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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 * arch/s390/kernel/machine_kexec.c
3 *
4 * Copyright IBM Corp. 2005,2011
5 *
6 * Author(s): Rolf Adelsberger,
7 * Heiko Carstens <heiko.carstens@de.ibm.com>
8 * Michael Holzheu <holzheu@linux.vnet.ibm.com>
9 */
10
11#include <linux/device.h>
12#include <linux/mm.h>
13#include <linux/kexec.h>
14#include <linux/delay.h>
15#include <linux/reboot.h>
16#include <linux/ftrace.h>
17#include <linux/debug_locks.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/reset.h>
24#include <asm/ipl.h>
25#include <asm/diag.h>
26#include <asm/asm-offsets.h>
27#include <asm/os_info.h>
28
29typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
30
31extern const unsigned char relocate_kernel[];
32extern const unsigned long long relocate_kernel_len;
33
34#ifdef CONFIG_CRASH_DUMP
35
36void *fill_cpu_elf_notes(void *ptr, struct save_area *sa);
37
38/*
39 * Create ELF notes for one CPU
40 */
41static void add_elf_notes(int cpu)
42{
43 struct save_area *sa = (void *) 4608 + store_prefix();
44 void *ptr;
45
46 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
47 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
48 ptr = fill_cpu_elf_notes(ptr, sa);
49 memset(ptr, 0, sizeof(struct elf_note));
50}
51
52/*
53 * Initialize CPU ELF notes
54 */
55void setup_regs(void)
56{
57 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
58 int cpu, this_cpu;
59
60 this_cpu = smp_find_processor_id(stap());
61 add_elf_notes(this_cpu);
62 for_each_online_cpu(cpu) {
63 if (cpu == this_cpu)
64 continue;
65 if (smp_store_status(cpu))
66 continue;
67 add_elf_notes(cpu);
68 }
69 /* Copy dump CPU store status info to absolute zero */
70 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
71}
72
73#endif
74
75/*
76 * Start kdump: We expect here that a store status has been done on our CPU
77 */
78static void __do_machine_kdump(void *image)
79{
80#ifdef CONFIG_CRASH_DUMP
81 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
82
83 setup_regs();
84 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
85 start_kdump(1);
86#endif
87}
88
89/*
90 * Check if kdump checksums are valid: We call purgatory with parameter "0"
91 */
92static int kdump_csum_valid(struct kimage *image)
93{
94#ifdef CONFIG_CRASH_DUMP
95 int (*start_kdump)(int) = (void *)image->start;
96 int rc;
97
98 __arch_local_irq_stnsm(0xfb); /* disable DAT */
99 rc = start_kdump(0);
100 __arch_local_irq_stosm(0x04); /* enable DAT */
101 return rc ? 0 : -EINVAL;
102#else
103 return -EINVAL;
104#endif
105}
106
107/*
108 * Map or unmap crashkernel memory
109 */
110static void crash_map_pages(int enable)
111{
112 unsigned long size = resource_size(&crashk_res);
113
114 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
115 size % KEXEC_CRASH_MEM_ALIGN);
116 if (enable)
117 vmem_add_mapping(crashk_res.start, size);
118 else {
119 vmem_remove_mapping(crashk_res.start, size);
120 if (size)
121 os_info_crashkernel_add(crashk_res.start, size);
122 else
123 os_info_crashkernel_add(0, 0);
124 }
125}
126
127/*
128 * Map crashkernel memory
129 */
130void crash_map_reserved_pages(void)
131{
132 crash_map_pages(1);
133}
134
135/*
136 * Unmap crashkernel memory
137 */
138void crash_unmap_reserved_pages(void)
139{
140 crash_map_pages(0);
141}
142
143/*
144 * Give back memory to hypervisor before new kdump is loaded
145 */
146static int machine_kexec_prepare_kdump(void)
147{
148#ifdef CONFIG_CRASH_DUMP
149 if (MACHINE_IS_VM)
150 diag10_range(PFN_DOWN(crashk_res.start),
151 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
152 return 0;
153#else
154 return -EINVAL;
155#endif
156}
157
158int machine_kexec_prepare(struct kimage *image)
159{
160 void *reboot_code_buffer;
161
162 /* Can't replace kernel image since it is read-only. */
163 if (ipl_flags & IPL_NSS_VALID)
164 return -ENOSYS;
165
166 if (image->type == KEXEC_TYPE_CRASH)
167 return machine_kexec_prepare_kdump();
168
169 /* We don't support anything but the default image type for now. */
170 if (image->type != KEXEC_TYPE_DEFAULT)
171 return -EINVAL;
172
173 /* Get the destination where the assembler code should be copied to.*/
174 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
175
176 /* Then copy it */
177 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
178 return 0;
179}
180
181void machine_kexec_cleanup(struct kimage *image)
182{
183}
184
185void arch_crash_save_vmcoreinfo(void)
186{
187 VMCOREINFO_SYMBOL(lowcore_ptr);
188 VMCOREINFO_SYMBOL(high_memory);
189 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
190}
191
192void machine_shutdown(void)
193{
194}
195
196/*
197 * Do normal kexec
198 */
199static void __do_machine_kexec(void *data)
200{
201 relocate_kernel_t data_mover;
202 struct kimage *image = data;
203
204 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
205
206 /* Call the moving routine */
207 (*data_mover)(&image->head, image->start);
208}
209
210/*
211 * Reset system and call either kdump or normal kexec
212 */
213static void __machine_kexec(void *data)
214{
215 struct kimage *image = data;
216
217 __arch_local_irq_stosm(0x04); /* enable DAT */
218 pfault_fini();
219 tracing_off();
220 debug_locks_off();
221 if (image->type == KEXEC_TYPE_CRASH) {
222 lgr_info_log();
223 s390_reset_system(__do_machine_kdump, data);
224 } else {
225 s390_reset_system(__do_machine_kexec, data);
226 }
227 disabled_wait((unsigned long) __builtin_return_address(0));
228}
229
230/*
231 * Do either kdump or normal kexec. In case of kdump we first ask
232 * purgatory, if kdump checksums are valid.
233 */
234void machine_kexec(struct kimage *image)
235{
236 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
237 return;
238 tracer_disable();
239 smp_send_stop();
240 smp_call_ipl_cpu(__machine_kexec, image);
241}