[PATCH v5 11/19] remoteproc: Introduce function __rproc_detach()

From: Mathieu Poirier
Date: Thu Feb 11 2021 - 18:52:04 EST


Introduce function __rproc_detach() to perform the same kind of
operation as rproc_stop(), but instead of switching off the
remote processor using rproc->ops->stop(), it uses
rproc->ops->detach(). That way it is possible for the core
to release the resources associated with a remote processor while
the latter is kept operating.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Reviewed-by: Peng Fan <peng.fan@xxxxxxx>
---
New for V5:
- Removed fancy error recovery when ops->detach() fails to replicate what is
done in rproc->stop().
---
drivers/remoteproc/remoteproc_core.c | 30 ++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 5c52c612a7f0..b150138542d4 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1709,6 +1709,36 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
return 0;
}

+/*
+ * __rproc_detach(): Does the opposite of __rproc_attach()
+ */
+static int __maybe_unused __rproc_detach(struct rproc *rproc)
+{
+ struct device *dev = &rproc->dev;
+ int ret;
+
+ /* No need to continue if a detach() operation has not been provided */
+ if (!rproc->ops->detach)
+ return -EINVAL;
+
+ /* Stop any subdevices for the remote processor */
+ rproc_stop_subdevices(rproc, false);
+
+ /* Tell the remote processor the core isn't available anymore */
+ ret = rproc->ops->detach(rproc);
+ if (ret) {
+ dev_err(dev, "can't detach from rproc: %d\n", ret);
+ return ret;
+ }
+
+ rproc_unprepare_subdevices(rproc);
+
+ rproc->state = RPROC_DETACHED;
+
+ dev_info(dev, "detached remote processor %s\n", rproc->name);
+
+ return 0;
+}

/**
* rproc_trigger_recovery() - recover a remoteproc
--
2.25.1