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 #include <linux/slab.h>
39
40 #include <asm/page.h>
41 #include <asm/prom.h>
42 #include <asm/rtas.h>
43 #include <asm/fadump.h>
44 #include <asm/debug.h>
45 #include <asm/setup.h>
46
47 static struct fw_dump fw_dump;
48 static struct fadump_mem_struct fdm;
49 static const struct fadump_mem_struct *fdm_active;
50
51 static DEFINE_MUTEX(fadump_mutex);
52 struct fad_crash_memory_ranges *crash_memory_ranges;
53 int crash_memory_ranges_size;
54 int crash_mem_ranges;
55 int max_crash_mem_ranges;
56
57 /* Scan the Firmware Assisted dump configuration details. */
early_init_dt_scan_fw_dump(unsigned long node,const char * uname,int depth,void * data)58 int __init early_init_dt_scan_fw_dump(unsigned long node,
59 const char *uname, int depth, void *data)
60 {
61 const __be32 *sections;
62 int i, num_sections;
63 int size;
64 const __be32 *token;
65
66 if (depth != 1 || strcmp(uname, "rtas") != 0)
67 return 0;
68
69 /*
70 * Check if Firmware Assisted dump is supported. if yes, check
71 * if dump has been initiated on last reboot.
72 */
73 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
74 if (!token)
75 return 1;
76
77 fw_dump.fadump_supported = 1;
78 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
79
80 /*
81 * The 'ibm,kernel-dump' rtas node is present only if there is
82 * dump data waiting for us.
83 */
84 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
85 if (fdm_active)
86 fw_dump.dump_active = 1;
87
88 /* Get the sizes required to store dump data for the firmware provided
89 * dump sections.
90 * For each dump section type supported, a 32bit cell which defines
91 * the ID of a supported section followed by two 32 bit cells which
92 * gives teh size of the section in bytes.
93 */
94 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
95 &size);
96
97 if (!sections)
98 return 1;
99
100 num_sections = size / (3 * sizeof(u32));
101
102 for (i = 0; i < num_sections; i++, sections += 3) {
103 u32 type = (u32)of_read_number(sections, 1);
104
105 switch (type) {
106 case FADUMP_CPU_STATE_DATA:
107 fw_dump.cpu_state_data_size =
108 of_read_ulong(§ions[1], 2);
109 break;
110 case FADUMP_HPTE_REGION:
111 fw_dump.hpte_region_size =
112 of_read_ulong(§ions[1], 2);
113 break;
114 }
115 }
116
117 return 1;
118 }
119
is_fadump_active(void)120 int is_fadump_active(void)
121 {
122 return fw_dump.dump_active;
123 }
124
125 /* Print firmware assisted dump configurations for debugging purpose. */
fadump_show_config(void)126 static void fadump_show_config(void)
127 {
128 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
129 (fw_dump.fadump_supported ? "present" : "no support"));
130
131 if (!fw_dump.fadump_supported)
132 return;
133
134 pr_debug("Fadump enabled : %s\n",
135 (fw_dump.fadump_enabled ? "yes" : "no"));
136 pr_debug("Dump Active : %s\n",
137 (fw_dump.dump_active ? "yes" : "no"));
138 pr_debug("Dump section sizes:\n");
139 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
140 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
141 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
142 }
143
init_fadump_mem_struct(struct fadump_mem_struct * fdm,unsigned long addr)144 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
145 unsigned long addr)
146 {
147 if (!fdm)
148 return 0;
149
150 memset(fdm, 0, sizeof(struct fadump_mem_struct));
151 addr = addr & PAGE_MASK;
152
153 fdm->header.dump_format_version = cpu_to_be32(0x00000001);
154 fdm->header.dump_num_sections = cpu_to_be16(3);
155 fdm->header.dump_status_flag = 0;
156 fdm->header.offset_first_dump_section =
157 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
158
159 /*
160 * Fields for disk dump option.
161 * We are not using disk dump option, hence set these fields to 0.
162 */
163 fdm->header.dd_block_size = 0;
164 fdm->header.dd_block_offset = 0;
165 fdm->header.dd_num_blocks = 0;
166 fdm->header.dd_offset_disk_path = 0;
167
168 /* set 0 to disable an automatic dump-reboot. */
169 fdm->header.max_time_auto = 0;
170
171 /* Kernel dump sections */
172 /* cpu state data section. */
173 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
174 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
175 fdm->cpu_state_data.source_address = 0;
176 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
177 fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
178 addr += fw_dump.cpu_state_data_size;
179
180 /* hpte region section */
181 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
182 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
183 fdm->hpte_region.source_address = 0;
184 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
185 fdm->hpte_region.destination_address = cpu_to_be64(addr);
186 addr += fw_dump.hpte_region_size;
187
188 /* RMA region section */
189 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
190 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
191 fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
192 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
193 fdm->rmr_region.destination_address = cpu_to_be64(addr);
194 addr += fw_dump.boot_memory_size;
195
196 return addr;
197 }
198
199 /**
200 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
201 *
202 * Function to find the largest memory size we need to reserve during early
203 * boot process. This will be the size of the memory that is required for a
204 * kernel to boot successfully.
205 *
206 * This function has been taken from phyp-assisted dump feature implementation.
207 *
208 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
209 *
210 * TODO: Come up with better approach to find out more accurate memory size
211 * that is required for a kernel to boot successfully.
