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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
4 * dump with assistance from firmware. This approach does not use kexec,
5 * instead firmware assists in booting the kdump kernel while preserving
6 * memory contents. The most of the code implementation has been adapted
7 * from phyp assisted dump implementation written by Linas Vepstas and
8 * Manish Ahuja
9 *
10 * Copyright 2011 IBM Corporation
11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
12 */
13
14#undef DEBUG
15#define pr_fmt(fmt) "fadump: " fmt
16
17#include <linux/string.h>
18#include <linux/memblock.h>
19#include <linux/delay.h>
20#include <linux/seq_file.h>
21#include <linux/crash_dump.h>
22#include <linux/kobject.h>
23#include <linux/sysfs.h>
24#include <linux/slab.h>
25#include <linux/cma.h>
26#include <linux/hugetlb.h>
27
28#include <asm/debugfs.h>
29#include <asm/page.h>
30#include <asm/prom.h>
31#include <asm/fadump.h>
32#include <asm/fadump-internal.h>
33#include <asm/setup.h>
34
35/*
36 * The CPU who acquired the lock to trigger the fadump crash should
37 * wait for other CPUs to enter.
38 *
39 * The timeout is in milliseconds.
40 */
41#define CRASH_TIMEOUT 500
42
43static struct fw_dump fw_dump;
44
45static void __init fadump_reserve_crash_area(u64 base);
46
47struct kobject *fadump_kobj;
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static atomic_t cpus_in_fadump;
52static DEFINE_MUTEX(fadump_mutex);
53
54struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
55
56#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
57#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
58 sizeof(struct fadump_memory_range))
59static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
60struct fadump_mrange_info reserved_mrange_info = { "reserved", rngs,
61 RESERVED_RNGS_SZ, 0,
62 RESERVED_RNGS_CNT, true };
63
64static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
65
66#ifdef CONFIG_CMA
67static struct cma *fadump_cma;
68
69/*
70 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
71 *
72 * This function initializes CMA area from fadump reserved memory.
73 * The total size of fadump reserved memory covers for boot memory size
74 * + cpu data size + hpte size and metadata.
75 * Initialize only the area equivalent to boot memory size for CMA use.
76 * The reamining portion of fadump reserved memory will be not given
77 * to CMA and pages for thoes will stay reserved. boot memory size is
78 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
79 * But for some reason even if it fails we still have the memory reservation
80 * with us and we can still continue doing fadump.
81 */
82int __init fadump_cma_init(void)
83{
84 unsigned long long base, size;
85 int rc;
86
87 if (!fw_dump.fadump_enabled)
88 return 0;
89
90 /*
91 * Do not use CMA if user has provided fadump=nocma kernel parameter.
92 * Return 1 to continue with fadump old behaviour.
93 */
94 if (fw_dump.nocma)
95 return 1;
96
97 base = fw_dump.reserve_dump_area_start;
98 size = fw_dump.boot_memory_size;
99
100 if (!size)
101 return 0;
102
103 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
104 if (rc) {
105 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
106 /*
107 * Though the CMA init has failed we still have memory
108 * reservation with us. The reserved memory will be
109 * blocked from production system usage. Hence return 1,
110 * so that we can continue with fadump.
111 */
112 return 1;
113 }
114
115 /*
116 * So we now have successfully initialized cma area for fadump.
117 */
118 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
119 "bytes of memory reserved for firmware-assisted dump\n",
120 cma_get_size(fadump_cma),
121 (unsigned long)cma_get_base(fadump_cma) >> 20,
122 fw_dump.reserve_dump_area_size);
123 return 1;
124}
125#else
126static int __init fadump_cma_init(void) { return 1; }
127#endif /* CONFIG_CMA */
128
129/* Scan the Firmware Assisted dump configuration details. */
130int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
131 int depth, void *data)
132{
133 if (depth == 0) {
134 early_init_dt_scan_reserved_ranges(node);
135 return 0;
136 }
137
138 if (depth != 1)
139 return 0;
140
141 if (strcmp(uname, "rtas") == 0) {
142 rtas_fadump_dt_scan(&fw_dump, node);
143 return 1;
144 }
145
146 if (strcmp(uname, "ibm,opal") == 0) {
147 opal_fadump_dt_scan(&fw_dump, node);
148 return 1;
149 }
150
151 return 0;
152}
153
154/*
155 * If fadump is registered, check if the memory provided
156 * falls within boot memory area and reserved memory area.
157 */
158int is_fadump_memory_area(u64 addr, unsigned long size)
159{
160 u64 d_start, d_end;
161
162 if (!fw_dump.dump_registered)
163 return 0;
164
165 if (!size)
166 return 0;
167
168 d_start = fw_dump.reserve_dump_area_start;
169 d_end = d_start + fw_dump.reserve_dump_area_size;
170 if (((addr + size) > d_start) && (addr <= d_end))
171 return 1;
172
173 return (addr <= fw_dump.boot_mem_top);
174}
175
176int should_fadump_crash(void)
177{
178 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
179 return 0;
180 return 1;
181}
182
183int is_fadump_active(void)
184{
185 return fw_dump.dump_active;
186}
187
188/*
189 * Returns true, if there are no holes in memory area between d_start to d_end,
190 * false otherwise.
191 */
192static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
193{
194 struct memblock_region *reg;
195 bool ret = false;
196 u64 start, end;
197
198 for_each_memblock(memory, reg) {
199 start = max_t(u64, d_start, reg->base);
200 end = min_t(u64, d_end, (reg->base + reg->size));
201 if (d_start < end) {
202 /* Memory hole from d_start to start */
203 if (start > d_start)
204 break;
205
206 if (end == d_end) {
207 ret = true;
208 break;
209 }
210
211 d_start = end + 1;
212 }
213 }
214
215 return ret;
216}
217
218/*
219 * Returns true, if there are no holes in boot memory area,
220 * false otherwise.
221 */
222bool is_fadump_boot_mem_contiguous(void)
223{
224 unsigned long d_start, d_end;
225 bool ret = false;
226 int i;
227
228 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
229 d_start = fw_dump.boot_mem_addr[i];
230 d_end = d_start + fw_dump.boot_mem_sz[i];
231
232 ret = is_fadump_mem_area_contiguous(d_start, d_end);
233 if (!ret)
234 break;
235 }
236
237 return ret;
238}
239
240/*
241 * Returns true, if there are no holes in reserved memory area,
242 * false otherwise.
243 */
244bool is_fadump_reserved_mem_contiguous(void)
245{
246 u64 d_start, d_end;
247
248 d_start = fw_dump.reserve_dump_area_start;
249 d_end = d_start + fw_dump.reserve_dump_area_size;
250 return is_fadump_mem_area_contiguous(d_start, d_end);
251}
252
253/* Print firmware assisted dump configurations for debugging purpose. */
254static void fadump_show_config(void)
255{
256 int i;
257
258 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
259 (fw_dump.fadump_supported ? "present" : "no support"));
260
261 if (!fw_dump.fadump_supported)
262 return;
263
264 pr_debug("Fadump enabled : %s\n",
265 (fw_dump.fadump_enabled ? "yes" : "no"));
266 pr_debug("Dump Active : %s\n",
267 (fw_dump.dump_active ? "yes" : "no"));
268 pr_debug("Dump section sizes:\n");
269 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
270 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
271 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
272 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
273 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
274 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
275 pr_debug("[%03d] base = %llx, size = %llx\n", i,
276 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
277 }
278}
279
280/**
281 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
282 *
283 * Function to find the largest memory size we need to reserve during early
284 * boot process. This will be the size of the memory that is required for a
285 * kernel to boot successfully.
286 *
287 * This function has been taken from phyp-assisted dump feature implementation.
288 *
289 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
290 *
291 * TODO: Come up with better approach to find out more accurate memory size
292 * that is required for a kernel to boot successfully.
293 *
294 */
295static inline u64 fadump_calculate_reserve_size(void)
296{
297 u64 base, size, bootmem_min;
298 int ret;
299
300 if (fw_dump.reserve_bootvar)
301 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
302
303 /*
304 * Check if the size is specified through crashkernel= cmdline
305 * option. If yes, then use that but ignore base as fadump reserves
306 * memory at a predefined offset.
307 */
308 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
309 &size, &base);
310 if (ret == 0 && size > 0) {
311 unsigned long max_size;
312
313 if (fw_dump.reserve_bootvar)
314 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
315
316 fw_dump.reserve_bootvar = (unsigned long)size;
317
318 /*
319 * Adjust if the boot memory size specified is above
320 * the upper limit.
321 */
322 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
323 if (fw_dump.reserve_bootvar > max_size) {
324 fw_dump.reserve_bootvar = max_size;
325 pr_info("Adjusted boot memory size to %luMB\n",
326 (fw_dump.reserve_bootvar >> 20));
327 }
328
329 return fw_dump.reserve_bootvar;
330 } else if (fw_dump.reserve_bootvar) {
331 /*
332 * 'fadump_reserve_mem=' is being used to reserve memory
333 * for firmware-assisted dump.
334 */
335 return fw_dump.reserve_bootvar;
336 }
337
338 /* divide by 20 to get 5% of value */
339 size = memblock_phys_mem_size() / 20;
340
341 /* round it down in multiples of 256 */
342 size = size & ~0x0FFFFFFFUL;
343
344 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
345 if (memory_limit && size > memory_limit)
346 size = memory_limit;
347
348 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
349 return (size > bootmem_min ? size : bootmem_min);
350}
351
352/*
353 * Calculate the total memory size required to be reserved for
354 * firmware-assisted dump registration.
355 */
356static unsigned long get_fadump_area_size(void)
357{
358 unsigned long size = 0;
359
360 size += fw_dump.cpu_state_data_size;
361 size += fw_dump.hpte_region_size;
362 size += fw_dump.boot_memory_size;
363 size += sizeof(struct fadump_crash_info_header);
364 size += sizeof(struct elfhdr); /* ELF core header.*/
365 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
366 /* Program headers for crash memory regions. */
367 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
368
369 size = PAGE_ALIGN(size);
370
371 /* This is to hold kernel metadata on platforms that support it */
372 size += (fw_dump.ops->fadump_get_metadata_size ?
373 fw_dump.ops->fadump_get_metadata_size() : 0);
374 return size;
375}
376
377static int __init add_boot_mem_region(unsigned long rstart,
378 unsigned long rsize)
379{
380 int i = fw_dump.boot_mem_regs_cnt++;
381
382 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
383 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
384 return 0;
385 }
386
387 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
388 i, rstart, (rstart + rsize));
389 fw_dump.boot_mem_addr[i] = rstart;
390 fw_dump.boot_mem_sz[i] = rsize;
391 return 1;
392}
393
394/*
395 * Firmware usually has a hard limit on the data it can copy per region.
396 * Honour that by splitting a memory range into multiple regions.
397 */
398static int __init add_boot_mem_regions(unsigned long mstart,
399 unsigned long msize)
400{
401 unsigned long rstart, rsize, max_size;
402 int ret = 1;
403
404 rstart = mstart;
405 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
406 while (msize) {
407 if (msize > max_size)
408 rsize = max_size;
409 else
410 rsize = msize;
411
412 ret = add_boot_mem_region(rstart, rsize);
413 if (!ret)
414 break;
415
416 msize -= rsize;
417 rstart += rsize;
418 }
419
420 return ret;
421}
422
423static int __init fadump_get_boot_mem_regions(void)
424{
425 unsigned long base, size, cur_size, hole_size, last_end;
426 unsigned long mem_size = fw_dump.boot_memory_size;
427 struct memblock_region *reg;
428 int ret = 1;
429
430 fw_dump.boot_mem_regs_cnt = 0;
431
432 last_end = 0;
433 hole_size = 0;
434 cur_size = 0;
435 for_each_memblock(memory, reg) {
436 base = reg->base;
437 size = reg->size;
438 hole_size += (base - last_end);
439
440 if ((cur_size + size) >= mem_size) {
441 size = (mem_size - cur_size);
442 ret = add_boot_mem_regions(base, size);
443 break;
444 }
445
446 mem_size -= size;
447 cur_size += size;
448 ret = add_boot_mem_regions(base, size);
449 if (!ret)
450 break;
451
452 last_end = base + size;
453 }
454 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
455
456 return ret;
457}
458
459/*
460 * Returns true, if the given range overlaps with reserved memory ranges
461 * starting at idx. Also, updates idx to index of overlapping memory range
462 * with the given memory range.
