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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
4 * dump with assistance from firmware. This approach does not use kexec,
5 * instead firmware assists in booting the kdump kernel while preserving
6 * memory contents. The most of the code implementation has been adapted
7 * from phyp assisted dump implementation written by Linas Vepstas and
8 * Manish Ahuja
9 *
10 * Copyright 2011 IBM Corporation
11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
12 */
13
14#undef DEBUG
15#define pr_fmt(fmt) "fadump: " fmt
16
17#include <linux/string.h>
18#include <linux/memblock.h>
19#include <linux/delay.h>
20#include <linux/seq_file.h>
21#include <linux/crash_dump.h>
22#include <linux/kobject.h>
23#include <linux/sysfs.h>
24#include <linux/slab.h>
25#include <linux/cma.h>
26#include <linux/hugetlb.h>
27#include <linux/debugfs.h>
28#include <linux/of.h>
29#include <linux/of_fdt.h>
30
31#include <asm/page.h>
32#include <asm/fadump.h>
33#include <asm/fadump-internal.h>
34#include <asm/setup.h>
35#include <asm/interrupt.h>
36
37/*
38 * The CPU who acquired the lock to trigger the fadump crash should
39 * wait for other CPUs to enter.
40 *
41 * The timeout is in milliseconds.
42 */
43#define CRASH_TIMEOUT 500
44
45static struct fw_dump fw_dump;
46
47static void __init fadump_reserve_crash_area(u64 base);
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static struct kobject *fadump_kobj;
52
53static atomic_t cpus_in_fadump;
54static DEFINE_MUTEX(fadump_mutex);
55
56static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
57
58#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
59#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
60 sizeof(struct fadump_memory_range))
61static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
62static struct fadump_mrange_info
63reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
64
65static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
66
67#ifdef CONFIG_CMA
68static struct cma *fadump_cma;
69
70/*
71 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
72 *
73 * This function initializes CMA area from fadump reserved memory.
74 * The total size of fadump reserved memory covers for boot memory size
75 * + cpu data size + hpte size and metadata.
76 * Initialize only the area equivalent to boot memory size for CMA use.
77 * The remaining portion of fadump reserved memory will be not given
78 * to CMA and pages for those will stay reserved. boot memory size is
79 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
80 * But for some reason even if it fails we still have the memory reservation
81 * with us and we can still continue doing fadump.
82 */
83static int __init fadump_cma_init(void)
84{
85 unsigned long long base, size;
86 int rc;
87
88 if (!fw_dump.fadump_enabled)
89 return 0;
90
91 /*
92 * Do not use CMA if user has provided fadump=nocma kernel parameter.
93 * Return 1 to continue with fadump old behaviour.
94 */
95 if (fw_dump.nocma)
96 return 1;
97
98 base = fw_dump.reserve_dump_area_start;
99 size = fw_dump.boot_memory_size;
100
101 if (!size)
102 return 0;
103
104 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
105 if (rc) {
106 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
107 /*
108 * Though the CMA init has failed we still have memory
109 * reservation with us. The reserved memory will be
110 * blocked from production system usage. Hence return 1,
111 * so that we can continue with fadump.
112 */
113 return 1;
114 }
115
116 /*
117 * If CMA activation fails, keep the pages reserved, instead of
118 * exposing them to buddy allocator. Same as 'fadump=nocma' case.
119 */
120 cma_reserve_pages_on_error(fadump_cma);
121
122 /*
123 * So we now have successfully initialized cma area for fadump.
124 */
125 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
126 "bytes of memory reserved for firmware-assisted dump\n",
127 cma_get_size(fadump_cma),
128 (unsigned long)cma_get_base(fadump_cma) >> 20,
129 fw_dump.reserve_dump_area_size);
130 return 1;
131}
132#else
133static int __init fadump_cma_init(void) { return 1; }
134#endif /* CONFIG_CMA */
135
136/* Scan the Firmware Assisted dump configuration details. */
137int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
138 int depth, void *data)
139{
140 if (depth == 0) {
141 early_init_dt_scan_reserved_ranges(node);
142 return 0;
143 }
144
145 if (depth != 1)
146 return 0;
147
148 if (strcmp(uname, "rtas") == 0) {
149 rtas_fadump_dt_scan(&fw_dump, node);
150 return 1;
151 }
152
153 if (strcmp(uname, "ibm,opal") == 0) {
154 opal_fadump_dt_scan(&fw_dump, node);
155 return 1;
156 }
157
158 return 0;
159}
160
161/*
162 * If fadump is registered, check if the memory provided
163 * falls within boot memory area and reserved memory area.
164 */
165int is_fadump_memory_area(u64 addr, unsigned long size)
166{
167 u64 d_start, d_end;
168
169 if (!fw_dump.dump_registered)
170 return 0;
171
172 if (!size)
173 return 0;
174
175 d_start = fw_dump.reserve_dump_area_start;
176 d_end = d_start + fw_dump.reserve_dump_area_size;
177 if (((addr + size) > d_start) && (addr <= d_end))
178 return 1;
179
180 return (addr <= fw_dump.boot_mem_top);
181}
182
183int should_fadump_crash(void)
184{
185 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
186 return 0;
187 return 1;
188}
189
190int is_fadump_active(void)
191{
192 return fw_dump.dump_active;
193}
194
195/*
196 * Returns true, if there are no holes in memory area between d_start to d_end,
197 * false otherwise.
198 */
199static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
200{
201 phys_addr_t reg_start, reg_end;
202 bool ret = false;
203 u64 i, start, end;
204
205 for_each_mem_range(i, ®_start, ®_end) {
206 start = max_t(u64, d_start, reg_start);
207 end = min_t(u64, d_end, reg_end);
208 if (d_start < end) {
209 /* Memory hole from d_start to start */
210 if (start > d_start)
211 break;
212
213 if (end == d_end) {
214 ret = true;
215 break;
216 }
217
218 d_start = end + 1;
219 }
220 }
221
222 return ret;
223}
224
225/*
226 * Returns true, if there are no holes in boot memory area,
227 * false otherwise.
228 */
229bool is_fadump_boot_mem_contiguous(void)
230{
231 unsigned long d_start, d_end;
232 bool ret = false;
233 int i;
234
235 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
236 d_start = fw_dump.boot_mem_addr[i];
237 d_end = d_start + fw_dump.boot_mem_sz[i];
238
239 ret = is_fadump_mem_area_contiguous(d_start, d_end);
240 if (!ret)
241 break;
242 }
243
244 return ret;
245}
246
247/*
248 * Returns true, if there are no holes in reserved memory area,
249 * false otherwise.
250 */
251bool is_fadump_reserved_mem_contiguous(void)
252{
253 u64 d_start, d_end;
254
255 d_start = fw_dump.reserve_dump_area_start;
256 d_end = d_start + fw_dump.reserve_dump_area_size;
257 return is_fadump_mem_area_contiguous(d_start, d_end);
258}
259
260/* Print firmware assisted dump configurations for debugging purpose. */
261static void __init fadump_show_config(void)
262{
263 int i;
264
265 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
266 (fw_dump.fadump_supported ? "present" : "no support"));
267
268 if (!fw_dump.fadump_supported)
269 return;
270
271 pr_debug("Fadump enabled : %s\n",
272 (fw_dump.fadump_enabled ? "yes" : "no"));
273 pr_debug("Dump Active : %s\n",
274 (fw_dump.dump_active ? "yes" : "no"));
275 pr_debug("Dump section sizes:\n");
276 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
277 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
278 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
279 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
280 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
281 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
282 pr_debug("[%03d] base = %llx, size = %llx\n", i,
283 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
284 }
285}
286
287/**
288 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
289 *
290 * Function to find the largest memory size we need to reserve during early
291 * boot process. This will be the size of the memory that is required for a
292 * kernel to boot successfully.
293 *
294 * This function has been taken from phyp-assisted dump feature implementation.
295 *
296 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
297 *
298 * TODO: Come up with better approach to find out more accurate memory size
299 * that is required for a kernel to boot successfully.
300 *
301 */
302static __init u64 fadump_calculate_reserve_size(void)
303{
304 u64 base, size, bootmem_min;
305 int ret;
306
307 if (fw_dump.reserve_bootvar)
308 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
309
310 /*
311 * Check if the size is specified through crashkernel= cmdline
312 * option. If yes, then use that but ignore base as fadump reserves
313 * memory at a predefined offset.
314 */
315 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
316 &size, &base);
317 if (ret == 0 && size > 0) {
318 unsigned long max_size;
319
320 if (fw_dump.reserve_bootvar)
321 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
322
323 fw_dump.reserve_bootvar = (unsigned long)size;
324
325 /*
326 * Adjust if the boot memory size specified is above
327 * the upper limit.
328 */
329 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
330 if (fw_dump.reserve_bootvar > max_size) {
331 fw_dump.reserve_bootvar = max_size;
332 pr_info("Adjusted boot memory size to %luMB\n",
333 (fw_dump.reserve_bootvar >> 20));
334 }
335
336 return fw_dump.reserve_bootvar;
337 } else if (fw_dump.reserve_bootvar) {
338 /*
339 * 'fadump_reserve_mem=' is being used to reserve memory
340 * for firmware-assisted dump.
341 */
342 return fw_dump.reserve_bootvar;
343 }
344
345 /* divide by 20 to get 5% of value */
346 size = memblock_phys_mem_size() / 20;
347
348 /* round it down in multiples of 256 */
349 size = size & ~0x0FFFFFFFUL;
350
351 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
352 if (memory_limit && size > memory_limit)
353 size = memory_limit;
354
355 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
356 return (size > bootmem_min ? size : bootmem_min);
357}
358
359/*
360 * Calculate the total memory size required to be reserved for
361 * firmware-assisted dump registration.
362 */
363static unsigned long __init get_fadump_area_size(void)
364{
365 unsigned long size = 0;
366
367 size += fw_dump.cpu_state_data_size;
368 size += fw_dump.hpte_region_size;
369 /*
370 * Account for pagesize alignment of boot memory area destination address.
371 * This faciliates in mmap reading of first kernel's memory.
372 */
373 size = PAGE_ALIGN(size);
374 size += fw_dump.boot_memory_size;
375 size += sizeof(struct fadump_crash_info_header);
376 size += sizeof(struct elfhdr); /* ELF core header.*/
377 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
378 /* Program headers for crash memory regions. */
379 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
380
381 size = PAGE_ALIGN(size);
382
383 /* This is to hold kernel metadata on platforms that support it */
384 size += (fw_dump.ops->fadump_get_metadata_size ?
385 fw_dump.ops->fadump_get_metadata_size() : 0);
386 return size;
387}
388
389static int __init add_boot_mem_region(unsigned long rstart,
390 unsigned long rsize)
391{
392 int i = fw_dump.boot_mem_regs_cnt++;
393
394 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
395 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
396 return 0;
397 }
398
399 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
400 i, rstart, (rstart + rsize));
401 fw_dump.boot_mem_addr[i] = rstart;
402 fw_dump.boot_mem_sz[i] = rsize;
403 return 1;
404}
405
406/*
407 * Firmware usually has a hard limit on the data it can copy per region.
