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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
4 * dump with assistance from firmware. This approach does not use kexec,
5 * instead firmware assists in booting the kdump kernel while preserving
6 * memory contents. The most of the code implementation has been adapted
7 * from phyp assisted dump implementation written by Linas Vepstas and
8 * Manish Ahuja
9 *
10 * Copyright 2011 IBM Corporation
11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
12 */
13
14#undef DEBUG
15#define pr_fmt(fmt) "fadump: " fmt
16
17#include <linux/string.h>
18#include <linux/memblock.h>
19#include <linux/delay.h>
20#include <linux/seq_file.h>
21#include <linux/crash_dump.h>
22#include <linux/kobject.h>
23#include <linux/sysfs.h>
24#include <linux/slab.h>
25#include <linux/cma.h>
26#include <linux/hugetlb.h>
27#include <linux/debugfs.h>
28#include <linux/of.h>
29#include <linux/of_fdt.h>
30
31#include <asm/page.h>
32#include <asm/fadump.h>
33#include <asm/fadump-internal.h>
34#include <asm/setup.h>
35#include <asm/interrupt.h>
36
37/*
38 * The CPU who acquired the lock to trigger the fadump crash should
39 * wait for other CPUs to enter.
40 *
41 * The timeout is in milliseconds.
42 */
43#define CRASH_TIMEOUT 500
44
45static struct fw_dump fw_dump;
46
47static void __init fadump_reserve_crash_area(u64 base);
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static struct kobject *fadump_kobj;
52
53static atomic_t cpus_in_fadump;
54static DEFINE_MUTEX(fadump_mutex);
55
56static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
57
58#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
59#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
60 sizeof(struct fadump_memory_range))
61static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
62static struct fadump_mrange_info
63reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
64
65static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
66
67#ifdef CONFIG_CMA
68static struct cma *fadump_cma;
69
70/*
71 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
72 *
73 * This function initializes CMA area from fadump reserved memory.
74 * The total size of fadump reserved memory covers for boot memory size
75 * + cpu data size + hpte size and metadata.
76 * Initialize only the area equivalent to boot memory size for CMA use.
77 * The remaining portion of fadump reserved memory will be not given
78 * to CMA and pages for those will stay reserved. boot memory size is
79 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
80 * But for some reason even if it fails we still have the memory reservation
81 * with us and we can still continue doing fadump.
82 */
83static int __init fadump_cma_init(void)
84{
85 unsigned long long base, size;
86 int rc;
87
88 if (!fw_dump.fadump_enabled)
89 return 0;
90
91 /*
92 * Do not use CMA if user has provided fadump=nocma kernel parameter.
93 * Return 1 to continue with fadump old behaviour.
94 */
95 if (fw_dump.nocma)
96 return 1;
97
98 base = fw_dump.reserve_dump_area_start;
99 size = fw_dump.boot_memory_size;
100
101 if (!size)
102 return 0;
103
104 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
105 if (rc) {
106 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
107 /*
108 * Though the CMA init has failed we still have memory
109 * reservation with us. The reserved memory will be
110 * blocked from production system usage. Hence return 1,
111 * so that we can continue with fadump.
112 */
113 return 1;
114 }
115
116 /*
117 * If CMA activation fails, keep the pages reserved, instead of
118 * exposing them to buddy allocator. Same as 'fadump=nocma' case.
119 */
120 cma_reserve_pages_on_error(fadump_cma);
121
122 /*
123 * So we now have successfully initialized cma area for fadump.
124 */
125 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
126 "bytes of memory reserved for firmware-assisted dump\n",
127 cma_get_size(fadump_cma),
128 (unsigned long)cma_get_base(fadump_cma) >> 20,
129 fw_dump.reserve_dump_area_size);
130 return 1;
131}
132#else
133static int __init fadump_cma_init(void) { return 1; }
134#endif /* CONFIG_CMA */
135
136/* Scan the Firmware Assisted dump configuration details. */
137int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
138 int depth, void *data)
139{
140 if (depth == 0) {
141 early_init_dt_scan_reserved_ranges(node);
142 return 0;
143 }
144
145 if (depth != 1)
146 return 0;
147
148 if (strcmp(uname, "rtas") == 0) {
149 rtas_fadump_dt_scan(&fw_dump, node);
150 return 1;
151 }
152
153 if (strcmp(uname, "ibm,opal") == 0) {
154 opal_fadump_dt_scan(&fw_dump, node);
155 return 1;
156 }
157
158 return 0;
159}
160
161/*
162 * If fadump is registered, check if the memory provided
163 * falls within boot memory area and reserved memory area.
164 */
165int is_fadump_memory_area(u64 addr, unsigned long size)
166{
167 u64 d_start, d_end;
168
169 if (!fw_dump.dump_registered)
170 return 0;
171
172 if (!size)
173 return 0;
174
175 d_start = fw_dump.reserve_dump_area_start;
176 d_end = d_start + fw_dump.reserve_dump_area_size;
177 if (((addr + size) > d_start) && (addr <= d_end))
178 return 1;
179
180 return (addr <= fw_dump.boot_mem_top);
181}
182
183int should_fadump_crash(void)
184{
185 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
186 return 0;
187 return 1;
188}
189
190int is_fadump_active(void)
191{
192 return fw_dump.dump_active;
193}
194
195/*
196 * Returns true, if there are no holes in memory area between d_start to d_end,
197 * false otherwise.
198 */
199static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
200{
201 phys_addr_t reg_start, reg_end;
202 bool ret = false;
203 u64 i, start, end;
204
205 for_each_mem_range(i, ®_start, ®_end) {
206 start = max_t(u64, d_start, reg_start);
207 end = min_t(u64, d_end, reg_end);
208 if (d_start < end) {
209 /* Memory hole from d_start to start */
210 if (start > d_start)
211 break;
212
213 if (end == d_end) {
214 ret = true;
215 break;
216 }
217
218 d_start = end + 1;
219 }
220 }
221
222 return ret;
223}
224
225/*
226 * Returns true, if there are no holes in boot memory area,
227 * false otherwise.
228 */
229bool is_fadump_boot_mem_contiguous(void)
230{
231 unsigned long d_start, d_end;
232 bool ret = false;
233 int i;
234
235 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
236 d_start = fw_dump.boot_mem_addr[i];
237 d_end = d_start + fw_dump.boot_mem_sz[i];
238
239 ret = is_fadump_mem_area_contiguous(d_start, d_end);
240 if (!ret)
241 break;
242 }
243
244 return ret;
245}
246
247/*
248 * Returns true, if there are no holes in reserved memory area,
249 * false otherwise.
250 */
251bool is_fadump_reserved_mem_contiguous(void)
252{
253 u64 d_start, d_end;
254
255 d_start = fw_dump.reserve_dump_area_start;
256 d_end = d_start + fw_dump.reserve_dump_area_size;
257 return is_fadump_mem_area_contiguous(d_start, d_end);
258}
259
260/* Print firmware assisted dump configurations for debugging purpose. */
261static void __init fadump_show_config(void)
262{
263 int i;
264
265 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
266 (fw_dump.fadump_supported ? "present" : "no support"));
267
268 if (!fw_dump.fadump_supported)
269 return;
270
271 pr_debug("Fadump enabled : %s\n",
272 (fw_dump.fadump_enabled ? "yes" : "no"));
273 pr_debug("Dump Active : %s\n",
274 (fw_dump.dump_active ? "yes" : "no"));
275 pr_debug("Dump section sizes:\n");
276 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
277 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
278 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
279 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
280 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
281 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
282 pr_debug("[%03d] base = %llx, size = %llx\n", i,
283 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
284 }
285}
286
287/**
288 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
289 *
290 * Function to find the largest memory size we need to reserve during early
291 * boot process. This will be the size of the memory that is required for a
292 * kernel to boot successfully.
293 *
294 * This function has been taken from phyp-assisted dump feature implementation.
295 *
296 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
297 *
298 * TODO: Come up with better approach to find out more accurate memory size
299 * that is required for a kernel to boot successfully.
300 *
301 */
302static __init u64 fadump_calculate_reserve_size(void)
303{
304 u64 base, size, bootmem_min;
305 int ret;
306
307 if (fw_dump.reserve_bootvar)
308 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
309
310 /*
311 * Check if the size is specified through crashkernel= cmdline
312 * option. If yes, then use that but ignore base as fadump reserves
313 * memory at a predefined offset.
314 */
315 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
316 &size, &base, NULL, NULL);
317 if (ret == 0 && size > 0) {
318 unsigned long max_size;
319
320 if (fw_dump.reserve_bootvar)
321 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
322
323 fw_dump.reserve_bootvar = (unsigned long)size;
324
325 /*
326 * Adjust if the boot memory size specified is above
327 * the upper limit.
328 */
329 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
330 if (fw_dump.reserve_bootvar > max_size) {
331 fw_dump.reserve_bootvar = max_size;
332 pr_info("Adjusted boot memory size to %luMB\n",
333 (fw_dump.reserve_bootvar >> 20));
334 }
335
336 return fw_dump.reserve_bootvar;
337 } else if (fw_dump.reserve_bootvar) {
338 /*
339 * 'fadump_reserve_mem=' is being used to reserve memory
340 * for firmware-assisted dump.
341 */
342 return fw_dump.reserve_bootvar;
343 }
344
345 /* divide by 20 to get 5% of value */
346 size = memblock_phys_mem_size() / 20;
347
348 /* round it down in multiples of 256 */
349 size = size & ~0x0FFFFFFFUL;
350
351 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
352 if (memory_limit && size > memory_limit)
353 size = memory_limit;
354
355 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
356 return (size > bootmem_min ? size : bootmem_min);
357}
358
359/*
360 * Calculate the total memory size required to be reserved for
361 * firmware-assisted dump registration.
362 */
363static unsigned long __init get_fadump_area_size(void)
364{
365 unsigned long size = 0;
366
367 size += fw_dump.cpu_state_data_size;
368 size += fw_dump.hpte_region_size;
369 /*
370 * Account for pagesize alignment of boot memory area destination address.
371 * This faciliates in mmap reading of first kernel's memory.
372 */
373 size = PAGE_ALIGN(size);
374 size += fw_dump.boot_memory_size;
375 size += sizeof(struct fadump_crash_info_header);
376 size += sizeof(struct elfhdr); /* ELF core header.*/
377 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
378 /* Program headers for crash memory regions. */
379 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
380
381 size = PAGE_ALIGN(size);
382
383 /* This is to hold kernel metadata on platforms that support it */
384 size += (fw_dump.ops->fadump_get_metadata_size ?
385 fw_dump.ops->fadump_get_metadata_size() : 0);
386 return size;
387}
388
389static int __init add_boot_mem_region(unsigned long rstart,
390 unsigned long rsize)
391{
392 int i = fw_dump.boot_mem_regs_cnt++;
393
394 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
395 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
396 return 0;
397 }
398
399 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
400 i, rstart, (rstart + rsize));
401 fw_dump.boot_mem_addr[i] = rstart;
402 fw_dump.boot_mem_sz[i] = rsize;
403 return 1;
404}
405
406/*
407 * Firmware usually has a hard limit on the data it can copy per region.
408 * Honour that by splitting a memory range into multiple regions.