212 *
213 */
fadump_calculate_reserve_size(void)214 static inline unsigned long fadump_calculate_reserve_size(void)
215 {
216 unsigned long size;
217
218 /*
219 * Check if the size is specified through fadump_reserve_mem= cmdline
220 * option. If yes, then use that.
221 */
222 if (fw_dump.reserve_bootvar)
223 return fw_dump.reserve_bootvar;
224
225 /* divide by 20 to get 5% of value */
226 size = memblock_end_of_DRAM() / 20;
227
228 /* round it down in multiples of 256 */
229 size = size & ~0x0FFFFFFFUL;
230
231 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
232 if (memory_limit && size > memory_limit)
233 size = memory_limit;
234
235 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
236 }
237
238 /*
239 * Calculate the total memory size required to be reserved for
240 * firmware-assisted dump registration.
241 */
get_fadump_area_size(void)242 static unsigned long get_fadump_area_size(void)
243 {
244 unsigned long size = 0;
245
246 size += fw_dump.cpu_state_data_size;
247 size += fw_dump.hpte_region_size;
248 size += fw_dump.boot_memory_size;
249 size += sizeof(struct fadump_crash_info_header);
250 size += sizeof(struct elfhdr); /* ELF core header.*/
251 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
252 /* Program headers for crash memory regions. */
253 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
254
255 size = PAGE_ALIGN(size);
256 return size;
257 }
258
fadump_reserve_mem(void)259 int __init fadump_reserve_mem(void)
260 {
261 unsigned long base, size, memory_boundary;
262
263 if (!fw_dump.fadump_enabled)
264 return 0;
265
266 if (!fw_dump.fadump_supported) {
267 printk(KERN_INFO "Firmware-assisted dump is not supported on"
268 " this hardware\n");
269 fw_dump.fadump_enabled = 0;
270 return 0;
271 }
272 /*
273 * Initialize boot memory size
274 * If dump is active then we have already calculated the size during
275 * first kernel.
276 */
277 if (fdm_active)
278 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
279 else
280 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
281
282 /*
283 * Calculate the memory boundary.
284 * If memory_limit is less than actual memory boundary then reserve
285 * the memory for fadump beyond the memory_limit and adjust the
286 * memory_limit accordingly, so that the running kernel can run with
287 * specified memory_limit.
288 */
289 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
290 size = get_fadump_area_size();
291 if ((memory_limit + size) < memblock_end_of_DRAM())
292 memory_limit += size;
293 else
294 memory_limit = memblock_end_of_DRAM();
295 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
296 " dump, now %#016llx\n", memory_limit);
297 }
298 if (memory_limit)
299 memory_boundary = memory_limit;
300 else
301 memory_boundary = memblock_end_of_DRAM();
302
303 if (fw_dump.dump_active) {
304 printk(KERN_INFO "Firmware-assisted dump is active.\n");
305 /*
306 * If last boot has crashed then reserve all the memory
307 * above boot_memory_size so that we don't touch it until
308 * dump is written to disk by userspace tool. This memory
309 * will be released for general use once the dump is saved.
310 */
311 base = fw_dump.boot_memory_size;
312 size = memory_boundary - base;
313 memblock_reserve(base, size);
314 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
315 "for saving crash dump\n",
316 (unsigned long)(size >> 20),
317 (unsigned long)(base >> 20));
318
319 fw_dump.fadumphdr_addr =
320 be64_to_cpu(fdm_active->rmr_region.destination_address) +
321 be64_to_cpu(fdm_active->rmr_region.source_len);
322 pr_debug("fadumphdr_addr = %p\n",
323 (void *) fw_dump.fadumphdr_addr);
324 } else {
325 /* Reserve the memory at the top of memory. */
326 size = get_fadump_area_size();
327 base = memory_boundary - size;
328 memblock_reserve(base, size);
329 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
330 "for firmware-assisted dump\n",
331 (unsigned long)(size >> 20),
332 (unsigned long)(base >> 20));
333 }
334 fw_dump.reserve_dump_area_start = base;
335 fw_dump.reserve_dump_area_size = size;
336 return 1;
337 }
338
339 /* Look for fadump= cmdline option. */
early_fadump_param(char * p)340 static int __init early_fadump_param(char *p)
341 {
342 if (!p)
343 return 1;
344
345 if (strncmp(p, "on", 2) == 0)
346 fw_dump.fadump_enabled = 1;
347 else if (strncmp(p, "off", 3) == 0)
348 fw_dump.fadump_enabled = 0;
349
350 return 0;
351 }
352 early_param("fadump", early_fadump_param);
353
354 /* Look for fadump_reserve_mem= cmdline option */
early_fadump_reserve_mem(char * p)355 static int __init early_fadump_reserve_mem(char *p)
356 {
357 if (p)
358 fw_dump.reserve_bootvar = memparse(p, &p);
359 return 0;
360 }
361 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
362
