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
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.
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.
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.
23 * Copyright 2011 IBM Corporation
24 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
28 #define pr_fmt(fmt) "fadump: " fmt
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>
42 #include <asm/fadump.h>
44 static struct fw_dump fw_dump
;
45 static struct fadump_mem_struct fdm
;
46 static const struct fadump_mem_struct
*fdm_active
;
48 static DEFINE_MUTEX(fadump_mutex
);
49 struct fad_crash_memory_ranges crash_memory_ranges
[INIT_CRASHMEM_RANGES
];
52 /* Scan the Firmware Assisted dump configuration details. */
53 int __init
early_init_dt_scan_fw_dump(unsigned long node
,
54 const char *uname
, int depth
, void *data
)
61 if (depth
!= 1 || strcmp(uname
, "rtas") != 0)
65 * Check if Firmware Assisted dump is supported. if yes, check
66 * if dump has been initiated on last reboot.
68 token
= of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump", NULL
);
72 fw_dump
.fadump_supported
= 1;
73 fw_dump
.ibm_configure_kernel_dump
= *token
;
76 * The 'ibm,kernel-dump' rtas node is present only if there is
77 * dump data waiting for us.
79 fdm_active
= of_get_flat_dt_prop(node
, "ibm,kernel-dump", NULL
);
81 fw_dump
.dump_active
= 1;
83 /* Get the sizes required to store dump data for the firmware provided
85 * For each dump section type supported, a 32bit cell which defines
86 * the ID of a supported section followed by two 32 bit cells which
87 * gives teh size of the section in bytes.
89 sections
= of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump-sizes",
95 num_sections
= size
/ (3 * sizeof(u32
));
97 for (i
= 0; i
< num_sections
; i
++, sections
+= 3) {
98 u32 type
= (u32
)of_read_number(sections
, 1);
101 case FADUMP_CPU_STATE_DATA
:
102 fw_dump
.cpu_state_data_size
=
103 of_read_ulong(§ions
[1], 2);
105 case FADUMP_HPTE_REGION
:
106 fw_dump
.hpte_region_size
=
107 of_read_ulong(§ions
[1], 2);
114 int is_fadump_active(void)
116 return fw_dump
.dump_active
;
119 /* Print firmware assisted dump configurations for debugging purpose. */
120 static void fadump_show_config(void)
122 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
123 (fw_dump
.fadump_supported
? "present" : "no support"));
125 if (!fw_dump
.fadump_supported
)
128 pr_debug("Fadump enabled : %s\n",
129 (fw_dump
.fadump_enabled
? "yes" : "no"));
130 pr_debug("Dump Active : %s\n",
131 (fw_dump
.dump_active
? "yes" : "no"));
132 pr_debug("Dump section sizes:\n");
133 pr_debug(" CPU state data size: %lx\n", fw_dump
.cpu_state_data_size
);
134 pr_debug(" HPTE region size : %lx\n", fw_dump
.hpte_region_size
);
135 pr_debug("Boot memory size : %lx\n", fw_dump
.boot_memory_size
);
138 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct
*fdm
,
144 memset(fdm
, 0, sizeof(struct fadump_mem_struct
));
145 addr
= addr
& PAGE_MASK
;
147 fdm
->header
.dump_format_version
= 0x00000001;
148 fdm
->header
.dump_num_sections
= 3;
149 fdm
->header
.dump_status_flag
= 0;
150 fdm
->header
.offset_first_dump_section
=
151 (u32
)offsetof(struct fadump_mem_struct
, cpu_state_data
);
154 * Fields for disk dump option.
155 * We are not using disk dump option, hence set these fields to 0.
157 fdm
->header
.dd_block_size
= 0;
158 fdm
->header
.dd_block_offset
= 0;
159 fdm
->header
.dd_num_blocks
= 0;
160 fdm
->header
.dd_offset_disk_path
= 0;
162 /* set 0 to disable an automatic dump-reboot. */
163 fdm
->header
.max_time_auto
= 0;
165 /* Kernel dump sections */
166 /* cpu state data section. */
167 fdm
->cpu_state_data
.request_flag
= FADUMP_REQUEST_FLAG
;
168 fdm
->cpu_state_data
.source_data_type
= FADUMP_CPU_STATE_DATA
;
169 fdm
->cpu_state_data
.source_address
= 0;
170 fdm
->cpu_state_data
.source_len
= fw_dump
.cpu_state_data_size
;
171 fdm
->cpu_state_data
.destination_address
= addr
;
172 addr
+= fw_dump
.cpu_state_data_size
;
174 /* hpte region section */
175 fdm
->hpte_region
.request_flag
= FADUMP_REQUEST_FLAG
;
176 fdm
->hpte_region
.source_data_type
= FADUMP_HPTE_REGION
;
177 fdm
->hpte_region
.source_address
= 0;
178 fdm
->hpte_region
.source_len
= fw_dump
.hpte_region_size
;
179 fdm
->hpte_region
.destination_address
= addr
;
180 addr
+= fw_dump
.hpte_region_size
;
182 /* RMA region section */
183 fdm
->rmr_region
.request_flag
= FADUMP_REQUEST_FLAG
;
184 fdm
->rmr_region
.source_data_type
= FADUMP_REAL_MODE_REGION
;
185 fdm
->rmr_region
.source_address
= RMA_START
;
186 fdm
->rmr_region
.source_len
= fw_dump
.boot_memory_size
;
187 fdm
->rmr_region
.destination_address
= addr
;
188 addr
+= fw_dump
.boot_memory_size
;
194 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
196 * Function to find the largest memory size we need to reserve during early
197 * boot process. This will be the size of the memory that is required for a
198 * kernel to boot successfully.
