zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/netback.c b/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/netback.c
new file mode 100644
index 0000000..cd4966b
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/net/xen-netback/netback.c
@@ -0,0 +1,1915 @@
+/*
+ * Back-end of the driver for virtual network devices. This portion of the
+ * driver exports a 'unified' network-device interface that can be accessed
+ * by any operating system that implements a compatible front end. A
+ * reference front-end implementation can be found in:
+ * drivers/net/xen-netfront.c
+ *
+ * Copyright (c) 2002-2005, K A Fraser
+ *
+ * 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 "common.h"
+
+#include <linux/kthread.h>
+#include <linux/if_vlan.h>
+#include <linux/udp.h>
+
+#include <net/tcp.h>
+
+#include <xen/events.h>
+#include <xen/interface/memory.h>
+
+#include <asm/xen/hypercall.h>
+#include <asm/xen/page.h>
+
+/*
+ * This is the maximum slots a skb can have. If a guest sends a skb
+ * which exceeds this limit it is considered malicious.
+ */
+#define MAX_SKB_SLOTS_DEFAULT 20
+static unsigned int max_skb_slots = MAX_SKB_SLOTS_DEFAULT;
+module_param(max_skb_slots, uint, 0444);
+
+typedef unsigned int pending_ring_idx_t;
+#define INVALID_PENDING_RING_IDX (~0U)
+
+struct pending_tx_info {
+ struct xen_netif_tx_request req; /* coalesced tx request */
+ struct xenvif *vif;
+ pending_ring_idx_t head; /* head != INVALID_PENDING_RING_IDX
+ * if it is head of one or more tx
+ * reqs
+ */
+};
+
+struct netbk_rx_meta {
+ int id;
+ int size;
+ int gso_size;
+};
+
+#define MAX_PENDING_REQS 256
+
+/* Discriminate from any valid pending_idx value. */
+#define INVALID_PENDING_IDX 0xFFFF
+
+#define MAX_BUFFER_OFFSET PAGE_SIZE
+
+/* extra field used in struct page */
+union page_ext {
+ struct {
+#if BITS_PER_LONG < 64
+#define IDX_WIDTH 8
+#define GROUP_WIDTH (BITS_PER_LONG - IDX_WIDTH)
+ unsigned int group:GROUP_WIDTH;
+ unsigned int idx:IDX_WIDTH;
+#else
+ unsigned int group, idx;
+#endif
+ } e;
+ void *mapping;
+};
+
+struct xen_netbk {
+ wait_queue_head_t wq;
+ struct task_struct *task;
+
+ struct sk_buff_head rx_queue;
+ struct sk_buff_head tx_queue;
+
+ struct timer_list net_timer;
+
+ struct page *mmap_pages[MAX_PENDING_REQS];
+
+ pending_ring_idx_t pending_prod;
+ pending_ring_idx_t pending_cons;
+ struct list_head net_schedule_list;
+
+ /* Protect the net_schedule_list in netif. */
+ spinlock_t net_schedule_list_lock;
+
+ atomic_t netfront_count;
+
+ struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
+ /* Coalescing tx requests before copying makes number of grant
+ * copy ops greater or equal to number of slots required. In
+ * worst case a tx request consumes 2 gnttab_copy.
+ */
+ struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS];
+
+ u16 pending_ring[MAX_PENDING_REQS];
+
+ /*
+ * Given MAX_BUFFER_OFFSET of 4096 the worst case is that each
+ * head/fragment page uses 2 copy operations because it
+ * straddles two buffers in the frontend.
+ */
+ struct gnttab_copy grant_copy_op[2*XEN_NETIF_RX_RING_SIZE];
+ struct netbk_rx_meta meta[2*XEN_NETIF_RX_RING_SIZE];
+};
+
+static struct xen_netbk *xen_netbk;
+static int xen_netbk_group_nr;
+
+/*
+ * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of
+ * one or more merged tx requests, otherwise it is the continuation of
+ * previous tx request.
+ */
+static inline int pending_tx_is_head(struct xen_netbk *netbk, RING_IDX idx)
+{
+ return netbk->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX;
+}
+
+void xen_netbk_add_xenvif(struct xenvif *vif)
+{
+ int i;
+ int min_netfront_count;
+ int min_group = 0;
+ struct xen_netbk *netbk;
+
+ min_netfront_count = atomic_read(&xen_netbk[0].netfront_count);
+ for (i = 0; i < xen_netbk_group_nr; i++) {
+ int netfront_count = atomic_read(&xen_netbk[i].netfront_count);
+ if (netfront_count < min_netfront_count) {
+ min_group = i;
+ min_netfront_count = netfront_count;
+ }
+ }
+
+ netbk = &xen_netbk[min_group];
+
+ vif->netbk = netbk;
+ atomic_inc(&netbk->netfront_count);
+}
+
+void xen_netbk_remove_xenvif(struct xenvif *vif)
+{
+ struct xen_netbk *netbk = vif->netbk;
+ vif->netbk = NULL;
+ atomic_dec(&netbk->netfront_count);
+}
+
+static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx,
+ u8 status);
+static void make_tx_response(struct xenvif *vif,
+ struct xen_netif_tx_request *txp,
+ s8 st);
+static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags);
+
+static inline unsigned long idx_to_pfn(struct xen_netbk *netbk,
+ u16 idx)
+{
+ return page_to_pfn(netbk->mmap_pages[idx]);
+}
+
+static inline unsigned long idx_to_kaddr(struct xen_netbk *netbk,
+ u16 idx)
+{
+ return (unsigned long)pfn_to_kaddr(idx_to_pfn(netbk, idx));
+}
+
+/* extra field used in struct page */
+static inline void set_page_ext(struct page *pg, struct xen_netbk *netbk,
+ unsigned int idx)
+{
+ unsigned int group = netbk - xen_netbk;
+ union page_ext ext = { .e = { .group = group + 1, .idx = idx } };
+
+ BUILD_BUG_ON(sizeof(ext) > sizeof(ext.mapping));
+ pg->mapping = ext.mapping;
+}
+
+static int get_page_ext(struct page *pg,
+ unsigned int *pgroup, unsigned int *pidx)
+{
+ union page_ext ext = { .mapping = pg->mapping };
+ struct xen_netbk *netbk;
+ unsigned int group, idx;
+
+ group = ext.e.group - 1;
+
+ if (group < 0 || group >= xen_netbk_group_nr)
+ return 0;
+
+ netbk = &xen_netbk[group];
+
+ idx = ext.e.idx;
+
+ if ((idx < 0) || (idx >= MAX_PENDING_REQS))
+ return 0;
+
+ if (netbk->mmap_pages[idx] != pg)
+ return 0;
+
+ *pgroup = group;
+ *pidx = idx;
+
+ return 1;
+}
+
+/*
+ * This is the amount of packet we copy rather than map, so that the
+ * guest can't fiddle with the contents of the headers while we do
+ * packet processing on them (netfilter, routing, etc).
