blob: 836f92db7983bfd97c0e263ff2458852695b073f [file] [log] [blame]
/*
*
* Intel Management Engine Interface (Intel MEI) Linux driver
* Copyright (c) 2003-2012, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "hw-me.h"
/**
* mei_hbm_me_cl_allocate - allocates storage for me clients
*
* @dev: the device structure
*
* returns 0 on success -ENOMEM on allocation failure
*/
static int mei_hbm_me_cl_allocate(struct mei_device *dev)
{
struct mei_me_client *clients;
int b;
dev->me_clients_num = 0;
dev->me_client_presentation_num = 0;
dev->me_client_index = 0;
/* count how many ME clients we have */
for_each_set_bit(b, dev->me_clients_map, MEI_CLIENTS_MAX)
dev->me_clients_num++;
if (dev->me_clients_num == 0)
return 0;
kfree(dev->me_clients);
dev->me_clients = NULL;
dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%ld.\n",
dev->me_clients_num * sizeof(struct mei_me_client));
/* allocate storage for ME clients representation */
clients = kcalloc(dev->me_clients_num,
sizeof(struct mei_me_client), GFP_KERNEL);
if (!clients) {
dev_err(&dev->pdev->dev, "memory allocation for ME clients failed.\n");
return -ENOMEM;
}
dev->me_clients = clients;
return 0;
}
/**
* mei_hbm_cl_hdr - construct client hbm header
*
* @cl: - client
* @hbm_cmd: host bus message command
* @buf: buffer for cl header
* @len: buffer length
*/
static inline
void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
{
struct mei_hbm_cl_cmd *cmd = buf;
memset(cmd, 0, len);
cmd->hbm_cmd = hbm_cmd;
cmd->host_addr = cl->host_client_id;
cmd->me_addr = cl->me_client_id;
}
/**
* same_disconn_addr - tells if they have the same address
*
* @file: private data of the file object.
* @disconn: disconnection request.
*
* returns true if addres are same
*/
static inline
bool mei_hbm_cl_addr_equal(struct mei_cl *cl, void *buf)
{
struct mei_hbm_cl_cmd *cmd = buf;
return cl->host_client_id == cmd->host_addr &&
cl->me_client_id == cmd->me_addr;
}
/**
* is_treat_specially_client - checks if the message belongs
* to the file private data.
*
* @cl: private data of the file object
* @rs: connect response bus message
*
*/
static bool is_treat_specially_client(struct mei_cl *cl,
struct hbm_client_connect_response *rs)
{
if (mei_hbm_cl_addr_equal(cl, rs)) {
if (!rs->status) {
cl->state = MEI_FILE_CONNECTED;
cl->status = 0;
} else {
cl->state = MEI_FILE_DISCONNECTED;
cl->status = -ENODEV;
}
cl->timer_count = 0;
return true;
}
return false;
}
/**
* mei_hbm_idle - set hbm to idle state
*
* @dev: the device structure
*/
void mei_hbm_idle(struct mei_device *dev)
{
dev->init_clients_timer = 0;
dev->hbm_state = MEI_HBM_IDLE;
}
int mei_hbm_start_wait(struct mei_device *dev)
{
int ret;
if (dev->hbm_state > MEI_HBM_START)
return 0;
mutex_unlock(&dev->device_lock);
ret = wait_event_interruptible_timeout(dev->wait_recvd_msg,
dev->hbm_state == MEI_HBM_IDLE ||
dev->hbm_state >= MEI_HBM_STARTED,
mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
mutex_lock(&dev->device_lock);
if (ret <= 0 && (dev->hbm_state <= MEI_HBM_START)) {
dev->hbm_state = MEI_HBM_IDLE;
dev_err(&dev->pdev->dev, "waiting for mei start failed\n");
return -ETIMEDOUT;
}
return 0;
}
/**
* mei_hbm_start_req - sends start request message.
