// SPDX-License-Identifier: GPL-2.0-or-later /* * Firmware-Assisted Dump support on POWER platform (OPAL). * * Copyright 2019, Hari Bathini, IBM Corporation. */ #define pr_fmt(fmt) "opal fadump: " fmt #include #include #include #include #include #include #include #include #include #include #include "opal-fadump.h" #ifdef CONFIG_PRESERVE_FA_DUMP /* * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel, * ensure crash data is preserved in hope that the subsequent memory * preserving kernel boot is going to process this crash data. */ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node) { const struct opal_fadump_mem_struct *opal_fdm_active; const __be32 *prop; unsigned long dn; u64 addr = 0; s64 ret; dn = of_get_flat_dt_subnode_by_name(node, "dump"); if (dn == -FDT_ERR_NOTFOUND) return; /* * Check if dump has been initiated on last reboot. */ prop = of_get_flat_dt_prop(dn, "mpipl-boot", NULL); if (!prop) return; ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &addr); if ((ret != OPAL_SUCCESS) || !addr) { pr_debug("Could not get Kernel metadata (%lld)\n", ret); return; } /* * Preserve memory only if kernel memory regions are registered * with f/w for MPIPL. */ addr = be64_to_cpu(addr); pr_debug("Kernel metadata addr: %llx\n", addr); opal_fdm_active = (void *)addr; if (be16_to_cpu(opal_fdm_active->registered_regions) == 0) return; ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_BOOT_MEM, &addr); if ((ret != OPAL_SUCCESS) || !addr) { pr_err("Failed to get boot memory tag (%lld)\n", ret); return; } /* * Memory below this address can be used for booting a * capture kernel or petitboot kernel. Preserve everything * above this address for processing crashdump. */ fadump_conf->boot_mem_top = be64_to_cpu(addr); pr_debug("Preserve everything above %llx\n", fadump_conf->boot_mem_top); pr_info("Firmware-assisted dump is active.\n"); fadump_conf->dump_active = 1; } #else /* CONFIG_PRESERVE_FA_DUMP */ static const struct opal_fadump_mem_struct *opal_fdm_active; static const struct opal_mpipl_fadump *opal_cpu_metadata; static struct opal_fadump_mem_struct *opal_fdm; #ifdef CONFIG_OPAL_CORE extern bool kernel_initiated; #endif static int opal_fadump_unregister(struct fw_dump *fadump_conf); static void opal_fadump_update_config(struct fw_dump *fadump_conf, const struct opal_fadump_mem_struct *fdm) { pr_debug("Boot memory regions count: %d\n", be16_to_cpu(fdm->region_cnt)); /* * The destination address of the first boot memory region is the * destination address of boot memory regions. */ fadump_conf->boot_mem_dest_addr = be64_to_cpu(fdm->rgn[0].dest); pr_debug("Destination address of boot memory regions: %#016llx\n", fadump_conf->boot_mem_dest_addr); fadump_conf->fadumphdr_addr = be64_to_cpu(fdm->fadumphdr_addr); } /* * This function is called in the capture kernel to get configuration details * from metadata setup by the first kernel. */ static void __init opal_fadump_get_config(struct fw_dump *fadump_conf, const struct opal_fadump_mem_struct *fdm) { unsigned long base, size, last_end, hole_size; int i; if (!fadump_conf->dump_active) return; last_end = 0; hole_size = 0; fadump_conf->boot_memory_size = 0; pr_debug("Boot memory regions:\n"); for (i = 0; i < be16_to_cpu(fdm->region_cnt); i++) { base = be64_to_cpu(fdm->rgn[i].src); size = be64_to_cpu(fdm->rgn[i].size); pr_debug("\t[%03d] base: 