ixgbe: Improve performance and reduce size of ixgbe_tx_map

This change is meant to both improve the performance and reduce the size of
ixgbe_tx_map.  To do this I have expanded the work done in the main loop by
pushing first into tx_buffer.  This allows us to pull in the dma_mapping_error
check, the tx_buffer value assignment, and the initial DMA value assignment to
the Tx descriptor.  The net result is that the function reduces in size by a
little over a 100 bytes and is about 1% or 2% faster.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Alexander Duyck 2012-10-30 06:01:55 +00:00 committed by Jeff Kirsher
parent 472148c320
commit ec718254cb

View File

@ -6091,21 +6091,22 @@ static void ixgbe_tx_map(struct ixgbe_ring *tx_ring,
struct ixgbe_tx_buffer *first,
const u8 hdr_len)
{
dma_addr_t dma;
struct sk_buff *skb = first->skb;
struct ixgbe_tx_buffer *tx_buffer;
union ixgbe_adv_tx_desc *tx_desc;
struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
unsigned int data_len = skb->data_len;
unsigned int size = skb_headlen(skb);
unsigned int paylen = skb->len - hdr_len;
struct skb_frag_struct *frag;
dma_addr_t dma;
unsigned int data_len, size;
u32 tx_flags = first->tx_flags;
u32 cmd_type = ixgbe_tx_cmd_type(skb, tx_flags);
u16 i = tx_ring->next_to_use;
tx_desc = IXGBE_TX_DESC(tx_ring, i);
ixgbe_tx_olinfo_status(tx_desc, tx_flags, paylen);
ixgbe_tx_olinfo_status(tx_desc, tx_flags, skb->len - hdr_len);
size = skb_headlen(skb);
data_len = skb->data_len;
#ifdef IXGBE_FCOE
if (tx_flags & IXGBE_TX_FLAGS_FCOE) {
@ -6119,16 +6120,19 @@ static void ixgbe_tx_map(struct ixgbe_ring *tx_ring,
#endif
dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
/* record length, and DMA address */
dma_unmap_len_set(first, len, size);
dma_unmap_addr_set(first, dma, dma);
tx_buffer = first;
tx_desc->read.buffer_addr = cpu_to_le64(dma);
for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
/* record length, and DMA address */
dma_unmap_len_set(tx_buffer, len, size);
dma_unmap_addr_set(tx_buffer, dma, dma);
tx_desc->read.buffer_addr = cpu_to_le64(dma);
for (;;) {
while (unlikely(size > IXGBE_MAX_DATA_PER_TXD)) {
tx_desc->read.cmd_type_len =
cpu_to_le32(cmd_type ^ IXGBE_MAX_DATA_PER_TXD);
@ -6139,12 +6143,12 @@ static void ixgbe_tx_map(struct ixgbe_ring *tx_ring,
tx_desc = IXGBE_TX_DESC(tx_ring, 0);
i = 0;
}
tx_desc->read.olinfo_status = 0;
dma += IXGBE_MAX_DATA_PER_TXD;
size -= IXGBE_MAX_DATA_PER_TXD;
tx_desc->read.buffer_addr = cpu_to_le64(dma);
tx_desc->read.olinfo_status = 0;
}
if (likely(!data_len))
@ -6158,6 +6162,7 @@ static void ixgbe_tx_map(struct ixgbe_ring *tx_ring,
tx_desc = IXGBE_TX_DESC(tx_ring, 0);
i = 0;
}
tx_desc->read.olinfo_status = 0;
#ifdef IXGBE_FCOE
size = min_t(unsigned int, data_len, skb_frag_size(frag));
@ -6168,17 +6173,8 @@ static void ixgbe_tx_map(struct ixgbe_ring *tx_ring,
dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
DMA_TO_DEVICE);
if (dma_mapping_error(tx_ring->dev, dma))
goto dma_error;
tx_buffer = &tx_ring->tx_buffer_info[i];
dma_unmap_len_set(tx_buffer, len, size);
dma_unmap_addr_set(tx_buffer, dma, dma);
tx_desc->read.buffer_addr = cpu_to_le64(dma);
tx_desc->read.olinfo_status = 0;
frag++;
}
/* write last descriptor with RS and EOP bits */