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