clear-pkgs-linux-iot-lts2018/0149-mei-bus-use-zero-vtag-for-bus-clients.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Wed, 24 Oct 2018 14:30:40 +0300
Subject: [PATCH] mei: bus: use zero vtag for bus clients.

Once vtags are enabled a zero vtag is required
for the read flow to work for also for devices on mei client bus.

Change-Id: I932ca3227348fa3415a8a7b4689b4da32e363594
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/misc/mei/bus.c    | 29 +++++++++++++++++++++++++++++
 drivers/misc/mei/client.c | 19 +++++++++++++++++--
 drivers/misc/mei/client.h |  1 +
 drivers/misc/mei/main.c   | 17 +----------------
 4 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 26bf76108950..24282139a261 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -504,6 +504,16 @@ static void mei_cl_bus_module_put(struct mei_cl_device *cldev)
 	module_put(cldev->bus->dev->driver->owner);
 }
 
+static int mei_cldev_vm_support_check(struct mei_cl_device *cldev)
+{
+	struct mei_device *bus = cldev->bus;
+
+	if (!bus->hbm_f_vm_supported)
+		return -EOPNOTSUPP;
+
+	return cldev->me_cl->props.vm_supported ? 0 : -EOPNOTSUPP;
+}
+
 /**
  * mei_cldev_enable - enable me client device
  *     create connection with me client
@@ -516,6 +526,7 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
 {
 	struct mei_device *bus = cldev->bus;
 	struct mei_cl *cl;
+	struct mei_cl_vtag *cl_vtag;
 	int ret;
 
 	cl = cldev->cl;
@@ -540,6 +551,16 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
 		goto out;
 	}
 
+	if (!mei_cldev_vm_support_check(cldev)) {
+		cl_vtag = mei_cl_vtag_alloc(NULL, 0);
+		if (IS_ERR(cl_vtag)) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		list_add_tail(&cl_vtag->list, &cl->vtag_map);
+	}
+
 	ret = mei_cl_connect(cl, cldev->me_cl, NULL);
 	if (ret < 0)
 		dev_err(&cldev->dev, "cannot connect\n");
@@ -582,6 +603,7 @@ int mei_cldev_disable(struct mei_cl_device *cldev)
 {
 	struct mei_device *bus;
 	struct mei_cl *cl;
+	struct mei_cl_vtag *cl_vtag;
 	int err;
 
 	if (!cldev)
@@ -595,6 +617,13 @@ int mei_cldev_disable(struct mei_cl_device *cldev)
 
 	mutex_lock(&bus->device_lock);
 
+	cl_vtag = list_first_entry_or_null(&cl->vtag_map,
+					   struct mei_cl_vtag, list);
+	if (cl_vtag) {
+		list_del(&cl_vtag->list);
+		kfree(cl_vtag);
+	}
+
 	if (!mei_cl_is_connected(cl)) {
 		dev_dbg(bus->dev, "Already disconnected\n");
 		err = 0;
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 893af8985620..d6e871fb25af 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1279,6 +1279,21 @@ static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
 	return 0;
 }
 
+struct mei_cl_vtag *mei_cl_vtag_alloc(struct file *fp, u8 vtag)
+{
+	struct mei_cl_vtag *cl_vtag;
+
+	cl_vtag = kzalloc(sizeof(*cl_vtag), GFP_KERNEL);
+	if (!cl_vtag)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&cl_vtag->list);
+	cl_vtag->vtag = vtag;
+	cl_vtag->fp = fp;
+
+	return cl_vtag;
+}
+
 const struct file *mei_cl_fp_by_vtag(const struct mei_cl *cl, u8 vtag)
 {
 	struct mei_cl_vtag *vtag_l;
@@ -1287,7 +1302,7 @@ const struct file *mei_cl_fp_by_vtag(const struct mei_cl *cl, u8 vtag)
 		if (vtag_l->vtag == vtag)
 			return vtag_l->fp;
 
-	return NULL;
+	return ERR_PTR(-ENOENT);
 }
 
 static void mei_cl_reset_read_by_vtag(const struct mei_cl *cl, u8 vtag)
@@ -1337,7 +1352,7 @@ void mei_cl_add_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb)
 
 	if (!mei_cl_vm_support_check(cl)) {
 		fp = mei_cl_fp_by_vtag(cl, cb->vtag);
-		if (!fp) {
+		if (IS_ERR(fp)) {
 			/* client already disconnected, discarding */
 			mei_io_cb_free(cb);
 			return;
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 656eadea32a4..234b75ddf427 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -114,6 +114,7 @@ struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
 					    const struct file *fp);
 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp);
 
+struct mei_cl_vtag *mei_cl_vtag_alloc(struct file *fp, u8 vtag);
 const struct file *mei_cl_fp_by_vtag(const struct mei_cl *cl, u8 vtag);
 /*
  *  MEI input output function prototype
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 7e6c3586cbcf..59a6a7a19621 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -458,21 +458,6 @@ static int mei_vm_support_check(struct mei_device *dev, const uuid_le *uuid)
 	return ret;
 }
 
-static struct mei_cl_vtag *mei_cl_vtag_alloc(struct file *fp, u8 vtag)
-{
-	struct mei_cl_vtag *cl_vtag;
-
-	cl_vtag = kzalloc(sizeof(*cl_vtag), GFP_KERNEL);
-	if (!cl_vtag)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&cl_vtag->list);
-	cl_vtag->vtag = vtag;
-	cl_vtag->fp = fp;
-
-	return cl_vtag;
-}
-
 static int mei_ioctl_connect_vtag(struct file *file,
 				  const uuid_le *in_client_uuid,
 				  struct mei_client *client,
@@ -503,7 +488,7 @@ static int mei_ioctl_connect_vtag(struct file *file,
 			continue;
 
 		/* if tag already exist try another fp */
-		if (mei_cl_fp_by_vtag(pos, vtag))
+		if (!IS_ERR(mei_cl_fp_by_vtag(pos, vtag)))
 			continue;
 
 		/* replace cl with acquired one */
-- 
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