C++ WARN_ON函数代码示例

static struct dentry *ovl_clear_empty(struct dentry *dentry,
				      struct list_head *list)
{
	struct dentry *workdir = ovl_workdir(dentry);
	struct inode *wdir = workdir->d_inode;
	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
	struct inode *udir = upperdir->d_inode;
	struct path upperpath;
	struct dentry *upper;
	struct dentry *opaquedir;
	struct kstat stat;
	int err;

	if (WARN_ON(!workdir))
		return ERR_PTR(-EROFS);

	err = ovl_lock_rename_workdir(workdir, upperdir);
	if (err)
		goto out;

	ovl_path_upper(dentry, &upperpath);
	err = vfs_getattr(&upperpath, &stat);
	if (err)
		goto out_unlock;

	err = -ESTALE;
	if (!S_ISDIR(stat.mode))
		goto out_unlock;
	upper = upperpath.dentry;
	if (upper->d_parent->d_inode != udir)
		goto out_unlock;

	opaquedir = ovl_lookup_temp(workdir, dentry);
	err = PTR_ERR(opaquedir);
	if (IS_ERR(opaquedir))
		goto out_unlock;

	err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true);
	if (err)
		goto out_dput;

	err = ovl_copy_xattr(upper, opaquedir);
	if (err)
		goto out_cleanup;

	err = ovl_set_opaque(opaquedir);
	if (err)
		goto out_cleanup;

	inode_lock(opaquedir->d_inode);
	err = ovl_set_attr(opaquedir, &stat);
	inode_unlock(opaquedir->d_inode);
	if (err)
		goto out_cleanup;

	err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
	if (err)
		goto out_cleanup;

	ovl_cleanup_whiteouts(upper, list);
	ovl_cleanup(wdir, upper);
	unlock_rename(workdir, upperdir);

	/* dentry's upper doesn't match now, get rid of it */
	d_drop(dentry);

	return opaquedir;

out_cleanup:
	ovl_cleanup(wdir, opaquedir);
out_dput:
	dput(opaquedir);
out_unlock:
	unlock_rename(workdir, upperdir);
out:
	return ERR_PTR(err);
}

/*
 * Starting point for SD card init.
 */
int mmc_attach_sd(struct mmc_host *host)
{
	int err;
	u32 ocr;
#ifdef CONFIG_MMC_PARANOID_SD_INIT
	int retries;
#endif

	BUG_ON(!host);
	WARN_ON(!host->claimed);

	err = mmc_send_app_op_cond(host, 0, &ocr);
	if (err)
		return err;

	mmc_sd_attach_bus_ops(host);
	if (host->ocr_avail_sd)
		host->ocr_avail = host->ocr_avail_sd;

	/*
	 * We need to get OCR a different way for SPI.
	 */
	if (mmc_host_is_spi(host)) {
		mmc_go_idle(host);

		err = mmc_spi_read_ocr(host, 0, &ocr);
		if (err)
			goto err;
	}

	/*
	 * Sanity check the voltages that the card claims to
	 * support.
	 */
	if (ocr & 0x7F) {
		printk(KERN_WARNING "%s: card claims to support voltages "
		       "below the defined range. These will be ignored.\n",
		       mmc_hostname(host));
		ocr &= ~0x7F;
	}

	if ((ocr & MMC_VDD_165_195) &&
	    !(host->ocr_avail_sd & MMC_VDD_165_195)) {
		printk(KERN_WARNING "%s: SD card claims to support the "
		       "incompletely defined 'low voltage range'. This "
		       "will be ignored.\n", mmc_hostname(host));
		ocr &= ~MMC_VDD_165_195;
	}

	host->ocr = mmc_select_voltage(host, ocr);

	/*
	 * Can we support the voltage(s) of the card(s)?
	 */
	if (!host->ocr) {
		err = -EINVAL;
		goto err;
	}

	/*
	 * Detect and init the card.
	 */
#ifdef CONFIG_MMC_PARANOID_SD_INIT
	retries = 5;
	while (retries) {
		err = mmc_sd_init_card(host, host->ocr, NULL);
		if (err) {
			retries--;
			continue;
		}
		break;
	}

	if (!retries) {
		printk(KERN_ERR "%s: mmc_sd_init_card() failure (err = %d)\n",
		       mmc_hostname(host), err);
		goto err;
	}
#else
	err = mmc_sd_init_card(host, host->ocr, NULL);
	if (err)
		goto err;
#endif

	mmc_release_host(host);
	err = mmc_add_card(host->card);
	mmc_claim_host(host);
	if (err)
		goto remove_card;

	return 0;

remove_card:
	mmc_release_host(host);
	mmc_remove_card(host->card);
	host->card = NULL;
	mmc_claim_host(host);
//.........这里部分代码省略.........

