From 124b74c18e0e31b24638d256afee7122a994e1b3 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Thu, 11 Dec 2014 15:02:28 -0800 Subject: [PATCH] fm10k/igb/ixgbe: Use dma_rmb on Rx descriptor reads 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 Cc: Don Skidmore Acked-by: Jeff Kirsher Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- Reading git-format-patch failed