register_fw_dump(struct fadump_mem_struct * fdm)363 static int register_fw_dump(struct fadump_mem_struct *fdm)
364 {
365 int rc, err;
366 unsigned int wait_time;
367
368 pr_debug("Registering for firmware-assisted kernel dump...\n");
369
370 /* TODO: Add upper time limit for the delay */
371 do {
372 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
373 FADUMP_REGISTER, fdm,
374 sizeof(struct fadump_mem_struct));
375
376 wait_time = rtas_busy_delay_time(rc);
377 if (wait_time)
378 mdelay(wait_time);
379
380 } while (wait_time);
381
382 err = -EIO;
383 switch (rc) {
384 default:
385 pr_err("Failed to register. Unknown Error(%d).\n", rc);
386 break;
387 case -1:
388 printk(KERN_ERR "Failed to register firmware-assisted kernel"
389 " dump. Hardware Error(%d).\n", rc);
390 break;
391 case -3:
392 printk(KERN_ERR "Failed to register firmware-assisted kernel"
393 " dump. Parameter Error(%d).\n", rc);
394 err = -EINVAL;
395 break;
396 case -9:
397 printk(KERN_ERR "firmware-assisted kernel dump is already "
398 " registered.");
399 fw_dump.dump_registered = 1;
400 err = -EEXIST;
401 break;
402 case 0:
403 printk(KERN_INFO "firmware-assisted kernel dump registration"
404 " is successful\n");
405 fw_dump.dump_registered = 1;
406 err = 0;
407 break;
408 }
409 return err;
410 }
411
crash_fadump(struct pt_regs * regs,const char * str)412 void crash_fadump(struct pt_regs *regs, const char *str)
413 {
414 struct fadump_crash_info_header *fdh = NULL;
415
416 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
417 return;
418
419 fdh = __va(fw_dump.fadumphdr_addr);
420 crashing_cpu = smp_processor_id();
421 fdh->crashing_cpu = crashing_cpu;
422 crash_save_vmcoreinfo();
423
424 if (regs)
425 fdh->regs = *regs;
426 else
427 ppc_save_regs(&fdh->regs);
428
429 fdh->cpu_online_mask = *cpu_online_mask;
430
431 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
432 rtas_os_term((char *)str);
433 }
434
435 #define GPR_MASK 0xffffff0000000000
fadump_gpr_index(u64 id)436 static inline int fadump_gpr_index(u64 id)
437 {
438 int i = -1;
439 char str[3];
440
441 if ((id & GPR_MASK) == REG_ID("GPR")) {
442 /* get the digits at the end */
443 id &= ~GPR_MASK;
444 id >>= 24;
445 str[2] = '\0';
446 str[1] = id & 0xff;
447 str[0] = (id >> 8) & 0xff;
448 sscanf(str, "%d", &i);
449 if (i > 31)
450 i = -1;
451 }
452 return i;
453 }
454
fadump_set_regval(struct pt_regs * regs,u64 reg_id,u64 reg_val)455 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
456 u64 reg_val)
457 {
458 int i;
459
460 i = fadump_gpr_index(reg_id);
461 if (i >= 0)
462 regs->gpr[i] = (unsigned long)reg_val;
463 else if (reg_id == REG_ID("NIA"))
464 regs->nip = (unsigned long)reg_val;
465 else if (reg_id == REG_ID("MSR"))
466 regs->msr = (unsigned long)reg_val;
467 else if (reg_id == REG_ID("CTR"))
468 regs->ctr = (unsigned long)reg_val;
469 else if (reg_id == REG_ID("LR"))
470 regs->link = (unsigned long)reg_val;
471 else if (reg_id == REG_ID("XER"))
472 regs->xer = (unsigned long)reg_val;
473 else if (reg_id == REG_ID("CR"))
474 regs->ccr = (unsigned long)reg_val;
475 else if (reg_id == REG_ID("DAR"))
476 regs->dar = (unsigned long)reg_val;
477 else if (reg_id == REG_ID("DSISR"))
478 regs->dsisr = (unsigned long)reg_val;
479 }
480
481 static struct fadump_reg_entry*
fadump_read_registers(struct fadump_reg_entry * reg_entry,struct pt_regs * regs)482 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
483 {
484 memset(regs, 0, sizeof(struct pt_regs));
485
486 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
487 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
488 be64_to_cpu(reg_entry->reg_value));
489 reg_entry++;
490 }
491 reg_entry++;
492 return reg_entry;
493 }
494
fadump_append_elf_note(u32 * buf,char * name,unsigned type,void * data,size_t data_len)495 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
496 void *data, size_t data_len)
497 {
498 struct elf_note note;
499
500 note.n_namesz = strlen(name) + 1;
501 note.n_descsz = data_len;
502 note.n_type = type;
503 memcpy(buf, ¬e, sizeof(note));
504 buf += (sizeof(note) + 3)/4;
505 memcpy(buf, name, note.n_namesz);
506 buf += (note.n_namesz + 3)/4;
507 memcpy(buf, data, note.n_descsz);
508 buf += (note.n_descsz + 3)/4;
509
510 return buf;
511 }
512
fadump_final_note(u32 * buf)513 static void fadump_final_note(u32 *buf)
514 {
515 struct elf_note note;
516
517 note.n_namesz = 0;
518 note.n_descsz = 0;
519 note.n_type = 0;
520 memcpy(buf, ¬e, sizeof(note));
521 }
522
fadump_regs_to_elf_notes(u32 * buf,struct pt_regs * regs)523 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
524 {
525 struct elf_prstatus prstatus;
526
527 memset(&prstatus, 0, sizeof(prstatus));
528 /*
529 * FIXME: How do i get PID? Do I really need it?
530 * prstatus.pr_pid = ????