408 * Honour that by splitting a memory range into multiple regions.
409 */
410static int __init add_boot_mem_regions(unsigned long mstart,
411 unsigned long msize)
412{
413 unsigned long rstart, rsize, max_size;
414 int ret = 1;
415
416 rstart = mstart;
417 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
418 while (msize) {
419 if (msize > max_size)
420 rsize = max_size;
421 else
422 rsize = msize;
423
424 ret = add_boot_mem_region(rstart, rsize);
425 if (!ret)
426 break;
427
428 msize -= rsize;
429 rstart += rsize;
430 }
431
432 return ret;
433}
434
435static int __init fadump_get_boot_mem_regions(void)
436{
437 unsigned long size, cur_size, hole_size, last_end;
438 unsigned long mem_size = fw_dump.boot_memory_size;
439 phys_addr_t reg_start, reg_end;
440 int ret = 1;
441 u64 i;
442
443 fw_dump.boot_mem_regs_cnt = 0;
444
445 last_end = 0;
446 hole_size = 0;
447 cur_size = 0;
448 for_each_mem_range(i, ®_start, ®_end) {
449 size = reg_end - reg_start;
450 hole_size += (reg_start - last_end);
451
452 if ((cur_size + size) >= mem_size) {
453 size = (mem_size - cur_size);
454 ret = add_boot_mem_regions(reg_start, size);
455 break;
456 }
457
458 mem_size -= size;
459 cur_size += size;
460 ret = add_boot_mem_regions(reg_start, size);
461 if (!ret)
462 break;
463
464 last_end = reg_end;
465 }
466 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
467
468 return ret;
469}
470
471/*
472 * Returns true, if the given range overlaps with reserved memory ranges
473 * starting at idx. Also, updates idx to index of overlapping memory range
474 * with the given memory range.
475 * False, otherwise.
476 */
477static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
478{
479 bool ret = false;
480 int i;
481
482 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
483 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
484 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
485
486 if (end <= rbase)
487 break;
488
489 if ((end > rbase) && (base < rend)) {
490 *idx = i;
491 ret = true;
492 break;
493 }
494 }
495
496 return ret;
497}
498
499/*
500 * Locate a suitable memory area to reserve memory for FADump. While at it,
501 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
502 */
503static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
504{
505 struct fadump_memory_range *mrngs;
506 phys_addr_t mstart, mend;
507 int idx = 0;
508 u64 i, ret = 0;
509
510 mrngs = reserved_mrange_info.mem_ranges;
511 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
512 &mstart, &mend, NULL) {
513 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
514 i, mstart, mend, base);
515
516 if (mstart > base)
517 base = PAGE_ALIGN(mstart);
518
519 while ((mend > base) && ((mend - base) >= size)) {
520 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
521 ret = base;
522 goto out;
523 }
524
525 base = mrngs[idx].base + mrngs[idx].size;
526 base = PAGE_ALIGN(base);
527 }
528 }
529
530out:
531 return ret;
532}
533
534int __init fadump_reserve_mem(void)
535{
536 u64 base, size, mem_boundary, bootmem_min;
537 int ret = 1;
538
539 if (!fw_dump.fadump_enabled)
540 return 0;
541
542 if (!fw_dump.fadump_supported) {
543 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
544 goto error_out;
545 }
546
547 /*
548 * Initialize boot memory size
549 * If dump is active then we have already calculated the size during
550 * first kernel.
551 */
552 if (!fw_dump.dump_active) {
553 fw_dump.boot_memory_size =
554 PAGE_ALIGN(fadump_calculate_reserve_size());
555#ifdef CONFIG_CMA
556 if (!fw_dump.nocma) {
557 fw_dump.boot_memory_size =
558 ALIGN(fw_dump.boot_memory_size,
559 CMA_MIN_ALIGNMENT_BYTES);
560 }
561#endif
562
563 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
564 if (fw_dump.boot_memory_size < bootmem_min) {
565 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
566 fw_dump.boot_memory_size, bootmem_min);
567 goto error_out;
568 }
569
570 if (!fadump_get_boot_mem_regions()) {
571 pr_err("Too many holes in boot memory area to enable fadump\n");
572 goto error_out;
573 }
574 }
575
576 /*
577 * Calculate the memory boundary.
578 * If memory_limit is less than actual memory boundary then reserve
579 * the memory for fadump beyond the memory_limit and adjust the
580 * memory_limit accordingly, so that the running kernel can run with
581 * specified memory_limit.
582 */
583 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
584 size = get_fadump_area_size();
585 if ((memory_limit + size) < memblock_end_of_DRAM())
586 memory_limit += size;
587 else
588 memory_limit = memblock_end_of_DRAM();
589 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
590 " dump, now %#016llx\n", memory_limit);
591 }
592 if (memory_limit)
593 mem_boundary = memory_limit;
594 else
595 mem_boundary = memblock_end_of_DRAM();
596
597 base = fw_dump.boot_mem_top;
598 size = get_fadump_area_size();
599 fw_dump.reserve_dump_area_size = size;
600 if (fw_dump.dump_active) {
601 pr_info("Firmware-assisted dump is active.\n");
602
603#ifdef CONFIG_HUGETLB_PAGE
604 /*
605 * FADump capture kernel doesn't care much about hugepages.
606 * In fact, handling hugepages in capture kernel is asking for
607 * trouble. So, disable HugeTLB support when fadump is active.
608 */
609 hugetlb_disabled = true;
610#endif
611 /*
612 * If last boot has crashed then reserve all the memory
613 * above boot memory size so that we don't touch it until
614 * dump is written to disk by userspace tool. This memory
615 * can be released for general use by invalidating fadump.
616 */
617 fadump_reserve_crash_area(base);
618
619 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
620 pr_debug("Reserve dump area start address: 0x%lx\n",
621 fw_dump.reserve_dump_area_start);
622 } else {
623 /*
624 * Reserve memory at an offset closer to bottom of the RAM to
625 * minimize the impact of memory hot-remove operation.
626 */
627 base = fadump_locate_reserve_mem(base, size);
628
629 if (!base || (base + size > mem_boundary)) {
630 pr_err("Failed to find memory chunk for reservation!\n");
631 goto error_out;
632 }
633 fw_dump.reserve_dump_area_start = base;
634
635 /*
636 * Calculate the kernel metadata address and register it with
637 * f/w if the platform supports.
638 */
639 if (fw_dump.ops->fadump_setup_metadata &&
640 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
641 goto error_out;
642
643 if (memblock_reserve(base, size)) {
644 pr_err("Failed to reserve memory!\n");
645 goto error_out;
646 }
647
648 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
649 (size >> 20), base, (memblock_phys_mem_size() >> 20));
650
651 ret = fadump_cma_init();
652 }
653
654 return ret;
655error_out:
656 fw_dump.fadump_enabled = 0;
657 return 0;
658}
659
660/* Look for fadump= cmdline option. */
661static int __init early_fadump_param(char *p)
662{
663 if (!p)
664 return 1;
665
666 if (strncmp(p, "on", 2) == 0)
667 fw_dump.fadump_enabled = 1;
668 else if (strncmp(p, "off", 3) == 0)
669 fw_dump.fadump_enabled = 0;
670 else if (strncmp(p, "nocma", 5) == 0) {
671 fw_dump.fadump_enabled = 1;
672 fw_dump.nocma = 1;
673 }
674
675 return 0;
676}
677early_param("fadump", early_fadump_param);
678
679/*
680 * Look for fadump_reserve_mem= cmdline option
681 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
682 * the sooner 'crashkernel=' parameter is accustomed to.
683 */
684static int __init early_fadump_reserve_mem(char *p)
685{
686 if (p)
687 fw_dump.reserve_bootvar = memparse(p, &p);
688 return 0;
689}
690early_param("fadump_reserve_mem", early_fadump_reserve_mem);
691
692void crash_fadump(struct pt_regs *regs, const char *str)
693{
694 unsigned int msecs;
695 struct fadump_crash_info_header *fdh = NULL;
696 int old_cpu, this_cpu;
697 /* Do not include first CPU */
698 unsigned int ncpus = num_online_cpus() - 1;
699
700 if (!should_fadump_crash())
701 return;
702
703 /*
704 * old_cpu == -1 means this is the first CPU which has come here,
705 * go ahead and trigger fadump.
706 *
707 * old_cpu != -1 means some other CPU has already on it's way
708 * to trigger fadump, just keep looping here.
709 */
710 this_cpu = smp_processor_id();
711 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
712
713 if (old_cpu != -1) {
714 atomic_inc(&cpus_in_fadump);
715
716 /*
717 * We can't loop here indefinitely. Wait as long as fadump
718 * is in force. If we race with fadump un-registration this
719 * loop will break and then we go down to normal panic path
720 * and reboot. If fadump is in force the first crashing
721 * cpu will definitely trigger fadump.
722 */
723 while (fw_dump.dump_registered)
724 cpu_relax();
725 return;
726 }
727
728 fdh = __va(fw_dump.fadumphdr_addr);
729 fdh->crashing_cpu = crashing_cpu;
730 crash_save_vmcoreinfo();
731
732 if (regs)
733 fdh->regs = *regs;
734 else
735 ppc_save_regs(&fdh->regs);
736
737 fdh->cpu_mask = *cpu_online_mask;
738
739 /*
740 * If we came in via system reset, wait a while for the secondary
741 * CPUs to enter.
742 */
743 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
744 msecs = CRASH_TIMEOUT;
745 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
746 mdelay(1);
747 }
748
749 fw_dump.ops->fadump_trigger(fdh, str);
750}
751
752u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
753{
754 struct elf_prstatus prstatus;
755
756 memset(&prstatus, 0, sizeof(prstatus));
757 /*
758 * FIXME: How do i get PID? Do I really need it?
759 * prstatus.pr_pid = ????
760 */
761 elf_core_copy_regs(&prstatus.pr_reg, regs);
762 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
763 &prstatus, sizeof(prstatus));
764 return buf;
765}
766
767void __init fadump_update_elfcore_header(char *bufp)
768{
769 struct elf_phdr *phdr;
770
771 bufp += sizeof(struct elfhdr);
772
773 /* First note is a place holder for cpu notes info. */
774 phdr = (struct elf_phdr *)bufp;
775
776 if (phdr->p_type == PT_NOTE) {
777 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
778 phdr->p_offset = phdr->p_paddr;
779 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
780 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
781 }
782 return;
783}
784
785static void *__init fadump_alloc_buffer(unsigned long size)
786{
787 unsigned long count, i;
788 struct page *page;
789 void *vaddr;
790
791 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
792 if (!vaddr)
793 return NULL;
794
795 count = PAGE_ALIGN(size) / PAGE_SIZE;
796 page = virt_to_page(vaddr);
797 for (i = 0; i < count; i++)
798 mark_page_reserved(page + i);
799 return vaddr;
800}
801
802static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
803{
804 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
805}
806
807s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
808{
809 /* Allocate buffer to hold cpu crash notes. */
810 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
811 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
812 fw_dump.cpu_notes_buf_vaddr =
813 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
814 if (!fw_dump.cpu_notes_buf_vaddr) {
815 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
816 fw_dump.cpu_notes_buf_size);
817 return -ENOMEM;
818 }
819
820 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
821 fw_dump.cpu_notes_buf_size,
822 fw_dump.cpu_notes_buf_vaddr);
823 return 0;
824}
825
826void fadump_free_cpu_notes_buf(void)
827{
828 if (!fw_dump.cpu_notes_buf_vaddr)
829 return;
830
831 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
832 fw_dump.cpu_notes_buf_size);
833 fw_dump.cpu_notes_buf_vaddr = 0;
834 fw_dump.cpu_notes_buf_size = 0;
835}
836
837static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
838{
839 if (mrange_info->is_static) {
840 mrange_info->mem_range_cnt = 0;
841 return;
842 }
843
844 kfree(mrange_info->mem_ranges);
845 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
846 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
847}
848
849/*
850 * Allocate or reallocate mem_ranges array in incremental units
851 * of PAGE_SIZE.
