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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/*
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/seq_file.h>
34#include <linux/crash_dump.h>
35#include <linux/kobject.h>
36#include <linux/sysfs.h>
37
38#include <asm/debugfs.h>
39#include <asm/page.h>
40#include <asm/prom.h>
41#include <asm/rtas.h>
42#include <asm/fadump.h>
43#include <asm/setup.h>
44
45static struct fw_dump fw_dump;
46static struct fadump_mem_struct fdm;
47static const struct fadump_mem_struct *fdm_active;
48
49static DEFINE_MUTEX(fadump_mutex);
50struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
51int crash_mem_ranges;
52
53/* Scan the Firmware Assisted dump configuration details. */
54int __init early_init_dt_scan_fw_dump(unsigned long node,
55 const char *uname, int depth, void *data)
56{
57 const __be32 *sections;
58 int i, num_sections;
59 int size;
60 const __be32 *token;
61
62 if (depth != 1 || strcmp(uname, "rtas") != 0)
63 return 0;
64
65 /*
66 * Check if Firmware Assisted dump is supported. if yes, check
67 * if dump has been initiated on last reboot.
68 */
69 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
70 if (!token)
71 return 1;
72
73 fw_dump.fadump_supported = 1;
74 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
75
76 /*
77 * The 'ibm,kernel-dump' rtas node is present only if there is
78 * dump data waiting for us.
79 */
80 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
81 if (fdm_active)
82 fw_dump.dump_active = 1;
83
84 /* Get the sizes required to store dump data for the firmware provided
85 * dump sections.
86 * For each dump section type supported, a 32bit cell which defines
87 * the ID of a supported section followed by two 32 bit cells which
88 * gives teh size of the section in bytes.
89 */
90 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
91 &size);
92
93 if (!sections)
94 return 1;
95
96 num_sections = size / (3 * sizeof(u32));
97
98 for (i = 0; i < num_sections; i++, sections += 3) {
99 u32 type = (u32)of_read_number(sections, 1);
100
101 switch (type) {
102 case FADUMP_CPU_STATE_DATA:
103 fw_dump.cpu_state_data_size =
104 of_read_ulong(§ions[1], 2);
105 break;
106 case FADUMP_HPTE_REGION:
107 fw_dump.hpte_region_size =
108 of_read_ulong(§ions[1], 2);
109 break;
110 }
111 }
112
113 return 1;
114}
115
116/*
117 * If fadump is registered, check if the memory provided
118 * falls within boot memory area.
119 */
120int is_fadump_boot_memory_area(u64 addr, ulong size)
121{
122 if (!fw_dump.dump_registered)
123 return 0;
124
125 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size;
126}
127
128int should_fadump_crash(void)
129{
130 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
131 return 0;
132 return 1;
133}
134
135int is_fadump_active(void)
136{
137 return fw_dump.dump_active;
138}
139
140/*
141 * Returns 1, if there are no holes in boot memory area,
142 * 0 otherwise.
143 */
144static int is_boot_memory_area_contiguous(void)
145{
146 struct memblock_region *reg;
147 unsigned long tstart, tend;
148 unsigned long start_pfn = PHYS_PFN(RMA_START);
149 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size);
150 unsigned int ret = 0;
151
152 for_each_memblock(memory, reg) {
153 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
154 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
155 if (tstart < tend) {
156 /* Memory hole from start_pfn to tstart */
157 if (tstart > start_pfn)
158 break;
159
160 if (tend == end_pfn) {
161 ret = 1;
162 break;
163 }
164
165 start_pfn = tend + 1;
166 }
167 }
168
169 return ret;
170}
171
172/* Print firmware assisted dump configurations for debugging purpose. */
173static void fadump_show_config(void)
174{
175 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
176 (fw_dump.fadump_supported ? "present" : "no support"));
177
178 if (!fw_dump.fadump_supported)
179 return;
180
181 pr_debug("Fadump enabled : %s\n",
182 (fw_dump.fadump_enabled ? "yes" : "no"));
183 pr_debug("Dump Active : %s\n",
184 (fw_dump.dump_active ? "yes" : "no"));
185 pr_debug("Dump section sizes:\n");
186 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
187 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size);
188 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
189}
190
191static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
192 unsigned long addr)
193{
194 if (!fdm)
195 return 0;
196
197 memset(fdm, 0, sizeof(struct fadump_mem_struct));
198 addr = addr & PAGE_MASK;
199
200 fdm->header.dump_format_version = cpu_to_be32(0x00000001);
201 fdm->header.dump_num_sections = cpu_to_be16(3);
202 fdm->header.dump_status_flag = 0;
203 fdm->header.offset_first_dump_section =
204 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
205
206 /*
207 * Fields for disk dump option.
208 * We are not using disk dump option, hence set these fields to 0.
209 */
210 fdm->header.dd_block_size = 0;
211 fdm->header.dd_block_offset = 0;
212 fdm->header.dd_num_blocks = 0;
213 fdm->header.dd_offset_disk_path = 0;
214
215 /* set 0 to disable an automatic dump-reboot. */
216 fdm->header.max_time_auto = 0;
217
218 /* Kernel dump sections */
219 /* cpu state data section. */
220 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
221 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
222 fdm->cpu_state_data.source_address = 0;
223 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
224 fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
225 addr += fw_dump.cpu_state_data_size;
226
227 /* hpte region section */
228 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
229 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
230 fdm->hpte_region.source_address = 0;
231 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
232 fdm->hpte_region.destination_address = cpu_to_be64(addr);
233 addr += fw_dump.hpte_region_size;
234
235 /* RMA region section */
236 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
237 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
238 fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
239 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
240 fdm->rmr_region.destination_address = cpu_to_be64(addr);
241 addr += fw_dump.boot_memory_size;
242
243 return addr;
244}
245
246/**
247 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
248 *
249 * Function to find the largest memory size we need to reserve during early
250 * boot process. This will be the size of the memory that is required for a
251 * kernel to boot successfully.
