// SPDX-License-Identifier: GPL-2.0+
// Copyright (c) 2016-2017 Hisilicon Limited.

#include "hclge_mbx.h"
#include "hclgevf_main.h"
#include "hnae3.h"

static void hclgevf_reset_mbx_resp_status(struct hclgevf_dev *hdev)
{
        /* this function should be called with mbx_resp.mbx_mutex held
         * to prtect the received_response from race condition
         */
        hdev->mbx_resp.received_resp  = false;
        hdev->mbx_resp.origin_mbx_msg = 0;
        hdev->mbx_resp.resp_status    = 0;
        memset(hdev->mbx_resp.additional_info, 0, HCLGE_MBX_MAX_RESP_DATA_SIZE);
}

/* hclgevf_get_mbx_resp: used to get a response from PF after VF sends a mailbox
 * message to PF.
 * @hdev: pointer to struct hclgevf_dev
 * @resp_msg: pointer to store the original message type and response status
 * @len: the resp_msg data array length.
 */
static int hclgevf_get_mbx_resp(struct hclgevf_dev *hdev, u16 code0, u16 code1,
                                u8 *resp_data, u16 resp_len)
{
#define HCLGEVF_MAX_TRY_TIMES   500
#define HCLGEVF_SLEEP_USCOEND   1000
        struct hclgevf_mbx_resp_status *mbx_resp;
        u16 r_code0, r_code1;
        int i = 0;

        if (resp_len > HCLGE_MBX_MAX_RESP_DATA_SIZE) {
                dev_err(&hdev->pdev->dev,
                        "VF mbx response len(=%d) exceeds maximum(=%d)\n",
                        resp_len,
                        HCLGE_MBX_MAX_RESP_DATA_SIZE);
                return -EINVAL;
        }

        while ((!hdev->mbx_resp.received_resp) && (i < HCLGEVF_MAX_TRY_TIMES)) {
                udelay(HCLGEVF_SLEEP_USCOEND);
                i++;
        }

        if (i >= HCLGEVF_MAX_TRY_TIMES) {
                dev_err(&hdev->pdev->dev,
                        "VF could not get mbx resp(=%d) from PF in %d tries\n",
                        hdev->mbx_resp.received_resp, i);
                return -EIO;
        }

        mbx_resp = &hdev->mbx_resp;
        r_code0 = (u16)(mbx_resp->origin_mbx_msg >> 16);
        r_code1 = (u16)(mbx_resp->origin_mbx_msg & 0xff);

        if (mbx_resp->resp_status)
                return mbx_resp->resp_status;

        if (resp_data)
                memcpy(resp_data, &mbx_resp->additional_info[0], resp_len);

        hclgevf_reset_mbx_resp_status(hdev);

        if (!(r_code0 == code0 && r_code1 == code1 && !mbx_resp->resp_status)) {
                dev_err(&hdev->pdev->dev,
                        "VF could not match resp code(code0=%d,code1=%d), %d",
                        code0, code1, mbx_resp->resp_status);
                return -EIO;
        }

        return 0;
}

int hclgevf_send_mbx_msg(struct hclgevf_dev *hdev, u16 code, u16 subcode,
                         const u8 *msg_data, u8 msg_len, bool need_resp,
                         u8 *resp_data, u16 resp_len)
{
        struct hclge_mbx_vf_to_pf_cmd *req;
        struct hclgevf_desc desc;
        int status;

        req = (struct hclge_mbx_vf_to_pf_cmd *)desc.data;

        /* first two bytes are reserved for code & subcode */
        if (msg_len > (HCLGE_MBX_MAX_MSG_SIZE - 2)) {
                dev_err(&hdev->pdev->dev,
                        "VF send mbx msg fail, msg len %d exceeds max len %d\n",
                        msg_len, HCLGE_MBX_MAX_MSG_SIZE);
                return -EINVAL;
        }

        hclgevf_cmd_setup_basic_desc(&desc, HCLGEVF_OPC_MBX_VF_TO_PF, false);
        req->msg[0] = code;
        req->msg[1] = subcode;
        memcpy(&req->msg[2], msg_data, msg_len);

        /* synchronous send */
        if (need_resp) {
                mutex_lock(&hdev->mbx_resp.mbx_mutex);
                hclgevf_reset_mbx_resp_status(hdev);
                status = hclgevf_cmd_send(&hdev->hw, &desc, 1);
                if (status) {
                        dev_err(&hdev->pdev->dev,
                                "VF failed(=%d) to send mbx message to PF\n",
                                status);
                        mutex_unlock(&hdev->mbx_resp.mbx_mutex);
                        return status;
                }

                status = hclgevf_get_mbx_resp(hdev, code, subcode, resp_data,
                                              resp_len);
                mutex_unlock(&hdev->mbx_resp.mbx_mutex);
        } else {
                /* asynchronous send */
                status = hclgevf_cmd_send(&hdev->hw, &desc, 1);
                if (status) {
                        dev_err(&hdev->pdev->dev,
                                "VF failed(=%d) to send mbx message to PF\n",
                                status);
                        return status;
                }
        }

        return status;
}

static bool hclgevf_cmd_crq_empty(struct hclgevf_hw *hw)
{
        u32 tail = hclgevf_read_dev(hw, HCLGEVF_NIC_CRQ_TAIL_REG);

        return tail == hw->cmq.crq.next_to_use;
}

void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
{
        struct hclgevf_mbx_resp_status *resp;
        struct hclge_mbx_pf_to_vf_cmd *req;
        struct hclgevf_cmq_ring *crq;
        struct hclgevf_desc *desc;
        u16 *msg_q;
        u16 flag;
        u8 *temp;
        int i;

        resp = &hdev->mbx_resp;
        crq = &hdev->hw.cmq.crq;

        while (!hclgevf_cmd_crq_empty(&hdev->hw)) {
                desc = &crq->desc[crq->next_to_use];
                req = (struct hclge_mbx_pf_to_vf_cmd *)desc->data;

                flag = le16_to_cpu(crq->desc[crq->next_to_use].flag);
                if (unlikely(!hnae3_get_bit(flag, HCLGEVF_CMDQ_RX_OUTVLD_B))) {
                        dev_warn(&hdev->pdev->dev,
                                 "dropped invalid mailbox message, code = %d\n",
                                 req->msg[0]);

