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TOMOYO Linux Cross Reference
Linux/arch/powerpc/kernel/fadump.c

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  1 /*
  2  * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
  3  * dump with assistance from firmware. This approach does not use kexec,
  4  * instead firmware assists in booting the kdump kernel while preserving
  5  * memory contents. The most of the code implementation has been adapted
  6  * from phyp assisted dump implementation written by Linas Vepstas and
  7  * Manish Ahuja
  8  *
  9  * This program is free software; you can redistribute it and/or modify
 10  * it under the terms of the GNU General Public License as published by
 11  * the Free Software Foundation; either version 2 of the License, or
 12  * (at your option) any later version.
 13  *
 14  * This program is distributed in the hope that it will be useful,
 15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17  * GNU General Public License for more details.
 18  *
 19  * You should have received a copy of the GNU General Public License
 20  * along with this program; if not, write to the Free Software
 21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 22  *
 23  * Copyright 2011 IBM Corporation
 24  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
 25  */
 26 
 27 #undef DEBUG
 28 #define pr_fmt(fmt) "fadump: " fmt
 29 
 30 #include <linux/string.h>
 31 #include <linux/memblock.h>
 32 #include <linux/delay.h>
 33 #include <linux/debugfs.h>
 34 #include <linux/seq_file.h>
 35 #include <linux/crash_dump.h>
 36 #include <linux/kobject.h>
 37 #include <linux/sysfs.h>
 38 #include <linux/slab.h>
 39 
 40 #include <asm/page.h>
 41 #include <asm/prom.h>
 42 #include <asm/rtas.h>
 43 #include <asm/fadump.h>
 44 #include <asm/debug.h>
 45 #include <asm/setup.h>
 46 
 47 static struct fw_dump fw_dump;
 48 static struct fadump_mem_struct fdm;
 49 static const struct fadump_mem_struct *fdm_active;
 50 
 51 static DEFINE_MUTEX(fadump_mutex);
 52 struct fad_crash_memory_ranges *crash_memory_ranges;
 53 int crash_memory_ranges_size;
 54 int crash_mem_ranges;
 55 int max_crash_mem_ranges;
 56 
 57 /* Scan the Firmware Assisted dump configuration details. */
 58 int __init early_init_dt_scan_fw_dump(unsigned long node,
 59                         const char *uname, int depth, void *data)
 60 {
 61         const __be32 *sections;
 62         int i, num_sections;
 63         int size;
 64         const __be32 *token;
 65 
 66         if (depth != 1 || strcmp(uname, "rtas") != 0)
 67                 return 0;
 68 
 69         /*
 70          * Check if Firmware Assisted dump is supported. if yes, check
 71          * if dump has been initiated on last reboot.
 72          */
 73         token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
 74         if (!token)
 75                 return 1;
 76 
 77         fw_dump.fadump_supported = 1;
 78         fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
 79 
 80         /*
 81          * The 'ibm,kernel-dump' rtas node is present only if there is
 82          * dump data waiting for us.
 83          */
 84         fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
 85         if (fdm_active)
 86                 fw_dump.dump_active = 1;
 87 
 88         /* Get the sizes required to store dump data for the firmware provided
 89          * dump sections.
 90          * For each dump section type supported, a 32bit cell which defines
 91          * the ID of a supported section followed by two 32 bit cells which
 92          * gives teh size of the section in bytes.
 93          */
 94         sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
 95                                         &size);
 96 
 97         if (!sections)
 98                 return 1;
 99 
100         num_sections = size / (3 * sizeof(u32));
101 
102         for (i = 0; i < num_sections; i++, sections += 3) {
103                 u32 type = (u32)of_read_number(sections, 1);
104 
105                 switch (type) {
106                 case FADUMP_CPU_STATE_DATA:
107                         fw_dump.cpu_state_data_size =
108                                         of_read_ulong(&sections[1], 2);
109                         break;
110                 case FADUMP_HPTE_REGION:
111                         fw_dump.hpte_region_size =
112                                         of_read_ulong(&sections[1], 2);
113                         break;
114                 }
115         }
116 
117         return 1;
118 }
119 
120 int is_fadump_active(void)
121 {
122         return fw_dump.dump_active;
123 }
124 
125 /* Print firmware assisted dump configurations for debugging purpose. */
126 static void fadump_show_config(void)
127 {
128         pr_debug("Support for firmware-assisted dump (fadump): %s\n",
129                         (fw_dump.fadump_supported ? "present" : "no support"));
130 
131         if (!fw_dump.fadump_supported)
132                 return;
133 
134         pr_debug("Fadump enabled    : %s\n",
135                                 (fw_dump.fadump_enabled ? "yes" : "no"));
136         pr_debug("Dump Active       : %s\n",
137                                 (fw_dump.dump_active ? "yes" : "no"));
138         pr_debug("Dump section sizes:\n");
139         pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
140         pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
141         pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
142 }
143 
144 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
145                                 unsigned long addr)
146 {
147         if (!fdm)
148                 return 0;
149 
150         memset(fdm, 0, sizeof(struct fadump_mem_struct));
151         addr = addr & PAGE_MASK;
152 
153         fdm->header.dump_format_version = cpu_to_be32(0x00000001);
154         fdm->header.dump_num_sections = cpu_to_be16(3);
155         fdm->header.dump_status_flag = 0;
156         fdm->header.offset_first_dump_section =
157                 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
158 
159         /*
160          * Fields for disk dump option.
161          * We are not using disk dump option, hence set these fields to 0.
