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

#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/dma-direction.h>
#include "hclge_cmd.h"
#include "hnae3.h"
#include "hclge_main.h"

#define hclge_is_csq(ring) ((ring)->flag & HCLGE_TYPE_CSQ)

#define cmq_ring_to_dev(ring)   (&(ring)->dev->pdev->dev)

static int hclge_ring_space(struct hclge_cmq_ring *ring)
{
        int ntu = ring->next_to_use;
        int ntc = ring->next_to_clean;
        int used = (ntu - ntc + ring->desc_num) % ring->desc_num;

        return ring->desc_num - used - 1;
}

static int is_valid_csq_clean_head(struct hclge_cmq_ring *ring, int h)
{
        int u = ring->next_to_use;
        int c = ring->next_to_clean;

        if (unlikely(h >= ring->desc_num))
                return 0;

        return u > c ? (h > c && h <= u) : (h > c || h <= u);
}

static int hclge_alloc_cmd_desc(struct hclge_cmq_ring *ring)
{
        int size  = ring->desc_num * sizeof(struct hclge_desc);

        ring->desc = dma_zalloc_coherent(cmq_ring_to_dev(ring),
                                         size, &ring->desc_dma_addr,
                                         GFP_KERNEL);
        if (!ring->desc)
                return -ENOMEM;

        return 0;
}

static void hclge_free_cmd_desc(struct hclge_cmq_ring *ring)
{
        int size  = ring->desc_num * sizeof(struct hclge_desc);

        if (ring->desc) {
                dma_free_coherent(cmq_ring_to_dev(ring), size,
                                  ring->desc, ring->desc_dma_addr);
                ring->desc = NULL;
        }
}

static int hclge_alloc_cmd_queue(struct hclge_dev *hdev, int ring_type)
{
        struct hclge_hw *hw = &hdev->hw;
        struct hclge_cmq_ring *ring =
                (ring_type == HCLGE_TYPE_CSQ) ? &hw->cmq.csq : &hw->cmq.crq;
        int ret;

        ring->ring_type = ring_type;
        ring->dev = hdev;

        ret = hclge_alloc_cmd_desc(ring);
        if (ret) {
                dev_err(&hdev->pdev->dev, "descriptor %s alloc error %d\n",
                        (ring_type == HCLGE_TYPE_CSQ) ? "CSQ" : "CRQ", ret);
                return ret;
        }

        return 0;
}

void hclge_cmd_reuse_desc(struct hclge_desc *desc, bool is_read)
{
        desc->flag = cpu_to_le16(HCLGE_CMD_FLAG_NO_INTR | HCLGE_CMD_FLAG_IN);
        if (is_read)
                desc->flag |= cpu_to_le16(HCLGE_CMD_FLAG_WR);
        else
                desc->flag &= cpu_to_le16(~HCLGE_CMD_FLAG_WR);
}

void hclge_cmd_setup_basic_desc(struct hclge_desc *desc,
                                enum hclge_opcode_type opcode, bool is_read)
{
        memset((void *)desc, 0, sizeof(struct hclge_desc));
        desc->opcode = cpu_to_le16(opcode);
        desc->flag = cpu_to_le16(HCLGE_CMD_FLAG_NO_INTR | HCLGE_CMD_FLAG_IN);

        if (is_read)
                desc->flag |= cpu_to_le16(HCLGE_CMD_FLAG_WR);
}

static void hclge_cmd_config_regs(struct hclge_cmq_ring *ring)
{
        dma_addr_t dma = ring->desc_dma_addr;
        struct hclge_dev *hdev = ring->dev;
        struct hclge_hw *hw = &hdev->hw;

        if (ring->ring_type == HCLGE_TYPE_CSQ) {
                hclge_write_dev(hw, HCLGE_NIC_CSQ_BASEADDR_L_REG,
                                lower_32_bits(dma));
                hclge_write_dev(hw, HCLGE_NIC_CSQ_BASEADDR_H_REG,
                                upper_32_bits(dma));
                hclge_write_dev(hw, HCLGE_NIC_CSQ_DEPTH_REG,
                                (ring->desc_num >> HCLGE_NIC_CMQ_DESC_NUM_S) |
                                HCLGE_NIC_CMQ_ENABLE);
                hclge_write_dev(hw, HCLGE_NIC_CSQ_HEAD_REG, 0);
                hclge_write_dev(hw, HCLGE_NIC_CSQ_TAIL_REG, 0);
        } else {
                hclge_write_dev(hw, HCLGE_NIC_CRQ_BASEADDR_L_REG,
                                lower_32_bits(dma));
                hclge_write_dev(hw, HCLGE_NIC_CRQ_BASEADDR_H_REG,
                                upper_32_bits(dma));
                hclge_write_dev(hw, HCLGE_NIC_CRQ_DEPTH_REG,
                                (ring->desc_num >> HCLGE_NIC_CMQ_DESC_NUM_S) |
                                HCLGE_NIC_CMQ_ENABLE);
                hclge_write_dev(hw, HCLGE_NIC_CRQ_HEAD_REG, 0);
                hclge_write_dev(hw, HCLGE_NIC_CRQ_TAIL_REG, 0);
        }
}

