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ixgbe: Roll RSC code into non-EOP code 

This change moves the RSC code into the non-EOP descriptor handling
function. The main motivation behind this change is to help reduce the
overhead in the non-RSC case. Previously the non-RSC path code would
always be checking for append count even if RSC had been disabled. Now
this code is completely skipped in a single conditional check instead of
having to make two separate checks.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
This commit is contained in:
Alexander Duyck 2012-07-20 08:08:51 +00:00 committed by Peter P Waskiewicz Jr
parent 18806c9ea2
commit 5a02cbd10d
1 changed files with 19 additions and 32 deletions
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51
drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
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@ -1320,29 +1320,6 @@ static unsigned int ixgbe_get_headlen(unsigned char *data,
return max_len; return max_len;
} }
static void ixgbe_get_rsc_cnt(struct ixgbe_ring *rx_ring,
union ixgbe_adv_rx_desc *rx_desc,
struct sk_buff *skb)
{
__le32 rsc_enabled;
u32 rsc_cnt;
if (!ring_is_rsc_enabled(rx_ring))
return;
rsc_enabled = rx_desc->wb.lower.lo_dword.data &
cpu_to_le32(IXGBE_RXDADV_RSCCNT_MASK);
/* If this is an RSC frame rsc_cnt should be non-zero */
if (!rsc_enabled)
return;
rsc_cnt = le32_to_cpu(rsc_enabled);
rsc_cnt >>= IXGBE_RXDADV_RSCCNT_SHIFT;
IXGBE_CB(skb)->append_cnt += rsc_cnt - 1;
}
static void ixgbe_set_rsc_gso_size(struct ixgbe_ring *ring, static void ixgbe_set_rsc_gso_size(struct ixgbe_ring *ring,
struct sk_buff *skb) struct sk_buff *skb)
{ {
@ -1440,16 +1417,28 @@ static bool ixgbe_is_non_eop(struct ixgbe_ring *rx_ring,
prefetch(IXGBE_RX_DESC(rx_ring, ntc)); prefetch(IXGBE_RX_DESC(rx_ring, ntc));
/* update RSC append count if present */
if (ring_is_rsc_enabled(rx_ring)) {
__le32 rsc_enabled = rx_desc->wb.lower.lo_dword.data &
cpu_to_le32(IXGBE_RXDADV_RSCCNT_MASK);
if (unlikely(rsc_enabled)) {
u32 rsc_cnt = le32_to_cpu(rsc_enabled);
rsc_cnt >>= IXGBE_RXDADV_RSCCNT_SHIFT;
IXGBE_CB(skb)->append_cnt += rsc_cnt - 1;
/* update ntc based on RSC value */
ntc = le32_to_cpu(rx_desc->wb.upper.status_error);
ntc &= IXGBE_RXDADV_NEXTP_MASK;
ntc >>= IXGBE_RXDADV_NEXTP_SHIFT;
}
}
/* if we are the last buffer then there is nothing else to do */
if (likely(ixgbe_test_staterr(rx_desc, IXGBE_RXD_STAT_EOP))) if (likely(ixgbe_test_staterr(rx_desc, IXGBE_RXD_STAT_EOP)))
return false; return false;
/* append_cnt indicates packet is RSC, if so fetch nextp */
if (IXGBE_CB(skb)->append_cnt) {
ntc = le32_to_cpu(rx_desc->wb.upper.status_error);
ntc &= IXGBE_RXDADV_NEXTP_MASK;
ntc >>= IXGBE_RXDADV_NEXTP_SHIFT;
}
/* place skb in next buffer to be received */ /* place skb in next buffer to be received */
rx_ring->rx_buffer_info[ntc].skb = skb; rx_ring->rx_buffer_info[ntc].skb = skb;
rx_ring->rx_stats.non_eop_descs++; rx_ring->rx_stats.non_eop_descs++;
@ -1829,8 +1818,6 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
if (!skb) if (!skb)
break; break;
ixgbe_get_rsc_cnt(rx_ring, rx_desc, skb);
cleaned_count++; cleaned_count++;
/* place incomplete frames back on ring for completion */ /* place incomplete frames back on ring for completion */