252 *
253 * This function has been taken from phyp-assisted dump feature implementation.
254 *
255 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
256 *
257 * TODO: Come up with better approach to find out more accurate memory size
258 * that is required for a kernel to boot successfully.
259 *
260 */
261static inline unsigned long fadump_calculate_reserve_size(void)
262{
263 int ret;
264 unsigned long long base, size;
265
266 if (fw_dump.reserve_bootvar)
267 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
268
269 /*
270 * Check if the size is specified through crashkernel= cmdline
271 * option. If yes, then use that but ignore base as fadump reserves
272 * memory at a predefined offset.
273 */
274 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
275 &size, &base);
276 if (ret == 0 && size > 0) {
277 unsigned long max_size;
278
279 if (fw_dump.reserve_bootvar)
280 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
281
282 fw_dump.reserve_bootvar = (unsigned long)size;
283
284 /*
285 * Adjust if the boot memory size specified is above
286 * the upper limit.
287 */
288 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
289 if (fw_dump.reserve_bootvar > max_size) {
290 fw_dump.reserve_bootvar = max_size;
291 pr_info("Adjusted boot memory size to %luMB\n",
292 (fw_dump.reserve_bootvar >> 20));
293 }
294
295 return fw_dump.reserve_bootvar;
296 } else if (fw_dump.reserve_bootvar) {
297 /*
298 * 'fadump_reserve_mem=' is being used to reserve memory
299 * for firmware-assisted dump.
300 */
301 return fw_dump.reserve_bootvar;
302 }
303
304 /* divide by 20 to get 5% of value */
305 size = memblock_phys_mem_size() / 20;
306
307 /* round it down in multiples of 256 */
308 size = size & ~0x0FFFFFFFUL;
309
310 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
311 if (memory_limit && size > memory_limit)
312 size = memory_limit;
313
314 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
315}
316
317/*
318 * Calculate the total memory size required to be reserved for
319 * firmware-assisted dump registration.
320 */
321static unsigned long get_fadump_area_size(void)
322{
323 unsigned long size = 0;
324
325 size += fw_dump.cpu_state_data_size;
326 size += fw_dump.hpte_region_size;
327 size += fw_dump.boot_memory_size;
328 size += sizeof(struct fadump_crash_info_header);
329 size += sizeof(struct elfhdr); /* ELF core header.*/
330 size += sizeof(struct elf_phdr); /* place holder for cpu notes */
331 /* Program headers for crash memory regions. */
332 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
333
334 size = PAGE_ALIGN(size);
335 return size;
336}
337
338int __init fadump_reserve_mem(void)
339{
340 unsigned long base, size, memory_boundary;
341
342 if (!fw_dump.fadump_enabled)
343 return 0;
344
345 if (!fw_dump.fadump_supported) {
346 printk(KERN_INFO "Firmware-assisted dump is not supported on"
347 " this hardware\n");
348 fw_dump.fadump_enabled = 0;
349 return 0;
350 }
351 /*
352 * Initialize boot memory size
353 * If dump is active then we have already calculated the size during
354 * first kernel.
355 */
356 if (fdm_active)
357 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
358 else
359 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
360
361 /*
362 * Calculate the memory boundary.
363 * If memory_limit is less than actual memory boundary then reserve
364 * the memory for fadump beyond the memory_limit and adjust the
365 * memory_limit accordingly, so that the running kernel can run with
366 * specified memory_limit.
367 */
368 if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
369 size = get_fadump_area_size();
370 if ((memory_limit + size) < memblock_end_of_DRAM())
371 memory_limit += size;
372 else
373 memory_limit = memblock_end_of_DRAM();
374 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
375 " dump, now %#016llx\n", memory_limit);
376 }
377 if (memory_limit)
378 memory_boundary = memory_limit;
379 else
380 memory_boundary = memblock_end_of_DRAM();
381
382 if (fw_dump.dump_active) {
383 printk(KERN_INFO "Firmware-assisted dump is active.\n");
384 /*
385 * If last boot has crashed then reserve all the memory
386 * above boot_memory_size so that we don't touch it until
387 * dump is written to disk by userspace tool. This memory
388 * will be released for general use once the dump is saved.
389 */
390 base = fw_dump.boot_memory_size;
391 size = memory_boundary - base;
392 memblock_reserve(base, size);
393 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
394 "for saving crash dump\n",
395 (unsigned long)(size >> 20),
396 (unsigned long)(base >> 20));
397
398 fw_dump.fadumphdr_addr =
399 be64_to_cpu(fdm_active->rmr_region.destination_address) +
400 be64_to_cpu(fdm_active->rmr_region.source_len);
401 pr_debug("fadumphdr_addr = %p\n",
402 (void *) fw_dump.fadumphdr_addr);
403 } else {
404 size = get_fadump_area_size();
405
406 /*
407 * Reserve memory at an offset closer to bottom of the RAM to
408 * minimize the impact of memory hot-remove operation. We can't
409 * use memblock_find_in_range() here since it doesn't allocate
410 * from bottom to top.