200 * This function has been taken from phyp-assisted dump feature implementation.
202 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
204 * TODO: Come up with better approach to find out more accurate memory size
205 * that is required for a kernel to boot successfully.
208 static inline unsigned long fadump_calculate_reserve_size(void)
213 * Check if the size is specified through fadump_reserve_mem= cmdline
214 * option. If yes, then use that.
216 if (fw_dump
.reserve_bootvar
)
217 return fw_dump
.reserve_bootvar
;
219 /* divide by 20 to get 5% of value */
220 size
= memblock_end_of_DRAM() / 20;
222 /* round it down in multiples of 256 */
223 size
= size
& ~0x0FFFFFFFUL
;
225 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
226 if (memory_limit
&& size
> memory_limit
)
229 return (size
> MIN_BOOT_MEM
? size
: MIN_BOOT_MEM
);
233 * Calculate the total memory size required to be reserved for
234 * firmware-assisted dump registration.
236 static unsigned long get_fadump_area_size(void)
238 unsigned long size
= 0;
240 size
+= fw_dump
.cpu_state_data_size
;
241 size
+= fw_dump
.hpte_region_size
;
242 size
+= fw_dump
.boot_memory_size
;
243 size
+= sizeof(struct fadump_crash_info_header
);
244 size
+= sizeof(struct elfhdr
); /* ELF core header.*/
245 size
+= sizeof(struct elf_phdr
); /* place holder for cpu notes */
246 /* Program headers for crash memory regions. */
247 size
+= sizeof(struct elf_phdr
) * (memblock_num_regions(memory
) + 2);
249 size
= PAGE_ALIGN(size
);
253 int __init
fadump_reserve_mem(void)
255 unsigned long base
, size
, memory_boundary
;
257 if (!fw_dump
.fadump_enabled
)
260 if (!fw_dump
.fadump_supported
) {
261 printk(KERN_INFO
"Firmware-assisted dump is not supported on"
263 fw_dump
.fadump_enabled
= 0;
267 * Initialize boot memory size
268 * If dump is active then we have already calculated the size during
272 fw_dump
.boot_memory_size
= fdm_active
->rmr_region
.source_len
;
274 fw_dump
.boot_memory_size
= fadump_calculate_reserve_size();
277 * Calculate the memory boundary.
278 * If memory_limit is less than actual memory boundary then reserve
279 * the memory for fadump beyond the memory_limit and adjust the
280 * memory_limit accordingly, so that the running kernel can run with
281 * specified memory_limit.
283 if (memory_limit
&& memory_limit
< memblock_end_of_DRAM()) {
284 size
= get_fadump_area_size();
285 if ((memory_limit
+ size
) < memblock_end_of_DRAM())
286 memory_limit
+= size
;
288 memory_limit
= memblock_end_of_DRAM();
289 printk(KERN_INFO
"Adjusted memory_limit for firmware-assisted"
290 " dump, now %#016llx\n",
291 (unsigned long long)memory_limit
);
294 memory_boundary
= memory_limit
;
296 memory_boundary
= memblock_end_of_DRAM();
298 if (fw_dump
.dump_active
) {
299 printk(KERN_INFO
"Firmware-assisted dump is active.\n");
301 * If last boot has crashed then reserve all the memory
302 * above boot_memory_size so that we don't touch it until
303 * dump is written to disk by userspace tool. This memory
304 * will be released for general use once the dump is saved.
