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 #include <asm/switch_to.h>
29
30 typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
31
32 extern const unsigned char relocate_kernel[];
33 extern const unsigned long long relocate_kernel_len;
34
35 #ifdef CONFIG_CRASH_DUMP
36
37 /*
38 * Create ELF notes for one CPU
39 */
add_elf_notes(int cpu)40 static void add_elf_notes(int cpu)
41 {
42 struct save_area *sa = (void *) 4608 + store_prefix();
43 void *ptr;
44
45 memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
46 ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
47 ptr = fill_cpu_elf_notes(ptr, sa, NULL);
48 memset(ptr, 0, sizeof(struct elf_note));
49 }
50
51 /*
52 * Initialize CPU ELF notes
53 */
setup_regs(void)54 static void setup_regs(void)
55 {
56 unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
57 struct _lowcore *lc;
58 int cpu, this_cpu;
59
60 /* Get lowcore pointer from store status of this CPU (absolute zero) */
61 lc = (struct _lowcore *)(unsigned long)S390_lowcore.prefixreg_save_area;
62 this_cpu = smp_find_processor_id(stap());
63 add_elf_notes(this_cpu);
64 for_each_online_cpu(cpu) {
65 if (cpu == this_cpu)
66 continue;
67 if (smp_store_status(cpu))
68 continue;
69 add_elf_notes(cpu);
70 }
71 if (MACHINE_HAS_VX)
72 save_vx_regs_safe((void *) lc->vector_save_area_addr);
73 /* Copy dump CPU store status info to absolute zero */
74 memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
75 }
76
77 /*
78 * PM notifier callback for kdump
79 */
machine_kdump_pm_cb(struct notifier_block * nb,unsigned long action,void * ptr)80 static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
81 void *ptr)
82 {
83 switch (action) {
84 case PM_SUSPEND_PREPARE:
85 case PM_HIBERNATION_PREPARE:
86 if (crashk_res.start)
87 crash_map_reserved_pages();
88 break;
89 case PM_POST_SUSPEND:
90 case PM_POST_HIBERNATION:
91 if (crashk_res.start)
92 crash_unmap_reserved_pages();
93 break;
94 default:
95 return NOTIFY_DONE;
96 }
97 return NOTIFY_OK;
98 }
99
machine_kdump_pm_init(void)100 static int __init machine_kdump_pm_init(void)
101 {
102 pm_notifier(machine_kdump_pm_cb, 0);
103 return 0;
104 }
105 arch_initcall(machine_kdump_pm_init);
106 #endif
107
108 /*
109 * Start kdump: We expect here that a store status has been done on our CPU
110 */
__do_machine_kdump(void * image)111 static void __do_machine_kdump(void *image)
112 {
113 #ifdef CONFIG_CRASH_DUMP
114 int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
115
116 setup_regs();
117 __load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
118 start_kdump(1);
119 #endif
120 }
121
122 /*
123 * Check if kdump checksums are valid: We call purgatory with parameter "0"
124 */
kdump_csum_valid(struct kimage * image)125 static int kdump_csum_valid(struct kimage *image)
126 {
127 #ifdef CONFIG_CRASH_DUMP
128 int (*start_kdump)(int) = (void *)image->start;
129 int rc;
130
131 __arch_local_irq_stnsm(0xfb); /* disable DAT */
132 rc = start_kdump(0);
133 __arch_local_irq_stosm(0x04); /* enable DAT */
134 return rc ? 0 : -EINVAL;
135 #else
136 return -EINVAL;
137 #endif
138 }
139
140 /*
141 * Map or unmap crashkernel memory
142 */
crash_map_pages(int enable)143 static void crash_map_pages(int enable)
144 {
145 unsigned long size = resource_size(&crashk_res);
146
147 BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
148 size % KEXEC_CRASH_MEM_ALIGN);
149 if (enable)
150 vmem_add_mapping(crashk_res.start, size);
