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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
28#include <asm/debugfs.h>
29#include <asm/page.h>
30#include <asm/prom.h>
31#include <asm/fadump.h>
32#include <asm/fadump-internal.h>
33#include <asm/setup.h>
34
35/*
36 * The CPU who acquired the lock to trigger the fadump crash should
37 * wait for other CPUs to enter.
38 *
39 * The timeout is in milliseconds.
40 */
41#define CRASH_TIMEOUT 500
42
43static struct fw_dump fw_dump;
44
45static void __init fadump_reserve_crash_area(u64 base);
46
47struct kobject *fadump_kobj;
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static atomic_t cpus_in_fadump;
52static DEFINE_MUTEX(fadump_mutex);
53
54struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
55
56#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
57#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
58 sizeof(struct fadump_memory_range))
59static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
60struct fadump_mrange_info reserved_mrange_info = { "reserved", rngs,
61 RESERVED_RNGS_SZ, 0,
62 RESERVED_RNGS_CNT, true };
63
64static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
65
66#ifdef CONFIG_CMA
67static struct cma *fadump_cma;
68
69/*
70 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
71 *
72 * This function initializes CMA area from fadump reserved memory.
73 * The total size of fadump reserved memory covers for boot memory size
74 * + cpu data size + hpte size and metadata.
75 * Initialize only the area equivalent to boot memory size for CMA use.
76 * The reamining portion of fadump reserved memory will be not given
77 * to CMA and pages for thoes will stay reserved. boot memory size is
78 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
79 * But for some reason even if it fails we still have the memory reservation
80 * with us and we can still continue doing fadump.
81 */
82int __init fadump_cma_init(void)
83{
84 unsigned long long base, size;
85 int rc;
86
87 if (!fw_dump.fadump_enabled)
88 return 0;
89
90 /*
91 * Do not use CMA if user has provided fadump=nocma kernel parameter.
92 * Return 1 to continue with fadump old behaviour.
93 */
94 if (fw_dump.nocma)
95 return 1;
96
97 base = fw_dump.reserve_dump_area_start;
98 size = fw_dump.boot_memory_size;
99
100 if (!size)
101 return 0;
102
103 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
104 if (rc) {
105 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
106 /*
107 * Though the CMA init has failed we still have memory
108 * reservation with us. The reserved memory will be
109 * blocked from production system usage. Hence return 1,
110 * so that we can continue with fadump.
111 */
112 return 1;
113 }
114
115 /*
116 * So we now have successfully initialized cma area for fadump.
117 */
118 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
119 "bytes of memory reserved for firmware-assisted dump\n",
120 cma_get_size(fadump_cma),
121 (unsigned long)cma_get_base(fadump_cma) >> 20,
122 fw_dump.reserve_dump_area_size);
123 return 1;
124}
125#else
126static int __init fadump_cma_init(void) { return 1; }
127#endif /* CONFIG_CMA */
128
129/* Scan the Firmware Assisted dump configuration details. */
130int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
131 int depth, void *data)
132{
133 if (depth == 0) {
134 early_init_dt_scan_reserved_ranges(node);
135 return 0;
136 }
137
138 if (depth != 1)
139 return 0;
140
141 if (strcmp(uname, "rtas") == 0) {
142 rtas_fadump_dt_scan(&fw_dump, node);
143 return 1;
144 }
145
146 if (strcmp(uname, "ibm,opal") == 0) {
147 opal_fadump_dt_scan(&fw_dump, node);
148 return 1;
149 }
150
151 return 0;
152}
153
154/*
155 * If fadump is registered, check if the memory provided
156 * falls within boot memory area and reserved memory area.
157 */
158int is_fadump_memory_area(u64 addr, unsigned long size)
159{
160 u64 d_start, d_end;
161
162 if (!fw_dump.dump_registered)
163 return 0;
164
165 if (!size)
166 return 0;
167
168 d_start = fw_dump.reserve_dump_area_start;
169 d_end = d_start + fw_dump.reserve_dump_area_size;
170 if (((addr + size) > d_start) && (addr <= d_end))
171 return 1;
172
173 return (addr <= fw_dump.boot_mem_top);
174}
175
176int should_fadump_crash(void)
177{
178 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
179 return 0;
180 return 1;
181}
182
183int is_fadump_active(void)
184{
185 return fw_dump.dump_active;
186}
187
188/*
189 * Returns true, if there are no holes in memory area between d_start to d_end,
190 * false otherwise.
191 */
192static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
193{
194 struct memblock_region *reg;
195 bool ret = false;
196 u64 start, end;
197
198 for_each_memblock(memory, reg) {
199 start = max_t(u64, d_start, reg->base);
200 end = min_t(u64, d_end, (reg->base + reg->size));
201 if (d_start < end) {
202 /* Memory hole from d_start to start */
203 if (start > d_start)
204 break;
205
206 if (end == d_end) {
207 ret = true;
208 break;
209 }
210
211 d_start = end + 1;
212 }
213 }
214
215 return ret;
216}
217
218/*
219 * Returns true, if there are no holes in boot memory area,
220 * false otherwise.
221 */
222bool is_fadump_boot_mem_contiguous(void)
223{
224 unsigned long d_start, d_end;
225 bool ret = false;
226 int i;
227
228 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
229 d_start = fw_dump.boot_mem_addr[i];
230 d_end = d_start + fw_dump.boot_mem_sz[i];
231
232 ret = is_fadump_mem_area_contiguous(d_start, d_end);
233 if (!ret)
234 break;
235 }
236
237 return ret;
238}
239
240/*
241 * Returns true, if there are no holes in reserved memory area,
242 * false otherwise.
243 */
244bool is_fadump_reserved_mem_contiguous(void)
245{
246 u64 d_start, d_end;
247
248 d_start = fw_dump.reserve_dump_area_start;
249 d_end = d_start + fw_dump.reserve_dump_area_size;
250 return is_fadump_mem_area_contiguous(d_start, d_end);
251}
252
253/* Print firmware assisted dump configurations for debugging purpose. */
254static void fadump_show_config(void)
255{
256 int i;
257
258 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
259 (fw_dump.fadump_supported ? "present" : "no support"));
260
261 if (!fw_dump.fadump_supported)
262 return;
263
264 pr_debug("Fadump enabled : %s\n",
265 (fw_dump.fadump_enabled ? "yes" : "no"));
266 pr_debug("Dump Active : %s\n",
267 (fw_dump.dump_active ? "yes" : "no"));
268 pr_debug("Dump section sizes:\n");
269 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
270 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
271 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
272 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
273 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
274 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
275 pr_debug("[%03d] base = %llx, size = %llx\n", i,
276 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
277 }
278}
279
280/**
281 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
282 *
283 * Function to find the largest memory size we need to reserve during early
284 * boot process. This will be the size of the memory that is required for a
285 * kernel to boot successfully.
286 *
287 * This function has been taken from phyp-assisted dump feature implementation.
288 *
289 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
290 *
291 * TODO: Come up with better approach to find out more accurate memory size
292 * that is required for a kernel to boot successfully.
293 *
294 */
295static inline u64 fadump_calculate_reserve_size(void)
296{
297 u64 base, size, bootmem_min;
298 int ret;
299
300 if (fw_dump.reserve_bootvar)
301 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
302
303 /*
304 * Check if the size is specified through crashkernel= cmdline
305 * option. If yes, then use that but ignore base as fadump reserves
306 * memory at a predefined offset.
307 */
308 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
309 &size, &base);
310 if (ret == 0 && size > 0) {
311 unsigned long max_size;
312
313 if (fw_dump.reserve_bootvar)
314 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
315
316 fw_dump.reserve_bootvar = (unsigned long)size;
317
318 /*
319 * Adjust if the boot memory size specified is above
320 * the upper limit.
321 */
322 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
323 if (fw_dump.reserve_bootvar > max_size) {
324 fw_dump.reserve_bootvar = max_size;
325 pr_info("Adjusted boot memory size to %luMB\n",
326 (fw_dump.reserve_bootvar >> 20));
327 }
328
329 return fw_dump.reserve_bootvar;
330 } else if (fw_dump.reserve_bootvar) {
331 /*
332 * 'fadump_reserve_mem=' is being used to reserve memory
333 * for firmware-assisted dump.
334 */
335 return fw_dump.reserve_bootvar;
336 }
337
338 /* divide by 20 to get 5% of value */
339 size = memblock_phys_mem_size() / 20;
340
341 /* round it down in multiples of 256 */
342 size = size & ~0x0FFFFFFFUL;
343
344 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
345 if (memory_limit && size > memory_limit)
346 size = memory_limit;
347
348 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
349 return (size > bootmem_min ? size : bootmem_min);
350}
351
352/*
353 * Calculate the total memory size required to be reserved for
354 * firmware-assisted dump registration.
355 */
356static unsigned long get_fadump_area_size(void)
357{
358 unsigned long size = 0;
359
360 size += fw_dump.cpu_state_data_size;
361 size += fw_dump.hpte_region_size;
362 size += fw_dump.boot_memory_size;
363 size += sizeof(struct fadump_crash_info_header);
364 size += sizeof(struct elfhdr); /* ELF core header.*/
365 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
366 /* Program headers for crash memory regions. */
367 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
368
369 size = PAGE_ALIGN(size);
370
371 /* This is to hold kernel metadata on platforms that support it */
372 size += (fw_dump.ops->fadump_get_metadata_size ?
373 fw_dump.ops->fadump_get_metadata_size() : 0);
374 return size;
375}
376
377static int __init add_boot_mem_region(unsigned long rstart,
378 unsigned long rsize)
379{
380 int i = fw_dump.boot_mem_regs_cnt++;
381
382 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
383 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
384 return 0;
385 }
386
387 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
388 i, rstart, (rstart + rsize));
389 fw_dump.boot_mem_addr[i] = rstart;
390 fw_dump.boot_mem_sz[i] = rsize;
391 return 1;
392}
393
394/*
395 * Firmware usually has a hard limit on the data it can copy per region.
396 * Honour that by splitting a memory range into multiple regions.
397 */
398static int __init add_boot_mem_regions(unsigned long mstart,
399 unsigned long msize)
400{
401 unsigned long rstart, rsize, max_size;
402 int ret = 1;
403
404 rstart = mstart;
405 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
406 while (msize) {
407 if (msize > max_size)
408 rsize = max_size;
409 else
410 rsize = msize;
411
412 ret = add_boot_mem_region(rstart, rsize);
413 if (!ret)
414 break;
415
416 msize -= rsize;
417 rstart += rsize;
418 }
419
420 return ret;
421}
422
423static int __init fadump_get_boot_mem_regions(void)
424{
425 unsigned long base, size, cur_size, hole_size, last_end;
426 unsigned long mem_size = fw_dump.boot_memory_size;
427 struct memblock_region *reg;
428 int ret = 1;
429
430 fw_dump.boot_mem_regs_cnt = 0;
431
432 last_end = 0;
433 hole_size = 0;
434 cur_size = 0;
435 for_each_memblock(memory, reg) {
436 base = reg->base;
437 size = reg->size;
438 hole_size += (base - last_end);
439
440 if ((cur_size + size) >= mem_size) {
441 size = (mem_size - cur_size);
442 ret = add_boot_mem_regions(base, size);
443 break;
444 }
445
446 mem_size -= size;
447 cur_size += size;
448 ret = add_boot_mem_regions(base, size);
449 if (!ret)
450 break;
451
452 last_end = base + size;
453 }
454 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
455
456 return ret;
457}
458
459/*
460 * Returns true, if the given range overlaps with reserved memory ranges
461 * starting at idx. Also, updates idx to index of overlapping memory range
462 * with the given memory range.
463 * False, otherwise.
464 */
465static bool overlaps_reserved_ranges(u64 base, u64 end, int *idx)
466{
467 bool ret = false;
468 int i;
469
470 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
471 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
472 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
473
474 if (end <= rbase)
475 break;
476
477 if ((end > rbase) && (base < rend)) {
478 *idx = i;
479 ret = true;
480 break;
481 }
482 }
483
484 return ret;
485}
486
487/*
488 * Locate a suitable memory area to reserve memory for FADump. While at it,
489 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
490 */
491static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
492{
493 struct fadump_memory_range *mrngs;
494 phys_addr_t mstart, mend;
495 int idx = 0;
496 u64 i, ret = 0;
497
498 mrngs = reserved_mrange_info.mem_ranges;
499 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
500 &mstart, &mend, NULL) {
501 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
502 i, mstart, mend, base);
503
504 if (mstart > base)
505 base = PAGE_ALIGN(mstart);
506
507 while ((mend > base) && ((mend - base) >= size)) {
508 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
509 ret = base;
510 goto out;
511 }
512
513 base = mrngs[idx].base + mrngs[idx].size;
514 base = PAGE_ALIGN(base);
515 }
516 }
517
518out:
519 return ret;
520}
521
522int __init fadump_reserve_mem(void)
523{
524 u64 base, size, mem_boundary, bootmem_min;
525 int ret = 1;
526
527 if (!fw_dump.fadump_enabled)
528 return 0;
529
530 if (!fw_dump.fadump_supported) {
531 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
532 goto error_out;
533 }
534
535 /*
536 * Initialize boot memory size
537 * If dump is active then we have already calculated the size during
538 * first kernel.
