[PATCH 3/3 v2] net/macb: Try to optimize struct macb layout

From: Nicolas Ferre
Date: Mon Dec 17 2012 - 08:02:25 EST

From: Havard Skinnemoen <havard@xxxxxxxxxxxxxx>

Move TX-related fields to the top of the struct so that they end up on
the same cache line. Move the NAPI struct below that since it is used
from the interrupt handler. RX-related fields go below those.

Move the spinlock before regs since they are usually used together.

Signed-off-by: Havard Skinnemoen <havard@xxxxxxxxxxxxxx>
[nicolas.ferre@xxxxxxxxx: adapt to newer kernel]
Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
drivers/net/ethernet/cadence/macb.h | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index cef146f..aeeb729 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -548,38 +548,39 @@ struct macb_or_gem_ops {

struct macb {
+ spinlock_t lock;
void __iomem *regs;

+ unsigned int tx_head;
+ unsigned int tx_tail;
+ struct macb_dma_desc *tx_ring;
+ struct macb_tx_skb *tx_skb;
+ dma_addr_t tx_ring_dma;
+ struct work_struct tx_error_task;
+ struct napi_struct napi;
unsigned int rx_tail;
unsigned int rx_prepared_head;
struct macb_dma_desc *rx_ring;
struct sk_buff **rx_skbuff;
void *rx_buffers;
size_t rx_buffer_size;
+ dma_addr_t rx_ring_dma;
+ dma_addr_t rx_buffers_dma;

- unsigned int tx_head, tx_tail;
- struct macb_dma_desc *tx_ring;
- struct macb_tx_skb *tx_skb;
+ struct macb_or_gem_ops macbgem_ops;

- spinlock_t lock;
struct platform_device *pdev;
struct clk *pclk;
struct clk *hclk;
struct net_device *dev;
- struct napi_struct napi;
- struct work_struct tx_error_task;
struct net_device_stats stats;
union {
struct macb_stats macb;
struct gem_stats gem;
} hw_stats;

- dma_addr_t rx_ring_dma;
- dma_addr_t tx_ring_dma;
- dma_addr_t rx_buffers_dma;
- struct macb_or_gem_ops macbgem_ops;
struct mii_bus *mii_bus;
struct phy_device *phy_dev;
unsigned int link;

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