151 else {
152 vmem_remove_mapping(crashk_res.start, size);
153 if (size)
154 os_info_crashkernel_add(crashk_res.start, size);
155 else
156 os_info_crashkernel_add(0, 0);
157 }
158 }
159
160 /*
161 * Map crashkernel memory
162 */
crash_map_reserved_pages(void)163 void crash_map_reserved_pages(void)
164 {
165 crash_map_pages(1);
166 }
167
168 /*
169 * Unmap crashkernel memory
170 */
crash_unmap_reserved_pages(void)171 void crash_unmap_reserved_pages(void)
172 {
173 crash_map_pages(0);
174 }
175
176 /*
177 * Give back memory to hypervisor before new kdump is loaded
178 */
machine_kexec_prepare_kdump(void)179 static int machine_kexec_prepare_kdump(void)
180 {
181 #ifdef CONFIG_CRASH_DUMP
182 if (MACHINE_IS_VM)
183 diag10_range(PFN_DOWN(crashk_res.start),
184 PFN_DOWN(crashk_res.end - crashk_res.start + 1));
185 return 0;
186 #else
187 return -EINVAL;
188 #endif
189 }
190
machine_kexec_prepare(struct kimage * image)191 int machine_kexec_prepare(struct kimage *image)
192 {
193 void *reboot_code_buffer;
194
195 /* Can't replace kernel image since it is read-only. */
196 if (ipl_flags & IPL_NSS_VALID)
197 return -EOPNOTSUPP;
198
199 if (image->type == KEXEC_TYPE_CRASH)
200 return machine_kexec_prepare_kdump();
201
202 /* We don't support anything but the default image type for now. */
203 if (image->type != KEXEC_TYPE_DEFAULT)
204 return -EINVAL;
205
206 /* Get the destination where the assembler code should be copied to.*/
207 reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
208
209 /* Then copy it */
210 memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
211 return 0;
212 }
213
machine_kexec_cleanup(struct kimage * image)214 void machine_kexec_cleanup(struct kimage *image)
215 {
216 }
217
arch_crash_save_vmcoreinfo(void)218 void arch_crash_save_vmcoreinfo(void)
219 {
220 VMCOREINFO_SYMBOL(lowcore_ptr);
221 VMCOREINFO_SYMBOL(high_memory);
222 VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
223 }
224
machine_shutdown(void)225 void machine_shutdown(void)
226 {
227 }
228
machine_crash_shutdown(struct pt_regs * regs)229 void machine_crash_shutdown(struct pt_regs *regs)
230 {
231 }
232
233 /*
234 * Do normal kexec
235 */
__do_machine_kexec(void * data)236 static void __do_machine_kexec(void *data)
237 {
238 relocate_kernel_t data_mover;
239 struct kimage *image = data;
240
241 data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
242
243 /* Call the moving routine */
244 (*data_mover)(&image->head, image->start);
245 }
246
247 /*
248 * Reset system and call either kdump or normal kexec
249 */
__machine_kexec(void * data)250 static void __machine_kexec(void *data)
251 {
252 struct kimage *image = data;
253
254 __arch_local_irq_stosm(0x04); /* enable DAT */
255 pfault_fini();
256 tracing_off();
257 debug_locks_off();
258 if (image->type == KEXEC_TYPE_CRASH) {
259 lgr_info_log();
260 s390_reset_system(__do_machine_kdump, data);
261 } else {
262 s390_reset_system(__do_machine_kexec, data);
263 }
264 disabled_wait((unsigned long) __builtin_return_address(0));
265 }
266
267 /*
268 * Do either kdump or normal kexec. In case of kdump we first ask
269 * purgatory, if kdump checksums are valid.
270 */
machine_kexec(struct kimage * image)271 void machine_kexec(struct kimage *image)
272 {
273 if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
274 return;
275 tracer_disable();
276 smp_send_stop();
277 smp_call_ipl_cpu(__machine_kexec, image);
278 }
279