// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * NETC NTMP (NETC Table Management Protocol) 2.0 Library
 * Copyright 2025 NXP
 */

#include <linux/dma-mapping.h>
#include <linux/fsl/netc_global.h>
#include <linux/iopoll.h>

#include "ntmp_private.h"

#define NETC_CBDR_TIMEOUT               1000 /* us */
#define NETC_CBDR_DELAY_US              10
#define NETC_CBDR_MR_EN                 BIT(31)

#define NTMP_BASE_ADDR_ALIGN            128
#define NTMP_DATA_ADDR_ALIGN            32

/* Define NTMP Table ID */
#define NTMP_MAFT_ID                    1
#define NTMP_RSST_ID                    3

/* Generic Update Actions for most tables */
#define NTMP_GEN_UA_CFGEU               BIT(0)
#define NTMP_GEN_UA_STSEU               BIT(1)

#define NTMP_ENTRY_ID_SIZE              4
#define RSST_ENTRY_NUM                  64
#define RSST_STSE_DATA_SIZE(n)          ((n) * 8)
#define RSST_CFGE_DATA_SIZE(n)          (n)

int ntmp_init_cbdr(struct netc_cbdr *cbdr, struct device *dev,
                   const struct netc_cbdr_regs *regs)
{
        int cbd_num = NETC_CBDR_BD_NUM;
        size_t size;

        size = cbd_num * sizeof(union netc_cbd) + NTMP_BASE_ADDR_ALIGN;
        cbdr->addr_base = dma_alloc_coherent(dev, size, &cbdr->dma_base,
                                             GFP_KERNEL);
        if (!cbdr->addr_base)
                return -ENOMEM;

        cbdr->dma_size = size;
        cbdr->bd_num = cbd_num;
        cbdr->regs = *regs;
        cbdr->dev = dev;

        /* The base address of the Control BD Ring must be 128 bytes aligned */
        cbdr->dma_base_align =  ALIGN(cbdr->dma_base,  NTMP_BASE_ADDR_ALIGN);
        cbdr->addr_base_align = PTR_ALIGN(cbdr->addr_base,
                                          NTMP_BASE_ADDR_ALIGN);

        spin_lock_init(&cbdr->ring_lock);

        cbdr->next_to_use = netc_read(cbdr->regs.pir);
        cbdr->next_to_clean = netc_read(cbdr->regs.cir);

        /* Step 1: Configure the base address of the Control BD Ring */
        netc_write(cbdr->regs.bar0, lower_32_bits(cbdr->dma_base_align));
        netc_write(cbdr->regs.bar1, upper_32_bits(cbdr->dma_base_align));

        /* Step 2: Configure the number of BDs of the Control BD Ring */
        netc_write(cbdr->regs.lenr, cbdr->bd_num);

        /* Step 3: Enable the Control BD Ring */
        netc_write(cbdr->regs.mr, NETC_CBDR_MR_EN);

        return 0;
}
EXPORT_SYMBOL_GPL(ntmp_init_cbdr);

void ntmp_free_cbdr(struct netc_cbdr *cbdr)
{
        /* Disable the Control BD Ring */
        netc_write(cbdr->regs.mr, 0);
        dma_free_coherent(cbdr->dev, cbdr->dma_size, cbdr->addr_base,
                          cbdr->dma_base);
        memset(cbdr, 0, sizeof(*cbdr));
}
EXPORT_SYMBOL_GPL(ntmp_free_cbdr);

static int ntmp_get_free_cbd_num(struct netc_cbdr *cbdr)
{
        return (cbdr->next_to_clean - cbdr->next_to_use - 1 +
                cbdr->bd_num) % cbdr->bd_num;
}

static union netc_cbd *ntmp_get_cbd(struct netc_cbdr *cbdr, int index)
{
        return &((union netc_cbd *)(cbdr->addr_base_align))[index];
}

static void ntmp_clean_cbdr(struct netc_cbdr *cbdr)
{
        union netc_cbd *cbd;
        int i;

        i = cbdr->next_to_clean;
        while (netc_read(cbdr->regs.cir) != i) {
                cbd = ntmp_get_cbd(cbdr, i);
                memset(cbd, 0, sizeof(*cbd));
                i = (i + 1) % cbdr->bd_num;
        }

        cbdr->next_to_clean = i;
}

static int netc_xmit_ntmp_cmd(struct ntmp_user *user, union netc_cbd *cbd)
{
        union netc_cbd *cur_cbd;
        struct netc_cbdr *cbdr;
        int i, err;
        u16 status;
        u32 val;

