cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cfctrl.c (16051B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright (C) ST-Ericsson AB 2010
      4 * Author:	Sjur Brendeland
      5 */
      6
      7#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
      8
      9#include <linux/stddef.h>
     10#include <linux/spinlock.h>
     11#include <linux/slab.h>
     12#include <linux/pkt_sched.h>
     13#include <net/caif/caif_layer.h>
     14#include <net/caif/cfpkt.h>
     15#include <net/caif/cfctrl.h>
     16
     17#define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
     18#define UTILITY_NAME_LENGTH 16
     19#define CFPKT_CTRL_PKT_LEN 20
     20
     21#ifdef CAIF_NO_LOOP
     22static int handle_loop(struct cfctrl *ctrl,
     23		       int cmd, struct cfpkt *pkt){
     24	return -1;
     25}
     26#else
     27static int handle_loop(struct cfctrl *ctrl,
     28		       int cmd, struct cfpkt *pkt);
     29#endif
     30static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
     31static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
     32			   int phyid);
     33
     34
     35struct cflayer *cfctrl_create(void)
     36{
     37	struct dev_info dev_info;
     38	struct cfctrl *this =
     39		kzalloc(sizeof(struct cfctrl), GFP_ATOMIC);
     40	if (!this)
     41		return NULL;
     42	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
     43	memset(&dev_info, 0, sizeof(dev_info));
     44	dev_info.id = 0xff;
     45	cfsrvl_init(&this->serv, 0, &dev_info, false);
     46	atomic_set(&this->req_seq_no, 1);
     47	atomic_set(&this->rsp_seq_no, 1);
     48	this->serv.layer.receive = cfctrl_recv;
     49	sprintf(this->serv.layer.name, "ctrl");
     50	this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
     51#ifndef CAIF_NO_LOOP
     52	spin_lock_init(&this->loop_linkid_lock);
     53	this->loop_linkid = 1;
     54#endif
     55	spin_lock_init(&this->info_list_lock);
     56	INIT_LIST_HEAD(&this->list);
     57	return &this->serv.layer;
     58}
     59
     60void cfctrl_remove(struct cflayer *layer)
     61{
     62	struct cfctrl_request_info *p, *tmp;
     63	struct cfctrl *ctrl = container_obj(layer);
     64
     65	spin_lock_bh(&ctrl->info_list_lock);
     66	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
     67		list_del(&p->list);
     68		kfree(p);
     69	}
     70	spin_unlock_bh(&ctrl->info_list_lock);
     71	kfree(layer);
     72}
     73
     74static bool param_eq(const struct cfctrl_link_param *p1,
     75		     const struct cfctrl_link_param *p2)
     76{
     77	bool eq =
     78	    p1->linktype == p2->linktype &&
     79	    p1->priority == p2->priority &&
     80	    p1->phyid == p2->phyid &&
     81	    p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
     82
     83	if (!eq)
     84		return false;
     85
     86	switch (p1->linktype) {
     87	case CFCTRL_SRV_VEI:
     88		return true;
     89	case CFCTRL_SRV_DATAGRAM:
     90		return p1->u.datagram.connid == p2->u.datagram.connid;
     91	case CFCTRL_SRV_RFM:
     92		return
     93		    p1->u.rfm.connid == p2->u.rfm.connid &&
     94		    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
     95	case CFCTRL_SRV_UTIL:
     96		return
     97		    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
     98		    && p1->u.utility.fifosize_bufs ==
     99		    p2->u.utility.fifosize_bufs
    100		    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
    101		    && p1->u.utility.paramlen == p2->u.utility.paramlen
    102		    && memcmp(p1->u.utility.params, p2->u.utility.params,
    103			      p1->u.utility.paramlen) == 0;
    104
    105	case CFCTRL_SRV_VIDEO:
    106		return p1->u.video.connid == p2->u.video.connid;
    107	case CFCTRL_SRV_DBG:
    108		return true;
    109	case CFCTRL_SRV_DECM:
    110		return false;
    111	default:
    112		return false;
    113	}
    114	return false;
    115}
    116
    117static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
    118			  const struct cfctrl_request_info *r2)
    119{
    120	if (r1->cmd != r2->cmd)
    121		return false;
    122	if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