463 * False, otherwise.
464 */
465static bool overlaps_reserved_ranges(u64 base, u64 end, int *idx)
466{
467 bool ret = false;
468 int i;
469
470 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
471 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
472 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
473
474 if (end <= rbase)
475 break;
476
477 if ((end > rbase) && (base < rend)) {
478 *idx = i;
479 ret = true;
480 break;
481 }
482 }
483
484 return ret;
485}
486
487/*
488 * Locate a suitable memory area to reserve memory for FADump. While at it,
489 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
490 */
491static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
492{
493 struct fadump_memory_range *mrngs;
494 phys_addr_t mstart, mend;
495 int idx = 0;
496 u64 i, ret = 0;
497
498 mrngs = reserved_mrange_info.mem_ranges;
499 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
500 &mstart, &mend, NULL) {
501 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
502 i, mstart, mend, base);
503
504 if (mstart > base)
505 base = PAGE_ALIGN(mstart);
506
507 while ((mend > base) && ((mend - base) >= size)) {
508 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
509 ret = base;
510 goto out;
511 }
512
513 base = mrngs[idx].base + mrngs[idx].size;
514 base = PAGE_ALIGN(base);
515 }
516 }
517
518out:
519 return ret;
520}
521
522int __init fadump_reserve_mem(void)
523{
524 u64 base, size, mem_boundary, bootmem_min;
525 int ret = 1;
526
527 if (!fw_dump.fadump_enabled)
528 return 0;
529
530 if (!fw_dump.fadump_supported) {
531 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
532 goto error_out;
533 }
534
535 /*
536 * Initialize boot memory size
537 * If dump is active then we have already calculated the size during
538 * first kernel.
539 */
540 if (!fw_dump.dump_active) {
541 fw_dump.boot_memory_size =
542 PAGE_ALIGN(fadump_calculate_reserve_size());
543#ifdef CONFIG_CMA
544 if (!fw_dump.nocma) {
545 fw_dump.boot_memory_size =
546 ALIGN(fw_dump.boot_memory_size,
547 FADUMP_CMA_ALIGNMENT);
548 }
549#endif
550
551 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
552 if (fw_dump.boot_memory_size < bootmem_min) {
553 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
554 fw_dump.boot_memory_size, bootmem_min);
555 goto error_out;
556 }
557
558 if (!fadump_get_boot_mem_regions()) {
559 pr_err("Too many holes in boot memory area to enable fadump\n");
560 goto error_out;
561 }
562 }
563
564 /*
565 * Calculate the memory boundary.
566 * If memory_limit is less than actual memory boundary then reserve
567 * the memory for fadump beyond the memory_limit and adjust the
568 * memory_limit accordingly, so that the running kernel can run with
569 * specified memory_limit.
570 */
571 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
572 size = get_fadump_area_size();
573 if ((memory_limit + size) < memblock_end_of_DRAM())
574 memory_limit += size;
575 else
576 memory_limit = memblock_end_of_DRAM();
577 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
578 " dump, now %#016llx\n", memory_limit);
579 }
580 if (memory_limit)
581 mem_boundary = memory_limit;
582 else
583 mem_boundary = memblock_end_of_DRAM();
584
585 base = fw_dump.boot_mem_top;
586 size = get_fadump_area_size();
587 fw_dump.reserve_dump_area_size = size;
588 if (fw_dump.dump_active) {
589 pr_info("Firmware-assisted dump is active.\n");
590
591#ifdef CONFIG_HUGETLB_PAGE
592 /*
593 * FADump capture kernel doesn't care much about hugepages.
594 * In fact, handling hugepages in capture kernel is asking for
595 * trouble. So, disable HugeTLB support when fadump is active.
596 */
597 hugetlb_disabled = true;
598#endif
599 /*
600 * If last boot has crashed then reserve all the memory
601 * above boot memory size so that we don't touch it until
602 * dump is written to disk by userspace tool. This memory
603 * can be released for general use by invalidating fadump.
604 */
605 fadump_reserve_crash_area(base);
606
607 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
608 pr_debug("Reserve dump area start address: 0x%lx\n",
609 fw_dump.reserve_dump_area_start);
610 } else {
611 /*
612 * Reserve memory at an offset closer to bottom of the RAM to
613 * minimize the impact of memory hot-remove operation.
614 */
615 base = fadump_locate_reserve_mem(base, size);
616
617 if (!base || (base + size > mem_boundary)) {
618 pr_err("Failed to find memory chunk for reservation!\n");
619 goto error_out;
620 }
621 fw_dump.reserve_dump_area_start = base;
622
623 /*
624 * Calculate the kernel metadata address and register it with
625 * f/w if the platform supports.
626 */
627 if (fw_dump.ops->fadump_setup_metadata &&
628 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
629 goto error_out;
630
631 if (memblock_reserve(base, size)) {
632 pr_err("Failed to reserve memory!\n");
633 goto error_out;
634 }
635
636 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
637 (size >> 20), base, (memblock_phys_mem_size() >> 20));
638
639 ret = fadump_cma_init();
640 }
641
642 return ret;
643error_out:
644 fw_dump.fadump_enabled = 0;
645 return 0;
646}
647
648/* Look for fadump= cmdline option. */
649static int __init early_fadump_param(char *p)
650{
651 if (!p)
652 return 1;
653
654 if (strncmp(p, "on", 2) == 0)
655 fw_dump.fadump_enabled = 1;
656 else if (strncmp(p, "off", 3) == 0)
657 fw_dump.fadump_enabled = 0;
658 else if (strncmp(p, "nocma", 5) == 0) {
659 fw_dump.fadump_enabled = 1;
660 fw_dump.nocma = 1;
661 }
662
663 return 0;
664}
665early_param("fadump", early_fadump_param);
666
667/*
668 * Look for fadump_reserve_mem= cmdline option
669 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
670 * the sooner 'crashkernel=' parameter is accustomed to.
671 */
672static int __init early_fadump_reserve_mem(char *p)
673{
674 if (p)
675 fw_dump.reserve_bootvar = memparse(p, &p);
676 return 0;
677}
678early_param("fadump_reserve_mem", early_fadump_reserve_mem);
679
680void crash_fadump(struct pt_regs *regs, const char *str)
681{
682 unsigned int msecs;
683 struct fadump_crash_info_header *fdh = NULL;
684 int old_cpu, this_cpu;
685 /* Do not include first CPU */
686 unsigned int ncpus = num_online_cpus() - 1;
687
688 if (!should_fadump_crash())
689 return;
690
691 /*
692 * old_cpu == -1 means this is the first CPU which has come here,
693 * go ahead and trigger fadump.
694 *
695 * old_cpu != -1 means some other CPU has already on it's way
696 * to trigger fadump, just keep looping here.
697 */
698 this_cpu = smp_processor_id();
699 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
700
701 if (old_cpu != -1) {
702 atomic_inc(&cpus_in_fadump);
703
704 /*
705 * We can't loop here indefinitely. Wait as long as fadump
706 * is in force. If we race with fadump un-registration this
707 * loop will break and then we go down to normal panic path
708 * and reboot. If fadump is in force the first crashing
709 * cpu will definitely trigger fadump.
710 */
711 while (fw_dump.dump_registered)
712 cpu_relax();
713 return;
714 }
715
716 fdh = __va(fw_dump.fadumphdr_addr);
717 fdh->crashing_cpu = crashing_cpu;
718 crash_save_vmcoreinfo();
719
720 if (regs)
721 fdh->regs = *regs;
722 else
723 ppc_save_regs(&fdh->regs);
724
725 fdh->online_mask = *cpu_online_mask;
726
727 /*
728 * If we came in via system reset, wait a while for the secondary
729 * CPUs to enter.
730 */
731 if (TRAP(&(fdh->regs)) == 0x100) {
732 msecs = CRASH_TIMEOUT;
733 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
734 mdelay(1);
735 }
736
737 fw_dump.ops->fadump_trigger(fdh, str);
738}
739
740u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
741{
742 struct elf_prstatus prstatus;
743
744 memset(&prstatus, 0, sizeof(prstatus));
745 /*
746 * FIXME: How do i get PID? Do I really need it?
747 * prstatus.pr_pid = ????
748 */
749 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
750 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
751 &prstatus, sizeof(prstatus));
752 return buf;
753}
754
755void fadump_update_elfcore_header(char *bufp)
756{
757 struct elfhdr *elf;
758 struct elf_phdr *phdr;
759
760 elf = (struct elfhdr *)bufp;
761 bufp += sizeof(struct elfhdr);
762
763 /* First note is a place holder for cpu notes info. */
764 phdr = (struct elf_phdr *)bufp;
765
766 if (phdr->p_type == PT_NOTE) {
767 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
768 phdr->p_offset = phdr->p_paddr;
769 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
770 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
771 }
772 return;
773}
774
775static void *fadump_alloc_buffer(unsigned long size)
776{
777 unsigned long count, i;
778 struct page *page;
779 void *vaddr;
780
781 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
782 if (!vaddr)
783 return NULL;
784
785 count = PAGE_ALIGN(size) / PAGE_SIZE;
786 page = virt_to_page(vaddr);
787 for (i = 0; i < count; i++)
788 mark_page_reserved(page + i);
789 return vaddr;
790}
791
792static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
793{
794 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
795}
796
797s32 fadump_setup_cpu_notes_buf(u32 num_cpus)
798{
799 /* Allocate buffer to hold cpu crash notes. */
800 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
801 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
802 fw_dump.cpu_notes_buf_vaddr =
803 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
804 if (!fw_dump.cpu_notes_buf_vaddr) {
805 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
806 fw_dump.cpu_notes_buf_size);
807 return -ENOMEM;
808 }
809
810 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
811 fw_dump.cpu_notes_buf_size,
812 fw_dump.cpu_notes_buf_vaddr);
813 return 0;
814}
815
816void fadump_free_cpu_notes_buf(void)
817{
818 if (!fw_dump.cpu_notes_buf_vaddr)
819 return;
820
821 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
822 fw_dump.cpu_notes_buf_size);
823 fw_dump.cpu_notes_buf_vaddr = 0;
824 fw_dump.cpu_notes_buf_size = 0;
825}
826
827static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
828{
829 if (mrange_info->is_static) {
830 mrange_info->mem_range_cnt = 0;
831 return;
832 }
833
834 kfree(mrange_info->mem_ranges);
835 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
836 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
837}
838
839/*
840 * Allocate or reallocate mem_ranges array in incremental units
841 * of PAGE_SIZE.
842 */
843static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
844{
845 struct fadump_memory_range *new_array;
846 u64 new_size;
847
848 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
849 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
850 new_size, mrange_info->name);
851
852 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
853 if (new_array == NULL) {
854 pr_err("Insufficient memory for setting up %s memory ranges\n",
855 mrange_info->name);
856 fadump_free_mem_ranges(mrange_info);
857 return -ENOMEM;
858 }
859
860 mrange_info->mem_ranges = new_array;
861 mrange_info->mem_ranges_sz = new_size;
862 mrange_info->max_mem_ranges = (new_size /
863 sizeof(struct fadump_memory_range));
864 return 0;
865}
866
867static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
868 u64 base, u64 end)
869{
870 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
871 bool is_adjacent = false;
872 u64 start, size;
873
874 if (base == end)
875 return 0;
876
877 /*
878 * Fold adjacent memory ranges to bring down the memory ranges/
879 * PT_LOAD segments count.
