mei: normalize me host client linking routines

In order we can use the same code pattern for in-kernel
and user space host clients we replace mei_cl_link_to_me
with mei_cl_link function.
We then have to keep me client lookupout of the new link function.

The unlinking cannot be yet symetric due to amthif connection
handling

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

7 files changed, 98 insertions, 75 deletions

diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index 64a9bfa5ad20..88e6aa0f6b4e 100644
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -65,22 +65,22 @@ void mei_amthif_reset_params(struct mei_device *dev)
  * @dev: the device structure
  *
  */
-void mei_amthif_host_init(struct mei_device *dev)
+int mei_amthif_host_init(struct mei_device *dev)
 {
-        int i;
+        struct mei_cl *cl = &dev->iamthif_cl;
         unsigned char *msg_buf;
+        int ret, i;
 
-        mei_cl_init(&dev->iamthif_cl, dev);
-        dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
+        mei_cl_init(cl, dev);
 
-        /* find ME amthif client */
-        i = mei_cl_link_me(&dev->iamthif_cl,
-                            &mei_amthif_guid, MEI_IAMTHIF_HOST_CLIENT_ID);
+        i = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
         if (i < 0) {
-                dev_info(&dev->pdev->dev, "failed to find iamthif client.\n");
-                return;
+                dev_info(&dev->pdev->dev, "amthif: failed to find the client\n");
+                return -ENOENT;
         }
 
+        cl->me_client_id = dev->me_clients[i].client_id;
+
         /* Assign iamthif_mtu to the value received from ME  */
 
         dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
@@ -94,19 +94,29 @@ void mei_amthif_host_init(struct mei_device *dev)
         msg_buf = kcalloc(dev->iamthif_mtu,
                         sizeof(unsigned char), GFP_KERNEL);
         if (!msg_buf) {
-                dev_dbg(&dev->pdev->dev, "memory allocation for ME message buffer failed.\n");
-                return;
+                dev_err(&dev->pdev->dev, "amthif: memory allocation for ME message buffer failed.\n");
+                return -ENOMEM;
         }
 
         dev->iamthif_msg_buf = msg_buf;
 
-        if (mei_hbm_cl_connect_req(dev, &dev->iamthif_cl)) {
-                dev_dbg(&dev->pdev->dev, "Failed to connect to AMTHI client\n");
-                dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
-                dev->iamthif_cl.host_client_id = 0;
+        ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
+
+        if (ret < 0) {
+                dev_err(&dev->pdev->dev, "amthif: failed link client\n");
+                return -ENOENT;
+        }
+
+        cl->state = MEI_FILE_CONNECTING;
+
+        if (mei_hbm_cl_connect_req(dev, cl)) {
+                dev_dbg(&dev->pdev->dev, "amthif: Failed to connect to ME client\n");
+                cl->state = MEI_FILE_DISCONNECTED;
+                cl->host_client_id = 0;
         } else {
-                dev->iamthif_cl.timer_count = MEI_CONNECT_TIMEOUT;
+                cl->timer_count = MEI_CONNECT_TIMEOUT;
         }
+        return 0;
 }
 
 /**
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 8103d94facb8..d566dd880eb0 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -258,54 +258,61 @@ struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
         return NULL;
 }
 
-
-/**
- * mei_me_cl_link - create link between host and me clinet and add
- *   me_cl to the list
- *
- * @cl: link between me and host client assocated with opened file descriptor
- * @uuid: uuid of ME client
- * @client_id: id of the host client
+/** mei_cl_link: allocte host id in the host map
  *
- * returns ME client index if ME client
+ * @cl - host client
+ * @id - fixed host id or -1 for genereting one
+ * returns 0 on success
  *      -EINVAL on incorrect values
  *      -ENONET if client not found
  */
-int mei_cl_link_me(struct mei_cl *cl, const uuid_le *uuid, u8 host_cl_id)
+int mei_cl_link(struct mei_cl *cl, int id)
 {
         struct mei_device *dev;
-        int i;
 
-        if (WARN_ON(!cl || !cl->dev || !uuid))
+        if (WARN_ON(!cl || !cl->dev))
                 return -EINVAL;
 
         dev = cl->dev;
 