        /* Currently only i.MX95 ENETC is supported, and it only has one
         * command BD ring
         */
        cbdr = &user->ring[0];

        spin_lock_bh(&cbdr->ring_lock);

        if (unlikely(!ntmp_get_free_cbd_num(cbdr)))
                ntmp_clean_cbdr(cbdr);

        i = cbdr->next_to_use;
        cur_cbd = ntmp_get_cbd(cbdr, i);
        *cur_cbd = *cbd;
        dma_wmb();

        /* Update producer index of both software and hardware */
        i = (i + 1) % cbdr->bd_num;
        cbdr->next_to_use = i;
        netc_write(cbdr->regs.pir, i);

        err = read_poll_timeout_atomic(netc_read, val, val == i,
                                       NETC_CBDR_DELAY_US, NETC_CBDR_TIMEOUT,
                                       true, cbdr->regs.cir);
        if (unlikely(err))
                goto cbdr_unlock;

        dma_rmb();
        /* Get the writeback command BD, because the caller may need
         * to check some other fields of the response header.
         */
        *cbd = *cur_cbd;

        /* Check the writeback error status */
        status = le16_to_cpu(cbd->resp_hdr.error_rr) & NTMP_RESP_ERROR;
        if (unlikely(status)) {
                err = -EIO;
                dev_err(user->dev, "Command BD error: 0x%04x\n", status);
        }

        ntmp_clean_cbdr(cbdr);
        dma_wmb();

cbdr_unlock:
        spin_unlock_bh(&cbdr->ring_lock);

        return err;
}

static int ntmp_alloc_data_mem(struct ntmp_dma_buf *data, void **buf_align)
{
        void *buf;

        buf = dma_alloc_coherent(data->dev, data->size + NTMP_DATA_ADDR_ALIGN,
                                 &data->dma, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        data->buf = buf;
        *buf_align = PTR_ALIGN(buf, NTMP_DATA_ADDR_ALIGN);

        return 0;
}

static void ntmp_free_data_mem(struct ntmp_dma_buf *data)
{
        dma_free_coherent(data->dev, data->size + NTMP_DATA_ADDR_ALIGN,
                          data->buf, data->dma);
}

static void ntmp_fill_request_hdr(union netc_cbd *cbd, dma_addr_t dma,
                                  int len, int table_id, int cmd,
                                  int access_method)
{
        dma_addr_t dma_align;

        memset(cbd, 0, sizeof(*cbd));
        dma_align = ALIGN(dma, NTMP_DATA_ADDR_ALIGN);
        cbd->req_hdr.addr = cpu_to_le64(dma_align);
        cbd->req_hdr.len = cpu_to_le32(len);
        cbd->req_hdr.cmd = cmd;
        cbd->req_hdr.access_method = FIELD_PREP(NTMP_ACCESS_METHOD,
                                                access_method);
        cbd->req_hdr.table_id = table_id;
        cbd->req_hdr.ver_cci_rr = FIELD_PREP(NTMP_HDR_VERSION,
                                             NTMP_HDR_VER2);
        /* For NTMP version 2.0 or later version */
        cbd->req_hdr.npf = cpu_to_le32(NTMP_NPF);
}

static void ntmp_fill_crd(struct ntmp_cmn_req_data *crd, u8 tblv,
                          u8 qa, u16 ua)
{
        crd->update_act = cpu_to_le16(ua);
        crd->tblv_qact = NTMP_TBLV_QACT(tblv, qa);
}

static void ntmp_fill_crd_eid(struct ntmp_req_by_eid *rbe, u8 tblv,
                              u8 qa, u16 ua, u32 entry_id)
{
        ntmp_fill_crd(&rbe->crd, tblv, qa, ua);
        rbe->entry_id = cpu_to_le32(entry_id);
}

static const char *ntmp_table_name(int tbl_id)
{
        switch (tbl_id) {
        case NTMP_MAFT_ID:
                return "MAC Address Filter Table";
        case NTMP_RSST_ID:
                return "RSS Table";
        default:
                return "Unknown Table";
        };
}

