| /* |
| * Virtual network driver for conversing with remote driver backends. |
| * |
| * Copyright (c) 2002-2005, K A Fraser |
| * Copyright (c) 2005, XenSource Ltd |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License version 2 |
| * as published by the Free Software Foundation; or, when distributed |
| * separately from the Linux kernel or incorporated into other |
| * software packages, subject to the following license: |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this source file (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, modify, |
| * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| * and to permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/netdevice.h> |
| #include <linux/etherdevice.h> |
| #include <linux/skbuff.h> |
| #include <linux/ethtool.h> |
| #include <linux/if_ether.h> |
| #include <net/tcp.h> |
| #include <linux/udp.h> |
| #include <linux/moduleparam.h> |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <net/ip.h> |
| |
| #include <asm/xen/page.h> |
| #include <xen/xen.h> |
| #include <xen/xenbus.h> |
| #include <xen/events.h> |
| #include <xen/page.h> |
| #include <xen/platform_pci.h> |
| #include <xen/grant_table.h> |
| |
| #include <xen/interface/io/netif.h> |
| #include <xen/interface/memory.h> |
| #include <xen/interface/grant_table.h> |
| |
| static const struct ethtool_ops xennet_ethtool_ops; |
| |
| struct netfront_cb { |
| int pull_to; |
| }; |
| |
| #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) |
| |
| #define RX_COPY_THRESHOLD 256 |
| |
| #define GRANT_INVALID_REF 0 |
| |
| #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE) |
| #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE) |
| #define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256) |
| |
| struct netfront_stats { |
| u64 rx_packets; |
| u64 tx_packets; |
| u64 rx_bytes; |
| u64 tx_bytes; |
| struct u64_stats_sync syncp; |
| }; |
| |
| struct netfront_info { |
| struct list_head list; |
| struct net_device *netdev; |
| |
| struct napi_struct napi; |
| |
| unsigned int evtchn; |
| struct xenbus_device *xbdev; |
| |
| spinlock_t tx_lock; |
| struct xen_netif_tx_front_ring tx; |
| int tx_ring_ref; |
| |
| /* |
| * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries |
| * are linked from tx_skb_freelist through skb_entry.link. |
| * |
| * NB. Freelist index entries are always going to be less than |
| * PAGE_OFFSET, whereas pointers to skbs will always be equal or |
| * greater than PAGE_OFFSET: we use this property to distinguish |
| * them. |
| */ |
| union skb_entry { |
| struct sk_buff *skb; |
| unsigned long link; |
| } tx_skbs[NET_TX_RING_SIZE]; |
| grant_ref_t gref_tx_head; |
| grant_ref_t grant_tx_ref[NET_TX_RING_SIZE]; |
| struct page *grant_tx_page[NET_TX_RING_SIZE]; |
| unsigned tx_skb_freelist; |
| |
| spinlock_t rx_lock ____cacheline_aligned_in_smp; |
| struct xen_netif_rx_front_ring rx; |
| int rx_ring_ref; |
| |
| /* Receive-ring batched refills. */ |
| #define RX_MIN_TARGET 8 |
| #define RX_DFL_MIN_TARGET 64 |
| #define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) |
| unsigned rx_min_target, rx_max_target, rx_target; |
| struct sk_buff_head rx_batch; |
| |
| struct timer_list rx_refill_timer; |
| |
| 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]; |
| |
| /* Statistics */ |
| struct netfront_stats __percpu *stats; |
| |
| unsigned long rx_gso_checksum_fixup; |
| }; |
| |
| struct netfront_rx_info { |
| struct xen_netif_rx_response rx; |
| struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1]; |
| }; |
| |
| static void skb_entry_set_link(union skb_entry *list, unsigned short id) |
| { |
| list->link = id; |
| } |
| |
| static int skb_entry_is_link(const union skb_entry *list) |
| { |
| BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link)); |
| return (unsigned long)list->skb < PAGE_OFFSET; |
| } |
| |
| /* |
| * Access macros for acquiring freeing slots in tx_skbs[]. |
| */ |
| |
| static void add_id_to_freelist(unsigned *head, union skb_entry *list, |
| unsigned short id) |
| { |
| skb_entry_set_link(&list[id], *head); |
| *head = id; |
| } |
| |
| static unsigned short get_id_from_freelist(unsigned *head, |
| union skb_entry *list) |
| { |
| unsigned int id = *head; |
| *head = list[id].link; |
| return id; |
| } |
| |
| static int xennet_rxidx(RING_IDX idx) |
| { |
| return idx & (NET_RX_RING_SIZE - 1); |
| } |
| |
| static struct sk_buff *xennet_get_rx_skb(struct netfront_info *np, |
| RING_IDX ri) |
| { |
| int i = xennet_rxidx(ri); |
| struct sk_buff *skb = np->rx_skbs[i]; |
| np->rx_skbs[i] = NULL; |
| return skb; |
| } |
| |
| static grant_ref_t xennet_get_rx_ref(struct netfront_info *np, |
| RING_IDX ri) |
| { |
| int i = xennet_rxidx(ri); |
| grant_ref_t ref = np->grant_rx_ref[i]; |
| np->grant_rx_ref[i] = GRANT_INVALID_REF; |
| return ref; |
| } |
| |
| #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) |
| #endif |
| |
| static bool xennet_can_sg(struct net_device *dev) |
| { |
| return dev->features & NETIF_F_SG; |
| } |
| |
| |
| static void rx_refill_timeout(unsigned long data) |
| { |
| struct net_device *dev = (struct net_device *)data; |
| struct netfront_info *np = netdev_priv(dev); |
| napi_schedule(&np->napi); |
| } |
| |
| static int netfront_tx_slot_available(struct netfront_info *np) |
| { |
| return (np->tx.req_prod_pvt - np->tx.rsp_cons) < |
| (TX_MAX_TARGET - MAX_SKB_FRAGS - 2); |
| } |
| |
| static void xennet_maybe_wake_tx(struct net_device *dev) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| |
| if (unlikely(netif_queue_stopped(dev)) && |
| netfront_tx_slot_available(np) && |
| likely(netif_running(dev))) |
| netif_wake_queue(dev); |
| } |
| |
| static void xennet_alloc_rx_buffers(struct net_device *dev) |
| { |
| unsigned short id; |
| struct netfront_info *np = netdev_priv(dev); |
| struct sk_buff *skb; |
| struct page *page; |
| int i, batch_target, notify; |
| RING_IDX req_prod = np->rx.req_prod_pvt; |
| grant_ref_t ref; |
| unsigned long pfn; |
| void *vaddr; |
| struct xen_netif_rx_request *req; |
| |
| if (unlikely(!netif_carrier_ok(dev))) |
| return; |
| |
| /* |
| * Allocate skbuffs greedily, even though we batch updates to the |
| * receive ring. This creates a less bursty demand on the memory |
| * allocator, so should reduce the chance of failed allocation requests |
