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由 Alexander Duyck 提交于
This change makes it so that dma_rmb is used when reading the Rx descriptor. The advantage of dma_rmb is that it allows for a much lower cost barrier on x86, powerpc, arm, and arm64 architectures than a traditional memory barrier when dealing with reads that only have to synchronize to coherent memory. In addition I have updated the code so that it just checks to see if any bits have been set instead of just the DD bit since the DD bit will always be set as a part of a descriptor write-back so we just need to check for a non-zero value being present at that memory location rather than just checking for any specific bit. This allows the code itself to appear much cleaner and allows the compiler more room to optimize. Cc: Matthew Vick <matthew.vick@intel.com> Cc: Don Skidmore <donald.c.skidmore@intel.com> Acked-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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