*
* @dev: the device structure
*
* returns 0 on success and < 0 on failure
*/
int mei_hbm_start_req(struct mei_device *dev)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
struct hbm_host_version_request *start_req;
const size_t len = sizeof(struct hbm_host_version_request);
int ret;
mei_hbm_hdr(mei_hdr, len);
/* host start message */
start_req = (struct hbm_host_version_request *)dev->wr_msg.data;
memset(start_req, 0, len);
start_req->hbm_cmd = HOST_START_REQ_CMD;
start_req->host_version.major_version = HBM_MAJOR_VERSION;
start_req->host_version.minor_version = HBM_MINOR_VERSION;
dev->hbm_state = MEI_HBM_IDLE;
ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
if (ret) {
dev_err(&dev->pdev->dev, "version message write failed: ret = %d\n",
ret);
return ret;
}
dev->hbm_state = MEI_HBM_START;
dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
return 0;
}
/*
* mei_hbm_enum_clients_req - sends enumeration client request message.
*
* @dev: the device structure
*
* returns 0 on success and < 0 on failure
*/
static int mei_hbm_enum_clients_req(struct mei_device *dev)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
struct hbm_host_enum_request *enum_req;
const size_t len = sizeof(struct hbm_host_enum_request);
int ret;
/* enumerate clients */
mei_hbm_hdr(mei_hdr, len);
enum_req = (struct hbm_host_enum_request *)dev->wr_msg.data;
memset(enum_req, 0, len);
enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
if (ret) {
dev_err(&dev->pdev->dev, "enumeration request write failed: ret = %d.\n",
ret);
return ret;
}
dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
return 0;
}
/**
* mei_hbm_prop_req - request property for a single client
*
* @dev: the device structure
*
* returns 0 on success and < 0 on failure
*/
static int mei_hbm_prop_req(struct mei_device *dev)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
struct hbm_props_request *prop_req;
const size_t len = sizeof(struct hbm_props_request);
unsigned long next_client_index;
unsigned long client_num;
int ret;
client_num = dev->me_client_presentation_num;
next_client_index = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX,
dev->me_client_index);
/* We got all client properties */
if (next_client_index == MEI_CLIENTS_MAX) {
dev->hbm_state = MEI_HBM_STARTED;
schedule_work(&dev->init_work);
return 0;
}
dev->me_clients[client_num].client_id = next_client_index;
dev->me_clients[client_num].mei_flow_ctrl_creds = 0;
mei_hbm_hdr(mei_hdr, len);
prop_req = (struct hbm_props_request *)dev->wr_msg.data;
memset(prop_req, 0, sizeof(struct hbm_props_request));
prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
prop_req->address = next_client_index;
ret = mei_write_message(dev, mei_hdr, dev->wr_msg.data);
if (ret) {
dev_err(&dev->pdev->dev, "properties request write failed: ret = %d\n",
ret);
return ret;
}
dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
dev->me_client_index = next_client_index;
return 0;
}
/**
* mei_hbm_stop_req_prepare - perpare stop request message
*
* @dev - mei device
* @mei_hdr - mei message header
* @data - hbm message body buffer
*/
static void mei_hbm_stop_req_prepare(struct mei_device *dev,
struct mei_msg_hdr *mei_hdr, unsigned char *data)
{
struct hbm_host_stop_request *req =
(struct hbm_host_stop_request *)data;
const size_t len = sizeof(struct hbm_host_stop_request);
mei_hbm_hdr(mei_hdr, len);
memset(req, 0, len);
req->hbm_cmd = HOST_STOP_REQ_CMD;
req->reason = DRIVER_STOP_REQUEST;
}
/**
* mei_hbm_cl_flow_control_req - sends flow control requst.
*
* @dev: the device structure
* @cl: client info
*
* This function returns -EIO on write failure
*/
int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
const size_t len = sizeof(struct hbm_flow_control);
mei_hbm_hdr(mei_hdr, len);
mei_hbm_cl_hdr(cl, MEI_FLOW_CONTROL_CMD, dev->wr_msg.data, len);
dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
cl->host_client_id, cl->me_client_id);
return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
}
/**
* mei_hbm_add_single_flow_creds - adds single buffer credentials.
*
* @dev: the device structure
* @flow: flow control.
