[PATCH v3 09/14] remoteproc: Deal with synchronisation when crashing

Mathieu Poirier
2020-04-24T20:02:19Z

Refactor function rproc_trigger_recovery() in order to avoid
reloading the firmware image when synchronising with a remote
processor rather than booting it. Also part of the process,
properly set the synchronisation flag in order to properly
recover the system.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/remoteproc/remoteproc_core.c | 23 ++++++++++++++------
drivers/remoteproc/remoteproc_internal.h | 27 ++++++++++++++++++++++++
2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index ef88d3e84bfb..3a84a38ba37b 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -1697,7 +1697,7 @@ static void rproc_coredump(struct rproc *rproc)
*/
int rproc_trigger_recovery(struct rproc *rproc)
{
- const struct firmware *firmware_p;
+ const struct firmware *firmware_p = NULL;
struct device *dev = &rproc->dev;
int ret;

@@ -1718,14 +1718,16 @@ int rproc_trigger_recovery(struct rproc *rproc)
/* generate coredump */
rproc_coredump(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;
+ /* load firmware if need be */
+ if (!rproc_needs_syncing(rproc)) {
+ ret = request_firmware(&firmware_p, rproc->firmware, dev);
+ if (ret < 0) {
+ dev_err(dev, "request_firmware failed: %d\n", ret);
+ goto unlock_mutex;
+ }
}

- /* boot the remote processor up again */
+ /* boot up or synchronise with the remote processor again */
ret = rproc_start(rproc, firmware_p);

release_firmware(firmware_p);
@@ -1761,6 +1763,13 @@ static void rproc_crash_handler_work(struct work_struct *work)
dev_err(dev, "handling crash #%u in %s\n", ++rproc->crash_cnt,
rproc->name);

+ /*
+ * The remote processor has crashed - tell the core what operation
+ * to use from hereon, i.e whether an external entity will reboot
+ * the MCU or it is now the remoteproc core's responsability.
+ */
+ rproc_set_sync_flag(rproc, RPROC_SYNC_STATE_CRASHED);
+
mutex_unlock(&rproc->lock);

if (!rproc->recovery_disabled)
diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h
index 3985c084b184..61500981155c 100644
--- a/drivers/remoteproc/remoteproc_internal.h
+++ b/drivers/remoteproc/remoteproc_internal.h
@@ -24,6 +24,33 @@ struct rproc_debug_trace {
struct rproc_mem_entry trace_mem;
};

+/*
+ * enum rproc_sync_states - remote processsor sync states
+ *
+ * @RPROC_SYNC_STATE_CRASHED state to use after the remote processor
+ * has crashed but has not been recovered by
+ * the remoteproc core yet.
+ *
+ * Keeping these separate from the enum rproc_state in order to avoid
+ * introducing coupling between the state of the MCU and the synchronisation
+ * operation to use.
+ */
+enum rproc_sync_states {
+ RPROC_SYNC_STATE_CRASHED,
+};
+
+static inline void rproc_set_sync_flag(struct rproc *rproc,
+ enum rproc_sync_states state)
+{
+ switch (state) {
+ case RPROC_SYNC_STATE_CRASHED:
+ rproc->sync_with_rproc = rproc->sync_flags.after_crash;
+ break;
+ default:
+ break;
+ }
+}
+
/* from remoteproc_core.c */
void rproc_release(struct kref *kref);
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
--
2.20.1