+ */
+#define PKT_PROT_LEN (ETH_HLEN + \
+ VLAN_HLEN + \
+ sizeof(struct iphdr) + MAX_IPOPTLEN + \
+ sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE)
+
+static u16 frag_get_pending_idx(skb_frag_t *frag)
+{
+ return (u16)frag->page_offset;
+}
+
+static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
+{
+ frag->page_offset = pending_idx;
+}
+
+static inline pending_ring_idx_t pending_index(unsigned i)
+{
+ return i & (MAX_PENDING_REQS-1);
+}
+
+static inline pending_ring_idx_t nr_pending_reqs(struct xen_netbk *netbk)
+{
+ return MAX_PENDING_REQS -
+ netbk->pending_prod + netbk->pending_cons;
+}
+
+static void xen_netbk_kick_thread(struct xen_netbk *netbk)
+{
+ wake_up(&netbk->wq);
+}
+
+static int max_required_rx_slots(struct xenvif *vif)
+{
+ int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
+
+ /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
+ if (vif->can_sg || vif->gso || vif->gso_prefix)
+ max += MAX_SKB_FRAGS + 1; /* extra_info + frags */
+
+ return max;
+}
+
+int xen_netbk_rx_ring_full(struct xenvif *vif)
+{
+ RING_IDX peek = vif->rx_req_cons_peek;
+ RING_IDX needed = max_required_rx_slots(vif);
+
+ return ((vif->rx.sring->req_prod - peek) < needed) ||
+ ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) < needed);
+}
+
+int xen_netbk_must_stop_queue(struct xenvif *vif)
+{
+ if (!xen_netbk_rx_ring_full(vif))
+ return 0;
+
+ vif->rx.sring->req_event = vif->rx_req_cons_peek +
+ max_required_rx_slots(vif);
+ mb(); /* request notification /then/ check the queue */
+
+ return xen_netbk_rx_ring_full(vif);
+}
+
+/*
+ * Returns true if we should start a new receive buffer instead of
+ * adding 'size' bytes to a buffer which currently contains 'offset'
+ * bytes.
+ */
+static bool start_new_rx_buffer(int offset, unsigned long size, int head)
+{
+ /* simple case: we have completely filled the current buffer. */
+ if (offset == MAX_BUFFER_OFFSET)
+ return true;
+
+ /*
+ * complex case: start a fresh buffer if the current frag
+ * would overflow the current buffer but only if:
+ * (i) this frag would fit completely in the next buffer
+ * and (ii) there is already some data in the current buffer
+ * and (iii) this is not the head buffer.
+ *
+ * Where:
+ * - (i) stops us splitting a frag into two copies
+ * unless the frag is too large for a single buffer.
+ * - (ii) stops us from leaving a buffer pointlessly empty.
+ * - (iii) stops us leaving the first buffer
+ * empty. Strictly speaking this is already covered
+ * by (ii) but is explicitly checked because
+ * netfront relies on the first buffer being
+ * non-empty and can crash otherwise.
+ *
+ * This means we will effectively linearise small
+ * frags but do not needlessly split large buffers
+ * into multiple copies tend to give large frags their
+ * own buffers as before.
+ */
+ BUG_ON(size > MAX_BUFFER_OFFSET);
+ if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head)
+ return true;
+
+ return false;
+}
+
+/*
+ * Figure out how many ring slots we're going to need to send @skb to
+ * the guest. This function is essentially a dry run of
+ * netbk_gop_frag_copy.
+ */
+unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff *skb)
+{
+ unsigned int count;
+ int i, copy_off;
+
+ count = DIV_ROUND_UP(
+ offset_in_page(skb->data)+skb_headlen(skb), PAGE_SIZE);
+
+ copy_off = skb_headlen(skb) % PAGE_SIZE;
+
+ if (skb_shinfo(skb)->gso_size)
+ count++;
+
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+ unsigned long size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+ unsigned long bytes;
+ while (size > 0) {
+ BUG_ON(copy_off > MAX_BUFFER_OFFSET);
+
+ if (start_new_rx_buffer(copy_off, size, 0)) {
+ count++;
+ copy_off = 0;
+ }
+
+ bytes = size;
+ if (copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - copy_off;
+
+ copy_off += bytes;
+ size -= bytes;
+ }
+ }
+ return count;
+}
+
+struct netrx_pending_operations {
+ unsigned copy_prod, copy_cons;
+ unsigned meta_prod, meta_cons;
+ struct gnttab_copy *copy;
+ struct netbk_rx_meta *meta;
+ int copy_off;
+ grant_ref_t copy_gref;
+};
+
+static struct netbk_rx_meta *get_next_rx_buffer(struct xenvif *vif,
+ struct netrx_pending_operations *npo)
+{
+ struct netbk_rx_meta *meta;
+ struct xen_netif_rx_request *req;
+
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = 0;
+ meta->size = 0;
+ meta->id = req->id;
+
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ return meta;
+}
+
+/*
+ * Set up the grant operations for this fragment. If it's a flipping
+ * interface, we also set up the unmap request from here.
