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/seq_file.h>
34 #include <linux/crash_dump.h>
35 #include <linux/kobject.h>
36 #include <linux/sysfs.h>
38 #include <asm/debugfs.h>
42 #include <asm/fadump.h>
43 #include <asm/setup.h>
45 static struct fw_dump fw_dump
;
46 static struct fadump_mem_struct fdm
;
47 static const struct fadump_mem_struct
*fdm_active
;
49 static DEFINE_MUTEX(fadump_mutex
);
50 struct fad_crash_memory_ranges crash_memory_ranges
[INIT_CRASHMEM_RANGES
];
53 /* Scan the Firmware Assisted dump configuration details. */
54 int __init
early_init_dt_scan_fw_dump(unsigned long node
,
55 const char *uname
, int depth
, void *data
)
57 const __be32
*sections
;
62 if (depth
!= 1 || strcmp(uname
, "rtas") != 0)
66 * Check if Firmware Assisted dump is supported. if yes, check
67 * if dump has been initiated on last reboot.
69 token
= of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump", NULL
);
73 fw_dump
.fadump_supported
= 1;
74 fw_dump
.ibm_configure_kernel_dump
= be32_to_cpu(*token
);
77 * The 'ibm,kernel-dump' rtas node is present only if there is
78 * dump data waiting for us.
80 fdm_active
= of_get_flat_dt_prop(node
, "ibm,kernel-dump", NULL
);
82 fw_dump
.dump_active
= 1;
84 /* Get the sizes required to store dump data for the firmware provided
86 * For each dump section type supported, a 32bit cell which defines
87 * the ID of a supported section followed by two 32 bit cells which
88 * gives teh size of the section in bytes.
90 sections
= of_get_flat_dt_prop(node
, "ibm,configure-kernel-dump-sizes",
96 num_sections
= size
/ (3 * sizeof(u32
));
98 for (i
= 0; i
< num_sections
; i
++, sections
+= 3) {
99 u32 type
= (u32
)of_read_number(sections
, 1);
102 case FADUMP_CPU_STATE_DATA
:
103 fw_dump
.cpu_state_data_size
=
104 of_read_ulong(§ions
[1], 2);
106 case FADUMP_HPTE_REGION
:
107 fw_dump
.hpte_region_size
=
108 of_read_ulong(§ions
[1], 2);
117 * If fadump is registered, check if the memory provided
118 * falls within boot memory area.
120 int is_fadump_boot_memory_area(u64 addr
, ulong size
)
122 if (!fw_dump
.dump_registered
)
125 return (addr
+ size
) > RMA_START
&& addr
<= fw_dump
.boot_memory_size
;
128 int should_fadump_crash(void)
130 if (!fw_dump
.dump_registered
|| !fw_dump
.fadumphdr_addr
)
135 int is_fadump_active(void)
137 return fw_dump
.dump_active
;
141 * Returns 1, if there are no holes in boot memory area,
144 static int is_boot_memory_area_contiguous(void)
146 struct memblock_region
*reg
;
147 unsigned long tstart
, tend
;
148 unsigned long start_pfn
= PHYS_PFN(RMA_START
);
149 unsigned long end_pfn
= PHYS_PFN(RMA_START
+ fw_dump
.boot_memory_size
);
150 unsigned int ret
= 0;
152 for_each_memblock(memory
, reg
) {
153 tstart
= max(start_pfn
, memblock_region_memory_base_pfn(reg
));
154 tend
= min(end_pfn
, memblock_region_memory_end_pfn(reg
));
156 /* Memory hole from start_pfn to tstart */
157 if (tstart
> start_pfn
)
160 if (tend
== end_pfn
) {
165 start_pfn
= tend
+ 1;
172 /* Print firmware assisted dump configurations for debugging purpose. */
173 static void fadump_show_config(void)
175 pr_debug("Support for firmware-assisted dump (fadump): %s\n",
176 (fw_dump
.fadump_supported
? "present" : "no support"));
178 if (!fw_dump
.fadump_supported
)
181 pr_debug("Fadump enabled : %s\n",
182 (fw_dump
.fadump_enabled
? "yes" : "no"));
183 pr_debug("Dump Active : %s\n",
184 (fw_dump
.dump_active
? "yes" : "no"));
185 pr_debug("Dump section sizes:\n");
186 pr_debug(" CPU state data size: %lx\n", fw_dump
.cpu_state_data_size
);
187 pr_debug(" HPTE region size : %lx\n", fw_dump
.hpte_region_size
);
188 pr_debug("Boot memory size : %lx\n", fw_dump
.boot_memory_size
);
191 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct
*fdm
,
197 memset(fdm
, 0, sizeof(struct fadump_mem_struct
));
198 addr
= addr
& PAGE_MASK
;
200 fdm
->header
.dump_format_version
= cpu_to_be32(0x00000001);
201 fdm
->header
.dump_num_sections
= cpu_to_be16(3);
202 fdm
->header
.dump_status_flag
= 0;
203 fdm
->header
.offset_first_dump_section
=
204 cpu_to_be32((u32
)offsetof(struct fadump_mem_struct
, cpu_state_data
));
207 * Fields for disk dump option.
208 * We are not using disk dump option, hence set these fields to 0.