880 */
881 if (mrange_info->mem_range_cnt) {
882 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
883 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
884
885 if ((start + size) == base)
886 is_adjacent = true;
887 }
888 if (!is_adjacent) {
889 /* resize the array on reaching the limit */
890 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
891 int ret;
892
893 if (mrange_info->is_static) {
894 pr_err("Reached array size limit for %s memory ranges\n",
895 mrange_info->name);
896 return -ENOSPC;
897 }
898
899 ret = fadump_alloc_mem_ranges(mrange_info);
900 if (ret)
901 return ret;
902
903 /* Update to the new resized array */
904 mem_ranges = mrange_info->mem_ranges;
905 }
906
907 start = base;
908 mem_ranges[mrange_info->mem_range_cnt].base = start;
909 mrange_info->mem_range_cnt++;
910 }
911
912 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
913 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
914 mrange_info->name, (mrange_info->mem_range_cnt - 1),
915 start, end - 1, (end - start));
916 return 0;
917}
918
919static int fadump_exclude_reserved_area(u64 start, u64 end)
920{
921 u64 ra_start, ra_end;
922 int ret = 0;
923
924 ra_start = fw_dump.reserve_dump_area_start;
925 ra_end = ra_start + fw_dump.reserve_dump_area_size;
926
927 if ((ra_start < end) && (ra_end > start)) {
928 if ((start < ra_start) && (end > ra_end)) {
929 ret = fadump_add_mem_range(&crash_mrange_info,
930 start, ra_start);
931 if (ret)
932 return ret;
933
934 ret = fadump_add_mem_range(&crash_mrange_info,
935 ra_end, end);
936 } else if (start < ra_start) {
937 ret = fadump_add_mem_range(&crash_mrange_info,
938 start, ra_start);
939 } else if (ra_end < end) {
940 ret = fadump_add_mem_range(&crash_mrange_info,
941 ra_end, end);
942 }
943 } else
944 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
945
946 return ret;
947}
948
949static int fadump_init_elfcore_header(char *bufp)
950{
951 struct elfhdr *elf;
952
953 elf = (struct elfhdr *) bufp;
954 bufp += sizeof(struct elfhdr);
955 memcpy(elf->e_ident, ELFMAG, SELFMAG);
956 elf->e_ident[EI_CLASS] = ELF_CLASS;
957 elf->e_ident[EI_DATA] = ELF_DATA;
958 elf->e_ident[EI_VERSION] = EV_CURRENT;
959 elf->e_ident[EI_OSABI] = ELF_OSABI;
960 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
961 elf->e_type = ET_CORE;
962 elf->e_machine = ELF_ARCH;
963 elf->e_version = EV_CURRENT;
964 elf->e_entry = 0;
965 elf->e_phoff = sizeof(struct elfhdr);
966 elf->e_shoff = 0;
967#if defined(_CALL_ELF)
968 elf->e_flags = _CALL_ELF;
969#else
970 elf->e_flags = 0;
971#endif
972 elf->e_ehsize = sizeof(struct elfhdr);
973 elf->e_phentsize = sizeof(struct elf_phdr);
974 elf->e_phnum = 0;
975 elf->e_shentsize = 0;
976 elf->e_shnum = 0;
977 elf->e_shstrndx = 0;
978
979 return 0;
980}
981
982/*
983 * Traverse through memblock structure and setup crash memory ranges. These
984 * ranges will be used create PT_LOAD program headers in elfcore header.
985 */
986static int fadump_setup_crash_memory_ranges(void)
987{
988 struct memblock_region *reg;
989 u64 start, end;
990 int i, ret;
991
992 pr_debug("Setup crash memory ranges.\n");
993 crash_mrange_info.mem_range_cnt = 0;
994
995 /*
996 * Boot memory region(s) registered with firmware are moved to
997 * different location at the time of crash. Create separate program
998 * header(s) for this memory chunk(s) with the correct offset.
999 */
1000 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1001 start = fw_dump.boot_mem_addr[i];
1002 end = start + fw_dump.boot_mem_sz[i];
1003 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1004 if (ret)
1005 return ret;
1006 }
1007
1008 for_each_memblock(memory, reg) {
1009 start = (u64)reg->base;
1010 end = start + (u64)reg->size;
1011
1012 /*
1013 * skip the memory chunk that is already added
1014 * (0 through boot_memory_top).
1015 */
1016 if (start < fw_dump.boot_mem_top) {
1017 if (end > fw_dump.boot_mem_top)
1018 start = fw_dump.boot_mem_top;
1019 else
1020 continue;
1021 }
1022
1023 /* add this range excluding the reserved dump area. */
1024 ret = fadump_exclude_reserved_area(start, end);
1025 if (ret)
1026 return ret;
1027 }
1028
1029 return 0;
1030}
1031
1032/*
1033 * If the given physical address falls within the boot memory region then
1034 * return the relocated address that points to the dump region reserved
1035 * for saving initial boot memory contents.
1036 */
1037static inline unsigned long fadump_relocate(unsigned long paddr)
1038{
1039 unsigned long raddr, rstart, rend, rlast, hole_size;
1040 int i;
1041
1042 hole_size = 0;
1043 rlast = 0;
1044 raddr = paddr;
1045 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1046 rstart = fw_dump.boot_mem_addr[i];
1047 rend = rstart + fw_dump.boot_mem_sz[i];
1048 hole_size += (rstart - rlast);
1049
1050 if (paddr >= rstart && paddr < rend) {
1051 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1052 break;
1053 }
1054
1055 rlast = rend;
1056 }
1057
1058 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1059 return raddr;
1060}
1061
1062static int fadump_create_elfcore_headers(char *bufp)
1063{
1064 unsigned long long raddr, offset;
1065 struct elf_phdr *phdr;
1066 struct elfhdr *elf;
1067 int i, j;
1068
1069 fadump_init_elfcore_header(bufp);
1070 elf = (struct elfhdr *)bufp;
1071 bufp += sizeof(struct elfhdr);
1072
1073 /*
1074 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1075 * will be populated during second kernel boot after crash. Hence
1076 * this PT_NOTE will always be the first elf note.
1077 *
1078 * NOTE: Any new ELF note addition should be placed after this note.
1079 */
1080 phdr = (struct elf_phdr *)bufp;
1081 bufp += sizeof(struct elf_phdr);
1082 phdr->p_type = PT_NOTE;
1083 phdr->p_flags = 0;
1084 phdr->p_vaddr = 0;
1085 phdr->p_align = 0;
1086
1087 phdr->p_offset = 0;
1088 phdr->p_paddr = 0;
1089 phdr->p_filesz = 0;
1090 phdr->p_memsz = 0;
1091
1092 (elf->e_phnum)++;
1093
1094 /* setup ELF PT_NOTE for vmcoreinfo */
1095 phdr = (struct elf_phdr *)bufp;
1096 bufp += sizeof(struct elf_phdr);
1097 phdr->p_type = PT_NOTE;
1098 phdr->p_flags = 0;
1099 phdr->p_vaddr = 0;
1100 phdr->p_align = 0;
1101
1102 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1103 phdr->p_offset = phdr->p_paddr;
1104 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1105
1106 /* Increment number of program headers. */
1107 (elf->e_phnum)++;
1108
1109 /* setup PT_LOAD sections. */
1110 j = 0;
1111 offset = 0;
1112 raddr = fw_dump.boot_mem_addr[0];
1113 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1114 u64 mbase, msize;
1115
1116 mbase = crash_mrange_info.mem_ranges[i].base;
1117 msize = crash_mrange_info.mem_ranges[i].size;
1118 if (!msize)
1119 continue;
1120
1121 phdr = (struct elf_phdr *)bufp;
1122 bufp += sizeof(struct elf_phdr);
1123 phdr->p_type = PT_LOAD;
1124 phdr->p_flags = PF_R|PF_W|PF_X;
1125 phdr->p_offset = mbase;
1126
1127 if (mbase == raddr) {
1128 /*
1129 * The entire real memory region will be moved by
1130 * firmware to the specified destination_address.
1131 * Hence set the correct offset.
1132 */
1133 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1134 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1135 offset += fw_dump.boot_mem_sz[j];
1136 raddr = fw_dump.boot_mem_addr[++j];
1137 }
1138 }
1139
1140 phdr->p_paddr = mbase;
1141 phdr->p_vaddr = (unsigned long)__va(mbase);
1142 phdr->p_filesz = msize;
1143 phdr->p_memsz = msize;
1144 phdr->p_align = 0;
1145
1146 /* Increment number of program headers. */
1147 (elf->e_phnum)++;
1148 }
1149 return 0;
1150}
1151
1152static unsigned long init_fadump_header(unsigned long addr)
1153{
1154 struct fadump_crash_info_header *fdh;
1155
1156 if (!addr)
1157 return 0;
1158
1159 fdh = __va(addr);
1160 addr += sizeof(struct fadump_crash_info_header);
1161
1162 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1163 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1164 fdh->elfcorehdr_addr = addr;
1165 /* We will set the crashing cpu id in crash_fadump() during crash. */
1166 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1167
1168 return addr;
1169}
1170
1171static int register_fadump(void)
1172{
1173 unsigned long addr;
1174 void *vaddr;
1175 int ret;
1176
1177 /*
1178 * If no memory is reserved then we can not register for firmware-
1179 * assisted dump.
1180 */
1181 if (!fw_dump.reserve_dump_area_size)
1182 return -ENODEV;
1183
1184 ret = fadump_setup_crash_memory_ranges();
1185 if (ret)
1186 return ret;
1187
1188 addr = fw_dump.fadumphdr_addr;
1189
1190 /* Initialize fadump crash info header. */
1191 addr = init_fadump_header(addr);
1192 vaddr = __va(addr);
1193
1194 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1195 fadump_create_elfcore_headers(vaddr);
1196
1197 /* register the future kernel dump with firmware. */
1198 pr_debug("Registering for firmware-assisted kernel dump...\n");
1199 return fw_dump.ops->fadump_register(&fw_dump);
1200}
1201
1202void fadump_cleanup(void)
1203{
1204 if (!fw_dump.fadump_supported)
1205 return;
1206
1207 /* Invalidate the registration only if dump is active. */
1208 if (fw_dump.dump_active) {
1209 pr_debug("Invalidating firmware-assisted dump registration\n");
1210 fw_dump.ops->fadump_invalidate(&fw_dump);
1211 } else if (fw_dump.dump_registered) {
1212 /* Un-register Firmware-assisted dump if it was registered. */
1213 fw_dump.ops->fadump_unregister(&fw_dump);
1214 fadump_free_mem_ranges(&crash_mrange_info);
1215 }
1216
1217 if (fw_dump.ops->fadump_cleanup)
1218 fw_dump.ops->fadump_cleanup(&fw_dump);
1219}
1220
1221static void fadump_free_reserved_memory(unsigned long start_pfn,
1222 unsigned long end_pfn)
1223{
1224 unsigned long pfn;
1225 unsigned long time_limit = jiffies + HZ;
1226
1227 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1228 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1229
1230 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1231 free_reserved_page(pfn_to_page(pfn));
1232
1233 if (time_after(jiffies, time_limit)) {
1234 cond_resched();
1235 time_limit = jiffies + HZ;
1236 }
1237 }
1238}
1239
1240/*
1241 * Skip memory holes and free memory that was actually reserved.
1242 */
1243static void fadump_release_reserved_area(u64 start, u64 end)
1244{
1245 u64 tstart, tend, spfn, epfn;
1246 struct memblock_region *reg;
1247
1248 spfn = PHYS_PFN(start);
1249 epfn = PHYS_PFN(end);
1250 for_each_memblock(memory, reg) {
1251 tstart = max_t(u64, spfn, memblock_region_memory_base_pfn(reg));
1252 tend = min_t(u64, epfn, memblock_region_memory_end_pfn(reg));
1253 if (tstart < tend) {
1254 fadump_free_reserved_memory(tstart, tend);
1255
1256 if (tend == epfn)
1257 break;
1258
1259 spfn = tend;
1260 }
1261 }
1262}
1263
1264/*
1265 * Sort the mem ranges in-place and merge adjacent ranges
1266 * to minimize the memory ranges count.
1267 */
1268static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1269{
1270 struct fadump_memory_range *mem_ranges;
1271 struct fadump_memory_range tmp_range;
1272 u64 base, size;
1273 int i, j, idx;
1274
1275 if (!reserved_mrange_info.mem_range_cnt)
1276 return;
1277
1278 /* Sort the memory ranges */
1279 mem_ranges = mrange_info->mem_ranges;
1280 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1281 idx = i;
1282 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1283 if (mem_ranges[idx].base > mem_ranges[j].base)
1284 idx = j;
1285 }
1286 if (idx != i) {
1287 tmp_range = mem_ranges[idx];
1288 mem_ranges[idx] = mem_ranges[i];
1289 mem_ranges[i] = tmp_range;
1290 }
1291 }
1292
1293 /* Merge adjacent reserved ranges */
1294 idx = 0;
1295 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1296 base = mem_ranges[i-1].base;
1297 size = mem_ranges[i-1].size;
1298 if (mem_ranges[i].base == (base + size))
1299 mem_ranges[idx].size += mem_ranges[i].size;
1300 else {
1301 idx++;
1302 if (i == idx)
1303 continue;
1304
1305 mem_ranges[idx] = mem_ranges[i];
1306 }
1307 }
1308 mrange_info->mem_range_cnt = idx + 1;
1309}
1310
1311/*
1312 * Scan reserved-ranges to consider them while reserving/releasing
1313 * memory for FADump.