int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid,
				  u16 timeout)
{
	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	struct ieee80211_local *local = sdata->local;
	struct tid_ampdu_tx *tid_tx;
	int ret = 0;

	trace_api_start_tx_ba_session(pubsta, tid);

	if (WARN_ON(!local->ops->ampdu_action))
		return -EINVAL;

	if ((tid >= STA_TID_NUM) ||
	    !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) ||
	    (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW))
		return -EINVAL;

#ifdef CONFIG_MAC80211_HT_DEBUG
	printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
	       pubsta->addr, tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */

	if (sdata->vif.type != NL80211_IFTYPE_STATION &&
	    sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
	    sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
	    sdata->vif.type != NL80211_IFTYPE_AP &&
	    sdata->vif.type != NL80211_IFTYPE_ADHOC)
		return -EINVAL;

	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA sessions blocked. "
		       "Denying BA session request\n");
#endif
		return -EINVAL;
	}

	/*
	 * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a
	 * member of an IBSS, and has no other existing Block Ack agreement
	 * with the recipient STA, then the initiating STA shall transmit a
	 * Probe Request frame to the recipient STA and shall not transmit an
	 * ADDBA Request frame unless it receives a Probe Response frame
	 * from the recipient within dot11ADDBAFailureTimeout.
	 *
	 * The probe request mechanism for ADDBA is currently not implemented,
	 * but we only build up Block Ack session with HT STAs. This information
	 * is set when we receive a bss info from a probe response or a beacon.
	 */
	if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC &&
	    !sta->sta.ht_cap.ht_supported) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - IBSS STA %pM"
		       "does not advertise HT support\n", pubsta->addr);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		return -EINVAL;
	}

	spin_lock_bh(&sta->lock);

	/* we have tried too many times, receiver does not want A-MPDU */
	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
		ret = -EBUSY;
		goto err_unlock_sta;
	}

	/*
	 * if we have tried more than HT_AGG_BURST_RETRIES times we
	 * will spread our requests in time to avoid stalling connection
	 * for too long
	 */
	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES &&
	    time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] +
			HT_AGG_RETRIES_PERIOD)) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - "
		       "waiting a grace period after %d failed requests "
		       "on tid %u\n",
		       sta->ampdu_mlme.addba_req_num[tid], tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		ret = -EBUSY;
		goto err_unlock_sta;
	}

	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
	/* check if the TID is not in aggregation flow already */
	if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
#ifdef CONFIG_MAC80211_HT_DEBUG
		printk(KERN_DEBUG "BA request denied - session is not "
				 "idle on tid %u\n", tid);
#endif /* CONFIG_MAC80211_HT_DEBUG */
		ret = -EAGAIN;
		goto err_unlock_sta;
	}

	/* prepare A-MPDU MLME for Tx aggregation */
	tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
	if (!tid_tx) {
//.........这里部分代码省略.........

static int idescsi_eh_reset (struct scsi_cmnd *cmd)
{
	struct request *req;
	idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
	ide_drive_t    *drive = scsi->drive;
	int             ready = 0;
	int             ret   = SUCCESS;

	/* In idescsi_eh_reset we forcefully remove the command from the ide subsystem and reset the device. */

	if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
		printk (KERN_WARNING "ide-scsi: reset called for %lu\n", cmd->serial_number);

	if (!drive) {
		printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_reset\n");
		WARN_ON(1);
		return FAILED;
	}

	spin_lock_irq(cmd->device->host->host_lock);
	spin_lock(&ide_lock);

	if (!scsi->pc || (req = scsi->pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
		printk (KERN_WARNING "ide-scsi: No active request in idescsi_eh_reset\n");
		spin_unlock(&ide_lock);
		spin_unlock_irq(cmd->device->host->host_lock);
		return FAILED;
	}

	/* kill current request */
	if (__blk_end_request(req, -EIO, 0))
		BUG();
	if (blk_sense_request(req))
		kfree(scsi->pc->buf);
	kfree(scsi->pc);
	scsi->pc = NULL;
	blk_put_request(req);

