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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
4 * dump with assistance from firmware. This approach does not use kexec,
5 * instead firmware assists in booting the kdump kernel while preserving
6 * memory contents. The most of the code implementation has been adapted
7 * from phyp assisted dump implementation written by Linas Vepstas and
8 * Manish Ahuja
9 *
10 * Copyright 2011 IBM Corporation
11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
12 */
13
14#undef DEBUG
15#define pr_fmt(fmt) "fadump: " fmt
16
17#include <linux/string.h>
18#include <linux/memblock.h>
19#include <linux/delay.h>
20#include <linux/seq_file.h>
21#include <linux/crash_dump.h>
22#include <linux/kobject.h>
23#include <linux/sysfs.h>
24#include <linux/slab.h>
25#include <linux/cma.h>
26#include <linux/hugetlb.h>
27#include <linux/debugfs.h>
28#include <linux/of.h>
29#include <linux/of_fdt.h>
30
31#include <asm/page.h>
32#include <asm/fadump.h>
33#include <asm/fadump-internal.h>
34#include <asm/setup.h>
35#include <asm/interrupt.h>
36
37/*
38 * The CPU who acquired the lock to trigger the fadump crash should
39 * wait for other CPUs to enter.
40 *
41 * The timeout is in milliseconds.
42 */
43#define CRASH_TIMEOUT 500
44
45static struct fw_dump fw_dump;
46
47static void __init fadump_reserve_crash_area(u64 base);
48
49#ifndef CONFIG_PRESERVE_FA_DUMP
50
51static struct kobject *fadump_kobj;
52
53static atomic_t cpus_in_fadump;
54static DEFINE_MUTEX(fadump_mutex);
55
56static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false };
57
58#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */
59#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \
60 sizeof(struct fadump_memory_range))
61static struct fadump_memory_range rngs[RESERVED_RNGS_CNT];
62static struct fadump_mrange_info
63reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true };
64
65static void __init early_init_dt_scan_reserved_ranges(unsigned long node);
66
67#ifdef CONFIG_CMA
68static struct cma *fadump_cma;
69
70/*
71 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory
72 *
73 * This function initializes CMA area from fadump reserved memory.
74 * The total size of fadump reserved memory covers for boot memory size
75 * + cpu data size + hpte size and metadata.
76 * Initialize only the area equivalent to boot memory size for CMA use.
77 * The remaining portion of fadump reserved memory will be not given
78 * to CMA and pages for those will stay reserved. boot memory size is
79 * aligned per CMA requirement to satisy cma_init_reserved_mem() call.
80 * But for some reason even if it fails we still have the memory reservation
81 * with us and we can still continue doing fadump.
82 */
83static int __init fadump_cma_init(void)
84{
85 unsigned long long base, size;
86 int rc;
87
88 if (!fw_dump.fadump_enabled)
89 return 0;
90
91 /*
92 * Do not use CMA if user has provided fadump=nocma kernel parameter.
93 * Return 1 to continue with fadump old behaviour.
94 */
95 if (fw_dump.nocma)
96 return 1;
97
98 base = fw_dump.reserve_dump_area_start;
99 size = fw_dump.boot_memory_size;
100
101 if (!size)
102 return 0;
103
104 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma);
105 if (rc) {
106 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc);
107 /*
108 * Though the CMA init has failed we still have memory
109 * reservation with us. The reserved memory will be
110 * blocked from production system usage. Hence return 1,
111 * so that we can continue with fadump.
112 */
113 return 1;
114 }
115
116 /*
117 * If CMA activation fails, keep the pages reserved, instead of
118 * exposing them to buddy allocator. Same as 'fadump=nocma' case.
119 */
120 cma_reserve_pages_on_error(fadump_cma);
121
122 /*
123 * So we now have successfully initialized cma area for fadump.
124 */
125 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx "
126 "bytes of memory reserved for firmware-assisted dump\n",
127 cma_get_size(fadump_cma),
128 (unsigned long)cma_get_base(fadump_cma) >> 20,
129 fw_dump.reserve_dump_area_size);
130 return 1;
131}
132#else
133static int __init fadump_cma_init(void) { return 1; }
134#endif /* CONFIG_CMA */
135
136/* Scan the Firmware Assisted dump configuration details. */
137int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
138 int depth, void *data)
139{
140 if (depth == 0) {
141 early_init_dt_scan_reserved_ranges(node);
142 return 0;
143 }
144
145 if (depth != 1)
146 return 0;
147
148 if (strcmp(uname, "rtas") == 0) {
149 rtas_fadump_dt_scan(&fw_dump, node);
150 return 1;
151 }
152
153 if (strcmp(uname, "ibm,opal") == 0) {
154 opal_fadump_dt_scan(&fw_dump, node);
155 return 1;
156 }
157
158 return 0;
159}
160
161/*
162 * If fadump is registered, check if the memory provided
163 * falls within boot memory area and reserved memory area.
164 */
165int is_fadump_memory_area(u64 addr, unsigned long size)
166{
167 u64 d_start, d_end;
168
169 if (!fw_dump.dump_registered)
170 return 0;
171
172 if (!size)
173 return 0;
174
175 d_start = fw_dump.reserve_dump_area_start;
176 d_end = d_start + fw_dump.reserve_dump_area_size;
177 if (((addr + size) > d_start) && (addr <= d_end))
178 return 1;
179
180 return (addr <= fw_dump.boot_mem_top);
181}
182
183int should_fadump_crash(void)
184{
185 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
186 return 0;
187 return 1;
188}
189
190int is_fadump_active(void)
191{
192 return fw_dump.dump_active;
193}
194
195/*
196 * Returns true, if there are no holes in memory area between d_start to d_end,
197 * false otherwise.
198 */
199static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end)
200{
201 phys_addr_t reg_start, reg_end;
202 bool ret = false;
203 u64 i, start, end;
204
205 for_each_mem_range(i, ®_start, ®_end) {
206 start = max_t(u64, d_start, reg_start);
207 end = min_t(u64, d_end, reg_end);
208 if (d_start < end) {
209 /* Memory hole from d_start to start */
210 if (start > d_start)
211 break;
212
213 if (end == d_end) {
214 ret = true;
215 break;
216 }
217
218 d_start = end + 1;
219 }
220 }
221
222 return ret;
223}
224
225/*
226 * Returns true, if there are no holes in boot memory area,
227 * false otherwise.
228 */
229bool is_fadump_boot_mem_contiguous(void)
230{
231 unsigned long d_start, d_end;
232 bool ret = false;
233 int i;
234
235 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
236 d_start = fw_dump.boot_mem_addr[i];
237 d_end = d_start + fw_dump.boot_mem_sz[i];
238
239 ret = is_fadump_mem_area_contiguous(d_start, d_end);
240 if (!ret)
241 break;
242 }
243
244 return ret;
245}
246
247/*
248 * Returns true, if there are no holes in reserved memory area,
249 * false otherwise.
250 */
251bool is_fadump_reserved_mem_contiguous(void)
252{
253 u64 d_start, d_end;
254
255 d_start = fw_dump.reserve_dump_area_start;
256 d_end = d_start + fw_dump.reserve_dump_area_size;
257 return is_fadump_mem_area_contiguous(d_start, d_end);
258}
259
260/* Print firmware assisted dump configurations for debugging purpose. */
261static void __init fadump_show_config(void)
262{
263 int i;
264
265 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
266 (fw_dump.fadump_supported ? "present" : "no support"));
267
268 if (!fw_dump.fadump_supported)
269 return;
270
271 pr_debug("Fadump enabled : %s\n",
272 (fw_dump.fadump_enabled ? "yes" : "no"));
273 pr_debug("Dump Active : %s\n",
274 (fw_dump.dump_active ? "yes" : "no"));
275 pr_debug("Dump section sizes:\n");
276 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
277 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
278 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size);
279 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top);
280 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt);
281 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
282 pr_debug("[%03d] base = %llx, size = %llx\n", i,
283 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]);
284 }
285}
286
287/**
288 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
289 *
290 * Function to find the largest memory size we need to reserve during early
291 * boot process. This will be the size of the memory that is required for a
292 * kernel to boot successfully.
293 *
294 * This function has been taken from phyp-assisted dump feature implementation.
295 *
296 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
297 *
298 * TODO: Come up with better approach to find out more accurate memory size
299 * that is required for a kernel to boot successfully.
300 *
301 */
302static __init u64 fadump_calculate_reserve_size(void)
303{
304 u64 base, size, bootmem_min;
305 int ret;
306
307 if (fw_dump.reserve_bootvar)
308 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
309
310 /*
311 * Check if the size is specified through crashkernel= cmdline
312 * option. If yes, then use that but ignore base as fadump reserves
313 * memory at a predefined offset.
314 */
315 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
316 &size, &base, NULL, NULL);
317 if (ret == 0 && size > 0) {
318 unsigned long max_size;
319
320 if (fw_dump.reserve_bootvar)
321 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
322
323 fw_dump.reserve_bootvar = (unsigned long)size;
324
325 /*
326 * Adjust if the boot memory size specified is above
327 * the upper limit.
328 */
329 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
330 if (fw_dump.reserve_bootvar > max_size) {
331 fw_dump.reserve_bootvar = max_size;
332 pr_info("Adjusted boot memory size to %luMB\n",
333 (fw_dump.reserve_bootvar >> 20));
334 }
335
336 return fw_dump.reserve_bootvar;
337 } else if (fw_dump.reserve_bootvar) {
338 /*
339 * 'fadump_reserve_mem=' is being used to reserve memory
340 * for firmware-assisted dump.
341 */
342 return fw_dump.reserve_bootvar;
343 }
344
345 /* divide by 20 to get 5% of value */
346 size = memblock_phys_mem_size() / 20;
347
348 /* round it down in multiples of 256 */
349 size = size & ~0x0FFFFFFFUL;
350
351 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
352 if (memory_limit && size > memory_limit)
353 size = memory_limit;
354
355 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
356 return (size > bootmem_min ? size : bootmem_min);
357}
358
359/*
360 * Calculate the total memory size required to be reserved for
361 * firmware-assisted dump registration.
362 */
363static unsigned long __init get_fadump_area_size(void)
364{
365 unsigned long size = 0;
366
367 size += fw_dump.cpu_state_data_size;
368 size += fw_dump.hpte_region_size;
369 /*
370 * Account for pagesize alignment of boot memory area destination address.
371 * This faciliates in mmap reading of first kernel's memory.
372 */
373 size = PAGE_ALIGN(size);
374 size += fw_dump.boot_memory_size;
375 size += sizeof(struct fadump_crash_info_header);
376 size += sizeof(struct elfhdr); /* ELF core header.*/
377 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
378 /* Program headers for crash memory regions. */
379 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
380
381 size = PAGE_ALIGN(size);
382
383 /* This is to hold kernel metadata on platforms that support it */
384 size += (fw_dump.ops->fadump_get_metadata_size ?
385 fw_dump.ops->fadump_get_metadata_size() : 0);
386 return size;
387}
388
389static int __init add_boot_mem_region(unsigned long rstart,
390 unsigned long rsize)
391{
392 int i = fw_dump.boot_mem_regs_cnt++;
393
394 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) {
395 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS;
396 return 0;
397 }
398
399 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n",
400 i, rstart, (rstart + rsize));
401 fw_dump.boot_mem_addr[i] = rstart;
402 fw_dump.boot_mem_sz[i] = rsize;
403 return 1;
404}
405
406/*
407 * Firmware usually has a hard limit on the data it can copy per region.
