remoteproc/omap: Report device exceptions and trigger recovery

The OMAP remote processors send a special mailbox message
(RP_MBOX_CRASH) when they crash and detect an internal device
exception.

Add support to the mailbox handling function upon detection of
this special message to report this crash to the remoteproc core.
The remoteproc core can trigger a recovery using the prevailing
recovery mechanism, already in use for MMU Fault recovery.

Co-developed-by: Subramaniam Chanderashekarapuram <subramaniam.ca@ti.com>
Signed-off-by: Subramaniam Chanderashekarapuram <subramaniam.ca@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Andrew F. Davis <afd@ti.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200324110035.29907-14-t-kristo@ti.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/omap_remoteproc.c

@@ -383,8 +383,12 @@ static void omap_rproc_mbox_callback(struct mbox_client *client, void *data)
 
 	switch (msg) {
 	case RP_MBOX_CRASH:
-		/* just log this for now. later, we'll also do recovery */
+		/*
+		 * remoteproc detected an exception, notify the rproc core.
+		 * The remoteproc core will handle the recovery.
+		 */
 		dev_err(dev, "omap rproc %s crashed\n", name);
+		rproc_report_crash(oproc->rproc, RPROC_FATAL_ERROR);
 		break;
 	case RP_MBOX_ECHO_REPLY:
 		dev_info(dev, "received echo reply from %s\n", name);