539 */
540 if (!fw_dump.dump_active) {
541 fw_dump.boot_memory_size =
542 PAGE_ALIGN(fadump_calculate_reserve_size());
543#ifdef CONFIG_CMA
544 if (!fw_dump.nocma) {
545 fw_dump.boot_memory_size =
546 ALIGN(fw_dump.boot_memory_size,
547 FADUMP_CMA_ALIGNMENT);
548 }
549#endif
550
551 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
552 if (fw_dump.boot_memory_size < bootmem_min) {
553 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
554 fw_dump.boot_memory_size, bootmem_min);
555 goto error_out;
556 }
557
558 if (!fadump_get_boot_mem_regions()) {
559 pr_err("Too many holes in boot memory area to enable fadump\n");
560 goto error_out;
561 }
562 }
563
564 /*
565 * Calculate the memory boundary.
566 * If memory_limit is less than actual memory boundary then reserve
567 * the memory for fadump beyond the memory_limit and adjust the
568 * memory_limit accordingly, so that the running kernel can run with
569 * specified memory_limit.
570 */
571 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
572 size = get_fadump_area_size();
573 if ((memory_limit + size) < memblock_end_of_DRAM())
574 memory_limit += size;
575 else
576 memory_limit = memblock_end_of_DRAM();
577 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
578 " dump, now %#016llx\n", memory_limit);
579 }
580 if (memory_limit)
581 mem_boundary = memory_limit;
582 else
583 mem_boundary = memblock_end_of_DRAM();
584
585 base = fw_dump.boot_mem_top;
586 size = get_fadump_area_size();
587 fw_dump.reserve_dump_area_size = size;
588 if (fw_dump.dump_active) {
589 pr_info("Firmware-assisted dump is active.\n");
590
591#ifdef CONFIG_HUGETLB_PAGE
592 /*
593 * FADump capture kernel doesn't care much about hugepages.
594 * In fact, handling hugepages in capture kernel is asking for
595 * trouble. So, disable HugeTLB support when fadump is active.
596 */
597 hugetlb_disabled = true;
598#endif
599 /*
600 * If last boot has crashed then reserve all the memory
601 * above boot memory size so that we don't touch it until
602 * dump is written to disk by userspace tool. This memory
603 * can be released for general use by invalidating fadump.
604 */
605 fadump_reserve_crash_area(base);
606
607 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
608 pr_debug("Reserve dump area start address: 0x%lx\n",
609 fw_dump.reserve_dump_area_start);
610 } else {
611 /*
612 * Reserve memory at an offset closer to bottom of the RAM to
613 * minimize the impact of memory hot-remove operation.
614 */
615 base = fadump_locate_reserve_mem(base, size);
616
617 if (!base || (base + size > mem_boundary)) {
618 pr_err("Failed to find memory chunk for reservation!\n");
619 goto error_out;
620 }
621 fw_dump.reserve_dump_area_start = base;
622
623 /*
624 * Calculate the kernel metadata address and register it with
625 * f/w if the platform supports.
626 */
627 if (fw_dump.ops->fadump_setup_metadata &&
628 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
629 goto error_out;
630
631 if (memblock_reserve(base, size)) {
632 pr_err("Failed to reserve memory!\n");
633 goto error_out;
634 }
635
636 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
637 (size >> 20), base, (memblock_phys_mem_size() >> 20));
638
639 ret = fadump_cma_init();
640 }
641
642 return ret;
643error_out:
644 fw_dump.fadump_enabled = 0;
645 return 0;
646}
647
648/* Look for fadump= cmdline option. */
649static int __init early_fadump_param(char *p)
650{
651 if (!p)
652 return 1;
653
654 if (strncmp(p, "on", 2) == 0)
655 fw_dump.fadump_enabled = 1;
656 else if (strncmp(p, "off", 3) == 0)
657 fw_dump.fadump_enabled = 0;
658 else if (strncmp(p, "nocma", 5) == 0) {
659 fw_dump.fadump_enabled = 1;
660 fw_dump.nocma = 1;
661 }
662
663 return 0;
664}
665early_param("fadump", early_fadump_param);
666
667/*
668 * Look for fadump_reserve_mem= cmdline option
669 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
670 * the sooner 'crashkernel=' parameter is accustomed to.
671 */
672static int __init early_fadump_reserve_mem(char *p)
673{
674 if (p)
675 fw_dump.reserve_bootvar = memparse(p, &p);
676 return 0;
677}
678early_param("fadump_reserve_mem", early_fadump_reserve_mem);
679
680void crash_fadump(struct pt_regs *regs, const char *str)
681{
682 unsigned int msecs;
683 struct fadump_crash_info_header *fdh = NULL;
684 int old_cpu, this_cpu;
685 /* Do not include first CPU */
686 unsigned int ncpus = num_online_cpus() - 1;
687
688 if (!should_fadump_crash())
689 return;
690
691 /*
692 * old_cpu == -1 means this is the first CPU which has come here,
693 * go ahead and trigger fadump.
694 *
695 * old_cpu != -1 means some other CPU has already on it's way
696 * to trigger fadump, just keep looping here.
697 */
698 this_cpu = smp_processor_id();
699 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
700
701 if (old_cpu != -1) {
702 atomic_inc(&cpus_in_fadump);
703
704 /*
705 * We can't loop here indefinitely. Wait as long as fadump
706 * is in force. If we race with fadump un-registration this
707 * loop will break and then we go down to normal panic path
708 * and reboot. If fadump is in force the first crashing
709 * cpu will definitely trigger fadump.
710 */
711 while (fw_dump.dump_registered)
712 cpu_relax();
713 return;
714 }
715
716 fdh = __va(fw_dump.fadumphdr_addr);
717 fdh->crashing_cpu = crashing_cpu;
718 crash_save_vmcoreinfo();
719
720 if (regs)
721 fdh->regs = *regs;
722 else
723 ppc_save_regs(&fdh->regs);
724
725 fdh->online_mask = *cpu_online_mask;
726
727 /*
728 * If we came in via system reset, wait a while for the secondary
729 * CPUs to enter.
730 */
731 if (TRAP(&(fdh->regs)) == 0x100) {
732 msecs = CRASH_TIMEOUT;
733 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
734 mdelay(1);
735 }
736
737 fw_dump.ops->fadump_trigger(fdh, str);
738}
739
740u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
741{
742 struct elf_prstatus prstatus;
743
744 memset(&prstatus, 0, sizeof(prstatus));
745 /*
746 * FIXME: How do i get PID? Do I really need it?
747 * prstatus.pr_pid = ????
748 */
749 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
750 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
751 &prstatus, sizeof(prstatus));
752 return buf;
753}
754
755void fadump_update_elfcore_header(char *bufp)
756{
757 struct elfhdr *elf;
758 struct elf_phdr *phdr;
759
760 elf = (struct elfhdr *)bufp;
761 bufp += sizeof(struct elfhdr);
762
763 /* First note is a place holder for cpu notes info. */
764 phdr = (struct elf_phdr *)bufp;
765
766 if (phdr->p_type == PT_NOTE) {
767 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
768 phdr->p_offset = phdr->p_paddr;
769 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
770 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
771 }
772 return;
773}
774
775static void *fadump_alloc_buffer(unsigned long size)
776{
777 unsigned long count, i;
778 struct page *page;
779 void *vaddr;
780
781 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
782 if (!vaddr)
783 return NULL;
784
785 count = PAGE_ALIGN(size) / PAGE_SIZE;
786 page = virt_to_page(vaddr);
787 for (i = 0; i < count; i++)
788 mark_page_reserved(page + i);
789 return vaddr;
790}
791
792static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
793{
794 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
795}
796
797s32 fadump_setup_cpu_notes_buf(u32 num_cpus)
798{
799 /* Allocate buffer to hold cpu crash notes. */
800 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
801 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
802 fw_dump.cpu_notes_buf_vaddr =
803 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
804 if (!fw_dump.cpu_notes_buf_vaddr) {
805 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
806 fw_dump.cpu_notes_buf_size);
807 return -ENOMEM;
808 }
809
810 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
811 fw_dump.cpu_notes_buf_size,
812 fw_dump.cpu_notes_buf_vaddr);
813 return 0;
814}
815
816void fadump_free_cpu_notes_buf(void)
817{
818 if (!fw_dump.cpu_notes_buf_vaddr)
819 return;
820
821 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
822 fw_dump.cpu_notes_buf_size);
823 fw_dump.cpu_notes_buf_vaddr = 0;
824 fw_dump.cpu_notes_buf_size = 0;
825}
826
827static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
828{
829 if (mrange_info->is_static) {
830 mrange_info->mem_range_cnt = 0;
831 return;
832 }
833
834 kfree(mrange_info->mem_ranges);
835 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
836 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
837}
838
839/*
840 * Allocate or reallocate mem_ranges array in incremental units
841 * of PAGE_SIZE.
842 */
843static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
844{
845 struct fadump_memory_range *new_array;
846 u64 new_size;
847
848 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
849 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
850 new_size, mrange_info->name);
851
852 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
853 if (new_array == NULL) {
854 pr_err("Insufficient memory for setting up %s memory ranges\n",
855 mrange_info->name);
856 fadump_free_mem_ranges(mrange_info);
857 return -ENOMEM;
858 }
859
860 mrange_info->mem_ranges = new_array;
861 mrange_info->mem_ranges_sz = new_size;
862 mrange_info->max_mem_ranges = (new_size /
863 sizeof(struct fadump_memory_range));
864 return 0;
865}
866
867static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
868 u64 base, u64 end)
869{
870 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
871 bool is_adjacent = false;
872 u64 start, size;
873
874 if (base == end)
875 return 0;
876
877 /*
878 * Fold adjacent memory ranges to bring down the memory ranges/
879 * PT_LOAD segments count.
880 */
881 if (mrange_info->mem_range_cnt) {
882 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
883 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
884
885 if ((start + size) == base)
886 is_adjacent = true;
887 }
888 if (!is_adjacent) {
889 /* resize the array on reaching the limit */
890 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
891 int ret;
892
893 if (mrange_info->is_static) {
894 pr_err("Reached array size limit for %s memory ranges\n",
895 mrange_info->name);
896 return -ENOSPC;
897 }
898
899 ret = fadump_alloc_mem_ranges(mrange_info);
900 if (ret)
901 return ret;
902
903 /* Update to the new resized array */
904 mem_ranges = mrange_info->mem_ranges;
905 }
906
907 start = base;
908 mem_ranges[mrange_info->mem_range_cnt].base = start;
909 mrange_info->mem_range_cnt++;
910 }
911
912 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
913 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
914 mrange_info->name, (mrange_info->mem_range_cnt - 1),
915 start, end - 1, (end - start));
916 return 0;
917}
918
919static int fadump_exclude_reserved_area(u64 start, u64 end)
920{
921 u64 ra_start, ra_end;
922 int ret = 0;
923
924 ra_start = fw_dump.reserve_dump_area_start;
925 ra_end = ra_start + fw_dump.reserve_dump_area_size;
926
927 if ((ra_start < end) && (ra_end > start)) {
928 if ((start < ra_start) && (end > ra_end)) {
929 ret = fadump_add_mem_range(&crash_mrange_info,
930 start, ra_start);
931 if (ret)
932 return ret;
933
934 ret = fadump_add_mem_range(&crash_mrange_info,
935 ra_end, end);
936 } else if (start < ra_start) {
937 ret = fadump_add_mem_range(&crash_mrange_info,
938 start, ra_start);
939 } else if (ra_end < end) {
940 ret = fadump_add_mem_range(&crash_mrange_info,
941 ra_end, end);
942 }
943 } else
944 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
945
946 return ret;
947}
948
949static int fadump_init_elfcore_header(char *bufp)
950{
951 struct elfhdr *elf;
952
953 elf = (struct elfhdr *) bufp;
954 bufp += sizeof(struct elfhdr);
955 memcpy(elf->e_ident, ELFMAG, SELFMAG);
956 elf->e_ident[EI_CLASS] = ELF_CLASS;
957 elf->e_ident[EI_DATA] = ELF_DATA;
958 elf->e_ident[EI_VERSION] = EV_CURRENT;
959 elf->e_ident[EI_OSABI] = ELF_OSABI;
960 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
961 elf->e_type = ET_CORE;
962 elf->e_machine = ELF_ARCH;
963 elf->e_version = EV_CURRENT;
964 elf->e_entry = 0;
965 elf->e_phoff = sizeof(struct elfhdr);
966 elf->e_shoff = 0;
967#if defined(_CALL_ELF)
968 elf->e_flags = _CALL_ELF;
969#else
970 elf->e_flags = 0;
971#endif
972 elf->e_ehsize = sizeof(struct elfhdr);
973 elf->e_phentsize = sizeof(struct elf_phdr);
974 elf->e_phnum = 0;
975 elf->e_shentsize = 0;
976 elf->e_shnum = 0;
977 elf->e_shstrndx = 0;
978
979 return 0;
980}
981
982/*
983 * Traverse through memblock structure and setup crash memory ranges. These
984 * ranges will be used create PT_LOAD program headers in elfcore header.