411 */
412 for (base = fw_dump.boot_memory_size;
413 base <= (memory_boundary - size);
414 base += size) {
415 if (memblock_is_region_memory(base, size) &&
416 !memblock_is_region_reserved(base, size))
417 break;
418 }
419 if ((base > (memory_boundary - size)) ||
420 memblock_reserve(base, size)) {
421 pr_err("Failed to reserve memory\n");
422 return 0;
423 }
424
425 pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
426 "assisted dump (System RAM: %ldMB)\n",
427 (unsigned long)(size >> 20),
428 (unsigned long)(base >> 20),
429 (unsigned long)(memblock_phys_mem_size() >> 20));
430 }
431
432 fw_dump.reserve_dump_area_start = base;
433 fw_dump.reserve_dump_area_size = size;
434 return 1;
435}
436
437unsigned long __init arch_reserved_kernel_pages(void)
438{
439 return memblock_reserved_size() / PAGE_SIZE;
440}
441
442/* Look for fadump= cmdline option. */
443static int __init early_fadump_param(char *p)
444{
445 if (!p)
446 return 1;
447
448 if (strncmp(p, "on", 2) == 0)
449 fw_dump.fadump_enabled = 1;
450 else if (strncmp(p, "off", 3) == 0)
451 fw_dump.fadump_enabled = 0;
452
453 return 0;
454}
455early_param("fadump", early_fadump_param);
456
457/*
458 * Look for fadump_reserve_mem= cmdline option
459 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
460 * the sooner 'crashkernel=' parameter is accustomed to.
461 */
462static int __init early_fadump_reserve_mem(char *p)
463{
464 if (p)
465 fw_dump.reserve_bootvar = memparse(p, &p);
466 return 0;
467}
468early_param("fadump_reserve_mem", early_fadump_reserve_mem);
469
470static int register_fw_dump(struct fadump_mem_struct *fdm)
471{
472 int rc, err;
473 unsigned int wait_time;
474
475 pr_debug("Registering for firmware-assisted kernel dump...\n");
476
477 /* TODO: Add upper time limit for the delay */
478 do {
479 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
480 FADUMP_REGISTER, fdm,
481 sizeof(struct fadump_mem_struct));
482
483 wait_time = rtas_busy_delay_time(rc);
484 if (wait_time)
485 mdelay(wait_time);
486
487 } while (wait_time);
488
489 err = -EIO;
490 switch (rc) {
491 default:
492 pr_err("Failed to register. Unknown Error(%d).\n", rc);
493 break;
494 case -1:
495 printk(KERN_ERR "Failed to register firmware-assisted kernel"
496 " dump. Hardware Error(%d).\n", rc);
497 break;
498 case -3:
499 if (!is_boot_memory_area_contiguous())
500 pr_err("Can't have holes in boot memory area while "
501 "registering fadump\n");
502
503 printk(KERN_ERR "Failed to register firmware-assisted kernel"
504 " dump. Parameter Error(%d).\n", rc);
505 err = -EINVAL;
506 break;
507 case -9:
508 printk(KERN_ERR "firmware-assisted kernel dump is already "
509 " registered.");
510 fw_dump.dump_registered = 1;
511 err = -EEXIST;
512 break;
513 case 0:
514 printk(KERN_INFO "firmware-assisted kernel dump registration"
515 " is successful\n");
516 fw_dump.dump_registered = 1;
517 err = 0;
518 break;
519 }
520 return err;
521}
522
523void crash_fadump(struct pt_regs *regs, const char *str)
524{
525 struct fadump_crash_info_header *fdh = NULL;
526 int old_cpu, this_cpu;
527
528 if (!should_fadump_crash())
529 return;
530
531 /*
532 * old_cpu == -1 means this is the first CPU which has come here,
533 * go ahead and trigger fadump.
534 *
535 * old_cpu != -1 means some other CPU has already on it's way
536 * to trigger fadump, just keep looping here.
537 */
538 this_cpu = smp_processor_id();
539 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
540
541 if (old_cpu != -1) {
542 /*
543 * We can't loop here indefinitely. Wait as long as fadump
544 * is in force. If we race with fadump un-registration this
545 * loop will break and then we go down to normal panic path
546 * and reboot. If fadump is in force the first crashing
547 * cpu will definitely trigger fadump.
548 */
549 while (fw_dump.dump_registered)
550 cpu_relax();
551 return;
552 }
553
554 fdh = __va(fw_dump.fadumphdr_addr);
555 fdh->crashing_cpu = crashing_cpu;
556 crash_save_vmcoreinfo();
557
558 if (regs)
559 fdh->regs = *regs;
560 else
561 ppc_save_regs(&fdh->regs);
562
563 fdh->online_mask = *cpu_online_mask;
564
565 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
566 rtas_os_term((char *)str);
567}
568
569#define GPR_MASK 0xffffff0000000000
570static inline int fadump_gpr_index(u64 id)
571{
572 int i = -1;
573 char str[3];
574
575 if ((id & GPR_MASK) == REG_ID("GPR")) {
576 /* get the digits at the end */
577 id &= ~GPR_MASK;
578 id >>= 24;
579 str[2] = '\0';
580 str[1] = id & 0xff;
581 str[0] = (id >> 8) & 0xff;
582 sscanf(str, "%d", &i);
583 if (i > 31)
584 i = -1;
585 }
586 return i;
587}
588
589static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
590 u64 reg_val)
591{
592 int i;
593
594 i = fadump_gpr_index(reg_id);
595 if (i >= 0)
596 regs->gpr[i] = (unsigned long)reg_val;
597 else if (reg_id == REG_ID("NIA"))
598 regs->nip = (unsigned long)reg_val;
599 else if (reg_id == REG_ID("MSR"))
600 regs->msr = (unsigned long)reg_val;
601 else if (reg_id == REG_ID("CTR"))
602 regs->ctr = (unsigned long)reg_val;
603 else if (reg_id == REG_ID("LR"))
604 regs->link = (unsigned long)reg_val;
605 else if (reg_id == REG_ID("XER"))
606 regs->xer = (unsigned long)reg_val;
607 else if (reg_id == REG_ID("CR"))
608 regs->ccr = (unsigned long)reg_val;
609 else if (reg_id == REG_ID("DAR"))
610 regs->dar = (unsigned long)reg_val;
611 else if (reg_id == REG_ID("DSISR"))
612 regs->dsisr = (unsigned long)reg_val;
613}
614
615static struct fadump_reg_entry*
616fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
617{
618 memset(regs, 0, sizeof(struct pt_regs));
619
620 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
621 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
622 be64_to_cpu(reg_entry->reg_value));
623 reg_entry++;
624 }
625 reg_entry++;
626 return reg_entry;
627}
628
629static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
630{
631 struct elf_prstatus prstatus;
632
633 memset(&prstatus, 0, sizeof(prstatus));
634 /*
635 * FIXME: How do i get PID? Do I really need it?