409 */
410static int __init add_boot_mem_regions(unsigned long mstart,
411 unsigned long msize)
412{
413 unsigned long rstart, rsize, max_size;
414 int ret = 1;
415
416 rstart = mstart;
417 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
418 while (msize) {
419 if (msize > max_size)
420 rsize = max_size;
421 else
422 rsize = msize;
423
424 ret = add_boot_mem_region(rstart, rsize);
425 if (!ret)
426 break;
427
428 msize -= rsize;
429 rstart += rsize;
430 }
431
432 return ret;
433}
434
435static int __init fadump_get_boot_mem_regions(void)
436{
437 unsigned long size, cur_size, hole_size, last_end;
438 unsigned long mem_size = fw_dump.boot_memory_size;
439 phys_addr_t reg_start, reg_end;
440 int ret = 1;
441 u64 i;
442
443 fw_dump.boot_mem_regs_cnt = 0;
444
445 last_end = 0;
446 hole_size = 0;
447 cur_size = 0;
448 for_each_mem_range(i, ®_start, ®_end) {
449 size = reg_end - reg_start;
450 hole_size += (reg_start - last_end);
451
452 if ((cur_size + size) >= mem_size) {
453 size = (mem_size - cur_size);
454 ret = add_boot_mem_regions(reg_start, size);
455 break;
456 }
457
458 mem_size -= size;
459 cur_size += size;
460 ret = add_boot_mem_regions(reg_start, size);
461 if (!ret)
462 break;
463
464 last_end = reg_end;
465 }
466 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
467
468 return ret;
469}
470
471/*
472 * Returns true, if the given range overlaps with reserved memory ranges
473 * starting at idx. Also, updates idx to index of overlapping memory range
474 * with the given memory range.
475 * False, otherwise.
476 */
477static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
478{
479 bool ret = false;
480 int i;
481
482 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
483 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
484 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
485
486 if (end <= rbase)
487 break;
488
489 if ((end > rbase) && (base < rend)) {
490 *idx = i;
491 ret = true;
492 break;
493 }
494 }
495
496 return ret;
497}
498
499/*
500 * Locate a suitable memory area to reserve memory for FADump. While at it,
501 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
502 */
503static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
504{
505 struct fadump_memory_range *mrngs;
506 phys_addr_t mstart, mend;
507 int idx = 0;
508 u64 i, ret = 0;
509
510 mrngs = reserved_mrange_info.mem_ranges;
511 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
512 &mstart, &mend, NULL) {
513 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
514 i, mstart, mend, base);
515
516 if (mstart > base)
517 base = PAGE_ALIGN(mstart);
518
519 while ((mend > base) && ((mend - base) >= size)) {
520 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
521 ret = base;
522 goto out;
523 }
524
525 base = mrngs[idx].base + mrngs[idx].size;
526 base = PAGE_ALIGN(base);
527 }
528 }
529
530out:
531 return ret;
532}
533
534int __init fadump_reserve_mem(void)
535{
536 u64 base, size, mem_boundary, bootmem_min;
537 int ret = 1;
538
539 if (!fw_dump.fadump_enabled)
540 return 0;
541
542 if (!fw_dump.fadump_supported) {
543 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
544 goto error_out;
545 }
546
547 /*
548 * Initialize boot memory size
549 * If dump is active then we have already calculated the size during
550 * first kernel.
551 */
552 if (!fw_dump.dump_active) {
553 fw_dump.boot_memory_size =
554 PAGE_ALIGN(fadump_calculate_reserve_size());
555#ifdef CONFIG_CMA
556 if (!fw_dump.nocma) {
557 fw_dump.boot_memory_size =
558 ALIGN(fw_dump.boot_memory_size,
559 CMA_MIN_ALIGNMENT_BYTES);
560 }
561#endif
562
563 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
564 if (fw_dump.boot_memory_size < bootmem_min) {
565 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
566 fw_dump.boot_memory_size, bootmem_min);
567 goto error_out;
568 }
569
570 if (!fadump_get_boot_mem_regions()) {
571 pr_err("Too many holes in boot memory area to enable fadump\n");
572 goto error_out;
573 }
574 }
575
576 /*
577 * Calculate the memory boundary.
578 * If memory_limit is less than actual memory boundary then reserve
579 * the memory for fadump beyond the memory_limit and adjust the
580 * memory_limit accordingly, so that the running kernel can run with
581 * specified memory_limit.
582 */
583 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
584 size = get_fadump_area_size();
585 if ((memory_limit + size) < memblock_end_of_DRAM())
586 memory_limit += size;
587 else
588 memory_limit = memblock_end_of_DRAM();
589 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
590 " dump, now %#016llx\n", memory_limit);
591 }
592 if (memory_limit)
593 mem_boundary = memory_limit;
594 else
595 mem_boundary = memblock_end_of_DRAM();
596
597 base = fw_dump.boot_mem_top;
598 size = get_fadump_area_size();
599 fw_dump.reserve_dump_area_size = size;
600 if (fw_dump.dump_active) {
601 pr_info("Firmware-assisted dump is active.\n");
602
603#ifdef CONFIG_HUGETLB_PAGE
604 /*
605 * FADump capture kernel doesn't care much about hugepages.
606 * In fact, handling hugepages in capture kernel is asking for
607 * trouble. So, disable HugeTLB support when fadump is active.
608 */
609 hugetlb_disabled = true;
610#endif
611 /*
612 * If last boot has crashed then reserve all the memory
613 * above boot memory size so that we don't touch it until
614 * dump is written to disk by userspace tool. This memory
615 * can be released for general use by invalidating fadump.
616 */
617 fadump_reserve_crash_area(base);
618
619 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
620 pr_debug("Reserve dump area start address: 0x%lx\n",
621 fw_dump.reserve_dump_area_start);
622 } else {
623 /*
624 * Reserve memory at an offset closer to bottom of the RAM to
625 * minimize the impact of memory hot-remove operation.
626 */
627 base = fadump_locate_reserve_mem(base, size);
628
629 if (!base || (base + size > mem_boundary)) {
630 pr_err("Failed to find memory chunk for reservation!\n");
631 goto error_out;
632 }
633 fw_dump.reserve_dump_area_start = base;
634
635 /*
636 * Calculate the kernel metadata address and register it with
637 * f/w if the platform supports.
638 */
639 if (fw_dump.ops->fadump_setup_metadata &&
640 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
641 goto error_out;
642
643 if (memblock_reserve(base, size)) {
644 pr_err("Failed to reserve memory!\n");
645 goto error_out;
646 }
647
648 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
649 (size >> 20), base, (memblock_phys_mem_size() >> 20));
650
651 ret = fadump_cma_init();
652 }
653
654 return ret;
655error_out:
656 fw_dump.fadump_enabled = 0;
657 fw_dump.reserve_dump_area_size = 0;
658 return 0;
659}
660
661/* Look for fadump= cmdline option. */
662static int __init early_fadump_param(char *p)
663{
664 if (!p)
665 return 1;
666
667 if (strncmp(p, "on", 2) == 0)
668 fw_dump.fadump_enabled = 1;
669 else if (strncmp(p, "off", 3) == 0)
670 fw_dump.fadump_enabled = 0;
671 else if (strncmp(p, "nocma", 5) == 0) {
672 fw_dump.fadump_enabled = 1;
673 fw_dump.nocma = 1;
674 }
675
676 return 0;
677}
678early_param("fadump", early_fadump_param);
679
680/*
681 * Look for fadump_reserve_mem= cmdline option
682 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
683 * the sooner 'crashkernel=' parameter is accustomed to.
684 */
685static int __init early_fadump_reserve_mem(char *p)
686{
687 if (p)
688 fw_dump.reserve_bootvar = memparse(p, &p);
689 return 0;
690}
691early_param("fadump_reserve_mem", early_fadump_reserve_mem);
692
693void crash_fadump(struct pt_regs *regs, const char *str)
694{
695 unsigned int msecs;
696 struct fadump_crash_info_header *fdh = NULL;
697 int old_cpu, this_cpu;
698 /* Do not include first CPU */
699 unsigned int ncpus = num_online_cpus() - 1;
700
701 if (!should_fadump_crash())
702 return;
703
704 /*
705 * old_cpu == -1 means this is the first CPU which has come here,
706 * go ahead and trigger fadump.
707 *
708 * old_cpu != -1 means some other CPU has already on it's way
709 * to trigger fadump, just keep looping here.
710 */
711 this_cpu = smp_processor_id();
712 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
713
714 if (old_cpu != -1) {
715 atomic_inc(&cpus_in_fadump);
716
717 /*
718 * We can't loop here indefinitely. Wait as long as fadump
719 * is in force. If we race with fadump un-registration this
720 * loop will break and then we go down to normal panic path
721 * and reboot. If fadump is in force the first crashing
722 * cpu will definitely trigger fadump.
723 */
724 while (fw_dump.dump_registered)
725 cpu_relax();
726 return;
727 }
728
729 fdh = __va(fw_dump.fadumphdr_addr);
730 fdh->crashing_cpu = crashing_cpu;
731 crash_save_vmcoreinfo();
732
733 if (regs)
734 fdh->regs = *regs;
735 else
736 ppc_save_regs(&fdh->regs);
737
738 fdh->cpu_mask = *cpu_online_mask;
739
740 /*
741 * If we came in via system reset, wait a while for the secondary
742 * CPUs to enter.
743 */
744 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
745 msecs = CRASH_TIMEOUT;
746 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
747 mdelay(1);
748 }
749
750 fw_dump.ops->fadump_trigger(fdh, str);
751}
752
753u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
754{
755 struct elf_prstatus prstatus;
756
757 memset(&prstatus, 0, sizeof(prstatus));
758 /*
759 * FIXME: How do i get PID? Do I really need it?
760 * prstatus.pr_pid = ????
761 */
762 elf_core_copy_regs(&prstatus.pr_reg, regs);
763 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
764 &prstatus, sizeof(prstatus));
765 return buf;
766}
767
768void __init fadump_update_elfcore_header(char *bufp)
769{
770 struct elf_phdr *phdr;
771
772 bufp += sizeof(struct elfhdr);
773
774 /* First note is a place holder for cpu notes info. */
775 phdr = (struct elf_phdr *)bufp;
776
777 if (phdr->p_type == PT_NOTE) {
778 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
779 phdr->p_offset = phdr->p_paddr;
780 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
781 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
782 }
783 return;
784}
785
786static void *__init fadump_alloc_buffer(unsigned long size)
787{
788 unsigned long count, i;
789 struct page *page;
790 void *vaddr;
791
792 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
793 if (!vaddr)
794 return NULL;
795
796 count = PAGE_ALIGN(size) / PAGE_SIZE;
797 page = virt_to_page(vaddr);
798 for (i = 0; i < count; i++)
799 mark_page_reserved(page + i);
800 return vaddr;
801}
802
803static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
804{
805 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
806}
807
808s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
809{
810 /* Allocate buffer to hold cpu crash notes. */
811 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
812 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
813 fw_dump.cpu_notes_buf_vaddr =
814 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
815 if (!fw_dump.cpu_notes_buf_vaddr) {
816 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
817 fw_dump.cpu_notes_buf_size);
818 return -ENOMEM;
819 }
820
821 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
822 fw_dump.cpu_notes_buf_size,
823 fw_dump.cpu_notes_buf_vaddr);
824 return 0;
825}
826
827void fadump_free_cpu_notes_buf(void)
828{
829 if (!fw_dump.cpu_notes_buf_vaddr)
830 return;
831
832 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
833 fw_dump.cpu_notes_buf_size);
834 fw_dump.cpu_notes_buf_vaddr = 0;
835 fw_dump.cpu_notes_buf_size = 0;
836}
837
838static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
839{
840 if (mrange_info->is_static) {
841 mrange_info->mem_range_cnt = 0;
842 return;
843 }
844
845 kfree(mrange_info->mem_ranges);
846 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
847 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
848}
849
850/*
851 * Allocate or reallocate mem_ranges array in incremental units
852 * of PAGE_SIZE.
