xref: /linux/arch/powerpc/kernel/fadump.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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>
32 #include <linux/delay.h>
33 #include <linux/debugfs.h>
34 #include <linux/seq_file.h>
35 #include <linux/crash_dump.h>
36 #include <linux/kobject.h>
37 #include <linux/sysfs.h>
38 
39 #include <asm/page.h>
40 #include <asm/prom.h>
41 #include <asm/rtas.h>
42 #include <asm/fadump.h>
43 #include <asm/debug.h>
44 #include <asm/setup.h>
45 
46 static struct fw_dump fw_dump;
47 static struct fadump_mem_struct fdm;
48 static const struct fadump_mem_struct *fdm_active;
49 
50 static DEFINE_MUTEX(fadump_mutex);
51 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
52 int crash_mem_ranges;
53 
54 /* Scan the Firmware Assisted dump configuration details. */
55 int __init early_init_dt_scan_fw_dump(unsigned long node,
56 			const char *uname, int depth, void *data)
57 {
58 	__be32 *sections;
59 	int i, num_sections;
60 	unsigned long size;
61 	const int *token;
62 
63 	if (depth != 1 || strcmp(uname, "rtas") != 0)
64 		return 0;
65 
66 	/*
67 	 * Check if Firmware Assisted dump is supported. if yes, check
68 	 * if dump has been initiated on last reboot.
69 	 */
70 	token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
71 	if (!token)
72 		return 0;
73 
74 	fw_dump.fadump_supported = 1;
75 	fw_dump.ibm_configure_kernel_dump = *token;
76 
77 	/*
78 	 * The 'ibm,kernel-dump' rtas node is present only if there is
79 	 * dump data waiting for us.
80 	 */
81 	fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
82 	if (fdm_active)
83 		fw_dump.dump_active = 1;
84 
85 	/* Get the sizes required to store dump data for the firmware provided
86 	 * dump sections.
87 	 * For each dump section type supported, a 32bit cell which defines
88 	 * the ID of a supported section followed by two 32 bit cells which
89 	 * gives teh size of the section in bytes.
90 	 */
91 	sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
92 					&size);
93 
94 	if (!sections)
95 		return 0;
96 
97 	num_sections = size / (3 * sizeof(u32));
98 
99 	for (i = 0; i < num_sections; i++, sections += 3) {
100 		u32 type = (u32)of_read_number(sections, 1);
101 
102 		switch (type) {
103 		case FADUMP_CPU_STATE_DATA:
104 			fw_dump.cpu_state_data_size =
105 					of_read_ulong(&sections[1], 2);
106 			break;
107 		case FADUMP_HPTE_REGION:
108 			fw_dump.hpte_region_size =
109 					of_read_ulong(&sections[1], 2);
110 			break;
111 		}
112 	}
113 	return 1;
114 }
115 
116 int is_fadump_active(void)
117 {
118 	return fw_dump.dump_active;
119 }
120 
121 /* Print firmware assisted dump configurations for debugging purpose. */
122 static void fadump_show_config(void)
123 {
124 	pr_debug("Support for firmware-assisted dump (fadump): %s\n",
125 			(fw_dump.fadump_supported ? "present" : "no support"));
126 
127 	if (!fw_dump.fadump_supported)
128 		return;
129 
130 	pr_debug("Fadump enabled    : %s\n",
131 				(fw_dump.fadump_enabled ? "yes" : "no"));
132 	pr_debug("Dump Active       : %s\n",
133 				(fw_dump.dump_active ? "yes" : "no"));
134 	pr_debug("Dump section sizes:\n");
135 	pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
136 	pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
137 	pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
138 }
139 
140 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
141 				unsigned long addr)
142 {
143 	if (!fdm)
144 		return 0;
145 
146 	memset(fdm, 0, sizeof(struct fadump_mem_struct));
147 	addr = addr & PAGE_MASK;
148 
149 	fdm->header.dump_format_version = 0x00000001;
150 	fdm->header.dump_num_sections = 3;
151 	fdm->header.dump_status_flag = 0;
152 	fdm->header.offset_first_dump_section =
153 		(u32)offsetof(struct fadump_mem_struct, cpu_state_data);
154 
155 	/*
156 	 * Fields for disk dump option.
157 	 * We are not using disk dump option, hence set these fields to 0.
158 	 */
159 	fdm->header.dd_block_size = 0;
160 	fdm->header.dd_block_offset = 0;
161 	fdm->header.dd_num_blocks = 0;
162 	fdm->header.dd_offset_disk_path = 0;
163 
164 	/* set 0 to disable an automatic dump-reboot. */
165 	fdm->header.max_time_auto = 0;
166 
167 	/* Kernel dump sections */
168 	/* cpu state data section. */
169 	fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG;
170 	fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA;
171 	fdm->cpu_state_data.source_address = 0;
172 	fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size;
173 	fdm->cpu_state_data.destination_address = addr;
174 	addr += fw_dump.cpu_state_data_size;
175 
176 	/* hpte region section */
177 	fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG;
178 	fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION;
179 	fdm->hpte_region.source_address = 0;
180 	fdm->hpte_region.source_len = fw_dump.hpte_region_size;
181 	fdm->hpte_region.destination_address = addr;
182 	addr += fw_dump.hpte_region_size;
183 
184 	/* RMA region section */
185 	fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG;
186 	fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION;
187 	fdm->rmr_region.source_address = RMA_START;
188 	fdm->rmr_region.source_len = fw_dump.boot_memory_size;
189 	fdm->rmr_region.destination_address = addr;
190 	addr += fw_dump.boot_memory_size;
191 
192 	return addr;
193 }
194 
195 /**
196  * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
197  *
198  * Function to find the largest memory size we need to reserve during early
199  * boot process. This will be the size of the memory that is required for a
200  * kernel to boot successfully.