1314 */
1315static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1316{
1317 const __be32 *prop;
1318 int len, ret = -1;
1319 unsigned long i;
1320
1321 /* reserved-ranges already scanned */
1322 if (reserved_mrange_info.mem_range_cnt != 0)
1323 return;
1324
1325 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1326 if (!prop)
1327 return;
1328
1329 /*
1330 * Each reserved range is an (address,size) pair, 2 cells each,
1331 * totalling 4 cells per range.
1332 */
1333 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1334 u64 base, size;
1335
1336 base = of_read_number(prop + (i * 4) + 0, 2);
1337 size = of_read_number(prop + (i * 4) + 2, 2);
1338
1339 if (size) {
1340 ret = fadump_add_mem_range(&reserved_mrange_info,
1341 base, base + size);
1342 if (ret < 0) {
1343 pr_warn("some reserved ranges are ignored!\n");
1344 break;
1345 }
1346 }
1347 }
1348
1349 /* Compact reserved ranges */
1350 sort_and_merge_mem_ranges(&reserved_mrange_info);
1351}
1352
1353/*
1354 * Release the memory that was reserved during early boot to preserve the
1355 * crash'ed kernel's memory contents except reserved dump area (permanent
1356 * reservation) and reserved ranges used by F/W. The released memory will
1357 * be available for general use.
1358 */
1359static void fadump_release_memory(u64 begin, u64 end)
1360{
1361 u64 ra_start, ra_end, tstart;
1362 int i, ret;
1363
1364 ra_start = fw_dump.reserve_dump_area_start;
1365 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1366
1367 /*
1368 * If reserved ranges array limit is hit, overwrite the last reserved
1369 * memory range with reserved dump area to ensure it is excluded from
1370 * the memory being released (reused for next FADump registration).
1371 */
1372 if (reserved_mrange_info.mem_range_cnt ==
1373 reserved_mrange_info.max_mem_ranges)
1374 reserved_mrange_info.mem_range_cnt--;
1375
1376 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1377 if (ret != 0)
1378 return;
1379
1380 /* Get the reserved ranges list in order first. */
1381 sort_and_merge_mem_ranges(&reserved_mrange_info);
1382
1383 /* Exclude reserved ranges and release remaining memory */
1384 tstart = begin;
1385 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1386 ra_start = reserved_mrange_info.mem_ranges[i].base;
1387 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1388
1389 if (tstart >= ra_end)
1390 continue;
1391
1392 if (tstart < ra_start)
1393 fadump_release_reserved_area(tstart, ra_start);
1394 tstart = ra_end;
1395 }
1396
1397 if (tstart < end)
1398 fadump_release_reserved_area(tstart, end);
1399}
1400
1401static void fadump_invalidate_release_mem(void)
1402{
1403 mutex_lock(&fadump_mutex);
1404 if (!fw_dump.dump_active) {
1405 mutex_unlock(&fadump_mutex);
1406 return;
1407 }
1408
1409 fadump_cleanup();
1410 mutex_unlock(&fadump_mutex);
1411
1412 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1413 fadump_free_cpu_notes_buf();
1414
1415 /*
1416 * Setup kernel metadata and initialize the kernel dump
1417 * memory structure for FADump re-registration.
1418 */
1419 if (fw_dump.ops->fadump_setup_metadata &&
1420 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1421 pr_warn("Failed to setup kernel metadata!\n");
1422 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1423}
1424
1425static ssize_t release_mem_store(struct kobject *kobj,
1426 struct kobj_attribute *attr,
1427 const char *buf, size_t count)
1428{
1429 int input = -1;
1430
1431 if (!fw_dump.dump_active)
1432 return -EPERM;
1433
1434 if (kstrtoint(buf, 0, &input))
1435 return -EINVAL;
1436
1437 if (input == 1) {
1438 /*
1439 * Take away the '/proc/vmcore'. We are releasing the dump
1440 * memory, hence it will not be valid anymore.
1441 */
1442#ifdef CONFIG_PROC_VMCORE
1443 vmcore_cleanup();
1444#endif
1445 fadump_invalidate_release_mem();
1446
1447 } else
1448 return -EINVAL;
1449 return count;
1450}
1451
1452/* Release the reserved memory and disable the FADump */
1453static void unregister_fadump(void)
1454{
1455 fadump_cleanup();
1456 fadump_release_memory(fw_dump.reserve_dump_area_start,
1457 fw_dump.reserve_dump_area_size);
1458 fw_dump.fadump_enabled = 0;
1459 kobject_put(fadump_kobj);
1460}
1461
1462static ssize_t enabled_show(struct kobject *kobj,
1463 struct kobj_attribute *attr,
1464 char *buf)
1465{
1466 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1467}
1468
1469static ssize_t mem_reserved_show(struct kobject *kobj,
1470 struct kobj_attribute *attr,
1471 char *buf)
1472{
1473 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1474}
1475
1476static ssize_t registered_show(struct kobject *kobj,
1477 struct kobj_attribute *attr,
1478 char *buf)
1479{
1480 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1481}
1482
1483static ssize_t registered_store(struct kobject *kobj,
1484 struct kobj_attribute *attr,
1485 const char *buf, size_t count)
1486{
1487 int ret = 0;
1488 int input = -1;
1489
1490 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1491 return -EPERM;
1492
1493 if (kstrtoint(buf, 0, &input))
1494 return -EINVAL;
1495
1496 mutex_lock(&fadump_mutex);
1497
1498 switch (input) {
1499 case 0:
1500 if (fw_dump.dump_registered == 0) {
1501 goto unlock_out;
1502 }
1503
1504 /* Un-register Firmware-assisted dump */
1505 pr_debug("Un-register firmware-assisted dump\n");
1506 fw_dump.ops->fadump_unregister(&fw_dump);
1507 break;
1508 case 1:
1509 if (fw_dump.dump_registered == 1) {
1510 /* Un-register Firmware-assisted dump */
1511 fw_dump.ops->fadump_unregister(&fw_dump);
1512 }
1513 /* Register Firmware-assisted dump */
1514 ret = register_fadump();
1515 break;
1516 default:
1517 ret = -EINVAL;
1518 break;
1519 }
1520
1521unlock_out:
1522 mutex_unlock(&fadump_mutex);
1523 return ret < 0 ? ret : count;
1524}
1525
1526static int fadump_region_show(struct seq_file *m, void *private)
1527{
1528 if (!fw_dump.fadump_enabled)
1529 return 0;
1530
1531 mutex_lock(&fadump_mutex);
1532 fw_dump.ops->fadump_region_show(&fw_dump, m);
1533 mutex_unlock(&fadump_mutex);
1534 return 0;
1535}
1536
1537static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1538static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1539static struct kobj_attribute register_attr = __ATTR_RW(registered);
1540static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1541
1542static struct attribute *fadump_attrs[] = {
1543 &enable_attr.attr,
1544 ®ister_attr.attr,
1545 &mem_reserved_attr.attr,
1546 NULL,
1547};
1548
1549ATTRIBUTE_GROUPS(fadump);
1550
1551DEFINE_SHOW_ATTRIBUTE(fadump_region);
1552
1553static void fadump_init_files(void)
1554{
1555 int rc = 0;
1556
1557 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1558 if (!fadump_kobj) {
1559 pr_err("failed to create fadump kobject\n");
1560 return;
1561 }
1562
1563 debugfs_create_file("fadump_region", 0444, powerpc_debugfs_root, NULL,
1564 &fadump_region_fops);
1565
1566 if (fw_dump.dump_active) {
1567 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1568 if (rc)
1569 pr_err("unable to create release_mem sysfs file (%d)\n",
1570 rc);
1571 }
1572
1573 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1574 if (rc) {
1575 pr_err("sysfs group creation failed (%d), unregistering FADump",
1576 rc);
1577 unregister_fadump();
1578 return;
1579 }
1580
1581 /*
1582 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1583 * create symlink at old location to maintain backward compatibility.
1584 *
1585 * - fadump_enabled -> fadump/enabled
1586 * - fadump_registered -> fadump/registered
1587 * - fadump_release_mem -> fadump/release_mem
1588 */
1589 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1590 "enabled", "fadump_enabled");
1591 if (rc) {
1592 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1593 return;
1594 }
1595
1596 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1597 "registered",
1598 "fadump_registered");
1599 if (rc) {
1600 pr_err("unable to create fadump_registered symlink (%d)", rc);
1601 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1602 return;
1603 }
1604
1605 if (fw_dump.dump_active) {
1606 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1607 fadump_kobj,
1608 "release_mem",
1609 "fadump_release_mem");
1610 if (rc)
1611 pr_err("unable to create fadump_release_mem symlink (%d)",
1612 rc);
1613 }
1614 return;
1615}
1616
1617/*
1618 * Prepare for firmware-assisted dump.
1619 */
1620int __init setup_fadump(void)
1621{
1622 if (!fw_dump.fadump_supported)
1623 return 0;
1624
1625 fadump_init_files();
1626 fadump_show_config();
1627
1628 if (!fw_dump.fadump_enabled)
1629 return 1;
1630
1631 /*
1632 * If dump data is available then see if it is valid and prepare for
1633 * saving it to the disk.
1634 */
1635 if (fw_dump.dump_active) {
1636 /*
1637 * if dump process fails then invalidate the registration
1638 * and release memory before proceeding for re-registration.
1639 */
1640 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1641 fadump_invalidate_release_mem();
1642 }
1643 /* Initialize the kernel dump memory structure for FAD registration. */
1644 else if (fw_dump.reserve_dump_area_size)
1645 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1646
1647 return 1;
1648}
1649subsys_initcall(setup_fadump);
1650#else /* !CONFIG_PRESERVE_FA_DUMP */
1651
1652/* Scan the Firmware Assisted dump configuration details. */
1653int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1654 int depth, void *data)
1655{
1656 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1657 return 0;
1658
1659 opal_fadump_dt_scan(&fw_dump, node);
1660 return 1;
1661}
1662
1663/*
1664 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1665 * preserve crash data. The subsequent memory preserving kernel boot
1666 * is likely to process this crash data.
1667 */
1668int __init fadump_reserve_mem(void)
1669{
1670 if (fw_dump.dump_active) {
1671 /*
1672 * If last boot has crashed then reserve all the memory
1673 * above boot memory to preserve crash data.
1674 */
1675 pr_info("Preserving crash data for processing in next boot.\n");
1676 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1677 } else
1678 pr_debug("FADump-aware kernel..\n");
1679
1680 return 1;
1681}
1682#endif /* CONFIG_PRESERVE_FA_DUMP */
1683
1684/* Preserve everything above the base address */
1685static void __init fadump_reserve_crash_area(u64 base)
1686{
1687 struct memblock_region *reg;
1688 u64 mstart, msize;
1689
1690 for_each_memblock(memory, reg) {
1691 mstart = reg->base;
1692 msize = reg->size;
1693
1694 if ((mstart + msize) < base)
1695 continue;
1696
1697 if (mstart < base) {
1698 msize -= (base - mstart);
1699 mstart = base;
1700 }
1701
1702 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1703 (msize >> 20), mstart);
1704 memblock_reserve(mstart, msize);
1705 }
1706}
1707
1708unsigned long __init arch_reserved_kernel_pages(void)
1709{
1710 return memblock_reserved_size() / PAGE_SIZE;
1711}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
4 * dump with assistance from firmware. This approach does not use kexec,
5 * instead firmware assists in booting the kdump kernel while preserving
6 * memory contents. The most of the code implementation has been adapted
7 * from phyp assisted dump implementation written by Linas Vepstas and
8 * Manish Ahuja
9 *
10 * Copyright 2011 IBM Corporation
11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
12 */
13
14#undef DEBUG
15#define pr_fmt(fmt) "fadump: " fmt
16
17#include <linux/string.h>
18#include <linux/memblock.h>
19#include <linux/delay.h>
20#include <linux/seq_file.h>
21#include <linux/crash_dump.h>
22#include <linux/kobject.h>
23#include <linux/sysfs.h>
24#include <linux/slab.h>
25#include <linux/cma.h>
26#include <linux/hugetlb.h>
27#include <linux/debugfs.h>
28#include <linux/of.h>
29#include <linux/of_fdt.h>
30
31#include <asm/page.h>
32#include <asm/fadump.h>
33#include <asm/fadump-internal.h>
34#include <asm/setup.h>
35#include <asm/interrupt.h>
36
37/*
38 * The CPU who acquired the lock to trigger the fadump crash should
39 * wait for other CPUs to enter.