408 * Honour that by splitting a memory range into multiple regions.
409 */
410static int __init add_boot_mem_regions(unsigned long mstart,
411 unsigned long msize)
412{
413 unsigned long rstart, rsize, max_size;
414 int ret = 1;
415
416 rstart = mstart;
417 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize;
418 while (msize) {
419 if (msize > max_size)
420 rsize = max_size;
421 else
422 rsize = msize;
423
424 ret = add_boot_mem_region(rstart, rsize);
425 if (!ret)
426 break;
427
428 msize -= rsize;
429 rstart += rsize;
430 }
431
432 return ret;
433}
434
435static int __init fadump_get_boot_mem_regions(void)
436{
437 unsigned long size, cur_size, hole_size, last_end;
438 unsigned long mem_size = fw_dump.boot_memory_size;
439 phys_addr_t reg_start, reg_end;
440 int ret = 1;
441 u64 i;
442
443 fw_dump.boot_mem_regs_cnt = 0;
444
445 last_end = 0;
446 hole_size = 0;
447 cur_size = 0;
448 for_each_mem_range(i, ®_start, ®_end) {
449 size = reg_end - reg_start;
450 hole_size += (reg_start - last_end);
451
452 if ((cur_size + size) >= mem_size) {
453 size = (mem_size - cur_size);
454 ret = add_boot_mem_regions(reg_start, size);
455 break;
456 }
457
458 mem_size -= size;
459 cur_size += size;
460 ret = add_boot_mem_regions(reg_start, size);
461 if (!ret)
462 break;
463
464 last_end = reg_end;
465 }
466 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size);
467
468 return ret;
469}
470
471/*
472 * Returns true, if the given range overlaps with reserved memory ranges
473 * starting at idx. Also, updates idx to index of overlapping memory range
474 * with the given memory range.
475 * False, otherwise.
476 */
477static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx)
478{
479 bool ret = false;
480 int i;
481
482 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) {
483 u64 rbase = reserved_mrange_info.mem_ranges[i].base;
484 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size;
485
486 if (end <= rbase)
487 break;
488
489 if ((end > rbase) && (base < rend)) {
490 *idx = i;
491 ret = true;
492 break;
493 }
494 }
495
496 return ret;
497}
498
499/*
500 * Locate a suitable memory area to reserve memory for FADump. While at it,
501 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W.
502 */
503static u64 __init fadump_locate_reserve_mem(u64 base, u64 size)
504{
505 struct fadump_memory_range *mrngs;
506 phys_addr_t mstart, mend;
507 int idx = 0;
508 u64 i, ret = 0;
509
510 mrngs = reserved_mrange_info.mem_ranges;
511 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE,
512 &mstart, &mend, NULL) {
513 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n",
514 i, mstart, mend, base);
515
516 if (mstart > base)
517 base = PAGE_ALIGN(mstart);
518
519 while ((mend > base) && ((mend - base) >= size)) {
520 if (!overlaps_reserved_ranges(base, base+size, &idx)) {
521 ret = base;
522 goto out;
523 }
524
525 base = mrngs[idx].base + mrngs[idx].size;
526 base = PAGE_ALIGN(base);
527 }
528 }
529
530out:
531 return ret;
532}
533
534int __init fadump_reserve_mem(void)
535{
536 u64 base, size, mem_boundary, bootmem_min;
537 int ret = 1;
538
539 if (!fw_dump.fadump_enabled)
540 return 0;
541
542 if (!fw_dump.fadump_supported) {
543 pr_info("Firmware-Assisted Dump is not supported on this hardware\n");
544 goto error_out;
545 }
546
547 /*
548 * Initialize boot memory size
549 * If dump is active then we have already calculated the size during
550 * first kernel.
551 */
552 if (!fw_dump.dump_active) {
553 fw_dump.boot_memory_size =
554 PAGE_ALIGN(fadump_calculate_reserve_size());
555#ifdef CONFIG_CMA
556 if (!fw_dump.nocma) {
557 fw_dump.boot_memory_size =
558 ALIGN(fw_dump.boot_memory_size,
559 CMA_MIN_ALIGNMENT_BYTES);
560 }
561#endif
562
563 bootmem_min = fw_dump.ops->fadump_get_bootmem_min();
564 if (fw_dump.boot_memory_size < bootmem_min) {
565 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n",
566 fw_dump.boot_memory_size, bootmem_min);
567 goto error_out;
568 }
569
570 if (!fadump_get_boot_mem_regions()) {
571 pr_err("Too many holes in boot memory area to enable fadump\n");
572 goto error_out;
573 }
574 }
575
576 /*
577 * Calculate the memory boundary.
578 * If memory_limit is less than actual memory boundary then reserve
579 * the memory for fadump beyond the memory_limit and adjust the
580 * memory_limit accordingly, so that the running kernel can run with
581 * specified memory_limit.
582 */
583 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
584 size = get_fadump_area_size();
585 if ((memory_limit + size) < memblock_end_of_DRAM())
586 memory_limit += size;
587 else
588 memory_limit = memblock_end_of_DRAM();
589 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
590 " dump, now %#016llx\n", memory_limit);
591 }
592 if (memory_limit)
593 mem_boundary = memory_limit;
594 else
595 mem_boundary = memblock_end_of_DRAM();
596
597 base = fw_dump.boot_mem_top;
598 size = get_fadump_area_size();
599 fw_dump.reserve_dump_area_size = size;
600 if (fw_dump.dump_active) {
601 pr_info("Firmware-assisted dump is active.\n");
602
603#ifdef CONFIG_HUGETLB_PAGE
604 /*
605 * FADump capture kernel doesn't care much about hugepages.
606 * In fact, handling hugepages in capture kernel is asking for
607 * trouble. So, disable HugeTLB support when fadump is active.
608 */
609 hugetlb_disabled = true;
610#endif
611 /*
612 * If last boot has crashed then reserve all the memory
613 * above boot memory size so that we don't touch it until
614 * dump is written to disk by userspace tool. This memory
615 * can be released for general use by invalidating fadump.
616 */
617 fadump_reserve_crash_area(base);
618
619 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr);
620 pr_debug("Reserve dump area start address: 0x%lx\n",
621 fw_dump.reserve_dump_area_start);
622 } else {
623 /*
624 * Reserve memory at an offset closer to bottom of the RAM to
625 * minimize the impact of memory hot-remove operation.
626 */
627 base = fadump_locate_reserve_mem(base, size);
628
629 if (!base || (base + size > mem_boundary)) {
630 pr_err("Failed to find memory chunk for reservation!\n");
631 goto error_out;
632 }
633 fw_dump.reserve_dump_area_start = base;
634
635 /*
636 * Calculate the kernel metadata address and register it with
637 * f/w if the platform supports.
638 */
639 if (fw_dump.ops->fadump_setup_metadata &&
640 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
641 goto error_out;
642
643 if (memblock_reserve(base, size)) {
644 pr_err("Failed to reserve memory!\n");
645 goto error_out;
646 }
647
648 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
649 (size >> 20), base, (memblock_phys_mem_size() >> 20));
650
651 ret = fadump_cma_init();
652 }
653
654 return ret;
655error_out:
656 fw_dump.fadump_enabled = 0;
657 fw_dump.reserve_dump_area_size = 0;
658 return 0;
659}
660
661/* Look for fadump= cmdline option. */
662static int __init early_fadump_param(char *p)
663{
664 if (!p)
665 return 1;
666
667 if (strncmp(p, "on", 2) == 0)
668 fw_dump.fadump_enabled = 1;
669 else if (strncmp(p, "off", 3) == 0)
670 fw_dump.fadump_enabled = 0;
671 else if (strncmp(p, "nocma", 5) == 0) {
672 fw_dump.fadump_enabled = 1;
673 fw_dump.nocma = 1;
674 }
675
676 return 0;
677}
678early_param("fadump", early_fadump_param);
679
680/*
681 * Look for fadump_reserve_mem= cmdline option
682 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
683 * the sooner 'crashkernel=' parameter is accustomed to.
684 */
685static int __init early_fadump_reserve_mem(char *p)
686{
687 if (p)
688 fw_dump.reserve_bootvar = memparse(p, &p);
689 return 0;
690}
691early_param("fadump_reserve_mem", early_fadump_reserve_mem);
692
693void crash_fadump(struct pt_regs *regs, const char *str)
694{
695 unsigned int msecs;
696 struct fadump_crash_info_header *fdh = NULL;
697 int old_cpu, this_cpu;
698 /* Do not include first CPU */
699 unsigned int ncpus = num_online_cpus() - 1;
700
701 if (!should_fadump_crash())
702 return;
703
704 /*
705 * old_cpu == -1 means this is the first CPU which has come here,
706 * go ahead and trigger fadump.
707 *
708 * old_cpu != -1 means some other CPU has already on it's way
709 * to trigger fadump, just keep looping here.
710 */
711 this_cpu = smp_processor_id();
712 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
713
714 if (old_cpu != -1) {
715 atomic_inc(&cpus_in_fadump);
716
717 /*
718 * We can't loop here indefinitely. Wait as long as fadump
719 * is in force. If we race with fadump un-registration this
720 * loop will break and then we go down to normal panic path
721 * and reboot. If fadump is in force the first crashing
722 * cpu will definitely trigger fadump.
723 */
724 while (fw_dump.dump_registered)
725 cpu_relax();
726 return;
727 }
728
729 fdh = __va(fw_dump.fadumphdr_addr);
730 fdh->crashing_cpu = crashing_cpu;
731 crash_save_vmcoreinfo();
732
733 if (regs)
734 fdh->regs = *regs;
735 else
736 ppc_save_regs(&fdh->regs);
737
738 fdh->cpu_mask = *cpu_online_mask;
739
740 /*
741 * If we came in via system reset, wait a while for the secondary
742 * CPUs to enter.
743 */
744 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
745 msecs = CRASH_TIMEOUT;
746 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
747 mdelay(1);
748 }
749
750 fw_dump.ops->fadump_trigger(fdh, str);
751}
752
753u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
754{
755 struct elf_prstatus prstatus;
756
757 memset(&prstatus, 0, sizeof(prstatus));
758 /*
759 * FIXME: How do i get PID? Do I really need it?
760 * prstatus.pr_pid = ????