531 */
532 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
533 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
534 &prstatus, sizeof(prstatus));
535 return buf;
536 }
537
fadump_update_elfcore_header(char * bufp)538 static void fadump_update_elfcore_header(char *bufp)
539 {
540 struct elfhdr *elf;
541 struct elf_phdr *phdr;
542
543 elf = (struct elfhdr *)bufp;
544 bufp += sizeof(struct elfhdr);
545
546 /* First note is a place holder for cpu notes info. */
547 phdr = (struct elf_phdr *)bufp;
548
549 if (phdr->p_type == PT_NOTE) {
550 phdr->p_paddr = fw_dump.cpu_notes_buf;
551 phdr->p_offset = phdr->p_paddr;
552 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
553 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
554 }
555 return;
556 }
557
fadump_cpu_notes_buf_alloc(unsigned long size)558 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
559 {
560 void *vaddr;
561 struct page *page;
562 unsigned long order, count, i;
563
564 order = get_order(size);
565 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
566 if (!vaddr)
567 return NULL;
568
569 count = 1 << order;
570 page = virt_to_page(vaddr);
571 for (i = 0; i < count; i++)
572 SetPageReserved(page + i);
573 return vaddr;
574 }
575
fadump_cpu_notes_buf_free(unsigned long vaddr,unsigned long size)576 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
577 {
578 struct page *page;
579 unsigned long order, count, i;
580
581 order = get_order(size);
582 count = 1 << order;
583 page = virt_to_page(vaddr);
584 for (i = 0; i < count; i++)
585 ClearPageReserved(page + i);
586 __free_pages(page, order);
587 }
588
589 /*
590 * Read CPU state dump data and convert it into ELF notes.
591 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
592 * used to access the data to allow for additional fields to be added without
593 * affecting compatibility. Each list of registers for a CPU starts with
594 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
595 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
596 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
597 * of register value. For more details refer to PAPR document.
598 *
599 * Only for the crashing cpu we ignore the CPU dump data and get exact
600 * state from fadump crash info structure populated by first kernel at the
601 * time of crash.
602 */
fadump_build_cpu_notes(const struct fadump_mem_struct * fdm)603 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
604 {
605 struct fadump_reg_save_area_header *reg_header;
606 struct fadump_reg_entry *reg_entry;
607 struct fadump_crash_info_header *fdh = NULL;
608 void *vaddr;
609 unsigned long addr;
610 u32 num_cpus, *note_buf;
611 struct pt_regs regs;
612 int i, rc = 0, cpu = 0;
613
614 if (!fdm->cpu_state_data.bytes_dumped)
615 return -EINVAL;
616
617 addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
618 vaddr = __va(addr);
619
620 reg_header = vaddr;
621 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
622 printk(KERN_ERR "Unable to read register save area.\n");
623 return -ENOENT;
624 }
625 pr_debug("--------CPU State Data------------\n");
626 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
627 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
628
629 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
630 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
631 pr_debug("NumCpus : %u\n", num_cpus);
632 vaddr += sizeof(u32);
633 reg_entry = (struct fadump_reg_entry *)vaddr;
634
635 /* Allocate buffer to hold cpu crash notes. */
636 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
637 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
638 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
639 if (!note_buf) {
640 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
641 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
642 return -ENOMEM;
643 }
644 fw_dump.cpu_notes_buf = __pa(note_buf);
645
646 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
647 (num_cpus * sizeof(note_buf_t)), note_buf);
648
649 if (fw_dump.fadumphdr_addr)
650 fdh = __va(fw_dump.fadumphdr_addr);
651
652 for (i = 0; i < num_cpus; i++) {
653 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
654 printk(KERN_ERR "Unable to read CPU state data\n");
655 rc = -ENOENT;
656 goto error_out;
657 }
658 /* Lower 4 bytes of reg_value contains logical cpu id */
659 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
660 if (fdh && !cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
661 SKIP_TO_NEXT_CPU(reg_entry);
662 continue;
663 }
664 pr_debug("Reading register data for cpu %d...\n", cpu);
665 if (fdh && fdh->crashing_cpu == cpu) {
666 regs = fdh->regs;
667 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
668 SKIP_TO_NEXT_CPU(reg_entry);
669 } else {
670 reg_entry++;
671 reg_entry = fadump_read_registers(reg_entry, ®s);
672 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
673 }
674 }
675 fadump_final_note(note_buf);
676
677 if (fdh) {
678 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
679 fdh->elfcorehdr_addr);
680 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
681 }
682 return 0;
683
684 error_out:
685 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
686 fw_dump.cpu_notes_buf_size);
687 fw_dump.cpu_notes_buf = 0;
688 fw_dump.cpu_notes_buf_size = 0;
689 return rc;
690
691 }
692
693 /*
694 * Validate and process the dump data stored by firmware before exporting
695 * it through '/proc/vmcore'.
696 */
process_fadump(const struct fadump_mem_struct * fdm_active)697 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
698 {
699 struct fadump_crash_info_header *fdh;
700 int rc = 0;
701
702 if (!fdm_active || !fw_dump.fadumphdr_addr)
703 return -EINVAL;
704
705 /* Check if the dump data is valid. */
706 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
707 (fdm_active->cpu_state_data.error_flags != 0) ||
708 (fdm_active->rmr_region.error_flags != 0)) {
709 printk(KERN_ERR "Dump taken by platform is not valid\n");
710 return -EINVAL;
711 }
712 if ((fdm_active->rmr_region.bytes_dumped !=
713 fdm_active->rmr_region.source_len) ||
714 !fdm_active->cpu_state_data.bytes_dumped) {
715 printk(KERN_ERR "Dump taken by platform is incomplete\n");
716 return -EINVAL;
717 }
718
719 /* Validate the fadump crash info header */
720 fdh = __va(fw_dump.fadumphdr_addr);
721 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
722 printk(KERN_ERR "Crash info header is not valid.\n");
723 return -EINVAL;
724 }
725
726 rc = fadump_build_cpu_notes(fdm_active);
727 if (rc)
728 return rc;
729
730 /*
731 * We are done validating dump info and elfcore header is now ready
732 * to be exported. set elfcorehdr_addr so that vmcore module will
733 * export the elfcore header through '/proc/vmcore'.
