mei: bus: enable OS version only for SPT and newer

Sending OS version for support of TPM2_ChangeEPS() is required only
for SPT FW (HMB version 2.0) and newer.
On older platforms the command should be just ignored by the firmware
but some older platforms misbehave so it's safer to send the command
only if required.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=192051
Fixes: 7279b238 (mei: send OS type to the FW)
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Tested-by: Jan Niehusmann <jan@gondor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus-fixup.c

@@ -152,6 +152,9 @@ static void mei_mkhi_fix(struct mei_cl_device *cldev)
 {
 	int ret;
 
+	if (!cldev->bus->hbm_f_os_supported)
+		return;
+
 	ret = mei_cldev_enable(cldev);
 	if (ret)
 		return;

drivers/misc/mei/debugfs.c

@@ -180,6 +180,8 @@ static ssize_t mei_dbgfs_read_devstate(struct file *fp, char __user *ubuf,
 				 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, "\tOS: %01d\n",
+				 dev->hbm_f_os_supported);
 	}
 
 	pos += scnprintf(buf + pos, bufsz - pos, "pg:  %s, %s\n",

drivers/misc/mei/hbm.c

@@ -989,6 +989,10 @@ static void mei_hbm_config_features(struct mei_device *dev)
 	/* Fixed Address Client Support */
 	if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
 		dev->hbm_f_fa_supported = 1;
+
+	/* OS ver message Support */
+	if (dev->version.major_version >= HBM_MAJOR_VERSION_OS)
+		dev->hbm_f_os_supported = 1;
 }
 
 /**

drivers/misc/mei/hw.h

@@ -76,6 +76,12 @@
 #define HBM_MINOR_VERSION_FA               0
 #define HBM_MAJOR_VERSION_FA               2
 
+/*
+ * MEI version with OS ver message support
+ */
+#define HBM_MINOR_VERSION_OS               0
+#define HBM_MAJOR_VERSION_OS               2
+
 /* Host bus message command opcode */
 #define MEI_HBM_CMD_OP_MSK                  0x7f
 /* Host bus message command RESPONSE */

drivers/misc/mei/mei_dev.h

@@ -406,6 +406,7 @@ const char *mei_pg_state_str(enum mei_pg_state state);
  * @hbm_f_ev_supported  : hbm feature event notification
  * @hbm_f_fa_supported  : hbm feature fixed address client
  * @hbm_f_ie_supported  : hbm feature immediate reply to enum request
+ * @hbm_f_os_supported  : hbm feature support OS ver message
  *
  * @me_clients_rwsem: rw lock over me_clients list
  * @me_clients  : list of FW clients
@@ -487,6 +488,7 @@ struct mei_device {
 	unsigned int hbm_f_ev_supported:1;
 	unsigned int hbm_f_fa_supported:1;
 	unsigned int hbm_f_ie_supported:1;
+	unsigned int hbm_f_os_supported:1;
 
 	struct rw_semaphore me_clients_rwsem;
 	struct list_head me_clients;