1 files changed, 177 insertions, 120 deletions

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 1ee2b9492a8..8c078b808cd 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -29,20 +29,21 @@
  * mei_me_cl_by_uuid - locate index of me client
  *
  * @dev: mei device
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
  * returns me client index or -ENOENT if not found
  */
 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *uuid)
 {
-	int i, res = -ENOENT;
+	int i;
 
 	for (i = 0; i < dev->me_clients_num; ++i)
 		if (uuid_le_cmp(*uuid,
-				dev->me_clients[i].props.protocol_name) == 0) {
-			res = i;
-			break;
-		}
+				dev->me_clients[i].props.protocol_name) == 0)
+			return i;
 
-	return res;
+	return -ENOENT;
 }
 
 
@@ -60,37 +61,79 @@ int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *uuid)
 int mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
 {
 	int i;
+
 	for (i = 0; i < dev->me_clients_num; i++)
 		if (dev->me_clients[i].client_id == client_id)
-			break;
-	if (WARN_ON(dev->me_clients[i].client_id != client_id))
-		return -ENOENT;
+			return i;
 
-	if (i == dev->me_clients_num)
-		return -ENOENT;
-
-	return i;
+	return -ENOENT;
 }
 
 
 /**
- * mei_io_list_flush - removes list entry belonging to cl.
+ * mei_cl_cmp_id - tells if the clients are the same
  *
- * @list:  An instance of our list structure
- * @cl: host client
+ * @cl1: host client 1
+ * @cl2: host client 2
+ *
+ * returns true  - if the clients has same host and me ids
+ *         false - otherwise
+ */
+static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
+				const struct mei_cl *cl2)
+{
+	return cl1 && cl2 &&
+		(cl1->host_client_id == cl2->host_client_id) &&
+		(cl1->me_client_id == cl2->me_client_id);
+}
+
+/**
+ * mei_io_list_flush - removes cbs belonging to cl.
+ *
+ * @list:  an instance of our list structure
+ * @cl:    host client, can be NULL for flushing the whole list
+ * @free:  whether to free the cbs
  */
-void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
+static void __mei_io_list_flush(struct mei_cl_cb *list,
+				struct mei_cl *cl, bool free)
 {
 	struct mei_cl_cb *cb;
 	struct mei_cl_cb *next;
 
+	/* enable removing everything if no cl is specified */
 	list_for_each_entry_safe(cb, next, &list->list, list) {
-		if (cb->cl && mei_cl_cmp_id(cl, cb->cl))
+		if (!cl || (cb->cl && mei_cl_cmp_id(cl, cb->cl))) {
 			list_del(&cb->list);
+			if (free)
+				mei_io_cb_free(cb);
+		}
 	}
 }
 
 /**
+ * mei_io_list_flush - removes list entry belonging to cl.
+ *
+ * @list:  An instance of our list structure
+ * @cl: host client
+ */
+static inline void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
+{
+	__mei_io_list_flush(list, cl, false);
+}
+
+
+/**
+ * mei_io_list_free - removes cb belonging to cl and free them
+ *
+ * @list:  An instance of our list structure
+ * @cl: host client
+ */
+static inline void mei_io_list_free(struct mei_cl_cb *list, struct mei_cl *cl)
+{
+	__mei_io_list_flush(list, cl, true);
+}
+
+/**
  * mei_io_cb_free - free mei_cb_private related memory
  *
  * @cb: mei callback struct
@@ -196,8 +239,8 @@ int mei_cl_flush_queues(struct mei_cl *cl)
 
 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
 	mei_io_list_flush(&cl->dev->read_list, cl);
-	mei_io_list_flush(&cl->dev->write_list, cl);
-	mei_io_list_flush(&cl->dev->write_waiting_list, cl);
+	mei_io_list_free(&cl->dev->write_list, cl);
+	mei_io_list_free(&cl->dev->write_waiting_list, cl);
 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
@@ -254,10 +297,9 @@ struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
 {
 	struct mei_device *dev = cl->dev;
-	struct mei_cl_cb *cb = NULL;
-	struct mei_cl_cb *next = NULL;
+	struct mei_cl_cb *cb;
 
-	list_for_each_entry_safe(cb, next, &dev->read_list.list, list)
+	list_for_each_entry(cb, &dev->read_list.list, list)
 		if (mei_cl_cmp_id(cl, cb->cl))
 			return cb;
 	return NULL;
@@ -375,6 +417,23 @@ void mei_host_client_init(struct work_struct *work)
 	mutex_unlock(&dev->device_lock);
 }
 