162          */
163         fdm->header.dd_block_size = 0;
164         fdm->header.dd_block_offset = 0;
165         fdm->header.dd_num_blocks = 0;
166         fdm->header.dd_offset_disk_path = 0;
167 
168         /* set 0 to disable an automatic dump-reboot. */
169         fdm->header.max_time_auto = 0;
170 
171         /* Kernel dump sections */
172         /* cpu state data section. */
173         fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
174         fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
175         fdm->cpu_state_data.source_address = 0;
176         fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
177         fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
178         addr += fw_dump.cpu_state_data_size;
179 
180         /* hpte region section */
181         fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
182         fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
183         fdm->hpte_region.source_address = 0;
184         fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
185         fdm->hpte_region.destination_address = cpu_to_be64(addr);
186         addr += fw_dump.hpte_region_size;
187 
188         /* RMA region section */
189         fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
190         fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
191         fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
192         fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
193         fdm->rmr_region.destination_address = cpu_to_be64(addr);
194         addr += fw_dump.boot_memory_size;
195 
196         return addr;
197 }
198 
199 /**
200  * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
201  *
202  * Function to find the largest memory size we need to reserve during early
203  * boot process. This will be the size of the memory that is required for a
204  * kernel to boot successfully.
205  *
206  * This function has been taken from phyp-assisted dump feature implementation.
207  *
208  * returns larger of 256MB or 5% rounded down to multiples of 256MB.
209  *
210  * TODO: Come up with better approach to find out more accurate memory size
211  * that is required for a kernel to boot successfully.
212  *
213  */
214 static inline unsigned long fadump_calculate_reserve_size(void)
215 {
216         unsigned long size;
217 
218         /*
219          * Check if the size is specified through fadump_reserve_mem= cmdline
220          * option. If yes, then use that.
221          */
222         if (fw_dump.reserve_bootvar)
223                 return fw_dump.reserve_bootvar;
224 
225         /* divide by 20 to get 5% of value */
226         size = memblock_end_of_DRAM() / 20;
227 
228         /* round it down in multiples of 256 */
229         size = size & ~0x0FFFFFFFUL;
230 
231         /* Truncate to memory_limit. We don't want to over reserve the memory.*/
232         if (memory_limit && size > memory_limit)
233                 size = memory_limit;
234 
235         return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
236 }
237 
238 /*
239  * Calculate the total memory size required to be reserved for
240  * firmware-assisted dump registration.
241  */
242 static unsigned long get_fadump_area_size(void)
243 {
244         unsigned long size = 0;
245 
246         size += fw_dump.cpu_state_data_size;
247         size += fw_dump.hpte_region_size;
248         size += fw_dump.boot_memory_size;
249         size += sizeof(struct fadump_crash_info_header);
250         size += sizeof(struct elfhdr); /* ELF core header.*/
251         size += sizeof(struct elf_phdr); /* place holder for cpu notes */
252         /* Program headers for crash memory regions. */
253         size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
254 
255         size = PAGE_ALIGN(size);
256         return size;
257 }
258 
259 int __init fadump_reserve_mem(void)
260 {
261         unsigned long base, size, memory_boundary;
262 
263         if (!fw_dump.fadump_enabled)
264                 return 0;
265 
266         if (!fw_dump.fadump_supported) {
267                 printk(KERN_INFO "Firmware-assisted dump is not supported on"
268                                 " this hardware\n");
269                 fw_dump.fadump_enabled = 0;
270                 return 0;
271         }
272         /*
273          * Initialize boot memory size
274          * If dump is active then we have already calculated the size during
275          * first kernel.
276          */
277         if (fdm_active)
278                 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
279         else
280                 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
281 
282         /*
283          * Calculate the memory boundary.
284          * If memory_limit is less than actual memory boundary then reserve
285          * the memory for fadump beyond the memory_limit and adjust the
286          * memory_limit accordingly, so that the running kernel can run with
287          * specified memory_limit.
288          */
289         if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
290                 size = get_fadump_area_size();
291                 if ((memory_limit + size) < memblock_end_of_DRAM())
292                         memory_limit += size;
293                 else
294                         memory_limit = memblock_end_of_DRAM();
295                 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
296                                 " dump, now %#016llx\n", memory_limit);
297         }
298         if (memory_limit)
299                 memory_boundary = memory_limit;
300         else
301                 memory_boundary = memblock_end_of_DRAM();
302 
303         if (fw_dump.dump_active) {
304                 printk(KERN_INFO "Firmware-assisted dump is active.\n");
305                 /*
306                  * If last boot has crashed then reserve all the memory
307                  * above boot_memory_size so that we don't touch it until
308                  * dump is written to disk by userspace tool. This memory
309                  * will be released for general use once the dump is saved.