| * both for ourself and for other kernel subsystems. |
| */ |
| batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); |
| for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { |
| skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, |
| GFP_ATOMIC | __GFP_NOWARN); |
| if (unlikely(!skb)) |
| goto no_skb; |
| |
| /* Align ip header to a 16 bytes boundary */ |
| skb_reserve(skb, NET_IP_ALIGN); |
| |
| page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); |
| if (!page) { |
| kfree_skb(skb); |
| no_skb: |
| /* Any skbuffs queued for refill? Force them out. */ |
| if (i != 0) |
| goto refill; |
| /* Could not allocate any skbuffs. Try again later. */ |
| mod_timer(&np->rx_refill_timer, |
| jiffies + (HZ/10)); |
| break; |
| } |
| |
| skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE); |
| __skb_queue_tail(&np->rx_batch, skb); |
| } |
| |
| /* Is the batch large enough to be worthwhile? */ |
| if (i < (np->rx_target/2)) { |
| if (req_prod > np->rx.sring->req_prod) |
| goto push; |
| return; |
| } |
| |
| /* Adjust our fill target if we risked running out of buffers. */ |
| if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && |
| ((np->rx_target *= 2) > np->rx_max_target)) |
| np->rx_target = np->rx_max_target; |
| |
| refill: |
| for (i = 0; ; i++) { |
| skb = __skb_dequeue(&np->rx_batch); |
| if (skb == NULL) |
| break; |
| |
| skb->dev = dev; |
| |
| id = xennet_rxidx(req_prod + i); |
| |
| BUG_ON(np->rx_skbs[id]); |
| np->rx_skbs[id] = skb; |
| |
| ref = gnttab_claim_grant_reference(&np->gref_rx_head); |
| BUG_ON((signed short)ref < 0); |
| np->grant_rx_ref[id] = ref; |
| |
| pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0])); |
| vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0])); |
| |
| req = RING_GET_REQUEST(&np->rx, req_prod + i); |
| gnttab_grant_foreign_access_ref(ref, |
| np->xbdev->otherend_id, |
| pfn_to_mfn(pfn), |
| 0); |
| |
| req->id = id; |
| req->gref = ref; |
| } |
| |
| wmb(); /* barrier so backend seens requests */ |
| |
| /* Above is a suitable barrier to ensure backend will see requests. */ |
| np->rx.req_prod_pvt = req_prod + i; |
| push: |
| RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); |
| if (notify) |
| notify_remote_via_irq(np->netdev->irq); |
| } |
| |
| static int xennet_open(struct net_device *dev) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| |
| napi_enable(&np->napi); |
| |
| spin_lock_bh(&np->rx_lock); |
| if (netif_carrier_ok(dev)) { |
| xennet_alloc_rx_buffers(dev); |
| np->rx.sring->rsp_event = np->rx.rsp_cons + 1; |
| if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) |
| napi_schedule(&np->napi); |
| } |
| spin_unlock_bh(&np->rx_lock); |
| |
| netif_start_queue(dev); |
| |
| return 0; |
| } |
| |
| static void xennet_tx_buf_gc(struct net_device *dev) |
| { |
| RING_IDX cons, prod; |
| unsigned short id; |
| struct netfront_info *np = netdev_priv(dev); |
| struct sk_buff *skb; |
| |
| BUG_ON(!netif_carrier_ok(dev)); |
| |
| do { |
| prod = np->tx.sring->rsp_prod; |
| rmb(); /* Ensure we see responses up to 'rp'. */ |
| |
| for (cons = np->tx.rsp_cons; cons != prod; cons++) { |
| struct xen_netif_tx_response *txrsp; |
| |
| txrsp = RING_GET_RESPONSE(&np->tx, cons); |
| if (txrsp->status == XEN_NETIF_RSP_NULL) |
| continue; |
| |
| id = txrsp->id; |
| skb = np->tx_skbs[id].skb; |
| if (unlikely(gnttab_query_foreign_access( |
| np->grant_tx_ref[id]) != 0)) { |
| printk(KERN_ALERT "xennet_tx_buf_gc: warning " |
| "-- grant still in use by backend " |
| "domain.\n"); |
| BUG(); |
| } |
| gnttab_end_foreign_access_ref( |
| np->grant_tx_ref[id], GNTMAP_readonly); |
| gnttab_release_grant_reference( |
| &np->gref_tx_head, np->grant_tx_ref[id]); |
| np->grant_tx_ref[id] = GRANT_INVALID_REF; |
| np->grant_tx_page[id] = NULL; |
| add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, id); |
| dev_kfree_skb_irq(skb); |
| } |
| |
| np->tx.rsp_cons = prod; |
| |
| /* |
| * Set a new event, then check for race with update of tx_cons. |
| * Note that it is essential to schedule a callback, no matter |
| * how few buffers are pending. Even if there is space in the |
| * transmit ring, higher layers may be blocked because too much |
| * data is outstanding: in such cases notification from Xen is |
| * likely to be the only kick that we'll get. |
| */ |
| np->tx.sring->rsp_event = |
| prod + ((np->tx.sring->req_prod - prod) >> 1) + 1; |
| mb(); /* update shared area */ |
| } while ((cons == prod) && (prod != np->tx.sring->rsp_prod)); |
| |
| xennet_maybe_wake_tx(dev); |
| } |
| |
| static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, |
| struct xen_netif_tx_request *tx) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| char *data = skb->data; |
| unsigned long mfn; |
| RING_IDX prod = np->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; |
| 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; |
| |
| id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); |
| np->tx_skbs[id].skb = skb_get(skb); |
| tx = RING_GET_REQUEST(&np->tx, prod++); |
| tx->id = id; |
| ref = gnttab_claim_grant_reference(&np->gref_tx_head); |
| BUG_ON((signed short)ref < 0); |
| |
| mfn = virt_to_mfn(data); |
| gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, |
| mfn, GNTMAP_readonly); |
| |
| np->grant_tx_page[id] = virt_to_page(data); |
| tx->gref = np->grant_tx_ref[id] = ref; |
| tx->offset = offset; |
| tx->size = len; |
| tx->flags = 0; |
| } |
| |
| /* 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); |
| |
| len = skb_frag_size(frag); |
| offset = frag->page_offset; |
| |
| /* Data must not cross a page boundary. */ |
| BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); |
| |
| /* Skip unused frames from start of page */ |
| page += offset >> PAGE_SHIFT; |
| offset &= ~PAGE_MASK; |
| |
| while (len > 0) { |
| unsigned long bytes; |
| |
| BUG_ON(offset >= PAGE_SIZE); |
| |
| bytes = PAGE_SIZE - offset; |
| if (bytes > len) |
| bytes = len; |
| |
| tx->flags |= XEN_NETTXF_more_data; |
| |
| id = get_id_from_freelist(&np->tx_skb_freelist, |
| np->tx_skbs); |
| np->tx_skbs[id].skb = skb_get(skb); |
| tx = RING_GET_REQUEST(&np->tx, prod++); |
| tx->id = id; |
| ref = gnttab_claim_grant_reference(&np->gref_tx_head); |
| BUG_ON((signed short)ref < 0); |
| |
| mfn = pfn_to_mfn(page_to_pfn(page)); |
