Commit | Line | Data |
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eb39c880 MS |
1 | /* |
2 | * Firmware Assisted dump: A robust mechanism to get reliable kernel crash | |
3 | * dump with assistance from firmware. This approach does not use kexec, | |
4 | * instead firmware assists in booting the kdump kernel while preserving | |
5 | * memory contents. The most of the code implementation has been adapted | |
6 | * from phyp assisted dump implementation written by Linas Vepstas and | |
7 | * Manish Ahuja | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
22 | * | |
23 | * Copyright 2011 IBM Corporation | |
24 | * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> | |
25 | */ | |
26 | ||
27 | #undef DEBUG | |
28 | #define pr_fmt(fmt) "fadump: " fmt | |
29 | ||
30 | #include <linux/string.h> | |
31 | #include <linux/memblock.h> | |
3ccc00a7 MS |
32 | #include <linux/delay.h> |
33 | #include <linux/debugfs.h> | |
34 | #include <linux/seq_file.h> | |
eb39c880 MS |
35 | |
36 | #include <asm/page.h> | |
37 | #include <asm/prom.h> | |
38 | #include <asm/rtas.h> | |
39 | #include <asm/fadump.h> | |
40 | ||
41 | static struct fw_dump fw_dump; | |
3ccc00a7 MS |
42 | static struct fadump_mem_struct fdm; |
43 | static const struct fadump_mem_struct *fdm_active; | |
44 | ||
45 | static DEFINE_MUTEX(fadump_mutex); | |
eb39c880 MS |
46 | |
47 | /* Scan the Firmware Assisted dump configuration details. */ | |
48 | int __init early_init_dt_scan_fw_dump(unsigned long node, | |
49 | const char *uname, int depth, void *data) | |
50 | { | |
51 | __be32 *sections; | |
52 | int i, num_sections; | |
53 | unsigned long size; | |
54 | const int *token; | |
55 | ||
56 | if (depth != 1 || strcmp(uname, "rtas") != 0) | |
57 | return 0; | |
58 | ||
59 | /* | |
60 | * Check if Firmware Assisted dump is supported. if yes, check | |
61 | * if dump has been initiated on last reboot. | |
62 | */ | |
63 | token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); | |
64 | if (!token) | |
65 | return 0; | |
66 | ||
67 | fw_dump.fadump_supported = 1; | |
68 | fw_dump.ibm_configure_kernel_dump = *token; | |
69 | ||
70 | /* | |
71 | * The 'ibm,kernel-dump' rtas node is present only if there is | |
72 | * dump data waiting for us. | |
73 | */ | |
3ccc00a7 MS |
74 | fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); |
75 | if (fdm_active) | |
eb39c880 MS |
76 | fw_dump.dump_active = 1; |
77 | ||
78 | /* Get the sizes required to store dump data for the firmware provided | |
79 | * dump sections. | |
80 | * For each dump section type supported, a 32bit cell which defines | |
81 | * the ID of a supported section followed by two 32 bit cells which | |
82 | * gives teh size of the section in bytes. | |
83 | */ | |
84 | sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", | |
85 | &size); | |
86 | ||
87 | if (!sections) | |
88 | return 0; | |
89 | ||
90 | num_sections = size / (3 * sizeof(u32)); | |
91 | ||
92 | for (i = 0; i < num_sections; i++, sections += 3) { | |
93 | u32 type = (u32)of_read_number(sections, 1); | |
94 | ||
95 | switch (type) { | |
96 | case FADUMP_CPU_STATE_DATA: | |
97 | fw_dump.cpu_state_data_size = | |
98 | of_read_ulong(§ions[1], 2); | |
99 | break; | |
100 | case FADUMP_HPTE_REGION: | |
101 | fw_dump.hpte_region_size = | |
102 | of_read_ulong(§ions[1], 2); | |
103 | break; | |
104 | } | |
105 | } | |
106 | return 1; | |
107 | } | |
108 | ||
3ccc00a7 MS |
