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