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Commit | Line | Data |
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fce0d574 | 1 | /* |
3d1229d6 | 2 | * PPC64 code to handle Linux booting another kernel. |
fce0d574 S |
3 | * |
4 | * Copyright (C) 2004-2005, IBM Corp. | |
5 | * | |
6 | * Created by: Milton D Miller II | |
7 | * | |
8 | * This source code is licensed under the GNU General Public License, | |
9 | * Version 2. See the file COPYING for more details. | |
10 | */ | |
11 | ||
12 | ||
fce0d574 S |
13 | #include <linux/kexec.h> |
14 | #include <linux/smp.h> | |
15 | #include <linux/thread_info.h> | |
16 | #include <linux/errno.h> | |
17 | ||
18 | #include <asm/page.h> | |
19 | #include <asm/current.h> | |
20 | #include <asm/machdep.h> | |
21 | #include <asm/cacheflush.h> | |
22 | #include <asm/paca.h> | |
23 | #include <asm/mmu.h> | |
24 | #include <asm/sections.h> /* _end */ | |
25 | #include <asm/prom.h> | |
2249ca9d | 26 | #include <asm/smp.h> |
fce0d574 | 27 | |
3d1229d6 | 28 | int default_machine_kexec_prepare(struct kimage *image) |
fce0d574 S |
29 | { |
30 | int i; | |
31 | unsigned long begin, end; /* limits of segment */ | |
32 | unsigned long low, high; /* limits of blocked memory range */ | |
33 | struct device_node *node; | |
a7f67bdf JK |
34 | const unsigned long *basep; |
35 | const unsigned int *sizep; | |
fce0d574 S |
36 | |
37 | if (!ppc_md.hpte_clear_all) | |
38 | return -ENOENT; | |
39 | ||
40 | /* | |
41 | * Since we use the kernel fault handlers and paging code to | |
42 | * handle the virtual mode, we must make sure no destination | |
43 | * overlaps kernel static data or bss. | |
44 | */ | |
72414d3f | 45 | for (i = 0; i < image->nr_segments; i++) |
fce0d574 S |
46 | if (image->segment[i].mem < __pa(_end)) |
47 | return -ETXTBSY; | |
48 | ||
49 | /* | |
50 | * For non-LPAR, we absolutely can not overwrite the mmu hash | |
51 | * table, since we are still using the bolted entries in it to | |
52 | * do the copy. Check that here. | |
53 | * | |
54 | * It is safe if the end is below the start of the blocked | |
55 | * region (end <= low), or if the beginning is after the | |
56 | * end of the blocked region (begin >= high). Use the | |
57 | * boolean identity !(a || b) === (!a && !b). | |
58 | */ | |
59 | if (htab_address) { | |
60 | low = __pa(htab_address); | |
337a7128 | 61 | high = low + htab_size_bytes; |
fce0d574 | 62 | |
72414d3f | 63 | for (i = 0; i < image->nr_segments; i++) { |
fce0d574 S |
64 | begin = image->segment[i].mem; |
65 | end = begin + image->segment[i].memsz; | |
66 | ||
67 | if ((begin < high) && (end > low)) | |
68 | return -ETXTBSY; | |
69 | } | |
70 | } | |
71 | ||
72 | /* We also should not overwrite the tce tables */ | |
73 | for (node = of_find_node_by_type(NULL, "pci"); node != NULL; | |
74 | node = of_find_node_by_type(node, "pci")) { | |
e2eb6392 SR |
75 | basep = of_get_property(node, "linux,tce-base", NULL); |
76 | sizep = of_get_property(node, "linux,tce-size", NULL); | |
fce0d574 S |
77 | if (basep == NULL || sizep == NULL) |
78 | continue; | |
79 | ||
80 | low = *basep; | |
81 | high = low + (*sizep); | |
82 | ||
72414d3f | 83 | for (i = 0; i < image->nr_segments; i++) { |
fce0d574 S |
84 | begin = image->segment[i].mem; |
85 | end = begin + image->segment[i].memsz; | |
86 | ||
87 | if ((begin < high) && (end > low)) | |
88 | return -ETXTBSY; | |
89 | } | |
90 | } | |
91 | ||
92 | return 0; | |
93 | } | |
94 | ||
fce0d574 S |
95 | #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE) |
96 | ||
97 | static void copy_segments(unsigned long ind) | |
