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shareable attribute in armv8

Hi Experts,

                    I was going through the arm v8 mmu page table formation, when it's compared to arm v7 it is completely different.

I could see how to set the different page attributes like caching policies, but I couldn't get how to mark a page as shareable to enable the exclusive load store instructions.

can you please help me with correct location where we can set the shareable attribute ?

Parents
  • The sharabilty is set in the descriptor in the AArch64 translation tables, it is controlled by a combination of the lower attributes and the memory type.  Device and non-cacheable memory is treated as being outer shareable. 

    For normal cacheable memory; in the lower attributes of the block descriptor you have a 2 bit shareability field SH[1:0]:

    00 Non-shareable

    01 UNPREDICTABLE

    10 Outer Shareable

    11 Inner Shareable

    SH is bits [9:8] of the descriptor.

Reply
  • The sharabilty is set in the descriptor in the AArch64 translation tables, it is controlled by a combination of the lower attributes and the memory type.  Device and non-cacheable memory is treated as being outer shareable. 

    For normal cacheable memory; in the lower attributes of the block descriptor you have a 2 bit shareability field SH[1:0]:

    00 Non-shareable

    01 UNPREDICTABLE

    10 Outer Shareable

    11 Inner Shareable

    SH is bits [9:8] of the descriptor.

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