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:
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.
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 ajones@ventanamicro.com