98 | { | |
99 | unsigned long entry; | |
100 | unsigned long *ptr; | |
101 | void *dest; | |
102 | void *addr; | |
103 | ||
104 | /* | |
105 | * We rely on kexec_load to create a lists that properly | |
106 | * initializes these pointers before they are used. | |
107 | * We will still crash if the list is wrong, but at least | |
108 | * the compiler will be quiet. | |
109 | */ | |
110 | ptr = NULL; | |
111 | dest = NULL; | |
112 | ||
113 | for (entry = ind; !(entry & IND_DONE); entry = *ptr++) { | |
114 | addr = __va(entry & PAGE_MASK); | |
115 | ||
116 | switch (entry & IND_FLAGS) { | |
117 | case IND_DESTINATION: | |
118 | dest = addr; | |
119 | break; | |
120 | case IND_INDIRECTION: | |
121 | ptr = addr; | |
122 | break; | |
123 | case IND_SOURCE: | |
124 | copy_page(dest, addr); | |
125 | dest += PAGE_SIZE; | |
126 | } | |
127 | } | |
128 | } | |
129 | ||
130 | void kexec_copy_flush(struct kimage *image) | |
131 | { | |
132 | long i, nr_segments = image->nr_segments; | |
133 | struct kexec_segment ranges[KEXEC_SEGMENT_MAX]; | |
134 | ||
135 | /* save the ranges on the stack to efficiently flush the icache */ | |
136 | memcpy(ranges, image->segment, sizeof(ranges)); | |
137 | ||
138 | /* | |
139 | * After this call we may not use anything allocated in dynamic | |
140 | * memory, including *image. | |
141 | * | |
142 | * Only globals and the stack are allowed. | |
143 | */ | |
144 | copy_segments(image->head); | |
145 | ||
146 | /* | |
147 | * we need to clear the icache for all dest pages sometime, | |
148 | * including ones that were in place on the original copy | |
149 | */ | |
150 | for (i = 0; i < nr_segments; i++) | |
b5666f70 ME |
151 | flush_icache_range((unsigned long)__va(ranges[i].mem), |
152 | (unsigned long)__va(ranges[i].mem + ranges[i].memsz)); | |
fce0d574 S |
153 | } |
154 | ||
155 | #ifdef CONFIG_SMP | |
156 | ||
157 | /* FIXME: we should schedule this function to be called on all cpus based | |
158 | * on calling the interrupts, but we would like to call it off irq level | |
159 | * so that the interrupt controller is clean. | |
160 | */ | |
1c21a293 | 161 | static void kexec_smp_down(void *arg) |
fce0d574 | 162 | { |
c5e24354 ME |
163 | if (ppc_md.kexec_cpu_down) |
164 | ppc_md.kexec_cpu_down(0, 1); | |
fce0d574 S |
165 | |
166 | local_irq_disable(); | |
167 | kexec_smp_wait(); | |
168 | /* NOTREACHED */ | |
169 | } | |
170 | ||
171 | static void kexec_prepare_cpus(void) | |
172 | { | |
173 | int my_cpu, i, notified=-1; | |
174 | ||
392096e9 | 175 | smp_call_function(kexec_smp_down, NULL, /* wait */0); |
fce0d574 S |
176 | my_cpu = get_cpu(); |
177 | ||
178 | /* check the others cpus are now down (via paca hw cpu id == -1) */ | |
179 | for (i=0; i < NR_CPUS; i++) { | |
180 | if (i == my_cpu) | |
181 | continue; | |
182 | ||
183 | while (paca[i].hw_cpu_id != -1) { | |
b3ca8093 | 184 | barrier(); |
fce0d574 S |
185 | if (!cpu_possible(i)) { |
186 | printk("kexec: cpu %d hw_cpu_id %d is not" | |
187 | " possible, ignoring\n", | |
188 | i, paca[i].hw_cpu_id); | |
189 | break; | |
190 | } | |
191 | if (!cpu_online(i)) { | |
192 | /* Fixme: this can be spinning in | |
193 | * pSeries_secondary_wait with a paca | |
194 | * waiting for it to go online. | |
195 | */ | |
196 | printk("kexec: cpu %d hw_cpu_id %d is not" | |
197 | " online, ignoring\n", | |
198 | i, paca[i].hw_cpu_id); | |
199 | break; | |
200 | } | |
201 | if (i != notified) { | |
202 | printk( "kexec: waiting for cpu %d (physical" | |
203 | " %d) to go down\n", | |
204 | i, paca[i].hw_cpu_id); | |
205 | notified = i; | |
206 | } | |
207 | } | |
