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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/seq_file.h>
34#include <linux/crash_dump.h>
35#include <linux/kobject.h>
36#include <linux/sysfs.h>
37
38#include <asm/debugfs.h>
39#include <asm/page.h>
40#include <asm/prom.h>
41#include <asm/rtas.h>
42#include <asm/fadump.h>
43#include <asm/setup.h>
44
45static struct fw_dump fw_dump;
46static struct fadump_mem_struct fdm;
47static const struct fadump_mem_struct *fdm_active;
48
49static DEFINE_MUTEX(fadump_mutex);
50struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
51int crash_mem_ranges;
52
53/* Scan the Firmware Assisted dump configuration details. */
54int __init early_init_dt_scan_fw_dump(unsigned long node,
55 const char *uname, int depth, void *data)
56{
57 const __be32 *sections;
58 int i, num_sections;
59 int size;
60 const __be32 *token;
61
62 if (depth != 1 || strcmp(uname, "rtas") != 0)
63 return 0;
64
65 /*
66 * Check if Firmware Assisted dump is supported. if yes, check
67 * if dump has been initiated on last reboot.
68 */
69 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
70 if (!token)
71 return 1;
72
73 fw_dump.fadump_supported = 1;
74 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
75
76 /*
77 * The 'ibm,kernel-dump' rtas node is present only if there is
78 * dump data waiting for us.
79 */
80 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
81 if (fdm_active)
82 fw_dump.dump_active = 1;
83
84 /* Get the sizes required to store dump data for the firmware provided
85 * dump sections.
86 * For each dump section type supported, a 32bit cell which defines
87 * the ID of a supported section followed by two 32 bit cells which
88 * gives teh size of the section in bytes.
89 */
90 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
91 &size);
92
93 if (!sections)
94 return 1;
95
96 num_sections = size / (3 * sizeof(u32));
97
98 for (i = 0; i < num_sections; i++, sections += 3) {
99 u32 type = (u32)of_read_number(sections, 1);
100
101 switch (type) {
102 case FADUMP_CPU_STATE_DATA:
103 fw_dump.cpu_state_data_size =
104 of_read_ulong(§ions[1], 2);
105 break;
106 case FADUMP_HPTE_REGION:
107 fw_dump.hpte_region_size =
108 of_read_ulong(§ions[1], 2);
109 break;
110 }
111 }
112
113 return 1;
114}
115
116/*
117 * If fadump is registered, check if the memory provided
118 * falls within boot memory area.
119 */
120int is_fadump_boot_memory_area(u64 addr, ulong size)
121{
122 if (!fw_dump.dump_registered)
123 return 0;
124
125 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size;
126}
127
128int should_fadump_crash(void)
129{
130 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
131 return 0;
132 return 1;
133}
134
135int is_fadump_active(void)
136{
137 return fw_dump.dump_active;
138}
139
140/*
141 * Returns 1, if there are no holes in boot memory area,
142 * 0 otherwise.
143 */
144static int is_boot_memory_area_contiguous(void)
145{
146 struct memblock_region *reg;
147 unsigned long tstart, tend;
148 unsigned long start_pfn = PHYS_PFN(RMA_START);
149 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size);
150 unsigned int ret = 0;
151
152 for_each_memblock(memory, reg) {
153 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
154 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
155 if (tstart < tend) {
156 /* Memory hole from start_pfn to tstart */
157 if (tstart > start_pfn)
158 break;
159
160 if (tend == end_pfn) {
161 ret = 1;
162 break;
163 }
164
165 start_pfn = tend + 1;
166 }
167 }
168
169 return ret;
170}
171
172/* Print firmware assisted dump configurations for debugging purpose. */
173static void fadump_show_config(void)
174{
175 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
176 (fw_dump.fadump_supported ? "present" : "no support"));
177
178 if (!fw_dump.fadump_supported)
179 return;
180
181 pr_debug("Fadump enabled : %s\n",
182 (fw_dump.fadump_enabled ? "yes" : "no"));
183 pr_debug("Dump Active : %s\n",
184 (fw_dump.dump_active ? "yes" : "no"));
185 pr_debug("Dump section sizes:\n");
186 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
187 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
188 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
189}
190
191static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
192 unsigned long addr)
193{
194 if (!fdm)
195 return 0;
196
197 memset(fdm, 0, sizeof(struct fadump_mem_struct));
198 addr = addr & PAGE_MASK;
199
200 fdm->header.dump_format_version = cpu_to_be32(0x00000001);
201 fdm->header.dump_num_sections = cpu_to_be16(3);
202 fdm->header.dump_status_flag = 0;
203 fdm->header.offset_first_dump_section =
204 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
205
206 /*
207 * Fields for disk dump option.
208 * We are not using disk dump option, hence set these fields to 0.
209 */
210 fdm->header.dd_block_size = 0;
211 fdm->header.dd_block_offset = 0;
212 fdm->header.dd_num_blocks = 0;
213 fdm->header.dd_offset_disk_path = 0;
214
215 /* set 0 to disable an automatic dump-reboot. */
216 fdm->header.max_time_auto = 0;
217
218 /* Kernel dump sections */
219 /* cpu state data section. */
220 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
221 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
222 fdm->cpu_state_data.source_address = 0;
223 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
224 fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
225 addr += fw_dump.cpu_state_data_size;
226
227 /* hpte region section */
228 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
229 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
230 fdm->hpte_region.source_address = 0;
231 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
232 fdm->hpte_region.destination_address = cpu_to_be64(addr);
233 addr += fw_dump.hpte_region_size;
234
235 /* RMA region section */
236 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
237 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
238 fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
239 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
240 fdm->rmr_region.destination_address = cpu_to_be64(addr);
241 addr += fw_dump.boot_memory_size;
242
243 return addr;
244}
245
246/**
247 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
248 *
249 * Function to find the largest memory size we need to reserve during early
250 * boot process. This will be the size of the memory that is required for a
251 * kernel to boot successfully.
252 *
253 * This function has been taken from phyp-assisted dump feature implementation.
254 *
255 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
256 *
257 * TODO: Come up with better approach to find out more accurate memory size
258 * that is required for a kernel to boot successfully.
259 *
260 */
261static inline unsigned long fadump_calculate_reserve_size(void)
262{
263 int ret;
264 unsigned long long base, size;
265
266 if (fw_dump.reserve_bootvar)
267 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
268
269 /*
270 * Check if the size is specified through crashkernel= cmdline
271 * option. If yes, then use that but ignore base as fadump reserves
272 * memory at a predefined offset.
273 */
274 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
275 &size, &base);
276 if (ret == 0 && size > 0) {
277 unsigned long max_size;
278
279 if (fw_dump.reserve_bootvar)
280 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
281
282 fw_dump.reserve_bootvar = (unsigned long)size;
283
284 /*
285 * Adjust if the boot memory size specified is above
286 * the upper limit.
287 */
288 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
289 if (fw_dump.reserve_bootvar > max_size) {
290 fw_dump.reserve_bootvar = max_size;
291 pr_info("Adjusted boot memory size to %luMB\n",
292 (fw_dump.reserve_bootvar >> 20));
293 }
294
295 return fw_dump.reserve_bootvar;
296 } else if (fw_dump.reserve_bootvar) {
297 /*
298 * 'fadump_reserve_mem=' is being used to reserve memory
299 * for firmware-assisted dump.
300 */
301 return fw_dump.reserve_bootvar;
302 }
303
304 /* divide by 20 to get 5% of value */
305 size = memblock_phys_mem_size() / 20;
306
307 /* round it down in multiples of 256 */
308 size = size & ~0x0FFFFFFFUL;
309
310 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
311 if (memory_limit && size > memory_limit)
312 size = memory_limit;
313
314 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
315}
316
317/*
318 * Calculate the total memory size required to be reserved for
319 * firmware-assisted dump registration.
320 */
321static unsigned long get_fadump_area_size(void)
322{
323 unsigned long size = 0;
324
325 size += fw_dump.cpu_state_data_size;
326 size += fw_dump.hpte_region_size;
327 size += fw_dump.boot_memory_size;
328 size += sizeof(struct fadump_crash_info_header);
329 size += sizeof(struct elfhdr); /* ELF core header.*/
330 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
331 /* Program headers for crash memory regions. */
332 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
333
334 size = PAGE_ALIGN(size);
335 return size;
336}
337
338int __init fadump_reserve_mem(void)
339{
340 unsigned long base, size, memory_boundary;
341
342 if (!fw_dump.fadump_enabled)
343 return 0;
344
345 if (!fw_dump.fadump_supported) {
346 printk(KERN_INFO "Firmware-assisted dump is not supported on"
347 " this hardware\n");
348 fw_dump.fadump_enabled = 0;
349 return 0;
350 }
351 /*
352 * Initialize boot memory size
353 * If dump is active then we have already calculated the size during
354 * first kernel.
355 */
356 if (fdm_active)
357 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
358 else
359 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
360
361 /*
362 * Calculate the memory boundary.
363 * If memory_limit is less than actual memory boundary then reserve
364 * the memory for fadump beyond the memory_limit and adjust the
365 * memory_limit accordingly, so that the running kernel can run with
366 * specified memory_limit.
367 */
368 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
369 size = get_fadump_area_size();
370 if ((memory_limit + size) < memblock_end_of_DRAM())
371 memory_limit += size;
372 else
373 memory_limit = memblock_end_of_DRAM();
374 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
375 " dump, now %#016llx\n", memory_limit);
376 }
377 if (memory_limit)
378 memory_boundary = memory_limit;
379 else
380 memory_boundary = memblock_end_of_DRAM();
381
382 if (fw_dump.dump_active) {
383 printk(KERN_INFO "Firmware-assisted dump is active.\n");
384 /*
385 * If last boot has crashed then reserve all the memory
386 * above boot_memory_size so that we don't touch it until
387 * dump is written to disk by userspace tool. This memory
388 * will be released for general use once the dump is saved.
