[Intel-wired-lan] [next PATCH 06/11] ixgbe: Use length to determine if descriptor is done
Alexander Duyck
alexander.duyck at gmail.com
Fri Jan 6 16:07:13 UTC 2017
From: Alexander Duyck <alexander.h.duyck at intel.com>
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.
Signed-off-by: Alexander Duyck <alexander.h.duyck at intel.com>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 1b6f1f584044..6ce596816954 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1653,8 +1653,8 @@ void ixgbe_alloc_rx_buffers(struct ixgbe_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);
@@ -2170,7 +2170,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
rx_desc = IXGBE_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
@@ -3749,6 +3749,7 @@ void ixgbe_configure_rx_ring(struct ixgbe_adapter *adapter,
struct ixgbe_ring *ring)
{
struct ixgbe_hw *hw = &adapter->hw;
+ union ixgbe_adv_rx_desc *rx_desc;
u64 rdba = ring->dma;
u32 rxdctl;
u8 reg_idx = ring->reg_idx;
@@ -3783,6 +3784,10 @@ void ixgbe_configure_rx_ring(struct ixgbe_adapter *adapter,
rxdctl |= 0x080420;
}
+ /* initialize Rx descriptor 0 */
+ rx_desc = IXGBE_RX_DESC(ring, 0);
+ rx_desc->wb.upper.length = 0;
+
/* enable receive descriptor ring */
rxdctl |= IXGBE_RXDCTL_ENABLE;
IXGBE_WRITE_REG(hw, IXGBE_RXDCTL(reg_idx), rxdctl);
@@ -4998,9 +5003,6 @@ static void ixgbe_clean_rx_ring(struct ixgbe_ring *rx_ring)
size = sizeof(struct ixgbe_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;
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