853 */
854static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
855{
856 struct fadump_memory_range *new_array;
857 u64 new_size;
858
859 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
860 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
861 new_size, mrange_info->name);
862
863 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
864 if (new_array == NULL) {
865 pr_err("Insufficient memory for setting up %s memory ranges\n",
866 mrange_info->name);
867 fadump_free_mem_ranges(mrange_info);
868 return -ENOMEM;
869 }
870
871 mrange_info->mem_ranges = new_array;
872 mrange_info->mem_ranges_sz = new_size;
873 mrange_info->max_mem_ranges = (new_size /
874 sizeof(struct fadump_memory_range));
875 return 0;
876}
877static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
878 u64 base, u64 end)
879{
880 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
881 bool is_adjacent = false;
882 u64 start, size;
883
884 if (base == end)
885 return 0;
886
887 /*
888 * Fold adjacent memory ranges to bring down the memory ranges/
889 * PT_LOAD segments count.
890 */
891 if (mrange_info->mem_range_cnt) {
892 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
893 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
894
895 /*
896 * Boot memory area needs separate PT_LOAD segment(s) as it
897 * is moved to a different location at the time of crash.
898 * So, fold only if the region is not boot memory area.
899 */
900 if ((start + size) == base && start >= fw_dump.boot_mem_top)
901 is_adjacent = true;
902 }
903 if (!is_adjacent) {
904 /* resize the array on reaching the limit */
905 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
906 int ret;
907
908 if (mrange_info->is_static) {
909 pr_err("Reached array size limit for %s memory ranges\n",
910 mrange_info->name);
911 return -ENOSPC;
912 }
913
914 ret = fadump_alloc_mem_ranges(mrange_info);
915 if (ret)
916 return ret;
917
918 /* Update to the new resized array */
919 mem_ranges = mrange_info->mem_ranges;
920 }
921
922 start = base;
923 mem_ranges[mrange_info->mem_range_cnt].base = start;
924 mrange_info->mem_range_cnt++;
925 }
926
927 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
928 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
929 mrange_info->name, (mrange_info->mem_range_cnt - 1),
930 start, end - 1, (end - start));
931 return 0;
932}
933
934static int fadump_exclude_reserved_area(u64 start, u64 end)
935{
936 u64 ra_start, ra_end;
937 int ret = 0;
938
939 ra_start = fw_dump.reserve_dump_area_start;
940 ra_end = ra_start + fw_dump.reserve_dump_area_size;
941
942 if ((ra_start < end) && (ra_end > start)) {
943 if ((start < ra_start) && (end > ra_end)) {
944 ret = fadump_add_mem_range(&crash_mrange_info,
945 start, ra_start);
946 if (ret)
947 return ret;
948
949 ret = fadump_add_mem_range(&crash_mrange_info,
950 ra_end, end);
951 } else if (start < ra_start) {
952 ret = fadump_add_mem_range(&crash_mrange_info,
953 start, ra_start);
954 } else if (ra_end < end) {
955 ret = fadump_add_mem_range(&crash_mrange_info,
956 ra_end, end);
957 }
958 } else
959 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
960
961 return ret;
962}
963
964static int fadump_init_elfcore_header(char *bufp)
965{
966 struct elfhdr *elf;
967
968 elf = (struct elfhdr *) bufp;
969 bufp += sizeof(struct elfhdr);
970 memcpy(elf->e_ident, ELFMAG, SELFMAG);
971 elf->e_ident[EI_CLASS] = ELF_CLASS;
972 elf->e_ident[EI_DATA] = ELF_DATA;
973 elf->e_ident[EI_VERSION] = EV_CURRENT;
974 elf->e_ident[EI_OSABI] = ELF_OSABI;
975 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
976 elf->e_type = ET_CORE;
977 elf->e_machine = ELF_ARCH;
978 elf->e_version = EV_CURRENT;
979 elf->e_entry = 0;
980 elf->e_phoff = sizeof(struct elfhdr);
981 elf->e_shoff = 0;
982
983 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
984 elf->e_flags = 2;
985 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
986 elf->e_flags = 1;
987 else
988 elf->e_flags = 0;
989
990 elf->e_ehsize = sizeof(struct elfhdr);
991 elf->e_phentsize = sizeof(struct elf_phdr);
992 elf->e_phnum = 0;
993 elf->e_shentsize = 0;
994 elf->e_shnum = 0;
995 elf->e_shstrndx = 0;
996
997 return 0;
998}
999
1000/*
1001 * Traverse through memblock structure and setup crash memory ranges. These
1002 * ranges will be used create PT_LOAD program headers in elfcore header.
1003 */
1004static int fadump_setup_crash_memory_ranges(void)
1005{
1006 u64 i, start, end;
1007 int ret;
1008
1009 pr_debug("Setup crash memory ranges.\n");
1010 crash_mrange_info.mem_range_cnt = 0;
1011
1012 /*
1013 * Boot memory region(s) registered with firmware are moved to
1014 * different location at the time of crash. Create separate program
1015 * header(s) for this memory chunk(s) with the correct offset.
1016 */
1017 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1018 start = fw_dump.boot_mem_addr[i];
1019 end = start + fw_dump.boot_mem_sz[i];
1020 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1021 if (ret)
1022 return ret;
1023 }
1024
1025 for_each_mem_range(i, &start, &end) {
1026 /*
1027 * skip the memory chunk that is already added
1028 * (0 through boot_memory_top).
1029 */
1030 if (start < fw_dump.boot_mem_top) {
1031 if (end > fw_dump.boot_mem_top)
1032 start = fw_dump.boot_mem_top;
1033 else
1034 continue;
1035 }
1036
1037 /* add this range excluding the reserved dump area. */
1038 ret = fadump_exclude_reserved_area(start, end);
1039 if (ret)
1040 return ret;
1041 }
1042
1043 return 0;
1044}
1045
1046/*
1047 * If the given physical address falls within the boot memory region then
1048 * return the relocated address that points to the dump region reserved
1049 * for saving initial boot memory contents.
1050 */
1051static inline unsigned long fadump_relocate(unsigned long paddr)
1052{
1053 unsigned long raddr, rstart, rend, rlast, hole_size;
1054 int i;
1055
1056 hole_size = 0;
1057 rlast = 0;
1058 raddr = paddr;
1059 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1060 rstart = fw_dump.boot_mem_addr[i];
1061 rend = rstart + fw_dump.boot_mem_sz[i];
1062 hole_size += (rstart - rlast);
1063
1064 if (paddr >= rstart && paddr < rend) {
1065 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1066 break;
1067 }
1068
1069 rlast = rend;
1070 }
1071
1072 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1073 return raddr;
1074}
1075
1076static int fadump_create_elfcore_headers(char *bufp)
1077{
1078 unsigned long long raddr, offset;
1079 struct elf_phdr *phdr;
1080 struct elfhdr *elf;
1081 int i, j;
1082
1083 fadump_init_elfcore_header(bufp);
1084 elf = (struct elfhdr *)bufp;
1085 bufp += sizeof(struct elfhdr);
1086
1087 /*
1088 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1089 * will be populated during second kernel boot after crash. Hence
1090 * this PT_NOTE will always be the first elf note.
1091 *
1092 * NOTE: Any new ELF note addition should be placed after this note.
1093 */
1094 phdr = (struct elf_phdr *)bufp;
1095 bufp += sizeof(struct elf_phdr);
1096 phdr->p_type = PT_NOTE;
1097 phdr->p_flags = 0;
1098 phdr->p_vaddr = 0;
1099 phdr->p_align = 0;
1100
1101 phdr->p_offset = 0;
1102 phdr->p_paddr = 0;
1103 phdr->p_filesz = 0;
1104 phdr->p_memsz = 0;
1105
1106 (elf->e_phnum)++;
1107
1108 /* setup ELF PT_NOTE for vmcoreinfo */
1109 phdr = (struct elf_phdr *)bufp;
1110 bufp += sizeof(struct elf_phdr);
1111 phdr->p_type = PT_NOTE;
1112 phdr->p_flags = 0;
1113 phdr->p_vaddr = 0;
1114 phdr->p_align = 0;
1115
1116 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1117 phdr->p_offset = phdr->p_paddr;
1118 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1119
1120 /* Increment number of program headers. */
1121 (elf->e_phnum)++;
1122
1123 /* setup PT_LOAD sections. */
1124 j = 0;
1125 offset = 0;
1126 raddr = fw_dump.boot_mem_addr[0];
1127 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1128 u64 mbase, msize;
1129
1130 mbase = crash_mrange_info.mem_ranges[i].base;
1131 msize = crash_mrange_info.mem_ranges[i].size;
1132 if (!msize)
1133 continue;
1134
1135 phdr = (struct elf_phdr *)bufp;
1136 bufp += sizeof(struct elf_phdr);
1137 phdr->p_type = PT_LOAD;
1138 phdr->p_flags = PF_R|PF_W|PF_X;
1139 phdr->p_offset = mbase;
1140
1141 if (mbase == raddr) {
1142 /*
1143 * The entire real memory region will be moved by
1144 * firmware to the specified destination_address.
1145 * Hence set the correct offset.
1146 */
1147 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1148 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1149 offset += fw_dump.boot_mem_sz[j];
1150 raddr = fw_dump.boot_mem_addr[++j];
1151 }
1152 }
1153
1154 phdr->p_paddr = mbase;
1155 phdr->p_vaddr = (unsigned long)__va(mbase);
1156 phdr->p_filesz = msize;
1157 phdr->p_memsz = msize;
1158 phdr->p_align = 0;
1159
1160 /* Increment number of program headers. */
1161 (elf->e_phnum)++;
1162 }
1163 return 0;
1164}
1165
1166static unsigned long init_fadump_header(unsigned long addr)
1167{
1168 struct fadump_crash_info_header *fdh;
1169
1170 if (!addr)
1171 return 0;
1172
1173 fdh = __va(addr);
1174 addr += sizeof(struct fadump_crash_info_header);
1175
1176 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1177 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1178 fdh->elfcorehdr_addr = addr;
1179 /* We will set the crashing cpu id in crash_fadump() during crash. */
1180 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1181 /*
1182 * When LPAR is terminated by PYHP, ensure all possible CPUs'
1183 * register data is processed while exporting the vmcore.
1184 */
1185 fdh->cpu_mask = *cpu_possible_mask;
1186
1187 return addr;
1188}
1189
1190static int register_fadump(void)
1191{
1192 unsigned long addr;
1193 void *vaddr;
1194 int ret;
1195
1196 /*
1197 * If no memory is reserved then we can not register for firmware-
1198 * assisted dump.
1199 */
1200 if (!fw_dump.reserve_dump_area_size)
1201 return -ENODEV;
1202
1203 ret = fadump_setup_crash_memory_ranges();
1204 if (ret)
1205 return ret;
1206
1207 addr = fw_dump.fadumphdr_addr;
1208
1209 /* Initialize fadump crash info header. */
1210 addr = init_fadump_header(addr);
1211 vaddr = __va(addr);
1212
1213 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1214 fadump_create_elfcore_headers(vaddr);
1215
1216 /* register the future kernel dump with firmware. */
1217 pr_debug("Registering for firmware-assisted kernel dump...\n");
1218 return fw_dump.ops->fadump_register(&fw_dump);
1219}
1220
1221void fadump_cleanup(void)
1222{
1223 if (!fw_dump.fadump_supported)
1224 return;
1225
1226 /* Invalidate the registration only if dump is active. */
1227 if (fw_dump.dump_active) {
1228 pr_debug("Invalidating firmware-assisted dump registration\n");
1229 fw_dump.ops->fadump_invalidate(&fw_dump);
1230 } else if (fw_dump.dump_registered) {
1231 /* Un-register Firmware-assisted dump if it was registered. */
1232 fw_dump.ops->fadump_unregister(&fw_dump);
1233 fadump_free_mem_ranges(&crash_mrange_info);
1234 }
1235
1236 if (fw_dump.ops->fadump_cleanup)
1237 fw_dump.ops->fadump_cleanup(&fw_dump);
1238}
1239
1240static void fadump_free_reserved_memory(unsigned long start_pfn,
1241 unsigned long end_pfn)
1242{
1243 unsigned long pfn;
1244 unsigned long time_limit = jiffies + HZ;
1245
1246 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1247 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1248
1249 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1250 free_reserved_page(pfn_to_page(pfn));
1251
1252 if (time_after(jiffies, time_limit)) {
1253 cond_resched();
1254 time_limit = jiffies + HZ;
1255 }
1256 }
1257}
1258
1259/*
1260 * Skip memory holes and free memory that was actually reserved.