761 */
762 elf_core_copy_regs(&prstatus.pr_reg, regs);
763 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
764 &prstatus, sizeof(prstatus));
765 return buf;
766}
767
768void __init fadump_update_elfcore_header(char *bufp)
769{
770 struct elf_phdr *phdr;
771
772 bufp += sizeof(struct elfhdr);
773
774 /* First note is a place holder for cpu notes info. */
775 phdr = (struct elf_phdr *)bufp;
776
777 if (phdr->p_type == PT_NOTE) {
778 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr);
779 phdr->p_offset = phdr->p_paddr;
780 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
781 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
782 }
783 return;
784}
785
786static void *__init fadump_alloc_buffer(unsigned long size)
787{
788 unsigned long count, i;
789 struct page *page;
790 void *vaddr;
791
792 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
793 if (!vaddr)
794 return NULL;
795
796 count = PAGE_ALIGN(size) / PAGE_SIZE;
797 page = virt_to_page(vaddr);
798 for (i = 0; i < count; i++)
799 mark_page_reserved(page + i);
800 return vaddr;
801}
802
803static void fadump_free_buffer(unsigned long vaddr, unsigned long size)
804{
805 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL);
806}
807
808s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus)
809{
810 /* Allocate buffer to hold cpu crash notes. */
811 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
812 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
813 fw_dump.cpu_notes_buf_vaddr =
814 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size);
815 if (!fw_dump.cpu_notes_buf_vaddr) {
816 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n",
817 fw_dump.cpu_notes_buf_size);
818 return -ENOMEM;
819 }
820
821 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n",
822 fw_dump.cpu_notes_buf_size,
823 fw_dump.cpu_notes_buf_vaddr);
824 return 0;
825}
826
827void fadump_free_cpu_notes_buf(void)
828{
829 if (!fw_dump.cpu_notes_buf_vaddr)
830 return;
831
832 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr,
833 fw_dump.cpu_notes_buf_size);
834 fw_dump.cpu_notes_buf_vaddr = 0;
835 fw_dump.cpu_notes_buf_size = 0;
836}
837
838static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info)
839{
840 if (mrange_info->is_static) {
841 mrange_info->mem_range_cnt = 0;
842 return;
843 }
844
845 kfree(mrange_info->mem_ranges);
846 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0,
847 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ));
848}
849
850/*
851 * Allocate or reallocate mem_ranges array in incremental units
852 * of PAGE_SIZE.
853 */
854static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info)
855{
856 struct fadump_memory_range *new_array;
857 u64 new_size;
858
859 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE;
860 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n",
861 new_size, mrange_info->name);
862
863 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL);
864 if (new_array == NULL) {
865 pr_err("Insufficient memory for setting up %s memory ranges\n",
866 mrange_info->name);
867 fadump_free_mem_ranges(mrange_info);
868 return -ENOMEM;
869 }
870
871 mrange_info->mem_ranges = new_array;
872 mrange_info->mem_ranges_sz = new_size;
873 mrange_info->max_mem_ranges = (new_size /
874 sizeof(struct fadump_memory_range));
875 return 0;
876}
877static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info,
878 u64 base, u64 end)
879{
880 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges;
881 bool is_adjacent = false;
882 u64 start, size;
883
884 if (base == end)
885 return 0;
886
887 /*
888 * Fold adjacent memory ranges to bring down the memory ranges/
889 * PT_LOAD segments count.
890 */
891 if (mrange_info->mem_range_cnt) {
892 start = mem_ranges[mrange_info->mem_range_cnt - 1].base;
893 size = mem_ranges[mrange_info->mem_range_cnt - 1].size;
894
895 /*
896 * Boot memory area needs separate PT_LOAD segment(s) as it
897 * is moved to a different location at the time of crash.
898 * So, fold only if the region is not boot memory area.
899 */
900 if ((start + size) == base && start >= fw_dump.boot_mem_top)
901 is_adjacent = true;
902 }
903 if (!is_adjacent) {
904 /* resize the array on reaching the limit */
905 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) {
906 int ret;
907
908 if (mrange_info->is_static) {
909 pr_err("Reached array size limit for %s memory ranges\n",
910 mrange_info->name);
911 return -ENOSPC;
912 }
913
914 ret = fadump_alloc_mem_ranges(mrange_info);
915 if (ret)
916 return ret;
917
918 /* Update to the new resized array */
919 mem_ranges = mrange_info->mem_ranges;
920 }
921
922 start = base;
923 mem_ranges[mrange_info->mem_range_cnt].base = start;
924 mrange_info->mem_range_cnt++;
925 }
926
927 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start);
928 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
929 mrange_info->name, (mrange_info->mem_range_cnt - 1),
930 start, end - 1, (end - start));
931 return 0;
932}
933
934static int fadump_exclude_reserved_area(u64 start, u64 end)
935{
936 u64 ra_start, ra_end;
937 int ret = 0;
938
939 ra_start = fw_dump.reserve_dump_area_start;
940 ra_end = ra_start + fw_dump.reserve_dump_area_size;
941
942 if ((ra_start < end) && (ra_end > start)) {
943 if ((start < ra_start) && (end > ra_end)) {
944 ret = fadump_add_mem_range(&crash_mrange_info,
945 start, ra_start);
946 if (ret)
947 return ret;
948
949 ret = fadump_add_mem_range(&crash_mrange_info,
950 ra_end, end);
951 } else if (start < ra_start) {
952 ret = fadump_add_mem_range(&crash_mrange_info,
953 start, ra_start);
954 } else if (ra_end < end) {
955 ret = fadump_add_mem_range(&crash_mrange_info,
956 ra_end, end);
957 }
958 } else
959 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
960
961 return ret;
962}
963
964static int fadump_init_elfcore_header(char *bufp)
965{
966 struct elfhdr *elf;
967
968 elf = (struct elfhdr *) bufp;
969 bufp += sizeof(struct elfhdr);
970 memcpy(elf->e_ident, ELFMAG, SELFMAG);
971 elf->e_ident[EI_CLASS] = ELF_CLASS;
972 elf->e_ident[EI_DATA] = ELF_DATA;
973 elf->e_ident[EI_VERSION] = EV_CURRENT;
974 elf->e_ident[EI_OSABI] = ELF_OSABI;
975 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
976 elf->e_type = ET_CORE;
977 elf->e_machine = ELF_ARCH;
978 elf->e_version = EV_CURRENT;
979 elf->e_entry = 0;
980 elf->e_phoff = sizeof(struct elfhdr);
981 elf->e_shoff = 0;
982
983 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
984 elf->e_flags = 2;
985 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
986 elf->e_flags = 1;
987 else
988 elf->e_flags = 0;
989
990 elf->e_ehsize = sizeof(struct elfhdr);
991 elf->e_phentsize = sizeof(struct elf_phdr);
992 elf->e_phnum = 0;
993 elf->e_shentsize = 0;
994 elf->e_shnum = 0;
995 elf->e_shstrndx = 0;
996
997 return 0;
998}
999
1000/*
1001 * Traverse through memblock structure and setup crash memory ranges. These
1002 * ranges will be used create PT_LOAD program headers in elfcore header.
1003 */
1004static int fadump_setup_crash_memory_ranges(void)
1005{
1006 u64 i, start, end;
1007 int ret;
1008
1009 pr_debug("Setup crash memory ranges.\n");
1010 crash_mrange_info.mem_range_cnt = 0;
1011
1012 /*
1013 * Boot memory region(s) registered with firmware are moved to
1014 * different location at the time of crash. Create separate program
1015 * header(s) for this memory chunk(s) with the correct offset.
1016 */
1017 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1018 start = fw_dump.boot_mem_addr[i];
1019 end = start + fw_dump.boot_mem_sz[i];
1020 ret = fadump_add_mem_range(&crash_mrange_info, start, end);
1021 if (ret)
1022 return ret;
1023 }
1024
1025 for_each_mem_range(i, &start, &end) {
1026 /*
1027 * skip the memory chunk that is already added
1028 * (0 through boot_memory_top).
1029 */
1030 if (start < fw_dump.boot_mem_top) {
1031 if (end > fw_dump.boot_mem_top)
1032 start = fw_dump.boot_mem_top;
1033 else
1034 continue;
1035 }
1036
1037 /* add this range excluding the reserved dump area. */
1038 ret = fadump_exclude_reserved_area(start, end);
1039 if (ret)
1040 return ret;
1041 }
1042
1043 return 0;
1044}
1045
1046/*
1047 * If the given physical address falls within the boot memory region then
1048 * return the relocated address that points to the dump region reserved
1049 * for saving initial boot memory contents.
1050 */
1051static inline unsigned long fadump_relocate(unsigned long paddr)
1052{
1053 unsigned long raddr, rstart, rend, rlast, hole_size;
1054 int i;
1055
1056 hole_size = 0;
1057 rlast = 0;
1058 raddr = paddr;
1059 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) {
1060 rstart = fw_dump.boot_mem_addr[i];
1061 rend = rstart + fw_dump.boot_mem_sz[i];
1062 hole_size += (rstart - rlast);
1063
1064 if (paddr >= rstart && paddr < rend) {
1065 raddr += fw_dump.boot_mem_dest_addr - hole_size;
1066 break;
1067 }
1068
1069 rlast = rend;
1070 }
1071
1072 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr);
1073 return raddr;
1074}
1075
1076static int fadump_create_elfcore_headers(char *bufp)
1077{
1078 unsigned long long raddr, offset;
1079 struct elf_phdr *phdr;
1080 struct elfhdr *elf;
1081 int i, j;
1082
1083 fadump_init_elfcore_header(bufp);
1084 elf = (struct elfhdr *)bufp;
1085 bufp += sizeof(struct elfhdr);
1086
1087 /*
1088 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1089 * will be populated during second kernel boot after crash. Hence
1090 * this PT_NOTE will always be the first elf note.
1091 *
1092 * NOTE: Any new ELF note addition should be placed after this note.
1093 */
1094 phdr = (struct elf_phdr *)bufp;
1095 bufp += sizeof(struct elf_phdr);
1096 phdr->p_type = PT_NOTE;
1097 phdr->p_flags = 0;
1098 phdr->p_vaddr = 0;
1099 phdr->p_align = 0;
1100
1101 phdr->p_offset = 0;
1102 phdr->p_paddr = 0;
1103 phdr->p_filesz = 0;
1104 phdr->p_memsz = 0;
1105
1106 (elf->e_phnum)++;
1107
1108 /* setup ELF PT_NOTE for vmcoreinfo */
1109 phdr = (struct elf_phdr *)bufp;
1110 bufp += sizeof(struct elf_phdr);
1111 phdr->p_type = PT_NOTE;
1112 phdr->p_flags = 0;
1113 phdr->p_vaddr = 0;
1114 phdr->p_align = 0;
1115
1116 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1117 phdr->p_offset = phdr->p_paddr;
1118 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1119
1120 /* Increment number of program headers. */
1121 (elf->e_phnum)++;
1122
1123 /* setup PT_LOAD sections. */
1124 j = 0;
1125 offset = 0;
1126 raddr = fw_dump.boot_mem_addr[0];
1127 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) {
1128 u64 mbase, msize;
1129
1130 mbase = crash_mrange_info.mem_ranges[i].base;
1131 msize = crash_mrange_info.mem_ranges[i].size;
1132 if (!msize)
1133 continue;
1134
1135 phdr = (struct elf_phdr *)bufp;
1136 bufp += sizeof(struct elf_phdr);
1137 phdr->p_type = PT_LOAD;
1138 phdr->p_flags = PF_R|PF_W|PF_X;
1139 phdr->p_offset = mbase;
1140
1141 if (mbase == raddr) {
1142 /*
1143 * The entire real memory region will be moved by
1144 * firmware to the specified destination_address.
1145 * Hence set the correct offset.
