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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/pfault.h>
17#include <asm/cio.h>
18#include <asm/setup.h>
19#include <asm/smp.h>
20#include <asm/ipl.h>
21#include <asm/diag.h>
22#include <asm/elf.h>
23#include <asm/asm-offsets.h>
24#include <asm/cacheflush.h>
25#include <asm/abs_lowcore.h>
26#include <asm/os_info.h>
27#include <asm/set_memory.h>
28#include <asm/stacktrace.h>
29#include <asm/switch_to.h>
30#include <asm/nmi.h>
31#include <asm/sclp.h>
32
33typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
34typedef int (*purgatory_t)(int);
35
36extern const unsigned char relocate_kernel[];
37extern const unsigned long long relocate_kernel_len;
38
39#ifdef CONFIG_CRASH_DUMP
40
41/*
42 * Reset the system, copy boot CPU registers to absolute zero,
43 * and jump to the kdump image
44 */
45static void __do_machine_kdump(void *data)
46{
47 struct kimage *image = data;
48 purgatory_t purgatory;
49 unsigned long prefix;
50
51 purgatory = (purgatory_t)image->start;
52
53 /* store_status() saved the prefix register to lowcore */
54 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
55
56 /* Now do the reset */
57 s390_reset_system();
58
59 /*
60 * Copy dump CPU store status info to absolute zero.
61 * This need to be done *after* s390_reset_system set the
62 * prefix register of this CPU to zero
63 */
64 memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
65 phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
66
67 call_nodat(1, int, purgatory, int, 1);
68
69 /* Die if kdump returns */
70 disabled_wait();
71}
72
73/*
74 * Start kdump: create a LGR log entry, store status of all CPUs and
75 * branch to __do_machine_kdump.
76 */
77static noinline void __machine_kdump(void *image)
78{
79 struct mcesa *mcesa;
80 union ctlreg2 cr2_old, cr2_new;
81 int this_cpu, cpu;
82
83 lgr_info_log();
84 /* Get status of the other CPUs */
85 this_cpu = smp_find_processor_id(stap());
86 for_each_online_cpu(cpu) {
87 if (cpu == this_cpu)
88 continue;
89 if (smp_store_status(cpu))
90 continue;
91 }
92 /* Store status of the boot CPU */
93 mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
94 if (cpu_has_vx())
95 save_vx_regs((__vector128 *) mcesa->vector_save_area);
96 if (MACHINE_HAS_GS) {
97 local_ctl_store(2, &cr2_old.reg);
98 cr2_new = cr2_old;
99 cr2_new.gse = 1;
100 local_ctl_load(2, &cr2_new.reg);
101 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
102 local_ctl_load(2, &cr2_old.reg);
103 }
104 /*
105 * To create a good backchain for this CPU in the dump store_status
106 * is passed the address of a function. The address is saved into
107 * the PSW save area of the boot CPU and the function is invoked as
108 * a tail call of store_status. The backchain in the dump will look
109 * like this:
110 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
111 * The call to store_status() will not return.
112 */
113 store_status(__do_machine_kdump, image);
114}
115
116#endif /* CONFIG_CRASH_DUMP */
117
118/*
119 * Check if kdump checksums are valid: We call purgatory with parameter "0"
120 */
121static bool kdump_csum_valid(struct kimage *image)
122{
123#ifdef CONFIG_CRASH_DUMP
124 purgatory_t purgatory = (purgatory_t)image->start;
125 int rc;
126
127 rc = call_nodat(1, int, purgatory, int, 0);
128 return rc == 0;
129#else
130 return false;
131#endif
132}
133
134#ifdef CONFIG_CRASH_DUMP
135
136void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
137{
138 unsigned long addr, size;
139
140 for (addr = begin; addr < end; addr += PAGE_SIZE)
141 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
142 size = begin - crashk_res.start;
143 if (size)
144 os_info_crashkernel_add(crashk_res.start, size);
145 else
146 os_info_crashkernel_add(0, 0);
147}
148
149static void crash_protect_pages(int protect)
150{
151 unsigned long size;
152
153 if (!crashk_res.end)
154 return;
155 size = resource_size(&crashk_res);
156 if (protect)
157 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
158 else
159 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
160}
161
162void arch_kexec_protect_crashkres(void)
163{
164 crash_protect_pages(1);
165}
166
167void arch_kexec_unprotect_crashkres(void)
168{
169 crash_protect_pages(0);
170}
171
172#endif
173
174/*
