// SPDX-License-Identifier: GPL-2.0-only
/*
 * Extended Error Log driver
 *
 * Copyright (C) 2013 Intel Corp.
 * Author: Chen, Gong <gong.chen@intel.com>
 */

#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/cper.h>
#include <linux/ratelimit.h>
#include <linux/edac.h>
#include <linux/ras.h>
#include <cxl/event.h>
#include <acpi/ghes.h>
#include <asm/cpu.h>
#include <asm/mce.h>
#include <asm/msr.h>

#include "apei/apei-internal.h"
#include <ras/ras_event.h>

#define EXT_ELOG_ENTRY_MASK     GENMASK_ULL(51, 0) /* elog entry address mask */

#define EXTLOG_DSM_REV          0x0
#define EXTLOG_FN_ADDR          0x1

#define FLAG_OS_OPTIN           BIT(0)
#define ELOG_ENTRY_VALID        (1ULL<<63)
#define ELOG_ENTRY_LEN          0x1000

#define EMCA_BUG \
        "Can not request iomem region <0x%016llx-0x%016llx> - eMCA disabled\n"

struct extlog_l1_head {
        u32 ver;        /* Header Version */
        u32 hdr_len;    /* Header Length */
        u64 total_len;  /* entire L1 Directory length including this header */
        u64 elog_base;  /* MCA Error Log Directory base address */
        u64 elog_len;   /* MCA Error Log Directory length */
        u32 flags;      /* bit 0 - OS/VMM Opt-in */
        u8  rev0[12];
        u32 entries;    /* Valid L1 Directory entries per logical processor */
        u8  rev1[12];
};

static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";

/* L1 table related physical address */
static u64 elog_base;
static size_t elog_size;
static u64 l1_dirbase;
static size_t l1_size;

/* L1 table related virtual address */
static void __iomem *extlog_l1_addr;
static void __iomem *elog_addr;

static void *elog_buf;

static u64 *l1_entry_base;
static u32 l1_percpu_entry;

#define ELOG_IDX(cpu, bank) \
        (cpu_physical_id(cpu) * l1_percpu_entry + (bank))

#define ELOG_ENTRY_DATA(idx) \
        (*(l1_entry_base + (idx)))

#define ELOG_ENTRY_ADDR(phyaddr) \
        (phyaddr - elog_base + (u8 *)elog_addr)

static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int bank)
{
        int idx;
        u64 data;
        struct acpi_hest_generic_status *estatus;

        WARN_ON(cpu < 0);
        idx = ELOG_IDX(cpu, bank);
        data = ELOG_ENTRY_DATA(idx);
        if ((data & ELOG_ENTRY_VALID) == 0)
                return NULL;

        data &= EXT_ELOG_ENTRY_MASK;
        estatus = (struct acpi_hest_generic_status *)ELOG_ENTRY_ADDR(data);

        /* if no valid data in elog entry, just return */
        if (estatus->block_status == 0)
                return NULL;

        return estatus;
}

static void __print_extlog_rcd(const char *pfx,
                               struct acpi_hest_generic_status *estatus, int cpu)
{
        static atomic_t seqno;
        unsigned int curr_seqno;
        char pfx_seq[64];

        if (!pfx) {
                if (estatus->error_severity <= CPER_SEV_CORRECTED)
                        pfx = KERN_INFO;
                else
                        pfx = KERN_ERR;
        }
        curr_seqno = atomic_inc_return(&seqno);
        snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
        printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
        cper_estatus_print(pfx_seq, estatus);
}

static int print_extlog_rcd(const char *pfx,
                            struct acpi_hest_generic_status *estatus, int cpu)
{
        /* Not more than 2 messages every 5 seconds */
        static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
        static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
        struct ratelimit_state *ratelimit;

        if (estatus->error_severity == CPER_SEV_CORRECTED ||
            (estatus->error_severity == CPER_SEV_INFORMATIONAL))
                ratelimit = &ratelimit_corrected;
        else
                ratelimit = &ratelimit_uncorrected;
        if (__ratelimit(ratelimit)) {
                __print_extlog_rcd(pfx, estatus, cpu);
                return 0;
        }

