diff options
| -rw-r--r-- | drivers/net/hyperv/netvsc_drv.c | 43 |
1 files changed, 33 insertions, 10 deletions
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 63c98bbbc596..0d78727f1a14 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -315,14 +315,34 @@ static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb, return slots_used; } -/* Estimate number of page buffers neede to transmit - * Need at most 2 for RNDIS header plus skb body and fragments. - */ -static unsigned int netvsc_get_slots(const struct sk_buff *skb) +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) { - return PFN_UP(offset_in_page(skb->data) + skb_headlen(skb)) - + skb_shinfo(skb)->nr_frags - + 2; + 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 u32 net_checksum_info(struct sk_buff *skb) @@ -360,18 +380,21 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) struct hv_page_buffer page_buf[MAX_PAGE_BUFFER_COUNT]; struct hv_page_buffer *pb = page_buf; - /* We can only transmit MAX_PAGE_BUFFER_COUNT number + /* 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. If skb is scattered around * more pages we try linearizing it. */ - num_data_pgs = netvsc_get_slots(skb); + + num_data_pgs = netvsc_get_slots(skb) + 2; + if (unlikely(num_data_pgs > MAX_PAGE_BUFFER_COUNT)) { ++net_device_ctx->eth_stats.tx_scattered; if (skb_linearize(skb)) goto no_memory; - num_data_pgs = netvsc_get_slots(skb); + num_data_pgs = netvsc_get_slots(skb) + 2; if (num_data_pgs > MAX_PAGE_BUFFER_COUNT) { ++net_device_ctx->eth_stats.tx_too_big; goto drop; |