389 */
390 base = fw_dump.boot_memory_size;
391 size = memory_boundary - base;
392 memblock_reserve(base, size);
393 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
394 "for saving crash dump\n",
395 (unsigned long)(size >> 20),
396 (unsigned long)(base >> 20));
397
398 fw_dump.fadumphdr_addr =
399 be64_to_cpu(fdm_active->rmr_region.destination_address) +
400 be64_to_cpu(fdm_active->rmr_region.source_len);
401 pr_debug("fadumphdr_addr = %p\n",
402 (void *) fw_dump.fadumphdr_addr);
403 } else {
404 size = get_fadump_area_size();
405
406 /*
407 * Reserve memory at an offset closer to bottom of the RAM to
408 * minimize the impact of memory hot-remove operation. We can't
409 * use memblock_find_in_range() here since it doesn't allocate
410 * from bottom to top.
411 */
412 for (base = fw_dump.boot_memory_size;
413 base <= (memory_boundary - size);
414 base += size) {
415 if (memblock_is_region_memory(base, size) &&
416 !memblock_is_region_reserved(base, size))
417 break;
418 }
419 if ((base > (memory_boundary - size)) ||
420 memblock_reserve(base, size)) {
421 pr_err("Failed to reserve memory\n");
422 return 0;
423 }
424
425 pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
426 "assisted dump (System RAM: %ldMB)\n",
427 (unsigned long)(size >> 20),
428 (unsigned long)(base >> 20),
429 (unsigned long)(memblock_phys_mem_size() >> 20));
430 }
431
432 fw_dump.reserve_dump_area_start = base;
433 fw_dump.reserve_dump_area_size = size;
434 return 1;
435}
436
437unsigned long __init arch_reserved_kernel_pages(void)
438{
439 return memblock_reserved_size() / PAGE_SIZE;
440}
441
442/* Look for fadump= cmdline option. */
443static int __init early_fadump_param(char *p)
444{
445 if (!p)
446 return 1;
447
448 if (strncmp(p, "on", 2) == 0)
449 fw_dump.fadump_enabled = 1;
450 else if (strncmp(p, "off", 3) == 0)
451 fw_dump.fadump_enabled = 0;
452
453 return 0;
454}
455early_param("fadump", early_fadump_param);
456
457/*
458 * Look for fadump_reserve_mem= cmdline option
459 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
460 * the sooner 'crashkernel=' parameter is accustomed to.
461 */
462static int __init early_fadump_reserve_mem(char *p)
463{
464 if (p)
465 fw_dump.reserve_bootvar = memparse(p, &p);
466 return 0;
467}
468early_param("fadump_reserve_mem", early_fadump_reserve_mem);
469
470static int register_fw_dump(struct fadump_mem_struct *fdm)
471{
472 int rc, err;
473 unsigned int wait_time;
474
475 pr_debug("Registering for firmware-assisted kernel dump...\n");
476
477 /* TODO: Add upper time limit for the delay */
478 do {
479 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
480 FADUMP_REGISTER, fdm,
481 sizeof(struct fadump_mem_struct));
482
483 wait_time = rtas_busy_delay_time(rc);
484 if (wait_time)
485 mdelay(wait_time);
486
487 } while (wait_time);
488
489 err = -EIO;
490 switch (rc) {
491 default:
492 pr_err("Failed to register. Unknown Error(%d).\n", rc);
493 break;
494 case -1:
495 printk(KERN_ERR "Failed to register firmware-assisted kernel"
496 " dump. Hardware Error(%d).\n", rc);
497 break;
498 case -3:
499 if (!is_boot_memory_area_contiguous())
500 pr_err("Can't have holes in boot memory area while "
501 "registering fadump\n");
502
503 printk(KERN_ERR "Failed to register firmware-assisted kernel"
504 " dump. Parameter Error(%d).\n", rc);
505 err = -EINVAL;
506 break;
507 case -9:
508 printk(KERN_ERR "firmware-assisted kernel dump is already "
509 " registered.");
510 fw_dump.dump_registered = 1;
511 err = -EEXIST;
512 break;
513 case 0:
514 printk(KERN_INFO "firmware-assisted kernel dump registration"
515 " is successful\n");
516 fw_dump.dump_registered = 1;
517 err = 0;
518 break;
519 }
520 return err;
521}
522
523void crash_fadump(struct pt_regs *regs, const char *str)
524{
525 struct fadump_crash_info_header *fdh = NULL;
526 int old_cpu, this_cpu;
527
528 if (!should_fadump_crash())
529 return;
530
531 /*
532 * old_cpu == -1 means this is the first CPU which has come here,
533 * go ahead and trigger fadump.
534 *
535 * old_cpu != -1 means some other CPU has already on it's way
536 * to trigger fadump, just keep looping here.
537 */
538 this_cpu = smp_processor_id();
539 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
540
541 if (old_cpu != -1) {
542 /*
543 * We can't loop here indefinitely. Wait as long as fadump
544 * is in force. If we race with fadump un-registration this
545 * loop will break and then we go down to normal panic path
546 * and reboot. If fadump is in force the first crashing
547 * cpu will definitely trigger fadump.
548 */
549 while (fw_dump.dump_registered)
550 cpu_relax();
551 return;
552 }
553
554 fdh = __va(fw_dump.fadumphdr_addr);
555 fdh->crashing_cpu = crashing_cpu;
556 crash_save_vmcoreinfo();
557
558 if (regs)
559 fdh->regs = *regs;
560 else
561 ppc_save_regs(&fdh->regs);
562
563 fdh->online_mask = *cpu_online_mask;
564
565 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
566 rtas_os_term((char *)str);
567}
568
569#define GPR_MASK 0xffffff0000000000
570static inline int fadump_gpr_index(u64 id)
571{
572 int i = -1;
573 char str[3];
574
575 if ((id & GPR_MASK) == REG_ID("GPR")) {
576 /* get the digits at the end */
577 id &= ~GPR_MASK;
578 id >>= 24;
579 str[2] = '\0';
580 str[1] = id & 0xff;
581 str[0] = (id >> 8) & 0xff;
582 sscanf(str, "%d", &i);
583 if (i > 31)
584 i = -1;
585 }
586 return i;
587}
588
589static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
590 u64 reg_val)
591{
592 int i;
593
594 i = fadump_gpr_index(reg_id);
595 if (i >= 0)
596 regs->gpr[i] = (unsigned long)reg_val;
597 else if (reg_id == REG_ID("NIA"))
598 regs->nip = (unsigned long)reg_val;
599 else if (reg_id == REG_ID("MSR"))
600 regs->msr = (unsigned long)reg_val;
601 else if (reg_id == REG_ID("CTR"))
602 regs->ctr = (unsigned long)reg_val;
603 else if (reg_id == REG_ID("LR"))
604 regs->link = (unsigned long)reg_val;
605 else if (reg_id == REG_ID("XER"))
606 regs->xer = (unsigned long)reg_val;
607 else if (reg_id == REG_ID("CR"))
608 regs->ccr = (unsigned long)reg_val;
609 else if (reg_id == REG_ID("DAR"))
610 regs->dar = (unsigned long)reg_val;
611 else if (reg_id == REG_ID("DSISR"))
612 regs->dsisr = (unsigned long)reg_val;
613}
614
615static struct fadump_reg_entry*
616fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
617{
618 memset(regs, 0, sizeof(struct pt_regs));
619
620 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
621 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
622 be64_to_cpu(reg_entry->reg_value));
623 reg_entry++;
624 }
625 reg_entry++;
626 return reg_entry;
627}
628
629static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
630{
631 struct elf_prstatus prstatus;
632
633 memset(&prstatus, 0, sizeof(prstatus));
634 /*
635 * FIXME: How do i get PID? Do I really need it?
636 * prstatus.pr_pid = ????
637 */
638 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
639 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
640 &prstatus, sizeof(prstatus));
641 return buf;
642}
643
644static void fadump_update_elfcore_header(char *bufp)
645{
646 struct elfhdr *elf;
647 struct elf_phdr *phdr;
648
649 elf = (struct elfhdr *)bufp;
650 bufp += sizeof(struct elfhdr);
651
652 /* First note is a place holder for cpu notes info. */
653 phdr = (struct elf_phdr *)bufp;
654
655 if (phdr->p_type == PT_NOTE) {
656 phdr->p_paddr = fw_dump.cpu_notes_buf;
657 phdr->p_offset = phdr->p_paddr;
658 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
659 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
660 }
661 return;
662}
663
664static void *fadump_cpu_notes_buf_alloc(unsigned long size)
665{
666 void *vaddr;
667 struct page *page;
668 unsigned long order, count, i;
669
670 order = get_order(size);
671 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
672 if (!vaddr)
673 return NULL;
674
675 count = 1 << order;
676 page = virt_to_page(vaddr);
677 for (i = 0; i < count; i++)
678 SetPageReserved(page + i);
679 return vaddr;
680}
681
682static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
683{
684 struct page *page;
685 unsigned long order, count, i;
686
687 order = get_order(size);
688 count = 1 << order;
689 page = virt_to_page(vaddr);
690 for (i = 0; i < count; i++)
691 ClearPageReserved(page + i);
692 __free_pages(page, order);
693}
694
695/*
696 * Read CPU state dump data and convert it into ELF notes.
697 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
698 * used to access the data to allow for additional fields to be added without
699 * affecting compatibility. Each list of registers for a CPU starts with
700 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
701 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
702 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
703 * of register value. For more details refer to PAPR document.
704 *
705 * Only for the crashing cpu we ignore the CPU dump data and get exact
706 * state from fadump crash info structure populated by first kernel at the
707 * time of crash.