636 * prstatus.pr_pid = ????
637 */
638 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
639 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
640 &prstatus, sizeof(prstatus));
641 return buf;
642}
643
644static void fadump_update_elfcore_header(char *bufp)
645{
646 struct elfhdr *elf;
647 struct elf_phdr *phdr;
648
649 elf = (struct elfhdr *)bufp;
650 bufp += sizeof(struct elfhdr);
651
652 /* First note is a place holder for cpu notes info. */
653 phdr = (struct elf_phdr *)bufp;
654
655 if (phdr->p_type == PT_NOTE) {
656 phdr->p_paddr = fw_dump.cpu_notes_buf;
657 phdr->p_offset = phdr->p_paddr;
658 phdr->p_filesz = fw_dump.cpu_notes_buf_size;
659 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
660 }
661 return;
662}
663
664static void *fadump_cpu_notes_buf_alloc(unsigned long size)
665{
666 void *vaddr;
667 struct page *page;
668 unsigned long order, count, i;
669
670 order = get_order(size);
671 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
672 if (!vaddr)
673 return NULL;
674
675 count = 1 << order;
676 page = virt_to_page(vaddr);
677 for (i = 0; i < count; i++)
678 SetPageReserved(page + i);
679 return vaddr;
680}
681
682static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
683{
684 struct page *page;
685 unsigned long order, count, i;
686
687 order = get_order(size);
688 count = 1 << order;
689 page = virt_to_page(vaddr);
690 for (i = 0; i < count; i++)
691 ClearPageReserved(page + i);
692 __free_pages(page, order);
693}
694
695/*
696 * Read CPU state dump data and convert it into ELF notes.
697 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
698 * used to access the data to allow for additional fields to be added without
699 * affecting compatibility. Each list of registers for a CPU starts with
700 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
701 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
702 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
703 * of register value. For more details refer to PAPR document.
704 *
705 * Only for the crashing cpu we ignore the CPU dump data and get exact
706 * state from fadump crash info structure populated by first kernel at the
707 * time of crash.
708 */
709static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
710{
711 struct fadump_reg_save_area_header *reg_header;
712 struct fadump_reg_entry *reg_entry;
713 struct fadump_crash_info_header *fdh = NULL;
714 void *vaddr;
715 unsigned long addr;
716 u32 num_cpus, *note_buf;
717 struct pt_regs regs;
718 int i, rc = 0, cpu = 0;
719
720 if (!fdm->cpu_state_data.bytes_dumped)
721 return -EINVAL;
722
723 addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
724 vaddr = __va(addr);
725
726 reg_header = vaddr;
727 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
728 printk(KERN_ERR "Unable to read register save area.\n");
729 return -ENOENT;
730 }
731 pr_debug("--------CPU State Data------------\n");
732 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
733 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
734
735 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
736 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
737 pr_debug("NumCpus : %u\n", num_cpus);
738 vaddr += sizeof(u32);
739 reg_entry = (struct fadump_reg_entry *)vaddr;
740
741 /* Allocate buffer to hold cpu crash notes. */
742 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
743 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
744 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
745 if (!note_buf) {
746 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
747 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
748 return -ENOMEM;
749 }
750 fw_dump.cpu_notes_buf = __pa(note_buf);
751
752 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
753 (num_cpus * sizeof(note_buf_t)), note_buf);
754
755 if (fw_dump.fadumphdr_addr)
756 fdh = __va(fw_dump.fadumphdr_addr);
757
758 for (i = 0; i < num_cpus; i++) {
759 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
760 printk(KERN_ERR "Unable to read CPU state data\n");
761 rc = -ENOENT;
762 goto error_out;
763 }
764 /* Lower 4 bytes of reg_value contains logical cpu id */
765 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
766 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
767 SKIP_TO_NEXT_CPU(reg_entry);
768 continue;
769 }
770 pr_debug("Reading register data for cpu %d...\n", cpu);
771 if (fdh && fdh->crashing_cpu == cpu) {
772 regs = fdh->regs;
773 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
774 SKIP_TO_NEXT_CPU(reg_entry);
775 } else {
776 reg_entry++;
777 reg_entry = fadump_read_registers(reg_entry, ®s);
778 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
779 }
780 }
781 final_note(note_buf);
782
783 if (fdh) {
784 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
785 fdh->elfcorehdr_addr);
786 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
787 }
788 return 0;
789
790error_out:
791 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
792 fw_dump.cpu_notes_buf_size);
793 fw_dump.cpu_notes_buf = 0;
794 fw_dump.cpu_notes_buf_size = 0;
795 return rc;
796
797}
798
799/*
800 * Validate and process the dump data stored by firmware before exporting
801 * it through '/proc/vmcore'.
