// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:      Sjur Brendeland
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/pkt_sched.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfctrl.h>

#define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
#define UTILITY_NAME_LENGTH 16
#define CFPKT_CTRL_PKT_LEN 20

#ifdef CAIF_NO_LOOP
static int handle_loop(struct cfctrl *ctrl,
                       int cmd, struct cfpkt *pkt){
        return -1;
}
#else
static int handle_loop(struct cfctrl *ctrl,
                       int cmd, struct cfpkt *pkt);
#endif
static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
                           int phyid);


struct cflayer *cfctrl_create(void)
{
        struct dev_info dev_info;
        struct cfctrl *this =
                kzalloc_obj(struct cfctrl, GFP_ATOMIC);
        if (!this)
                return NULL;
        caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
        memset(&dev_info, 0, sizeof(dev_info));
        dev_info.id = 0xff;
        cfsrvl_init(&this->serv, 0, &dev_info, false);
        atomic_set(&this->req_seq_no, 1);
        atomic_set(&this->rsp_seq_no, 1);
        this->serv.layer.receive = cfctrl_recv;
        sprintf(this->serv.layer.name, "ctrl");
        this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
#ifndef CAIF_NO_LOOP
        spin_lock_init(&this->loop_linkid_lock);
        this->loop_linkid = 1;
#endif
        spin_lock_init(&this->info_list_lock);
        INIT_LIST_HEAD(&this->list);
        return &this->serv.layer;
}

void cfctrl_remove(struct cflayer *layer)
{
        struct cfctrl_request_info *p, *tmp;
        struct cfctrl *ctrl = container_obj(layer);

        spin_lock_bh(&ctrl->info_list_lock);
        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
                list_del(&p->list);
                kfree(p);
        }
        spin_unlock_bh(&ctrl->info_list_lock);
        kfree(layer);
}

static bool param_eq(const struct cfctrl_link_param *p1,
                     const struct cfctrl_link_param *p2)
{
        bool eq =
            p1->linktype == p2->linktype &&
            p1->priority == p2->priority &&
            p1->phyid == p2->phyid &&
            p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;

        if (!eq)
                return false;

        switch (p1->linktype) {
        case CFCTRL_SRV_VEI:
                return true;
        case CFCTRL_SRV_DATAGRAM:
                return p1->u.datagram.connid == p2->u.datagram.connid;
        case CFCTRL_SRV_RFM:
                return
                    p1->u.rfm.connid == p2->u.rfm.connid &&
                    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
        case CFCTRL_SRV_UTIL:
                return
                    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
                    && p1->u.utility.fifosize_bufs ==
                    p2->u.utility.fifosize_bufs
                    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
                    && p1->u.utility.paramlen == p2->u.utility.paramlen
                    && memcmp(p1->u.utility.params, p2->u.utility.params,
                              p1->u.utility.paramlen) == 0;

        case CFCTRL_SRV_VIDEO:
                return p1->u.video.connid == p2->u.video.connid;
        case CFCTRL_SRV_DBG:
                return true;
        case CFCTRL_SRV_DECM:
                return false;
        default:
                return false;
        }
        return false;
}

static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
                          const struct cfctrl_request_info *r2)
{
        if (r1->cmd != r2->cmd)
                return false;
        if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
                return param_eq(&r1->param, &r2->param);
        else
                return r1->channel_id == r2->channel_id;
}

/* Insert request at the end */
static void cfctrl_insert_req(struct cfctrl *ctrl,
                              struct cfctrl_request_info *req)
{
        spin_lock_bh(&ctrl->info_list_lock);
        atomic_inc(&ctrl->req_seq_no);
        req->sequence_no = atomic_read(&ctrl->req_seq_no);
        list_add_tail(&req->list, &ctrl->list);
        spin_unlock_bh(&ctrl->info_list_lock);
}

/* Compare and remove request */
static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
                                                struct cfctrl_request_info *req)
{
        struct cfctrl_request_info *p, *tmp, *first;

        first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);

