Esempio n. 1
0
File: main.c Progetto: 020gzh/linux
/**
 * mei_read - the read function.
 *
 * @file: pointer to file structure
 * @ubuf: pointer to user buffer
 * @length: buffer length
 * @offset: data offset in buffer
 *
 * Return: >=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_device *dev;
	struct mei_cl_cb *cb = NULL;
	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 (ubuf == NULL) {
		rets = -EMSGSIZE;
		goto out;
	}

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

	cb = mei_cl_read_cb(cl, file);
	if (cb)
		goto copy_buffer;

	if (*offset > 0)
		*offset = 0;

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

	if (list_empty(&cl->rd_completed) && !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,
				(!list_empty(&cl->rd_completed)) ||
				(!mei_cl_is_connected(cl)))) {

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

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

	cb = mei_cl_read_cb(cl, file);
	if (!cb) {
		rets = 0;
		goto out;
	}

copy_buffer:
	/* now copy the data to user space */
	if (cb->status) {
		rets = cb->status;
		cl_dbg(dev, cl, "read operation failed %d\n", rets);
		goto free;
	}

	cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
	       cb->buf.size, cb->buf_idx, *offset);
	if (*offset >= cb->buf_idx) {
		rets = 0;
		goto free;
	}

	/* length is being truncated to PAGE_SIZE,
	 * however buf_idx may point beyond that */
	length = min_t(size_t, length, cb->buf_idx - *offset);

	if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
		dev_dbg(dev->dev, "failed to copy data to userland\n");
		rets = -EFAULT;
		goto free;
	}

	rets = length;
	*offset += length;
	/* not all data was read, keep the cb */
	if (*offset < cb->buf_idx)
		goto out;

free:
	mei_io_cb_free(cb);
	*offset = 0;

out:
	cl_dbg(dev, cl, "end mei read rets = %d\n", rets);
	mutex_unlock(&dev->device_lock);
	return rets;
}
Esempio n. 2
0
/**
 * 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)
			*offset = 0;
	} else if (*offset > 0) {
		*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;
		goto out;
	}
	if (cl->reading_state != MEI_READ_COMPLETE) {
		rets = 0;
		goto out;
	}
	/* now copy the data to user space */
copy_buffer:
	dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
	    cb->response_buffer.size, cb->buf_idx);
	if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
		rets = -EMSGSIZE;
		goto free;
	}

	/* length is being truncated to PAGE_SIZE,
	 * however buf_idx may point beyond that */
	length = min_t(size_t, length, cb->buf_idx - *offset);

	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
		dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
		rets = -EFAULT;
		goto free;
	}

	rets = length;
	*offset += length;
	if ((unsigned long)*offset < cb->buf_idx)
		goto out;

free:
	cb_pos = mei_cl_find_read_cb(cl);
	/* Remove entry from read list */
	if (cb_pos)
		list_del(&cb_pos->list);
	mei_io_cb_free(cb);
	cl->reading_state = MEI_IDLE;
	cl->read_cb = NULL;
out:
	dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
	mutex_unlock(&dev->device_lock);
	return rets;
}
Esempio n. 3
0
/**
 * 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 i;
	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 ((cl->sm_state & MEI_WD_STATE_INDEPENDENCE_MSG_SENT) == 0) {
		/* Do not allow to read watchdog client */
		i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
		if (i >= 0) {
			struct mei_me_client *me_client = &dev->me_clients[i];
			if (cl->me_client_id == me_client->client_id) {
				rets = -EBADF;
				goto out;
			}
		}
	} else {
		cl->sm_state &= ~MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
	}

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

	if (cl->read_cb && cl->read_cb->buf_idx > *offset) {
		cb = cl->read_cb;
		goto copy_buffer;
	} else if (cl->read_cb && cl->read_cb->buf_idx > 0 &&
		   cl->read_cb->buf_idx <= *offset) {
		cb = cl->read_cb;
		rets = 0;
		goto free;
	} else if ((!cl->read_cb || !cl->read_cb->buf_idx) && *offset > 0) {
		/*Offset needs to be cleaned for contiguous reads*/
		*offset = 0;
		rets = 0;
		goto out;
	}

	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_FILE_INITIALIZING == cl->state ||
			 MEI_FILE_DISCONNECTED == cl->state ||
			 MEI_FILE_DISCONNECTING == cl->state))) {
			if (signal_pending(current))
				return -EINTR;
			return -ERESTARTSYS;
		}

		mutex_lock(&dev->device_lock);
		if (MEI_FILE_INITIALIZING == cl->state ||
		    MEI_FILE_DISCONNECTED == cl->state ||
		    MEI_FILE_DISCONNECTING == cl->state) {
			rets = -EBUSY;
			goto out;
		}
	}

	cb = cl->read_cb;

	if (!cb) {
		rets = -ENODEV;
		goto out;
	}
	if (cl->reading_state != MEI_READ_COMPLETE) {
		rets = 0;
		goto out;
	}
	/* now copy the data to user space */
copy_buffer:
	dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
	    cb->response_buffer.size, cb->buf_idx);
	if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
		rets = -EMSGSIZE;
		goto free;
	}

	/* length is being truncated to PAGE_SIZE,
	 * however buf_idx may point beyond that */
	length = min_t(size_t, length, cb->buf_idx - *offset);

	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
		rets = -EFAULT;
		goto free;
	}

	rets = length;
	*offset += length;
	if ((unsigned long)*offset < cb->buf_idx)
		goto out;

free:
	cb_pos = mei_cl_find_read_cb(cl);
	/* Remove entry from read list */
	if (cb_pos)
		list_del(&cb_pos->list);
	mei_io_cb_free(cb);
	cl->reading_state = MEI_IDLE;
	cl->read_cb = NULL;
out:
	dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
	mutex_unlock(&dev->device_lock);
	return rets;
}