| gnttab_grant_foreign_access_ref(ref, |
| np->xbdev->otherend_id, |
| mfn, GNTMAP_readonly); |
| |
| np->grant_tx_page[id] = page; |
| tx->gref = np->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; |
| } |
| } |
| } |
| |
| np->tx.req_prod_pvt = prod; |
| } |
| |
| /* |
| * Count how many ring slots are required to send the frags of this |
| * skb. Each frag might be a compound page. |
| */ |
| static int xennet_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 xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| unsigned short id; |
| struct netfront_info *np = netdev_priv(dev); |
| struct netfront_stats *stats = this_cpu_ptr(np->stats); |
| struct xen_netif_tx_request *tx; |
| char *data = skb->data; |
| RING_IDX i; |
| grant_ref_t ref; |
| unsigned long mfn; |
| int notify; |
| int slots; |
| unsigned int offset = offset_in_page(data); |
| unsigned int len = skb_headlen(skb); |
| unsigned long flags; |
| |
| /* If skb->len is too big for wire format, drop skb and alert |
| * user about misconfiguration. |
| */ |
| if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { |
| net_alert_ratelimited( |
| "xennet: skb->len = %u, too big for wire format\n", |
| skb->len); |
| goto drop; |
| } |
| |
| slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + |
| xennet_count_skb_frag_slots(skb); |
| if (unlikely(slots > MAX_SKB_FRAGS + 1)) { |
| net_alert_ratelimited( |
| "xennet: skb rides the rocket: %d slots\n", slots); |
| goto drop; |
| } |
| |
| spin_lock_irqsave(&np->tx_lock, flags); |
| |
| if (unlikely(!netif_carrier_ok(dev) || |
| (slots > 1 && !xennet_can_sg(dev)) || |
| netif_needs_gso(skb, netif_skb_features(skb)))) { |
| spin_unlock_irqrestore(&np->tx_lock, flags); |
| goto drop; |
| } |
| |
| i = np->tx.req_prod_pvt; |
| |
| id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); |
| np->tx_skbs[id].skb = skb; |
| |
| tx = RING_GET_REQUEST(&np->tx, i); |
| |
| tx->id = id; |
| ref = gnttab_claim_grant_reference(&np->gref_tx_head); |
| BUG_ON((signed short)ref < 0); |
| mfn = virt_to_mfn(data); |
| gnttab_grant_foreign_access_ref( |
| ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); |
| np->grant_tx_page[id] = virt_to_page(data); |
| tx->gref = np->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; |
| else if (skb->ip_summed == CHECKSUM_UNNECESSARY) |
| /* remote but checksummed. */ |
| tx->flags |= XEN_NETTXF_data_validated; |
| |
| if (skb_shinfo(skb)->gso_size) { |
| struct xen_netif_extra_info *gso; |
| |
| gso = (struct xen_netif_extra_info *) |
| RING_GET_REQUEST(&np->tx, ++i); |
| |
| tx->flags |= XEN_NETTXF_extra_info; |
| |
| gso->u.gso.size = skb_shinfo(skb)->gso_size; |
| gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; |
| gso->u.gso.pad = 0; |
| gso->u.gso.features = 0; |
| |
| gso->type = XEN_NETIF_EXTRA_TYPE_GSO; |
| gso->flags = 0; |
| } |
| |
| np->tx.req_prod_pvt = i + 1; |
| |
| xennet_make_frags(skb, dev, tx); |
| tx->size = skb->len; |
| |
| RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); |
| if (notify) |
| notify_remote_via_irq(np->netdev->irq); |
| |
| u64_stats_update_begin(&stats->syncp); |
| stats->tx_bytes += skb->len; |
| stats->tx_packets++; |
| u64_stats_update_end(&stats->syncp); |
| |
| /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ |
| xennet_tx_buf_gc(dev); |
| |
| if (!netfront_tx_slot_available(np)) |
| netif_stop_queue(dev); |
| |
| spin_unlock_irqrestore(&np->tx_lock, flags); |
| |
| return NETDEV_TX_OK; |
| |
| drop: |
| dev->stats.tx_dropped++; |
| dev_kfree_skb(skb); |
| return NETDEV_TX_OK; |
| } |
| |
| static int xennet_close(struct net_device *dev) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| netif_stop_queue(np->netdev); |
| napi_disable(&np->napi); |
| return 0; |
| } |
| |
| static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb, |
| grant_ref_t ref) |
| { |
| int new = xennet_rxidx(np->rx.req_prod_pvt); |
| |
| BUG_ON(np->rx_skbs[new]); |
| np->rx_skbs[new] = skb; |
| np->grant_rx_ref[new] = ref; |
| RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new; |
| RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref; |
| np->rx.req_prod_pvt++; |
| } |
| |
| static int xennet_get_extras(struct netfront_info *np, |
| struct xen_netif_extra_info *extras, |
| RING_IDX rp) |
| |
| { |
| struct xen_netif_extra_info *extra; |
| struct device *dev = &np->netdev->dev; |
| RING_IDX cons = np->rx.rsp_cons; |
| int err = 0; |
| |
| do { |
| struct sk_buff *skb; |
| grant_ref_t ref; |
| |
| if (unlikely(cons + 1 == rp)) { |
| if (net_ratelimit()) |
| dev_warn(dev, "Missing extra info\n"); |
| err = -EBADR; |
| break; |
| } |
| |
| extra = (struct xen_netif_extra_info *) |
| RING_GET_RESPONSE(&np->rx, ++cons); |
| |
| if (unlikely(!extra->type || |
| extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) { |
| if (net_ratelimit()) |
| dev_warn(dev, "Invalid extra type: %d\n", |
| extra->type); |
| err = -EINVAL; |
| } else { |
| memcpy(&extras[extra->type - 1], extra, |
| sizeof(*extra)); |
| } |
| |
| skb = xennet_get_rx_skb(np, cons); |
| ref = xennet_get_rx_ref(np, cons); |
| xennet_move_rx_slot(np, skb, ref); |
| } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); |
| |
| np->rx.rsp_cons = cons; |
| return err; |
| } |
| |
| static int xennet_get_responses(struct netfront_info *np, |
| struct netfront_rx_info *rinfo, RING_IDX rp, |
| struct sk_buff_head *list) |
| { |
| struct xen_netif_rx_response *rx = &rinfo->rx; |
| struct xen_netif_extra_info *extras = rinfo->extras; |
| struct device *dev = &np->netdev->dev; |
| RING_IDX cons = np->rx.rsp_cons; |
| struct sk_buff *skb = xennet_get_rx_skb(np, cons); |
| grant_ref_t ref = xennet_get_rx_ref(np, cons); |
| int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD); |
| int slots = 1; |
| int err = 0; |
| unsigned long ret; |
| |
| if (rx->flags & XEN_NETRXF_extra_info) { |
| err = xennet_get_extras(np, extras, rp); |
| cons = np->rx.rsp_cons; |
| } |
| |
| for (;;) { |
| if (unlikely(rx->status < 0 || |
| rx->offset + rx->status > PAGE_SIZE)) { |
| if (net_ratelimit()) |
| dev_warn(dev, "rx->offset: %x, size: %u\n", |
| rx->offset, rx->status); |
| xennet_move_rx_slot(np, skb, ref); |
| err = -EINVAL; |
| goto next; |
| } |
| |
| /* |
| * This definitely indicates a bug, either in this driver or in |
| * the backend driver. In future this should flag the bad |