310                  */
311                 base = fw_dump.boot_memory_size;
312                 size = memory_boundary - base;
313                 memblock_reserve(base, size);
314                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
315                                 "for saving crash dump\n",
316                                 (unsigned long)(size >> 20),
317                                 (unsigned long)(base >> 20));
318 
319                 fw_dump.fadumphdr_addr =
320                                 be64_to_cpu(fdm_active->rmr_region.destination_address) +
321                                 be64_to_cpu(fdm_active->rmr_region.source_len);
322                 pr_debug("fadumphdr_addr = %p\n",
323                                 (void *) fw_dump.fadumphdr_addr);
324         } else {
325                 /* Reserve the memory at the top of memory. */
326                 size = get_fadump_area_size();
327                 base = memory_boundary - size;
328                 memblock_reserve(base, size);
329                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
330                                 "for firmware-assisted dump\n",
331                                 (unsigned long)(size >> 20),
332                                 (unsigned long)(base >> 20));
333         }
334         fw_dump.reserve_dump_area_start = base;
335         fw_dump.reserve_dump_area_size = size;
336         return 1;
337 }
338 
339 /* Look for fadump= cmdline option. */
340 static int __init early_fadump_param(char *p)
341 {
342         if (!p)
343                 return 1;
344 
345         if (strncmp(p, "on", 2) == 0)
346                 fw_dump.fadump_enabled = 1;
347         else if (strncmp(p, "off", 3) == 0)
348                 fw_dump.fadump_enabled = 0;
349 
350         return 0;
351 }
352 early_param("fadump", early_fadump_param);
353 
354 /* Look for fadump_reserve_mem= cmdline option */
355 static int __init early_fadump_reserve_mem(char *p)
356 {
357         if (p)
358                 fw_dump.reserve_bootvar = memparse(p, &p);
359         return 0;
360 }
361 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
362 
363 static void register_fw_dump(struct fadump_mem_struct *fdm)
364 {
365         int rc;
366         unsigned int wait_time;
367 
368         pr_debug("Registering for firmware-assisted kernel dump...\n");
369 
370         /* TODO: Add upper time limit for the delay */
371         do {
372                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
373                         FADUMP_REGISTER, fdm,
374                         sizeof(struct fadump_mem_struct));
375 
376                 wait_time = rtas_busy_delay_time(rc);
377                 if (wait_time)
378                         mdelay(wait_time);
379 
380         } while (wait_time);
381 
382         switch (rc) {
383         case -1:
384                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
385                         " dump. Hardware Error(%d).\n", rc);
386                 break;
387         case -3:
388                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
389                         " dump. Parameter Error(%d).\n", rc);
390                 break;
391         case -9:
392                 printk(KERN_ERR "firmware-assisted kernel dump is already "
393                         " registered.");
394                 fw_dump.dump_registered = 1;
395                 break;
396         case 0:
397                 printk(KERN_INFO "firmware-assisted kernel dump registration"
398                         " is successful\n");
399                 fw_dump.dump_registered = 1;
400                 break;
401         }
402 }
403 
404 void crash_fadump(struct pt_regs *regs, const char *str)
405 {
406         struct fadump_crash_info_header *fdh = NULL;
407 
408         if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
409                 return;
410 
411         fdh = __va(fw_dump.fadumphdr_addr);
412         crashing_cpu = smp_processor_id();
413         fdh->crashing_cpu = crashing_cpu;
414         crash_save_vmcoreinfo();
415 
416         if (regs)
417                 fdh->regs = *regs;
418         else
419                 ppc_save_regs(&fdh->regs);
420 
421         fdh->cpu_online_mask = *cpu_online_mask;
422 
423         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
424         rtas_os_term((char *)str);
425 }
426 
427 #define GPR_MASK        0xffffff0000000000
428 static inline int fadump_gpr_index(u64 id)
429 {
430         int i = -1;
431         char str[3];
432 
433         if ((id & GPR_MASK) == REG_ID("GPR")) {
434                 /* get the digits at the end */
435                 id &= ~GPR_MASK;
436                 id >>= 24;
437                 str[2] = '\0';
438                 str[1] = id & 0xff;
439                 str[0] = (id >> 8) & 0xff;
440                 sscanf(str, "%d", &i);
441                 if (i > 31)
442                         i = -1;
443         }
444         return i;
445 }
446 
447 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
448                                                                 u64 reg_val)
449 {
450         int i;
451 
452         i = fadump_gpr_index(reg_id);
453         if (i >= 0)
454                 regs->gpr[i] = (unsigned long)reg_val;
455         else if (reg_id == REG_ID("NIA"))
456                 regs->nip = (unsigned long)reg_val;
457         else if (reg_id == REG_ID("MSR"))
458                 regs->msr = (unsigned long)reg_val;
459         else if (reg_id == REG_ID("CTR"))
460                 regs->ctr = (unsigned long)reg_val;
461         else if (reg_id == REG_ID("LR"))
462                 regs->link = (unsigned long)reg_val;
463         else if (reg_id == REG_ID("XER"))
464                 regs->xer = (unsigned long)reg_val;
465         else if (reg_id == REG_ID("CR"))
466                 regs->ccr = (unsigned long)reg_val;
467         else if (reg_id == REG_ID("DAR"))
468                 regs->dar = (unsigned long)reg_val;
469         else if (reg_id == REG_ID("DSISR"))
470                 regs->dsisr = (unsigned long)reg_val;
471 }
472 
473 static struct fadump_reg_entry*
474 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
475 {
476         memset(regs, 0, sizeof(struct pt_regs));
477 
478         while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
479                 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
480                                         be64_to_cpu(reg_entry->reg_value));
481                 reg_entry++;
482         }
483         reg_entry++;
484         return reg_entry;
485 }
486 
487 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
488                                                 void *data, size_t data_len)
489 {
490         struct elf_note note;
491 
492         note.n_namesz = strlen(name) + 1;
493         note.n_descsz = data_len;
494         note.n_type   = type;
495         memcpy(buf, &note, sizeof(note));
496         buf += (sizeof(note) + 3)/4;
497         memcpy(buf, name, note.n_namesz);
498         buf += (note.n_namesz + 3)/4;
499         memcpy(buf, data, note.n_descsz);
500         buf += (note.n_descsz + 3)/4;
501 
502         return buf;
503 }
504 
505 static void fadump_final_note(u32 *buf)
506 {
507         struct elf_note note;
508 
509         note.n_namesz = 0;
510         note.n_descsz = 0;
511         note.n_type   = 0;
512         memcpy(buf, &note, sizeof(note));
513 }
514 
515 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
516 {
517         struct elf_prstatus prstatus;
518 
519         memset(&prstatus, 0, sizeof(prstatus));
520         /*
521          * FIXME: How do i get PID? Do I really need it?
