// SPDX-License-Identifier: GPL-2.0
/*
 * AMD Platform Management Framework Driver
 *
 * Copyright (c) 2022, Advanced Micro Devices, Inc.
 * All Rights Reserved.
 *
 * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
 */

#include <linux/acpi.h>
#include <linux/array_size.h>
#include <linux/cleanup.h>
#include <linux/dev_printk.h>
#include "pmf.h"

#define APMF_CQL_NOTIFICATION  2
#define APMF_AMT_NOTIFICATION  3

static union acpi_object *apmf_if_call(struct amd_pmf_dev *pdev, int fn, struct acpi_buffer *param)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        acpi_handle ahandle = ACPI_HANDLE(pdev->dev);
        struct acpi_object_list apmf_if_arg_list;
        union acpi_object apmf_if_args[2];
        acpi_status status;

        apmf_if_arg_list.count = 2;
        apmf_if_arg_list.pointer = &apmf_if_args[0];

        apmf_if_args[0].type = ACPI_TYPE_INTEGER;
        apmf_if_args[0].integer.value = fn;

        if (param) {
                apmf_if_args[1].type = ACPI_TYPE_BUFFER;
                apmf_if_args[1].buffer.length = param->length;
                apmf_if_args[1].buffer.pointer = param->pointer;
        } else {
                apmf_if_args[1].type = ACPI_TYPE_INTEGER;
                apmf_if_args[1].integer.value = 0;
        }

        status = acpi_evaluate_object(ahandle, "APMF", &apmf_if_arg_list, &buffer);
        if (ACPI_FAILURE(status)) {
                dev_err(pdev->dev, "APMF method:%d call failed\n", fn);
                kfree(buffer.pointer);
                return NULL;
        }

        return buffer.pointer;
}

static int apmf_if_call_store_buffer(struct amd_pmf_dev *pdev, int fn, void *dest, size_t out_sz)
{
        union acpi_object *info;
        size_t size;
        int err = 0;

        info = apmf_if_call(pdev, fn, NULL);
        if (!info)
                return -EIO;

        if (info->type != ACPI_TYPE_BUFFER) {
                dev_err(pdev->dev, "object is not a buffer\n");
                err = -EINVAL;
                goto out;
        }

        if (info->buffer.length < 2) {
                dev_err(pdev->dev, "buffer too small\n");
                err = -EINVAL;
                goto out;
        }

        size = *(u16 *)info->buffer.pointer;
        if (info->buffer.length < size) {
                dev_err(pdev->dev, "buffer smaller then headersize %u < %zu\n",
                        info->buffer.length, size);
                err = -EINVAL;
                goto out;
        }

        if (size < out_sz) {
                dev_err(pdev->dev, "buffer too small %zu\n", size);
                err = -EINVAL;
                goto out;
        }

        memcpy(dest, info->buffer.pointer, out_sz);

out:
        kfree(info);
        return err;
}

static union acpi_object *apts_if_call(struct amd_pmf_dev *pdev, u32 state_index)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        acpi_handle ahandle = ACPI_HANDLE(pdev->dev);
        struct acpi_object_list apts_if_arg_list;
        union acpi_object apts_if_args[3];
        acpi_status status;

        apts_if_arg_list.count = 3;
        apts_if_arg_list.pointer = &apts_if_args[0];

        apts_if_args[0].type = ACPI_TYPE_INTEGER;
        apts_if_args[0].integer.value = 1;
        apts_if_args[1].type = ACPI_TYPE_INTEGER;
        apts_if_args[1].integer.value = state_index;
        apts_if_args[2].type = ACPI_TYPE_INTEGER;
        apts_if_args[2].integer.value = 0;

        status = acpi_evaluate_object(ahandle, "APTS", &apts_if_arg_list, &buffer);
        if (ACPI_FAILURE(status)) {
                dev_err(pdev->dev, "APTS state_idx:%u call failed\n", state_index);
                kfree(buffer.pointer);
                return NULL;
        }

        return buffer.pointer;
}

static int apts_if_call_store_buffer(struct amd_pmf_dev *pdev,
                                     u32 index, void *data, size_t out_sz)
{
        union acpi_object *info;
        size_t size;
        int err = 0;

        info = apts_if_call(pdev, index);
        if (!info)
                return -EIO;

        if (info->type != ACPI_TYPE_BUFFER) {
                dev_err(pdev->dev, "object is not a buffer\n");
                err = -EINVAL;
                goto out;
        }