802 */
803static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
804{
805 struct fadump_crash_info_header *fdh;
806 int rc = 0;
807
808 if (!fdm_active || !fw_dump.fadumphdr_addr)
809 return -EINVAL;
810
811 /* Check if the dump data is valid. */
812 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
813 (fdm_active->cpu_state_data.error_flags != 0) ||
814 (fdm_active->rmr_region.error_flags != 0)) {
815 printk(KERN_ERR "Dump taken by platform is not valid\n");
816 return -EINVAL;
817 }
818 if ((fdm_active->rmr_region.bytes_dumped !=
819 fdm_active->rmr_region.source_len) ||
820 !fdm_active->cpu_state_data.bytes_dumped) {
821 printk(KERN_ERR "Dump taken by platform is incomplete\n");
822 return -EINVAL;
823 }
824
825 /* Validate the fadump crash info header */
826 fdh = __va(fw_dump.fadumphdr_addr);
827 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
828 printk(KERN_ERR "Crash info header is not valid.\n");
829 return -EINVAL;
830 }
831
832 rc = fadump_build_cpu_notes(fdm_active);
833 if (rc)
834 return rc;
835
836 /*
837 * We are done validating dump info and elfcore header is now ready
838 * to be exported. set elfcorehdr_addr so that vmcore module will
839 * export the elfcore header through '/proc/vmcore'.
840 */
841 elfcorehdr_addr = fdh->elfcorehdr_addr;
842
843 return 0;
844}
845
846static inline void fadump_add_crash_memory(unsigned long long base,
847 unsigned long long end)
848{
849 if (base == end)
850 return;
851
852 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
853 crash_mem_ranges, base, end - 1, (end - base));
854 crash_memory_ranges[crash_mem_ranges].base = base;
855 crash_memory_ranges[crash_mem_ranges].size = end - base;
856 crash_mem_ranges++;
857}
858
859static void fadump_exclude_reserved_area(unsigned long long start,
860 unsigned long long end)
861{
862 unsigned long long ra_start, ra_end;
863
864 ra_start = fw_dump.reserve_dump_area_start;
865 ra_end = ra_start + fw_dump.reserve_dump_area_size;
866
867 if ((ra_start < end) && (ra_end > start)) {
868 if ((start < ra_start) && (end > ra_end)) {
869 fadump_add_crash_memory(start, ra_start);
870 fadump_add_crash_memory(ra_end, end);
871 } else if (start < ra_start) {
872 fadump_add_crash_memory(start, ra_start);
873 } else if (ra_end < end) {
874 fadump_add_crash_memory(ra_end, end);
875 }
876 } else
877 fadump_add_crash_memory(start, end);
878}
879
880static int fadump_init_elfcore_header(char *bufp)
881{
882 struct elfhdr *elf;
883
884 elf = (struct elfhdr *) bufp;
885 bufp += sizeof(struct elfhdr);
886 memcpy(elf->e_ident, ELFMAG, SELFMAG);
887 elf->e_ident[EI_CLASS] = ELF_CLASS;
888 elf->e_ident[EI_DATA] = ELF_DATA;
889 elf->e_ident[EI_VERSION] = EV_CURRENT;
890 elf->e_ident[EI_OSABI] = ELF_OSABI;
891 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
892 elf->e_type = ET_CORE;
893 elf->e_machine = ELF_ARCH;
894 elf->e_version = EV_CURRENT;
895 elf->e_entry = 0;
896 elf->e_phoff = sizeof(struct elfhdr);
897 elf->e_shoff = 0;
898#if defined(_CALL_ELF)
899 elf->e_flags = _CALL_ELF;
900#else
901 elf->e_flags = 0;
902#endif
903 elf->e_ehsize = sizeof(struct elfhdr);
904 elf->e_phentsize = sizeof(struct elf_phdr);
905 elf->e_phnum = 0;
906 elf->e_shentsize = 0;
907 elf->e_shnum = 0;
908 elf->e_shstrndx = 0;
909
910 return 0;
911}
912
913/*
914 * Traverse through memblock structure and setup crash memory ranges. These
915 * ranges will be used create PT_LOAD program headers in elfcore header.
916 */
917static void fadump_setup_crash_memory_ranges(void)
918{
919 struct memblock_region *reg;
920 unsigned long long start, end;
921
922 pr_debug("Setup crash memory ranges.\n");
923 crash_mem_ranges = 0;
924 /*
925 * add the first memory chunk (RMA_START through boot_memory_size) as
926 * a separate memory chunk. The reason is, at the time crash firmware
927 * will move the content of this memory chunk to different location
928 * specified during fadump registration. We need to create a separate
929 * program header for this chunk with the correct offset.
930 */
931 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
932
933 for_each_memblock(memory, reg) {
934 start = (unsigned long long)reg->base;
935 end = start + (unsigned long long)reg->size;
936
937 /*
938 * skip the first memory chunk that is already added (RMA_START
939 * through boot_memory_size). This logic needs a relook if and
940 * when RMA_START changes to a non-zero value.