0x%lx, size: 0x%lx\n", i, base, size); fadump_conf->boot_mem_addr[i] = base; fadump_conf->boot_mem_sz[i] = size; fadump_conf->boot_memory_size += size; hole_size += (base - last_end); last_end = base + size; } /* * Start address of reserve dump area (permanent reservation) for * re-registering FADump after dump capture. */ fadump_conf->reserve_dump_area_start = be64_to_cpu(fdm->rgn[0].dest); /* * Rarely, but it can so happen that system crashes before all * boot memory regions are registered for MPIPL. In such * cases, warn that the vmcore may not be accurate and proceed * anyway as that is the best bet considering free pages, cache * pages, user pages, etc are usually filtered out. * * Hope the memory that could not be preserved only has pages * that are usually filtered out while saving the vmcore. */ if (be16_to_cpu(fdm->region_cnt) > be16_to_cpu(fdm->registered_regions)) { pr_warn("Not all memory regions were saved!!!\n"); pr_warn(" Unsaved memory regions:\n"); i = be16_to_cpu(fdm->registered_regions); while (i < be16_to_cpu(fdm->region_cnt)) { pr_warn("\t[%03d] base: 0x%llx, size: 0x%llx\n", i, be64_to_cpu(fdm->rgn[i].src), be64_to_cpu(fdm->rgn[i].size)); i++; } pr_warn("If the unsaved regions only contain pages that are filtered out (eg. free/user pages), the vmcore should still be usable.\n"); pr_warn("WARNING: If the unsaved regions contain kernel pages, the vmcore will be corrupted.\n"); } fadump_conf->boot_mem_top = (fadump_conf->boot_memory_size + hole_size); fadump_conf->boot_mem_regs_cnt = be16_to_cpu(fdm->region_cnt); opal_fadump_update_config(fadump_conf, fdm); } /* Initialize kernel metadata */ static void opal_fadump_init_metadata(struct opal_fadump_mem_struct *fdm) { fdm->version = OPAL_FADUMP_VERSION; fdm->region_cnt = cpu_to_be16(0); fdm->registered_regions = cpu_to_be16(0); fdm->fadumphdr_addr = cpu_to_be64(0); } static u64 opal_fadump_init_mem_struct(struct fw_dump *fadump_conf) { u64 addr = fadump_conf->reserve_dump_area_start; u16 reg_cnt; int i; opal_fdm = __va(fadump_conf->kernel_metadata); opal_fadump_init_metadata(opal_fdm); /* Boot memory regions */ reg_cnt = be16_to_cpu(opal_fdm->region_cnt); for (i = 0; i < fadump_conf->boot_mem_regs_cnt; i++) { opal_fdm->rgn[i].src = cpu_to_be64(fadump_conf->boot_mem_addr[i]); opal_fdm->rgn[i].dest = cpu_to_be64(addr); opal_fdm->rgn[i].size = cpu_to_be64(fadump_conf->boot_mem_sz[i]); reg_cnt++; addr += fadump_conf->boot_mem_sz[i]; } opal_fdm->region_cnt = cpu_to_be16(reg_cnt); /* * Kernel metadata is passed to f/w and retrieved in capture kerenl. * So, use it to save fadump header address instead of calculating it. */ opal_fdm->fadumphdr_addr = cpu_to_be64(be64_to_cpu(opal_fdm->rgn[0].dest) + fadump_conf->boot_memory_size); opal_fadump_update_config(fadump_conf, opal_fdm); return addr; } static u64 opal_fadump_get_metadata_size(void) { return PAGE_ALIGN(sizeof(struct opal_fadump_mem_struct)); } static int opal_fadump_setup_metadata(struct fw_dump *fadump_conf) { int err = 0; s64 ret; /* * Use the last page(s) in FADump memory reservation for * kernel metadata. */ fadump_conf->kernel_metadata = (fadump_conf->reserve_dump_area_start + fadump_conf->reserve_dump_area_size - opal_fadump_get_metadata_size()); pr_info("Kernel metadata addr: %llx\n", fadump_conf->kernel_metadata); /* Initialize kernel metadata before registering the address with f/w */ opal_fdm = __va(fadump_conf->kernel_metadata); opal_fadump_init_metadata(opal_fdm); /* * Register metadata address with f/w. Can be retrieved in * the capture kernel. */ ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_KERNEL, fadump_conf->kernel_metadata); if (ret != OPAL_SUCCESS) { pr_err("Failed to set kernel metadata tag!