708 */
709static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
710{
711 struct fadump_reg_save_area_header *reg_header;
712 struct fadump_reg_entry *reg_entry;
713 struct fadump_crash_info_header *fdh = NULL;
714 void *vaddr;
715 unsigned long addr;
716 u32 num_cpus, *note_buf;
717 struct pt_regs regs;
718 int i, rc = 0, cpu = 0;
719
720 if (!fdm->cpu_state_data.bytes_dumped)
721 return -EINVAL;
722
723 addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
724 vaddr = __va(addr);
725
726 reg_header = vaddr;
727 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
728 printk(KERN_ERR "Unable to read register save area.\n");
729 return -ENOENT;
730 }
731 pr_debug("--------CPU State Data------------\n");
732 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
733 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
734
735 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
736 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
737 pr_debug("NumCpus : %u\n", num_cpus);
738 vaddr += sizeof(u32);
739 reg_entry = (struct fadump_reg_entry *)vaddr;
740
741 /* Allocate buffer to hold cpu crash notes. */
742 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
743 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
744 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
745 if (!note_buf) {
746 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
747 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
748 return -ENOMEM;
749 }
750 fw_dump.cpu_notes_buf = __pa(note_buf);
751
752 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
753 (num_cpus * sizeof(note_buf_t)), note_buf);
754
755 if (fw_dump.fadumphdr_addr)
756 fdh = __va(fw_dump.fadumphdr_addr);
757
758 for (i = 0; i < num_cpus; i++) {
759 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
760 printk(KERN_ERR "Unable to read CPU state data\n");
761 rc = -ENOENT;
762 goto error_out;
763 }
764 /* Lower 4 bytes of reg_value contains logical cpu id */
765 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
766 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
767 SKIP_TO_NEXT_CPU(reg_entry);
768 continue;
769 }
770 pr_debug("Reading register data for cpu %d...\n", cpu);
771 if (fdh && fdh->crashing_cpu == cpu) {
772 regs = fdh->regs;
773 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
774 SKIP_TO_NEXT_CPU(reg_entry);
775 } else {
776 reg_entry++;
777 reg_entry = fadump_read_registers(reg_entry, ®s);
778 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
779 }
780 }
781 final_note(note_buf);
782
783 if (fdh) {
784 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
785 fdh->elfcorehdr_addr);
786 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
787 }
788 return 0;
789
790error_out:
791 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
792 fw_dump.cpu_notes_buf_size);
793 fw_dump.cpu_notes_buf = 0;
794 fw_dump.cpu_notes_buf_size = 0;
795 return rc;
796
797}
798
799/*
800 * Validate and process the dump data stored by firmware before exporting
801 * it through '/proc/vmcore'.
802 */
803static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
804{
805 struct fadump_crash_info_header *fdh;
806 int rc = 0;
807
808 if (!fdm_active || !fw_dump.fadumphdr_addr)
809 return -EINVAL;
810
811 /* Check if the dump data is valid. */
812 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
813 (fdm_active->cpu_state_data.error_flags != 0) ||
814 (fdm_active->rmr_region.error_flags != 0)) {
815 printk(KERN_ERR "Dump taken by platform is not valid\n");
816 return -EINVAL;
817 }
818 if ((fdm_active->rmr_region.bytes_dumped !=
819 fdm_active->rmr_region.source_len) ||
820 !fdm_active->cpu_state_data.bytes_dumped) {
821 printk(KERN_ERR "Dump taken by platform is incomplete\n");
822 return -EINVAL;
823 }
824
825 /* Validate the fadump crash info header */
826 fdh = __va(fw_dump.fadumphdr_addr);
827 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
828 printk(KERN_ERR "Crash info header is not valid.\n");
829 return -EINVAL;
830 }
831
832 rc = fadump_build_cpu_notes(fdm_active);
833 if (rc)
834 return rc;
835
836 /*
837 * We are done validating dump info and elfcore header is now ready
838 * to be exported. set elfcorehdr_addr so that vmcore module will
839 * export the elfcore header through '/proc/vmcore'.
840 */
841 elfcorehdr_addr = fdh->elfcorehdr_addr;
842
843 return 0;
844}
845
846static inline void fadump_add_crash_memory(unsigned long long base,
847 unsigned long long end)
848{
849 if (base == end)
850 return;
851
852 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
853 crash_mem_ranges, base, end - 1, (end - base));
854 crash_memory_ranges[crash_mem_ranges].base = base;
855 crash_memory_ranges[crash_mem_ranges].size = end - base;
856 crash_mem_ranges++;
857}
858
859static void fadump_exclude_reserved_area(unsigned long long start,
860 unsigned long long end)
861{
862 unsigned long long ra_start, ra_end;
863
864 ra_start = fw_dump.reserve_dump_area_start;
865 ra_end = ra_start + fw_dump.reserve_dump_area_size;
866
867 if ((ra_start < end) && (ra_end > start)) {
868 if ((start < ra_start) && (end > ra_end)) {
869 fadump_add_crash_memory(start, ra_start);
870 fadump_add_crash_memory(ra_end, end);
871 } else if (start < ra_start) {
872 fadump_add_crash_memory(start, ra_start);
873 } else if (ra_end < end) {
874 fadump_add_crash_memory(ra_end, end);
875 }
876 } else
877 fadump_add_crash_memory(start, end);
878}
879
880static int fadump_init_elfcore_header(char *bufp)
881{
882 struct elfhdr *elf;
883
884 elf = (struct elfhdr *) bufp;
885 bufp += sizeof(struct elfhdr);
886 memcpy(elf->e_ident, ELFMAG, SELFMAG);
887 elf->e_ident[EI_CLASS] = ELF_CLASS;
888 elf->e_ident[EI_DATA] = ELF_DATA;
889 elf->e_ident[EI_VERSION] = EV_CURRENT;
890 elf->e_ident[EI_OSABI] = ELF_OSABI;
891 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
892 elf->e_type = ET_CORE;
893 elf->e_machine = ELF_ARCH;
894 elf->e_version = EV_CURRENT;
895 elf->e_entry = 0;
896 elf->e_phoff = sizeof(struct elfhdr);
897 elf->e_shoff = 0;
898#if defined(_CALL_ELF)
899 elf->e_flags = _CALL_ELF;
900#else
901 elf->e_flags = 0;
902#endif
903 elf->e_ehsize = sizeof(struct elfhdr);
904 elf->e_phentsize = sizeof(struct elf_phdr);
905 elf->e_phnum = 0;
906 elf->e_shentsize = 0;
907 elf->e_shnum = 0;
908 elf->e_shstrndx = 0;
909
910 return 0;
911}
912
913/*
914 * Traverse through memblock structure and setup crash memory ranges. These
915 * ranges will be used create PT_LOAD program headers in elfcore header.
916 */
917static void fadump_setup_crash_memory_ranges(void)
918{
919 struct memblock_region *reg;
920 unsigned long long start, end;
921
922 pr_debug("Setup crash memory ranges.\n");
923 crash_mem_ranges = 0;
924 /*
925 * add the first memory chunk (RMA_START through boot_memory_size) as
926 * a separate memory chunk. The reason is, at the time crash firmware
927 * will move the content of this memory chunk to different location
928 * specified during fadump registration. We need to create a separate
929 * program header for this chunk with the correct offset.
930 */
931 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
932
933 for_each_memblock(memory, reg) {
934 start = (unsigned long long)reg->base;
935 end = start + (unsigned long long)reg->size;
936
937 /*
938 * skip the first memory chunk that is already added (RMA_START
939 * through boot_memory_size). This logic needs a relook if and
940 * when RMA_START changes to a non-zero value.
941 */
942 BUILD_BUG_ON(RMA_START != 0);
943 if (start < fw_dump.boot_memory_size) {
944 if (end > fw_dump.boot_memory_size)
945 start = fw_dump.boot_memory_size;
946 else
947 continue;
948 }
949
950 /* add this range excluding the reserved dump area. */
951 fadump_exclude_reserved_area(start, end);
952 }
953}
954
955/*
956 * If the given physical address falls within the boot memory region then
957 * return the relocated address that points to the dump region reserved
958 * for saving initial boot memory contents.
959 */
960static inline unsigned long fadump_relocate(unsigned long paddr)
961{
962 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
963 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
964 else
965 return paddr;
966}
967
968static int fadump_create_elfcore_headers(char *bufp)
969{
970 struct elfhdr *elf;
971 struct elf_phdr *phdr;
972 int i;
973
974 fadump_init_elfcore_header(bufp);
975 elf = (struct elfhdr *)bufp;
976 bufp += sizeof(struct elfhdr);
977
978 /*
979 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
980 * will be populated during second kernel boot after crash. Hence
981 * this PT_NOTE will always be the first elf note.
982 *
983 * NOTE: Any new ELF note addition should be placed after this note.
984 */
985 phdr = (struct elf_phdr *)bufp;
986 bufp += sizeof(struct elf_phdr);
987 phdr->p_type = PT_NOTE;
988 phdr->p_flags = 0;
989 phdr->p_vaddr = 0;
990 phdr->p_align = 0;
991
992 phdr->p_offset = 0;
993 phdr->p_paddr = 0;
994 phdr->p_filesz = 0;
995 phdr->p_memsz = 0;
996
997 (elf->e_phnum)++;
998
999 /* setup ELF PT_NOTE for vmcoreinfo */
1000 phdr = (struct elf_phdr *)bufp;
1001 bufp += sizeof(struct elf_phdr);
1002 phdr->p_type = PT_NOTE;
1003 phdr->p_flags = 0;
1004 phdr->p_vaddr = 0;
1005 phdr->p_align = 0;
1006
1007 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1008 phdr->p_offset = phdr->p_paddr;
1009 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1010
1011 /* Increment number of program headers. */
1012 (elf->e_phnum)++;
1013
1014 /* setup PT_LOAD sections. */
1015
1016 for (i = 0; i < crash_mem_ranges; i++) {
1017 unsigned long long mbase, msize;
1018 mbase = crash_memory_ranges[i].base;
1019 msize = crash_memory_ranges[i].size;
1020
1021 if (!msize)
1022 continue;
1023
1024 phdr = (struct elf_phdr *)bufp;
1025 bufp += sizeof(struct elf_phdr);
1026 phdr->p_type = PT_LOAD;
1027 phdr->p_flags = PF_R|PF_W|PF_X;
1028 phdr->p_offset = mbase;
1029
1030 if (mbase == RMA_START) {
1031 /*
1032 * The entire RMA region will be moved by firmware
1033 * to the specified destination_address. Hence set
1034 * the correct offset.