941 */
942 BUILD_BUG_ON(RMA_START != 0);
943 if (start < fw_dump.boot_memory_size) {
944 if (end > fw_dump.boot_memory_size)
945 start = fw_dump.boot_memory_size;
946 else
947 continue;
948 }
949
950 /* add this range excluding the reserved dump area. */
951 fadump_exclude_reserved_area(start, end);
952 }
953}
954
955/*
956 * If the given physical address falls within the boot memory region then
957 * return the relocated address that points to the dump region reserved
958 * for saving initial boot memory contents.
959 */
960static inline unsigned long fadump_relocate(unsigned long paddr)
961{
962 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
963 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
964 else
965 return paddr;
966}
967
968static int fadump_create_elfcore_headers(char *bufp)
969{
970 struct elfhdr *elf;
971 struct elf_phdr *phdr;
972 int i;
973
974 fadump_init_elfcore_header(bufp);
975 elf = (struct elfhdr *)bufp;
976 bufp += sizeof(struct elfhdr);
977
978 /*
979 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
980 * will be populated during second kernel boot after crash. Hence
981 * this PT_NOTE will always be the first elf note.
982 *
983 * NOTE: Any new ELF note addition should be placed after this note.
984 */
985 phdr = (struct elf_phdr *)bufp;
986 bufp += sizeof(struct elf_phdr);
987 phdr->p_type = PT_NOTE;
988 phdr->p_flags = 0;
989 phdr->p_vaddr = 0;
990 phdr->p_align = 0;
991
992 phdr->p_offset = 0;
993 phdr->p_paddr = 0;
994 phdr->p_filesz = 0;
995 phdr->p_memsz = 0;
996
997 (elf->e_phnum)++;
998
999 /* setup ELF PT_NOTE for vmcoreinfo */
1000 phdr = (struct elf_phdr *)bufp;
1001 bufp += sizeof(struct elf_phdr);
1002 phdr->p_type = PT_NOTE;
1003 phdr->p_flags = 0;
1004 phdr->p_vaddr = 0;
1005 phdr->p_align = 0;
1006
1007 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note());
1008 phdr->p_offset = phdr->p_paddr;
1009 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1010
1011 /* Increment number of program headers. */
1012 (elf->e_phnum)++;
1013
1014 /* setup PT_LOAD sections. */
1015
1016 for (i = 0; i < crash_mem_ranges; i++) {
1017 unsigned long long mbase, msize;
1018 mbase = crash_memory_ranges[i].base;
1019 msize = crash_memory_ranges[i].size;
1020
1021 if (!msize)
1022 continue;
1023
1024 phdr = (struct elf_phdr *)bufp;
1025 bufp += sizeof(struct elf_phdr);
1026 phdr->p_type = PT_LOAD;
1027 phdr->p_flags = PF_R|PF_W|PF_X;
1028 phdr->p_offset = mbase;
1029
1030 if (mbase == RMA_START) {
1031 /*
1032 * The entire RMA region will be moved by firmware
1033 * to the specified destination_address. Hence set
1034 * the correct offset.
1035 */
1036 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
1037 }
1038
1039 phdr->p_paddr = mbase;
1040 phdr->p_vaddr = (unsigned long)__va(mbase);
1041 phdr->p_filesz = msize;
1042 phdr->p_memsz = msize;
1043 phdr->p_align = 0;
1044
1045 /* Increment number of program headers. */
1046 (elf->e_phnum)++;
1047 }
1048 return 0;
1049}
1050
1051static unsigned long init_fadump_header(unsigned long addr)
1052{
1053 struct fadump_crash_info_header *fdh;
1054
1055 if (!addr)
1056 return 0;
1057
1058 fw_dump.fadumphdr_addr = addr;
1059 fdh = __va(addr);
1060 addr += sizeof(struct fadump_crash_info_header);
1061
1062 memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1063 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1064 fdh->elfcorehdr_addr = addr;
1065 /* We will set the crashing cpu id in crash_fadump() during crash. */
1066 fdh->crashing_cpu = CPU_UNKNOWN;
1067
1068 return addr;
1069}
1070
1071static int register_fadump(void)
1072{
1073 unsigned long addr;
1074 void *vaddr;
1075
1076 /*
1077 * If no memory is reserved then we can not register for firmware-
1078 * assisted dump.
1079 */
1080 if (!fw_dump.reserve_dump_area_size)
1081 return -ENODEV;
1082
1083 fadump_setup_crash_memory_ranges();
1084
1085 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1086 /* Initialize fadump crash info header. */
1087 addr = init_fadump_header(addr);
1088 vaddr = __va(addr);
1089
1090 pr_debug("Creating ELF core headers at %#016lx\n", addr);
1091 fadump_create_elfcore_headers(vaddr);
1092
1093 /* register the future kernel dump with firmware. */
1094 return register_fw_dump(&fdm);
1095}
1096
1097static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1098{
1099 int rc = 0;
1100 unsigned int wait_time;
1101
1102 pr_debug("Un-register firmware-assisted dump\n");
1103
1104 /* TODO: Add upper time limit for the delay */
1105 do {
1106 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1107 FADUMP_UNREGISTER, fdm,
1108 sizeof(struct fadump_mem_struct));
1109
1110 wait_time = rtas_busy_delay_time(rc);
1111 if (wait_time)
1112 mdelay(wait_time);
1113 } while (wait_time);
1114
1115 if (rc) {
1116 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1117 " unexpected error(%d).\n", rc);
1118 return rc;
1119 }
1120 fw_dump.dump_registered = 0;
1121 return 0;
1122}
1123
1124static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1125{
1126 int rc = 0;
1127 unsigned int wait_time;
1128
1129 pr_debug("Invalidating firmware-assisted dump registration\n");
1130
1131 /* TODO: Add upper time limit for the delay */
1132 do {
1133 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1134 FADUMP_INVALIDATE, fdm,
1135 sizeof(struct fadump_mem_struct));
1136
1137 wait_time = rtas_busy_delay_time(rc);
1138 if (wait_time)
1139 mdelay(wait_time);
1140 } while (wait_time);
1141
1142 if (rc) {
1143 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1144 return rc;
1145 }
1146 fw_dump.dump_active = 0;
1147 fdm_active = NULL;
1148 return 0;
1149}
1150
1151void fadump_cleanup(void)
1152{
1153 /* Invalidate the registration only if dump is active. */
1154 if (fw_dump.dump_active) {
1155 init_fadump_mem_struct(&fdm,
1156 be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1157 fadump_invalidate_dump(&fdm);
1158 }
1159}
1160
1161static void fadump_free_reserved_memory(unsigned long start_pfn,
1162 unsigned long end_pfn)
1163{
1164 unsigned long pfn;
1165 unsigned long time_limit = jiffies + HZ;
1166
1167 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1168 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1169
1170 for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1171 free_reserved_page(pfn_to_page(pfn));
1172
1173 if (time_after(jiffies, time_limit)) {
1174 cond_resched();
1175 time_limit = jiffies + HZ;
1176 }
1177 }
1178}
1179
1180/*
1181 * Skip memory holes and free memory that was actually reserved.
