Re: [PATCH v2 12/18] ARM64: mmu: add dynamic optee memory mapping support

[Sascha Hauer <sha@pengutronix.de>]

On Tue, Jan 16, 2024 at 06:07:32PM +0100, Marco Felsch wrote:
> Use the dynamic optee memory base address for the early mapping if
> possible and fallback to the static mapping if the query failed.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  arch/arm/cpu/mmu_64.c      | 14 ++++++++++++--
>  arch/arm/mach-imx/esdctl.c |  4 ++++
>  common/Makefile            |  2 +-
>  3 files changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
> index 84f45bc2c3c1..27fd15ea1233 100644
> --- a/arch/arm/cpu/mmu_64.c
> +++ b/arch/arm/cpu/mmu_64.c
> @@ -20,6 +20,7 @@
>  #include <memory.h>
>  #include <asm/system_info.h>
>  #include <linux/pagemap.h>
> +#include <tee/optee.h>
>  
>  #include "mmu_64.h"
>  
> @@ -310,6 +311,7 @@ static void init_range(size_t total_level0_tables)
>  void mmu_early_enable(unsigned long membase, unsigned long memsize)
>  {
>  	int el;
> +	u64 optee_membase;
>  	unsigned long ttb = arm_mem_ttb(membase + memsize);
>  
>  	pr_debug("enabling MMU, ttb @ 0x%08lx\n", ttb);
> @@ -326,8 +328,16 @@ void mmu_early_enable(unsigned long membase, unsigned long memsize)
>  	 * Set 1:1 mapping of VA->PA. So to cover the full 1TB range we need 2 tables.
>  	 */
>  	init_range(2);
> -	early_remap_range(membase, memsize - OPTEE_SIZE, MAP_CACHED);
> -	early_remap_range(membase + memsize - OPTEE_SIZE, OPTEE_SIZE, MAP_FAULT);
> +
> +	if (optee_get_membase(&optee_membase)) {
> +		/* Fallback and place OP-TEE at the memory end region */
> +		early_remap_range(membase, memsize - OPTEE_SIZE, MAP_CACHED);
> +		early_remap_range(membase + memsize - OPTEE_SIZE, OPTEE_SIZE, MAP_FAULT);
> +	} else {
> +		early_remap_range(membase, memsize, MAP_CACHED);
> +		early_remap_range(optee_membase, OPTEE_SIZE, MAP_FAULT);
> +	}

You could replace the above with:

	early_remap_range(membase, memsize, MAP_CACHED);

	optee_membase = membase + memsize - OPTEE_SIZE;
	optee_get_membase(&optee_membase);
	early_remap_range(optee_membase, OPTEE_SIZE, MAP_FAULT);

Sascha

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