210 fdm
->header
.dd_block_size
= 0;
211 fdm
->header
.dd_block_offset
= 0;
212 fdm
->header
.dd_num_blocks
= 0;
213 fdm
->header
.dd_offset_disk_path
= 0;
215 /* set 0 to disable an automatic dump-reboot. */
216 fdm
->header
.max_time_auto
= 0;
218 /* Kernel dump sections */
219 /* cpu state data section. */
220 fdm
->cpu_state_data
.request_flag
= cpu_to_be32(FADUMP_REQUEST_FLAG
);
221 fdm
->cpu_state_data
.source_data_type
= cpu_to_be16(FADUMP_CPU_STATE_DATA
);
222 fdm
->cpu_state_data
.source_address
= 0;
223 fdm
->cpu_state_data
.source_len
= cpu_to_be64(fw_dump
.cpu_state_data_size
);
224 fdm
->cpu_state_data
.destination_address
= cpu_to_be64(addr
);
225 addr
+= fw_dump
.cpu_state_data_size
;
227 /* hpte region section */
228 fdm
->hpte_region
.request_flag
= cpu_to_be32(FADUMP_REQUEST_FLAG
);
229 fdm
->hpte_region
.source_data_type
= cpu_to_be16(FADUMP_HPTE_REGION
);
230 fdm
->hpte_region
.source_address
= 0;
231 fdm
->hpte_region
.source_len
= cpu_to_be64(fw_dump
.hpte_region_size
);
232 fdm
->hpte_region
.destination_address
= cpu_to_be64(addr
);
233 addr
+= fw_dump
.hpte_region_size
;
235 /* RMA region section */
236 fdm
->rmr_region
.request_flag
= cpu_to_be32(FADUMP_REQUEST_FLAG
);
237 fdm
->rmr_region
.source_data_type
= cpu_to_be16(FADUMP_REAL_MODE_REGION
);
238 fdm
->rmr_region
.source_address
= cpu_to_be64(RMA_START
);
239 fdm
->rmr_region
.source_len
= cpu_to_be64(fw_dump
.boot_memory_size
);
240 fdm
->rmr_region
.destination_address
= cpu_to_be64(addr
);
241 addr
+= fw_dump
.boot_memory_size
;
247 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
249 * Function to find the largest memory size we need to reserve during early
250 * boot process. This will be the size of the memory that is required for a
251 * kernel to boot successfully.
253 * This function has been taken from phyp-assisted dump feature implementation.
255 * returns larger of 256MB or 5% rounded down to multiples of 256MB.
257 * TODO: Come up with better approach to find out more accurate memory size
258 * that is required for a kernel to boot successfully.
261 static inline unsigned long fadump_calculate_reserve_size(void)
264 unsigned long long base
, size
;
266 if (fw_dump
.reserve_bootvar
)
267 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
270 * Check if the size is specified through crashkernel= cmdline
271 * option. If yes, then use that but ignore base as fadump reserves
272 * memory at a predefined offset.
274 ret
= parse_crashkernel(boot_command_line
, memblock_phys_mem_size(),
276 if (ret
== 0 && size
> 0) {
277 unsigned long max_size
;
279 if (fw_dump
.reserve_bootvar
)
280 pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
282 fw_dump
.reserve_bootvar
= (unsigned long)size
;
285 * Adjust if the boot memory size specified is above
288 max_size
= memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO
;
289 if (fw_dump
.reserve_bootvar
> max_size
) {
290 fw_dump
.reserve_bootvar
= max_size
;
291 pr_info("Adjusted boot memory size to %luMB\n",
292 (fw_dump
.reserve_bootvar
>> 20));
295 return fw_dump
.reserve_bootvar
;
296 } else if (fw_dump
.reserve_bootvar
) {
298 * 'fadump_reserve_mem=' is being used to reserve memory
299 * for firmware-assisted dump.
301 return fw_dump
.reserve_bootvar
;
304 /* divide by 20 to get 5% of value */
305 size
= memblock_phys_mem_size() / 20;
307 /* round it down in multiples of 256 */
308 size
= size
& ~0x0FFFFFFFUL
;
310 /* Truncate to memory_limit. We don't want to over reserve the memory.*/
311 if (memory_limit
&& size
> memory_limit
)
314 return (size
> MIN_BOOT_MEM
? size
: MIN_BOOT_MEM
);
318 * Calculate the total memory size required to be reserved for
319 * firmware-assisted dump registration.
321 static unsigned long get_fadump_area_size(void)
323 unsigned long size
= 0;
325 size
+= fw_dump
.cpu_state_data_size
;
326 size
+= fw_dump
.hpte_region_size
;
327 size
+= fw_dump
.boot_memory_size
;
328 size
+= sizeof(struct fadump_crash_info_header
);
329 size
+= sizeof(struct elfhdr
); /* ELF core header.*/
330 size
+= sizeof(struct elf_phdr
); /* place holder for cpu notes */
331 /* Program headers for crash memory regions. */
332 size
+= sizeof(struct elf_phdr
) * (memblock_num_regions(memory
) + 2);
334 size
= PAGE_ALIGN(size
);
338 int __init
fadump_reserve_mem(void)
340 unsigned long base
, size
, memory_boundary
;
342 if (!fw_dump
.fadump_enabled
)
345 if (!fw_dump
.fadump_supported
) {
346 printk(KERN_INFO
"Firmware-assisted dump is not supported on"
348 fw_dump
.fadump_enabled
= 0;
352 * Initialize boot memory size
353 * If dump is active then we have already calculated the size during
357 fw_dump
.boot_memory_size
= be64_to_cpu(fdm_active
->rmr_region
.source_len
);
359 fw_dump
.boot_memory_size
= fadump_calculate_reserve_size();
362 * Calculate the memory boundary.
363 * If memory_limit is less than actual memory boundary then reserve
364 * the memory for fadump beyond the memory_limit and adjust the
365 * memory_limit accordingly, so that the running kernel can run with
366 * specified memory_limit.
368 if (memory_limit
&& memory_limit
< memblock_end_of_DRAM()) {
369 size
= get_fadump_area_size();
370 if ((memory_limit
+ size
) < memblock_end_of_DRAM())
371 memory_limit
+= size
;
373 memory_limit
= memblock_end_of_DRAM();
374 printk(KERN_INFO
"Adjusted memory_limit for firmware-assisted"
375 " dump, now %#016llx\n", memory_limit
);
378 memory_boundary
= memory_limit
;
380 memory_boundary
= memblock_end_of_DRAM();
382 if (fw_dump
.dump_active
) {
383 printk(KERN_INFO
"Firmware-assisted dump is active.\n");
385 * If last boot has crashed then reserve all the memory
386 * above boot_memory_size so that we don't touch it until
387 * dump is written to disk by userspace tool. This memory
388 * will be released for general use once the dump is saved.
