/* * Firmware Assisted dump: A robust mechanism to get reliable kernel crash * dump with assistance from firmware. This approach does not use kexec, * instead firmware assists in booting the kdump kernel while preserving * memory contents. The most of the code implementation has been adapted * from phyp assisted dump implementation written by Linas Vepstas and * Manish Ahuja * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Copyright 2011 IBM Corporation * Author: Mahesh Salgaonkar */ #undef DEBUG #define pr_fmt(fmt) "fadump: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct fw_dump fw_dump; static struct fadump_mem_struct fdm; static const struct fadump_mem_struct *fdm_active; static DEFINE_MUTEX(fadump_mutex); struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES]; int crash_mem_ranges; /* Scan the Firmware Assisted dump configuration details. */ int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname, int depth, void *data) { const __be32 *sections; int i, num_sections; int size; const int *token; if (depth != 1 || strcmp(uname, "rtas") != 0) return 0; /* * Check if Firmware Assisted dump is supported. if yes, check * if dump has been initiated on last reboot. */ token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); if (!token) return 0; fw_dump.fadump_supported = 1; fw_dump.ibm_configure_kernel_dump = *token; /* * The 'ibm,kernel-dump' rtas node is present only if there is * dump data waiting for us. */ fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); if (fdm_active) fw_dump.dump_active = 1; /* Get the sizes required to store dump data for the firmware provided * dump sections. * For each dump section type supported, a 32bit cell which defines * the ID of a supported section followed by two 32 bit cells which * gives teh size of the section in bytes. */ sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", &size); if (!sections) return 0; num_sections = size / (3 * sizeof(u32)); for (i = 0; i < num_sections; i++, sections += 3) { u32 type = (u32)of_read_number(sections, 1); switch (type) { case FADUMP_CPU_STATE_DATA: fw_dump.cpu_state_data_size = of_read_ulong(§ions[1], 2); break; case FADUMP_HPTE_REGION: fw_dump.hpte_region_size = of_read_ulong(§ions[1], 2); break; } } return 1; } int is_fadump_active(void) { return fw_dump.dump_active; } /* Print firmware assisted dump configurations for debugging purpose. */ static void fadump_show_config(void) { pr_debug("Support for firmware-assisted dump (fadump): %s\n", (fw_dump.fadump_supported ? "present" : "no support")); if (!fw_dump.fadump_supported) return; pr_debug("Fadump enabled : %s\n", (fw_dump.fadump_enabled ? "yes" : "no")); pr_debug("Dump Active : %s\n", (fw_dump.dump_active ? "yes" : "no")); pr_debug("Dump section sizes:\n"); pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); } static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, unsigned long addr) { if (!fdm) return 0; memset(fdm, 0, sizeof(struct fadump_mem_struct)); addr = addr & PAGE_MASK; fdm->header.dump_format_version = 0x00000001; fdm->header.dump_num_sections = 3; fdm->header.dump_status_flag = 0; fdm->header.offset_first_dump_section = (u32)offsetof(struct fadump_mem_struct, cpu_state_data); /* * Fields for disk dump option. * We are not using disk dump option, hence set these fields to 0. */ fdm->header.dd_block_size = 0; fdm->header.dd_block_offset = 0; fdm->header.dd_num_blocks = 0; fdm->header.dd_offset_disk_path = 0; /* set 0 to disable an automatic dump-reboot. */ fdm->header.max_time_auto = 0; /* Kernel dump sections */ /* cpu state data section. */ fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG; fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA; fdm->cpu_state_data.source_address = 0; fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size; fdm->cpu_state_data.destination_address = addr; addr += fw_dump.cpu_state_data_size; /* hpte region section */ fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG; fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION; fdm->hpte_region.source_address = 0; fdm->hpte_region.source_len = fw_dump.hpte_region_size; fdm->hpte_region.destination_address = addr; addr += fw_dump.hpte_region_size; /* RMA region section */ fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG; fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION; fdm->rmr_region.source_address = RMA_START; fdm->rmr_region.source_len = fw_dump.boot_memory_size; fdm->rmr_region.destination_address = addr; addr += fw_dump.boot_memory_size; return addr; } /** * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM * * Function to find the largest memory size we need to reserve during early * boot process. This will be the size of the memory that is required for a * kernel to boot successfully. * * This function has been taken from phyp-assisted dump feature implementation. * * returns larger of 256MB or 5% rounded down to multiples of 256MB. * * TODO: Come up with better approach to find out more accurate memory size * that is required for a kernel to boot successfully. * */ static inline unsigned long fadump_calculate_reserve_size(void) { unsigned long size; /* * Check if the size is specified through fadump_reserve_mem= cmdline * option. If yes, then use that. */ if (fw_dump.reserve_bootvar) return fw_dump.reserve_bootvar; /* divide by 20 to get 5% of value */ size = memblock_end_of_DRAM() / 20; /* round it down in multiples of 256 */ size = size & ~0x0FFFFFFFUL; /* Truncate to memory_limit. We don't want to over reserve the memory.*/ if (memory_limit && size > memory_limit) size = memory_limit; return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); } /* * Calculate the total memory size required to be reserved for * firmware-assisted dump registration. */ static unsigned long get_fadump_area_size(void) { unsigned long size = 0; size += fw_dump.cpu_state_data_size; size += fw_dump.hpte_region_size; size += fw_dump.boot_memory_size; size += sizeof(struct fadump_crash_info_header); size += sizeof(struct elfhdr); /* ELF core header.*/ size += sizeof(struct elf_phdr); /* place holder for cpu notes */ /* Program headers for crash memory regions. */ size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); size = PAGE_ALIGN(size); return size; } int __init fadump_reserve_mem(void) { unsigned long base, size, memory_boundary; if (!fw_dump.fadump_enabled) return 0; if (!fw_dump.fadump_supported) { printk(KERN_INFO "Firmware-assisted dump is not supported on" " this hardware\n"); fw_dump.fadump_enabled = 0; return 0; } /* * Initialize boot memory size * If dump is active then we have already calculated the size during * first kernel. */ if (fdm_active) fw_dump.boot_memory_size = fdm_active->rmr_region.source_len; else fw_dump.boot_memory_size = fadump_calculate_reserve_size(); /* * Calculate the memory boundary. * If memory_limit is less than actual memory boundary then reserve * the memory for fadump beyond the memory_limit and adjust the * memory_limit accordingly, so that the running kernel can run with * specified memory_limit. */ if (memory_limit && memory_limit < memblock_end_of_DRAM()) { size = get_fadump_area_size(); if ((memory_limit + size) < memblock_end_of_DRAM()) memory_limit += size; else memory_limit = memblock_end_of_DRAM(); printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" " dump, now %#016llx\n", memory_limit); } if (memory_limit) memory_boundary = memory_limit; else memory_boundary = memblock_end_of_DRAM(); if (fw_dump.dump_active) { printk(KERN_INFO "Firmware-assisted dump is active.