[PATCH 3/4] mmu-early: remove OP-TEE from the MMU mapping

[Ahmad Fatoum]

Hello,

On 11/2/20 10:30 AM, Rouven Czerwinski wrote:
> Remove OP-TEE from the CACHED mapping to preserve the XN bit set in the
> default mapping. This should ensure that the Cortex-A7 does not try to
> speculate into secure world memory.
> 
> Signed-off-by: Rouven Czerwinski <r.czerwinski at pengutronix.de>
> ---
>  arch/arm/cpu/mmu-early.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm/cpu/mmu-early.c b/arch/arm/cpu/mmu-early.c
> index b985aa455f..a480cd7707 100644
> --- a/arch/arm/cpu/mmu-early.c
> +++ b/arch/arm/cpu/mmu-early.c
> @@ -3,6 +3,7 @@
>  #include <errno.h>
>  #include <linux/sizes.h>
>  #include <asm/memory.h>
> +#include <asm-generic/memory_layout.h>
>  #include <asm/system.h>
>  #include <asm/cache.h>
>  #include <asm-generic/sections.h>
> @@ -55,6 +56,10 @@ void mmu_early_enable(unsigned long membase, unsigned long memsize,
>  	 */
>  	map_region((unsigned long)_stext, _etext - _stext, PMD_SECT_DEF_UNCACHED);
>  
> +	/* In case we might early load OP-TEE, remove it from the MMU mapping */
> +	if(IS_ENABLED(CONFIG_PBL_OPTEE))
> +		memsize -= OPTEE_SIZE;

You could remove the if condition. OPTEE_SIZE evaluates to zero if the condition
is false.

Reviewed-by: Ahmad Fatoum <a.fatoum at pengutronix.de>

> +
>  	/* maps main memory as cachable */
>  	map_region(membase, memsize, PMD_SECT_DEF_CACHED);
>  
> 

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