390 base
= fw_dump
.boot_memory_size
;
391 size
= memory_boundary
- base
;
392 memblock_reserve(base
, size
);
393 printk(KERN_INFO
"Reserved %ldMB of memory at %ldMB "
394 "for saving crash dump\n",
395 (unsigned long)(size
>> 20),
396 (unsigned long)(base
>> 20));
398 fw_dump
.fadumphdr_addr
=
399 be64_to_cpu(fdm_active
->rmr_region
.destination_address
) +
400 be64_to_cpu(fdm_active
->rmr_region
.source_len
);
401 pr_debug("fadumphdr_addr = %p\n",
402 (void *) fw_dump
.fadumphdr_addr
);
404 size
= get_fadump_area_size();
407 * Reserve memory at an offset closer to bottom of the RAM to
408 * minimize the impact of memory hot-remove operation. We can't
409 * use memblock_find_in_range() here since it doesn't allocate
410 * from bottom to top.
412 for (base
= fw_dump
.boot_memory_size
;
413 base
<= (memory_boundary
- size
);
415 if (memblock_is_region_memory(base
, size
) &&
416 !memblock_is_region_reserved(base
, size
))
419 if ((base
> (memory_boundary
- size
)) ||
420 memblock_reserve(base
, size
)) {
421 pr_err("Failed to reserve memory\n");
425 pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
426 "assisted dump (System RAM: %ldMB)\n",
427 (unsigned long)(size
>> 20),
428 (unsigned long)(base
>> 20),
429 (unsigned long)(memblock_phys_mem_size() >> 20));
432 fw_dump
.reserve_dump_area_start
= base
;
433 fw_dump
.reserve_dump_area_size
= size
;
437 unsigned long __init
arch_reserved_kernel_pages(void)
439 return memblock_reserved_size() / PAGE_SIZE
;
442 /* Look for fadump= cmdline option. */
443 static int __init
early_fadump_param(char *p
)
448 if (strncmp(p
, "on", 2) == 0)
449 fw_dump
.fadump_enabled
= 1;
450 else if (strncmp(p
, "off", 3) == 0)
451 fw_dump
.fadump_enabled
= 0;
455 early_param("fadump", early_fadump_param
);
458 * Look for fadump_reserve_mem= cmdline option
459 * TODO: Remove references to 'fadump_reserve_mem=' parameter,
460 * the sooner 'crashkernel=' parameter is accustomed to.
462 static int __init
early_fadump_reserve_mem(char *p
)
465 fw_dump
.reserve_bootvar
= memparse(p
, &p
);
468 early_param("fadump_reserve_mem", early_fadump_reserve_mem
);
470 static int register_fw_dump(struct fadump_mem_struct
*fdm
)
473 unsigned int wait_time
;
475 pr_debug("Registering for firmware-assisted kernel dump...\n");
477 /* TODO: Add upper time limit for the delay */
479 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
480 FADUMP_REGISTER
, fdm
,
481 sizeof(struct fadump_mem_struct
));
483 wait_time
= rtas_busy_delay_time(rc
);
492 pr_err("Failed to register. Unknown Error(%d).\n", rc
);
495 printk(KERN_ERR
"Failed to register firmware-assisted kernel"
496 " dump. Hardware Error(%d).\n", rc
);
499 if (!is_boot_memory_area_contiguous())
500 pr_err("Can't have holes in boot memory area while "
501 "registering fadump\n");
503 printk(KERN_ERR
"Failed to register firmware-assisted kernel"
504 " dump. Parameter Error(%d).\n", rc
);
508 printk(KERN_ERR
"firmware-assisted kernel dump is already "
510 fw_dump
.dump_registered
= 1;
514 printk(KERN_INFO
"firmware-assisted kernel dump registration"
516 fw_dump
.dump_registered
= 1;
523 void crash_fadump(struct pt_regs
*regs
, const char *str
)
525 struct fadump_crash_info_header
*fdh
= NULL
;
526 int old_cpu
, this_cpu
;
528 if (!should_fadump_crash())
532 * old_cpu == -1 means this is the first CPU which has come here,
533 * go ahead and trigger fadump.
535 * old_cpu != -1 means some other CPU has already on it's way
536 * to trigger fadump, just keep looping here.
538 this_cpu
= smp_processor_id();
539 old_cpu
= cmpxchg(&crashing_cpu
, -1, this_cpu
);
543 * We can't loop here indefinitely. Wait as long as fadump
544 * is in force. If we race with fadump un-registration this
545 * loop will break and then we go down to normal panic path
546 * and reboot. If fadump is in force the first crashing
547 * cpu will definitely trigger fadump.
549 while (fw_dump
.dump_registered
)
554 fdh
= __va(fw_dump
.fadumphdr_addr
);
555 fdh
->crashing_cpu
= crashing_cpu
;
556 crash_save_vmcoreinfo();
561 ppc_save_regs(&fdh
->regs
);
563 fdh
->online_mask
= *cpu_online_mask
;
565 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
566 rtas_os_term((char *)str
);
569 #define GPR_MASK 0xffffff0000000000
570 static inline int fadump_gpr_index(u64 id
)
575 if ((id
& GPR_MASK
) == REG_ID("GPR")) {
576 /* get the digits at the end */
581 str
[0] = (id
>> 8) & 0xff;
582 sscanf(str
, "%d", &i
);
589 static inline void fadump_set_regval(struct pt_regs
*regs
, u64 reg_id
,
594 i
= fadump_gpr_index(reg_id
);
596 regs
->gpr
[i
] = (unsigned long)reg_val
;
597 else if (reg_id
== REG_ID("NIA"))
598 regs
->nip
= (unsigned long)reg_val
;
599 else if (reg_id
== REG_ID("MSR"))
600 regs
->msr
= (unsigned long)reg_val
;
601 else if (reg_id
== REG_ID("CTR"))
602 regs
->ctr
= (unsigned long)reg_val
;
603 else if (reg_id
== REG_ID("LR"))
604 regs
->link
= (unsigned long)reg_val
;
605 else if (reg_id
== REG_ID("XER"))
606 regs
->xer
= (unsigned long)reg_val
;
607 else if (reg_id
== REG_ID("CR"))
608 regs
->ccr
= (unsigned long)reg_val
;
609 else if (reg_id
== REG_ID("DAR"))
610 regs
->dar
= (unsigned long)reg_val
;
611 else if (reg_id
== REG_ID("DSISR"))
612 regs
->dsisr
= (unsigned long)reg_val
;
615 static struct fadump_reg_entry
*
616 fadump_read_registers(struct fadump_reg_entry
*reg_entry
, struct pt_regs
*regs
)
618 memset(regs
, 0, sizeof(struct pt_regs
));
620 while (be64_to_cpu(reg_entry
->reg_id
) != REG_ID("CPUEND")) {
621 fadump_set_regval(regs
, be64_to_cpu(reg_entry
->reg_id
),
622 be64_to_cpu(reg_entry
->reg_value
));
629 static u32
*fadump_regs_to_elf_notes(u32
*buf
, struct pt_regs
*regs
)
631 struct elf_prstatus prstatus
;
633 memset(&prstatus
, 0, sizeof(prstatus
));
635 * FIXME: How do i get PID? Do I really need it?
636 * prstatus.pr_pid = ????
638 elf_core_copy_kernel_regs(&prstatus
.pr_reg
, regs
);
639 buf
= append_elf_note(buf
, CRASH_CORE_NOTE_NAME
, NT_PRSTATUS
,
640 &prstatus
, sizeof(prstatus
));
644 static void fadump_update_elfcore_header(char *bufp
)
647 struct elf_phdr
*phdr
;
649 elf
= (struct elfhdr
*)bufp
;
650 bufp
+= sizeof(struct elfhdr
);
652 /* First note is a place holder for cpu notes info. */
653 phdr
= (struct elf_phdr
*)bufp
;
655 if (phdr
->p_type
== PT_NOTE
) {
656 phdr
->p_paddr
= fw_dump
.cpu_notes_buf
;
657 phdr
->p_offset
= phdr
->p_paddr
;
658 phdr
->p_filesz
= fw_dump
.cpu_notes_buf_size
;
659 phdr
->p_memsz
= fw_dump
.cpu_notes_buf_size
;
664 static void *fadump_cpu_notes_buf_alloc(unsigned long size
)
668 unsigned long order
, count
, i
;
670 order
= get_order(size
);
671 vaddr
= (void *)__get_free_pages(GFP_KERNEL
|__GFP_ZERO
, order
);
676 page
= virt_to_page(vaddr
);
677 for (i
= 0; i
< count
; i
++)
678 SetPageReserved(page
+ i
);
682 static void fadump_cpu_notes_buf_free(unsigned long vaddr
, unsigned long size
)
685 unsigned long order
, count
, i
;
687 order
= get_order(size
);
689 page
= virt_to_page(vaddr
);
690 for (i
= 0; i
< count
; i
++)
691 ClearPageReserved(page
+ i
);
692 __free_pages(page
, order
);
696 * Read CPU state dump data and convert it into ELF notes.
697 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
698 * used to access the data to allow for additional fields to be added without
699 * affecting compatibility. Each list of registers for a CPU starts with
700 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
701 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
702 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
703 * of register value. For more details refer to PAPR document.
705 * Only for the crashing cpu we ignore the CPU dump data and get exact
706 * state from fadump crash info structure populated by first kernel at the
709 static int __init
fadump_build_cpu_notes(const struct fadump_mem_struct
*fdm
)
711 struct fadump_reg_save_area_header
*reg_header
;
712 struct fadump_reg_entry
*reg_entry
;
713 struct fadump_crash_info_header
*fdh
= NULL
;
716 u32 num_cpus
, *note_buf
;
718 int i
, rc
= 0, cpu
= 0;
720 if (!fdm
->cpu_state_data
.bytes_dumped
)
723 addr
= be64_to_cpu(fdm
->cpu_state_data
.destination_address
);
727 if (be64_to_cpu(reg_header
->magic_number
) != REGSAVE_AREA_MAGIC
) {
728 printk(KERN_ERR
"Unable to read register save area.\n");
731 pr_debug("--------CPU State Data------------\n");
732 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header
->magic_number
));
733 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header
->num_cpu_offset
));
735 vaddr
+= be32_to_cpu(reg_header
->num_cpu_offset
);
736 num_cpus
= be32_to_cpu(*((__be32
*)(vaddr
)));
737 pr_debug("NumCpus : %u\n", num_cpus
);
738 vaddr
+= sizeof(u32
);
739 reg_entry
= (struct fadump_reg_entry
*)vaddr
;
741 /* Allocate buffer to hold cpu crash notes. */
742 fw_dump
.cpu_notes_buf_size
= num_cpus
* sizeof(note_buf_t
);
743 fw_dump
.cpu_notes_buf_size
= PAGE_ALIGN(fw_dump
.cpu_notes_buf_size
);
744 note_buf
= fadump_cpu_notes_buf_alloc(fw_dump
.cpu_notes_buf_size
);
746 printk(KERN_ERR
"Failed to allocate 0x%lx bytes for "
747 "cpu notes buffer\n", fw_dump
.cpu_notes_buf_size
);
750 fw_dump
.cpu_notes_buf
= __pa(note_buf
);
752 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
753 (num_cpus
* sizeof(note_buf_t
)), note_buf
);
755 if (fw_dump
.fadumphdr_addr
)
756 fdh
= __va(fw_dump
.fadumphdr_addr
);
758 for (i
= 0; i
< num_cpus
; i
++) {
759 if (be64_to_cpu(reg_entry
->reg_id
) != REG_ID("CPUSTRT")) {
760 printk(KERN_ERR
"Unable to read CPU state data\n");
764 /* Lower 4 bytes of reg_value contains logical cpu id */
765 cpu
= be64_to_cpu(reg_entry
->reg_value
) & FADUMP_CPU_ID_MASK
;
766 if (fdh
&& !cpumask_test_cpu(cpu
, &fdh
->online_mask
)) {
767 SKIP_TO_NEXT_CPU(reg_entry
);
770 pr_debug("Reading register data for cpu %d...\n", cpu
);
771 if (fdh
&& fdh
->crashing_cpu
== cpu
) {
773 note_buf
= fadump_regs_to_elf_notes(note_buf
, ®s
);
774 SKIP_TO_NEXT_CPU(reg_entry
);
777 reg_entry
= fadump_read_registers(reg_entry
, ®s
);
778 note_buf
= fadump_regs_to_elf_notes(note_buf
, ®s
);
781 final_note(note_buf
);
784 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
785 fdh
->elfcorehdr_addr
);
786 fadump_update_elfcore_header((char *)__va(fdh
->elfcorehdr_addr
));
791 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump
.cpu_notes_buf
),
792 fw_dump
.cpu_notes_buf_size
);
793 fw_dump
.cpu_notes_buf
= 0;
794 fw_dump
.cpu_notes_buf_size
= 0;
800 * Validate and process the dump data stored by firmware before exporting
801 * it through '/proc/vmcore'.