109 | int is_fadump_active(void) |
110 | { | |
111 | return fw_dump.dump_active; | |
112 | } | |
113 | ||
114 | /* Print firmware assisted dump configurations for debugging purpose. */ | |
115 | static void fadump_show_config(void) | |
116 | { | |
117 | pr_debug("Support for firmware-assisted dump (fadump): %s\n", | |
118 | (fw_dump.fadump_supported ? "present" : "no support")); | |
119 | ||
120 | if (!fw_dump.fadump_supported) | |
121 | return; | |
122 | ||
123 | pr_debug("Fadump enabled : %s\n", | |
124 | (fw_dump.fadump_enabled ? "yes" : "no")); | |
125 | pr_debug("Dump Active : %s\n", | |
126 | (fw_dump.dump_active ? "yes" : "no")); | |
127 | pr_debug("Dump section sizes:\n"); | |
128 | pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); | |
129 | pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); | |
130 | pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); | |
131 | } | |
132 | ||
133 | static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, | |
134 | unsigned long addr) | |
135 | { | |
136 | if (!fdm) | |
137 | return 0; | |
138 | ||
139 | memset(fdm, 0, sizeof(struct fadump_mem_struct)); | |
140 | addr = addr & PAGE_MASK; | |
141 | ||
142 | fdm->header.dump_format_version = 0x00000001; | |
143 | fdm->header.dump_num_sections = 3; | |
144 | fdm->header.dump_status_flag = 0; | |
145 | fdm->header.offset_first_dump_section = | |
146 | (u32)offsetof(struct fadump_mem_struct, cpu_state_data); | |
147 | ||
148 | /* | |
149 | * Fields for disk dump option. | |
150 | * We are not using disk dump option, hence set these fields to 0. | |
151 | */ | |
152 | fdm->header.dd_block_size = 0; | |
153 | fdm->header.dd_block_offset = 0; | |
154 | fdm->header.dd_num_blocks = 0; | |
155 | fdm->header.dd_offset_disk_path = 0; | |
156 | ||
157 | /* set 0 to disable an automatic dump-reboot. */ | |
158 | fdm->header.max_time_auto = 0; | |
159 | ||
160 | /* Kernel dump sections */ | |
161 | /* cpu state data section. */ | |
162 | fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG; | |
163 | fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA; | |
164 | fdm->cpu_state_data.source_address = 0; | |
165 | fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size; | |
166 | fdm->cpu_state_data.destination_address = addr; | |
167 | addr += fw_dump.cpu_state_data_size; | |
168 | ||
169 | /* hpte region section */ | |
170 | fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG; | |
171 | fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION; | |
172 | fdm->hpte_region.source_address = 0; | |
173 | fdm->hpte_region.source_len = fw_dump.hpte_region_size; | |
174 | fdm->hpte_region.destination_address = addr; | |
175 | addr += fw_dump.hpte_region_size; | |
176 | ||
177 | /* RMA region section */ | |
178 | fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG; | |
179 | fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION; | |
180 | fdm->rmr_region.source_address = RMA_START; | |
181 | fdm->rmr_region.source_len = fw_dump.boot_memory_size; | |
182 | fdm->rmr_region.destination_address = addr; | |
183 | addr += fw_dump.boot_memory_size; | |
184 | ||
185 | return addr; | |
186 | } | |
187 | ||
eb39c880 MS |
188 | /** |
189 | * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM | |
190 | * | |
191 | * Function to find the largest memory size we need to reserve during early | |
192 | * boot process. This will be the size of the memory that is required for a | |