| * situation to the system controller to reboot the backend. |
| */ |
| if (ref == GRANT_INVALID_REF) { |
| if (net_ratelimit()) |
| dev_warn(dev, "Bad rx response id %d.\n", |
| rx->id); |
| err = -EINVAL; |
| goto next; |
| } |
| |
| ret = gnttab_end_foreign_access_ref(ref, 0); |
| BUG_ON(!ret); |
| |
| gnttab_release_grant_reference(&np->gref_rx_head, ref); |
| |
| __skb_queue_tail(list, skb); |
| |
| next: |
| if (!(rx->flags & XEN_NETRXF_more_data)) |
| break; |
| |
| if (cons + slots == rp) { |
| if (net_ratelimit()) |
| dev_warn(dev, "Need more slots\n"); |
| err = -ENOENT; |
| break; |
| } |
| |
| rx = RING_GET_RESPONSE(&np->rx, cons + slots); |
| skb = xennet_get_rx_skb(np, cons + slots); |
| ref = xennet_get_rx_ref(np, cons + slots); |
| slots++; |
| } |
| |
| if (unlikely(slots > max)) { |
| if (net_ratelimit()) |
| dev_warn(dev, "Too many slots\n"); |
| err = -E2BIG; |
| } |
| |
| if (unlikely(err)) |
| np->rx.rsp_cons = cons + slots; |
| |
| return err; |
| } |
| |
| static int xennet_set_skb_gso(struct sk_buff *skb, |
| struct xen_netif_extra_info *gso) |
| { |
| if (!gso->u.gso.size) { |
| if (net_ratelimit()) |
| printk(KERN_WARNING "GSO size must not be zero.\n"); |
| return -EINVAL; |
| } |
| |
| /* Currently only TCPv4 S.O. is supported. */ |
| if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) { |
| if (net_ratelimit()) |
| printk(KERN_WARNING "Bad GSO type %d.\n", gso->u.gso.type); |
| return -EINVAL; |
| } |
| |
| skb_shinfo(skb)->gso_size = gso->u.gso.size; |
| skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; |
| |
| /* Header must be checked, and gso_segs computed. */ |
| skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; |
| skb_shinfo(skb)->gso_segs = 0; |
| |
| return 0; |
| } |
| |
| static RING_IDX xennet_fill_frags(struct netfront_info *np, |
| struct sk_buff *skb, |
| struct sk_buff_head *list) |
| { |
| struct skb_shared_info *shinfo = skb_shinfo(skb); |
| RING_IDX cons = np->rx.rsp_cons; |
| struct sk_buff *nskb; |
| |
| while ((nskb = __skb_dequeue(list))) { |
| struct xen_netif_rx_response *rx = |
| RING_GET_RESPONSE(&np->rx, ++cons); |
| skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0]; |
| |
| if (shinfo->nr_frags == MAX_SKB_FRAGS) { |
| unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to; |
| |
| BUG_ON(pull_to <= skb_headlen(skb)); |
| __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); |
| } |
| BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS); |
| |
| skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag), |
| rx->offset, rx->status, PAGE_SIZE); |
| |
| skb_shinfo(nskb)->nr_frags = 0; |
| kfree_skb(nskb); |
| } |
| |
| return cons; |
| } |
| |
| static int checksum_setup(struct net_device *dev, struct sk_buff *skb) |
| { |
| struct iphdr *iph; |
| unsigned char *th; |
| int err = -EPROTO; |
| int recalculate_partial_csum = 0; |
| |
| /* |
| * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy |
| * peers can fail to set NETRXF_csum_blank when sending a GSO |
| * frame. In this case force the SKB to CHECKSUM_PARTIAL and |
| * recalculate the partial checksum. |
| */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) { |
| struct netfront_info *np = netdev_priv(dev); |
| np->rx_gso_checksum_fixup++; |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| recalculate_partial_csum = 1; |
| } |
| |
| /* A non-CHECKSUM_PARTIAL SKB does not require setup. */ |
| if (skb->ip_summed != CHECKSUM_PARTIAL) |
| return 0; |
| |
| if (skb->protocol != htons(ETH_P_IP)) |
| goto out; |
| |
| iph = (void *)skb->data; |
| th = skb->data + 4 * iph->ihl; |
| if (th >= skb_tail_pointer(skb)) |
| goto out; |
| |
| skb->csum_start = th - skb->head; |
| switch (iph->protocol) { |
| case IPPROTO_TCP: |
| skb->csum_offset = offsetof(struct tcphdr, check); |
| |
| if (recalculate_partial_csum) { |
| struct tcphdr *tcph = (struct tcphdr *)th; |
| tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, |
| skb->len - iph->ihl*4, |
| IPPROTO_TCP, 0); |
| } |
| break; |
| case IPPROTO_UDP: |
| skb->csum_offset = offsetof(struct udphdr, check); |
| |
| if (recalculate_partial_csum) { |
| struct udphdr *udph = (struct udphdr *)th; |
| udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, |
| skb->len - iph->ihl*4, |
| IPPROTO_UDP, 0); |
| } |
| break; |
| default: |
| if (net_ratelimit()) |
| printk(KERN_ERR "Attempting to checksum a non-" |
| "TCP/UDP packet, dropping a protocol" |
| " %d packet", iph->protocol); |
| goto out; |
| } |
| |
| if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb)) |
| goto out; |
| |
| err = 0; |
| |
| out: |
| return err; |
| } |
| |
| static int handle_incoming_queue(struct net_device *dev, |
| struct sk_buff_head *rxq) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| struct netfront_stats *stats = this_cpu_ptr(np->stats); |
| int packets_dropped = 0; |
| struct sk_buff *skb; |
| |
| while ((skb = __skb_dequeue(rxq)) != NULL) { |
| int pull_to = NETFRONT_SKB_CB(skb)->pull_to; |
| |
| if (pull_to > skb_headlen(skb)) |
| __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); |
| |
| /* Ethernet work: Delayed to here as it peeks the header. */ |
| skb->protocol = eth_type_trans(skb, dev); |
| |
| if (checksum_setup(dev, skb)) { |
| kfree_skb(skb); |
| packets_dropped++; |
| dev->stats.rx_errors++; |
| continue; |
| } |
| |
| u64_stats_update_begin(&stats->syncp); |
| stats->rx_packets++; |
| stats->rx_bytes += skb->len; |
| u64_stats_update_end(&stats->syncp); |
| |
| /* Pass it up. */ |
| netif_receive_skb(skb); |
| } |
| |
| return packets_dropped; |
| } |
| |
| static int xennet_poll(struct napi_struct *napi, int budget) |
| { |
| struct netfront_info *np = container_of(napi, struct netfront_info, napi); |
| struct net_device *dev = np->netdev; |
| struct sk_buff *skb; |
| struct netfront_rx_info rinfo; |
| struct xen_netif_rx_response *rx = &rinfo.rx; |
| struct xen_netif_extra_info *extras = rinfo.extras; |
| RING_IDX i, rp; |
| int work_done; |
| struct sk_buff_head rxq; |
| struct sk_buff_head errq; |
| struct sk_buff_head tmpq; |
| unsigned long flags; |
| int err; |
| |
| spin_lock(&np->rx_lock); |
| |
| skb_queue_head_init(&rxq); |
| skb_queue_head_init(&errq); |
| skb_queue_head_init(&tmpq); |
| |
| rp = np->rx.sring->rsp_prod; |
| rmb(); /* Ensure we see queued responses up to 'rp'. */ |
| |