201  *
202  * This function has been taken from phyp-assisted dump feature implementation.
203  *
204  * returns larger of 256MB or 5% rounded down to multiples of 256MB.
205  *
206  * TODO: Come up with better approach to find out more accurate memory size
207  * that is required for a kernel to boot successfully.
208  *
209  */
210 static inline unsigned long fadump_calculate_reserve_size(void)
211 {
212 	unsigned long size;
213 
214 	/*
215 	 * Check if the size is specified through fadump_reserve_mem= cmdline
216 	 * option. If yes, then use that.
217 	 */
218 	if (fw_dump.reserve_bootvar)
219 		return fw_dump.reserve_bootvar;
220 
221 	/* divide by 20 to get 5% of value */
222 	size = memblock_end_of_DRAM() / 20;
223 
224 	/* round it down in multiples of 256 */
225 	size = size & ~0x0FFFFFFFUL;
226 
227 	/* Truncate to memory_limit. We don't want to over reserve the memory.*/
228 	if (memory_limit && size > memory_limit)
229 		size = memory_limit;
230 
231 	return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
232 }
233 
234 /*
235  * Calculate the total memory size required to be reserved for
236  * firmware-assisted dump registration.
237  */
238 static unsigned long get_fadump_area_size(void)
239 {
240 	unsigned long size = 0;
241 
242 	size += fw_dump.cpu_state_data_size;
243 	size += fw_dump.hpte_region_size;
244 	size += fw_dump.boot_memory_size;
245 	size += sizeof(struct fadump_crash_info_header);
246 	size += sizeof(struct elfhdr); /* ELF core header.*/
247 	size += sizeof(struct elf_phdr); /* place holder for cpu notes */
248 	/* Program headers for crash memory regions. */
249 	size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
250 
251 	size = PAGE_ALIGN(size);
252 	return size;
253 }
254 
255 int __init fadump_reserve_mem(void)
256 {
257 	unsigned long base, size, memory_boundary;
258 
259 	if (!fw_dump.fadump_enabled)
260 		return 0;
261 
262 	if (!fw_dump.fadump_supported) {
263 		printk(KERN_INFO "Firmware-assisted dump is not supported on"
264 				" this hardware\n");
265 		fw_dump.fadump_enabled = 0;
266 		return 0;
267 	}
268 	/*
269 	 * Initialize boot memory size
270 	 * If dump is active then we have already calculated the size during
271 	 * first kernel.
272 	 */
273 	if (fdm_active)
274 		fw_dump.boot_memory_size = fdm_active->rmr_region.source_len;
275 	else
276 		fw_dump.boot_memory_size = fadump_calculate_reserve_size();
277 
278 	/*
279 	 * Calculate the memory boundary.
280 	 * If memory_limit is less than actual memory boundary then reserve
281 	 * the memory for fadump beyond the memory_limit and adjust the
282 	 * memory_limit accordingly, so that the running kernel can run with
283 	 * specified memory_limit.
284 	 */
285 	if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
286 		size = get_fadump_area_size();
287 		if ((memory_limit + size) < memblock_end_of_DRAM())
288 			memory_limit += size;
289 		else
290 			memory_limit = memblock_end_of_DRAM();
291 		printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
292 				" dump, now %#016llx\n",
293 				(unsigned long long)memory_limit);
294 	}
295 	if (memory_limit)
296 		memory_boundary = memory_limit;
297 	else
298 		memory_boundary = memblock_end_of_DRAM();
299 
300 	if (fw_dump.dump_active) {
301 		printk(KERN_INFO "Firmware-assisted dump is active.\n");
302 		/*
303 		 * If last boot has crashed then reserve all the memory
304 		 * above boot_memory_size so that we don't touch it until
305 		 * dump is written to disk by userspace tool. This memory
306 		 * will be released for general use once the dump is saved.
307 		 */
308 		base = fw_dump.boot_memory_size;
309 		size = memory_boundary - base;
310 		memblock_reserve(base, size);
311 		printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
312 				"for saving crash dump\n",
313 				(unsigned long)(size >> 20),
314 				(unsigned long)(base >> 20));
315 
316 		fw_dump.fadumphdr_addr =
317 				fdm_active->rmr_region.destination_address +
318 				fdm_active->rmr_region.source_len;
319 		pr_debug("fadumphdr_addr = %p\n",
320 				(void *) fw_dump.fadumphdr_addr);
321 	} else {
322 		/* Reserve the memory at the top of memory. */
323 		size = get_fadump_area_size();
324 		base = memory_boundary - size;
325 		memblock_reserve(base, size);
326 		printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
327 				"for firmware-assisted dump\n",
328 				(unsigned long)(size >> 20),
329 				(unsigned long)(base >> 20));
330 	}
331 	fw_dump.reserve_dump_area_start = base;
332 	fw_dump.reserve_dump_area_size = size;
333 	return 1;
334 }
335 
336 /* Look for fadump= cmdline option. */
337 static int __init early_fadump_param(char *p)
338 {
339 	if (!p)
340 		return 1;
341 
342 	if (strncmp(p, "on", 2) == 0)
343 		fw_dump.fadump_enabled = 1;