852 */
853static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
854{
855 struct fadump_memory_range *new_array;
856 u64 new_size;
857
858 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
859 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
860 new_size, mrange_info->name);
861
862 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
863 if (new_array == NULL) {
864 pr_err("Insufficient memory for setting up %s memory ranges\n",
865 mrange_info->name);
866 fadump_free_mem_ranges(mrange_info);
867 return -ENOMEM;
868 }
869
870 mrange_info->mem_ranges = new_array;
871 mrange_info->mem_ranges_sz = new_size;
872 mrange_info->max_mem_ranges = (new_size /
873 sizeof(struct fadump_memory_range));
874 return 0;
875}
876static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
877 u64 base, u64 end)
878{
879 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
880 bool is_adjacent = false;
881 u64 start, size;
882
883 if (base == end)
884 return 0;
885
886 /*
887 * Fold adjacent memory ranges to bring down the memory ranges/
888 * PT_LOAD segments count.
889 */
890 if (mrange_info->mem_range_cnt) {
891 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
892 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
893
894 /*
895 * Boot memory area needs separate PT_LOAD segment(s) as it
896 * is moved to a different location at the time of crash.
897 * So, fold only if the region is not boot memory area.
898 */
899 if ((start + size) == base && start >= fw_dump.boot_mem_top)
900 is_adjacent = true;
901 }
902 if (!is_adjacent) {
903 /* resize the array on reaching the limit */
904 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
905 int ret;
906
907 if (mrange_info->is_static) {
908 pr_err("Reached array size limit for %s memory ranges\n",
909 mrange_info->name);
910 return -ENOSPC;
911 }
912
913 ret = fadump_alloc_mem_ranges(mrange_info);
914 if (ret)
915 return ret;
916
917 /* Update to the new resized array */
918 mem_ranges = mrange_info->mem_ranges;
919 }
920
921 start = base;
922 mem_ranges[mrange_info->mem_range_cnt].base = start;
923 mrange_info->mem_range_cnt++;
924 }
925
926 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
927 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
928 mrange_info->name, (mrange_info->mem_range_cnt - 1),
929 start, end - 1, (end - start));
930 return 0;
931}
932
933static int fadump_exclude_reserved_area(u64 start, u64 end)
934{
935 u64 ra_start, ra_end;
936 int ret = 0;
937
938 ra_start = fw_dump.reserve_dump_area_start;
939 ra_end = ra_start + fw_dump.reserve_dump_area_size;
940
941 if ((ra_start < end) && (ra_end > start)) {
942 if ((start < ra_start) && (end > ra_end)) {
943 ret = fadump_add_mem_range(&crash_mrange_info,
944 start, ra_start);
945 if (ret)
946 return ret;
947
948 ret = fadump_add_mem_range(&crash_mrange_info,
949 ra_end, end);
950 } else if (start < ra_start) {
951 ret = fadump_add_mem_range(&crash_mrange_info,
952 start, ra_start);
953 } else if (ra_end < end) {
954 ret = fadump_add_mem_range(&crash_mrange_info,
955 ra_end, end);
956 }
957 } else
958 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
959
960 return ret;
961}
962
963static int fadump_init_elfcore_header(char *bufp)
964{
965 struct elfhdr *elf;
966
967 elf = (struct elfhdr *) bufp;
968 bufp += sizeof(struct elfhdr);
969 memcpy(elf->e_ident, ELFMAG, SELFMAG);
970 elf->e_ident[EI_CLASS] = ELF_CLASS;
971 elf->e_ident[EI_DATA] = ELF_DATA;
972 elf->e_ident[EI_VERSION] = EV_CURRENT;
973 elf->e_ident[EI_OSABI] = ELF_OSABI;
974 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
975 elf->e_type = ET_CORE;
976 elf->e_machine = ELF_ARCH;
977 elf->e_version = EV_CURRENT;
978 elf->e_entry = 0;
979 elf->e_phoff = sizeof(struct elfhdr);
980 elf->e_shoff = 0;
981
982 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
983 elf->e_flags = 2;
984 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
985 elf->e_flags = 1;
986 else
987 elf->e_flags = 0;
988
989 elf->e_ehsize = sizeof(struct elfhdr);
990 elf->e_phentsize = sizeof(struct elf_phdr);
991 elf->e_phnum = 0;
992 elf->e_shentsize = 0;
993 elf->e_shnum = 0;
994 elf->e_shstrndx = 0;
995
996 return 0;
997}
998
999/*
1000 * Traverse through memblock structure and setup crash memory ranges. These
1001 * ranges will be used create PT_LOAD program headers in elfcore header.
1002 */
1003static int fadump_setup_crash_memory_ranges(void)
1004{
1005 u64 i, start, end;
1006 int ret;
1007
1008 pr_debug("Setup crash memory ranges.\n");
1009 crash_mrange_info.mem_range_cnt = 0;
1010
1011 /*
1012 * Boot memory region(s) registered with firmware are moved to
1013 * different location at the time of crash. Create separate program
1014 * header(s) for this memory chunk(s) with the correct offset.
1015 */
1016 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1017 start = fw_dump.boot_mem_addr[i];
1018 end = start + fw_dump.boot_mem_sz[i];
1019 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1020 if (ret)
1021 return ret;
1022 }
1023
1024 for_each_mem_range(i, &start, &end) {
1025 /*
1026 * skip the memory chunk that is already added
1027 * (0 through boot_memory_top).
1028 */
1029 if (start < fw_dump.boot_mem_top) {
1030 if (end > fw_dump.boot_mem_top)
1031 start = fw_dump.boot_mem_top;
1032 else
1033 continue;
1034 }
1035
1036 /* add this range excluding the reserved dump area. */
1037 ret = fadump_exclude_reserved_area(start, end);
1038 if (ret)
1039 return ret;
1040 }
1041
1042 return 0;
1043}
1044
1045/*
1046 * If the given physical address falls within the boot memory region then
1047 * return the relocated address that points to the dump region reserved
1048 * for saving initial boot memory contents.
1049 */
1050static inline unsigned long fadump_relocate(unsigned long paddr)
1051{
1052 unsigned long raddr, rstart, rend, rlast, hole_size;
1053 int i;
1054
1055 hole_size = 0;
1056 rlast = 0;
1057 raddr = paddr;
1058 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1059 rstart = fw_dump.boot_mem_addr[i];
1060 rend = rstart + fw_dump.boot_mem_sz[i];
1061 hole_size += (rstart - rlast);
1062
1063 if (paddr >= rstart && paddr < rend) {
1064 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1065 break;
1066 }
1067
1068 rlast = rend;
1069 }
1070
1071 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1072 return raddr;
1073}
1074
1075static int fadump_create_elfcore_headers(char *bufp)
1076{
1077 unsigned long long raddr, offset;
1078 struct elf_phdr *phdr;
1079 struct elfhdr *elf;
1080 int i, j;
1081
1082 fadump_init_elfcore_header(bufp);
1083 elf = (struct elfhdr *)bufp;
1084 bufp += sizeof(struct elfhdr);
1085
1086 /*
1087 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1088 * will be populated during second kernel boot after crash. Hence
1089 * this PT_NOTE will always be the first elf note.
1090 *
1091 * NOTE: Any new ELF note addition should be placed after this note.
1092 */
1093 phdr = (struct elf_phdr *)bufp;
1094 bufp += sizeof(struct elf_phdr);
1095 phdr->p_type = PT_NOTE;
1096 phdr->p_flags = 0;
1097 phdr->p_vaddr = 0;
1098 phdr->p_align = 0;
1099
1100 phdr->p_offset = 0;
1101 phdr->p_paddr = 0;
1102 phdr->p_filesz = 0;
1103 phdr->p_memsz = 0;
1104
1105 (elf->e_phnum)++;
1106
1107 /* setup ELF PT_NOTE for vmcoreinfo */
1108 phdr = (struct elf_phdr *)bufp;
1109 bufp += sizeof(struct elf_phdr);
1110 phdr->p_type = PT_NOTE;
1111 phdr->p_flags = 0;
1112 phdr->p_vaddr = 0;
1113 phdr->p_align = 0;
1114
1115 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1116 phdr->p_offset = phdr->p_paddr;
1117 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1118
1119 /* Increment number of program headers. */
1120 (elf->e_phnum)++;
1121
1122 /* setup PT_LOAD sections. */
1123 j = 0;
1124 offset = 0;
1125 raddr = fw_dump.boot_mem_addr[0];
1126 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1127 u64 mbase, msize;
1128
1129 mbase = crash_mrange_info.mem_ranges[i].base;
1130 msize = crash_mrange_info.mem_ranges[i].size;
1131 if (!msize)
1132 continue;
1133
1134 phdr = (struct elf_phdr *)bufp;
1135 bufp += sizeof(struct elf_phdr);
1136 phdr->p_type = PT_LOAD;
1137 phdr->p_flags = PF_R|PF_W|PF_X;
1138 phdr->p_offset = mbase;
1139
1140 if (mbase == raddr) {
1141 /*
1142 * The entire real memory region will be moved by
1143 * firmware to the specified destination_address.
1144 * Hence set the correct offset.
1145 */
1146 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1147 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1148 offset += fw_dump.boot_mem_sz[j];
1149 raddr = fw_dump.boot_mem_addr[++j];
1150 }
1151 }
1152
1153 phdr->p_paddr = mbase;
1154 phdr->p_vaddr = (unsigned long)__va(mbase);
1155 phdr->p_filesz = msize;
1156 phdr->p_memsz = msize;
1157 phdr->p_align = 0;
1158
1159 /* Increment number of program headers. */
1160 (elf->e_phnum)++;
1161 }
1162 return 0;
1163}
1164
1165static unsigned long init_fadump_header(unsigned long addr)
1166{
1167 struct fadump_crash_info_header *fdh;
1168
1169 if (!addr)
1170 return 0;
1171
1172 fdh = __va(addr);
1173 addr += sizeof(struct fadump_crash_info_header);
1174
1175 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1176 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1177 fdh->elfcorehdr_addr = addr;
1178 /* We will set the crashing cpu id in crash_fadump() during crash. */
1179 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1180 /*
1181 * When LPAR is terminated by PYHP, ensure all possible CPUs'
1182 * register data is processed while exporting the vmcore.