| i = np->rx.rsp_cons; |
| work_done = 0; |
| while ((i != rp) && (work_done < budget)) { |
| memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx)); |
| memset(extras, 0, sizeof(rinfo.extras)); |
| |
| err = xennet_get_responses(np, &rinfo, rp, &tmpq); |
| |
| if (unlikely(err)) { |
| err: |
| while ((skb = __skb_dequeue(&tmpq))) |
| __skb_queue_tail(&errq, skb); |
| dev->stats.rx_errors++; |
| i = np->rx.rsp_cons; |
| continue; |
| } |
| |
| skb = __skb_dequeue(&tmpq); |
| |
| if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) { |
| struct xen_netif_extra_info *gso; |
| gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1]; |
| |
| if (unlikely(xennet_set_skb_gso(skb, gso))) { |
| __skb_queue_head(&tmpq, skb); |
| np->rx.rsp_cons += skb_queue_len(&tmpq); |
| goto err; |
| } |
| } |
| |
| NETFRONT_SKB_CB(skb)->pull_to = rx->status; |
| if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) |
| NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; |
| |
| skb_shinfo(skb)->frags[0].page_offset = rx->offset; |
| skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); |
| skb->data_len = rx->status; |
| skb->len += rx->status; |
| |
| i = xennet_fill_frags(np, skb, &tmpq); |
| |
| if (rx->flags & XEN_NETRXF_csum_blank) |
| skb->ip_summed = CHECKSUM_PARTIAL; |
| else if (rx->flags & XEN_NETRXF_data_validated) |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| __skb_queue_tail(&rxq, skb); |
| |
| np->rx.rsp_cons = ++i; |
| work_done++; |
| } |
| |
| __skb_queue_purge(&errq); |
| |
| work_done -= handle_incoming_queue(dev, &rxq); |
| |
| /* If we get a callback with very few responses, reduce fill target. */ |
| /* NB. Note exponential increase, linear decrease. */ |
| if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) > |
| ((3*np->rx_target) / 4)) && |
| (--np->rx_target < np->rx_min_target)) |
| np->rx_target = np->rx_min_target; |
| |
| xennet_alloc_rx_buffers(dev); |
| |
| if (work_done < budget) { |
| int more_to_do = 0; |
| |
| local_irq_save(flags); |
| |
| RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, more_to_do); |
| if (!more_to_do) |
| __napi_complete(napi); |
| |
| local_irq_restore(flags); |
| } |
| |
| spin_unlock(&np->rx_lock); |
| |
| return work_done; |
| } |
| |
| static int xennet_change_mtu(struct net_device *dev, int mtu) |
| { |
| int max = xennet_can_sg(dev) ? |
| XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER : ETH_DATA_LEN; |
| |
| if (mtu > max) |
| return -EINVAL; |
| dev->mtu = mtu; |
| return 0; |
| } |
| |
| static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev, |
| struct rtnl_link_stats64 *tot) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| int cpu; |
| |
| for_each_possible_cpu(cpu) { |
| struct netfront_stats *stats = per_cpu_ptr(np->stats, cpu); |
| u64 rx_packets, rx_bytes, tx_packets, tx_bytes; |
| unsigned int start; |
| |
| do { |
| start = u64_stats_fetch_begin_bh(&stats->syncp); |
| |
| rx_packets = stats->rx_packets; |
| tx_packets = stats->tx_packets; |
| rx_bytes = stats->rx_bytes; |
| tx_bytes = stats->tx_bytes; |
| } while (u64_stats_fetch_retry_bh(&stats->syncp, start)); |
| |
| tot->rx_packets += rx_packets; |
| tot->tx_packets += tx_packets; |
| tot->rx_bytes += rx_bytes; |
| tot->tx_bytes += tx_bytes; |
| } |
| |
| tot->rx_errors = dev->stats.rx_errors; |
| tot->tx_dropped = dev->stats.tx_dropped; |
| |
| return tot; |
| } |
| |
| static void xennet_release_tx_bufs(struct netfront_info *np) |
| { |
| struct sk_buff *skb; |
| int i; |
| |
| for (i = 0; i < NET_TX_RING_SIZE; i++) { |
| /* Skip over entries which are actually freelist references */ |
| if (skb_entry_is_link(&np->tx_skbs[i])) |
| continue; |
| |
| skb = np->tx_skbs[i].skb; |
| get_page(np->grant_tx_page[i]); |
| gnttab_end_foreign_access(np->grant_tx_ref[i], |
| GNTMAP_readonly, |
| (unsigned long)page_address(np->grant_tx_page[i])); |
| np->grant_tx_page[i] = NULL; |
| np->grant_tx_ref[i] = GRANT_INVALID_REF; |
| add_id_to_freelist(&np->tx_skb_freelist, np->tx_skbs, i); |
| dev_kfree_skb_irq(skb); |
| } |
| } |
| |
| static void xennet_release_rx_bufs(struct netfront_info *np) |
| { |
| int id, ref; |
| |
| spin_lock_bh(&np->rx_lock); |
| |
| for (id = 0; id < NET_RX_RING_SIZE; id++) { |
| struct sk_buff *skb; |
| struct page *page; |
| |
| skb = np->rx_skbs[id]; |
| if (!skb) |
| continue; |
| |
| ref = np->grant_rx_ref[id]; |
| if (ref == GRANT_INVALID_REF) |
| continue; |
| |
| page = skb_frag_page(&skb_shinfo(skb)->frags[0]); |
| |
| /* gnttab_end_foreign_access() needs a page ref until |
| * foreign access is ended (which may be deferred). |
| */ |
| get_page(page); |
| gnttab_end_foreign_access(ref, 0, |
| (unsigned long)page_address(page)); |
| np->grant_rx_ref[id] = GRANT_INVALID_REF; |
| |
| kfree_skb(skb); |
| } |
| |
| spin_unlock_bh(&np->rx_lock); |
| } |
| |
| static void xennet_uninit(struct net_device *dev) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| xennet_release_tx_bufs(np); |
| xennet_release_rx_bufs(np); |
| gnttab_free_grant_references(np->gref_tx_head); |
| gnttab_free_grant_references(np->gref_rx_head); |
| } |
| |
| static netdev_features_t xennet_fix_features(struct net_device *dev, |
| netdev_features_t features) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| int val; |
| |
| if (features & NETIF_F_SG) { |
| if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg", |
| "%d", &val) < 0) |
| val = 0; |
| |
| if (!val) |
| features &= ~NETIF_F_SG; |
| } |
| |
| if (features & NETIF_F_TSO) { |
| if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, |
| "feature-gso-tcpv4", "%d", &val) < 0) |
| val = 0; |
| |
| if (!val) |
| features &= ~NETIF_F_TSO; |
| } |
| |
| return features; |
| } |
| |
| static int xennet_set_features(struct net_device *dev, |
| netdev_features_t features) |
| { |
| if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) { |
| netdev_info(dev, "Reducing MTU because no SG offload"); |
| dev->mtu = ETH_DATA_LEN; |
| } |
| |
| return 0; |
| } |
| |
| static irqreturn_t xennet_interrupt(int irq, void *dev_id) |
| { |
| struct net_device *dev = dev_id; |
| struct netfront_info *np = netdev_priv(dev); |
| unsigned long flags; |
| |
| spin_lock_irqsave(&np->tx_lock, flags); |
| |
| if (likely(netif_carrier_ok(dev))) { |
| xennet_tx_buf_gc(dev); |
| /* Under tx_lock: protects access to rx shared-ring indexes. */ |