+/**
+ * mei_hbuf_acquire: try to acquire host buffer
+ *
+ * @dev: the device structure
+ * returns true if host buffer was acquired
+ */
+bool mei_hbuf_acquire(struct mei_device *dev)
+{
+	if (!dev->hbuf_is_ready) {
+		dev_dbg(&dev->pdev->dev, "hbuf is not ready\n");
+		return false;
+	}
+
+	dev->hbuf_is_ready = false;
+
+	return true;
+}
 
 /**
  * mei_cl_disconnect - disconnect host client from the me one
@@ -406,8 +465,7 @@ int mei_cl_disconnect(struct mei_cl *cl)
 		return -ENOMEM;
 
 	cb->fop_type = MEI_FOP_CLOSE;
-	if (dev->hbuf_is_ready) {
-		dev->hbuf_is_ready = false;
+	if (mei_hbuf_acquire(dev)) {
 		if (mei_hbm_cl_disconnect_req(dev, cl)) {
 			rets = -ENODEV;
 			cl_err(dev, cl, "failed to disconnect.\n");
@@ -461,17 +519,17 @@ free:
 bool mei_cl_is_other_connecting(struct mei_cl *cl)
 {
 	struct mei_device *dev;
-	struct mei_cl *pos;
-	struct mei_cl *next;
+	struct mei_cl *ocl; /* the other client */
 
 	if (WARN_ON(!cl || !cl->dev))
 		return false;
 
 	dev = cl->dev;
 
-	list_for_each_entry_safe(pos, next, &dev->file_list, link) {
-		if ((pos->state == MEI_FILE_CONNECTING) &&
-		    (pos != cl) && cl->me_client_id == pos->me_client_id)
+	list_for_each_entry(ocl, &dev->file_list, link) {
+		if (ocl->state == MEI_FILE_CONNECTING &&
+		    ocl != cl &&
+		    cl->me_client_id == ocl->me_client_id)
 			return true;
 
 	}
@@ -505,11 +563,10 @@ int mei_cl_connect(struct mei_cl *cl, struct file *file)
 		goto out;
 	}
 
-	cb->fop_type = MEI_FOP_IOCTL;
-
-	if (dev->hbuf_is_ready && !mei_cl_is_other_connecting(cl)) {
-		dev->hbuf_is_ready = false;
+	cb->fop_type = MEI_FOP_CONNECT;
 
+	/* run hbuf acquire last so we don't have to undo */
+	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
 		if (mei_hbm_cl_connect_req(dev, cl)) {
 			rets = -ENODEV;
 			goto out;
@@ -521,18 +578,19 @@ int mei_cl_connect(struct mei_cl *cl, struct file *file)
 	}
 
 	mutex_unlock(&dev->device_lock);
-	rets = wait_event_timeout(dev->wait_recvd_msg,
-				 (cl->state == MEI_FILE_CONNECTED ||
-				  cl->state == MEI_FILE_DISCONNECTED),
-				 mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
+	wait_event_timeout(dev->wait_recvd_msg,
+			(cl->state == MEI_FILE_CONNECTED ||
+			 cl->state == MEI_FILE_DISCONNECTED),
+			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 	mutex_lock(&dev->device_lock);
 
 	if (cl->state != MEI_FILE_CONNECTED) {
-		rets = -EFAULT;
+		/* something went really wrong */
+		if (!cl->status)
+			cl->status = -EFAULT;
 
 		mei_io_list_flush(&dev->ctrl_rd_list, cl);
 		mei_io_list_flush(&dev->ctrl_wr_list, cl);
-		goto out;
 	}
 
 	rets = cl->status;
@@ -554,7 +612,8 @@ out:
 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
 {
 	struct mei_device *dev;
-	int i;
+	struct mei_me_client *me_cl;
+	int id;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -EINVAL;
@@ -567,19 +626,19 @@ int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
 	if (cl->mei_flow_ctrl_creds > 0)
 		return 1;
 
-	for (i = 0; i < dev->me_clients_num; i++) {
-		struct mei_me_client  *me_cl = &dev->me_clients[i];
-		if (me_cl->client_id == cl->me_client_id) {
-			if (me_cl->mei_flow_ctrl_creds) {
-				if (WARN_ON(me_cl->props.single_recv_buf == 0))
-					return -EINVAL;
-				return 1;
-			} else {
-				return 0;
-			}
-		}
+	id = mei_me_cl_by_id(dev, cl->me_client_id);
+	if (id < 0) {
+		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
+		return id;
 	}
-	return -ENOENT;
+
+	me_cl = &dev->me_clients[id];
+	if (me_cl->mei_flow_ctrl_creds) {
+		if (WARN_ON(me_cl->props.single_recv_buf == 0))
+			return -EINVAL;
+		return 1;
+	}
+	return 0;
 }
 
