// 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 <linux/string.h>
#include <linux/seq_file.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/mm.h>
#include <linux/crash_dump.h>

#include <asm/page.h>
#include <asm/opal.h>
#include <asm/fadump-internal.h>

#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 (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", 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 = fdm->rgn[0].dest;
        pr_debug("Destination address of boot memory regions: %#016llx\n",
                 fadump_conf->boot_mem_dest_addr);

        fadump_conf->fadumphdr_addr = fdm->fadumphdr_addr;
}

/*
 * This function is called in the capture kernel to get configuration details
 * from metadata setup by the first kernel.
 */
static void 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 < fdm->region_cnt; i++) {
                base = fdm->rgn[i].src;
                size = 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 = 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 (fdm->region_cnt > fdm->registered_regions) {
                pr_warn("Not all memory regions were saved!!!\n");
                pr_warn("  Unsaved memory regions:\n");
                i = fdm->registered_regions;
                while (i < fdm->region_cnt) {
                        pr_warn("\t[%03d] base: 0x%llx, size: 0x%llx\n",
                                i, fdm->rgn[i].src, 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 = 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 = 0;
        fdm->registered_regions = 0;
        fdm->fadumphdr_addr = 0;
}

static u64 opal_fadump_init_mem_struct(struct fw_dump *fadump_conf)
{
        u64 addr = fadump_conf->reserve_dump_area_start;
        int i;

        opal_fdm = __va(fadump_conf->kernel_metadata);
        opal_fadump_init_metadata(opal_fdm);

        /* Boot memory regions */
        for (i = 0; i < fadump_conf->boot_mem_regs_cnt; i++) {
                opal_fdm->rgn[i].src    = fadump_conf->boot_mem_addr[i];
                opal_fdm->rgn[i].dest   = addr;
                opal_fdm->rgn[i].size   = fadump_conf->boot_mem_sz[i];

                opal_fdm->region_cnt++;
                addr += fadump_conf->boot_mem_sz[i];
        }

        /*
         * 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 = (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;
        int i, err = -EIO;

        for (i = 0; i < opal_fdm->region_cnt; i++) {
                rc = opal_mpipl_update(OPAL_MPIPL_ADD_RANGE,
                                       opal_fdm->rgn[i].src,
                                       opal_fdm->rgn[i].dest,
                                       opal_fdm->rgn[i].size);
                if (rc != OPAL_SUCCESS)
                        break;

                opal_fdm->registered_regions++;
        }

        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",
                        (opal_fdm->region_cnt - 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) && (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 = 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, &regs);
                note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
                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 < fdm_ptr->region_cnt; i++) {
                /*
                 * Only regions that are registered for MPIPL
                 * would have dump data.
                 */
                if ((fadump_conf->dump_active) &&
                    (i < fdm_ptr->registered_regions))
                        dumped_bytes = fdm_ptr->rgn[i].size;

                seq_printf(m, "DUMP: Src: %#016llx, Dest: %#016llx, ",
                           fdm_ptr->rgn[i].src, fdm_ptr->rgn[i].dest);
                seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n",
                           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;
        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, &addr);
        if ((ret != OPAL_SUCCESS) || !addr) {
                pr_err("Failed to get Kernel metadata (%lld)\n", ret);
                return;
        }

        addr = be64_to_cpu(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 (opal_fdm_active->registered_regions == 0) {
                opal_fdm_active = NULL;
                return;
        }

        ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &addr);
        if (addr) {
                addr = be64_to_cpu(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 */