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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/guarded_storage.h>
17#include <asm/pfault.h>
18#include <asm/cio.h>
19#include <asm/fpu.h>
20#include <asm/setup.h>
21#include <asm/smp.h>
22#include <asm/ipl.h>
23#include <asm/diag.h>
24#include <asm/elf.h>
25#include <asm/asm-offsets.h>
26#include <asm/cacheflush.h>
27#include <asm/abs_lowcore.h>
28#include <asm/os_info.h>
29#include <asm/set_memory.h>
30#include <asm/stacktrace.h>
31#include <asm/nmi.h>
32#include <asm/sclp.h>
33
34typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
35typedef int (*purgatory_t)(int);
36
37extern const unsigned char relocate_kernel[];
38extern const unsigned long long relocate_kernel_len;
39
40#ifdef CONFIG_CRASH_DUMP
41
42/*
43 * Reset the system, copy boot CPU registers to absolute zero,
44 * and jump to the kdump image
45 */
46static void __do_machine_kdump(void *data)
47{
48 struct kimage *image = data;
49 purgatory_t purgatory;
50 unsigned long prefix;
51
52 purgatory = (purgatory_t)image->start;
53
54 /* store_status() saved the prefix register to lowcore */
55 prefix = (unsigned long)get_lowcore()->prefixreg_save_area;
56
57 /* Now do the reset */
58 s390_reset_system();
59
60 /*
61 * Copy dump CPU store status info to absolute zero.
62 * This need to be done *after* s390_reset_system set the
63 * prefix register of this CPU to zero
64 */
65 memcpy(absolute_pointer(get_lowcore()->floating_pt_save_area),
66 phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
67
68 call_nodat(1, int, purgatory, int, 1);
69
70 /* Die if kdump returns */
71 disabled_wait();
72}
73
74/*
75 * Start kdump: create a LGR log entry, store status of all CPUs and
76 * branch to __do_machine_kdump.
77 */
78static noinline void __machine_kdump(void *image)
79{
80 struct mcesa *mcesa;
81 union ctlreg2 cr2_old, cr2_new;
82 int this_cpu, cpu;
83
84 lgr_info_log();
85 /* Get status of the other CPUs */
86 this_cpu = smp_find_processor_id(stap());
87 for_each_online_cpu(cpu) {
88 if (cpu == this_cpu)
89 continue;
90 if (smp_store_status(cpu))
91 continue;
92 }
93 /* Store status of the boot CPU */
94 mcesa = __va(get_lowcore()->mcesad & MCESA_ORIGIN_MASK);
95 if (cpu_has_vx())
96 save_vx_regs((__vector128 *) mcesa->vector_save_area);
97 if (MACHINE_HAS_GS) {
98 local_ctl_store(2, &cr2_old.reg);
99 cr2_new = cr2_old;
100 cr2_new.gse = 1;
101 local_ctl_load(2, &cr2_new.reg);
102 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
103 local_ctl_load(2, &cr2_old.reg);
104 }
105 /*
106 * To create a good backchain for this CPU in the dump store_status
107 * is passed the address of a function. The address is saved into
108 * the PSW save area of the boot CPU and the function is invoked as
109 * a tail call of store_status. The backchain in the dump will look
110 * like this:
111 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
112 * The call to store_status() will not return.
113 */
114 store_status(__do_machine_kdump, image);
115}
116
117#endif /* CONFIG_CRASH_DUMP */
118
119/*
120 * Check if kdump checksums are valid: We call purgatory with parameter "0"
121 */
122static bool kdump_csum_valid(struct kimage *image)
123{
124#ifdef CONFIG_CRASH_DUMP
125 purgatory_t purgatory = (purgatory_t)image->start;
126 int rc;
127
128 rc = call_nodat(1, int, purgatory, int, 0);
129 return rc == 0;
130#else
131 return false;
132#endif
133}
134
135#ifdef CONFIG_CRASH_DUMP
136
137void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
138{
139 unsigned long addr, size;
140
141 for (addr = begin; addr < end; addr += PAGE_SIZE)
142 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
143 size = begin - crashk_res.start;
144 if (size)
145 os_info_crashkernel_add(crashk_res.start, size);
146 else
147 os_info_crashkernel_add(0, 0);
148}
149
150static void crash_protect_pages(int protect)
151{
152 unsigned long size;
153
154 if (!crashk_res.end)
155 return;
156 size = resource_size(&crashk_res);
157 if (protect)
158 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
159 else
160 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
161}
162
163void arch_kexec_protect_crashkres(void)
164{
165 crash_protect_pages(1);
166}
167
168void arch_kexec_unprotect_crashkres(void)
169{
170 crash_protect_pages(0);
171}
172
173#endif
174
175/*
176 * Give back memory to hypervisor before new kdump is loaded
177 */
178static int machine_kexec_prepare_kdump(void)
179{
180#ifdef CONFIG_CRASH_DUMP
181 if (MACHINE_IS_VM)
182 diag10_range(PFN_DOWN(crashk_res.start),
183 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
184 return 0;
185#else
186 return -EINVAL;
187#endif
188}
189
190int machine_kexec_prepare(struct kimage *image)
191{
192 void *reboot_code_buffer;
193
194 if (image->type == KEXEC_TYPE_CRASH)
195 return machine_kexec_prepare_kdump();
196
197 /* We don't support anything but the default image type for now. */
198 if (image->type != KEXEC_TYPE_DEFAULT)
199 return -EINVAL;
200
201 /* Get the destination where the assembler code should be copied to.*/
202 reboot_code_buffer = page_to_virt(image->control_code_page);
203
204 /* Then copy it */
205 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
206 return 0;
207}
208
209void machine_kexec_cleanup(struct kimage *image)
210{
211}
212
213void machine_shutdown(void)
214{
215}
216
217void machine_crash_shutdown(struct pt_regs *regs)
218{
219 set_os_info_reipl_block();
220}
221
222/*
223 * Do normal kexec
224 */
225static void __do_machine_kexec(void *data)
226{
227 unsigned long data_mover, entry, diag308_subcode;
228 struct kimage *image = data;
229
230 data_mover = page_to_phys(image->control_code_page);
231 entry = virt_to_phys(&image->head);
232 diag308_subcode = DIAG308_CLEAR_RESET;
233 if (sclp.has_iplcc)
234 diag308_subcode |= DIAG308_FLAG_EI;
235 s390_reset_system();
236
237 call_nodat(3, void, (relocate_kernel_t)data_mover,
238 unsigned long, entry,
239 unsigned long, image->start,
240 unsigned long, diag308_subcode);
241
242 /* Die if kexec returns */
243 disabled_wait();
244}
245
246/*
247 * Reset system and call either kdump or normal kexec
248 */
249static void __machine_kexec(void *data)
250{
251 pfault_fini();
252 tracing_off();
253 debug_locks_off();
254#ifdef CONFIG_CRASH_DUMP
255 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
256 __machine_kdump(data);
257#endif
258 __do_machine_kexec(data);
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}
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}