 /**
@@ -595,32 +654,31 @@ int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
 {
 	struct mei_device *dev;
-	int i;
+	struct mei_me_client *me_cl;
+	int id;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -EINVAL;
 
 	dev = cl->dev;
 
-	if (!dev->me_clients_num)
-		return -ENOENT;
+	id = mei_me_cl_by_id(dev, cl->me_client_id);
+	if (id < 0) {
+		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
+		return id;
+	}
 
-	for (i = 0; i < dev->me_clients_num; i++) {
-		struct mei_me_client  *me_cl = &dev->me_clients[i];
-		if (me_cl->client_id == cl->me_client_id) {
-			if (me_cl->props.single_recv_buf != 0) {
-				if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
-					return -EINVAL;
-				dev->me_clients[i].mei_flow_ctrl_creds--;
-			} else {
-				if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
-					return -EINVAL;
-				cl->mei_flow_ctrl_creds--;
-			}
-			return 0;
-		}
+	me_cl = &dev->me_clients[id];
+	if (me_cl->props.single_recv_buf != 0) {
+		if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
+			return -EINVAL;
+		me_cl->mei_flow_ctrl_creds--;
+	} else {
+		if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
+			return -EINVAL;
+		cl->mei_flow_ctrl_creds--;
 	}
-	return -ENOENT;
+	return 0;
 }
 
 /**
@@ -652,7 +710,7 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length)
 	i = mei_me_cl_by_id(dev, cl->me_client_id);
 	if (i < 0) {
 		cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
-		return  -ENODEV;
+		return  -ENOTTY;
 	}
 
 	cb = mei_io_cb_init(cl, NULL);
@@ -666,9 +724,7 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length)
 		goto err;
 
 	cb->fop_type = MEI_FOP_READ;
-	cl->read_cb = cb;
-	if (dev->hbuf_is_ready) {
-		dev->hbuf_is_ready = false;
+	if (mei_hbuf_acquire(dev)) {
 		if (mei_hbm_cl_flow_control_req(dev, cl)) {
 			cl_err(dev, cl, "flow control send failed\n");
 			rets = -ENODEV;
@@ -678,6 +734,9 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length)
 	} else {
 		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 	}
+
+	cl->read_cb = cb;
+
 	return rets;
 err:
 	mei_io_cb_free(cb);
@@ -685,27 +744,26 @@ err:
 }
 
 /**
- * mei_cl_irq_write_complete - write a message to device
+ * mei_cl_irq_write - write a message to device
  *	from the interrupt thread context
  *
  * @cl: client
  * @cb: callback block.
- * @slots: free slots.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise error.
  */
-int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
-				     s32 *slots, struct mei_cl_cb *cmpl_list)
+int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
+		     struct mei_cl_cb *cmpl_list)
 {
 	struct mei_device *dev;
 	struct mei_msg_data *buf;
 	struct mei_msg_hdr mei_hdr;
 	size_t len;
 	u32 msg_slots;
+	int slots;
 	int rets;
 
-
 	if (WARN_ON(!cl || !cl->dev))
 		return -ENODEV;
 
@@ -722,6 +780,7 @@ int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
 		return 0;
 	}
 
+	slots = mei_hbuf_empty_slots(dev);
 	len = buf->size - cb->buf_idx;
 	msg_slots = mei_data2slots(len);
 
@@ -730,13 +789,13 @@ int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
 	mei_hdr.reserved = 0;
 	mei_hdr.internal = cb->internal;
 
-	if (*slots >= msg_slots) {
+	if (slots >= msg_slots) {
 		mei_hdr.length = len;
 		mei_hdr.msg_complete = 1;
 	/* Split the message only if we can write the whole host buffer */
-	} else if (*slots == dev->hbuf_depth) {
-		msg_slots = *slots;
-		len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
+	} else if (slots == dev->hbuf_depth) {
+		msg_slots = slots;
+		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 		mei_hdr.length = len;
 		mei_hdr.msg_complete = 0;
 	} else {
@@ -747,7 +806,6 @@ int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
 	cl_dbg(dev, cl, "buf: size = %d idx = %lu\n",
 			cb->request_buffer.size, cb->buf_idx);
 