	/* now nuke the drive queue */
	while ((req = elv_next_request(drive->queue))) {
		if (__blk_end_request(req, -EIO, 0))
			BUG();
	}

	HWGROUP(drive)->rq = NULL;
	HWGROUP(drive)->handler = NULL;
	HWGROUP(drive)->busy = 1;		/* will set this to zero when ide reset finished */
	spin_unlock(&ide_lock);

	ide_do_reset(drive);

	/* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */

	do {
		spin_unlock_irq(cmd->device->host->host_lock);
		msleep(50);
		spin_lock_irq(cmd->device->host->host_lock);
	} while ( HWGROUP(drive)->handler );

	ready = drive_is_ready(drive);
	HWGROUP(drive)->busy--;
	if (!ready) {
		printk (KERN_ERR "ide-scsi: reset failed!\n");
		ret = FAILED;
	}

	spin_unlock_irq(cmd->device->host->host_lock);
	return ret;
}

static int cardhu_panel_enable(void)
{
	int ret;
	printk("Check cardhu_panel_enable \n");

	if (tegra3_get_project_id()==0x4){
		if (gpio_get_value(TEGRA_GPIO_PI6)==0){	//Panel is Panasonic
			printk("Check panel is panasonic \n");
			if (cardhu_lvds_vdd_bl == NULL) {
				cardhu_lvds_vdd_bl = regulator_get(NULL, "vdd_backlight");
				if (WARN_ON(IS_ERR(cardhu_lvds_vdd_bl)))
					pr_err("%s: couldn't get regulator vdd_backlight: %ld\n",
					__func__, PTR_ERR(cardhu_lvds_vdd_bl));
				else
					regulator_enable(cardhu_lvds_vdd_bl);
			}

			ret = gpio_direction_output(TEGRA_GPIO_PU5, 1);
			if (ret < 0) {
				printk("Check can not pull high TEGRA_GPIO_PU5 \n");
				gpio_free(TEGRA_GPIO_PU5);
				return ret;
			}
		}
		else{								//Panel is hydis
			printk("Check panel is hydis \n");
			gpio_set_value(TEGRA_GPIO_PH3, 0);
			ret = gpio_direction_output(TEGRA_GPIO_PU5, 0);
			if (ret < 0) {
				printk("Check can not pull low TEGRA_GPIO_PU5 \n");
				gpio_free(TEGRA_GPIO_PU5);
				return ret;
			}
		}
		mdelay(5);
	}

	if (tegra3_get_project_id()==0x4)
	{
		if (cardhu_lvds_reg == NULL) {
			cardhu_lvds_reg = regulator_get(NULL, "vdd_lvds");
			if (WARN_ON(IS_ERR(cardhu_lvds_reg)))
				pr_err("%s: couldn't get regulator vdd_lvds: %ld\n",
					__func__, PTR_ERR(cardhu_lvds_reg));
			else
				regulator_enable(cardhu_lvds_reg);
		}
	}

	if (cardhu_lvds_vdd_panel == NULL) {
		cardhu_lvds_vdd_panel = regulator_get(NULL, "vdd_lcd_panel");
		if (WARN_ON(IS_ERR(cardhu_lvds_vdd_panel)))
			pr_err("%s: couldn't get regulator vdd_lcd_panel: %ld\n",
				__func__, PTR_ERR(cardhu_lvds_vdd_panel));
		else
			regulator_enable(cardhu_lvds_vdd_panel);
	}
	msleep(20);

	if (tegra3_get_project_id()==0x4){
			printk("Check power on/off for bridge IC \n");
			ret = gpio_direction_output(TEGRA_GPIO_PBB3, 1);
			if (ret < 0) {
					printk("Check can not pull high TEGRA_GPIO_PBB3 \n");
					gpio_free(TEGRA_GPIO_PBB3);
					return ret;
			}

			ret = gpio_direction_output(TEGRA_GPIO_PC6, 1);
			if (ret < 0) {
					printk("Check can not pull high TF700T_1.8V(TEGRA_GPIO_PC6) \n");
					gpio_free(TEGRA_GPIO_PC6);
					return ret;
			}

			mdelay(10);

			ret = gpio_direction_output(TEGRA_GPIO_PX0, 1);
			if (ret < 0) {
					printk("Check can not pull high TF700T_I2C_Switch(TEGRA_GPIO_PX0) \n");
					gpio_free(TEGRA_GPIO_PX0);
					return ret;
			}
			mdelay(10);