1035 */
1036 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
1037 }
1038
1039 phdr->p_paddr = mbase;
1040 phdr->p_vaddr = (unsigned long)__va(mbase);
1041 phdr->p_filesz = msize;
1042 phdr->p_memsz = msize;
1043 phdr->p_align = 0;
1044
1045 /* Increment number of program headers. */
1046 (elf->e_phnum)++;
1047 }
1048 return 0;
1049}
1050
1051static unsigned long init_fadump_header(unsigned long addr)
1052{
1053 struct fadump_crash_info_header *fdh;
1054
1055 if (!addr)
1056 return 0;
1057
1058 fw_dump.fadumphdr_addr = addr;
1059 fdh = __va(addr);
1060 addr += sizeof(struct fadump_crash_info_header);
1061
1062 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1063 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1064 fdh->elfcorehdr_addr = addr;
1065 /* We will set the crashing cpu id in crash_fadump() during crash. */
1066 fdh->crashing_cpu = CPU_UNKNOWN;
1067
1068 return addr;
1069}
1070
1071static int register_fadump(void)
1072{
1073 unsigned long addr;
1074 void *vaddr;
1075
1076 /*
1077 * If no memory is reserved then we can not register for firmware-
1078 * assisted dump.
1079 */
1080 if (!fw_dump.reserve_dump_area_size)
1081 return -ENODEV;
1082
1083 fadump_setup_crash_memory_ranges();
1084
1085 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1086 /* Initialize fadump crash info header. */
1087 addr = init_fadump_header(addr);
1088 vaddr = __va(addr);
1089
1090 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1091 fadump_create_elfcore_headers(vaddr);
1092
1093 /* register the future kernel dump with firmware. */
1094 return register_fw_dump(&fdm);
1095}
1096
1097static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1098{
1099 int rc = 0;
1100 unsigned int wait_time;
1101
1102 pr_debug("Un-register firmware-assisted dump\n");
1103
1104 /* TODO: Add upper time limit for the delay */
1105 do {
1106 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1107 FADUMP_UNREGISTER, fdm,
1108 sizeof(struct fadump_mem_struct));
1109
1110 wait_time = rtas_busy_delay_time(rc);
1111 if (wait_time)
1112 mdelay(wait_time);
1113 } while (wait_time);
1114
1115 if (rc) {
1116 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1117 " unexpected error(%d).\n", rc);
1118 return rc;
1119 }
1120 fw_dump.dump_registered = 0;
1121 return 0;
1122}
1123
1124static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1125{
1126 int rc = 0;
1127 unsigned int wait_time;
1128
1129 pr_debug("Invalidating firmware-assisted dump registration\n");
1130
1131 /* TODO: Add upper time limit for the delay */
1132 do {
1133 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1134 FADUMP_INVALIDATE, fdm,
1135 sizeof(struct fadump_mem_struct));
1136
1137 wait_time = rtas_busy_delay_time(rc);
1138 if (wait_time)
1139 mdelay(wait_time);
1140 } while (wait_time);
1141
1142 if (rc) {
1143 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1144 return rc;
1145 }
1146 fw_dump.dump_active = 0;
1147 fdm_active = NULL;
1148 return 0;
1149}
1150
1151void fadump_cleanup(void)
1152{
1153 /* Invalidate the registration only if dump is active. */
1154 if (fw_dump.dump_active) {
1155 init_fadump_mem_struct(&fdm,
1156 be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1157 fadump_invalidate_dump(&fdm);
1158 }
1159}
1160
1161static void fadump_free_reserved_memory(unsigned long start_pfn,
1162 unsigned long end_pfn)
1163{
1164 unsigned long pfn;
1165 unsigned long time_limit = jiffies + HZ;
1166
1167 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1168 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1169
1170 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1171 free_reserved_page(pfn_to_page(pfn));
1172
1173 if (time_after(jiffies, time_limit)) {
1174 cond_resched();
1175 time_limit = jiffies + HZ;
1176 }
1177 }
1178}
1179
1180/*
1181 * Skip memory holes and free memory that was actually reserved.
1182 */
1183static void fadump_release_reserved_area(unsigned long start, unsigned long end)
1184{
1185 struct memblock_region *reg;
1186 unsigned long tstart, tend;
1187 unsigned long start_pfn = PHYS_PFN(start);
1188 unsigned long end_pfn = PHYS_PFN(end);
1189
1190 for_each_memblock(memory, reg) {
1191 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
1192 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
1193 if (tstart < tend) {
1194 fadump_free_reserved_memory(tstart, tend);
1195
1196 if (tend == end_pfn)
1197 break;
1198
1199 start_pfn = tend + 1;
1200 }
1201 }
1202}
1203
1204/*
1205 * Release the memory that was reserved in early boot to preserve the memory
1206 * contents. The released memory will be available for general use.
1207 */
1208static void fadump_release_memory(unsigned long begin, unsigned long end)
1209{
1210 unsigned long ra_start, ra_end;
1211
1212 ra_start = fw_dump.reserve_dump_area_start;
1213 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1214
1215 /*
1216 * exclude the dump reserve area. Will reuse it for next
1217 * fadump registration.
1218 */
1219 if (begin < ra_end && end > ra_start) {
1220 if (begin < ra_start)
1221 fadump_release_reserved_area(begin, ra_start);
1222 if (end > ra_end)
1223 fadump_release_reserved_area(ra_end, end);
1224 } else
1225 fadump_release_reserved_area(begin, end);
1226}
1227
1228static void fadump_invalidate_release_mem(void)
1229{
1230 unsigned long reserved_area_start, reserved_area_end;
1231 unsigned long destination_address;
1232
1233 mutex_lock(&fadump_mutex);
1234 if (!fw_dump.dump_active) {
1235 mutex_unlock(&fadump_mutex);
1236 return;
1237 }
1238
1239 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1240 fadump_cleanup();
1241 mutex_unlock(&fadump_mutex);
1242
1243 /*
1244 * Save the current reserved memory bounds we will require them
1245 * later for releasing the memory for general use.
1246 */
1247 reserved_area_start = fw_dump.reserve_dump_area_start;
1248 reserved_area_end = reserved_area_start +
1249 fw_dump.reserve_dump_area_size;
1250 /*
1251 * Setup reserve_dump_area_start and its size so that we can
1252 * reuse this reserved memory for Re-registration.
1253 */
1254 fw_dump.reserve_dump_area_start = destination_address;
1255 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1256
1257 fadump_release_memory(reserved_area_start, reserved_area_end);
1258 if (fw_dump.cpu_notes_buf) {
1259 fadump_cpu_notes_buf_free(
1260 (unsigned long)__va(fw_dump.cpu_notes_buf),
1261 fw_dump.cpu_notes_buf_size);
1262 fw_dump.cpu_notes_buf = 0;
1263 fw_dump.cpu_notes_buf_size = 0;
1264 }
1265 /* Initialize the kernel dump memory structure for FAD registration. */
1266 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1267}
1268
1269static ssize_t fadump_release_memory_store(struct kobject *kobj,
1270 struct kobj_attribute *attr,
1271 const char *buf, size_t count)
1272{
1273 int input = -1;
1274
1275 if (!fw_dump.dump_active)
1276 return -EPERM;
1277
1278 if (kstrtoint(buf, 0, &input))
1279 return -EINVAL;
1280
1281 if (input == 1) {
1282 /*
1283 * Take away the '/proc/vmcore'. We are releasing the dump
1284 * memory, hence it will not be valid anymore.