-	*slots -=  msg_slots;
 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
 	if (rets) {
 		cl->status = rets;
@@ -800,21 +858,29 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 
 
 	cb->fop_type = MEI_FOP_WRITE;
+	cb->buf_idx = 0;
+	cl->writing_state = MEI_IDLE;
+
+	mei_hdr.host_addr = cl->host_client_id;
+	mei_hdr.me_addr = cl->me_client_id;
+	mei_hdr.reserved = 0;
+	mei_hdr.msg_complete = 0;
+	mei_hdr.internal = cb->internal;
 
 	rets = mei_cl_flow_ctrl_creds(cl);
 	if (rets < 0)
 		goto err;
 
-	/* Host buffer is not ready, we queue the request */
-	if (rets == 0 || !dev->hbuf_is_ready) {
-		cb->buf_idx = 0;
-		/* unseting complete will enqueue the cb for write */
-		mei_hdr.msg_complete = 0;
+	if (rets == 0) {
+		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
+		rets = buf->size;
+		goto out;
+	}
+	if (!mei_hbuf_acquire(dev)) {
+		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
 		rets = buf->size;
 		goto out;
 	}
-
-	dev->hbuf_is_ready = false;
 
 	/* Check for a maximum length */
 	if (buf->size > mei_hbuf_max_len(dev)) {
@@ -825,12 +891,6 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 		mei_hdr.msg_complete = 1;
 	}
 
-	mei_hdr.host_addr = cl->host_client_id;
-	mei_hdr.me_addr = cl->me_client_id;
-	mei_hdr.reserved = 0;
-	mei_hdr.internal = cb->internal;
-
-
 	rets = mei_write_message(dev, &mei_hdr, buf->data);
 	if (rets)
 		goto err;
@@ -838,13 +898,12 @@ int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 	cl->writing_state = MEI_WRITING;
 	cb->buf_idx = mei_hdr.length;
 
-	rets = buf->size;
 out:
 	if (mei_hdr.msg_complete) {
-		if (mei_cl_flow_ctrl_reduce(cl)) {
-			rets = -ENODEV;
+		rets = mei_cl_flow_ctrl_reduce(cl);
+		if (rets < 0)
 			goto err;
-		}
+
 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
 	} else {
 		list_add_tail(&cb->list, &dev->write_list.list);
@@ -854,15 +913,18 @@ out:
 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
 
 		mutex_unlock(&dev->device_lock);
-		if (wait_event_interruptible(cl->tx_wait,
-			cl->writing_state == MEI_WRITE_COMPLETE)) {
-				if (signal_pending(current))
-					rets = -EINTR;
-				else
-					rets = -ERESTARTSYS;
-		}
+		rets = wait_event_interruptible(cl->tx_wait,
+				cl->writing_state == MEI_WRITE_COMPLETE);
 		mutex_lock(&dev->device_lock);
+		/* wait_event_interruptible returns -ERESTARTSYS */
+		if (rets) {
+			if (signal_pending(current))
+				rets = -EINTR;
+			goto err;
+		}
 	}
+
+	rets = buf->size;
 err:
 	return rets;
 }
@@ -903,12 +965,11 @@ void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 
 void mei_cl_all_disconnect(struct mei_device *dev)
 {
-	struct mei_cl *cl, *next;
+	struct mei_cl *cl;
 
-	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
+	list_for_each_entry(cl, &dev->file_list, link) {
 		cl->state = MEI_FILE_DISCONNECTED;
 		cl->mei_flow_ctrl_creds = 0;
-		cl->read_cb = NULL;
 		cl->timer_count = 0;
 	}
 }
@@ -921,8 +982,8 @@ void mei_cl_all_disconnect(struct mei_device *dev)
  */
 void mei_cl_all_wakeup(struct mei_device *dev)
 {
-	struct mei_cl *cl, *next;
-	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
+	struct mei_cl *cl;
+	list_for_each_entry(cl, &dev->file_list, link) {
 		if (waitqueue_active(&cl->rx_wait)) {
 			cl_dbg(dev, cl, "Waking up reading client!\n");
 			wake_up_interruptible(&cl->rx_wait);
@@ -941,12 +1002,8 @@ void mei_cl_all_wakeup(struct mei_device *dev)
  */
 void mei_cl_all_write_clear(struct mei_device *dev)
 {
-	struct mei_cl_cb *cb, *next;
-
-	list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
-		list_del(&cb->list);
-		mei_io_cb_free(cb);
-	}
+	mei_io_list_free(&dev->write_list, NULL);
+	mei_io_list_free(&dev->write_waiting_list, NULL);
 }