[PATCH] stm32mp: Reserve OPTEE area in EFI memory map

[Patrice CHOTARD]

On 4/17/24 09:45, Heinrich Schuchardt wrote:
> On 17.04.24 09:25, Patrick DELAUNAY wrote:
>> Hi,
>>
>> On 3/8/24 11:12, Patrice Chotard wrote:
>>> Since commit 7b78d6438a2b3 ("efi_loader: Reserve unaccessible memory")
>>> memory region above ram_top is tagged in EFI memory map as
>>> EFI_BOOT_SERVICES_DATA.
>>> In case of STM32MP1 platform, above ram_top, there is one reserved-memory
>>> region tagged "no-map" dedicated to OP-TEE (addr=de000000 size=2000000).
>>>
>>> Before booting kernel, EFI memory map is first built, the OPTEE region is
>>> tagged as EFI_BOOT_SERVICES_DATA and when reserving LMB, the tag LMB_NONE
>>> is used.
>>>
>>> Then after, the LMB are completed by boot_fdt_add_mem_rsv_regions()
>>> which try to add again the same OPTEE region (addr=de000000 size=2000000)
>>> but now with LMB_NOMAP tag which produces the following error message :
>>>
>>> "ERROR: reserving fdt memory region failed (addr=de000000 size=2000000
>>> flags=4)"
>>>
>>> To avoid this, OPTEE area shouldn't be used by EFI, so we need to mark
>>> it as reserved.
>>>
>>> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
>>> ---
>>>
>>>   arch/arm/mach-stm32mp/dram_init.c | 12 ++++++++++++
>>>   1 file changed, 12 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-stm32mp/dram_init.c
>>> b/arch/arm/mach-stm32mp/dram_init.c
>>> index fb1208fc5d5..f67f54f2ae0 100644
>>> --- a/arch/arm/mach-stm32mp/dram_init.c
>>> +++ b/arch/arm/mach-stm32mp/dram_init.c
>>> @@ -7,6 +7,7 @@
>>>   #include <common.h>
>>>   #include <dm.h>
>>> +#include <efi_loader.h>
>>>   #include <image.h>
>>>   #include <init.h>
>>>   #include <lmb.h>
>>> @@ -75,3 +76,14 @@ phys_addr_t board_get_usable_ram_top(phys_size_t
>>> total_size)
>>>       return reg + size;
>>>   }
>>> +
>>> +void efi_add_known_memory(void)
>>> +{
>>> +    if (IS_ENABLED(CONFIG_EFI_LOADER))
>>> +        /*
>>> +         * Memory over ram_top is reserved to OPTEE.
>>> +         * Declare to EFI only memory area below ram_top
>>> +         */
>>> +        efi_add_memory_map(gd->ram_base, gd->ram_top - gd->ram_base,
>>> +                   EFI_CONVENTIONAL_MEMORY);
> 
> With this change the EFI memory map passed to the operating system will
> not contain any memory above gd->ram_top. Is this really your intent?
> Don't you have any memory above 0xe0000000?

Hi Heinrich

On stm32mp157x-dk and stm32mp135x-dk boards, there is no memory above 0xe0000000.
But, on stm32mp157x-ed1 or stm32mp157x-ev1, you are right, we got memory above 0xe0000000.

I will rework this patch to take into account memory that could be present above OPTEE area.

Thanks for pointing this
Patrice

> 
> Best regards
> 
> Heinrich
> 
>>> +}
>>
>>
>>
>> Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
>>
>> Thanks
>> Patrick
>>
>