+ */
+static void netbk_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
+ struct netrx_pending_operations *npo,
+ struct page *page, unsigned long size,
+ unsigned long offset, int *head)
+{
+ struct gnttab_copy *copy_gop;
+ struct netbk_rx_meta *meta;
+ /*
+ * These variables are used iff get_page_ext returns true,
+ * in which case they are guaranteed to be initialized.
+ */
+ unsigned int uninitialized_var(group), uninitialized_var(idx);
+ int foreign = get_page_ext(page, &group, &idx);
+ unsigned long bytes;
+
+ /* Data must not cross a page boundary. */
+ BUG_ON(size + offset > PAGE_SIZE);
+
+ meta = npo->meta + npo->meta_prod - 1;
+
+ while (size > 0) {
+ BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
+
+ if (start_new_rx_buffer(npo->copy_off, size, *head)) {
+ /*
+ * Netfront requires there to be some data in the head
+ * buffer.
+ */
+ BUG_ON(*head);
+
+ meta = get_next_rx_buffer(vif, npo);
+ }
+
+ bytes = size;
+ if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
+ bytes = MAX_BUFFER_OFFSET - npo->copy_off;
+
+ copy_gop = npo->copy + npo->copy_prod++;
+ copy_gop->flags = GNTCOPY_dest_gref;
+ if (foreign) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ struct pending_tx_info *src_pend;
+
+ src_pend = &netbk->pending_tx_info[idx];
+
+ copy_gop->source.domid = src_pend->vif->domid;
+ copy_gop->source.u.ref = src_pend->req.gref;
+ copy_gop->flags |= GNTCOPY_source_gref;
+ } else {
+ void *vaddr = page_address(page);
+ copy_gop->source.domid = DOMID_SELF;
+ copy_gop->source.u.gmfn = virt_to_mfn(vaddr);
+ }
+ copy_gop->source.offset = offset;
+ copy_gop->dest.domid = vif->domid;
+
+ copy_gop->dest.offset = npo->copy_off;
+ copy_gop->dest.u.ref = npo->copy_gref;
+ copy_gop->len = bytes;
+
+ npo->copy_off += bytes;
+ meta->size += bytes;
+
+ offset += bytes;
+ size -= bytes;
+
+ /* Leave a gap for the GSO descriptor. */
+ if (*head && skb_shinfo(skb)->gso_size && !vif->gso_prefix)
+ vif->rx.req_cons++;
+
+ *head = 0; /* There must be something in this buffer now. */
+
+ }
+}
+
+/*
+ * Prepare an SKB to be transmitted to the frontend.
+ *
+ * This function is responsible for allocating grant operations, meta
+ * structures, etc.
+ *
+ * It returns the number of meta structures consumed. The number of
+ * ring slots used is always equal to the number of meta slots used
+ * plus the number of GSO descriptors used. Currently, we use either
+ * zero GSO descriptors (for non-GSO packets) or one descriptor (for
+ * frontend-side LRO).
+ */
+static int netbk_gop_skb(struct sk_buff *skb,
+ struct netrx_pending_operations *npo)
+{
+ struct xenvif *vif = netdev_priv(skb->dev);
+ int nr_frags = skb_shinfo(skb)->nr_frags;
+ int i;
+ struct xen_netif_rx_request *req;
+ struct netbk_rx_meta *meta;
+ unsigned char *data;
+ int head = 1;
+ int old_meta_prod;
+
+ old_meta_prod = npo->meta_prod;
+
+ /* Set up a GSO prefix descriptor, if necessary */
+ if (skb_shinfo(skb)->gso_size && vif->gso_prefix) {
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ meta->size = 0;
+ meta->id = req->id;
+ }
+
+ req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
+ meta = npo->meta + npo->meta_prod++;
+
+ if (!vif->gso_prefix)
+ meta->gso_size = skb_shinfo(skb)->gso_size;
+ else
+ meta->gso_size = 0;
+
+ meta->size = 0;
+ meta->id = req->id;
+ npo->copy_off = 0;
+ npo->copy_gref = req->gref;
+
+ data = skb->data;
+ while (data < skb_tail_pointer(skb)) {
+ unsigned int offset = offset_in_page(data);
+ unsigned int len = PAGE_SIZE - offset;
+
+ if (data + len > skb_tail_pointer(skb))
+ len = skb_tail_pointer(skb) - data;
+
+ netbk_gop_frag_copy(vif, skb, npo,
+ virt_to_page(data), len, offset, &head);
+ data += len;
+ }
+
+ for (i = 0; i < nr_frags; i++) {
+ netbk_gop_frag_copy(vif, skb, npo,
+ skb_frag_page(&skb_shinfo(skb)->frags[i]),
+ skb_frag_size(&skb_shinfo(skb)->frags[i]),
+ skb_shinfo(skb)->frags[i].page_offset,
+ &head);
+ }
+
+ return npo->meta_prod - old_meta_prod;
+}
+
+/*
+ * This is a twin to netbk_gop_skb. Assume that netbk_gop_skb was
+ * used to set up the operations on the top of
+ * netrx_pending_operations, which have since been done. Check that
+ * they didn't give any errors and advance over them.