1183 */
1184 fdh->cpu_mask = *cpu_possible_mask;
1185
1186 return addr;
1187}
1188
1189static int register_fadump(void)
1190{
1191 unsigned long addr;
1192 void *vaddr;
1193 int ret;
1194
1195 /*
1196 * If no memory is reserved then we can not register for firmware-
1197 * assisted dump.
1198 */
1199 if (!fw_dump.reserve_dump_area_size)
1200 return -ENODEV;
1201
1202 ret = fadump_setup_crash_memory_ranges();
1203 if (ret)
1204 return ret;
1205
1206 addr = fw_dump.fadumphdr_addr;
1207
1208 /* Initialize fadump crash info header. */
1209 addr = init_fadump_header(addr);
1210 vaddr = __va(addr);
1211
1212 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1213 fadump_create_elfcore_headers(vaddr);
1214
1215 /* register the future kernel dump with firmware. */
1216 pr_debug("Registering for firmware-assisted kernel dump...\n");
1217 return fw_dump.ops->fadump_register(&fw_dump);
1218}
1219
1220void fadump_cleanup(void)
1221{
1222 if (!fw_dump.fadump_supported)
1223 return;
1224
1225 /* Invalidate the registration only if dump is active. */
1226 if (fw_dump.dump_active) {
1227 pr_debug("Invalidating firmware-assisted dump registration\n");
1228 fw_dump.ops->fadump_invalidate(&fw_dump);
1229 } else if (fw_dump.dump_registered) {
1230 /* Un-register Firmware-assisted dump if it was registered. */
1231 fw_dump.ops->fadump_unregister(&fw_dump);
1232 fadump_free_mem_ranges(&crash_mrange_info);
1233 }
1234
1235 if (fw_dump.ops->fadump_cleanup)
1236 fw_dump.ops->fadump_cleanup(&fw_dump);
1237}
1238
1239static void fadump_free_reserved_memory(unsigned long start_pfn,
1240 unsigned long end_pfn)
1241{
1242 unsigned long pfn;
1243 unsigned long time_limit = jiffies + HZ;
1244
1245 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1246 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1247
1248 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1249 free_reserved_page(pfn_to_page(pfn));
1250
1251 if (time_after(jiffies, time_limit)) {
1252 cond_resched();
1253 time_limit = jiffies + HZ;
1254 }
1255 }
1256}
1257
1258/*
1259 * Skip memory holes and free memory that was actually reserved.
1260 */
1261static void fadump_release_reserved_area(u64 start, u64 end)
1262{
1263 unsigned long reg_spfn, reg_epfn;
1264 u64 tstart, tend, spfn, epfn;
1265 int i;
1266
1267 spfn = PHYS_PFN(start);
1268 epfn = PHYS_PFN(end);
1269
1270 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) {
1271 tstart = max_t(u64, spfn, reg_spfn);
1272 tend = min_t(u64, epfn, reg_epfn);
1273
1274 if (tstart < tend) {
1275 fadump_free_reserved_memory(tstart, tend);
1276
1277 if (tend == epfn)
1278 break;
1279
1280 spfn = tend;
1281 }
1282 }
1283}
1284
1285/*
1286 * Sort the mem ranges in-place and merge adjacent ranges
1287 * to minimize the memory ranges count.
1288 */
1289static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1290{
1291 struct fadump_memory_range *mem_ranges;
1292 u64 base, size;
1293 int i, j, idx;
1294
1295 if (!reserved_mrange_info.mem_range_cnt)
1296 return;
1297
1298 /* Sort the memory ranges */
1299 mem_ranges = mrange_info->mem_ranges;
1300 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1301 idx = i;
1302 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1303 if (mem_ranges[idx].base > mem_ranges[j].base)
1304 idx = j;
1305 }
1306 if (idx != i)
1307 swap(mem_ranges[idx], mem_ranges[i]);
1308 }
1309
1310 /* Merge adjacent reserved ranges */
1311 idx = 0;
1312 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1313 base = mem_ranges[i-1].base;
1314 size = mem_ranges[i-1].size;
1315 if (mem_ranges[i].base == (base + size))
1316 mem_ranges[idx].size += mem_ranges[i].size;
1317 else {
1318 idx++;
1319 if (i == idx)
1320 continue;
1321
1322 mem_ranges[idx] = mem_ranges[i];
1323 }
1324 }
1325 mrange_info->mem_range_cnt = idx + 1;
1326}
1327
1328/*
1329 * Scan reserved-ranges to consider them while reserving/releasing
1330 * memory for FADump.
1331 */
1332static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1333{
1334 const __be32 *prop;
1335 int len, ret = -1;
1336 unsigned long i;
1337
1338 /* reserved-ranges already scanned */
1339 if (reserved_mrange_info.mem_range_cnt != 0)
1340 return;
1341
1342 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1343 if (!prop)
1344 return;
1345
1346 /*
1347 * Each reserved range is an (address,size) pair, 2 cells each,
1348 * totalling 4 cells per range.
1349 */
1350 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1351 u64 base, size;
1352
1353 base = of_read_number(prop + (i * 4) + 0, 2);
1354 size = of_read_number(prop + (i * 4) + 2, 2);
1355
1356 if (size) {
1357 ret = fadump_add_mem_range(&reserved_mrange_info,
1358 base, base + size);
1359 if (ret < 0) {
1360 pr_warn("some reserved ranges are ignored!\n");
1361 break;
1362 }
1363 }
1364 }
1365
1366 /* Compact reserved ranges */
1367 sort_and_merge_mem_ranges(&reserved_mrange_info);
1368}
1369
1370/*
1371 * Release the memory that was reserved during early boot to preserve the
1372 * crash'ed kernel's memory contents except reserved dump area (permanent
1373 * reservation) and reserved ranges used by F/W. The released memory will
1374 * be available for general use.
1375 */
1376static void fadump_release_memory(u64 begin, u64 end)
1377{
1378 u64 ra_start, ra_end, tstart;
1379 int i, ret;
1380
1381 ra_start = fw_dump.reserve_dump_area_start;
1382 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1383
1384 /*
1385 * If reserved ranges array limit is hit, overwrite the last reserved
1386 * memory range with reserved dump area to ensure it is excluded from
1387 * the memory being released (reused for next FADump registration).
1388 */
1389 if (reserved_mrange_info.mem_range_cnt ==
1390 reserved_mrange_info.max_mem_ranges)
1391 reserved_mrange_info.mem_range_cnt--;
1392
1393 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1394 if (ret != 0)
1395 return;
1396
1397 /* Get the reserved ranges list in order first. */
1398 sort_and_merge_mem_ranges(&reserved_mrange_info);
1399
1400 /* Exclude reserved ranges and release remaining memory */
1401 tstart = begin;
1402 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1403 ra_start = reserved_mrange_info.mem_ranges[i].base;
1404 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1405
1406 if (tstart >= ra_end)
1407 continue;
1408
1409 if (tstart < ra_start)
1410 fadump_release_reserved_area(tstart, ra_start);
1411 tstart = ra_end;
1412 }
1413
1414 if (tstart < end)
1415 fadump_release_reserved_area(tstart, end);
1416}
1417
1418static void fadump_invalidate_release_mem(void)
1419{
1420 mutex_lock(&fadump_mutex);
1421 if (!fw_dump.dump_active) {
1422 mutex_unlock(&fadump_mutex);
1423 return;
1424 }
1425
1426 fadump_cleanup();
1427 mutex_unlock(&fadump_mutex);
1428
1429 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1430 fadump_free_cpu_notes_buf();
1431
1432 /*
1433 * Setup kernel metadata and initialize the kernel dump
1434 * memory structure for FADump re-registration.
1435 */
1436 if (fw_dump.ops->fadump_setup_metadata &&
1437 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1438 pr_warn("Failed to setup kernel metadata!\n");
1439 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1440}
1441
1442static ssize_t release_mem_store(struct kobject *kobj,
1443 struct kobj_attribute *attr,
1444 const char *buf, size_t count)
1445{
1446 int input = -1;
1447
1448 if (!fw_dump.dump_active)
1449 return -EPERM;
1450
1451 if (kstrtoint(buf, 0, &input))
1452 return -EINVAL;
1453
1454 if (input == 1) {
1455 /*
1456 * Take away the '/proc/vmcore'. We are releasing the dump
1457 * memory, hence it will not be valid anymore.
1458 */
1459#ifdef CONFIG_PROC_VMCORE
1460 vmcore_cleanup();
1461#endif
1462 fadump_invalidate_release_mem();
1463
1464 } else
1465 return -EINVAL;
1466 return count;
1467}
1468
1469/* Release the reserved memory and disable the FADump */
1470static void __init unregister_fadump(void)
1471{
1472 fadump_cleanup();
1473 fadump_release_memory(fw_dump.reserve_dump_area_start,
1474 fw_dump.reserve_dump_area_size);
1475 fw_dump.fadump_enabled = 0;
1476 kobject_put(fadump_kobj);
1477}
1478
1479static ssize_t enabled_show(struct kobject *kobj,
1480 struct kobj_attribute *attr,
1481 char *buf)
1482{
1483 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1484}
1485
1486static ssize_t mem_reserved_show(struct kobject *kobj,
1487 struct kobj_attribute *attr,
1488 char *buf)
1489{
1490 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1491}
1492
1493static ssize_t registered_show(struct kobject *kobj,
1494 struct kobj_attribute *attr,
1495 char *buf)
1496{
1497 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1498}
1499
1500static ssize_t registered_store(struct kobject *kobj,
1501 struct kobj_attribute *attr,
1502 const char *buf, size_t count)
1503{
1504 int ret = 0;
1505 int input = -1;
1506
1507 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1508 return -EPERM;
1509
1510 if (kstrtoint(buf, 0, &input))
1511 return -EINVAL;
1512
1513 mutex_lock(&fadump_mutex);
1514
1515 switch (input) {
1516 case 0:
1517 if (fw_dump.dump_registered == 0) {
1518 goto unlock_out;
1519 }
1520
1521 /* Un-register Firmware-assisted dump */
1522 pr_debug("Un-register firmware-assisted dump\n");
1523 fw_dump.ops->fadump_unregister(&fw_dump);
1524 break;
1525 case 1:
1526 if (fw_dump.dump_registered == 1) {
1527 /* Un-register Firmware-assisted dump */
1528 fw_dump.ops->fadump_unregister(&fw_dump);
1529 }
1530 /* Register Firmware-assisted dump */
1531 ret = register_fadump();
1532 break;
1533 default:
1534 ret = -EINVAL;
1535 break;
1536 }
1537
1538unlock_out:
1539 mutex_unlock(&fadump_mutex);
1540 return ret < 0 ? ret : count;
1541}
1542
1543static int fadump_region_show(struct seq_file *m, void *private)
1544{
1545 if (!fw_dump.fadump_enabled)
1546 return 0;
1547
1548 mutex_lock(&fadump_mutex);
1549 fw_dump.ops->fadump_region_show(&fw_dump, m);
1550 mutex_unlock(&fadump_mutex);
1551 return 0;
1552}
1553
1554static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1555static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1556static struct kobj_attribute register_attr = __ATTR_RW(registered);
1557static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1558
1559static struct attribute *fadump_attrs[] = {
1560 &enable_attr.attr,
1561 ®ister_attr.attr,
1562 &mem_reserved_attr.attr,
1563 NULL,
1564};
1565
1566ATTRIBUTE_GROUPS(fadump);
1567
1568DEFINE_SHOW_ATTRIBUTE(fadump_region);
1569
1570static void __init fadump_init_files(void)
1571{
1572 int rc = 0;
1573
1574 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1575 if (!fadump_kobj) {
1576 pr_err("failed to create fadump kobject\n");
1577 return;
1578 }
1579
1580 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
1581 &fadump_region_fops);
1582
1583 if (fw_dump.dump_active) {
1584 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1585 if (rc)
1586 pr_err("unable to create release_mem sysfs file (%d)\n",
1587 rc);
1588 }
1589
1590 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1591 if (rc) {
1592 pr_err("sysfs group creation failed (%d), unregistering FADump",
1593 rc);
1594 unregister_fadump();
1595 return;
1596 }
1597
1598 /*
1599 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1600 * create symlink at old location to maintain backward compatibility.