522          * prstatus.pr_pid = ????
523          */
524         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
525         buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
526                                 &prstatus, sizeof(prstatus));
527         return buf;
528 }
529 
530 static void fadump_update_elfcore_header(char *bufp)
531 {
532         struct elfhdr *elf;
533         struct elf_phdr *phdr;
534 
535         elf = (struct elfhdr *)bufp;
536         bufp += sizeof(struct elfhdr);
537 
538         /* First note is a place holder for cpu notes info. */
539         phdr = (struct elf_phdr *)bufp;
540 
541         if (phdr->p_type == PT_NOTE) {
542                 phdr->p_paddr = fw_dump.cpu_notes_buf;
543                 phdr->p_offset  = phdr->p_paddr;
544                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
545                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
546         }
547         return;
548 }
549 
550 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
551 {
552         void *vaddr;
553         struct page *page;
554         unsigned long order, count, i;
555 
556         order = get_order(size);
557         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
558         if (!vaddr)
559                 return NULL;
560 
561         count = 1 << order;
562         page = virt_to_page(vaddr);
563         for (i = 0; i < count; i++)
564                 SetPageReserved(page + i);
565         return vaddr;
566 }
567 
568 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
569 {
570         struct page *page;
571         unsigned long order, count, i;
572 
573         order = get_order(size);
574         count = 1 << order;
575         page = virt_to_page(vaddr);
576         for (i = 0; i < count; i++)
577                 ClearPageReserved(page + i);
578         __free_pages(page, order);
579 }
580 
581 /*
582  * Read CPU state dump data and convert it into ELF notes.
583  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
584  * used to access the data to allow for additional fields to be added without
585  * affecting compatibility. Each list of registers for a CPU starts with
586  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
587  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
588  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
589  * of register value. For more details refer to PAPR document.
590  *
591  * Only for the crashing cpu we ignore the CPU dump data and get exact
592  * state from fadump crash info structure populated by first kernel at the
593  * time of crash.
594  */
595 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
596 {
597         struct fadump_reg_save_area_header *reg_header;
598         struct fadump_reg_entry *reg_entry;
599         struct fadump_crash_info_header *fdh = NULL;
600         void *vaddr;
601         unsigned long addr;
602         u32 num_cpus, *note_buf;
603         struct pt_regs regs;
604         int i, rc = 0, cpu = 0;
605 
606         if (!fdm->cpu_state_data.bytes_dumped)
607                 return -EINVAL;
608 
609         addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
610         vaddr = __va(addr);
611 
612         reg_header = vaddr;
613         if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
614                 printk(KERN_ERR "Unable to read register save area.\n");
615                 return -ENOENT;
616         }
617         pr_debug("--------CPU State Data------------\n");
618         pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
619         pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
620 
621         vaddr += be32_to_cpu(reg_header->num_cpu_offset);
622         num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
623         pr_debug("NumCpus     : %u\n", num_cpus);
624         vaddr += sizeof(u32);
625         reg_entry = (struct fadump_reg_entry *)vaddr;
626 
627         /* Allocate buffer to hold cpu crash notes. */
628         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
629         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
630         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
631         if (!note_buf) {
632                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
633                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
634                 return -ENOMEM;
635         }
636         fw_dump.cpu_notes_buf = __pa(note_buf);
637 
638         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
639                         (num_cpus * sizeof(note_buf_t)), note_buf);
640 
641         if (fw_dump.fadumphdr_addr)
642                 fdh = __va(fw_dump.fadumphdr_addr);
643 
644         for (i = 0; i < num_cpus; i++) {
645                 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
646                         printk(KERN_ERR "Unable to read CPU state data\n");
647                         rc = -ENOENT;
648                         goto error_out;
649                 }
650                 /* Lower 4 bytes of reg_value contains logical cpu id */
651                 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
652                 if (fdh && !cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
653                         SKIP_TO_NEXT_CPU(reg_entry);
654                         continue;
655                 }
656                 pr_debug("Reading register data for cpu %d...\n", cpu);
657                 if (fdh && fdh->crashing_cpu == cpu) {
658                         regs = fdh->regs;
659                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
660                         SKIP_TO_NEXT_CPU(reg_entry);
661                 } else {
662                         reg_entry++;
663                         reg_entry = fadump_read_registers(reg_entry, &regs);
664                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
665                 }
666         }
667         fadump_final_note(note_buf);
668 
669         if (fdh) {
670                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
671                                                         fdh->elfcorehdr_addr);
672                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
673         }
674         return 0;
675 
676 error_out:
677         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
678                                         fw_dump.cpu_notes_buf_size);
679         fw_dump.cpu_notes_buf = 0;
680         fw_dump.cpu_notes_buf_size = 0;
681         return rc;
682 
683 }
684 
685 /*
686  * Validate and process the dump data stored by firmware before exporting
687  * it through '/proc/vmcore'.