1261 */
1262static void fadump_release_reserved_area(u64 start, u64 end)
1263{
1264 unsigned long reg_spfn, reg_epfn;
1265 u64 tstart, tend, spfn, epfn;
1266 int i;
1267
1268 spfn = PHYS_PFN(start);
1269 epfn = PHYS_PFN(end);
1270
1271 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) {
1272 tstart = max_t(u64, spfn, reg_spfn);
1273 tend = min_t(u64, epfn, reg_epfn);
1274
1275 if (tstart < tend) {
1276 fadump_free_reserved_memory(tstart, tend);
1277
1278 if (tend == epfn)
1279 break;
1280
1281 spfn = tend;
1282 }
1283 }
1284}
1285
1286/*
1287 * Sort the mem ranges in-place and merge adjacent ranges
1288 * to minimize the memory ranges count.
1289 */
1290static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1291{
1292 struct fadump_memory_range *mem_ranges;
1293 u64 base, size;
1294 int i, j, idx;
1295
1296 if (!reserved_mrange_info.mem_range_cnt)
1297 return;
1298
1299 /* Sort the memory ranges */
1300 mem_ranges = mrange_info->mem_ranges;
1301 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1302 idx = i;
1303 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1304 if (mem_ranges[idx].base > mem_ranges[j].base)
1305 idx = j;
1306 }
1307 if (idx != i)
1308 swap(mem_ranges[idx], mem_ranges[i]);
1309 }
1310
1311 /* Merge adjacent reserved ranges */
1312 idx = 0;
1313 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1314 base = mem_ranges[i-1].base;
1315 size = mem_ranges[i-1].size;
1316 if (mem_ranges[i].base == (base + size))
1317 mem_ranges[idx].size += mem_ranges[i].size;
1318 else {
1319 idx++;
1320 if (i == idx)
1321 continue;
1322
1323 mem_ranges[idx] = mem_ranges[i];
1324 }
1325 }
1326 mrange_info->mem_range_cnt = idx + 1;
1327}
1328
1329/*
1330 * Scan reserved-ranges to consider them while reserving/releasing
1331 * memory for FADump.
1332 */
1333static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1334{
1335 const __be32 *prop;
1336 int len, ret = -1;
1337 unsigned long i;
1338
1339 /* reserved-ranges already scanned */
1340 if (reserved_mrange_info.mem_range_cnt != 0)
1341 return;
1342
1343 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1344 if (!prop)
1345 return;
1346
1347 /*
1348 * Each reserved range is an (address,size) pair, 2 cells each,
1349 * totalling 4 cells per range.
1350 */
1351 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1352 u64 base, size;
1353
1354 base = of_read_number(prop + (i * 4) + 0, 2);
1355 size = of_read_number(prop + (i * 4) + 2, 2);
1356
1357 if (size) {
1358 ret = fadump_add_mem_range(&reserved_mrange_info,
1359 base, base + size);
1360 if (ret < 0) {
1361 pr_warn("some reserved ranges are ignored!\n");
1362 break;
1363 }
1364 }
1365 }
1366
1367 /* Compact reserved ranges */
1368 sort_and_merge_mem_ranges(&reserved_mrange_info);
1369}
1370
1371/*
1372 * Release the memory that was reserved during early boot to preserve the
1373 * crash'ed kernel's memory contents except reserved dump area (permanent
1374 * reservation) and reserved ranges used by F/W. The released memory will
1375 * be available for general use.
1376 */
1377static void fadump_release_memory(u64 begin, u64 end)
1378{
1379 u64 ra_start, ra_end, tstart;
1380 int i, ret;
1381
1382 ra_start = fw_dump.reserve_dump_area_start;
1383 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1384
1385 /*
1386 * If reserved ranges array limit is hit, overwrite the last reserved
1387 * memory range with reserved dump area to ensure it is excluded from
1388 * the memory being released (reused for next FADump registration).
1389 */
1390 if (reserved_mrange_info.mem_range_cnt ==
1391 reserved_mrange_info.max_mem_ranges)
1392 reserved_mrange_info.mem_range_cnt--;
1393
1394 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1395 if (ret != 0)
1396 return;
1397
1398 /* Get the reserved ranges list in order first. */
1399 sort_and_merge_mem_ranges(&reserved_mrange_info);
1400
1401 /* Exclude reserved ranges and release remaining memory */
1402 tstart = begin;
1403 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1404 ra_start = reserved_mrange_info.mem_ranges[i].base;
1405 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1406
1407 if (tstart >= ra_end)
1408 continue;
1409
1410 if (tstart < ra_start)
1411 fadump_release_reserved_area(tstart, ra_start);
1412 tstart = ra_end;
1413 }
1414
1415 if (tstart < end)
1416 fadump_release_reserved_area(tstart, end);
1417}
1418
1419static void fadump_invalidate_release_mem(void)
1420{
1421 mutex_lock(&fadump_mutex);
1422 if (!fw_dump.dump_active) {
1423 mutex_unlock(&fadump_mutex);
1424 return;
1425 }
1426
1427 fadump_cleanup();
1428 mutex_unlock(&fadump_mutex);
1429
1430 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1431 fadump_free_cpu_notes_buf();
1432
1433 /*
1434 * Setup kernel metadata and initialize the kernel dump
1435 * memory structure for FADump re-registration.
1436 */
1437 if (fw_dump.ops->fadump_setup_metadata &&
1438 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1439 pr_warn("Failed to setup kernel metadata!\n");
1440 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1441}
1442
1443static ssize_t release_mem_store(struct kobject *kobj,
1444 struct kobj_attribute *attr,
1445 const char *buf, size_t count)
1446{
1447 int input = -1;
1448
1449 if (!fw_dump.dump_active)
1450 return -EPERM;
1451
1452 if (kstrtoint(buf, 0, &input))
1453 return -EINVAL;
1454
1455 if (input == 1) {
1456 /*
1457 * Take away the '/proc/vmcore'. We are releasing the dump
1458 * memory, hence it will not be valid anymore.
1459 */
1460#ifdef CONFIG_PROC_VMCORE
1461 vmcore_cleanup();
1462#endif
1463 fadump_invalidate_release_mem();
1464
1465 } else
1466 return -EINVAL;
1467 return count;
1468}
1469
1470/* Release the reserved memory and disable the FADump */
1471static void __init unregister_fadump(void)
1472{
1473 fadump_cleanup();
1474 fadump_release_memory(fw_dump.reserve_dump_area_start,
1475 fw_dump.reserve_dump_area_size);
1476 fw_dump.fadump_enabled = 0;
1477 kobject_put(fadump_kobj);
1478}
1479
1480static ssize_t enabled_show(struct kobject *kobj,
1481 struct kobj_attribute *attr,
1482 char *buf)
1483{
1484 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1485}
1486
1487static ssize_t mem_reserved_show(struct kobject *kobj,
1488 struct kobj_attribute *attr,
1489 char *buf)
1490{
1491 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1492}
1493
1494static ssize_t registered_show(struct kobject *kobj,
1495 struct kobj_attribute *attr,
1496 char *buf)
1497{
1498 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1499}
1500
1501static ssize_t registered_store(struct kobject *kobj,
1502 struct kobj_attribute *attr,
1503 const char *buf, size_t count)
1504{
1505 int ret = 0;
1506 int input = -1;
1507
1508 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1509 return -EPERM;
1510
1511 if (kstrtoint(buf, 0, &input))
1512 return -EINVAL;
1513
1514 mutex_lock(&fadump_mutex);
1515
1516 switch (input) {
1517 case 0:
1518 if (fw_dump.dump_registered == 0) {
1519 goto unlock_out;
1520 }
1521
1522 /* Un-register Firmware-assisted dump */
1523 pr_debug("Un-register firmware-assisted dump\n");
1524 fw_dump.ops->fadump_unregister(&fw_dump);
1525 break;
1526 case 1:
1527 if (fw_dump.dump_registered == 1) {
1528 /* Un-register Firmware-assisted dump */
1529 fw_dump.ops->fadump_unregister(&fw_dump);
1530 }
1531 /* Register Firmware-assisted dump */
1532 ret = register_fadump();
1533 break;
1534 default:
1535 ret = -EINVAL;
1536 break;
1537 }
1538
1539unlock_out:
1540 mutex_unlock(&fadump_mutex);
1541 return ret < 0 ? ret : count;
1542}
1543
1544static int fadump_region_show(struct seq_file *m, void *private)
1545{
1546 if (!fw_dump.fadump_enabled)
1547 return 0;
1548
1549 mutex_lock(&fadump_mutex);
1550 fw_dump.ops->fadump_region_show(&fw_dump, m);
1551 mutex_unlock(&fadump_mutex);
1552 return 0;
1553}
1554
1555static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1556static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1557static struct kobj_attribute register_attr = __ATTR_RW(registered);
1558static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1559
1560static struct attribute *fadump_attrs[] = {
1561 &enable_attr.attr,
1562 ®ister_attr.attr,
1563 &mem_reserved_attr.attr,
1564 NULL,
1565};
1566
1567ATTRIBUTE_GROUPS(fadump);
1568
1569DEFINE_SHOW_ATTRIBUTE(fadump_region);
1570
1571static void __init fadump_init_files(void)
1572{
1573 int rc = 0;
1574
1575 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1576 if (!fadump_kobj) {
1577 pr_err("failed to create fadump kobject\n");
1578 return;
1579 }
1580
1581 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
1582 &fadump_region_fops);
1583
1584 if (fw_dump.dump_active) {
1585 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1586 if (rc)
1587 pr_err("unable to create release_mem sysfs file (%d)\n",
1588 rc);
1589 }
1590
1591 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1592 if (rc) {
1593 pr_err("sysfs group creation failed (%d), unregistering FADump",
1594 rc);
1595 unregister_fadump();
1596 return;
1597 }
1598
1599 /*
1600 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1601 * create symlink at old location to maintain backward compatibility.
1602 *
1603 * - fadump_enabled -> fadump/enabled
1604 * - fadump_registered -> fadump/registered
1605 * - fadump_release_mem -> fadump/release_mem
1606 */
1607 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1608 "enabled", "fadump_enabled");
1609 if (rc) {
1610 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1611 return;
1612 }
1613
1614 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1615 "registered",
1616 "fadump_registered");
1617 if (rc) {
1618 pr_err("unable to create fadump_registered symlink (%d)", rc);
1619 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1620 return;
1621 }
1622
1623 if (fw_dump.dump_active) {
1624 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1625 fadump_kobj,
1626 "release_mem",
1627 "fadump_release_mem");
1628 if (rc)
1629 pr_err("unable to create fadump_release_mem symlink (%d)",
1630 rc);
1631 }
1632 return;
1633}
1634
1635/*
1636 * Prepare for firmware-assisted dump.
1637 */
1638int __init setup_fadump(void)
1639{
1640 if (!fw_dump.fadump_supported)
1641 return 0;
1642
1643 fadump_init_files();
1644 fadump_show_config();
1645
1646 if (!fw_dump.fadump_enabled)
1647 return 1;
1648
1649 /*
1650 * If dump data is available then see if it is valid and prepare for
1651 * saving it to the disk.