985 */
986static int fadump_setup_crash_memory_ranges(void)
987{
988 struct memblock_region *reg;
989 u64 start, end;
990 int i, ret;
991
992 pr_debug("Setup crash memory ranges.\n");
993 crash_mrange_info.mem_range_cnt = 0;
994
995 /*
996 * Boot memory region(s) registered with firmware are moved to
997 * different location at the time of crash. Create separate program
998 * header(s) for this memory chunk(s) with the correct offset.
999 */
1000 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1001 start = fw_dump.boot_mem_addr[i];
1002 end = start + fw_dump.boot_mem_sz[i];
1003 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1004 if (ret)
1005 return ret;
1006 }
1007
1008 for_each_memblock(memory, reg) {
1009 start = (u64)reg->base;
1010 end = start + (u64)reg->size;
1011
1012 /*
1013 * skip the memory chunk that is already added
1014 * (0 through boot_memory_top).
1015 */
1016 if (start < fw_dump.boot_mem_top) {
1017 if (end > fw_dump.boot_mem_top)
1018 start = fw_dump.boot_mem_top;
1019 else
1020 continue;
1021 }
1022
1023 /* add this range excluding the reserved dump area. */
1024 ret = fadump_exclude_reserved_area(start, end);
1025 if (ret)
1026 return ret;
1027 }
1028
1029 return 0;
1030}
1031
1032/*
1033 * If the given physical address falls within the boot memory region then
1034 * return the relocated address that points to the dump region reserved
1035 * for saving initial boot memory contents.
1036 */
1037static inline unsigned long fadump_relocate(unsigned long paddr)
1038{
1039 unsigned long raddr, rstart, rend, rlast, hole_size;
1040 int i;
1041
1042 hole_size = 0;
1043 rlast = 0;
1044 raddr = paddr;
1045 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1046 rstart = fw_dump.boot_mem_addr[i];
1047 rend = rstart + fw_dump.boot_mem_sz[i];
1048 hole_size += (rstart - rlast);
1049
1050 if (paddr >= rstart && paddr < rend) {
1051 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1052 break;
1053 }
1054
1055 rlast = rend;
1056 }
1057
1058 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1059 return raddr;
1060}
1061
1062static int fadump_create_elfcore_headers(char *bufp)
1063{
1064 unsigned long long raddr, offset;
1065 struct elf_phdr *phdr;
1066 struct elfhdr *elf;
1067 int i, j;
1068
1069 fadump_init_elfcore_header(bufp);
1070 elf = (struct elfhdr *)bufp;
1071 bufp += sizeof(struct elfhdr);
1072
1073 /*
1074 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1075 * will be populated during second kernel boot after crash. Hence
1076 * this PT_NOTE will always be the first elf note.
1077 *
1078 * NOTE: Any new ELF note addition should be placed after this note.
1079 */
1080 phdr = (struct elf_phdr *)bufp;
1081 bufp += sizeof(struct elf_phdr);
1082 phdr->p_type = PT_NOTE;
1083 phdr->p_flags = 0;
1084 phdr->p_vaddr = 0;
1085 phdr->p_align = 0;
1086
1087 phdr->p_offset = 0;
1088 phdr->p_paddr = 0;
1089 phdr->p_filesz = 0;
1090 phdr->p_memsz = 0;
1091
1092 (elf->e_phnum)++;
1093
1094 /* setup ELF PT_NOTE for vmcoreinfo */
1095 phdr = (struct elf_phdr *)bufp;
1096 bufp += sizeof(struct elf_phdr);
1097 phdr->p_type = PT_NOTE;
1098 phdr->p_flags = 0;
1099 phdr->p_vaddr = 0;
1100 phdr->p_align = 0;
1101
1102 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1103 phdr->p_offset = phdr->p_paddr;
1104 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1105
1106 /* Increment number of program headers. */
1107 (elf->e_phnum)++;
1108
1109 /* setup PT_LOAD sections. */
1110 j = 0;
1111 offset = 0;
1112 raddr = fw_dump.boot_mem_addr[0];
1113 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1114 u64 mbase, msize;
1115
1116 mbase = crash_mrange_info.mem_ranges[i].base;
1117 msize = crash_mrange_info.mem_ranges[i].size;
1118 if (!msize)
1119 continue;
1120
1121 phdr = (struct elf_phdr *)bufp;
1122 bufp += sizeof(struct elf_phdr);
1123 phdr->p_type = PT_LOAD;
1124 phdr->p_flags = PF_R|PF_W|PF_X;
1125 phdr->p_offset = mbase;
1126
1127 if (mbase == raddr) {
1128 /*
1129 * The entire real memory region will be moved by
1130 * firmware to the specified destination_address.
1131 * Hence set the correct offset.
1132 */
1133 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1134 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1135 offset += fw_dump.boot_mem_sz[j];
1136 raddr = fw_dump.boot_mem_addr[++j];
1137 }
1138 }
1139
1140 phdr->p_paddr = mbase;
1141 phdr->p_vaddr = (unsigned long)__va(mbase);
1142 phdr->p_filesz = msize;
1143 phdr->p_memsz = msize;
1144 phdr->p_align = 0;
1145
1146 /* Increment number of program headers. */
1147 (elf->e_phnum)++;
1148 }
1149 return 0;
1150}
1151
1152static unsigned long init_fadump_header(unsigned long addr)
1153{
1154 struct fadump_crash_info_header *fdh;
1155
1156 if (!addr)
1157 return 0;
1158
1159 fdh = __va(addr);
1160 addr += sizeof(struct fadump_crash_info_header);
1161
1162 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1163 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1164 fdh->elfcorehdr_addr = addr;
1165 /* We will set the crashing cpu id in crash_fadump() during crash. */
1166 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1167
1168 return addr;
1169}
1170
1171static int register_fadump(void)
1172{
1173 unsigned long addr;
1174 void *vaddr;
1175 int ret;
1176
1177 /*
1178 * If no memory is reserved then we can not register for firmware-
1179 * assisted dump.
1180 */
1181 if (!fw_dump.reserve_dump_area_size)
1182 return -ENODEV;
1183
1184 ret = fadump_setup_crash_memory_ranges();
1185 if (ret)
1186 return ret;
1187
1188 addr = fw_dump.fadumphdr_addr;
1189
1190 /* Initialize fadump crash info header. */
1191 addr = init_fadump_header(addr);
1192 vaddr = __va(addr);
1193
1194 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1195 fadump_create_elfcore_headers(vaddr);
1196
1197 /* register the future kernel dump with firmware. */
1198 pr_debug("Registering for firmware-assisted kernel dump...\n");
1199 return fw_dump.ops->fadump_register(&fw_dump);
1200}
1201
1202void fadump_cleanup(void)
1203{
1204 if (!fw_dump.fadump_supported)
1205 return;
1206
1207 /* Invalidate the registration only if dump is active. */
1208 if (fw_dump.dump_active) {
1209 pr_debug("Invalidating firmware-assisted dump registration\n");
1210 fw_dump.ops->fadump_invalidate(&fw_dump);
1211 } else if (fw_dump.dump_registered) {
1212 /* Un-register Firmware-assisted dump if it was registered. */
1213 fw_dump.ops->fadump_unregister(&fw_dump);
1214 fadump_free_mem_ranges(&crash_mrange_info);
1215 }
1216
1217 if (fw_dump.ops->fadump_cleanup)
1218 fw_dump.ops->fadump_cleanup(&fw_dump);
1219}
1220
1221static void fadump_free_reserved_memory(unsigned long start_pfn,
1222 unsigned long end_pfn)
1223{
1224 unsigned long pfn;
1225 unsigned long time_limit = jiffies + HZ;
1226
1227 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1228 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1229
1230 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1231 free_reserved_page(pfn_to_page(pfn));
1232
1233 if (time_after(jiffies, time_limit)) {
1234 cond_resched();
1235 time_limit = jiffies + HZ;
1236 }
1237 }
1238}
1239
1240/*
1241 * Skip memory holes and free memory that was actually reserved.
1242 */
1243static void fadump_release_reserved_area(u64 start, u64 end)
1244{
1245 u64 tstart, tend, spfn, epfn;
1246 struct memblock_region *reg;
1247
1248 spfn = PHYS_PFN(start);
1249 epfn = PHYS_PFN(end);
1250 for_each_memblock(memory, reg) {
1251 tstart = max_t(u64, spfn, memblock_region_memory_base_pfn(reg));
1252 tend = min_t(u64, epfn, memblock_region_memory_end_pfn(reg));
1253 if (tstart < tend) {
1254 fadump_free_reserved_memory(tstart, tend);
1255
1256 if (tend == epfn)
1257 break;
1258
1259 spfn = tend;
1260 }
1261 }
1262}
1263
1264/*
1265 * Sort the mem ranges in-place and merge adjacent ranges
1266 * to minimize the memory ranges count.
1267 */
1268static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1269{
1270 struct fadump_memory_range *mem_ranges;
1271 struct fadump_memory_range tmp_range;
1272 u64 base, size;
1273 int i, j, idx;
1274
1275 if (!reserved_mrange_info.mem_range_cnt)
1276 return;
1277
1278 /* Sort the memory ranges */
1279 mem_ranges = mrange_info->mem_ranges;
1280 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1281 idx = i;
1282 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1283 if (mem_ranges[idx].base > mem_ranges[j].base)
1284 idx = j;
1285 }
1286 if (idx != i) {
1287 tmp_range = mem_ranges[idx];
1288 mem_ranges[idx] = mem_ranges[i];
1289 mem_ranges[i] = tmp_range;
1290 }
1291 }
1292
1293 /* Merge adjacent reserved ranges */
1294 idx = 0;
1295 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1296 base = mem_ranges[i-1].base;
1297 size = mem_ranges[i-1].size;
1298 if (mem_ranges[i].base == (base + size))
1299 mem_ranges[idx].size += mem_ranges[i].size;
1300 else {
1301 idx++;
1302 if (i == idx)
1303 continue;
1304
1305 mem_ranges[idx] = mem_ranges[i];
1306 }
1307 }
1308 mrange_info->mem_range_cnt = idx + 1;
1309}
1310
1311/*
1312 * Scan reserved-ranges to consider them while reserving/releasing
1313 * memory for FADump.
1314 */
1315static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1316{
1317 const __be32 *prop;
1318 int len, ret = -1;
1319 unsigned long i;
1320
1321 /* reserved-ranges already scanned */
1322 if (reserved_mrange_info.mem_range_cnt != 0)
1323 return;
1324
1325 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1326 if (!prop)
1327 return;
1328
1329 /*
1330 * Each reserved range is an (address,size) pair, 2 cells each,
1331 * totalling 4 cells per range.
1332 */
1333 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1334 u64 base, size;
1335
1336 base = of_read_number(prop + (i * 4) + 0, 2);
1337 size = of_read_number(prop + (i * 4) + 2, 2);
1338
1339 if (size) {
1340 ret = fadump_add_mem_range(&reserved_mrange_info,
1341 base, base + size);
1342 if (ret < 0) {
1343 pr_warn("some reserved ranges are ignored!\n");
1344 break;
1345 }
1346 }
1347 }
1348
1349 /* Compact reserved ranges */
1350 sort_and_merge_mem_ranges(&reserved_mrange_info);
1351}
1352
1353/*
1354 * Release the memory that was reserved during early boot to preserve the
1355 * crash'ed kernel's memory contents except reserved dump area (permanent
1356 * reservation) and reserved ranges used by F/W. The released memory will
1357 * be available for general use.
1358 */
1359static void fadump_release_memory(u64 begin, u64 end)
1360{
1361 u64 ra_start, ra_end, tstart;
1362 int i, ret;
1363
1364 ra_start = fw_dump.reserve_dump_area_start;
1365 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1366
1367 /*
1368 * If reserved ranges array limit is hit, overwrite the last reserved
1369 * memory range with reserved dump area to ensure it is excluded from
1370 * the memory being released (reused for next FADump registration).
1371 */
1372 if (reserved_mrange_info.mem_range_cnt ==
1373 reserved_mrange_info.max_mem_ranges)
1374 reserved_mrange_info.mem_range_cnt--;
1375
1376 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1377 if (ret != 0)
1378 return;
1379
1380 /* Get the reserved ranges list in order first. */
1381 sort_and_merge_mem_ranges(&reserved_mrange_info);
1382
1383 /* Exclude reserved ranges and release remaining memory */
1384 tstart = begin;
1385 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1386 ra_start = reserved_mrange_info.mem_ranges[i].base;
1387 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1388
1389 if (tstart >= ra_end)
1390 continue;
1391
1392 if (tstart < ra_start)
1393 fadump_release_reserved_area(tstart, ra_start);
1394 tstart = ra_end;
1395 }
1396
1397 if (tstart < end)
1398 fadump_release_reserved_area(tstart, end);
1399}
1400
1401static void fadump_invalidate_release_mem(void)
1402{
1403 mutex_lock(&fadump_mutex);
1404 if (!fw_dump.dump_active) {
1405 mutex_unlock(&fadump_mutex);
1406 return;
1407 }
1408
1409 fadump_cleanup();
1410 mutex_unlock(&fadump_mutex);
1411
1412 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1413 fadump_free_cpu_notes_buf();
1414
1415 /*
1416 * Setup kernel metadata and initialize the kernel dump
1417 * memory structure for FADump re-registration.