static int ntmp_delete_entry_by_id(struct ntmp_user *user, int tbl_id,
                                   u8 tbl_ver, u32 entry_id, u32 req_len,
                                   u32 resp_len)
{
        struct ntmp_dma_buf data = {
                .dev = user->dev,
                .size = max(req_len, resp_len),
        };
        struct ntmp_req_by_eid *req;
        union netc_cbd cbd;
        int err;

        err = ntmp_alloc_data_mem(&data, (void **)&req);
        if (err)
                return err;

        ntmp_fill_crd_eid(req, tbl_ver, 0, 0, entry_id);
        ntmp_fill_request_hdr(&cbd, data.dma, NTMP_LEN(req_len, resp_len),
                              tbl_id, NTMP_CMD_DELETE, NTMP_AM_ENTRY_ID);

        err = netc_xmit_ntmp_cmd(user, &cbd);
        if (err)
                dev_err(user->dev,
                        "Failed to delete entry 0x%x of %s, err: %pe",
                        entry_id, ntmp_table_name(tbl_id), ERR_PTR(err));

        ntmp_free_data_mem(&data);

        return err;
}

static int ntmp_query_entry_by_id(struct ntmp_user *user, int tbl_id,
                                  u32 len, struct ntmp_req_by_eid *req,
                                  dma_addr_t dma, bool compare_eid)
{
        struct ntmp_cmn_resp_query *resp;
        int cmd = NTMP_CMD_QUERY;
        union netc_cbd cbd;
        u32 entry_id;
        int err;

        entry_id = le32_to_cpu(req->entry_id);
        if (le16_to_cpu(req->crd.update_act))
                cmd = NTMP_CMD_QU;

        /* Request header */
        ntmp_fill_request_hdr(&cbd, dma, len, tbl_id, cmd, NTMP_AM_ENTRY_ID);
        err = netc_xmit_ntmp_cmd(user, &cbd);
        if (err) {
                dev_err(user->dev,
                        "Failed to query entry 0x%x of %s, err: %pe\n",
                        entry_id, ntmp_table_name(tbl_id), ERR_PTR(err));
                return err;
        }

        /* For a few tables, the first field of their response data is not
         * entry_id, so directly return success.
         */
        if (!compare_eid)
                return 0;

        resp = (struct ntmp_cmn_resp_query *)req;
        if (unlikely(le32_to_cpu(resp->entry_id) != entry_id)) {
                dev_err(user->dev,
                        "%s: query EID 0x%x doesn't match response EID 0x%x\n",
                        ntmp_table_name(tbl_id), entry_id, le32_to_cpu(resp->entry_id));
                return -EIO;
        }

        return 0;
}

int ntmp_maft_add_entry(struct ntmp_user *user, u32 entry_id,
                        struct maft_entry_data *maft)
{
        struct ntmp_dma_buf data = {
                .dev = user->dev,
                .size = sizeof(struct maft_req_add),
        };
        struct maft_req_add *req;
        union netc_cbd cbd;
        int err;

        err = ntmp_alloc_data_mem(&data, (void **)&req);
        if (err)
                return err;

        /* Set mac address filter table request data buffer */
        ntmp_fill_crd_eid(&req->rbe, user->tbl.maft_ver, 0, 0, entry_id);
        req->keye = maft->keye;
        req->cfge = maft->cfge;

        ntmp_fill_request_hdr(&cbd, data.dma, NTMP_LEN(data.size, 0),
                              NTMP_MAFT_ID, NTMP_CMD_ADD, NTMP_AM_ENTRY_ID);
        err = netc_xmit_ntmp_cmd(user, &cbd);
        if (err)
                dev_err(user->dev, "Failed to add MAFT entry 0x%x, err: %pe\n",
                        entry_id, ERR_PTR(err));

        ntmp_free_data_mem(&data);

        return err;
}
EXPORT_SYMBOL_GPL(ntmp_maft_add_entry);

int ntmp_maft_query_entry(struct ntmp_user *user, u32 entry_id,
                          struct maft_entry_data *maft)
{
        struct ntmp_dma_buf data = {
                .dev = user->dev,
                .size = sizeof(struct maft_resp_query),
        };
        struct maft_resp_query *resp;
        struct ntmp_req_by_eid *req;
        int err;

