mei: fixed address clients for the new platforms

Enable by default connection to fixed address clients
from user-space for skylake and newer platform.

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>

5 files changed, 57 insertions, 6 deletions

diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
index 6bdd75424fe8..8ad406315741 100644
--- a/drivers/misc/mei/debugfs.c
+++ b/drivers/misc/mei/debugfs.c
@@ -176,6 +176,8 @@ static ssize_t mei_dbgfs_read_devstate(struct file *fp, char __user *ubuf,
                                  dev->hbm_f_dot_supported);
                 pos += scnprintf(buf + pos, bufsz - pos, "\tEV: %01d\n",
                                  dev->hbm_f_ev_supported);
+                pos += scnprintf(buf + pos, bufsz - pos, "\tFA: %01d\n",
+                                 dev->hbm_f_fa_supported);
         }
 
         pos += scnprintf(buf + pos, bufsz - pos, "pg:  %s, %s\n",
@@ -191,6 +193,30 @@ static const struct file_operations mei_dbgfs_fops_devstate = {
         .llseek = generic_file_llseek,
 };
 
+static ssize_t mei_dbgfs_write_allow_fa(struct file *file,
+                                        const char __user *user_buf,
+                                        size_t count, loff_t *ppos)
+{
+        struct mei_device *dev;
+        int ret;
+
+        dev = container_of(file->private_data,
+                           struct mei_device, allow_fixed_address);
+
+        ret = debugfs_write_file_bool(file, user_buf, count, ppos);
+        if (ret < 0)
+                return ret;
+        dev->override_fixed_address = true;
+        return ret;
+}
+
+static const struct file_operations mei_dbgfs_fops_allow_fa = {
+        .open = simple_open,
+        .read = debugfs_read_file_bool,
+        .write = mei_dbgfs_write_allow_fa,
+        .llseek = generic_file_llseek,
+};
+
 /**
  * mei_dbgfs_deregister - Remove the debugfs files and directories
  *
@@ -240,8 +266,9 @@ int mei_dbgfs_register(struct mei_device *dev, const char *name)
                 dev_err(dev->dev, "devstate: registration failed\n");
                 goto err;
         }
-        f = debugfs_create_bool("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
-                                &dev->allow_fixed_address);
+        f = debugfs_create_file("allow_fixed_address", S_IRUSR | S_IWUSR, dir,
+                                &dev->allow_fixed_address,
+                                &mei_dbgfs_fops_allow_fa);
         if (!f) {
                 dev_err(dev->dev, "allow_fixed_address: registration failed\n");
                 goto err;
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index e7b7aad0999b..3915b8e8d0f1 100644
--- a/drivers/misc/mei/hbm.c
+++ b/drivers/misc/mei/hbm.c
@@ -979,6 +979,10 @@ static void mei_hbm_config_features(struct mei_device *dev)
         /* Notification Event Support */
         if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
                 dev->hbm_f_ev_supported = 1;
+
+        /* Fixed Address Client Support */
+        if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
+                dev->hbm_f_fa_supported = 1;
 }
 
 /**
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 4c5d6cfd79b4..459ad596df66 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -64,6 +64,12 @@
 #define HBM_MINOR_VERSION_EV               0
 #define HBM_MAJOR_VERSION_EV               2
 
+/*
+ * MEI version with fixed address client support
+ */
+#define HBM_MINOR_VERSION_FA               0
+#define HBM_MAJOR_VERSION_FA               2
+
 /* Host bus message command opcode */
 #define MEI_HBM_CMD_OP_MSK                  0x7f
 /* Host bus message command RESPONSE */
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index f1fdd65e9678..58fa2c83ee39 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -369,12 +369,22 @@ static int mei_ioctl_connect_client(struct file *file,
 
         /* find ME client we're trying to connect to */
         me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
-        if (!me_cl ||
-            (me_cl->props.fixed_address && !dev->allow_fixed_address)) {
+        if (!me_cl) {
                 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
                         &data->in_client_uuid);
-                mei_me_cl_put(me_cl);
-                return  -ENOTTY;
+                rets = -ENOTTY;
+                goto end;
+        }
+
+        if (me_cl->props.fixed_address) {
+                bool forbidden = dev->override_fixed_address ?
+                         !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
+                if (forbidden) {
+                        dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
+                                &data->in_client_uuid);
+                        rets = -ENOTTY;
+                        goto end;
+                }
         }
 
         dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 70c4da015401..6d97f3335e22 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -396,6 +396,7 @@ const char *mei_pg_state_str(enum mei_pg_state state);
  * @hbm_f_dc_supported  : hbm feature dynamic clients
  * @hbm_f_dot_supported : hbm feature disconnect on timeout
  * @hbm_f_ev_supported  : hbm feature event notification
+ * @hbm_f_fa_supported  : hbm feature fixed address client
  *
  * @me_clients_rwsem: rw lock over me_clients list
  * @me_clients  : list of FW clients
@@ -404,6 +405,7 @@ const char *mei_pg_state_str(enum mei_pg_state state);
  * @me_client_index : last FW client index in enumeration
  *
  * @allow_fixed_address: allow user space to connect a fixed client
+ * @override_fixed_address: force allow fixed address behavior
  *
  * @amthif_cmd_list : amthif list for cmd waiting
  * @iamthif_fp : file for current amthif operation
@@ -483,6 +485,7 @@ struct mei_device {
         unsigned int hbm_f_dc_supported:1;
         unsigned int hbm_f_dot_supported:1;
         unsigned int hbm_f_ev_supported:1;
+        unsigned int hbm_f_fa_supported:1;
 
         struct rw_semaphore me_clients_rwsem;
         struct list_head me_clients;
@@ -491,6 +494,7 @@ struct mei_device {
         unsigned long me_client_index;
 
         bool allow_fixed_address;
+        bool override_fixed_address;
 
         /* amthif list for cmd waiting */
         struct mei_cl_cb amthif_cmd_list;