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Commit f986afcb authored by Sathya Perla's avatar Sathya Perla Committed by David S. Miller
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be2net: avoid unncessary swapping of fields in eth_tx_wrb 



The 32-bit fields of a tx-wrb are little endian. The driver is currently
using be_dws_le_to_cpu() routine to swap (cpu to le) all the fields of
a tx-wrb. So, the rsvd field is also unnecessarily swapped.

This patch fixes this by individually swapping the required fields.
Also, the type of the fields in eth_tx_wrb{} is now changed to __le32
from u32 to avoid sparse warnings.

Signed-off-by: default avatarSathya Perla <sathya.perla@emulex.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 21252377

drivers/net/ethernet/emulex/benet/be_hw.h

+5 −5
Original line number Diff line number Diff line
@@ -193,10 +193,10 @@ struct be_eq_entry { 
/* TX Queue Descriptor */

#define ETH_WRB_FRAG_LEN_MASK		0xFFFF

struct be_eth_wrb {

	u32 frag_pa_hi;		/* dword 0 */

	u32 frag_pa_lo;		/* dword 1 */

	__le32 frag_pa_hi;		/* dword 0 */

	__le32 frag_pa_lo;		/* dword 1 */

	u32 rsvd0;			/* dword 2 */

	u32 frag_len;		/* dword 3: bits 0 - 15 */

	__le32 frag_len;		/* dword 3: bits 0 - 15 */

} __packed;



/* Pseudo amap definition for eth_hdr_wrb in which each bit of the
@@ -229,7 +229,7 @@ struct amap_eth_hdr_wrb { 
#define TX_HDR_WRB_NUM_MASK		0x1F		/* word 2: bits 13:17 */



struct be_eth_hdr_wrb {

	u32 dw[4];

	__le32 dw[4];

};



/********* Tx Compl Status Encoding *********/

drivers/net/ethernet/emulex/benet/be_main.c

+22 −13
Original line number Diff line number Diff line
@@ -682,9 +682,20 @@ static u32 skb_wrb_cnt(struct sk_buff *skb) 


static inline void wrb_fill(struct be_eth_wrb *wrb, u64 addr, int len)

{

	wrb->frag_pa_hi = upper_32_bits(addr);

	wrb->frag_pa_lo = addr & 0xFFFFFFFF;

	wrb->frag_len = len & ETH_WRB_FRAG_LEN_MASK;

	wrb->frag_pa_hi = cpu_to_le32(upper_32_bits(addr));

	wrb->frag_pa_lo = cpu_to_le32(lower_32_bits(addr));

	wrb->frag_len = cpu_to_le32(len & ETH_WRB_FRAG_LEN_MASK);

	wrb->rsvd0 = 0;

}



/* A dummy wrb is just all zeros. Using a separate routine for dummy-wrb

 * to avoid the swap and shift/mask operations in wrb_fill().

 */

static inline void wrb_fill_dummy(struct be_eth_wrb *wrb)

{

	wrb->frag_pa_hi = 0;

	wrb->frag_pa_lo = 0;

	wrb->frag_len = 0;

	wrb->rsvd0 = 0;

}
@@ -765,16 +776,16 @@ static void unmap_tx_frag(struct device *dev, struct be_eth_wrb *wrb, 
			  bool unmap_single)

{

	dma_addr_t dma;

	u32 frag_len = le32_to_cpu(wrb->frag_len);



	be_dws_le_to_cpu(wrb, sizeof(*wrb));



	dma = (u64)wrb->frag_pa_hi << 32 | (u64)wrb->frag_pa_lo;

	if (wrb->frag_len) {

	dma = (u64)le32_to_cpu(wrb->frag_pa_hi) << 32 |

		(u64)le32_to_cpu(wrb->frag_pa_lo);

	if (frag_len) {

		if (unmap_single)

			dma_unmap_single(dev, dma, wrb->frag_len,

					 DMA_TO_DEVICE);

			dma_unmap_single(dev, dma, frag_len, DMA_TO_DEVICE);

		else

			dma_unmap_page(dev, dma, wrb->frag_len, DMA_TO_DEVICE);

			dma_unmap_page(dev, dma, frag_len, DMA_TO_DEVICE);

	}

}
@@ -806,7 +817,6 @@ static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo, 
		map_single = true;

		wrb = queue_head_node(txq);

		wrb_fill(wrb, busaddr, len);

		be_dws_cpu_to_le(wrb, sizeof(*wrb));

		queue_head_inc(txq);

		copied += len;

	}
@@ -820,7 +830,6 @@ static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo, 
			goto dma_err;

		wrb = queue_head_node(txq);

		wrb_fill(wrb, busaddr, skb_frag_size(frag));

		be_dws_cpu_to_le(wrb, sizeof(*wrb));

		queue_head_inc(txq);

		copied += skb_frag_size(frag);

	}
@@ -846,7 +855,7 @@ static u32 be_xmit_enqueue(struct be_adapter *adapter, struct be_tx_obj *txo, 
		wrb = queue_head_node(txq);

		unmap_tx_frag(dev, wrb, map_single);

		map_single = false;

		copied -= wrb->frag_len;

		copied -= le32_to_cpu(wrb->frag_len);

		adapter->drv_stats.dma_map_errors++;

		queue_head_inc(txq);

	}
@@ -1037,7 +1046,7 @@ static void be_xmit_flush(struct be_adapter *adapter, struct be_tx_obj *txo) 


	/* compose a dummy wrb if there are odd set of wrbs to notify */

	if (!lancer_chip(adapter) && (txo->pend_wrb_cnt & 1)) {

		wrb_fill(queue_head_node(txq), 0, 0);

		wrb_fill_dummy(queue_head_node(txq));

		queue_head_inc(txq);

		atomic_inc(&txq->used);

		txo->pend_wrb_cnt++;