344 	else if (strncmp(p, "off", 3) == 0)
345 		fw_dump.fadump_enabled = 0;
346 
347 	return 0;
348 }
349 early_param("fadump", early_fadump_param);
350 
351 /* Look for fadump_reserve_mem= cmdline option */
352 static int __init early_fadump_reserve_mem(char *p)
353 {
354 	if (p)
355 		fw_dump.reserve_bootvar = memparse(p, &p);
356 	return 0;
357 }
358 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
359 
360 static void register_fw_dump(struct fadump_mem_struct *fdm)
361 {
362 	int rc;
363 	unsigned int wait_time;
364 
365 	pr_debug("Registering for firmware-assisted kernel dump...\n");
366 
367 	/* TODO: Add upper time limit for the delay */
368 	do {
369 		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
370 			FADUMP_REGISTER, fdm,
371 			sizeof(struct fadump_mem_struct));
372 
373 		wait_time = rtas_busy_delay_time(rc);
374 		if (wait_time)
375 			mdelay(wait_time);
376 
377 	} while (wait_time);
378 
379 	switch (rc) {
380 	case -1:
381 		printk(KERN_ERR "Failed to register firmware-assisted kernel"
382 			" dump. Hardware Error(%d).\n", rc);
383 		break;
384 	case -3:
385 		printk(KERN_ERR "Failed to register firmware-assisted kernel"
386 			" dump. Parameter Error(%d).\n", rc);
387 		break;
388 	case -9:
389 		printk(KERN_ERR "firmware-assisted kernel dump is already "
390 			" registered.");
391 		fw_dump.dump_registered = 1;
392 		break;
393 	case 0:
394 		printk(KERN_INFO "firmware-assisted kernel dump registration"
395 			" is successful\n");
396 		fw_dump.dump_registered = 1;
397 		break;
398 	}
399 }
400 
401 void crash_fadump(struct pt_regs *regs, const char *str)
402 {
403 	struct fadump_crash_info_header *fdh = NULL;
404 
405 	if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
406 		return;
407 
408 	fdh = __va(fw_dump.fadumphdr_addr);
409 	crashing_cpu = smp_processor_id();
410 	fdh->crashing_cpu = crashing_cpu;
411 	crash_save_vmcoreinfo();
412 
413 	if (regs)
414 		fdh->regs = *regs;
415 	else
416 		ppc_save_regs(&fdh->regs);
417 
418 	fdh->cpu_online_mask = *cpu_online_mask;
419 
420 	/* Call ibm,os-term rtas call to trigger firmware assisted dump */
421 	rtas_os_term((char *)str);
422 }
423 
424 #define GPR_MASK	0xffffff0000000000
425 static inline int fadump_gpr_index(u64 id)
426 {
427 	int i = -1;
428 	char str[3];
429 
430 	if ((id & GPR_MASK) == REG_ID("GPR")) {
431 		/* get the digits at the end */
432 		id &= ~GPR_MASK;
433 		id >>= 24;
434 		str[2] = '\0';
435 		str[1] = id & 0xff;
436 		str[0] = (id >> 8) & 0xff;
437 		sscanf(str, "%d", &i);
438 		if (i > 31)
439 			i = -1;
440 	}
441 	return i;
442 }
443 
444 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
445 								u64 reg_val)
446 {
447 	int i;
448 
449 	i = fadump_gpr_index(reg_id);
450 	if (i >= 0)
451 		regs->gpr[i] = (unsigned long)reg_val;
452 	else if (reg_id == REG_ID("NIA"))
453 		regs->nip = (unsigned long)reg_val;
454 	else if (reg_id == REG_ID("MSR"))
455 		regs->msr = (unsigned long)reg_val;
456 	else if (reg_id == REG_ID("CTR"))
457 		regs->ctr = (unsigned long)reg_val;
458 	else if (reg_id == REG_ID("LR"))
459 		regs->link = (unsigned long)reg_val;
460 	else if (reg_id == REG_ID("XER"))
461 		regs->xer = (unsigned long)reg_val;
462 	else if (reg_id == REG_ID("CR"))
463 		regs->ccr = (unsigned long)reg_val;
464 	else if (reg_id == REG_ID("DAR"))
465 		regs->dar = (unsigned long)reg_val;
466 	else if (reg_id == REG_ID("DSISR"))
467 		regs->dsisr = (unsigned long)reg_val;
468 }
469 
470 static struct fadump_reg_entry*
471 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
472 {
473 	memset(regs, 0, sizeof(struct pt_regs));
474 
475 	while (reg_entry->reg_id != REG_ID("CPUEND")) {
476 		fadump_set_regval(regs, reg_entry->reg_id,
477 					reg_entry->reg_value);
478 		reg_entry++;
479 	}
480 	reg_entry++;
481 	return reg_entry;
482 }
483 
484 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
485 						void *data, size_t data_len)
486 {
487 	struct elf_note note;
488 
489 	note.n_namesz = strlen(name) + 1;
490 	note.n_descsz = data_len;
491 	note.n_type   = type;
492 	memcpy(buf, &note, sizeof(note));
493 	buf += (sizeof(note) + 3)/4;
494 	memcpy(buf, name, note.n_namesz);
495 	buf += (note.n_namesz + 3)/4;
496 	memcpy(buf, data, note.n_descsz);
497 	buf += (note.n_descsz + 3)/4;
498 
499 	return buf;
500 }
501 
502 static void fadump_final_note(u32 *buf)
503 {
504 	struct elf_note note;
505 
506 	note.n_namesz = 0;
507 	note.n_descsz = 0;
508 	note.n_type   = 0;
509 	memcpy(buf, &note, sizeof(note));
510 }
511 
512 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
513 {
514 	struct elf_prstatus prstatus;
515 
516 	memset(&prstatus, 0, sizeof(prstatus));
517 	/*
518 	 * FIXME: How do i get PID? Do I really need it?
519 	 * prstatus.pr_pid = ????