1418 */
1419 if (fw_dump.ops->fadump_setup_metadata &&
1420 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1421 pr_warn("Failed to setup kernel metadata!\n");
1422 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1423}
1424
1425static ssize_t release_mem_store(struct kobject *kobj,
1426 struct kobj_attribute *attr,
1427 const char *buf, size_t count)
1428{
1429 int input = -1;
1430
1431 if (!fw_dump.dump_active)
1432 return -EPERM;
1433
1434 if (kstrtoint(buf, 0, &input))
1435 return -EINVAL;
1436
1437 if (input == 1) {
1438 /*
1439 * Take away the '/proc/vmcore'. We are releasing the dump
1440 * memory, hence it will not be valid anymore.
1441 */
1442#ifdef CONFIG_PROC_VMCORE
1443 vmcore_cleanup();
1444#endif
1445 fadump_invalidate_release_mem();
1446
1447 } else
1448 return -EINVAL;
1449 return count;
1450}
1451
1452/* Release the reserved memory and disable the FADump */
1453static void unregister_fadump(void)
1454{
1455 fadump_cleanup();
1456 fadump_release_memory(fw_dump.reserve_dump_area_start,
1457 fw_dump.reserve_dump_area_size);
1458 fw_dump.fadump_enabled = 0;
1459 kobject_put(fadump_kobj);
1460}
1461
1462static ssize_t enabled_show(struct kobject *kobj,
1463 struct kobj_attribute *attr,
1464 char *buf)
1465{
1466 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1467}
1468
1469static ssize_t mem_reserved_show(struct kobject *kobj,
1470 struct kobj_attribute *attr,
1471 char *buf)
1472{
1473 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1474}
1475
1476static ssize_t registered_show(struct kobject *kobj,
1477 struct kobj_attribute *attr,
1478 char *buf)
1479{
1480 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1481}
1482
1483static ssize_t registered_store(struct kobject *kobj,
1484 struct kobj_attribute *attr,
1485 const char *buf, size_t count)
1486{
1487 int ret = 0;
1488 int input = -1;
1489
1490 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1491 return -EPERM;
1492
1493 if (kstrtoint(buf, 0, &input))
1494 return -EINVAL;
1495
1496 mutex_lock(&fadump_mutex);
1497
1498 switch (input) {
1499 case 0:
1500 if (fw_dump.dump_registered == 0) {
1501 goto unlock_out;
1502 }
1503
1504 /* Un-register Firmware-assisted dump */
1505 pr_debug("Un-register firmware-assisted dump\n");
1506 fw_dump.ops->fadump_unregister(&fw_dump);
1507 break;
1508 case 1:
1509 if (fw_dump.dump_registered == 1) {
1510 /* Un-register Firmware-assisted dump */
1511 fw_dump.ops->fadump_unregister(&fw_dump);
1512 }
1513 /* Register Firmware-assisted dump */
1514 ret = register_fadump();
1515 break;
1516 default:
1517 ret = -EINVAL;
1518 break;
1519 }
1520
1521unlock_out:
1522 mutex_unlock(&fadump_mutex);
1523 return ret < 0 ? ret : count;
1524}
1525
1526static int fadump_region_show(struct seq_file *m, void *private)
1527{
1528 if (!fw_dump.fadump_enabled)
1529 return 0;
1530
1531 mutex_lock(&fadump_mutex);
1532 fw_dump.ops->fadump_region_show(&fw_dump, m);
1533 mutex_unlock(&fadump_mutex);
1534 return 0;
1535}
1536
1537static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1538static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1539static struct kobj_attribute register_attr = __ATTR_RW(registered);
1540static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1541
1542static struct attribute *fadump_attrs[] = {
1543 &enable_attr.attr,
1544 ®ister_attr.attr,
1545 &mem_reserved_attr.attr,
1546 NULL,
1547};
1548
1549ATTRIBUTE_GROUPS(fadump);
1550
1551DEFINE_SHOW_ATTRIBUTE(fadump_region);
1552
1553static void fadump_init_files(void)
1554{
1555 int rc = 0;
1556
1557 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1558 if (!fadump_kobj) {
1559 pr_err("failed to create fadump kobject\n");
1560 return;
1561 }
1562
1563 debugfs_create_file("fadump_region", 0444, powerpc_debugfs_root, NULL,
1564 &fadump_region_fops);
1565
1566 if (fw_dump.dump_active) {
1567 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1568 if (rc)
1569 pr_err("unable to create release_mem sysfs file (%d)\n",
1570 rc);
1571 }
1572
1573 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1574 if (rc) {
1575 pr_err("sysfs group creation failed (%d), unregistering FADump",
1576 rc);
1577 unregister_fadump();
1578 return;
1579 }
1580
1581 /*
1582 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1583 * create symlink at old location to maintain backward compatibility.
1584 *
1585 * - fadump_enabled -> fadump/enabled
1586 * - fadump_registered -> fadump/registered
1587 * - fadump_release_mem -> fadump/release_mem
1588 */
1589 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1590 "enabled", "fadump_enabled");
1591 if (rc) {
1592 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1593 return;
1594 }
1595
1596 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1597 "registered",
1598 "fadump_registered");
1599 if (rc) {
1600 pr_err("unable to create fadump_registered symlink (%d)", rc);
1601 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1602 return;
1603 }
1604
1605 if (fw_dump.dump_active) {
1606 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1607 fadump_kobj,
1608 "release_mem",
1609 "fadump_release_mem");
1610 if (rc)
1611 pr_err("unable to create fadump_release_mem symlink (%d)",
1612 rc);
1613 }
1614 return;
1615}
1616
1617/*
1618 * Prepare for firmware-assisted dump.
1619 */
1620int __init setup_fadump(void)
1621{
1622 if (!fw_dump.fadump_supported)
1623 return 0;
1624
1625 fadump_init_files();
1626 fadump_show_config();
1627
1628 if (!fw_dump.fadump_enabled)
1629 return 1;
1630
1631 /*
1632 * If dump data is available then see if it is valid and prepare for
1633 * saving it to the disk.
1634 */
1635 if (fw_dump.dump_active) {
1636 /*
1637 * if dump process fails then invalidate the registration
1638 * and release memory before proceeding for re-registration.
1639 */
1640 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1641 fadump_invalidate_release_mem();
1642 }
1643 /* Initialize the kernel dump memory structure for FAD registration. */
1644 else if (fw_dump.reserve_dump_area_size)
1645 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1646
1647 return 1;
1648}
1649subsys_initcall(setup_fadump);
1650#else /* !CONFIG_PRESERVE_FA_DUMP */
1651
1652/* Scan the Firmware Assisted dump configuration details. */
1653int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1654 int depth, void *data)
1655{
1656 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1657 return 0;
1658
1659 opal_fadump_dt_scan(&fw_dump, node);
1660 return 1;
1661}
1662
1663/*
1664 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1665 * preserve crash data. The subsequent memory preserving kernel boot
1666 * is likely to process this crash data.
1667 */
1668int __init fadump_reserve_mem(void)
1669{
1670 if (fw_dump.dump_active) {
1671 /*
1672 * If last boot has crashed then reserve all the memory
1673 * above boot memory to preserve crash data.
1674 */
1675 pr_info("Preserving crash data for processing in next boot.\n");
1676 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1677 } else
1678 pr_debug("FADump-aware kernel..\n");
1679
1680 return 1;
1681}
1682#endif /* CONFIG_PRESERVE_FA_DUMP */
1683
1684/* Preserve everything above the base address */
1685static void __init fadump_reserve_crash_area(u64 base)
1686{
1687 struct memblock_region *reg;
1688 u64 mstart, msize;
1689
1690 for_each_memblock(memory, reg) {
1691 mstart = reg->base;
1692 msize = reg->size;
1693
1694 if ((mstart + msize) < base)
1695 continue;
1696
1697 if (mstart < base) {
1698 msize -= (base - mstart);
1699 mstart = base;
1700 }
1701
1702 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1703 (msize >> 20), mstart);
1704 memblock_reserve(mstart, msize);
1705 }
1706}
1707
1708unsigned long __init arch_reserved_kernel_pages(void)
1709{
1710 return memblock_reserved_size() / PAGE_SIZE;
1711}
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
56#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
57#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
58 sizeof(struct fadump_memory_range))
59static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
60static struct fadump_mrange_info
61reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
62
63static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
64
65#ifdef CONFIG_CMA
66static struct cma *fadump_cma;
67
68/*
69 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
70 *
71 * This function initializes CMA area from fadump reserved memory.
72 * The total size of fadump reserved memory covers for boot memory size
73 * + cpu data size + hpte size and metadata.
74 * Initialize only the area equivalent to boot memory size for CMA use.
75 * The remaining portion of fadump reserved memory will be not given
76 * to CMA and pages for those will stay reserved. boot memory size is
77 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
78 * But for some reason even if it fails we still have the memory reservation
79 * with us and we can still continue doing fadump.
80 */
81void __init fadump_cma_init(void)
82{
83 unsigned long long base, size, end;
84 int rc;
85
86 if (!fw_dump.fadump_supported || !fw_dump.fadump_enabled ||
87 fw_dump.dump_active)
88 return;
89 /*
90 * Do not use CMA if user has provided fadump=nocma kernel parameter.
91 */
92 if (fw_dump.nocma || !fw_dump.boot_memory_size)
93 return;
94
95 /*
96 * [base, end) should be reserved during early init in
97 * fadump_reserve_mem(). No need to check this here as
98 * cma_init_reserved_mem() already checks for overlap.
99 * Here we give the aligned chunk of this reserved memory to CMA.
100 */
101 base = fw_dump.reserve_dump_area_start;
102 size = fw_dump.boot_memory_size;
103 end = base + size;
104
105 base = ALIGN(base, CMA_MIN_ALIGNMENT_BYTES);
106 end = ALIGN_DOWN(end, CMA_MIN_ALIGNMENT_BYTES);
107 size = end - base;
108
109 if (end <= base) {
110 pr_warn("%s: Too less memory to give to CMA\n", __func__);
111 return;
112 }
113
114 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
115 if (rc) {
116 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
117 /*
118 * Though the CMA init has failed we still have memory
119 * reservation with us. The reserved memory will be
120 * blocked from production system usage. Hence return 1,
121 * so that we can continue with fadump.
122 */
123 return;
124 }
125
126 /*
127 * If CMA activation fails, keep the pages reserved, instead of
128 * exposing them to buddy allocator. Same as 'fadump=nocma' case.
129 */
130 cma_reserve_pages_on_error(fadump_cma);
131
132 /*
133 * So we now have successfully initialized cma area for fadump.
134 */
135 pr_info("Initialized [0x%llx, %luMB] cma area from [0x%lx, %luMB] "
136 "bytes of memory reserved for firmware-assisted dump\n",
137 cma_get_base(fadump_cma), cma_get_size(fadump_cma) >> 20,
138 fw_dump.reserve_dump_area_start,
139 fw_dump.boot_memory_size >> 20);
140 return;
141}
142#endif /* CONFIG_CMA */
143
144/*
145 * Additional parameters meant for capture kernel are placed in a dedicated area.
146 * If this is capture kernel boot, append these parameters to bootargs.
147 */
148void __init fadump_append_bootargs(void)
149{
150 char *append_args;
151 size_t len;
152
153 if (!fw_dump.dump_active || !fw_dump.param_area_supported || !fw_dump.param_area)
154 return;
155
156 if (fw_dump.param_area < fw_dump.boot_mem_top) {
157 if (memblock_reserve(fw_dump.param_area, COMMAND_LINE_SIZE)) {
158 pr_warn("WARNING: Can't use additional parameters area!\n");
159 fw_dump.param_area = 0;
160 return;
161 }
162 }
163
164 append_args = (char *)fw_dump.param_area;
165 len = strlen(boot_command_line);
166
167 /*
168 * Too late to fail even if cmdline size exceeds. Truncate additional parameters
169 * to cmdline size and proceed anyway.
