Commit 6048718d authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Greg Kroah-Hartman
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Staging: hv: transmit scatter gather support 



The transmit management of pages was confusing for handling
fragmented SKB's. (But since NETIF_F_SG was never set, the code was never hit).

The parameter AdditionalRequestPageBufferCount is always one,
(and leads to ugly code), so just inline and add comments.

Signed-off-by: default avatarStephen Hemminger <shemminger@vyatta.com>
Acked-by: default avatarHank Janssen <hjanssen@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 9f8bd8ba

drivers/staging/hv/RndisFilter.c

+0 −1
Original line number Diff line number Diff line
@@ -624,7 +624,6 @@ int RndisFilterInit(struct netvsc_driver *Driver) 
		   sizeof(struct rndis_filter_packet));



	Driver->RequestExtSize = sizeof(struct rndis_filter_packet);

	Driver->AdditionalRequestPageBufferCount = 1; /* For rndis header */



	/* Driver->Context = rndisDriver; */

drivers/staging/hv/netvsc_drv.c

+22 −31
Original line number Diff line number Diff line
@@ -144,27 +144,21 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) 
		(struct netvsc_driver_context *)driver_ctx;

	struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;

	struct hv_netvsc_packet *packet;

	int i;

	int ret;

	int num_frags;

	unsigned int i, num_pages;

	int retries = 0;



	DPRINT_ENTER(NETVSC_DRV);



	/* Support only 1 chain of frags */

	ASSERT(skb_shinfo(skb)->frag_list == NULL);

	ASSERT(skb->dev == net);



	DPRINT_DBG(NETVSC_DRV, "xmit packet - len %d data_len %d",

		   skb->len, skb->data_len);



	/* Add 1 for skb->data and any additional ones requested */

	num_frags = skb_shinfo(skb)->nr_frags + 1 +

		    net_drv_obj->AdditionalRequestPageBufferCount;

	/* Add 1 for skb->data and additional one for RNDIS */

	num_pages = skb_shinfo(skb)->nr_frags + 1 + 1;



	/* Allocate a netvsc packet based on # of frags. */

	packet = kzalloc(sizeof(struct hv_netvsc_packet) +

			 (num_frags * sizeof(struct hv_page_buffer)) +

			 (num_pages * sizeof(struct hv_page_buffer)) +

			 net_drv_obj->RequestExtSize, GFP_ATOMIC);

	if (!packet) {

		DPRINT_ERR(NETVSC_DRV, "unable to allocate hv_netvsc_packet");
@@ -173,36 +167,30 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) 


	packet->Extension = (void *)(unsigned long)packet +

				sizeof(struct hv_netvsc_packet) +

				    (num_frags * sizeof(struct hv_page_buffer));

				    (num_pages * sizeof(struct hv_page_buffer));



	/* Setup the rndis header */

	packet->PageBufferCount = num_frags;

	packet->PageBufferCount = num_pages;



	/* TODO: Flush all write buffers/ memory fence ??? */

	/* wmb(); */



	/* Initialize it from the skb */

	ASSERT(skb->data);

	packet->TotalDataBufferLength	= skb->len;



	/*

	 * Start filling in the page buffers starting at

	 * AdditionalRequestPageBufferCount offset

	 */

	packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;

	packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Offset = (unsigned long)skb->data & (PAGE_SIZE - 1);

	packet->PageBuffers[net_drv_obj->AdditionalRequestPageBufferCount].Length = skb->len - skb->data_len;

	/* Start filling in the page buffers starting after RNDIS buffer. */

	packet->PageBuffers[1].Pfn = virt_to_phys(skb->data) >> PAGE_SHIFT;

	packet->PageBuffers[1].Offset

		= (unsigned long)skb->data & (PAGE_SIZE - 1);

	packet->PageBuffers[1].Length = skb_headlen(skb);



	ASSERT((skb->len - skb->data_len) <= PAGE_SIZE);

	/* Additional fragments are after SKB data */

	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {

		skb_frag_t *f = &skb_shinfo(skb)->frags[i];



	for (i = net_drv_obj->AdditionalRequestPageBufferCount + 1;

	     i < num_frags; i++) {

		packet->PageBuffers[i].Pfn =

			page_to_pfn(skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].page);

		packet->PageBuffers[i].Offset =

			skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].page_offset;

		packet->PageBuffers[i].Length =

			skb_shinfo(skb)->frags[i-(net_drv_obj->AdditionalRequestPageBufferCount+1)].size;

		packet->PageBuffers[i+2].Pfn = page_to_pfn(f->page);

		packet->PageBuffers[i+2].Offset = f->page_offset;

		packet->PageBuffers[i+2].Length = f->size;

	}



	/* Set the completion routine */
@@ -423,6 +411,9 @@ static int netvsc_probe(struct device *device) 


	net->netdev_ops = &device_ops;



	/* TODO: Add GSO and Checksum offload */

	net->features = NETIF_F_SG;



	SET_NETDEV_DEV(net, device);



	ret = register_netdev(net);