From 7ec0116c9131a8cd58dc456ae2bd5bc9976460d1 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 6 Feb 2017 18:25:41 -0800 Subject: [PATCH] igb: Use length to determine if descriptor is done This change makes it so that we use the length of the packet instead of the DD status bit to determine if a new descriptor is ready to be processed. The obvious advantage is that it cuts down on reads as we don't really even need the DD bit if going from a 0 to a non-zero value on size is enough to inform us that the packet has been completed. In addition I have updated the code so that we only reset the Rx descriptor length for descriptor zero when resetting a ring instead of having to do a memset with 0 over the entire ring. By doing this we can save some time on initialization. Signed-off-by: Alexander Duyck Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igb/igb_ethtool.c | 2 +- drivers/net/ethernet/intel/igb/igb_main.c | 14 ++++++++------ 2 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c index 737b664d004c..3f5f7744c90f 100644 --- a/drivers/net/ethernet/intel/igb/igb_ethtool.c +++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c @@ -1811,7 +1811,7 @@ static int igb_clean_test_rings(struct igb_ring *rx_ring, tx_ntc = tx_ring->next_to_clean; rx_desc = IGB_RX_DESC(rx_ring, rx_ntc); - while (igb_test_staterr(rx_desc, E1000_RXD_STAT_DD)) { + while (rx_desc->wb.upper.length) { /* check Rx buffer */ rx_buffer_info = &rx_ring->rx_buffer_info[rx_ntc]; diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index cf7ee9cdac6f..1d76d3a90a17 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3720,6 +3720,7 @@ void igb_configure_rx_ring(struct igb_adapter *adapter, struct igb_ring *ring) { struct e1000_hw *hw = &adapter->hw; + union e1000_adv_rx_desc *rx_desc; u64 rdba = ring->dma; int reg_idx = ring->reg_idx; u32 srrctl = 0, rxdctl = 0; @@ -3758,6 +3759,10 @@ void igb_configure_rx_ring(struct igb_adapter *adapter, rxdctl |= IGB_RX_HTHRESH << 8; rxdctl |= IGB_RX_WTHRESH << 16; + /* initialize Rx descriptor 0 */ + rx_desc = IGB_RX_DESC(ring, 0); + rx_desc->wb.upper.length = 0; + /* enable receive descriptor fetching */ rxdctl |= E1000_RXDCTL_QUEUE_ENABLE; wr32(E1000_RXDCTL(reg_idx), rxdctl); @@ -3973,9 +3978,6 @@ static void igb_clean_rx_ring(struct igb_ring *rx_ring) size = sizeof(struct igb_rx_buffer) * rx_ring->count; memset(rx_ring->rx_buffer_info, 0, size); - /* Zero out the descriptor ring */ - memset(rx_ring->desc, 0, rx_ring->size); - rx_ring->next_to_alloc = 0; rx_ring->next_to_clean = 0; rx_ring->next_to_use = 0; @@ -7172,7 +7174,7 @@ static int igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget) rx_desc = IGB_RX_DESC(rx_ring, rx_ring->next_to_clean); - if (!rx_desc->wb.upper.status_error) + if (!rx_desc->wb.upper.length) break; /* This memory barrier is needed to keep us from reading @@ -7312,8 +7314,8 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16 cleaned_count) i -= rx_ring->count; } - /* clear the status bits for the next_to_use descriptor */ - rx_desc->wb.upper.status_error = 0; + /* clear the length for the next_to_use descriptor */ + rx_desc->wb.upper.length = 0; cleaned_count--; } while (cleaned_count); -- 2.20.1