1285 */
1286#ifdef CONFIG_PROC_VMCORE
1287 vmcore_cleanup();
1288#endif
1289 fadump_invalidate_release_mem();
1290
1291 } else
1292 return -EINVAL;
1293 return count;
1294}
1295
1296static ssize_t fadump_enabled_show(struct kobject *kobj,
1297 struct kobj_attribute *attr,
1298 char *buf)
1299{
1300 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1301}
1302
1303static ssize_t fadump_register_show(struct kobject *kobj,
1304 struct kobj_attribute *attr,
1305 char *buf)
1306{
1307 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1308}
1309
1310static ssize_t fadump_register_store(struct kobject *kobj,
1311 struct kobj_attribute *attr,
1312 const char *buf, size_t count)
1313{
1314 int ret = 0;
1315 int input = -1;
1316
1317 if (!fw_dump.fadump_enabled || fdm_active)
1318 return -EPERM;
1319
1320 if (kstrtoint(buf, 0, &input))
1321 return -EINVAL;
1322
1323 mutex_lock(&fadump_mutex);
1324
1325 switch (input) {
1326 case 0:
1327 if (fw_dump.dump_registered == 0) {
1328 goto unlock_out;
1329 }
1330 /* Un-register Firmware-assisted dump */
1331 fadump_unregister_dump(&fdm);
1332 break;
1333 case 1:
1334 if (fw_dump.dump_registered == 1) {
1335 ret = -EEXIST;
1336 goto unlock_out;
1337 }
1338 /* Register Firmware-assisted dump */
1339 ret = register_fadump();
1340 break;
1341 default:
1342 ret = -EINVAL;
1343 break;
1344 }
1345
1346unlock_out:
1347 mutex_unlock(&fadump_mutex);
1348 return ret < 0 ? ret : count;
1349}
1350
1351static int fadump_region_show(struct seq_file *m, void *private)
1352{
1353 const struct fadump_mem_struct *fdm_ptr;
1354
1355 if (!fw_dump.fadump_enabled)
1356 return 0;
1357
1358 mutex_lock(&fadump_mutex);
1359 if (fdm_active)
1360 fdm_ptr = fdm_active;
1361 else {
1362 mutex_unlock(&fadump_mutex);
1363 fdm_ptr = &fdm;
1364 }
1365
1366 seq_printf(m,
1367 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1368 "Dumped: %#llx\n",
1369 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1370 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1371 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1372 be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1373 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1374 seq_printf(m,
1375 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1376 "Dumped: %#llx\n",
1377 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1378 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1379 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1380 be64_to_cpu(fdm_ptr->hpte_region.source_len),
1381 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1382 seq_printf(m,
1383 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1384 "Dumped: %#llx\n",
1385 be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1386 be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1387 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1388 be64_to_cpu(fdm_ptr->rmr_region.source_len),
1389 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1390
1391 if (!fdm_active ||
1392 (fw_dump.reserve_dump_area_start ==
1393 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1394 goto out;
1395
1396 /* Dump is active. Show reserved memory region. */
1397 seq_printf(m,
1398 " : [%#016llx-%#016llx] %#llx bytes, "
1399 "Dumped: %#llx\n",
1400 (unsigned long long)fw_dump.reserve_dump_area_start,
1401 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1402 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1403 fw_dump.reserve_dump_area_start,
1404 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1405 fw_dump.reserve_dump_area_start);
1406out:
1407 if (fdm_active)
1408 mutex_unlock(&fadump_mutex);
1409 return 0;
1410}
1411
1412static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1413 0200, NULL,
1414 fadump_release_memory_store);
1415static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1416 0444, fadump_enabled_show,
1417 NULL);
1418static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1419 0644, fadump_register_show,
1420 fadump_register_store);
1421
1422static int fadump_region_open(struct inode *inode, struct file *file)
1423{
1424 return single_open(file, fadump_region_show, inode->i_private);
1425}
1426
1427static const struct file_operations fadump_region_fops = {
1428 .open = fadump_region_open,
1429 .read = seq_read,
1430 .llseek = seq_lseek,
1431 .release = single_release,
1432};
1433
1434static void fadump_init_files(void)
1435{
1436 struct dentry *debugfs_file;
1437 int rc = 0;
1438
1439 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1440 if (rc)
1441 printk(KERN_ERR "fadump: unable to create sysfs file"
1442 " fadump_enabled (%d)\n", rc);
1443
1444 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1445 if (rc)
1446 printk(KERN_ERR "fadump: unable to create sysfs file"
1447 " fadump_registered (%d)\n", rc);
1448
1449 debugfs_file = debugfs_create_file("fadump_region", 0444,
1450 powerpc_debugfs_root, NULL,
1451 &fadump_region_fops);
1452 if (!debugfs_file)
1453 printk(KERN_ERR "fadump: unable to create debugfs file"
1454 " fadump_region\n");
1455
1456 if (fw_dump.dump_active) {
1457 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1458 if (rc)
1459 printk(KERN_ERR "fadump: unable to create sysfs file"
1460 " fadump_release_mem (%d)\n", rc);
1461 }
1462 return;
1463}
1464
1465/*
1466 * Prepare for firmware-assisted dump.
1467 */
1468int __init setup_fadump(void)
1469{
1470 if (!fw_dump.fadump_enabled)
1471 return 0;
1472
1473 if (!fw_dump.fadump_supported) {
1474 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1475 " this hardware\n");
1476 return 0;
1477 }
1478
1479 fadump_show_config();
1480 /*
1481 * If dump data is available then see if it is valid and prepare for
1482 * saving it to the disk.
1483 */
1484 if (fw_dump.dump_active) {
1485 /*
1486 * if dump process fails then invalidate the registration
1487 * and release memory before proceeding for re-registration.
1488 */
1489 if (process_fadump(fdm_active) < 0)
1490 fadump_invalidate_release_mem();
1491 }
1492 /* Initialize the kernel dump memory structure for FAD registration. */
1493 else if (fw_dump.reserve_dump_area_size)
1494 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1495 fadump_init_files();
1496
1497 return 1;
1498}
1499subsys_initcall(setup_fadump);
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
46static struct fw_dump fw_dump;
47static struct fadump_mem_struct fdm;
48static const struct fadump_mem_struct *fdm_active;
49
50static DEFINE_MUTEX(fadump_mutex);
51struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
52int crash_mem_ranges;
53
54/* Scan the Firmware Assisted dump configuration details. */
55int __init early_init_dt_scan_fw_dump(unsigned long node,
56 const char *uname, int depth, void *data)
57{
58 const __be32 *sections;
59 int i, num_sections;
60 int size;
61 const __be32 *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 1;
73
74 fw_dump.fadump_supported = 1;
75 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*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 1;
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(§ions[1], 2);
106 break;
107 case FADUMP_HPTE_REGION:
108 fw_dump.hpte_region_size =
109 of_read_ulong(§ions[1], 2);
110 break;
111 }
112 }
113
114 return 1;
115}
116
117int is_fadump_active(void)
118{
119 return fw_dump.dump_active;
120}
121
122/* Print firmware assisted dump configurations for debugging purpose. */
123static void fadump_show_config(void)
124{
125 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
126 (fw_dump.fadump_supported ? "present" : "no support"));
127
128 if (!fw_dump.fadump_supported)
129 return;
130
131 pr_debug("Fadump enabled : %s\n",
132 (fw_dump.fadump_enabled ? "yes" : "no"));
133 pr_debug("Dump Active : %s\n",
134 (fw_dump.dump_active ? "yes" : "no"));
135 pr_debug("Dump section sizes:\n");
136 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
137 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
138 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
139}
140
141static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
142 unsigned long addr)
143{
144 if (!fdm)
145 return 0;
146
147 memset(fdm, 0, sizeof(struct fadump_mem_struct));
148 addr = addr & PAGE_MASK;
149
150 fdm->header.dump_format_version = cpu_to_be32(0x00000001);
151 fdm->header.dump_num_sections = cpu_to_be16(3);
152 fdm->header.dump_status_flag = 0;
153 fdm->header.offset_first_dump_section =
154 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
155
156 /*
157 * Fields for disk dump option.
158 * We are not using disk dump option, hence set these fields to 0.
159 */
160 fdm->header.dd_block_size = 0;
161 fdm->header.dd_block_offset = 0;
162 fdm->header.dd_num_blocks = 0;
163 fdm->header.dd_offset_disk_path = 0;
164
165 /* set 0 to disable an automatic dump-reboot. */
166 fdm->header.max_time_auto = 0;
167
168 /* Kernel dump sections */
169 /* cpu state data section. */
170 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
171 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
172 fdm->cpu_state_data.source_address = 0;
173 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
174 fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
175 addr += fw_dump.cpu_state_data_size;
176
177 /* hpte region section */
178 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
179 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
180 fdm->hpte_region.source_address = 0;
181 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
182 fdm->hpte_region.destination_address = cpu_to_be64(addr);
183 addr += fw_dump.hpte_region_size;
184
185 /* RMA region section */
186 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
187 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
188 fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
189 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
190 fdm->rmr_region.destination_address = cpu_to_be64(addr);
191 addr += fw_dump.boot_memory_size;
192
193 return addr;
194}
195
196/**
197 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
198 *
199 * Function to find the largest memory size we need to reserve during early
200 * boot process. This will be the size of the memory that is required for a
201 * kernel to boot successfully.
202 *
203 * This function has been taken from phyp-assisted dump feature implementation.
204 *
205 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
206 *
207 * TODO: Come up with better approach to find out more accurate memory size
208 * that is required for a kernel to boot successfully.
209 *
210 */
211static inline unsigned long fadump_calculate_reserve_size(void)
212{
213 unsigned long size;
214
215 /*
216 * Check if the size is specified through fadump_reserve_mem= cmdline
217 * option. If yes, then use that.
218 */
219 if (fw_dump.reserve_bootvar)
220 return fw_dump.reserve_bootvar;
221
222 /* divide by 20 to get 5% of value */
223 size = memblock_end_of_DRAM() / 20;
224
225 /* round it down in multiples of 256 */
226 size = size & ~0x0FFFFFFFUL;
227
228 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
229 if (memory_limit && size > memory_limit)
230 size = memory_limit;
231
232 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
233}
234
235/*
236 * Calculate the total memory size required to be reserved for
237 * firmware-assisted dump registration.
238 */
239static unsigned long get_fadump_area_size(void)
240{
241 unsigned long size = 0;
242
243 size += fw_dump.cpu_state_data_size;
244 size += fw_dump.hpte_region_size;
245 size += fw_dump.boot_memory_size;
246 size += sizeof(struct fadump_crash_info_header);
247 size += sizeof(struct elfhdr); /* ELF core header.*/
248 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
249 /* Program headers for crash memory regions. */
250 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
251
252 size = PAGE_ALIGN(size);
253 return size;
254}
255
256int __init fadump_reserve_mem(void)
257{
258 unsigned long base, size, memory_boundary;
259
260 if (!fw_dump.fadump_enabled)
261 return 0;
262
263 if (!fw_dump.fadump_supported) {
264 printk(KERN_INFO "Firmware-assisted dump is not supported on"
265 " this hardware\n");
266 fw_dump.fadump_enabled = 0;
267 return 0;
268 }
269 /*
270 * Initialize boot memory size
271 * If dump is active then we have already calculated the size during
272 * first kernel.
273 */
274 if (fdm_active)
275 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
276 else
277 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
278
279 /*
280 * Calculate the memory boundary.
281 * If memory_limit is less than actual memory boundary then reserve
282 * the memory for fadump beyond the memory_limit and adjust the
283 * memory_limit accordingly, so that the running kernel can run with
284 * specified memory_limit.