                        /* dropping/not processing this invalid message */
                        crq->desc[crq->next_to_use].flag = 0;
                        hclge_mbx_ring_ptr_move_crq(crq);
                        continue;
                }

                /* synchronous messages are time critical and need preferential
                 * treatment. Therefore, we need to acknowledge all the sync
                 * responses as quickly as possible so that waiting tasks do not
                 * timeout and simultaneously queue the async messages for later
                 * prcessing in context of mailbox task i.e. the slow path.
                 */
                switch (req->msg[0]) {
                case HCLGE_MBX_PF_VF_RESP:
                        if (resp->received_resp)
                                dev_warn(&hdev->pdev->dev,
                                         "VF mbx resp flag not clear(%d)\n",
                                         req->msg[1]);
                        resp->received_resp = true;

                        resp->origin_mbx_msg = (req->msg[1] << 16);
                        resp->origin_mbx_msg |= req->msg[2];
                        resp->resp_status = req->msg[3];

                        temp = (u8 *)&req->msg[4];
                        for (i = 0; i < HCLGE_MBX_MAX_RESP_DATA_SIZE; i++) {
                                resp->additional_info[i] = *temp;
                                temp++;
                        }
                        break;
                case HCLGE_MBX_LINK_STAT_CHANGE:
                case HCLGE_MBX_ASSERTING_RESET:
                        /* set this mbx event as pending. This is required as we
                         * might loose interrupt event when mbx task is busy
                         * handling. This shall be cleared when mbx task just
                         * enters handling state.
                         */
                        hdev->mbx_event_pending = true;

                        /* we will drop the async msg if we find ARQ as full
                         * and continue with next message
                         */
                        if (hdev->arq.count >= HCLGE_MBX_MAX_ARQ_MSG_NUM) {
                                dev_warn(&hdev->pdev->dev,
                                         "Async Q full, dropping msg(%d)\n",
                                         req->msg[1]);
                                break;
                        }

                        /* tail the async message in arq */
                        msg_q = hdev->arq.msg_q[hdev->arq.tail];
                        memcpy(&msg_q[0], req->msg,
                               HCLGE_MBX_MAX_ARQ_MSG_SIZE * sizeof(u16));
                        hclge_mbx_tail_ptr_move_arq(hdev->arq);
                        hdev->arq.count++;

                        hclgevf_mbx_task_schedule(hdev);

                        break;
                default:
                        dev_err(&hdev->pdev->dev,
                                "VF received unsupported(%d) mbx msg from PF\n",
                                req->msg[0]);
                        break;
                }
                crq->desc[crq->next_to_use].flag = 0;
                hclge_mbx_ring_ptr_move_crq(crq);
        }

        /* Write back CMDQ_RQ header pointer, M7 need this pointer */
        hclgevf_write_dev(&hdev->hw, HCLGEVF_NIC_CRQ_HEAD_REG,
                          crq->next_to_use);
}

void hclgevf_mbx_async_handler(struct hclgevf_dev *hdev)
{
        u16 link_status;
        u16 *msg_q;
        u8 duplex;
        u32 speed;
        u32 tail;

        /* we can safely clear it now as we are at start of the async message
         * processing
         */
        hdev->mbx_event_pending = false;

        tail = hdev->arq.tail;

        /* process all the async queue messages */
        while (tail != hdev->arq.head) {
                msg_q = hdev->arq.msg_q[hdev->arq.head];

                switch (msg_q[0]) {
                case HCLGE_MBX_LINK_STAT_CHANGE:
                        link_status = le16_to_cpu(msg_q[1]);
                        memcpy(&speed, &msg_q[2], sizeof(speed));
                        duplex = (u8)le16_to_cpu(msg_q[4]);

                        /* update upper layer with new link link status */
                        hclgevf_update_link_status(hdev, link_status);
                        hclgevf_update_speed_duplex(hdev, speed, duplex);

                        break;
                case HCLGE_MBX_ASSERTING_RESET:
                        /* PF has asserted reset hence VF should go in pending
                         * state and poll for the hardware reset status till it
                         * has been completely reset. After this stack should
                         * eventually be re-initialized.
                         */
                        hdev->nic.reset_level = HNAE3_VF_RESET;
                        set_bit(HCLGEVF_RESET_PENDING, &hdev->reset_state);
                        hclgevf_reset_task_schedule(hdev);

                        break;
                default:
                        dev_err(&hdev->pdev->dev,
                                "fetched unsupported(%d) message from arq\n",
                                msg_q[0]);
                        break;
                }

                hclge_mbx_head_ptr_move_arq(hdev->arq);
                hdev->arq.count--;
                msg_q = hdev->arq.msg_q[hdev->arq.head];
        }
}