1652 */
1653 if (fw_dump.dump_active) {
1654 /*
1655 * if dump process fails then invalidate the registration
1656 * and release memory before proceeding for re-registration.
1657 */
1658 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1659 fadump_invalidate_release_mem();
1660 }
1661 /* Initialize the kernel dump memory structure and register with f/w */
1662 else if (fw_dump.reserve_dump_area_size) {
1663 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1664 register_fadump();
1665 }
1666
1667 /*
1668 * In case of panic, fadump is triggered via ppc_panic_event()
1669 * panic notifier. Setting crash_kexec_post_notifiers to 'true'
1670 * lets panic() function take crash friendly path before panic
1671 * notifiers are invoked.
1672 */
1673 crash_kexec_post_notifiers = true;
1674
1675 return 1;
1676}
1677/*
1678 * Use subsys_initcall_sync() here because there is dependency with
1679 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
1680 * is done before registering with f/w.
1681 */
1682subsys_initcall_sync(setup_fadump);
1683#else /* !CONFIG_PRESERVE_FA_DUMP */
1684
1685/* Scan the Firmware Assisted dump configuration details. */
1686int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1687 int depth, void *data)
1688{
1689 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1690 return 0;
1691
1692 opal_fadump_dt_scan(&fw_dump, node);
1693 return 1;
1694}
1695
1696/*
1697 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1698 * preserve crash data. The subsequent memory preserving kernel boot
1699 * is likely to process this crash data.
1700 */
1701int __init fadump_reserve_mem(void)
1702{
1703 if (fw_dump.dump_active) {
1704 /*
1705 * If last boot has crashed then reserve all the memory
1706 * above boot memory to preserve crash data.
1707 */
1708 pr_info("Preserving crash data for processing in next boot.\n");
1709 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1710 } else
1711 pr_debug("FADump-aware kernel..\n");
1712
1713 return 1;
1714}
1715#endif /* CONFIG_PRESERVE_FA_DUMP */
1716
1717/* Preserve everything above the base address */
1718static void __init fadump_reserve_crash_area(u64 base)
1719{
1720 u64 i, mstart, mend, msize;
1721
1722 for_each_mem_range(i, &mstart, &mend) {
1723 msize = mend - mstart;
1724
1725 if ((mstart + msize) < base)
1726 continue;
1727
1728 if (mstart < base) {
1729 msize -= (base - mstart);
1730 mstart = base;
1731 }
1732
1733 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1734 (msize >> 20), mstart);
1735 memblock_reserve(mstart, msize);
1736 }
1737}
1738
1739unsigned long __init arch_reserved_kernel_pages(void)
1740{
1741 return memblock_reserved_size() / PAGE_SIZE;
1742}
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
35static struct fw_dump fw_dump;
36
37static void __init fadump_reserve_crash_area(u64 base);
38
39#ifndef CONFIG_PRESERVE_FA_DUMP
40static DEFINE_MUTEX(fadump_mutex);
41struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };
42struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 };
43
44#ifdef CONFIG_CMA
45static struct cma *fadump_cma;
46
47/*
48 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
49 *
50 * This function initializes CMA area from fadump reserved memory.
51 * The total size of fadump reserved memory covers for boot memory size
52 * + cpu data size + hpte size and metadata.
53 * Initialize only the area equivalent to boot memory size for CMA use.
54 * The reamining portion of fadump reserved memory will be not given
55 * to CMA and pages for thoes will stay reserved. boot memory size is
56 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
57 * But for some reason even if it fails we still have the memory reservation
58 * with us and we can still continue doing fadump.
59 */
60int __init fadump_cma_init(void)
61{
62 unsigned long long base, size;
63 int rc;
64
65 if (!fw_dump.fadump_enabled)
66 return 0;
67
68 /*
69 * Do not use CMA if user has provided fadump=nocma kernel parameter.
70 * Return 1 to continue with fadump old behaviour.
71 */
72 if (fw_dump.nocma)
73 return 1;
74
75 base = fw_dump.reserve_dump_area_start;
76 size = fw_dump.boot_memory_size;
77
78 if (!size)
79 return 0;
80
81 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
82 if (rc) {
83 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
84 /*
85 * Though the CMA init has failed we still have memory
86 * reservation with us. The reserved memory will be
87 * blocked from production system usage. Hence return 1,
88 * so that we can continue with fadump.
89 */
90 return 1;
91 }
92
93 /*
94 * So we now have successfully initialized cma area for fadump.
95 */
96 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
97 "bytes of memory reserved for firmware-assisted dump\n",
98 cma_get_size(fadump_cma),
99 (unsigned long)cma_get_base(fadump_cma) >> 20,
100 fw_dump.reserve_dump_area_size);
101 return 1;
102}
103#else
104static int __init fadump_cma_init(void) { return 1; }
105#endif /* CONFIG_CMA */
106
107/* Scan the Firmware Assisted dump configuration details. */
108int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
109 int depth, void *data)
110{
111 if (depth != 1)
112 return 0;
113
114 if (strcmp(uname, "rtas") == 0) {
115 rtas_fadump_dt_scan(&fw_dump, node);
116 return 1;
117 }
118
119 if (strcmp(uname, "ibm,opal") == 0) {
120 opal_fadump_dt_scan(&fw_dump, node);
121 return 1;
122 }
123
124 return 0;
125}
126
127/*
128 * If fadump is registered, check if the memory provided
129 * falls within boot memory area and reserved memory area.
130 */
131int is_fadump_memory_area(u64 addr, unsigned long size)
132{
133 u64 d_start, d_end;
134
135 if (!fw_dump.dump_registered)
136 return 0;
137
138 if (!size)
139 return 0;
140
141 d_start = fw_dump.reserve_dump_area_start;
142 d_end = d_start + fw_dump.reserve_dump_area_size;
143 if (((addr + size) > d_start) && (addr <= d_end))
144 return 1;
145
146 return (addr <= fw_dump.boot_mem_top);
147}
148
149int should_fadump_crash(void)
150{
151 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
152 return 0;
153 return 1;
154}
155
156int is_fadump_active(void)
157{
158 return fw_dump.dump_active;
159}
160
161/*
162 * Returns true, if there are no holes in memory area between d_start to d_end,
163 * false otherwise.
164 */
165static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
166{
167 struct memblock_region *reg;
168 bool ret = false;
169 u64 start, end;
170
171 for_each_memblock(memory, reg) {
172 start = max_t(u64, d_start, reg->base);
173 end = min_t(u64, d_end, (reg->base + reg->size));
174 if (d_start < end) {
175 /* Memory hole from d_start to start */
176 if (start > d_start)
177 break;
178
179 if (end == d_end) {
180 ret = true;
181 break;
182 }
183
184 d_start = end + 1;
185 }
186 }
187
188 return ret;
189}
190
191/*
192 * Returns true, if there are no holes in boot memory area,
193 * false otherwise.
194 */
195bool is_fadump_boot_mem_contiguous(void)
196{
197 unsigned long d_start, d_end;
198 bool ret = false;
199 int i;
200
201 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
202 d_start = fw_dump.boot_mem_addr[i];
203 d_end = d_start + fw_dump.boot_mem_sz[i];
204
205 ret = is_fadump_mem_area_contiguous(d_start, d_end);
206 if (!ret)
207 break;
208 }
209
210 return ret;
211}
212
213/*
214 * Returns true, if there are no holes in reserved memory area,
215 * false otherwise.
216 */
217bool is_fadump_reserved_mem_contiguous(void)
218{
219 u64 d_start, d_end;
220
221 d_start = fw_dump.reserve_dump_area_start;
222 d_end = d_start + fw_dump.reserve_dump_area_size;
223 return is_fadump_mem_area_contiguous(d_start, d_end);
224}
225
226/* Print firmware assisted dump configurations for debugging purpose. */
227static void fadump_show_config(void)
228{
229 int i;
230
231 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
232 (fw_dump.fadump_supported ? "present" : "no support"));
233
234 if (!fw_dump.fadump_supported)
235 return;
236
237 pr_debug("Fadump enabled : %s\n",
238 (fw_dump.fadump_enabled ? "yes" : "no"));
239 pr_debug("Dump Active : %s\n",
240 (fw_dump.dump_active ? "yes" : "no"));
241 pr_debug("Dump section sizes:\n");
242 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
243 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
244 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
245 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
246 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
247 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
248 pr_debug("[%03d] base = %llx, size = %llx\n", i,
249 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
250 }
251}
252
253/**
254 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
255 *
256 * Function to find the largest memory size we need to reserve during early
257 * boot process. This will be the size of the memory that is required for a
258 * kernel to boot successfully.
259 *
260 * This function has been taken from phyp-assisted dump feature implementation.
261 *
262 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
263 *
264 * TODO: Come up with better approach to find out more accurate memory size
265 * that is required for a kernel to boot successfully.
266 *
267 */
268static inline u64 fadump_calculate_reserve_size(void)
269{
270 u64 base, size, bootmem_min;
271 int ret;
272
273 if (fw_dump.reserve_bootvar)
274 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
275
276 /*
277 * Check if the size is specified through crashkernel= cmdline
278 * option. If yes, then use that but ignore base as fadump reserves
279 * memory at a predefined offset.
280 */
281 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
282 &size, &base);
283 if (ret == 0 && size > 0) {
284 unsigned long max_size;
285
286 if (fw_dump.reserve_bootvar)
287 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
288
289 fw_dump.reserve_bootvar = (unsigned long)size;
290
291 /*
292 * Adjust if the boot memory size specified is above
293 * the upper limit.
294 */
295 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
296 if (fw_dump.reserve_bootvar > max_size) {
297 fw_dump.reserve_bootvar = max_size;
298 pr_info("Adjusted boot memory size to %luMB\n",
299 (fw_dump.reserve_bootvar >> 20));
300 }
301
302 return fw_dump.reserve_bootvar;
303 } else if (fw_dump.reserve_bootvar) {
304 /*
305 * 'fadump_reserve_mem=' is being used to reserve memory
306 * for firmware-assisted dump.
307 */
308 return fw_dump.reserve_bootvar;
309 }
310
311 /* divide by 20 to get 5% of value */
312 size = memblock_phys_mem_size() / 20;
313
314 /* round it down in multiples of 256 */
315 size = size & ~0x0FFFFFFFUL;
316
317 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
318 if (memory_limit && size > memory_limit)
319 size = memory_limit;
320
321 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
322 return (size > bootmem_min ? size : bootmem_min);
323}
324
325/*
326 * Calculate the total memory size required to be reserved for
327 * firmware-assisted dump registration.
328 */
329static unsigned long get_fadump_area_size(void)
330{
331 unsigned long size = 0;
332
333 size += fw_dump.cpu_state_data_size;
334 size += fw_dump.hpte_region_size;
335 size += fw_dump.boot_memory_size;
336 size += sizeof(struct fadump_crash_info_header);
337 size += sizeof(struct elfhdr); /* ELF core header.*/
338 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
339 /* Program headers for crash memory regions. */
340 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
341
342 size = PAGE_ALIGN(size);
343
344 /* This is to hold kernel metadata on platforms that support it */
345 size += (fw_dump.ops->fadump_get_metadata_size ?
346 fw_dump.ops->fadump_get_metadata_size() : 0);
347 return size;
348}
349
350static int __init add_boot_mem_region(unsigned long rstart,
351 unsigned long rsize)
352{
353 int i = fw_dump.boot_mem_regs_cnt++;
354
355 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
356 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
357 return 0;
358 }
359
360 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
361 i, rstart, (rstart + rsize));
362 fw_dump.boot_mem_addr[i] = rstart;
363 fw_dump.boot_mem_sz[i] = rsize;
364 return 1;
365}
366
367/*
368 * Firmware usually has a hard limit on the data it can copy per region.
