From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh

---
 kernel/drivers/mailbox/mailbox.c |  127 ++++++++++++++++++++++++++++++++++--------
 1 files changed, 103 insertions(+), 24 deletions(-)

diff --git a/kernel/drivers/mailbox/mailbox.c b/kernel/drivers/mailbox/mailbox.c
index 3980e50..3e7d4b2 100644
--- a/kernel/drivers/mailbox/mailbox.c
+++ b/kernel/drivers/mailbox/mailbox.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Mailbox: Common code for Mailbox controllers and users
  *
  * Copyright (C) 2013-2014 Linaro Ltd.
  * Author: Jassi Brar <jassisinghbrar@gmail.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
 #include <linux/interrupt.h>
@@ -53,7 +50,7 @@
 	return idx;
 }
 
-static int __msg_submit(struct mbox_chan *chan)
+static void msg_submit(struct mbox_chan *chan)
 {
 	unsigned count, idx;
 	unsigned long flags;
@@ -84,24 +81,6 @@
 	}
 exit:
 	spin_unlock_irqrestore(&chan->lock, flags);
-
-	return err;
-}
-
-static void msg_submit(struct mbox_chan *chan)
-{
-	int err = 0;
-
-	/*
-	 * If the controller returns -EAGAIN, then it means, our spinlock
-	 * here is preventing the controller from receiving its interrupt,
-	 * that would help clear the controller channels that are currently
-	 * blocked waiting on the interrupt response.
-	 * Retry again.
-	 */
-	do {
-		err = __msg_submit(chan);
-	} while (err == -EAGAIN);
 
 	/* kick start the timer immediately to avoid delays */
 	if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {
@@ -304,6 +283,35 @@
 EXPORT_SYMBOL_GPL(mbox_send_message);
 
 /**
+ * mbox_flush - flush a mailbox channel
+ * @chan: mailbox channel to flush
+ * @timeout: time, in milliseconds, to allow the flush operation to succeed
+ *
+ * Mailbox controllers that need to work in atomic context can implement the
+ * ->flush() callback to busy loop until a transmission has been completed.
+ * The implementation must call mbox_chan_txdone() upon success. Clients can
+ * call the mbox_flush() function at any time after mbox_send_message() to
+ * flush the transmission. After the function returns success, the mailbox
+ * transmission is guaranteed to have completed.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int mbox_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+	int ret;
+
+	if (!chan->mbox->ops->flush)
+		return -ENOTSUPP;
+
+	ret = chan->mbox->ops->flush(chan, timeout);
+	if (ret < 0)
+		tx_tick(chan, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mbox_flush);
+
+/**
  * mbox_request_channel - Request a mailbox channel.
  * @cl: Identity of the client requesting the channel.
  * @index: Index of mailbox specifier in 'mboxes' property.
@@ -347,7 +355,8 @@
 	list_for_each_entry(mbox, &mbox_cons, node)
 		if (mbox->dev->of_node == spec.np) {
 			chan = mbox->of_xlate(mbox, &spec);
-			break;
+			if (!IS_ERR(chan))
+				break;
 		}
 
 	of_node_put(spec.np);
@@ -537,3 +546,73 @@
 	mutex_unlock(&con_mutex);
 }
 EXPORT_SYMBOL_GPL(mbox_controller_unregister);
+
+static void __devm_mbox_controller_unregister(struct device *dev, void *res)
+{
+	struct mbox_controller **mbox = res;
+
+	mbox_controller_unregister(*mbox);
+}
+
+static int devm_mbox_controller_match(struct device *dev, void *res, void *data)
+{
+	struct mbox_controller **mbox = res;
+
+	if (WARN_ON(!mbox || !*mbox))
+		return 0;
+
+	return *mbox == data;
+}
+
+/**
+ * devm_mbox_controller_register() - managed mbox_controller_register()
+ * @dev: device owning the mailbox controller being registered
+ * @mbox: mailbox controller being registered
+ *
+ * This function adds a device-managed resource that will make sure that the
+ * mailbox controller, which is registered using mbox_controller_register()
+ * as part of this function, will be unregistered along with the rest of
+ * device-managed resources upon driver probe failure or driver removal.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int devm_mbox_controller_register(struct device *dev,
+				  struct mbox_controller *mbox)
+{
+	struct mbox_controller **ptr;
+	int err;
+
+	ptr = devres_alloc(__devm_mbox_controller_unregister, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	err = mbox_controller_register(mbox);
+	if (err < 0) {
+		devres_free(ptr);
+		return err;
+	}
+
+	devres_add(dev, ptr);
+	*ptr = mbox;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_register);
+
+/**
+ * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
+ * @dev: device owning the mailbox controller being unregistered
+ * @mbox: mailbox controller being unregistered
+ *
+ * This function unregisters the mailbox controller and removes the device-
+ * managed resource that was set up to automatically unregister the mailbox
+ * controller on driver probe failure or driver removal. It's typically not
+ * necessary to call this function.
+ */
+void devm_mbox_controller_unregister(struct device *dev, struct mbox_controller *mbox)
+{
+	WARN_ON(devres_release(dev, __devm_mbox_controller_unregister,
+			       devm_mbox_controller_match, mbox));
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister);

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