mei: revamp open handler counts

Make open counter to be incremented and decremented
from mei_cl_link and mei_cl_unlik function respectively

Nfc was assuming symmetric linking API and thus open handler
count was never decreased. This patch fixes that.
We need to add separate open hander count for amthif which
is handled out of link/unlink functions and doesn't break
the symmetric API.

Last we do not waste clients slots if amthif or wd are not present
in the device. we don't need to allocates slots ahead
it is all covered by link/unlink before the devices is responding
to user space connection and thus not racing on allocation

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

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 88770e040dd16..a48c0e71e69d2 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -275,6 +275,7 @@ struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
 int mei_cl_link(struct mei_cl *cl, int id)
 {
 	struct mei_device *dev;
+	long open_handle_count;
 
 	if (WARN_ON(!cl || !cl->dev))
 		return -EINVAL;
@@ -291,7 +292,8 @@ int mei_cl_link(struct mei_cl *cl, int id)
 		return -EMFILE;
 	}
 
-	if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
+	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
+	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
 		dev_err(&dev->pdev->dev, "open_handle_count exceded %d",
 			MEI_MAX_OPEN_HANDLE_COUNT);
 		return -EMFILE;
@@ -337,6 +339,17 @@ int mei_cl_unlink(struct mei_cl *cl)
 
 	cl_dbg(dev, cl, "unlink client");
 
+	if (dev->open_handle_count > 0)
+		dev->open_handle_count--;
+
+	/* never clear the 0 bit */
+	if (cl->host_client_id)
+		clear_bit(cl->host_client_id, dev->host_clients_map);
+
+	list_del_init(&cl->link);
+
+	cl->state = MEI_FILE_INITIALIZING;
+
 	list_del_init(&cl->link);
 
 	return 0;
@@ -358,10 +371,8 @@ void mei_host_client_init(struct work_struct *work)
 	/*
 	 * Reserving the first three client IDs
 	 * 0: Reserved for MEI Bus Message communications
-	 * 1: Reserved for Watchdog
-	 * 2: Reserved for AMTHI
 	 */
-	bitmap_set(dev->host_clients_map, 0, 3);
+	bitmap_set(dev->host_clients_map, 0, 1);
 
 	for (i = 0; i < dev->me_clients_num; i++) {
 		client_props = &dev->me_clients[i].props;