    123		return param_eq(&r1->param, &r2->param);
    124	else
    125		return r1->channel_id == r2->channel_id;
    126}
    127
    128/* Insert request at the end */
    129static void cfctrl_insert_req(struct cfctrl *ctrl,
    130			      struct cfctrl_request_info *req)
    131{
    132	spin_lock_bh(&ctrl->info_list_lock);
    133	atomic_inc(&ctrl->req_seq_no);
    134	req->sequence_no = atomic_read(&ctrl->req_seq_no);
    135	list_add_tail(&req->list, &ctrl->list);
    136	spin_unlock_bh(&ctrl->info_list_lock);
    137}
    138
    139/* Compare and remove request */
    140static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
    141						struct cfctrl_request_info *req)
    142{
    143	struct cfctrl_request_info *p, *tmp, *first;
    144
    145	first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
    146
    147	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
    148		if (cfctrl_req_eq(req, p)) {
    149			if (p != first)
    150				pr_warn("Requests are not received in order\n");
    151
    152			atomic_set(&ctrl->rsp_seq_no,
    153					 p->sequence_no);
    154			list_del(&p->list);
    155			goto out;
    156		}
    157	}
    158	p = NULL;
    159out:
    160	return p;
    161}
    162
    163struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
    164{
    165	struct cfctrl *this = container_obj(layer);
    166	return &this->res;
    167}
    168
    169static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
    170{
    171	info->hdr_len = 0;
    172	info->channel_id = cfctrl->serv.layer.id;
    173	info->dev_info = &cfctrl->serv.dev_info;
    174}
    175
    176void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
    177{
    178	struct cfpkt *pkt;
    179	struct cfctrl *cfctrl = container_obj(layer);
    180	struct cflayer *dn = cfctrl->serv.layer.dn;
    181
    182	if (!dn) {
    183		pr_debug("not able to send enum request\n");
    184		return;
    185	}
    186	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
    187	if (!pkt)
    188		return;
    189	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
    190	init_info(cfpkt_info(pkt), cfctrl);
    191	cfpkt_info(pkt)->dev_info->id = physlinkid;
    192	cfctrl->serv.dev_info.id = physlinkid;
    193	cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
    194	cfpkt_addbdy(pkt, physlinkid);
    195	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
    196	dn->transmit(dn, pkt);
    197}
    198
    199int cfctrl_linkup_request(struct cflayer *layer,
    200			  struct cfctrl_link_param *param,
    201			  struct cflayer *user_layer)
    202{
    203	struct cfctrl *cfctrl = container_obj(layer);
    204	u32 tmp32;
    205	u16 tmp16;
    206	u8 tmp8;
    207	struct cfctrl_request_info *req;
    208	int ret;
    209	char utility_name[16];
    210	struct cfpkt *pkt;
    211	struct cflayer *dn = cfctrl->serv.layer.dn;
    212
    213	if (!dn) {
    214		pr_debug("not able to send linkup request\n");
    215		return -ENODEV;
    216	}
    217
    218	if (cfctrl_cancel_req(layer, user_layer) > 0) {
    219		/* Slight Paranoia, check if already connecting */
    220		pr_err("Duplicate connect request for same client\n");
    221		WARN_ON(1);
    222		return -EALREADY;
    223	}
    224
    225	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
    226	if (!pkt)
    227		return -ENOMEM;
    228	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
    229	cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
    230	cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
    231	cfpkt_addbdy(pkt, param->endpoint & 0x03);
    232
    233	switch (param->linktype) {
    234	case CFCTRL_SRV_VEI:
    235		break;
    236	case CFCTRL_SRV_VIDEO:
    237		cfpkt_addbdy(pkt, (u8) param->u.video.connid);
    238		break;
    239	case CFCTRL_SRV_DBG:
    240		break;
    241	case CFCTRL_SRV_DATAGRAM:
    242		tmp32 = cpu_to_le32(param->u.datagram.connid);
    243		cfpkt_add_body(pkt, &tmp32, 4);
    244		break;
    245	case CFCTRL_SRV_RFM:
    246		/* Construct a frame, convert DatagramConnectionID to network
    247		 * format long and copy it out...