	}
	if(tegra3_get_project_id()==0x4)
	{
		if (display_board_info.board_id == BOARD_DISPLAY_PM313) {
			/* lvds configuration */
			gpio_set_value(pm313_R_FDE, 1);
			gpio_set_value(pm313_R_FB, 1);
			gpio_set_value(pm313_MODE0, 1);
			gpio_set_value(pm313_MODE1, 0);
			gpio_set_value(pm313_BPP, PM313_LVDS_PANEL_BPP);

			/* FIXME : it may require more or less delay for latching
			  values correctly before enabling RGB2LVDS */
			mdelay(100);
			gpio_set_value(pm313_lvds_shutdown, 1);
//.........这里部分代码省略.........

/*
 * Handle the detection and initialisation of a card.
 *
 * In the case of a resume, "oldcard" will contain the card
 * we're trying to reinitialise.
 */
static int mmc_init_card(struct mmc_host *host, u32 ocr,
	struct mmc_card *oldcard)
{
	struct mmc_card *card;
	int err;
	u32 cid[4];
	unsigned int max_dtr;
	u32 rocr;

	BUG_ON(!host);
	WARN_ON(!host->claimed);

	/*
	 * Since we're changing the OCR value, we seem to
	 * need to tell some cards to go back to the idle
	 * state.  We wait 1ms to give cards time to
	 * respond.
	 */
	mmc_go_idle(host);

	/* The extra bit indicates that we support high capacity */
	err = mmc_send_op_cond(host, ocr | MMC_CARD_SECTOR_ADDR, &rocr);
	if (err)
		goto err;

	/*
	 * For SPI, enable CRC as appropriate.
	 */
	if (mmc_host_is_spi(host)) {
		err = mmc_spi_set_crc(host, use_spi_crc);
		if (err)
			goto err;
	}

	/*
	 * Fetch CID from card.
	 */
	if (mmc_host_is_spi(host))
		err = mmc_send_cid(host, cid);
	else
		err = mmc_all_send_cid(host, cid);
	if (err)
		goto err;

	if (oldcard) {
		if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0) {
			err = -ENOENT;
			goto err;
		}

		card = oldcard;
	} else {
		/*
		 * Allocate card structure.
		 */
		card = mmc_alloc_card(host, &mmc_type);
		if (IS_ERR(card)) {
			err = PTR_ERR(card);
			goto err;
		}

		card->type = MMC_TYPE_MMC;
		card->rca = 1;
		memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
	}

	/*
	 * For native busses:  set card RCA and quit open drain mode.
	 */
	if (!mmc_host_is_spi(host)) {
		err = mmc_set_relative_addr(card);
		if (err)
			goto free_card;

		mmc_set_bus_mode(host, MMC_BUSMODE_PUSHPULL);
	}

	if (!oldcard) {
		/*
		 * Fetch CSD from card.
		 */
		err = mmc_send_csd(card, card->raw_csd);
		if (err)
			goto free_card;

		err = mmc_decode_csd(card);
		if (err)
			goto free_card;
		err = mmc_decode_cid(card);
		if (err)
			goto free_card;
	}

	/*
//.........这里部分代码省略.........

/**
 * mei_ioctl_connect_client - the connect to fw client IOCTL function
 *
 * @dev: the device structure
 * @data: IOCTL connect data, input and output parameters
 * @file: private data of the file object
 *
 * Locking: called under "dev->device_lock" lock
 *
 * returns 0 on success, <0 on failure.
 */
static int mei_ioctl_connect_client(struct file *file,
			struct mei_connect_client_data *data)
{
	struct mei_device *dev;
	struct mei_client *client;
	struct mei_cl *cl;
	int i;
	int rets;

	cl = file->private_data;
	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	dev = cl->dev;

	if (dev->dev_state != MEI_DEV_ENABLED) {
		rets = -ENODEV;
		goto end;
	}

	if (cl->state != MEI_FILE_INITIALIZING &&
	    cl->state != MEI_FILE_DISCONNECTED) {
		rets = -EBUSY;
		goto end;
	}

