From 54a7357f7ac408be4ef4ca82900bd24cb6789f36 Mon Sep 17 00:00:00 2001 From: KY Srinivasan Date: Sat, 8 Mar 2014 19:23:13 -0800 Subject: [PATCH] Drivers: net: hyperv: Enable scatter gather I/O Cleanup the code and enable scatter gather I/O. Signed-off-by: K. Y. Srinivasan Reviewed-by: Haiyang Zhang Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc_drv.c | 153 ++++++++++++++++++++++++-------- 1 file changed, 114 insertions(+), 39 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 9ef6be90a81c..1f7b12f9e6fb 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -140,21 +140,123 @@ static void netvsc_xmit_completion(void *context) dev_kfree_skb_any(skb); } +static u32 fill_pg_buf(struct page *page, u32 offset, u32 len, + struct hv_page_buffer *pb) +{ + int j = 0; + + /* Deal with compund pages by ignoring unused part + * of the page. + */ + page += (offset >> PAGE_SHIFT); + offset &= ~PAGE_MASK; + + while (len > 0) { + unsigned long bytes; + + bytes = PAGE_SIZE - offset; + if (bytes > len) + bytes = len; + pb[j].pfn = page_to_pfn(page); + pb[j].offset = offset; + pb[j].len = bytes; + + offset += bytes; + len -= bytes; + + if (offset == PAGE_SIZE && len) { + page++; + offset = 0; + j++; + } + } + + return j + 1; +} + +static void init_page_array(void *hdr, u32 len, struct sk_buff *skb, + struct hv_page_buffer *pb) +{ + u32 slots_used = 0; + char *data = skb->data; + int frags = skb_shinfo(skb)->nr_frags; + int i; + + /* The packet is laid out thus: + * 1. hdr + * 2. skb linear data + * 3. skb fragment data + */ + if (hdr != NULL) + slots_used += fill_pg_buf(virt_to_page(hdr), + offset_in_page(hdr), + len, &pb[slots_used]); + + slots_used += fill_pg_buf(virt_to_page(data), + offset_in_page(data), + skb_headlen(skb), &pb[slots_used]); + + for (i = 0; i < frags; i++) { + skb_frag_t *frag = skb_shinfo(skb)->frags + i; + + slots_used += fill_pg_buf(skb_frag_page(frag), + frag->page_offset, + skb_frag_size(frag), &pb[slots_used]); + } +} + +static int count_skb_frag_slots(struct sk_buff *skb) +{ + int i, frags = skb_shinfo(skb)->nr_frags; + int pages = 0; + + for (i = 0; i < frags; i++) { + skb_frag_t *frag = skb_shinfo(skb)->frags + i; + unsigned long size = skb_frag_size(frag); + unsigned long offset = frag->page_offset; + + /* Skip unused frames from start of page */ + offset &= ~PAGE_MASK; + pages += PFN_UP(offset + size); + } + return pages; +} + +static int netvsc_get_slots(struct sk_buff *skb) +{ + char *data = skb->data; + unsigned int offset = offset_in_page(data); + unsigned int len = skb_headlen(skb); + int slots; + int frag_slots; + + slots = DIV_ROUND_UP(offset + len, PAGE_SIZE); + frag_slots = count_skb_frag_slots(skb); + return slots + frag_slots; +} + static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) { struct net_device_context *net_device_ctx = netdev_priv(net); struct hv_netvsc_packet *packet; int ret; - unsigned int i, num_pages, npg_data; + unsigned int num_data_pages; - /* Add multipages for skb->data and additional 2 for RNDIS */ - npg_data = (((unsigned long)skb->data + skb_headlen(skb) - 1) - >> PAGE_SHIFT) - ((unsigned long)skb->data >> PAGE_SHIFT) + 1; - num_pages = skb_shinfo(skb)->nr_frags + npg_data + 2; + /* We will atmost need two pages to describe the rndis + * header. We can only transmit MAX_PAGE_BUFFER_COUNT number + * of pages in a single packet. + */ + num_data_pages = netvsc_get_slots(skb) + 2; + if (num_data_pages > MAX_PAGE_BUFFER_COUNT) { + netdev_err(net, "Packet too big: %u\n", skb->len); + dev_kfree_skb(skb); + net->stats.tx_dropped++; + return NETDEV_TX_OK; + } /* Allocate a netvsc packet based on # of frags. */ packet = kzalloc(sizeof(struct hv_netvsc_packet) + - (num_pages * sizeof(struct hv_page_buffer)) + + (num_data_pages * sizeof(struct hv_page_buffer)) + sizeof(struct rndis_message) + NDIS_VLAN_PPI_SIZE, GFP_ATOMIC); if (!packet) { @@ -169,44 +271,17 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) packet->vlan_tci = skb->vlan_tci; packet->extension = (void *)(unsigned long)packet + - sizeof(struct hv_netvsc_packet) + - (num_pages * sizeof(struct hv_page_buffer)); + sizeof(struct hv_netvsc_packet) + + (num_data_pages * sizeof(struct hv_page_buffer)); /* If the rndis msg goes beyond 1 page, we will add 1 later */ - packet->page_buf_cnt = num_pages - 1; + packet->page_buf_cnt = num_data_pages - 1; /* Initialize it from the skb */ packet->total_data_buflen = skb->len; /* Start filling in the page buffers starting after RNDIS buffer. */ - packet->page_buf[1].pfn = virt_to_phys(skb->data) >> PAGE_SHIFT; - packet->page_buf[1].offset - = (unsigned long)skb->data & (PAGE_SIZE - 1); - if (npg_data == 1) - packet->page_buf[1].len = skb_headlen(skb); - else - packet->page_buf[1].len = PAGE_SIZE - - packet->page_buf[1].offset; - - for (i = 2; i <= npg_data; i++) { - packet->page_buf[i].pfn = virt_to_phys(skb->data - + PAGE_SIZE * (i-1)) >> PAGE_SHIFT; - packet->page_buf[i].offset = 0; - packet->page_buf[i].len = PAGE_SIZE; - } - if (npg_data > 1) - packet->page_buf[npg_data].len = (((unsigned long)skb->data - + skb_headlen(skb) - 1) & (PAGE_SIZE - 1)) + 1; - - /* Additional fragments are after SKB data */ - for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { - const skb_frag_t *f = &skb_shinfo(skb)->frags[i]; - - packet->page_buf[i+npg_data+1].pfn = - page_to_pfn(skb_frag_page(f)); - packet->page_buf[i+npg_data+1].offset = f->page_offset; - packet->page_buf[i+npg_data+1].len = skb_frag_size(f); - } + init_page_array(NULL, 0, skb, &packet->page_buf[1]); /* Set the completion routine */ packet->completion.send.send_completion = netvsc_xmit_completion; @@ -451,8 +526,8 @@ static int netvsc_probe(struct hv_device *dev, net->netdev_ops = &device_ops; /* TODO: Add GSO and Checksum offload */ - net->hw_features = 0; - net->features = NETIF_F_HW_VLAN_CTAG_TX; + net->hw_features = NETIF_F_SG; + net->features = NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG; SET_ETHTOOL_OPS(net, ðtool_ops); SET_NETDEV_DEV(net, &dev->device); -- 2.20.1