193 | * kernel to boot successfully. | |
194 | * | |
195 | * This function has been taken from phyp-assisted dump feature implementation. | |
196 | * | |
197 | * returns larger of 256MB or 5% rounded down to multiples of 256MB. | |
198 | * | |
199 | * TODO: Come up with better approach to find out more accurate memory size | |
200 | * that is required for a kernel to boot successfully. | |
201 | * | |
202 | */ | |
203 | static inline unsigned long fadump_calculate_reserve_size(void) | |
204 | { | |
205 | unsigned long size; | |
206 | ||
207 | /* | |
208 | * Check if the size is specified through fadump_reserve_mem= cmdline | |
209 | * option. If yes, then use that. | |
210 | */ | |
211 | if (fw_dump.reserve_bootvar) | |
212 | return fw_dump.reserve_bootvar; | |
213 | ||
214 | /* divide by 20 to get 5% of value */ | |
215 | size = memblock_end_of_DRAM() / 20; | |
216 | ||
217 | /* round it down in multiples of 256 */ | |
218 | size = size & ~0x0FFFFFFFUL; | |
219 | ||
220 | /* Truncate to memory_limit. We don't want to over reserve the memory.*/ | |
221 | if (memory_limit && size > memory_limit) | |
222 | size = memory_limit; | |
223 | ||
224 | return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); | |
225 | } | |
226 | ||
227 | /* | |
228 | * Calculate the total memory size required to be reserved for | |
229 | * firmware-assisted dump registration. | |
230 | */ | |
231 | static unsigned long get_fadump_area_size(void) | |
232 | { | |
233 | unsigned long size = 0; | |
234 | ||
235 | size += fw_dump.cpu_state_data_size; | |
236 | size += fw_dump.hpte_region_size; | |
237 | size += fw_dump.boot_memory_size; | |
238 | ||
239 | size = PAGE_ALIGN(size); | |
240 | return size; | |
241 | } | |
242 | ||
243 | int __init fadump_reserve_mem(void) | |
244 | { | |
245 | unsigned long base, size, memory_boundary; | |
246 | ||
247 | if (!fw_dump.fadump_enabled) | |
248 | return 0; | |
249 | ||
250 | if (!fw_dump.fadump_supported) { | |
251 | printk(KERN_INFO "Firmware-assisted dump is not supported on" | |
252 | " this hardware\n"); | |
253 | fw_dump.fadump_enabled = 0; | |
254 | return 0; | |
255 | } | |
3ccc00a7 MS |
256 | /* |
257 | * Initialize boot memory size | |
258 | * If dump is active then we have already calculated the size during | |
259 | * first kernel. | |
260 | */ | |
261 | if (fdm_active) | |
262 | fw_dump.boot_memory_size = fdm_active->rmr_region.source_len; | |
263 | else | |
264 | fw_dump.boot_memory_size = fadump_calculate_reserve_size(); | |
eb39c880 MS |
265 | |
266 | /* | |
267 | * Calculate the memory boundary. | |
268 | * If memory_limit is less than actual memory boundary then reserve | |
269 | * the memory for fadump beyond the memory_limit and adjust the | |
270 | * memory_limit accordingly, so that the running kernel can run with | |
271 | * specified memory_limit. | |
272 | */ | |
273 | if (memory_limit && memory_limit < memblock_end_of_DRAM()) { | |
274 | size = get_fadump_area_size(); | |
275 | if ((memory_limit + size) < memblock_end_of_DRAM()) | |
276 | memory_limit += size; | |
277 | else | |
278 | memory_limit = memblock_end_of_DRAM(); | |
279 | printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" | |
280 | " dump, now %#016llx\n", | |
281 | (unsigned long long)memory_limit); | |
282 | } | |
283 | if (memory_limit) | |
284 | memory_boundary = memory_limit; | |
285 | else | |
286 | memory_boundary = memblock_end_of_DRAM(); | |
287 | ||
