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Commit 16958a2b authored by Lendacky, Thomas's avatar Lendacky, Thomas Committed by David S. Miller
Browse files

amd-xgbe: Add support for the skb->xmit_more flag 



Add support to delay telling the hardware about data that is ready to
be transmitted if the skb->xmit_more flag is set.

Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent eb79e640

drivers/net/ethernet/amd/xgbe/xgbe-desc.c

+2 −3
Original line number Diff line number Diff line
@@ -378,7 +378,7 @@ static void xgbe_wrapper_tx_descriptor_init(struct xgbe_prv_data *pdata) 


		ring->cur = 0;

		ring->dirty = 0;

		ring->tx.queue_stopped = 0;

		memset(&ring->tx, 0, sizeof(ring->tx));



		hw_if->tx_desc_init(channel);

	}
@@ -422,8 +422,7 @@ static void xgbe_wrapper_rx_descriptor_init(struct xgbe_prv_data *pdata) 


		ring->cur = 0;

		ring->dirty = 0;

		ring->rx.realloc_index = 0;

		ring->rx.realloc_threshold = 0;

		memset(&ring->rx, 0, sizeof(ring->rx));



		hw_if->rx_desc_init(channel);

	}

drivers/net/ethernet/amd/xgbe/xgbe-dev.c

+30 −13
Original line number Diff line number Diff line
@@ -1325,6 +1325,29 @@ static void xgbe_config_dcb_pfc(struct xgbe_prv_data *pdata) 
	xgbe_config_flow_control(pdata);

}



static void xgbe_tx_start_xmit(struct xgbe_channel *channel,

			       struct xgbe_ring *ring)

{

	struct xgbe_prv_data *pdata = channel->pdata;

	struct xgbe_ring_data *rdata;



	/* Issue a poll command to Tx DMA by writing address

	 * of next immediate free descriptor */

	rdata = XGBE_GET_DESC_DATA(ring, ring->cur);

	XGMAC_DMA_IOWRITE(channel, DMA_CH_TDTR_LO,

			  lower_32_bits(rdata->rdesc_dma));



	/* Start the Tx coalescing timer */

	if (pdata->tx_usecs && !channel->tx_timer_active) {

		channel->tx_timer_active = 1;

		hrtimer_start(&channel->tx_timer,

			      ktime_set(0, pdata->tx_usecs * NSEC_PER_USEC),

			      HRTIMER_MODE_REL);

	}



	ring->tx.xmit_more = 0;

}



static void xgbe_dev_xmit(struct xgbe_channel *channel)

{

	struct xgbe_prv_data *pdata = channel->pdata;
@@ -1528,20 +1551,13 @@ static void xgbe_dev_xmit(struct xgbe_channel *channel) 
	/* Make sure ownership is written to the descriptor */

	wmb();



	/* Issue a poll command to Tx DMA by writing address

	 * of next immediate free descriptor */

	ring->cur++;

	rdata = XGBE_GET_DESC_DATA(ring, ring->cur);

	XGMAC_DMA_IOWRITE(channel, DMA_CH_TDTR_LO,

			  lower_32_bits(rdata->rdesc_dma));



	/* Start the Tx coalescing timer */

	if (pdata->tx_usecs && !channel->tx_timer_active) {

		channel->tx_timer_active = 1;

		hrtimer_start(&channel->tx_timer,

			      ktime_set(0, pdata->tx_usecs * NSEC_PER_USEC),

			      HRTIMER_MODE_REL);

	}

	if (!packet->skb->xmit_more ||

	    netif_xmit_stopped(netdev_get_tx_queue(pdata->netdev,

						   channel->queue_index)))

		xgbe_tx_start_xmit(channel, ring);

	else

		ring->tx.xmit_more = 1;



	DBGPR("  %s: descriptors %u to %u written\n",

	      channel->name, start_index & (ring->rdesc_count - 1),
@@ -2802,6 +2818,7 @@ void xgbe_init_function_ptrs_dev(struct xgbe_hw_if *hw_if) 
	hw_if->rx_desc_reset = xgbe_rx_desc_reset;

	hw_if->is_last_desc = xgbe_is_last_desc;

	hw_if->is_context_desc = xgbe_is_context_desc;

	hw_if->tx_start_xmit = xgbe_tx_start_xmit;



	/* For FLOW ctrl */

	hw_if->config_tx_flow_control = xgbe_config_tx_flow_control;

drivers/net/ethernet/amd/xgbe/xgbe-drv.c

+31 −6
Original line number Diff line number Diff line
@@ -225,6 +225,28 @@ static inline unsigned int xgbe_tx_avail_desc(struct xgbe_ring *ring) 
	return (ring->rdesc_count - (ring->cur - ring->dirty));