1146 */
1147 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset;
1148 if (j < (fw_dump.boot_mem_regs_cnt - 1)) {
1149 offset += fw_dump.boot_mem_sz[j];
1150 raddr = fw_dump.boot_mem_addr[++j];
1151 }
1152 }
1153
1154 phdr->p_paddr = mbase;
1155 phdr->p_vaddr = (unsigned long)__va(mbase);
1156 phdr->p_filesz = msize;
1157 phdr->p_memsz = msize;
1158 phdr->p_align = 0;
1159
1160 /* Increment number of program headers. */
1161 (elf->e_phnum)++;
1162 }
1163 return 0;
1164}
1165
1166static unsigned long init_fadump_header(unsigned long addr)
1167{
1168 struct fadump_crash_info_header *fdh;
1169
1170 if (!addr)
1171 return 0;
1172
1173 fdh = __va(addr);
1174 addr += sizeof(struct fadump_crash_info_header);
1175
1176 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1177 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1178 fdh->elfcorehdr_addr = addr;
1179 /* We will set the crashing cpu id in crash_fadump() during crash. */
1180 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN;
1181 /*
1182 * When LPAR is terminated by PYHP, ensure all possible CPUs'
1183 * register data is processed while exporting the vmcore.
1184 */
1185 fdh->cpu_mask = *cpu_possible_mask;
1186
1187 return addr;
1188}
1189
1190static int register_fadump(void)
1191{
1192 unsigned long addr;
1193 void *vaddr;
1194 int ret;
1195
1196 /*
1197 * If no memory is reserved then we can not register for firmware-
1198 * assisted dump.
1199 */
1200 if (!fw_dump.reserve_dump_area_size)
1201 return -ENODEV;
1202
1203 ret = fadump_setup_crash_memory_ranges();
1204 if (ret)
1205 return ret;
1206
1207 addr = fw_dump.fadumphdr_addr;
1208
1209 /* Initialize fadump crash info header. */
1210 addr = init_fadump_header(addr);
1211 vaddr = __va(addr);
1212
1213 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1214 fadump_create_elfcore_headers(vaddr);
1215
1216 /* register the future kernel dump with firmware. */
1217 pr_debug("Registering for firmware-assisted kernel dump...\n");
1218 return fw_dump.ops->fadump_register(&fw_dump);
1219}
1220
1221void fadump_cleanup(void)
1222{
1223 if (!fw_dump.fadump_supported)
1224 return;
1225
1226 /* Invalidate the registration only if dump is active. */
1227 if (fw_dump.dump_active) {
1228 pr_debug("Invalidating firmware-assisted dump registration\n");
1229 fw_dump.ops->fadump_invalidate(&fw_dump);
1230 } else if (fw_dump.dump_registered) {
1231 /* Un-register Firmware-assisted dump if it was registered. */
1232 fw_dump.ops->fadump_unregister(&fw_dump);
1233 fadump_free_mem_ranges(&crash_mrange_info);
1234 }
1235
1236 if (fw_dump.ops->fadump_cleanup)
1237 fw_dump.ops->fadump_cleanup(&fw_dump);
1238}
1239
1240static void fadump_free_reserved_memory(unsigned long start_pfn,
1241 unsigned long end_pfn)
1242{
1243 unsigned long pfn;
1244 unsigned long time_limit = jiffies + HZ;
1245
1246 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1247 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1248
1249 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1250 free_reserved_page(pfn_to_page(pfn));
1251
1252 if (time_after(jiffies, time_limit)) {
1253 cond_resched();
1254 time_limit = jiffies + HZ;
1255 }
1256 }
1257}
1258
1259/*
1260 * Skip memory holes and free memory that was actually reserved.
1261 */
1262static void fadump_release_reserved_area(u64 start, u64 end)
1263{
1264 unsigned long reg_spfn, reg_epfn;
1265 u64 tstart, tend, spfn, epfn;
1266 int i;
1267
1268 spfn = PHYS_PFN(start);
1269 epfn = PHYS_PFN(end);
1270
1271 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) {
1272 tstart = max_t(u64, spfn, reg_spfn);
1273 tend = min_t(u64, epfn, reg_epfn);
1274
1275 if (tstart < tend) {
1276 fadump_free_reserved_memory(tstart, tend);
1277
1278 if (tend == epfn)
1279 break;
1280
1281 spfn = tend;
1282 }
1283 }
1284}
1285
1286/*
1287 * Sort the mem ranges in-place and merge adjacent ranges
1288 * to minimize the memory ranges count.
1289 */
1290static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info)
1291{
1292 struct fadump_memory_range *mem_ranges;
1293 u64 base, size;
1294 int i, j, idx;
1295
1296 if (!reserved_mrange_info.mem_range_cnt)
1297 return;
1298
1299 /* Sort the memory ranges */
1300 mem_ranges = mrange_info->mem_ranges;
1301 for (i = 0; i < mrange_info->mem_range_cnt; i++) {
1302 idx = i;
1303 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) {
1304 if (mem_ranges[idx].base > mem_ranges[j].base)
1305 idx = j;
1306 }
1307 if (idx != i)
1308 swap(mem_ranges[idx], mem_ranges[i]);
1309 }
1310
1311 /* Merge adjacent reserved ranges */
1312 idx = 0;
1313 for (i = 1; i < mrange_info->mem_range_cnt; i++) {
1314 base = mem_ranges[i-1].base;
1315 size = mem_ranges[i-1].size;
1316 if (mem_ranges[i].base == (base + size))
1317 mem_ranges[idx].size += mem_ranges[i].size;
1318 else {
1319 idx++;
1320 if (i == idx)
1321 continue;
1322
1323 mem_ranges[idx] = mem_ranges[i];
1324 }
1325 }
1326 mrange_info->mem_range_cnt = idx + 1;
1327}
1328
1329/*
1330 * Scan reserved-ranges to consider them while reserving/releasing
1331 * memory for FADump.
1332 */
1333static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
1334{
1335 const __be32 *prop;
1336 int len, ret = -1;
1337 unsigned long i;
1338
1339 /* reserved-ranges already scanned */
1340 if (reserved_mrange_info.mem_range_cnt != 0)
1341 return;
1342
1343 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len);
1344 if (!prop)
1345 return;
1346
1347 /*
1348 * Each reserved range is an (address,size) pair, 2 cells each,
1349 * totalling 4 cells per range.
1350 */
1351 for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
1352 u64 base, size;
1353
1354 base = of_read_number(prop + (i * 4) + 0, 2);
1355 size = of_read_number(prop + (i * 4) + 2, 2);
1356
1357 if (size) {
1358 ret = fadump_add_mem_range(&reserved_mrange_info,
1359 base, base + size);
1360 if (ret < 0) {
1361 pr_warn("some reserved ranges are ignored!\n");
1362 break;
1363 }
1364 }
1365 }
1366
1367 /* Compact reserved ranges */
1368 sort_and_merge_mem_ranges(&reserved_mrange_info);
1369}
1370
1371/*
1372 * Release the memory that was reserved during early boot to preserve the
1373 * crash'ed kernel's memory contents except reserved dump area (permanent
1374 * reservation) and reserved ranges used by F/W. The released memory will
1375 * be available for general use.
1376 */
1377static void fadump_release_memory(u64 begin, u64 end)
1378{
1379 u64 ra_start, ra_end, tstart;
1380 int i, ret;
1381
1382 ra_start = fw_dump.reserve_dump_area_start;
1383 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1384
1385 /*
1386 * If reserved ranges array limit is hit, overwrite the last reserved
1387 * memory range with reserved dump area to ensure it is excluded from
1388 * the memory being released (reused for next FADump registration).
1389 */
1390 if (reserved_mrange_info.mem_range_cnt ==
1391 reserved_mrange_info.max_mem_ranges)
1392 reserved_mrange_info.mem_range_cnt--;
1393
1394 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end);
1395 if (ret != 0)
1396 return;
1397
1398 /* Get the reserved ranges list in order first. */
1399 sort_and_merge_mem_ranges(&reserved_mrange_info);
1400
1401 /* Exclude reserved ranges and release remaining memory */
1402 tstart = begin;
1403 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) {
1404 ra_start = reserved_mrange_info.mem_ranges[i].base;
1405 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size;
1406
1407 if (tstart >= ra_end)
1408 continue;
1409
1410 if (tstart < ra_start)
1411 fadump_release_reserved_area(tstart, ra_start);
1412 tstart = ra_end;
1413 }
1414
1415 if (tstart < end)
1416 fadump_release_reserved_area(tstart, end);
1417}
1418
1419static void fadump_invalidate_release_mem(void)
1420{
1421 mutex_lock(&fadump_mutex);
1422 if (!fw_dump.dump_active) {
1423 mutex_unlock(&fadump_mutex);
1424 return;
1425 }
1426
1427 fadump_cleanup();
1428 mutex_unlock(&fadump_mutex);
1429
1430 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM());
1431 fadump_free_cpu_notes_buf();
1432
1433 /*
1434 * Setup kernel metadata and initialize the kernel dump
1435 * memory structure for FADump re-registration.
1436 */
1437 if (fw_dump.ops->fadump_setup_metadata &&
1438 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
1439 pr_warn("Failed to setup kernel metadata!\n");
1440 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1441}
1442
1443static ssize_t release_mem_store(struct kobject *kobj,
1444 struct kobj_attribute *attr,
1445 const char *buf, size_t count)
1446{
1447 int input = -1;
1448
1449 if (!fw_dump.dump_active)
1450 return -EPERM;
1451
1452 if (kstrtoint(buf, 0, &input))
1453 return -EINVAL;
1454
1455 if (input == 1) {
1456 /*
1457 * Take away the '/proc/vmcore'. We are releasing the dump
1458 * memory, hence it will not be valid anymore.
1459 */
1460#ifdef CONFIG_PROC_VMCORE
1461 vmcore_cleanup();
1462#endif
1463 fadump_invalidate_release_mem();
1464
1465 } else
1466 return -EINVAL;
1467 return count;
1468}
1469
1470/* Release the reserved memory and disable the FADump */
1471static void __init unregister_fadump(void)
1472{
1473 fadump_cleanup();
1474 fadump_release_memory(fw_dump.reserve_dump_area_start,
1475 fw_dump.reserve_dump_area_size);
1476 fw_dump.fadump_enabled = 0;
1477 kobject_put(fadump_kobj);
1478}
1479
1480static ssize_t enabled_show(struct kobject *kobj,
1481 struct kobj_attribute *attr,
1482 char *buf)
1483{
1484 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1485}
1486
1487static ssize_t mem_reserved_show(struct kobject *kobj,
1488 struct kobj_attribute *attr,
1489 char *buf)
1490{
1491 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size);
1492}
1493
1494static ssize_t registered_show(struct kobject *kobj,
1495 struct kobj_attribute *attr,
1496 char *buf)
1497{
1498 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1499}
1500
1501static ssize_t registered_store(struct kobject *kobj,
1502 struct kobj_attribute *attr,
1503 const char *buf, size_t count)
1504{
1505 int ret = 0;
1506 int input = -1;
1507
1508 if (!fw_dump.fadump_enabled || fw_dump.dump_active)
1509 return -EPERM;
1510
1511 if (kstrtoint(buf, 0, &input))
1512 return -EINVAL;
1513
1514 mutex_lock(&fadump_mutex);
1515
1516 switch (input) {
1517 case 0:
1518 if (fw_dump.dump_registered == 0) {
1519 goto unlock_out;
1520 }
1521
1522 /* Un-register Firmware-assisted dump */
1523 pr_debug("Un-register firmware-assisted dump\n");
1524 fw_dump.ops->fadump_unregister(&fw_dump);
1525 break;
1526 case 1:
1527 if (fw_dump.dump_registered == 1) {
1528 /* Un-register Firmware-assisted dump */
1529 fw_dump.ops->fadump_unregister(&fw_dump);
1530 }
1531 /* Register Firmware-assisted dump */
1532 ret = register_fadump();
1533 break;
1534 default:
1535 ret = -EINVAL;
1536 break;
1537 }
1538
1539unlock_out:
1540 mutex_unlock(&fadump_mutex);
1541 return ret < 0 ? ret : count;
1542}
1543
1544static int fadump_region_show(struct seq_file *m, void *private)
1545{
1546 if (!fw_dump.fadump_enabled)
1547 return 0;
1548
1549 mutex_lock(&fadump_mutex);
1550 fw_dump.ops->fadump_region_show(&fw_dump, m);
1551 mutex_unlock(&fadump_mutex);
1552 return 0;
1553}
1554
1555static struct kobj_attribute release_attr = __ATTR_WO(release_mem);
1556static struct kobj_attribute enable_attr = __ATTR_RO(enabled);
1557static struct kobj_attribute register_attr = __ATTR_RW(registered);
1558static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved);
1559
1560static struct attribute *fadump_attrs[] = {
1561 &enable_attr.attr,
1562 ®ister_attr.attr,
1563 &mem_reserved_attr.attr,
1564 NULL,
1565};
1566
1567ATTRIBUTE_GROUPS(fadump);
1568
1569DEFINE_SHOW_ATTRIBUTE(fadump_region);
1570
1571static void __init fadump_init_files(void)
1572{
1573 int rc = 0;
1574
1575 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj);
1576 if (!fadump_kobj) {
1577 pr_err("failed to create fadump kobject\n");
1578 return;
1579 }
1580
1581 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL,
1582 &fadump_region_fops);
1583
1584 if (fw_dump.dump_active) {
1585 rc = sysfs_create_file(fadump_kobj, &release_attr.attr);
1586 if (rc)
1587 pr_err("unable to create release_mem sysfs file (%d)\n",
1588 rc);
1589 }
1590
1591 rc = sysfs_create_groups(fadump_kobj, fadump_groups);
1592 if (rc) {
1593 pr_err("sysfs group creation failed (%d), unregistering FADump",
1594 rc);
1595 unregister_fadump();
1596 return;
1597 }
1598
1599 /*
1600 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to
1601 * create symlink at old location to maintain backward compatibility.