520 	 */
521 	elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
522 	buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
523 				&prstatus, sizeof(prstatus));
524 	return buf;
525 }
526 
527 static void fadump_update_elfcore_header(char *bufp)
528 {
529 	struct elfhdr *elf;
530 	struct elf_phdr *phdr;
531 
532 	elf = (struct elfhdr *)bufp;
533 	bufp += sizeof(struct elfhdr);
534 
535 	/* First note is a place holder for cpu notes info. */
536 	phdr = (struct elf_phdr *)bufp;
537 
538 	if (phdr->p_type == PT_NOTE) {
539 		phdr->p_paddr = fw_dump.cpu_notes_buf;
540 		phdr->p_offset	= phdr->p_paddr;
541 		phdr->p_filesz	= fw_dump.cpu_notes_buf_size;
542 		phdr->p_memsz = fw_dump.cpu_notes_buf_size;
543 	}
544 	return;
545 }
546 
547 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
548 {
549 	void *vaddr;
550 	struct page *page;
551 	unsigned long order, count, i;
552 
553 	order = get_order(size);
554 	vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
555 	if (!vaddr)
556 		return NULL;
557 
558 	count = 1 << order;
559 	page = virt_to_page(vaddr);
560 	for (i = 0; i < count; i++)
561 		SetPageReserved(page + i);
562 	return vaddr;
563 }
564 
565 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
566 {
567 	struct page *page;
568 	unsigned long order, count, i;
569 
570 	order = get_order(size);
571 	count = 1 << order;
572 	page = virt_to_page(vaddr);
573 	for (i = 0; i < count; i++)
574 		ClearPageReserved(page + i);
575 	__free_pages(page, order);
576 }
577 
578 /*
579  * Read CPU state dump data and convert it into ELF notes.
580  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
581  * used to access the data to allow for additional fields to be added without
582  * affecting compatibility. Each list of registers for a CPU starts with
583  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
584  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
585  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
586  * of register value. For more details refer to PAPR document.
587  *
588  * Only for the crashing cpu we ignore the CPU dump data and get exact
589  * state from fadump crash info structure populated by first kernel at the
590  * time of crash.
591  */
592 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
593 {
594 	struct fadump_reg_save_area_header *reg_header;
595 	struct fadump_reg_entry *reg_entry;
596 	struct fadump_crash_info_header *fdh = NULL;
597 	void *vaddr;
598 	unsigned long addr;
599 	u32 num_cpus, *note_buf;
600 	struct pt_regs regs;
601 	int i, rc = 0, cpu = 0;
602 
603 	if (!fdm->cpu_state_data.bytes_dumped)
604 		return -EINVAL;
605 
606 	addr = fdm->cpu_state_data.destination_address;
607 	vaddr = __va(addr);
608 
609 	reg_header = vaddr;
610 	if (reg_header->magic_number != REGSAVE_AREA_MAGIC) {
611 		printk(KERN_ERR "Unable to read register save area.\n");
612 		return -ENOENT;
613 	}
614 	pr_debug("--------CPU State Data------------\n");
615 	pr_debug("Magic Number: %llx\n", reg_header->magic_number);
616 	pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset);
617 
618 	vaddr += reg_header->num_cpu_offset;
619 	num_cpus = *((u32 *)(vaddr));
620 	pr_debug("NumCpus     : %u\n", num_cpus);
621 	vaddr += sizeof(u32);
622 	reg_entry = (struct fadump_reg_entry *)vaddr;
623 
624 	/* Allocate buffer to hold cpu crash notes. */
625 	fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
626 	fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
627 	note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
628 	if (!note_buf) {
629 		printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
630 			"cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
631 		return -ENOMEM;
632 	}
633 	fw_dump.cpu_notes_buf = __pa(note_buf);
634 
635 	pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
636 			(num_cpus * sizeof(note_buf_t)), note_buf);
637 
638 	if (fw_dump.fadumphdr_addr)
639 		fdh = __va(fw_dump.fadumphdr_addr);
640 
641 	for (i = 0; i < num_cpus; i++) {
642 		if (reg_entry->reg_id != REG_ID("CPUSTRT")) {
643 			printk(KERN_ERR "Unable to read CPU state data\n");
644 			rc = -ENOENT;
645 			goto error_out;
646 		}
647 		/* Lower 4 bytes of reg_value contains logical cpu id */
648 		cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK;
649 		if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
650 			SKIP_TO_NEXT_CPU(reg_entry);
651 			continue;
652 		}
653 		pr_debug("Reading register data for cpu %d...\n", cpu);
654 		if (fdh && fdh->crashing_cpu == cpu) {
655 			regs = fdh->regs;
656 			note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
657 			SKIP_TO_NEXT_CPU(reg_entry);
658 		} else {
659 			reg_entry++;
660 			reg_entry = fadump_read_registers(reg_entry, &regs);
661 			note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
662 		}
663 	}
664 	fadump_final_note(note_buf);
665 
666 	pr_debug("Updating elfcore header (%llx) with cpu notes\n",
667 							fdh->elfcorehdr_addr);
668 	fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
669 	return 0;
670 
671 error_out:
672 	fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
673 					fw_dump.cpu_notes_buf_size);
674 	fw_dump.cpu_notes_buf = 0;
675 	fw_dump.cpu_notes_buf_size = 0;
676 	return rc;
677 
678 }
679 
680 /*
681  * Validate and process the dump data stored by firmware before exporting
682  * it through '/proc/vmcore'.
