Cleanup the code and enable scatter gather I/O.
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
---
drivers/net/hyperv/netvsc_drv.c | 155 +++++++++++++++++++++++++++++----------
1 files changed, 116 insertions(+), 39 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 9ef6be9..afa9c53 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -140,21 +140,125 @@ 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 +273,17 @@ 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 +528,8 @@ 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);
--
1.7.4.1
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