// SPDX-License-Identifier: GPL-2.0-only
/*
 * intel_rapl_tpmi: Intel RAPL driver via TPMI interface
 *
 * Copyright (c) 2023, Intel Corporation.
 * All Rights Reserved.
 *
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/auxiliary_bus.h>
#include <linux/intel_rapl.h>
#include <linux/intel_tpmi.h>
#include <linux/intel_vsec.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/slab.h>

#define TPMI_RAPL_MAJOR_VERSION 0
#define TPMI_RAPL_MINOR_VERSION 1

/* 1 header + 10 registers + 5 reserved. 8 bytes for each. */
#define TPMI_RAPL_DOMAIN_SIZE 128

enum tpmi_rapl_domain_type {
        TPMI_RAPL_DOMAIN_INVALID,
        TPMI_RAPL_DOMAIN_SYSTEM,
        TPMI_RAPL_DOMAIN_PACKAGE,
        TPMI_RAPL_DOMAIN_RESERVED,
        TPMI_RAPL_DOMAIN_MEMORY,
        TPMI_RAPL_DOMAIN_MAX,
};

enum tpmi_rapl_register {
        TPMI_RAPL_REG_HEADER,
        TPMI_RAPL_REG_UNIT,
        TPMI_RAPL_REG_PL1,
        TPMI_RAPL_REG_PL2,
        TPMI_RAPL_REG_PL3,
        TPMI_RAPL_REG_PL4,
        TPMI_RAPL_REG_RESERVED,
        TPMI_RAPL_REG_ENERGY_STATUS,
        TPMI_RAPL_REG_PERF_STATUS,
        TPMI_RAPL_REG_POWER_INFO,
        TPMI_RAPL_REG_DOMAIN_INFO,
        TPMI_RAPL_REG_INTERRUPT,
        TPMI_RAPL_REG_MAX = 15,
};

struct tpmi_rapl_package {
        struct rapl_if_priv priv;
        struct oobmsm_plat_info *tpmi_info;
        struct rapl_package *rp;
        void __iomem *base;
        struct list_head node;
};

static LIST_HEAD(tpmi_rapl_packages);
static DEFINE_MUTEX(tpmi_rapl_lock);

static struct powercap_control_type *tpmi_control_type;

static int tpmi_rapl_read_raw(int id, struct reg_action *ra, bool atomic)
{
        if (!ra->reg.mmio)
                return -EINVAL;

        ra->value = readq(ra->reg.mmio);

        ra->value &= ra->mask;
        return 0;
}

static int tpmi_rapl_write_raw(int id, struct reg_action *ra)
{
        u64 val;

        if (!ra->reg.mmio)
                return -EINVAL;

        val = readq(ra->reg.mmio);

        val &= ~ra->mask;
        val |= ra->value;

        writeq(val, ra->reg.mmio);
        return 0;
}

static struct tpmi_rapl_package *trp_alloc(int pkg_id)
{
        struct tpmi_rapl_package *trp;
        int ret;

        mutex_lock(&tpmi_rapl_lock);

        if (list_empty(&tpmi_rapl_packages)) {
                tpmi_control_type = powercap_register_control_type(NULL, "intel-rapl", NULL);
                if (IS_ERR(tpmi_control_type)) {
                        ret = PTR_ERR(tpmi_control_type);
                        goto err_unlock;
                }
        }

        trp = kzalloc_obj(*trp);
        if (!trp) {
                ret = -ENOMEM;
                goto err_del_powercap;
        }

        list_add(&trp->node, &tpmi_rapl_packages);

        mutex_unlock(&tpmi_rapl_lock);
        return trp;

err_del_powercap:
        if (list_empty(&tpmi_rapl_packages))
                powercap_unregister_control_type(tpmi_control_type);
err_unlock:
        mutex_unlock(&tpmi_rapl_lock);
        return ERR_PTR(ret);
}

static void trp_release(struct tpmi_rapl_package *trp)
{
        mutex_lock(&tpmi_rapl_lock);
        list_del(&trp->node);

        if (list_empty(&tpmi_rapl_packages))
                powercap_unregister_control_type(tpmi_control_type);

        kfree(trp);
        mutex_unlock(&tpmi_rapl_lock);
}

/*
 * Bit 0 of TPMI_RAPL_REG_DOMAIN_INFO indicates if the current package is a domain
 * root or not. Only domain root packages can enumerate System (Psys) Domain.
 */
#define TPMI_RAPL_DOMAIN_ROOT   BIT(0)

static int parse_one_domain(struct tpmi_rapl_package *trp, u32 offset)
{
        u8 tpmi_domain_version;
        enum rapl_domain_type domain_type;
        enum tpmi_rapl_domain_type tpmi_domain_type;
        enum tpmi_rapl_register reg_index;
        enum rapl_domain_reg_id reg_id;
        int tpmi_domain_size, tpmi_domain_flags;
        u64 tpmi_domain_header = readq(trp->base + offset);
        u64 tpmi_domain_info;