\n"); /* * If last boot has crashed then reserve all the memory * above boot_memory_size so that we don't touch it until * dump is written to disk by userspace tool. This memory * will be released for general use once the dump is saved. */ base = fw_dump.boot_memory_size; size = memory_boundary - base; memblock_reserve(base, size); printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " "for saving crash dump\n", (unsigned long)(size >> 20), (unsigned long)(base >> 20)); fw_dump.fadumphdr_addr = fdm_active->rmr_region.destination_address + fdm_active->rmr_region.source_len; pr_debug("fadumphdr_addr = %p\n", (void *) fw_dump.fadumphdr_addr); } else { /* Reserve the memory at the top of memory. */ size = get_fadump_area_size(); base = memory_boundary - size; memblock_reserve(base, size); printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " "for firmware-assisted dump\n", (unsigned long)(size >> 20), (unsigned long)(base >> 20)); } fw_dump.reserve_dump_area_start = base; fw_dump.reserve_dump_area_size = size; return 1; } /* Look for fadump= cmdline option. */ static int __init early_fadump_param(char *p) { if (!p) return 1; if (strncmp(p, "on", 2) == 0) fw_dump.fadump_enabled = 1; else if (strncmp(p, "off", 3) == 0) fw_dump.fadump_enabled = 0; return 0; } early_param("fadump", early_fadump_param); /* Look for fadump_reserve_mem= cmdline option */ static int __init early_fadump_reserve_mem(char *p) { if (p) fw_dump.reserve_bootvar = memparse(p, &p); return 0; } early_param("fadump_reserve_mem", early_fadump_reserve_mem); static void register_fw_dump(struct fadump_mem_struct *fdm) { int rc; unsigned int wait_time; pr_debug("Registering for firmware-assisted kernel dump...\n"); /* TODO: Add upper time limit for the delay */ do { rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, FADUMP_REGISTER, fdm, sizeof(struct fadump_mem_struct)); wait_time = rtas_busy_delay_time(rc); if (wait_time) mdelay(wait_time); } while (wait_time); switch (rc) { case -1: printk(KERN_ERR "Failed to register firmware-assisted kernel" " dump. Hardware Error(%d).\n", rc); break; case -3: printk(KERN_ERR "Failed to register firmware-assisted kernel" " dump. Parameter Error(%d).\n", rc); break; case -9: printk(KERN_ERR "firmware-assisted kernel dump is already " " registered."); fw_dump.dump_registered = 1; break; case 0: printk(KERN_INFO "firmware-assisted kernel dump registration" " is successful\n"); fw_dump.dump_registered = 1; break; } } void crash_fadump(struct pt_regs *regs, const char *str) { struct fadump_crash_info_header *fdh = NULL; if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) return; fdh = __va(fw_dump.fadumphdr_addr); crashing_cpu = smp_processor_id(); fdh->crashing_cpu = crashing_cpu; crash_save_vmcoreinfo(); if (regs) fdh->regs = *regs; else ppc_save_regs(&fdh->regs); fdh->cpu_online_mask = *cpu_online_mask; /* Call ibm,os-term rtas call to trigger firmware assisted dump */ rtas_os_term((char *)str); } #define GPR_MASK 0xffffff0000000000 static inline int fadump_gpr_index(u64 id) { int i = -1; char str[3]; if ((id & GPR_MASK) == REG_ID("GPR")) { /* get the digits at the end */ id &= ~GPR_MASK; id >>= 24; str[2] = '\0'; str[1] = id & 0xff; str[0] = (id >> 8) & 0xff; sscanf(str, "%d", &i); if (i > 31) i = -1; } return i; } static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, u64 reg_val) { int i; i = fadump_gpr_index(reg_id); if (i >= 0) regs->gpr[i] = (unsigned long)reg_val; else if (reg_id == REG_ID("NIA")) regs->nip = (unsigned long)reg_val; else if (reg_id == REG_ID("MSR")) regs->msr = (unsigned long)reg_val; else if (reg_id == REG_ID("CTR")) regs->ctr = (unsigned long)reg_val; else if (reg_id == REG_ID("LR")) regs->link = (unsigned long)reg_val; else if (reg_id == REG_ID("XER")) regs->xer = (unsigned long)reg_val; else if (reg_id == REG_ID("CR")) regs->ccr = (unsigned long)reg_val; else if (reg_id == REG_ID("DAR")) regs->dar = (unsigned long)reg_val; else if (reg_id == REG_ID("DSISR")) regs->dsisr = (unsigned long)reg_val; } static struct fadump_reg_entry* fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) { memset(regs, 0, sizeof(struct pt_regs)); while (reg_entry->reg_id != REG_ID("CPUEND")) { fadump_set_regval(regs, reg_entry->reg_id, reg_entry->reg_value); reg_entry++; } reg_entry++; return reg_entry; } static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type, void *data, size_t data_len) { struct elf_note note; note.n_namesz = strlen(name) + 1; note.n_descsz = data_len; note.n_type = type; memcpy(buf, ¬e, sizeof(note)); buf += (sizeof(note) + 3)/4; memcpy(buf, name, note.n_namesz); buf += (note.n_namesz + 