*/
static void mei_hbm_add_single_flow_creds(struct mei_device *dev,
struct hbm_flow_control *flow)
{
struct mei_me_client *client;
int i;
for (i = 0; i < dev->me_clients_num; i++) {
client = &dev->me_clients[i];
if (client && flow->me_addr == client->client_id) {
if (client->props.single_recv_buf) {
client->mei_flow_ctrl_creds++;
dev_dbg(&dev->pdev->dev, "recv flow ctrl msg ME %d (single).\n",
flow->me_addr);
dev_dbg(&dev->pdev->dev, "flow control credentials =%d.\n",
client->mei_flow_ctrl_creds);
} else {
BUG(); /* error in flow control */
}
}
}
}
/**
* mei_hbm_cl_flow_control_res - flow control response from me
*
* @dev: the device structure
* @flow_control: flow control response bus message
*/
static void mei_hbm_cl_flow_control_res(struct mei_device *dev,
struct hbm_flow_control *flow_control)
{
struct mei_cl *cl = NULL;
struct mei_cl *next = NULL;
if (!flow_control->host_addr) {
/* single receive buffer */
mei_hbm_add_single_flow_creds(dev, flow_control);
return;
}
/* normal connection */
list_for_each_entry_safe(cl, next, &dev->file_list, link) {
if (mei_hbm_cl_addr_equal(cl, flow_control)) {
cl->mei_flow_ctrl_creds++;
dev_dbg(&dev->pdev->dev, "flow ctrl msg for host %d ME %d.\n",
flow_control->host_addr, flow_control->me_addr);
dev_dbg(&dev->pdev->dev, "flow control credentials = %d.\n",
cl->mei_flow_ctrl_creds);
break;
}
}
}
/**
* mei_hbm_cl_disconnect_req - sends disconnect message to fw.
*
* @dev: the device structure
* @cl: a client to disconnect from
*
* This function returns -EIO on write failure
*/
int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
const size_t len = sizeof(struct hbm_client_connect_request);
mei_hbm_hdr(mei_hdr, len);
mei_hbm_cl_hdr(cl, CLIENT_DISCONNECT_REQ_CMD, dev->wr_msg.data, len);
return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
}
/**
* mei_hbm_cl_disconnect_res - disconnect response from ME
*
* @dev: the device structure
* @rs: disconnect response bus message
*/
static void mei_hbm_cl_disconnect_res(struct mei_device *dev,
struct hbm_client_connect_response *rs)
{
struct mei_cl *cl;
struct mei_cl_cb *pos = NULL, *next = NULL;
dev_dbg(&dev->pdev->dev,
"disconnect_response:\n"
"ME Client = %d\n"
"Host Client = %d\n"
"Status = %d\n",
rs->me_addr,
rs->host_addr,
rs->status);
list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
cl = pos->cl;
if (!cl) {
list_del(&pos->list);
return;
}
dev_dbg(&dev->pdev->dev, "list_for_each_entry_safe in ctrl_rd_list.\n");
if (mei_hbm_cl_addr_equal(cl, rs)) {
list_del(&pos->list);
if (!rs->status)
cl->state = MEI_FILE_DISCONNECTED;
cl->status = 0;
cl->timer_count = 0;
break;
}
}
}
/**
* mei_hbm_cl_connect_req - send connection request to specific me client
*
* @dev: the device structure
* @cl: a client to connect to
*
* returns -EIO on write failure
*/
int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
{
struct mei_msg_hdr *mei_hdr = &dev->wr_msg.hdr;
const size_t len = sizeof(struct hbm_client_connect_request);
mei_hbm_hdr(mei_hdr, len);
mei_hbm_cl_hdr(cl, CLIENT_CONNECT_REQ_CMD, dev->wr_msg.data, len);
return mei_write_message(dev, mei_hdr, dev->wr_msg.data);
}
/**
* mei_hbm_cl_connect_res - connect resposne from the ME
*
* @dev: the device structure
* @rs: connect response bus message
*/
static void mei_hbm_cl_connect_res(struct mei_device *dev,
struct hbm_client_connect_response *rs)
{
struct mei_cl *cl;
struct mei_cl_cb *pos = NULL, *next = NULL;
dev_dbg(&dev->pdev->dev,
"connect_response:\n"
"ME Client = %d\n"
"Host Client = %d\n"
"Status = %d\n",
rs->me_addr,
rs->host_addr,
rs->status);
/* if WD or iamthif client treat specially */
if (is_treat_specially_client(&dev->wd_cl, rs)) {
dev_dbg(&dev->pdev->dev, "successfully connected to WD client.\n");
mei_watchdog_register(dev);
return;
}
if (is_treat_specially_client(&dev->iamthif_cl, rs)) {
dev->iamthif_state = MEI_IAMTHIF_IDLE;
return;
}
list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
cl = pos->cl;
if (!cl) {
list_del(&pos->list);
return;
}
if (pos->fop_type == MEI_FOP_IOCTL) {
if (is_treat_specially_client(cl, rs)) {
list_del(&pos->list);
cl->status = 0;
cl->timer_count = 0;
break;
}
}
}
}
/**
* mei_hbm_fw_disconnect_req - disconnect request initiated by me
* host sends disoconnect response
*
* @dev: the device structure.
* @disconnect_req: disconnect request bus message from the me
*/
static void mei_hbm_fw_disconnect_req(struct mei_device *dev,
struct hbm_client_connect_request *disconnect_req)
{
struct mei_cl *cl, *next;
const size_t len = sizeof(struct hbm_client_connect_response);
list_for_each_entry_safe(cl, next, &dev->file_list, link) {
if (mei_hbm_cl_addr_equal(cl, disconnect_req)) {
dev_dbg(&dev->pdev->dev, "disconnect request host client %d ME client %d.\n",
disconnect_req->host_addr,
disconnect_req->me_addr);
cl->state = MEI_FILE_DISCONNECTED;
cl->timer_count = 0;
if (cl == &dev->wd_cl)
dev->wd_pending = false;
else if (cl == &dev->iamthif_cl)
dev->iamthif_timer = 0;
/* prepare disconnect response */
mei_hbm_hdr(&dev->wr_ext_msg.hdr, len);
mei_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD,
dev->wr_ext_msg.data, len);
break;
}
}
}
/**
* mei_hbm_version_is_supported - checks whether the driver can
* support the hbm version of the device
*
* @dev: the device structure
* returns true if driver can support hbm version of the device
*/
bool mei_hbm_version_is_supported(struct mei_device *dev)
{
return (dev->version.major_version < HBM_MAJOR_VERSION) ||
(dev->version.major_version == HBM_MAJOR_VERSION &&
dev->version.minor_version <= HBM_MINOR_VERSION);
}
/**
* mei_hbm_dispatch - bottom half read routine after ISR to
* handle the read bus message cmd processing.
*
* @dev: the device structure
* @mei_hdr: header of bus message
*
* returns 0 on success and < 0 on failure
*/
int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
{
struct mei_bus_message *mei_msg;
struct mei_me_client *me_client;
struct hbm_host_version_response *version_res;
struct hbm_client_connect_response *connect_res;
struct hbm_client_connect_response *disconnect_res;
struct hbm_client_connect_request *disconnect_req;
struct hbm_flow_control *flow_control;
struct hbm_props_response *props_res;
struct hbm_host_enum_response *enum_res;
/* read the message to our buffer */
BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
/* ignore spurious message and prevent reset nesting
* hbm is put to idle during system reset
*/
if (dev->hbm_state == MEI_HBM_IDLE) {
dev_dbg(&dev->pdev->dev, "hbm: state is idle ignore spurious messages\n");
return 0;
}
switch (mei_msg->hbm_cmd) {
case HOST_START_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: start: response message received.\n");
dev->init_clients_timer = 0;
version_res = (struct hbm_host_version_response *)mei_msg;
dev_dbg(&dev->pdev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
version_res->me_max_version.major_version,
version_res->me_max_version.minor_version);
if (version_res->host_version_supported) {
dev->version.major_version = HBM_MAJOR_VERSION;
dev->version.minor_version = HBM_MINOR_VERSION;
} else {
dev->version.major_version =
version_res->me_max_version.major_version;
dev->version.minor_version =
version_res->me_max_version.minor_version;
}
if (!mei_hbm_version_is_supported(dev)) {
dev_warn(&dev->pdev->dev, "hbm: start: version mismatch - stopping the driver.\n");
dev->hbm_state = MEI_HBM_STOPPED;
mei_hbm_stop_req_prepare(dev, &dev->wr_msg.hdr,
dev->wr_msg.data);
if (mei_write_message(dev, &dev->wr_msg.hdr,
dev->wr_msg.data)) {
dev_err(&dev->pdev->dev, "hbm: start: failed to send stop request\n");
return -EIO;
}
break;
}
if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
dev->hbm_state != MEI_HBM_START) {
dev_err(&dev->pdev->dev, "hbm: start: state mismatch, [%d, %d]\n",
dev->dev_state, dev->hbm_state);
return -EPROTO;
}
dev->hbm_state = MEI_HBM_STARTED;
if (mei_hbm_enum_clients_req(dev)) {
dev_err(&dev->pdev->dev, "hbm: start: failed to send enumeration request\n");