734 */
735 elfcorehdr_addr = fdh->elfcorehdr_addr;
736
737 return 0;
738 }
739
free_crash_memory_ranges(void)740 static void free_crash_memory_ranges(void)
741 {
742 kfree(crash_memory_ranges);
743 crash_memory_ranges = NULL;
744 crash_memory_ranges_size = 0;
745 max_crash_mem_ranges = 0;
746 }
747
748 /*
749 * Allocate or reallocate crash memory ranges array in incremental units
750 * of PAGE_SIZE.
751 */
allocate_crash_memory_ranges(void)752 static int allocate_crash_memory_ranges(void)
753 {
754 struct fad_crash_memory_ranges *new_array;
755 u64 new_size;
756
757 new_size = crash_memory_ranges_size + PAGE_SIZE;
758 pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
759 new_size);
760
761 new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
762 if (new_array == NULL) {
763 pr_err("Insufficient memory for setting up crash memory ranges\n");
764 free_crash_memory_ranges();
765 return -ENOMEM;
766 }
767
768 crash_memory_ranges = new_array;
769 crash_memory_ranges_size = new_size;
770 max_crash_mem_ranges = (new_size /
771 sizeof(struct fad_crash_memory_ranges));
772 return 0;
773 }
774
fadump_add_crash_memory(unsigned long long base,unsigned long long end)775 static inline int fadump_add_crash_memory(unsigned long long base,
776 unsigned long long end)
777 {
778 if (base == end)
779 return 0;
780
781 if (crash_mem_ranges == max_crash_mem_ranges) {
782 int ret;
783
784 ret = allocate_crash_memory_ranges();
785 if (ret)
786 return ret;
787 }
788
789 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
790 crash_mem_ranges, base, end - 1, (end - base));
791 crash_memory_ranges[crash_mem_ranges].base = base;
792 crash_memory_ranges[crash_mem_ranges].size = end - base;
793 crash_mem_ranges++;
794 return 0;
795 }
796
fadump_exclude_reserved_area(unsigned long long start,unsigned long long end)797 static int fadump_exclude_reserved_area(unsigned long long start,
798 unsigned long long end)
799 {
800 unsigned long long ra_start, ra_end;
801 int ret = 0;
802
803 ra_start = fw_dump.reserve_dump_area_start;
804 ra_end = ra_start + fw_dump.reserve_dump_area_size;
805
806 if ((ra_start < end) && (ra_end > start)) {
807 if ((start < ra_start) && (end > ra_end)) {
808 ret = fadump_add_crash_memory(start, ra_start);
809 if (ret)
810 return ret;
811
812 ret = fadump_add_crash_memory(ra_end, end);
813 } else if (start < ra_start) {
814 ret = fadump_add_crash_memory(start, ra_start);
815 } else if (ra_end < end) {
816 ret = fadump_add_crash_memory(ra_end, end);
817 }
818 } else
819 ret = fadump_add_crash_memory(start, end);
820
821 return ret;
822 }
823
fadump_init_elfcore_header(char * bufp)824 static int fadump_init_elfcore_header(char *bufp)
825 {
826 struct elfhdr *elf;
827
828 elf = (struct elfhdr *) bufp;
829 bufp += sizeof(struct elfhdr);
830 memcpy(elf->e_ident, ELFMAG, SELFMAG);
831 elf->e_ident[EI_CLASS] = ELF_CLASS;
832 elf->e_ident[EI_DATA] = ELF_DATA;
833 elf->e_ident[EI_VERSION] = EV_CURRENT;
834 elf->e_ident[EI_OSABI] = ELF_OSABI;
835 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
836 elf->e_type = ET_CORE;
837 elf->e_machine = ELF_ARCH;
838 elf->e_version = EV_CURRENT;
839 elf->e_entry = 0;
840 elf->e_phoff = sizeof(struct elfhdr);
841 elf->e_shoff = 0;
842 elf->e_flags = ELF_CORE_EFLAGS;
843 elf->e_ehsize = sizeof(struct elfhdr);
844 elf->e_phentsize = sizeof(struct elf_phdr);
845 elf->e_phnum = 0;
846 elf->e_shentsize = 0;
847 elf->e_shnum = 0;
848 elf->e_shstrndx = 0;
849
850 return 0;
851 }
852
853 /*
854 * Traverse through memblock structure and setup crash memory ranges. These
855 * ranges will be used create PT_LOAD program headers in elfcore header.
856 */
fadump_setup_crash_memory_ranges(void)857 static int fadump_setup_crash_memory_ranges(void)
858 {
859 struct memblock_region *reg;
860 unsigned long long start, end;
861 int ret;
862
863 pr_debug("Setup crash memory ranges.\n");
864 crash_mem_ranges = 0;
865 /*
866 * add the first memory chunk (RMA_START through boot_memory_size) as
867 * a separate memory chunk. The reason is, at the time crash firmware
868 * will move the content of this memory chunk to different location
869 * specified during fadump registration. We need to create a separate
870 * program header for this chunk with the correct offset.