285 */
286 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
287 size = get_fadump_area_size();
288 if ((memory_limit + size) < memblock_end_of_DRAM())
289 memory_limit += size;
290 else
291 memory_limit = memblock_end_of_DRAM();
292 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
293 " dump, now %#016llx\n", 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 be64_to_cpu(fdm_active->rmr_region.destination_address) +
318 be64_to_cpu(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
336unsigned long __init arch_reserved_kernel_pages(void)
337{
338 return memblock_reserved_size() / PAGE_SIZE;
339}
340
341/* Look for fadump= cmdline option. */
342static int __init early_fadump_param(char *p)
343{
344 if (!p)
345 return 1;
346
347 if (strncmp(p, "on", 2) == 0)
348 fw_dump.fadump_enabled = 1;
349 else if (strncmp(p, "off", 3) == 0)
350 fw_dump.fadump_enabled = 0;
351
352 return 0;
353}
354early_param("fadump", early_fadump_param);
355
356/* Look for fadump_reserve_mem= cmdline option */
357static int __init early_fadump_reserve_mem(char *p)
358{
359 if (p)
360 fw_dump.reserve_bootvar = memparse(p, &p);
361 return 0;
362}
363early_param("fadump_reserve_mem", early_fadump_reserve_mem);
364
365static void register_fw_dump(struct fadump_mem_struct *fdm)
366{
367 int rc;
368 unsigned int wait_time;
369
370 pr_debug("Registering for firmware-assisted kernel dump...\n");
371
372 /* TODO: Add upper time limit for the delay */
373 do {
374 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
375 FADUMP_REGISTER, fdm,
376 sizeof(struct fadump_mem_struct));
377
378 wait_time = rtas_busy_delay_time(rc);
379 if (wait_time)
380 mdelay(wait_time);
381
382 } while (wait_time);
383
384 switch (rc) {
385 case -1:
386 printk(KERN_ERR "Failed to register firmware-assisted kernel"
387 " dump. Hardware Error(%d).\n", rc);
388 break;
389 case -3:
390 printk(KERN_ERR "Failed to register firmware-assisted kernel"
391 " dump. Parameter Error(%d).\n", rc);
392 break;
393 case -9:
394 printk(KERN_ERR "firmware-assisted kernel dump is already "
395 " registered.");
396 fw_dump.dump_registered = 1;
397 break;
398 case 0:
399 printk(KERN_INFO "firmware-assisted kernel dump registration"
400 " is successful\n");
401 fw_dump.dump_registered = 1;
402 break;
403 }
404}
405
406void crash_fadump(struct pt_regs *regs, const char *str)
407{
408 struct fadump_crash_info_header *fdh = NULL;
409
410 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
411 return;
412
413 fdh = __va(fw_dump.fadumphdr_addr);
414 crashing_cpu = smp_processor_id();
415 fdh->crashing_cpu = crashing_cpu;
416 crash_save_vmcoreinfo();
417
418 if (regs)
419 fdh->regs = *regs;
420 else
421 ppc_save_regs(&fdh->regs);
422
423 fdh->online_mask = *cpu_online_mask;
424
425 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
426 rtas_os_term((char *)str);
427}
428
429#define GPR_MASK 0xffffff0000000000
430static inline int fadump_gpr_index(u64 id)
431{
432 int i = -1;
433 char str[3];
434
435 if ((id & GPR_MASK) == REG_ID("GPR")) {
436 /* get the digits at the end */
437 id &= ~GPR_MASK;
438 id >>= 24;
439 str[2] = '\0';
440 str[1] = id & 0xff;
441 str[0] = (id >> 8) & 0xff;
442 sscanf(str, "%d", &i);
443 if (i > 31)
444 i = -1;
445 }
446 return i;
447}
448
449static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
450 u64 reg_val)
451{
452 int i;
453
454 i = fadump_gpr_index(reg_id);
455 if (i >= 0)
456 regs->gpr[i] = (unsigned long)reg_val;
457 else if (reg_id == REG_ID("NIA"))
458 regs->nip = (unsigned long)reg_val;
459 else if (reg_id == REG_ID("MSR"))
460 regs->msr = (unsigned long)reg_val;
461 else if (reg_id == REG_ID("CTR"))
462 regs->ctr = (unsigned long)reg_val;
463 else if (reg_id == REG_ID("LR"))
464 regs->link = (unsigned long)reg_val;
465 else if (reg_id == REG_ID("XER"))
466 regs->xer = (unsigned long)reg_val;
467 else if (reg_id == REG_ID("CR"))
468 regs->ccr = (unsigned long)reg_val;
469 else if (reg_id == REG_ID("DAR"))
470 regs->dar = (unsigned long)reg_val;
471 else if (reg_id == REG_ID("DSISR"))
472 regs->dsisr = (unsigned long)reg_val;
473}
474
475static struct fadump_reg_entry*
476fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
477{
478 memset(regs, 0, sizeof(struct pt_regs));
479
480 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
481 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
482 be64_to_cpu(reg_entry->reg_value));
483 reg_entry++;
484 }
485 reg_entry++;
486 return reg_entry;
487}
488
489static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
490 void *data, size_t data_len)
491{
492 struct elf_note note;
493
494 note.n_namesz = strlen(name) + 1;
495 note.n_descsz = data_len;
496 note.n_type = type;
497 memcpy(buf, ¬e, sizeof(note));
498 buf += (sizeof(note) + 3)/4;
499 memcpy(buf, name, note.n_namesz);
500 buf += (note.n_namesz + 3)/4;
501 memcpy(buf, data, note.n_descsz);
502 buf += (note.n_descsz + 3)/4;
503
504 return buf;
505}
506
507static void fadump_final_note(u32 *buf)
508{
509 struct elf_note note;
510
511 note.n_namesz = 0;
512 note.n_descsz = 0;
513 note.n_type = 0;
514 memcpy(buf, ¬e, sizeof(note));
515}
516
517static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
518{
519 struct elf_prstatus prstatus;
520
521 memset(&prstatus, 0, sizeof(prstatus));
522 /*
523 * FIXME: How do i get PID? Do I really need it?
524 * prstatus.pr_pid = ????
525 */
526 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
527 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
528 &prstatus, sizeof(prstatus));
529 return buf;
530}
531
532static void fadump_update_elfcore_header(char *bufp)
533{
534 struct elfhdr *elf;
535 struct elf_phdr *phdr;
536
537 elf = (struct elfhdr *)bufp;
538 bufp += sizeof(struct elfhdr);
539
540 /* First note is a place holder for cpu notes info. */
541 phdr = (struct elf_phdr *)bufp;
542
543 if (phdr->p_type == PT_NOTE) {
544 phdr->p_paddr = fw_dump.cpu_notes_buf;
545 phdr->p_offset = phdr->p_paddr;
546 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
547 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
548 }
549 return;
550}
551
552static void *fadump_cpu_notes_buf_alloc(unsigned long size)
553{
554 void *vaddr;
555 struct page *page;
556 unsigned long order, count, i;
557
558 order = get_order(size);
559 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
560 if (!vaddr)
561 return NULL;
562
563 count = 1 << order;
564 page = virt_to_page(vaddr);
565 for (i = 0; i < count; i++)
566 SetPageReserved(page + i);
567 return vaddr;
568}
569
570static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
571{
572 struct page *page;
573 unsigned long order, count, i;
574
575 order = get_order(size);
576 count = 1 << order;
577 page = virt_to_page(vaddr);
578 for (i = 0; i < count; i++)
579 ClearPageReserved(page + i);
580 __free_pages(page, order);
581}
582
583/*
584 * Read CPU state dump data and convert it into ELF notes.
585 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
586 * used to access the data to allow for additional fields to be added without
587 * affecting compatibility. Each list of registers for a CPU starts with
588 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
589 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
590 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
591 * of register value. For more details refer to PAPR document.
592 *
593 * Only for the crashing cpu we ignore the CPU dump data and get exact
594 * state from fadump crash info structure populated by first kernel at the
595 * time of crash.
596 */
597static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
598{
599 struct fadump_reg_save_area_header *reg_header;
600 struct fadump_reg_entry *reg_entry;
601 struct fadump_crash_info_header *fdh = NULL;
602 void *vaddr;
603 unsigned long addr;
604 u32 num_cpus, *note_buf;
605 struct pt_regs regs;
606 int i, rc = 0, cpu = 0;
607
608 if (!fdm->cpu_state_data.bytes_dumped)
609 return -EINVAL;
610
611 addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
612 vaddr = __va(addr);
613
614 reg_header = vaddr;
615 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
616 printk(KERN_ERR "Unable to read register save area.\n");
617 return -ENOENT;
618 }
619 pr_debug("--------CPU State Data------------\n");
620 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
621 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
622
623 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
624 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
625 pr_debug("NumCpus : %u\n", num_cpus);
626 vaddr += sizeof(u32);
627 reg_entry = (struct fadump_reg_entry *)vaddr;
628
629 /* Allocate buffer to hold cpu crash notes. */
630 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
631 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
632 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
633 if (!note_buf) {
634 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
635 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
636 return -ENOMEM;
637 }
638 fw_dump.cpu_notes_buf = __pa(note_buf);
639
640 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
641 (num_cpus * sizeof(note_buf_t)), note_buf);
642
643 if (fw_dump.fadumphdr_addr)
644 fdh = __va(fw_dump.fadumphdr_addr);
645
646 for (i = 0; i < num_cpus; i++) {
647 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
648 printk(KERN_ERR "Unable to read CPU state data\n");
649 rc = -ENOENT;
650 goto error_out;
651 }
652 /* Lower 4 bytes of reg_value contains logical cpu id */
653 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
654 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
655 SKIP_TO_NEXT_CPU(reg_entry);
656 continue;
657 }
658 pr_debug("Reading register data for cpu %d...\n", cpu);
659 if (fdh && fdh->crashing_cpu == cpu) {
660 regs = fdh->regs;
661 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
662 SKIP_TO_NEXT_CPU(reg_entry);
663 } else {
664 reg_entry++;
665 reg_entry = fadump_read_registers(reg_entry, ®s);
666 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
667 }
668 }
669 fadump_final_note(note_buf);
670
671 if (fdh) {
672 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
673 fdh->elfcorehdr_addr);
674 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
675 }
676 return 0;
677
678error_out:
679 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
680 fw_dump.cpu_notes_buf_size);
681 fw_dump.cpu_notes_buf = 0;
682 fw_dump.cpu_notes_buf_size = 0;
683 return rc;
684
685}
686
687/*
688 * Validate and process the dump data stored by firmware before exporting
689 * it through '/proc/vmcore'.