        size = *(u16 *)info->buffer.pointer;
        if (info->buffer.length < size) {
                dev_err(pdev->dev, "buffer smaller than header size %u < %zu\n",
                        info->buffer.length, size);
                err = -EINVAL;
                goto out;
        }

        if (size < out_sz) {
                dev_err(pdev->dev, "buffer too small %zu\n", size);
                err = -EINVAL;
                goto out;
        }

        memcpy(data, info->buffer.pointer, out_sz);
out:
        kfree(info);
        return err;
}

int is_apmf_func_supported(struct amd_pmf_dev *pdev, unsigned long index)
{
        /* If bit-n is set, that indicates function n+1 is supported */
        return !!(pdev->supported_func & BIT(index - 1));
}

int is_apmf_bios_input_notifications_supported(struct amd_pmf_dev *pdev)
{
        return !!(pdev->notifications & CUSTOM_BIOS_INPUT_BITS);
}

int apts_get_static_slider_granular_v2(struct amd_pmf_dev *pdev,
                                       struct amd_pmf_apts_granular_output *data, u32 apts_idx)
{
        if (!is_apmf_func_supported(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR))
                return -EINVAL;

        return apts_if_call_store_buffer(pdev, apts_idx, data, sizeof(*data));
}

int apmf_get_static_slider_granular_v2(struct amd_pmf_dev *pdev,
                                       struct apmf_static_slider_granular_output_v2 *data)
{
        if (!is_apmf_func_supported(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR))
                return -EINVAL;

        return apmf_if_call_store_buffer(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR,
                                         data, sizeof(*data));
}

int apmf_get_static_slider_granular(struct amd_pmf_dev *pdev,
                                    struct apmf_static_slider_granular_output *data)
{
        if (!is_apmf_func_supported(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR))
                return -EINVAL;

        return apmf_if_call_store_buffer(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR,
                                                                         data, sizeof(*data));
}

int apmf_os_power_slider_update(struct amd_pmf_dev *pdev, u8 event)
{
        struct os_power_slider args;
        struct acpi_buffer params;
        union acpi_object *info;

        args.size = sizeof(args);
        args.slider_event = event;

        params.length = sizeof(args);
        params.pointer = (void *)&args;

        info = apmf_if_call(pdev, APMF_FUNC_OS_POWER_SLIDER_UPDATE, &params);
        if (!info)
                return -EIO;

        kfree(info);
        return 0;
}

static void apmf_sbios_heartbeat_notify(struct work_struct *work)
{
        struct amd_pmf_dev *dev = container_of(work, struct amd_pmf_dev, heart_beat.work);
        union acpi_object *info;

        dev_dbg(dev->dev, "Sending heartbeat to SBIOS\n");
        info = apmf_if_call(dev, APMF_FUNC_SBIOS_HEARTBEAT, NULL);
        if (!info)
                return;

        schedule_delayed_work(&dev->heart_beat, secs_to_jiffies(dev->hb_interval));
        kfree(info);
}

int amd_pmf_notify_sbios_heartbeat_event_v2(struct amd_pmf_dev *dev, u8 flag)
{
        struct sbios_hb_event_v2 args = { };
        struct acpi_buffer params;
        union acpi_object *info;

        args.size = sizeof(args);

        switch (flag) {
        case ON_LOAD:
                args.load = 1;
                break;
        case ON_UNLOAD:
                args.unload = 1;
                break;
        case ON_SUSPEND:
                args.suspend = 1;
                break;
        case ON_RESUME:
                args.resume = 1;
                break;
        default:
                dev_dbg(dev->dev, "Failed to send v2 heartbeat event, flag:0x%x\n", flag);
                return -EINVAL;
        }

        params.length = sizeof(args);
        params.pointer = &args;

        info = apmf_if_call(dev, APMF_FUNC_SBIOS_HEARTBEAT_V2, &params);
        if (!info)
                return -EIO;

        kfree(info);
        return 0;
}

int apmf_update_fan_idx(struct amd_pmf_dev *pdev, bool manual, u32 idx)
{
        union acpi_object *info;
        struct apmf_fan_idx args;
        struct acpi_buffer params;

        args.size = sizeof(args);
        args.fan_ctl_mode = manual;
        args.fan_ctl_idx = idx;

        params.length = sizeof(args);
        params.pointer = (void *)&args;

        info = apmf_if_call(pdev, APMF_FUNC_SET_FAN_IDX, &params);
        if (!info)
                return -EIO;

