Subject: [PATCH v3 1/2] remoteproc: Introduce rproc_{start,stop}() functions

From: [email-masked] (Sarangdhar Joshi)
Date: Fri, 26 May 2017 16:51:00 -0700

In the context of recovering from crash, rproc_trigger_recovery() does
rproc_shutdown() followed by rproc_boot(). The remoteproc resources are
cleaned up in rproc_shutdown() and immediately reallocated in
rproc_boot() which is an unnecessary overhead. Furthermore, we want the
memory regions to be accessible after stopping the remote processor, to
be able to extract the memory content for a coredump.

This patch factors out the code in rproc_boot() and rproc_shutdown()
path and introduces rproc_{start,stop}() in order to avoid resource
allocation overhead.

Signed-off-by: Sarangdhar Joshi <[email-masked]>
---

Changes from v2:

* Rebase on top of v4.12-rc1

 drivers/remoteproc/remoteproc_core.c | 143 +++++++++++++++++++++--------------
 1 file changed, 87 insertions(+), 56 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 3dabb20..c8cb54b 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -847,6 +847,63 @@ static void rproc_resource_cleanup(struct rproc *rproc)
 		kref_put(&rvdev->refcount, rproc_vdev_release);
 }
 
+static int rproc_start(struct rproc *rproc, const struct firmware *fw)
+{
+	struct resource_table *table, *loaded_table;
+	struct device *dev = &rproc->dev;
+	int ret, tablesz;
+
+	/* look for the resource table */
+	table = rproc_find_rsc_table(rproc, fw, &tablesz);
+	if (!table) {
+		dev_err(dev, "Resouce table look up failed\n");
+		return -EINVAL;
+	}
+
+	/* load the ELF segments to memory */
+	ret = rproc_load_segments(rproc, fw);
+	if (ret) {
+		dev_err(dev, "Failed to load program segments: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * The starting device has been given the rproc->cached_table as the
+	 * resource table. The address of the vring along with the other
+	 * allocated resources (carveouts etc) is stored in cached_table.
+	 * In order to pass this information to the remote device we must copy
+	 * this information to device memory. We also update the table_ptr so
+	 * that any subsequent changes will be applied to the loaded version.
+	 */
+	loaded_table = rproc_find_loaded_rsc_table(rproc, fw);
+	if (loaded_table) {
+		memcpy(loaded_table, rproc->cached_table, tablesz);
+		rproc->table_ptr = loaded_table;
+	}
+
+	/* power up the remote processor */
+	ret = rproc->ops->start(rproc);
+	if (ret) {
+		dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
+		return ret;
+	}
+
+	/* probe any subdevices for the remote processor */
+	ret = rproc_probe_subdevices(rproc);
+	if (ret) {
+		dev_err(dev, "failed to probe subdevices for %s: %d\n",
+			rproc->name, ret);
+		rproc->ops->stop(rproc);
+		return ret;
+	}
+
+	rproc->state = RPROC_RUNNING;
+
+	dev_info(dev, "remote processor %s is now up\n", rproc->name);
+
+	return 0;
+}
+
 /*
  * take a firmware and boot a remote processor with it.
  */
@@ -854,7 +911,7 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 {
 	struct device *dev = &rproc->dev;
 	const char *name = rproc->firmware;
-	struct resource_table *table, *loaded_table;
+	struct resource_table *table;
 	int ret, tablesz;
 
 	ret = rproc_fw_sanity_check(rproc, fw);
@@ -905,50 +962,12 @@ static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw)
 		goto clean_up_resources;
 	}
 
-	/* load the ELF segments to memory */
-	ret = rproc_load_segments(rproc, fw);
-	if (ret) {
-		dev_err(dev, "Failed to load program segments: %d\n", ret);
-		goto clean_up_resources;
-	}
-
-	/*
-	 * The starting device has been given the rproc->cached_table as the
-	 * resource table. The address of the vring along with the other
-	 * allocated resources (carveouts etc) is stored in cached_table.
-	 * In order to pass this information to the remote device we must copy
-	 * this information to device memory. We also update the table_ptr so
-	 * that any subsequent changes will be applied to the loaded version.
-	 */
-	loaded_table = rproc_find_loaded_rsc_table(rproc, fw);
-	if (loaded_table) {
-		memcpy(loaded_table, rproc->cached_table, tablesz);
-		rproc->table_ptr = loaded_table;
-	}
-
-	/* power up the remote processor */
-	ret = rproc->ops->start(rproc);
-	if (ret) {
-		dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret);
+	ret = rproc_start(rproc, fw);
+	if (ret)
 		goto clean_up_resources;
-	}
-
-	/* probe any subdevices for the remote processor */
-	ret = rproc_probe_subdevices(rproc);
-	if (ret) {
-		dev_err(dev, "failed to probe subdevices for %s: %d\n",
-			rproc->name, ret);
-		goto stop_rproc;
-	}
-
-	rproc->state = RPROC_RUNNING;
-
-	dev_info(dev, "remote processor %s is now up\n", rproc->name);
 
 	return 0;
 
-stop_rproc:
-	rproc->ops->stop(rproc);
 clean_up_resources:
 	rproc_resource_cleanup(rproc);
 clean_up:
@@ -994,6 +1013,32 @@ static int rproc_trigger_auto_boot(struct rproc *rproc)
 	return ret;
 }
 
+static int rproc_stop(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	/* remove any subdevices for the remote processor */
+	rproc_remove_subdevices(rproc);
+
+	/* power off the remote processor */
+	ret = rproc->ops->stop(rproc);
+	if (ret) {
+		dev_err(dev, "can't stop rproc: %d\n", ret);
+		return ret;
+	}
+
+	/* if in crash state, unlock crash handler */
+	if (rproc->state == RPROC_CRASHED)
+		complete_all(&rproc->crash_comp);
+
+	rproc->state = RPROC_OFFLINE;
+
+	dev_info(dev, "stopped remote processor %s\n", rproc->name);
+
+	return 0;
+}
+
 /**
  * rproc_trigger_recovery() - recover a remoteproc
  * @rproc: the remote processor
@@ -1163,14 +1208,9 @@ void rproc_shutdown(struct rproc *rproc)
 	if (!atomic_dec_and_test(&rproc->power))
 		goto out;
 
-	/* remove any subdevices for the remote processor */
-	rproc_remove_subdevices(rproc);
-
-	/* power off the remote processor */
-	ret = rproc->ops->stop(rproc);
+	ret = rproc_stop(rproc);
 	if (ret) {
 		atomic_inc(&rproc->power);
-		dev_err(dev, "can't stop rproc: %d\n", ret);
 		goto out;
 	}
 
@@ -1183,15 +1223,6 @@ void rproc_shutdown(struct rproc *rproc)
 	kfree(rproc->cached_table);
 	rproc->cached_table = NULL;
 	rproc->table_ptr = NULL;
-
-	/* if in crash state, unlock crash handler */
-	if (rproc->state == RPROC_CRASHED)
-		complete_all(&rproc->crash_comp);
-
-	rproc->state = RPROC_OFFLINE;
-
-	dev_info(dev, "stopped remote processor %s\n", rproc->name);
-
 out:
 	mutex_unlock(&rproc->lock);
 }
-- 
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