170 */
171 if (len + strlen(append_args) >= COMMAND_LINE_SIZE - 1)
172 pr_warn("WARNING: Appending parameters exceeds cmdline size. Truncating!\n");
173
174 pr_debug("Cmdline: %s\n", boot_command_line);
175 snprintf(boot_command_line + len, COMMAND_LINE_SIZE - len, " %s", append_args);
176 pr_info("Updated cmdline: %s\n", boot_command_line);
177}
178
179/* Scan the Firmware Assisted dump configuration details. */
180int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
181 int depth, void *data)
182{
183 if (depth == 0) {
184 early_init_dt_scan_reserved_ranges(node);
185 return 0;
186 }
187
188 if (depth != 1)
189 return 0;
190
191 if (strcmp(uname, "rtas") == 0) {
192 rtas_fadump_dt_scan(&fw_dump, node);
193 return 1;
194 }
195
196 if (strcmp(uname, "ibm,opal") == 0) {
197 opal_fadump_dt_scan(&fw_dump, node);
198 return 1;
199 }
200
201 return 0;
202}
203
204/*
205 * If fadump is registered, check if the memory provided
206 * falls within boot memory area and reserved memory area.
207 */
208int is_fadump_memory_area(u64 addr, unsigned long size)
209{
210 u64 d_start, d_end;
211
212 if (!fw_dump.dump_registered)
213 return 0;
214
215 if (!size)
216 return 0;
217
218 d_start = fw_dump.reserve_dump_area_start;
219 d_end = d_start + fw_dump.reserve_dump_area_size;
220 if (((addr + size) > d_start) && (addr <= d_end))
221 return 1;
222
223 return (addr <= fw_dump.boot_mem_top);
224}
225
226int should_fadump_crash(void)
227{
228 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
229 return 0;
230 return 1;
231}
232
233int is_fadump_active(void)
234{
235 return fw_dump.dump_active;
236}
237
238/*
239 * Returns true, if there are no holes in memory area between d_start to d_end,
240 * false otherwise.
241 */
242static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
243{
244 phys_addr_t reg_start, reg_end;
245 bool ret = false;
246 u64 i, start, end;
247
248 for_each_mem_range(i, ®_start, ®_end) {
249 start = max_t(u64, d_start, reg_start);
250 end = min_t(u64, d_end, reg_end);
251 if (d_start < end) {
252 /* Memory hole from d_start to start */
253 if (start > d_start)
254 break;
255
256 if (end == d_end) {
257 ret = true;
258 break;
259 }
260
261 d_start = end + 1;
262 }
263 }
264
265 return ret;
266}
267
268/*
269 * Returns true, if there are no holes in reserved memory area,
270 * false otherwise.
271 */
272bool is_fadump_reserved_mem_contiguous(void)
273{
274 u64 d_start, d_end;
275
276 d_start = fw_dump.reserve_dump_area_start;
277 d_end = d_start + fw_dump.reserve_dump_area_size;
278 return is_fadump_mem_area_contiguous(d_start, d_end);
279}
280
281/* Print firmware assisted dump configurations for debugging purpose. */
282static void __init fadump_show_config(void)
283{
284 int i;
285
286 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
287 (fw_dump.fadump_supported ? "present" : "no support"));
288
289 if (!fw_dump.fadump_supported)
290 return;
291
292 pr_debug("Fadump enabled : %s\n",
293 (fw_dump.fadump_enabled ? "yes" : "no"));
294 pr_debug("Dump Active : %s\n",
295 (fw_dump.dump_active ? "yes" : "no"));
296 pr_debug("Dump section sizes:\n");
297 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
298 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
299 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
300 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
301 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
302 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
303 pr_debug("[%03d] base = %llx, size = %llx\n", i,
304 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
305 }
306}
307
308/**
309 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
310 *
311 * Function to find the largest memory size we need to reserve during early
312 * boot process. This will be the size of the memory that is required for a
313 * kernel to boot successfully.
314 *
315 * This function has been taken from phyp-assisted dump feature implementation.
316 *
317 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
318 *
319 * TODO: Come up with better approach to find out more accurate memory size
320 * that is required for a kernel to boot successfully.
321 *
322 */
323static __init u64 fadump_calculate_reserve_size(void)
324{
325 u64 base, size, bootmem_min;
326 int ret;
327
328 if (fw_dump.reserve_bootvar)
329 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
330
331 /*
332 * Check if the size is specified through crashkernel= cmdline
333 * option. If yes, then use that but ignore base as fadump reserves
334 * memory at a predefined offset.
335 */
336 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
337 &size, &base, NULL, NULL);
338 if (ret == 0 && size > 0) {
339 unsigned long max_size;
340
341 if (fw_dump.reserve_bootvar)
342 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
343
344 fw_dump.reserve_bootvar = (unsigned long)size;
345
346 /*
347 * Adjust if the boot memory size specified is above
348 * the upper limit.
349 */
350 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
351 if (fw_dump.reserve_bootvar > max_size) {
352 fw_dump.reserve_bootvar = max_size;
353 pr_info("Adjusted boot memory size to %luMB\n",
354 (fw_dump.reserve_bootvar >> 20));
355 }
356
357 return fw_dump.reserve_bootvar;
358 } else if (fw_dump.reserve_bootvar) {
359 /*
360 * 'fadump_reserve_mem=' is being used to reserve memory
361 * for firmware-assisted dump.
362 */
363 return fw_dump.reserve_bootvar;
364 }
365
366 /* divide by 20 to get 5% of value */
367 size = memblock_phys_mem_size() / 20;
368
369 /* round it down in multiples of 256 */
370 size = size & ~0x0FFFFFFFUL;
371
372 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
373 if (memory_limit && size > memory_limit)
374 size = memory_limit;
375
376 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
377 return (size > bootmem_min ? size : bootmem_min);
378}
379
380/*
381 * Calculate the total memory size required to be reserved for
382 * firmware-assisted dump registration.
383 */
384static unsigned long __init get_fadump_area_size(void)
385{
386 unsigned long size = 0;
387
388 size += fw_dump.cpu_state_data_size;
389 size += fw_dump.hpte_region_size;
390 /*
391 * Account for pagesize alignment of boot memory area destination address.
392 * This faciliates in mmap reading of first kernel's memory.
393 */
394 size = PAGE_ALIGN(size);
395 size += fw_dump.boot_memory_size;
396 size += sizeof(struct fadump_crash_info_header);
397
398 /* This is to hold kernel metadata on platforms that support it */
399 size += (fw_dump.ops->fadump_get_metadata_size ?
400 fw_dump.ops->fadump_get_metadata_size() : 0);
401 return size;
402}
403
404static int __init add_boot_mem_region(unsigned long rstart,
405 unsigned long rsize)
406{
407 int max_boot_mem_rgns = fw_dump.ops->fadump_max_boot_mem_rgns();
408 int i = fw_dump.boot_mem_regs_cnt++;
409
410 if (fw_dump.boot_mem_regs_cnt > max_boot_mem_rgns) {
411 fw_dump.boot_mem_regs_cnt = max_boot_mem_rgns;
412 return 0;
413 }
414
415 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
416 i, rstart, (rstart + rsize));
417 fw_dump.boot_mem_addr[i] = rstart;
418 fw_dump.boot_mem_sz[i] = rsize;
419 return 1;
420}
421
422/*
423 * Firmware usually has a hard limit on the data it can copy per region.
424 * Honour that by splitting a memory range into multiple regions.
425 */
426static int __init add_boot_mem_regions(unsigned long mstart,
427 unsigned long msize)
428{
429 unsigned long rstart, rsize, max_size;
430 int ret = 1;
431
432 rstart = mstart;
433 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
434 while (msize) {
435 if (msize > max_size)
436 rsize = max_size;
437 else
438 rsize = msize;
439
440 ret = add_boot_mem_region(rstart, rsize);
441 if (!ret)
442 break;
443
444 msize -= rsize;
445 rstart += rsize;
446 }
447
448 return ret;
449}
450
451static int __init fadump_get_boot_mem_regions(void)
452{
453 unsigned long size, cur_size, hole_size, last_end;
454 unsigned long mem_size = fw_dump.boot_memory_size;
455 phys_addr_t reg_start, reg_end;
456 int ret = 1;
457 u64 i;
458
459 fw_dump.boot_mem_regs_cnt = 0;
460
461 last_end = 0;
462 hole_size = 0;
463 cur_size = 0;
464 for_each_mem_range(i, ®_start, ®_end) {
465 size = reg_end - reg_start;
466 hole_size += (reg_start - last_end);
467
468 if ((cur_size + size) >= mem_size) {
469 size = (mem_size - cur_size);
470 ret = add_boot_mem_regions(reg_start, size);
471 break;
472 }
473
474 mem_size -= size;
475 cur_size += size;
476 ret = add_boot_mem_regions(reg_start, size);
477 if (!ret)
478 break;
479
480 last_end = reg_end;
481 }
482 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
483
484 return ret;
485}
486
487/*
488 * Returns true, if the given range overlaps with reserved memory ranges
489 * starting at idx. Also, updates idx to index of overlapping memory range
490 * with the given memory range.
491 * False, otherwise.
492 */
493static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
494{
495 bool ret = false;
496 int i;
497
498 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
499 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
500 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
501
502 if (end <= rbase)
503 break;
504
505 if ((end > rbase) && (base < rend)) {
506 *idx = i;
507 ret = true;
508 break;
509 }
510 }
511
512 return ret;
513}
514
515/*
516 * Locate a suitable memory area to reserve memory for FADump. While at it,
517 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
518 */
519static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
520{
521 struct fadump_memory_range *mrngs;
522 phys_addr_t mstart, mend;
523 int idx = 0;
524 u64 i, ret = 0;
525
526 mrngs = reserved_mrange_info.mem_ranges;
527 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
528 &mstart, &mend, NULL) {
529 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
530 i, mstart, mend, base);
531
532 if (mstart > base)
533 base = PAGE_ALIGN(mstart);
534
535 while ((mend > base) && ((mend - base) >= size)) {
536 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
537 ret = base;
538 goto out;
539 }
540
541 base = mrngs[idx].base + mrngs[idx].size;
542 base = PAGE_ALIGN(base);
543 }
544 }
545
546out:
547 return ret;
548}
549
550int __init fadump_reserve_mem(void)
551{
552 u64 base, size, mem_boundary, bootmem_min;
553 int ret = 1;
554
555 if (!fw_dump.fadump_enabled)
556 return 0;
557
558 if (!fw_dump.fadump_supported) {
559 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
560 goto error_out;
561 }
562
563 /*
564 * Initialize boot memory size
565 * If dump is active then we have already calculated the size during
566 * first kernel.
567 */
568 if (!fw_dump.dump_active) {
569 fw_dump.boot_memory_size =
570 PAGE_ALIGN(fadump_calculate_reserve_size());
571
572 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
573 if (fw_dump.boot_memory_size < bootmem_min) {
574 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
575 fw_dump.boot_memory_size, bootmem_min);
576 goto error_out;
577 }
578
579 if (!fadump_get_boot_mem_regions()) {
580 pr_err("Too many holes in boot memory area to enable fadump\n");
581 goto error_out;
582 }
583 }
584
585 if (memory_limit)
586 mem_boundary = memory_limit;
587 else
588 mem_boundary = memblock_end_of_DRAM();
589
590 base = fw_dump.boot_mem_top;
591 size = get_fadump_area_size();
592 fw_dump.reserve_dump_area_size = size;
593 if (fw_dump.dump_active) {
594 pr_info("Firmware-assisted dump is active.\n");
595
596#ifdef CONFIG_HUGETLB_PAGE
597 /*
598 * FADump capture kernel doesn't care much about hugepages.
599 * In fact, handling hugepages in capture kernel is asking for
600 * trouble. So, disable HugeTLB support when fadump is active.
601 */
602 hugetlb_disabled = true;
603#endif
604 /*
605 * If last boot has crashed then reserve all the memory
606 * above boot memory size so that we don't touch it until
607 * dump is written to disk by userspace tool. This memory
608 * can be released for general use by invalidating fadump.
609 */
610 fadump_reserve_crash_area(base);
611
612 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
613 pr_debug("Reserve dump area start address: 0x%lx\n",
614 fw_dump.reserve_dump_area_start);
615 } else {
616 /*
617 * Reserve memory at an offset closer to bottom of the RAM to
618 * minimize the impact of memory hot-remove operation.
619 */
620 base = fadump_locate_reserve_mem(base, size);
621
622 if (!base || (base + size > mem_boundary)) {
623 pr_err("Failed to find memory chunk for reservation!\n");
624 goto error_out;
625 }
626 fw_dump.reserve_dump_area_start = base;
627
628 /*
629 * Calculate the kernel metadata address and register it with
630 * f/w if the platform supports.
631 */
632 if (fw_dump.ops->fadump_setup_metadata &&
633 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
634 goto error_out;
635
636 if (memblock_reserve(base, size)) {
637 pr_err("Failed to reserve memory!\n");
638 goto error_out;
639 }
640
641 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
642 (size >> 20), base, (memblock_phys_mem_size() >> 20));
643 }
644
645 return ret;
646error_out:
647 fw_dump.fadump_enabled = 0;
648 fw_dump.reserve_dump_area_size = 0;
649 return 0;
650}
651
652/* Look for fadump= cmdline option. */
653static int __init early_fadump_param(char *p)
654{
655 if (!p)
656 return 1;
657
658 if (strncmp(p, "on", 2) == 0)
659 fw_dump.fadump_enabled = 1;
660 else if (strncmp(p, "off", 3) == 0)
661 fw_dump.fadump_enabled = 0;
662 else if (strncmp(p, "nocma", 5) == 0) {
663 fw_dump.fadump_enabled = 1;
664 fw_dump.nocma = 1;
665 }
666
667 return 0;
668}
669early_param("fadump", early_fadump_param);
670
671/*
672 * Look for fadump_reserve_mem= cmdline option
673 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
674 * the sooner 'crashkernel=' parameter is accustomed to.
