From bb3b2cfeb206f5b10b859e134651b54120e3f530 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linusw@kernel.org>
Date: Tue, 30 Jun 2026 18:05:56 +0100
Subject: ARM: 9480/1: entry: expand comment in __switch_to

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 arch/powerpc/sysdev/dcr.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 arch/powerpc/sysdev/dcr.c

(limited to 'arch/powerpc/sysdev/dcr.c')

diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
new file mode 100644
index 000000000..cb44a6995
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ */
+
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/of_address.h>
+#include <asm/dcr.h>
+
+unsigned int dcr_resource_start(const struct device_node *np,
+				unsigned int index)
+{
+	unsigned int ds;
+	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
+
+	if (dr == NULL || ds & 1 || index >= (ds / 8))
+		return 0;
+
+	return dr[index * 2];
+}
+EXPORT_SYMBOL_GPL(dcr_resource_start);
+
+unsigned int dcr_resource_len(const struct device_node *np, unsigned int index)
+{
+	unsigned int ds;
+	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
+
+	if (dr == NULL || ds & 1 || index >= (ds / 8))
+		return 0;
+
+	return dr[index * 2 + 1];
+}
+EXPORT_SYMBOL_GPL(dcr_resource_len);
+
+DEFINE_SPINLOCK(dcr_ind_lock);
+EXPORT_SYMBOL_GPL(dcr_ind_lock);
-- 
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