+ */
+static int netbk_check_gop(struct xenvif *vif, int nr_meta_slots,
+ struct netrx_pending_operations *npo)
+{
+ struct gnttab_copy *copy_op;
+ int status = XEN_NETIF_RSP_OKAY;
+ int i;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ copy_op = npo->copy + npo->copy_cons++;
+ if (copy_op->status != GNTST_okay) {
+ netdev_dbg(vif->dev,
+ "Bad status %d from copy to DOM%d.\n",
+ copy_op->status, vif->domid);
+ status = XEN_NETIF_RSP_ERROR;
+ }
+ }
+
+ return status;
+}
+
+static void netbk_add_frag_responses(struct xenvif *vif, int status,
+ struct netbk_rx_meta *meta,
+ int nr_meta_slots)
+{
+ int i;
+ unsigned long offset;
+
+ /* No fragments used */
+ if (nr_meta_slots <= 1)
+ return;
+
+ nr_meta_slots--;
+
+ for (i = 0; i < nr_meta_slots; i++) {
+ int flags;
+ if (i == nr_meta_slots - 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ offset = 0;
+ make_rx_response(vif, meta[i].id, status, offset,
+ meta[i].size, flags);
+ }
+}
+
+struct skb_cb_overlay {
+ int meta_slots_used;
+};
+
+static void xen_netbk_rx_action(struct xen_netbk *netbk)
+{
+ struct xenvif *vif = NULL, *tmp;
+ s8 status;
+ u16 irq, flags;
+ struct xen_netif_rx_response *resp;
+ struct sk_buff_head rxq;
+ struct sk_buff *skb;
+ LIST_HEAD(notify);
+ int ret;
+ int nr_frags;
+ int count;
+ unsigned long offset;
+ struct skb_cb_overlay *sco;
+
+ struct netrx_pending_operations npo = {
+ .copy = netbk->grant_copy_op,
+ .meta = netbk->meta,
+ };
+
+ skb_queue_head_init(&rxq);
+
+ count = 0;
+
+ while ((skb = skb_dequeue(&netbk->rx_queue)) != NULL) {
+ vif = netdev_priv(skb->dev);
+ nr_frags = skb_shinfo(skb)->nr_frags;
+
+ sco = (struct skb_cb_overlay *)skb->cb;
+ sco->meta_slots_used = netbk_gop_skb(skb, &npo);
+
+ count += nr_frags + 1;
+
+ __skb_queue_tail(&rxq, skb);
+
+ /* Filled the batch queue? */
+ /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
+ if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
+ break;
+ }
+
+ BUG_ON(npo.meta_prod > ARRAY_SIZE(netbk->meta));
+
+ if (!npo.copy_prod)
+ return;
+
+ BUG_ON(npo.copy_prod > ARRAY_SIZE(netbk->grant_copy_op));
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_copy, &netbk->grant_copy_op,
+ npo.copy_prod);
+ BUG_ON(ret != 0);
+
+ while ((skb = __skb_dequeue(&rxq)) != NULL) {
+ sco = (struct skb_cb_overlay *)skb->cb;
+
+ vif = netdev_priv(skb->dev);
+
+ if (netbk->meta[npo.meta_cons].gso_size && vif->gso_prefix) {
+ resp = RING_GET_RESPONSE(&vif->rx,
+ vif->rx.rsp_prod_pvt++);
+
+ resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
+
+ resp->offset = netbk->meta[npo.meta_cons].gso_size;
+ resp->id = netbk->meta[npo.meta_cons].id;
+ resp->status = sco->meta_slots_used;
+
+ npo.meta_cons++;
+ sco->meta_slots_used--;
+ }
+
+
+ vif->dev->stats.tx_bytes += skb->len;
+ vif->dev->stats.tx_packets++;
+
+ status = netbk_check_gop(vif, sco->meta_slots_used, &npo);
+
+ if (sco->meta_slots_used == 1)
+ flags = 0;
+ else
+ flags = XEN_NETRXF_more_data;
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
+ flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
+ else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
+ /* remote but checksummed. */
+ flags |= XEN_NETRXF_data_validated;
+
+ offset = 0;
+ resp = make_rx_response(vif, netbk->meta[npo.meta_cons].id,
+ status, offset,
+ netbk->meta[npo.meta_cons].size,
+ flags);
+
+ if (netbk->meta[npo.meta_cons].gso_size && !vif->gso_prefix) {
+ struct xen_netif_extra_info *gso =
+ (struct xen_netif_extra_info *)
+ RING_GET_RESPONSE(&vif->rx,
+ vif->rx.rsp_prod_pvt++);
+
+ resp->flags |= XEN_NETRXF_extra_info;
+
+ gso->u.gso.size = netbk->meta[npo.meta_cons].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;
+ }
+
+ netbk_add_frag_responses(vif, status,
+ netbk->meta + npo.meta_cons + 1,
+ sco->meta_slots_used);
+
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
+ irq = vif->irq;
+ if (ret && list_empty(&vif->notify_list))
+ list_add_tail(&vif->notify_list, ¬ify);
+
+ xenvif_notify_tx_completion(vif);
+
+ xenvif_put(vif);
+ npo.meta_cons += sco->meta_slots_used;
+ dev_kfree_skb(skb);
+ }
+
+ list_for_each_entry_safe(vif, tmp, ¬ify, notify_list) {
+ notify_remote_via_irq(vif->irq);
+ list_del_init(&vif->notify_list);
+ }
+
+ /* More work to do? */