675 */
676static int __init early_fadump_reserve_mem(char *p)
677{
678 if (p)
679 fw_dump.reserve_bootvar = memparse(p, &p);
680 return 0;
681}
682early_param("fadump_reserve_mem", early_fadump_reserve_mem);
683
684void crash_fadump(struct pt_regs *regs, const char *str)
685{
686 unsigned int msecs;
687 struct fadump_crash_info_header *fdh = NULL;
688 int old_cpu, this_cpu;
689 /* Do not include first CPU */
690 unsigned int ncpus = num_online_cpus() - 1;
691
692 if (!should_fadump_crash())
693 return;
694
695 /*
696 * old_cpu == -1 means this is the first CPU which has come here,
697 * go ahead and trigger fadump.
698 *
699 * old_cpu != -1 means some other CPU has already on its way
700 * to trigger fadump, just keep looping here.
701 */
702 this_cpu = smp_processor_id();
703 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
704
705 if (old_cpu != -1) {
706 atomic_inc(&cpus_in_fadump);
707
708 /*
709 * We can't loop here indefinitely. Wait as long as fadump
710 * is in force. If we race with fadump un-registration this
711 * loop will break and then we go down to normal panic path
712 * and reboot. If fadump is in force the first crashing
713 * cpu will definitely trigger fadump.
714 */
715 while (fw_dump.dump_registered)
716 cpu_relax();
717 return;
718 }
719
720 fdh = __va(fw_dump.fadumphdr_addr);
721 fdh->crashing_cpu = crashing_cpu;
722 crash_save_vmcoreinfo();
723
724 if (regs)
725 fdh->regs = *regs;
726 else
727 ppc_save_regs(&fdh->regs);
728
729 fdh->cpu_mask = *cpu_online_mask;
730
731 /*
732 * If we came in via system reset, wait a while for the secondary
733 * CPUs to enter.
734 */
735 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
736 msecs = CRASH_TIMEOUT;
737 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
738 mdelay(1);
739 }
740
741 fw_dump.ops->fadump_trigger(fdh, str);
742}
743
744u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
745{
746 struct elf_prstatus prstatus;
747
748 memset(&prstatus, 0, sizeof(prstatus));
749 /*
750 * FIXME: How do i get PID? Do I really need it?
751 * prstatus.pr_pid = ????
752 */
753 elf_core_copy_regs(&prstatus.pr_reg, regs);
754 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
755 &prstatus, sizeof(prstatus));
756 return buf;
757}
758
759void __init fadump_update_elfcore_header(char *bufp)
760{
761 struct elf_phdr *phdr;
762
763 bufp += sizeof(struct elfhdr);
764
765 /* First note is a place holder for cpu notes info. */
766 phdr = (struct elf_phdr *)bufp;
767
768 if (phdr->p_type == PT_NOTE) {
769 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
770 phdr->p_offset = phdr->p_paddr;
771 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
772 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
773 }
774 return;
775}
776
777static void *__init fadump_alloc_buffer(unsigned long size)
778{
779 unsigned long count, i;
780 struct page *page;
781 void *vaddr;
782
783 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
784 if (!vaddr)
785 return NULL;
786
787 count = PAGE_ALIGN(size) / PAGE_SIZE;
788 page = virt_to_page(vaddr);
789 for (i = 0; i < count; i++)
790 mark_page_reserved(page + i);
791 return vaddr;
792}
793
794static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
795{
796 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
797}
798
799s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
800{
801 /* Allocate buffer to hold cpu crash notes. */
802 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
803 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
804 fw_dump.cpu_notes_buf_vaddr =
805 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
806 if (!fw_dump.cpu_notes_buf_vaddr) {
807 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
808 fw_dump.cpu_notes_buf_size);
809 return -ENOMEM;
810 }
811
812 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
813 fw_dump.cpu_notes_buf_size,
814 fw_dump.cpu_notes_buf_vaddr);
815 return 0;
816}
817
818void fadump_free_cpu_notes_buf(void)
819{
820 if (!fw_dump.cpu_notes_buf_vaddr)
821 return;
822
823 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
824 fw_dump.cpu_notes_buf_size);
825 fw_dump.cpu_notes_buf_vaddr = 0;
826 fw_dump.cpu_notes_buf_size = 0;
827}
828
829static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
830{
831 if (mrange_info->is_static) {
832 mrange_info->mem_range_cnt = 0;
833 return;
834 }
835
836 kfree(mrange_info->mem_ranges);
837 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
838 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
839}
840
841/*
842 * Allocate or reallocate mem_ranges array in incremental units
843 * of PAGE_SIZE.
844 */
845static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
846{
847 struct fadump_memory_range *new_array;
848 u64 new_size;
849
850 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
851 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
852 new_size, mrange_info->name);
853
854 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
855 if (new_array == NULL) {
856 pr_err("Insufficient memory for setting up %s memory ranges\n",
857 mrange_info->name);
858 fadump_free_mem_ranges(mrange_info);
859 return -ENOMEM;
860 }
861
862 mrange_info->mem_ranges = new_array;
863 mrange_info->mem_ranges_sz = new_size;
864 mrange_info->max_mem_ranges = (new_size /
865 sizeof(struct fadump_memory_range));
866 return 0;
867}
868static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
869 u64 base, u64 end)
870{
871 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
872 bool is_adjacent = false;
873 u64 start, size;
874
875 if (base == end)
876 return 0;
877
878 /*
879 * Fold adjacent memory ranges to bring down the memory ranges/
880 * PT_LOAD segments count.
881 */
882 if (mrange_info->mem_range_cnt) {
883 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
884 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
885
886 /*
887 * Boot memory area needs separate PT_LOAD segment(s) as it
888 * is moved to a different location at the time of crash.
889 * So, fold only if the region is not boot memory area.
890 */
891 if ((start + size) == base && start >= fw_dump.boot_mem_top)
892 is_adjacent = true;
893 }
894 if (!is_adjacent) {
895 /* resize the array on reaching the limit */
896 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
897 int ret;
898
899 if (mrange_info->is_static) {
900 pr_err("Reached array size limit for %s memory ranges\n",
901 mrange_info->name);
902 return -ENOSPC;
903 }
904
905 ret = fadump_alloc_mem_ranges(mrange_info);
906 if (ret)
907 return ret;
908
909 /* Update to the new resized array */
910 mem_ranges = mrange_info->mem_ranges;
911 }
912
913 start = base;
914 mem_ranges[mrange_info->mem_range_cnt].base = start;
915 mrange_info->mem_range_cnt++;
916 }
917
918 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
919 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
920 mrange_info->name, (mrange_info->mem_range_cnt - 1),
921 start, end - 1, (end - start));
922 return 0;
923}
924
925static int fadump_init_elfcore_header(char *bufp)
926{
927 struct elfhdr *elf;
928
929 elf = (struct elfhdr *) bufp;
930 bufp += sizeof(struct elfhdr);
931 memcpy(elf->e_ident, ELFMAG, SELFMAG);
932 elf->e_ident[EI_CLASS] = ELF_CLASS;
933 elf->e_ident[EI_DATA] = ELF_DATA;
934 elf->e_ident[EI_VERSION] = EV_CURRENT;
935 elf->e_ident[EI_OSABI] = ELF_OSABI;
936 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
937 elf->e_type = ET_CORE;
938 elf->e_machine = ELF_ARCH;
939 elf->e_version = EV_CURRENT;
940 elf->e_entry = 0;
941 elf->e_phoff = sizeof(struct elfhdr);
942 elf->e_shoff = 0;
943
944 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
945 elf->e_flags = 2;
946 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
947 elf->e_flags = 1;
948 else
949 elf->e_flags = 0;
950
951 elf->e_ehsize = sizeof(struct elfhdr);
952 elf->e_phentsize = sizeof(struct elf_phdr);
953 elf->e_phnum = 0;
954 elf->e_shentsize = 0;
955 elf->e_shnum = 0;
956 elf->e_shstrndx = 0;
957
958 return 0;
959}
960
961/*
962 * If the given physical address falls within the boot memory region then
963 * return the relocated address that points to the dump region reserved
964 * for saving initial boot memory contents.
965 */
966static inline unsigned long fadump_relocate(unsigned long paddr)
967{
968 unsigned long raddr, rstart, rend, rlast, hole_size;
969 int i;
970
971 hole_size = 0;
972 rlast = 0;
973 raddr = paddr;
974 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
975 rstart = fw_dump.boot_mem_addr[i];
976 rend = rstart + fw_dump.boot_mem_sz[i];
977 hole_size += (rstart - rlast);
978
979 if (paddr >= rstart && paddr < rend) {
980 raddr += fw_dump.boot_mem_dest_addr - hole_size;
981 break;
982 }
983
984 rlast = rend;
985 }
986
987 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
988 return raddr;
989}
990
991static void __init populate_elf_pt_load(struct elf_phdr *phdr, u64 start,
992 u64 size, unsigned long long offset)
993{
994 phdr->p_align = 0;
995 phdr->p_memsz = size;
996 phdr->p_filesz = size;
997 phdr->p_paddr = start;
998 phdr->p_offset = offset;
999 phdr->p_type = PT_LOAD;
1000 phdr->p_flags = PF_R|PF_W|PF_X;
1001 phdr->p_vaddr = (unsigned long)__va(start);
1002}
1003
1004static void __init fadump_populate_elfcorehdr(struct fadump_crash_info_header *fdh)
1005{
1006 char *bufp;
1007 struct elfhdr *elf;
1008 struct elf_phdr *phdr;
1009 u64 boot_mem_dest_offset;
1010 unsigned long long i, ra_start, ra_end, ra_size, mstart, mend;
1011
1012 bufp = (char *) fw_dump.elfcorehdr_addr;
1013 fadump_init_elfcore_header(bufp);
1014 elf = (struct elfhdr *)bufp;
1015 bufp += sizeof(struct elfhdr);
1016
1017 /*
1018 * Set up ELF PT_NOTE, a placeholder for CPU notes information.
1019 * The notes info will be populated later by platform-specific code.
1020 * Hence, this PT_NOTE will always be the first ELF note.
1021 *
1022 * NOTE: Any new ELF note addition should be placed after this note.
1023 */
1024 phdr = (struct elf_phdr *)bufp;
1025 bufp += sizeof(struct elf_phdr);
1026 phdr->p_type = PT_NOTE;
1027 phdr->p_flags = 0;
1028 phdr->p_vaddr = 0;
1029 phdr->p_align = 0;
1030 phdr->p_offset = 0;
1031 phdr->p_paddr = 0;
1032 phdr->p_filesz = 0;
1033 phdr->p_memsz = 0;
1034 /* Increment number of program headers. */
1035 (elf->e_phnum)++;
1036
1037 /* setup ELF PT_NOTE for vmcoreinfo */
1038 phdr = (struct elf_phdr *)bufp;
1039 bufp += sizeof(struct elf_phdr);
1040 phdr->p_type = PT_NOTE;
1041 phdr->p_flags = 0;
1042 phdr->p_vaddr = 0;
1043 phdr->p_align = 0;
1044 phdr->p_paddr = phdr->p_offset = fdh->vmcoreinfo_raddr;
1045 phdr->p_memsz = phdr->p_filesz = fdh->vmcoreinfo_size;
1046 /* Increment number of program headers. */
1047 (elf->e_phnum)++;
1048
1049 /*
1050 * Setup PT_LOAD sections. first include boot memory regions
1051 * and then add rest of the memory regions.