-        /* check for valid client id */
-        i = mei_me_cl_by_uuid(dev, uuid);
-        if (i >= 0) {
-                cl->me_client_id = dev->me_clients[i].client_id;
-                cl->state = MEI_FILE_CONNECTING;
-                cl->host_client_id = host_cl_id;
+        /* If Id is not asigned get one*/
+        if (id == MEI_HOST_CLIENT_ID_ANY)
+                id = find_first_zero_bit(dev->host_clients_map,
+                                        MEI_CLIENTS_MAX);
 
-                list_add_tail(&cl->link, &dev->file_list);
-                return (u8)i;
+        if (id >= MEI_CLIENTS_MAX) {
+                dev_err(&dev->pdev->dev, "id exceded %d", MEI_CLIENTS_MAX) ;
+                return -ENOENT;
         }
 
-        return -ENOENT;
+        dev->open_handle_count++;
+
+        cl->host_client_id = id;
+        list_add_tail(&cl->link, &dev->file_list);
+
+        set_bit(id, dev->host_clients_map);
+
+        cl->state = MEI_FILE_INITIALIZING;
+
+        dev_dbg(&dev->pdev->dev, "link cl host id = %d\n", cl->host_client_id);
+        return 0;
 }
+
 /**
  * mei_cl_unlink - remove me_cl from the list
  *
  * @dev: the device structure
- * @host_client_id: host client id to be removed
  */
 int mei_cl_unlink(struct mei_cl *cl)
 {
         struct mei_device *dev;
         struct mei_cl *pos, *next;
 
-        if (WARN_ON(!cl || !cl->dev))
+        /* don't shout on error exit path */
+        if (!cl)
+                return 0;
+
+        if (WARN_ON(!cl->dev))
                 return -EINVAL;
 
         dev = cl->dev;
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 8dfd052dd0e6..240a1f321342 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -55,7 +55,7 @@ struct mei_cl *mei_cl_allocate(struct mei_device *dev);
 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev);
 
 
-int mei_cl_link_me(struct mei_cl *cl, const uuid_le *uuid, u8 host_cl_id);
+int mei_cl_link(struct mei_cl *cl, int id);
 int mei_cl_unlink(struct mei_cl *cl);
 
 int mei_cl_flush_queues(struct mei_cl *cl);
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 636639fbfc0a..9e4011ef8508 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -242,7 +242,11 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
                 /* remove entry if already in list */
                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
                 mei_cl_unlink(&dev->wd_cl);
+                if (dev->open_handle_count > 0)
+                        dev->open_handle_count--;
                 mei_cl_unlink(&dev->iamthif_cl);
+                if (dev->open_handle_count > 0)
+                        dev->open_handle_count--;
 
                 mei_amthif_reset_params(dev);
                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index d5d1a5957d5f..ec5fd7a0e289 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -103,7 +103,6 @@ static int mei_open(struct inode *inode, struct file *file)
 {
         struct mei_cl *cl;
         struct mei_device *dev;
-        unsigned long cl_id;
         int err;
 
         err = -ENODEV;
@@ -133,24 +132,9 @@ static int mei_open(struct inode *inode, struct file *file)
                 goto out_unlock;
         }
 
-        cl_id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
-        if (cl_id >= MEI_CLIENTS_MAX) {
-                dev_err(&dev->pdev->dev, "client_id exceded %d",
-                                MEI_CLIENTS_MAX) ;
+        err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
+        if (err)
                 goto out_unlock;
-        }
-
-        cl->host_client_id  = cl_id;
-
-        dev_dbg(&dev->pdev->dev, "client_id = %d\n", cl->host_client_id);
-
-        dev->open_handle_count++;
-
-        list_add_tail(&cl->link, &dev->file_list);
-
-        set_bit(cl->host_client_id, dev->host_clients_map);
-        cl->state = MEI_FILE_INITIALIZING;
-        cl->sm_state = 0;
 
         file->private_data = cl;
         mutex_unlock(&dev->device_lock);
@@ -209,6 +193,7 @@ static int mei_release(struct inode *inode, struct file *file)
         }
         mei_cl_unlink(cl);
 
