remoteproc: Introduce function __rproc_detach()

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@linaro.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Link: https://lore.kernel.org/r/20210312162453.1234145-10-mathieu.poirier@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index de670f4..23e9040 100644 (file)
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1712,6 +1712,36 @@ 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