[PATCH v4 5/9] remoteproc: Introducing function rproc_validate()

[Mathieu Poirier]

Add a new function to assert the general health of the remote
processor before handing it to the remoteproc core.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_core.c | 45 ++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index c70fa0372d07..0be8343dd851 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2060,6 +2060,47 @@ struct rproc *rproc_get_by_phandle(phandle phandle)
 #endif
 EXPORT_SYMBOL(rproc_get_by_phandle);
 
+static int rproc_validate(struct rproc *rproc)
+{
+	/*
+	 * When adding a remote processor, the state of the device
+	 * can be offline or detached, nothing else.
+	 */
+	if (rproc->state != RPROC_OFFLINE &&
+	    rproc->state != RPROC_DETACHED)
+		goto inval;
+
+	if (rproc->state == RPROC_OFFLINE) {
+		/*
+		 * An offline processor without a start()
+		 * function makes no sense.
+		 */
+		if (!rproc->ops->start)
+			goto inval;
+	}
+
+	if (rproc->state == RPROC_DETACHED) {
+		/*
+		 * A remote processor in a detached state without an
+		 * attach() function makes not sense.
+		 */
+		if (!rproc->ops->attach)
+			goto inval;
+		/*
+		 * When attaching to a remote processor the device memory
+		 * is already available and as such there is no need to have a
+		 * cached table.
+		 */
+		if (rproc->cached_table)
+			goto inval;
+	}
+
+	return 0;
+
+inval:
+	return -EINVAL;
+}
+
 /**
  * rproc_add() - register a remote processor
  * @rproc: the remote processor handle to register
@@ -2089,6 +2130,10 @@ int rproc_add(struct rproc *rproc)
 	if (ret < 0)
 		return ret;
 
+	ret = rproc_validate(rproc);
+	if (ret < 0)
+		return ret;
+
 	dev_info(dev, "%s is available\n", rproc->name);
 
 	/* create debugfs entries */
-- 
2.20.1