306 base
= fw_dump
.boot_memory_size
;
307 size
= memory_boundary
- base
;
308 memblock_reserve(base
, size
);
309 printk(KERN_INFO
"Reserved %ldMB of memory at %ldMB "
310 "for saving crash dump\n",
311 (unsigned long)(size
>> 20),
312 (unsigned long)(base
>> 20));
314 fw_dump
.fadumphdr_addr
=
315 fdm_active
->rmr_region
.destination_address
+
316 fdm_active
->rmr_region
.source_len
;
317 pr_debug("fadumphdr_addr = %p\n",
318 (void *) fw_dump
.fadumphdr_addr
);
320 /* Reserve the memory at the top of memory. */
321 size
= get_fadump_area_size();
322 base
= memory_boundary
- size
;
323 memblock_reserve(base
, size
);
324 printk(KERN_INFO
"Reserved %ldMB of memory at %ldMB "
325 "for firmware-assisted dump\n",
326 (unsigned long)(size
>> 20),
327 (unsigned long)(base
>> 20));
329 fw_dump
.reserve_dump_area_start
= base
;
330 fw_dump
.reserve_dump_area_size
= size
;
334 /* Look for fadump= cmdline option. */
335 static int __init
early_fadump_param(char *p
)
340 if (strncmp(p
, "on", 2) == 0)
341 fw_dump
.fadump_enabled
= 1;
342 else if (strncmp(p
, "off", 3) == 0)
343 fw_dump
.fadump_enabled
= 0;
347 early_param("fadump", early_fadump_param
);
349 /* Look for fadump_reserve_mem= cmdline option */
350 static int __init
early_fadump_reserve_mem(char *p
)
353 fw_dump
.reserve_bootvar
= memparse(p
, &p
);
356 early_param("fadump_reserve_mem", early_fadump_reserve_mem
);
358 static void register_fw_dump(struct fadump_mem_struct
*fdm
)
361 unsigned int wait_time
;
363 pr_debug("Registering for firmware-assisted kernel dump...\n");
365 /* TODO: Add upper time limit for the delay */
367 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
368 FADUMP_REGISTER
, fdm
,
369 sizeof(struct fadump_mem_struct
));
371 wait_time
= rtas_busy_delay_time(rc
);
379 printk(KERN_ERR
"Failed to register firmware-assisted kernel"
380 " dump. Hardware Error(%d).\n", rc
);
383 printk(KERN_ERR
"Failed to register firmware-assisted kernel"
384 " dump. Parameter Error(%d).\n", rc
);
387 printk(KERN_ERR
"firmware-assisted kernel dump is already "
389 fw_dump
.dump_registered
= 1;
392 printk(KERN_INFO
"firmware-assisted kernel dump registration"
394 fw_dump
.dump_registered
= 1;
399 void crash_fadump(struct pt_regs
*regs
, const char *str
)
401 struct fadump_crash_info_header
*fdh
= NULL
;
403 if (!fw_dump
.dump_registered
|| !fw_dump
.fadumphdr_addr
)
406 fdh
= __va(fw_dump
.fadumphdr_addr
);
407 crashing_cpu
= smp_processor_id();
408 fdh
->crashing_cpu
= crashing_cpu
;
409 crash_save_vmcoreinfo();
414 ppc_save_regs(&fdh
->regs
);
416 fdh
->cpu_online_mask
= *cpu_online_mask
;
418 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
419 rtas_os_term((char *)str
);
422 #define GPR_MASK 0xffffff0000000000
423 static inline int fadump_gpr_index(u64 id
)
428 if ((id
& GPR_MASK
) == REG_ID("GPR")) {
429 /* get the digits at the end */
434 str
[0] = (id
>> 8) & 0xff;
435 sscanf(str
, "%d", &i
);
442 static inline void fadump_set_regval(struct pt_regs
*regs
, u64 reg_id
,
447 i
= fadump_gpr_index(reg_id
);
449 regs
->gpr
[i
] = (unsigned long)reg_val
;
450 else if (reg_id
== REG_ID("NIA"))
451 regs
->nip
= (unsigned long)reg_val
;
452 else if (reg_id
== REG_ID("MSR"))
453 regs
->msr
= (unsigned long)reg_val
;
454 else if (reg_id
== REG_ID("CTR"))
455 regs
->ctr
= (unsigned long)reg_val
;
456 else if (reg_id
== REG_ID("LR"))
457 regs
->link
= (unsigned long)reg_val
;
458 else if (reg_id
== REG_ID("XER"))
459 regs
->xer
= (unsigned long)reg_val
;
460 else if (reg_id
== REG_ID("CR"))
461 regs
->ccr
= (unsigned long)reg_val
;
462 else if (reg_id
== REG_ID("DAR"))
463 regs
->dar
= (unsigned long)reg_val
;
464 else if (reg_id
== REG_ID("DSISR"))
465 regs
->dsisr
= (unsigned long)reg_val
;
468 static struct fadump_reg_entry
*
469 fadump_read_registers(struct fadump_reg_entry
*reg_entry
, struct pt_regs
*regs
)
471 memset(regs
, 0, sizeof(struct pt_regs
));
473 while (reg_entry
->reg_id
!= REG_ID("CPUEND")) {
474 fadump_set_regval(regs
, reg_entry
->reg_id
,
475 reg_entry
->reg_value
);
482 static u32
*fadump_append_elf_note(u32
*buf
, char *name
, unsigned type
,
483 void *data
, size_t data_len
)
485 struct elf_note note
;
487 note
.n_namesz
= strlen(name
) + 1;
488 note
.n_descsz
= data_len
;
490 memcpy(buf
, ¬e
, sizeof(note
));
491 buf
+= (sizeof(note
) + 3)/4;
492 memcpy(buf
, name
, note
.n_namesz
);
493 buf
+= (note
.n_namesz
+ 3)/4;
494 memcpy(buf
, data
, note
.n_descsz
);
495 buf
+= (note
.n_descsz
+ 3)/4;
500 static void fadump_final_note(u32
*buf
)
502 struct elf_note note
;
507 memcpy(buf
, ¬e
, sizeof(note
));
510 static u32
*fadump_regs_to_elf_notes(u32
*buf
, struct pt_regs
*regs
)
512 struct elf_prstatus prstatus
;
514 memset(&prstatus
, 0, sizeof(prstatus
));
516 * FIXME: How do i get PID? Do I really need it?