688  */
689 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
690 {
691         struct fadump_crash_info_header *fdh;
692         int rc = 0;
693 
694         if (!fdm_active || !fw_dump.fadumphdr_addr)
695                 return -EINVAL;
696 
697         /* Check if the dump data is valid. */
698         if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
699                         (fdm_active->cpu_state_data.error_flags != 0) ||
700                         (fdm_active->rmr_region.error_flags != 0)) {
701                 printk(KERN_ERR "Dump taken by platform is not valid\n");
702                 return -EINVAL;
703         }
704         if ((fdm_active->rmr_region.bytes_dumped !=
705                         fdm_active->rmr_region.source_len) ||
706                         !fdm_active->cpu_state_data.bytes_dumped) {
707                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
708                 return -EINVAL;
709         }
710 
711         /* Validate the fadump crash info header */
712         fdh = __va(fw_dump.fadumphdr_addr);
713         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
714                 printk(KERN_ERR "Crash info header is not valid.\n");
715                 return -EINVAL;
716         }
717 
718         rc = fadump_build_cpu_notes(fdm_active);
719         if (rc)
720                 return rc;
721 
722         /*
723          * We are done validating dump info and elfcore header is now ready
724          * to be exported. set elfcorehdr_addr so that vmcore module will
725          * export the elfcore header through '/proc/vmcore'.
726          */
727         elfcorehdr_addr = fdh->elfcorehdr_addr;
728 
729         return 0;
730 }
731 
732 static void free_crash_memory_ranges(void)
733 {
734         kfree(crash_memory_ranges);
735         crash_memory_ranges = NULL;
736         crash_memory_ranges_size = 0;
737         max_crash_mem_ranges = 0;
738 }
739 
740 /*
741  * Allocate or reallocate crash memory ranges array in incremental units
742  * of PAGE_SIZE.
743  */
744 static int allocate_crash_memory_ranges(void)
745 {
746         struct fad_crash_memory_ranges *new_array;
747         u64 new_size;
748 
749         new_size = crash_memory_ranges_size + PAGE_SIZE;
750         pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
751                  new_size);
752 
753         new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
754         if (new_array == NULL) {
755                 pr_err("Insufficient memory for setting up crash memory ranges\n");
756                 free_crash_memory_ranges();
757                 return -ENOMEM;
758         }
759 
760         crash_memory_ranges = new_array;
761         crash_memory_ranges_size = new_size;
762         max_crash_mem_ranges = (new_size /
763                                 sizeof(struct fad_crash_memory_ranges));
764         return 0;
765 }
766 
767 static inline int fadump_add_crash_memory(unsigned long long base,
768                                           unsigned long long end)
769 {
770         if (base == end)
771                 return 0;
772 
773         if (crash_mem_ranges == max_crash_mem_ranges) {
774                 int ret;
775 
776                 ret = allocate_crash_memory_ranges();
777                 if (ret)
778                         return ret;
779         }
780 
781         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
782                 crash_mem_ranges, base, end - 1, (end - base));
783         crash_memory_ranges[crash_mem_ranges].base = base;
784         crash_memory_ranges[crash_mem_ranges].size = end - base;
785         crash_mem_ranges++;
786         return 0;
787 }
788 
789 static int fadump_exclude_reserved_area(unsigned long long start,
790                                         unsigned long long end)
791 {
792         unsigned long long ra_start, ra_end;
793         int ret = 0;
794 
795         ra_start = fw_dump.reserve_dump_area_start;
796         ra_end = ra_start + fw_dump.reserve_dump_area_size;
797 
798         if ((ra_start < end) && (ra_end > start)) {
799                 if ((start < ra_start) && (end > ra_end)) {
800                         ret = fadump_add_crash_memory(start, ra_start);
801                         if (ret)
802                                 return ret;
803 
804                         ret = fadump_add_crash_memory(ra_end, end);
805                 } else if (start < ra_start) {
806                         ret = fadump_add_crash_memory(start, ra_start);
807                 } else if (ra_end < end) {
808                         ret = fadump_add_crash_memory(ra_end, end);
809                 }
810         } else
811                 ret = fadump_add_crash_memory(start, end);
812 
813         return ret;
814 }
815 
816 static int fadump_init_elfcore_header(char *bufp)
817 {
818         struct elfhdr *elf;
819 
820         elf = (struct elfhdr *) bufp;
821         bufp += sizeof(struct elfhdr);
822         memcpy(elf->e_ident, ELFMAG, SELFMAG);
823         elf->e_ident[EI_CLASS] = ELF_CLASS;
824         elf->e_ident[EI_DATA] = ELF_DATA;
825         elf->e_ident[EI_VERSION] = EV_CURRENT;
826         elf->e_ident[EI_OSABI] = ELF_OSABI;
827         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
828         elf->e_type = ET_CORE;
829         elf->e_machine = ELF_ARCH;
830         elf->e_version = EV_CURRENT;
831         elf->e_entry = 0;
832         elf->e_phoff = sizeof(struct elfhdr);
833         elf->e_shoff = 0;
834         elf->e_flags = ELF_CORE_EFLAGS;
835         elf->e_ehsize = sizeof(struct elfhdr);
836         elf->e_phentsize = sizeof(struct elf_phdr);
837         elf->e_phnum = 0;
838         elf->e_shentsize = 0;
839         elf->e_shnum = 0;
840         elf->e_shstrndx = 0;
841 
842         return 0;
843 }
844 
845 /*
846  * Traverse through memblock structure and setup crash memory ranges. These
847  * ranges will be used create PT_LOAD program headers in elfcore header.