288 | if (fw_dump.dump_active) { | |
289 | printk(KERN_INFO "Firmware-assisted dump is active.\n"); | |
290 | /* | |
291 | * If last boot has crashed then reserve all the memory | |
292 | * above boot_memory_size so that we don't touch it until | |
293 | * dump is written to disk by userspace tool. This memory | |
294 | * will be released for general use once the dump is saved. | |
295 | */ | |
296 | base = fw_dump.boot_memory_size; | |
297 | size = memory_boundary - base; | |
298 | memblock_reserve(base, size); | |
299 | printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " | |
300 | "for saving crash dump\n", | |
301 | (unsigned long)(size >> 20), | |
302 | (unsigned long)(base >> 20)); | |
303 | } else { | |
304 | /* Reserve the memory at the top of memory. */ | |
305 | size = get_fadump_area_size(); | |
306 | base = memory_boundary - size; | |
307 | memblock_reserve(base, size); | |
308 | printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " | |
309 | "for firmware-assisted dump\n", | |
310 | (unsigned long)(size >> 20), | |
311 | (unsigned long)(base >> 20)); | |
312 | } | |
313 | fw_dump.reserve_dump_area_start = base; | |
314 | fw_dump.reserve_dump_area_size = size; | |
315 | return 1; | |
316 | } | |
317 | ||
318 | /* Look for fadump= cmdline option. */ | |
319 | static int __init early_fadump_param(char *p) | |
320 | { | |
321 | if (!p) | |
322 | return 1; | |
323 | ||
324 | if (strncmp(p, "on", 2) == 0) | |
325 | fw_dump.fadump_enabled = 1; | |
326 | else if (strncmp(p, "off", 3) == 0) | |
327 | fw_dump.fadump_enabled = 0; | |
328 | ||
329 | return 0; | |
330 | } | |
331 | early_param("fadump", early_fadump_param); | |
332 | ||
333 | /* Look for fadump_reserve_mem= cmdline option */ | |
334 | static int __init early_fadump_reserve_mem(char *p) | |
335 | { | |
336 | if (p) | |
337 | fw_dump.reserve_bootvar = memparse(p, &p); | |
338 | return 0; | |
339 | } | |
340 | early_param("fadump_reserve_mem", early_fadump_reserve_mem); | |
3ccc00a7 MS |
341 | |
342 | static void register_fw_dump(struct fadump_mem_struct *fdm) | |
343 | { | |
344 | int rc; | |
345 | unsigned int wait_time; | |
346 | ||
347 | pr_debug("Registering for firmware-assisted kernel dump...\n"); | |
348 | ||
349 | /* TODO: Add upper time limit for the delay */ | |
350 | do { | |
351 | rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, | |
352 | FADUMP_REGISTER, fdm, | |
353 | sizeof(struct fadump_mem_struct)); | |
354 | ||
355 | wait_time = rtas_busy_delay_time(rc); | |
356 | if (wait_time) | |
357 | mdelay(wait_time); | |
358 | ||
359 | } while (wait_time); | |
360 | ||
361 | switch (rc) { | |
362 | case -1: | |
363 | printk(KERN_ERR "Failed to register firmware-assisted kernel" | |
364 | " dump. Hardware Error(%d).\n", rc); | |
365 | break; | |
366 | case -3: | |
367 | printk(KERN_ERR "Failed to register firmware-assisted kernel" | |
368 | " dump. Parameter Error(%d).\n", rc); | |
369 | break; | |
370 | case -9: | |
371 | printk(KERN_ERR "firmware-assisted kernel dump is already " | |
372 | " registered."); | |
373 | fw_dump.dump_registered = 1; | |
374 | break; | |
375 | case 0: | |
376 | printk(KERN_INFO "firmware-assisted kernel dump registration" | |
377 | " is successful\n"); | |
378 | fw_dump.dump_registered = 1; | |
379 | break; | |
380 | } | |
381 | } | |
382 | ||
383 | static void register_fadump(void) | |
384 | { | |
385 | /* | |
386 | * If no memory is reserved then we can not register for firmware- | |
