[PATCH v1 1/3] remoteproc: qcom: q6v5: Send subdevice notifications before panic

[Gokul krishna Krishnakumar <quic_gokukris@xxxxxxxxxxx>]

Subdevice notifications after a remoteproc has crashed are useful to any
clients that might want to preserve data pertaining to the driver after the
remoteproc crashed. Sending subdevice notifications before triggering a
kernel panic gives these drivers the time to do collect this information.

Change-Id: Id6e55fb038b70f54ff5854d2adff72b74b6a9570
Signed-off-by: Gokul krishna Krishnakumar <quic_gokukris@xxxxxxxxxxx>
---
 drivers/remoteproc/qcom_q6v5.c | 31 +++++++++++++++++++++++++++++++
 drivers/remoteproc/qcom_q6v5.h |  2 ++
 2 files changed, 33 insertions(+)

diff --git a/drivers/remoteproc/qcom_q6v5.c b/drivers/remoteproc/qcom_q6v5.c
index 497acfb..89f5384 100644
--- a/drivers/remoteproc/qcom_q6v5.c
+++ b/drivers/remoteproc/qcom_q6v5.c
@@ -15,6 +15,7 @@
 #include <linux/soc/qcom/smem.h>
 #include <linux/soc/qcom/smem_state.h>
 #include <linux/remoteproc.h>
+#include <linux/delay.h>
 #include "qcom_common.h"
 #include "qcom_q6v5.h"
 
@@ -94,6 +95,29 @@ int qcom_q6v5_unprepare(struct qcom_q6v5 *q6v5)
 }
 EXPORT_SYMBOL_GPL(qcom_q6v5_unprepare);
 
+static void qcom_q6v5_crash_handler_work(struct work_struct *work)
+{
+	struct qcom_q6v5 *q6v5 = container_of(work, struct qcom_q6v5, crash_handler);
+	struct rproc *rproc = q6v5->rproc;
+	struct rproc_subdev *subdev;
+
+	mutex_lock(&rproc->lock);
+
+	list_for_each_entry_reverse(subdev, &rproc->subdevs, node) {
+		if (subdev->stop)
+			subdev->stop(subdev, true);
+	}
+
+	mutex_unlock(&rproc->lock);
+
+	/*
+	 * Temporary workaround until ramdump userspace application calls
+	 * sync() and fclose() on attempting the dump.
+	 */
+	msleep(100);
+	panic("Panicking, remoteproc %s crashed\n", q6v5->rproc->name);
+}
+
 static irqreturn_t q6v5_wdog_interrupt(int irq, void *data)
 {
 	struct qcom_q6v5 *q6v5 = data;
@@ -113,6 +137,9 @@ static irqreturn_t q6v5_wdog_interrupt(int irq, void *data)
 		dev_err(q6v5->dev, "watchdog without message\n");
 
 	q6v5->running = false;
+	if (q6v5->rproc->recovery_disabled)
+		schedule_work(&q6v5->crash_handler);
+
 	rproc_report_crash(q6v5->rproc, RPROC_WATCHDOG);
 
 	return IRQ_HANDLED;
@@ -134,6 +161,9 @@ static irqreturn_t q6v5_fatal_interrupt(int irq, void *data)
 		dev_err(q6v5->dev, "fatal error without message\n");
 
 	q6v5->running = false;
+	if (q6v5->rproc->recovery_disabled)
+		schedule_work(&q6v5->crash_handler);
+
 	rproc_report_crash(q6v5->rproc, RPROC_FATAL_ERROR);
 
 	return IRQ_HANDLED;
@@ -354,6 +384,7 @@ int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
 	if (IS_ERR(q6v5->path))
 		return dev_err_probe(&pdev->dev, PTR_ERR(q6v5->path),
 				     "failed to acquire interconnect path\n");
+	INIT_WORK(&q6v5->crash_handler, qcom_q6v5_crash_handler_work);
 
 	return 0;
 }
diff --git a/drivers/remoteproc/qcom_q6v5.h b/drivers/remoteproc/qcom_q6v5.h
index 5a859c4..b1654be 100644
--- a/drivers/remoteproc/qcom_q6v5.h
+++ b/drivers/remoteproc/qcom_q6v5.h
@@ -29,6 +29,8 @@ struct qcom_q6v5 {
 	int handover_irq;
 	int stop_irq;
 
+	struct work_struct crash_handler;
+
 	bool handover_issued;
 
 	struct completion start_done;
-- 
2.7.4