1182 */
1183static void fadump_release_reserved_area(unsigned long start, unsigned long end)
1184{
1185 struct memblock_region *reg;
1186 unsigned long tstart, tend;
1187 unsigned long start_pfn = PHYS_PFN(start);
1188 unsigned long end_pfn = PHYS_PFN(end);
1189
1190 for_each_memblock(memory, reg) {
1191 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
1192 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
1193 if (tstart < tend) {
1194 fadump_free_reserved_memory(tstart, tend);
1195
1196 if (tend == end_pfn)
1197 break;
1198
1199 start_pfn = tend + 1;
1200 }
1201 }
1202}
1203
1204/*
1205 * Release the memory that was reserved in early boot to preserve the memory
1206 * contents. The released memory will be available for general use.
1207 */
1208static void fadump_release_memory(unsigned long begin, unsigned long end)
1209{
1210 unsigned long ra_start, ra_end;
1211
1212 ra_start = fw_dump.reserve_dump_area_start;
1213 ra_end = ra_start + fw_dump.reserve_dump_area_size;
1214
1215 /*
1216 * exclude the dump reserve area. Will reuse it for next
1217 * fadump registration.
1218 */
1219 if (begin < ra_end && end > ra_start) {
1220 if (begin < ra_start)
1221 fadump_release_reserved_area(begin, ra_start);
1222 if (end > ra_end)
1223 fadump_release_reserved_area(ra_end, end);
1224 } else
1225 fadump_release_reserved_area(begin, end);
1226}
1227
1228static void fadump_invalidate_release_mem(void)
1229{
1230 unsigned long reserved_area_start, reserved_area_end;
1231 unsigned long destination_address;
1232
1233 mutex_lock(&fadump_mutex);
1234 if (!fw_dump.dump_active) {
1235 mutex_unlock(&fadump_mutex);
1236 return;
1237 }
1238
1239 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1240 fadump_cleanup();
1241 mutex_unlock(&fadump_mutex);
1242
1243 /*
1244 * Save the current reserved memory bounds we will require them
1245 * later for releasing the memory for general use.
1246 */
1247 reserved_area_start = fw_dump.reserve_dump_area_start;
1248 reserved_area_end = reserved_area_start +
1249 fw_dump.reserve_dump_area_size;
1250 /*
1251 * Setup reserve_dump_area_start and its size so that we can
1252 * reuse this reserved memory for Re-registration.
1253 */
1254 fw_dump.reserve_dump_area_start = destination_address;
1255 fw_dump.reserve_dump_area_size = get_fadump_area_size();
1256
1257 fadump_release_memory(reserved_area_start, reserved_area_end);
1258 if (fw_dump.cpu_notes_buf) {
1259 fadump_cpu_notes_buf_free(
1260 (unsigned long)__va(fw_dump.cpu_notes_buf),
1261 fw_dump.cpu_notes_buf_size);
1262 fw_dump.cpu_notes_buf = 0;
1263 fw_dump.cpu_notes_buf_size = 0;
1264 }
1265 /* Initialize the kernel dump memory structure for FAD registration. */
1266 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1267}
1268
1269static ssize_t fadump_release_memory_store(struct kobject *kobj,
1270 struct kobj_attribute *attr,
1271 const char *buf, size_t count)
1272{
1273 int input = -1;
1274
1275 if (!fw_dump.dump_active)
1276 return -EPERM;
1277
1278 if (kstrtoint(buf, 0, &input))
1279 return -EINVAL;
1280
1281 if (input == 1) {
1282 /*
1283 * Take away the '/proc/vmcore'. We are releasing the dump
1284 * memory, hence it will not be valid anymore.