387 | * assisted dump. | |
388 | */ | |
389 | if (!fw_dump.reserve_dump_area_size) | |
390 | return; | |
391 | ||
392 | /* register the future kernel dump with firmware. */ | |
393 | register_fw_dump(&fdm); | |
394 | } | |
395 | ||
396 | static int fadump_unregister_dump(struct fadump_mem_struct *fdm) | |
397 | { | |
398 | int rc = 0; | |
399 | unsigned int wait_time; | |
400 | ||
401 | pr_debug("Un-register firmware-assisted dump\n"); | |
402 | ||
403 | /* TODO: Add upper time limit for the delay */ | |
404 | do { | |
405 | rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, | |
406 | FADUMP_UNREGISTER, fdm, | |
407 | sizeof(struct fadump_mem_struct)); | |
408 | ||
409 | wait_time = rtas_busy_delay_time(rc); | |
410 | if (wait_time) | |
411 | mdelay(wait_time); | |
412 | } while (wait_time); | |
413 | ||
414 | if (rc) { | |
415 | printk(KERN_ERR "Failed to un-register firmware-assisted dump." | |
416 | " unexpected error(%d).\n", rc); | |
417 | return rc; | |
418 | } | |
419 | fw_dump.dump_registered = 0; | |
420 | return 0; | |
421 | } | |
422 | ||
423 | static ssize_t fadump_enabled_show(struct kobject *kobj, | |
424 | struct kobj_attribute *attr, | |
425 | char *buf) | |
426 | { | |
427 | return sprintf(buf, "%d\n", fw_dump.fadump_enabled); | |
428 | } | |
429 | ||
430 | static ssize_t fadump_register_show(struct kobject *kobj, | |
431 | struct kobj_attribute *attr, | |
432 | char *buf) | |
433 | { | |
434 | return sprintf(buf, "%d\n", fw_dump.dump_registered); | |
435 | } | |
436 | ||
437 | static ssize_t fadump_register_store(struct kobject *kobj, | |
438 | struct kobj_attribute *attr, | |
439 | const char *buf, size_t count) | |
440 | { | |
441 | int ret = 0; | |
442 | ||
443 | if (!fw_dump.fadump_enabled || fdm_active) | |
444 | return -EPERM; | |
445 | ||
446 | mutex_lock(&fadump_mutex); | |
447 | ||
448 | switch (buf[0]) { | |
449 | case '0': | |
450 | if (fw_dump.dump_registered == 0) { | |
451 | ret = -EINVAL; | |
452 | goto unlock_out; | |
453 | } | |
454 | /* Un-register Firmware-assisted dump */ | |
455 | fadump_unregister_dump(&fdm); | |
456 | break; | |
457 | case '1': | |
458 | if (fw_dump.dump_registered == 1) { | |
459 | ret = -EINVAL; | |
460 | goto unlock_out; | |
461 | } | |
462 | /* Register Firmware-assisted dump */ | |
463 | register_fadump(); | |
464 | break; | |
465 | default: | |
466 | ret = -EINVAL; | |
467 | break; | |
468 | } | |
469 | ||
470 | unlock_out: | |
471 | mutex_unlock(&fadump_mutex); | |
472 | return ret < 0 ? ret : count; | |
473 | } | |
474 | ||
475 | static int fadump_region_show(struct seq_file *m, void *private) | |
476 | { | |
477 | const struct fadump_mem_struct *fdm_ptr; | |
478 | ||
479 | if (!fw_dump.fadump_enabled) | |
480 | return 0; | |
481 | ||
482 | if (fdm_active) | |
483 | fdm_ptr = fdm_active; | |
484 | else | |
485 | fdm_ptr = &fdm; | |
486 | ||
487 | seq_printf(m, | |
488 | "CPU : [%#016llx-%#016llx] %#llx bytes, " | |
489 | "Dumped: %#llx\n", | |
490 | fdm_ptr->cpu_state_data.destination_address, | |
491 | fdm_ptr->cpu_state_data.destination_address + | |
492 | fdm_ptr->cpu_state_data.source_len - 1, | |
493 | fdm_ptr->cpu_state_data.source_len, | |
494 | fdm_ptr->cpu_state_data.bytes_dumped); | |
495 | seq_printf(m, | |
496 | "HPTE: [%#016llx-%#016llx] %#llx bytes, " | |
497 | "Dumped: %#llx\n", | |
498 | fdm_ptr->hpte_region.destination_address, | |
499 | fdm_ptr->hpte_region.destination_address + | |