517 * prstatus.pr_pid = ????
519 elf_core_copy_kernel_regs(&prstatus
.pr_reg
, regs
);
520 buf
= fadump_append_elf_note(buf
, KEXEC_CORE_NOTE_NAME
, NT_PRSTATUS
,
521 &prstatus
, sizeof(prstatus
));
525 static void fadump_update_elfcore_header(char *bufp
)
528 struct elf_phdr
*phdr
;
530 elf
= (struct elfhdr
*)bufp
;
531 bufp
+= sizeof(struct elfhdr
);
533 /* First note is a place holder for cpu notes info. */
534 phdr
= (struct elf_phdr
*)bufp
;
536 if (phdr
->p_type
== PT_NOTE
) {
537 phdr
->p_paddr
= fw_dump
.cpu_notes_buf
;
538 phdr
->p_offset
= phdr
->p_paddr
;
539 phdr
->p_filesz
= fw_dump
.cpu_notes_buf_size
;
540 phdr
->p_memsz
= fw_dump
.cpu_notes_buf_size
;
545 static void *fadump_cpu_notes_buf_alloc(unsigned long size
)
549 unsigned long order
, count
, i
;
551 order
= get_order(size
);
552 vaddr
= (void *)__get_free_pages(GFP_KERNEL
|__GFP_ZERO
, order
);
557 page
= virt_to_page(vaddr
);
558 for (i
= 0; i
< count
; i
++)
559 SetPageReserved(page
+ i
);
563 static void fadump_cpu_notes_buf_free(unsigned long vaddr
, unsigned long size
)
566 unsigned long order
, count
, i
;
568 order
= get_order(size
);
570 page
= virt_to_page(vaddr
);
571 for (i
= 0; i
< count
; i
++)
572 ClearPageReserved(page
+ i
);
573 __free_pages(page
, order
);
577 * Read CPU state dump data and convert it into ELF notes.
578 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
579 * used to access the data to allow for additional fields to be added without
580 * affecting compatibility. Each list of registers for a CPU starts with
581 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
582 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
583 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
584 * of register value. For more details refer to PAPR document.
586 * Only for the crashing cpu we ignore the CPU dump data and get exact
587 * state from fadump crash info structure populated by first kernel at the
590 static int __init
fadump_build_cpu_notes(const struct fadump_mem_struct
*fdm
)
592 struct fadump_reg_save_area_header
*reg_header
;
593 struct fadump_reg_entry
*reg_entry
;
594 struct fadump_crash_info_header
*fdh
= NULL
;
597 u32 num_cpus
, *note_buf
;
599 int i
, rc
= 0, cpu
= 0;
601 if (!fdm
->cpu_state_data
.bytes_dumped
)
604 addr
= fdm
->cpu_state_data
.destination_address
;
608 if (reg_header
->magic_number
!= REGSAVE_AREA_MAGIC
) {
609 printk(KERN_ERR
"Unable to read register save area.\n");
612 pr_debug("--------CPU State Data------------\n");
613 pr_debug("Magic Number: %llx\n", reg_header
->magic_number
);
614 pr_debug("NumCpuOffset: %x\n", reg_header
->num_cpu_offset
);
616 vaddr
+= reg_header
->num_cpu_offset
;
617 num_cpus
= *((u32
*)(vaddr
));
618 pr_debug("NumCpus : %u\n", num_cpus
);
619 vaddr
+= sizeof(u32
);
620 reg_entry
= (struct fadump_reg_entry
*)vaddr
;
622 /* Allocate buffer to hold cpu crash notes. */
623 fw_dump
.cpu_notes_buf_size
= num_cpus
* sizeof(note_buf_t
);
624 fw_dump
.cpu_notes_buf_size
= PAGE_ALIGN(fw_dump
.cpu_notes_buf_size
);
625 note_buf
= fadump_cpu_notes_buf_alloc(fw_dump
.cpu_notes_buf_size
);
627 printk(KERN_ERR
"Failed to allocate 0x%lx bytes for "
628 "cpu notes buffer\n", fw_dump
.cpu_notes_buf_size
);
631 fw_dump
.cpu_notes_buf
= __pa(note_buf
);
633 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
634 (num_cpus
* sizeof(note_buf_t
)), note_buf
);
636 if (fw_dump
.fadumphdr_addr
)
637 fdh
= __va(fw_dump
.fadumphdr_addr
);
639 for (i
= 0; i
< num_cpus
; i
++) {
640 if (reg_entry
->reg_id
!= REG_ID("CPUSTRT")) {
641 printk(KERN_ERR
"Unable to read CPU state data\n");
645 /* Lower 4 bytes of reg_value contains logical cpu id */
646 cpu
= reg_entry
->reg_value
& FADUMP_CPU_ID_MASK
;
647 if (!cpumask_test_cpu(cpu
, &fdh
->cpu_online_mask
)) {
648 SKIP_TO_NEXT_CPU(reg_entry
);
651 pr_debug("Reading register data for cpu %d...\n", cpu
);
652 if (fdh
&& fdh
->crashing_cpu
== cpu
) {
654 note_buf
= fadump_regs_to_elf_notes(note_buf
, ®s
);
655 SKIP_TO_NEXT_CPU(reg_entry
);
658 reg_entry
= fadump_read_registers(reg_entry
, ®s
);
659 note_buf
= fadump_regs_to_elf_notes(note_buf
, ®s
);
662 fadump_final_note(note_buf
);
664 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
665 fdh
->elfcorehdr_addr
);
666 fadump_update_elfcore_header((char *)__va(fdh
->elfcorehdr_addr
));
670 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump
.cpu_notes_buf
),
671 fw_dump
.cpu_notes_buf_size
);
672 fw_dump
.cpu_notes_buf
= 0;
673 fw_dump
.cpu_notes_buf_size
= 0;
679 * Validate and process the dump data stored by firmware before exporting
680 * it through '/proc/vmcore'.