1601 *
1602 * - fadump_enabled -> fadump/enabled
1603 * - fadump_registered -> fadump/registered
1604 * - fadump_release_mem -> fadump/release_mem
1605 */
1606 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1607 "enabled", "fadump_enabled");
1608 if (rc) {
1609 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1610 return;
1611 }
1612
1613 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1614 "registered",
1615 "fadump_registered");
1616 if (rc) {
1617 pr_err("unable to create fadump_registered symlink (%d)", rc);
1618 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1619 return;
1620 }
1621
1622 if (fw_dump.dump_active) {
1623 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1624 fadump_kobj,
1625 "release_mem",
1626 "fadump_release_mem");
1627 if (rc)
1628 pr_err("unable to create fadump_release_mem symlink (%d)",
1629 rc);
1630 }
1631 return;
1632}
1633
1634/*
1635 * Prepare for firmware-assisted dump.
1636 */
1637int __init setup_fadump(void)
1638{
1639 if (!fw_dump.fadump_supported)
1640 return 0;
1641
1642 fadump_init_files();
1643 fadump_show_config();
1644
1645 if (!fw_dump.fadump_enabled)
1646 return 1;
1647
1648 /*
1649 * If dump data is available then see if it is valid and prepare for
1650 * saving it to the disk.
1651 */
1652 if (fw_dump.dump_active) {
1653 /*
1654 * if dump process fails then invalidate the registration
1655 * and release memory before proceeding for re-registration.
1656 */
1657 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1658 fadump_invalidate_release_mem();
1659 }
1660 /* Initialize the kernel dump memory structure and register with f/w */
1661 else if (fw_dump.reserve_dump_area_size) {
1662 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1663 register_fadump();
1664 }
1665
1666 /*
1667 * In case of panic, fadump is triggered via ppc_panic_event()
1668 * panic notifier. Setting crash_kexec_post_notifiers to 'true'
1669 * lets panic() function take crash friendly path before panic
1670 * notifiers are invoked.
1671 */
1672 crash_kexec_post_notifiers = true;
1673
1674 return 1;
1675}
1676/*
1677 * Use subsys_initcall_sync() here because there is dependency with
1678 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
1679 * is done before registering with f/w.
1680 */
1681subsys_initcall_sync(setup_fadump);
1682#else /* !CONFIG_PRESERVE_FA_DUMP */
1683
1684/* Scan the Firmware Assisted dump configuration details. */
1685int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1686 int depth, void *data)
1687{
1688 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1689 return 0;
1690
1691 opal_fadump_dt_scan(&fw_dump, node);
1692 return 1;
1693}
1694
1695/*
1696 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1697 * preserve crash data. The subsequent memory preserving kernel boot
1698 * is likely to process this crash data.
1699 */
1700int __init fadump_reserve_mem(void)
1701{
1702 if (fw_dump.dump_active) {
1703 /*
1704 * If last boot has crashed then reserve all the memory
1705 * above boot memory to preserve crash data.
1706 */
1707 pr_info("Preserving crash data for processing in next boot.\n");
1708 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1709 } else
1710 pr_debug("FADump-aware kernel..\n");
1711
1712 return 1;
1713}
1714#endif /* CONFIG_PRESERVE_FA_DUMP */
1715
1716/* Preserve everything above the base address */
1717static void __init fadump_reserve_crash_area(u64 base)
1718{
1719 u64 i, mstart, mend, msize;
1720
1721 for_each_mem_range(i, &mstart, &mend) {
1722 msize = mend - mstart;
1723
1724 if ((mstart + msize) < base)
1725 continue;
1726
1727 if (mstart < base) {
1728 msize -= (base - mstart);
1729 mstart = base;
1730 }
1731
1732 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1733 (msize >> 20), mstart);
1734 memblock_reserve(mstart, msize);
1735 }
1736}
1737
1738unsigned long __init arch_reserved_kernel_pages(void)
1739{
1740 return memblock_reserved_size() / PAGE_SIZE;
1741}
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 __be32 *sections;
59 int i, num_sections;
60 unsigned long size;
61 const int *token;
62
63 if (depth != 1 || strcmp(uname, "rtas") != 0)
64 return 0;
65
66 /*
67 * Check if Firmware Assisted dump is supported. if yes, check
68 * if dump has been initiated on last reboot.
69 */
70 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
71 if (!token)
72 return 0;
73
74 fw_dump.fadump_supported = 1;
75 fw_dump.ibm_configure_kernel_dump = *token;
76
77 /*
78 * The 'ibm,kernel-dump' rtas node is present only if there is
79 * dump data waiting for us.
80 */
81 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
82 if (fdm_active)
83 fw_dump.dump_active = 1;
84
85 /* Get the sizes required to store dump data for the firmware provided
86 * dump sections.
87 * For each dump section type supported, a 32bit cell which defines
88 * the ID of a supported section followed by two 32 bit cells which
89 * gives teh size of the section in bytes.
90 */
91 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
92 &size);
93
94 if (!sections)
95 return 0;
96
97 num_sections = size / (3 * sizeof(u32));
98
99 for (i = 0; i < num_sections; i++, sections += 3) {
100 u32 type = (u32)of_read_number(sections, 1);
101
102 switch (type) {
103 case FADUMP_CPU_STATE_DATA:
104 fw_dump.cpu_state_data_size =
105 of_read_ulong(§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 return 1;
114}
115
116int is_fadump_active(void)
117{
118 return fw_dump.dump_active;
119}
120
121/* Print firmware assisted dump configurations for debugging purpose. */
122static void fadump_show_config(void)
123{
124 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
125 (fw_dump.fadump_supported ? "present" : "no support"));
126
127 if (!fw_dump.fadump_supported)
128 return;
129
130 pr_debug("Fadump enabled : %s\n",
131 (fw_dump.fadump_enabled ? "yes" : "no"));
132 pr_debug("Dump Active : %s\n",
133 (fw_dump.dump_active ? "yes" : "no"));
134 pr_debug("Dump section sizes:\n");
135 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
136 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
137 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
138}
139
140static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
141 unsigned long addr)
142{
143 if (!fdm)
144 return 0;
145
146 memset(fdm, 0, sizeof(struct fadump_mem_struct));
147 addr = addr & PAGE_MASK;
148
149 fdm->header.dump_format_version = 0x00000001;
150 fdm->header.dump_num_sections = 3;
151 fdm->header.dump_status_flag = 0;
152 fdm->header.offset_first_dump_section =
153 (u32)offsetof(struct fadump_mem_struct, cpu_state_data);
154
155 /*
156 * Fields for disk dump option.
157 * We are not using disk dump option, hence set these fields to 0.
158 */
159 fdm->header.dd_block_size = 0;
160 fdm->header.dd_block_offset = 0;
161 fdm->header.dd_num_blocks = 0;
162 fdm->header.dd_offset_disk_path = 0;
163
164 /* set 0 to disable an automatic dump-reboot. */
165 fdm->header.max_time_auto = 0;
166
167 /* Kernel dump sections */
168 /* cpu state data section. */
169 fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG;
170 fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA;
171 fdm->cpu_state_data.source_address = 0;
172 fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size;
173 fdm->cpu_state_data.destination_address = addr;
174 addr += fw_dump.cpu_state_data_size;
175
176 /* hpte region section */
177 fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG;
178 fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION;
179 fdm->hpte_region.source_address = 0;
180 fdm->hpte_region.source_len = fw_dump.hpte_region_size;
181 fdm->hpte_region.destination_address = addr;
182 addr += fw_dump.hpte_region_size;
183
184 /* RMA region section */
185 fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG;
186 fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION;
187 fdm->rmr_region.source_address = RMA_START;
188 fdm->rmr_region.source_len = fw_dump.boot_memory_size;
189 fdm->rmr_region.destination_address = addr;
190 addr += fw_dump.boot_memory_size;
191
192 return addr;
193}
194
195/**
196 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
197 *
198 * Function to find the largest memory size we need to reserve during early
199 * boot process. This will be the size of the memory that is required for a
200 * kernel to boot successfully.
201 *
202 * This function has been taken from phyp-assisted dump feature implementation.
203 *
204 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
205 *
206 * TODO: Come up with better approach to find out more accurate memory size
207 * that is required for a kernel to boot successfully.
208 *
209 */
210static inline unsigned long fadump_calculate_reserve_size(void)
211{
212 unsigned long size;
213
214 /*
215 * Check if the size is specified through fadump_reserve_mem= cmdline
216 * option. If yes, then use that.
217 */
218 if (fw_dump.reserve_bootvar)
219 return fw_dump.reserve_bootvar;
220
221 /* divide by 20 to get 5% of value */
222 size = memblock_end_of_DRAM() / 20;
223
224 /* round it down in multiples of 256 */
225 size = size & ~0x0FFFFFFFUL;
226
227 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
228 if (memory_limit && size > memory_limit)
229 size = memory_limit;
230
231 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
232}
233
234/*
235 * Calculate the total memory size required to be reserved for
236 * firmware-assisted dump registration.
237 */
238static unsigned long get_fadump_area_size(void)
239{
240 unsigned long size = 0;
241
242 size += fw_dump.cpu_state_data_size;
243 size += fw_dump.hpte_region_size;
244 size += fw_dump.boot_memory_size;
245 size += sizeof(struct fadump_crash_info_header);
246 size += sizeof(struct elfhdr); /* ELF core header.*/
247 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
248 /* Program headers for crash memory regions. */
249 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
250
251 size = PAGE_ALIGN(size);
252 return size;
253}
254
255int __init fadump_reserve_mem(void)
256{
257 unsigned long base, size, memory_boundary;
258
259 if (!fw_dump.fadump_enabled)
260 return 0;
261
262 if (!fw_dump.fadump_supported) {
263 printk(KERN_INFO "Firmware-assisted dump is not supported on"
264 " this hardware\n");
265 fw_dump.fadump_enabled = 0;
266 return 0;
267 }
268 /*
269 * Initialize boot memory size
270 * If dump is active then we have already calculated the size during
271 * first kernel.