690 */
691static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
692{
693 struct fadump_crash_info_header *fdh;
694 int rc = 0;
695
696 if (!fdm_active || !fw_dump.fadumphdr_addr)
697 return -EINVAL;
698
699 /* Check if the dump data is valid. */
700 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
701 (fdm_active->cpu_state_data.error_flags != 0) ||
702 (fdm_active->rmr_region.error_flags != 0)) {
703 printk(KERN_ERR "Dump taken by platform is not valid\n");
704 return -EINVAL;
705 }
706 if ((fdm_active->rmr_region.bytes_dumped !=
707 fdm_active->rmr_region.source_len) ||
708 !fdm_active->cpu_state_data.bytes_dumped) {
709 printk(KERN_ERR "Dump taken by platform is incomplete\n");
710 return -EINVAL;
711 }
712
713 /* Validate the fadump crash info header */
714 fdh = __va(fw_dump.fadumphdr_addr);
715 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
716 printk(KERN_ERR "Crash info header is not valid.\n");
717 return -EINVAL;
718 }
719
720 rc = fadump_build_cpu_notes(fdm_active);
721 if (rc)
722 return rc;
723
724 /*
725 * We are done validating dump info and elfcore header is now ready
726 * to be exported. set elfcorehdr_addr so that vmcore module will
727 * export the elfcore header through '/proc/vmcore'.
728 */
729 elfcorehdr_addr = fdh->elfcorehdr_addr;
730
731 return 0;
732}
733
734static inline void fadump_add_crash_memory(unsigned long long base,
735 unsigned long long end)
736{
737 if (base == end)
738 return;
739
740 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
741 crash_mem_ranges, base, end - 1, (end - base));
742 crash_memory_ranges[crash_mem_ranges].base = base;
743 crash_memory_ranges[crash_mem_ranges].size = end - base;
744 crash_mem_ranges++;
745}
746
747static void fadump_exclude_reserved_area(unsigned long long start,
748 unsigned long long end)
749{
750 unsigned long long ra_start, ra_end;
751
752 ra_start = fw_dump.reserve_dump_area_start;
753 ra_end = ra_start + fw_dump.reserve_dump_area_size;
754
755 if ((ra_start < end) && (ra_end > start)) {
756 if ((start < ra_start) && (end > ra_end)) {
757 fadump_add_crash_memory(start, ra_start);
758 fadump_add_crash_memory(ra_end, end);
759 } else if (start < ra_start) {
760 fadump_add_crash_memory(start, ra_start);
761 } else if (ra_end < end) {
762 fadump_add_crash_memory(ra_end, end);
763 }
764 } else
765 fadump_add_crash_memory(start, end);
766}
767
768static int fadump_init_elfcore_header(char *bufp)
769{
770 struct elfhdr *elf;
771
772 elf = (struct elfhdr *) bufp;
773 bufp += sizeof(struct elfhdr);
774 memcpy(elf->e_ident, ELFMAG, SELFMAG);
775 elf->e_ident[EI_CLASS] = ELF_CLASS;
776 elf->e_ident[EI_DATA] = ELF_DATA;
777 elf->e_ident[EI_VERSION] = EV_CURRENT;
778 elf->e_ident[EI_OSABI] = ELF_OSABI;
779 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
780 elf->e_type = ET_CORE;
781 elf->e_machine = ELF_ARCH;
782 elf->e_version = EV_CURRENT;
783 elf->e_entry = 0;
784 elf->e_phoff = sizeof(struct elfhdr);
785 elf->e_shoff = 0;
786#if defined(_CALL_ELF)
787 elf->e_flags = _CALL_ELF;
788#else
789 elf->e_flags = 0;
790#endif
791 elf->e_ehsize = sizeof(struct elfhdr);
792 elf->e_phentsize = sizeof(struct elf_phdr);
793 elf->e_phnum = 0;
794 elf->e_shentsize = 0;
795 elf->e_shnum = 0;
796 elf->e_shstrndx = 0;
797
798 return 0;
799}
800
801/*
802 * Traverse through memblock structure and setup crash memory ranges. These
803 * ranges will be used create PT_LOAD program headers in elfcore header.
804 */
805static void fadump_setup_crash_memory_ranges(void)
806{
807 struct memblock_region *reg;
808 unsigned long long start, end;
809
810 pr_debug("Setup crash memory ranges.\n");
811 crash_mem_ranges = 0;
812 /*
813 * add the first memory chunk (RMA_START through boot_memory_size) as
814 * a separate memory chunk. The reason is, at the time crash firmware
815 * will move the content of this memory chunk to different location
816 * specified during fadump registration. We need to create a separate
817 * program header for this chunk with the correct offset.
818 */
819 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
820
821 for_each_memblock(memory, reg) {
822 start = (unsigned long long)reg->base;
823 end = start + (unsigned long long)reg->size;
824 if (start == RMA_START && end >= fw_dump.boot_memory_size)
825 start = fw_dump.boot_memory_size;
826
827 /* add this range excluding the reserved dump area. */
828 fadump_exclude_reserved_area(start, end);
829 }
830}
831
832/*
833 * If the given physical address falls within the boot memory region then
834 * return the relocated address that points to the dump region reserved
835 * for saving initial boot memory contents.
836 */
837static inline unsigned long fadump_relocate(unsigned long paddr)
838{
839 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
840 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
841 else
842 return paddr;
843}
844
845static int fadump_create_elfcore_headers(char *bufp)
846{
847 struct elfhdr *elf;
848 struct elf_phdr *phdr;
849 int i;
850
851 fadump_init_elfcore_header(bufp);
852 elf = (struct elfhdr *)bufp;
853 bufp += sizeof(struct elfhdr);
854
855 /*
856 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
857 * will be populated during second kernel boot after crash. Hence
858 * this PT_NOTE will always be the first elf note.
859 *
860 * NOTE: Any new ELF note addition should be placed after this note.
861 */
862 phdr = (struct elf_phdr *)bufp;
863 bufp += sizeof(struct elf_phdr);
864 phdr->p_type = PT_NOTE;
865 phdr->p_flags = 0;
866 phdr->p_vaddr = 0;
867 phdr->p_align = 0;
868
869 phdr->p_offset = 0;
870 phdr->p_paddr = 0;
871 phdr->p_filesz = 0;
872 phdr->p_memsz = 0;
873
874 (elf->e_phnum)++;
875
876 /* setup ELF PT_NOTE for vmcoreinfo */
877 phdr = (struct elf_phdr *)bufp;
878 bufp += sizeof(struct elf_phdr);
879 phdr->p_type = PT_NOTE;
880 phdr->p_flags = 0;
881 phdr->p_vaddr = 0;
882 phdr->p_align = 0;
883
884 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
885 phdr->p_offset = phdr->p_paddr;
886 phdr->p_memsz = vmcoreinfo_max_size;
887 phdr->p_filesz = vmcoreinfo_max_size;
888
889 /* Increment number of program headers. */
890 (elf->e_phnum)++;
891
892 /* setup PT_LOAD sections. */
893
894 for (i = 0; i < crash_mem_ranges; i++) {
895 unsigned long long mbase, msize;
896 mbase = crash_memory_ranges[i].base;
897 msize = crash_memory_ranges[i].size;
898
899 if (!msize)
900 continue;
901
902 phdr = (struct elf_phdr *)bufp;
903 bufp += sizeof(struct elf_phdr);
904 phdr->p_type = PT_LOAD;
905 phdr->p_flags = PF_R|PF_W|PF_X;
906 phdr->p_offset = mbase;
907
908 if (mbase == RMA_START) {
909 /*
910 * The entire RMA region will be moved by firmware
911 * to the specified destination_address. Hence set
912 * the correct offset.
913 */
914 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
915 }
916
917 phdr->p_paddr = mbase;
918 phdr->p_vaddr = (unsigned long)__va(mbase);
919 phdr->p_filesz = msize;
920 phdr->p_memsz = msize;
921 phdr->p_align = 0;
922
923 /* Increment number of program headers. */
924 (elf->e_phnum)++;
925 }
926 return 0;
927}
928
929static unsigned long init_fadump_header(unsigned long addr)
930{
931 struct fadump_crash_info_header *fdh;
932
933 if (!addr)
934 return 0;
935
936 fw_dump.fadumphdr_addr = addr;
937 fdh = __va(addr);
938 addr += sizeof(struct fadump_crash_info_header);
939
940 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
941 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
942 fdh->elfcorehdr_addr = addr;
943 /* We will set the crashing cpu id in crash_fadump() during crash. */
944 fdh->crashing_cpu = CPU_UNKNOWN;
945
946 return addr;
947}
948
949static void register_fadump(void)
950{
951 unsigned long addr;
952 void *vaddr;
953
954 /*
955 * If no memory is reserved then we can not register for firmware-
956 * assisted dump.