        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
                if (cfctrl_req_eq(req, p)) {
                        if (p != first)
                                pr_warn("Requests are not received in order\n");

                        atomic_set(&ctrl->rsp_seq_no,
                                         p->sequence_no);
                        list_del(&p->list);
                        goto out;
                }
        }
        p = NULL;
out:
        return p;
}

struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
{
        struct cfctrl *this = container_obj(layer);
        return &this->res;
}

static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
{
        info->hdr_len = 0;
        info->channel_id = cfctrl->serv.layer.id;
        info->dev_info = &cfctrl->serv.dev_info;
}

void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
{
        struct cfpkt *pkt;
        struct cfctrl *cfctrl = container_obj(layer);
        struct cflayer *dn = cfctrl->serv.layer.dn;

        if (!dn) {
                pr_debug("not able to send enum request\n");
                return;
        }
        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
        if (!pkt)
                return;
        caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
        init_info(cfpkt_info(pkt), cfctrl);
        cfpkt_info(pkt)->dev_info->id = physlinkid;
        cfctrl->serv.dev_info.id = physlinkid;
        cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
        cfpkt_addbdy(pkt, physlinkid);
        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
        dn->transmit(dn, pkt);
}

int cfctrl_linkup_request(struct cflayer *layer,
                          struct cfctrl_link_param *param,
                          struct cflayer *user_layer)
{
        struct cfctrl *cfctrl = container_obj(layer);
        struct cflayer *dn = cfctrl->serv.layer.dn;
        char utility_name[UTILITY_NAME_LENGTH];
        struct cfctrl_request_info *req;
        struct cfpkt *pkt;
        u32 tmp32;
        u16 tmp16;
        u8 tmp8;
        int ret;

        if (!dn) {
                pr_debug("not able to send linkup request\n");
                return -ENODEV;
        }

        if (cfctrl_cancel_req(layer, user_layer) > 0) {
                /* Slight Paranoia, check if already connecting */
                pr_err("Duplicate connect request for same client\n");
                WARN_ON(1);
                return -EALREADY;
        }

        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
        if (!pkt)
                return -ENOMEM;
        cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
        cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
        cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
        cfpkt_addbdy(pkt, param->endpoint & 0x03);

        switch (param->linktype) {
        case CFCTRL_SRV_VEI:
                break;
        case CFCTRL_SRV_VIDEO:
                cfpkt_addbdy(pkt, (u8) param->u.video.connid);
                break;
        case CFCTRL_SRV_DBG:
                break;
        case CFCTRL_SRV_DATAGRAM:
                tmp32 = cpu_to_le32(param->u.datagram.connid);
                cfpkt_add_body(pkt, &tmp32, 4);
                break;
        case CFCTRL_SRV_RFM:
                /* Construct a frame, convert DatagramConnectionID to network
                 * format long and copy it out...
                 */
                tmp32 = cpu_to_le32(param->u.rfm.connid);
                cfpkt_add_body(pkt, &tmp32, 4);
                /* Add volume name, including zero termination... */
                cfpkt_add_body(pkt, param->u.rfm.volume,
                               strlen(param->u.rfm.volume) + 1);
                break;
        case CFCTRL_SRV_UTIL:
                tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
                cfpkt_add_body(pkt, &tmp16, 2);
                tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
                cfpkt_add_body(pkt, &tmp16, 2);
                strscpy_pad(utility_name, param->u.utility.name);
                cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
                tmp8 = param->u.utility.paramlen;
                cfpkt_add_body(pkt, &tmp8, 1);
                cfpkt_add_body(pkt, param->u.utility.params,
                               param->u.utility.paramlen);
                break;
        default:
                pr_warn("Request setup of bad link type = %d\n",
                        param->linktype);
                cfpkt_destroy(pkt);
                return -EINVAL;
        }
        req = kzalloc_obj(*req);
        if (!req) {
                cfpkt_destroy(pkt);
                return -ENOMEM;
        }

