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Linux/DRA745: memory reserve for GP version SOC in linux kernel

Part Number: DRA745

Tool/software: Linux

Hi all,

Customer is using DRA745 GP version, the software is PSDK3.04. there is some memory reserve questions

-1-

Customer used DRA745 GP version, Could it remove the 2M bytes reserve space in function omap_secure_ram_reserve_memblock of filel "omap-secure.c" ?

-2-

Could it remove the reserve 2M bytes memory in function omap_barrier_reserve_memblock of file "omap4-common.c"?

-3-

Could it decrease the memory map size from 1M bytes to 4K bytes in function omap_barriers_init?

please give us some suggestions.

Regards

Joe

  • Hi
    Some of the reserved regions are required to ensure right IO access behavior(esp. ones related to barrier above) - do you really need to optimize down to the last few MBs of memory , would recommend not to
  • Hi Sriram,

    I have discussed with customer whether it need to optimise these few MBs, Customer have tried these changes and lunch stability test.
    it did not see failure in these two days but they want to check whether there is risk?

    Could you please give us some function explanations about above reserved regions?

    Regards
    Joe
  • Hi
    the IO barrier related regions are required to enforce ordering of updates to the HW registers vs descriptors in memory - it is fundamental for drivers/peripherals that support queued data transfers(involving descriptors in memory). You cannot get rid of this

    Regarding "Customer used DRA745 GP version, Could it remove the 2M bytes reserve space in function omap_secure_ram_reserve_memblock of filel "omap-secure.c" ?"
    Need to check on this