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1/*
2 * arch/s390/kernel/machine_kexec.c
3 *
4 * Copyright IBM Corp. 2005,2006
5 *
6 * Author(s): Rolf Adelsberger,
7 * Heiko Carstens <heiko.carstens@de.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 <asm/cio.h>
17#include <asm/setup.h>
18#include <asm/pgtable.h>
19#include <asm/pgalloc.h>
20#include <asm/system.h>
21#include <asm/smp.h>
22#include <asm/reset.h>
23#include <asm/ipl.h>
24
25typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
26
27extern const unsigned char relocate_kernel[];
28extern const unsigned long long relocate_kernel_len;
29
30int machine_kexec_prepare(struct kimage *image)
31{
32 void *reboot_code_buffer;
33
34 /* Can't replace kernel image since it is read-only. */
35 if (ipl_flags & IPL_NSS_VALID)
36 return -ENOSYS;
37
38 /* We don't support anything but the default image type for now. */
39 if (image->type != KEXEC_TYPE_DEFAULT)
40 return -EINVAL;
41
42 /* Get the destination where the assembler code should be copied to.*/
43 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
44
45 /* Then copy it */
46 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
47 return 0;
48}
49
50void machine_kexec_cleanup(struct kimage *image)
51{
52}
53
54void machine_shutdown(void)
55{
56}
57
58static void __machine_kexec(void *data)
59{
60 relocate_kernel_t data_mover;
61 struct kimage *image = data;
62
63 pfault_fini();
64 s390_reset_system();
65
66 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
67
68 /* Call the moving routine */
69 (*data_mover)(&image->head, image->start);
70 for (;;);
71}
72
73void machine_kexec(struct kimage *image)
74{
75 tracer_disable();
76 smp_send_stop();
77 smp_switch_to_ipl_cpu(__machine_kexec, image);
78}
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 <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/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
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 * Reset the system, copy boot CPU registers to absolute zero,
40 * and jump to the kdump image
41 */
42static void __do_machine_kdump(void *image)
43{
44 int (*start_kdump)(int);
45 unsigned long prefix;
46
47 /* store_status() saved the prefix register to lowcore */
48 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
49
50 /* Now do the reset */
51 s390_reset_system();
52
53 /*
54 * Copy dump CPU store status info to absolute zero.
55 * This need to be done *after* s390_reset_system set the
56 * prefix register of this CPU to zero
57 */
58 memcpy((void *) __LC_FPREGS_SAVE_AREA,
59 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
60
61 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
62 start_kdump = (void *)((struct kimage *) image)->start;
63 start_kdump(1);
64
65 /* Die if start_kdump returns */
66 disabled_wait();
67}
68
69/*
70 * Start kdump: create a LGR log entry, store status of all CPUs and
71 * branch to __do_machine_kdump.
72 */
73static noinline void __machine_kdump(void *image)
74{
75 struct mcesa *mcesa;
76 union ctlreg2 cr2_old, cr2_new;
77 int this_cpu, cpu;
78
79 lgr_info_log();
80 /* Get status of the other CPUs */
81 this_cpu = smp_find_processor_id(stap());
82 for_each_online_cpu(cpu) {
83 if (cpu == this_cpu)
84 continue;
85 if (smp_store_status(cpu))
86 continue;
87 }
88 /* Store status of the boot CPU */
89 mcesa = (struct mcesa *)(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
90 if (MACHINE_HAS_VX)
91 save_vx_regs((__vector128 *) mcesa->vector_save_area);
92 if (MACHINE_HAS_GS) {
93 __ctl_store(cr2_old.val, 2, 2);
94 cr2_new = cr2_old;
95 cr2_new.gse = 1;
96 __ctl_load(cr2_new.val, 2, 2);
97 save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
98 __ctl_load(cr2_old.val, 2, 2);
99 }
100 /*
101 * To create a good backchain for this CPU in the dump store_status
102 * is passed the address of a function. The address is saved into
103 * the PSW save area of the boot CPU and the function is invoked as
104 * a tail call of store_status. The backchain in the dump will look
105 * like this:
106 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
107 * The call to store_status() will not return.