3)/4; memcpy(buf, data, note.n_descsz); buf += (note.n_descsz + 3)/4; return buf; } static void fadump_final_note(u32 *buf) { struct elf_note note; note.n_namesz = 0; note.n_descsz = 0; note.n_type = 0; memcpy(buf, ¬e, sizeof(note)); } static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) { struct elf_prstatus prstatus; memset(&prstatus, 0, sizeof(prstatus)); /* * FIXME: How do i get PID? Do I really need it? * prstatus.pr_pid = ???? */ elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, &prstatus, sizeof(prstatus)); return buf; } static void fadump_update_elfcore_header(char *bufp) { struct elfhdr *elf; struct elf_phdr *phdr; elf = (struct elfhdr *)bufp; bufp += sizeof(struct elfhdr); /* First note is a place holder for cpu notes info. */ phdr = (struct elf_phdr *)bufp; if (phdr->p_type == PT_NOTE) { phdr->p_paddr = fw_dump.cpu_notes_buf; phdr->p_offset = phdr->p_paddr; phdr->p_filesz = fw_dump.cpu_notes_buf_size; phdr->p_memsz = fw_dump.cpu_notes_buf_size; } return; } static void *fadump_cpu_notes_buf_alloc(unsigned long size) { void *vaddr; struct page *page; unsigned long order, count, i; order = get_order(size); vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); if (!vaddr) return NULL; count = 1 << order; page = virt_to_page(vaddr); for (i = 0; i < count; i++) SetPageReserved(page + i); return vaddr; } static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) { struct page *page; unsigned long order, count, i; order = get_order(size); count = 1 << order; page = virt_to_page(vaddr); for (i = 0; i < count; i++) ClearPageReserved(page + i); __free_pages(page, order); } /* * Read CPU state dump data and convert it into ELF notes. * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be * used to access the data to allow for additional fields to be added without * affecting compatibility. Each list of registers for a CPU starts with * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, * 8 Byte ASCII identifier and 8 Byte register value. The register entry * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part * of register value. For more details refer to PAPR document. * * Only for the crashing cpu we ignore the CPU dump data and get exact * state from fadump crash info structure populated by first kernel at the * time of crash. */ static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) { struct fadump_reg_save_area_header *reg_header; struct fadump_reg_entry *reg_entry; struct fadump_crash_info_header *fdh = NULL; void *vaddr; unsigned long addr; u32 num_cpus, *note_buf; struct pt_regs regs; int i, rc = 0, cpu = 0; if (!fdm->cpu_state_data.bytes_dumped) return -EINVAL; addr = fdm->cpu_state_data.destination_address; vaddr = __va(addr); reg_header = vaddr; if (reg_header->magic_number != REGSAVE_AREA_MAGIC) { printk(KERN_ERR "Unable to read register save area.\n"); return -ENOENT; } pr_debug("--------CPU State Data------------\n"); pr_debug("Magic Number: %llx\n", reg_header->magic_number); pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset); vaddr += reg_header->num_cpu_offset; num_cpus = *((u32 *)(vaddr)); pr_debug("NumCpus : %u\n", num_cpus); vaddr += sizeof(u32); reg_entry = (struct fadump_reg_entry *)vaddr; /* Allocate buffer to hold cpu crash notes. */ fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); if (!note_buf) { printk(KERN_ERR "Failed to allocate 0x%lx bytes for " "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); return -ENOMEM; } fw_dump.cpu_notes_buf = __pa(note_buf); pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", (num_cpus * sizeof(note_buf_t)), note_buf); if (fw_dump.fadumphdr_addr) fdh = __va(fw_dump.fadumphdr_addr); for (i = 0; i < num_cpus; i++) { if (reg_entry->reg_id != REG_ID("CPUSTRT")) { printk(KERN_ERR "Unable to read CPU state data\n"); rc = -ENOENT; goto error_out; } /* Lower 4 bytes of reg_value contains logical cpu id */ cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK; if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) { SKIP_TO_NEXT_CPU(reg_entry); continue; } pr_debug("Reading register data for cpu %d...