682 static int __init
process_fadump(const struct fadump_mem_struct
*fdm_active
)
684 struct fadump_crash_info_header
*fdh
;
687 if (!fdm_active
|| !fw_dump
.fadumphdr_addr
)
690 /* Check if the dump data is valid. */
691 if ((fdm_active
->header
.dump_status_flag
== FADUMP_ERROR_FLAG
) ||
692 (fdm_active
->cpu_state_data
.error_flags
!= 0) ||
693 (fdm_active
->rmr_region
.error_flags
!= 0)) {
694 printk(KERN_ERR
"Dump taken by platform is not valid\n");
697 if ((fdm_active
->rmr_region
.bytes_dumped
!=
698 fdm_active
->rmr_region
.source_len
) ||
699 !fdm_active
->cpu_state_data
.bytes_dumped
) {
700 printk(KERN_ERR
"Dump taken by platform is incomplete\n");
704 /* Validate the fadump crash info header */
705 fdh
= __va(fw_dump
.fadumphdr_addr
);
706 if (fdh
->magic_number
!= FADUMP_CRASH_INFO_MAGIC
) {
707 printk(KERN_ERR
"Crash info header is not valid.\n");
711 rc
= fadump_build_cpu_notes(fdm_active
);
716 * We are done validating dump info and elfcore header is now ready
717 * to be exported. set elfcorehdr_addr so that vmcore module will
718 * export the elfcore header through '/proc/vmcore'.
720 elfcorehdr_addr
= fdh
->elfcorehdr_addr
;
725 static inline void fadump_add_crash_memory(unsigned long long base
,
726 unsigned long long end
)
731 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
732 crash_mem_ranges
, base
, end
- 1, (end
- base
));
733 crash_memory_ranges
[crash_mem_ranges
].base
= base
;
734 crash_memory_ranges
[crash_mem_ranges
].size
= end
- base
;
738 static void fadump_exclude_reserved_area(unsigned long long start
,
739 unsigned long long end
)
741 unsigned long long ra_start
, ra_end
;
743 ra_start
= fw_dump
.reserve_dump_area_start
;
744 ra_end
= ra_start
+ fw_dump
.reserve_dump_area_size
;
746 if ((ra_start
< end
) && (ra_end
> start
)) {
747 if ((start
< ra_start
) && (end
> ra_end
)) {
748 fadump_add_crash_memory(start
, ra_start
);
749 fadump_add_crash_memory(ra_end
, end
);
750 } else if (start
< ra_start
) {
751 fadump_add_crash_memory(start
, ra_start
);
752 } else if (ra_end
< end
) {
753 fadump_add_crash_memory(ra_end
, end
);
756 fadump_add_crash_memory(start
, end
);
759 static int fadump_init_elfcore_header(char *bufp
)
763 elf
= (struct elfhdr
*) bufp
;
764 bufp
+= sizeof(struct elfhdr
);
765 memcpy(elf
->e_ident
, ELFMAG
, SELFMAG
);
766 elf
->e_ident
[EI_CLASS
] = ELF_CLASS
;
767 elf
->e_ident
[EI_DATA
] = ELF_DATA
;
768 elf
->e_ident
[EI_VERSION
] = EV_CURRENT
;
769 elf
->e_ident
[EI_OSABI
] = ELF_OSABI
;
770 memset(elf
->e_ident
+EI_PAD
, 0, EI_NIDENT
-EI_PAD
);
771 elf
->e_type
= ET_CORE
;
772 elf
->e_machine
= ELF_ARCH
;
773 elf
->e_version
= EV_CURRENT
;
775 elf
->e_phoff
= sizeof(struct elfhdr
);
777 elf
->e_flags
= ELF_CORE_EFLAGS
;
778 elf
->e_ehsize
= sizeof(struct elfhdr
);
779 elf
->e_phentsize
= sizeof(struct elf_phdr
);
781 elf
->e_shentsize
= 0;
789 * Traverse through memblock structure and setup crash memory ranges. These
790 * ranges will be used create PT_LOAD program headers in elfcore header.
792 static void fadump_setup_crash_memory_ranges(void)
794 struct memblock_region
*reg
;
795 unsigned long long start
, end
;
797 pr_debug("Setup crash memory ranges.\n");
798 crash_mem_ranges
= 0;
800 * add the first memory chunk (RMA_START through boot_memory_size) as
801 * a separate memory chunk. The reason is, at the time crash firmware
802 * will move the content of this memory chunk to different location
803 * specified during fadump registration. We need to create a separate
804 * program header for this chunk with the correct offset.