        req->client_layer = user_layer;
        req->cmd = CFCTRL_CMD_LINK_SETUP;
        req->param = *param;
        cfctrl_insert_req(cfctrl, req);
        init_info(cfpkt_info(pkt), cfctrl);
        /*
         * NOTE:Always send linkup and linkdown request on the same
         *      device as the payload. Otherwise old queued up payload
         *      might arrive with the newly allocated channel ID.
         */
        cfpkt_info(pkt)->dev_info->id = param->phyid;
        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
        ret =
            dn->transmit(dn, pkt);
        if (ret < 0) {
                int count;

                count = cfctrl_cancel_req(&cfctrl->serv.layer,
                                                user_layer);
                if (count != 1) {
                        pr_err("Could not remove request (%d)", count);
                        return -ENODEV;
                }
        }
        return 0;
}

int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
                        struct cflayer *client)
{
        int ret;
        struct cfpkt *pkt;
        struct cfctrl *cfctrl = container_obj(layer);
        struct cflayer *dn = cfctrl->serv.layer.dn;

        if (!dn) {
                pr_debug("not able to send link-down request\n");
                return -ENODEV;
        }
        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
        if (!pkt)
                return -ENOMEM;
        cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
        cfpkt_addbdy(pkt, channelid);
        init_info(cfpkt_info(pkt), cfctrl);
        cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
        ret =
            dn->transmit(dn, pkt);
#ifndef CAIF_NO_LOOP
        cfctrl->loop_linkused[channelid] = 0;
#endif
        return ret;
}

int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
{
        struct cfctrl_request_info *p, *tmp;
        struct cfctrl *ctrl = container_obj(layr);
        int found = 0;
        spin_lock_bh(&ctrl->info_list_lock);

        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
                if (p->client_layer == adap_layer) {
                        list_del(&p->list);
                        kfree(p);
                        found++;
                }
        }

        spin_unlock_bh(&ctrl->info_list_lock);
        return found;
}

static int cfctrl_link_setup(struct cfctrl *cfctrl, struct cfpkt *pkt, u8 cmdrsp)
{
        u8 len;
        u8 linkid = 0;
        enum cfctrl_srv serv;
        enum cfctrl_srv servtype;
        u8 endpoint;
        u8 physlinkid;
        u8 prio;
        u8 tmp;
        u8 *cp;
        int i;
        struct cfctrl_link_param linkparam;
        struct cfctrl_request_info rsp, *req;

        memset(&linkparam, 0, sizeof(linkparam));

        tmp = cfpkt_extr_head_u8(pkt);

        serv = tmp & CFCTRL_SRV_MASK;
        linkparam.linktype = serv;

        servtype = tmp >> 4;
        linkparam.chtype = servtype;

        tmp = cfpkt_extr_head_u8(pkt);
        physlinkid = tmp & 0x07;
        prio = tmp >> 3;

        linkparam.priority = prio;
        linkparam.phyid = physlinkid;
        endpoint = cfpkt_extr_head_u8(pkt);
        linkparam.endpoint = endpoint & 0x03;

        switch (serv) {
        case CFCTRL_SRV_VEI:
        case CFCTRL_SRV_DBG:
                if (CFCTRL_ERR_BIT & cmdrsp)
                        break;
                /* Link ID */
                linkid = cfpkt_extr_head_u8(pkt);
                break;
        case CFCTRL_SRV_VIDEO:
                tmp = cfpkt_extr_head_u8(pkt);
                linkparam.u.video.connid = tmp;
                if (CFCTRL_ERR_BIT & cmdrsp)
                        break;
                /* Link ID */
                linkid = cfpkt_extr_head_u8(pkt);
                break;

