mei: add reference counting for me clients
To support dynamic addition and removal of
me clients we add reference counter.
Update kdoc with locking requirements.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 3be18b7..dfbddfe 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -27,7 +27,63 @@
#include "client.h"
/**
+ * mei_me_cl_init - initialize me client
+ *
+ * @me_cl: me client
+ */
+void mei_me_cl_init(struct mei_me_client *me_cl)
+{
+ INIT_LIST_HEAD(&me_cl->list);
+ kref_init(&me_cl->refcnt);
+}
+
+/**
+ * mei_me_cl_get - increases me client refcount
+ *
+ * @me_cl: me client
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * Return: me client or NULL
+ */
+struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)
+{
+ if (me_cl)
+ kref_get(&me_cl->refcnt);
+
+ return me_cl;
+}
+
+/**
+ * mei_me_cl_release - unlink and free me client
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * @ref: me_client refcount
+ */
+static void mei_me_cl_release(struct kref *ref)
+{
+ struct mei_me_client *me_cl =
+ container_of(ref, struct mei_me_client, refcnt);
+ list_del(&me_cl->list);
+ kfree(me_cl);
+}
+/**
+ * mei_me_cl_put - decrease me client refcount and free client if necessary
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * @me_cl: me client
+ */
+void mei_me_cl_put(struct mei_me_client *me_cl)
+{
+ if (me_cl)
+ kref_put(&me_cl->refcnt, mei_me_cl_release);
+}
+
+/**
* mei_me_cl_by_uuid - locate me client by uuid
+ * increases ref count
*
* @dev: mei device
* @uuid: me client uuid
@@ -43,13 +99,14 @@
list_for_each_entry(me_cl, &dev->me_clients, list)
if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0)
- return me_cl;
+ return mei_me_cl_get(me_cl);
return NULL;
}
/**
* mei_me_cl_by_id - locate me client by client id
+ * increases ref count
*
* @dev: the device structure
* @client_id: me client id
@@ -65,12 +122,14 @@
list_for_each_entry(me_cl, &dev->me_clients, list)
if (me_cl->client_id == client_id)
- return me_cl;
+ return mei_me_cl_get(me_cl);
+
return NULL;
}
/**
* mei_me_cl_by_uuid_id - locate me client by client id and uuid
+ * increases ref count
*
* @dev: the device structure
* @uuid: me client uuid
@@ -88,31 +147,67 @@
list_for_each_entry(me_cl, &dev->me_clients, list)
if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0 &&
me_cl->client_id == client_id)
- return me_cl;
+ return mei_me_cl_get(me_cl);
+
return NULL;
}
/**
- * mei_me_cl_remove - remove me client matching uuid and client_id
+ * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
*
* @dev: the device structure
* @uuid: me client uuid
- * @client_id: me client address
+ *
+ * Locking: called under "dev->device_lock" lock
*/
-void mei_me_cl_remove(struct mei_device *dev, const uuid_le *uuid, u8 client_id)
+void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
{
struct mei_me_client *me_cl, *next;
+ dev_dbg(dev->dev, "remove %pUl\n", uuid);
+ list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
+ if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0)
+ mei_me_cl_put(me_cl);
+}
+
+/**
+ * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
+ *
+ * @dev: the device structure
+ * @uuid: me client uuid
+ * @id: me client id
+ *
+ * Locking: called under "dev->device_lock" lock
+ */
+void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
+{
+ struct mei_me_client *me_cl, *next;
+ const uuid_le *pn;
+
+ dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
list_for_each_entry_safe(me_cl, next, &dev->me_clients, list) {
- if (uuid_le_cmp(*uuid, me_cl->props.protocol_name) == 0 &&
- me_cl->client_id == client_id) {
- list_del(&me_cl->list);
- kfree(me_cl);
- break;
- }
+ pn = &me_cl->props.protocol_name;
+ if (me_cl->client_id == id && uuid_le_cmp(*uuid, *pn) == 0)
+ mei_me_cl_put(me_cl);
}
}
+/**
+ * mei_me_cl_rm_all - remove all me clients
+ *
+ * @dev: the device structure
+ *
+ * Locking: called under "dev->device_lock" lock
+ */
+void mei_me_cl_rm_all(struct mei_device *dev)
+{
+ struct mei_me_client *me_cl, *next;
+
+ list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
+ mei_me_cl_put(me_cl);
+}
+
+
/**
* mei_cl_cmp_id - tells if the clients are the same
@@ -695,6 +790,7 @@
{
struct mei_device *dev;
struct mei_me_client *me_cl;
+ int rets = 0;
if (WARN_ON(!cl || !cl->dev))
return -EINVAL;
@@ -710,12 +806,13 @@
return -ENOENT;
}
- if (me_cl->mei_flow_ctrl_creds) {
+ if (me_cl->mei_flow_ctrl_creds > 0) {
+ rets = 1;
if (WARN_ON(me_cl->props.single_recv_buf == 0))
- return -EINVAL;
- return 1;
+ rets = -EINVAL;
}
- return 0;
+ mei_me_cl_put(me_cl);
+ return rets;
}
/**
@@ -732,6 +829,7 @@
{
struct mei_device *dev;
struct mei_me_client *me_cl;
+ int rets;
if (WARN_ON(!cl || !cl->dev))
return -EINVAL;
@@ -745,15 +843,22 @@
}
if (me_cl->props.single_recv_buf) {
- if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
- return -EINVAL;
+ if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0)) {
+ rets = -EINVAL;
+ goto out;
+ }
me_cl->mei_flow_ctrl_creds--;
} else {
- if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
- return -EINVAL;
+ if (WARN_ON(cl->mei_flow_ctrl_creds <= 0)) {
+ rets = -EINVAL;
+ goto out;
+ }
cl->mei_flow_ctrl_creds--;
}
- return 0;
+ rets = 0;
+out:
+ mei_me_cl_put(me_cl);
+ return rets;
}
/**
@@ -788,6 +893,9 @@
cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
return -ENOTTY;
}
+ /* always allocate at least client max message */
+ length = max_t(size_t, length, me_cl->props.max_msg_length);
+ mei_me_cl_put(me_cl);
rets = pm_runtime_get(dev->dev);
if (rets < 0 && rets != -EINPROGRESS) {
@@ -802,8 +910,6 @@
goto out;
}
- /* always allocate at least client max message */
- length = max_t(size_t, length, me_cl->props.max_msg_length);
rets = mei_io_cb_alloc_resp_buf(cb, length);
if (rets)
goto out;