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