cfctrl.c

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/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:  Sjur Brendeland/[email protected]
 * License terms: GNU General Public License (GPL) version 2
 */

#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(sizeof(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);
    u32 tmp32;
    u16 tmp16;
    u8 tmp8;
    struct cfctrl_request_info *req;
    int ret;
    char utility_name[16];
    struct cfpkt *pkt;
    struct cflayer *dn = cfctrl->serv.layer.dn;

    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);
        memset(utility_name, 0, sizeof(utility_name));
        strncpy(utility_name, param->u.utility.name,
            UTILITY_NAME_LENGTH - 1);
        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);
        return -EINVAL;
    }
    req = kzalloc(sizeof(*req), GFP_KERNEL);
    if (!req)
        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_recv(struct cflayer *layer, struct cfpkt *pkt)
{
    u8 cmdrsp;
    u8 cmd;
    int ret = -1;
    u16 tmp16;
    u8 len;
    u8 param[255];
    u8 linkid;
    struct cfctrl *cfctrl = container_obj(layer);
    struct cfctrl_request_info rsp, *req;


    cfpkt_extr_head(pkt, &cmdrsp, 1);
    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:
        {
            enum cfctrl_srv serv;
            enum cfctrl_srv servtype;
            u8 endpoint;
            u8 physlinkid;
            u8 prio;
            u8 tmp;
            u32 tmp32;
            u8 *cp;
            int i;
            struct cfctrl_link_param linkparam;
            memset(&linkparam, 0, sizeof(linkparam));

            cfpkt_extr_head(pkt, &tmp, 1);

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

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

            cfpkt_extr_head(pkt, &tmp, 1);
            physlinkid = tmp & 0x07;
            prio = tmp >> 3;

            linkparam.priority = prio;
            linkparam.phyid = physlinkid;
            cfpkt_extr_head(pkt, &endpoint, 1);
            linkparam.endpoint = endpoint & 0x03;

            switch (serv) {
            case CFCTRL_SRV_VEI:
            case CFCTRL_SRV_DBG:
                if (CFCTRL_ERR_BIT & cmdrsp)
                    break;
                /* Link ID */
                cfpkt_extr_head(pkt, &linkid, 1);
                break;
            case CFCTRL_SRV_VIDEO:
                cfpkt_extr_head(pkt, &tmp, 1);
                linkparam.u.video.connid = tmp;
                if (CFCTRL_ERR_BIT & cmdrsp)
                    break;
                /* Link ID */
                cfpkt_extr_head(pkt, &linkid, 1);
                break;

            case CFCTRL_SRV_DATAGRAM:
                cfpkt_extr_head(pkt, &tmp32, 4);
                linkparam.u.datagram.connid =
                    le32_to_cpu(tmp32);
                if (CFCTRL_ERR_BIT & cmdrsp)
                    break;
                /* Link ID */
                cfpkt_extr_head(pkt, &linkid, 1);
                break;
            case CFCTRL_SRV_RFM:
                /* Construct a frame, convert
                 * DatagramConnectionID
                 * to network format long and copy it out...
                 */
                cfpkt_extr_head(pkt, &tmp32, 4);
                linkparam.u.rfm.connid =
                  le32_to_cpu(tmp32);
                cp = (u8 *) linkparam.u.rfm.volume;
                for (cfpkt_extr_head(pkt, &tmp, 1);
                     cfpkt_more(pkt) && tmp != '\0';
                     cfpkt_extr_head(pkt, &tmp, 1))
                    *cp++ = tmp;
                *cp = '\0';

                if (CFCTRL_ERR_BIT & cmdrsp)
                    break;
                /* Link ID */
                cfpkt_extr_head(pkt, &linkid, 1);

                break;
            case CFCTRL_SRV_UTIL:
                /* Construct a frame, convert
                 * DatagramConnectionID
                 * to network format long and copy it out...
                 */
                /* Fifosize KB */
                cfpkt_extr_head(pkt, &tmp16, 2);
                linkparam.u.utility.fifosize_kb =
                    le16_to_cpu(tmp16);
                /* Fifosize bufs */
                cfpkt_extr_head(pkt, &tmp16, 2);
                linkparam.u.utility.fifosize_bufs =
                    le16_to_cpu(tmp16);
                /* 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++) {
                    cfpkt_extr_head(pkt, &tmp, 1);
                    *cp++ = tmp;
                }
                /* Length */
                cfpkt_extr_head(pkt, &len, 1);
                linkparam.u.utility.paramlen = len;
                /* Param Data */
                cp = linkparam.u.utility.params;
                while (cfpkt_more(pkt) && len--) {
                    cfpkt_extr_head(pkt, &tmp, 1);
                    *cp++ = tmp;
                }
                if (CFCTRL_ERR_BIT & cmdrsp)
                    break;
                /* Link ID */
                cfpkt_extr_head(pkt, &linkid, 1);
                /* Length */
                cfpkt_extr_head(pkt, &len, 1);
                /* Param Data */
                cfpkt_extr_head(pkt, &param, len);
                break;
            default:
                pr_warn("Request setup, invalid type (%d)\n",
                    serv);
                goto error;
            }

            rsp.cmd = cmd;
            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);
            }

            if (req != NULL)
                kfree(req);

            spin_unlock_bh(&cfctrl->info_list_lock);
        }
        break;
    case CFCTRL_CMD_LINK_DESTROY:
        cfpkt_extr_head(pkt, &linkid, 1);
        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");
        goto error;
        break;
    }
    ret = 0;
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