        kfree(info);
        return 0;
}

static int apmf_notify_smart_pc_update(struct amd_pmf_dev *pdev, u32 val, u32 preq, u32 index)
{
        struct amd_pmf_notify_smart_pc_update args;
        struct acpi_buffer params;
        union acpi_object *info;

        args.size = sizeof(args);
        args.pending_req = preq;
        args.custom_bios[index] = val;

        params.length = sizeof(args);
        params.pointer = &args;

        info = apmf_if_call(pdev, APMF_FUNC_NOTIFY_SMART_PC_UPDATES, &params);
        if (!info)
                return -EIO;

        kfree(info);
        dev_dbg(pdev->dev, "Notify smart pc update, val: %u\n", val);

        return 0;
}

int apmf_get_auto_mode_def(struct amd_pmf_dev *pdev, struct apmf_auto_mode *data)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_AUTO_MODE, data, sizeof(*data));
}

int apmf_get_sbios_requests_v2(struct amd_pmf_dev *pdev, struct apmf_sbios_req_v2 *req)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_SBIOS_REQUESTS, req, sizeof(*req));
}

int apmf_get_sbios_requests_v1(struct amd_pmf_dev *pdev, struct apmf_sbios_req_v1 *req)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_SBIOS_REQUESTS, req, sizeof(*req));
}

int apmf_get_sbios_requests(struct amd_pmf_dev *pdev, struct apmf_sbios_req *req)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_SBIOS_REQUESTS,
                                                                         req, sizeof(*req));
}

/* Store custom BIOS inputs data in ring buffer */
static void amd_pmf_custom_bios_inputs_rb(struct amd_pmf_dev *pmf_dev)
{
        struct pmf_cbi_ring_buffer *rb = &pmf_dev->cbi_buf;
        int i;

        guard(mutex)(&pmf_dev->cbi_mutex);

        switch (pmf_dev->cpu_id) {
        case AMD_CPU_ID_PS:
                for (i = 0; i < ARRAY_SIZE(custom_bios_inputs_v1); i++)
                        rb->data[rb->head].val[i] = pmf_dev->req1.custom_policy[i];
                rb->data[rb->head].preq = pmf_dev->req1.pending_req;
                break;
        case PCI_DEVICE_ID_AMD_1AH_M20H_ROOT:
        case PCI_DEVICE_ID_AMD_1AH_M60H_ROOT:
                for (i = 0; i < ARRAY_SIZE(custom_bios_inputs); i++)
                        rb->data[rb->head].val[i] = pmf_dev->req.custom_policy[i];
                rb->data[rb->head].preq = pmf_dev->req.pending_req;
                break;
        default:
                return;
        }

        if (CIRC_SPACE(rb->head, rb->tail, CUSTOM_BIOS_INPUT_RING_ENTRIES) == 0) {
                /* Rare case: ensures the newest BIOS input value is kept */
                dev_warn(pmf_dev->dev, "Overwriting BIOS input value, data may be lost\n");
                rb->tail = (rb->tail + 1) & (CUSTOM_BIOS_INPUT_RING_ENTRIES - 1);
        }

        rb->head = (rb->head + 1) & (CUSTOM_BIOS_INPUT_RING_ENTRIES - 1);
}

static void amd_pmf_handle_early_preq(struct amd_pmf_dev *pdev)
{
        if (!pdev->cb_flag)
                return;

        amd_pmf_invoke_cmd_enact(pdev);
        pdev->cb_flag = false;
}

static void apmf_event_handler_v2(acpi_handle handle, u32 event, void *data)
{
        struct amd_pmf_dev *pmf_dev = data;
        int ret;

        guard(mutex)(&pmf_dev->cb_mutex);

        ret = apmf_get_sbios_requests_v2(pmf_dev, &pmf_dev->req);
        if (ret) {
                dev_err(pmf_dev->dev, "Failed to get v2 SBIOS requests: %d\n", ret);
                return;
        }

        dev_dbg(pmf_dev->dev, "Pending request (preq): 0x%x\n", pmf_dev->req.pending_req);

        amd_pmf_handle_early_preq(pmf_dev);

        amd_pmf_custom_bios_inputs_rb(pmf_dev);
}

static void apmf_event_handler_v1(acpi_handle handle, u32 event, void *data)
{
        struct amd_pmf_dev *pmf_dev = data;
        int ret;

        guard(mutex)(&pmf_dev->cb_mutex);

        ret = apmf_get_sbios_requests_v1(pmf_dev, &pmf_dev->req1);
        if (ret) {
                dev_err(pmf_dev->dev, "Failed to get v1 SBIOS requests: %d\n", ret);
                return;
        }

