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

[Heinrich Schuchardt]

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?

Best regards

Heinrich

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