[U-Boot] [PATCH v5 00/11] Rewrite ARMv8 layerscape MMU

[york sun]

On 03/06/2017 09:03 AM, York Sun wrote:
> A recent debug revealed MMU for DDR shouldn't be enabled before
> DDR is initialized. Otherwise, a "normal memory" mapping may cause
> speculative access which may hang the system if accessing to DDR
> is not allowed at time.  For Layerscape platforms, we have early
> MMU setup to speed up execution on emulators. The solution is to
> update MMU after DDR is ready. The same idea goes to final MMU as
> well. Actual DDR size is used to create the mappings. Non-exist
> address should be marked as "fault", i.e. invalid to avoid unwanted
> speculative access. Break-before-make process is followed when
> change is made for MMU.
>
> Aside from the DDR size, reserved memory used for secure RAM and
> Management Complex (MC) makes things more complicated. To simplify
> it, a new global is added to track the reserved RAM. Secure RAM
> is excluded from U-Boot MMU. The reserved RAM is still mapped
> under U-Boot since we will need to copy data into it. Reserved
> RAM is excluded when device tree is fixed up so OS won't see it.
> An SoC level efi_add_known_memory() is implemented to add valid
> memory banks. DP-DDR is not added as memory.
>
> Some MC configurations are moved to Kconfig.
>
> Verified on LS2080ARDB with regular Linux boot and distro boot from USB.
>
> Changes in v5:
>   Rename RESV_RAM_TOP to RESV_RAM in Kconfig
>   Revise "help" message and add comment to explain how RESV_RAM is used.
>
> Changes in v4:
>   Revert the change of C bit in v3 patch.
>
> Changes in v3:
>   Instead of flushing d-cache, following the break-before-make process
>   to change MMU table.
>   Add a patch to drop early MMU setup for LS2080A SPL build.
>
> Changes in v2:
>   Add change to efi mapping
>   Implement SoC level efi_add_known_memory(). DP-DDR is skipped so no
>   need to add it as reserved memory later.
>
> York Sun (11):
>   armv8: Add global variable resv_ram
>   armv8: ls2080a: Move CONFIG_FSL_MC_ENET to Kconfig
>   armv8: ls2080a: Move CONFIG_SYS_MC_RSV_MEM_ALIGN to Kconfig
>   efi: Add a hook to allow adding memory mapping
>   armv8: layerscape: Rewrite memory reservation
>   driver: net: fsl-mc: Update calculation of MC RAM
>   armv8: layerscape: Update MMU mapping with actual DDR size
>   armv8: layerscape: Fix the sequence of changing MMU table
>   armv8: ls2080a: Drop early MMU for SPL build
>   armv8: mmu: Add a function to change mapping attributes
>   armv8: layerscape: Update early MMU for DDR after initialization
>

Applied to u-boot-fsl-qoriq master, awaiting upstream.

York