[PATCH] fixup! ARM: always call cache_invalidate_stale before enabling D-Cache

[PATCH] fixup! ARM: always call cache_invalidate_stale before enabling D-Cache

[Ahmad Fatoum]

The invalidate was removed from __barebox_arm_entry, so it precedes MMU
setup. This was missed for ARM64 and it happened even when the MMU was
already enabled.

Additionally, the invalidate was done even if MMU was already enabled.
We have this check for barebox as EFI payload, where we shouldn't really
do any cache maintenance ourselves, so move it after the check.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/cpu/mmu_32.c | 4 ++--
 arch/arm/cpu/mmu_64.c | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
index 7b49643fd79b..6821088c4340 100644
--- a/arch/arm/cpu/mmu_32.c
+++ b/arch/arm/cpu/mmu_32.c
@@ -613,11 +613,11 @@ void mmu_early_enable(unsigned long membase, unsigned long memsize)
 
 	pr_debug("enabling MMU, ttb @ 0x%p\n", ttb);
 
-	cache_invalidate_stale();
-
 	if (get_cr() & CR_M)
 		return;
 
+	cache_invalidate_stale();
+
 	set_ttbr(ttb);
 
 	set_domain(DOMAIN_CLIENT);
diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
index bf44cc7bccf2..a49beac350d3 100644
--- a/arch/arm/cpu/mmu_64.c
+++ b/arch/arm/cpu/mmu_64.c
@@ -392,6 +392,8 @@ void mmu_early_enable(unsigned long membase, unsigned long memsize)
 	if (get_cr() & CR_M)
 		return;
 
+	cache_invalidate_stale();
+
 	pr_debug("enabling MMU, ttb @ 0x%08lx\n", ttb);
 
 	el = current_el();
-- 
2.47.3

Re: [PATCH] fixup! ARM: always call cache_invalidate_stale before enabling D-Cache

[Sascha Hauer]

On Fri, 28 Aug 2026 21:27:08 +0200, Ahmad Fatoum wrote:
> The invalidate was removed from __barebox_arm_entry, so it precedes MMU
> setup. This was missed for ARM64 and it happened even when the MMU was
> already enabled.
> 
> Additionally, the invalidate was done even if MMU was already enabled.
> We have this check for barebox as EFI payload, where we shouldn't really
> do any cache maintenance ourselves, so move it after the check.
> 
> [...]

Applied, thanks!

[1/1] fixup! ARM: always call cache_invalidate_stale before enabling D-Cache
      https://git.pengutronix.de/cgit/barebox/commit/?id=0c88df132f66 (link may not be stable)

Best regards,
-- 
Sascha Hauer <s.hauer@pengutronix.de>