369 * Honour that by splitting a memory range into multiple regions.
370 */
371static int __init add_boot_mem_regions(unsigned long mstart,
372 unsigned long msize)
373{
374 unsigned long rstart, rsize, max_size;
375 int ret = 1;
376
377 rstart = mstart;
378 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
379 while (msize) {
380 if (msize > max_size)
381 rsize = max_size;
382 else
383 rsize = msize;
384
385 ret = add_boot_mem_region(rstart, rsize);
386 if (!ret)
387 break;
388
389 msize -= rsize;
390 rstart += rsize;
391 }
392
393 return ret;
394}
395
396static int __init fadump_get_boot_mem_regions(void)
397{
398 unsigned long base, size, cur_size, hole_size, last_end;
399 unsigned long mem_size = fw_dump.boot_memory_size;
400 struct memblock_region *reg;
401 int ret = 1;
402
403 fw_dump.boot_mem_regs_cnt = 0;
404
405 last_end = 0;
406 hole_size = 0;
407 cur_size = 0;
408 for_each_memblock(memory, reg) {
409 base = reg->base;
410 size = reg->size;
411 hole_size += (base - last_end);
412
413 if ((cur_size + size) >= mem_size) {
414 size = (mem_size - cur_size);
415 ret = add_boot_mem_regions(base, size);
416 break;
417 }
418
419 mem_size -= size;
420 cur_size += size;
421 ret = add_boot_mem_regions(base, size);
422 if (!ret)
423 break;
424
425 last_end = base + size;
426 }
427 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
428
429 return ret;
430}
431
432int __init fadump_reserve_mem(void)
433{
434 u64 base, size, mem_boundary, bootmem_min, align = PAGE_SIZE;
435 bool is_memblock_bottom_up = memblock_bottom_up();
436 int ret = 1;
437
438 if (!fw_dump.fadump_enabled)
439 return 0;
440
441 if (!fw_dump.fadump_supported) {
442 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
443 goto error_out;
444 }
445
446 /*
447 * Initialize boot memory size
448 * If dump is active then we have already calculated the size during
449 * first kernel.
450 */
451 if (!fw_dump.dump_active) {
452 fw_dump.boot_memory_size =
453 PAGE_ALIGN(fadump_calculate_reserve_size());
454#ifdef CONFIG_CMA
455 if (!fw_dump.nocma) {
456 align = FADUMP_CMA_ALIGNMENT;
457 fw_dump.boot_memory_size =
458 ALIGN(fw_dump.boot_memory_size, align);
459 }
460#endif
461
462 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
463 if (fw_dump.boot_memory_size < bootmem_min) {
464 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
465 fw_dump.boot_memory_size, bootmem_min);
466 goto error_out;
467 }
468
469 if (!fadump_get_boot_mem_regions()) {
470 pr_err("Too many holes in boot memory area to enable fadump\n");
471 goto error_out;
472 }
473 }
474
475 /*
476 * Calculate the memory boundary.
477 * If memory_limit is less than actual memory boundary then reserve
478 * the memory for fadump beyond the memory_limit and adjust the
479 * memory_limit accordingly, so that the running kernel can run with
480 * specified memory_limit.
481 */
482 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
483 size = get_fadump_area_size();
484 if ((memory_limit + size) < memblock_end_of_DRAM())
485 memory_limit += size;
486 else
487 memory_limit = memblock_end_of_DRAM();
488 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
489 " dump, now %#016llx\n", memory_limit);
490 }
491 if (memory_limit)
492 mem_boundary = memory_limit;
493 else
494 mem_boundary = memblock_end_of_DRAM();
495
496 base = fw_dump.boot_mem_top;
497 size = get_fadump_area_size();
498 fw_dump.reserve_dump_area_size = size;
499 if (fw_dump.dump_active) {
500 pr_info("Firmware-assisted dump is active.\n");
501
502#ifdef CONFIG_HUGETLB_PAGE
503 /*
504 * FADump capture kernel doesn't care much about hugepages.
505 * In fact, handling hugepages in capture kernel is asking for
506 * trouble. So, disable HugeTLB support when fadump is active.
507 */
508 hugetlb_disabled = true;
509#endif
510 /*
511 * If last boot has crashed then reserve all the memory
512 * above boot memory size so that we don't touch it until
513 * dump is written to disk by userspace tool. This memory
514 * can be released for general use by invalidating fadump.
515 */
516 fadump_reserve_crash_area(base);
517
518 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
519 pr_debug("Reserve dump area start address: 0x%lx\n",
520 fw_dump.reserve_dump_area_start);
521 } else {
522 /*
523 * Reserve memory at an offset closer to bottom of the RAM to
524 * minimize the impact of memory hot-remove operation.
525 */
526 memblock_set_bottom_up(true);
527 base = memblock_find_in_range(base, mem_boundary, size, align);
528
529 /* Restore the previous allocation mode */
530 memblock_set_bottom_up(is_memblock_bottom_up);
531
532 if (!base) {
533 pr_err("Failed to find memory chunk for reservation!\n");
534 goto error_out;
535 }
536 fw_dump.reserve_dump_area_start = base;
537
538 /*
539 * Calculate the kernel metadata address and register it with
540 * f/w if the platform supports.
541 */
542 if (fw_dump.ops->fadump_setup_metadata &&
543 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
544 goto error_out;
545
546 if (memblock_reserve(base, size)) {
547 pr_err("Failed to reserve memory!\n");
548 goto error_out;
549 }
550
551 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
552 (size >> 20), base, (memblock_phys_mem_size() >> 20));
553
554 ret = fadump_cma_init();
555 }
556
557 return ret;
558error_out:
559 fw_dump.fadump_enabled = 0;
560 return 0;
561}
562
563/* Look for fadump= cmdline option. */
564static int __init early_fadump_param(char *p)
565{
566 if (!p)
567 return 1;
568
569 if (strncmp(p, "on", 2) == 0)
570 fw_dump.fadump_enabled = 1;
571 else if (strncmp(p, "off", 3) == 0)
572 fw_dump.fadump_enabled = 0;
573 else if (strncmp(p, "nocma", 5) == 0) {
574 fw_dump.fadump_enabled = 1;
575 fw_dump.nocma = 1;
576 }
577
578 return 0;
579}
580early_param("fadump", early_fadump_param);
581
582/*
583 * Look for fadump_reserve_mem= cmdline option
584 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
585 * the sooner 'crashkernel=' parameter is accustomed to.
586 */
587static int __init early_fadump_reserve_mem(char *p)
588{
589 if (p)
590 fw_dump.reserve_bootvar = memparse(p, &p);
591 return 0;
592}
593early_param("fadump_reserve_mem", early_fadump_reserve_mem);
594
595void crash_fadump(struct pt_regs *regs, const char *str)
596{
597 struct fadump_crash_info_header *fdh = NULL;
598 int old_cpu, this_cpu;
599
600 if (!should_fadump_crash())
601 return;
602
603 /*
604 * old_cpu == -1 means this is the first CPU which has come here,
605 * go ahead and trigger fadump.
606 *
607 * old_cpu != -1 means some other CPU has already on it's way
608 * to trigger fadump, just keep looping here.
609 */
610 this_cpu = smp_processor_id();
611 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
612
613 if (old_cpu != -1) {
614 /*
615 * We can't loop here indefinitely. Wait as long as fadump
616 * is in force. If we race with fadump un-registration this
617 * loop will break and then we go down to normal panic path
618 * and reboot. If fadump is in force the first crashing
619 * cpu will definitely trigger fadump.
620 */
621 while (fw_dump.dump_registered)
622 cpu_relax();
623 return;
624 }
625
626 fdh = __va(fw_dump.fadumphdr_addr);
627 fdh->crashing_cpu = crashing_cpu;
628 crash_save_vmcoreinfo();
629
630 if (regs)
631 fdh->regs = *regs;
632 else
633 ppc_save_regs(&fdh->regs);
634
635 fdh->online_mask = *cpu_online_mask;
636
637 fw_dump.ops->fadump_trigger(fdh, str);
638}
639
640u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
641{
642 struct elf_prstatus prstatus;
643
644 memset(&prstatus, 0, sizeof(prstatus));
645 /*
646 * FIXME: How do i get PID? Do I really need it?
647 * prstatus.pr_pid = ????
648 */
649 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
650 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
651 &prstatus, sizeof(prstatus));
652 return buf;
653}
654
655void fadump_update_elfcore_header(char *bufp)
656{
657 struct elfhdr *elf;
658 struct elf_phdr *phdr;
659
660 elf = (struct elfhdr *)bufp;
661 bufp += sizeof(struct elfhdr);
662
663 /* First note is a place holder for cpu notes info. */
664 phdr = (struct elf_phdr *)bufp;
665
666 if (phdr->p_type == PT_NOTE) {
667 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
668 phdr->p_offset = phdr->p_paddr;
669 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
670 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
671 }
672 return;
673}
674
675static void *fadump_alloc_buffer(unsigned long size)
676{
677 unsigned long count, i;
678 struct page *page;
679 void *vaddr;
680
681 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
682 if (!vaddr)
683 return NULL;
684
685 count = PAGE_ALIGN(size) / PAGE_SIZE;
686 page = virt_to_page(vaddr);
687 for (i = 0; i < count; i++)
688 mark_page_reserved(page + i);
689 return vaddr;
690}
691
692static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
693{
694 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
695}
696
697s32 fadump_setup_cpu_notes_buf(u32 num_cpus)
698{
699 /* Allocate buffer to hold cpu crash notes. */
700 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
701 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
702 fw_dump.cpu_notes_buf_vaddr =
703 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
704 if (!fw_dump.cpu_notes_buf_vaddr) {
705 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
706 fw_dump.cpu_notes_buf_size);
707 return -ENOMEM;
708 }
709
710 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
711 fw_dump.cpu_notes_buf_size,
712 fw_dump.cpu_notes_buf_vaddr);
713 return 0;
714}
715
716void fadump_free_cpu_notes_buf(void)
717{
718 if (!fw_dump.cpu_notes_buf_vaddr)
719 return;
720
721 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
722 fw_dump.cpu_notes_buf_size);
723 fw_dump.cpu_notes_buf_vaddr = 0;
724 fw_dump.cpu_notes_buf_size = 0;
725}
726
727static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
728{
729 kfree(mrange_info->mem_ranges);
730 mrange_info->mem_ranges = NULL;
731 mrange_info->mem_ranges_sz = 0;
732 mrange_info->max_mem_ranges = 0;
733}
734
735/*
736 * Allocate or reallocate mem_ranges array in incremental units
737 * of PAGE_SIZE.
738 */
739static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
740{
741 struct fadump_memory_range *new_array;
742 u64 new_size;
743
744 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
745 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
746 new_size, mrange_info->name);
747
748 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
749 if (new_array == NULL) {
750 pr_err("Insufficient memory for setting up %s memory ranges\n",
751 mrange_info->name);
752 fadump_free_mem_ranges(mrange_info);
753 return -ENOMEM;
754 }
755
756 mrange_info->mem_ranges = new_array;
757 mrange_info->mem_ranges_sz = new_size;
758 mrange_info->max_mem_ranges = (new_size /
759 sizeof(struct fadump_memory_range));
760 return 0;
761}
762
763static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
764 u64 base, u64 end)
765{
766 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
767 bool is_adjacent = false;
768 u64 start, size;
769
770 if (base == end)
771 return 0;
772
773 /*
774 * Fold adjacent memory ranges to bring down the memory ranges/
775 * PT_LOAD segments count.