803 static int __init
process_fadump(const struct fadump_mem_struct
*fdm_active
)
805 struct fadump_crash_info_header
*fdh
;
808 if (!fdm_active
|| !fw_dump
.fadumphdr_addr
)
811 /* Check if the dump data is valid. */
812 if ((be16_to_cpu(fdm_active
->header
.dump_status_flag
) == FADUMP_ERROR_FLAG
) ||
813 (fdm_active
->cpu_state_data
.error_flags
!= 0) ||
814 (fdm_active
->rmr_region
.error_flags
!= 0)) {
815 printk(KERN_ERR
"Dump taken by platform is not valid\n");
818 if ((fdm_active
->rmr_region
.bytes_dumped
!=
819 fdm_active
->rmr_region
.source_len
) ||
820 !fdm_active
->cpu_state_data
.bytes_dumped
) {
821 printk(KERN_ERR
"Dump taken by platform is incomplete\n");
825 /* Validate the fadump crash info header */
826 fdh
= __va(fw_dump
.fadumphdr_addr
);
827 if (fdh
->magic_number
!= FADUMP_CRASH_INFO_MAGIC
) {
828 printk(KERN_ERR
"Crash info header is not valid.\n");
832 rc
= fadump_build_cpu_notes(fdm_active
);
837 * We are done validating dump info and elfcore header is now ready
838 * to be exported. set elfcorehdr_addr so that vmcore module will
839 * export the elfcore header through '/proc/vmcore'.
841 elfcorehdr_addr
= fdh
->elfcorehdr_addr
;
846 static inline void fadump_add_crash_memory(unsigned long long base
,
847 unsigned long long end
)
852 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
853 crash_mem_ranges
, base
, end
- 1, (end
- base
));
854 crash_memory_ranges
[crash_mem_ranges
].base
= base
;
855 crash_memory_ranges
[crash_mem_ranges
].size
= end
- base
;
859 static void fadump_exclude_reserved_area(unsigned long long start
,
860 unsigned long long end
)
862 unsigned long long ra_start
, ra_end
;
864 ra_start
= fw_dump
.reserve_dump_area_start
;
865 ra_end
= ra_start
+ fw_dump
.reserve_dump_area_size
;
867 if ((ra_start
< end
) && (ra_end
> start
)) {
868 if ((start
< ra_start
) && (end
> ra_end
)) {
869 fadump_add_crash_memory(start
, ra_start
);
870 fadump_add_crash_memory(ra_end
, end
);
871 } else if (start
< ra_start
) {
872 fadump_add_crash_memory(start
, ra_start
);
873 } else if (ra_end
< end
) {
874 fadump_add_crash_memory(ra_end
, end
);
877 fadump_add_crash_memory(start
, end
);
880 static int fadump_init_elfcore_header(char *bufp
)
884 elf
= (struct elfhdr
*) bufp
;
885 bufp
+= sizeof(struct elfhdr
);
886 memcpy(elf
->e_ident
, ELFMAG
, SELFMAG
);
887 elf
->e_ident
[EI_CLASS
] = ELF_CLASS
;
888 elf
->e_ident
[EI_DATA
] = ELF_DATA
;
889 elf
->e_ident
[EI_VERSION
] = EV_CURRENT
;
890 elf
->e_ident
[EI_OSABI
] = ELF_OSABI
;
891 memset(elf
->e_ident
+EI_PAD
, 0, EI_NIDENT
-EI_PAD
);
892 elf
->e_type
= ET_CORE
;
893 elf
->e_machine
= ELF_ARCH
;
894 elf
->e_version
= EV_CURRENT
;
896 elf
->e_phoff
= sizeof(struct elfhdr
);
898 #if defined(_CALL_ELF)
899 elf
->e_flags
= _CALL_ELF
;
903 elf
->e_ehsize
= sizeof(struct elfhdr
);
904 elf
->e_phentsize
= sizeof(struct elf_phdr
);
906 elf
->e_shentsize
= 0;
914 * Traverse through memblock structure and setup crash memory ranges. These
915 * ranges will be used create PT_LOAD program headers in elfcore header.