683  */
684 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
685 {
686 	struct fadump_crash_info_header *fdh;
687 	int rc = 0;
688 
689 	if (!fdm_active || !fw_dump.fadumphdr_addr)
690 		return -EINVAL;
691 
692 	/* Check if the dump data is valid. */
693 	if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
694 			(fdm_active->cpu_state_data.error_flags != 0) ||
695 			(fdm_active->rmr_region.error_flags != 0)) {
696 		printk(KERN_ERR "Dump taken by platform is not valid\n");
697 		return -EINVAL;
698 	}
699 	if ((fdm_active->rmr_region.bytes_dumped !=
700 			fdm_active->rmr_region.source_len) ||
701 			!fdm_active->cpu_state_data.bytes_dumped) {
702 		printk(KERN_ERR "Dump taken by platform is incomplete\n");
703 		return -EINVAL;
704 	}
705 
706 	/* Validate the fadump crash info header */
707 	fdh = __va(fw_dump.fadumphdr_addr);
708 	if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
709 		printk(KERN_ERR "Crash info header is not valid.\n");
710 		return -EINVAL;
711 	}
712 
713 	rc = fadump_build_cpu_notes(fdm_active);
714 	if (rc)
715 		return rc;
716 
717 	/*
718 	 * We are done validating dump info and elfcore header is now ready
719 	 * to be exported. set elfcorehdr_addr so that vmcore module will
720 	 * export the elfcore header through '/proc/vmcore'.
721 	 */
722 	elfcorehdr_addr = fdh->elfcorehdr_addr;
723 
724 	return 0;
725 }
726 
727 static inline void fadump_add_crash_memory(unsigned long long base,
728 					unsigned long long end)
729 {
730 	if (base == end)
731 		return;
732 
733 	pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
734 		crash_mem_ranges, base, end - 1, (end - base));
735 	crash_memory_ranges[crash_mem_ranges].base = base;
736 	crash_memory_ranges[crash_mem_ranges].size = end - base;
737 	crash_mem_ranges++;
738 }
739 
740 static void fadump_exclude_reserved_area(unsigned long long start,
741 					unsigned long long end)
742 {
743 	unsigned long long ra_start, ra_end;
744 
745 	ra_start = fw_dump.reserve_dump_area_start;
746 	ra_end = ra_start + fw_dump.reserve_dump_area_size;
747 
748 	if ((ra_start < end) && (ra_end > start)) {
749 		if ((start < ra_start) && (end > ra_end)) {
750 			fadump_add_crash_memory(start, ra_start);
751 			fadump_add_crash_memory(ra_end, end);
752 		} else if (start < ra_start) {
753 			fadump_add_crash_memory(start, ra_start);
754 		} else if (ra_end < end) {
755 			fadump_add_crash_memory(ra_end, end);
756 		}
757 	} else
758 		fadump_add_crash_memory(start, end);
759 }
760 
761 static int fadump_init_elfcore_header(char *bufp)
762 {
763 	struct elfhdr *elf;
764 
765 	elf = (struct elfhdr *) bufp;
766 	bufp += sizeof(struct elfhdr);
767 	memcpy(elf->e_ident, ELFMAG, SELFMAG);
768 	elf->e_ident[EI_CLASS] = ELF_CLASS;
769 	elf->e_ident[EI_DATA] = ELF_DATA;
770 	elf->e_ident[EI_VERSION] = EV_CURRENT;
771 	elf->e_ident[EI_OSABI] = ELF_OSABI;
772 	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
773 	elf->e_type = ET_CORE;
774 	elf->e_machine = ELF_ARCH;
775 	elf->e_version = EV_CURRENT;
776 	elf->e_entry = 0;
777 	elf->e_phoff = sizeof(struct elfhdr);
778 	elf->e_shoff = 0;
779 	elf->e_flags = ELF_CORE_EFLAGS;
780 	elf->e_ehsize = sizeof(struct elfhdr);
781 	elf->e_phentsize = sizeof(struct elf_phdr);
782 	elf->e_phnum = 0;
783 	elf->e_shentsize = 0;
784 	elf->e_shnum = 0;
785 	elf->e_shstrndx = 0;
786 
787 	return 0;
788 }
789 
790 /*
791  * Traverse through memblock structure and setup crash memory ranges. These
792  * ranges will be used create PT_LOAD program headers in elfcore header.
793  */
794 static void fadump_setup_crash_memory_ranges(void)
795 {
796 	struct memblock_region *reg;
797 	unsigned long long start, end;
798 
799 	pr_debug("Setup crash memory ranges.\n");
800 	crash_mem_ranges = 0;
801 	/*
802 	 * add the first memory chunk (RMA_START through boot_memory_size) as
803 	 * a separate memory chunk. The reason is, at the time crash firmware
804 	 * will move the content of this memory chunk to different location
805 	 * specified during fadump registration. We need to create a separate
806 	 * program header for this chunk with the correct offset.
807 	 */
808 	fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
809 
810 	for_each_memblock(memory, reg) {
811 		start = (unsigned long long)reg->base;
812 		end = start + (unsigned long long)reg->size;
813 		if (start == RMA_START && end >= fw_dump.boot_memory_size)
814 			start = fw_dump.boot_memory_size;
815 
816 		/* add this range excluding the reserved dump area. */
817 		fadump_exclude_reserved_area(start, end);
818 	}
819 }
820 
821 /*
822  * If the given physical address falls within the boot memory region then
823  * return the relocated address that points to the dump region reserved
824  * for saving initial boot memory contents.
825  */
826 static inline unsigned long fadump_relocate(unsigned long paddr)
827 {
828 	if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
829 		return fdm.rmr_region.destination_address + paddr;
830 	else
831 		return paddr;
832 }
833 
834 static int fadump_create_elfcore_headers(char *bufp)
835 {
836 	struct elfhdr *elf;
837 	struct elf_phdr *phdr;
838 	int i;
839 
840 	fadump_init_elfcore_header(bufp);
841 	elf = (struct elfhdr *)bufp;
842 	bufp += sizeof(struct elfhdr);
843 
844 	/*
845 	 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
846 	 * will be populated during second kernel boot after crash. Hence
847 	 * this PT_NOTE will always be the first elf note.