return -EIO;
}
wake_up_interruptible(&dev->wait_recvd_msg);
break;
case CLIENT_CONNECT_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: client connect response: message received.\n");
connect_res = (struct hbm_client_connect_response *) mei_msg;
mei_hbm_cl_connect_res(dev, connect_res);
wake_up(&dev->wait_recvd_msg);
break;
case CLIENT_DISCONNECT_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: client disconnect response: message received.\n");
disconnect_res = (struct hbm_client_connect_response *) mei_msg;
mei_hbm_cl_disconnect_res(dev, disconnect_res);
wake_up(&dev->wait_recvd_msg);
break;
case MEI_FLOW_CONTROL_CMD:
dev_dbg(&dev->pdev->dev, "hbm: client flow control response: message received.\n");
flow_control = (struct hbm_flow_control *) mei_msg;
mei_hbm_cl_flow_control_res(dev, flow_control);
break;
case HOST_CLIENT_PROPERTIES_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: properties response: message received.\n");
dev->init_clients_timer = 0;
if (dev->me_clients == NULL) {
dev_err(&dev->pdev->dev, "hbm: properties response: mei_clients not allocated\n");
return -EPROTO;
}
props_res = (struct hbm_props_response *)mei_msg;
me_client = &dev->me_clients[dev->me_client_presentation_num];
if (props_res->status) {
dev_err(&dev->pdev->dev, "hbm: properties response: wrong status = %d\n",
props_res->status);
return -EPROTO;
}
if (me_client->client_id != props_res->address) {
dev_err(&dev->pdev->dev, "hbm: properties response: address mismatch %d ?= %d\n",
me_client->client_id, props_res->address);
return -EPROTO;
}
if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
dev_err(&dev->pdev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
dev->dev_state, dev->hbm_state);
return -EPROTO;
}
me_client->props = props_res->client_properties;
dev->me_client_index++;
dev->me_client_presentation_num++;
/* request property for the next client */
if (mei_hbm_prop_req(dev))
return -EIO;
break;
case HOST_ENUM_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: enumeration response: message received\n");
dev->init_clients_timer = 0;
enum_res = (struct hbm_host_enum_response *) mei_msg;
BUILD_BUG_ON(sizeof(dev->me_clients_map)
< sizeof(enum_res->valid_addresses));
memcpy(dev->me_clients_map, enum_res->valid_addresses,
sizeof(enum_res->valid_addresses));
if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
dev_err(&dev->pdev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
dev->dev_state, dev->hbm_state);
return -EPROTO;
}
if (mei_hbm_me_cl_allocate(dev)) {
dev_err(&dev->pdev->dev, "hbm: enumeration response: cannot allocate clients array\n");
return -ENOMEM;
}
dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;
/* first property request */
if (mei_hbm_prop_req(dev))
return -EIO;
break;
case HOST_STOP_RES_CMD:
dev_dbg(&dev->pdev->dev, "hbm: stop response: message received\n");
dev->init_clients_timer = 0;
if (dev->hbm_state != MEI_HBM_STOPPED) {
dev_err(&dev->pdev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
dev->dev_state, dev->hbm_state);
return -EPROTO;
}
dev->dev_state = MEI_DEV_DISABLED;
dev_info(&dev->pdev->dev, "hbm: stop response: resetting.\n");
/* force the reset */
return -EPROTO;
break;
case CLIENT_DISCONNECT_REQ_CMD:
dev_dbg(&dev->pdev->dev, "hbm: disconnect request: message received\n");
disconnect_req = (struct hbm_client_connect_request *)mei_msg;
mei_hbm_fw_disconnect_req(dev, disconnect_req);
break;
case ME_STOP_REQ_CMD:
dev_dbg(&dev->pdev->dev, "hbm: stop request: message received\n");
dev->hbm_state = MEI_HBM_STOPPED;
mei_hbm_stop_req_prepare(dev, &dev->wr_ext_msg.hdr,
dev->wr_ext_msg.data);
break;
default:
BUG();
break;
}
return 0;
}