871 */
872 ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
873 if (ret)
874 return ret;
875
876 for_each_memblock(memory, reg) {
877 start = (unsigned long long)reg->base;
878 end = start + (unsigned long long)reg->size;
879 if (start == RMA_START && end >= fw_dump.boot_memory_size)
880 start = fw_dump.boot_memory_size;
881
882 /* add this range excluding the reserved dump area. */
883 ret = fadump_exclude_reserved_area(start, end);
884 if (ret)
885 return ret;
886 }
887
888 return 0;
889 }
890
891 /*
892 * If the given physical address falls within the boot memory region then
893 * return the relocated address that points to the dump region reserved
894 * for saving initial boot memory contents.
895 */
fadump_relocate(unsigned long paddr)896 static inline unsigned long fadump_relocate(unsigned long paddr)
897 {
898 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
899 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
900 else
901 return paddr;
902 }
903
fadump_create_elfcore_headers(char * bufp)904 static int fadump_create_elfcore_headers(char *bufp)
905 {
906 struct elfhdr *elf;
907 struct elf_phdr *phdr;
908 int i;
909
910 fadump_init_elfcore_header(bufp);
911 elf = (struct elfhdr *)bufp;
912 bufp += sizeof(struct elfhdr);
913
914 /*
915 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
916 * will be populated during second kernel boot after crash. Hence
917 * this PT_NOTE will always be the first elf note.
918 *
919 * NOTE: Any new ELF note addition should be placed after this note.
920 */
921 phdr = (struct elf_phdr *)bufp;
922 bufp += sizeof(struct elf_phdr);
923 phdr->p_type = PT_NOTE;
924 phdr->p_flags = 0;
925 phdr->p_vaddr = 0;
926 phdr->p_align = 0;
927
928 phdr->p_offset = 0;
929 phdr->p_paddr = 0;
930 phdr->p_filesz = 0;
931 phdr->p_memsz = 0;
932
933 (elf->e_phnum)++;
934
935 /* setup ELF PT_NOTE for vmcoreinfo */
936 phdr = (struct elf_phdr *)bufp;
937 bufp += sizeof(struct elf_phdr);
938 phdr->p_type = PT_NOTE;
939 phdr->p_flags = 0;
940 phdr->p_vaddr = 0;
941 phdr->p_align = 0;
942
943 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
944 phdr->p_offset = phdr->p_paddr;
945 phdr->p_memsz = vmcoreinfo_max_size;
946 phdr->p_filesz = vmcoreinfo_max_size;
947
948 /* Increment number of program headers. */
949 (elf->e_phnum)++;
950
951 /* setup PT_LOAD sections. */
952
953 for (i = 0; i < crash_mem_ranges; i++) {
954 unsigned long long mbase, msize;
955 mbase = crash_memory_ranges[i].base;
956 msize = crash_memory_ranges[i].size;
957
958 if (!msize)
959 continue;
960
961 phdr = (struct elf_phdr *)bufp;
962 bufp += sizeof(struct elf_phdr);
963 phdr->p_type = PT_LOAD;
964 phdr->p_flags = PF_R|PF_W|PF_X;
965 phdr->p_offset = mbase;
966
967 if (mbase == RMA_START) {
968 /*
969 * The entire RMA region will be moved by firmware
970 * to the specified destination_address. Hence set
971 * the correct offset.
972 */
973 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
974 }
975
976 phdr->p_paddr = mbase;
977 phdr->p_vaddr = (unsigned long)__va(mbase);
978 phdr->p_filesz = msize;
979 phdr->p_memsz = msize;
980 phdr->p_align = 0;
981
982 /* Increment number of program headers. */
983 (elf->e_phnum)++;
984 }
985 return 0;
986 }
987
init_fadump_header(unsigned long addr)988 static unsigned long init_fadump_header(unsigned long addr)
989 {
990 struct fadump_crash_info_header *fdh;
991
992 if (!addr)
993 return 0;
994
995 fw_dump.fadumphdr_addr = addr;
996 fdh = __va(addr);
997 addr += sizeof(struct fadump_crash_info_header);
998
999 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1000 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1001 fdh->elfcorehdr_addr = addr;
1002 /* We will set the crashing cpu id in crash_fadump() during crash. */
1003 fdh->crashing_cpu = CPU_UNKNOWN;
1004
1005 return addr;
1006 }
1007
register_fadump(void)1008 static int register_fadump(void)
1009 {
1010 unsigned long addr;
1011 void *vaddr;
1012 int ret;
1013
1014 /*
1015 * If no memory is reserved then we can not register for firmware-
1016 * assisted dump.