    248		 */
    249		tmp32 = cpu_to_le32(param->u.rfm.connid);
    250		cfpkt_add_body(pkt, &tmp32, 4);
    251		/* Add volume name, including zero termination... */
    252		cfpkt_add_body(pkt, param->u.rfm.volume,
    253			       strlen(param->u.rfm.volume) + 1);
    254		break;
    255	case CFCTRL_SRV_UTIL:
    256		tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
    257		cfpkt_add_body(pkt, &tmp16, 2);
    258		tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
    259		cfpkt_add_body(pkt, &tmp16, 2);
    260		memset(utility_name, 0, sizeof(utility_name));
    261		strlcpy(utility_name, param->u.utility.name,
    262			UTILITY_NAME_LENGTH);
    263		cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
    264		tmp8 = param->u.utility.paramlen;
    265		cfpkt_add_body(pkt, &tmp8, 1);
    266		cfpkt_add_body(pkt, param->u.utility.params,
    267			       param->u.utility.paramlen);
    268		break;
    269	default:
    270		pr_warn("Request setup of bad link type = %d\n",
    271			param->linktype);
    272		return -EINVAL;
    273	}
    274	req = kzalloc(sizeof(*req), GFP_KERNEL);
    275	if (!req)
    276		return -ENOMEM;
    277	req->client_layer = user_layer;
    278	req->cmd = CFCTRL_CMD_LINK_SETUP;
    279	req->param = *param;
    280	cfctrl_insert_req(cfctrl, req);
    281	init_info(cfpkt_info(pkt), cfctrl);
    282	/*
    283	 * NOTE:Always send linkup and linkdown request on the same
    284	 *	device as the payload. Otherwise old queued up payload
    285	 *	might arrive with the newly allocated channel ID.
    286	 */
    287	cfpkt_info(pkt)->dev_info->id = param->phyid;
    288	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
    289	ret =
    290	    dn->transmit(dn, pkt);
    291	if (ret < 0) {
    292		int count;
    293
    294		count = cfctrl_cancel_req(&cfctrl->serv.layer,
    295						user_layer);
    296		if (count != 1) {
    297			pr_err("Could not remove request (%d)", count);
    298			return -ENODEV;
    299		}
    300	}
    301	return 0;
    302}
    303
    304int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
    305			struct cflayer *client)
    306{
    307	int ret;
    308	struct cfpkt *pkt;
    309	struct cfctrl *cfctrl = container_obj(layer);
    310	struct cflayer *dn = cfctrl->serv.layer.dn;
    311
    312	if (!dn) {
    313		pr_debug("not able to send link-down request\n");
    314		return -ENODEV;
    315	}
    316	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
    317	if (!pkt)
    318		return -ENOMEM;
    319	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
    320	cfpkt_addbdy(pkt, channelid);
    321	init_info(cfpkt_info(pkt), cfctrl);
    322	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);
    323	ret =
    324	    dn->transmit(dn, pkt);
    325#ifndef CAIF_NO_LOOP
    326	cfctrl->loop_linkused[channelid] = 0;
    327#endif
    328	return ret;
    329}
    330
    331int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
    332{
    333	struct cfctrl_request_info *p, *tmp;
    334	struct cfctrl *ctrl = container_obj(layr);
    335	int found = 0;
    336	spin_lock_bh(&ctrl->info_list_lock);
    337
    338	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
    339		if (p->client_layer == adap_layer) {
    340			list_del(&p->list);
    341			kfree(p);
    342			found++;
    343		}
    344	}
    345
    346	spin_unlock_bh(&ctrl->info_list_lock);
    347	return found;
    348}
    349
    350static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
    351{
    352	u8 cmdrsp;
    353	u8 cmd;
    354	int ret = -1;
    355	u8 len;
    356	u8 param[255];
    357	u8 linkid = 0;
    358	struct cfctrl *cfctrl = container_obj(layer);
    359	struct cfctrl_request_info rsp, *req;
    360
    361
    362	cmdrsp = cfpkt_extr_head_u8(pkt);
    363	cmd = cmdrsp & CFCTRL_CMD_MASK;
    364	if (cmd != CFCTRL_CMD_LINK_ERR
    365	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
    366		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {
    367		if (handle_loop(cfctrl, cmd, pkt) != 0)
    368			cmdrsp |= CFCTRL_ERR_BIT;
    369	}
    370
    371	switch (cmd) {
    372	case CFCTRL_CMD_LINK_SETUP:
    373		{
    374			enum cfctrl_srv serv;
    375			enum cfctrl_srv servtype;