272 */
273 if (fdm_active)
274 fw_dump.boot_memory_size = fdm_active->rmr_region.source_len;
275 else
276 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
277
278 /*
279 * Calculate the memory boundary.
280 * If memory_limit is less than actual memory boundary then reserve
281 * the memory for fadump beyond the memory_limit and adjust the
282 * memory_limit accordingly, so that the running kernel can run with
283 * specified memory_limit.
284 */
285 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
286 size = get_fadump_area_size();
287 if ((memory_limit + size) < memblock_end_of_DRAM())
288 memory_limit += size;
289 else
290 memory_limit = memblock_end_of_DRAM();
291 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
292 " dump, now %#016llx\n",
293 (unsigned long long)memory_limit);
294 }
295 if (memory_limit)
296 memory_boundary = memory_limit;
297 else
298 memory_boundary = memblock_end_of_DRAM();
299
300 if (fw_dump.dump_active) {
301 printk(KERN_INFO "Firmware-assisted dump is active.\n");
302 /*
303 * If last boot has crashed then reserve all the memory
304 * above boot_memory_size so that we don't touch it until
305 * dump is written to disk by userspace tool. This memory
306 * will be released for general use once the dump is saved.
307 */
308 base = fw_dump.boot_memory_size;
309 size = memory_boundary - base;
310 memblock_reserve(base, size);
311 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
312 "for saving crash dump\n",
313 (unsigned long)(size >> 20),
314 (unsigned long)(base >> 20));
315
316 fw_dump.fadumphdr_addr =
317 fdm_active->rmr_region.destination_address +
318 fdm_active->rmr_region.source_len;
319 pr_debug("fadumphdr_addr = %p\n",
320 (void *) fw_dump.fadumphdr_addr);
321 } else {
322 /* Reserve the memory at the top of memory. */
323 size = get_fadump_area_size();
324 base = memory_boundary - size;
325 memblock_reserve(base, size);
326 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
327 "for firmware-assisted dump\n",
328 (unsigned long)(size >> 20),
329 (unsigned long)(base >> 20));
330 }
331 fw_dump.reserve_dump_area_start = base;
332 fw_dump.reserve_dump_area_size = size;
333 return 1;
334}
335
336/* Look for fadump= cmdline option. */
337static int __init early_fadump_param(char *p)
338{
339 if (!p)
340 return 1;
341
342 if (strncmp(p, "on", 2) == 0)
343 fw_dump.fadump_enabled = 1;
344 else if (strncmp(p, "off", 3) == 0)
345 fw_dump.fadump_enabled = 0;
346
347 return 0;
348}
349early_param("fadump", early_fadump_param);
350
351/* Look for fadump_reserve_mem= cmdline option */
352static int __init early_fadump_reserve_mem(char *p)
353{
354 if (p)
355 fw_dump.reserve_bootvar = memparse(p, &p);
356 return 0;
357}
358early_param("fadump_reserve_mem", early_fadump_reserve_mem);
359
360static void register_fw_dump(struct fadump_mem_struct *fdm)
361{
362 int rc;
363 unsigned int wait_time;
364
365 pr_debug("Registering for firmware-assisted kernel dump...\n");
366
367 /* TODO: Add upper time limit for the delay */
368 do {
369 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
370 FADUMP_REGISTER, fdm,
371 sizeof(struct fadump_mem_struct));
372
373 wait_time = rtas_busy_delay_time(rc);
374 if (wait_time)
375 mdelay(wait_time);
376
377 } while (wait_time);
378
379 switch (rc) {
380 case -1:
381 printk(KERN_ERR "Failed to register firmware-assisted kernel"
382 " dump. Hardware Error(%d).\n", rc);
383 break;
384 case -3:
385 printk(KERN_ERR "Failed to register firmware-assisted kernel"
386 " dump. Parameter Error(%d).\n", rc);
387 break;
388 case -9:
389 printk(KERN_ERR "firmware-assisted kernel dump is already "
390 " registered.");
391 fw_dump.dump_registered = 1;
392 break;
393 case 0:
394 printk(KERN_INFO "firmware-assisted kernel dump registration"
395 " is successful\n");
396 fw_dump.dump_registered = 1;
397 break;
398 }
399}
400
401void crash_fadump(struct pt_regs *regs, const char *str)
402{
403 struct fadump_crash_info_header *fdh = NULL;
404
405 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
406 return;
407
408 fdh = __va(fw_dump.fadumphdr_addr);
409 crashing_cpu = smp_processor_id();
410 fdh->crashing_cpu = crashing_cpu;
411 crash_save_vmcoreinfo();
412
413 if (regs)
414 fdh->regs = *regs;
415 else
416 ppc_save_regs(&fdh->regs);
417
418 fdh->cpu_online_mask = *cpu_online_mask;
419
420 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
421 rtas_os_term((char *)str);
422}
423
424#define GPR_MASK 0xffffff0000000000
425static inline int fadump_gpr_index(u64 id)
426{
427 int i = -1;
428 char str[3];
429
430 if ((id & GPR_MASK) == REG_ID("GPR")) {
431 /* get the digits at the end */
432 id &= ~GPR_MASK;
433 id >>= 24;
434 str[2] = '\0';
435 str[1] = id & 0xff;
436 str[0] = (id >> 8) & 0xff;
437 sscanf(str, "%d", &i);
438 if (i > 31)
439 i = -1;
440 }
441 return i;
442}
443
444static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
445 u64 reg_val)
446{
447 int i;
448
449 i = fadump_gpr_index(reg_id);
450 if (i >= 0)
451 regs->gpr[i] = (unsigned long)reg_val;
452 else if (reg_id == REG_ID("NIA"))
453 regs->nip = (unsigned long)reg_val;
454 else if (reg_id == REG_ID("MSR"))
455 regs->msr = (unsigned long)reg_val;
456 else if (reg_id == REG_ID("CTR"))
457 regs->ctr = (unsigned long)reg_val;
458 else if (reg_id == REG_ID("LR"))
459 regs->link = (unsigned long)reg_val;
460 else if (reg_id == REG_ID("XER"))
461 regs->xer = (unsigned long)reg_val;
462 else if (reg_id == REG_ID("CR"))
463 regs->ccr = (unsigned long)reg_val;
464 else if (reg_id == REG_ID("DAR"))
465 regs->dar = (unsigned long)reg_val;
466 else if (reg_id == REG_ID("DSISR"))
467 regs->dsisr = (unsigned long)reg_val;
468}
469
470static struct fadump_reg_entry*
471fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
472{
473 memset(regs, 0, sizeof(struct pt_regs));
474
475 while (reg_entry->reg_id != REG_ID("CPUEND")) {
476 fadump_set_regval(regs, reg_entry->reg_id,
477 reg_entry->reg_value);
478 reg_entry++;
479 }
480 reg_entry++;
481 return reg_entry;
482}
483
484static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
485 void *data, size_t data_len)
486{
487 struct elf_note note;
488
489 note.n_namesz = strlen(name) + 1;
490 note.n_descsz = data_len;
491 note.n_type = type;
492 memcpy(buf, ¬e, sizeof(note));
493 buf += (sizeof(note) + 3)/4;
494 memcpy(buf, name, note.n_namesz);
495 buf += (note.n_namesz + 3)/4;
496 memcpy(buf, data, note.n_descsz);
497 buf += (note.n_descsz + 3)/4;
498
499 return buf;
500}
501
502static void fadump_final_note(u32 *buf)
503{
504 struct elf_note note;
505
506 note.n_namesz = 0;
507 note.n_descsz = 0;
508 note.n_type = 0;
509 memcpy(buf, ¬e, sizeof(note));
510}
511
512static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
513{
514 struct elf_prstatus prstatus;
515
516 memset(&prstatus, 0, sizeof(prstatus));
517 /*
518 * FIXME: How do i get PID? Do I really need it?
519 * prstatus.pr_pid = ????
520 */
521 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
522 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
523 &prstatus, sizeof(prstatus));
524 return buf;
525}
526
527static void fadump_update_elfcore_header(char *bufp)
528{
529 struct elfhdr *elf;
530 struct elf_phdr *phdr;
531
532 elf = (struct elfhdr *)bufp;
533 bufp += sizeof(struct elfhdr);
534
535 /* First note is a place holder for cpu notes info. */
536 phdr = (struct elf_phdr *)bufp;
537
538 if (phdr->p_type == PT_NOTE) {
539 phdr->p_paddr = fw_dump.cpu_notes_buf;
540 phdr->p_offset = phdr->p_paddr;
541 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
542 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
543 }
544 return;
545}
546
547static void *fadump_cpu_notes_buf_alloc(unsigned long size)
548{
549 void *vaddr;
550 struct page *page;
551 unsigned long order, count, i;
552
553 order = get_order(size);
554 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
555 if (!vaddr)
556 return NULL;
557
558 count = 1 << order;
559 page = virt_to_page(vaddr);
560 for (i = 0; i < count; i++)
561 SetPageReserved(page + i);
562 return vaddr;
563}
564
565static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
566{
567 struct page *page;
568 unsigned long order, count, i;
569
570 order = get_order(size);
571 count = 1 << order;
572 page = virt_to_page(vaddr);
573 for (i = 0; i < count; i++)
574 ClearPageReserved(page + i);
575 __free_pages(page, order);
576}
577
578/*
579 * Read CPU state dump data and convert it into ELF notes.
580 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
581 * used to access the data to allow for additional fields to be added without
582 * affecting compatibility. Each list of registers for a CPU starts with
583 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
584 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
585 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
586 * of register value. For more details refer to PAPR document.
587 *
588 * Only for the crashing cpu we ignore the CPU dump data and get exact
589 * state from fadump crash info structure populated by first kernel at the
590 * time of crash.