	/* find ME client we're trying to connect to */
	i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
	if (i < 0 || dev->me_clients[i].props.fixed_address) {
		dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
				&data->in_client_uuid);
		rets = -ENODEV;
		goto end;
	}

	cl->me_client_id = dev->me_clients[i].client_id;
	cl->state = MEI_FILE_CONNECTING;

	dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
			cl->me_client_id);
	dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
			dev->me_clients[i].props.protocol_version);
	dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
			dev->me_clients[i].props.max_msg_length);

	/* if we're connecting to amthif client then we will use the
	 * existing connection
	 */
	if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
		dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
		if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
			rets = -ENODEV;
			goto end;
		}
		mei_cl_unlink(cl);

		kfree(cl);
		cl = NULL;
		dev->iamthif_open_count++;
		file->private_data = &dev->iamthif_cl;

		client = &data->out_client_properties;
		client->max_msg_length =
			dev->me_clients[i].props.max_msg_length;
		client->protocol_version =
			dev->me_clients[i].props.protocol_version;
		rets = dev->iamthif_cl.status;

		goto end;
	}


	/* prepare the output buffer */
	client = &data->out_client_properties;
	client->max_msg_length = dev->me_clients[i].props.max_msg_length;
	client->protocol_version = dev->me_clients[i].props.protocol_version;
	dev_dbg(&dev->pdev->dev, "Can connect?\n");


	rets = mei_cl_connect(cl, file);

end:
	return rets;
}

/**
 * mei_ioctl - the IOCTL function
 *
 * @file: pointer to file structure
 * @cmd: ioctl command
 * @data: pointer to mei message structure
 *
 * returns 0 on success , <0 on error
 */
static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
{
	struct mei_device *dev;
	struct mei_cl *cl = file->private_data;
	struct mei_connect_client_data *connect_data = NULL;
	int rets;

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	dev = cl->dev;

	dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);

	mutex_lock(&dev->device_lock);
	if (dev->dev_state != MEI_DEV_ENABLED) {
		rets = -ENODEV;
		goto out;
	}

	switch (cmd) {
	case IOCTL_MEI_CONNECT_CLIENT:
		dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
		connect_data = kzalloc(sizeof(struct mei_connect_client_data),
			GFP_KERNEL);

		if (!connect_data) {
			rets = -ENOMEM;
			goto out;
		}

		dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
		if (copy_from_user(connect_data, (char __user *)data,
			sizeof(struct mei_connect_client_data))) {

			dev_err(&dev->pdev->dev,
				"failed to copy data from userland\n");
			rets = -EFAULT;
			goto out;
		}

		rets = mei_ioctl_connect_client(file, connect_data);

		/* Error out if this failed */
		if (rets) {
			dev_err(&dev->pdev->dev,
				"failed mei_ioctl_connect_client\n");
			goto out;
		}

		/* if all is ok, copying the data back to user. */
		dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
		if (copy_to_user((char __user *)data, connect_data,
			sizeof(struct mei_connect_client_data))) {

			dev_err(&dev->pdev->dev, "failed to copy data to userland\n");
			rets = -EFAULT;
			goto out;
		}
		break;
	case IOCTL_MEI_SETUP_DMA_BUF:
		dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_SETUP_DMA_BUF\n");
		rets = -EOPNOTSUPP;
		break;
	case IOCTL_MEI_UNSET_DMA_BUF:
		dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_UNSET_DMA_BUF\n");
		rets = -EOPNOTSUPP;
		break;
	default:
		dev_err(&dev->pdev->dev, ": unsupported ioctl %d.\n", cmd);
		rets = -EINVAL;
		break;
	}

out:
	kfree(connect_data);
	mutex_unlock(&dev->device_lock);
	return rets;
}

/**
 * mei_read - the read function.
 *
 * @file: pointer to file structure
 * @ubuf: pointer to user buffer
 * @length: buffer length
 * @offset: data offset in buffer
 *
 * returns >=0 data length on success , <0 on error
 */
static ssize_t mei_read(struct file *file, char __user *ubuf,
			size_t length, loff_t *offset)
{
	struct mei_cl *cl = file->private_data;
	struct mei_cl_cb *cb_pos = NULL;
	struct mei_cl_cb *cb = NULL;
	struct mei_device *dev;
	int rets;
	int err;