        return 1;
}

static void extlog_print_pcie(struct cper_sec_pcie *pcie_err,
                              int severity)
{
#ifdef ACPI_APEI_PCIEAER
        struct aer_capability_regs *aer;
        struct pci_dev *pdev;
        unsigned int devfn;
        unsigned int bus;
        int aer_severity;
        int domain;

        if (!(pcie_err->validation_bits & CPER_PCIE_VALID_DEVICE_ID &&
              pcie_err->validation_bits & CPER_PCIE_VALID_AER_INFO))
                return;

        aer_severity = cper_severity_to_aer(severity);
        aer = (struct aer_capability_regs *)pcie_err->aer_info;
        domain = pcie_err->device_id.segment;
        bus = pcie_err->device_id.bus;
        devfn = PCI_DEVFN(pcie_err->device_id.device,
                          pcie_err->device_id.function);
        pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
        if (!pdev)
                return;

        pci_print_aer(pdev, aer_severity, aer);
        pci_dev_put(pdev);
#endif
}

static void
extlog_cxl_cper_handle_prot_err(struct cxl_cper_sec_prot_err *prot_err,
                                int severity)
{
#ifdef ACPI_APEI_PCIEAER
        struct cxl_cper_prot_err_work_data wd;

        if (cxl_cper_sec_prot_err_valid(prot_err))
                return;

        if (cxl_cper_setup_prot_err_work_data(&wd, prot_err, severity))
                return;

        cxl_cper_handle_prot_err(&wd);
#endif
}

static int extlog_print(struct notifier_block *nb, unsigned long val,
                        void *data)
{
        struct mce *mce = (struct mce *)data;
        int     bank = mce->bank;
        int     cpu = mce->extcpu;
        struct acpi_hest_generic_status *estatus, *tmp;
        struct acpi_hest_generic_data *gdata;
        const guid_t *fru_id;
        char *fru_text;
        guid_t *sec_type;
        static u32 err_seq;

        estatus = extlog_elog_entry_check(cpu, bank);
        if (!estatus)
                return NOTIFY_DONE;

        if (mce->kflags & MCE_HANDLED_CEC) {
                estatus->block_status = 0;
                return NOTIFY_DONE;
        }

        memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
        /* clear record status to enable BIOS to update it again */
        estatus->block_status = 0;

        tmp = (struct acpi_hest_generic_status *)elog_buf;

        if (!ras_userspace_consumers()) {
                print_extlog_rcd(NULL, tmp, cpu);
                goto out;
        }

        /* log event via trace */
        err_seq++;
        apei_estatus_for_each_section(tmp, gdata) {
                if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
                        fru_id = (guid_t *)gdata->fru_id;
                else
                        fru_id = &guid_null;
                if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
                        fru_text = gdata->fru_text;
                else
                        fru_text = "";
                sec_type = (guid_t *)gdata->section_type;
                if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
                        struct cper_sec_mem_err *mem = acpi_hest_get_payload(gdata);

                        if (gdata->error_data_length >= sizeof(*mem))
                                trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
                                                       (u8)gdata->error_severity);
                } else if (guid_equal(sec_type, &CPER_SEC_CXL_PROT_ERR)) {
                        struct cxl_cper_sec_prot_err *prot_err =
                                acpi_hest_get_payload(gdata);

                        extlog_cxl_cper_handle_prot_err(prot_err,
                                                        gdata->error_severity);
                } else if (guid_equal(sec_type, &CPER_SEC_PCIE)) {
                        struct cper_sec_pcie *pcie_err = acpi_hest_get_payload(gdata);

                        extlog_print_pcie(pcie_err, gdata->error_severity);
                } else {
                        void *err = acpi_hest_get_payload(gdata);