        /* Domain Parent bits are ignored for now */
        tpmi_domain_version = tpmi_domain_header & 0xff;
        tpmi_domain_type = tpmi_domain_header >> 8 & 0xff;
        tpmi_domain_size = tpmi_domain_header >> 16 & 0xff;
        tpmi_domain_flags = tpmi_domain_header >> 32 & 0xffff;

        if (tpmi_domain_version == TPMI_VERSION_INVALID) {
                pr_debug("Invalid version, other instances may be valid\n");
                return -ENODEV;
        }

        if (TPMI_MAJOR_VERSION(tpmi_domain_version) != TPMI_RAPL_MAJOR_VERSION) {
                pr_warn(FW_BUG "Unsupported major version:%ld\n",
                        TPMI_MAJOR_VERSION(tpmi_domain_version));
                return -ENODEV;
        }

        if (TPMI_MINOR_VERSION(tpmi_domain_version) > TPMI_RAPL_MINOR_VERSION)
                pr_info("Ignore: Unsupported minor version:%ld\n",
                        TPMI_MINOR_VERSION(tpmi_domain_version));

        /* Domain size: in unit of 128 Bytes */
        if (tpmi_domain_size != 1) {
                pr_warn(FW_BUG "Invalid Domain size %d\n", tpmi_domain_size);
                return -EINVAL;
        }

        /* Unit register and Energy Status register are mandatory for each domain */
        if (!(tpmi_domain_flags & BIT(TPMI_RAPL_REG_UNIT)) ||
            !(tpmi_domain_flags & BIT(TPMI_RAPL_REG_ENERGY_STATUS))) {
                pr_warn(FW_BUG "Invalid Domain flag 0x%x\n", tpmi_domain_flags);
                return -EINVAL;
        }

        switch (tpmi_domain_type) {
        case TPMI_RAPL_DOMAIN_PACKAGE:
                domain_type = RAPL_DOMAIN_PACKAGE;
                break;
        case TPMI_RAPL_DOMAIN_SYSTEM:
                if (!(tpmi_domain_flags & BIT(TPMI_RAPL_REG_DOMAIN_INFO))) {
                        pr_warn(FW_BUG "System domain must support Domain Info register\n");
                        return -ENODEV;
                }
                tpmi_domain_info = readq(trp->base + offset + TPMI_RAPL_REG_DOMAIN_INFO * 8);
                if (!(tpmi_domain_info & TPMI_RAPL_DOMAIN_ROOT))
                        return 0;
                domain_type = RAPL_DOMAIN_PLATFORM;
                break;
        case TPMI_RAPL_DOMAIN_MEMORY:
                domain_type = RAPL_DOMAIN_DRAM;
                break;
        default:
                pr_warn(FW_BUG "Unsupported Domain type %d\n", tpmi_domain_type);
                return -EINVAL;
        }

        if (trp->priv.regs[domain_type][RAPL_DOMAIN_REG_UNIT].mmio) {
                pr_warn(FW_BUG "Duplicate Domain type %d\n", tpmi_domain_type);
                return -EINVAL;
        }

        reg_index = TPMI_RAPL_REG_HEADER;
        while (++reg_index != TPMI_RAPL_REG_MAX) {
                if (!(tpmi_domain_flags & BIT(reg_index)))
                        continue;