        err = ntmp_alloc_data_mem(&data, (void **)&req);
        if (err)
                return err;

        ntmp_fill_crd_eid(req, user->tbl.maft_ver, 0, 0, entry_id);
        err = ntmp_query_entry_by_id(user, NTMP_MAFT_ID,
                                     NTMP_LEN(sizeof(*req), data.size),
                                     req, data.dma, true);
        if (err)
                goto end;

        resp = (struct maft_resp_query *)req;
        maft->keye = resp->keye;
        maft->cfge = resp->cfge;

end:
        ntmp_free_data_mem(&data);

        return err;
}
EXPORT_SYMBOL_GPL(ntmp_maft_query_entry);

int ntmp_maft_delete_entry(struct ntmp_user *user, u32 entry_id)
{
        return ntmp_delete_entry_by_id(user, NTMP_MAFT_ID, user->tbl.maft_ver,
                                       entry_id, NTMP_EID_REQ_LEN, 0);
}
EXPORT_SYMBOL_GPL(ntmp_maft_delete_entry);

int ntmp_rsst_update_entry(struct ntmp_user *user, const u32 *table,
                           int count)
{
        struct ntmp_dma_buf data = {.dev = user->dev};
        struct rsst_req_update *req;
        union netc_cbd cbd;
        int err, i;

        if (count != RSST_ENTRY_NUM)
                /* HW only takes in a full 64 entry table */
                return -EINVAL;

        data.size = struct_size(req, groups, count);
        err = ntmp_alloc_data_mem(&data, (void **)&req);
        if (err)
                return err;

        /* Set the request data buffer */
        ntmp_fill_crd_eid(&req->rbe, user->tbl.rsst_ver, 0,
                          NTMP_GEN_UA_CFGEU | NTMP_GEN_UA_STSEU, 0);
        for (i = 0; i < count; i++)
                req->groups[i] = (u8)(table[i]);

        ntmp_fill_request_hdr(&cbd, data.dma, NTMP_LEN(data.size, 0),
                              NTMP_RSST_ID, NTMP_CMD_UPDATE, NTMP_AM_ENTRY_ID);

        err = netc_xmit_ntmp_cmd(user, &cbd);
        if (err)
                dev_err(user->dev, "Failed to update RSST entry, err: %pe\n",
                        ERR_PTR(err));

        ntmp_free_data_mem(&data);

        return err;
}
EXPORT_SYMBOL_GPL(ntmp_rsst_update_entry);

int ntmp_rsst_query_entry(struct ntmp_user *user, u32 *table, int count)
{
        struct ntmp_dma_buf data = {.dev = user->dev};
        struct ntmp_req_by_eid *req;
        union netc_cbd cbd;
        int err, i;
        u8 *group;

        if (count != RSST_ENTRY_NUM)
                /* HW only takes in a full 64 entry table */
                return -EINVAL;

        data.size = NTMP_ENTRY_ID_SIZE + RSST_STSE_DATA_SIZE(count) +
                    RSST_CFGE_DATA_SIZE(count);
        err = ntmp_alloc_data_mem(&data, (void **)&req);
        if (err)
                return err;

        /* Set the request data buffer */
        ntmp_fill_crd_eid(req, user->tbl.rsst_ver, 0, 0, 0);
        ntmp_fill_request_hdr(&cbd, data.dma, NTMP_LEN(sizeof(*req), data.size),
                              NTMP_RSST_ID, NTMP_CMD_QUERY, NTMP_AM_ENTRY_ID);
        err = netc_xmit_ntmp_cmd(user, &cbd);
        if (err) {
                dev_err(user->dev, "Failed to query RSST entry, err: %pe\n",
                        ERR_PTR(err));
                goto end;
        }

        group = (u8 *)req;
        group += NTMP_ENTRY_ID_SIZE + RSST_STSE_DATA_SIZE(count);
        for (i = 0; i < count; i++)
                table[i] = group[i];

end:
        ntmp_free_data_mem(&data);

        return err;
}
EXPORT_SYMBOL_GPL(ntmp_rsst_query_entry);

MODULE_DESCRIPTION("NXP NETC Library");
MODULE_LICENSE("Dual BSD/GPL");