1 files changed, 89 insertions, 169 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index d8c10764f130..e9b960f0ff32 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -142,10 +142,6 @@ struct netfront_queue {
         struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
         grant_ref_t gref_rx_head;
         grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
-
-        unsigned long rx_pfn_array[NET_RX_RING_SIZE];
-        struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
-        struct mmu_update rx_mmu[NET_RX_RING_SIZE];
 };
 
 struct netfront_info {
@@ -223,11 +219,7 @@ static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
 }
 
 #ifdef CONFIG_SYSFS
-static int xennet_sysfs_addif(struct net_device *netdev);
-static void xennet_sysfs_delif(struct net_device *netdev);
-#else /* !CONFIG_SYSFS */
-#define xennet_sysfs_addif(dev) (0)
-#define xennet_sysfs_delif(dev) do { } while (0)
+static const struct attribute_group xennet_dev_group;
 #endif
 
 static bool xennet_can_sg(struct net_device *dev)
@@ -424,109 +416,68 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
         xennet_maybe_wake_tx(queue);
 }
 
-static void xennet_make_frags(struct sk_buff *skb, struct netfront_queue *queue,
-                              struct xen_netif_tx_request *tx)
+static struct xen_netif_tx_request *xennet_make_one_txreq(
+        struct netfront_queue *queue, struct sk_buff *skb,
+        struct page *page, unsigned int offset, unsigned int len)
 {
-        char *data = skb->data;
-        unsigned long mfn;
-        RING_IDX prod = queue->tx.req_prod_pvt;
-        int frags = skb_shinfo(skb)->nr_frags;
-        unsigned int offset = offset_in_page(data);
-        unsigned int len = skb_headlen(skb);
         unsigned int id;
+        struct xen_netif_tx_request *tx;
         grant_ref_t ref;
-        int i;
 
-        /* While the header overlaps a page boundary (including being
-           larger than a page), split it it into page-sized chunks. */
-        while (len > PAGE_SIZE - offset) {
-                tx->size = PAGE_SIZE - offset;
-                tx->flags |= XEN_NETTXF_more_data;
-                len -= tx->size;
-                data += tx->size;
-                offset = 0;
+        len = min_t(unsigned int, PAGE_SIZE - offset, len);
 
-                id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
-                queue->tx_skbs[id].skb = skb_get(skb);
-                tx = RING_GET_REQUEST(&queue->tx, prod++);
-                tx->id = id;
-                ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
-                BUG_ON((signed short)ref < 0);
+        id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
+        tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
+        ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
+        BUG_ON((signed short)ref < 0);
 
-                mfn = virt_to_mfn(data);
-                gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
-                                                mfn, GNTMAP_readonly);
+        gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
+                                        page_to_mfn(page), GNTMAP_readonly);
 
-                queue->grant_tx_page[id] = virt_to_page(data);
-                tx->gref = queue->grant_tx_ref[id] = ref;
-                tx->offset = offset;
-                tx->size = len;
-                tx->flags = 0;
-        }
+        queue->tx_skbs[id].skb = skb;
+        queue->grant_tx_page[id] = page;
+        queue->grant_tx_ref[id] = ref;
 
-        /* Grant backend access to each skb fragment page. */
-        for (i = 0; i < frags; i++) {
-                skb_frag_t *frag = skb_shinfo(skb)->frags + i;
-                struct page *page = skb_frag_page(frag);
+        tx->id = id;
+        tx->gref = ref;
+        tx->offset = offset;
+        tx->size = len;
+        tx->flags = 0;
 
-                len = skb_frag_size(frag);
-                offset = frag->page_offset;
+        return tx;
+}
 
-                /* Skip unused frames from start of page */
-                page += offset >> PAGE_SHIFT;
-                offset &= ~PAGE_MASK;
+static struct xen_netif_tx_request *xennet_make_txreqs(
+        struct netfront_queue *queue, struct xen_netif_tx_request *tx,
+        struct sk_buff *skb, struct page *page,
+        unsigned int offset, unsigned int len)
+{
+        /* Skip unused frames from start of page */
+        page += offset >> PAGE_SHIFT;
+        offset &= ~PAGE_MASK;
 