40 *
41 * The timeout is in milliseconds.
42 */
43#define CRASH_TIMEOUT 500
44
45static struct fw_dump fw_dump;
46
47static void __init fadump_reserve_crash_area(u64 base);
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static struct kobject *fadump_kobj;
52
53static atomic_t cpus_in_fadump;
54static DEFINE_MUTEX(fadump_mutex);
55
56static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
57
58#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
59#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
60 sizeof(struct fadump_memory_range))
61static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
62static struct fadump_mrange_info
63reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
64
65static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
66
67#ifdef CONFIG_CMA
68static struct cma *fadump_cma;
69
70/*
71 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
72 *
73 * This function initializes CMA area from fadump reserved memory.
74 * The total size of fadump reserved memory covers for boot memory size
75 * + cpu data size + hpte size and metadata.
76 * Initialize only the area equivalent to boot memory size for CMA use.
77 * The remaining portion of fadump reserved memory will be not given
78 * to CMA and pages for those will stay reserved. boot memory size is
79 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
80 * But for some reason even if it fails we still have the memory reservation
81 * with us and we can still continue doing fadump.
82 */
83static int __init fadump_cma_init(void)
84{
85 unsigned long long base, size;
86 int rc;
87
88 if (!fw_dump.fadump_enabled)
89 return 0;
90
91 /*
92 * Do not use CMA if user has provided fadump=nocma kernel parameter.
93 * Return 1 to continue with fadump old behaviour.
94 */
95 if (fw_dump.nocma)
96 return 1;
97
98 base = fw_dump.reserve_dump_area_start;
99 size = fw_dump.boot_memory_size;
100
101 if (!size)
102 return 0;
103
104 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
105 if (rc) {
106 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
107 /*
108 * Though the CMA init has failed we still have memory
109 * reservation with us. The reserved memory will be
110 * blocked from production system usage. Hence return 1,
111 * so that we can continue with fadump.
112 */
113 return 1;
114 }
115
116 /*
117 * If CMA activation fails, keep the pages reserved, instead of
118 * exposing them to buddy allocator. Same as 'fadump=nocma' case.
119 */
120 cma_reserve_pages_on_error(fadump_cma);
121
122 /*
123 * So we now have successfully initialized cma area for fadump.
124 */
125 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
126 "bytes of memory reserved for firmware-assisted dump\n",
127 cma_get_size(fadump_cma),
128 (unsigned long)cma_get_base(fadump_cma) >> 20,
129 fw_dump.reserve_dump_area_size);
130 return 1;
131}
132#else
133static int __init fadump_cma_init(void) { return 1; }
134#endif /* CONFIG_CMA */
135
136/* Scan the Firmware Assisted dump configuration details. */
137int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
138 int depth, void *data)
139{
140 if (depth == 0) {
141 early_init_dt_scan_reserved_ranges(node);
142 return 0;
143 }
144
145 if (depth != 1)
146 return 0;
147
148 if (strcmp(uname, "rtas") == 0) {
149 rtas_fadump_dt_scan(&fw_dump, node);
150 return 1;
151 }
152
153 if (strcmp(uname, "ibm,opal") == 0) {
154 opal_fadump_dt_scan(&fw_dump, node);
155 return 1;
156 }
157
158 return 0;
159}
160
161/*
162 * If fadump is registered, check if the memory provided
163 * falls within boot memory area and reserved memory area.
164 */
165int is_fadump_memory_area(u64 addr, unsigned long size)
166{
167 u64 d_start, d_end;
168
169 if (!fw_dump.dump_registered)
170 return 0;
171
172 if (!size)
173 return 0;
174
175 d_start = fw_dump.reserve_dump_area_start;
176 d_end = d_start + fw_dump.reserve_dump_area_size;
177 if (((addr + size) > d_start) && (addr <= d_end))
178 return 1;
179
180 return (addr <= fw_dump.boot_mem_top);
181}
182
183int should_fadump_crash(void)
184{
185 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
186 return 0;
187 return 1;
188}
189
190int is_fadump_active(void)
191{
192 return fw_dump.dump_active;
193}
194
195/*
196 * Returns true, if there are no holes in memory area between d_start to d_end,
197 * false otherwise.
198 */
199static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
200{
201 phys_addr_t reg_start, reg_end;
202 bool ret = false;
203 u64 i, start, end;
204
205 for_each_mem_range(i, ®_start, ®_end) {
206 start = max_t(u64, d_start, reg_start);
207 end = min_t(u64, d_end, reg_end);
208 if (d_start < end) {
209 /* Memory hole from d_start to start */
210 if (start > d_start)
211 break;
212
213 if (end == d_end) {
214 ret = true;
215 break;
216 }
217
218 d_start = end + 1;
219 }
220 }
221
222 return ret;
223}
224
225/*
226 * Returns true, if there are no holes in boot memory area,
227 * false otherwise.
228 */
229bool is_fadump_boot_mem_contiguous(void)
230{
231 unsigned long d_start, d_end;
232 bool ret = false;
233 int i;
234
235 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
236 d_start = fw_dump.boot_mem_addr[i];
237 d_end = d_start + fw_dump.boot_mem_sz[i];
238
239 ret = is_fadump_mem_area_contiguous(d_start, d_end);
240 if (!ret)
241 break;
242 }
243
244 return ret;
245}
246
247/*
248 * Returns true, if there are no holes in reserved memory area,
249 * false otherwise.
250 */
251bool is_fadump_reserved_mem_contiguous(void)
252{
253 u64 d_start, d_end;
254
255 d_start = fw_dump.reserve_dump_area_start;
256 d_end = d_start + fw_dump.reserve_dump_area_size;
257 return is_fadump_mem_area_contiguous(d_start, d_end);
258}
259
260/* Print firmware assisted dump configurations for debugging purpose. */
261static void __init fadump_show_config(void)
262{
263 int i;
264
265 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
266 (fw_dump.fadump_supported ? "present" : "no support"));
267
268 if (!fw_dump.fadump_supported)
269 return;
270
271 pr_debug("Fadump enabled : %s\n",
272 (fw_dump.fadump_enabled ? "yes" : "no"));
273 pr_debug("Dump Active : %s\n",
274 (fw_dump.dump_active ? "yes" : "no"));
275 pr_debug("Dump section sizes:\n");
276 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
277 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
278 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
279 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
280 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
281 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
282 pr_debug("[%03d] base = %llx, size = %llx\n", i,
283 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
284 }
285}
286
287/**
288 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
289 *
290 * Function to find the largest memory size we need to reserve during early
291 * boot process. This will be the size of the memory that is required for a
292 * kernel to boot successfully.
293 *
294 * This function has been taken from phyp-assisted dump feature implementation.
295 *
296 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
297 *
298 * TODO: Come up with better approach to find out more accurate memory size
299 * that is required for a kernel to boot successfully.
300 *
301 */
302static __init u64 fadump_calculate_reserve_size(void)
303{
304 u64 base, size, bootmem_min;
305 int ret;
306
307 if (fw_dump.reserve_bootvar)
308 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
309
310 /*
311 * Check if the size is specified through crashkernel= cmdline
312 * option. If yes, then use that but ignore base as fadump reserves
313 * memory at a predefined offset.
314 */
315 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
316 &size, &base);
317 if (ret == 0 && size > 0) {
318 unsigned long max_size;
319
320 if (fw_dump.reserve_bootvar)
321 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
322
323 fw_dump.reserve_bootvar = (unsigned long)size;
324
325 /*
326 * Adjust if the boot memory size specified is above
327 * the upper limit.
328 */
329 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
330 if (fw_dump.reserve_bootvar > max_size) {
331 fw_dump.reserve_bootvar = max_size;
332 pr_info("Adjusted boot memory size to %luMB\n",
333 (fw_dump.reserve_bootvar >> 20));
334 }
335
336 return fw_dump.reserve_bootvar;
337 } else if (fw_dump.reserve_bootvar) {
338 /*
339 * 'fadump_reserve_mem=' is being used to reserve memory
340 * for firmware-assisted dump.
341 */
342 return fw_dump.reserve_bootvar;
343 }
344
345 /* divide by 20 to get 5% of value */
346 size = memblock_phys_mem_size() / 20;
347
348 /* round it down in multiples of 256 */
349 size = size & ~0x0FFFFFFFUL;
350
351 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
352 if (memory_limit && size > memory_limit)
353 size = memory_limit;
354
355 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
356 return (size > bootmem_min ? size : bootmem_min);
357}
358
359/*
360 * Calculate the total memory size required to be reserved for
361 * firmware-assisted dump registration.
362 */
363static unsigned long __init get_fadump_area_size(void)
364{
365 unsigned long size = 0;
366
367 size += fw_dump.cpu_state_data_size;
368 size += fw_dump.hpte_region_size;
369 /*
370 * Account for pagesize alignment of boot memory area destination address.
371 * This faciliates in mmap reading of first kernel's memory.
372 */
373 size = PAGE_ALIGN(size);
374 size += fw_dump.boot_memory_size;
375 size += sizeof(struct fadump_crash_info_header);
376 size += sizeof(struct elfhdr); /* ELF core header.*/
377 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
378 /* Program headers for crash memory regions. */
379 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
380
381 size = PAGE_ALIGN(size);
382
383 /* This is to hold kernel metadata on platforms that support it */
384 size += (fw_dump.ops->fadump_get_metadata_size ?
385 fw_dump.ops->fadump_get_metadata_size() : 0);
386 return size;
387}
388
389static int __init add_boot_mem_region(unsigned long rstart,
390 unsigned long rsize)
391{
392 int i = fw_dump.boot_mem_regs_cnt++;
393
394 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
395 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
396 return 0;
397 }
398
399 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
400 i, rstart, (rstart + rsize));
401 fw_dump.boot_mem_addr[i] = rstart;
402 fw_dump.boot_mem_sz[i] = rsize;
403 return 1;
404}
405
406/*
407 * Firmware usually has a hard limit on the data it can copy per region.
408 * Honour that by splitting a memory range into multiple regions.
409 */
410static int __init add_boot_mem_regions(unsigned long mstart,
411 unsigned long msize)
412{
413 unsigned long rstart, rsize, max_size;
414 int ret = 1;
415
416 rstart = mstart;
417 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
418 while (msize) {
419 if (msize > max_size)
420 rsize = max_size;
421 else
422 rsize = msize;
423
424 ret = add_boot_mem_region(rstart, rsize);
425 if (!ret)
426 break;
427
428 msize -= rsize;
429 rstart += rsize;
430 }
431
432 return ret;
433}
434
435static int __init fadump_get_boot_mem_regions(void)
436{
437 unsigned long size, cur_size, hole_size, last_end;
438 unsigned long mem_size = fw_dump.boot_memory_size;
439 phys_addr_t reg_start, reg_end;
440 int ret = 1;
441 u64 i;
442
443 fw_dump.boot_mem_regs_cnt = 0;
444
445 last_end = 0;
446 hole_size = 0;
447 cur_size = 0;
448 for_each_mem_range(i, ®_start, ®_end) {
449 size = reg_end - reg_start;
450 hole_size += (reg_start - last_end);
451
452 if ((cur_size + size) >= mem_size) {
453 size = (mem_size - cur_size);
454 ret = add_boot_mem_regions(reg_start, size);
455 break;
456 }
457
458 mem_size -= size;
459 cur_size += size;
460 ret = add_boot_mem_regions(reg_start, size);
461 if (!ret)
462 break;
463
464 last_end = reg_end;
465 }
466 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
467
468 return ret;
469}
470
471/*
472 * Returns true, if the given range overlaps with reserved memory ranges
473 * starting at idx. Also, updates idx to index of overlapping memory range
474 * with the given memory range.
