From 2790d01d1e1d22735d848eec55668f7d44417e22 Mon Sep 17 00:00:00 2001
From: Hari Bathini <hbathini@linux.ibm.com>
Date: Wed, 11 Sep 2019 20:21:16 +0530
Subject: [PATCH] powerpc/fadump: reset metadata address during clean up

References: jsc#PM-1318 jsc#SLE-9099 jsc#SLE-9176
Patch-mainline: v5.4-rc1
Git-commit: 2790d01d1e1d22735d848eec55668f7d44417e22

During kexec boot, metadata address needs to be reset to avoid running
into errors interpreting stale metadata address, in case the kexec'ed
kernel crashes before metadata address could be setup again.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821346629.5656.10783321582005237813.stgit@hbathini.in.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/include/asm/fadump-internal.h   |  1 +
 arch/powerpc/kernel/fadump.c                 |  6 ++++++
 arch/powerpc/platforms/powernv/opal-fadump.c | 10 ++++++++++
 3 files changed, 17 insertions(+)

diff --git a/arch/powerpc/include/asm/fadump-internal.h b/arch/powerpc/include/asm/fadump-internal.h
index 5262c764c5fc..0c2c4f58d365 100644
--- a/arch/powerpc/include/asm/fadump-internal.h
+++ b/arch/powerpc/include/asm/fadump-internal.h
@@ -117,6 +117,7 @@ struct fadump_ops {
 	int	(*fadump_register)(struct fw_dump *fadump_conf);
 	int	(*fadump_unregister)(struct fw_dump *fadump_conf);
 	int	(*fadump_invalidate)(struct fw_dump *fadump_conf);
+	void	(*fadump_cleanup)(struct fw_dump *fadump_conf);
 	int	(*fadump_process)(struct fw_dump *fadump_conf);
 	void	(*fadump_region_show)(struct fw_dump *fadump_conf,
 				      struct seq_file *m);
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 7e7056382d98..aab9b4db0363 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -965,6 +965,9 @@ static int register_fadump(void)
 
 void fadump_cleanup(void)
 {
+	if (!fw_dump.fadump_supported)
+		return;
+
 	/* Invalidate the registration only if dump is active. */
 	if (fw_dump.dump_active) {
 		pr_debug("Invalidating firmware-assisted dump registration\n");
@@ -974,6 +977,9 @@ void fadump_cleanup(void)
 		fw_dump.ops->fadump_unregister(&fw_dump);
 		free_crash_memory_ranges();
 	}
+
+	if (fw_dump.ops->fadump_cleanup)
+		fw_dump.ops->fadump_cleanup(&fw_dump);
 }
 
 static void fadump_free_reserved_memory(unsigned long start_pfn,
diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c
index 21de832f2ba4..871a129c73d3 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -105,6 +105,15 @@ static int opal_fadump_invalidate(struct fw_dump *fadump_conf)
 	return -EIO;
 }
 
+static void opal_fadump_cleanup(struct fw_dump *fadump_conf)
+{
+	s64 ret;
+
+	ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_KERNEL, 0);
+	if (ret != OPAL_SUCCESS)
+		pr_warn("Could not reset (%llu) kernel metadata tag!\n", ret);
+}
+
 static int __init opal_fadump_process(struct fw_dump *fadump_conf)
 {
 	return -EINVAL;
@@ -145,6 +154,7 @@ static struct fadump_ops opal_fadump_ops = {
 	.fadump_register		= opal_fadump_register,
 	.fadump_unregister		= opal_fadump_unregister,
 	.fadump_invalidate		= opal_fadump_invalidate,
+	.fadump_cleanup			= opal_fadump_cleanup,
 	.fadump_process			= opal_fadump_process,
 	.fadump_region_show		= opal_fadump_region_show,
 	.fadump_trigger			= opal_fadump_trigger,
-- 
2.23.0