[PATCH -next v6 04/10] arm: armv8: invalidate dcache entries on dcache_enable

[Ilias Apalodimas]

On Fri, 5 Sept 2025 at 11:19, Anshul Dalal <anshuld at ti.com> wrote:
>
> In dcache_enable, currently the dcache entries are only invalidated when
> the MMU is not enabled. This causes issues when dcache_enable is called
> with the MMU already configured, in such cases the existing dcache
> entries are not flushed which might result in un-expected behavior.
>
> This patch invalidates the cache entries on every call of dcache_enable
> before enabling dcache (by setting CR_C). This makes dcache_enable
> behave similar to icache_enable as well.
>
> Signed-off-by: Anshul Dalal <anshuld at ti.com>
> ---
>  arch/arm/cpu/armv8/cache_v8.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
> index 1c1e33bec24..6e662395a83 100644
> --- a/arch/arm/cpu/armv8/cache_v8.c
> +++ b/arch/arm/cpu/armv8/cache_v8.c
> @@ -830,16 +830,15 @@ void flush_dcache_range(unsigned long start, unsigned long stop)
>  void dcache_enable(void)
>  {
>         /* The data cache is not active unless the mmu is enabled */
> -       if (!(get_sctlr() & CR_M)) {
> -               invalidate_dcache_all();
> -               __asm_invalidate_tlb_all();
> +       if (!mmu_status())
>                 mmu_setup();
> -       }
>
>         /* Set up page tables only once (it is done also by mmu_setup()) */
>         if (!gd->arch.tlb_fillptr)
>                 setup_all_pgtables();
>
> +       invalidate_dcache_all();
> +       __asm_invalidate_tlb_all();
>         set_sctlr(get_sctlr() | CR_C);
>  }
>
> --
> 2.50.1
>

Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>