208 | } | |
209 | ||
210 | /* after we tell the others to go down */ | |
c5e24354 ME |
211 | if (ppc_md.kexec_cpu_down) |
212 | ppc_md.kexec_cpu_down(0, 0); | |
fce0d574 S |
213 | |
214 | put_cpu(); | |
215 | ||
216 | local_irq_disable(); | |
217 | } | |
218 | ||
219 | #else /* ! SMP */ | |
220 | ||
221 | static void kexec_prepare_cpus(void) | |
222 | { | |
223 | /* | |
224 | * move the secondarys to us so that we can copy | |
225 | * the new kernel 0-0x100 safely | |
226 | * | |
227 | * do this if kexec in setup.c ? | |
75eedfed OJ |
228 | * |
229 | * We need to release the cpus if we are ever going from an | |
230 | * UP to an SMP kernel. | |
fce0d574 | 231 | */ |
75eedfed | 232 | smp_release_cpus(); |
c5e24354 ME |
233 | if (ppc_md.kexec_cpu_down) |
234 | ppc_md.kexec_cpu_down(0, 0); | |
fce0d574 S |
235 | local_irq_disable(); |
236 | } | |
237 | ||
238 | #endif /* SMP */ | |
239 | ||
240 | /* | |
241 | * kexec thread structure and stack. | |
242 | * | |
243 | * We need to make sure that this is 16384-byte aligned due to the | |
244 | * way process stacks are handled. It also must be statically allocated | |
245 | * or allocated as part of the kimage, because everything else may be | |
246 | * overwritten when we copy the kexec image. We piggyback on the | |
247 | * "init_task" linker section here to statically allocate a stack. | |
248 | * | |
249 | * We could use a smaller stack if we don't care about anything using | |
250 | * current, but that audit has not been performed. | |
251 | */ | |
1c21a293 | 252 | static union thread_union kexec_stack |
fce0d574 S |
253 | __attribute__((__section__(".data.init_task"))) = { }; |
254 | ||
255 | /* Our assembly helper, in kexec_stub.S */ | |
256 | extern NORET_TYPE void kexec_sequence(void *newstack, unsigned long start, | |
72414d3f | 257 | void *image, void *control, |
54622f10 MK |
258 | void (*clear_all)(void), |
259 | unsigned long kdump_flag) ATTRIB_NORET; | |
fce0d574 S |
260 | |
261 | /* too late to fail here */ | |
3d1229d6 | 262 | void default_machine_kexec(struct kimage *image) |
fce0d574 | 263 | { |
54622f10 MK |
264 | unsigned long kdump_flag = 0; |
265 | ||
fce0d574 S |
266 | /* prepare control code if any */ |
267 | ||
cc532915 ME |
268 | /* |
269 | * If the kexec boot is the normal one, need to shutdown other cpus | |
270 | * into our wait loop and quiesce interrupts. | |
271 | * Otherwise, in the case of crashed mode (crashing_cpu >= 0), | |
272 | * stopping other CPUs and collecting their pt_regs is done before | |
273 | * using debugger IPI. | |
274 | */ | |
275 | ||
54622f10 MK |
276 | if (crashing_cpu == -1) |
277 | kexec_prepare_cpus(); | |
278 | else | |
279 | kdump_flag = KDUMP_SIGNATURE; | |
fce0d574 S |
280 | |
281 | /* switch to a staticly allocated stack. Based on irq stack code. | |
282 | * XXX: the task struct will likely be invalid once we do the copy! | |
283 | */ | |
284 | kexec_stack.thread_info.task = current_thread_info()->task; | |
285 | kexec_stack.thread_info.flags = 0; | |
286 | ||
287 | /* Some things are best done in assembly. Finding globals with | |
288 | * a toc is easier in C, so pass in what we can. | |
289 | */ | |
290 | kexec_sequence(&kexec_stack, image->start, image, | |
291 | page_address(image->control_code_page), | |
54622f10 | 292 | ppc_md.hpte_clear_all, kdump_flag); |
fce0d574 S |
293 | /* NOTREACHED */ |
294 | } | |
593e537b ME |
295 | |
296 | /* Values we need to export to the second kernel via the device tree. */ | |
337a7128 | 297 | static unsigned long htab_base, kernel_end; |
593e537b ME |
298 | |
299 | static struct property htab_base_prop = { | |