\n", cpu); if (fdh && fdh->crashing_cpu == cpu) { regs = fdh->regs; note_buf = fadump_regs_to_elf_notes(note_buf, ®s); SKIP_TO_NEXT_CPU(reg_entry); } else { reg_entry++; reg_entry = fadump_read_registers(reg_entry, ®s); note_buf = fadump_regs_to_elf_notes(note_buf, ®s); } } fadump_final_note(note_buf); pr_debug("Updating elfcore header (%llx) with cpu notes\n", fdh->elfcorehdr_addr); fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); return 0; error_out: fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), fw_dump.cpu_notes_buf_size); fw_dump.cpu_notes_buf = 0; fw_dump.cpu_notes_buf_size = 0; return rc; } /* * Validate and process the dump data stored by firmware before exporting * it through '/proc/vmcore'. */ static int __init process_fadump(const struct fadump_mem_struct *fdm_active) { struct fadump_crash_info_header *fdh; int rc = 0; if (!fdm_active || !fw_dump.fadumphdr_addr) return -EINVAL; /* Check if the dump data is valid. */ if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) || (fdm_active->cpu_state_data.error_flags != 0) || (fdm_active->rmr_region.error_flags != 0)) { printk(KERN_ERR "Dump taken by platform is not valid\n"); return -EINVAL; } if ((fdm_active->rmr_region.bytes_dumped != fdm_active->rmr_region.source_len) || !fdm_active->cpu_state_data.bytes_dumped) { printk(KERN_ERR "Dump taken by platform is incomplete\n"); return -EINVAL; } /* Validate the fadump crash info header */ fdh = __va(fw_dump.fadumphdr_addr); if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { printk(KERN_ERR "Crash info header is not valid.\n"); return -EINVAL; } rc = fadump_build_cpu_notes(fdm_active); if (rc) return rc; /* * We are done validating dump info and elfcore header is now ready * to be exported. set elfcorehdr_addr so that vmcore module will * export the elfcore header through '/proc/vmcore'. */ elfcorehdr_addr = fdh->elfcorehdr_addr; return 0; } static inline void fadump_add_crash_memory(unsigned long long base, unsigned long long end) { if (base == end) return; pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", crash_mem_ranges, base, end - 1, (end - base)); crash_memory_ranges[crash_mem_ranges].base = base; crash_memory_ranges[crash_mem_ranges].size = end - base; crash_mem_ranges++; } static void fadump_exclude_reserved_area(unsigned long long start, unsigned long long end) { unsigned long long ra_start, ra_end; ra_start = fw_dump.reserve_dump_area_start; ra_end = ra_start + fw_dump.reserve_dump_area_size; if ((ra_start < end) && (ra_end > start)) { if ((start < ra_start) && (end > ra_end)) { fadump_add_crash_memory(start, ra_start); fadump_add_crash_memory(ra_end, end); } else if (start < ra_start) { fadump_add_crash_memory(start, ra_start); } else if (ra_end < end) { fadump_add_crash_memory(ra_end, end); } } else fadump_add_crash_memory(start, end); } static int fadump_init_elfcore_header(char *bufp) { struct elfhdr *elf; elf = (struct elfhdr *) bufp; bufp += sizeof(struct elfhdr); memcpy(elf->e_ident, ELFMAG, SELFMAG); elf->e_ident[EI_CLASS] = ELF_CLASS; elf->e_ident[EI_DATA] = ELF_DATA; elf->e_ident[EI_VERSION] = EV_CURRENT; elf->e_ident[EI_OSABI] = ELF_OSABI; memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); elf->e_type = ET_CORE; elf->e_machine = ELF_ARCH; elf->e_version = EV_CURRENT; elf->e_entry = 0; elf->e_phoff = sizeof(struct elfhdr); elf->e_shoff = 0; elf->e_flags = ELF_CORE_EFLAGS; elf->e_ehsize = sizeof(struct elfhdr); elf->e_phentsize = sizeof(struct elf_phdr); elf->e_phnum = 0; elf->e_shentsize = 0; elf->e_shnum = 0; elf->e_shstrndx = 0; return 0; } /* * Traverse through memblock structure and setup crash memory ranges. These * ranges will be used create PT_LOAD program headers in elfcore header. */ static void fadump_setup_crash_memory_ranges(void) { struct memblock_region *reg; unsigned long long start, end; pr_debug("Setup crash memory ranges.