diff options
| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2017-03-14 10:15:22 -0700 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2017-03-29 02:15:06 -0700 |
| commit | d57c0e08c70162feab9ccab085fc34095d2dfd11 (patch) | |
| tree | bcb9e56e6dc5bdcd7d5e4c0ed6ac62161259f07a /drivers/net/ethernet/intel/i40evf/i40e_txrx.c | |
| parent | 3a104f8df2ca87d6d116eae5f2442b57dc3baec4 (diff) | |
i40e/i40evf: 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.
Change-ID: Iebdf9cdb36c454ef092df27199b92ad09c374231
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel/i40evf/i40e_txrx.c')
| -rw-r--r-- | drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index f1a99a8dc7ea..e41eb46b02fe 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1116,6 +1116,7 @@ add_tail_frag: * i40evf_fetch_rx_buffer - Allocate skb and populate it * @rx_ring: rx descriptor ring to transact packets on * @rx_desc: descriptor containing info written by hardware + * @size: size of buffer to add to skb * * This function allocates an skb on the fly, and populates it with the page * data from the current receive descriptor, taking care to set up the skb @@ -1125,13 +1126,9 @@ add_tail_frag: static inline struct sk_buff *i40evf_fetch_rx_buffer(struct i40e_ring *rx_ring, union i40e_rx_desc *rx_desc, - struct sk_buff *skb) + struct sk_buff *skb, + unsigned int size) { - u64 local_status_error_len = - le64_to_cpu(rx_desc->wb.qword1.status_error_len); - unsigned int size = - (local_status_error_len & I40E_RXD_QW1_LENGTH_PBUF_MASK) >> - I40E_RXD_QW1_LENGTH_PBUF_SHIFT; struct i40e_rx_buffer *rx_buffer; struct page *page; @@ -1244,6 +1241,7 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget) while (likely(total_rx_packets < budget)) { union i40e_rx_desc *rx_desc; + unsigned int size; u16 vlan_tag; u8 rx_ptype; u64 qword; @@ -1260,19 +1258,21 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget) /* status_error_len will always be zero for unused descriptors * because it's cleared in cleanup, and overlaps with hdr_addr * which is always zero because packet split isn't used, if the - * hardware wrote DD then it will be non-zero + * hardware wrote DD then the length will be non-zero */ - if (!i40e_test_staterr(rx_desc, - BIT(I40E_RX_DESC_STATUS_DD_SHIFT))) + qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); + size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >> + I40E_RXD_QW1_LENGTH_PBUF_SHIFT; + if (!size) break; /* This memory barrier is needed to keep us from reading - * any other fields out of the rx_desc until we know the - * DD bit is set. + * any other fields out of the rx_desc until we have + * verified the descriptor has been written back. */ dma_rmb(); - skb = i40evf_fetch_rx_buffer(rx_ring, rx_desc, skb); + skb = i40evf_fetch_rx_buffer(rx_ring, rx_desc, skb, size); if (!skb) break; |