+
         /* free read cb */
         cb = NULL;
         if (cl->read_cb) {
@@ -991,7 +976,13 @@ static void mei_remove(struct pci_dev *pdev)
 
         /* remove entry if already in list */
         dev_dbg(&pdev->dev, "list del iamthif and wd file list.\n");
+
+        if (dev->open_handle_count > 0)
+                dev->open_handle_count--;
         mei_cl_unlink(&dev->wd_cl);
+
+        if (dev->open_handle_count > 0)
+                dev->open_handle_count--;
         mei_cl_unlink(&dev->iamthif_cl);
 
         dev->iamthif_current_cb = NULL;
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 285e8e01d429..dcd7a44a806e 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -67,16 +67,16 @@ extern const u8 mei_wd_state_independence_msg[3][4];
  * Number of File descriptors/handles
  * that can be opened to the driver.
  *
- * Limit to 253: 256 Total Clients
+ * Limit to 255: 256 Total Clients
  * minus internal client for MEI Bus Messags
- * minus internal client for AMTHI
- * minus internal client for Watchdog
  */
-#define  MEI_MAX_OPEN_HANDLE_COUNT (MEI_CLIENTS_MAX - 3)
+#define  MEI_MAX_OPEN_HANDLE_COUNT (MEI_CLIENTS_MAX - 1)
 
 /*
  * Internal Clients Number
  */
+#define MEI_HOST_CLIENT_ID_ANY        (-1)
+#define MEI_HBM_HOST_CLIENT_ID         0 /* not used, just for documentation */
 #define MEI_WD_HOST_CLIENT_ID          1
 #define MEI_IAMTHIF_HOST_CLIENT_ID     2
 
@@ -339,7 +339,7 @@ void mei_timer(struct work_struct *work);
  */
 void mei_amthif_reset_params(struct mei_device *dev);
 
-void mei_amthif_host_init(struct mei_device *dev);
+int mei_amthif_host_init(struct mei_device *dev);
 
 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *priv_cb);
 
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c
index bfcbcc8c028b..77b3820380b0 100644
--- a/drivers/misc/mei/wd.c
+++ b/drivers/misc/mei/wd.c
@@ -64,30 +64,41 @@ static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  */
 int mei_wd_host_init(struct mei_device *dev)
 {
-        int id;
-        mei_cl_init(&dev->wd_cl, dev);
+        struct mei_cl *cl = &dev->wd_cl;
+        int i;
+        int ret;
+
+        mei_cl_init(cl, dev);
 
-        /* look for WD client and connect to it */
-        dev->wd_cl.state = MEI_FILE_DISCONNECTED;
         dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
         dev->wd_state = MEI_WD_IDLE;
 
-        /* Connect WD ME client to the host client */
-        id = mei_cl_link_me(&dev->wd_cl,
-                                &mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
 
-        if (id < 0) {
+        /* check for valid client id */
+        i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
+        if (i < 0) {
                 dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
                 return -ENOENT;
         }
 
-        if (mei_hbm_cl_connect_req(dev, &dev->wd_cl)) {
+        cl->me_client_id = dev->me_clients[i].client_id;
+
+        ret = mei_cl_link(cl, MEI_WD_HOST_CLIENT_ID);
+
+        if (ret < 0) {
+                dev_info(&dev->pdev->dev, "wd: failed link client\n");
+                return -ENOENT;
+        }
+
+        cl->state = MEI_FILE_CONNECTING;
+
+        if (mei_hbm_cl_connect_req(dev, cl)) {
                 dev_err(&dev->pdev->dev, "wd: failed to connect to the client\n");
-                dev->wd_cl.state = MEI_FILE_DISCONNECTED;
-                dev->wd_cl.host_client_id = 0;
+                cl->state = MEI_FILE_DISCONNECTED;
+                cl->host_client_id = 0;
                 return -EIO;
         }
-        dev->wd_cl.timer_count = MEI_CONNECT_TIMEOUT;
+        cl->timer_count = MEI_CONNECT_TIMEOUT;
 
         return 0;
 }