	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	dev = cl->dev;


	mutex_lock(&dev->device_lock);
	if (dev->dev_state != MEI_DEV_ENABLED) {
		rets = -ENODEV;
		goto out;
	}

	if (length == 0) {
		rets = 0;
		goto out;
	}

	if (cl == &dev->iamthif_cl) {
		rets = mei_amthif_read(dev, file, ubuf, length, offset);
		goto out;
	}

	if (cl->read_cb) {
		cb = cl->read_cb;
		/* read what left */
		if (cb->buf_idx > *offset)
			goto copy_buffer;
		/* offset is beyond buf_idx we have no more data return 0 */
		if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
			rets = 0;
			goto free;
		}
		/* Offset needs to be cleaned for contiguous reads*/
		if (cb->buf_idx == 0 && *offset > 0) {
			dev_dbg(&dev->pdev->dev, "idx = 0 offset = %lld\n", (unsigned long long)*offset);
			*offset = 0;
		}
	} else if (*offset > 0) {
		dev_dbg(&dev->pdev->dev, "offset = %lld\n", (unsigned long long)*offset);
		*offset = 0;
	}

	err = mei_cl_read_start(cl, length);
	if (err && err != -EBUSY) {
		dev_dbg(&dev->pdev->dev,
			"mei start read failure with status = %d\n", err);
		rets = err;
		goto out;
	}

	if (MEI_READ_COMPLETE != cl->reading_state &&
			!waitqueue_active(&cl->rx_wait)) {
		if (file->f_flags & O_NONBLOCK) {
			rets = -EAGAIN;
			goto out;
		}

		mutex_unlock(&dev->device_lock);

		if (wait_event_interruptible(cl->rx_wait,
				MEI_READ_COMPLETE == cl->reading_state ||
				mei_cl_is_transitioning(cl))) {

			if (signal_pending(current))
				return -EINTR;
			return -ERESTARTSYS;
		}

		mutex_lock(&dev->device_lock);
		if (mei_cl_is_transitioning(cl)) {
			rets = -EBUSY;
			goto out;
		}
	}

	cb = cl->read_cb;

	if (!cb) {
		rets = -ENODEV;
//.........这里部分代码省略.........

/**
 * mei_write - the write function.
 *
 * @file: pointer to file structure
 * @ubuf: pointer to user buffer
 * @length: buffer length
 * @offset: data offset in buffer
 *
 * returns >=0 data length on success , <0 on error
 */
static ssize_t mei_write(struct file *file, const char __user *ubuf,
			 size_t length, loff_t *offset)
{
	struct mei_cl *cl = file->private_data;
	struct mei_cl_cb *write_cb = NULL;
	struct mei_device *dev;
	unsigned long timeout = 0;
	int rets;
	int id;

	if (WARN_ON(!cl || !cl->dev))
		return -ENODEV;

	dev = cl->dev;

	mutex_lock(&dev->device_lock);

	if (dev->dev_state != MEI_DEV_ENABLED) {
		rets = -ENODEV;
		goto out;
	}

	id = mei_me_cl_by_id(dev, cl->me_client_id);
	if (id < 0) {
		rets = -ENODEV;
		goto out;
	}

	if (length == 0) {
		rets = 0;
		goto out;
	}

	if (length > dev->me_clients[id].props.max_msg_length) {
		rets = -EFBIG;
		goto out;
	}

	if (cl->state != MEI_FILE_CONNECTED) {
		dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
			cl->host_client_id, cl->me_client_id);
		rets = -ENODEV;
		goto out;
	}
	if (cl == &dev->iamthif_cl) {
		write_cb = mei_amthif_find_read_list_entry(dev, file);

		if (write_cb) {
			timeout = write_cb->read_time +
				mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);

			if (time_after(jiffies, timeout) ||
			    cl->reading_state == MEI_READ_COMPLETE) {
				*offset = 0;
				list_del(&write_cb->list);
				mei_io_cb_free(write_cb);
				write_cb = NULL;
			}
		}
	}

	/* free entry used in read */
	if (cl->reading_state == MEI_READ_COMPLETE) {
		*offset = 0;
		write_cb = mei_cl_find_read_cb(cl);
		if (write_cb) {
			list_del(&write_cb->list);
			mei_io_cb_free(write_cb);
			write_cb = NULL;
			cl->reading_state = MEI_IDLE;
			cl->read_cb = NULL;
		}
	} else if (cl->reading_state == MEI_IDLE)
		*offset = 0;


	write_cb = mei_io_cb_init(cl, file);
	if (!write_cb) {
		dev_err(&dev->pdev->dev, "write cb allocation failed\n");
		rets = -ENOMEM;
		goto out;
	}
	rets = mei_io_cb_alloc_req_buf(write_cb, length);
	if (rets)
		goto out;

	rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
	if (rets) {
		dev_err(&dev->pdev->dev, "failed to copy data from userland\n");
		rets = -EFAULT;
//.........这里部分代码省略.........

