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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}
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/cacheflush.h>
28#include <asm/os_info.h>
29#include <asm/switch_to.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 * PM notifier callback for kdump
40 */
41static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
42 void *ptr)
43{
44 switch (action) {
45 case PM_SUSPEND_PREPARE:
46 case PM_HIBERNATION_PREPARE:
47 if (kexec_crash_image)
48 arch_kexec_unprotect_crashkres();
49 break;
50 case PM_POST_SUSPEND:
51 case PM_POST_HIBERNATION:
52 if (kexec_crash_image)
53 arch_kexec_protect_crashkres();
54 break;
55 default:
56 return NOTIFY_DONE;
57 }
58 return NOTIFY_OK;
59}
60
61static int __init machine_kdump_pm_init(void)
62{
63 pm_notifier(machine_kdump_pm_cb, 0);
64 return 0;
65}
66arch_initcall(machine_kdump_pm_init);
67
68/*
69 * Reset the system, copy boot CPU registers to absolute zero,
70 * and jump to the kdump image
71 */
72static void __do_machine_kdump(void *image)
73{
74 int (*start_kdump)(int);
75 unsigned long prefix;
76
77 /* store_status() saved the prefix register to lowcore */
78 prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
79
80 /* Now do the reset */
81 s390_reset_system();
82
83 /*
84 * Copy dump CPU store status info to absolute zero.
85 * This need to be done *after* s390_reset_system set the
86 * prefix register of this CPU to zero
87 */
88 memcpy((void *) __LC_FPREGS_SAVE_AREA,
89 (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
90
91 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
92 start_kdump = (void *)((struct kimage *) image)->start;
93 start_kdump(1);
94
95 /* Die if start_kdump returns */
96 disabled_wait((unsigned long) __builtin_return_address(0));
97}
98
99/*
100 * Start kdump: create a LGR log entry, store status of all CPUs and
101 * branch to __do_machine_kdump.
102 */
103static noinline void __machine_kdump(void *image)
104{
105 int this_cpu, cpu;
106
107 lgr_info_log();
108 /* Get status of the other CPUs */
109 this_cpu = smp_find_processor_id(stap());
110 for_each_online_cpu(cpu) {
111 if (cpu == this_cpu)
112 continue;
113 if (smp_store_status(cpu))
114 continue;
115 }
116 /* Store status of the boot CPU */
117 if (MACHINE_HAS_VX)
118 save_vx_regs((void *) &S390_lowcore.vector_save_area);
119 /*
120 * To create a good backchain for this CPU in the dump store_status
121 * is passed the address of a function. The address is saved into
122 * the PSW save area of the boot CPU and the function is invoked as
123 * a tail call of store_status. The backchain in the dump will look
124 * like this:
125 * restart_int_handler -> __machine_kexec -> __do_machine_kdump
126 * The call to store_status() will not return.
127 */
128 store_status(__do_machine_kdump, image);
129}
130#endif
131
132/*
133 * Check if kdump checksums are valid: We call purgatory with parameter "0"
134 */
135static int kdump_csum_valid(struct kimage *image)
136{
137#ifdef CONFIG_CRASH_DUMP
138 int (*start_kdump)(int) = (void *)image->start;
139 int rc;
140
141 __arch_local_irq_stnsm(0xfb); /* disable DAT */
142 rc = start_kdump(0);
143 __arch_local_irq_stosm(0x04); /* enable DAT */
144 return rc ? 0 : -EINVAL;
145#else
146 return -EINVAL;
147#endif
148}
149
150#ifdef CONFIG_CRASH_DUMP
151
152void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
153{
154 unsigned long addr, size;
155
156 for (addr = begin; addr < end; addr += PAGE_SIZE)
157 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
158 size = begin - crashk_res.start;
159 if (size)
160 os_info_crashkernel_add(crashk_res.start, size);
161 else
162 os_info_crashkernel_add(0, 0);
163}
164
165static void crash_protect_pages(int protect)
166{
167 unsigned long size;
168
169 if (!crashk_res.end)
170 return;
171 size = resource_size(&crashk_res);
172 if (protect)
173 set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
174 else
175 set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
176}
177
178void arch_kexec_protect_crashkres(void)
179{
180 crash_protect_pages(1);
181}
182
183void arch_kexec_unprotect_crashkres(void)
184{
185 crash_protect_pages(0);
186}
187
188#endif
189
190/*
191 * Give back memory to hypervisor before new kdump is loaded
192 */
193static int machine_kexec_prepare_kdump(void)
194{
195#ifdef CONFIG_CRASH_DUMP
196 if (MACHINE_IS_VM)
197 diag10_range(PFN_DOWN(crashk_res.start),
198 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
199 return 0;
200#else
201 return -EINVAL;
202#endif
203}
204
205int machine_kexec_prepare(struct kimage *image)
206{
207 void *reboot_code_buffer;
208
209 /* Can't replace kernel image since it is read-only. */
210 if (ipl_flags & IPL_NSS_VALID)
211 return -EOPNOTSUPP;
212
213 if (image->type == KEXEC_TYPE_CRASH)
214 return machine_kexec_prepare_kdump();
215
216 /* We don't support anything but the default image type for now. */
217 if (image->type != KEXEC_TYPE_DEFAULT)
218 return -EINVAL;
219
220 /* Get the destination where the assembler code should be copied to.*/
221 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
222
223 /* Then copy it */
224 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
225 return 0;
226}
227
228void machine_kexec_cleanup(struct kimage *image)
229{
230}
231
232void arch_crash_save_vmcoreinfo(void)
233{
234 VMCOREINFO_SYMBOL(lowcore_ptr);
235 VMCOREINFO_SYMBOL(high_memory);
236 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
237}
238
239void machine_shutdown(void)
240{
241}
242
243void machine_crash_shutdown(struct pt_regs *regs)
244{
245}
246
247/*
248 * Do normal kexec
249 */
250static void __do_machine_kexec(void *data)
251{
252 relocate_kernel_t data_mover;
253 struct kimage *image = data;
254
255 s390_reset_system();
256 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
257
258 /* Call the moving routine */
259 (*data_mover)(&image->head, image->start);
260
261 /* Die if kexec returns */
262 disabled_wait((unsigned long) __builtin_return_address(0));
263}
264
265/*
266 * Reset system and call either kdump or normal kexec
267 */
268static void __machine_kexec(void *data)
269{
270 __arch_local_irq_stosm(0x04); /* enable DAT */
271 pfault_fini();
272 tracing_off();
273 debug_locks_off();
274#ifdef CONFIG_CRASH_DUMP
275 if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
276 __machine_kdump(data);
277#endif
278 __do_machine_kexec(data);
279}
280
281/*
282 * Do either kdump or normal kexec. In case of kdump we first ask
283 * purgatory, if kdump checksums are valid.
284 */
285void machine_kexec(struct kimage *image)
286{
287 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
288 return;
289 tracer_disable();
290 smp_send_stop();
291 smp_call_ipl_cpu(__machine_kexec, image);
292}