From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <mirq-linux@rere.qmqm.pl>
Date: Thu, 4 Nov 2021 17:28:28 +0100
Subject: ARM: 9155/1: fix early early_iounmap()
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Git-commit: 0d08e7bf0d0d1a29aff7b16ef516f7415eb1aa05
Patch-mainline: v5.16-rc1
References: git-fixes

Currently __set_fixmap() bails out with a warning when called in early boot
from early_iounmap(). Fix it, and while at it, make the comment a bit easier
to understand.

Cc: <stable@vger.kernel.org>
Fixes: b089c31c519c ("ARM: 8667/3: Fix memory attribute inconsistencies when using fixmap")
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Ivan T. Ivanov <iivanov@suse.de>
---
 arch/arm/mm/mmu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -413,9 +413,9 @@ void __set_fixmap(enum fixed_addresses i
 		     FIXADDR_END);
 	BUG_ON(idx >= __end_of_fixed_addresses);
 
-	/* we only support device mappings until pgprot_kernel has been set */
+	/* We support only device mappings before pgprot_kernel is set. */
 	if (WARN_ON(pgprot_val(prot) != pgprot_val(FIXMAP_PAGE_IO) &&
-		    pgprot_val(pgprot_kernel) == 0))
+		    pgprot_val(prot) && pgprot_val(pgprot_kernel) == 0))
 		return;
 
 	if (pgprot_val(prot))