static void hclge_cmd_init_regs(struct hclge_hw *hw)
{
        hclge_cmd_config_regs(&hw->cmq.csq);
        hclge_cmd_config_regs(&hw->cmq.crq);
}

static int hclge_cmd_csq_clean(struct hclge_hw *hw)
{
        struct hclge_dev *hdev = container_of(hw, struct hclge_dev, hw);
        struct hclge_cmq_ring *csq = &hw->cmq.csq;
        u32 head;
        int clean;

        head = hclge_read_dev(hw, HCLGE_NIC_CSQ_HEAD_REG);
        rmb(); /* Make sure head is ready before touch any data */

        if (!is_valid_csq_clean_head(csq, head)) {
                dev_warn(&hdev->pdev->dev, "wrong cmd head (%d, %d-%d)\n", head,
                         csq->next_to_use, csq->next_to_clean);
                dev_warn(&hdev->pdev->dev,
                         "Disabling any further commands to IMP firmware\n");
                set_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);
                dev_warn(&hdev->pdev->dev,
                         "IMP firmware watchdog reset soon expected!\n");
                return -EIO;
        }

        clean = (head - csq->next_to_clean + csq->desc_num) % csq->desc_num;
        csq->next_to_clean = head;
        return clean;
}

static int hclge_cmd_csq_done(struct hclge_hw *hw)
{
        u32 head = hclge_read_dev(hw, HCLGE_NIC_CSQ_HEAD_REG);
        return head == hw->cmq.csq.next_to_use;
}

static bool hclge_is_special_opcode(u16 opcode)
{
        /* these commands have several descriptors,
         * and use the first one to save opcode and return value
         */
        u16 spec_opcode[3] = {HCLGE_OPC_STATS_64_BIT,
                HCLGE_OPC_STATS_32_BIT, HCLGE_OPC_STATS_MAC};
        int i;

        for (i = 0; i < ARRAY_SIZE(spec_opcode); i++) {
                if (spec_opcode[i] == opcode)
                        return true;
        }

        return false;
}

/**
 * hclge_cmd_send - send command to command queue
 * @hw: pointer to the hw struct
 * @desc: prefilled descriptor for describing the command
 * @num : the number of descriptors to be sent
 *
 * This is the main send command for command queue, it
 * sends the queue, cleans the queue, etc
 **/
int hclge_cmd_send(struct hclge_hw *hw, struct hclge_desc *desc, int num)
{
        struct hclge_dev *hdev = container_of(hw, struct hclge_dev, hw);
        struct hclge_desc *desc_to_use;
        bool complete = false;
        u32 timeout = 0;
        int handle = 0;
        int retval = 0;
        u16 opcode, desc_ret;
        int ntc;

        spin_lock_bh(&hw->cmq.csq.lock);

        if (num > hclge_ring_space(&hw->cmq.csq) ||
            test_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state)) {
                spin_unlock_bh(&hw->cmq.csq.lock);
                return -EBUSY;
        }

        /**
         * Record the location of desc in the ring for this time
         * which will be use for hardware to write back
         */
        ntc = hw->cmq.csq.next_to_use;
        opcode = le16_to_cpu(desc[0].opcode);
        while (handle < num) {
                desc_to_use = &hw->cmq.csq.desc[hw->cmq.csq.next_to_use];
                *desc_to_use = desc[handle];
                (hw->cmq.csq.next_to_use)++;
                if (hw->cmq.csq.next_to_use == hw->cmq.csq.desc_num)
                        hw->cmq.csq.next_to_use = 0;
                handle++;
        }

        /* Write to hardware */
        hclge_write_dev(hw, HCLGE_NIC_CSQ_TAIL_REG, hw->cmq.csq.next_to_use);

