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 <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 @@
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 @@
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 @@
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;
}