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

[Scott Wood]

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 at 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?

> +	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?

> +
>  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?


> 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).

-Scott