1602 *
1603 * - fadump_enabled -> fadump/enabled
1604 * - fadump_registered -> fadump/registered
1605 * - fadump_release_mem -> fadump/release_mem
1606 */
1607 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1608 "enabled", "fadump_enabled");
1609 if (rc) {
1610 pr_err("unable to create fadump_enabled symlink (%d)", rc);
1611 return;
1612 }
1613
1614 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj,
1615 "registered",
1616 "fadump_registered");
1617 if (rc) {
1618 pr_err("unable to create fadump_registered symlink (%d)", rc);
1619 sysfs_remove_link(kernel_kobj, "fadump_enabled");
1620 return;
1621 }
1622
1623 if (fw_dump.dump_active) {
1624 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj,
1625 fadump_kobj,
1626 "release_mem",
1627 "fadump_release_mem");
1628 if (rc)
1629 pr_err("unable to create fadump_release_mem symlink (%d)",
1630 rc);
1631 }
1632 return;
1633}
1634
1635/*
1636 * Prepare for firmware-assisted dump.
1637 */
1638int __init setup_fadump(void)
1639{
1640 if (!fw_dump.fadump_supported)
1641 return 0;
1642
1643 fadump_init_files();
1644 fadump_show_config();
1645
1646 if (!fw_dump.fadump_enabled)
1647 return 1;
1648
1649 /*
1650 * If dump data is available then see if it is valid and prepare for
1651 * saving it to the disk.
1652 */
1653 if (fw_dump.dump_active) {
1654 /*
1655 * if dump process fails then invalidate the registration
1656 * and release memory before proceeding for re-registration.
1657 */
1658 if (fw_dump.ops->fadump_process(&fw_dump) < 0)
1659 fadump_invalidate_release_mem();
1660 }
1661 /* Initialize the kernel dump memory structure and register with f/w */
1662 else if (fw_dump.reserve_dump_area_size) {
1663 fw_dump.ops->fadump_init_mem_struct(&fw_dump);
1664 register_fadump();
1665 }
1666
1667 /*
1668 * In case of panic, fadump is triggered via ppc_panic_event()
1669 * panic notifier. Setting crash_kexec_post_notifiers to 'true'
1670 * lets panic() function take crash friendly path before panic
1671 * notifiers are invoked.
1672 */
1673 crash_kexec_post_notifiers = true;
1674
1675 return 1;
1676}
1677/*
1678 * Use subsys_initcall_sync() here because there is dependency with
1679 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization
1680 * is done before registering with f/w.
1681 */
1682subsys_initcall_sync(setup_fadump);
1683#else /* !CONFIG_PRESERVE_FA_DUMP */
1684
1685/* Scan the Firmware Assisted dump configuration details. */
1686int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
1687 int depth, void *data)
1688{
1689 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
1690 return 0;
1691
1692 opal_fadump_dt_scan(&fw_dump, node);
1693 return 1;
1694}
1695
1696/*
1697 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
1698 * preserve crash data. The subsequent memory preserving kernel boot
1699 * is likely to process this crash data.
1700 */
1701int __init fadump_reserve_mem(void)
1702{
1703 if (fw_dump.dump_active) {
1704 /*
1705 * If last boot has crashed then reserve all the memory
1706 * above boot memory to preserve crash data.
1707 */
1708 pr_info("Preserving crash data for processing in next boot.\n");
1709 fadump_reserve_crash_area(fw_dump.boot_mem_top);
1710 } else
1711 pr_debug("FADump-aware kernel..\n");
1712
1713 return 1;
1714}
1715#endif /* CONFIG_PRESERVE_FA_DUMP */
1716
1717/* Preserve everything above the base address */
1718static void __init fadump_reserve_crash_area(u64 base)
1719{
1720 u64 i, mstart, mend, msize;
1721
1722 for_each_mem_range(i, &mstart, &mend) {
1723 msize = mend - mstart;
1724
1725 if ((mstart + msize) < base)
1726 continue;
1727
1728 if (mstart < base) {
1729 msize -= (base - mstart);
1730 mstart = base;
1731 }
1732
1733 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data",
1734 (msize >> 20), mstart);
1735 memblock_reserve(mstart, msize);
1736 }
1737}
1738
1739unsigned long __init arch_reserved_kernel_pages(void)
1740{
1741 return memblock_reserved_size() / PAGE_SIZE;
1742}
1/*
2 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
3 * dump with assistance from firmware. This approach does not use kexec,
4 * instead firmware assists in booting the kdump kernel while preserving
5 * memory contents. The most of the code implementation has been adapted
6 * from phyp assisted dump implementation written by Linas Vepstas and
7 * Manish Ahuja
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 *
23 * Copyright 2011 IBM Corporation
24 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
25 */
26
27#undef DEBUG
28#define pr_fmt(fmt) "fadump: " fmt
29
30#include <linux/string.h>
31#include <linux/memblock.h>
32#include <linux/delay.h>
33#include <linux/debugfs.h>
34#include <linux/seq_file.h>
35#include <linux/crash_dump.h>
36#include <linux/kobject.h>
37#include <linux/sysfs.h>
38
39#include <asm/page.h>
40#include <asm/prom.h>
41#include <asm/rtas.h>
42#include <asm/fadump.h>
43#include <asm/debug.h>
44#include <asm/setup.h>
45
46static struct fw_dump fw_dump;
47static struct fadump_mem_struct fdm;
48static const struct fadump_mem_struct *fdm_active;
49
50static DEFINE_MUTEX(fadump_mutex);
51struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
52int crash_mem_ranges;
53
54/* Scan the Firmware Assisted dump configuration details. */
55int __init early_init_dt_scan_fw_dump(unsigned long node,
56 const char *uname, int depth, void *data)
57{
58 const __be32 *sections;
59 int i, num_sections;
60 int size;
61 const __be32 *token;
62
63 if (depth != 1 || strcmp(uname, "rtas") != 0)
64 return 0;
65
66 /*
67 * Check if Firmware Assisted dump is supported. if yes, check
68 * if dump has been initiated on last reboot.
69 */
70 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
71 if (!token)
72 return 1;
73
74 fw_dump.fadump_supported = 1;
75 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
76
77 /*
78 * The 'ibm,kernel-dump' rtas node is present only if there is
79 * dump data waiting for us.
80 */
81 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
82 if (fdm_active)
83 fw_dump.dump_active = 1;
84
85 /* Get the sizes required to store dump data for the firmware provided
86 * dump sections.
87 * For each dump section type supported, a 32bit cell which defines
88 * the ID of a supported section followed by two 32 bit cells which
89 * gives teh size of the section in bytes.
90 */
91 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
92 &size);
93
94 if (!sections)
95 return 1;
96
97 num_sections = size / (3 * sizeof(u32));
98
99 for (i = 0; i < num_sections; i++, sections += 3) {
100 u32 type = (u32)of_read_number(sections, 1);
101
102 switch (type) {
103 case FADUMP_CPU_STATE_DATA:
104 fw_dump.cpu_state_data_size =
105 of_read_ulong(§ions[1], 2);
106 break;
107 case FADUMP_HPTE_REGION:
108 fw_dump.hpte_region_size =
109 of_read_ulong(§ions[1], 2);
110 break;
111 }
112 }
113
114 return 1;
115}
116
117int is_fadump_active(void)
118{
119 return fw_dump.dump_active;
120}
121
122/* Print firmware assisted dump configurations for debugging purpose. */
123static void fadump_show_config(void)
124{
125 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
126 (fw_dump.fadump_supported ? "present" : "no support"));
127
128 if (!fw_dump.fadump_supported)
129 return;
130
131 pr_debug("Fadump enabled : %s\n",
132 (fw_dump.fadump_enabled ? "yes" : "no"));
133 pr_debug("Dump Active : %s\n",
134 (fw_dump.dump_active ? "yes" : "no"));
135 pr_debug("Dump section sizes:\n");
136 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
137 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
138 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
139}
140
141static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
142 unsigned long addr)
143{
144 if (!fdm)
145 return 0;
146
147 memset(fdm, 0, sizeof(struct fadump_mem_struct));
148 addr = addr & PAGE_MASK;
149
150 fdm->header.dump_format_version = cpu_to_be32(0x00000001);
151 fdm->header.dump_num_sections = cpu_to_be16(3);
152 fdm->header.dump_status_flag = 0;
153 fdm->header.offset_first_dump_section =
154 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
155
156 /*
157 * Fields for disk dump option.
158 * We are not using disk dump option, hence set these fields to 0.
159 */
160 fdm->header.dd_block_size = 0;
161 fdm->header.dd_block_offset = 0;
162 fdm->header.dd_num_blocks = 0;
163 fdm->header.dd_offset_disk_path = 0;
164
165 /* set 0 to disable an automatic dump-reboot. */
166 fdm->header.max_time_auto = 0;
167
168 /* Kernel dump sections */
169 /* cpu state data section. */
170 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
171 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
172 fdm->cpu_state_data.source_address = 0;
173 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
174 fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
175 addr += fw_dump.cpu_state_data_size;
176
177 /* hpte region section */
178 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
179 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
180 fdm->hpte_region.source_address = 0;
181 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
182 fdm->hpte_region.destination_address = cpu_to_be64(addr);
183 addr += fw_dump.hpte_region_size;
184
185 /* RMA region section */
186 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
187 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
188 fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
189 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
190 fdm->rmr_region.destination_address = cpu_to_be64(addr);
191 addr += fw_dump.boot_memory_size;
192
193 return addr;
194}
195
196/**
197 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
198 *
199 * Function to find the largest memory size we need to reserve during early
200 * boot process. This will be the size of the memory that is required for a
201 * kernel to boot successfully.
