.h>
25#include <asm/os_info.h>
26#include <asm/set_memory.h>
27#include <asm/stacktrace.h>
28#include <asm/switch_to.h>
29#include <asm/nmi.h>
30#include <asm/sclp.h>
31
32typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long,
33 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 * Reset the system, copy boot CPU registers to absolute zero,
42 * and jump to the kdump image
43 */
44static void __do_machine_kdump(void *image)
45{
46 int (*start_kdump)(int);
47 unsigned long prefix;
48
49 /* store_status() saved the prefix register to lowcore */
50 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
51
52 /* Now do the reset */
53 s390_reset_system();
54
55 /*
56 * Copy dump CPU store status info to absolute zero.
57 * This need to be done *after* s390_reset_system set the
58 * prefix register of this CPU to zero
59 */
60 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
61 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
62
63 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
64 start_kdump = (void *)((struct kimage *) image)->start;
65 start_kdump(1);
66
67 /* Die if start_kdump returns */
68 disabled_wait();
69}
70
71/*
72 * Start kdump: create a LGR log entry, store status of all CPUs and
73 * branch to __do_machine_kdump.
74 */
75static noinline void __machine_kdump(void *image)
76{
77 struct mcesa *mcesa;
78 union ctlreg2 cr2_old, cr2_new;
79 int this_cpu, cpu;
80
81 lgr_info_log();
82 /* Get status of the other CPUs */
83 this_cpu = smp_find_processor_id(stap());
84 for_each_online_cpu(cpu) {
85 if (cpu == this_cpu)
86 continue;
87 if (smp_store_status(cpu))
88 continue;
89 }
90 /* Store status of the boot CPU */
91 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
92 if (MACHINE_HAS_VX)
93 save_vx_regs((__vector128 *) mcesa->vector_save_area);
94 if (MACHINE_HAS_GS) {
95 __ctl_store(cr2_old.val, 2, 2);
96 cr2_new = cr2_old;
97 cr2_new.gse = 1;
98 __ctl_load(cr2_new.val, 2, 2);
99 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
100 __ctl_load(cr2_old.val, 2, 2);
101 }
102 /*
103 * To create a good backchain for this CPU in the dump store_status
104 * is passed the address of a function. The address is saved into
105 * the PSW save area of the boot CPU and the function is invoked as
106 * a tail call of store_status. The backchain in the dump will look
107 * like this:
108 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
109 * The call to store_status() will not return.
110 */
111 store_status(__do_machine_kdump, image);
112}
113
114static unsigned long do_start_kdump(unsigned long addr)
115{
116 struct kimage *image = (struct kimage *) addr;
117 int (*start_kdump)(int) = (void *)image->start;
118 int rc;
119
120 __arch_local_irq_stnsm(0xfb); /* disable DAT */
121 rc = start_kdump(0);
122 __arch_local_irq_stosm(0x04); /* enable DAT */
123 return rc;
124}
125
126#endif /* CONFIG_CRASH_DUMP */
127
128/*
129 * Check if kdump checksums are valid: We call purgatory with parameter "0"
130 */
131static bool kdump_csum_valid(struct kimage *image)
132{
133#ifdef CONFIG_CRASH_DUMP
134 int rc;
135
136 preempt_disable();
137 rc = call_on_stack(1, S390_lowcore.nodat_stack, unsigned long, do_start_kdump,
138 unsigned long, (unsigned long)image);
139 preempt_enable();
140 return rc == 0;
141#else
142 return false;
143#endif
144}
145
146#ifdef CONFIG_CRASH_DUMP
147
148void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
149{
150 unsigned long addr, size;
151
152 for (addr = begin; addr < end; addr += PAGE_SIZE)
153 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
154 size = begin - crashk_res.start;
155 if (size)
156 os_info_crashkernel_add(crashk_res.start, size);
157 else
158 os_info_crashkernel_add(0, 0);
159}
160
161static void crash_protect_pages(int protect)
162{
163 unsigned long size;
164
165 if (!crashk_res.end)
166 return;
167 size = resource_size(&crashk_res);
168 if (protect)
169 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
170 else
171 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
172}
173
174void arch_kexec_protect_crashkres(void)
175{
176 crash_protect_pages(1);
177}
178
179void arch_kexec_unprotect_crashkres(void)
180{
181 crash_protect_pages(0);
182}
183
184#endif
185
186/*
187 * Give back memory to hypervisor before new kdump is loaded
188 */
189static int machine_kexec_prepare_kdump(void)
190{
191#ifdef CONFIG_CRASH_DUMP
192 if (MACHINE_IS_VM)
193 diag10_range(PFN_DOWN(crashk_res.start),
194 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
195 return 0;
196#else
197 return -EINVAL;
198#endif
199}
200
201int machine_kexec_prepare(struct kimage *image)
202{
203 void *reboot_code_buffer;
204
205 if (image->type == KEXEC_TYPE_CRASH)
206 return machine_kexec_prepare_kdump();
207
208 /* We don't support anything but the default image type for now. */
209 if (image->type != KEXEC_TYPE_DEFAULT)
210 return -EINVAL;
211
212 /* Get the destination where the assembler code should be copied to.*/
213 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
214
215 /* Then copy it */
216 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
217 return 0;
218}
219
220void machine_kexec_cleanup(struct kimage *image)
221{
222}
223
224void arch_crash_save_vmcoreinfo(void)
225{
226 struct lowcore *abs_lc;
227 unsigned long flags;
228
229 VMCOREINFO_SYMBOL(lowcore_ptr);
230 VMCOREINFO_SYMBOL(high_memory);
231 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
232 vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
233 vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
234 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
235 abs_lc = get_abs_lowcore(&flags);
236 abs_lc->vmcore_info = paddr_vmcoreinfo_note();
237 put_abs_lowcore(abs_lc, flags);
238}
239
240void machine_shutdown(void)
241{
242}
243
244void machine_crash_shutdown(struct pt_regs *regs)
245{
246 set_os_info_reipl_block();
247}
248
249/*
250 * Do normal kexec
251 */
252static void __do_machine_kexec(void *data)
253{
254 unsigned long diag308_subcode;
255 relocate_kernel_t data_mover;
256 struct kimage *image = data;
257
258 s390_reset_system();
259 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
260
261 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
262 /* Call the moving routine */
263 diag308_subcode = DIAG308_CLEAR_RESET;
264 if (sclp.has_iplcc)
265 diag308_subcode |= DIAG308_FLAG_EI;
266 (*data_mover)(&image->head, image->start, diag308_subcode);
267
268 /* Die if kexec returns */
269 disabled_wait();
270}
271
272/*
273 * Reset system and call either kdump or normal kexec
274 */
275static void __machine_kexec(void *data)
276{
277 pfault_fini();
278 tracing_off();
279 debug_locks_off();
280#ifdef CONFIG_CRASH_DUMP
281 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
282 __machine_kdump(data);
283#endif
284 __do_machine_kexec(data);
285}
286
287/*
288 * Do either kdump or normal kexec. In case of kdump we first ask
289 * purgatory, if kdump checksums are valid.
290 */
291void machine_kexec(struct kimage *image)
292{
293 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
294 return;
295 tracer_disable();
296 smp_send_stop();
297 smp_call_ipl_cpu(__machine_kexec, image);
298}
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}