// SPDX-License-Identifier: GPL-2.0-only

/*
 * FPDT support for exporting boot and suspend/resume performance data
 *
 * Copyright (C) 2021 Intel Corporation. All rights reserved.
 */

#define pr_fmt(fmt) "ACPI FPDT: " fmt

#include <linux/acpi.h>

/*
 * FPDT contains ACPI table header and a number of fpdt_subtable_entries.
 * Each fpdt_subtable_entry points to a subtable: FBPT or S3PT.
 * Each FPDT subtable (FBPT/S3PT) is composed of a fpdt_subtable_header
 * and a number of fpdt performance records.
 * Each FPDT performance record is composed of a fpdt_record_header and
 * performance data fields, for boot or suspend or resume phase.
 */
enum fpdt_subtable_type {
        SUBTABLE_FBPT,
        SUBTABLE_S3PT,
};

struct fpdt_subtable_entry {
        u16 type;               /* refer to enum fpdt_subtable_type */
        u8 length;
        u8 revision;
        u32 reserved;
        u64 address;            /* physical address of the S3PT/FBPT table */
};

struct fpdt_subtable_header {
        u32 signature;
        u32 length;
};

enum fpdt_record_type {
        RECORD_S3_RESUME,
        RECORD_S3_SUSPEND,
        RECORD_BOOT,
};

struct fpdt_record_header {
        u16 type;               /* refer to enum fpdt_record_type */
        u8 length;
        u8 revision;
};

struct resume_performance_record {
        struct fpdt_record_header header;
        u32 resume_count;
        u64 resume_prev;
        u64 resume_avg;
} __attribute__((packed));

struct boot_performance_record {
        struct fpdt_record_header header;
        u32 reserved;
        u64 firmware_start;
        u64 bootloader_load;
        u64 bootloader_launch;
        u64 exitbootservice_start;
        u64 exitbootservice_end;
} __attribute__((packed));

struct suspend_performance_record {
        struct fpdt_record_header header;
        u64 suspend_start;
        u64 suspend_end;
} __attribute__((packed));


static struct resume_performance_record *record_resume;
static struct suspend_performance_record *record_suspend;
static struct boot_performance_record *record_boot;

#define FPDT_ATTR(phase, name)  \
static ssize_t name##_show(struct kobject *kobj,        \
                 struct kobj_attribute *attr, char *buf)        \
{       \
        return sprintf(buf, "%llu\n", record_##phase->name);    \
}       \
static struct kobj_attribute name##_attr =      \
__ATTR(name##_ns, 0444, name##_show, NULL)

FPDT_ATTR(resume, resume_prev);
FPDT_ATTR(resume, resume_avg);
FPDT_ATTR(suspend, suspend_start);
FPDT_ATTR(suspend, suspend_end);
FPDT_ATTR(boot, firmware_start);
FPDT_ATTR(boot, bootloader_load);
FPDT_ATTR(boot, bootloader_launch);
FPDT_ATTR(boot, exitbootservice_start);
FPDT_ATTR(boot, exitbootservice_end);

static ssize_t resume_count_show(struct kobject *kobj,
                                 struct kobj_attribute *attr, char *buf)
{
        return sprintf(buf, "%u\n", record_resume->resume_count);
}

static struct kobj_attribute resume_count_attr =
__ATTR_RO(resume_count);

static struct attribute *resume_attrs[] = {
        &resume_count_attr.attr,
        &resume_prev_attr.attr,
        &resume_avg_attr.attr,
        NULL
};

static const struct attribute_group resume_attr_group = {
        .attrs = resume_attrs,
        .name = "resume",
};

static struct attribute *suspend_attrs[] = {
        &suspend_start_attr.attr,
        &suspend_end_attr.attr,
        NULL
};

static const struct attribute_group suspend_attr_group = {
        .attrs = suspend_attrs,
        .name = "suspend",
};

static struct attribute *boot_attrs[] = {
        &firmware_start_attr.attr,
        &bootloader_load_attr.attr,
        &bootloader_launch_attr.attr,
        &exitbootservice_start_attr.attr,
        &exitbootservice_end_attr.attr,
        NULL
};

static const struct attribute_group boot_attr_group = {
        .attrs = boot_attrs,
        .name = "boot",
};

static struct kobject *fpdt_kobj;