848  */
849 static int fadump_setup_crash_memory_ranges(void)
850 {
851         struct memblock_region *reg;
852         unsigned long long start, end;
853         int ret;
854 
855         pr_debug("Setup crash memory ranges.\n");
856         crash_mem_ranges = 0;
857         /*
858          * add the first memory chunk (RMA_START through boot_memory_size) as
859          * a separate memory chunk. The reason is, at the time crash firmware
860          * will move the content of this memory chunk to different location
861          * specified during fadump registration. We need to create a separate
862          * program header for this chunk with the correct offset.
863          */
864         ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
865         if (ret)
866                 return ret;
867 
868         for_each_memblock(memory, reg) {
869                 start = (unsigned long long)reg->base;
870                 end = start + (unsigned long long)reg->size;
871                 if (start == RMA_START && end >= fw_dump.boot_memory_size)
872                         start = fw_dump.boot_memory_size;
873 
874                 /* add this range excluding the reserved dump area. */
875                 ret = fadump_exclude_reserved_area(start, end);
876                 if (ret)
877                         return ret;
878         }
879 
880         return 0;
881 }
882 
883 /*
884  * If the given physical address falls within the boot memory region then
885  * return the relocated address that points to the dump region reserved
886  * for saving initial boot memory contents.
887  */
888 static inline unsigned long fadump_relocate(unsigned long paddr)
889 {
890         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
891                 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
892         else
893                 return paddr;
894 }
895 
896 static int fadump_create_elfcore_headers(char *bufp)
897 {
898         struct elfhdr *elf;
899         struct elf_phdr *phdr;
900         int i;
901 
902         fadump_init_elfcore_header(bufp);
903         elf = (struct elfhdr *)bufp;
904         bufp += sizeof(struct elfhdr);
905 
906         /*
907          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
908          * will be populated during second kernel boot after crash. Hence
909          * this PT_NOTE will always be the first elf note.
910          *
911          * NOTE: Any new ELF note addition should be placed after this note.
912          */
913         phdr = (struct elf_phdr *)bufp;
914         bufp += sizeof(struct elf_phdr);
915         phdr->p_type = PT_NOTE;
916         phdr->p_flags = 0;
917         phdr->p_vaddr = 0;
918         phdr->p_align = 0;
919 
920         phdr->p_offset = 0;
921         phdr->p_paddr = 0;
922         phdr->p_filesz = 0;
923         phdr->p_memsz = 0;
924 
925         (elf->e_phnum)++;
926 
927         /* setup ELF PT_NOTE for vmcoreinfo */
928         phdr = (struct elf_phdr *)bufp;
929         bufp += sizeof(struct elf_phdr);
930         phdr->p_type    = PT_NOTE;
931         phdr->p_flags   = 0;
932         phdr->p_vaddr   = 0;
933         phdr->p_align   = 0;
934 
935         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
936         phdr->p_offset  = phdr->p_paddr;
937         phdr->p_memsz   = vmcoreinfo_max_size;
938         phdr->p_filesz  = vmcoreinfo_max_size;
939 
940         /* Increment number of program headers. */
941         (elf->e_phnum)++;
942 
943         /* setup PT_LOAD sections. */
944 
945         for (i = 0; i < crash_mem_ranges; i++) {
946                 unsigned long long mbase, msize;
947                 mbase = crash_memory_ranges[i].base;
948                 msize = crash_memory_ranges[i].size;
949 
950                 if (!msize)
951                         continue;
952 
953                 phdr = (struct elf_phdr *)bufp;
954                 bufp += sizeof(struct elf_phdr);
955                 phdr->p_type    = PT_LOAD;
956                 phdr->p_flags   = PF_R|PF_W|PF_X;
957                 phdr->p_offset  = mbase;
958 
959                 if (mbase == RMA_START) {
960                         /*
961                          * The entire RMA region will be moved by firmware
962                          * to the specified destination_address. Hence set
963                          * the correct offset.
964                          */
965                         phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
966                 }
967 
968                 phdr->p_paddr = mbase;
969                 phdr->p_vaddr = (unsigned long)__va(mbase);
970                 phdr->p_filesz = msize;
971                 phdr->p_memsz = msize;
972                 phdr->p_align = 0;
973 
974                 /* Increment number of program headers. */
975                 (elf->e_phnum)++;
976         }
977         return 0;
978 }
979 
980 static unsigned long init_fadump_header(unsigned long addr)
981 {
982         struct fadump_crash_info_header *fdh;
983 
984         if (!addr)
985                 return 0;
986 
987         fw_dump.fadumphdr_addr = addr;
988         fdh = __va(addr);
989         addr += sizeof(struct fadump_crash_info_header);
990 
991         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
992         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
993         fdh->elfcorehdr_addr = addr;
994         /* We will set the crashing cpu id in crash_fadump() during crash. */
995         fdh->crashing_cpu = CPU_UNKNOWN;
996 
997         return addr;
998 }
999 
1000 static void register_fadump(void)
1001 {
1002         unsigned long addr;
1003         void *vaddr;
1004         int ret;
1005 
1006         /*
1007          * If no memory is reserved then we can not register for firmware-
1008          * assisted dump.