591 */
592static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
593{
594 struct fadump_reg_save_area_header *reg_header;
595 struct fadump_reg_entry *reg_entry;
596 struct fadump_crash_info_header *fdh = NULL;
597 void *vaddr;
598 unsigned long addr;
599 u32 num_cpus, *note_buf;
600 struct pt_regs regs;
601 int i, rc = 0, cpu = 0;
602
603 if (!fdm->cpu_state_data.bytes_dumped)
604 return -EINVAL;
605
606 addr = fdm->cpu_state_data.destination_address;
607 vaddr = __va(addr);
608
609 reg_header = vaddr;
610 if (reg_header->magic_number != REGSAVE_AREA_MAGIC) {
611 printk(KERN_ERR "Unable to read register save area.\n");
612 return -ENOENT;
613 }
614 pr_debug("--------CPU State Data------------\n");
615 pr_debug("Magic Number: %llx\n", reg_header->magic_number);
616 pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset);
617
618 vaddr += reg_header->num_cpu_offset;
619 num_cpus = *((u32 *)(vaddr));
620 pr_debug("NumCpus : %u\n", num_cpus);
621 vaddr += sizeof(u32);
622 reg_entry = (struct fadump_reg_entry *)vaddr;
623
624 /* Allocate buffer to hold cpu crash notes. */
625 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
626 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
627 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
628 if (!note_buf) {
629 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
630 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
631 return -ENOMEM;
632 }
633 fw_dump.cpu_notes_buf = __pa(note_buf);
634
635 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
636 (num_cpus * sizeof(note_buf_t)), note_buf);
637
638 if (fw_dump.fadumphdr_addr)
639 fdh = __va(fw_dump.fadumphdr_addr);
640
641 for (i = 0; i < num_cpus; i++) {
642 if (reg_entry->reg_id != REG_ID("CPUSTRT")) {
643 printk(KERN_ERR "Unable to read CPU state data\n");
644 rc = -ENOENT;
645 goto error_out;
646 }
647 /* Lower 4 bytes of reg_value contains logical cpu id */
648 cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK;
649 if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
650 SKIP_TO_NEXT_CPU(reg_entry);
651 continue;
652 }
653 pr_debug("Reading register data for cpu %d...\n", cpu);
654 if (fdh && fdh->crashing_cpu == cpu) {
655 regs = fdh->regs;
656 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
657 SKIP_TO_NEXT_CPU(reg_entry);
658 } else {
659 reg_entry++;
660 reg_entry = fadump_read_registers(reg_entry, ®s);
661 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
662 }
663 }
664 fadump_final_note(note_buf);
665
666 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
667 fdh->elfcorehdr_addr);
668 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
669 return 0;
670
671error_out:
672 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
673 fw_dump.cpu_notes_buf_size);
674 fw_dump.cpu_notes_buf = 0;
675 fw_dump.cpu_notes_buf_size = 0;
676 return rc;
677
678}
679
680/*
681 * Validate and process the dump data stored by firmware before exporting
682 * it through '/proc/vmcore'.
683 */
684static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
685{
686 struct fadump_crash_info_header *fdh;
687 int rc = 0;
688
689 if (!fdm_active || !fw_dump.fadumphdr_addr)
690 return -EINVAL;
691
692 /* Check if the dump data is valid. */
693 if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
694 (fdm_active->cpu_state_data.error_flags != 0) ||
695 (fdm_active->rmr_region.error_flags != 0)) {
696 printk(KERN_ERR "Dump taken by platform is not valid\n");
697 return -EINVAL;
698 }
699 if ((fdm_active->rmr_region.bytes_dumped !=
700 fdm_active->rmr_region.source_len) ||
701 !fdm_active->cpu_state_data.bytes_dumped) {
702 printk(KERN_ERR "Dump taken by platform is incomplete\n");
703 return -EINVAL;
704 }
705
706 /* Validate the fadump crash info header */
707 fdh = __va(fw_dump.fadumphdr_addr);
708 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
709 printk(KERN_ERR "Crash info header is not valid.\n");
710 return -EINVAL;
711 }
712
713 rc = fadump_build_cpu_notes(fdm_active);
714 if (rc)
715 return rc;
716
717 /*
718 * We are done validating dump info and elfcore header is now ready
719 * to be exported. set elfcorehdr_addr so that vmcore module will
720 * export the elfcore header through '/proc/vmcore'.
721 */
722 elfcorehdr_addr = fdh->elfcorehdr_addr;
723
724 return 0;
725}
726
727static inline void fadump_add_crash_memory(unsigned long long base,
728 unsigned long long end)
729{
730 if (base == end)
731 return;
732
733 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
734 crash_mem_ranges, base, end - 1, (end - base));
735 crash_memory_ranges[crash_mem_ranges].base = base;
736 crash_memory_ranges[crash_mem_ranges].size = end - base;
737 crash_mem_ranges++;
738}
739
740static void fadump_exclude_reserved_area(unsigned long long start,
741 unsigned long long end)
742{
743 unsigned long long ra_start, ra_end;
744
745 ra_start = fw_dump.reserve_dump_area_start;
746 ra_end = ra_start + fw_dump.reserve_dump_area_size;
747
748 if ((ra_start < end) && (ra_end > start)) {
749 if ((start < ra_start) && (end > ra_end)) {
750 fadump_add_crash_memory(start, ra_start);
751 fadump_add_crash_memory(ra_end, end);
752 } else if (start < ra_start) {
753 fadump_add_crash_memory(start, ra_start);
754 } else if (ra_end < end) {
755 fadump_add_crash_memory(ra_end, end);
756 }
757 } else
758 fadump_add_crash_memory(start, end);
759}
760
761static int fadump_init_elfcore_header(char *bufp)
762{
763 struct elfhdr *elf;
764
765 elf = (struct elfhdr *) bufp;
766 bufp += sizeof(struct elfhdr);
767 memcpy(elf->e_ident, ELFMAG, SELFMAG);
768 elf->e_ident[EI_CLASS] = ELF_CLASS;
769 elf->e_ident[EI_DATA] = ELF_DATA;
770 elf->e_ident[EI_VERSION] = EV_CURRENT;
771 elf->e_ident[EI_OSABI] = ELF_OSABI;
772 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
773 elf->e_type = ET_CORE;
774 elf->e_machine = ELF_ARCH;
775 elf->e_version = EV_CURRENT;
776 elf->e_entry = 0;
777 elf->e_phoff = sizeof(struct elfhdr);
778 elf->e_shoff = 0;
779 elf->e_flags = ELF_CORE_EFLAGS;
780 elf->e_ehsize = sizeof(struct elfhdr);
781 elf->e_phentsize = sizeof(struct elf_phdr);
782 elf->e_phnum = 0;
783 elf->e_shentsize = 0;
784 elf->e_shnum = 0;
785 elf->e_shstrndx = 0;
786
787 return 0;
788}
789
790/*
791 * Traverse through memblock structure and setup crash memory ranges. These
792 * ranges will be used create PT_LOAD program headers in elfcore header.
793 */
794static void fadump_setup_crash_memory_ranges(void)
795{
796 struct memblock_region *reg;
797 unsigned long long start, end;
798
799 pr_debug("Setup crash memory ranges.\n");
800 crash_mem_ranges = 0;
801 /*
802 * add the first memory chunk (RMA_START through boot_memory_size) as
803 * a separate memory chunk. The reason is, at the time crash firmware
804 * will move the content of this memory chunk to different location
805 * specified during fadump registration. We need to create a separate
806 * program header for this chunk with the correct offset.
807 */
808 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
809
810 for_each_memblock(memory, reg) {
811 start = (unsigned long long)reg->base;
812 end = start + (unsigned long long)reg->size;
813 if (start == RMA_START && end >= fw_dump.boot_memory_size)
814 start = fw_dump.boot_memory_size;
815
816 /* add this range excluding the reserved dump area. */
817 fadump_exclude_reserved_area(start, end);
818 }
819}
820
821/*
822 * If the given physical address falls within the boot memory region then
823 * return the relocated address that points to the dump region reserved
824 * for saving initial boot memory contents.
825 */
826static inline unsigned long fadump_relocate(unsigned long paddr)
827{
828 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
829 return fdm.rmr_region.destination_address + paddr;
830 else
831 return paddr;
832}
833
834static int fadump_create_elfcore_headers(char *bufp)
835{
836 struct elfhdr *elf;
837 struct elf_phdr *phdr;
838 int i;
839
840 fadump_init_elfcore_header(bufp);
841 elf = (struct elfhdr *)bufp;
842 bufp += sizeof(struct elfhdr);
843
844 /*
845 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
846 * will be populated during second kernel boot after crash. Hence
847 * this PT_NOTE will always be the first elf note.
848 *
849 * NOTE: Any new ELF note addition should be placed after this note.
850 */
851 phdr = (struct elf_phdr *)bufp;
852 bufp += sizeof(struct elf_phdr);
853 phdr->p_type = PT_NOTE;
854 phdr->p_flags = 0;
855 phdr->p_vaddr = 0;
856 phdr->p_align = 0;
857
858 phdr->p_offset = 0;
859 phdr->p_paddr = 0;
860 phdr->p_filesz = 0;
861 phdr->p_memsz = 0;
862
863 (elf->e_phnum)++;
864
865 /* setup ELF PT_NOTE for vmcoreinfo */
866 phdr = (struct elf_phdr *)bufp;
867 bufp += sizeof(struct elf_phdr);
868 phdr->p_type = PT_NOTE;
869 phdr->p_flags = 0;
870 phdr->p_vaddr = 0;
871 phdr->p_align = 0;
872
873 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
874 phdr->p_offset = phdr->p_paddr;
875 phdr->p_memsz = vmcoreinfo_max_size;
876 phdr->p_filesz = vmcoreinfo_max_size;
877
878 /* Increment number of program headers. */
879 (elf->e_phnum)++;
880
881 /* setup PT_LOAD sections. */
882
883 for (i = 0; i < crash_mem_ranges; i++) {
884 unsigned long long mbase, msize;
885 mbase = crash_memory_ranges[i].base;
886 msize = crash_memory_ranges[i].size;
887
888 if (!msize)
889 continue;
890
891 phdr = (struct elf_phdr *)bufp;
892 bufp += sizeof(struct elf_phdr);
893 phdr->p_type = PT_LOAD;
894 phdr->p_flags = PF_R|PF_W|PF_X;
895 phdr->p_offset = mbase;
896
897 if (mbase == RMA_START) {
898 /*
899 * The entire RMA region will be moved by firmware
900 * to the specified destination_address. Hence set
901 * the correct offset.
902 */
903 phdr->p_offset = fdm.rmr_region.destination_address;
904 }
905
906 phdr->p_paddr = mbase;
907 phdr->p_vaddr = (unsigned long)__va(mbase);
908 phdr->p_filesz = msize;
909 phdr->p_memsz = msize;
910 phdr->p_align = 0;
911
912 /* Increment number of program headers. */
913 (elf->e_phnum)++;
914 }
915 return 0;
916}
917
918static unsigned long init_fadump_header(unsigned long addr)
919{
920 struct fadump_crash_info_header *fdh;
921
922 if (!addr)
923 return 0;
924
925 fw_dump.fadumphdr_addr = addr;
926 fdh = __va(addr);
927 addr += sizeof(struct fadump_crash_info_header);
928
929 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
930 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
931 fdh->elfcorehdr_addr = addr;
932 /* We will set the crashing cpu id in crash_fadump() during crash. */
933 fdh->crashing_cpu = CPU_UNKNOWN;
934
935 return addr;
936}
937
938static void register_fadump(void)
939{
940 unsigned long addr;
941 void *vaddr;
942
943 /*
944 * If no memory is reserved then we can not register for firmware-
945 * assisted dump.
