From: Venkatesh Srinivas Date: Mon, 10 Jun 2019 21:27:50 +0000 (-0700) Subject: e1000: Use dma_wmb() instead of wmb() before doorbell writes X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=583cf7be751987005c70f4614e148eb5611f8060;p=openwrt%2Fstaging%2Fblogic.git e1000: Use dma_wmb() instead of wmb() before doorbell writes e1000 writes to doorbells to post transmit descriptors and fill the receive ring. After writing descriptors to memory but before writing to doorbells, use dma_wmb() rather than wmb(). wmb() is more heavyweight than necessary for a device to see descriptor writes. On x86, this avoids SFENCEs before doorbell writes in both the Tx and Rx paths. On ARM, this converts DSB ST -> DMB OSHST. Tested: 82576EB / x86; QEMU (qemu emulates an 8257x) Signed-off-by: Venkatesh Srinivas Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 551de8c2fef2..f703fa58458e 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3019,7 +3019,7 @@ static void e1000_tx_queue(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); tx_ring->next_to_use = i; } @@ -4540,7 +4540,7 @@ e1000_alloc_jumbo_rx_buffers(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); writel(i, adapter->hw.hw_addr + rx_ring->rdt); } } @@ -4655,7 +4655,7 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); writel(i, hw->hw_addr + rx_ring->rdt); } }