-                while (len > 0) {
-                        unsigned long bytes;
-
-                        bytes = PAGE_SIZE - offset;
-                        if (bytes > len)
-                                bytes = len;
-
-                        tx->flags |= XEN_NETTXF_more_data;
-
-                        id = get_id_from_freelist(&queue->tx_skb_freelist,
-                                                  queue->tx_skbs);
-                        queue->tx_skbs[id].skb = skb_get(skb);
-                        tx = RING_GET_REQUEST(&queue->tx, prod++);
-                        tx->id = id;
-                        ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
-                        BUG_ON((signed short)ref < 0);
-
-                        mfn = pfn_to_mfn(page_to_pfn(page));
-                        gnttab_grant_foreign_access_ref(ref,
-                                                        queue->info->xbdev->otherend_id,
-                                                        mfn, GNTMAP_readonly);
-
-                        queue->grant_tx_page[id] = page;
-                        tx->gref = queue->grant_tx_ref[id] = ref;
-                        tx->offset = offset;
-                        tx->size = bytes;
-                        tx->flags = 0;
-
-                        offset += bytes;
-                        len -= bytes;
-
-                        /* Next frame */
-                        if (offset == PAGE_SIZE && len) {
-                                BUG_ON(!PageCompound(page));
-                                page++;
-                                offset = 0;
-                        }
-                }
+        while (len) {
+                tx->flags |= XEN_NETTXF_more_data;
+                tx = xennet_make_one_txreq(queue, skb_get(skb),
+                                           page, offset, len);
+                page++;
+                offset = 0;
+                len -= tx->size;
         }
 
-        queue->tx.req_prod_pvt = prod;
+        return tx;
 }
 
 /*
- * Count how many ring slots are required to send the frags of this
- * skb. Each frag might be a compound page.
+ * Count how many ring slots are required to send this skb. Each frag
+ * might be a compound page.
  */
-static int xennet_count_skb_frag_slots(struct sk_buff *skb)
+static int xennet_count_skb_slots(struct sk_buff *skb)
 {
         int i, frags = skb_shinfo(skb)->nr_frags;
-        int pages = 0;
+        int pages;
+
+        pages = PFN_UP(offset_in_page(skb->data) + skb_headlen(skb));
 
         for (i = 0; i < frags; i++) {
                 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
@@ -562,18 +513,15 @@ static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
 
 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
-        unsigned short id;
         struct netfront_info *np = netdev_priv(dev);
         struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
-        struct xen_netif_tx_request *tx;
-        char *data = skb->data;
-        RING_IDX i;
-        grant_ref_t ref;
-        unsigned long mfn;
+        struct xen_netif_tx_request *tx, *first_tx;
+        unsigned int i;
         int notify;
         int slots;
-        unsigned int offset = offset_in_page(data);
-        unsigned int len = skb_headlen(skb);
+        struct page *page;
+        unsigned int offset;
+        unsigned int len;
         unsigned long flags;
         struct netfront_queue *queue = NULL;
         unsigned int num_queues = dev->real_num_tx_queues;
@@ -596,18 +544,18 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 goto drop;
         }
 
-        slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) +
-                xennet_count_skb_frag_slots(skb);
+        slots = xennet_count_skb_slots(skb);
         if (unlikely(slots > MAX_SKB_FRAGS + 1)) {
                 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
                                     slots, skb->len);
                 if (skb_linearize(skb))
                         goto drop;
-                data = skb->data;
-                offset = offset_in_page(data);
-                len = skb_headlen(skb);
         }
 
+        page = virt_to_page(skb->data);
+        offset = offset_in_page(skb->data);
+        len = skb_headlen(skb);
+
         spin_lock_irqsave(&queue->tx_lock, flags);
 
         if (unlikely(!netif_carrier_ok(dev) ||
@@ -617,25 +565,13 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 goto drop;
         }
 
-        i = queue->tx.req_prod_pvt;
-
-        id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
-        queue->tx_skbs[id].skb = skb;
-
-        tx = RING_GET_REQUEST(&queue->tx, i);
+        /* First request for the linear area. */
+        first_tx = tx = xennet_make_one_txreq(queue, skb,
+                                              page, offset, len);
+        page++;
+        offset = 0;
+        len -= tx->size;
 