202 *
203 * This function has been taken from phyp-assisted dump feature implementation.
204 *
205 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
206 *
207 * TODO: Come up with better approach to find out more accurate memory size
208 * that is required for a kernel to boot successfully.
209 *
210 */
211static inline unsigned long fadump_calculate_reserve_size(void)
212{
213 unsigned long size;
214
215 /*
216 * Check if the size is specified through fadump_reserve_mem= cmdline
217 * option. If yes, then use that.
218 */
219 if (fw_dump.reserve_bootvar)
220 return fw_dump.reserve_bootvar;
221
222 /* divide by 20 to get 5% of value */
223 size = memblock_end_of_DRAM() / 20;
224
225 /* round it down in multiples of 256 */
226 size = size & ~0x0FFFFFFFUL;
227
228 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
229 if (memory_limit && size > memory_limit)
230 size = memory_limit;
231
232 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
233}
234
235/*
236 * Calculate the total memory size required to be reserved for
237 * firmware-assisted dump registration.
238 */
239static unsigned long get_fadump_area_size(void)
240{
241 unsigned long size = 0;
242
243 size += fw_dump.cpu_state_data_size;
244 size += fw_dump.hpte_region_size;
245 size += fw_dump.boot_memory_size;
246 size += sizeof(struct fadump_crash_info_header);
247 size += sizeof(struct elfhdr); /* ELF core header.*/
248 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
249 /* Program headers for crash memory regions. */
250 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
251
252 size = PAGE_ALIGN(size);
253 return size;
254}
255
256int __init fadump_reserve_mem(void)
257{
258 unsigned long base, size, memory_boundary;
259
260 if (!fw_dump.fadump_enabled)
261 return 0;
262
263 if (!fw_dump.fadump_supported) {
264 printk(KERN_INFO "Firmware-assisted dump is not supported on"
265 " this hardware\n");
266 fw_dump.fadump_enabled = 0;
267 return 0;
268 }
269 /*
270 * Initialize boot memory size
271 * If dump is active then we have already calculated the size during
272 * first kernel.
273 */
274 if (fdm_active)
275 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
276 else
277 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
278
279 /*
280 * Calculate the memory boundary.
281 * If memory_limit is less than actual memory boundary then reserve
282 * the memory for fadump beyond the memory_limit and adjust the
283 * memory_limit accordingly, so that the running kernel can run with
284 * specified memory_limit.
285 */
286 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
287 size = get_fadump_area_size();
288 if ((memory_limit + size) < memblock_end_of_DRAM())
289 memory_limit += size;
290 else
291 memory_limit = memblock_end_of_DRAM();
292 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
293 " dump, now %#016llx\n", memory_limit);
294 }
295 if (memory_limit)
296 memory_boundary = memory_limit;
297 else
298 memory_boundary = memblock_end_of_DRAM();
299
300 if (fw_dump.dump_active) {
301 printk(KERN_INFO "Firmware-assisted dump is active.\n");
302 /*
303 * If last boot has crashed then reserve all the memory
304 * above boot_memory_size so that we don't touch it until
305 * dump is written to disk by userspace tool. This memory
306 * will be released for general use once the dump is saved.
307 */
308 base = fw_dump.boot_memory_size;
309 size = memory_boundary - base;
310 memblock_reserve(base, size);
311 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
312 "for saving crash dump\n",
313 (unsigned long)(size >> 20),
314 (unsigned long)(base >> 20));
315
316 fw_dump.fadumphdr_addr =
317 be64_to_cpu(fdm_active->rmr_region.destination_address) +
318 be64_to_cpu(fdm_active->rmr_region.source_len);
319 pr_debug("fadumphdr_addr = %p\n",
320 (void *) fw_dump.fadumphdr_addr);
321 } else {
322 /* Reserve the memory at the top of memory. */
323 size = get_fadump_area_size();
324 base = memory_boundary - size;
325 memblock_reserve(base, size);
326 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
327 "for firmware-assisted dump\n",
328 (unsigned long)(size >> 20),
329 (unsigned long)(base >> 20));
330 }
331 fw_dump.reserve_dump_area_start = base;
332 fw_dump.reserve_dump_area_size = size;
333 return 1;
334}
335
336unsigned long __init arch_reserved_kernel_pages(void)
337{
338 return memblock_reserved_size() / PAGE_SIZE;
339}
340
341/* Look for fadump= cmdline option. */
342static int __init early_fadump_param(char *p)
343{
344 if (!p)
345 return 1;
346
347 if (strncmp(p, "on", 2) == 0)
348 fw_dump.fadump_enabled = 1;
349 else if (strncmp(p, "off", 3) == 0)
350 fw_dump.fadump_enabled = 0;
351
352 return 0;
353}
354early_param("fadump", early_fadump_param);
355
356/* Look for fadump_reserve_mem= cmdline option */
357static int __init early_fadump_reserve_mem(char *p)
358{
359 if (p)
360 fw_dump.reserve_bootvar = memparse(p, &p);
361 return 0;
362}
363early_param("fadump_reserve_mem", early_fadump_reserve_mem);
364
365static void register_fw_dump(struct fadump_mem_struct *fdm)
366{
367 int rc;
368 unsigned int wait_time;
369
370 pr_debug("Registering for firmware-assisted kernel dump...\n");
371
372 /* TODO: Add upper time limit for the delay */
373 do {
374 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
375 FADUMP_REGISTER, fdm,
376 sizeof(struct fadump_mem_struct));
377
378 wait_time = rtas_busy_delay_time(rc);
379 if (wait_time)
380 mdelay(wait_time);
381
382 } while (wait_time);
383
384 switch (rc) {
385 case -1:
386 printk(KERN_ERR "Failed to register firmware-assisted kernel"
387 " dump. Hardware Error(%d).\n", rc);
388 break;
389 case -3:
390 printk(KERN_ERR "Failed to register firmware-assisted kernel"
391 " dump. Parameter Error(%d).\n", rc);
392 break;
393 case -9:
394 printk(KERN_ERR "firmware-assisted kernel dump is already "
395 " registered.");
396 fw_dump.dump_registered = 1;
397 break;
398 case 0:
399 printk(KERN_INFO "firmware-assisted kernel dump registration"
400 " is successful\n");
401 fw_dump.dump_registered = 1;
402 break;
403 }
404}
405
406void crash_fadump(struct pt_regs *regs, const char *str)
407{
408 struct fadump_crash_info_header *fdh = NULL;
409
410 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
411 return;
412
413 fdh = __va(fw_dump.fadumphdr_addr);
414 crashing_cpu = smp_processor_id();
415 fdh->crashing_cpu = crashing_cpu;
416 crash_save_vmcoreinfo();
417
418 if (regs)
419 fdh->regs = *regs;
420 else
421 ppc_save_regs(&fdh->regs);
422
423 fdh->online_mask = *cpu_online_mask;
424
425 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
426 rtas_os_term((char *)str);
427}
428
429#define GPR_MASK 0xffffff0000000000
430static inline int fadump_gpr_index(u64 id)
431{
432 int i = -1;
433 char str[3];
434
435 if ((id & GPR_MASK) == REG_ID("GPR")) {
436 /* get the digits at the end */
437 id &= ~GPR_MASK;
438 id >>= 24;
439 str[2] = '\0';
440 str[1] = id & 0xff;
441 str[0] = (id >> 8) & 0xff;
442 sscanf(str, "%d", &i);
443 if (i > 31)
444 i = -1;
445 }
446 return i;
447}
448
449static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
450 u64 reg_val)
451{
452 int i;
453
454 i = fadump_gpr_index(reg_id);
455 if (i >= 0)
456 regs->gpr[i] = (unsigned long)reg_val;
457 else if (reg_id == REG_ID("NIA"))
458 regs->nip = (unsigned long)reg_val;
459 else if (reg_id == REG_ID("MSR"))
460 regs->msr = (unsigned long)reg_val;
461 else if (reg_id == REG_ID("CTR"))
462 regs->ctr = (unsigned long)reg_val;
463 else if (reg_id == REG_ID("LR"))
464 regs->link = (unsigned long)reg_val;
465 else if (reg_id == REG_ID("XER"))
466 regs->xer = (unsigned long)reg_val;
467 else if (reg_id == REG_ID("CR"))
468 regs->ccr = (unsigned long)reg_val;
469 else if (reg_id == REG_ID("DAR"))
470 regs->dar = (unsigned long)reg_val;
471 else if (reg_id == REG_ID("DSISR"))
472 regs->dsisr = (unsigned long)reg_val;
473}
474
475static struct fadump_reg_entry*
476fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
477{
478 memset(regs, 0, sizeof(struct pt_regs));
479
480 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
481 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
482 be64_to_cpu(reg_entry->reg_value));
483 reg_entry++;
484 }
485 reg_entry++;
486 return reg_entry;
487}
488
489static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
490 void *data, size_t data_len)
491{
492 struct elf_note note;
493
494 note.n_namesz = strlen(name) + 1;
495 note.n_descsz = data_len;
496 note.n_type = type;
497 memcpy(buf, ¬e, sizeof(note));
498 buf += (sizeof(note) + 3)/4;
499 memcpy(buf, name, note.n_namesz);
500 buf += (note.n_namesz + 3)/4;
501 memcpy(buf, data, note.n_descsz);
502 buf += (note.n_descsz + 3)/4;
503
504 return buf;
505}
506
507static void fadump_final_note(u32 *buf)
508{
509 struct elf_note note;
510
511 note.n_namesz = 0;
512 note.n_descsz = 0;
513 note.n_type = 0;
514 memcpy(buf, ¬e, sizeof(note));
515}
516
517static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
518{
519 struct elf_prstatus prstatus;
520
521 memset(&prstatus, 0, sizeof(prstatus));
522 /*
523 * FIXME: How do i get PID? Do I really need it?
524 * prstatus.pr_pid = ????
525 */
526 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
527 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
528 &prstatus, sizeof(prstatus));
529 return buf;
530}
531
532static void fadump_update_elfcore_header(char *bufp)
533{
534 struct elfhdr *elf;
535 struct elf_phdr *phdr;
536
537 elf = (struct elfhdr *)bufp;
538 bufp += sizeof(struct elfhdr);
539
540 /* First note is a place holder for cpu notes info. */
541 phdr = (struct elf_phdr *)bufp;
542
543 if (phdr->p_type == PT_NOTE) {
544 phdr->p_paddr = fw_dump.cpu_notes_buf;
545 phdr->p_offset = phdr->p_paddr;
546 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
547 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
548 }
549 return;
550}
551
552static void *fadump_cpu_notes_buf_alloc(unsigned long size)
553{
554 void *vaddr;
555 struct page *page;
556 unsigned long order, count, i;
557
558 order = get_order(size);
559 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
560 if (!vaddr)
561 return NULL;
562
563 count = 1 << order;
564 page = virt_to_page(vaddr);
565 for (i = 0; i < count; i++)
566 SetPageReserved(page + i);
567 return vaddr;
568}
569
570static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
571{
572 struct page *page;
573 unsigned long order, count, i;
574
575 order = get_order(size);
576 count = 1 << order;
577 page = virt_to_page(vaddr);
578 for (i = 0; i < count; i++)
579 ClearPageReserved(page + i);
580 __free_pages(page, order);
581}
582
583/*
584 * Read CPU state dump data and convert it into ELF notes.