848 	 *
849 	 * NOTE: Any new ELF note addition should be placed after this note.
850 	 */
851 	phdr = (struct elf_phdr *)bufp;
852 	bufp += sizeof(struct elf_phdr);
853 	phdr->p_type = PT_NOTE;
854 	phdr->p_flags = 0;
855 	phdr->p_vaddr = 0;
856 	phdr->p_align = 0;
857 
858 	phdr->p_offset = 0;
859 	phdr->p_paddr = 0;
860 	phdr->p_filesz = 0;
861 	phdr->p_memsz = 0;
862 
863 	(elf->e_phnum)++;
864 
865 	/* setup ELF PT_NOTE for vmcoreinfo */
866 	phdr = (struct elf_phdr *)bufp;
867 	bufp += sizeof(struct elf_phdr);
868 	phdr->p_type	= PT_NOTE;
869 	phdr->p_flags	= 0;
870 	phdr->p_vaddr	= 0;
871 	phdr->p_align	= 0;
872 
873 	phdr->p_paddr	= fadump_relocate(paddr_vmcoreinfo_note());
874 	phdr->p_offset	= phdr->p_paddr;
875 	phdr->p_memsz	= vmcoreinfo_max_size;
876 	phdr->p_filesz	= vmcoreinfo_max_size;
877 
878 	/* Increment number of program headers. */
879 	(elf->e_phnum)++;
880 
881 	/* setup PT_LOAD sections. */
882 
883 	for (i = 0; i < crash_mem_ranges; i++) {
884 		unsigned long long mbase, msize;
885 		mbase = crash_memory_ranges[i].base;
886 		msize = crash_memory_ranges[i].size;
887 
888 		if (!msize)
889 			continue;
890 
891 		phdr = (struct elf_phdr *)bufp;
892 		bufp += sizeof(struct elf_phdr);
893 		phdr->p_type	= PT_LOAD;
894 		phdr->p_flags	= PF_R|PF_W|PF_X;
895 		phdr->p_offset	= mbase;
896 
897 		if (mbase == RMA_START) {
898 			/*
899 			 * The entire RMA region will be moved by firmware
900 			 * to the specified destination_address. Hence set
901 			 * the correct offset.
902 			 */
903 			phdr->p_offset = fdm.rmr_region.destination_address;
904 		}
905 
906 		phdr->p_paddr = mbase;
907 		phdr->p_vaddr = (unsigned long)__va(mbase);
908 		phdr->p_filesz = msize;
909 		phdr->p_memsz = msize;
910 		phdr->p_align = 0;
911 
912 		/* Increment number of program headers. */
913 		(elf->e_phnum)++;
914 	}
915 	return 0;
916 }
917 
918 static unsigned long init_fadump_header(unsigned long addr)
919 {
920 	struct fadump_crash_info_header *fdh;
921 
922 	if (!addr)
923 		return 0;
924 
925 	fw_dump.fadumphdr_addr = addr;
926 	fdh = __va(addr);
927 	addr += sizeof(struct fadump_crash_info_header);
928 
929 	memset(fdh, 0, sizeof(struct fadump_crash_info_header));
930 	fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
931 	fdh->elfcorehdr_addr = addr;
932 	/* We will set the crashing cpu id in crash_fadump() during crash. */
933 	fdh->crashing_cpu = CPU_UNKNOWN;
934 
935 	return addr;
936 }
937 
938 static void register_fadump(void)
939 {
940 	unsigned long addr;
941 	void *vaddr;
942 
943 	/*
944 	 * If no memory is reserved then we can not register for firmware-
945 	 * assisted dump.
946 	 */
947 	if (!fw_dump.reserve_dump_area_size)
948 		return;
949 
950 	fadump_setup_crash_memory_ranges();
951 
952 	addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
953 	/* Initialize fadump crash info header. */
954 	addr = init_fadump_header(addr);
955 	vaddr = __va(addr);
956 
957 	pr_debug("Creating ELF core headers at %#016lx\n", addr);
958 	fadump_create_elfcore_headers(vaddr);
959 
960 	/* register the future kernel dump with firmware. */
961 	register_fw_dump(&fdm);
962 }
963 
964 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
965 {
966 	int rc = 0;
967 	unsigned int wait_time;
968 
969 	pr_debug("Un-register firmware-assisted dump\n");
970 
971 	/* TODO: Add upper time limit for the delay */
972 	do {
973 		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
974 			FADUMP_UNREGISTER, fdm,
975 			sizeof(struct fadump_mem_struct));
976 
977 		wait_time = rtas_busy_delay_time(rc);
978 		if (wait_time)
979 			mdelay(wait_time);
980 	} while (wait_time);
981 
982 	if (rc) {
983 		printk(KERN_ERR "Failed to un-register firmware-assisted dump."
984 			" unexpected error(%d).\n", rc);
985 		return rc;
986 	}
987 	fw_dump.dump_registered = 0;
988 	return 0;
989 }
990 
991 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
992 {
993 	int rc = 0;
994 	unsigned int wait_time;
995 
996 	pr_debug("Invalidating firmware-assisted dump registration\n");
997 
998 	/* TODO: Add upper time limit for the delay */
999 	do {
1000 		rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1001 			FADUMP_INVALIDATE, fdm,
1002 			sizeof(struct fadump_mem_struct));
1003 
1004 		wait_time = rtas_busy_delay_time(rc);
1005 		if (wait_time)
1006 			mdelay(wait_time);
1007 	} while (wait_time);
1008 
1009 	if (rc) {
1010 		printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1011 			"rgistration. unexpected error(%d).\n", rc);
1012 		return rc;
1013 	}
1014 	fw_dump.dump_active = 0;
1015 	fdm_active = NULL;
1016 	return 0;
1017 }
1018 
1019 void fadump_cleanup(void)
1020 {
1021 	/* Invalidate the registration only if dump is active. */
1022 	if (fw_dump.dump_active) {
1023 		init_fadump_mem_struct(&fdm,
1024 			fdm_active->cpu_state_data.destination_address);
1025 		fadump_invalidate_dump(&fdm);
1026 	}
1027 }
1028 
1029 /*
1030  * Release the memory that was reserved in early boot to preserve the memory
1031  * contents. The released memory will be available for general use.
