[PATCH 5.15 847/917] ARM: 9155/1: fix early early_iounmap()

Greg Kroah-Hartman
2021-11-16T00:38:20Z

From: Michał Mirosław <mirq-linux@rere.qmqm.pl>

commit 0d08e7bf0d0d1a29aff7b16ef516f7415eb1aa05 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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
@@ -390,9 +390,9 @@ void __set_fixmap(enum fixed_addresses i
BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) < FIXADDR_START);
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))