500 | fdm_ptr->hpte_region.source_len - 1, | |
501 | fdm_ptr->hpte_region.source_len, | |
502 | fdm_ptr->hpte_region.bytes_dumped); | |
503 | seq_printf(m, | |
504 | "DUMP: [%#016llx-%#016llx] %#llx bytes, " | |
505 | "Dumped: %#llx\n", | |
506 | fdm_ptr->rmr_region.destination_address, | |
507 | fdm_ptr->rmr_region.destination_address + | |
508 | fdm_ptr->rmr_region.source_len - 1, | |
509 | fdm_ptr->rmr_region.source_len, | |
510 | fdm_ptr->rmr_region.bytes_dumped); | |
511 | ||
512 | if (!fdm_active || | |
513 | (fw_dump.reserve_dump_area_start == | |
514 | fdm_ptr->cpu_state_data.destination_address)) | |
515 | return 0; | |
516 | ||
517 | /* Dump is active. Show reserved memory region. */ | |
518 | seq_printf(m, | |
519 | " : [%#016llx-%#016llx] %#llx bytes, " | |
520 | "Dumped: %#llx\n", | |
521 | (unsigned long long)fw_dump.reserve_dump_area_start, | |
522 | fdm_ptr->cpu_state_data.destination_address - 1, | |
523 | fdm_ptr->cpu_state_data.destination_address - | |
524 | fw_dump.reserve_dump_area_start, | |
525 | fdm_ptr->cpu_state_data.destination_address - | |
526 | fw_dump.reserve_dump_area_start); | |
527 | return 0; | |
528 | } | |
529 | ||
530 | static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, | |
531 | 0444, fadump_enabled_show, | |
532 | NULL); | |
533 | static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, | |
534 | 0644, fadump_register_show, | |
535 | fadump_register_store); | |
536 | ||
537 | static int fadump_region_open(struct inode *inode, struct file *file) | |
538 | { | |
539 | return single_open(file, fadump_region_show, inode->i_private); | |
540 | } | |
541 | ||
542 | static const struct file_operations fadump_region_fops = { | |
543 | .open = fadump_region_open, | |
544 | .read = seq_read, | |
545 | .llseek = seq_lseek, | |
546 | .release = single_release, | |
547 | }; | |
548 | ||
549 | static void fadump_init_files(void) | |
550 | { | |
551 | struct dentry *debugfs_file; | |
552 | int rc = 0; | |
553 | ||
554 | rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); | |
555 | if (rc) | |
556 | printk(KERN_ERR "fadump: unable to create sysfs file" | |
557 | " fadump_enabled (%d)\n", rc); | |
558 | ||
559 | rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); | |
560 | if (rc) | |
561 | printk(KERN_ERR "fadump: unable to create sysfs file" | |
562 | " fadump_registered (%d)\n", rc); | |
563 | ||
564 | debugfs_file = debugfs_create_file("fadump_region", 0444, | |
565 | powerpc_debugfs_root, NULL, | |
566 | &fadump_region_fops); | |
567 | if (!debugfs_file) | |
568 | printk(KERN_ERR "fadump: unable to create debugfs file" | |
569 | " fadump_region\n"); | |
570 | return; | |
571 | } | |
572 | ||
573 | /* | |
574 | * Prepare for firmware-assisted dump. | |
575 | */ | |
576 | int __init setup_fadump(void) | |
577 | { | |
578 | if (!fw_dump.fadump_enabled) | |
579 | return 0; | |
580 | ||
581 | if (!fw_dump.fadump_supported) { | |
582 | printk(KERN_ERR "Firmware-assisted dump is not supported on" | |
583 | " this hardware\n"); | |
584 | return 0; | |
585 | } | |
586 | ||
587 | fadump_show_config(); | |
588 | /* Initialize the kernel dump memory structure for FAD registration. */ | |
589 | if (fw_dump.reserve_dump_area_size) | |
590 | init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); | |
591 | fadump_init_files(); | |
592 | ||
593 | return 1; | |
594 | } | |
595 | subsys_initcall(setup_fadump); |