1009          */
1010         if (!fw_dump.reserve_dump_area_size)
1011                 return;
1012 
1013         ret = fadump_setup_crash_memory_ranges();
1014         if (ret)
1015                 return ret;
1016 
1017         addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1018         /* Initialize fadump crash info header. */
1019         addr = init_fadump_header(addr);
1020         vaddr = __va(addr);
1021 
1022         pr_debug("Creating ELF core headers at %#016lx\n", addr);
1023         fadump_create_elfcore_headers(vaddr);
1024 
1025         /* register the future kernel dump with firmware. */
1026         register_fw_dump(&fdm);
1027 }
1028 
1029 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1030 {
1031         int rc = 0;
1032         unsigned int wait_time;
1033 
1034         pr_debug("Un-register firmware-assisted dump\n");
1035 
1036         /* TODO: Add upper time limit for the delay */
1037         do {
1038                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1039                         FADUMP_UNREGISTER, fdm,
1040                         sizeof(struct fadump_mem_struct));
1041 
1042                 wait_time = rtas_busy_delay_time(rc);
1043                 if (wait_time)
1044                         mdelay(wait_time);
1045         } while (wait_time);
1046 
1047         if (rc) {
1048                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1049                         " unexpected error(%d).\n", rc);
1050                 return rc;
1051         }
1052         fw_dump.dump_registered = 0;
1053         return 0;
1054 }
1055 
1056 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1057 {
1058         int rc = 0;
1059         unsigned int wait_time;
1060 
1061         pr_debug("Invalidating firmware-assisted dump registration\n");
1062 
1063         /* TODO: Add upper time limit for the delay */
1064         do {
1065                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1066                         FADUMP_INVALIDATE, fdm,
1067                         sizeof(struct fadump_mem_struct));
1068 
1069                 wait_time = rtas_busy_delay_time(rc);
1070                 if (wait_time)
1071                         mdelay(wait_time);
1072         } while (wait_time);
1073 
1074         if (rc) {
1075                 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1076                         "rgistration. unexpected error(%d).\n", rc);
1077                 return rc;
1078         }
1079         fw_dump.dump_active = 0;
1080         fdm_active = NULL;
1081         return 0;
1082 }
1083 
1084 void fadump_cleanup(void)
1085 {
1086         /* Invalidate the registration only if dump is active. */
1087         if (fw_dump.dump_active) {
1088                 init_fadump_mem_struct(&fdm,
1089                         be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1090                 fadump_invalidate_dump(&fdm);
1091         } else if (fw_dump.dump_registered) {
1092                 /* Un-register Firmware-assisted dump if it was registered. */
1093                 fadump_unregister_dump(&fdm);
1094                 free_crash_memory_ranges();
1095         }
1096 }
1097 
1098 /*
1099  * Release the memory that was reserved in early boot to preserve the memory
1100  * contents. The released memory will be available for general use.
1101  */
1102 static void fadump_release_memory(unsigned long begin, unsigned long end)
1103 {
1104         unsigned long addr;
1105         unsigned long ra_start, ra_end;
1106 
1107         ra_start = fw_dump.reserve_dump_area_start;
1108         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1109 
1110         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1111                 /*
1112                  * exclude the dump reserve area. Will reuse it for next
1113                  * fadump registration.
1114                  */
1115                 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1116                         continue;
1117 
1118                 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1119         }
1120 }
1121 
1122 static void fadump_invalidate_release_mem(void)
1123 {
1124         unsigned long reserved_area_start, reserved_area_end;
1125         unsigned long destination_address;
1126 
1127         mutex_lock(&fadump_mutex);
1128         if (!fw_dump.dump_active) {
1129                 mutex_unlock(&fadump_mutex);
1130                 return;
1131         }
1132 
1133         destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1134         fadump_cleanup();
1135         mutex_unlock(&fadump_mutex);
1136 
1137         /*
1138          * Save the current reserved memory bounds we will require them
1139          * later for releasing the memory for general use.
1140          */
1141         reserved_area_start = fw_dump.reserve_dump_area_start;
1142         reserved_area_end = reserved_area_start +
1143                         fw_dump.reserve_dump_area_size;
1144         /*
1145          * Setup reserve_dump_area_start and its size so that we can
1146          * reuse this reserved memory for Re-registration.
1147          */
1148         fw_dump.reserve_dump_area_start = destination_address;
1149         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1150 
1151         fadump_release_memory(reserved_area_start, reserved_area_end);
1152         if (fw_dump.cpu_notes_buf) {
1153                 fadump_cpu_notes_buf_free(
1154                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1155                                 fw_dump.cpu_notes_buf_size);
1156                 fw_dump.cpu_notes_buf = 0;
1157                 fw_dump.cpu_notes_buf_size = 0;
1158         }
1159         /* Initialize the kernel dump memory structure for FAD registration. */
1160         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1161 }
1162 
1163 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1164                                         struct kobj_attribute *attr,
1165                                         const char *buf, size_t count)
1166 {
1167         if (!fw_dump.dump_active)
1168                 return -EPERM;
1169 
1170         if (buf[0] == '1') {
1171                 /*
1172                  * Take away the '/proc/vmcore'. We are releasing the dump
1173                  * memory, hence it will not be valid anymore.