        case CFCTRL_SRV_DATAGRAM:
                linkparam.u.datagram.connid = cfpkt_extr_head_u32(pkt);
                if (CFCTRL_ERR_BIT & cmdrsp)
                        break;
                /* Link ID */
                linkid = cfpkt_extr_head_u8(pkt);
                break;
        case CFCTRL_SRV_RFM:
                /* Construct a frame, convert
                 * DatagramConnectionID
                 * to network format long and copy it out...
                 */
                linkparam.u.rfm.connid = cfpkt_extr_head_u32(pkt);
                cp = (u8 *) linkparam.u.rfm.volume;
                for (tmp = cfpkt_extr_head_u8(pkt);
                     cfpkt_more(pkt) && tmp != '\0';
                     tmp = cfpkt_extr_head_u8(pkt))
                        *cp++ = tmp;
                *cp = '\0';

                if (CFCTRL_ERR_BIT & cmdrsp)
                        break;
                /* Link ID */
                linkid = cfpkt_extr_head_u8(pkt);

                break;
        case CFCTRL_SRV_UTIL:
                /* Construct a frame, convert
                 * DatagramConnectionID
                 * to network format long and copy it out...
                 */
                /* Fifosize KB */
                linkparam.u.utility.fifosize_kb = cfpkt_extr_head_u16(pkt);
                /* Fifosize bufs */
                linkparam.u.utility.fifosize_bufs = cfpkt_extr_head_u16(pkt);
                /* name */
                cp = (u8 *) linkparam.u.utility.name;
                caif_assert(sizeof(linkparam.u.utility.name)
                             >= UTILITY_NAME_LENGTH);
                for (i = 0; i < UTILITY_NAME_LENGTH && cfpkt_more(pkt); i++) {
                        tmp = cfpkt_extr_head_u8(pkt);
                        *cp++ = tmp;
                }
                /* Length */
                len = cfpkt_extr_head_u8(pkt);
                linkparam.u.utility.paramlen = len;
                /* Param Data */
                cp = linkparam.u.utility.params;
                while (cfpkt_more(pkt) && len--) {
                        tmp = cfpkt_extr_head_u8(pkt);
                        *cp++ = tmp;
                }
                if (CFCTRL_ERR_BIT & cmdrsp)
                        break;
                /* Link ID */
                linkid = cfpkt_extr_head_u8(pkt);
                /* Length */
                len = cfpkt_extr_head_u8(pkt);
                /* Param Data */
                cfpkt_extr_head(pkt, NULL, len);
                break;
        default:
                pr_warn("Request setup, invalid type (%d)\n", serv);
                return -1;
        }

        rsp.cmd = CFCTRL_CMD_LINK_SETUP;
        rsp.param = linkparam;
        spin_lock_bh(&cfctrl->info_list_lock);
        req = cfctrl_remove_req(cfctrl, &rsp);

        if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
                cfpkt_erroneous(pkt)) {
                pr_err("Invalid O/E bit or parse error "
                                "on CAIF control channel\n");
                cfctrl->res.reject_rsp(cfctrl->serv.layer.up, 0,
                                       req ? req->client_layer : NULL);
        } else {
                cfctrl->res.linksetup_rsp(cfctrl->serv.layer.up, linkid,
                                          serv, physlinkid,
                                          req ?  req->client_layer : NULL);
        }

        kfree(req);

        spin_unlock_bh(&cfctrl->info_list_lock);

        return 0;
}

static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
{
        u8 cmdrsp;
        u8 cmd;
        int ret = 0;
        u8 linkid = 0;
        struct cfctrl *cfctrl = container_obj(layer);

        cmdrsp = cfpkt_extr_head_u8(pkt);
        cmd = cmdrsp & CFCTRL_CMD_MASK;
        if (cmd != CFCTRL_CMD_LINK_ERR
            && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
                && CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
                if (handle_loop(cfctrl, cmd, pkt) != 0)
                        cmdrsp |= CFCTRL_ERR_BIT;
        }