585 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
586 * used to access the data to allow for additional fields to be added without
587 * affecting compatibility. Each list of registers for a CPU starts with
588 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
589 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
590 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
591 * of register value. For more details refer to PAPR document.
592 *
593 * Only for the crashing cpu we ignore the CPU dump data and get exact
594 * state from fadump crash info structure populated by first kernel at the
595 * time of crash.
596 */
597static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
598{
599 struct fadump_reg_save_area_header *reg_header;
600 struct fadump_reg_entry *reg_entry;
601 struct fadump_crash_info_header *fdh = NULL;
602 void *vaddr;
603 unsigned long addr;
604 u32 num_cpus, *note_buf;
605 struct pt_regs regs;
606 int i, rc = 0, cpu = 0;
607
608 if (!fdm->cpu_state_data.bytes_dumped)
609 return -EINVAL;
610
611 addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
612 vaddr = __va(addr);
613
614 reg_header = vaddr;
615 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
616 printk(KERN_ERR "Unable to read register save area.\n");
617 return -ENOENT;
618 }
619 pr_debug("--------CPU State Data------------\n");
620 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
621 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
622
623 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
624 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
625 pr_debug("NumCpus : %u\n", num_cpus);
626 vaddr += sizeof(u32);
627 reg_entry = (struct fadump_reg_entry *)vaddr;
628
629 /* Allocate buffer to hold cpu crash notes. */
630 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
631 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
632 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
633 if (!note_buf) {
634 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
635 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
636 return -ENOMEM;
637 }
638 fw_dump.cpu_notes_buf = __pa(note_buf);
639
640 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
641 (num_cpus * sizeof(note_buf_t)), note_buf);
642
643 if (fw_dump.fadumphdr_addr)
644 fdh = __va(fw_dump.fadumphdr_addr);
645
646 for (i = 0; i < num_cpus; i++) {
647 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
648 printk(KERN_ERR "Unable to read CPU state data\n");
649 rc = -ENOENT;
650 goto error_out;
651 }
652 /* Lower 4 bytes of reg_value contains logical cpu id */
653 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
654 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
655 SKIP_TO_NEXT_CPU(reg_entry);
656 continue;
657 }
658 pr_debug("Reading register data for cpu %d...\n", cpu);
659 if (fdh && fdh->crashing_cpu == cpu) {
660 regs = fdh->regs;
661 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
662 SKIP_TO_NEXT_CPU(reg_entry);
663 } else {
664 reg_entry++;
665 reg_entry = fadump_read_registers(reg_entry, ®s);
666 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
667 }
668 }
669 fadump_final_note(note_buf);
670
671 if (fdh) {
672 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
673 fdh->elfcorehdr_addr);
674 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
675 }
676 return 0;
677
678error_out:
679 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
680 fw_dump.cpu_notes_buf_size);
681 fw_dump.cpu_notes_buf = 0;
682 fw_dump.cpu_notes_buf_size = 0;
683 return rc;
684
685}
686
687/*
688 * Validate and process the dump data stored by firmware before exporting
689 * it through '/proc/vmcore'.
690 */
691static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
692{
693 struct fadump_crash_info_header *fdh;
694 int rc = 0;
695
696 if (!fdm_active || !fw_dump.fadumphdr_addr)
697 return -EINVAL;
698
699 /* Check if the dump data is valid. */
700 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
701 (fdm_active->cpu_state_data.error_flags != 0) ||
702 (fdm_active->rmr_region.error_flags != 0)) {
703 printk(KERN_ERR "Dump taken by platform is not valid\n");
704 return -EINVAL;
705 }
706 if ((fdm_active->rmr_region.bytes_dumped !=
707 fdm_active->rmr_region.source_len) ||
708 !fdm_active->cpu_state_data.bytes_dumped) {
709 printk(KERN_ERR "Dump taken by platform is incomplete\n");
710 return -EINVAL;
711 }
712
713 /* Validate the fadump crash info header */
714 fdh = __va(fw_dump.fadumphdr_addr);
715 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
716 printk(KERN_ERR "Crash info header is not valid.\n");
717 return -EINVAL;
718 }
719
720 rc = fadump_build_cpu_notes(fdm_active);
721 if (rc)
722 return rc;
723
724 /*
725 * We are done validating dump info and elfcore header is now ready
726 * to be exported. set elfcorehdr_addr so that vmcore module will
727 * export the elfcore header through '/proc/vmcore'.
728 */
729 elfcorehdr_addr = fdh->elfcorehdr_addr;
730
731 return 0;
732}
733
734static inline void fadump_add_crash_memory(unsigned long long base,
735 unsigned long long end)
736{
737 if (base == end)
738 return;
739
740 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
741 crash_mem_ranges, base, end - 1, (end - base));
742 crash_memory_ranges[crash_mem_ranges].base = base;
743 crash_memory_ranges[crash_mem_ranges].size = end - base;
744 crash_mem_ranges++;
745}
746
747static void fadump_exclude_reserved_area(unsigned long long start,
748 unsigned long long end)
749{
750 unsigned long long ra_start, ra_end;
751
752 ra_start = fw_dump.reserve_dump_area_start;
753 ra_end = ra_start + fw_dump.reserve_dump_area_size;
754
755 if ((ra_start < end) && (ra_end > start)) {
756 if ((start < ra_start) && (end > ra_end)) {
757 fadump_add_crash_memory(start, ra_start);
758 fadump_add_crash_memory(ra_end, end);
759 } else if (start < ra_start) {
760 fadump_add_crash_memory(start, ra_start);
761 } else if (ra_end < end) {
762 fadump_add_crash_memory(ra_end, end);
763 }
764 } else
765 fadump_add_crash_memory(start, end);
766}
767
768static int fadump_init_elfcore_header(char *bufp)
769{
770 struct elfhdr *elf;
771
772 elf = (struct elfhdr *) bufp;
773 bufp += sizeof(struct elfhdr);
774 memcpy(elf->e_ident, ELFMAG, SELFMAG);
775 elf->e_ident[EI_CLASS] = ELF_CLASS;
776 elf->e_ident[EI_DATA] = ELF_DATA;
777 elf->e_ident[EI_VERSION] = EV_CURRENT;
778 elf->e_ident[EI_OSABI] = ELF_OSABI;
779 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
780 elf->e_type = ET_CORE;
781 elf->e_machine = ELF_ARCH;
782 elf->e_version = EV_CURRENT;
783 elf->e_entry = 0;
784 elf->e_phoff = sizeof(struct elfhdr);
785 elf->e_shoff = 0;
786#if defined(_CALL_ELF)
787 elf->e_flags = _CALL_ELF;
788#else
789 elf->e_flags = 0;
790#endif
791 elf->e_ehsize = sizeof(struct elfhdr);
792 elf->e_phentsize = sizeof(struct elf_phdr);
793 elf->e_phnum = 0;
794 elf->e_shentsize = 0;
795 elf->e_shnum = 0;
796 elf->e_shstrndx = 0;
797
798 return 0;
799}
800
801/*
802 * Traverse through memblock structure and setup crash memory ranges. These
803 * ranges will be used create PT_LOAD program headers in elfcore header.
804 */
805static void fadump_setup_crash_memory_ranges(void)
806{
807 struct memblock_region *reg;
808 unsigned long long start, end;
809
810 pr_debug("Setup crash memory ranges.\n");
811 crash_mem_ranges = 0;
812 /*
813 * add the first memory chunk (RMA_START through boot_memory_size) as
814 * a separate memory chunk. The reason is, at the time crash firmware
815 * will move the content of this memory chunk to different location
816 * specified during fadump registration. We need to create a separate
817 * program header for this chunk with the correct offset.
818 */
819 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
820
821 for_each_memblock(memory, reg) {
822 start = (unsigned long long)reg->base;
823 end = start + (unsigned long long)reg->size;
824 if (start == RMA_START && end >= fw_dump.boot_memory_size)
825 start = fw_dump.boot_memory_size;
826
827 /* add this range excluding the reserved dump area. */
828 fadump_exclude_reserved_area(start, end);
829 }
830}
831
832/*
833 * If the given physical address falls within the boot memory region then
834 * return the relocated address that points to the dump region reserved
835 * for saving initial boot memory contents.
836 */
837static inline unsigned long fadump_relocate(unsigned long paddr)
838{
839 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
840 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
841 else
842 return paddr;
843}
844
845static int fadump_create_elfcore_headers(char *bufp)
846{
847 struct elfhdr *elf;
848 struct elf_phdr *phdr;
849 int i;
850
851 fadump_init_elfcore_header(bufp);
852 elf = (struct elfhdr *)bufp;
853 bufp += sizeof(struct elfhdr);
854
855 /*
856 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
857 * will be populated during second kernel boot after crash. Hence
858 * this PT_NOTE will always be the first elf note.
859 *
860 * NOTE: Any new ELF note addition should be placed after this note.
861 */
862 phdr = (struct elf_phdr *)bufp;
863 bufp += sizeof(struct elf_phdr);
864 phdr->p_type = PT_NOTE;
865 phdr->p_flags = 0;
866 phdr->p_vaddr = 0;
867 phdr->p_align = 0;
868
869 phdr->p_offset = 0;
870 phdr->p_paddr = 0;
871 phdr->p_filesz = 0;
872 phdr->p_memsz = 0;
873
874 (elf->e_phnum)++;
875
876 /* setup ELF PT_NOTE for vmcoreinfo */
877 phdr = (struct elf_phdr *)bufp;
878 bufp += sizeof(struct elf_phdr);
879 phdr->p_type = PT_NOTE;
880 phdr->p_flags = 0;
881 phdr->p_vaddr = 0;
882 phdr->p_align = 0;
883
884 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
885 phdr->p_offset = phdr->p_paddr;
886 phdr->p_memsz = vmcoreinfo_max_size;
887 phdr->p_filesz = vmcoreinfo_max_size;
888
889 /* Increment number of program headers. */
890 (elf->e_phnum)++;
891
892 /* setup PT_LOAD sections. */
893
894 for (i = 0; i < crash_mem_ranges; i++) {
895 unsigned long long mbase, msize;
896 mbase = crash_memory_ranges[i].base;
897 msize = crash_memory_ranges[i].size;
898
899 if (!msize)
900 continue;
901
902 phdr = (struct elf_phdr *)bufp;
903 bufp += sizeof(struct elf_phdr);
904 phdr->p_type = PT_LOAD;
905 phdr->p_flags = PF_R|PF_W|PF_X;
906 phdr->p_offset = mbase;
907
908 if (mbase == RMA_START) {
909 /*
910 * The entire RMA region will be moved by firmware
911 * to the specified destination_address. Hence set
912 * the correct offset.