+ if (!skb_queue_empty(&netbk->rx_queue) &&
+ !timer_pending(&netbk->net_timer))
+ xen_netbk_kick_thread(netbk);
+}
+
+void xen_netbk_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb)
+{
+ struct xen_netbk *netbk = vif->netbk;
+
+ skb_queue_tail(&netbk->rx_queue, skb);
+
+ xen_netbk_kick_thread(netbk);
+}
+
+static void xen_netbk_alarm(unsigned long data)
+{
+ struct xen_netbk *netbk = (struct xen_netbk *)data;
+ xen_netbk_kick_thread(netbk);
+}
+
+static int __on_net_schedule_list(struct xenvif *vif)
+{
+ return !list_empty(&vif->schedule_list);
+}
+
+/* Must be called with net_schedule_list_lock held */
+static void remove_from_net_schedule_list(struct xenvif *vif)
+{
+ if (likely(__on_net_schedule_list(vif))) {
+ list_del_init(&vif->schedule_list);
+ xenvif_put(vif);
+ }
+}
+
+static struct xenvif *poll_net_schedule_list(struct xen_netbk *netbk)
+{
+ struct xenvif *vif = NULL;
+
+ spin_lock_irq(&netbk->net_schedule_list_lock);
+ if (list_empty(&netbk->net_schedule_list))
+ goto out;
+
+ vif = list_first_entry(&netbk->net_schedule_list,
+ struct xenvif, schedule_list);
+ if (!vif)
+ goto out;
+
+ xenvif_get(vif);
+
+ remove_from_net_schedule_list(vif);
+out:
+ spin_unlock_irq(&netbk->net_schedule_list_lock);
+ return vif;
+}
+
+void xen_netbk_schedule_xenvif(struct xenvif *vif)
+{
+ unsigned long flags;
+ struct xen_netbk *netbk = vif->netbk;
+
+ if (__on_net_schedule_list(vif))
+ goto kick;
+
+ spin_lock_irqsave(&netbk->net_schedule_list_lock, flags);
+ if (!__on_net_schedule_list(vif) &&
+ likely(xenvif_schedulable(vif))) {
+ list_add_tail(&vif->schedule_list, &netbk->net_schedule_list);
+ xenvif_get(vif);
+ }
+ spin_unlock_irqrestore(&netbk->net_schedule_list_lock, flags);
+
+kick:
+ smp_mb();
+ if ((nr_pending_reqs(netbk) < (MAX_PENDING_REQS/2)) &&
+ !list_empty(&netbk->net_schedule_list))
+ xen_netbk_kick_thread(netbk);
+}
+
+void xen_netbk_deschedule_xenvif(struct xenvif *vif)
+{
+ struct xen_netbk *netbk = vif->netbk;
+ spin_lock_irq(&netbk->net_schedule_list_lock);
+ remove_from_net_schedule_list(vif);
+ spin_unlock_irq(&netbk->net_schedule_list_lock);
+}
+
+void xen_netbk_check_rx_xenvif(struct xenvif *vif)
+{
+ int more_to_do;
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
+
+ if (more_to_do)
+ xen_netbk_schedule_xenvif(vif);
+}
+
+static void tx_add_credit(struct xenvif *vif)
+{
+ unsigned long max_burst, max_credit;
+
+ /*
+ * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
+ * Otherwise the interface can seize up due to insufficient credit.
+ */
+ max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
+ max_burst = min(max_burst, 131072UL);
+ max_burst = max(max_burst, vif->credit_bytes);
+
+ /* Take care that adding a new chunk of credit doesn't wrap to zero. */
+ max_credit = vif->remaining_credit + vif->credit_bytes;
+ if (max_credit < vif->remaining_credit)
+ max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
+
+ vif->remaining_credit = min(max_credit, max_burst);
+}
+
+static void tx_credit_callback(unsigned long data)
+{
+ struct xenvif *vif = (struct xenvif *)data;
+ tx_add_credit(vif);
+ xen_netbk_check_rx_xenvif(vif);
+}
+
+static void netbk_tx_err(struct xenvif *vif,
+ struct xen_netif_tx_request *txp, RING_IDX end)
+{
+ RING_IDX cons = vif->tx.req_cons;
+
+ do {
+ make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
+ if (cons == end)
+ break;
+ txp = RING_GET_REQUEST(&vif->tx, cons++);
+ } while (1);
+ vif->tx.req_cons = cons;
+ xen_netbk_check_rx_xenvif(vif);
+ xenvif_put(vif);
+}
+
+static void netbk_fatal_tx_err(struct xenvif *vif)
+{
+ netdev_err(vif->dev, "fatal error; disabling device\n");
+ xenvif_carrier_off(vif);
+ xenvif_put(vif);
+}
+
+static int netbk_count_requests(struct xenvif *vif,
+ struct xen_netif_tx_request *first,
+ RING_IDX first_idx,
+ struct xen_netif_tx_request *txp,
+ int work_to_do)
+{
+ RING_IDX cons = vif->tx.req_cons;
+ int slots = 0;
+ int drop_err = 0;
+
+ if (!(first->flags & XEN_NETTXF_more_data))
+ return 0;
+
+ do {
+ if (slots >= work_to_do) {
+ netdev_err(vif->dev,
+ "Asked for %d slots but exceeds this limit\n",
+ work_to_do);
+ netbk_fatal_tx_err(vif);
+ return -ENODATA;
+ }
+
+ /* This guest is really using too many slots and
+ * considered malicious.