1017 */
1018 if (!fw_dump.reserve_dump_area_size)
1019 return -ENODEV;
1020
1021 ret = fadump_setup_crash_memory_ranges();
1022 if (ret)
1023 return ret;
1024
1025 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1026 /* Initialize fadump crash info header. */
1027 addr = init_fadump_header(addr);
1028 vaddr = __va(addr);
1029
1030 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1031 fadump_create_elfcore_headers(vaddr);
1032
1033 /* register the future kernel dump with firmware. */
1034 return register_fw_dump(&fdm);
1035 }
1036
fadump_unregister_dump(struct fadump_mem_struct * fdm)1037 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1038 {
1039 int rc = 0;
1040 unsigned int wait_time;
1041
1042 pr_debug("Un-register firmware-assisted dump\n");
1043
1044 /* TODO: Add upper time limit for the delay */
1045 do {
1046 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1047 FADUMP_UNREGISTER, fdm,
1048 sizeof(struct fadump_mem_struct));
1049
1050 wait_time = rtas_busy_delay_time(rc);
1051 if (wait_time)
1052 mdelay(wait_time);
1053 } while (wait_time);
1054
1055 if (rc) {
1056 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1057 " unexpected error(%d).\n", rc);
1058 return rc;
1059 }
1060 fw_dump.dump_registered = 0;
1061 return 0;
1062 }
1063
fadump_invalidate_dump(struct fadump_mem_struct * fdm)1064 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1065 {
1066 int rc = 0;
1067 unsigned int wait_time;
1068
1069 pr_debug("Invalidating firmware-assisted dump registration\n");
1070
1071 /* TODO: Add upper time limit for the delay */
1072 do {
1073 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1074 FADUMP_INVALIDATE, fdm,
1075 sizeof(struct fadump_mem_struct));
1076
1077 wait_time = rtas_busy_delay_time(rc);
1078 if (wait_time)
1079 mdelay(wait_time);
1080 } while (wait_time);
1081
1082 if (rc) {
1083 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1084 "rgistration. unexpected error(%d).\n", rc);
1085 return rc;
1086 }
1087 fw_dump.dump_active = 0;
1088 fdm_active = NULL;
1089 return 0;
1090 }
1091
fadump_cleanup(void)1092 void fadump_cleanup(void)
1093 {
1094 /* Invalidate the registration only if dump is active. */
1095 if (fw_dump.dump_active) {
1096 init_fadump_mem_struct(&fdm,
1097 be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1098 fadump_invalidate_dump(&fdm);
1099 } else if (fw_dump.dump_registered) {
1100 /* Un-register Firmware-assisted dump if it was registered. */
1101 fadump_unregister_dump(&fdm);
1102 free_crash_memory_ranges();
1103 }
1104 }
1105
1106 /*
1107 * Release the memory that was reserved in early boot to preserve the memory
1108 * contents. The released memory will be available for general use.
1109 */
fadump_release_memory(unsigned long begin,unsigned long end)1110 static void fadump_release_memory(unsigned long begin, unsigned long end)
1111 {
1112 unsigned long addr;
1113 unsigned long ra_start, ra_end;
1114
1115 ra_start = fw_dump.reserve_dump_area_start;
1116 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1117
1118 for (addr = begin; addr < end; addr += PAGE_SIZE) {
1119 /*
1120 * exclude the dump reserve area. Will reuse it for next
1121 * fadump registration.
1122 */
1123 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1124 continue;
1125
1126 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1127 }
1128 }
1129
fadump_invalidate_release_mem(void)1130 static void fadump_invalidate_release_mem(void)
1131 {
1132 unsigned long reserved_area_start, reserved_area_end;
1133 unsigned long destination_address;
1134
1135 mutex_lock(&fadump_mutex);
1136 if (!fw_dump.dump_active) {
1137 mutex_unlock(&fadump_mutex);
1138 return;
1139 }
1140
1141 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1142 fadump_cleanup();
1143 mutex_unlock(&fadump_mutex);
1144
1145 /*
1146 * Save the current reserved memory bounds we will require them
1147 * later for releasing the memory for general use.
1148 */
1149 reserved_area_start = fw_dump.reserve_dump_area_start;
1150 reserved_area_end = reserved_area_start +
1151 fw_dump.reserve_dump_area_size;
1152 /*
1153 * Setup reserve_dump_area_start and its size so that we can
1154 * reuse this reserved memory for Re-registration.
1155 */
1156 fw_dump.reserve_dump_area_start = destination_address;
1157 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1158
1159 fadump_release_memory(reserved_area_start, reserved_area_end);
1160 if (fw_dump.cpu_notes_buf) {
1161 fadump_cpu_notes_buf_free(
1162 (unsigned long)__va(fw_dump.cpu_notes_buf),
1163 fw_dump.cpu_notes_buf_size);
1164 fw_dump.cpu_notes_buf = 0;
1165 fw_dump.cpu_notes_buf_size = 0;
1166 }
1167 /* Initialize the kernel dump memory structure for FAD registration. */
1168 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1169 }
1170
fadump_release_memory_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)1171 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1172 struct kobj_attribute *attr,
1173 const char *buf, size_t count)
1174 {
1175 if (!fw_dump.dump_active)
1176 return -EPERM;
1177
1178 if (buf[0] == '1') {
1179 /*
1180 * Take away the '/proc/vmcore'. We are releasing the dump
1181 * memory, hence it will not be valid anymore.