#if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT
#include <linux/processor.h>
static bool fpdt_address_valid(u64 address)
{
        /*
         * On some systems the table contains invalid addresses
         * with unsuppored high address bits set, check for this.
         */
        return !(address >> boot_cpu_data.x86_phys_bits);
}
#else
static bool fpdt_address_valid(u64 address)
{
        return true;
}
#endif

static int fpdt_process_subtable(u64 address, u32 subtable_type)
{
        struct fpdt_subtable_header *subtable_header;
        struct fpdt_record_header *record_header;
        char *signature = (subtable_type == SUBTABLE_FBPT ? "FBPT" : "S3PT");
        u32 length, offset;
        int result;

        if (!fpdt_address_valid(address)) {
                pr_info(FW_BUG "invalid physical address: 0x%llx!\n", address);
                return -EINVAL;
        }

        subtable_header = acpi_os_map_memory(address, sizeof(*subtable_header));
        if (!subtable_header)
                return -ENOMEM;

        if (strncmp((char *)&subtable_header->signature, signature, 4)) {
                pr_info(FW_BUG "subtable signature and type mismatch!\n");
                return -EINVAL;
        }

        length = subtable_header->length;
        acpi_os_unmap_memory(subtable_header, sizeof(*subtable_header));

        subtable_header = acpi_os_map_memory(address, length);
        if (!subtable_header)
                return -ENOMEM;

        offset = sizeof(*subtable_header);
        while (offset < length) {
                record_header = (void *)subtable_header + offset;
                offset += record_header->length;

                if (!record_header->length) {
                        pr_err(FW_BUG "Zero-length record found in FPTD.\n");
                        result = -EINVAL;
                        goto err;
                }

                switch (record_header->type) {
                case RECORD_S3_RESUME:
                        if (subtable_type != SUBTABLE_S3PT) {
                                pr_err(FW_BUG "Invalid record %d for subtable %s\n",
                                     record_header->type, signature);
                                result = -EINVAL;
                                goto err;
                        }
                        if (record_resume) {
                                pr_err("Duplicate resume performance record found.\n");
                                continue;
                        }
                        record_resume = (struct resume_performance_record *)record_header;
                        result = sysfs_create_group(fpdt_kobj, &resume_attr_group);
                        if (result)
                                goto err;
                        break;
                case RECORD_S3_SUSPEND:
                        if (subtable_type != SUBTABLE_S3PT) {
                                pr_err(FW_BUG "Invalid %d for subtable %s\n",
                                     record_header->type, signature);
                                continue;
                        }
                        if (record_suspend) {
                                pr_err("Duplicate suspend performance record found.\n");
                                continue;
                        }
                        record_suspend = (struct suspend_performance_record *)record_header;
                        result = sysfs_create_group(fpdt_kobj, &suspend_attr_group);
                        if (result)
                                goto err;
                        break;
                case RECORD_BOOT:
                        if (subtable_type != SUBTABLE_FBPT) {
                                pr_err(FW_BUG "Invalid %d for subtable %s\n",
                                     record_header->type, signature);
                                result = -EINVAL;
                                goto err;
                        }
                        if (record_boot) {
                                pr_err("Duplicate boot performance record found.\n");
                                continue;
                        }
                        record_boot = (struct boot_performance_record *)record_header;
                        result = sysfs_create_group(fpdt_kobj, &boot_attr_group);
                        if (result)
                                goto err;
                        break;

                default:
                        /* Other types are reserved in ACPI 6.4 spec. */
                        break;
                }
        }
        return 0;

err:
        if (record_boot)
                sysfs_remove_group(fpdt_kobj, &boot_attr_group);

        if (record_suspend)
                sysfs_remove_group(fpdt_kobj, &suspend_attr_group);

        if (record_resume)
                sysfs_remove_group(fpdt_kobj, &resume_attr_group);

        return result;
}

static int __init acpi_init_fpdt(void)
{
        acpi_status status;
        struct acpi_table_header *header;
        struct fpdt_subtable_entry *subtable;
        u32 offset = sizeof(*header);
        int result;

        status = acpi_get_table(ACPI_SIG_FPDT, 0, &header);

        if (ACPI_FAILURE(status))
                return 0;

        fpdt_kobj = kobject_create_and_add("fpdt", acpi_kobj);
        if (!fpdt_kobj) {
                result = -ENOMEM;
                goto err_nomem;
        }

        while (offset < header->length) {
                subtable = (void *)header + offset;
                switch (subtable->type) {
                case SUBTABLE_FBPT:
                case SUBTABLE_S3PT:
                        result = fpdt_process_subtable(subtable->address,
                                              subtable->type);
                        if (result)
                                goto err_subtable;
                        break;
                default:
                        /* Other types are reserved in ACPI 6.4 spec. */
                        break;
                }
                offset += sizeof(*subtable);
        }
        return 0;
err_subtable:
        kobject_put(fpdt_kobj);

err_nomem:
        acpi_put_table(header);
        return result;
}

fs_initcall(acpi_init_fpdt);