        /**
         * If the command is sync, wait for the firmware to write back,
         * if multi descriptors to be sent, use the first one to check
         */
        if (HCLGE_SEND_SYNC(le16_to_cpu(desc->flag))) {
                do {
                        if (hclge_cmd_csq_done(hw)) {
                                complete = true;
                                break;
                        }
                        udelay(1);
                        timeout++;
                } while (timeout < hw->cmq.tx_timeout);
        }

        if (!complete) {
                retval = -EAGAIN;
        } else {
                handle = 0;
                while (handle < num) {
                        /* Get the result of hardware write back */
                        desc_to_use = &hw->cmq.csq.desc[ntc];
                        desc[handle] = *desc_to_use;

                        if (likely(!hclge_is_special_opcode(opcode)))
                                desc_ret = le16_to_cpu(desc[handle].retval);
                        else
                                desc_ret = le16_to_cpu(desc[0].retval);

                        if (desc_ret == HCLGE_CMD_EXEC_SUCCESS)
                                retval = 0;
                        else
                                retval = -EIO;
                        hw->cmq.last_status = desc_ret;
                        ntc++;
                        handle++;
                        if (ntc == hw->cmq.csq.desc_num)
                                ntc = 0;
                }
        }

        /* Clean the command send queue */
        handle = hclge_cmd_csq_clean(hw);
        if (handle < 0)
                retval = handle;
        else if (handle != num)
                dev_warn(&hdev->pdev->dev,
                         "cleaned %d, need to clean %d\n", handle, num);

        spin_unlock_bh(&hw->cmq.csq.lock);

        return retval;
}

static enum hclge_cmd_status hclge_cmd_query_firmware_version(
                struct hclge_hw *hw, u32 *version)
{
        struct hclge_query_version_cmd *resp;
        struct hclge_desc desc;
        int ret;

        hclge_cmd_setup_basic_desc(&desc, HCLGE_OPC_QUERY_FW_VER, 1);
        resp = (struct hclge_query_version_cmd *)desc.data;

        ret = hclge_cmd_send(hw, &desc, 1);
        if (!ret)
                *version = le32_to_cpu(resp->firmware);

        return ret;
}

int hclge_cmd_queue_init(struct hclge_dev *hdev)
{
        int ret;

        /* Setup the queue entries for use cmd queue */
        hdev->hw.cmq.csq.desc_num = HCLGE_NIC_CMQ_DESC_NUM;
        hdev->hw.cmq.crq.desc_num = HCLGE_NIC_CMQ_DESC_NUM;

        /* Setup Tx write back timeout */
        hdev->hw.cmq.tx_timeout = HCLGE_CMDQ_TX_TIMEOUT;

        /* Setup queue rings */
        ret = hclge_alloc_cmd_queue(hdev, HCLGE_TYPE_CSQ);
        if (ret) {
                dev_err(&hdev->pdev->dev,
                        "CSQ ring setup error %d\n", ret);
                return ret;
        }

        ret = hclge_alloc_cmd_queue(hdev, HCLGE_TYPE_CRQ);
        if (ret) {
                dev_err(&hdev->pdev->dev,
                        "CRQ ring setup error %d\n", ret);
                goto err_csq;
        }

        return 0;
err_csq:
        hclge_free_cmd_desc(&hdev->hw.cmq.csq);
        return ret;
}

int hclge_cmd_init(struct hclge_dev *hdev)
{
        u32 version;
        int ret;

        hdev->hw.cmq.csq.next_to_clean = 0;
        hdev->hw.cmq.csq.next_to_use = 0;
        hdev->hw.cmq.crq.next_to_clean = 0;
        hdev->hw.cmq.crq.next_to_use = 0;

        /* Setup the lock for command queue */
        spin_lock_init(&hdev->hw.cmq.csq.lock);
        spin_lock_init(&hdev->hw.cmq.crq.lock);

        hclge_cmd_init_regs(&hdev->hw);
        clear_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);

        ret = hclge_cmd_query_firmware_version(&hdev->hw, &version);
        if (ret) {
                dev_err(&hdev->pdev->dev,
                        "firmware version query failed %d\n", ret);
                return ret;
        }
        hdev->fw_version = version;

        dev_info(&hdev->pdev->dev, "The firmware version is %08x\n", version);

        return 0;
}

static void hclge_destroy_queue(struct hclge_cmq_ring *ring)
{
        spin_lock(&ring->lock);
        hclge_free_cmd_desc(ring);
        spin_unlock(&ring->lock);
}

void hclge_destroy_cmd_queue(struct hclge_hw *hw)
{
        hclge_destroy_queue(&hw->cmq.csq);
        hclge_destroy_queue(&hw->cmq.crq);
}