1182 */
1183 vmcore_cleanup();
1184 fadump_invalidate_release_mem();
1185
1186 } else
1187 return -EINVAL;
1188 return count;
1189 }
1190
fadump_enabled_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1191 static ssize_t fadump_enabled_show(struct kobject *kobj,
1192 struct kobj_attribute *attr,
1193 char *buf)
1194 {
1195 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1196 }
1197
fadump_register_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)1198 static ssize_t fadump_register_show(struct kobject *kobj,
1199 struct kobj_attribute *attr,
1200 char *buf)
1201 {
1202 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1203 }
1204
fadump_register_store(struct kobject * kobj,struct kobj_attribute * attr,const char * buf,size_t count)1205 static ssize_t fadump_register_store(struct kobject *kobj,
1206 struct kobj_attribute *attr,
1207 const char *buf, size_t count)
1208 {
1209 int ret = 0;
1210
1211 if (!fw_dump.fadump_enabled || fdm_active)
1212 return -EPERM;
1213
1214 mutex_lock(&fadump_mutex);
1215
1216 switch (buf[0]) {
1217 case '0':
1218 if (fw_dump.dump_registered == 0) {
1219 goto unlock_out;
1220 }
1221 /* Un-register Firmware-assisted dump */
1222 fadump_unregister_dump(&fdm);
1223 break;
1224 case '1':
1225 if (fw_dump.dump_registered == 1) {
1226 ret = -EEXIST;
1227 goto unlock_out;
1228 }
1229 /* Register Firmware-assisted dump */
1230 ret = register_fadump();
1231 break;
1232 default:
1233 ret = -EINVAL;
1234 break;
1235 }
1236
1237 unlock_out:
1238 mutex_unlock(&fadump_mutex);
1239 return ret < 0 ? ret : count;
1240 }
1241
fadump_region_show(struct seq_file * m,void * private)1242 static int fadump_region_show(struct seq_file *m, void *private)
1243 {
1244 const struct fadump_mem_struct *fdm_ptr;
1245
1246 if (!fw_dump.fadump_enabled)
1247 return 0;
1248
1249 mutex_lock(&fadump_mutex);
1250 if (fdm_active)
1251 fdm_ptr = fdm_active;
1252 else {
1253 mutex_unlock(&fadump_mutex);
1254 fdm_ptr = &fdm;
1255 }
1256
1257 seq_printf(m,
1258 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1259 "Dumped: %#llx\n",
1260 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1261 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1262 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1263 be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1264 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1265 seq_printf(m,
1266 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1267 "Dumped: %#llx\n",
1268 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1269 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1270 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1271 be64_to_cpu(fdm_ptr->hpte_region.source_len),
1272 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1273 seq_printf(m,
1274 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1275 "Dumped: %#llx\n",
1276 be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1277 be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1278 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1279 be64_to_cpu(fdm_ptr->rmr_region.source_len),
1280 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1281
1282 if (!fdm_active ||
1283 (fw_dump.reserve_dump_area_start ==
1284 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1285 goto out;
1286
1287 /* Dump is active. Show reserved memory region. */
1288 seq_printf(m,
1289 " : [%#016llx-%#016llx] %#llx bytes, "
1290 "Dumped: %#llx\n",
1291 (unsigned long long)fw_dump.reserve_dump_area_start,
1292 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1293 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1294 fw_dump.reserve_dump_area_start,
1295 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1296 fw_dump.reserve_dump_area_start);
1297 out:
1298 if (fdm_active)
1299 mutex_unlock(&fadump_mutex);
1300 return 0;
1301 }
1302
1303 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1304 0200, NULL,
1305 fadump_release_memory_store);
1306 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1307 0444, fadump_enabled_show,
1308 NULL);
1309 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1310 0644, fadump_register_show,
1311 fadump_register_store);
1312
fadump_region_open(struct inode * inode,struct file * file)1313 static int fadump_region_open(struct inode *inode, struct file *file)
1314 {
1315 return single_open(file, fadump_region_show, inode->i_private);
1316 }
1317
1318 static const struct file_operations fadump_region_fops = {
1319 .open = fadump_region_open,
1320 .read = seq_read,
1321 .llseek = seq_lseek,
1322 .release = single_release,
1323 };
1324
fadump_init_files(void)1325 static void fadump_init_files(void)
1326 {
1327 struct dentry *debugfs_file;
1328 int rc = 0;
1329
1330 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1331 if (rc)
1332 printk(KERN_ERR "fadump: unable to create sysfs file"
1333 " fadump_enabled (%d)\n", rc);
1334
1335 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1336 if (rc)
1337 printk(KERN_ERR "fadump: unable to create sysfs file"
1338 " fadump_registered (%d)\n", rc);
1339
1340 debugfs_file = debugfs_create_file("fadump_region", 0444,
1341 powerpc_debugfs_root, NULL,
1342 &fadump_region_fops);
1343 if (!debugfs_file)
1344 printk(KERN_ERR "fadump: unable to create debugfs file"
1345 " fadump_region\n");
1346
1347 if (fw_dump.dump_active) {
1348 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1349 if (rc)
1350 printk(KERN_ERR "fadump: unable to create sysfs file"
1351 " fadump_release_mem (%d)\n", rc);
1352 }
1353 return;
1354 }
1355
1356 /*
1357 * Prepare for firmware-assisted dump.
1358 */
setup_fadump(void)1359 int __init setup_fadump(void)
1360 {
1361 if (!fw_dump.fadump_enabled)
1362 return 0;
1363
1364 if (!fw_dump.fadump_supported) {
1365 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1366 " this hardware\n");
1367 return 0;
1368 }
1369
1370 fadump_show_config();
1371 /*
1372 * If dump data is available then see if it is valid and prepare for
1373 * saving it to the disk.
1374 */
1375 if (fw_dump.dump_active) {
1376 /*
1377 * if dump process fails then invalidate the registration
1378 * and release memory before proceeding for re-registration.
1379 */
1380 if (process_fadump(fdm_active) < 0)
1381 fadump_invalidate_release_mem();
1382 }
1383 /* Initialize the kernel dump memory structure for FAD registration. */
1384 else if (fw_dump.reserve_dump_area_size)
1385 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1386 fadump_init_files();
1387
1388 return 1;
1389 }
1390 subsys_initcall(setup_fadump);
1391