175 * Give back memory to hypervisor before new kdump is loaded
176 */
177static int machine_kexec_prepare_kdump(void)
178{
179#ifdef CONFIG_CRASH_DUMP
180 if (MACHINE_IS_VM)
181 diag10_range(PFN_DOWN(crashk_res.start),
182 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
183 return 0;
184#else
185 return -EINVAL;
186#endif
187}
188
189int machine_kexec_prepare(struct kimage *image)
190{
191 void *reboot_code_buffer;
192
193 if (image->type == KEXEC_TYPE_CRASH)
194 return machine_kexec_prepare_kdump();
195
196 /* We don't support anything but the default image type for now. */
197 if (image->type != KEXEC_TYPE_DEFAULT)
198 return -EINVAL;
199
200 /* Get the destination where the assembler code should be copied to.*/
201 reboot_code_buffer = page_to_virt(image->control_code_page);
202
203 /* Then copy it */
204 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
205 return 0;
206}
207
208void machine_kexec_cleanup(struct kimage *image)
209{
210}
211
212void arch_crash_save_vmcoreinfo(void)
213{
214 struct lowcore *abs_lc;
215
216 VMCOREINFO_SYMBOL(lowcore_ptr);
217 VMCOREINFO_SYMBOL(high_memory);
218 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
219 vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
220 vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
221 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
222 abs_lc = get_abs_lowcore();
223 abs_lc->vmcore_info = paddr_vmcoreinfo_note();
224 put_abs_lowcore(abs_lc);
225}
226
227void machine_shutdown(void)
228{
229}
230
231void machine_crash_shutdown(struct pt_regs *regs)
232{
233 set_os_info_reipl_block();
234}
235
236/*
237 * Do normal kexec
238 */
239static void __do_machine_kexec(void *data)
240{
241 unsigned long data_mover, entry, diag308_subcode;
242 struct kimage *image = data;
243
244 data_mover = page_to_phys(image->control_code_page);
245 entry = virt_to_phys(&image->head);
246 diag308_subcode = DIAG308_CLEAR_RESET;
247 if (sclp.has_iplcc)
248 diag308_subcode |= DIAG308_FLAG_EI;
249 s390_reset_system();
250
251 call_nodat(3, void, (relocate_kernel_t)data_mover,
252 unsigned long, entry,
253 unsigned long, image->start,
254 unsigned long, diag308_subcode);
255
256 /* Die if kexec returns */
257 disabled_wait();
258}
259
260/*
261 * Reset system and call either kdump or normal kexec
262 */
263static void __machine_kexec(void *data)
264{
265 pfault_fini();
266 tracing_off();
267 debug_locks_off();
268#ifdef CONFIG_CRASH_DUMP
269 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
270 __machine_kdump(data);
271#endif
272 __do_machine_kexec(data);
273}
274
275/*
276 * Do either kdump or normal kexec. In case of kdump we first ask
277 * purgatory, if kdump checksums are valid.
278 */
279void machine_kexec(struct kimage *image)
280{
281 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
282 return;
283 tracer_disable();
284 smp_send_stop();
285 smp_call_ipl_cpu(__machine_kexec, image);
286}
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
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
36/*
37 * Create ELF notes for one CPU
38 */
39static void add_elf_notes(int cpu)
40{
41 struct save_area *sa = (void *) 4608 + store_prefix();
42 void *ptr;
43
44 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
45 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
46 ptr = fill_cpu_elf_notes(ptr, sa);
47 memset(ptr, 0, sizeof(struct elf_note));
48}
49
50/*
51 * Initialize CPU ELF notes
52 */
53static void setup_regs(void)
54{
55 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
56 int cpu, this_cpu;
57
58 this_cpu = smp_find_processor_id(stap());
59 add_elf_notes(this_cpu);
60 for_each_online_cpu(cpu) {
61 if (cpu == this_cpu)
62 continue;
63 if (smp_store_status(cpu))
64 continue;
65 add_elf_notes(cpu);
66 }
67 /* Copy dump CPU store status info to absolute zero */
68 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
69}
70
71/*
72 * PM notifier callback for kdump
73 */
74static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
75 void *ptr)
76{
77 switch (action) {
78 case PM_SUSPEND_PREPARE:
79 case PM_HIBERNATION_PREPARE:
80 if (crashk_res.start)
81 crash_map_reserved_pages();
82 break;
83 case PM_POST_SUSPEND:
84 case PM_POST_HIBERNATION:
85 if (crashk_res.start)
86 crash_unmap_reserved_pages();
87 break;
88 default:
89 return NOTIFY_DONE;
