[PATCH v4 4/9] remoteproc: Introducing function rproc_actuate()

[Mathieu Poirier]

Introduce function rproc_actuate() that provides the same
functionatlity as rproc_fw_boot(), but without the steps that
involve interaction with the firmware image.  That way we can
deal with scenarios where the remoteproc core is attaching
to a remote processor that has already been started by another
entity.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
 drivers/remoteproc/remoteproc_core.c | 68 +++++++++++++++++++++++++++-
 1 file changed, 67 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 0b323f6b554b..c70fa0372d07 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1370,7 +1370,7 @@ static int rproc_start(struct rproc *rproc, const struct firmware *fw)
 	return ret;
 }
 
-static int __maybe_unused rproc_attach(struct rproc *rproc)
+static int rproc_attach(struct rproc *rproc)
 {
 	struct device *dev = &rproc->dev;
 	int ret;
@@ -1499,6 +1499,72 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 	return ret;
 }
 
+/*
+ * Attach to remote processor - similar to rproc_fw_boot() but without
+ * the steps that deal with the firmware image.
+ */
+static int __maybe_unused rproc_actuate(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* Tell the PM runtime core we need to keep this device powered */
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * if enabling an IOMMU isn't relevant for this rproc, this is
+	 * just a nop
+	 */
+	ret = rproc_enable_iommu(rproc);
+	if (ret) {
+		dev_err(dev, "can't enable iommu: %d\n", ret);
+		goto put_pm_runtime;
+	}
+
+	/* reset max_notifyid */
+	rproc->max_notifyid = -1;
+
+	/* reset handled vdev */
+	rproc->nb_vdev = 0;
+
+	/*
+	 * Handle firmware resources required to attach to a remote processor.
+	 * Because we are attaching rather than booting the remote processor,
+	 * we expect the platform driver to properly set rproc->table_ptr.
+	 */
+	ret = rproc_handle_resources(rproc, rproc_loading_handlers);
+	if (ret) {
+		dev_err(dev, "Failed to process resources: %d\n", ret);
+		goto disable_iommu;
+	}
+
+	/* Allocate carveout resources associated to rproc */
+	ret = rproc_alloc_registered_carveouts(rproc);
+	if (ret) {
+		dev_err(dev, "Failed to allocate associated carveouts: %d\n",
+			ret);
+		goto clean_up_resources;
+	}
+
+	ret = rproc_attach(rproc);
+	if (ret)
+		goto clean_up_resources;
+
+	return 0;
+
+clean_up_resources:
+	rproc_resource_cleanup(rproc);
+disable_iommu:
+	rproc_disable_iommu(rproc);
+put_pm_runtime:
+	pm_runtime_put(dev);
+	return ret;
+}
+
 /*
  * take a firmware and boot it up.
  *
-- 
2.20.1