776 */
777 if (mrange_info->mem_range_cnt) {
778 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
779 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
780
781 if ((start + size) == base)
782 is_adjacent = true;
783 }
784 if (!is_adjacent) {
785 /* resize the array on reaching the limit */
786 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
787 int ret;
788
789 ret = fadump_alloc_mem_ranges(mrange_info);
790 if (ret)
791 return ret;
792
793 /* Update to the new resized array */
794 mem_ranges = mrange_info->mem_ranges;
795 }
796
797 start = base;
798 mem_ranges[mrange_info->mem_range_cnt].base = start;
799 mrange_info->mem_range_cnt++;
800 }
801
802 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
803 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
804 mrange_info->name, (mrange_info->mem_range_cnt - 1),
805 start, end - 1, (end - start));
806 return 0;
807}
808
809static int fadump_exclude_reserved_area(u64 start, u64 end)
810{
811 u64 ra_start, ra_end;
812 int ret = 0;
813
814 ra_start = fw_dump.reserve_dump_area_start;
815 ra_end = ra_start + fw_dump.reserve_dump_area_size;
816
817 if ((ra_start < end) && (ra_end > start)) {
818 if ((start < ra_start) && (end > ra_end)) {
819 ret = fadump_add_mem_range(&crash_mrange_info,
820 start, ra_start);
821 if (ret)
822 return ret;
823
824 ret = fadump_add_mem_range(&crash_mrange_info,
825 ra_end, end);
826 } else if (start < ra_start) {
827 ret = fadump_add_mem_range(&crash_mrange_info,
828 start, ra_start);
829 } else if (ra_end < end) {
830 ret = fadump_add_mem_range(&crash_mrange_info,
831 ra_end, end);
832 }
833 } else
834 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
835
836 return ret;
837}
838
839static int fadump_init_elfcore_header(char *bufp)
840{
841 struct elfhdr *elf;
842
843 elf = (struct elfhdr *) bufp;
844 bufp += sizeof(struct elfhdr);
845 memcpy(elf->e_ident, ELFMAG, SELFMAG);
846 elf->e_ident[EI_CLASS] = ELF_CLASS;
847 elf->e_ident[EI_DATA] = ELF_DATA;
848 elf->e_ident[EI_VERSION] = EV_CURRENT;
849 elf->e_ident[EI_OSABI] = ELF_OSABI;
850 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
851 elf->e_type = ET_CORE;
852 elf->e_machine = ELF_ARCH;
853 elf->e_version = EV_CURRENT;
854 elf->e_entry = 0;
855 elf->e_phoff = sizeof(struct elfhdr);
856 elf->e_shoff = 0;
857#if defined(_CALL_ELF)
858 elf->e_flags = _CALL_ELF;
859#else
860 elf->e_flags = 0;
861#endif
862 elf->e_ehsize = sizeof(struct elfhdr);
863 elf->e_phentsize = sizeof(struct elf_phdr);
864 elf->e_phnum = 0;
865 elf->e_shentsize = 0;
866 elf->e_shnum = 0;
867 elf->e_shstrndx = 0;
868
869 return 0;
870}
871
872/*
873 * Traverse through memblock structure and setup crash memory ranges. These
874 * ranges will be used create PT_LOAD program headers in elfcore header.
875 */
876static int fadump_setup_crash_memory_ranges(void)
877{
878 struct memblock_region *reg;
879 u64 start, end;
880 int i, ret;
881
882 pr_debug("Setup crash memory ranges.\n");
883 crash_mrange_info.mem_range_cnt = 0;
884
885 /*
886 * Boot memory region(s) registered with firmware are moved to
887 * different location at the time of crash. Create separate program
888 * header(s) for this memory chunk(s) with the correct offset.
889 */
890 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
891 start = fw_dump.boot_mem_addr[i];
892 end = start + fw_dump.boot_mem_sz[i];
893 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
894 if (ret)
895 return ret;
896 }
897
898 for_each_memblock(memory, reg) {
899 start = (u64)reg->base;
900 end = start + (u64)reg->size;
901
902 /*
903 * skip the memory chunk that is already added
904 * (0 through boot_memory_top).
905 */
906 if (start < fw_dump.boot_mem_top) {
907 if (end > fw_dump.boot_mem_top)
908 start = fw_dump.boot_mem_top;
909 else
910 continue;
911 }
912
913 /* add this range excluding the reserved dump area. */
914 ret = fadump_exclude_reserved_area(start, end);
915 if (ret)
916 return ret;
917 }
918
919 return 0;
920}
921
922/*
923 * If the given physical address falls within the boot memory region then
924 * return the relocated address that points to the dump region reserved
925 * for saving initial boot memory contents.
926 */
927static inline unsigned long fadump_relocate(unsigned long paddr)
928{
929 unsigned long raddr, rstart, rend, rlast, hole_size;
930 int i;
931
932 hole_size = 0;
933 rlast = 0;
934 raddr = paddr;
935 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
936 rstart = fw_dump.boot_mem_addr[i];
937 rend = rstart + fw_dump.boot_mem_sz[i];
938 hole_size += (rstart - rlast);
939
940 if (paddr >= rstart && paddr < rend) {
941 raddr += fw_dump.boot_mem_dest_addr - hole_size;
942 break;
943 }
944
945 rlast = rend;
946 }
947
948 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
949 return raddr;
950}
951
952static int fadump_create_elfcore_headers(char *bufp)
953{
954 unsigned long long raddr, offset;
955 struct elf_phdr *phdr;
956 struct elfhdr *elf;
957 int i, j;
958
959 fadump_init_elfcore_header(bufp);
960 elf = (struct elfhdr *)bufp;
961 bufp += sizeof(struct elfhdr);
962
963 /*
964 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
965 * will be populated during second kernel boot after crash. Hence
966 * this PT_NOTE will always be the first elf note.
967 *
968 * NOTE: Any new ELF note addition should be placed after this note.
969 */
970 phdr = (struct elf_phdr *)bufp;
971 bufp += sizeof(struct elf_phdr);
972 phdr->p_type = PT_NOTE;
973 phdr->p_flags = 0;
974 phdr->p_vaddr = 0;
975 phdr->p_align = 0;
976
977 phdr->p_offset = 0;
978 phdr->p_paddr = 0;
979 phdr->p_filesz = 0;
980 phdr->p_memsz = 0;
981
982 (elf->e_phnum)++;
983
984 /* setup ELF PT_NOTE for vmcoreinfo */
985 phdr = (struct elf_phdr *)bufp;
986 bufp += sizeof(struct elf_phdr);
987 phdr->p_type = PT_NOTE;
988 phdr->p_flags = 0;
989 phdr->p_vaddr = 0;
990 phdr->p_align = 0;
991
992 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
993 phdr->p_offset = phdr->p_paddr;
994 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
995
996 /* Increment number of program headers. */
997 (elf->e_phnum)++;
998
999 /* setup PT_LOAD sections. */
1000 j = 0;
1001 offset = 0;
1002 raddr = fw_dump.boot_mem_addr[0];
1003 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1004 u64 mbase, msize;
1005
1006 mbase = crash_mrange_info.mem_ranges[i].base;
1007 msize = crash_mrange_info.mem_ranges[i].size;
1008 if (!msize)
1009 continue;
1010
1011 phdr = (struct elf_phdr *)bufp;
1012 bufp += sizeof(struct elf_phdr);
1013 phdr->p_type = PT_LOAD;
1014 phdr->p_flags = PF_R|PF_W|PF_X;
1015 phdr->p_offset = mbase;
1016
1017 if (mbase == raddr) {
1018 /*
1019 * The entire real memory region will be moved by
1020 * firmware to the specified destination_address.
1021 * Hence set the correct offset.
1022 */
1023 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1024 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1025 offset += fw_dump.boot_mem_sz[j];
1026 raddr = fw_dump.boot_mem_addr[++j];
1027 }
1028 }
1029
1030 phdr->p_paddr = mbase;
1031 phdr->p_vaddr = (unsigned long)__va(mbase);
1032 phdr->p_filesz = msize;
1033 phdr->p_memsz = msize;
1034 phdr->p_align = 0;
1035
1036 /* Increment number of program headers. */
1037 (elf->e_phnum)++;
1038 }
1039 return 0;
1040}
1041
1042static unsigned long init_fadump_header(unsigned long addr)
1043{
1044 struct fadump_crash_info_header *fdh;
1045
1046 if (!addr)
1047 return 0;
1048
1049 fdh = __va(addr);
1050 addr += sizeof(struct fadump_crash_info_header);
1051
1052 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1053 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1054 fdh->elfcorehdr_addr = addr;
1055 /* We will set the crashing cpu id in crash_fadump() during crash. */
1056 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1057
1058 return addr;
1059}
1060
1061static int register_fadump(void)
1062{
1063 unsigned long addr;
1064 void *vaddr;
1065 int ret;
1066
1067 /*
1068 * If no memory is reserved then we can not register for firmware-
1069 * assisted dump.
1070 */
1071 if (!fw_dump.reserve_dump_area_size)
1072 return -ENODEV;
1073
1074 ret = fadump_setup_crash_memory_ranges();
1075 if (ret)
1076 return ret;
1077
1078 addr = fw_dump.fadumphdr_addr;
1079
1080 /* Initialize fadump crash info header. */
1081 addr = init_fadump_header(addr);
1082 vaddr = __va(addr);
1083
1084 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1085 fadump_create_elfcore_headers(vaddr);
1086
1087 /* register the future kernel dump with firmware. */
1088 pr_debug("Registering for firmware-assisted kernel dump...\n");
1089 return fw_dump.ops->fadump_register(&fw_dump);
1090}
1091
1092void fadump_cleanup(void)
1093{
1094 if (!fw_dump.fadump_supported)
1095 return;
1096
1097 /* Invalidate the registration only if dump is active. */
1098 if (fw_dump.dump_active) {
1099 pr_debug("Invalidating firmware-assisted dump registration\n");
1100 fw_dump.ops->fadump_invalidate(&fw_dump);
1101 } else if (fw_dump.dump_registered) {
1102 /* Un-register Firmware-assisted dump if it was registered. */
1103 fw_dump.ops->fadump_unregister(&fw_dump);
1104 fadump_free_mem_ranges(&crash_mrange_info);
1105 }
1106
1107 if (fw_dump.ops->fadump_cleanup)
1108 fw_dump.ops->fadump_cleanup(&fw_dump);
1109}
1110
1111static void fadump_free_reserved_memory(unsigned long start_pfn,
1112 unsigned long end_pfn)
1113{
1114 unsigned long pfn;
1115 unsigned long time_limit = jiffies + HZ;
1116
1117 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1118 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1119
1120 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1121 free_reserved_page(pfn_to_page(pfn));
1122
1123 if (time_after(jiffies, time_limit)) {
1124 cond_resched();
1125 time_limit = jiffies + HZ;
1126 }
1127 }
1128}
1129
1130/*
1131 * Skip memory holes and free memory that was actually reserved.
1132 */
1133static void fadump_release_reserved_area(u64 start, u64 end)
1134{
1135 u64 tstart, tend, spfn, epfn;
1136 struct memblock_region *reg;
1137
1138 spfn = PHYS_PFN(start);
1139 epfn = PHYS_PFN(end);
1140 for_each_memblock(memory, reg) {
1141 tstart = max_t(u64, spfn, memblock_region_memory_base_pfn(reg));
1142 tend = min_t(u64, epfn, memblock_region_memory_end_pfn(reg));
1143 if (tstart < tend) {
1144 fadump_free_reserved_memory(tstart, tend);
1145
1146 if (tend == epfn)
1147 break;
1148
1149 spfn = tend;
1150 }
1151 }
1152}
1153
1154/*
1155 * Sort the mem ranges in-place and merge adjacent ranges
1156 * to minimize the memory ranges count.
1157 */
1158static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1159{
1160 struct fadump_memory_range *mem_ranges;
1161 struct fadump_memory_range tmp_range;
1162 u64 base, size;
1163 int i, j, idx;
1164
1165 if (!reserved_mrange_info.mem_range_cnt)
1166 return;
1167
1168 /* Sort the memory ranges */
1169 mem_ranges = mrange_info->mem_ranges;
1170 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1171 idx = i;
1172 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1173 if (mem_ranges[idx].base > mem_ranges[j].base)
1174 idx = j;
1175 }
1176 if (idx != i) {
1177 tmp_range = mem_ranges[idx];
1178 mem_ranges[idx] = mem_ranges[i];
1179 mem_ranges[i] = tmp_range;
1180 }
1181 }
1182
1183 /* Merge adjacent reserved ranges */
1184 idx = 0;
1185 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1186 base = mem_ranges[i-1].base;
1187 size = mem_ranges[i-1].size;
1188 if (mem_ranges[i].base == (base + size))
1189 mem_ranges[idx].size += mem_ranges[i].size;
1190 else {
1191 idx++;
1192 if (i == idx)
1193 continue;
1194
1195 mem_ranges[idx] = mem_ranges[i];
1196 }
1197 }
1198 mrange_info->mem_range_cnt = idx + 1;
1199}
1200
1201/*
1202 * Scan reserved-ranges to consider them while reserving/releasing
1203 * memory for FADump.
1204 */
1205static inline int fadump_scan_reserved_mem_ranges(void)
1206{
1207 struct device_node *root;
1208 const __be32 *prop;
1209 int len, ret = -1;
1210 unsigned long i;
1211
1212 root = of_find_node_by_path("/");
1213 if (!root)
1214 return ret;
1215
1216 prop = of_get_property(root, "reserved-ranges", &len);
1217 if (!prop)
1218 return ret;
1219
1220 /*
1221 * Each reserved range is an (address,size) pair, 2 cells each,
1222 * totalling 4 cells per range.
1223 */
1224 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1225 u64 base, size;
1226
1227 base = of_read_number(prop + (i * 4) + 0, 2);
1228 size = of_read_number(prop + (i * 4) + 2, 2);
1229
1230 if (size) {
1231 ret = fadump_add_mem_range(&reserved_mrange_info,
1232 base, base + size);
1233 if (ret < 0) {
1234 pr_warn("some reserved ranges are ignored!\n");
1235 break;
1236 }
1237 }
1238 }
1239
1240 return ret;
1241}
1242
1243/*
1244 * Release the memory that was reserved during early boot to preserve the
1245 * crash'ed kernel's memory contents except reserved dump area (permanent
1246 * reservation) and reserved ranges used by F/W. The released memory will
1247 * be available for general use.
1248 */
1249static void fadump_release_memory(u64 begin, u64 end)
1250{
1251 u64 ra_start, ra_end, tstart;
1252 int i, ret;
1253
1254 fadump_scan_reserved_mem_ranges();
1255
1256 ra_start = fw_dump.reserve_dump_area_start;
1257 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1258
1259 /*
1260 * Add reserved dump area to reserved ranges list
1261 * and exclude all these ranges while releasing memory.
1262 */
1263 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1264 if (ret != 0) {
1265 /*
1266 * Not enough memory to setup reserved ranges but the system is
1267 * running shortage of memory. So, release all the memory except
1268 * Reserved dump area (reused for next fadump registration).
1269 */
1270 if (begin < ra_end && end > ra_start) {
1271 if (begin < ra_start)
1272 fadump_release_reserved_area(begin, ra_start);
1273 if (end > ra_end)
1274 fadump_release_reserved_area(ra_end, end);
1275 } else
1276 fadump_release_reserved_area(begin, end);
1277
1278 return;
1279 }
1280
1281 /* Get the reserved ranges list in order first. */
1282 sort_and_merge_mem_ranges(&reserved_mrange_info);
1283
1284 /* Exclude reserved ranges and release remaining memory */
1285 tstart = begin;
1286 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1287 ra_start = reserved_mrange_info.mem_ranges[i].base;
1288 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1289
1290 if (tstart >= ra_end)
1291 continue;
1292
1293 if (tstart < ra_start)
1294 fadump_release_reserved_area(tstart, ra_start);
1295 tstart = ra_end;
1296 }
1297
1298 if (tstart < end)
1299 fadump_release_reserved_area(tstart, end);
1300}
1301
1302static void fadump_invalidate_release_mem(void)
1303{
1304 mutex_lock(&fadump_mutex);
1305 if (!fw_dump.dump_active) {
1306 mutex_unlock(&fadump_mutex);
1307 return;
1308 }
1309
1310 fadump_cleanup();
1311 mutex_unlock(&fadump_mutex);
1312
1313 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1314 fadump_free_cpu_notes_buf();
1315
1316 /*
1317 * Setup kernel metadata and initialize the kernel dump
1318 * memory structure for FADump re-registration.
1319 */
1320 if (fw_dump.ops->fadump_setup_metadata &&
1321 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1322 pr_warn("Failed to setup kernel metadata!\n");
1323 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1324}
1325
1326static ssize_t fadump_release_memory_store(struct kobject *kobj,
1327 struct kobj_attribute *attr,
1328 const char *buf, size_t count)
1329{
1330 int input = -1;
1331
1332 if (!fw_dump.dump_active)
1333 return -EPERM;
1334
1335 if (kstrtoint(buf, 0, &input))
1336 return -EINVAL;
1337
1338 if (input == 1) {
1339 /*
1340 * Take away the '/proc/vmcore'. We are releasing the dump
1341 * memory, hence it will not be valid anymore.
1342 */
1343#ifdef CONFIG_PROC_VMCORE
1344 vmcore_cleanup();
1345#endif
1346 fadump_invalidate_release_mem();
1347
1348 } else
1349 return -EINVAL;
1350 return count;
1351}
1352
1353static ssize_t fadump_enabled_show(struct kobject *kobj,
1354 struct kobj_attribute *attr,
1355 char *buf)
1356{
1357 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1358}
1359
1360static ssize_t fadump_register_show(struct kobject *kobj,
1361 struct kobj_attribute *attr,
1362 char *buf)
1363{
1364 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1365}
1366
1367static ssize_t fadump_register_store(struct kobject *kobj,
1368 struct kobj_attribute *attr,
1369 const char *buf, size_t count)
1370{
1371 int ret = 0;
1372 int input = -1;
1373
1374 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1375 return -EPERM;
1376
1377 if (kstrtoint(buf, 0, &input))
1378 return -EINVAL;
1379
1380 mutex_lock(&fadump_mutex);
1381
1382 switch (input) {
1383 case 0:
1384 if (fw_dump.dump_registered == 0) {
1385 goto unlock_out;
1386 }
1387
1388 /* Un-register Firmware-assisted dump */
1389 pr_debug("Un-register firmware-assisted dump\n");
1390 fw_dump.ops->fadump_unregister(&fw_dump);
1391 break;
1392 case 1:
1393 if (fw_dump.dump_registered == 1) {
1394 /* Un-register Firmware-assisted dump */
1395 fw_dump.ops->fadump_unregister(&fw_dump);
1396 }
1397 /* Register Firmware-assisted dump */
1398 ret = register_fadump();
1399 break;
1400 default:
1401 ret = -EINVAL;
1402 break;
1403 }
1404
1405unlock_out:
1406 mutex_unlock(&fadump_mutex);
1407 return ret < 0 ? ret : count;
1408}
1409
1410static int fadump_region_show(struct seq_file *m, void *private)
1411{
1412 if (!fw_dump.fadump_enabled)
1413 return 0;
1414
1415 mutex_lock(&fadump_mutex);
1416 fw_dump.ops->fadump_region_show(&fw_dump, m);
1417 mutex_unlock(&fadump_mutex);
1418 return 0;
1419}
1420
1421static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1422 0200, NULL,
1423 fadump_release_memory_store);
1424static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1425 0444, fadump_enabled_show,
1426 NULL);
1427static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1428 0644, fadump_register_show,
1429 fadump_register_store);
1430
1431DEFINE_SHOW_ATTRIBUTE(fadump_region);
1432
1433static void fadump_init_files(void)
1434{
1435 struct dentry *debugfs_file;
1436 int rc = 0;
1437
1438 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1439 if (rc)
1440 printk(KERN_ERR "fadump: unable to create sysfs file"
1441 " fadump_enabled (%d)\n", rc);
1442
1443 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1444 if (rc)
1445 printk(KERN_ERR "fadump: unable to create sysfs file"
1446 " fadump_registered (%d)\n", rc);
1447
1448 debugfs_file = debugfs_create_file("fadump_region", 0444,
1449 powerpc_debugfs_root, NULL,
1450 &fadump_region_fops);
1451 if (!debugfs_file)
1452 printk(KERN_ERR "fadump: unable to create debugfs file"
1453 " fadump_region\n");
1454
1455 if (fw_dump.dump_active) {
1456 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1457 if (rc)
1458 printk(KERN_ERR "fadump: unable to create sysfs file"
1459 " fadump_release_mem (%d)\n", rc);
1460 }
1461 return;
1462}
1463
1464/*
1465 * Prepare for firmware-assisted dump.
1466 */
1467int __init setup_fadump(void)
1468{
1469 if (!fw_dump.fadump_enabled)
1470 return 0;
1471
1472 if (!fw_dump.fadump_supported) {
1473 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1474 " this hardware\n");
1475 return 0;
1476 }
1477
1478 fadump_show_config();
1479 /*
1480 * If dump data is available then see if it is valid and prepare for
1481 * saving it to the disk.
1482 */
1483 if (fw_dump.dump_active) {
1484 /*
1485 * if dump process fails then invalidate the registration
1486 * and release memory before proceeding for re-registration.
1487 */
1488 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1489 fadump_invalidate_release_mem();
1490 }
1491 /* Initialize the kernel dump memory structure for FAD registration. */
1492 else if (fw_dump.reserve_dump_area_size)
1493 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1494
1495 fadump_init_files();
1496
1497 return 1;
1498}
1499subsys_initcall(setup_fadump);
1500#else /* !CONFIG_PRESERVE_FA_DUMP */
1501
1502/* Scan the Firmware Assisted dump configuration details. */
1503int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1504 int depth, void *data)
1505{
1506 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1507 return 0;
1508
1509 opal_fadump_dt_scan(&fw_dump, node);
1510 return 1;
1511}
1512
1513/*
1514 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1515 * preserve crash data. The subsequent memory preserving kernel boot
1516 * is likely to process this crash data.
1517 */
1518int __init fadump_reserve_mem(void)
1519{
1520 if (fw_dump.dump_active) {
1521 /*
1522 * If last boot has crashed then reserve all the memory
1523 * above boot memory to preserve crash data.
1524 */
1525 pr_info("Preserving crash data for processing in next boot.\n");
1526 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1527 } else
1528 pr_debug("FADump-aware kernel..\n");
1529
1530 return 1;
1531}
1532#endif /* CONFIG_PRESERVE_FA_DUMP */
1533
1534/* Preserve everything above the base address */
1535static void __init fadump_reserve_crash_area(u64 base)
1536{
1537 struct memblock_region *reg;
1538 u64 mstart, msize;
1539
1540 for_each_memblock(memory, reg) {
1541 mstart = reg->base;
1542 msize = reg->size;
1543
1544 if ((mstart + msize) < base)
1545 continue;
1546
1547 if (mstart < base) {
1548 msize -= (base - mstart);
1549 mstart = base;
1550 }
1551
1552 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1553 (msize >> 20), mstart);
1554 memblock_reserve(mstart, msize);
1555 }
1556}
1557
1558unsigned long __init arch_reserved_kernel_pages(void)
1559{
1560 return memblock_reserved_size() / PAGE_SIZE;
1561}