mei: hbm: revamp client connect and disconnection status

1. Return -ENOTTY on client connect if the requested client was not found
 on the enumeration list or the client was internally disabled, in the later
 case FW will return NOT_FOUND.
2. Return -EBUSY if the client cannot be connected because of resource
 contention
3. Change response status enum to have MEI_CL_ prefix
4. Add function to translate response status to a string
for more readable logging

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

4 files changed, 59 insertions, 39 deletions

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 9ac72f1ea6b9..8afba0534779 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -521,18 +521,19 @@ 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;
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index d3fcb23bb081..d360e9a5a1a5 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -23,6 +23,40 @@
 #include "hbm.h"
 #include "hw-me.h"
 
+static const char *mei_cl_conn_status_str(enum mei_cl_connect_status status)
+{
+#define MEI_CL_CS(status) case MEI_CL_CONN_##status: return #status
+        switch (status) {
+        MEI_CL_CS(SUCCESS);
+        MEI_CL_CS(NOT_FOUND);
+        MEI_CL_CS(ALREADY_STARTED);
+        MEI_CL_CS(OUT_OF_RESOURCES);
+        MEI_CL_CS(MESSAGE_SMALL);
+        default: return "unknown";
+        }
+#undef MEI_CL_CCS
+}
+
+/**
+ * mei_cl_conn_status_to_errno - convert client connect response
+ * status to error code
+ *
+ * @status: client connect response status
+ *
+ * returns corresponding error code
+ */
+static int mei_cl_conn_status_to_errno(enum mei_cl_connect_status status)
+{
+        switch (status) {
+        case MEI_CL_CONN_SUCCESS:          return 0;
+        case MEI_CL_CONN_NOT_FOUND:        return -ENOTTY;
+        case MEI_CL_CONN_ALREADY_STARTED:  return -EBUSY;
+        case MEI_CL_CONN_OUT_OF_RESOURCES: return -EBUSY;
+        case MEI_CL_CONN_MESSAGE_SMALL:    return -EINVAL;
+        default:                           return -EINVAL;
+        }
+}
+
 /**
  * mei_hbm_me_cl_allocate - allocates storage for me clients
  *
@@ -111,14 +145,11 @@ 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) {
+                if (rs->status == MEI_CL_CONN_SUCCESS)
                         cl->state = MEI_FILE_CONNECTED;
-                        cl->status = 0;
-
-                } else {
+                else
                         cl->state = MEI_FILE_DISCONNECTED;
-                        cl->status = -ENODEV;
-                }
+                cl->status = mei_cl_conn_status_to_errno(rs->status);
                 cl->timer_count = 0;
 
                 return true;
@@ -438,14 +469,8 @@ static void mei_hbm_cl_disconnect_res(struct mei_device *dev,
         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);
+        dev_dbg(&dev->pdev->dev, "hbm: disconnect response cl:host=%02d me=%02d 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;
@@ -458,7 +483,7 @@ static void mei_hbm_cl_disconnect_res(struct mei_device *dev,
                 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)
+                        if (rs->status == MEI_CL_DISCONN_SUCCESS)
                                 cl->state = MEI_FILE_DISCONNECTED;
 
                         cl->status = 0;
@@ -500,14 +525,9 @@ static void mei_hbm_cl_connect_res(struct mei_device *dev,
         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);
+        dev_dbg(&dev->pdev->dev, "hbm: connect response cl:host=%02d me=%02d status=%s\n",
+                        rs->me_addr, rs->host_addr,
+                        mei_cl_conn_status_str(rs->status));
 
         /* if WD or iamthif client treat specially */
 
@@ -532,7 +552,6 @@ static void mei_hbm_cl_connect_res(struct mei_device *dev,
                 if (pos->fop_type == MEI_FOP_CONNECT) {
                         if (is_treat_specially_client(cl, rs)) {
                                 list_del(&pos->list);
-                                cl->status = 0;
                                 cl->timer_count = 0;
                                 break;
                         }
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index e06779d4413e..6b476ab49b2e 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -89,19 +89,19 @@ enum mei_stop_reason_types {
  * Client Connect Status
  * used by hbm_client_connect_response.status
  */
-enum client_connect_status_types {
-        CCS_SUCCESS = 0x00,
-        CCS_NOT_FOUND = 0x01,
-        CCS_ALREADY_STARTED = 0x02,
-        CCS_OUT_OF_RESOURCES = 0x03,
-        CCS_MESSAGE_SMALL = 0x04
+enum mei_cl_connect_status {
+        MEI_CL_CONN_SUCCESS          = 0x00,
+        MEI_CL_CONN_NOT_FOUND        = 0x01,
+        MEI_CL_CONN_ALREADY_STARTED  = 0x02,
+        MEI_CL_CONN_OUT_OF_RESOURCES = 0x03,
+        MEI_CL_CONN_MESSAGE_SMALL    = 0x04
 };
 
 /*
  * Client Disconnect Status
  */
-enum client_disconnect_status_types {
-        CDS_SUCCESS = 0x00
+enum  mei_cl_disconnect_status {
+        MEI_CL_DISCONN_SUCCESS = 0x00
 };
 
 /*
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 5424f8ff3f7f..434242bada89 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -471,7 +471,7 @@ static int mei_ioctl_connect_client(struct file *file,
         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;
+                rets = -ENOTTY;
                 goto end;
         }