1032  */
1033 static void fadump_release_memory(unsigned long begin, unsigned long end)
1034 {
1035 	unsigned long addr;
1036 	unsigned long ra_start, ra_end;
1037 
1038 	ra_start = fw_dump.reserve_dump_area_start;
1039 	ra_end = ra_start + fw_dump.reserve_dump_area_size;
1040 
1041 	for (addr = begin; addr < end; addr += PAGE_SIZE) {
1042 		/*
1043 		 * exclude the dump reserve area. Will reuse it for next
1044 		 * fadump registration.
1045 		 */
1046 		if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1047 			continue;
1048 
1049 		ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1050 		init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1051 		free_page((unsigned long)__va(addr));
1052 		totalram_pages++;
1053 	}
1054 }
1055 
1056 static void fadump_invalidate_release_mem(void)
1057 {
1058 	unsigned long reserved_area_start, reserved_area_end;
1059 	unsigned long destination_address;
1060 
1061 	mutex_lock(&fadump_mutex);
1062 	if (!fw_dump.dump_active) {
1063 		mutex_unlock(&fadump_mutex);
1064 		return;
1065 	}
1066 
1067 	destination_address = fdm_active->cpu_state_data.destination_address;
1068 	fadump_cleanup();
1069 	mutex_unlock(&fadump_mutex);
1070 
1071 	/*
1072 	 * Save the current reserved memory bounds we will require them
1073 	 * later for releasing the memory for general use.
1074 	 */
1075 	reserved_area_start = fw_dump.reserve_dump_area_start;
1076 	reserved_area_end = reserved_area_start +
1077 			fw_dump.reserve_dump_area_size;
1078 	/*
1079 	 * Setup reserve_dump_area_start and its size so that we can
1080 	 * reuse this reserved memory for Re-registration.
1081 	 */
1082 	fw_dump.reserve_dump_area_start = destination_address;
1083 	fw_dump.reserve_dump_area_size = get_fadump_area_size();
1084 
1085 	fadump_release_memory(reserved_area_start, reserved_area_end);
1086 	if (fw_dump.cpu_notes_buf) {
1087 		fadump_cpu_notes_buf_free(
1088 				(unsigned long)__va(fw_dump.cpu_notes_buf),
1089 				fw_dump.cpu_notes_buf_size);
1090 		fw_dump.cpu_notes_buf = 0;
1091 		fw_dump.cpu_notes_buf_size = 0;
1092 	}
1093 	/* Initialize the kernel dump memory structure for FAD registration. */
1094 	init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1095 }
1096 
1097 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1098 					struct kobj_attribute *attr,
1099 					const char *buf, size_t count)
1100 {
1101 	if (!fw_dump.dump_active)
1102 		return -EPERM;
1103 
1104 	if (buf[0] == '1') {
1105 		/*
1106 		 * Take away the '/proc/vmcore'. We are releasing the dump
1107 		 * memory, hence it will not be valid anymore.
1108 		 */
1109 		vmcore_cleanup();
1110 		fadump_invalidate_release_mem();
1111 
1112 	} else
1113 		return -EINVAL;
1114 	return count;
1115 }
1116 
1117 static ssize_t fadump_enabled_show(struct kobject *kobj,
1118 					struct kobj_attribute *attr,
1119 					char *buf)
1120 {
1121 	return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1122 }
1123 
1124 static ssize_t fadump_register_show(struct kobject *kobj,
1125 					struct kobj_attribute *attr,
1126 					char *buf)
1127 {
1128 	return sprintf(buf, "%d\n", fw_dump.dump_registered);
1129 }
1130 
1131 static ssize_t fadump_register_store(struct kobject *kobj,
1132 					struct kobj_attribute *attr,
1133 					const char *buf, size_t count)
1134 {
1135 	int ret = 0;
1136 
1137 	if (!fw_dump.fadump_enabled || fdm_active)
1138 		return -EPERM;
1139 
1140 	mutex_lock(&fadump_mutex);
1141 
1142 	switch (buf[0]) {
1143 	case '0':
1144 		if (fw_dump.dump_registered == 0) {
1145 			ret = -EINVAL;
1146 			goto unlock_out;
1147 		}
1148 		/* Un-register Firmware-assisted dump */
1149 		fadump_unregister_dump(&fdm);
1150 		break;
1151 	case '1':
1152 		if (fw_dump.dump_registered == 1) {
1153 			ret = -EINVAL;
1154 			goto unlock_out;
1155 		}
1156 		/* Register Firmware-assisted dump */
1157 		register_fadump();
1158 		break;
1159 	default:
1160 		ret = -EINVAL;
1161 		break;
1162 	}
1163 
1164 unlock_out:
1165 	mutex_unlock(&fadump_mutex);
1166 	return ret < 0 ? ret : count;
1167 }
1168 
1169 static int fadump_region_show(struct seq_file *m, void *private)
1170 {
1171 	const struct fadump_mem_struct *fdm_ptr;
1172 
1173 	if (!fw_dump.fadump_enabled)
1174 		return 0;
1175 
1176 	mutex_lock(&fadump_mutex);
1177 	if (fdm_active)
1178 		fdm_ptr = fdm_active;
1179 	else {
1180 		mutex_unlock(&fadump_mutex);
1181 		fdm_ptr = &fdm;
1182 	}
1183 
1184 	seq_printf(m,