        switch (cmd) {
        case CFCTRL_CMD_LINK_SETUP:
                ret = cfctrl_link_setup(cfctrl, pkt, cmdrsp);
                break;
        case CFCTRL_CMD_LINK_DESTROY:
                linkid = cfpkt_extr_head_u8(pkt);
                cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
                break;
        case CFCTRL_CMD_LINK_ERR:
                pr_err("Frame Error Indication received\n");
                cfctrl->res.linkerror_ind();
                break;
        case CFCTRL_CMD_ENUM:
                cfctrl->res.enum_rsp();
                break;
        case CFCTRL_CMD_SLEEP:
                cfctrl->res.sleep_rsp();
                break;
        case CFCTRL_CMD_WAKE:
                cfctrl->res.wake_rsp();
                break;
        case CFCTRL_CMD_LINK_RECONF:
                cfctrl->res.restart_rsp();
                break;
        case CFCTRL_CMD_RADIO_SET:
                cfctrl->res.radioset_rsp();
                break;
        default:
                pr_err("Unrecognized Control Frame\n");
                ret = -1;
                goto error;
        }
error:
        cfpkt_destroy(pkt);
        return ret;
}

static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
                           int phyid)
{
        struct cfctrl *this = container_obj(layr);
        switch (ctrl) {
        case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
        case CAIF_CTRLCMD_FLOW_OFF_IND:
                spin_lock_bh(&this->info_list_lock);
                if (!list_empty(&this->list))
                        pr_debug("Received flow off in control layer\n");
                spin_unlock_bh(&this->info_list_lock);
                break;
        case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
                struct cfctrl_request_info *p, *tmp;

                /* Find all connect request and report failure */
                spin_lock_bh(&this->info_list_lock);
                list_for_each_entry_safe(p, tmp, &this->list, list) {
                        if (p->param.phyid == phyid) {
                                list_del(&p->list);
                                p->client_layer->ctrlcmd(p->client_layer,
                                                CAIF_CTRLCMD_INIT_FAIL_RSP,
                                                phyid);
                                kfree(p);
                        }
                }
                spin_unlock_bh(&this->info_list_lock);
                break;
        }
        default:
                break;
        }
}

#ifndef CAIF_NO_LOOP
static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
{
        static int last_linkid;
        static int dec;
        u8 linkid, linktype, tmp;
        switch (cmd) {
        case CFCTRL_CMD_LINK_SETUP:
                spin_lock_bh(&ctrl->loop_linkid_lock);
                if (!dec) {
                        for (linkid = last_linkid + 1; linkid < 254; linkid++)
                                if (!ctrl->loop_linkused[linkid])
                                        goto found;
                }
                dec = 1;
                for (linkid = last_linkid - 1; linkid > 1; linkid--)
                        if (!ctrl->loop_linkused[linkid])
                                goto found;
                spin_unlock_bh(&ctrl->loop_linkid_lock);
                return -1;
found:
                if (linkid < 10)
                        dec = 0;

                if (!ctrl->loop_linkused[linkid])
                        ctrl->loop_linkused[linkid] = 1;

                last_linkid = linkid;

                cfpkt_add_trail(pkt, &linkid, 1);
                spin_unlock_bh(&ctrl->loop_linkid_lock);
                cfpkt_peek_head(pkt, &linktype, 1);
                if (linktype ==  CFCTRL_SRV_UTIL) {
                        tmp = 0x01;
                        cfpkt_add_trail(pkt, &tmp, 1);
                        cfpkt_add_trail(pkt, &tmp, 1);
                }
                break;

        case CFCTRL_CMD_LINK_DESTROY:
                spin_lock_bh(&ctrl->loop_linkid_lock);
                cfpkt_peek_head(pkt, &linkid, 1);
                ctrl->loop_linkused[linkid] = 0;
                spin_unlock_bh(&ctrl->loop_linkid_lock);
                break;
        default:
                break;
        }
        return 0;
}
#endif