From 5dce95e5687a5a335202b03d133c1b4411ef7ce3 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 18 Aug 2009 15:17:06 +0000 Subject: [PATCH] sky2: transmit ring 64 bit conservation This patch saves elements on transmit ring by only updating the upper 64 bit address when it changes. With many workloads skb's are located in same region, so it saves space. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/sky2.c | 17 +++++++++++------ drivers/net/sky2.h | 1 + 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index fb841c8..88041e5 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -1016,6 +1016,7 @@ static void tx_init(struct sky2_port *sky2) le = get_tx_le(sky2, &sky2->tx_prod); le->addr = 0; le->opcode = OP_ADDR64 | HW_OWNER; + sky2->tx_last_upper = 0; } static inline struct tx_ring_info *tx_le_re(struct sky2_port *sky2, @@ -1573,8 +1574,9 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) struct sky2_tx_le *le = NULL; struct tx_ring_info *re; unsigned i, len; - u16 slot; dma_addr_t mapping; + u32 upper; + u16 slot; u16 mss; u8 ctrl; @@ -1593,9 +1595,11 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) dev->name, slot, skb->len); /* Send high bits if needed */ - if (sizeof(dma_addr_t) > sizeof(u32)) { + upper = upper_32_bits(mapping); + if (upper != sky2->tx_last_upper) { le = get_tx_le(sky2, &slot); - le->addr = cpu_to_le32(upper_32_bits(mapping)); + le->addr = cpu_to_le32(upper); + sky2->tx_last_upper = upper; le->opcode = OP_ADDR64 | HW_OWNER; } @@ -1681,10 +1685,11 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev) if (pci_dma_mapping_error(hw->pdev, mapping)) goto mapping_unwind; - if (sizeof(dma_addr_t) > sizeof(u32)) { + upper = upper_32_bits(mapping); + if (upper != sky2->tx_last_upper) { le = get_tx_le(sky2, &slot); - le->addr = cpu_to_le32(upper_32_bits(mapping)); - le->ctrl = 0; + le->addr = cpu_to_le32(upper); + sky2->tx_last_upper = upper; le->opcode = OP_ADDR64 | HW_OWNER; } diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h index 65b94c3..feb3204 100644 --- a/drivers/net/sky2.h +++ b/drivers/net/sky2.h @@ -2017,6 +2017,7 @@ struct sky2_port { u16 tx_pending; u16 tx_last_mss; + u32 tx_last_upper; u32 tx_tcpsum; struct rx_ring_info *rx_ring ____cacheline_aligned_in_smp; -- 2.7.4