806 fadump_add_crash_memory(RMA_START
, fw_dump
.boot_memory_size
);
808 for_each_memblock(memory
, reg
) {
809 start
= (unsigned long long)reg
->base
;
810 end
= start
+ (unsigned long long)reg
->size
;
811 if (start
== RMA_START
&& end
>= fw_dump
.boot_memory_size
)
812 start
= fw_dump
.boot_memory_size
;
814 /* add this range excluding the reserved dump area. */
815 fadump_exclude_reserved_area(start
, end
);
820 * If the given physical address falls within the boot memory region then
821 * return the relocated address that points to the dump region reserved
822 * for saving initial boot memory contents.
824 static inline unsigned long fadump_relocate(unsigned long paddr
)
826 if (paddr
> RMA_START
&& paddr
< fw_dump
.boot_memory_size
)
827 return fdm
.rmr_region
.destination_address
+ paddr
;
832 static int fadump_create_elfcore_headers(char *bufp
)
835 struct elf_phdr
*phdr
;
838 fadump_init_elfcore_header(bufp
);
839 elf
= (struct elfhdr
*)bufp
;
840 bufp
+= sizeof(struct elfhdr
);
843 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
844 * will be populated during second kernel boot after crash. Hence
845 * this PT_NOTE will always be the first elf note.
847 * NOTE: Any new ELF note addition should be placed after this note.
849 phdr
= (struct elf_phdr
*)bufp
;
850 bufp
+= sizeof(struct elf_phdr
);
851 phdr
->p_type
= PT_NOTE
;
863 /* setup ELF PT_NOTE for vmcoreinfo */
864 phdr
= (struct elf_phdr
*)bufp
;
865 bufp
+= sizeof(struct elf_phdr
);
866 phdr
->p_type
= PT_NOTE
;
871 phdr
->p_paddr
= fadump_relocate(paddr_vmcoreinfo_note());
872 phdr
->p_offset
= phdr
->p_paddr
;
873 phdr
->p_memsz
= vmcoreinfo_max_size
;
874 phdr
->p_filesz
= vmcoreinfo_max_size
;
876 /* Increment number of program headers. */
879 /* setup PT_LOAD sections. */
881 for (i
= 0; i
< crash_mem_ranges
; i
++) {
882 unsigned long long mbase
, msize
;
883 mbase
= crash_memory_ranges
[i
].base
;
884 msize
= crash_memory_ranges
[i
].size
;
889 phdr
= (struct elf_phdr
*)bufp
;
890 bufp
+= sizeof(struct elf_phdr
);
891 phdr
->p_type
= PT_LOAD
;
892 phdr
->p_flags
= PF_R
|PF_W
|PF_X
;
893 phdr
->p_offset
= mbase
;
895 if (mbase
== RMA_START
) {
897 * The entire RMA region will be moved by firmware
898 * to the specified destination_address. Hence set
899 * the correct offset.
901 phdr
->p_offset
= fdm
.rmr_region
.destination_address
;
904 phdr
->p_paddr
= mbase
;
905 phdr
->p_vaddr
= (unsigned long)__va(mbase
);
906 phdr
->p_filesz
= msize
;
907 phdr
->p_memsz
= msize
;
910 /* Increment number of program headers. */
916 static unsigned long init_fadump_header(unsigned long addr
)
918 struct fadump_crash_info_header
*fdh
;
923 fw_dump
.fadumphdr_addr
= addr
;
925 addr
+= sizeof(struct fadump_crash_info_header
);
927 memset(fdh
, 0, sizeof(struct fadump_crash_info_header
));
928 fdh
->magic_number
= FADUMP_CRASH_INFO_MAGIC
;
929 fdh
->elfcorehdr_addr
= addr
;
930 /* We will set the crashing cpu id in crash_fadump() during crash. */
931 fdh
->crashing_cpu
= CPU_UNKNOWN
;
936 static void register_fadump(void)
942 * If no memory is reserved then we can not register for firmware-
945 if (!fw_dump
.reserve_dump_area_size
)
948 fadump_setup_crash_memory_ranges();
950 addr
= fdm
.rmr_region
.destination_address
+ fdm
.rmr_region
.source_len
;
951 /* Initialize fadump crash info header. */
952 addr
= init_fadump_header(addr
);
955 pr_debug("Creating ELF core headers at %#016lx\n", addr
);
956 fadump_create_elfcore_headers(vaddr
);
958 /* register the future kernel dump with firmware. */
959 register_fw_dump(&fdm
);
962 static int fadump_unregister_dump(struct fadump_mem_struct
*fdm
)
965 unsigned int wait_time
;
967 pr_debug("Un-register firmware-assisted dump\n");
969 /* TODO: Add upper time limit for the delay */
971 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
972 FADUMP_UNREGISTER
, fdm
,
973 sizeof(struct fadump_mem_struct
));
975 wait_time
= rtas_busy_delay_time(rc
);
981 printk(KERN_ERR
"Failed to un-register firmware-assisted dump."