917 static void fadump_setup_crash_memory_ranges(void)
919 struct memblock_region
*reg
;
920 unsigned long long start
, end
;
922 pr_debug("Setup crash memory ranges.\n");
923 crash_mem_ranges
= 0;
925 * add the first memory chunk (RMA_START through boot_memory_size) as
926 * a separate memory chunk. The reason is, at the time crash firmware
927 * will move the content of this memory chunk to different location
928 * specified during fadump registration. We need to create a separate
929 * program header for this chunk with the correct offset.
931 fadump_add_crash_memory(RMA_START
, fw_dump
.boot_memory_size
);
933 for_each_memblock(memory
, reg
) {
934 start
= (unsigned long long)reg
->base
;
935 end
= start
+ (unsigned long long)reg
->size
;
938 * skip the first memory chunk that is already added (RMA_START
939 * through boot_memory_size). This logic needs a relook if and
940 * when RMA_START changes to a non-zero value.
942 BUILD_BUG_ON(RMA_START
!= 0);
943 if (start
< fw_dump
.boot_memory_size
) {
944 if (end
> fw_dump
.boot_memory_size
)
945 start
= fw_dump
.boot_memory_size
;
950 /* add this range excluding the reserved dump area. */
951 fadump_exclude_reserved_area(start
, end
);
956 * If the given physical address falls within the boot memory region then
957 * return the relocated address that points to the dump region reserved
958 * for saving initial boot memory contents.
960 static inline unsigned long fadump_relocate(unsigned long paddr
)
962 if (paddr
> RMA_START
&& paddr
< fw_dump
.boot_memory_size
)
963 return be64_to_cpu(fdm
.rmr_region
.destination_address
) + paddr
;
968 static int fadump_create_elfcore_headers(char *bufp
)
971 struct elf_phdr
*phdr
;
974 fadump_init_elfcore_header(bufp
);
975 elf
= (struct elfhdr
*)bufp
;
976 bufp
+= sizeof(struct elfhdr
);
979 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
980 * will be populated during second kernel boot after crash. Hence
981 * this PT_NOTE will always be the first elf note.
983 * NOTE: Any new ELF note addition should be placed after this note.
985 phdr
= (struct elf_phdr
*)bufp
;
986 bufp
+= sizeof(struct elf_phdr
);
987 phdr
->p_type
= PT_NOTE
;
999 /* setup ELF PT_NOTE for vmcoreinfo */
1000 phdr
= (struct elf_phdr
*)bufp
;
1001 bufp
+= sizeof(struct elf_phdr
);
1002 phdr
->p_type
= PT_NOTE
;
1007 phdr
->p_paddr
= fadump_relocate(paddr_vmcoreinfo_note());
1008 phdr
->p_offset
= phdr
->p_paddr
;
1009 phdr
->p_memsz
= phdr
->p_filesz
= VMCOREINFO_NOTE_SIZE
;
1011 /* Increment number of program headers. */
1014 /* setup PT_LOAD sections. */
1016 for (i
= 0; i
< crash_mem_ranges
; i
++) {
1017 unsigned long long mbase
, msize
;
1018 mbase
= crash_memory_ranges
[i
].base
;
1019 msize
= crash_memory_ranges
[i
].size
;
1024 phdr
= (struct elf_phdr
*)bufp
;
1025 bufp
+= sizeof(struct elf_phdr
);
1026 phdr
->p_type
= PT_LOAD
;
1027 phdr
->p_flags
= PF_R
|PF_W
|PF_X
;
1028 phdr
->p_offset
= mbase
;
1030 if (mbase
== RMA_START
) {
1032 * The entire RMA region will be moved by firmware
1033 * to the specified destination_address. Hence set
1034 * the correct offset.
1036 phdr
->p_offset
= be64_to_cpu(fdm
.rmr_region
.destination_address
);
1039 phdr
->p_paddr
= mbase
;
1040 phdr
->p_vaddr
= (unsigned long)__va(mbase
);
1041 phdr
->p_filesz
= msize
;
1042 phdr
->p_memsz
= msize
;
1045 /* Increment number of program headers. */
1051 static unsigned long init_fadump_header(unsigned long addr
)
1053 struct fadump_crash_info_header
*fdh
;
1058 fw_dump
.fadumphdr_addr
= addr
;
1060 addr
+= sizeof(struct fadump_crash_info_header
);
1062 memset(fdh
, 0, sizeof(struct fadump_crash_info_header
));
1063 fdh
->magic_number
= FADUMP_CRASH_INFO_MAGIC
;
1064 fdh
->elfcorehdr_addr
= addr
;
1065 /* We will set the crashing cpu id in crash_fadump() during crash. */
1066 fdh
->crashing_cpu
= CPU_UNKNOWN
;
1071 static int register_fadump(void)
1077 * If no memory is reserved then we can not register for firmware-
1080 if (!fw_dump
.reserve_dump_area_size
)
1083 fadump_setup_crash_memory_ranges();
1085 addr
= be64_to_cpu(fdm
.rmr_region
.destination_address
) + be64_to_cpu(fdm
.rmr_region
.source_len
);
1086 /* Initialize fadump crash info header. */
1087 addr
= init_fadump_header(addr
);
1090 pr_debug("Creating ELF core headers at %#016lx\n", addr
);
1091 fadump_create_elfcore_headers(vaddr
);
1093 /* register the future kernel dump with firmware. */
1094 return register_fw_dump(&fdm
);
1097 static int fadump_unregister_dump(struct fadump_mem_struct
*fdm
)
1100 unsigned int wait_time
;
1102 pr_debug("Un-register firmware-assisted dump\n");
1104 /* TODO: Add upper time limit for the delay */
1106 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
1107 FADUMP_UNREGISTER
, fdm
,
1108 sizeof(struct fadump_mem_struct
));
1110 wait_time
= rtas_busy_delay_time(rc
);
1113 } while (wait_time
);
1116 printk(KERN_ERR
"Failed to un-register firmware-assisted dump."
