[char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT and newer

[Tomas Winkler <tomas.winkler@intel.com>]

From: Alexander Usyskin <alexander.usyskin@intel.com>

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: 7279b238bade (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>
---
V2: use correct sha1 of the original buggy patch

 drivers/misc/mei/bus-fixup.c | 3 +++
 drivers/misc/mei/debugfs.c   | 2 ++
 drivers/misc/mei/hbm.c       | 4 ++++
 drivers/misc/mei/hw.h        | 6 ++++++
 drivers/misc/mei/mei_dev.h   | 2 ++
 5 files changed, 17 insertions(+)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 18e05ca7584f..3600c9993a98 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/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;
diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
index c6c051b52f55..c6217a4993ad 100644
--- a/drivers/misc/mei/debugfs.c
+++ b/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",
diff --git a/drivers/misc/mei/hbm.c b/drivers/misc/mei/hbm.c
index dd7f15a65eed..25b4a1ba522d 100644
--- a/drivers/misc/mei/hbm.c
+++ b/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;
 }
 
 /**
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 9daf3f9aed25..e1e4d47d4d7d 100644
--- a/drivers/misc/mei/hw.h
+++ b/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 */
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 699693cd8c59..8dadb98662a9 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/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;
-- 
2.7.4