\n"); crash_mem_ranges = 0; /* * add the first memory chunk (RMA_START through boot_memory_size) as * a separate memory chunk. The reason is, at the time crash firmware * will move the content of this memory chunk to different location * specified during fadump registration. We need to create a separate * program header for this chunk with the correct offset. */ fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); for_each_memblock(memory, reg) { start = (unsigned long long)reg->base; end = start + (unsigned long long)reg->size; if (start == RMA_START && end >= fw_dump.boot_memory_size) start = fw_dump.boot_memory_size; /* add this range excluding the reserved dump area. */ fadump_exclude_reserved_area(start, end); } } /* * If the given physical address falls within the boot memory region then * return the relocated address that points to the dump region reserved * for saving initial boot memory contents. */ static inline unsigned long fadump_relocate(unsigned long paddr) { if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) return fdm.rmr_region.destination_address + paddr; else return paddr; } static int fadump_create_elfcore_headers(char *bufp) { struct elfhdr *elf; struct elf_phdr *phdr; int i; fadump_init_elfcore_header(bufp); elf = (struct elfhdr *)bufp; bufp += sizeof(struct elfhdr); /* * setup ELF PT_NOTE, place holder for cpu notes info. The notes info * will be populated during second kernel boot after crash. Hence * this PT_NOTE will always be the first elf note. * * NOTE: Any new ELF note addition should be placed after this note. */ phdr = (struct elf_phdr *)bufp; bufp += sizeof(struct elf_phdr); phdr->p_type = PT_NOTE; phdr->p_flags = 0; phdr->p_vaddr = 0; phdr->p_align = 0; phdr->p_offset = 0; phdr->p_paddr = 0; phdr->p_filesz = 0; phdr->p_memsz = 0; (elf->e_phnum)++; /* setup ELF PT_NOTE for vmcoreinfo */ phdr = (struct elf_phdr *)bufp; bufp += sizeof(struct elf_phdr); phdr->p_type = PT_NOTE; phdr->p_flags = 0; phdr->p_vaddr = 0; phdr->p_align = 0; phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); phdr->p_offset = phdr->p_paddr; phdr->p_memsz = vmcoreinfo_max_size; phdr->p_filesz = vmcoreinfo_max_size; /* Increment number of program headers. */ (elf->e_phnum)++; /* setup PT_LOAD sections. */ for (i = 0; i < crash_mem_ranges; i++) { unsigned long long mbase, msize; mbase = crash_memory_ranges[i].base; msize = crash_memory_ranges[i].size; if (!msize) continue; phdr = (struct elf_phdr *)bufp; bufp += sizeof(struct elf_phdr); phdr->p_type = PT_LOAD; phdr->p_flags = PF_R|PF_W|PF_X; phdr->p_offset = mbase; if (mbase == RMA_START) { /* * The entire RMA region will be moved by firmware * to the specified destination_address. Hence set * the correct offset. */ phdr->p_offset = fdm.rmr_region.destination_address; } phdr->p_paddr = mbase; phdr->p_vaddr = (unsigned long)__va(mbase); phdr->p_filesz = msize; phdr->p_memsz = msize; phdr->p_align = 0; /* Increment number of program headers. */ (elf->e_phnum)++; } return 0; } static unsigned long init_fadump_header(unsigned long addr) { struct fadump_crash_info_header *fdh; if (!addr) return 0; fw_dump.fadumphdr_addr = addr; fdh = __va(addr); addr += sizeof(struct fadump_crash_info_header); memset(fdh, 0, sizeof(struct fadump_crash_info_header)); fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; fdh->elfcorehdr_addr = addr; /* We will set the crashing cpu id in crash_fadump() during crash. */ fdh->crashing_cpu = CPU_UNKNOWN; return addr; } static void register_fadump(void) { unsigned long addr; void *vaddr; /* * If no memory is reserved then we can not register for firmware- * assisted dump. */ if (!fw_dump.reserve_dump_area_size) return; fadump_setup_crash_memory_ranges(); addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len; /* Initialize fadump crash info header. */ addr = init_fadump_header(addr); vaddr = __va(addr); pr_debug("Creating ELF core headers at %#016lx\n", addr); fadump_create_elfcore_headers(vaddr); /* register the future kernel dump with firmware. */ register_fw_dump(&fdm); } static int fadump_unregister_dump(struct fadump_mem_struct *fdm) { int rc = 0; unsigned int wait_time; pr_debug("Un-register firmware-assisted dump\n"); /* TODO: Add upper time limit for the delay */ do { rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, FADUMP_UNREGISTER, fdm, sizeof(struct fadump_mem_struct)); wait_time = rtas_busy_delay_time(rc); if (wait_time) mdelay(wait_time); } while (wait_time); if (rc) { printk(KERN_ERR "Failed to un-register firmware-assisted dump." " unexpected error(%d).\n", rc); return rc; } fw_dump.dump_registered = 0; return 0; } static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) { int rc = 0; unsigned int wait_time; pr_debug("Invalidating firmware-assisted dump registration\n"); /* TODO: Add upper time limit for the delay */ do { rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, FADUMP_INVALIDATE, fdm, sizeof(struct fadump_mem_struct)); wait_time = rtas_busy_delay_time(rc); if (wait_time) mdelay(wait_time); } while (wait_time); if (rc) { printk(KERN_ERR "Failed to invalidate firmware-assisted dump " "rgistration. unexpected error(%d).\n", rc); return rc; } fw_dump.dump_active = 0; fdm_active = NULL; return 0; } void fadump_cleanup(void) { /* Invalidate the registration only if dump is active. */ if (fw_dump.dump_active) { init_fadump_mem_struct(&fdm, fdm_active->cpu_state_data.destination_address); fadump_invalidate_dump(&fdm); } } /* * Release the memory that was reserved in early boot to preserve the memory * contents. The released memory will be available for general use. */ static void fadump_release_memory(unsigned long begin, unsigned long end) { unsigned long addr; unsigned long ra_start, ra_end; ra_start = fw_dump.reserve_dump_area_start; ra_end = ra_start + fw_dump.reserve_dump_area_size; for (addr = begin; addr < end; addr += PAGE_SIZE) { /* * exclude the dump reserve area. Will reuse it for next * fadump registration. */ if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start)) continue; free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); } } static void fadump_invalidate_release_mem(void) { unsigned long reserved_area_start, reserved_area_end; unsigned long destination_address; mutex_lock(&fadump_mutex); if (!fw_dump.dump_active) { mutex_unlock(&fadump_mutex); return; } destination_address = fdm_active->cpu_state_data.destination_address; fadump_cleanup(); mutex_unlock(&fadump_mutex); /* * Save the current reserved memory bounds we will require them * later for releasing the memory for general use. */ reserved_area_start = fw_dump.reserve_dump_area_start; reserved_area_end = reserved_area_start + fw_dump.reserve_dump_area_size; /* * Setup reserve_dump_area_start and its size so that we can * reuse this reserved memory for Re-registration. */ fw_dump.reserve_dump_area_start = destination_address; fw_dump.reserve_dump_area_size = get_fadump_area_size(); fadump_release_memory(reserved_area_start, reserved_area_end); if (fw_dump.cpu_notes_buf) { fadump_cpu_notes_buf_free( (unsigned long)__va(fw_dump.cpu_notes_buf), fw_dump.cpu_notes_buf_size); fw_dump.cpu_notes_buf = 0; fw_dump.cpu_notes_buf_size = 0; } /* Initialize the kernel dump memory structure for FAD registration. */ init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); } static ssize_t fadump_release_memory_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { if (!fw_dump.dump_active) return -EPERM; if (buf[0] == '1') { /* * Take away the '/proc/vmcore'. We are releasing the dump * memory, hence it will not be valid anymore. */ vmcore_cleanup(); fadump_invalidate_release_mem(); } else return -EINVAL; return count; } static ssize_t fadump_enabled_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", fw_dump.fadump_enabled); } static ssize_t fadump_register_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { return sprintf(buf, "%d\n", fw_dump.dump_registered); } static ssize_t fadump_register_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { int ret = 0; if (!fw_dump.fadump_enabled || fdm_active) return -EPERM; mutex_lock(&fadump_mutex); switch (buf[0]) { case '0': if (fw_dump.dump_registered == 0) { ret = -EINVAL; goto unlock_out; } /* Un-register Firmware-assisted dump */ fadump_unregister_dump(&fdm); break; case '1': if (fw_dump.dump_registered == 1) { ret = -EINVAL; goto unlock_out; } /* Register Firmware-assisted dump */ register_fadump(); break; default: ret = -EINVAL; break; } unlock_out: mutex_unlock(&fadump_mutex); return ret < 0 ? ret : count; } static int fadump_region_show(struct seq_file *m, void *private) { const struct fadump_mem_struct *fdm_ptr; if (!fw_dump.fadump_enabled) return 0; mutex_lock(&fadump_mutex); if (fdm_active) fdm_ptr = fdm_active; else { mutex_unlock(&fadump_mutex); fdm_ptr = &fdm; } seq_printf(m, "CPU : [%#016llx-%#016llx] %#llx bytes, " "Dumped: %#llx\n", fdm_ptr->cpu_state_data.destination_address, fdm_ptr->cpu_state_data.destination_address + fdm_ptr->cpu_state_data.source_len - 1, fdm_ptr->cpu_state_data.source_len, fdm_ptr->cpu_state_data.bytes_dumped); seq_printf(m, "HPTE: [%#016llx-%#016llx] %#llx bytes, " "Dumped: %#llx\n", fdm_ptr->hpte_region.destination_address, fdm_ptr->hpte_region.destination_address + fdm_ptr->hpte_region.source_len - 1, fdm_ptr->hpte_region.source_len, fdm_ptr->hpte_region.bytes_dumped); seq_printf(m, "DUMP: [%#016llx-%#016llx] %#llx bytes, " "Dumped: %#llx\n", fdm_ptr->rmr_region.destination_address, fdm_ptr->rmr_region.destination_address + fdm_ptr->rmr_region.source_len - 1, fdm_ptr->rmr_region.source_len, fdm_ptr->rmr_region.bytes_dumped); if (!fdm_active || (fw_dump.reserve_dump_area_start == fdm_ptr->cpu_state_data.destination_address)) goto out; /* Dump is active. Show reserved memory region. */ seq_printf(m, " : [%#016llx-%#016llx] %#llx bytes, " "Dumped: %#llx\n", (unsigned long long)fw_dump.reserve_dump_area_start, fdm_ptr->cpu_state_data.destination_address - 1, fdm_ptr->cpu_state_data.destination_address - fw_dump.reserve_dump_area_start, fdm_ptr->cpu_state_data.destination_address - fw_dump.reserve_dump_area_start); out: if (fdm_active) mutex_unlock(&fadump_mutex); return 0; } static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 0200, NULL, fadump_release_memory_store); static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 0444, fadump_enabled_show, NULL); static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 0644, fadump_register_show, fadump_register_store); static int fadump_region_open(struct inode *inode, struct file *file) { return single_open(file, fadump_region_show, inode->i_private); } static const struct file_operations fadump_region_fops = { .open = fadump_region_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static void fadump_init_files(void) { struct dentry *debugfs_file; int rc = 0; rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); if (rc) printk(KERN_ERR "fadump: unable to create sysfs file" " fadump_enabled (%d)\n", rc); rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); if (rc) printk(KERN_ERR "fadump: unable to create sysfs file" " fadump_registered (%d)\n", rc); debugfs_file = debugfs_create_file("fadump_region", 0444, powerpc_debugfs_root, NULL, &fadump_region_fops); if (!debugfs_file) printk(KERN_ERR "fadump: unable to create debugfs file" " fadump_region\n"); if (fw_dump.dump_active) { rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); if (rc) printk(KERN_ERR "fadump: unable to create sysfs file" " fadump_release_mem (%d)\n", rc); } return; } /* * Prepare for firmware-assisted dump. */ int __init setup_fadump(void) { if (!fw_dump.fadump_enabled) return 0; if (!fw_dump.fadump_supported) { printk(KERN_ERR "Firmware-assisted dump is not supported on" " this hardware\n"); return 0; } fadump_show_config(); /* * If dump data is available then see if it is valid and prepare for * saving it to the disk. */ if (fw_dump.dump_active) { /* * if dump process fails then invalidate the registration * and release memory before proceeding for re-registration. */ if (process_fadump(fdm_active) < 0) fadump_invalidate_release_mem(); } /* Initialize the kernel dump memory structure for FAD registration. */ else if (fw_dump.reserve_dump_area_size) init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); fadump_init_files(); return 1; } subsys_initcall(setup_fadump);