                        log_non_standard_event(sec_type, fru_id, fru_text,
                                               gdata->error_severity, err,
                                               gdata->error_data_length);
                }
        }

out:
        mce->kflags |= MCE_HANDLED_EXTLOG;
        return NOTIFY_OK;
}

static bool __init extlog_get_l1addr(void)
{
        guid_t guid;
        acpi_handle handle;
        union acpi_object *obj;

        if (guid_parse(extlog_dsm_uuid, &guid))
                return false;
        if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
                return false;
        if (!acpi_check_dsm(handle, &guid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
                return false;
        obj = acpi_evaluate_dsm_typed(handle, &guid, EXTLOG_DSM_REV,
                                      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
        if (!obj) {
                return false;
        } else {
                l1_dirbase = obj->integer.value;
                ACPI_FREE(obj);
        }

        /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
        if (l1_dirbase & ((1 << 12) - 1)) {
                pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
                        l1_dirbase);
                return false;
        }

        return true;
}
static struct notifier_block extlog_mce_dec = {
        .notifier_call  = extlog_print,
        .priority       = MCE_PRIO_EXTLOG,
};

static int __init extlog_init(void)
{
        struct extlog_l1_head *l1_head;
        void __iomem *extlog_l1_hdr;
        size_t l1_hdr_size;
        struct resource *r;
        u64 cap;
        int rc;

        if (rdmsrq_safe(MSR_IA32_MCG_CAP, &cap) ||
            !(cap & MCG_ELOG_P) ||
            !extlog_get_l1addr())
                return -ENODEV;

        rc = -EINVAL;
        /* get L1 header to fetch necessary information */
        l1_hdr_size = sizeof(struct extlog_l1_head);
        r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
        if (!r) {
                pr_warn(FW_BUG EMCA_BUG,
                        (unsigned long long)l1_dirbase,
                        (unsigned long long)l1_dirbase + l1_hdr_size);
                goto err;
        }

        extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
        if (!extlog_l1_hdr) {
                rc = -ENOMEM;
                goto err_release_l1_hdr;
        }
        l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
        l1_size = l1_head->total_len;
        l1_percpu_entry = l1_head->entries;
        elog_base = l1_head->elog_base;
        elog_size = l1_head->elog_len;
        acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
        release_mem_region(l1_dirbase, l1_hdr_size);

        /* remap L1 header again based on completed information */
        r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
        if (!r) {
                pr_warn(FW_BUG EMCA_BUG,
                        (unsigned long long)l1_dirbase,
                        (unsigned long long)l1_dirbase + l1_size);
                goto err;
        }
        extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
        if (!extlog_l1_addr) {
                rc = -ENOMEM;
                goto err_release_l1_dir;
        }
        l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);

        /* remap elog table */
        r = request_mem_region(elog_base, elog_size, "Elog Table");
        if (!r) {
                pr_warn(FW_BUG EMCA_BUG,
                        (unsigned long long)elog_base,
                        (unsigned long long)elog_base + elog_size);
                goto err_release_l1_dir;
        }
        elog_addr = acpi_os_map_iomem(elog_base, elog_size);
        if (!elog_addr) {
                rc = -ENOMEM;
                goto err_release_elog;
        }

        rc = -ENOMEM;
        /* allocate buffer to save elog record */
        elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
        if (elog_buf == NULL)
                goto err_release_elog;

        mce_register_decode_chain(&extlog_mce_dec);
        /* enable OS to be involved to take over management from BIOS */
        ((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;

        return 0;

err_release_elog:
        if (elog_addr)
                acpi_os_unmap_iomem(elog_addr, elog_size);
        release_mem_region(elog_base, elog_size);
err_release_l1_dir:
        if (extlog_l1_addr)
                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
        release_mem_region(l1_dirbase, l1_size);
err_release_l1_hdr:
        release_mem_region(l1_dirbase, l1_hdr_size);
err:
        pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
        return rc;
}

static void __exit extlog_exit(void)
{
        mce_unregister_decode_chain(&extlog_mce_dec);
        if (extlog_l1_addr) {
                ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
                acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
        }
        if (elog_addr)
                acpi_os_unmap_iomem(elog_addr, elog_size);
        release_mem_region(elog_base, elog_size);
        release_mem_region(l1_dirbase, l1_size);
        kfree(elog_buf);
}

module_init(extlog_init);
module_exit(extlog_exit);

MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
MODULE_DESCRIPTION("Extended MCA Error Log Driver");
MODULE_LICENSE("GPL");