913 */
914 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
915 }
916
917 phdr->p_paddr = mbase;
918 phdr->p_vaddr = (unsigned long)__va(mbase);
919 phdr->p_filesz = msize;
920 phdr->p_memsz = msize;
921 phdr->p_align = 0;
922
923 /* Increment number of program headers. */
924 (elf->e_phnum)++;
925 }
926 return 0;
927}
928
929static unsigned long init_fadump_header(unsigned long addr)
930{
931 struct fadump_crash_info_header *fdh;
932
933 if (!addr)
934 return 0;
935
936 fw_dump.fadumphdr_addr = addr;
937 fdh = __va(addr);
938 addr += sizeof(struct fadump_crash_info_header);
939
940 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
941 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
942 fdh->elfcorehdr_addr = addr;
943 /* We will set the crashing cpu id in crash_fadump() during crash. */
944 fdh->crashing_cpu = CPU_UNKNOWN;
945
946 return addr;
947}
948
949static void register_fadump(void)
950{
951 unsigned long addr;
952 void *vaddr;
953
954 /*
955 * If no memory is reserved then we can not register for firmware-
956 * assisted dump.
957 */
958 if (!fw_dump.reserve_dump_area_size)
959 return;
960
961 fadump_setup_crash_memory_ranges();
962
963 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
964 /* Initialize fadump crash info header. */
965 addr = init_fadump_header(addr);
966 vaddr = __va(addr);
967
968 pr_debug("Creating ELF core headers at %#016lx\n", addr);
969 fadump_create_elfcore_headers(vaddr);
970
971 /* register the future kernel dump with firmware. */
972 register_fw_dump(&fdm);
973}
974
975static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
976{
977 int rc = 0;
978 unsigned int wait_time;
979
980 pr_debug("Un-register firmware-assisted dump\n");
981
982 /* TODO: Add upper time limit for the delay */
983 do {
984 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
985 FADUMP_UNREGISTER, fdm,
986 sizeof(struct fadump_mem_struct));
987
988 wait_time = rtas_busy_delay_time(rc);
989 if (wait_time)
990 mdelay(wait_time);
991 } while (wait_time);
992
993 if (rc) {
994 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
995 " unexpected error(%d).\n", rc);
996 return rc;
997 }
998 fw_dump.dump_registered = 0;
999 return 0;
1000}
1001
1002static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1003{
1004 int rc = 0;
1005 unsigned int wait_time;
1006
1007 pr_debug("Invalidating firmware-assisted dump registration\n");
1008
1009 /* TODO: Add upper time limit for the delay */
1010 do {
1011 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1012 FADUMP_INVALIDATE, fdm,
1013 sizeof(struct fadump_mem_struct));
1014
1015 wait_time = rtas_busy_delay_time(rc);
1016 if (wait_time)
1017 mdelay(wait_time);
1018 } while (wait_time);
1019
1020 if (rc) {
1021 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1022 return rc;
1023 }
1024 fw_dump.dump_active = 0;
1025 fdm_active = NULL;
1026 return 0;
1027}
1028
1029void fadump_cleanup(void)
1030{
1031 /* Invalidate the registration only if dump is active. */
1032 if (fw_dump.dump_active) {
1033 init_fadump_mem_struct(&fdm,
1034 be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1035 fadump_invalidate_dump(&fdm);
1036 }
1037}
1038
1039/*
1040 * Release the memory that was reserved in early boot to preserve the memory
1041 * contents. The released memory will be available for general use.
1042 */
1043static void fadump_release_memory(unsigned long begin, unsigned long end)
1044{
1045 unsigned long addr;
1046 unsigned long ra_start, ra_end;
1047
1048 ra_start = fw_dump.reserve_dump_area_start;
1049 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1050
1051 for (addr = begin; addr < end; addr += PAGE_SIZE) {
1052 /*
1053 * exclude the dump reserve area. Will reuse it for next
1054 * fadump registration.
1055 */
1056 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1057 continue;
1058
1059 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1060 }
1061}
1062
1063static void fadump_invalidate_release_mem(void)
1064{
1065 unsigned long reserved_area_start, reserved_area_end;
1066 unsigned long destination_address;
1067
1068 mutex_lock(&fadump_mutex);
1069 if (!fw_dump.dump_active) {
1070 mutex_unlock(&fadump_mutex);
1071 return;
1072 }
1073
1074 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1075 fadump_cleanup();
1076 mutex_unlock(&fadump_mutex);
1077
1078 /*
1079 * Save the current reserved memory bounds we will require them
1080 * later for releasing the memory for general use.
1081 */
1082 reserved_area_start = fw_dump.reserve_dump_area_start;
1083 reserved_area_end = reserved_area_start +
1084 fw_dump.reserve_dump_area_size;
1085 /*
1086 * Setup reserve_dump_area_start and its size so that we can
1087 * reuse this reserved memory for Re-registration.
1088 */
1089 fw_dump.reserve_dump_area_start = destination_address;
1090 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1091
1092 fadump_release_memory(reserved_area_start, reserved_area_end);
1093 if (fw_dump.cpu_notes_buf) {
1094 fadump_cpu_notes_buf_free(
1095 (unsigned long)__va(fw_dump.cpu_notes_buf),
1096 fw_dump.cpu_notes_buf_size);
1097 fw_dump.cpu_notes_buf = 0;
1098 fw_dump.cpu_notes_buf_size = 0;
1099 }
1100 /* Initialize the kernel dump memory structure for FAD registration. */
1101 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1102}
1103
1104static ssize_t fadump_release_memory_store(struct kobject *kobj,
1105 struct kobj_attribute *attr,
1106 const char *buf, size_t count)
1107{
1108 if (!fw_dump.dump_active)
1109 return -EPERM;
1110
1111 if (buf[0] == '1') {
1112 /*
1113 * Take away the '/proc/vmcore'. We are releasing the dump
1114 * memory, hence it will not be valid anymore.
1115 */
1116#ifdef CONFIG_PROC_VMCORE
1117 vmcore_cleanup();
1118#endif
1119 fadump_invalidate_release_mem();
1120
1121 } else
1122 return -EINVAL;
1123 return count;
1124}
1125
1126static ssize_t fadump_enabled_show(struct kobject *kobj,
1127 struct kobj_attribute *attr,
1128 char *buf)
1129{
1130 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1131}
1132
1133static ssize_t fadump_register_show(struct kobject *kobj,
1134 struct kobj_attribute *attr,
1135 char *buf)
1136{
1137 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1138}
1139
1140static ssize_t fadump_register_store(struct kobject *kobj,
1141 struct kobj_attribute *attr,
1142 const char *buf, size_t count)
1143{
1144 int ret = 0;
1145
1146 if (!fw_dump.fadump_enabled || fdm_active)
1147 return -EPERM;
1148
1149 mutex_lock(&fadump_mutex);
1150
1151 switch (buf[0]) {
1152 case '0':
1153 if (fw_dump.dump_registered == 0) {
1154 ret = -EINVAL;
1155 goto unlock_out;
1156 }
1157 /* Un-register Firmware-assisted dump */
1158 fadump_unregister_dump(&fdm);
1159 break;
1160 case '1':
1161 if (fw_dump.dump_registered == 1) {
1162 ret = -EINVAL;
1163 goto unlock_out;
1164 }
1165 /* Register Firmware-assisted dump */
1166 register_fadump();
1167 break;
1168 default:
1169 ret = -EINVAL;
1170 break;
1171 }
1172
1173unlock_out:
1174 mutex_unlock(&fadump_mutex);
1175 return ret < 0 ? ret : count;
1176}
1177
1178static int fadump_region_show(struct seq_file *m, void *private)
1179{
1180 const struct fadump_mem_struct *fdm_ptr;
1181
1182 if (!fw_dump.fadump_enabled)
1183 return 0;
1184
1185 mutex_lock(&fadump_mutex);
1186 if (fdm_active)
1187 fdm_ptr = fdm_active;
1188 else {
1189 mutex_unlock(&fadump_mutex);
1190 fdm_ptr = &fdm;
1191 }
1192
1193 seq_printf(m,
1194 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1195 "Dumped: %#llx\n",
1196 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1197 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1198 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1199 be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1200 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1201 seq_printf(m,
1202 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1203 "Dumped: %#llx\n",
1204 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1205 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1206 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1207 be64_to_cpu(fdm_ptr->hpte_region.source_len),
1208 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1209 seq_printf(m,
1210 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1211 "Dumped: %#llx\n",
1212 be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1213 be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1214 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1215 be64_to_cpu(fdm_ptr->rmr_region.source_len),
1216 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1217
1218 if (!fdm_active ||
1219 (fw_dump.reserve_dump_area_start ==
1220 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1221 goto out;
1222
1223 /* Dump is active. Show reserved memory region. */
1224 seq_printf(m,
1225 " : [%#016llx-%#016llx] %#llx bytes, "
1226 "Dumped: %#llx\n",
1227 (unsigned long long)fw_dump.reserve_dump_area_start,
1228 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1229 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1230 fw_dump.reserve_dump_area_start,
1231 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1232 fw_dump.reserve_dump_area_start);
1233out:
1234 if (fdm_active)
1235 mutex_unlock(&fadump_mutex);
1236 return 0;
1237}
1238
1239static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1240 0200, NULL,
1241 fadump_release_memory_store);
1242static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1243 0444, fadump_enabled_show,
1244 NULL);
1245static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1246 0644, fadump_register_show,
1247 fadump_register_store);
1248
1249static int fadump_region_open(struct inode *inode, struct file *file)
1250{
1251 return single_open(file, fadump_region_show, inode->i_private);
1252}
1253
1254static const struct file_operations fadump_region_fops = {
1255 .open = fadump_region_open,
1256 .read = seq_read,
1257 .llseek = seq_lseek,
1258 .release = single_release,
1259};
1260
1261static void fadump_init_files(void)
1262{
1263 struct dentry *debugfs_file;
1264 int rc = 0;
1265
1266 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1267 if (rc)
1268 printk(KERN_ERR "fadump: unable to create sysfs file"
1269 " fadump_enabled (%d)\n", rc);
1270
1271 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1272 if (rc)
1273 printk(KERN_ERR "fadump: unable to create sysfs file"
1274 " fadump_registered (%d)\n", rc);
1275
1276 debugfs_file = debugfs_create_file("fadump_region", 0444,
1277 powerpc_debugfs_root, NULL,
1278 &fadump_region_fops);
1279 if (!debugfs_file)
1280 printk(KERN_ERR "fadump: unable to create debugfs file"
1281 " fadump_region\n");
1282
1283 if (fw_dump.dump_active) {
1284 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1285 if (rc)
1286 printk(KERN_ERR "fadump: unable to create sysfs file"
1287 " fadump_release_mem (%d)\n", rc);
1288 }
1289 return;
1290}
1291
1292/*
1293 * Prepare for firmware-assisted dump.
1294 */
1295int __init setup_fadump(void)
1296{
1297 if (!fw_dump.fadump_enabled)
1298 return 0;
1299
1300 if (!fw_dump.fadump_supported) {
1301 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1302 " this hardware\n");
1303 return 0;
1304 }
1305
1306 fadump_show_config();
1307 /*
1308 * If dump data is available then see if it is valid and prepare for
1309 * saving it to the disk.
1310 */
1311 if (fw_dump.dump_active) {
1312 /*
1313 * if dump process fails then invalidate the registration
1314 * and release memory before proceeding for re-registration.
1315 */
1316 if (process_fadump(fdm_active) < 0)
1317 fadump_invalidate_release_mem();
1318 }
1319 /* Initialize the kernel dump memory structure for FAD registration. */
1320 else if (fw_dump.reserve_dump_area_size)
1321 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1322 fadump_init_files();
1323
1324 return 1;
1325}
1326subsys_initcall(setup_fadump);