300 | .name = "linux,htab-base", | |
301 | .length = sizeof(unsigned long), | |
1a38147e | 302 | .value = &htab_base, |
593e537b ME |
303 | }; |
304 | ||
305 | static struct property htab_size_prop = { | |
306 | .name = "linux,htab-size", | |
307 | .length = sizeof(unsigned long), | |
1a38147e | 308 | .value = &htab_size_bytes, |
593e537b ME |
309 | }; |
310 | ||
311 | static struct property kernel_end_prop = { | |
312 | .name = "linux,kernel-end", | |
313 | .length = sizeof(unsigned long), | |
1a38147e | 314 | .value = &kernel_end, |
593e537b ME |
315 | }; |
316 | ||
317 | static void __init export_htab_values(void) | |
318 | { | |
319 | struct device_node *node; | |
ed7b2144 | 320 | struct property *prop; |
593e537b ME |
321 | |
322 | node = of_find_node_by_path("/chosen"); | |
323 | if (!node) | |
324 | return; | |
325 | ||
ed7b2144 MM |
326 | /* remove any stale propertys so ours can be found */ |
327 | prop = of_find_property(node, kernel_end_prop.name, NULL); | |
328 | if (prop) | |
329 | prom_remove_property(node, prop); | |
330 | prop = of_find_property(node, htab_base_prop.name, NULL); | |
331 | if (prop) | |
332 | prom_remove_property(node, prop); | |
333 | prop = of_find_property(node, htab_size_prop.name, NULL); | |
334 | if (prop) | |
335 | prom_remove_property(node, prop); | |
336 | ||
337 | /* information needed by userspace when using default_machine_kexec */ | |
593e537b ME |
338 | kernel_end = __pa(_end); |
339 | prom_add_property(node, &kernel_end_prop); | |
340 | ||
341 | /* On machines with no htab htab_address is NULL */ | |
342 | if (NULL == htab_address) | |
343 | goto out; | |
344 | ||
345 | htab_base = __pa(htab_address); | |
346 | prom_add_property(node, &htab_base_prop); | |
593e537b ME |
347 | prom_add_property(node, &htab_size_prop); |
348 | ||
349 | out: | |
350 | of_node_put(node); | |
351 | } | |
352 | ||
35dd5432 ME |
353 | static struct property crashk_base_prop = { |
354 | .name = "linux,crashkernel-base", | |
355 | .length = sizeof(unsigned long), | |
1a38147e | 356 | .value = &crashk_res.start, |
35dd5432 ME |
357 | }; |
358 | ||
359 | static unsigned long crashk_size; | |
360 | ||
361 | static struct property crashk_size_prop = { | |
362 | .name = "linux,crashkernel-size", | |
363 | .length = sizeof(unsigned long), | |
1a38147e | 364 | .value = &crashk_size, |
35dd5432 ME |
365 | }; |
366 | ||
367 | static void __init export_crashk_values(void) | |
368 | { | |
369 | struct device_node *node; | |
370 | struct property *prop; | |
371 | ||
372 | node = of_find_node_by_path("/chosen"); | |
373 | if (!node) | |
374 | return; | |
375 | ||
376 | /* There might be existing crash kernel properties, but we can't | |
377 | * be sure what's in them, so remove them. */ | |
378 | prop = of_find_property(node, "linux,crashkernel-base", NULL); | |
379 | if (prop) | |
380 | prom_remove_property(node, prop); | |
381 | ||
382 | prop = of_find_property(node, "linux,crashkernel-size", NULL); | |
383 | if (prop) | |
384 | prom_remove_property(node, prop); | |
385 | ||
386 | if (crashk_res.start != 0) { | |
387 | prom_add_property(node, &crashk_base_prop); | |
388 | crashk_size = crashk_res.end - crashk_res.start + 1; | |
389 | prom_add_property(node, &crashk_size_prop); | |
390 | } | |
391 | ||
392 | of_node_put(node); | |
393 | } | |
394 | ||
aa98c50d | 395 | static int __init kexec_setup(void) |
593e537b ME |
396 | { |
397 | export_htab_values(); | |
35dd5432 | 398 | export_crashk_values(); |
aa98c50d | 399 | return 0; |
35dd5432 | 400 | } |
aa98c50d | 401 | __initcall(kexec_setup); |