982 " unexpected error(%d).\n", rc
);
985 fw_dump
.dump_registered
= 0;
989 static int fadump_invalidate_dump(struct fadump_mem_struct
*fdm
)
992 unsigned int wait_time
;
994 pr_debug("Invalidating firmware-assisted dump registration\n");
996 /* TODO: Add upper time limit for the delay */
998 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
999 FADUMP_INVALIDATE
, fdm
,
1000 sizeof(struct fadump_mem_struct
));
1002 wait_time
= rtas_busy_delay_time(rc
);
1005 } while (wait_time
);
1008 printk(KERN_ERR
"Failed to invalidate firmware-assisted dump "
1009 "rgistration. unexpected error(%d).\n", rc
);
1012 fw_dump
.dump_active
= 0;
1017 void fadump_cleanup(void)
1019 /* Invalidate the registration only if dump is active. */
1020 if (fw_dump
.dump_active
) {
1021 init_fadump_mem_struct(&fdm
,
1022 fdm_active
->cpu_state_data
.destination_address
);
1023 fadump_invalidate_dump(&fdm
);
1028 * Release the memory that was reserved in early boot to preserve the memory
1029 * contents. The released memory will be available for general use.
1031 static void fadump_release_memory(unsigned long begin
, unsigned long end
)
1034 unsigned long ra_start
, ra_end
;
1036 ra_start
= fw_dump
.reserve_dump_area_start
;
1037 ra_end
= ra_start
+ fw_dump
.reserve_dump_area_size
;
1039 for (addr
= begin
; addr
< end
; addr
+= PAGE_SIZE
) {
1041 * exclude the dump reserve area. Will reuse it for next
1042 * fadump registration.
1044 if (addr
<= ra_end
&& ((addr
+ PAGE_SIZE
) > ra_start
))
1047 ClearPageReserved(pfn_to_page(addr
>> PAGE_SHIFT
));
1048 init_page_count(pfn_to_page(addr
>> PAGE_SHIFT
));
1049 free_page((unsigned long)__va(addr
));
1054 static void fadump_invalidate_release_mem(void)
1056 unsigned long reserved_area_start
, reserved_area_end
;
1057 unsigned long destination_address
;
1059 mutex_lock(&fadump_mutex
);
1060 if (!fw_dump
.dump_active
) {
1061 mutex_unlock(&fadump_mutex
);
1065 destination_address
= fdm_active
->cpu_state_data
.destination_address
;
1067 mutex_unlock(&fadump_mutex
);
1070 * Save the current reserved memory bounds we will require them
1071 * later for releasing the memory for general use.
1073 reserved_area_start
= fw_dump
.reserve_dump_area_start
;
1074 reserved_area_end
= reserved_area_start
+
1075 fw_dump
.reserve_dump_area_size
;
1077 * Setup reserve_dump_area_start and its size so that we can
1078 * reuse this reserved memory for Re-registration.
1080 fw_dump
.reserve_dump_area_start
= destination_address
;
1081 fw_dump
.reserve_dump_area_size
= get_fadump_area_size();
1083 fadump_release_memory(reserved_area_start
, reserved_area_end
);
1084 if (fw_dump
.cpu_notes_buf
) {
1085 fadump_cpu_notes_buf_free(
1086 (unsigned long)__va(fw_dump
.cpu_notes_buf
),
1087 fw_dump
.cpu_notes_buf_size
);
1088 fw_dump
.cpu_notes_buf
= 0;
1089 fw_dump
.cpu_notes_buf_size
= 0;
1091 /* Initialize the kernel dump memory structure for FAD registration. */
1092 init_fadump_mem_struct(&fdm
, fw_dump
.reserve_dump_area_start
);
1095 static ssize_t
fadump_release_memory_store(struct kobject
*kobj
,
1096 struct kobj_attribute
*attr
,
1097 const char *buf
, size_t count
)
1099 if (!fw_dump
.dump_active
)
1102 if (buf
[0] == '1') {
1104 * Take away the '/proc/vmcore'. We are releasing the dump
1105 * memory, hence it will not be valid anymore.