    376			u8 endpoint;
    377			u8 physlinkid;
    378			u8 prio;
    379			u8 tmp;
    380			u8 *cp;
    381			int i;
    382			struct cfctrl_link_param linkparam;
    383			memset(&linkparam, 0, sizeof(linkparam));
    384
    385			tmp = cfpkt_extr_head_u8(pkt);
    386
    387			serv = tmp & CFCTRL_SRV_MASK;
    388			linkparam.linktype = serv;
    389
    390			servtype = tmp >> 4;
    391			linkparam.chtype = servtype;
    392
    393			tmp = cfpkt_extr_head_u8(pkt);
    394			physlinkid = tmp & 0x07;
    395			prio = tmp >> 3;
    396
    397			linkparam.priority = prio;
    398			linkparam.phyid = physlinkid;
    399			endpoint = cfpkt_extr_head_u8(pkt);
    400			linkparam.endpoint = endpoint & 0x03;
    401
    402			switch (serv) {
    403			case CFCTRL_SRV_VEI:
    404			case CFCTRL_SRV_DBG:
    405				if (CFCTRL_ERR_BIT & cmdrsp)
    406					break;
    407				/* Link ID */
    408				linkid = cfpkt_extr_head_u8(pkt);
    409				break;
    410			case CFCTRL_SRV_VIDEO:
    411				tmp = cfpkt_extr_head_u8(pkt);
    412				linkparam.u.video.connid = tmp;
    413				if (CFCTRL_ERR_BIT & cmdrsp)
    414					break;
    415				/* Link ID */
    416				linkid = cfpkt_extr_head_u8(pkt);
    417				break;
    418
    419			case CFCTRL_SRV_DATAGRAM:
    420				linkparam.u.datagram.connid =
    421				    cfpkt_extr_head_u32(pkt);
    422				if (CFCTRL_ERR_BIT & cmdrsp)
    423					break;
    424				/* Link ID */
    425				linkid = cfpkt_extr_head_u8(pkt);
    426				break;
    427			case CFCTRL_SRV_RFM:
    428				/* Construct a frame, convert
    429				 * DatagramConnectionID
    430				 * to network format long and copy it out...
    431				 */
    432				linkparam.u.rfm.connid =
    433				    cfpkt_extr_head_u32(pkt);
    434				cp = (u8 *) linkparam.u.rfm.volume;
    435				for (tmp = cfpkt_extr_head_u8(pkt);
    436				     cfpkt_more(pkt) && tmp != '\0';
    437				     tmp = cfpkt_extr_head_u8(pkt))
    438					*cp++ = tmp;
    439				*cp = '\0';
    440
    441				if (CFCTRL_ERR_BIT & cmdrsp)
    442					break;
    443				/* Link ID */
    444				linkid = cfpkt_extr_head_u8(pkt);
    445
    446				break;
    447			case CFCTRL_SRV_UTIL:
    448				/* Construct a frame, convert
    449				 * DatagramConnectionID
    450				 * to network format long and copy it out...
    451				 */
    452				/* Fifosize KB */
    453				linkparam.u.utility.fifosize_kb =
    454				    cfpkt_extr_head_u16(pkt);
    455				/* Fifosize bufs */
    456				linkparam.u.utility.fifosize_bufs =
    457				    cfpkt_extr_head_u16(pkt);
    458				/* name */
    459				cp = (u8 *) linkparam.u.utility.name;
    460				caif_assert(sizeof(linkparam.u.utility.name)
    461					     >= UTILITY_NAME_LENGTH);
    462				for (i = 0;
    463				     i < UTILITY_NAME_LENGTH
    464				     && cfpkt_more(pkt); i++) {
    465					tmp = cfpkt_extr_head_u8(pkt);
    466					*cp++ = tmp;
    467				}
    468				/* Length */
    469				len = cfpkt_extr_head_u8(pkt);
    470				linkparam.u.utility.paramlen = len;
    471				/* Param Data */
    472				cp = linkparam.u.utility.params;
    473				while (cfpkt_more(pkt) && len--) {
    474					tmp = cfpkt_extr_head_u8(pkt);
    475					*cp++ = tmp;
    476				}
    477				if (CFCTRL_ERR_BIT & cmdrsp)
    478					break;
    479				/* Link ID */
    480				linkid = cfpkt_extr_head_u8(pkt);
    481				/* Length */
    482				len = cfpkt_extr_head_u8(pkt);
    483				/* Param Data */
    484				cfpkt_extr_head(pkt, &param, len);
    485				break;
    486			default:
    487				pr_warn("Request setup, invalid type (%d)\n",
    488					serv);
    489				goto error;
    490			}
    491
    492			rsp.cmd = cmd;
    493			rsp.param = linkparam;
    494			spin_lock_bh(&cfctrl->info_list_lock);
    495			req = cfctrl_remove_req(cfctrl, &rsp);
    496
    497			if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
    498				cfpkt_erroneous(pkt)) {
    499				pr_err("Invalid O/E bit or parse error "
    500						"on CAIF control channel\n");
    501				cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
    502						       0,
    503						       req ? req->client_layer
    504						       : NULL);
    505			} else {
    506				cfctrl->res.linksetup_rsp(cfctrl->serv.
    507							  layer.up, linkid,
    508							  serv, physlinkid,
    509							  req ? req->
    510							  client_layer : NULL);
    511			}
    512
    513			kfree(req);
    514
    515			spin_unlock_bh(&cfctrl->info_list_lock);
    516		}
    517		break;
    518	case CFCTRL_CMD_LINK_DESTROY:
    519		linkid = cfpkt_extr_head_u8(pkt);
    520		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);
    521		break;
    522	case CFCTRL_CMD_LINK_ERR:
    523		pr_err("Frame Error Indication received\n");
    524		cfctrl->res.linkerror_ind();
    525		break;
    526	case CFCTRL_CMD_ENUM:
    527		cfctrl->res.enum_rsp();
    528		break;
    529	case CFCTRL_CMD_SLEEP:
    530		cfctrl->res.sleep_rsp();
    531		break;
    532	case CFCTRL_CMD_WAKE:
    533		cfctrl->res.wake_rsp();
    534		break;
    535	case CFCTRL_CMD_LINK_RECONF:
    536		cfctrl->res.restart_rsp();
    537		break;
    538	case CFCTRL_CMD_RADIO_SET:
    539		cfctrl->res.radioset_rsp();
    540		break;
    541	default:
    542		pr_err("Unrecognized Control Frame\n");
    543		goto error;
    544	}
    545	ret = 0;
    546error:
    547	cfpkt_destroy(pkt);
    548	return ret;
    549}
    550
    551static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
    552			   int phyid)
    553{
    554	struct cfctrl *this = container_obj(layr);
    555	switch (ctrl) {
    556	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
    557	case CAIF_CTRLCMD_FLOW_OFF_IND:
    558		spin_lock_bh(&this->info_list_lock);
    559		if (!list_empty(&this->list))
    560			pr_debug("Received flow off in control layer\n");
    561		spin_unlock_bh(&this->info_list_lock);
    562		break;
    563	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
    564		struct cfctrl_request_info *p, *tmp;
    565
    566		/* Find all connect request and report failure */
    567		spin_lock_bh(&this->info_list_lock);
    568		list_for_each_entry_safe(p, tmp, &this->list, list) {
    569			if (p->param.phyid == phyid) {
    570				list_del(&p->list);
    571				p->client_layer->ctrlcmd(p->client_layer,
    572						CAIF_CTRLCMD_INIT_FAIL_RSP,
    573						phyid);
    574				kfree(p);
    575			}
    576		}
    577		spin_unlock_bh(&this->info_list_lock);
    578		break;
    579	}
    580	default:
    581		break;
    582	}
    583}
    584
    585#ifndef CAIF_NO_LOOP
    586static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
    587{
    588	static int last_linkid;
    589	static int dec;
    590	u8 linkid, linktype, tmp;
    591	switch (cmd) {
    592	case CFCTRL_CMD_LINK_SETUP:
    593		spin_lock_bh(&ctrl->loop_linkid_lock);
    594		if (!dec) {
    595			for (linkid = last_linkid + 1; linkid < 254; linkid++)
    596				if (!ctrl->loop_linkused[linkid])
    597					goto found;
    598		}
    599		dec = 1;
    600		for (linkid = last_linkid - 1; linkid > 1; linkid--)
    601			if (!ctrl->loop_linkused[linkid])
    602				goto found;
    603		spin_unlock_bh(&ctrl->loop_linkid_lock);
    604		return -1;
    605found:
    606		if (linkid < 10)
    607			dec = 0;
    608
    609		if (!ctrl->loop_linkused[linkid])
    610			ctrl->loop_linkused[linkid] = 1;
    611
    612		last_linkid = linkid;
    613
    614		cfpkt_add_trail(pkt, &linkid, 1);
    615		spin_unlock_bh(&ctrl->loop_linkid_lock);
    616		cfpkt_peek_head(pkt, &linktype, 1);
    617		if (linktype ==  CFCTRL_SRV_UTIL) {
    618			tmp = 0x01;
    619			cfpkt_add_trail(pkt, &tmp, 1);
    620			cfpkt_add_trail(pkt, &tmp, 1);
    621		}
    622		break;
    623
    624	case CFCTRL_CMD_LINK_DESTROY:
    625		spin_lock_bh(&ctrl->loop_linkid_lock);
    626		cfpkt_peek_head(pkt, &linkid, 1);
    627		ctrl->loop_linkused[linkid] = 0;
    628		spin_unlock_bh(&ctrl->loop_linkid_lock);
    629		break;
    630	default:
    631		break;
    632	}
    633	return 0;
    634}
    635#endif