mei: export active connections to debugfs

Export active connection state to debugfs
The information displayed is [me,host] id pair,
client connection state, and client's read and write states

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

1 files changed, 54 insertions, 0 deletions

diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
index a3ae154444b2..ced5b777c70f 100644
--- a/drivers/misc/mei/debugfs.c
+++ b/drivers/misc/mei/debugfs.c
@@ -75,6 +75,54 @@ static const struct file_operations mei_dbgfs_fops_meclients = {
         .llseek = generic_file_llseek,
 };
 
+static ssize_t mei_dbgfs_read_active(struct file *fp, char __user *ubuf,
+                                        size_t cnt, loff_t *ppos)
+{
+        struct mei_device *dev = fp->private_data;
+        struct mei_cl *cl;
+        const size_t bufsz = 1024;
+        char *buf;
+        int i = 0;
+        int pos = 0;
+        int ret;
+
+        if (!dev)
+                return -ENODEV;
+
+        buf = kzalloc(bufsz, GFP_KERNEL);
+        if  (!buf)
+                return -ENOMEM;
+
+        pos += scnprintf(buf + pos, bufsz - pos,
+                        "  |me|host|state|rd|wr|\n");
+
+        mutex_lock(&dev->device_lock);
+
+        /*  if the driver is not enabled the list won't b consitent */
+        if (dev->dev_state != MEI_DEV_ENABLED)
+                goto out;
+
+        list_for_each_entry(cl, &dev->file_list, link) {
+
+                pos += scnprintf(buf + pos, bufsz - pos,
+                        "%2d|%2d|%4d|%5d|%2d|%2d|\n",
+                        i, cl->me_client_id, cl->host_client_id, cl->state,
+                        cl->reading_state, cl->writing_state);
+                i++;
+        }
+out:
+        mutex_unlock(&dev->device_lock);
+        ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, pos);
+        kfree(buf);
+        return ret;
+}
+
+static const struct file_operations mei_dbgfs_fops_active = {
+        .open = simple_open,
+        .read = mei_dbgfs_read_active,
+        .llseek = generic_file_llseek,
+};
+
 static ssize_t mei_dbgfs_read_devstate(struct file *fp, char __user *ubuf,
                                         size_t cnt, loff_t *ppos)
 {
@@ -128,6 +176,12 @@ int mei_dbgfs_register(struct mei_device *dev, const char *name)
                 dev_err(&dev->pdev->dev, "meclients: registration failed\n");
                 goto err;
         }
+        f = debugfs_create_file("active", S_IRUSR, dir,
+                                dev, &mei_dbgfs_fops_active);
+        if (!f) {
+                dev_err(&dev->pdev->dev, "meclients: registration failed\n");
+                goto err;
+        }
         f = debugfs_create_file("devstate", S_IRUSR, dir,
                                 dev, &mei_dbgfs_fops_devstate);
         if (!f) {