| if (RING_HAS_UNCONSUMED_RESPONSES(&np->rx)) |
| napi_schedule(&np->napi); |
| } |
| |
| spin_unlock_irqrestore(&np->tx_lock, flags); |
| |
| return IRQ_HANDLED; |
| } |
| |
| #ifdef CONFIG_NET_POLL_CONTROLLER |
| static void xennet_poll_controller(struct net_device *dev) |
| { |
| xennet_interrupt(0, dev); |
| } |
| #endif |
| |
| static const struct net_device_ops xennet_netdev_ops = { |
| .ndo_open = xennet_open, |
| .ndo_uninit = xennet_uninit, |
| .ndo_stop = xennet_close, |
| .ndo_start_xmit = xennet_start_xmit, |
| .ndo_change_mtu = xennet_change_mtu, |
| .ndo_get_stats64 = xennet_get_stats64, |
| .ndo_set_mac_address = eth_mac_addr, |
| .ndo_validate_addr = eth_validate_addr, |
| .ndo_fix_features = xennet_fix_features, |
| .ndo_set_features = xennet_set_features, |
| #ifdef CONFIG_NET_POLL_CONTROLLER |
| .ndo_poll_controller = xennet_poll_controller, |
| #endif |
| }; |
| |
| static struct net_device *xennet_create_dev(struct xenbus_device *dev) |
| { |
| int i, err; |
| struct net_device *netdev; |
| struct netfront_info *np; |
| |
| netdev = alloc_etherdev(sizeof(struct netfront_info)); |
| if (!netdev) |
| return ERR_PTR(-ENOMEM); |
| |
| np = netdev_priv(netdev); |
| np->xbdev = dev; |
| |
| spin_lock_init(&np->tx_lock); |
| spin_lock_init(&np->rx_lock); |
| |
| skb_queue_head_init(&np->rx_batch); |
| np->rx_target = RX_DFL_MIN_TARGET; |
| np->rx_min_target = RX_DFL_MIN_TARGET; |
| np->rx_max_target = RX_MAX_TARGET; |
| |
| init_timer(&np->rx_refill_timer); |
| np->rx_refill_timer.data = (unsigned long)netdev; |
| np->rx_refill_timer.function = rx_refill_timeout; |
| |
| err = -ENOMEM; |
| np->stats = alloc_percpu(struct netfront_stats); |
| if (np->stats == NULL) |
| goto exit; |
| |
| /* Initialise tx_skbs as a free chain containing every entry. */ |
| np->tx_skb_freelist = 0; |
| for (i = 0; i < NET_TX_RING_SIZE; i++) { |
| skb_entry_set_link(&np->tx_skbs[i], i+1); |
| np->grant_tx_ref[i] = GRANT_INVALID_REF; |
| } |
| |
| /* Clear out rx_skbs */ |
| for (i = 0; i < NET_RX_RING_SIZE; i++) { |
| np->rx_skbs[i] = NULL; |
| np->grant_rx_ref[i] = GRANT_INVALID_REF; |
| np->grant_tx_page[i] = NULL; |
| } |
| |
| /* A grant for every tx ring slot */ |
| if (gnttab_alloc_grant_references(TX_MAX_TARGET, |
| &np->gref_tx_head) < 0) { |
| printk(KERN_ALERT "#### netfront can't alloc tx grant refs\n"); |
| err = -ENOMEM; |
| goto exit_free_stats; |
| } |
| /* A grant for every rx ring slot */ |
| if (gnttab_alloc_grant_references(RX_MAX_TARGET, |
| &np->gref_rx_head) < 0) { |
| printk(KERN_ALERT "#### netfront can't alloc rx grant refs\n"); |
| err = -ENOMEM; |
| goto exit_free_tx; |
| } |
| |
| netdev->netdev_ops = &xennet_netdev_ops; |
| |
| netif_napi_add(netdev, &np->napi, xennet_poll, 64); |
| netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM | |
| NETIF_F_GSO_ROBUST; |
| netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO; |
| |
| /* |
| * Assume that all hw features are available for now. This set |
| * will be adjusted by the call to netdev_update_features() in |
| * xennet_connect() which is the earliest point where we can |
| * negotiate with the backend regarding supported features. |
| */ |
| netdev->features |= netdev->hw_features; |
| |
| SET_ETHTOOL_OPS(netdev, &xennet_ethtool_ops); |
| SET_NETDEV_DEV(netdev, &dev->dev); |
| |
| netif_set_gso_max_size(netdev, XEN_NETIF_MAX_TX_SIZE - MAX_TCP_HEADER); |
| |
| np->netdev = netdev; |
| |
| netif_carrier_off(netdev); |
| |
| return netdev; |
| |
| exit_free_tx: |
| gnttab_free_grant_references(np->gref_tx_head); |
| exit_free_stats: |
| free_percpu(np->stats); |
| exit: |
| free_netdev(netdev); |
| return ERR_PTR(err); |
| } |
| |
| /** |
| * Entry point to this code when a new device is created. Allocate the basic |
| * structures and the ring buffers for communication with the backend, and |
| * inform the backend of the appropriate details for those. |
| */ |
| static int netfront_probe(struct xenbus_device *dev, |
| const struct xenbus_device_id *id) |
| { |
| int err; |
| struct net_device *netdev; |
| struct netfront_info *info; |
| |
| netdev = xennet_create_dev(dev); |
| if (IS_ERR(netdev)) { |
| err = PTR_ERR(netdev); |
| xenbus_dev_fatal(dev, err, "creating netdev"); |
| return err; |
| } |
| |
| info = netdev_priv(netdev); |
| dev_set_drvdata(&dev->dev, info); |
| |
| err = register_netdev(info->netdev); |
| if (err) { |
| printk(KERN_WARNING "%s: register_netdev err=%d\n", |
| __func__, err); |
| goto fail; |
| } |
| |
| err = xennet_sysfs_addif(info->netdev); |
| if (err) { |
| unregister_netdev(info->netdev); |
| printk(KERN_WARNING "%s: add sysfs failed err=%d\n", |
| __func__, err); |
| goto fail; |
| } |
| |
| return 0; |
| |
| fail: |
| free_netdev(netdev); |
| dev_set_drvdata(&dev->dev, NULL); |
| return err; |
| } |
| |
| static void xennet_end_access(int ref, void *page) |
| { |
| /* This frees the page as a side-effect */ |
| if (ref != GRANT_INVALID_REF) |
| gnttab_end_foreign_access(ref, 0, (unsigned long)page); |
| } |
| |
| static void xennet_disconnect_backend(struct netfront_info *info) |
| { |
| /* Stop old i/f to prevent errors whilst we rebuild the state. */ |
| spin_lock_bh(&info->rx_lock); |
| spin_lock_irq(&info->tx_lock); |
| netif_carrier_off(info->netdev); |
| spin_unlock_irq(&info->tx_lock); |
| spin_unlock_bh(&info->rx_lock); |
| |
| if (info->netdev->irq) |
| unbind_from_irqhandler(info->netdev->irq, info->netdev); |
| info->evtchn = info->netdev->irq = 0; |
| |
| /* End access and free the pages */ |
| xennet_end_access(info->tx_ring_ref, info->tx.sring); |
| xennet_end_access(info->rx_ring_ref, info->rx.sring); |
| |
| info->tx_ring_ref = GRANT_INVALID_REF; |
| info->rx_ring_ref = GRANT_INVALID_REF; |
| info->tx.sring = NULL; |
| info->rx.sring = NULL; |
| } |
| |
| /** |
| * We are reconnecting to the backend, due to a suspend/resume, or a backend |
| * driver restart. We tear down our netif structure and recreate it, but |
| * leave the device-layer structures intact so that this is transparent to the |
| * rest of the kernel. |
| */ |
| static int netfront_resume(struct xenbus_device *dev) |
| { |
| struct netfront_info *info = dev_get_drvdata(&dev->dev); |
| |
| dev_dbg(&dev->dev, "%s\n", dev->nodename); |
| |
| xennet_disconnect_backend(info); |
| return 0; |
| } |
| |