1052 */
1053 boot_mem_dest_offset = fw_dump.boot_mem_dest_addr;
1054 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1055 phdr = (struct elf_phdr *)bufp;
1056 bufp += sizeof(struct elf_phdr);
1057 populate_elf_pt_load(phdr, fw_dump.boot_mem_addr[i],
1058 fw_dump.boot_mem_sz[i],
1059 boot_mem_dest_offset);
1060 /* Increment number of program headers. */
1061 (elf->e_phnum)++;
1062 boot_mem_dest_offset += fw_dump.boot_mem_sz[i];
1063 }
1064
1065 /* Memory reserved for fadump in first kernel */
1066 ra_start = fw_dump.reserve_dump_area_start;
1067 ra_size = get_fadump_area_size();
1068 ra_end = ra_start + ra_size;
1069
1070 phdr = (struct elf_phdr *)bufp;
1071 for_each_mem_range(i, &mstart, &mend) {
1072 /* Boot memory regions already added, skip them now */
1073 if (mstart < fw_dump.boot_mem_top) {
1074 if (mend > fw_dump.boot_mem_top)
1075 mstart = fw_dump.boot_mem_top;
1076 else
1077 continue;
1078 }
1079
1080 /* Handle memblock regions overlaps with fadump reserved area */
1081 if ((ra_start < mend) && (ra_end > mstart)) {
1082 if ((mstart < ra_start) && (mend > ra_end)) {
1083 populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart);
1084 /* Increment number of program headers. */
1085 (elf->e_phnum)++;
1086 bufp += sizeof(struct elf_phdr);
1087 phdr = (struct elf_phdr *)bufp;
1088 populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end);
1089 } else if (mstart < ra_start) {
1090 populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart);
1091 } else if (ra_end < mend) {
1092 populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end);
1093 }
1094 } else {
1095 /* No overlap with fadump reserved memory region */
1096 populate_elf_pt_load(phdr, mstart, mend - mstart, mstart);
1097 }
1098
1099 /* Increment number of program headers. */
1100 (elf->e_phnum)++;
1101 bufp += sizeof(struct elf_phdr);
1102 phdr = (struct elf_phdr *) bufp;
1103 }
1104}
1105
1106static unsigned long init_fadump_header(unsigned long addr)
1107{
1108 struct fadump_crash_info_header *fdh;
1109
1110 if (!addr)
1111 return 0;
1112
1113 fdh = __va(addr);
1114 addr += sizeof(struct fadump_crash_info_header);
1115
1116 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1117 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1118 fdh->version = FADUMP_HEADER_VERSION;
1119 /* We will set the crashing cpu id in crash_fadump() during crash. */
1120 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1121
1122 /*
1123 * The physical address and size of vmcoreinfo are required in the
1124 * second kernel to prepare elfcorehdr.
1125 */
1126 fdh->vmcoreinfo_raddr = fadump_relocate(paddr_vmcoreinfo_note());
1127 fdh->vmcoreinfo_size = VMCOREINFO_NOTE_SIZE;
1128
1129
1130 fdh->pt_regs_sz = sizeof(struct pt_regs);
1131 /*
1132 * When LPAR is terminated by PYHP, ensure all possible CPUs'
1133 * register data is processed while exporting the vmcore.
1134 */
1135 fdh->cpu_mask = *cpu_possible_mask;
1136 fdh->cpu_mask_sz = sizeof(struct cpumask);
1137
1138 return addr;
1139}
1140
1141static int register_fadump(void)
1142{
1143 unsigned long addr;
1144
1145 /*
1146 * If no memory is reserved then we can not register for firmware-
1147 * assisted dump.
1148 */
1149 if (!fw_dump.reserve_dump_area_size)
1150 return -ENODEV;
1151
1152 addr = fw_dump.fadumphdr_addr;
1153
1154 /* Initialize fadump crash info header. */
1155 addr = init_fadump_header(addr);
1156
1157 /* register the future kernel dump with firmware. */
1158 pr_debug("Registering for firmware-assisted kernel dump...\n");
1159 return fw_dump.ops->fadump_register(&fw_dump);
1160}
1161
1162void fadump_cleanup(void)
1163{
1164 if (!fw_dump.fadump_supported)
1165 return;
1166
1167 /* Invalidate the registration only if dump is active. */
1168 if (fw_dump.dump_active) {
1169 pr_debug("Invalidating firmware-assisted dump registration\n");
1170 fw_dump.ops->fadump_invalidate(&fw_dump);
1171 } else if (fw_dump.dump_registered) {
1172 /* Un-register Firmware-assisted dump if it was registered. */
1173 fw_dump.ops->fadump_unregister(&fw_dump);
1174 }
1175
1176 if (fw_dump.ops->fadump_cleanup)
1177 fw_dump.ops->fadump_cleanup(&fw_dump);
1178}
1179
1180static void fadump_free_reserved_memory(unsigned long start_pfn,
1181 unsigned long end_pfn)
1182{
1183 unsigned long pfn;
1184 unsigned long time_limit = jiffies + HZ;
1185
1186 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1187 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1188
1189 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1190 free_reserved_page(pfn_to_page(pfn));
1191
1192 if (time_after(jiffies, time_limit)) {
1193 cond_resched();
1194 time_limit = jiffies + HZ;
1195 }
1196 }
1197}
1198
1199/*
1200 * Skip memory holes and free memory that was actually reserved.
1201 */
1202static void fadump_release_reserved_area(u64 start, u64 end)
1203{
1204 unsigned long reg_spfn, reg_epfn;
1205 u64 tstart, tend, spfn, epfn;
1206 int i;
1207
1208 spfn = PHYS_PFN(start);
1209 epfn = PHYS_PFN(end);
1210
1211 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) {
1212 tstart = max_t(u64, spfn, reg_spfn);
1213 tend = min_t(u64, epfn, reg_epfn);
1214
1215 if (tstart < tend) {
1216 fadump_free_reserved_memory(tstart, tend);
1217
1218 if (tend == epfn)
1219 break;
1220
1221 spfn = tend;
1222 }
1223 }
1224}
1225
1226/*
1227 * Sort the mem ranges in-place and merge adjacent ranges
1228 * to minimize the memory ranges count.
1229 */
1230static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1231{
1232 struct fadump_memory_range *mem_ranges;
1233 u64 base, size;
1234 int i, j, idx;
1235
1236 if (!reserved_mrange_info.mem_range_cnt)
1237 return;
1238
1239 /* Sort the memory ranges */
1240 mem_ranges = mrange_info->mem_ranges;
1241 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1242 idx = i;
1243 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1244 if (mem_ranges[idx].base > mem_ranges[j].base)
1245 idx = j;
1246 }
1247 if (idx != i)
1248 swap(mem_ranges[idx], mem_ranges[i]);
1249 }
1250
1251 /* Merge adjacent reserved ranges */
1252 idx = 0;
1253 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1254 base = mem_ranges[i-1].base;
1255 size = mem_ranges[i-1].size;
1256 if (mem_ranges[i].base == (base + size))
1257 mem_ranges[idx].size += mem_ranges[i].size;
1258 else {
1259 idx++;
1260 if (i == idx)
1261 continue;
1262
1263 mem_ranges[idx] = mem_ranges[i];
1264 }
1265 }
1266 mrange_info->mem_range_cnt = idx + 1;
1267}
1268
1269/*
1270 * Scan reserved-ranges to consider them while reserving/releasing
1271 * memory for FADump.
1272 */
1273static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1274{
1275 const __be32 *prop;
1276 int len, ret = -1;
1277 unsigned long i;
1278
1279 /* reserved-ranges already scanned */
1280 if (reserved_mrange_info.mem_range_cnt != 0)
1281 return;
1282
1283 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1284 if (!prop)
1285 return;
1286
1287 /*
1288 * Each reserved range is an (address,size) pair, 2 cells each,
1289 * totalling 4 cells per range.
1290 */
1291 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1292 u64 base, size;
1293
1294 base = of_read_number(prop + (i * 4) + 0, 2);
1295 size = of_read_number(prop + (i * 4) + 2, 2);
1296
1297 if (size) {
1298 ret = fadump_add_mem_range(&reserved_mrange_info,
1299 base, base + size);
1300 if (ret < 0) {
1301 pr_warn("some reserved ranges are ignored!\n");
1302 break;
1303 }
1304 }
1305 }
1306
1307 /* Compact reserved ranges */
1308 sort_and_merge_mem_ranges(&reserved_mrange_info);
1309}
1310
1311/*
1312 * Release the memory that was reserved during early boot to preserve the
1313 * crash'ed kernel's memory contents except reserved dump area (permanent
1314 * reservation) and reserved ranges used by F/W. The released memory will
1315 * be available for general use.
1316 */
1317static void fadump_release_memory(u64 begin, u64 end)
1318{
1319 u64 ra_start, ra_end, tstart;
1320 int i, ret;
1321
1322 ra_start = fw_dump.reserve_dump_area_start;
1323 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1324
1325 /*
1326 * If reserved ranges array limit is hit, overwrite the last reserved
1327 * memory range with reserved dump area to ensure it is excluded from
1328 * the memory being released (reused for next FADump registration).
1329 */
1330 if (reserved_mrange_info.mem_range_cnt ==
1331 reserved_mrange_info.max_mem_ranges)
1332 reserved_mrange_info.mem_range_cnt--;
1333
1334 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1335 if (ret != 0)
1336 return;
1337
1338 /* Get the reserved ranges list in order first. */
1339 sort_and_merge_mem_ranges(&reserved_mrange_info);
1340
1341 /* Exclude reserved ranges and release remaining memory */
1342 tstart = begin;
1343 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1344 ra_start = reserved_mrange_info.mem_ranges[i].base;
1345 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1346
1347 if (tstart >= ra_end)
1348 continue;
1349
1350 if (tstart < ra_start)
1351 fadump_release_reserved_area(tstart, ra_start);
1352 tstart = ra_end;
1353 }
1354
1355 if (tstart < end)
1356 fadump_release_reserved_area(tstart, end);
1357}
1358
1359static void fadump_free_elfcorehdr_buf(void)
1360{
1361 if (fw_dump.elfcorehdr_addr == 0 || fw_dump.elfcorehdr_size == 0)
1362 return;
1363
1364 /*
1365 * Before freeing the memory of `elfcorehdr`, reset the global
1366 * `elfcorehdr_addr` to prevent modules like `vmcore` from accessing
1367 * invalid memory.
1368 */
1369 elfcorehdr_addr = ELFCORE_ADDR_ERR;
1370 fadump_free_buffer(fw_dump.elfcorehdr_addr, fw_dump.elfcorehdr_size);
1371 fw_dump.elfcorehdr_addr = 0;
1372 fw_dump.elfcorehdr_size = 0;
1373}
1374
1375static void fadump_invalidate_release_mem(void)
1376{
1377 mutex_lock(&fadump_mutex);
1378 if (!fw_dump.dump_active) {
1379 mutex_unlock(&fadump_mutex);
1380 return;
1381 }
1382
1383 fadump_cleanup();
1384 mutex_unlock(&fadump_mutex);
1385
1386 fadump_free_elfcorehdr_buf();
1387 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1388 fadump_free_cpu_notes_buf();
1389
1390 /*
1391 * Setup kernel metadata and initialize the kernel dump
1392 * memory structure for FADump re-registration.
1393 */
1394 if (fw_dump.ops->fadump_setup_metadata &&
1395 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1396 pr_warn("Failed to setup kernel metadata!\n");
1397 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1398}
1399
1400static ssize_t release_mem_store(struct kobject *kobj,
1401 struct kobj_attribute *attr,
1402 const char *buf, size_t count)
1403{
1404 int input = -1;
1405
1406 if (!fw_dump.dump_active)
1407 return -EPERM;
1408
1409 if (kstrtoint(buf, 0, &input))
1410 return -EINVAL;
1411
1412 if (input == 1) {
1413 /*
1414 * Take away the '/proc/vmcore'. We are releasing the dump
1415 * memory, hence it will not be valid anymore.
1416 */
1417#ifdef CONFIG_PROC_VMCORE
1418 vmcore_cleanup();
1419#endif
1420 fadump_invalidate_release_mem();
1421
1422 } else
1423 return -EINVAL;
1424 return count;
1425}
1426
1427/* Release the reserved memory and disable the FADump */
1428static void __init unregister_fadump(void)
1429{
1430 fadump_cleanup();
1431 fadump_release_memory(fw_dump.reserve_dump_area_start,
1432 fw_dump.reserve_dump_area_size);
1433 fw_dump.fadump_enabled = 0;
1434 kobject_put(fadump_kobj);
1435}
1436
1437static ssize_t enabled_show(struct kobject *kobj,
1438 struct kobj_attribute *attr,
1439 char *buf)
1440{
1441 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1442}
1443
1444/*
1445 * /sys/kernel/fadump/hotplug_ready sysfs node returns 1, which inidcates
1446 * to usersapce that fadump re-registration is not required on memory
1447 * hotplug events.
1448 */
1449static ssize_t hotplug_ready_show(struct kobject *kobj,
1450 struct kobj_attribute *attr,
1451 char *buf)
1452{
1453 return sprintf(buf, "%d\n", 1);
1454}
1455
1456static ssize_t mem_reserved_show(struct kobject *kobj,
1457 struct kobj_attribute *attr,
1458 char *buf)
1459{
1460 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1461}
1462
1463static ssize_t registered_show(struct kobject *kobj,
1464 struct kobj_attribute *attr,
1465 char *buf)
1466{
1467 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1468}
1469
1470static ssize_t bootargs_append_show(struct kobject *kobj,
1471 struct kobj_attribute *attr,
1472 char *buf)
1473{
1474 return sprintf(buf, "%s\n", (char *)__va(fw_dump.param_area));
1475}
1476
1477static ssize_t bootargs_append_store(struct kobject *kobj,
1478 struct kobj_attribute *attr,
1479 const char *buf, size_t count)
1480{
1481 char *params;
1482
1483 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1484 return -EPERM;
1485
1486 if (count >= COMMAND_LINE_SIZE)
1487 return -EINVAL;
1488
1489 /*
1490 * Fail here instead of handling this scenario with
1491 * some silly workaround in capture kernel.