1185 			"CPU : [%#016llx-%#016llx] %#llx bytes, "
1186 			"Dumped: %#llx\n",
1187 			fdm_ptr->cpu_state_data.destination_address,
1188 			fdm_ptr->cpu_state_data.destination_address +
1189 			fdm_ptr->cpu_state_data.source_len - 1,
1190 			fdm_ptr->cpu_state_data.source_len,
1191 			fdm_ptr->cpu_state_data.bytes_dumped);
1192 	seq_printf(m,
1193 			"HPTE: [%#016llx-%#016llx] %#llx bytes, "
1194 			"Dumped: %#llx\n",
1195 			fdm_ptr->hpte_region.destination_address,
1196 			fdm_ptr->hpte_region.destination_address +
1197 			fdm_ptr->hpte_region.source_len - 1,
1198 			fdm_ptr->hpte_region.source_len,
1199 			fdm_ptr->hpte_region.bytes_dumped);
1200 	seq_printf(m,
1201 			"DUMP: [%#016llx-%#016llx] %#llx bytes, "
1202 			"Dumped: %#llx\n",
1203 			fdm_ptr->rmr_region.destination_address,
1204 			fdm_ptr->rmr_region.destination_address +
1205 			fdm_ptr->rmr_region.source_len - 1,
1206 			fdm_ptr->rmr_region.source_len,
1207 			fdm_ptr->rmr_region.bytes_dumped);
1208 
1209 	if (!fdm_active ||
1210 		(fw_dump.reserve_dump_area_start ==
1211 		fdm_ptr->cpu_state_data.destination_address))
1212 		goto out;
1213 
1214 	/* Dump is active. Show reserved memory region. */
1215 	seq_printf(m,
1216 			"    : [%#016llx-%#016llx] %#llx bytes, "
1217 			"Dumped: %#llx\n",
1218 			(unsigned long long)fw_dump.reserve_dump_area_start,
1219 			fdm_ptr->cpu_state_data.destination_address - 1,
1220 			fdm_ptr->cpu_state_data.destination_address -
1221 			fw_dump.reserve_dump_area_start,
1222 			fdm_ptr->cpu_state_data.destination_address -
1223 			fw_dump.reserve_dump_area_start);
1224 out:
1225 	if (fdm_active)
1226 		mutex_unlock(&fadump_mutex);
1227 	return 0;
1228 }
1229 
1230 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1231 						0200, NULL,
1232 						fadump_release_memory_store);
1233 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1234 						0444, fadump_enabled_show,
1235 						NULL);
1236 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1237 						0644, fadump_register_show,
1238 						fadump_register_store);
1239 
1240 static int fadump_region_open(struct inode *inode, struct file *file)
1241 {
1242 	return single_open(file, fadump_region_show, inode->i_private);
1243 }
1244 
1245 static const struct file_operations fadump_region_fops = {
1246 	.open    = fadump_region_open,
1247 	.read    = seq_read,
1248 	.llseek  = seq_lseek,
1249 	.release = single_release,
1250 };
1251 
1252 static void fadump_init_files(void)
1253 {
1254 	struct dentry *debugfs_file;
1255 	int rc = 0;
1256 
1257 	rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1258 	if (rc)
1259 		printk(KERN_ERR "fadump: unable to create sysfs file"
1260 			" fadump_enabled (%d)\n", rc);
1261 
1262 	rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1263 	if (rc)
1264 		printk(KERN_ERR "fadump: unable to create sysfs file"
1265 			" fadump_registered (%d)\n", rc);
1266 
1267 	debugfs_file = debugfs_create_file("fadump_region", 0444,
1268 					powerpc_debugfs_root, NULL,
1269 					&fadump_region_fops);
1270 	if (!debugfs_file)
1271 		printk(KERN_ERR "fadump: unable to create debugfs file"
1272 				" fadump_region\n");
1273 
1274 	if (fw_dump.dump_active) {
1275 		rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1276 		if (rc)
1277 			printk(KERN_ERR "fadump: unable to create sysfs file"
1278 				" fadump_release_mem (%d)\n", rc);
1279 	}
1280 	return;
1281 }
1282 
1283 /*
1284  * Prepare for firmware-assisted dump.
1285  */
1286 int __init setup_fadump(void)
1287 {
1288 	if (!fw_dump.fadump_enabled)
1289 		return 0;
1290 
1291 	if (!fw_dump.fadump_supported) {
1292 		printk(KERN_ERR "Firmware-assisted dump is not supported on"
1293 			" this hardware\n");
1294 		return 0;
1295 	}
1296 
1297 	fadump_show_config();
1298 	/*
1299 	 * If dump data is available then see if it is valid and prepare for
1300 	 * saving it to the disk.
1301 	 */
1302 	if (fw_dump.dump_active) {
1303 		/*
1304 		 * if dump process fails then invalidate the registration
1305 		 * and release memory before proceeding for re-registration.
1306 		 */
1307 		if (process_fadump(fdm_active) < 0)
1308 			fadump_invalidate_release_mem();
1309 	}
1310 	/* Initialize the kernel dump memory structure for FAD registration. */
1311 	else if (fw_dump.reserve_dump_area_size)
1312 		init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1313 	fadump_init_files();
1314 
1315 	return 1;
1316 }
1317 subsys_initcall(setup_fadump);
1318