475 * False, otherwise.
476 */
477static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
478{
479 bool ret = false;
480 int i;
481
482 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
483 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
484 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
485
486 if (end <= rbase)
487 break;
488
489 if ((end > rbase) && (base < rend)) {
490 *idx = i;
491 ret = true;
492 break;
493 }
494 }
495
496 return ret;
497}
498
499/*
500 * Locate a suitable memory area to reserve memory for FADump. While at it,
501 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
502 */
503static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
504{
505 struct fadump_memory_range *mrngs;
506 phys_addr_t mstart, mend;
507 int idx = 0;
508 u64 i, ret = 0;
509
510 mrngs = reserved_mrange_info.mem_ranges;
511 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
512 &mstart, &mend, NULL) {
513 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
514 i, mstart, mend, base);
515
516 if (mstart > base)
517 base = PAGE_ALIGN(mstart);
518
519 while ((mend > base) && ((mend - base) >= size)) {
520 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
521 ret = base;
522 goto out;
523 }
524
525 base = mrngs[idx].base + mrngs[idx].size;
526 base = PAGE_ALIGN(base);
527 }
528 }
529
530out:
531 return ret;
532}
533
534int __init fadump_reserve_mem(void)
535{
536 u64 base, size, mem_boundary, bootmem_min;
537 int ret = 1;
538
539 if (!fw_dump.fadump_enabled)
540 return 0;
541
542 if (!fw_dump.fadump_supported) {
543 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
544 goto error_out;
545 }
546
547 /*
548 * Initialize boot memory size
549 * If dump is active then we have already calculated the size during
550 * first kernel.
551 */
552 if (!fw_dump.dump_active) {
553 fw_dump.boot_memory_size =
554 PAGE_ALIGN(fadump_calculate_reserve_size());
555#ifdef CONFIG_CMA
556 if (!fw_dump.nocma) {
557 fw_dump.boot_memory_size =
558 ALIGN(fw_dump.boot_memory_size,
559 CMA_MIN_ALIGNMENT_BYTES);
560 }
561#endif
562
563 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
564 if (fw_dump.boot_memory_size < bootmem_min) {
565 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
566 fw_dump.boot_memory_size, bootmem_min);
567 goto error_out;
568 }
569
570 if (!fadump_get_boot_mem_regions()) {
571 pr_err("Too many holes in boot memory area to enable fadump\n");
572 goto error_out;
573 }
574 }
575
576 /*
577 * Calculate the memory boundary.
578 * If memory_limit is less than actual memory boundary then reserve
579 * the memory for fadump beyond the memory_limit and adjust the
580 * memory_limit accordingly, so that the running kernel can run with
581 * specified memory_limit.
582 */
583 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
584 size = get_fadump_area_size();
585 if ((memory_limit + size) < memblock_end_of_DRAM())
586 memory_limit += size;
587 else
588 memory_limit = memblock_end_of_DRAM();
589 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
590 " dump, now %#016llx\n", memory_limit);
591 }
592 if (memory_limit)
593 mem_boundary = memory_limit;
594 else
595 mem_boundary = memblock_end_of_DRAM();
596
597 base = fw_dump.boot_mem_top;
598 size = get_fadump_area_size();
599 fw_dump.reserve_dump_area_size = size;
600 if (fw_dump.dump_active) {
601 pr_info("Firmware-assisted dump is active.\n");
602
603#ifdef CONFIG_HUGETLB_PAGE
604 /*
605 * FADump capture kernel doesn't care much about hugepages.
606 * In fact, handling hugepages in capture kernel is asking for
607 * trouble. So, disable HugeTLB support when fadump is active.
608 */
609 hugetlb_disabled = true;
610#endif
611 /*
612 * If last boot has crashed then reserve all the memory
613 * above boot memory size so that we don't touch it until
614 * dump is written to disk by userspace tool. This memory
615 * can be released for general use by invalidating fadump.
616 */
617 fadump_reserve_crash_area(base);
618
619 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
620 pr_debug("Reserve dump area start address: 0x%lx\n",
621 fw_dump.reserve_dump_area_start);
622 } else {
623 /*
624 * Reserve memory at an offset closer to bottom of the RAM to
625 * minimize the impact of memory hot-remove operation.
626 */
627 base = fadump_locate_reserve_mem(base, size);
628
629 if (!base || (base + size > mem_boundary)) {
630 pr_err("Failed to find memory chunk for reservation!\n");
631 goto error_out;
632 }
633 fw_dump.reserve_dump_area_start = base;
634
635 /*
636 * Calculate the kernel metadata address and register it with
637 * f/w if the platform supports.
638 */
639 if (fw_dump.ops->fadump_setup_metadata &&
640 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
641 goto error_out;
642
643 if (memblock_reserve(base, size)) {
644 pr_err("Failed to reserve memory!\n");
645 goto error_out;
646 }
647
648 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
649 (size >> 20), base, (memblock_phys_mem_size() >> 20));
650
651 ret = fadump_cma_init();
652 }
653
654 return ret;
655error_out:
656 fw_dump.fadump_enabled = 0;
657 return 0;
658}
659
660/* Look for fadump= cmdline option. */
661static int __init early_fadump_param(char *p)
662{
663 if (!p)
664 return 1;
665
666 if (strncmp(p, "on", 2) == 0)
667 fw_dump.fadump_enabled = 1;
668 else if (strncmp(p, "off", 3) == 0)
669 fw_dump.fadump_enabled = 0;
670 else if (strncmp(p, "nocma", 5) == 0) {
671 fw_dump.fadump_enabled = 1;
672 fw_dump.nocma = 1;
673 }
674
675 return 0;
676}
677early_param("fadump", early_fadump_param);
678
679/*
680 * Look for fadump_reserve_mem= cmdline option
681 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
682 * the sooner 'crashkernel=' parameter is accustomed to.
683 */
684static int __init early_fadump_reserve_mem(char *p)
685{
686 if (p)
687 fw_dump.reserve_bootvar = memparse(p, &p);
688 return 0;
689}
690early_param("fadump_reserve_mem", early_fadump_reserve_mem);
691
692void crash_fadump(struct pt_regs *regs, const char *str)
693{
694 unsigned int msecs;
695 struct fadump_crash_info_header *fdh = NULL;
696 int old_cpu, this_cpu;
697 /* Do not include first CPU */
698 unsigned int ncpus = num_online_cpus() - 1;
699
700 if (!should_fadump_crash())
701 return;
702
703 /*
704 * old_cpu == -1 means this is the first CPU which has come here,
705 * go ahead and trigger fadump.
706 *
707 * old_cpu != -1 means some other CPU has already on it's way
708 * to trigger fadump, just keep looping here.
709 */
710 this_cpu = smp_processor_id();
711 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
712
713 if (old_cpu != -1) {
714 atomic_inc(&cpus_in_fadump);
715
716 /*
717 * We can't loop here indefinitely. Wait as long as fadump
718 * is in force. If we race with fadump un-registration this
719 * loop will break and then we go down to normal panic path
720 * and reboot. If fadump is in force the first crashing
721 * cpu will definitely trigger fadump.
722 */
723 while (fw_dump.dump_registered)
724 cpu_relax();
725 return;
726 }
727
728 fdh = __va(fw_dump.fadumphdr_addr);
729 fdh->crashing_cpu = crashing_cpu;
730 crash_save_vmcoreinfo();
731
732 if (regs)
733 fdh->regs = *regs;
734 else
735 ppc_save_regs(&fdh->regs);
736
737 fdh->cpu_mask = *cpu_online_mask;
738
739 /*
740 * If we came in via system reset, wait a while for the secondary
741 * CPUs to enter.
742 */
743 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
744 msecs = CRASH_TIMEOUT;
745 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
746 mdelay(1);
747 }
748
749 fw_dump.ops->fadump_trigger(fdh, str);
750}
751
752u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
753{
754 struct elf_prstatus prstatus;
755
756 memset(&prstatus, 0, sizeof(prstatus));
757 /*
758 * FIXME: How do i get PID? Do I really need it?
759 * prstatus.pr_pid = ????
760 */
761 elf_core_copy_regs(&prstatus.pr_reg, regs);
762 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
763 &prstatus, sizeof(prstatus));
764 return buf;
765}
766
767void __init fadump_update_elfcore_header(char *bufp)
768{
769 struct elf_phdr *phdr;
770
771 bufp += sizeof(struct elfhdr);
772
773 /* First note is a place holder for cpu notes info. */
774 phdr = (struct elf_phdr *)bufp;
775
776 if (phdr->p_type == PT_NOTE) {
777 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
778 phdr->p_offset = phdr->p_paddr;
779 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
780 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
781 }
782 return;
783}
784
785static void *__init fadump_alloc_buffer(unsigned long size)
786{
787 unsigned long count, i;
788 struct page *page;
789 void *vaddr;
790
791 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
792 if (!vaddr)
793 return NULL;
794
795 count = PAGE_ALIGN(size) / PAGE_SIZE;
796 page = virt_to_page(vaddr);
797 for (i = 0; i < count; i++)
798 mark_page_reserved(page + i);
799 return vaddr;
800}
801
802static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
803{
804 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
805}
806
807s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
808{
809 /* Allocate buffer to hold cpu crash notes. */
810 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
811 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
812 fw_dump.cpu_notes_buf_vaddr =
813 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
814 if (!fw_dump.cpu_notes_buf_vaddr) {
815 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
816 fw_dump.cpu_notes_buf_size);
817 return -ENOMEM;
818 }
819
820 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
821 fw_dump.cpu_notes_buf_size,
822 fw_dump.cpu_notes_buf_vaddr);
823 return 0;
824}
825
826void fadump_free_cpu_notes_buf(void)
827{
828 if (!fw_dump.cpu_notes_buf_vaddr)
829 return;
830
831 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
832 fw_dump.cpu_notes_buf_size);
833 fw_dump.cpu_notes_buf_vaddr = 0;
834 fw_dump.cpu_notes_buf_size = 0;
835}
836
837static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
838{
839 if (mrange_info->is_static) {
840 mrange_info->mem_range_cnt = 0;
841 return;
842 }
843
844 kfree(mrange_info->mem_ranges);
845 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
846 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
847}
848
849/*
850 * Allocate or reallocate mem_ranges array in incremental units
851 * of PAGE_SIZE.
852 */
853static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
854{
855 struct fadump_memory_range *new_array;
856 u64 new_size;
857
858 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
859 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
860 new_size, mrange_info->name);
861
862 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
863 if (new_array == NULL) {
864 pr_err("Insufficient memory for setting up %s memory ranges\n",
865 mrange_info->name);
866 fadump_free_mem_ranges(mrange_info);
867 return -ENOMEM;
868 }
869
870 mrange_info->mem_ranges = new_array;
871 mrange_info->mem_ranges_sz = new_size;
872 mrange_info->max_mem_ranges = (new_size /
873 sizeof(struct fadump_memory_range));
874 return 0;
875}
876static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
877 u64 base, u64 end)
878{
879 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
880 bool is_adjacent = false;
881 u64 start, size;
882
883 if (base == end)
884 return 0;
885
886 /*
887 * Fold adjacent memory ranges to bring down the memory ranges/
888 * PT_LOAD segments count.
889 */
890 if (mrange_info->mem_range_cnt) {
891 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
892 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
893
894 /*
895 * Boot memory area needs separate PT_LOAD segment(s) as it
896 * is moved to a different location at the time of crash.
897 * So, fold only if the region is not boot memory area.
898 */
899 if ((start + size) == base && start >= fw_dump.boot_mem_top)
900 is_adjacent = true;
901 }
902 if (!is_adjacent) {
903 /* resize the array on reaching the limit */
904 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
905 int ret;
906
907 if (mrange_info->is_static) {
908 pr_err("Reached array size limit for %s memory ranges\n",
909 mrange_info->name);
910 return -ENOSPC;
911 }
912
913 ret = fadump_alloc_mem_ranges(mrange_info);
914 if (ret)
915 return ret;
916
917 /* Update to the new resized array */
918 mem_ranges = mrange_info->mem_ranges;
919 }
920
921 start = base;
922 mem_ranges[mrange_info->mem_range_cnt].base = start;
923 mrange_info->mem_range_cnt++;
924 }
925
926 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
927 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
928 mrange_info->name, (mrange_info->mem_range_cnt - 1),
929 start, end - 1, (end - start));
930 return 0;
931}
932
933static int fadump_exclude_reserved_area(u64 start, u64 end)
934{
935 u64 ra_start, ra_end;
936 int ret = 0;
937
938 ra_start = fw_dump.reserve_dump_area_start;
939 ra_end = ra_start + fw_dump.reserve_dump_area_size;
940
941 if ((ra_start < end) && (ra_end > start)) {
942 if ((start < ra_start) && (end > ra_end)) {
943 ret = fadump_add_mem_range(&crash_mrange_info,
944 start, ra_start);
945 if (ret)
946 return ret;
947
948 ret = fadump_add_mem_range(&crash_mrange_info,
949 ra_end, end);
950 } else if (start < ra_start) {
951 ret = fadump_add_mem_range(&crash_mrange_info,
952 start, ra_start);
953 } else if (ra_end < end) {
954 ret = fadump_add_mem_range(&crash_mrange_info,
955 ra_end, end);
956 }
957 } else
958 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
959
960 return ret;
961}
962
963static int fadump_init_elfcore_header(char *bufp)
964{
965 struct elfhdr *elf;
966
967 elf = (struct elfhdr *) bufp;
968 bufp += sizeof(struct elfhdr);
969 memcpy(elf->e_ident, ELFMAG, SELFMAG);
970 elf->e_ident[EI_CLASS] = ELF_CLASS;
971 elf->e_ident[EI_DATA] = ELF_DATA;
972 elf->e_ident[EI_VERSION] = EV_CURRENT;
973 elf->e_ident[EI_OSABI] = ELF_OSABI;
974 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
975 elf->e_type = ET_CORE;
976 elf->e_machine = ELF_ARCH;
977 elf->e_version = EV_CURRENT;
978 elf->e_entry = 0;
979 elf->e_phoff = sizeof(struct elfhdr);
980 elf->e_shoff = 0;
981
982 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
983 elf->e_flags = 2;
984 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
985 elf->e_flags = 1;
986 else
987 elf->e_flags = 0;
988
989 elf->e_ehsize = sizeof(struct elfhdr);
990 elf->e_phentsize = sizeof(struct elf_phdr);
991 elf->e_phnum = 0;
992 elf->e_shentsize = 0;
993 elf->e_shnum = 0;
994 elf->e_shstrndx = 0;
995
996 return 0;
997}
998
999/*
1000 * Traverse through memblock structure and setup crash memory ranges. These
1001 * ranges will be used create PT_LOAD program headers in elfcore header.
1002 */
1003static int fadump_setup_crash_memory_ranges(void)
1004{
1005 u64 i, start, end;
1006 int ret;
1007
1008 pr_debug("Setup crash memory ranges.\n");
1009 crash_mrange_info.mem_range_cnt = 0;
1010
1011 /*
1012 * Boot memory region(s) registered with firmware are moved to
1013 * different location at the time of crash. Create separate program
1014 * header(s) for this memory chunk(s) with the correct offset.
1015 */
1016 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1017 start = fw_dump.boot_mem_addr[i];
1018 end = start + fw_dump.boot_mem_sz[i];
1019 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1020 if (ret)
1021 return ret;
1022 }
1023
1024 for_each_mem_range(i, &start, &end) {
1025 /*
1026 * skip the memory chunk that is already added
1027 * (0 through boot_memory_top).
1028 */
1029 if (start < fw_dump.boot_mem_top) {
1030 if (end > fw_dump.boot_mem_top)
1031 start = fw_dump.boot_mem_top;
1032 else
1033 continue;
1034 }
1035
1036 /* add this range excluding the reserved dump area. */
1037 ret = fadump_exclude_reserved_area(start, end);
1038 if (ret)
1039 return ret;
1040 }
1041
1042 return 0;
1043}
1044
1045/*
1046 * If the given physical address falls within the boot memory region then
1047 * return the relocated address that points to the dump region reserved
1048 * for saving initial boot memory contents.
1049 */
1050static inline unsigned long fadump_relocate(unsigned long paddr)
1051{
1052 unsigned long raddr, rstart, rend, rlast, hole_size;
1053 int i;
1054
1055 hole_size = 0;
1056 rlast = 0;
1057 raddr = paddr;
1058 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1059 rstart = fw_dump.boot_mem_addr[i];
1060 rend = rstart + fw_dump.boot_mem_sz[i];
1061 hole_size += (rstart - rlast);
1062
1063 if (paddr >= rstart && paddr < rend) {
1064 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1065 break;
1066 }
1067
1068 rlast = rend;
1069 }
1070
1071 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1072 return raddr;
1073}
1074
1075static int fadump_create_elfcore_headers(char *bufp)
1076{
1077 unsigned long long raddr, offset;
1078 struct elf_phdr *phdr;
1079 struct elfhdr *elf;
1080 int i, j;
1081
1082 fadump_init_elfcore_header(bufp);
1083 elf = (struct elfhdr *)bufp;
1084 bufp += sizeof(struct elfhdr);
1085
1086 /*
1087 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1088 * will be populated during second kernel boot after crash. Hence
1089 * this PT_NOTE will always be the first elf note.
1090 *
1091 * NOTE: Any new ELF note addition should be placed after this note.
1092 */
1093 phdr = (struct elf_phdr *)bufp;
1094 bufp += sizeof(struct elf_phdr);
1095 phdr->p_type = PT_NOTE;
1096 phdr->p_flags = 0;
1097 phdr->p_vaddr = 0;
1098 phdr->p_align = 0;
1099
1100 phdr->p_offset = 0;
1101 phdr->p_paddr = 0;
1102 phdr->p_filesz = 0;
1103 phdr->p_memsz = 0;
1104
1105 (elf->e_phnum)++;
1106
1107 /* setup ELF PT_NOTE for vmcoreinfo */
1108 phdr = (struct elf_phdr *)bufp;
1109 bufp += sizeof(struct elf_phdr);
1110 phdr->p_type = PT_NOTE;
1111 phdr->p_flags = 0;
1112 phdr->p_vaddr = 0;
1113 phdr->p_align = 0;
1114
1115 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1116 phdr->p_offset = phdr->p_paddr;
1117 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1118
1119 /* Increment number of program headers. */
1120 (elf->e_phnum)++;
1121
1122 /* setup PT_LOAD sections. */
1123 j = 0;
1124 offset = 0;
1125 raddr = fw_dump.boot_mem_addr[0];
1126 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1127 u64 mbase, msize;
1128
1129 mbase = crash_mrange_info.mem_ranges[i].base;
1130 msize = crash_mrange_info.mem_ranges[i].size;
1131 if (!msize)
1132 continue;
1133
1134 phdr = (struct elf_phdr *)bufp;
1135 bufp += sizeof(struct elf_phdr);
1136 phdr->p_type = PT_LOAD;
1137 phdr->p_flags = PF_R|PF_W|PF_X;
1138 phdr->p_offset = mbase;
1139
1140 if (mbase == raddr) {
1141 /*
1142 * The entire real memory region will be moved by
1143 * firmware to the specified destination_address.
1144 * Hence set the correct offset.
1145 */
1146 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1147 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1148 offset += fw_dump.boot_mem_sz[j];
1149 raddr = fw_dump.boot_mem_addr[++j];
1150 }
1151 }
1152
1153 phdr->p_paddr = mbase;
1154 phdr->p_vaddr = (unsigned long)__va(mbase);
1155 phdr->p_filesz = msize;
1156 phdr->p_memsz = msize;
1157 phdr->p_align = 0;
1158
1159 /* Increment number of program headers. */
1160 (elf->e_phnum)++;
1161 }
1162 return 0;
1163}
1164
1165static unsigned long init_fadump_header(unsigned long addr)
1166{
1167 struct fadump_crash_info_header *fdh;
1168
1169 if (!addr)
1170 return 0;
1171
1172 fdh = __va(addr);
1173 addr += sizeof(struct fadump_crash_info_header);
1174
1175 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1176 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1177 fdh->elfcorehdr_addr = addr;
1178 /* We will set the crashing cpu id in crash_fadump() during crash. */
1179 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1180 /*
1181 * When LPAR is terminated by PYHP, ensure all possible CPUs'
1182 * register data is processed while exporting the vmcore.
1183 */
1184 fdh->cpu_mask = *cpu_possible_mask;
1185
1186 return addr;
1187}
1188
1189static int register_fadump(void)
1190{
1191 unsigned long addr;
1192 void *vaddr;
1193 int ret;
1194
1195 /*
1196 * If no memory is reserved then we can not register for firmware-
1197 * assisted dump.
1198 */
1199 if (!fw_dump.reserve_dump_area_size)
1200 return -ENODEV;
1201
1202 ret = fadump_setup_crash_memory_ranges();
1203 if (ret)
1204 return ret;
1205
1206 addr = fw_dump.fadumphdr_addr;
1207
1208 /* Initialize fadump crash info header. */
1209 addr = init_fadump_header(addr);
1210 vaddr = __va(addr);
1211
1212 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1213 fadump_create_elfcore_headers(vaddr);
1214
1215 /* register the future kernel dump with firmware. */
1216 pr_debug("Registering for firmware-assisted kernel dump...\n");
1217 return fw_dump.ops->fadump_register(&fw_dump);
1218}
1219
1220void fadump_cleanup(void)
1221{
1222 if (!fw_dump.fadump_supported)
1223 return;
1224
1225 /* Invalidate the registration only if dump is active. */
1226 if (fw_dump.dump_active) {
1227 pr_debug("Invalidating firmware-assisted dump registration\n");
1228 fw_dump.ops->fadump_invalidate(&fw_dump);
1229 } else if (fw_dump.dump_registered) {
1230 /* Un-register Firmware-assisted dump if it was registered. */
1231 fw_dump.ops->fadump_unregister(&fw_dump);
1232 fadump_free_mem_ranges(&crash_mrange_info);
1233 }
1234
1235 if (fw_dump.ops->fadump_cleanup)
1236 fw_dump.ops->fadump_cleanup(&fw_dump);
1237}
1238
1239static void fadump_free_reserved_memory(unsigned long start_pfn,
1240 unsigned long end_pfn)
1241{
1242 unsigned long pfn;
1243 unsigned long time_limit = jiffies + HZ;
1244
1245 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1246 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1247
1248 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1249 free_reserved_page(pfn_to_page(pfn));
1250
1251 if (time_after(jiffies, time_limit)) {
1252 cond_resched();
1253 time_limit = jiffies + HZ;
1254 }
1255 }
1256}
1257
1258/*
1259 * Skip memory holes and free memory that was actually reserved.
1260 */
1261static void fadump_release_reserved_area(u64 start, u64 end)
1262{
1263 unsigned long reg_spfn, reg_epfn;
1264 u64 tstart, tend, spfn, epfn;
1265 int i;
1266
1267 spfn = PHYS_PFN(start);
1268 epfn = PHYS_PFN(end);
1269
1270 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) {
1271 tstart = max_t(u64, spfn, reg_spfn);
1272 tend = min_t(u64, epfn, reg_epfn);
1273
1274 if (tstart < tend) {
1275 fadump_free_reserved_memory(tstart, tend);
1276
1277 if (tend == epfn)
1278 break;
1279
1280 spfn = tend;
1281 }
1282 }
1283}
1284
1285/*
1286 * Sort the mem ranges in-place and merge adjacent ranges
1287 * to minimize the memory ranges count.
1288 */
1289static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1290{
1291 struct fadump_memory_range *mem_ranges;
1292 u64 base, size;
1293 int i, j, idx;
1294
1295 if (!reserved_mrange_info.mem_range_cnt)
1296 return;
1297
1298 /* Sort the memory ranges */
1299 mem_ranges = mrange_info->mem_ranges;
1300 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1301 idx = i;
1302 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1303 if (mem_ranges[idx].base > mem_ranges[j].base)
1304 idx = j;
1305 }
1306 if (idx != i)
1307 swap(mem_ranges[idx], mem_ranges[i]);
1308 }
1309
1310 /* Merge adjacent reserved ranges */
1311 idx = 0;
1312 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1313 base = mem_ranges[i-1].base;
1314 size = mem_ranges[i-1].size;
1315 if (mem_ranges[i].base == (base + size))
1316 mem_ranges[idx].size += mem_ranges[i].size;
1317 else {
1318 idx++;
1319 if (i == idx)
1320 continue;
1321
1322 mem_ranges[idx] = mem_ranges[i];
1323 }
1324 }
1325 mrange_info->mem_range_cnt = idx + 1;
1326}
1327
1328/*
1329 * Scan reserved-ranges to consider them while reserving/releasing
1330 * memory for FADump.
1331 */
1332static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1333{
1334 const __be32 *prop;
1335 int len, ret = -1;
1336 unsigned long i;
1337
1338 /* reserved-ranges already scanned */
1339 if (reserved_mrange_info.mem_range_cnt != 0)
1340 return;
1341
1342 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1343 if (!prop)
1344 return;
1345
1346 /*
1347 * Each reserved range is an (address,size) pair, 2 cells each,
1348 * totalling 4 cells per range.
1349 */
1350 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1351 u64 base, size;
1352
1353 base = of_read_number(prop + (i * 4) + 0, 2);
1354 size = of_read_number(prop + (i * 4) + 2, 2);
1355
1356 if (size) {
1357 ret = fadump_add_mem_range(&reserved_mrange_info,
1358 base, base + size);
1359 if (ret < 0) {
1360 pr_warn("some reserved ranges are ignored!\n");
1361 break;
1362 }
1363 }
1364 }
1365
1366 /* Compact reserved ranges */
1367 sort_and_merge_mem_ranges(&reserved_mrange_info);
1368}
1369
1370/*
1371 * Release the memory that was reserved during early boot to preserve the
1372 * crash'ed kernel's memory contents except reserved dump area (permanent
1373 * reservation) and reserved ranges used by F/W. The released memory will
1374 * be available for general use.
1375 */
1376static void fadump_release_memory(u64 begin, u64 end)
1377{
1378 u64 ra_start, ra_end, tstart;
1379 int i, ret;
1380
1381 ra_start = fw_dump.reserve_dump_area_start;
1382 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1383
1384 /*
1385 * If reserved ranges array limit is hit, overwrite the last reserved
1386 * memory range with reserved dump area to ensure it is excluded from
1387 * the memory being released (reused for next FADump registration).
1388 */
1389 if (reserved_mrange_info.mem_range_cnt ==
1390 reserved_mrange_info.max_mem_ranges)
1391 reserved_mrange_info.mem_range_cnt--;
1392
1393 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1394 if (ret != 0)
1395 return;
1396
1397 /* Get the reserved ranges list in order first. */
1398 sort_and_merge_mem_ranges(&reserved_mrange_info);
1399
1400 /* Exclude reserved ranges and release remaining memory */
1401 tstart = begin;
1402 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1403 ra_start = reserved_mrange_info.mem_ranges[i].base;
1404 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1405
1406 if (tstart >= ra_end)
1407 continue;
1408
1409 if (tstart < ra_start)
1410 fadump_release_reserved_area(tstart, ra_start);
1411 tstart = ra_end;
1412 }
1413
1414 if (tstart < end)
1415 fadump_release_reserved_area(tstart, end);
1416}
1417
1418static void fadump_invalidate_release_mem(void)
1419{
1420 mutex_lock(&fadump_mutex);
1421 if (!fw_dump.dump_active) {
1422 mutex_unlock(&fadump_mutex);
1423 return;
1424 }
1425
1426 fadump_cleanup();
1427 mutex_unlock(&fadump_mutex);
1428
1429 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1430 fadump_free_cpu_notes_buf();
1431
1432 /*
1433 * Setup kernel metadata and initialize the kernel dump
1434 * memory structure for FADump re-registration.
1435 */
1436 if (fw_dump.ops->fadump_setup_metadata &&
1437 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1438 pr_warn("Failed to setup kernel metadata!\n");
1439 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1440}
1441
1442static ssize_t release_mem_store(struct kobject *kobj,
1443 struct kobj_attribute *attr,
1444 const char *buf, size_t count)
1445{
1446 int input = -1;
1447
1448 if (!fw_dump.dump_active)
1449 return -EPERM;
1450
1451 if (kstrtoint(buf, 0, &input))
1452 return -EINVAL;
1453
1454 if (input == 1) {
1455 /*
1456 * Take away the '/proc/vmcore'. We are releasing the dump
1457 * memory, hence it will not be valid anymore.
1458 */
1459#ifdef CONFIG_PROC_VMCORE
1460 vmcore_cleanup();
1461#endif
1462 fadump_invalidate_release_mem();
1463
1464 } else
1465 return -EINVAL;
1466 return count;
1467}
1468
1469/* Release the reserved memory and disable the FADump */
1470static void __init unregister_fadump(void)
1471{
1472 fadump_cleanup();
1473 fadump_release_memory(fw_dump.reserve_dump_area_start,
1474 fw_dump.reserve_dump_area_size);
1475 fw_dump.fadump_enabled = 0;
1476 kobject_put(fadump_kobj);
1477}
1478
1479static ssize_t enabled_show(struct kobject *kobj,
1480 struct kobj_attribute *attr,
1481 char *buf)
1482{
1483 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1484}
1485
1486static ssize_t mem_reserved_show(struct kobject *kobj,
1487 struct kobj_attribute *attr,
1488 char *buf)
1489{
1490 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1491}
1492
1493static ssize_t registered_show(struct kobject *kobj,
1494 struct kobj_attribute *attr,
1495 char *buf)
1496{
1497 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1498}
1499
1500static ssize_t registered_store(struct kobject *kobj,
1501 struct kobj_attribute *attr,
1502 const char *buf, size_t count)
1503{
1504 int ret = 0;
1505 int input = -1;
1506
1507 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1508 return -EPERM;
1509
1510 if (kstrtoint(buf, 0, &input))
1511 return -EINVAL;
1512
1513 mutex_lock(&fadump_mutex);
1514
1515 switch (input) {
1516 case 0:
1517 if (fw_dump.dump_registered == 0) {
1518 goto unlock_out;
1519 }
1520
1521 /* Un-register Firmware-assisted dump */
1522 pr_debug("Un-register firmware-assisted dump\n");
1523 fw_dump.ops->fadump_unregister(&fw_dump);
1524 break;
1525 case 1:
1526 if (fw_dump.dump_registered == 1) {
1527 /* Un-register Firmware-assisted dump */
1528 fw_dump.ops->fadump_unregister(&fw_dump);
1529 }
1530 /* Register Firmware-assisted dump */
1531 ret = register_fadump();
1532 break;
1533 default:
1534 ret = -EINVAL;
1535 break;
1536 }
1537
1538unlock_out:
1539 mutex_unlock(&fadump_mutex);
1540 return ret < 0 ? ret : count;
1541}
1542
1543static int fadump_region_show(struct seq_file *m, void *private)
1544{
1545 if (!fw_dump.fadump_enabled)
1546 return 0;
1547
1548 mutex_lock(&fadump_mutex);
1549 fw_dump.ops->fadump_region_show(&fw_dump, m);
1550 mutex_unlock(&fadump_mutex);
1551 return 0;
1552}
1553
1554static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1555static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1556static struct kobj_attribute register_attr = __ATTR_RW(registered);
1557static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1558
1559static struct attribute *fadump_attrs[] = {
1560 &enable_attr.attr,
1561 ®ister_attr.attr,
1562 &mem_reserved_attr.attr,
1563 NULL,
1564};
1565
1566ATTRIBUTE_GROUPS(fadump);
1567
1568DEFINE_SHOW_ATTRIBUTE(fadump_region);
1569
1570static void __init fadump_init_files(void)
1571{
1572 int rc = 0;
1573
1574 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1575 if (!fadump_kobj) {
1576 pr_err("failed to create fadump kobject\n");
1577 return;
1578 }
1579
1580 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
1581 &fadump_region_fops);
1582
1583 if (fw_dump.dump_active) {
1584 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1585 if (rc)
1586 pr_err("unable to create release_mem sysfs file (%d)\n",
1587 rc);
1588 }
1589
1590 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1591 if (rc) {
1592 pr_err("sysfs group creation failed (%d), unregistering FADump",
1593 rc);
1594 unregister_fadump();
1595 return;
1596 }
1597
1598 /*
1599 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1600 * create symlink at old location to maintain backward compatibility.
1601 *
1602 * - fadump_enabled -> fadump/enabled
1603 * - fadump_registered -> fadump/registered
1604 * - fadump_release_mem -> fadump/release_mem
1605 */
1606 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1607 "enabled", "fadump_enabled");
1608 if (rc) {
1609 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1610 return;
1611 }
1612
1613 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1614 "registered",
1615 "fadump_registered");
1616 if (rc) {
1617 pr_err("unable to create fadump_registered symlink (%d)", rc);
1618 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1619 return;
1620 }
1621
1622 if (fw_dump.dump_active) {
1623 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1624 fadump_kobj,
1625 "release_mem",
1626 "fadump_release_mem");
1627 if (rc)
1628 pr_err("unable to create fadump_release_mem symlink (%d)",
1629 rc);
1630 }
1631 return;
1632}
1633
1634/*
1635 * Prepare for firmware-assisted dump.
1636 */
1637int __init setup_fadump(void)
1638{
1639 if (!fw_dump.fadump_supported)
1640 return 0;
1641
1642 fadump_init_files();
1643 fadump_show_config();
1644
1645 if (!fw_dump.fadump_enabled)
1646 return 1;
1647
1648 /*
1649 * If dump data is available then see if it is valid and prepare for
1650 * saving it to the disk.
1651 */
1652 if (fw_dump.dump_active) {
1653 /*
1654 * if dump process fails then invalidate the registration
1655 * and release memory before proceeding for re-registration.
1656 */
1657 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1658 fadump_invalidate_release_mem();
1659 }
1660 /* Initialize the kernel dump memory structure and register with f/w */
1661 else if (fw_dump.reserve_dump_area_size) {
1662 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1663 register_fadump();
1664 }
1665
1666 /*
1667 * In case of panic, fadump is triggered via ppc_panic_event()
1668 * panic notifier. Setting crash_kexec_post_notifiers to 'true'
1669 * lets panic() function take crash friendly path before panic
1670 * notifiers are invoked.
1671 */
1672 crash_kexec_post_notifiers = true;
1673
1674 return 1;
1675}
1676/*
1677 * Use subsys_initcall_sync() here because there is dependency with
1678 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
1679 * is done before registering with f/w.
1680 */
1681subsys_initcall_sync(setup_fadump);
1682#else /* !CONFIG_PRESERVE_FA_DUMP */
1683
1684/* Scan the Firmware Assisted dump configuration details. */
1685int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1686 int depth, void *data)
1687{
1688 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1689 return 0;
1690
1691 opal_fadump_dt_scan(&fw_dump, node);
1692 return 1;
1693}
1694
1695/*
1696 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1697 * preserve crash data. The subsequent memory preserving kernel boot
1698 * is likely to process this crash data.
1699 */
1700int __init fadump_reserve_mem(void)
1701{
1702 if (fw_dump.dump_active) {
1703 /*
1704 * If last boot has crashed then reserve all the memory
1705 * above boot memory to preserve crash data.
1706 */
1707 pr_info("Preserving crash data for processing in next boot.\n");
1708 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1709 } else
1710 pr_debug("FADump-aware kernel..\n");
1711
1712 return 1;
1713}
1714#endif /* CONFIG_PRESERVE_FA_DUMP */
1715
1716/* Preserve everything above the base address */
1717static void __init fadump_reserve_crash_area(u64 base)
1718{
1719 u64 i, mstart, mend, msize;
1720
1721 for_each_mem_range(i, &mstart, &mend) {
1722 msize = mend - mstart;
1723
1724 if ((mstart + msize) < base)
1725 continue;
1726
1727 if (mstart < base) {
1728 msize -= (base - mstart);
1729 mstart = base;
1730 }
1731
1732 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1733 (msize >> 20), mstart);
1734 memblock_reserve(mstart, msize);
1735 }
1736}
1737
1738unsigned long __init arch_reserved_kernel_pages(void)
1739{
1740 return memblock_reserved_size() / PAGE_SIZE;
1741}