Commit ea0d7d91 authored by Scott Feldman's avatar Scott Feldman Committed by David S. Miller
Browse files

enic: bug fix: split TSO fragments larger than 16K into multiple descs 



enic WQ desc supports a maximum 16K buf size, so split any send fragments
larger than 16K into several descs.

Signed-off-by: default avatarScott Feldman <scofeldm@cisco.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4badc385

drivers/net/enic/enic_main.c

+69 −18
Original line number Diff line number Diff line
@@ -44,10 +44,15 @@ 
#include "enic.h"



#define ENIC_NOTIFY_TIMER_PERIOD	(2 * HZ)

#define WQ_ENET_MAX_DESC_LEN		(1 << WQ_ENET_LEN_BITS)

#define MAX_TSO				(1 << 16)

#define ENIC_DESC_MAX_SPLITS		(MAX_TSO / WQ_ENET_MAX_DESC_LEN + 1)



#define PCI_DEVICE_ID_CISCO_VIC_ENET         0x0043  /* ethernet vnic */



/* Supported devices */

static struct pci_device_id enic_id_table[] = {

	{ PCI_VDEVICE(CISCO, 0x0043) },

	{ PCI_VDEVICE(CISCO, PCI_DEVICE_ID_CISCO_VIC_ENET) },

	{ 0, }	/* end of table */

};
@@ -310,7 +315,8 @@ static int enic_wq_service(struct vnic_dev *vdev, struct cq_desc *cq_desc, 
		opaque);



	if (netif_queue_stopped(enic->netdev) &&

	    vnic_wq_desc_avail(&enic->wq[q_number]) >= MAX_SKB_FRAGS + 1)

	    vnic_wq_desc_avail(&enic->wq[q_number]) >=

	    (MAX_SKB_FRAGS + ENIC_DESC_MAX_SPLITS))

		netif_wake_queue(enic->netdev);



	spin_unlock(&enic->wq_lock[q_number]);
@@ -525,7 +531,11 @@ static inline void enic_queue_wq_skb_vlan(struct enic *enic, 
	unsigned int len_left = skb->len - head_len;

	int eop = (len_left == 0);



	/* Queue the main skb fragment */

	/* Queue the main skb fragment. The fragments are no larger

	 * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less

	 * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor

	 * per fragment is queued.

	 */

	enic_queue_wq_desc(wq, skb,

		pci_map_single(enic->pdev, skb->data,

			head_len, PCI_DMA_TODEVICE),
@@ -547,7 +557,11 @@ static inline void enic_queue_wq_skb_csum_l4(struct enic *enic, 
	unsigned int csum_offset = hdr_len + skb->csum_offset;

	int eop = (len_left == 0);



	/* Queue the main skb fragment */

	/* Queue the main skb fragment. The fragments are no larger

	 * than max MTU(9000)+ETH_HDR_LEN(14) bytes, which is less

	 * than WQ_ENET_MAX_DESC_LEN length. So only one descriptor

	 * per fragment is queued.

	 */

	enic_queue_wq_desc_csum_l4(wq, skb,

		pci_map_single(enic->pdev, skb->data,

			head_len, PCI_DMA_TODEVICE),
@@ -565,10 +579,14 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic, 
	struct vnic_wq *wq, struct sk_buff *skb, unsigned int mss,

	int vlan_tag_insert, unsigned int vlan_tag)

{

	unsigned int head_len = skb_headlen(skb);

	unsigned int len_left = skb->len - head_len;

	unsigned int frag_len_left = skb_headlen(skb);

	unsigned int len_left = skb->len - frag_len_left;

	unsigned int hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb);

	int eop = (len_left == 0);

	unsigned int len;

	dma_addr_t dma_addr;

	unsigned int offset = 0;

	skb_frag_t *frag;



	/* Preload TCP csum field with IP pseudo hdr calculated

	 * with IP length set to zero.  HW will later add in length
@@ -584,17 +602,49 @@ static inline void enic_queue_wq_skb_tso(struct enic *enic, 
			&ipv6_hdr(skb)->daddr, 0, IPPROTO_TCP, 0);

	}



	/* Queue the main skb fragment */

	/* Queue WQ_ENET_MAX_DESC_LEN length descriptors

	 * for the main skb fragment

	 */

	while (frag_len_left) {

		len = min(frag_len_left, (unsigned int)WQ_ENET_MAX_DESC_LEN);

		dma_addr = pci_map_single(enic->pdev, skb->data + offset,

				len, PCI_DMA_TODEVICE);

		enic_queue_wq_desc_tso(wq, skb,

		pci_map_single(enic->pdev, skb->data,

			head_len, PCI_DMA_TODEVICE),

		head_len,

			dma_addr,

			len,

			mss, hdr_len,

			vlan_tag_insert, vlan_tag,

		eop);

			eop && (len == frag_len_left));

		frag_len_left -= len;

		offset += len;

	}



	if (!eop)

		enic_queue_wq_skb_cont(enic, wq, skb, len_left);

	if (eop)

		return;



	/* Queue WQ_ENET_MAX_DESC_LEN length descriptors

	 * for additional data fragments

	 */

	for (frag = skb_shinfo(skb)->frags; len_left; frag++) {

		len_left -= frag->size;

		frag_len_left = frag->size;

		offset = frag->page_offset;



		while (frag_len_left) {

			len = min(frag_len_left,

				(unsigned int)WQ_ENET_MAX_DESC_LEN);

			dma_addr = pci_map_page(enic->pdev, frag->page,

				offset, len,

				PCI_DMA_TODEVICE);

			enic_queue_wq_desc_cont(wq, skb,

				dma_addr,

				len,

				(len_left == 0) &&

				(len == frag_len_left));	/* EOP? */

			frag_len_left -= len;

			offset += len;

		}

	}

}



static inline void enic_queue_wq_skb(struct enic *enic,
@@ -648,7 +698,8 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, 


	spin_lock_irqsave(&enic->wq_lock[0], flags);



	if (vnic_wq_desc_avail(wq) < skb_shinfo(skb)->nr_frags + 1) {

	if (vnic_wq_desc_avail(wq) <

	    skb_shinfo(skb)->nr_frags + ENIC_DESC_MAX_SPLITS) {

		netif_stop_queue(netdev);

		/* This is a hard error, log it */

		printk(KERN_ERR PFX "%s: BUG! Tx ring full when "
@@ -659,7 +710,7 @@ static netdev_tx_t enic_hard_start_xmit(struct sk_buff *skb, 


	enic_queue_wq_skb(enic, wq, skb);



	if (vnic_wq_desc_avail(wq) < MAX_SKB_FRAGS + 1)

	if (vnic_wq_desc_avail(wq) < MAX_SKB_FRAGS + ENIC_DESC_MAX_SPLITS)

		netif_stop_queue(netdev);



	spin_unlock_irqrestore(&enic->wq_lock[0], flags);