static void dormant_restore_addnl_reg(void)
{
	int i;
	u32 reg_val, val1, val2;
	u32 insurance = 0;

	/* Allow write access to the CCU registers */
	writel_relaxed(0xA5A501, (KONA_PROC_CLK_VA +
	       KPROC_CLK_MGR_REG_WR_ACCESS_OFFSET));

	for (i = 0; i < ARRAY_SIZE(addnl_save_reg_list); i++) {
		/* Restore the saved data */
		writel_relaxed(addnl_save_reg_list[i][1],
			       addnl_save_reg_list[i][0]);

		if (addnl_save_reg_list[i][0] == (KONA_PROC_CLK_VA +
		    KPROC_CLK_MGR_REG_TGTMASK_DBG1_OFFSET)) {

			/* Finished restoring all the A9 CCU registers
			 * lock the state machine so writing the GO bit
			 * would not cause issues with the state machine
			 */
			writel_relaxed(readl(KONA_PROC_CLK_VA +
			       KPROC_CLK_MGR_REG_LVM_EN_OFFSET) |
			       KPROC_CLK_MGR_REG_LVM_EN_POLICY_CONFIG_EN_MASK,
			       KONA_PROC_CLK_VA +
			       KPROC_CLK_MGR_REG_LVM_EN_OFFSET);

			/* Wait for HW confirmation of policy lock */
			do {
				udelay(1);
				reg_val = readl(KONA_PROC_CLK_VA +
					KPROC_CLK_MGR_REG_LVM_EN_OFFSET);
				insurance++;
			} while ((reg_val &
			KPROC_CLK_MGR_REG_LVM_EN_POLICY_CONFIG_EN_MASK) &&
			insurance < 10000);
			WARN_ON(insurance >= 10000);

			/* Write the go bit to trigger the frequency change
			 */
			writel_relaxed(KPROC_CLK_MGR_REG_POLICY_CTL_GO_AC_MASK |
			       KPROC_CLK_MGR_REG_POLICY_CTL_GO_MASK,
			       KONA_PROC_CLK_VA +
			       KPROC_CLK_MGR_REG_POLICY_CTL_OFFSET);
		}
	}

	/* Wait until the new frequency takes effect */
	do {
		udelay(1);
		val1 =
		    readl(KONA_PROC_CLK_VA +
			  KPROC_CLK_MGR_REG_POLICY_CTL_OFFSET) &
			  KPROC_CLK_MGR_REG_POLICY_CTL_GO_MASK;
		val2 =
		    readl(KONA_PROC_CLK_VA +
			  KPROC_CLK_MGR_REG_POLICY_CTL_OFFSET) &
			  KPROC_CLK_MGR_REG_POLICY_CTL_GO_MASK;
	} while (val1 | val2);
	/* Lock CCU registers */
	writel_relaxed(0xA5A500, (KONA_PROC_CLK_VA +
	       KPROC_CLK_MGR_REG_WR_ACCESS_OFFSET));

}

static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
				    struct kstat *stat, const char *link,
				    struct dentry *hardlink)
{
	struct dentry *workdir = ovl_workdir(dentry);
	struct inode *wdir = workdir->d_inode;
	struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
	struct inode *udir = upperdir->d_inode;
	struct dentry *upper;
	struct dentry *newdentry;
	int err;

	if (WARN_ON(!workdir))
		return -EROFS;

	err = ovl_lock_rename_workdir(workdir, upperdir);
	if (err)
		goto out;

	newdentry = ovl_lookup_temp(workdir, dentry);
	err = PTR_ERR(newdentry);
	if (IS_ERR(newdentry))
		goto out_unlock;

	upper = lookup_one_len(dentry->d_name.name, upperdir,
			       dentry->d_name.len);
	err = PTR_ERR(upper);
	if (IS_ERR(upper))
		goto out_dput;

	err = ovl_create_real(wdir, newdentry, stat, link, hardlink, true);
	if (err)
		goto out_dput2;