1285 */
1286#ifdef CONFIG_PROC_VMCORE
1287 vmcore_cleanup();
1288#endif
1289 fadump_invalidate_release_mem();
1290
1291 } else
1292 return -EINVAL;
1293 return count;
1294}
1295
1296static ssize_t fadump_enabled_show(struct kobject *kobj,
1297 struct kobj_attribute *attr,
1298 char *buf)
1299{
1300 return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1301}
1302
1303static ssize_t fadump_register_show(struct kobject *kobj,
1304 struct kobj_attribute *attr,
1305 char *buf)
1306{
1307 return sprintf(buf, "%d\n", fw_dump.dump_registered);
1308}
1309
1310static ssize_t fadump_register_store(struct kobject *kobj,
1311 struct kobj_attribute *attr,
1312 const char *buf, size_t count)
1313{
1314 int ret = 0;
1315 int input = -1;
1316
1317 if (!fw_dump.fadump_enabled || fdm_active)
1318 return -EPERM;
1319
1320 if (kstrtoint(buf, 0, &input))
1321 return -EINVAL;
1322
1323 mutex_lock(&fadump_mutex);
1324
1325 switch (input) {
1326 case 0:
1327 if (fw_dump.dump_registered == 0) {
1328 goto unlock_out;
1329 }
1330 /* Un-register Firmware-assisted dump */
1331 fadump_unregister_dump(&fdm);
1332 break;
1333 case 1:
1334 if (fw_dump.dump_registered == 1) {
1335 ret = -EEXIST;
1336 goto unlock_out;
1337 }
1338 /* Register Firmware-assisted dump */
1339 ret = register_fadump();
1340 break;
1341 default:
1342 ret = -EINVAL;
1343 break;
1344 }
1345
1346unlock_out:
1347 mutex_unlock(&fadump_mutex);
1348 return ret < 0 ? ret : count;
1349}
1350
1351static int fadump_region_show(struct seq_file *m, void *private)
1352{
1353 const struct fadump_mem_struct *fdm_ptr;
1354
1355 if (!fw_dump.fadump_enabled)
1356 return 0;
1357
1358 mutex_lock(&fadump_mutex);
1359 if (fdm_active)
1360 fdm_ptr = fdm_active;
1361 else {
1362 mutex_unlock(&fadump_mutex);
1363 fdm_ptr = &fdm;
1364 }
1365
1366 seq_printf(m,
1367 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1368 "Dumped: %#llx\n",
1369 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1370 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1371 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1372 be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1373 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1374 seq_printf(m,
1375 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1376 "Dumped: %#llx\n",
1377 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1378 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1379 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1380 be64_to_cpu(fdm_ptr->hpte_region.source_len),
1381 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1382 seq_printf(m,
1383 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1384 "Dumped: %#llx\n",
1385 be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1386 be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1387 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1388 be64_to_cpu(fdm_ptr->rmr_region.source_len),
1389 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1390
1391 if (!fdm_active ||
1392 (fw_dump.reserve_dump_area_start ==
1393 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1394 goto out;
1395
1396 /* Dump is active. Show reserved memory region. */
1397 seq_printf(m,
1398 " : [%#016llx-%#016llx] %#llx bytes, "
1399 "Dumped: %#llx\n",
1400 (unsigned long long)fw_dump.reserve_dump_area_start,
1401 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1402 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1403 fw_dump.reserve_dump_area_start,
1404 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1405 fw_dump.reserve_dump_area_start);
1406out:
1407 if (fdm_active)
1408 mutex_unlock(&fadump_mutex);
1409 return 0;
1410}
1411
1412static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1413 0200, NULL,
1414 fadump_release_memory_store);
1415static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1416 0444, fadump_enabled_show,
1417 NULL);
1418static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1419 0644, fadump_register_show,
1420 fadump_register_store);
1421
1422static int fadump_region_open(struct inode *inode, struct file *file)
1423{
1424 return single_open(file, fadump_region_show, inode->i_private);
1425}
1426
1427static const struct file_operations fadump_region_fops = {
1428 .open = fadump_region_open,
1429 .read = seq_read,
1430 .llseek = seq_lseek,
1431 .release = single_release,
1432};
1433
1434static void fadump_init_files(void)
1435{
1436 struct dentry *debugfs_file;
1437 int rc = 0;
1438
1439 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1440 if (rc)
1441 printk(KERN_ERR "fadump: unable to create sysfs file"
1442 " fadump_enabled (%d)\n", rc);
1443
1444 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1445 if (rc)
1446 printk(KERN_ERR "fadump: unable to create sysfs file"
1447 " fadump_registered (%d)\n", rc);
1448
1449 debugfs_file = debugfs_create_file("fadump_region", 0444,
1450 powerpc_debugfs_root, NULL,
1451 &fadump_region_fops);
1452 if (!debugfs_file)
1453 printk(KERN_ERR "fadump: unable to create debugfs file"
1454 " fadump_region\n");
1455
1456 if (fw_dump.dump_active) {
1457 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1458 if (rc)
1459 printk(KERN_ERR "fadump: unable to create sysfs file"
1460 " fadump_release_mem (%d)\n", rc);
1461 }
1462 return;
1463}
1464
1465/*
1466 * Prepare for firmware-assisted dump.
1467 */
1468int __init setup_fadump(void)
1469{
1470 if (!fw_dump.fadump_enabled)
1471 return 0;
1472
1473 if (!fw_dump.fadump_supported) {
1474 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1475 " this hardware\n");
1476 return 0;
1477 }
1478
1479 fadump_show_config();
1480 /*
1481 * If dump data is available then see if it is valid and prepare for
1482 * saving it to the disk.
1483 */
1484 if (fw_dump.dump_active) {
1485 /*
1486 * if dump process fails then invalidate the registration
1487 * and release memory before proceeding for re-registration.
1488 */
1489 if (process_fadump(fdm_active) < 0)
1490 fadump_invalidate_release_mem();
1491 }
1492 /* Initialize the kernel dump memory structure for FAD registration. */
1493 else if (fw_dump.reserve_dump_area_size)
1494 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1495 fadump_init_files();
1496
1497 return 1;
1498}
1499subsys_initcall(setup_fadump);