}



static int xgbe_maybe_stop_tx_queue(struct xgbe_channel *channel,

				    struct xgbe_ring *ring, unsigned int count)

{

	struct xgbe_prv_data *pdata = channel->pdata;



	if (count > xgbe_tx_avail_desc(ring)) {

		DBGPR("  Tx queue stopped, not enough descriptors available\n");

		netif_stop_subqueue(pdata->netdev, channel->queue_index);

		ring->tx.queue_stopped = 1;



		/* If we haven't notified the hardware because of xmit_more

		 * support, tell it now

		 */

		if (ring->tx.xmit_more)

			pdata->hw_if.tx_start_xmit(channel, ring);



		return NETDEV_TX_BUSY;

	}



	return 0;

}



static int xgbe_calc_rx_buf_size(struct net_device *netdev, unsigned int mtu)

{

	unsigned int rx_buf_size;
@@ -1199,6 +1221,8 @@ static void xgbe_packet_info(struct xgbe_prv_data *pdata, 
	unsigned int len;

	unsigned int i;



	packet->skb = skb;



	context_desc = 0;

	packet->rdesc_count = 0;
@@ -1447,13 +1471,9 @@ static int xgbe_xmit(struct sk_buff *skb, struct net_device *netdev) 
	xgbe_packet_info(pdata, ring, skb, packet);



	/* Check that there are enough descriptors available */

	if (packet->rdesc_count > xgbe_tx_avail_desc(ring)) {

		DBGPR("  Tx queue stopped, not enough descriptors available\n");

		netif_stop_subqueue(netdev, channel->queue_index);

		ring->tx.queue_stopped = 1;

		ret = NETDEV_TX_BUSY;

	ret = xgbe_maybe_stop_tx_queue(channel, ring, packet->rdesc_count);

	if (ret)

		goto tx_netdev_return;

	}



	ret = xgbe_prep_tso(skb, packet);

	if (ret) {
@@ -1480,6 +1500,11 @@ static int xgbe_xmit(struct sk_buff *skb, struct net_device *netdev) 
	xgbe_print_pkt(netdev, skb, true);

#endif



	/* Stop the queue in advance if there may not be enough descriptors */

	xgbe_maybe_stop_tx_queue(channel, ring, XGBE_TX_MAX_DESCS);



	ret = NETDEV_TX_OK;



tx_netdev_return:

	spin_unlock_irqrestore(&ring->lock, flags);

drivers/net/ethernet/amd/xgbe/xgbe.h

+15 −0
Original line number Diff line number Diff line
@@ -140,6 +140,17 @@ 


#define XGBE_TX_MAX_BUF_SIZE	(0x3fff & ~(64 - 1))



/* Descriptors required for maximum contigous TSO/GSO packet */

#define XGBE_TX_MAX_SPLIT	((GSO_MAX_SIZE / XGBE_TX_MAX_BUF_SIZE) + 1)



/* Maximum possible descriptors needed for an SKB:

 * - Maximum number of SKB frags

 * - Maximum descriptors for contiguous TSO/GSO packet

 * - Possible context descriptor

 * - Possible TSO header descriptor

 */

#define XGBE_TX_MAX_DESCS	(MAX_SKB_FRAGS + XGBE_TX_MAX_SPLIT + 2)



#define XGBE_RX_MIN_BUF_SIZE	(ETH_FRAME_LEN + ETH_FCS_LEN + VLAN_HLEN)

#define XGBE_RX_BUF_ALIGN	64

#define XGBE_SKB_ALLOC_SIZE	256
@@ -225,6 +236,8 @@ 
struct xgbe_prv_data;



struct xgbe_packet_data {

	struct sk_buff *skb;



	unsigned int attributes;



	unsigned int errors;
@@ -360,6 +373,7 @@ struct xgbe_ring { 
	union {

		struct {

			unsigned int queue_stopped;

			unsigned int xmit_more;

			unsigned short cur_mss;

			unsigned short cur_vlan_ctag;

		} tx;
@@ -523,6 +537,7 @@ struct xgbe_hw_if { 
	void (*tx_desc_reset)(struct xgbe_ring_data *);

	int (*is_last_desc)(struct xgbe_ring_desc *);

	int (*is_context_desc)(struct xgbe_ring_desc *);

	void (*tx_start_xmit)(struct xgbe_channel *, struct xgbe_ring *);



	/* For FLOW ctrl */

	int (*config_tx_flow_control)(struct xgbe_prv_data *);