        dev_dbg(pmf_dev->dev, "Pending request (preq1): 0x%x\n", pmf_dev->req1.pending_req);

        amd_pmf_handle_early_preq(pmf_dev);

        amd_pmf_custom_bios_inputs_rb(pmf_dev);
}

static void apmf_event_handler(acpi_handle handle, u32 event, void *data)
{
        struct amd_pmf_dev *pmf_dev = data;
        struct apmf_sbios_req req;
        int ret;

        guard(mutex)(&pmf_dev->update_mutex);
        ret = apmf_get_sbios_requests(pmf_dev, &req);
        if (ret) {
                dev_err(pmf_dev->dev, "Failed to get SBIOS requests:%d\n", ret);
                return;
        }

        if (req.pending_req & BIT(APMF_AMT_NOTIFICATION)) {
                dev_dbg(pmf_dev->dev, "AMT is supported and notifications %s\n",
                        req.amt_event ? "Enabled" : "Disabled");
                pmf_dev->amt_enabled = !!req.amt_event;

                if (pmf_dev->amt_enabled)
                        amd_pmf_handle_amt(pmf_dev);
                else
                        amd_pmf_reset_amt(pmf_dev);
        }

        if (req.pending_req & BIT(APMF_CQL_NOTIFICATION)) {
                dev_dbg(pmf_dev->dev, "CQL is supported and notifications %s\n",
                        req.cql_event ? "Enabled" : "Disabled");

                /* update the target mode information */
                if (pmf_dev->amt_enabled)
                        amd_pmf_update_2_cql(pmf_dev, req.cql_event);
        }
}

static int apmf_if_verify_interface(struct amd_pmf_dev *pdev)
{
        struct apmf_verify_interface output;
        int err;

        err = apmf_if_call_store_buffer(pdev, APMF_FUNC_VERIFY_INTERFACE, &output, sizeof(output));
        if (err)
                return err;

        /* only set if not already set by a quirk */
        if (!pdev->supported_func)
                pdev->supported_func = output.supported_functions;

        dev_dbg(pdev->dev, "supported functions:0x%x notifications:0x%x version:%u\n",
                output.supported_functions, output.notification_mask, output.version);

        pdev->pmf_if_version = output.version;

        pdev->notifications =  output.notification_mask;
        return 0;
}

static int apmf_get_system_params(struct amd_pmf_dev *dev)
{
        struct apmf_system_params params;
        int err;

        if (!is_apmf_func_supported(dev, APMF_FUNC_GET_SYS_PARAMS))
                return -EINVAL;

        err = apmf_if_call_store_buffer(dev, APMF_FUNC_GET_SYS_PARAMS, &params, sizeof(params));
        if (err)
                return err;

        dev_dbg(dev->dev, "system params mask:0x%x flags:0x%x cmd_code:0x%x heartbeat:%d\n",
                params.valid_mask,
                params.flags,
                params.command_code,
                params.heartbeat_int);
        params.flags = params.flags & params.valid_mask;
        dev->hb_interval = params.heartbeat_int;

        return 0;
}

int apmf_get_dyn_slider_def_ac(struct amd_pmf_dev *pdev, struct apmf_dyn_slider_output *data)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_DYN_SLIDER_AC, data, sizeof(*data));
}

int apmf_get_dyn_slider_def_dc(struct amd_pmf_dev *pdev, struct apmf_dyn_slider_output *data)
{
        return apmf_if_call_store_buffer(pdev, APMF_FUNC_DYN_SLIDER_DC, data, sizeof(*data));
}

static apmf_event_handler_t apmf_event_handlers[] = {
        [PMF_IF_V1] = apmf_event_handler_v1,
        [PMF_IF_V2] = apmf_event_handler_v2,
};

int apmf_install_handler(struct amd_pmf_dev *pmf_dev)
{
        acpi_handle ahandle = ACPI_HANDLE(pmf_dev->dev);
        acpi_status status;

        /* Install the APMF Notify handler */
        if (is_apmf_func_supported(pmf_dev, APMF_FUNC_AUTO_MODE) &&
            is_apmf_func_supported(pmf_dev, APMF_FUNC_SBIOS_REQUESTS)) {
                status = acpi_install_notify_handler(ahandle, ACPI_ALL_NOTIFY,
                                                     apmf_event_handler, pmf_dev);
                if (ACPI_FAILURE(status)) {
                        dev_err(pmf_dev->dev, "failed to install notify handler\n");
                        return -ENODEV;
                }

