[U-Boot] [RFC PATCH v1 1/2] armv8: fsl-layerscape: Reserve memory for PPA

[York Sun <yorksun@freescale.com>]

On 11/10/2015 11:31 AM, Scott Wood wrote:
> On Tue, 2015-11-10 at 11:17 -0800, York Sun wrote:
>> Primary Protected Application (PPA) is the base of TrustZone for
>> Freescale Layerscape SoCs. It needs to run in secure memory while
>> the rest of u-boot can run in non-secure memory. The secure memory
>> is reserved at the very end of DDR, before debug server and MC
>> reservations. The address varies depending on the total size of
>> intalled DDR.
>>
>> Signed-off-by: York Sun <yorksun@freescale.com>
>>
>> ---
>>
>> Changes in v1:
>>   Initial patch.
>>   Depends on http://patchwork.ozlabs.org/patch/540248/
>>
>>  README                                            |   14 ++++++++++---
>>  arch/arm/cpu/armv8/fsl-layerscape/cpu.c           |   23
>> +++++++++++++++++++++
>>  arch/arm/include/asm/arch-fsl-layerscape/config.h |    3 +++
>>  board/freescale/ls2085a/ls2085a.c                 |   17 ---------------
>>  board/freescale/ls2085aqds/ls2085aqds.c           |   17 ---------------
>>  board/freescale/ls2085ardb/ls2085ardb.c           |   17 ---------------
>>  include/configs/ls2085a_common.h                  |    4 ++--
>>  7 files changed, 39 insertions(+), 56 deletions(-)
>>
>> diff --git a/README b/README
>> index ef8d437..e1ca7c2 100644
>> --- a/README
>> +++ b/README
>> @@ -3881,7 +3881,7 @@ Configuration Settings:
>>  		Scratch address used by the alternate memory test
>>  		You only need to set this if address zero isn't writeable
>>  
>> -- CONFIG_SYS_MEM_TOP_HIDE (PPC only):
>> +- CONFIG_SYS_MEM_TOP_HIDE:
>>  		If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config
>> header,
>>  		this specified memory area will get subtracted from the top
>>  		(end) of RAM and won't get "touched" at all by U-Boot. By
>> @@ -5048,6 +5048,10 @@ within that device.
>>  	normal addressable memory via the LBC. CONFIG_SYS_LS_MC_FW_ADDR is
>> the
>>  	virtual address in NOR flash.
>>  
>> +- CONFIG_SYS_MEM_TOP_HIDE_MIN
>> +	Define minimum DDR size to be hided from top of the DDR memory.
> 
> Defines the minimum DDR size to be hidden from the top of DDR memory.
> 
> How is this different from CONFIG_SYS_MEM_TOP_HIDE?

This is used by MC to make sure it is aligned.

> 
>> +	MC requires the region to be aligned with 512MB.
> 
> Why is this generically named symbol documented in the Layerscape section,
> with a reference to MC?
> 
> Why is a new symbol being added here rather than Kconfig?
> 
> Why does this talk about MC alignment as if this entire region were for MC?

I moved this section out of MC alignment. Maybe I should keep it there.

> 
>> +
>>  Freescale Layerscape Debug Server Support:
>>  -------------------------------------------
>>  The Freescale Layerscape Debug Server Support supports the loading of
>> @@ -5060,8 +5064,12 @@ This firmware often needs to be loaded during U-Boot
>> booting.
>>  - CONFIG_SYS_DEBUG_SERVER_DRAM_BLOCK_MIN_SIZE
>>  	Define minimum DDR size required for debug server image
>>  
>> -- CONFIG_SYS_MEM_TOP_HIDE_MIN
>> -	Define minimum DDR size to be hided from top of the DDR memory
>> +Freescale Layerscape Primary Protected Application (PPA) support
>> +----------------------------------------------------------------
>> +Freescale PPA runs in secure DDR, reserved from DDR pool.
>> +
>> +- CONFIG_FSL_PPA_RESERVED_DRAM_SIZE
>> +	If defined, this is reserved in highest address as secure memory
> 
> What is Freescale-specific about the concept of reserving memory for a secure
> monitor?

The PPA is a Freescale implementation of TrustZone application.

> 
> 
>> diff --git a/arch/arm/include/asm/arch-fsl-layerscape/config.h
>> b/arch/arm/include/asm/arch-fsl-layerscape/config.h
>> index 87bb937..77637a9 100644
>> --- a/arch/arm/include/asm/arch-fsl-layerscape/config.h
>> +++ b/arch/arm/include/asm/arch-fsl-layerscape/config.h
>> @@ -17,6 +17,9 @@
>>  #define CONFIG_SYS_FSL_DDR		/* Freescale DDR driver */
>>  #define CONFIG_SYS_FSL_DDR_VER		FSL_DDR_VER_5_0
>>  
>> +/* High memory for PPA, MC, debug server when applicable */
>> +#define CONFIG_SYS_MEM_TOP_HIDE		get_dram_size_to_hide()
> 
> Hiding code in config symbols is not friendly to kconfig conversion (and it's
> hard to read besides).
> 

It was made complicated by MC and debug server. Maybe we can fix the size for
them. They are fixed anyway for now.

York