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Commit 8d0557d2 authored by Hariprasad Shenai's avatar Hariprasad Shenai Committed by David S. Miller
Browse files

cxgb4: Deal with wrap-around of queue for Work request 



The WR headers  may not fit within one descriptor.
So we need to deal with wrap-around here.

Based on original patch by Pranjal Joshi <pjoshi@chelsio.com>

Signed-off-by: default avatarHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 126fca64

drivers/net/ethernet/chelsio/cxgb4/sge.c

+53 −4
Original line number Diff line number Diff line
@@ -1029,6 +1029,30 @@ static void inline_tx_skb(const struct sk_buff *skb, const struct sge_txq *q, 
		*p = 0;

}



static void *inline_tx_skb_header(const struct sk_buff *skb,

				  const struct sge_txq *q,  void *pos,

				  int length)

{

	u64 *p;

	int left = (void *)q->stat - pos;



	if (likely(length <= left)) {

		memcpy(pos, skb->data, length);

		pos += length;

	} else {

		memcpy(pos, skb->data, left);

		memcpy(q->desc, skb->data + left, length - left);

		pos = (void *)q->desc + (length - left);

	}

	/* 0-pad to multiple of 16 */

	p = PTR_ALIGN(pos, 8);

	if ((uintptr_t)p & 8) {

		*p = 0;

		return p + 1;

	}

	return p;

}



/*

 * Figure out what HW csum a packet wants and return the appropriate control

 * bits.
@@ -1561,9 +1585,11 @@ static void ofldtxq_stop(struct sge_ofld_txq *q, struct sk_buff *skb) 
 */

static void service_ofldq(struct sge_ofld_txq *q)

{

	u64 *pos;

	u64 *pos, *before, *end;

	int credits;

	struct sk_buff *skb;

	struct sge_txq *txq;

	unsigned int left;

	unsigned int written = 0;

	unsigned int flits, ndesc;
@@ -1607,9 +1633,32 @@ static void service_ofldq(struct sge_ofld_txq *q) 
		} else {

			int last_desc, hdr_len = skb_transport_offset(skb);



			memcpy(pos, skb->data, hdr_len);

			write_sgl(skb, &q->q, (void *)pos + hdr_len,

				  pos + flits, hdr_len,

			/* The WR headers  may not fit within one descriptor.

			 * So we need to deal with wrap-around here.

			 */

			before = (u64 *)pos;

			end = (u64 *)pos + flits;

			txq = &q->q;

			pos = (void *)inline_tx_skb_header(skb, &q->q,

							   (void *)pos,

							   hdr_len);

			if (before > (u64 *)pos) {

				left = (u8 *)end - (u8 *)txq->stat;

				end = (void *)txq->desc + left;

			}



			/* If current position is already at the end of the

			 * ofld queue, reset the current to point to

			 * start of the queue and update the end ptr as well.

			 */

			if (pos == (u64 *)txq->stat) {

				left = (u8 *)end - (u8 *)txq->stat;

				end = (void *)txq->desc + left;

				pos = (void *)txq->desc;

			}



			write_sgl(skb, &q->q, (void *)pos,

				  end, hdr_len,

				  (dma_addr_t *)skb->head);

#ifdef CONFIG_NEED_DMA_MAP_STATE

			skb->dev = q->adap->port[0];