                /* Call the handler once manually to catch up with possibly missed notifies. */
                apmf_event_handler(ahandle, 0, pmf_dev);
        }

        if (!pmf_dev->smart_pc_enabled)
                return -EINVAL;

        switch (pmf_dev->pmf_if_version) {
        case PMF_IF_V1:
                if (!is_apmf_bios_input_notifications_supported(pmf_dev))
                        break;
                fallthrough;
        case PMF_IF_V2:
                status = acpi_install_notify_handler(ahandle, ACPI_ALL_NOTIFY,
                                apmf_event_handlers[pmf_dev->pmf_if_version], pmf_dev);
                if (ACPI_FAILURE(status)) {
                        dev_err(pmf_dev->dev,
                                "failed to install notify handler v%d for custom BIOS inputs\n",
                                pmf_dev->pmf_if_version);
                        return -ENODEV;
                }
                break;
        default:
                break;
        }

        return 0;
}

int apmf_check_smart_pc(struct amd_pmf_dev *pmf_dev)
{
        struct platform_device *pdev = to_platform_device(pmf_dev->dev);

        pmf_dev->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!pmf_dev->res) {
                dev_dbg(pmf_dev->dev, "Failed to get I/O memory resource\n");
                return -EINVAL;
        }

        pmf_dev->policy_addr = pmf_dev->res->start;
        /*
         * We cannot use resource_size() here because it adds an extra byte to round off the size.
         * In the case of PMF ResourceTemplate(), this rounding is already handled within the _CRS.
         * Using resource_size() would increase the resource size by 1, causing a mismatch with the
         * length field and leading to issues. Therefore, simply use end-start of the ACPI resource
         * to obtain the actual length.
         */
        pmf_dev->policy_sz = pmf_dev->res->end - pmf_dev->res->start;

        if (!pmf_dev->policy_addr || pmf_dev->policy_sz > POLICY_BUF_MAX_SZ ||
            pmf_dev->policy_sz == 0) {
                dev_err(pmf_dev->dev, "Incorrect policy params, possibly a SBIOS bug\n");
                return -EINVAL;
        }

        return 0;
}

int amd_pmf_smartpc_apply_bios_output(struct amd_pmf_dev *dev, u32 val, u32 preq, u32 idx)
{
        if (!is_apmf_func_supported(dev, APMF_FUNC_NOTIFY_SMART_PC_UPDATES))
                return -EINVAL;

        return apmf_notify_smart_pc_update(dev, val, preq, idx);
}

void apmf_acpi_deinit(struct amd_pmf_dev *pmf_dev)
{
        acpi_handle ahandle = ACPI_HANDLE(pmf_dev->dev);

        if (pmf_dev->hb_interval && pmf_dev->pmf_if_version == PMF_IF_V1)
                cancel_delayed_work_sync(&pmf_dev->heart_beat);

        if (is_apmf_func_supported(pmf_dev, APMF_FUNC_AUTO_MODE) &&
            is_apmf_func_supported(pmf_dev, APMF_FUNC_SBIOS_REQUESTS))
                acpi_remove_notify_handler(ahandle, ACPI_ALL_NOTIFY, apmf_event_handler);

        if (!pmf_dev->smart_pc_enabled)
                return;

        switch (pmf_dev->pmf_if_version) {
        case PMF_IF_V1:
                if (!is_apmf_bios_input_notifications_supported(pmf_dev))
                        break;
                fallthrough;
        case PMF_IF_V2:
                acpi_remove_notify_handler(ahandle, ACPI_ALL_NOTIFY,
                                           apmf_event_handlers[pmf_dev->pmf_if_version]);
                break;
        default:
                break;
        }
}

int apmf_acpi_init(struct amd_pmf_dev *pmf_dev)
{
        int ret;

        ret = apmf_if_verify_interface(pmf_dev);
        if (ret) {
                dev_err(pmf_dev->dev, "APMF verify interface failed :%d\n", ret);
                goto out;
        }

        ret = apmf_get_system_params(pmf_dev);
        if (ret) {
                dev_dbg(pmf_dev->dev, "APMF apmf_get_system_params failed :%d\n", ret);
                goto out;
        }

        if (pmf_dev->hb_interval && pmf_dev->pmf_if_version == PMF_IF_V1) {
                /* send heartbeats only if the interval is not zero */
                INIT_DELAYED_WORK(&pmf_dev->heart_beat, apmf_sbios_heartbeat_notify);
                schedule_delayed_work(&pmf_dev->heart_beat, 0);
        }

out:
        return ret;
}