                switch (reg_index) {
                case TPMI_RAPL_REG_UNIT:
                        reg_id = RAPL_DOMAIN_REG_UNIT;
                        break;
                case TPMI_RAPL_REG_PL1:
                        reg_id = RAPL_DOMAIN_REG_LIMIT;
                        trp->priv.limits[domain_type] |= BIT(POWER_LIMIT1);
                        break;
                case TPMI_RAPL_REG_PL2:
                        reg_id = RAPL_DOMAIN_REG_PL2;
                        trp->priv.limits[domain_type] |= BIT(POWER_LIMIT2);
                        break;
                case TPMI_RAPL_REG_PL4:
                        reg_id = RAPL_DOMAIN_REG_PL4;
                        trp->priv.limits[domain_type] |= BIT(POWER_LIMIT4);
                        break;
                case TPMI_RAPL_REG_ENERGY_STATUS:
                        reg_id = RAPL_DOMAIN_REG_STATUS;
                        break;
                case TPMI_RAPL_REG_PERF_STATUS:
                        reg_id = RAPL_DOMAIN_REG_PERF;
                        break;
                case TPMI_RAPL_REG_POWER_INFO:
                        reg_id = RAPL_DOMAIN_REG_INFO;
                        break;
                default:
                        continue;
                }
                trp->priv.regs[domain_type][reg_id].mmio = trp->base + offset + reg_index * 8;
        }

        return 0;
}

static int intel_rapl_tpmi_probe(struct auxiliary_device *auxdev,
                                 const struct auxiliary_device_id *id)
{
        struct tpmi_rapl_package *trp;
        struct oobmsm_plat_info *info;
        struct resource *res;
        u32 offset;
        int ret;

        info = tpmi_get_platform_data(auxdev);
        if (!info)
                return -ENODEV;

        trp = trp_alloc(info->package_id);
        if (IS_ERR(trp))
                return PTR_ERR(trp);

        if (tpmi_get_resource_count(auxdev) > 1) {
                dev_err(&auxdev->dev, "does not support multiple resources\n");
                ret = -EINVAL;
                goto err;
        }

        res = tpmi_get_resource_at_index(auxdev, 0);
        if (!res) {
                dev_err(&auxdev->dev, "can't fetch device resource info\n");
                ret = -EIO;
                goto err;
        }

        trp->base = devm_ioremap_resource(&auxdev->dev, res);
        if (IS_ERR(trp->base)) {
                ret = PTR_ERR(trp->base);
                goto err;
        }

        for (offset = 0; offset < resource_size(res); offset += TPMI_RAPL_DOMAIN_SIZE) {
                ret = parse_one_domain(trp, offset);
                if (ret)
                        goto err;
        }

        trp->tpmi_info = info;
        trp->priv.type = RAPL_IF_TPMI;
        trp->priv.read_raw = tpmi_rapl_read_raw;
        trp->priv.write_raw = tpmi_rapl_write_raw;
        trp->priv.control_type = tpmi_control_type;

        /* RAPL TPMI I/F is per physical package */
        trp->rp = rapl_find_package_domain(info->package_id, &trp->priv, false);
        if (trp->rp) {
                dev_err(&auxdev->dev, "Domain for Package%d already exists\n", info->package_id);
                ret = -EEXIST;
                goto err;
        }

        trp->rp = rapl_add_package(info->package_id, &trp->priv, false);
        if (IS_ERR(trp->rp)) {
                dev_err(&auxdev->dev, "Failed to add RAPL Domain for Package%d, %ld\n",
                        info->package_id, PTR_ERR(trp->rp));
                ret = PTR_ERR(trp->rp);
                goto err;
        }

        rapl_package_add_pmu(trp->rp);

        auxiliary_set_drvdata(auxdev, trp);

        return 0;
err:
        trp_release(trp);
        return ret;
}

static void intel_rapl_tpmi_remove(struct auxiliary_device *auxdev)
{
        struct tpmi_rapl_package *trp = auxiliary_get_drvdata(auxdev);

        rapl_package_remove_pmu(trp->rp);
        rapl_remove_package(trp->rp);
        trp_release(trp);
}

static const struct auxiliary_device_id intel_rapl_tpmi_ids[] = {
        {.name = "intel_vsec.tpmi-rapl" },
        { }
};

MODULE_DEVICE_TABLE(auxiliary, intel_rapl_tpmi_ids);

static struct auxiliary_driver intel_rapl_tpmi_driver = {
        .probe = intel_rapl_tpmi_probe,
        .remove = intel_rapl_tpmi_remove,
        .id_table = intel_rapl_tpmi_ids,
};

module_auxiliary_driver(intel_rapl_tpmi_driver)

MODULE_IMPORT_NS("INTEL_TPMI");

MODULE_DESCRIPTION("Intel RAPL TPMI Driver");
MODULE_LICENSE("GPL");