-        tx->id   = id;
-        ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
-        BUG_ON((signed short)ref < 0);
-        mfn = virt_to_mfn(data);
-        gnttab_grant_foreign_access_ref(
-                ref, queue->info->xbdev->otherend_id, mfn, GNTMAP_readonly);
-        queue->grant_tx_page[id] = virt_to_page(data);
-        tx->gref = queue->grant_tx_ref[id] = ref;
-        tx->offset = offset;
-        tx->size = len;
-
-        tx->flags = 0;
         if (skb->ip_summed == CHECKSUM_PARTIAL)
                 /* local packet? */
                 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
@@ -643,11 +579,12 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 /* remote but checksummed. */
                 tx->flags |= XEN_NETTXF_data_validated;
 
+        /* Optional extra info after the first request. */
         if (skb_shinfo(skb)->gso_size) {
                 struct xen_netif_extra_info *gso;
 
                 gso = (struct xen_netif_extra_info *)
-                        RING_GET_REQUEST(&queue->tx, ++i);
+                        RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
 
                 tx->flags |= XEN_NETTXF_extra_info;
 
@@ -662,10 +599,19 @@ static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
                 gso->flags = 0;
         }
 
-        queue->tx.req_prod_pvt = i + 1;
+        /* Requests for the rest of the linear area. */
+        tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
+
+        /* Requests for all the frags. */
+        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+                tx = xennet_make_txreqs(queue, tx, skb,
+                                        skb_frag_page(frag), frag->page_offset,
+                                        skb_frag_size(frag));
+        }
 
-        xennet_make_frags(skb, queue, tx);
-        tx->size = skb->len;
+        /* First request has the packet length. */
+        first_tx->size = skb->len;
 
         RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
         if (notify)
@@ -1367,20 +1313,15 @@ static int netfront_probe(struct xenbus_device *dev,
 
         info = netdev_priv(netdev);
         dev_set_drvdata(&dev->dev, info);
-
+#ifdef CONFIG_SYSFS
+        info->netdev->sysfs_groups[0] = &xennet_dev_group;
+#endif
         err = register_netdev(info->netdev);
         if (err) {
                 pr_warn("%s: register_netdev err=%d\n", __func__, err);
                 goto fail;
         }
 
-        err = xennet_sysfs_addif(info->netdev);
-        if (err) {
-                unregister_netdev(info->netdev);
-                pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
-                goto fail;
-        }
-
         return 0;
 
  fail:
@@ -2144,39 +2085,20 @@ static ssize_t store_rxbuf(struct device *dev,
         return len;
 }
 
-static struct device_attribute xennet_attrs[] = {
-        __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
-        __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
-        __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
-};
-
-static int xennet_sysfs_addif(struct net_device *netdev)
-{
-        int i;
-        int err;
-
-        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
-                err = device_create_file(&netdev->dev,
-                                           &xennet_attrs[i]);
-                if (err)
-                        goto fail;
-        }
-        return 0;
-
- fail:
-        while (--i >= 0)
-                device_remove_file(&netdev->dev, &xennet_attrs[i]);
-        return err;
-}
-
-static void xennet_sysfs_delif(struct net_device *netdev)
-{
-        int i;
+static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
 
-        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
-                device_remove_file(&netdev->dev, &xennet_attrs[i]);
-}
+static struct attribute *xennet_dev_attrs[] = {
+        &dev_attr_rxbuf_min.attr,
+        &dev_attr_rxbuf_max.attr,
+        &dev_attr_rxbuf_cur.attr,
+        NULL
+};
 
+static const struct attribute_group xennet_dev_group = {
+        .attrs = xennet_dev_attrs
+};
 #endif /* CONFIG_SYSFS */
 
 static int xennet_remove(struct xenbus_device *dev)
@@ -2190,8 +2112,6 @@ static int xennet_remove(struct xenbus_device *dev)
 
         xennet_disconnect_backend(info);
 
-        xennet_sysfs_delif(info->netdev);
-
         unregister_netdev(info->netdev);
 
         for (i = 0; i < num_queues; ++i) {