+ */
+ if (unlikely(slots >= max_skb_slots)) {
+ netdev_err(vif->dev,
+ "Malicious frontend using %d slots, threshold %u\n",
+ slots, max_skb_slots);
+ netbk_fatal_tx_err(vif);
+ return -E2BIG;
+ }
+
+ /* Xen network protocol had implicit dependency on
+ * MAX_SKB_FRAGS. XEN_NETIF_NR_SLOTS_MIN is set to the
+ * historical MAX_SKB_FRAGS value 18 to honor the same
+ * behavior as before. Any packet using more than 18
+ * slots but less than max_skb_slots slots is dropped
+ */
+ if (!drop_err && slots >= XEN_NETIF_NR_SLOTS_MIN) {
+ if (net_ratelimit())
+ netdev_dbg(vif->dev,
+ "Too many slots (%d) exceeding limit (%d), dropping packet\n",
+ slots, XEN_NETIF_NR_SLOTS_MIN);
+ drop_err = -E2BIG;
+ }
+
+ memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots),
+ sizeof(*txp));
+
+ /* If the guest submitted a frame >= 64 KiB then
+ * first->size overflowed and following slots will
+ * appear to be larger than the frame.
+ *
+ * This cannot be fatal error as there are buggy
+ * frontends that do this.
+ *
+ * Consume all slots and drop the packet.
+ */
+ if (!drop_err && txp->size > first->size) {
+ if (net_ratelimit())
+ netdev_dbg(vif->dev,
+ "Invalid tx request, slot size %u > remaining size %u\n",
+ txp->size, first->size);
+ drop_err = -EIO;
+ }
+
+ first->size -= txp->size;
+ slots++;
+
+ if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
+ netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
+ txp->offset, txp->size);
+ netbk_fatal_tx_err(vif);
+ return -EINVAL;
+ }
+ } while ((txp++)->flags & XEN_NETTXF_more_data);
+
+ if (drop_err) {
+ netbk_tx_err(vif, first, first_idx + slots);
+ return drop_err;
+ }
+
+ return slots;
+}
+
+static struct page *xen_netbk_alloc_page(struct xen_netbk *netbk,
+ u16 pending_idx)
+{
+ struct page *page;
+ page = alloc_page(GFP_KERNEL|__GFP_COLD);
+ if (!page)
+ return NULL;
+ set_page_ext(page, netbk, pending_idx);
+ netbk->mmap_pages[pending_idx] = page;
+ return page;
+}
+
+static struct gnttab_copy *xen_netbk_get_requests(struct xen_netbk *netbk,
+ struct xenvif *vif,
+ struct sk_buff *skb,
+ struct xen_netif_tx_request *txp,
+ struct gnttab_copy *gop)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ skb_frag_t *frags = shinfo->frags;
+ u16 pending_idx = *((u16 *)skb->data);
+ u16 head_idx = 0;
+ int slot, start;
+ struct page *page;
+ pending_ring_idx_t index, start_idx = 0;
+ uint16_t dst_offset;
+ unsigned int nr_slots;
+ struct pending_tx_info *first = NULL;
+
+ /* At this point shinfo->nr_frags is in fact the number of
+ * slots, which can be as large as XEN_NETIF_NR_SLOTS_MIN.
+ */
+ nr_slots = shinfo->nr_frags;
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
+
+ /* Coalesce tx requests, at this point the packet passed in
+ * should be <= 64K. Any packets larger than 64K have been
+ * handled in netbk_count_requests().
+ */
+ for (shinfo->nr_frags = slot = start; slot < nr_slots;
+ shinfo->nr_frags++) {
+ struct pending_tx_info *pending_tx_info =
+ netbk->pending_tx_info;
+
+ page = alloc_page(GFP_KERNEL|__GFP_COLD);
+ if (!page)
+ goto err;
+
+ dst_offset = 0;
+ first = NULL;
+ while (dst_offset < PAGE_SIZE && slot < nr_slots) {
+ gop->flags = GNTCOPY_source_gref;
+
+ gop->source.u.ref = txp->gref;
+ gop->source.domid = vif->domid;
+ gop->source.offset = txp->offset;
+
+ gop->dest.domid = DOMID_SELF;
+
+ gop->dest.offset = dst_offset;
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+
+ if (dst_offset + txp->size > PAGE_SIZE) {
+ /* This page can only merge a portion
+ * of tx request. Do not increment any
+ * pointer / counter here. The txp
+ * will be dealt with in future
+ * rounds, eventually hitting the
+ * `else` branch.
+ */
+ gop->len = PAGE_SIZE - dst_offset;
+ txp->offset += gop->len;
+ txp->size -= gop->len;
+ dst_offset += gop->len; /* quit loop */
+ } else {
+ /* This tx request can be merged in the page */
+ gop->len = txp->size;
+ dst_offset += gop->len;
+
+ index = pending_index(netbk->pending_cons++);
+
+ pending_idx = netbk->pending_ring[index];
+
+ memcpy(&pending_tx_info[pending_idx].req, txp,
+ sizeof(*txp));
+ xenvif_get(vif);
+
+ pending_tx_info[pending_idx].vif = vif;
+
+ /* Poison these fields, corresponding
+ * fields for head tx req will be set
+ * to correct values after the loop.
+ */
+ netbk->mmap_pages[pending_idx] = (void *)(~0UL);
+ pending_tx_info[pending_idx].head =
+ INVALID_PENDING_RING_IDX;
+
+ if (!first) {
+ first = &pending_tx_info[pending_idx];
+ start_idx = index;
+ head_idx = pending_idx;
+ }
+
+ txp++;
+ slot++;
+ }
+
+ gop++;
+ }
+
+ first->req.offset = 0;
+ first->req.size = dst_offset;
+ first->head = start_idx;
+ set_page_ext(page, netbk, head_idx);
+ netbk->mmap_pages[head_idx] = page;
+ frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx);
+ }
+
+ BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS);
+
+ return gop;
+err:
+ /* Unwind, freeing all pages and sending error responses. */
+ while (shinfo->nr_frags-- > start) {
+ xen_netbk_idx_release(netbk,
+ frag_get_pending_idx(&frags[shinfo->nr_frags]),
+ XEN_NETIF_RSP_ERROR);
+ }
+ /* The head too, if necessary. */
+ if (start)
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
+
+ return NULL;
+}
+
+static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
+ struct sk_buff *skb,
+ struct gnttab_copy **gopp)
+{
+ struct gnttab_copy *gop = *gopp;
+ u16 pending_idx = *((u16 *)skb->data);
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ struct pending_tx_info *tx_info;
+ int nr_frags = shinfo->nr_frags;
+ int i, err, start;
+ u16 peek; /* peek into next tx request */
+
+ /* Check status of header. */
+ err = gop->status;
+ if (unlikely(err))
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
+
+ /* Skip first skb fragment if it is on same page as header fragment. */
+ start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
+
+ for (i = start; i < nr_frags; i++) {
+ int j, newerr;
+ pending_ring_idx_t head;
+
+ pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
+ tx_info = &netbk->pending_tx_info[pending_idx];
+ head = tx_info->head;
+
+ /* Check error status: if okay then remember grant handle. */
+ do {
+ newerr = (++gop)->status;
+ if (newerr)
+ break;
+ peek = netbk->pending_ring[pending_index(++head)];
+ } while (!pending_tx_is_head(netbk, peek));
+
+ if (likely(!newerr)) {
+ /* Had a previous error? Invalidate this fragment. */
+ if (unlikely(err))
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
+ continue;
+ }
+
+ /* Error on this fragment: respond to client with an error. */
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
+
+ /* Not the first error? Preceding frags already invalidated. */
+ if (err)
+ continue;
+
+ /* First error: invalidate header and preceding fragments. */
+ pending_idx = *((u16 *)skb->data);
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
+ for (j = start; j < i; j++) {
+ pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
+ }
+
+ /* Remember the error: invalidate all subsequent fragments. */
+ err = newerr;
+ }
+
+ *gopp = gop + 1;
+ return err;
+}
+
+static void xen_netbk_fill_frags(struct xen_netbk *netbk, struct sk_buff *skb)
+{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
+ int i;
+
+ for (i = 0; i < nr_frags; i++) {
+ skb_frag_t *frag = shinfo->frags + i;
+ struct xen_netif_tx_request *txp;
+ struct page *page;
+ u16 pending_idx;
+
+ pending_idx = frag_get_pending_idx(frag);
+
+ txp = &netbk->pending_tx_info[pending_idx].req;
+ page = virt_to_page(idx_to_kaddr(netbk, pending_idx));
+ __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
+ skb->len += txp->size;
+ skb->data_len += txp->size;
+ skb->truesize += txp->size;
+
+ /* Take an extra reference to offset xen_netbk_idx_release */
+ get_page(netbk->mmap_pages[pending_idx]);
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
+ }
+}
+
+static int xen_netbk_get_extras(struct xenvif *vif,
+ struct xen_netif_extra_info *extras,
+ int work_to_do)
+{
+ struct xen_netif_extra_info extra;
+ RING_IDX cons = vif->tx.req_cons;
+
+ do {
+ if (unlikely(work_to_do-- <= 0)) {
+ netdev_err(vif->dev, "Missing extra info\n");
+ netbk_fatal_tx_err(vif);
+ return -EBADR;
+ }
+
+ memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
+ sizeof(extra));
+ if (unlikely(!extra.type ||
+ extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
+ vif->tx.req_cons = ++cons;
+ netdev_err(vif->dev,
+ "Invalid extra type: %d\n", extra.type);
+ netbk_fatal_tx_err(vif);
+ return -EINVAL;
+ }
+
+ memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
+ vif->tx.req_cons = ++cons;
+ } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
+
+ return work_to_do;
+}
+
+static int netbk_set_skb_gso(struct xenvif *vif,
+ struct sk_buff *skb,
+ struct xen_netif_extra_info *gso)
+{
+ if (!gso->u.gso.size) {
+ netdev_err(vif->dev, "GSO size must not be zero.\n");
+ netbk_fatal_tx_err(vif);
+ return -EINVAL;
+ }
+
+ /* Currently only TCPv4 S.O. is supported. */
+ if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
+ netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
+ netbk_fatal_tx_err(vif);
+ 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 int checksum_setup(struct xenvif *vif, 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)) {
+ vif->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())
+ netdev_err(vif->dev,
+ "Attempting to checksum a non-TCP/UDP packet, dropping a protocol %d packet\n",
+ iph->protocol);
+ goto out;
+ }
+
+ if ((th + skb->csum_offset + 2) > skb_tail_pointer(skb))
+ goto out;
+
+ err = 0;
+
+out:
+ return err;
+}
+
+static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
+{
+ u64 now = get_jiffies_64();
+ u64 next_credit = vif->credit_window_start +
+ msecs_to_jiffies(vif->credit_usec / 1000);
+
+ /* Timer could already be pending in rare cases. */
+ if (timer_pending(&vif->credit_timeout))
+ return true;
+
+ /* Passed the point where we can replenish credit? */
+ if (time_after_eq64(now, next_credit)) {
+ vif->credit_window_start = now;
+ tx_add_credit(vif);
+ }
+
+ /* Still too big to send right now? Set a callback. */
+ if (size > vif->remaining_credit) {
+ vif->credit_timeout.data =
+ (unsigned long)vif;
+ vif->credit_timeout.function =
+ tx_credit_callback;
+ mod_timer(&vif->credit_timeout,
+ next_credit);
+ vif->credit_window_start = next_credit;
+
+ return true;
+ }
+
+ return false;
+}
+
+static unsigned xen_netbk_tx_build_gops(struct xen_netbk *netbk)
+{
+ struct gnttab_copy *gop = netbk->tx_copy_ops, *request_gop;
+ struct sk_buff *skb;
+ int ret;
+
+ while ((nr_pending_reqs(netbk) + XEN_NETIF_NR_SLOTS_MIN
+ < MAX_PENDING_REQS) &&
+ !list_empty(&netbk->net_schedule_list)) {
+ struct xenvif *vif;
+ struct xen_netif_tx_request txreq;
+ struct xen_netif_tx_request txfrags[max_skb_slots];
+ struct page *page;
+ struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
+ u16 pending_idx;
+ RING_IDX idx;
+ int work_to_do;
+ unsigned int data_len;
+ pending_ring_idx_t index;
+
+ /* Get a netif from the list with work to do. */
+ vif = poll_net_schedule_list(netbk);
+ /* This can sometimes happen because the test of
+ * list_empty(net_schedule_list) at the top of the
+ * loop is unlocked. Just go back and have another
+ * look.
