~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.14-rc3 ] ~ [ linux-5.13.5 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.53 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.135 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.198 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.240 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.276 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.276 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

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

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp