tee: add kernel internal client interface

Adds a kernel internal TEE client interface to be used by other drivers.
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Sumit Garg <sumit.garg@linaro.org>
Tested-by: Zeng Tao <prime.zeng@hisilicon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

drivers/tee/tee_core.c

@@ -38,15 +38,13 @@ static DEFINE_SPINLOCK(driver_lock);
 static struct class *tee_class;
 static dev_t tee_devt;
 
-static int tee_open(struct inode *inode, struct file *filp)
+static struct tee_context *teedev_open(struct tee_device *teedev)
 {
 	int rc;
-	struct tee_device *teedev;
 	struct tee_context *ctx;
 
-	teedev = container_of(inode->i_cdev, struct tee_device, cdev);
 	if (!tee_device_get(teedev))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx) {
@@ -57,16 +55,16 @@ static int tee_open(struct inode *inode, struct file *filp)
 	kref_init(&ctx->refcount);
 	ctx->teedev = teedev;
 	INIT_LIST_HEAD(&ctx->list_shm);
-	filp->private_data = ctx;
 	rc = teedev->desc->ops->open(ctx);
 	if (rc)
 		goto err;
 
-	return 0;
+	return ctx;
 err:
 	kfree(ctx);
 	tee_device_put(teedev);
-	return rc;
+	return ERR_PTR(rc);
+
 }
 
 void teedev_ctx_get(struct tee_context *ctx)
@@ -100,6 +98,18 @@ static void teedev_close_context(struct tee_context *ctx)
 	teedev_ctx_put(ctx);
 }
 
+static int tee_open(struct inode *inode, struct file *filp)
+{
+	struct tee_context *ctx;
+
+	ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	filp->private_data = ctx;
+	return 0;
+}
+
 static int tee_release(struct inode *inode, struct file *filp)
 {
 	teedev_close_context(filp->private_data);
@@ -928,6 +938,95 @@ void *tee_get_drvdata(struct tee_device *teedev)
 }
 EXPORT_SYMBOL_GPL(tee_get_drvdata);
 
+struct match_dev_data {
+	struct tee_ioctl_version_data *vers;
+	const void *data;
+	int (*match)(struct tee_ioctl_version_data *, const void *);
+};
+
+static int match_dev(struct device *dev, const void *data)
+{
+	const struct match_dev_data *match_data = data;
+	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
+
+	teedev->desc->ops->get_version(teedev, match_data->vers);
+	return match_data->match(match_data->vers, match_data->data);
+}
+
+struct tee_context *
+tee_client_open_context(struct tee_context *start,
+			int (*match)(struct tee_ioctl_version_data *,
+				     const void *),
+			const void *data, struct tee_ioctl_version_data *vers)
+{
+	struct device *dev = NULL;
+	struct device *put_dev = NULL;
+	struct tee_context *ctx = NULL;
+	struct tee_ioctl_version_data v;
+	struct match_dev_data match_data = { vers ? vers : &v, data, match };
+
+	if (start)
+		dev = &start->teedev->dev;
+
+	do {
+		dev = class_find_device(tee_class, dev, &match_data, match_dev);
+		if (!dev) {
+			ctx = ERR_PTR(-ENOENT);
+			break;
+		}
+
+		put_device(put_dev);
+		put_dev = dev;
+
+		ctx = teedev_open(container_of(dev, struct tee_device, dev));
+	} while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
+
+	put_device(put_dev);
+	return ctx;
+}
+EXPORT_SYMBOL_GPL(tee_client_open_context);
+
+void tee_client_close_context(struct tee_context *ctx)
+{
+	teedev_close_context(ctx);
+}
+EXPORT_SYMBOL_GPL(tee_client_close_context);
+
+void tee_client_get_version(struct tee_context *ctx,
+			    struct tee_ioctl_version_data *vers)
+{
+	ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
+}
+EXPORT_SYMBOL_GPL(tee_client_get_version);
+
+int tee_client_open_session(struct tee_context *ctx,
+			    struct tee_ioctl_open_session_arg *arg,
+			    struct tee_param *param)
+{
+	if (!ctx->teedev->desc->ops->open_session)
+		return -EINVAL;
+	return ctx->teedev->desc->ops->open_session(ctx, arg, param);
+}
+EXPORT_SYMBOL_GPL(tee_client_open_session);
+
+int tee_client_close_session(struct tee_context *ctx, u32 session)
+{
+	if (!ctx->teedev->desc->ops->close_session)
+		return -EINVAL;
+	return ctx->teedev->desc->ops->close_session(ctx, session);
+}
+EXPORT_SYMBOL_GPL(tee_client_close_session);
+
+int tee_client_invoke_func(struct tee_context *ctx,
+			   struct tee_ioctl_invoke_arg *arg,
+			   struct tee_param *param)
+{
+	if (!ctx->teedev->desc->ops->invoke_func)
+		return -EINVAL;
+	return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
+}
+EXPORT_SYMBOL_GPL(tee_client_invoke_func);
+
 static int __init tee_init(void)
 {
 	int rc;

include/linux/tee_drv.h

@@ -453,6 +453,79 @@ static inline int tee_shm_get_id(struct tee_shm *shm)
  */
 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);
 
+/**
+ * tee_client_open_context() - Open a TEE context
+ * @start:	if not NULL, continue search after this context
+ * @match:	function to check TEE device
+ * @data:	data for match function
+ * @vers:	if not NULL, version data of TEE device of the context returned
+ *
+ * This function does an operation similar to open("/dev/teeX") in user space.
+ * A returned context must be released with tee_client_close_context().
+ *
+ * Returns a TEE context of the first TEE device matched by the match()
+ * callback or an ERR_PTR.
+ */
+struct tee_context *
+tee_client_open_context(struct tee_context *start,
+			int (*match)(struct tee_ioctl_version_data *,
+				     const void *),
+			const void *data, struct tee_ioctl_version_data *vers);
+
+/**
+ * tee_client_close_context() - Close a TEE context
+ * @ctx:	TEE context to close
+ *
+ * Note that all sessions previously opened with this context will be
+ * closed when this function is called.
+ */
+void tee_client_close_context(struct tee_context *ctx);
+
+/**
+ * tee_client_get_version() - Query version of TEE
+ * @ctx:	TEE context to TEE to query
+ * @vers:	Pointer to version data
+ */
+void tee_client_get_version(struct tee_context *ctx,
+			    struct tee_ioctl_version_data *vers);
+
+/**
+ * tee_client_open_session() - Open a session to a Trusted Application
+ * @ctx:	TEE context
+ * @arg:	Open session arguments, see description of
+ *		struct tee_ioctl_open_session_arg
+ * @param:	Parameters passed to the Trusted Application
+ *
+ * Returns < 0 on error else see @arg->ret for result. If @arg->ret
+ * is TEEC_SUCCESS the session identifier is available in @arg->session.
+ */
+int tee_client_open_session(struct tee_context *ctx,
+			    struct tee_ioctl_open_session_arg *arg,
+			    struct tee_param *param);
+
+/**
+ * tee_client_close_session() - Close a session to a Trusted Application
+ * @ctx:	TEE Context
+ * @session:	Session id
+ *
+ * Return < 0 on error else 0, regardless the session will not be
+ * valid after this function has returned.
+ */
+int tee_client_close_session(struct tee_context *ctx, u32 session);
+
+/**
+ * tee_client_invoke_func() - Invoke a function in a Trusted Application
+ * @ctx:	TEE Context
+ * @arg:	Invoke arguments, see description of
+ *		struct tee_ioctl_invoke_arg
+ * @param:	Parameters passed to the Trusted Application
+ *
+ * Returns < 0 on error else see @arg->ret for result.
+ */
+int tee_client_invoke_func(struct tee_context *ctx,
+			   struct tee_ioctl_invoke_arg *arg,
+			   struct tee_param *param);
+
 static inline bool tee_param_is_memref(struct tee_param *param)
 {
 	switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {