[PATCH v4 8/9] remoteproc: Refactor function rproc_free_vring()

From: Mathieu Poirier
Date: Mon Jun 01 2020 - 13:52:03 EST


When function rproc_free_vring() clears the virtio device section
it does so on the cached resource table rather than the one
installed in the remote processor memory. When a remote processor
has been booted by another entity there is no need to use a cached
table and as such, no need to clear the virtio device section in
it.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
drivers/remoteproc/remoteproc_core.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index d32ac8f0c872..0e23284fbd25 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -411,10 +411,22 @@ void rproc_free_vring(struct rproc_vring *rvring)

idr_remove(&rproc->notifyids, rvring->notifyid);

- /* reset resource entry info */
- rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset;
- rsc->vring[idx].da = 0;
- rsc->vring[idx].notifyid = -1;
+ /*
+ * At this point rproc_stop() has been called and the installed resource
+ * table in the remote processor memory may no longer be accessible. As
+ * such and as per rproc_stop(), rproc->table_ptr points to the cached
+ * resource table (rproc->cached_table). The cached resource table is
+ * only available when a remote processor has been booted by the
+ * remoteproc core, otherwise it is NULL.
+ *
+ * Based on the above, reset the virtio device section in the cached
+ * resource table only if there is one to work with.
+ */
+ if (rproc->table_ptr) {
+ rsc = (void *)rproc->table_ptr + rvring->rvdev->rsc_offset;
+ rsc->vring[idx].da = 0;
+ rsc->vring[idx].notifyid = -1;
+ }
}

static int rproc_vdev_do_start(struct rproc_subdev *subdev)
--
2.20.1