\n"); err = -EPERM; } /* * Register boot memory top address with f/w. Should be retrieved * by a kernel that intends to preserve crash'ed kernel's memory. */ ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_BOOT_MEM, fadump_conf->boot_mem_top); if (ret != OPAL_SUCCESS) { pr_err("Failed to set boot memory tag!\n"); err = -EPERM; } return err; } static u64 opal_fadump_get_bootmem_min(void) { return OPAL_FADUMP_MIN_BOOT_MEM; } static int opal_fadump_register(struct fw_dump *fadump_conf) { s64 rc = OPAL_PARAMETER; u16 registered_regs; int i, err = -EIO; registered_regs = be16_to_cpu(opal_fdm->registered_regions); for (i = 0; i < be16_to_cpu(opal_fdm->region_cnt); i++) { rc = opal_mpipl_update(OPAL_MPIPL_ADD_RANGE, be64_to_cpu(opal_fdm->rgn[i].src), be64_to_cpu(opal_fdm->rgn[i].dest), be64_to_cpu(opal_fdm->rgn[i].size)); if (rc != OPAL_SUCCESS) break; registered_regs++; } opal_fdm->registered_regions = cpu_to_be16(registered_regs); switch (rc) { case OPAL_SUCCESS: pr_info("Registration is successful!\n"); fadump_conf->dump_registered = 1; err = 0; break; case OPAL_RESOURCE: /* If MAX regions limit in f/w is hit, warn and proceed. */ pr_warn("%d regions could not be registered for MPIPL as MAX limit is reached!\n", (be16_to_cpu(opal_fdm->region_cnt) - be16_to_cpu(opal_fdm->registered_regions))); fadump_conf->dump_registered = 1; err = 0; break; case OPAL_PARAMETER: pr_err("Failed to register. Parameter Error(%lld).\n", rc); break; case OPAL_HARDWARE: pr_err("Support not available.\n"); fadump_conf->fadump_supported = 0; fadump_conf->fadump_enabled = 0; break; default: pr_err("Failed to register. Unknown Error(%lld).\n", rc); break; } /* * If some regions were registered before OPAL_MPIPL_ADD_RANGE * OPAL call failed, unregister all regions. */ if ((err < 0) && (be16_to_cpu(opal_fdm->registered_regions) > 0)) opal_fadump_unregister(fadump_conf); return err; } static int opal_fadump_unregister(struct fw_dump *fadump_conf) { s64 rc; rc = opal_mpipl_update(OPAL_MPIPL_REMOVE_ALL, 0, 0, 0); if (rc) { pr_err("Failed to un-register - unexpected Error(%lld).\n", rc); return -EIO; } opal_fdm->registered_regions = cpu_to_be16(0); fadump_conf->dump_registered = 0; return 0; } static int opal_fadump_invalidate(struct fw_dump *fadump_conf) { s64 rc; rc = opal_mpipl_update(OPAL_MPIPL_FREE_PRESERVED_MEMORY, 0, 0, 0); if (rc) { pr_err("Failed to invalidate - unexpected Error(%lld).\n", rc); return -EIO; } fadump_conf->dump_active = 0; opal_fdm_active = NULL; return 0; } static void opal_fadump_cleanup(struct fw_dump *fadump_conf) { s64 ret; ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_KERNEL, 0); if (ret != OPAL_SUCCESS) pr_warn("Could not reset (%llu) kernel metadata tag!\n", ret); } /* * Verify if CPU state data is available. If available, do a bit of sanity * checking before processing this data. */ static bool __init is_opal_fadump_cpu_data_valid(struct fw_dump *fadump_conf) { if (!opal_cpu_metadata) return false; fadump_conf->cpu_state_data_version = be32_to_cpu(opal_cpu_metadata->cpu_data_version); fadump_conf->cpu_state_entry_size = be32_to_cpu(opal_cpu_metadata->cpu_data_size); fadump_conf->cpu_state_dest_vaddr = (u64)__va(be64_to_cpu(opal_cpu_metadata->region[0].dest)); fadump_conf->cpu_state_data_size = be64_to_cpu(opal_cpu_metadata->region[0].size); if (fadump_conf->cpu_state_data_version != HDAT_FADUMP_CPU_DATA_VER) { pr_warn("Supported CPU state data version: %u, found: %d!\n", HDAT_FADUMP_CPU_DATA_VER, fadump_conf->cpu_state_data_version); pr_warn("WARNING: F/W using newer CPU state data format!!\n"); } if ((fadump_conf->cpu_state_dest_vaddr == 0) || (fadump_conf->cpu_state_entry_size == 0) || (fadump_conf->cpu_state_entry_size > fadump_conf->cpu_state_data_size)) { pr_err("CPU state data is invalid. Ignoring!\n"); return false; } return true; } /* * Convert CPU state data saved at the time of crash into ELF notes. * * While the crashing CPU's register data is saved by the kernel, CPU state * data for all CPUs is saved by f/w. In CPU state data provided by f/w, * each register entry is of 16 bytes, a numerical identifier along with * a GPR/SPR flag in the first 8 bytes and the register value in the next * 8 bytes. For more details refer to F/W documentation. If this data is * missing or in unsupported format, append crashing CPU's register data * saved by the kernel in the PT_NOTE, to have something to work with in * the vmcore file. */ static int __init opal_fadump_build_cpu_notes(struct fw_dump *fadump_conf, struct fadump_crash_info_header *fdh) { u32 thread_pir, size_per_thread, regs_offset, regs_cnt, reg_esize; struct hdat_fadump_thread_hdr *thdr; bool is_cpu_data_valid = false; u32 num_cpus = 1, *note_buf; struct pt_regs regs; char *bufp; int rc, i; if (is_opal_fadump_cpu_data_valid(fadump_conf)) { size_per_thread = fadump_conf->cpu_state_entry_size; num_cpus = (fadump_conf->cpu_state_data_size / size_per_thread); bufp = __va(fadump_conf->cpu_state_dest_vaddr); is_cpu_data_valid = true; } rc = fadump_setup_cpu_notes_buf(num_cpus); if (rc != 0) return rc; note_buf = (u32 *)fadump_conf->cpu_notes_buf_vaddr; if (!is_cpu_data_valid) goto out; /* * Offset for register entries, entry size and registers count is * duplicated in every thread header in keeping with HDAT format. * Use these values from the first thread header. */ thdr = (struct hdat_fadump_thread_hdr *)bufp; regs_offset = (offsetof(struct hdat_fadump_thread_hdr, offset) + be32_to_cpu(thdr->offset)); reg_esize = be32_to_cpu(thdr->esize); regs_cnt = be32_to_cpu(thdr->ecnt); pr_debug("--------CPU State Data------------\n"); pr_debug("NumCpus : %u\n", num_cpus); pr_debug("\tOffset: %u, Entry size: %u, Cnt: %u\n", regs_offset, reg_esize, regs_cnt); for (i = 0; i < num_cpus; i++, bufp += size_per_thread) { thdr = (struct hdat_fadump_thread_hdr *)bufp; thread_pir = be32_to_cpu(thdr->pir); pr_debug("[%04d] PIR: 0x%x, core state: 0x%02x\n", i, thread_pir, thdr->core_state); /* * If this is kernel initiated crash, crashing_cpu would be set * appropriately and register data of the crashing CPU saved by * crashing kernel. Add this saved register data of crashing CPU * to elf notes and populate the pt_regs for the remaining CPUs * from register state data provided by firmware. */ if (fdh->crashing_cpu == thread_pir) { note_buf = fadump_regs_to_elf_notes(note_buf, &fdh->regs); pr_debug("Crashing CPU PIR: 0x%x - R1 : 0x%lx, NIP : 0x%lx\n", fdh->crashing_cpu, fdh->regs.gpr[1], fdh->regs.nip); continue; } /* * Register state data of MAX cores is provided by firmware, * but some of this cores may not be active. So, while * processing register state data, check core state and * skip threads that belong to inactive cores. */ if (thdr->core_state == HDAT_FADUMP_CORE_INACTIVE) continue; opal_fadump_read_regs((bufp + regs_offset), regs_cnt, reg_esize, true, ®s); note_buf = fadump_regs_to_elf_notes(note_buf, ®s); pr_debug("CPU PIR: 0x%x - R1 : 0x%lx, NIP : 0x%lx\n", thread_pir, regs.gpr[1], regs.nip); } out: /* * CPU state data is invalid/unsupported. Try appending crashing CPU's * register data, if it is saved by the kernel. */ if (fadump_conf->cpu_notes_buf_vaddr == (u64)note_buf) { if (fdh->crashing_cpu == FADUMP_CPU_UNKNOWN) { fadump_free_cpu_notes_buf(); return -ENODEV; } pr_warn("WARNING: appending only crashing CPU's register data\n"); note_buf = fadump_regs_to_elf_notes(note_buf, &(fdh->regs)); } final_note(note_buf); pr_debug("Updating elfcore header (%llx) with cpu notes\n", fdh->elfcorehdr_addr); fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr)); return 0; } static int __init opal_fadump_process(struct fw_dump *fadump_conf) { struct fadump_crash_info_header *fdh; int rc = -EINVAL; if (!opal_fdm_active || !fadump_conf->fadumphdr_addr) return rc; /* Validate the fadump crash info header */ fdh = __va(fadump_conf->fadumphdr_addr); if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { pr_err("Crash info header is not valid.\n"); return rc; } #ifdef CONFIG_OPAL_CORE /* * If this is a kernel initiated crash, crashing_cpu would be set * appropriately and register data of the crashing CPU saved by * crashing kernel. Add this saved register data of crashing CPU * to elf notes and populate the pt_regs for the remaining CPUs * from register state data provided by firmware. */ if (fdh->crashing_cpu != FADUMP_CPU_UNKNOWN) kernel_initiated = true; #endif rc = opal_fadump_build_cpu_notes(fadump_conf, fdh); 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 rc; } static void opal_fadump_region_show(struct fw_dump *fadump_conf, struct seq_file *m) { const struct opal_fadump_mem_struct *fdm_ptr; u64 dumped_bytes = 0; int i; if (fadump_conf->dump_active) fdm_ptr = opal_fdm_active; else fdm_ptr = opal_fdm; for (i = 0; i < be16_to_cpu(fdm_ptr->region_cnt); i++) { /* * Only regions that are registered for MPIPL * would have dump data. */ if ((fadump_conf->dump_active) && (i < be16_to_cpu(fdm_ptr->registered_regions))) dumped_bytes = be64_to_cpu(fdm_ptr->rgn[i].size); seq_printf(m, "DUMP: Src: %#016llx, Dest: %#016llx, ", be64_to_cpu(fdm_ptr->rgn[i].src), be64_to_cpu(fdm_ptr->rgn[i].dest)); seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n", be64_to_cpu(fdm_ptr->rgn[i].size), dumped_bytes); } /* Dump is active. Show reserved area start address. */ if (fadump_conf->dump_active) { seq_printf(m, "\nMemory above %#016lx is reserved for saving crash dump\n", fadump_conf->reserve_dump_area_start); } } static void opal_fadump_trigger(struct fadump_crash_info_header *fdh, const char *msg) { int rc; /* * Unlike on pSeries platform, logical CPU number is not provided * with architected register state data. So, store the crashing * CPU's PIR instead to plug the appropriate register data for * crashing CPU in the vmcore file. */ fdh->crashing_cpu = (u32)mfspr(SPRN_PIR); rc = opal_cec_reboot2(OPAL_REBOOT_MPIPL, msg); if (rc == OPAL_UNSUPPORTED) { pr_emerg("Reboot type %d not supported.\n", OPAL_REBOOT_MPIPL); } else if (rc == OPAL_HARDWARE) pr_emerg("No backend support for MPIPL!\n"); } static struct fadump_ops opal_fadump_ops = { .fadump_init_mem_struct = opal_fadump_init_mem_struct, .fadump_get_metadata_size = opal_fadump_get_metadata_size, .fadump_setup_metadata = opal_fadump_setup_metadata, .fadump_get_bootmem_min = opal_fadump_get_bootmem_min, .fadump_register = opal_fadump_register, .fadump_unregister = opal_fadump_unregister, .fadump_invalidate = opal_fadump_invalidate, .fadump_cleanup = opal_fadump_cleanup, .fadump_process = opal_fadump_process, .fadump_region_show = opal_fadump_region_show, .fadump_trigger = opal_fadump_trigger, }; void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node) { const __be32 *prop; unsigned long dn; __be64 be_addr; u64 addr = 0; int i, len; s64 ret; /* * Check if Firmware-Assisted Dump is supported. if yes, check * if dump has been initiated on last reboot. */ dn = of_get_flat_dt_subnode_by_name(node, "dump"); if (dn == -FDT_ERR_NOTFOUND) { pr_debug("FADump support is missing!\n"); return; } if (!of_flat_dt_is_compatible(dn, "ibm,opal-dump")) { pr_err("Support missing for this f/w version!\n"); return; } prop = of_get_flat_dt_prop(dn, "fw-load-area", &len); if (prop) { /* * Each f/w load area is an (address,size) pair, * 2 cells each, totalling 4 cells per range. */ for (i = 0; i < len / (sizeof(*prop) * 4); i++) { u64 base, end; base = of_read_number(prop + (i * 4) + 0, 2); end = base; end += of_read_number(prop + (i * 4) + 2, 2); if (end > OPAL_FADUMP_MIN_BOOT_MEM) { pr_err("F/W load area: 0x%llx-0x%llx\n", base, end); pr_err("F/W version not supported!\n"); return; } } } fadump_conf->ops = &opal_fadump_ops; fadump_conf->fadump_supported = 1; /* * Firmware supports 32-bit field for size. Align it to PAGE_SIZE * and request firmware to copy multiple kernel boot memory regions. */ fadump_conf->max_copy_size = ALIGN_DOWN(U32_MAX, PAGE_SIZE); /* * Check if dump has been initiated on last reboot. */ prop = of_get_flat_dt_prop(dn, "mpipl-boot", NULL); if (!prop) return; ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &be_addr); if ((ret != OPAL_SUCCESS) || !be_addr) { pr_err("Failed to get Kernel metadata (%lld)\n", ret); return; } addr = be64_to_cpu(be_addr); pr_debug("Kernel metadata addr: %llx\n", addr); opal_fdm_active = __va(addr); if (opal_fdm_active->version != OPAL_FADUMP_VERSION) { pr_warn("Supported kernel metadata version: %u, found: %d!\n", OPAL_FADUMP_VERSION, opal_fdm_active->version); pr_warn("WARNING: Kernel metadata format mismatch identified! Core file maybe corrupted..\n"); } /* Kernel regions not registered with f/w for MPIPL */ if (be16_to_cpu(opal_fdm_active->registered_regions) == 0) { opal_fdm_active = NULL; return; } ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &be_addr); if (be_addr) { addr = be64_to_cpu(be_addr); pr_debug("CPU metadata addr: %llx\n", addr); opal_cpu_metadata = __va(addr); } pr_info("Firmware-assisted dump is active.\n"); fadump_conf->dump_active = 1; opal_fadump_get_config(fadump_conf, opal_fdm_active); } #endif /* !CONFIG_PRESERVE_FA_DUMP */