	/*
	 * mode could have been mutilated due to umask (e.g. sgid directory)
	 */
	if (!hardlink &&
	    !S_ISLNK(stat->mode) && newdentry->d_inode->i_mode != stat->mode) {
		struct iattr attr = {
			.ia_valid = ATTR_MODE,
			.ia_mode = stat->mode,
		};
		inode_lock(newdentry->d_inode);
		err = notify_change(newdentry, &attr, NULL);
		inode_unlock(newdentry->d_inode);
		if (err)
			goto out_cleanup;
	}

	if (!hardlink && S_ISDIR(stat->mode)) {
		err = ovl_set_opaque(newdentry);
		if (err)
			goto out_cleanup;

		err = ovl_do_rename(wdir, newdentry, udir, upper,
				    RENAME_EXCHANGE);
		if (err)
			goto out_cleanup;

		ovl_cleanup(wdir, upper);
	} else {
		err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
		if (err)
			goto out_cleanup;
	}
	ovl_instantiate(dentry, inode, newdentry, !!hardlink);
	newdentry = NULL;
out_dput2:
	dput(upper);
out_dput:
	dput(newdentry);
out_unlock:
	unlock_rename(workdir, upperdir);
out:
	return err;

out_cleanup:
	ovl_cleanup(wdir, newdentry);
	goto out_dput2;
}

static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
			      struct kstat *stat, const char *link,
			      struct dentry *hardlink)
{
	int err;
	const struct cred *old_cred;
	struct cred *override_cred;

	err = ovl_copy_up(dentry->d_parent);
	if (err)
		return err;

	old_cred = ovl_override_creds(dentry->d_sb);
	err = -ENOMEM;
	override_cred = prepare_creds();
	if (override_cred) {
		override_cred->fsuid = inode->i_uid;
		override_cred->fsgid = inode->i_gid;
//.........这里部分代码省略.........

static void __lpss_ssp_write_priv(struct driver_data *drv_data,
				  unsigned offset, u32 value)
{
	WARN_ON(!drv_data->lpss_base);
	writel(value, drv_data->lpss_base + offset);
}

static int recover_dentry(struct inode *inode, struct page *ipage)
{
	struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
	nid_t pino = le32_to_cpu(raw_inode->i_pino);
	struct f2fs_dir_entry *de;
	struct qstr name;
	struct page *page;
	struct inode *dir, *einode;
	int err = 0;

	dir = f2fs_iget(inode->i_sb, pino);
	if (IS_ERR(dir)) {
		err = PTR_ERR(dir);
		goto out;
	}

	name.len = le32_to_cpu(raw_inode->i_namelen);
	name.name = raw_inode->i_name;

	if (unlikely(name.len > F2FS_NAME_LEN)) {
		WARN_ON(1);
		err = -ENAMETOOLONG;
		goto out_err;
	}
retry:
	de = f2fs_find_entry(dir, &name, &page);
	if (de && inode->i_ino == le32_to_cpu(de->ino)) {
		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
		goto out_unmap_put;
	}
	if (de) {
		einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
		if (IS_ERR(einode)) {
			WARN_ON(1);
			err = PTR_ERR(einode);
			if (err == -ENOENT)
				err = -EEXIST;
			goto out_unmap_put;
		}
		err = acquire_orphan_inode(F2FS_I_SB(inode));
		if (err) {
			iput(einode);
			goto out_unmap_put;
		}
		f2fs_delete_entry(de, page, dir, einode);
		iput(einode);
		goto retry;
	}
	err = __f2fs_add_link(dir, &name, inode);
	if (err)
		goto out_err;

	if (is_inode_flag_set(F2FS_I(dir), FI_DELAY_IPUT)) {
		iput(dir);
	} else {
		add_dirty_dir_inode(dir);
		set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
	}

	goto out;

out_unmap_put:
	f2fs_dentry_kunmap(dir, page);
	f2fs_put_page(page, 0);
out_err:
	iput(dir);
out:
	f2fs_msg(inode->i_sb, KERN_NOTICE,
			"%s: ino = %x, name = %s, dir = %lx, err = %d",
			__func__, ino_of_node(ipage), raw_inode->i_name,
			IS_ERR(dir) ? 0 : dir->i_ino, err);
	return err;
}

/*
 * Trapped FP/ASIMD access.
 */
void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs)
{
	/* TODO: implement lazy context saving/restoring */
	WARN_ON(1);
}