| static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[]) |
| { |
| char *s, *e, *macstr; |
| int i; |
| |
| macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL); |
| if (IS_ERR(macstr)) |
| return PTR_ERR(macstr); |
| |
| for (i = 0; i < ETH_ALEN; i++) { |
| mac[i] = simple_strtoul(s, &e, 16); |
| if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) { |
| kfree(macstr); |
| return -ENOENT; |
| } |
| s = e+1; |
| } |
| |
| kfree(macstr); |
| return 0; |
| } |
| |
| static int setup_netfront(struct xenbus_device *dev, struct netfront_info *info) |
| { |
| struct xen_netif_tx_sring *txs; |
| struct xen_netif_rx_sring *rxs; |
| int err; |
| struct net_device *netdev = info->netdev; |
| |
| info->tx_ring_ref = GRANT_INVALID_REF; |
| info->rx_ring_ref = GRANT_INVALID_REF; |
| info->rx.sring = NULL; |
| info->tx.sring = NULL; |
| netdev->irq = 0; |
| |
| err = xen_net_read_mac(dev, netdev->dev_addr); |
| if (err) { |
| xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename); |
| goto fail; |
| } |
| |
| txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); |
| if (!txs) { |
| err = -ENOMEM; |
| xenbus_dev_fatal(dev, err, "allocating tx ring page"); |
| goto fail; |
| } |
| SHARED_RING_INIT(txs); |
| FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE); |
| |
| err = xenbus_grant_ring(dev, virt_to_mfn(txs)); |
| if (err < 0) { |
| free_page((unsigned long)txs); |
| goto fail; |
| } |
| |
| info->tx_ring_ref = err; |
| rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH); |
| if (!rxs) { |
| err = -ENOMEM; |
| xenbus_dev_fatal(dev, err, "allocating rx ring page"); |
| goto fail; |
| } |
| SHARED_RING_INIT(rxs); |
| FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE); |
| |
| err = xenbus_grant_ring(dev, virt_to_mfn(rxs)); |
| if (err < 0) { |
| free_page((unsigned long)rxs); |
| goto fail; |
| } |
| info->rx_ring_ref = err; |
| |
| err = xenbus_alloc_evtchn(dev, &info->evtchn); |
| if (err) |
| goto fail; |
| |
| err = bind_evtchn_to_irqhandler(info->evtchn, xennet_interrupt, |
| 0, netdev->name, netdev); |
| if (err < 0) |
| goto fail; |
| netdev->irq = err; |
| return 0; |
| |
| fail: |
| return err; |
| } |
| |
| /* Common code used when first setting up, and when resuming. */ |
| static int talk_to_netback(struct xenbus_device *dev, |
| struct netfront_info *info) |
| { |
| const char *message; |
| struct xenbus_transaction xbt; |
| int err; |
| |
| /* Create shared ring, alloc event channel. */ |
| err = setup_netfront(dev, info); |
| if (err) |
| goto out; |
| |
| again: |
| err = xenbus_transaction_start(&xbt); |
| if (err) { |
| xenbus_dev_fatal(dev, err, "starting transaction"); |
| goto destroy_ring; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "tx-ring-ref", "%u", |
| info->tx_ring_ref); |
| if (err) { |
| message = "writing tx ring-ref"; |
| goto abort_transaction; |
| } |
| err = xenbus_printf(xbt, dev->nodename, "rx-ring-ref", "%u", |
| info->rx_ring_ref); |
| if (err) { |
| message = "writing rx ring-ref"; |
| goto abort_transaction; |
| } |
| err = xenbus_printf(xbt, dev->nodename, |
| "event-channel", "%u", info->evtchn); |
| if (err) { |
| message = "writing event-channel"; |
| goto abort_transaction; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u", |
| 1); |
| if (err) { |
| message = "writing request-rx-copy"; |
| goto abort_transaction; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1); |
| if (err) { |
| message = "writing feature-rx-notify"; |
| goto abort_transaction; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1); |
| if (err) { |
| message = "writing feature-sg"; |
| goto abort_transaction; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1); |
| if (err) { |
| message = "writing feature-gso-tcpv4"; |
| goto abort_transaction; |
| } |
| |
| err = xenbus_transaction_end(xbt, 0); |
| if (err) { |
| if (err == -EAGAIN) |
| goto again; |
| xenbus_dev_fatal(dev, err, "completing transaction"); |
| goto destroy_ring; |
| } |
| |
| return 0; |
| |
| abort_transaction: |
| xenbus_transaction_end(xbt, 1); |
| xenbus_dev_fatal(dev, err, "%s", message); |
| destroy_ring: |
| xennet_disconnect_backend(info); |
| out: |
| return err; |
| } |
| |
| static int xennet_connect(struct net_device *dev) |
| { |
| struct netfront_info *np = netdev_priv(dev); |
| int i, requeue_idx, err; |
| struct sk_buff *skb; |
| grant_ref_t ref; |
| struct xen_netif_rx_request *req; |
| unsigned int feature_rx_copy; |
| |
| err = xenbus_scanf(XBT_NIL, np->xbdev->otherend, |
| "feature-rx-copy", "%u", &feature_rx_copy); |
| if (err != 1) |
| feature_rx_copy = 0; |
| |
| if (!feature_rx_copy) { |
| dev_info(&dev->dev, |
| "backend does not support copying receive path\n"); |
| return -ENODEV; |
| } |
| |
| err = talk_to_netback(np->xbdev, np); |
| if (err) |
| return err; |
| |
| rtnl_lock(); |
| netdev_update_features(dev); |
| rtnl_unlock(); |
| |
| spin_lock_bh(&np->rx_lock); |
| spin_lock_irq(&np->tx_lock); |
| |
| /* Step 1: Discard all pending TX packet fragments. */ |
| xennet_release_tx_bufs(np); |
| |
| /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ |
| for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { |
| skb_frag_t *frag; |
| const struct page *page; |
| if (!np->rx_skbs[i]) |
| continue; |
| |
| skb = np->rx_skbs[requeue_idx] = xennet_get_rx_skb(np, i); |
| ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i); |
| req = RING_GET_REQUEST(&np->rx, requeue_idx); |
| |
| frag = &skb_shinfo(skb)->frags[0]; |
| page = skb_frag_page(frag); |
| gnttab_grant_foreign_access_ref( |
| ref, np->xbdev->otherend_id, |
| pfn_to_mfn(page_to_pfn(page)), |
| 0); |
| req->gref = ref; |
| req->id = requeue_idx; |
| |
| requeue_idx++; |
| } |
| |
| np->rx.req_prod_pvt = requeue_idx; |
| |
| /* |
| * Step 3: All public and private state should now be sane. Get |
| * ready to start sending and receiving packets and give the driver |
| * domain a kick because we've probably just requeued some |
| * packets. |
| */ |
| netif_carrier_on(np->netdev); |
| notify_remote_via_irq(np->netdev->irq); |
| xennet_tx_buf_gc(dev); |
| xennet_alloc_rx_buffers(dev); |
| |
| spin_unlock_irq(&np->tx_lock); |
| spin_unlock_bh(&np->rx_lock); |
| |
| return 0; |
| } |
| |
| /** |
| * Callback received when the backend's state changes. |
| */ |
| static void netback_changed(struct xenbus_device *dev, |
