riscv: mm: Add support for Svinval extension #176
Merged
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The Svinval extension splits SFENCE.VMA instruction into finer-grained invalidation and ordering operations and is mandatory for RVA23S64 profile. When Svinval is enabled the local_flush_tlb_range_threshold_asid function should use the following sequence to optimize the tlb flushes instead of a simple sfence.vma:
sfence.w.inval
svinval.vma
.
.
svinval.vma
sfence.inval.ir
The maximum number of consecutive svinval.vma instructions that can be executed in local_flush_tlb_range_threshold_asid function is limited to 64. This is required to avoid soft lockups and the approach is similar to that used in arm64.
Reviewed-by: Andrew Jones [email protected]