1174                  */
1175                 vmcore_cleanup();
1176                 fadump_invalidate_release_mem();
1177 
1178         } else
1179                 return -EINVAL;
1180         return count;
1181 }
1182 
1183 static ssize_t fadump_enabled_show(struct kobject *kobj,
1184                                         struct kobj_attribute *attr,
1185                                         char *buf)
1186 {
1187         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1188 }
1189 
1190 static ssize_t fadump_register_show(struct kobject *kobj,
1191                                         struct kobj_attribute *attr,
1192                                         char *buf)
1193 {
1194         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1195 }
1196 
1197 static ssize_t fadump_register_store(struct kobject *kobj,
1198                                         struct kobj_attribute *attr,
1199                                         const char *buf, size_t count)
1200 {
1201         int ret = 0;
1202 
1203         if (!fw_dump.fadump_enabled || fdm_active)
1204                 return -EPERM;
1205 
1206         mutex_lock(&fadump_mutex);
1207 
1208         switch (buf[0]) {
1209         case '':
1210                 if (fw_dump.dump_registered == 0) {
1211                         ret = -EINVAL;
1212                         goto unlock_out;
1213                 }
1214                 /* Un-register Firmware-assisted dump */
1215                 fadump_unregister_dump(&fdm);
1216                 break;
1217         case '1':
1218                 if (fw_dump.dump_registered == 1) {
1219                         ret = -EINVAL;
1220                         goto unlock_out;
1221                 }
1222                 /* Register Firmware-assisted dump */
1223                 register_fadump();
1224                 break;
1225         default:
1226                 ret = -EINVAL;
1227                 break;
1228         }
1229 
1230 unlock_out:
1231         mutex_unlock(&fadump_mutex);
1232         return ret < 0 ? ret : count;
1233 }
1234 
1235 static int fadump_region_show(struct seq_file *m, void *private)
1236 {
1237         const struct fadump_mem_struct *fdm_ptr;
1238 
1239         if (!fw_dump.fadump_enabled)
1240                 return 0;
1241 
1242         mutex_lock(&fadump_mutex);
1243         if (fdm_active)
1244                 fdm_ptr = fdm_active;
1245         else {
1246                 mutex_unlock(&fadump_mutex);
1247                 fdm_ptr = &fdm;
1248         }
1249 
1250         seq_printf(m,
1251                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1252                         "Dumped: %#llx\n",
1253                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1254                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1255                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1256                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1257                         be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1258         seq_printf(m,
1259                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1260                         "Dumped: %#llx\n",
1261                         be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1262                         be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1263                         be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1264                         be64_to_cpu(fdm_ptr->hpte_region.source_len),
1265                         be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1266         seq_printf(m,
1267                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1268                         "Dumped: %#llx\n",
1269                         be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1270                         be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1271                         be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1272                         be64_to_cpu(fdm_ptr->rmr_region.source_len),
1273                         be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1274 
1275         if (!fdm_active ||
1276                 (fw_dump.reserve_dump_area_start ==
1277                 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1278                 goto out;
1279 
1280         /* Dump is active. Show reserved memory region. */
1281         seq_printf(m,
1282                         "    : [%#016llx-%#016llx] %#llx bytes, "
1283                         "Dumped: %#llx\n",
1284                         (unsigned long long)fw_dump.reserve_dump_area_start,
1285                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1286                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1287                         fw_dump.reserve_dump_area_start,
1288                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1289                         fw_dump.reserve_dump_area_start);
1290 out:
1291         if (fdm_active)
1292                 mutex_unlock(&fadump_mutex);
1293         return 0;
1294 }
1295 
1296 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1297                                                 0200, NULL,
1298                                                 fadump_release_memory_store);
1299 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1300                                                 0444, fadump_enabled_show,
1301                                                 NULL);
1302 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1303                                                 0644, fadump_register_show,
1304                                                 fadump_register_store);
1305 
1306 static int fadump_region_open(struct inode *inode, struct file *file)
1307 {
1308         return single_open(file, fadump_region_show, inode->i_private);
1309 }
1310 
1311 static const struct file_operations fadump_region_fops = {
1312         .open    = fadump_region_open,
1313         .read    = seq_read,
1314         .llseek  = seq_lseek,
1315         .release = single_release,
1316 };
1317 
1318 static void fadump_init_files(void)
1319 {
1320         struct dentry *debugfs_file;
1321         int rc = 0;
1322 
1323         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1324         if (rc)
1325                 printk(KERN_ERR "fadump: unable to create sysfs file"
1326                         " fadump_enabled (%d)\n", rc);
1327 
1328         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1329         if (rc)
1330                 printk(KERN_ERR "fadump: unable to create sysfs file"
1331                         " fadump_registered (%d)\n", rc);
1332 
1333         debugfs_file = debugfs_create_file("fadump_region", 0444,
1334                                         powerpc_debugfs_root, NULL,
1335                                         &fadump_region_fops);
1336         if (!debugfs_file)
1337                 printk(KERN_ERR "fadump: unable to create debugfs file"
1338                                 " fadump_region\n");
1339 
1340         if (fw_dump.dump_active) {
1341                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1342                 if (rc)
1343                         printk(KERN_ERR "fadump: unable to create sysfs file"
1344                                 " fadump_release_mem (%d)\n", rc);
1345         }
1346         return;
1347 }
1348 
1349 /*
1350  * Prepare for firmware-assisted dump.
1351  */
1352 int __init setup_fadump(void)
1353 {
1354         if (!fw_dump.fadump_enabled)
1355                 return 0;
1356 
1357         if (!fw_dump.fadump_supported) {
1358                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1359                         " this hardware\n");
1360                 return 0;
1361         }
1362 
1363         fadump_show_config();
1364         /*
1365          * If dump data is available then see if it is valid and prepare for
1366          * saving it to the disk.
1367          */
1368         if (fw_dump.dump_active) {
1369                 /*
1370                  * if dump process fails then invalidate the registration
1371                  * and release memory before proceeding for re-registration.
1372                  */
1373                 if (process_fadump(fdm_active) < 0)
1374                         fadump_invalidate_release_mem();
1375         }
1376         /* Initialize the kernel dump memory structure for FAD registration. */
1377         else if (fw_dump.reserve_dump_area_size)
1378                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1379         fadump_init_files();
1380 
1381         return 1;
1382 }
1383 subsys_initcall(setup_fadump);
1384 

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