| enum xenbus_state backend_state) |
| { |
| struct netfront_info *np = dev_get_drvdata(&dev->dev); |
| struct net_device *netdev = np->netdev; |
| |
| dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state)); |
| |
| switch (backend_state) { |
| case XenbusStateInitialising: |
| case XenbusStateInitialised: |
| case XenbusStateReconfiguring: |
| case XenbusStateReconfigured: |
| case XenbusStateUnknown: |
| case XenbusStateClosed: |
| break; |
| |
| case XenbusStateInitWait: |
| if (dev->state != XenbusStateInitialising) |
| break; |
| if (xennet_connect(netdev) != 0) |
| break; |
| xenbus_switch_state(dev, XenbusStateConnected); |
| break; |
| |
| case XenbusStateConnected: |
| netdev_notify_peers(netdev); |
| break; |
| |
| case XenbusStateClosing: |
| xenbus_frontend_closed(dev); |
| break; |
| } |
| } |
| |
| static const struct xennet_stat { |
| char name[ETH_GSTRING_LEN]; |
| u16 offset; |
| } xennet_stats[] = { |
| { |
| "rx_gso_checksum_fixup", |
| offsetof(struct netfront_info, rx_gso_checksum_fixup) |
| }, |
| }; |
| |
| static int xennet_get_sset_count(struct net_device *dev, int string_set) |
| { |
| switch (string_set) { |
| case ETH_SS_STATS: |
| return ARRAY_SIZE(xennet_stats); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static void xennet_get_ethtool_stats(struct net_device *dev, |
| struct ethtool_stats *stats, u64 * data) |
| { |
| void *np = netdev_priv(dev); |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) |
| data[i] = *(unsigned long *)(np + xennet_stats[i].offset); |
| } |
| |
| static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data) |
| { |
| int i; |
| |
| switch (stringset) { |
| case ETH_SS_STATS: |
| for (i = 0; i < ARRAY_SIZE(xennet_stats); i++) |
| memcpy(data + i * ETH_GSTRING_LEN, |
| xennet_stats[i].name, ETH_GSTRING_LEN); |
| break; |
| } |
| } |
| |
| static const struct ethtool_ops xennet_ethtool_ops = |
| { |
| .get_link = ethtool_op_get_link, |
| |
| .get_sset_count = xennet_get_sset_count, |
| .get_ethtool_stats = xennet_get_ethtool_stats, |
| .get_strings = xennet_get_strings, |
| }; |
| |
| #ifdef CONFIG_SYSFS |
| static ssize_t show_rxbuf_min(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct net_device *netdev = to_net_dev(dev); |
| struct netfront_info *info = netdev_priv(netdev); |
| |
| return sprintf(buf, "%u\n", info->rx_min_target); |
| } |
| |
| static ssize_t store_rxbuf_min(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct net_device *netdev = to_net_dev(dev); |
| struct netfront_info *np = netdev_priv(netdev); |
| char *endp; |
| unsigned long target; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| target = simple_strtoul(buf, &endp, 0); |
| if (endp == buf) |
| return -EBADMSG; |
| |
| if (target < RX_MIN_TARGET) |
| target = RX_MIN_TARGET; |
| if (target > RX_MAX_TARGET) |
| target = RX_MAX_TARGET; |
| |
| spin_lock_bh(&np->rx_lock); |
| if (target > np->rx_max_target) |
| np->rx_max_target = target; |
| np->rx_min_target = target; |
| if (target > np->rx_target) |
| np->rx_target = target; |
| |
| xennet_alloc_rx_buffers(netdev); |
| |
| spin_unlock_bh(&np->rx_lock); |
| return len; |
| } |
| |
| static ssize_t show_rxbuf_max(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct net_device *netdev = to_net_dev(dev); |
| struct netfront_info *info = netdev_priv(netdev); |
| |
| return sprintf(buf, "%u\n", info->rx_max_target); |
| } |
| |
| static ssize_t store_rxbuf_max(struct device *dev, |
| struct device_attribute *attr, |
| const char *buf, size_t len) |
| { |
| struct net_device *netdev = to_net_dev(dev); |
| struct netfront_info *np = netdev_priv(netdev); |
| char *endp; |
| unsigned long target; |
| |
| if (!capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| |
| target = simple_strtoul(buf, &endp, 0); |
| if (endp == buf) |
| return -EBADMSG; |
| |
| if (target < RX_MIN_TARGET) |
| target = RX_MIN_TARGET; |
| if (target > RX_MAX_TARGET) |
| target = RX_MAX_TARGET; |
| |
| spin_lock_bh(&np->rx_lock); |
| if (target < np->rx_min_target) |
| np->rx_min_target = target; |
| np->rx_max_target = target; |
| if (target < np->rx_target) |
| np->rx_target = target; |
| |
| xennet_alloc_rx_buffers(netdev); |
| |
| spin_unlock_bh(&np->rx_lock); |
| return len; |
| } |
| |
| static ssize_t show_rxbuf_cur(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct net_device *netdev = to_net_dev(dev); |
| struct netfront_info *info = netdev_priv(netdev); |
| |
| return sprintf(buf, "%u\n", info->rx_target); |
| } |
| |
| static struct device_attribute xennet_attrs[] = { |
| __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min), |
| __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max), |
| __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, 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; |
| |
| for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) |
| device_remove_file(&netdev->dev, &xennet_attrs[i]); |
| } |
| |
| #endif /* CONFIG_SYSFS */ |
| |
| static const struct xenbus_device_id netfront_ids[] = { |
| { "vif" }, |
| { "" } |
| }; |
| |
| |
| static int xennet_remove(struct xenbus_device *dev) |
| { |
| struct netfront_info *info = dev_get_drvdata(&dev->dev); |
| |
| dev_dbg(&dev->dev, "%s\n", dev->nodename); |
| |
| xennet_disconnect_backend(info); |
| |
| xennet_sysfs_delif(info->netdev); |
| |
| unregister_netdev(info->netdev); |
| |
| del_timer_sync(&info->rx_refill_timer); |
| |
| free_percpu(info->stats); |
| |
| free_netdev(info->netdev); |
| |
| return 0; |
| } |
| |
| static DEFINE_XENBUS_DRIVER(netfront, , |
| .probe = netfront_probe, |
| .remove = xennet_remove, |
| .resume = netfront_resume, |
| .otherend_changed = netback_changed, |
| ); |
| |
| static int __init netif_init(void) |
| { |
| if (!xen_domain()) |
| return -ENODEV; |
| |
| if (xen_hvm_domain() && !xen_platform_pci_unplug) |
| return -ENODEV; |
| |
| printk(KERN_INFO "Initialising Xen virtual ethernet driver.\n"); |
| |
| return xenbus_register_frontend(&netfront_driver); |
| } |
| module_init(netif_init); |
| |
| |
| static void __exit netif_exit(void) |
| { |
| xenbus_unregister_driver(&netfront_driver); |
| } |
| module_exit(netif_exit); |
| |
| MODULE_DESCRIPTION("Xen virtual network device frontend"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("xen:vif"); |
| MODULE_ALIAS("xennet"); |