1117 " unexpected error(%d).\n", rc
);
1120 fw_dump
.dump_registered
= 0;
1124 static int fadump_invalidate_dump(struct fadump_mem_struct
*fdm
)
1127 unsigned int wait_time
;
1129 pr_debug("Invalidating firmware-assisted dump registration\n");
1131 /* TODO: Add upper time limit for the delay */
1133 rc
= rtas_call(fw_dump
.ibm_configure_kernel_dump
, 3, 1, NULL
,
1134 FADUMP_INVALIDATE
, fdm
,
1135 sizeof(struct fadump_mem_struct
));
1137 wait_time
= rtas_busy_delay_time(rc
);
1140 } while (wait_time
);
1143 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc
);
1146 fw_dump
.dump_active
= 0;
1151 void fadump_cleanup(void)
1153 /* Invalidate the registration only if dump is active. */
1154 if (fw_dump
.dump_active
) {
1155 init_fadump_mem_struct(&fdm
,
1156 be64_to_cpu(fdm_active
->cpu_state_data
.destination_address
));
1157 fadump_invalidate_dump(&fdm
);
1161 static void fadump_free_reserved_memory(unsigned long start_pfn
,
1162 unsigned long end_pfn
)
1165 unsigned long time_limit
= jiffies
+ HZ
;
1167 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1168 PFN_PHYS(start_pfn
), PFN_PHYS(end_pfn
));
1170 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
++) {
1171 free_reserved_page(pfn_to_page(pfn
));
1173 if (time_after(jiffies
, time_limit
)) {
1175 time_limit
= jiffies
+ HZ
;
1181 * Skip memory holes and free memory that was actually reserved.
1183 static void fadump_release_reserved_area(unsigned long start
, unsigned long end
)
1185 struct memblock_region
*reg
;
1186 unsigned long tstart
, tend
;
1187 unsigned long start_pfn
= PHYS_PFN(start
);
1188 unsigned long end_pfn
= PHYS_PFN(end
);
1190 for_each_memblock(memory
, reg
) {
1191 tstart
= max(start_pfn
, memblock_region_memory_base_pfn(reg
));
1192 tend
= min(end_pfn
, memblock_region_memory_end_pfn(reg
));
1193 if (tstart
< tend
) {
1194 fadump_free_reserved_memory(tstart
, tend
);
1196 if (tend
== end_pfn
)
1199 start_pfn
= tend
+ 1;
1205 * Release the memory that was reserved in early boot to preserve the memory
1206 * contents. The released memory will be available for general use.
1208 static void fadump_release_memory(unsigned long begin
, unsigned long end
)
1210 unsigned long ra_start
, ra_end
;
1212 ra_start
= fw_dump
.reserve_dump_area_start
;
1213 ra_end
= ra_start
+ fw_dump
.reserve_dump_area_size
;
1216 * exclude the dump reserve area. Will reuse it for next
1217 * fadump registration.
1219 if (begin
< ra_end
&& end
> ra_start
) {
1220 if (begin
< ra_start
)
1221 fadump_release_reserved_area(begin
, ra_start
);
1223 fadump_release_reserved_area(ra_end
, end
);
1225 fadump_release_reserved_area(begin
, end
);
1228 static void fadump_invalidate_release_mem(void)
1230 unsigned long reserved_area_start
, reserved_area_end
;
1231 unsigned long destination_address
;
1233 mutex_lock(&fadump_mutex
);
1234 if (!fw_dump
.dump_active
) {
1235 mutex_unlock(&fadump_mutex
);
1239 destination_address
= be64_to_cpu(fdm_active
->cpu_state_data
.destination_address
);
1241 mutex_unlock(&fadump_mutex
);
1244 * Save the current reserved memory bounds we will require them
1245 * later for releasing the memory for general use.
1247 reserved_area_start
= fw_dump
.reserve_dump_area_start
;
1248 reserved_area_end
= reserved_area_start
+
1249 fw_dump
.reserve_dump_area_size
;
1251 * Setup reserve_dump_area_start and its size so that we can
1252 * reuse this reserved memory for Re-registration.
1254 fw_dump
.reserve_dump_area_start
= destination_address
;
1255 fw_dump
.reserve_dump_area_size
= get_fadump_area_size();
1257 fadump_release_memory(reserved_area_start
, reserved_area_end
);
1258 if (fw_dump
.cpu_notes_buf
) {
1259 fadump_cpu_notes_buf_free(
1260 (unsigned long)__va(fw_dump
.cpu_notes_buf
),
1261 fw_dump
.cpu_notes_buf_size
);
1262 fw_dump
.cpu_notes_buf
= 0;
1263 fw_dump
.cpu_notes_buf_size
= 0;
1265 /* Initialize the kernel dump memory structure for FAD registration. */
1266 init_fadump_mem_struct(&fdm
, fw_dump
.reserve_dump_area_start
);
1269 static ssize_t
fadump_release_memory_store(struct kobject
*kobj
,
1270 struct kobj_attribute
*attr
,
1271 const char *buf
, size_t count
)
1275 if (!fw_dump
.dump_active
)
1278 if (kstrtoint(buf
, 0, &input
))
1283 * Take away the '/proc/vmcore'. We are releasing the dump
1284 * memory, hence it will not be valid anymore.
