remoteproc: Support attach recovery after rproc crash

Current logic only support main processor to stop/start the remote
processor after crash. However to SoC, such as i.MX8QM/QXP, the
remote processor could do attach recovery after crash and trigger watchdog
to reboot itself. It does not need main processor to load image, or
stop/start remote processor.

Introduce two functions: rproc_attach_recovery, rproc_boot_recovery
for the two cases. Boot recovery is as before, let main processor to
help recovery, while attach recovery is to recover itself without help.
To attach recovery, we only do detach and attach.
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20220928064756.4059662-3-peng.fan@oss.nxp.comSigned-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>

drivers/remoteproc/remoteproc_core.c

@@ -1770,6 +1770,45 @@ static int __rproc_detach(struct rproc *rproc)
 	return 0;
 }
 
+static int rproc_attach_recovery(struct rproc *rproc)
+{
+	int ret;
+
+	ret = __rproc_detach(rproc);
+	if (ret)
+		return ret;
+
+	return __rproc_attach(rproc);
+}
+
+static int rproc_boot_recovery(struct rproc *rproc)
+{
+	const struct firmware *firmware_p;
+	struct device *dev = &rproc->dev;
+	int ret;
+
+	ret = rproc_stop(rproc, true);
+	if (ret)
+		return ret;
+
+	/* generate coredump */
+	rproc->ops->coredump(rproc);
+
+	/* load firmware */
+	ret = request_firmware(&firmware_p, rproc->firmware, dev);
+	if (ret < 0) {
+		dev_err(dev, "request_firmware failed: %d\n", ret);
+		return ret;
+	}
+
+	/* boot the remote processor up again */
+	ret = rproc_start(rproc, firmware_p);
+
+	release_firmware(firmware_p);
+
+	return ret;
+}
+
 /**
  * rproc_trigger_recovery() - recover a remoteproc
  * @rproc: the remote processor
@@ -1784,7 +1823,6 @@ static int __rproc_detach(struct rproc *rproc)
  */
 int rproc_trigger_recovery(struct rproc *rproc)
 {
-	const struct firmware *firmware_p;
 	struct device *dev = &rproc->dev;
 	int ret;
 
@@ -1798,24 +1836,10 @@ int rproc_trigger_recovery(struct rproc *rproc)
 
 	dev_err(dev, "recovering %s\n", rproc->name);
 
-	ret = rproc_stop(rproc, true);
-	if (ret)
-		goto unlock_mutex;
-
-	/* generate coredump */
-	rproc->ops->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;
-	}
-
-	/* boot the remote processor up again */
-	ret = rproc_start(rproc, firmware_p);
-
-	release_firmware(firmware_p);
+	if (rproc_has_feature(rproc, RPROC_FEAT_ATTACH_ON_RECOVERY))
+		ret = rproc_attach_recovery(rproc);
+	else
+		ret = rproc_boot_recovery(rproc);
 
 unlock_mutex:
 	mutex_unlock(&rproc->lock);