108 */
109 store_status(__do_machine_kdump, image);
110}
111
112static unsigned long do_start_kdump(unsigned long addr)
113{
114 struct kimage *image = (struct kimage *) addr;
115 int (*start_kdump)(int) = (void *)image->start;
116 int rc;
117
118 __arch_local_irq_stnsm(0xfb); /* disable DAT */
119 rc = start_kdump(0);
120 __arch_local_irq_stosm(0x04); /* enable DAT */
121 return rc;
122}
123
124#endif /* CONFIG_CRASH_DUMP */
125
126/*
127 * Check if kdump checksums are valid: We call purgatory with parameter "0"
128 */
129static bool kdump_csum_valid(struct kimage *image)
130{
131#ifdef CONFIG_CRASH_DUMP
132 int rc;
133
134 preempt_disable();
135 rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image);
136 preempt_enable();
137 return rc == 0;
138#else
139 return false;
140#endif
141}
142
143#ifdef CONFIG_CRASH_DUMP
144
145void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
146{
147 unsigned long addr, size;
148
149 for (addr = begin; addr < end; addr += PAGE_SIZE)
150 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
151 size = begin - crashk_res.start;
152 if (size)
153 os_info_crashkernel_add(crashk_res.start, size);
154 else
155 os_info_crashkernel_add(0, 0);
156}
157
158static void crash_protect_pages(int protect)
159{
160 unsigned long size;
161
162 if (!crashk_res.end)
163 return;
164 size = resource_size(&crashk_res);
165 if (protect)
166 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
167 else
168 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
169}
170
171void arch_kexec_protect_crashkres(void)
172{
173 crash_protect_pages(1);
174}
175
176void arch_kexec_unprotect_crashkres(void)
177{
178 crash_protect_pages(0);
179}
180
181#endif
182
183/*
184 * Give back memory to hypervisor before new kdump is loaded
185 */
186static int machine_kexec_prepare_kdump(void)
187{
188#ifdef CONFIG_CRASH_DUMP
189 if (MACHINE_IS_VM)
190 diag10_range(PFN_DOWN(crashk_res.start),
191 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
192 return 0;
193#else
194 return -EINVAL;
195#endif
196}
197
198int machine_kexec_prepare(struct kimage *image)
199{
200 void *reboot_code_buffer;
201
202 if (image->type == KEXEC_TYPE_CRASH)
203 return machine_kexec_prepare_kdump();
204
205 /* We don't support anything but the default image type for now. */
206 if (image->type != KEXEC_TYPE_DEFAULT)
207 return -EINVAL;
208
209 /* Get the destination where the assembler code should be copied to.*/
210 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
211
212 /* Then copy it */
213 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
214 return 0;
215}
216
217void machine_kexec_cleanup(struct kimage *image)
218{
219}
220
221void arch_crash_save_vmcoreinfo(void)
222{
223 VMCOREINFO_SYMBOL(lowcore_ptr);
224 VMCOREINFO_SYMBOL(high_memory);
225 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
226 vmcoreinfo_append_str("SDMA=%lx\n", __sdma);
227 vmcoreinfo_append_str("EDMA=%lx\n", __edma);
228 vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
229 mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
230}
231
232void machine_shutdown(void)
233{
234}
235
236void machine_crash_shutdown(struct pt_regs *regs)
237{
238 set_os_info_reipl_block();
239}
240
241/*
242 * Do normal kexec
243 */
244static void __do_machine_kexec(void *data)
245{
246 relocate_kernel_t data_mover;
247 struct kimage *image = data;
248
249 s390_reset_system();
250 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
251
252 __arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
253 /* Call the moving routine */
254 (*data_mover)(&image->head, image->start);
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 __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}