946 */
947 if (!fw_dump.reserve_dump_area_size)
948 return;
949
950 fadump_setup_crash_memory_ranges();
951
952 addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
953 /* Initialize fadump crash info header. */
954 addr = init_fadump_header(addr);
955 vaddr = __va(addr);
956
957 pr_debug("Creating ELF core headers at %#016lx\n", addr);
958 fadump_create_elfcore_headers(vaddr);
959
960 /* register the future kernel dump with firmware. */
961 register_fw_dump(&fdm);
962}
963
964static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
965{
966 int rc = 0;
967 unsigned int wait_time;
968
969 pr_debug("Un-register firmware-assisted dump\n");
970
971 /* TODO: Add upper time limit for the delay */
972 do {
973 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
974 FADUMP_UNREGISTER, fdm,
975 sizeof(struct fadump_mem_struct));
976
977 wait_time = rtas_busy_delay_time(rc);
978 if (wait_time)
979 mdelay(wait_time);
980 } while (wait_time);
981
982 if (rc) {
983 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
984 " unexpected error(%d).\n", rc);
985 return rc;
986 }
987 fw_dump.dump_registered = 0;
988 return 0;
989}
990
991static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
992{
993 int rc = 0;
994 unsigned int wait_time;
995
996 pr_debug("Invalidating firmware-assisted dump registration\n");
997
998 /* TODO: Add upper time limit for the delay */
999 do {
1000 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1001 FADUMP_INVALIDATE, fdm,
1002 sizeof(struct fadump_mem_struct));
1003
1004 wait_time = rtas_busy_delay_time(rc);
1005 if (wait_time)
1006 mdelay(wait_time);
1007 } while (wait_time);
1008
1009 if (rc) {
1010 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1011 "rgistration. unexpected error(%d).\n", rc);
1012 return rc;
1013 }
1014 fw_dump.dump_active = 0;
1015 fdm_active = NULL;
1016 return 0;
1017}
1018
1019void fadump_cleanup(void)
1020{
1021 /* Invalidate the registration only if dump is active. */
1022 if (fw_dump.dump_active) {
1023 init_fadump_mem_struct(&fdm,
1024 fdm_active->cpu_state_data.destination_address);
1025 fadump_invalidate_dump(&fdm);
1026 }
1027}
1028
1029/*
1030 * Release the memory that was reserved in early boot to preserve the memory
1031 * contents. The released memory will be available for general use.
1032 */
1033static void fadump_release_memory(unsigned long begin, unsigned long end)
1034{
1035 unsigned long addr;
1036 unsigned long ra_start, ra_end;
1037
1038 ra_start = fw_dump.reserve_dump_area_start;
1039 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1040
1041 for (addr = begin; addr < end; addr += PAGE_SIZE) {
1042 /*
1043 * exclude the dump reserve area. Will reuse it for next
1044 * fadump registration.
1045 */
1046 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1047 continue;
1048
1049 ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1050 init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1051 free_page((unsigned long)__va(addr));
1052 totalram_pages++;
1053 }
1054}
1055
1056static void fadump_invalidate_release_mem(void)
1057{
1058 unsigned long reserved_area_start, reserved_area_end;
1059 unsigned long destination_address;
1060
1061 mutex_lock(&fadump_mutex);
1062 if (!fw_dump.dump_active) {
1063 mutex_unlock(&fadump_mutex);
1064 return;
1065 }
1066
1067 destination_address = fdm_active->cpu_state_data.destination_address;
1068 fadump_cleanup();
1069 mutex_unlock(&fadump_mutex);
1070
1071 /*
1072 * Save the current reserved memory bounds we will require them
1073 * later for releasing the memory for general use.
1074 */
1075 reserved_area_start = fw_dump.reserve_dump_area_start;
1076 reserved_area_end = reserved_area_start +
1077 fw_dump.reserve_dump_area_size;
1078 /*
1079 * Setup reserve_dump_area_start and its size so that we can
1080 * reuse this reserved memory for Re-registration.
1081 */
1082 fw_dump.reserve_dump_area_start = destination_address;
1083 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1084
1085 fadump_release_memory(reserved_area_start, reserved_area_end);
1086 if (fw_dump.cpu_notes_buf) {
1087 fadump_cpu_notes_buf_free(
1088 (unsigned long)__va(fw_dump.cpu_notes_buf),
1089 fw_dump.cpu_notes_buf_size);
1090 fw_dump.cpu_notes_buf = 0;
1091 fw_dump.cpu_notes_buf_size = 0;
1092 }
1093 /* Initialize the kernel dump memory structure for FAD registration. */
1094 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1095}
1096
1097static ssize_t fadump_release_memory_store(struct kobject *kobj,
1098 struct kobj_attribute *attr,
1099 const char *buf, size_t count)
1100{
1101 if (!fw_dump.dump_active)
1102 return -EPERM;
1103
1104 if (buf[0] == '1') {
1105 /*
1106 * Take away the '/proc/vmcore'. We are releasing the dump
1107 * memory, hence it will not be valid anymore.
1108 */
1109 vmcore_cleanup();
1110 fadump_invalidate_release_mem();
1111
1112 } else
1113 return -EINVAL;
1114 return count;
1115}
1116
1117static ssize_t fadump_enabled_show(struct kobject *kobj,
1118 struct kobj_attribute *attr,
1119 char *buf)
1120{
1121 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1122}
1123
1124static ssize_t fadump_register_show(struct kobject *kobj,
1125 struct kobj_attribute *attr,
1126 char *buf)
1127{
1128 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1129}
1130
1131static ssize_t fadump_register_store(struct kobject *kobj,
1132 struct kobj_attribute *attr,
1133 const char *buf, size_t count)
1134{
1135 int ret = 0;
1136
1137 if (!fw_dump.fadump_enabled || fdm_active)
1138 return -EPERM;
1139
1140 mutex_lock(&fadump_mutex);
1141
1142 switch (buf[0]) {
1143 case '0':
1144 if (fw_dump.dump_registered == 0) {
1145 ret = -EINVAL;
1146 goto unlock_out;
1147 }
1148 /* Un-register Firmware-assisted dump */
1149 fadump_unregister_dump(&fdm);
1150 break;
1151 case '1':
1152 if (fw_dump.dump_registered == 1) {
1153 ret = -EINVAL;
1154 goto unlock_out;
1155 }
1156 /* Register Firmware-assisted dump */
1157 register_fadump();
1158 break;
1159 default:
1160 ret = -EINVAL;
1161 break;
1162 }
1163
1164unlock_out:
1165 mutex_unlock(&fadump_mutex);
1166 return ret < 0 ? ret : count;
1167}
1168
1169static int fadump_region_show(struct seq_file *m, void *private)
1170{
1171 const struct fadump_mem_struct *fdm_ptr;
1172
1173 if (!fw_dump.fadump_enabled)
1174 return 0;
1175
1176 mutex_lock(&fadump_mutex);
1177 if (fdm_active)
1178 fdm_ptr = fdm_active;
1179 else {
1180 mutex_unlock(&fadump_mutex);
1181 fdm_ptr = &fdm;
1182 }
1183
1184 seq_printf(m,
1185 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1186 "Dumped: %#llx\n",
1187 fdm_ptr->cpu_state_data.destination_address,
1188 fdm_ptr->cpu_state_data.destination_address +
1189 fdm_ptr->cpu_state_data.source_len - 1,
1190 fdm_ptr->cpu_state_data.source_len,
1191 fdm_ptr->cpu_state_data.bytes_dumped);
1192 seq_printf(m,
1193 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1194 "Dumped: %#llx\n",
1195 fdm_ptr->hpte_region.destination_address,
1196 fdm_ptr->hpte_region.destination_address +
1197 fdm_ptr->hpte_region.source_len - 1,
1198 fdm_ptr->hpte_region.source_len,
1199 fdm_ptr->hpte_region.bytes_dumped);
1200 seq_printf(m,
1201 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1202 "Dumped: %#llx\n",
1203 fdm_ptr->rmr_region.destination_address,
1204 fdm_ptr->rmr_region.destination_address +
1205 fdm_ptr->rmr_region.source_len - 1,
1206 fdm_ptr->rmr_region.source_len,
1207 fdm_ptr->rmr_region.bytes_dumped);
1208
1209 if (!fdm_active ||
1210 (fw_dump.reserve_dump_area_start ==
1211 fdm_ptr->cpu_state_data.destination_address))
1212 goto out;
1213
1214 /* Dump is active. Show reserved memory region. */
1215 seq_printf(m,
1216 " : [%#016llx-%#016llx] %#llx bytes, "
1217 "Dumped: %#llx\n",
1218 (unsigned long long)fw_dump.reserve_dump_area_start,
1219 fdm_ptr->cpu_state_data.destination_address - 1,
1220 fdm_ptr->cpu_state_data.destination_address -
1221 fw_dump.reserve_dump_area_start,
1222 fdm_ptr->cpu_state_data.destination_address -
1223 fw_dump.reserve_dump_area_start);
1224out:
1225 if (fdm_active)
1226 mutex_unlock(&fadump_mutex);
1227 return 0;
1228}
1229
1230static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1231 0200, NULL,
1232 fadump_release_memory_store);
1233static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1234 0444, fadump_enabled_show,
1235 NULL);
1236static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1237 0644, fadump_register_show,
1238 fadump_register_store);
1239
1240static int fadump_region_open(struct inode *inode, struct file *file)
1241{
1242 return single_open(file, fadump_region_show, inode->i_private);
1243}
1244
1245static const struct file_operations fadump_region_fops = {
1246 .open = fadump_region_open,
1247 .read = seq_read,
1248 .llseek = seq_lseek,
1249 .release = single_release,
1250};
1251
1252static void fadump_init_files(void)
1253{
1254 struct dentry *debugfs_file;
1255 int rc = 0;
1256
1257 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1258 if (rc)
1259 printk(KERN_ERR "fadump: unable to create sysfs file"
1260 " fadump_enabled (%d)\n", rc);
1261
1262 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1263 if (rc)
1264 printk(KERN_ERR "fadump: unable to create sysfs file"
1265 " fadump_registered (%d)\n", rc);
1266
1267 debugfs_file = debugfs_create_file("fadump_region", 0444,
1268 powerpc_debugfs_root, NULL,
1269 &fadump_region_fops);
1270 if (!debugfs_file)
1271 printk(KERN_ERR "fadump: unable to create debugfs file"
1272 " fadump_region\n");
1273
1274 if (fw_dump.dump_active) {
1275 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1276 if (rc)
1277 printk(KERN_ERR "fadump: unable to create sysfs file"
1278 " fadump_release_mem (%d)\n", rc);
1279 }
1280 return;
1281}
1282
1283/*
1284 * Prepare for firmware-assisted dump.
1285 */
1286int __init setup_fadump(void)
1287{
1288 if (!fw_dump.fadump_enabled)
1289 return 0;
1290
1291 if (!fw_dump.fadump_supported) {
1292 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1293 " this hardware\n");
1294 return 0;
1295 }
1296
1297 fadump_show_config();
1298 /*
1299 * If dump data is available then see if it is valid and prepare for
1300 * saving it to the disk.
1301 */
1302 if (fw_dump.dump_active) {
1303 /*
1304 * if dump process fails then invalidate the registration
1305 * and release memory before proceeding for re-registration.
1306 */
1307 if (process_fadump(fdm_active) < 0)
1308 fadump_invalidate_release_mem();
1309 }
1310 /* Initialize the kernel dump memory structure for FAD registration. */
1311 else if (fw_dump.reserve_dump_area_size)
1312 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1313 fadump_init_files();
1314
1315 return 1;
1316}
1317subsys_initcall(setup_fadump);