1108 fadump_invalidate_release_mem();
1115 static ssize_t
fadump_enabled_show(struct kobject
*kobj
,
1116 struct kobj_attribute
*attr
,
1119 return sprintf(buf
, "%d\n", fw_dump
.fadump_enabled
);
1122 static ssize_t
fadump_register_show(struct kobject
*kobj
,
1123 struct kobj_attribute
*attr
,
1126 return sprintf(buf
, "%d\n", fw_dump
.dump_registered
);
1129 static ssize_t
fadump_register_store(struct kobject
*kobj
,
1130 struct kobj_attribute
*attr
,
1131 const char *buf
, size_t count
)
1135 if (!fw_dump
.fadump_enabled
|| fdm_active
)
1138 mutex_lock(&fadump_mutex
);
1142 if (fw_dump
.dump_registered
== 0) {
1146 /* Un-register Firmware-assisted dump */
1147 fadump_unregister_dump(&fdm
);
1150 if (fw_dump
.dump_registered
== 1) {
1154 /* Register Firmware-assisted dump */
1163 mutex_unlock(&fadump_mutex
);
1164 return ret
< 0 ? ret
: count
;
1167 static int fadump_region_show(struct seq_file
*m
, void *private)
1169 const struct fadump_mem_struct
*fdm_ptr
;
1171 if (!fw_dump
.fadump_enabled
)
1174 mutex_lock(&fadump_mutex
);
1176 fdm_ptr
= fdm_active
;
1178 mutex_unlock(&fadump_mutex
);
1183 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1185 fdm_ptr
->cpu_state_data
.destination_address
,
1186 fdm_ptr
->cpu_state_data
.destination_address
+
1187 fdm_ptr
->cpu_state_data
.source_len
- 1,
1188 fdm_ptr
->cpu_state_data
.source_len
,
1189 fdm_ptr
->cpu_state_data
.bytes_dumped
);
1191 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1193 fdm_ptr
->hpte_region
.destination_address
,
1194 fdm_ptr
->hpte_region
.destination_address
+
1195 fdm_ptr
->hpte_region
.source_len
- 1,
1196 fdm_ptr
->hpte_region
.source_len
,
1197 fdm_ptr
->hpte_region
.bytes_dumped
);
1199 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1201 fdm_ptr
->rmr_region
.destination_address
,
1202 fdm_ptr
->rmr_region
.destination_address
+
1203 fdm_ptr
->rmr_region
.source_len
- 1,
1204 fdm_ptr
->rmr_region
.source_len
,
1205 fdm_ptr
->rmr_region
.bytes_dumped
);
1208 (fw_dump
.reserve_dump_area_start
==
1209 fdm_ptr
->cpu_state_data
.destination_address
))
1212 /* Dump is active. Show reserved memory region. */
1214 " : [%#016llx-%#016llx] %#llx bytes, "
1216 (unsigned long long)fw_dump
.reserve_dump_area_start
,
1217 fdm_ptr
->cpu_state_data
.destination_address
- 1,
1218 fdm_ptr
->cpu_state_data
.destination_address
-
1219 fw_dump
.reserve_dump_area_start
,
1220 fdm_ptr
->cpu_state_data
.destination_address
-
1221 fw_dump
.reserve_dump_area_start
);
1224 mutex_unlock(&fadump_mutex
);
1228 static struct kobj_attribute fadump_release_attr
= __ATTR(fadump_release_mem
,
1230 fadump_release_memory_store
);
1231 static struct kobj_attribute fadump_attr
= __ATTR(fadump_enabled
,
1232 0444, fadump_enabled_show
,
1234 static struct kobj_attribute fadump_register_attr
= __ATTR(fadump_registered
,
1235 0644, fadump_register_show
,
1236 fadump_register_store
);
1238 static int fadump_region_open(struct inode
*inode
, struct file
*file
)
1240 return single_open(file
, fadump_region_show
, inode
->i_private
);
1243 static const struct file_operations fadump_region_fops
= {
1244 .open
= fadump_region_open
,
1246 .llseek
= seq_lseek
,
1247 .release
= single_release
,
1250 static void fadump_init_files(void)
1252 struct dentry
*debugfs_file
;
1255 rc
= sysfs_create_file(kernel_kobj
, &fadump_attr
.attr
);
1257 printk(KERN_ERR
"fadump: unable to create sysfs file"
1258 " fadump_enabled (%d)\n", rc
);
1260 rc
= sysfs_create_file(kernel_kobj
, &fadump_register_attr
.attr
);
1262 printk(KERN_ERR
"fadump: unable to create sysfs file"
1263 " fadump_registered (%d)\n", rc
);
1265 debugfs_file
= debugfs_create_file("fadump_region", 0444,
1266 powerpc_debugfs_root
, NULL
,
1267 &fadump_region_fops
);
1269 printk(KERN_ERR
"fadump: unable to create debugfs file"
1270 " fadump_region\n");
1272 if (fw_dump
.dump_active
) {
1273 rc
= sysfs_create_file(kernel_kobj
, &fadump_release_attr
.attr
);
1275 printk(KERN_ERR
"fadump: unable to create sysfs file"
1276 " fadump_release_mem (%d)\n", rc
);
1282 * Prepare for firmware-assisted dump.
1284 int __init
setup_fadump(void)
1286 if (!fw_dump
.fadump_enabled
)
1289 if (!fw_dump
.fadump_supported
) {
1290 printk(KERN_ERR
"Firmware-assisted dump is not supported on"
1291 " this hardware\n");
1295 fadump_show_config();
1297 * If dump data is available then see if it is valid and prepare for
1298 * saving it to the disk.
1300 if (fw_dump
.dump_active
) {
1302 * if dump process fails then invalidate the registration
1303 * and release memory before proceeding for re-registration.
1305 if (process_fadump(fdm_active
) < 0)
1306 fadump_invalidate_release_mem();
1308 /* Initialize the kernel dump memory structure for FAD registration. */
1309 else if (fw_dump
.reserve_dump_area_size
)
1310 init_fadump_mem_struct(&fdm
, fw_dump
.reserve_dump_area_start
);
1311 fadump_init_files();
1315 subsys_initcall(setup_fadump
);