957 */
958 if (!fw_dump.reserve_dump_area_size)
959 return;
960
961 fadump_setup_crash_memory_ranges();
962
963 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
964 /* Initialize fadump crash info header. */
965 addr = init_fadump_header(addr);
966 vaddr = __va(addr);
967
968 pr_debug("Creating ELF core headers at %#016lx\n", addr);
969 fadump_create_elfcore_headers(vaddr);
970
971 /* register the future kernel dump with firmware. */
972 register_fw_dump(&fdm);
973}
974
975static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
976{
977 int rc = 0;
978 unsigned int wait_time;
979
980 pr_debug("Un-register firmware-assisted dump\n");
981
982 /* TODO: Add upper time limit for the delay */
983 do {
984 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
985 FADUMP_UNREGISTER, fdm,
986 sizeof(struct fadump_mem_struct));
987
988 wait_time = rtas_busy_delay_time(rc);
989 if (wait_time)
990 mdelay(wait_time);
991 } while (wait_time);
992
993 if (rc) {
994 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
995 " unexpected error(%d).\n", rc);
996 return rc;
997 }
998 fw_dump.dump_registered = 0;
999 return 0;
1000}
1001
1002static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1003{
1004 int rc = 0;
1005 unsigned int wait_time;
1006
1007 pr_debug("Invalidating firmware-assisted dump registration\n");
1008
1009 /* TODO: Add upper time limit for the delay */
1010 do {
1011 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1012 FADUMP_INVALIDATE, fdm,
1013 sizeof(struct fadump_mem_struct));
1014
1015 wait_time = rtas_busy_delay_time(rc);
1016 if (wait_time)
1017 mdelay(wait_time);
1018 } while (wait_time);
1019
1020 if (rc) {
1021 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1022 return rc;
1023 }
1024 fw_dump.dump_active = 0;
1025 fdm_active = NULL;
1026 return 0;
1027}
1028
1029void fadump_cleanup(void)
1030{
1031 /* Invalidate the registration only if dump is active. */
1032 if (fw_dump.dump_active) {
1033 init_fadump_mem_struct(&fdm,
1034 be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1035 fadump_invalidate_dump(&fdm);
1036 }
1037}
1038
1039/*
1040 * Release the memory that was reserved in early boot to preserve the memory
1041 * contents. The released memory will be available for general use.
1042 */
1043static void fadump_release_memory(unsigned long begin, unsigned long end)
1044{
1045 unsigned long addr;
1046 unsigned long ra_start, ra_end;
1047
1048 ra_start = fw_dump.reserve_dump_area_start;
1049 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1050
1051 for (addr = begin; addr < end; addr += PAGE_SIZE) {
1052 /*
1053 * exclude the dump reserve area. Will reuse it for next
1054 * fadump registration.
1055 */
1056 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1057 continue;
1058
1059 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1060 }
1061}
1062
1063static void fadump_invalidate_release_mem(void)
1064{
1065 unsigned long reserved_area_start, reserved_area_end;
1066 unsigned long destination_address;
1067
1068 mutex_lock(&fadump_mutex);
1069 if (!fw_dump.dump_active) {
1070 mutex_unlock(&fadump_mutex);
1071 return;
1072 }
1073
1074 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1075 fadump_cleanup();
1076 mutex_unlock(&fadump_mutex);
1077
1078 /*
1079 * Save the current reserved memory bounds we will require them
1080 * later for releasing the memory for general use.
1081 */
1082 reserved_area_start = fw_dump.reserve_dump_area_start;
1083 reserved_area_end = reserved_area_start +
1084 fw_dump.reserve_dump_area_size;
1085 /*
1086 * Setup reserve_dump_area_start and its size so that we can
1087 * reuse this reserved memory for Re-registration.
1088 */
1089 fw_dump.reserve_dump_area_start = destination_address;
1090 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1091
1092 fadump_release_memory(reserved_area_start, reserved_area_end);
1093 if (fw_dump.cpu_notes_buf) {
1094 fadump_cpu_notes_buf_free(
1095 (unsigned long)__va(fw_dump.cpu_notes_buf),
1096 fw_dump.cpu_notes_buf_size);
1097 fw_dump.cpu_notes_buf = 0;
1098 fw_dump.cpu_notes_buf_size = 0;
1099 }
1100 /* Initialize the kernel dump memory structure for FAD registration. */
1101 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1102}
1103
1104static ssize_t fadump_release_memory_store(struct kobject *kobj,
1105 struct kobj_attribute *attr,
1106 const char *buf, size_t count)
1107{
1108 if (!fw_dump.dump_active)
1109 return -EPERM;
1110
1111 if (buf[0] == '1') {
1112 /*
1113 * Take away the '/proc/vmcore'. We are releasing the dump
1114 * memory, hence it will not be valid anymore.
1115 */
1116#ifdef CONFIG_PROC_VMCORE
1117 vmcore_cleanup();
1118#endif
1119 fadump_invalidate_release_mem();
1120
1121 } else
1122 return -EINVAL;
1123 return count;
1124}
1125
1126static ssize_t fadump_enabled_show(struct kobject *kobj,
1127 struct kobj_attribute *attr,
1128 char *buf)
1129{
1130 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1131}
1132
1133static ssize_t fadump_register_show(struct kobject *kobj,
1134 struct kobj_attribute *attr,
1135 char *buf)
1136{
1137 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1138}
1139
1140static ssize_t fadump_register_store(struct kobject *kobj,
1141 struct kobj_attribute *attr,
1142 const char *buf, size_t count)
1143{
1144 int ret = 0;
1145
1146 if (!fw_dump.fadump_enabled || fdm_active)
1147 return -EPERM;
1148
1149 mutex_lock(&fadump_mutex);
1150
1151 switch (buf[0]) {
1152 case '0':
1153 if (fw_dump.dump_registered == 0) {
1154 ret = -EINVAL;
1155 goto unlock_out;
1156 }
1157 /* Un-register Firmware-assisted dump */
1158 fadump_unregister_dump(&fdm);
1159 break;
1160 case '1':
1161 if (fw_dump.dump_registered == 1) {
1162 ret = -EINVAL;
1163 goto unlock_out;
1164 }
1165 /* Register Firmware-assisted dump */
1166 register_fadump();
1167 break;
1168 default:
1169 ret = -EINVAL;
1170 break;
1171 }
1172
1173unlock_out:
1174 mutex_unlock(&fadump_mutex);
1175 return ret < 0 ? ret : count;
1176}
1177
1178static int fadump_region_show(struct seq_file *m, void *private)
1179{
1180 const struct fadump_mem_struct *fdm_ptr;
1181
1182 if (!fw_dump.fadump_enabled)
1183 return 0;
1184
1185 mutex_lock(&fadump_mutex);
1186 if (fdm_active)
1187 fdm_ptr = fdm_active;
1188 else {
1189 mutex_unlock(&fadump_mutex);
1190 fdm_ptr = &fdm;
1191 }
1192
1193 seq_printf(m,
1194 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1195 "Dumped: %#llx\n",
1196 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1197 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1198 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1199 be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1200 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1201 seq_printf(m,
1202 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1203 "Dumped: %#llx\n",
1204 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1205 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1206 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1207 be64_to_cpu(fdm_ptr->hpte_region.source_len),
1208 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1209 seq_printf(m,
1210 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1211 "Dumped: %#llx\n",
1212 be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1213 be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1214 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1215 be64_to_cpu(fdm_ptr->rmr_region.source_len),
1216 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1217
1218 if (!fdm_active ||
1219 (fw_dump.reserve_dump_area_start ==
1220 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1221 goto out;
1222
1223 /* Dump is active. Show reserved memory region. */
1224 seq_printf(m,
1225 " : [%#016llx-%#016llx] %#llx bytes, "
1226 "Dumped: %#llx\n",
1227 (unsigned long long)fw_dump.reserve_dump_area_start,
1228 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1229 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1230 fw_dump.reserve_dump_area_start,
1231 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1232 fw_dump.reserve_dump_area_start);
1233out:
1234 if (fdm_active)
1235 mutex_unlock(&fadump_mutex);
1236 return 0;
1237}
1238
1239static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1240 0200, NULL,
1241 fadump_release_memory_store);
1242static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1243 0444, fadump_enabled_show,
1244 NULL);
1245static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1246 0644, fadump_register_show,
1247 fadump_register_store);
1248
1249static int fadump_region_open(struct inode *inode, struct file *file)
1250{
1251 return single_open(file, fadump_region_show, inode->i_private);
1252}
1253
1254static const struct file_operations fadump_region_fops = {
1255 .open = fadump_region_open,
1256 .read = seq_read,
1257 .llseek = seq_lseek,
1258 .release = single_release,
1259};
1260
1261static void fadump_init_files(void)
1262{
1263 struct dentry *debugfs_file;
1264 int rc = 0;
1265
1266 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1267 if (rc)
1268 printk(KERN_ERR "fadump: unable to create sysfs file"
1269 " fadump_enabled (%d)\n", rc);
1270
1271 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1272 if (rc)
1273 printk(KERN_ERR "fadump: unable to create sysfs file"
1274 " fadump_registered (%d)\n", rc);
1275
1276 debugfs_file = debugfs_create_file("fadump_region", 0444,
1277 powerpc_debugfs_root, NULL,
1278 &fadump_region_fops);
1279 if (!debugfs_file)
1280 printk(KERN_ERR "fadump: unable to create debugfs file"
1281 " fadump_region\n");
1282
1283 if (fw_dump.dump_active) {
1284 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1285 if (rc)
1286 printk(KERN_ERR "fadump: unable to create sysfs file"
1287 " fadump_release_mem (%d)\n", rc);
1288 }
1289 return;
1290}
1291
1292/*
1293 * Prepare for firmware-assisted dump.
1294 */
1295int __init setup_fadump(void)
1296{
1297 if (!fw_dump.fadump_enabled)
1298 return 0;
1299
1300 if (!fw_dump.fadump_supported) {
1301 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1302 " this hardware\n");
1303 return 0;
1304 }
1305
1306 fadump_show_config();
1307 /*
1308 * If dump data is available then see if it is valid and prepare for
1309 * saving it to the disk.
1310 */
1311 if (fw_dump.dump_active) {
1312 /*
1313 * if dump process fails then invalidate the registration
1314 * and release memory before proceeding for re-registration.
1315 */
1316 if (process_fadump(fdm_active) < 0)
1317 fadump_invalidate_release_mem();
1318 }
1319 /* Initialize the kernel dump memory structure for FAD registration. */
1320 else if (fw_dump.reserve_dump_area_size)
1321 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1322 fadump_init_files();
1323
1324 return 1;
1325}
1326subsys_initcall(setup_fadump);