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

Sarangdhar Joshi
2017-05-02T20:59:01Z

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.

The current 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 <spjoshi@codeaurora.org>
---

I had forgot to send the second patch (2/2) in this series earlier.
Hence resending both patches as a series.

drivers/remoteproc/remoteproc_core.c | 118 ++++++++++++++++++++++++++++++++---
1 file changed, 110 insertions(+), 8 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 9fd9ca5..169abb3 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -851,6 +851,61 @@ 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 device *dev = &rproc->dev;
+ struct resource_table *table, *loaded_table;
+ 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->table_ptr as the
+ * resource table. The address of the vring along with the other
+ * allocated resources (carveouts etc) is stored in table_ptr.
+ * 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->table_ptr, tablesz);
+
+ /* 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.
*/
@@ -993,6 +1048,32 @@ 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
@@ -1005,23 +1086,44 @@ static int rproc_trigger_auto_boot(struct rproc *rproc)
*/
int rproc_trigger_recovery(struct rproc *rproc)
{
+ const struct firmware *firmware_p;
+ struct device *dev;
+ int ret;
+
dev_err(&rproc->dev, "recovering %s\n", rproc->name);

init_completion(&rproc->crash_comp);

- /* shut down the remote */
- /* TODO: make sure this works with rproc->power > 1 */
- rproc_shutdown(rproc);
+ dev = &rproc->dev;
+
+ ret = mutex_lock_interruptible(&rproc->lock);
+ if (ret)
+ return ret;
+
+ ret = rproc_stop(rproc);
+ if (ret)
+ goto unlock_mutex;

/* wait until there is no more rproc users */
wait_for_completion(&rproc->crash_comp);

- /*
- * boot the remote processor up again
- */
- rproc_boot(rproc);
+ /* load firmware */
+ ret = request_firmware(&firmware_p, rproc->firmware, dev);
+ if (ret < 0) {
+ dev_err(dev, "request_firmware failed: %d\n", ret);
+ goto unlock_mutex;
+ }

- return 0;
+ /* boot the remote processor up again */
+ ret = rproc_start(rproc, firmware_p);
+ if (ret)
+ goto unlock_mutex;
+
+ release_firmware(firmware_p);
+
+unlock_mutex:
+ mutex_unlock(&rproc->lock);
+ return ret;
}

/**