1492 */
1493 if (saved_command_line_len + count >= COMMAND_LINE_SIZE) {
1494 pr_err("Appending parameters exceeds cmdline size!\n");
1495 return -ENOSPC;
1496 }
1497
1498 params = __va(fw_dump.param_area);
1499 strscpy_pad(params, buf, COMMAND_LINE_SIZE);
1500 /* Remove newline character at the end. */
1501 if (params[count-1] == '\n')
1502 params[count-1] = '\0';
1503
1504 return count;
1505}
1506
1507static ssize_t registered_store(struct kobject *kobj,
1508 struct kobj_attribute *attr,
1509 const char *buf, size_t count)
1510{
1511 int ret = 0;
1512 int input = -1;
1513
1514 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1515 return -EPERM;
1516
1517 if (kstrtoint(buf, 0, &input))
1518 return -EINVAL;
1519
1520 mutex_lock(&fadump_mutex);
1521
1522 switch (input) {
1523 case 0:
1524 if (fw_dump.dump_registered == 0) {
1525 goto unlock_out;
1526 }
1527
1528 /* Un-register Firmware-assisted dump */
1529 pr_debug("Un-register firmware-assisted dump\n");
1530 fw_dump.ops->fadump_unregister(&fw_dump);
1531 break;
1532 case 1:
1533 if (fw_dump.dump_registered == 1) {
1534 /* Un-register Firmware-assisted dump */
1535 fw_dump.ops->fadump_unregister(&fw_dump);
1536 }
1537 /* Register Firmware-assisted dump */
1538 ret = register_fadump();
1539 break;
1540 default:
1541 ret = -EINVAL;
1542 break;
1543 }
1544
1545unlock_out:
1546 mutex_unlock(&fadump_mutex);
1547 return ret < 0 ? ret : count;
1548}
1549
1550static int fadump_region_show(struct seq_file *m, void *private)
1551{
1552 if (!fw_dump.fadump_enabled)
1553 return 0;
1554
1555 mutex_lock(&fadump_mutex);
1556 fw_dump.ops->fadump_region_show(&fw_dump, m);
1557 mutex_unlock(&fadump_mutex);
1558 return 0;
1559}
1560
1561static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1562static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1563static struct kobj_attribute register_attr = __ATTR_RW(registered);
1564static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1565static struct kobj_attribute hotplug_ready_attr = __ATTR_RO(hotplug_ready);
1566static struct kobj_attribute bootargs_append_attr = __ATTR_RW(bootargs_append);
1567
1568static struct attribute *fadump_attrs[] = {
1569 &enable_attr.attr,
1570 ®ister_attr.attr,
1571 &mem_reserved_attr.attr,
1572 &hotplug_ready_attr.attr,
1573 NULL,
1574};
1575
1576ATTRIBUTE_GROUPS(fadump);
1577
1578DEFINE_SHOW_ATTRIBUTE(fadump_region);
1579
1580static void __init fadump_init_files(void)
1581{
1582 int rc = 0;
1583
1584 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1585 if (!fadump_kobj) {
1586 pr_err("failed to create fadump kobject\n");
1587 return;
1588 }
1589
1590 if (fw_dump.param_area) {
1591 rc = sysfs_create_file(fadump_kobj, &bootargs_append_attr.attr);
1592 if (rc)
1593 pr_err("unable to create bootargs_append sysfs file (%d)\n", rc);
1594 }
1595
1596 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
1597 &fadump_region_fops);
1598
1599 if (fw_dump.dump_active) {
1600 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1601 if (rc)
1602 pr_err("unable to create release_mem sysfs file (%d)\n",
1603 rc);
1604 }
1605
1606 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1607 if (rc) {
1608 pr_err("sysfs group creation failed (%d), unregistering FADump",
1609 rc);
1610 unregister_fadump();
1611 return;
1612 }
1613
1614 /*
1615 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1616 * create symlink at old location to maintain backward compatibility.
1617 *
1618 * - fadump_enabled -> fadump/enabled
1619 * - fadump_registered -> fadump/registered
1620 * - fadump_release_mem -> fadump/release_mem
1621 */
1622 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1623 "enabled", "fadump_enabled");
1624 if (rc) {
1625 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1626 return;
1627 }
1628
1629 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1630 "registered",
1631 "fadump_registered");
1632 if (rc) {
1633 pr_err("unable to create fadump_registered symlink (%d)", rc);
1634 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1635 return;
1636 }
1637
1638 if (fw_dump.dump_active) {
1639 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1640 fadump_kobj,
1641 "release_mem",
1642 "fadump_release_mem");
1643 if (rc)
1644 pr_err("unable to create fadump_release_mem symlink (%d)",
1645 rc);
1646 }
1647 return;
1648}
1649
1650static int __init fadump_setup_elfcorehdr_buf(void)
1651{
1652 int elf_phdr_cnt;
1653 unsigned long elfcorehdr_size;
1654
1655 /*
1656 * Program header for CPU notes comes first, followed by one for
1657 * vmcoreinfo, and the remaining program headers correspond to
1658 * memory regions.
1659 */
1660 elf_phdr_cnt = 2 + fw_dump.boot_mem_regs_cnt + memblock_num_regions(memory);
1661 elfcorehdr_size = sizeof(struct elfhdr) + (elf_phdr_cnt * sizeof(struct elf_phdr));
1662 elfcorehdr_size = PAGE_ALIGN(elfcorehdr_size);
1663
1664 fw_dump.elfcorehdr_addr = (u64)fadump_alloc_buffer(elfcorehdr_size);
1665 if (!fw_dump.elfcorehdr_addr) {
1666 pr_err("Failed to allocate %lu bytes for elfcorehdr\n",
1667 elfcorehdr_size);
1668 return -ENOMEM;
1669 }
1670 fw_dump.elfcorehdr_size = elfcorehdr_size;
1671 return 0;
1672}
1673
1674/*
1675 * Check if the fadump header of crashed kernel is compatible with fadump kernel.
1676 *
1677 * It checks the magic number, endianness, and size of non-primitive type
1678 * members of fadump header to ensure safe dump collection.
1679 */
1680static bool __init is_fadump_header_compatible(struct fadump_crash_info_header *fdh)
1681{
1682 if (fdh->magic_number == FADUMP_CRASH_INFO_MAGIC_OLD) {
1683 pr_err("Old magic number, can't process the dump.\n");
1684 return false;
1685 }
1686
1687 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
1688 if (fdh->magic_number == swab64(FADUMP_CRASH_INFO_MAGIC))
1689 pr_err("Endianness mismatch between the crashed and fadump kernels.\n");
1690 else
1691 pr_err("Fadump header is corrupted.\n");
1692
1693 return false;
1694 }
1695
1696 /*
1697 * Dump collection is not safe if the size of non-primitive type members
1698 * of the fadump header do not match between crashed and fadump kernel.
1699 */
1700 if (fdh->pt_regs_sz != sizeof(struct pt_regs) ||
1701 fdh->cpu_mask_sz != sizeof(struct cpumask)) {
1702 pr_err("Fadump header size mismatch.\n");
1703 return false;
1704 }
1705
1706 return true;
1707}
1708
1709static void __init fadump_process(void)
1710{
1711 struct fadump_crash_info_header *fdh;
1712
1713 fdh = (struct fadump_crash_info_header *) __va(fw_dump.fadumphdr_addr);
1714 if (!fdh) {
1715 pr_err("Crash info header is empty.\n");
1716 goto err_out;
1717 }
1718
1719 /* Avoid processing the dump if fadump header isn't compatible */
1720 if (!is_fadump_header_compatible(fdh))
1721 goto err_out;
1722
1723 /* Allocate buffer for elfcorehdr */
1724 if (fadump_setup_elfcorehdr_buf())
1725 goto err_out;
1726
1727 fadump_populate_elfcorehdr(fdh);
1728
1729 /* Let platform update the CPU notes in elfcorehdr */
1730 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1731 goto err_out;
1732
1733 /*
1734 * elfcorehdr is now ready to be exported.
1735 *
1736 * set elfcorehdr_addr so that vmcore module will export the
1737 * elfcorehdr through '/proc/vmcore'.
1738 */
1739 elfcorehdr_addr = virt_to_phys((void *)fw_dump.elfcorehdr_addr);
1740 return;
1741
1742err_out:
1743 fadump_invalidate_release_mem();
1744}
1745
1746/*
1747 * Reserve memory to store additional parameters to be passed
1748 * for fadump/capture kernel.
1749 */
1750void __init fadump_setup_param_area(void)
1751{
1752 phys_addr_t range_start, range_end;
1753
1754 if (!fw_dump.param_area_supported || fw_dump.dump_active)
1755 return;
1756
1757 /* This memory can't be used by PFW or bootloader as it is shared across kernels */
1758 if (early_radix_enabled()) {
1759 /*
1760 * Anywhere in the upper half should be good enough as all memory
1761 * is accessible in real mode.
1762 */
1763 range_start = memblock_end_of_DRAM() / 2;
1764 range_end = memblock_end_of_DRAM();
1765 } else {
1766 /*
1767 * Passing additional parameters is supported for hash MMU only
1768 * if the first memory block size is 768MB or higher.
1769 */
1770 if (ppc64_rma_size < 0x30000000)
1771 return;
1772
1773 /*
1774 * 640 MB to 768 MB is not used by PFW/bootloader. So, try reserving
1775 * memory for passing additional parameters in this range to avoid
1776 * being stomped on by PFW/bootloader.
1777 */
1778 range_start = 0x2A000000;
1779 range_end = range_start + 0x4000000;
1780 }
1781
1782 fw_dump.param_area = memblock_phys_alloc_range(COMMAND_LINE_SIZE,
1783 COMMAND_LINE_SIZE,
1784 range_start,
1785 range_end);
1786 if (!fw_dump.param_area) {
1787 pr_warn("WARNING: Could not setup area to pass additional parameters!\n");
1788 return;
1789 }
1790
1791 memset((void *)fw_dump.param_area, 0, COMMAND_LINE_SIZE);
1792}
1793
1794/*
1795 * Prepare for firmware-assisted dump.
1796 */
1797int __init setup_fadump(void)
1798{
1799 if (!fw_dump.fadump_supported)
1800 return 0;
1801
1802 fadump_init_files();
1803 fadump_show_config();
1804
1805 if (!fw_dump.fadump_enabled)
1806 return 1;
1807
1808 /*
1809 * If dump data is available then see if it is valid and prepare for
1810 * saving it to the disk.
1811 */
1812 if (fw_dump.dump_active) {
1813 fadump_process();
1814 }
1815 /* Initialize the kernel dump memory structure and register with f/w */
1816 else if (fw_dump.reserve_dump_area_size) {
1817 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1818 register_fadump();
1819 }
1820
1821 /*
1822 * In case of panic, fadump is triggered via ppc_panic_event()
1823 * panic notifier. Setting crash_kexec_post_notifiers to 'true'
1824 * lets panic() function take crash friendly path before panic
1825 * notifiers are invoked.
1826 */
1827 crash_kexec_post_notifiers = true;
1828
1829 return 1;
1830}
1831/*
1832 * Use subsys_initcall_sync() here because there is dependency with
1833 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
1834 * is done before registering with f/w.
1835 */
1836subsys_initcall_sync(setup_fadump);
1837#else /* !CONFIG_PRESERVE_FA_DUMP */
1838
1839/* Scan the Firmware Assisted dump configuration details. */
1840int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1841 int depth, void *data)
1842{
1843 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1844 return 0;
1845
1846 opal_fadump_dt_scan(&fw_dump, node);
1847 return 1;
1848}
1849
1850/*
1851 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1852 * preserve crash data. The subsequent memory preserving kernel boot
1853 * is likely to process this crash data.
1854 */
1855int __init fadump_reserve_mem(void)
1856{
1857 if (fw_dump.dump_active) {
1858 /*
1859 * If last boot has crashed then reserve all the memory
1860 * above boot memory to preserve crash data.
1861 */
1862 pr_info("Preserving crash data for processing in next boot.\n");
1863 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1864 } else
1865 pr_debug("FADump-aware kernel..\n");
1866
1867 return 1;
1868}
1869#endif /* CONFIG_PRESERVE_FA_DUMP */
1870
1871/* Preserve everything above the base address */
1872static void __init fadump_reserve_crash_area(u64 base)
1873{
1874 u64 i, mstart, mend, msize;
1875
1876 for_each_mem_range(i, &mstart, &mend) {
1877 msize = mend - mstart;
1878
1879 if ((mstart + msize) < base)
1880 continue;
1881
1882 if (mstart < base) {
1883 msize -= (base - mstart);
1884 mstart = base;
1885 }
1886
1887 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1888 (msize >> 20), mstart);
1889 memblock_reserve(mstart, msize);
1890 }
1891}