90 }
91 return NOTIFY_OK;
92}
93
94static int __init machine_kdump_pm_init(void)
95{
96 pm_notifier(machine_kdump_pm_cb, 0);
97 return 0;
98}
99arch_initcall(machine_kdump_pm_init);
100#endif
101
102/*
103 * Start kdump: We expect here that a store status has been done on our CPU
104 */
105static void __do_machine_kdump(void *image)
106{
107#ifdef CONFIG_CRASH_DUMP
108 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
109
110 setup_regs();
111 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
112 start_kdump(1);
113#endif
114}
115
116/*
117 * Check if kdump checksums are valid: We call purgatory with parameter "0"
118 */
119static int kdump_csum_valid(struct kimage *image)
120{
121#ifdef CONFIG_CRASH_DUMP
122 int (*start_kdump)(int) = (void *)image->start;
123 int rc;
124
125 __arch_local_irq_stnsm(0xfb); /* disable DAT */
126 rc = start_kdump(0);
127 __arch_local_irq_stosm(0x04); /* enable DAT */
128 return rc ? 0 : -EINVAL;
129#else
130 return -EINVAL;
131#endif
132}
133
134/*
135 * Map or unmap crashkernel memory
136 */
137static void crash_map_pages(int enable)
138{
139 unsigned long size = resource_size(&crashk_res);
140
141 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
142 size % KEXEC_CRASH_MEM_ALIGN);
143 if (enable)
144 vmem_add_mapping(crashk_res.start, size);
145 else {
146 vmem_remove_mapping(crashk_res.start, size);
147 if (size)
148 os_info_crashkernel_add(crashk_res.start, size);
149 else
150 os_info_crashkernel_add(0, 0);
151 }
152}
153
154/*
155 * Map crashkernel memory
156 */
157void crash_map_reserved_pages(void)
158{
159 crash_map_pages(1);
160}
161
162/*
163 * Unmap crashkernel memory
164 */
165void crash_unmap_reserved_pages(void)
166{
167 crash_map_pages(0);
168}
169
170/*
171 * Give back memory to hypervisor before new kdump is loaded
172 */
173static int machine_kexec_prepare_kdump(void)
174{
175#ifdef CONFIG_CRASH_DUMP
176 if (MACHINE_IS_VM)
177 diag10_range(PFN_DOWN(crashk_res.start),
178 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
179 return 0;
180#else
181 return -EINVAL;
182#endif
183}
184
185int machine_kexec_prepare(struct kimage *image)
186{
187 void *reboot_code_buffer;
188
189 /* Can't replace kernel image since it is read-only. */
190 if (ipl_flags & IPL_NSS_VALID)
191 return -EOPNOTSUPP;
192
193 if (image->type == KEXEC_TYPE_CRASH)
194 return machine_kexec_prepare_kdump();
195
196 /* We don't support anything but the default image type for now. */
197 if (image->type != KEXEC_TYPE_DEFAULT)
198 return -EINVAL;
199
200 /* Get the destination where the assembler code should be copied to.*/
201 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
202
203 /* Then copy it */
204 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
205 return 0;
206}
207
208void machine_kexec_cleanup(struct kimage *image)
209{
210}
211
212void arch_crash_save_vmcoreinfo(void)
213{
214 VMCOREINFO_SYMBOL(lowcore_ptr);
215 VMCOREINFO_SYMBOL(high_memory);
216 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
217}
218
219void machine_shutdown(void)
220{
221}
222
223void machine_crash_shutdown(struct pt_regs *regs)
224{
225}
226
227/*
228 * Do normal kexec
229 */
230static void __do_machine_kexec(void *data)
231{
232 relocate_kernel_t data_mover;
233 struct kimage *image = data;
234
235 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
236
237 /* Call the moving routine */
238 (*data_mover)(&image->head, image->start);
239}
240
241/*
242 * Reset system and call either kdump or normal kexec
243 */
244static void __machine_kexec(void *data)
245{
246 struct kimage *image = data;
247
248 __arch_local_irq_stosm(0x04); /* enable DAT */
249 pfault_fini();
250 tracing_off();
251 debug_locks_off();
252 if (image->type == KEXEC_TYPE_CRASH) {
253 lgr_info_log();
254 s390_reset_system(__do_machine_kdump, data);
255 } else {
256 s390_reset_system(__do_machine_kexec, data);
257 }
258 disabled_wait((unsigned long) __builtin_return_address(0));
259}
260
261/*
262 * Do either kdump or normal kexec. In case of kdump we first ask
263 * purgatory, if kdump checksums are valid.
264 */
265void machine_kexec(struct kimage *image)
266{
267 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
268 return;
269 tracer_disable();
270 smp_send_stop();
271 smp_call_ipl_cpu(__machine_kexec, image);
272}