1286 #ifdef CONFIG_PROC_VMCORE
1289 fadump_invalidate_release_mem();
1296 static ssize_t
fadump_enabled_show(struct kobject
*kobj
,
1297 struct kobj_attribute
*attr
,
1300 return sprintf(buf
, "%d\n", fw_dump
.fadump_enabled
);
1303 static ssize_t
fadump_register_show(struct kobject
*kobj
,
1304 struct kobj_attribute
*attr
,
1307 return sprintf(buf
, "%d\n", fw_dump
.dump_registered
);
1310 static ssize_t
fadump_register_store(struct kobject
*kobj
,
1311 struct kobj_attribute
*attr
,
1312 const char *buf
, size_t count
)
1317 if (!fw_dump
.fadump_enabled
|| fdm_active
)
1320 if (kstrtoint(buf
, 0, &input
))
1323 mutex_lock(&fadump_mutex
);
1327 if (fw_dump
.dump_registered
== 0) {
1330 /* Un-register Firmware-assisted dump */
1331 fadump_unregister_dump(&fdm
);
1334 if (fw_dump
.dump_registered
== 1) {
1338 /* Register Firmware-assisted dump */
1339 ret
= register_fadump();
1347 mutex_unlock(&fadump_mutex
);
1348 return ret
< 0 ? ret
: count
;
1351 static int fadump_region_show(struct seq_file
*m
, void *private)
1353 const struct fadump_mem_struct
*fdm_ptr
;
1355 if (!fw_dump
.fadump_enabled
)
1358 mutex_lock(&fadump_mutex
);
1360 fdm_ptr
= fdm_active
;
1362 mutex_unlock(&fadump_mutex
);
1367 "CPU : [%#016llx-%#016llx] %#llx bytes, "
1369 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
),
1370 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
) +
1371 be64_to_cpu(fdm_ptr
->cpu_state_data
.source_len
) - 1,
1372 be64_to_cpu(fdm_ptr
->cpu_state_data
.source_len
),
1373 be64_to_cpu(fdm_ptr
->cpu_state_data
.bytes_dumped
));
1375 "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1377 be64_to_cpu(fdm_ptr
->hpte_region
.destination_address
),
1378 be64_to_cpu(fdm_ptr
->hpte_region
.destination_address
) +
1379 be64_to_cpu(fdm_ptr
->hpte_region
.source_len
) - 1,
1380 be64_to_cpu(fdm_ptr
->hpte_region
.source_len
),
1381 be64_to_cpu(fdm_ptr
->hpte_region
.bytes_dumped
));
1383 "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1385 be64_to_cpu(fdm_ptr
->rmr_region
.destination_address
),
1386 be64_to_cpu(fdm_ptr
->rmr_region
.destination_address
) +
1387 be64_to_cpu(fdm_ptr
->rmr_region
.source_len
) - 1,
1388 be64_to_cpu(fdm_ptr
->rmr_region
.source_len
),
1389 be64_to_cpu(fdm_ptr
->rmr_region
.bytes_dumped
));
1392 (fw_dump
.reserve_dump_area_start
==
1393 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
)))
1396 /* Dump is active. Show reserved memory region. */
1398 " : [%#016llx-%#016llx] %#llx bytes, "
1400 (unsigned long long)fw_dump
.reserve_dump_area_start
,
1401 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
) - 1,
1402 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
) -
1403 fw_dump
.reserve_dump_area_start
,
1404 be64_to_cpu(fdm_ptr
->cpu_state_data
.destination_address
) -
1405 fw_dump
.reserve_dump_area_start
);
1408 mutex_unlock(&fadump_mutex
);
1412 static struct kobj_attribute fadump_release_attr
= __ATTR(fadump_release_mem
,
1414 fadump_release_memory_store
);
1415 static struct kobj_attribute fadump_attr
= __ATTR(fadump_enabled
,
1416 0444, fadump_enabled_show
,
1418 static struct kobj_attribute fadump_register_attr
= __ATTR(fadump_registered
,
1419 0644, fadump_register_show
,
1420 fadump_register_store
);
1422 static int fadump_region_open(struct inode
*inode
, struct file
*file
)
1424 return single_open(file
, fadump_region_show
, inode
->i_private
);
1427 static const struct file_operations fadump_region_fops
= {
1428 .open
= fadump_region_open
,
1430 .llseek
= seq_lseek
,
1431 .release
= single_release
,
1434 static void fadump_init_files(void)
1436 struct dentry
*debugfs_file
;
1439 rc
= sysfs_create_file(kernel_kobj
, &fadump_attr
.attr
);
1441 printk(KERN_ERR
"fadump: unable to create sysfs file"
1442 " fadump_enabled (%d)\n", rc
);
1444 rc
= sysfs_create_file(kernel_kobj
, &fadump_register_attr
.attr
);
1446 printk(KERN_ERR
"fadump: unable to create sysfs file"
1447 " fadump_registered (%d)\n", rc
);
1449 debugfs_file
= debugfs_create_file("fadump_region", 0444,
1450 powerpc_debugfs_root
, NULL
,
1451 &fadump_region_fops
);
1453 printk(KERN_ERR
"fadump: unable to create debugfs file"
1454 " fadump_region\n");
1456 if (fw_dump
.dump_active
) {
1457 rc
= sysfs_create_file(kernel_kobj
, &fadump_release_attr
.attr
);
1459 printk(KERN_ERR
"fadump: unable to create sysfs file"
1460 " fadump_release_mem (%d)\n", rc
);
1466 * Prepare for firmware-assisted dump.
1468 int __init
setup_fadump(void)
1470 if (!fw_dump
.fadump_enabled
)
1473 if (!fw_dump
.fadump_supported
) {
1474 printk(KERN_ERR
"Firmware-assisted dump is not supported on"
1475 " this hardware\n");
1479 fadump_show_config();
1481 * If dump data is available then see if it is valid and prepare for
1482 * saving it to the disk.
1484 if (fw_dump
.dump_active
) {
1486 * if dump process fails then invalidate the registration
1487 * and release memory before proceeding for re-registration.
1489 if (process_fadump(fdm_active
) < 0)
1490 fadump_invalidate_release_mem();
1492 /* Initialize the kernel dump memory structure for FAD registration. */
1493 else if (fw_dump
.reserve_dump_area_size
)
1494 init_fadump_mem_struct(&fdm
, fw_dump
.reserve_dump_area_start
);
1495 fadump_init_files();
1499 subsys_initcall(setup_fadump
);