stmmac: review private structure fields

recently many new supports have been added in the stmmac driver w/o taking care
about where each new field had to be placed inside the private structure for
guaranteeing the best cache usage.
This is what I wanted in the beginning, so this patch reorganizes all the fields
in order to keep adjacent fields for cache effect.
I have also tried to optimize them by using pahole.

V2: do not abuse with ____cacheline_aligned_in_smp and keep fields that
potentially could stay in the same cache-line for better usage in SMP systems.

Signed-off-by: Giuseppe Cavallaro <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/stmicro/stmmac/stmmac.h

···
 
 struct stmmac_priv {
 	/* Frequently used values are kept adjacent for cache effect */
-	struct dma_desc *dma_tx ____cacheline_aligned;	/* Basic TX desc */
-	struct dma_extended_desc *dma_etx;	/* Extended TX descriptor */
-	dma_addr_t dma_tx_phy;
+	struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
+	struct dma_desc *dma_tx;
 	struct sk_buff **tx_skbuff;
-	dma_addr_t *tx_skbuff_dma;
 	unsigned int cur_tx;
 	unsigned int dirty_tx;
 	unsigned int dma_tx_size;
+	u32 tx_count_frames;
+	u32 tx_coal_frames;
+	u32 tx_coal_timer;
+	dma_addr_t *tx_skbuff_dma;
+	dma_addr_t dma_tx_phy;
 	int tx_coalesce;
+	int hwts_tx_en;
+	spinlock_t tx_lock;
+	bool tx_path_in_lpi_mode;
+	struct timer_list txtimer;
 
-	struct dma_desc *dma_rx;		/* Basic RX descriptor */
-	struct dma_extended_desc *dma_erx;	/* Extended RX descriptor */
+	struct dma_desc *dma_rx	____cacheline_aligned_in_smp;
+	struct dma_extended_desc *dma_erx;
+	struct sk_buff **rx_skbuff;
 	unsigned int cur_rx;
 	unsigned int dirty_rx;
-	struct sk_buff **rx_skbuff;
-	dma_addr_t *rx_skbuff_dma;
-
-	struct net_device *dev;
-	dma_addr_t dma_rx_phy;
 	unsigned int dma_rx_size;
 	unsigned int dma_buf_sz;
+	u32 rx_riwt;
+	int hwts_rx_en;
+	dma_addr_t *rx_skbuff_dma;
+	dma_addr_t dma_rx_phy;
+
+	struct napi_struct napi ____cacheline_aligned_in_smp;
+
+	void __iomem *ioaddr;
+	struct net_device *dev;
 	struct device *device;
 	struct mac_device_info *hw;
-	void __iomem *ioaddr;
-
-	struct stmmac_extra_stats xstats;
-	struct napi_struct napi;
 	int no_csum_insertion;
+	spinlock_t lock;
 
-	struct phy_device *phydev;
+	struct phy_device *phydev ____cacheline_aligned_in_smp;
 	int oldlink;
 	int speed;
 	int oldduplex;
···
 	struct mii_bus *mii;
 	int mii_irq[PHY_MAX_ADDR];
 
+	struct stmmac_extra_stats xstats ____cacheline_aligned_in_smp;
+	struct plat_stmmacenet_data *plat;
+	struct dma_features dma_cap;
+	struct stmmac_counters mmc;
+	int hw_cap_support;
+	int synopsys_id;
 	u32 msg_enable;
-	spinlock_t lock;
-	spinlock_t tx_lock;
 	int wolopts;
 	int wol_irq;
-	struct plat_stmmacenet_data *plat;
-	struct stmmac_counters mmc;
-	struct dma_features dma_cap;
-	int hw_cap_support;
 	struct clk *stmmac_clk;
 	int clk_csr;
-	int synopsys_id;
 	struct timer_list eee_ctrl_timer;
-	bool tx_path_in_lpi_mode;
 	int lpi_irq;
 	int eee_enabled;
 	int eee_active;
 	int tx_lpi_timer;
-	struct timer_list txtimer;
-	u32 tx_count_frames;
-	u32 tx_coal_frames;
-	u32 tx_coal_timer;
-	int use_riwt;
-	u32 rx_riwt;
+	int pcs;
 	unsigned int mode;
 	int extend_desc;
-	int pcs;
-	int hwts_tx_en;
-	int hwts_rx_en;
-	unsigned int default_addend;
-	u32 adv_ts;
 	struct ptp_clock *ptp_clock;
 	struct ptp_clock_info ptp_clock_ops;
+	unsigned int default_addend;
+	u32 adv_ts;
+	int use_riwt;
 	spinlock_t ptp_lock;
 };