+ */
+ if (!vif)
+ continue;
+
+ if (vif->tx.sring->req_prod - vif->tx.req_cons >
+ XEN_NETIF_TX_RING_SIZE) {
+ netdev_err(vif->dev,
+ "Impossible number of requests. "
+ "req_prod %d, req_cons %d, size %ld\n",
+ vif->tx.sring->req_prod, vif->tx.req_cons,
+ XEN_NETIF_TX_RING_SIZE);
+ netbk_fatal_tx_err(vif);
+ continue;
+ }
+
+ RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, work_to_do);
+ if (!work_to_do) {
+ xenvif_put(vif);
+ continue;
+ }
+
+ idx = vif->tx.req_cons;
+ rmb(); /* Ensure that we see the request before we copy it. */
+ memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
+
+ /* Credit-based scheduling. */
+ if (txreq.size > vif->remaining_credit &&
+ tx_credit_exceeded(vif, txreq.size)) {
+ xenvif_put(vif);
+ continue;
+ }
+
+ vif->remaining_credit -= txreq.size;
+
+ work_to_do--;
+ vif->tx.req_cons = ++idx;
+
+ memset(extras, 0, sizeof(extras));
+ if (txreq.flags & XEN_NETTXF_extra_info) {
+ work_to_do = xen_netbk_get_extras(vif, extras,
+ work_to_do);
+ idx = vif->tx.req_cons;
+ if (unlikely(work_to_do < 0))
+ continue;
+ }
+
+ ret = netbk_count_requests(vif, &txreq, idx,
+ txfrags, work_to_do);
+ if (unlikely(ret < 0))
+ continue;
+
+ idx += ret;
+
+ if (unlikely(txreq.size < ETH_HLEN)) {
+ netdev_dbg(vif->dev,
+ "Bad packet size: %d\n", txreq.size);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+
+ /* No crossing a page as the payload mustn't fragment. */
+ if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
+ netdev_err(vif->dev,
+ "txreq.offset: %x, size: %u, end: %lu\n",
+ txreq.offset, txreq.size,
+ (txreq.offset&~PAGE_MASK) + txreq.size);
+ netbk_fatal_tx_err(vif);
+ continue;
+ }
+
+ index = pending_index(netbk->pending_cons);
+ pending_idx = netbk->pending_ring[index];
+
+ data_len = (txreq.size > PKT_PROT_LEN &&
+ ret < XEN_NETIF_NR_SLOTS_MIN) ?
+ PKT_PROT_LEN : txreq.size;
+
+ skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(skb == NULL)) {
+ netdev_dbg(vif->dev,
+ "Can't allocate a skb in start_xmit.\n");
+ netbk_tx_err(vif, &txreq, idx);
+ break;
+ }
+
+ /* Packets passed to netif_rx() must have some headroom. */
+ skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
+
+ if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
+ struct xen_netif_extra_info *gso;
+ gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
+
+ if (netbk_set_skb_gso(vif, skb, gso)) {
+ /* Failure in netbk_set_skb_gso is fatal. */
+ kfree_skb(skb);
+ continue;
+ }
+ }
+
+ /* XXX could copy straight to head */
+ page = xen_netbk_alloc_page(netbk, pending_idx);
+ if (!page) {
+ kfree_skb(skb);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+
+ gop->source.u.ref = txreq.gref;
+ gop->source.domid = vif->domid;
+ gop->source.offset = txreq.offset;
+
+ gop->dest.u.gmfn = virt_to_mfn(page_address(page));
+ gop->dest.domid = DOMID_SELF;
+ gop->dest.offset = txreq.offset;
+
+ gop->len = txreq.size;
+ gop->flags = GNTCOPY_source_gref;
+
+ gop++;
+
+ memcpy(&netbk->pending_tx_info[pending_idx].req,
+ &txreq, sizeof(txreq));
+ netbk->pending_tx_info[pending_idx].vif = vif;
+ netbk->pending_tx_info[pending_idx].head = index;
+ *((u16 *)skb->data) = pending_idx;
+
+ __skb_put(skb, data_len);
+
+ skb_shinfo(skb)->nr_frags = ret;
+ if (data_len < txreq.size) {
+ skb_shinfo(skb)->nr_frags++;
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ pending_idx);
+ } else {
+ frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
+ INVALID_PENDING_IDX);
+ }
+
+ __skb_queue_tail(&netbk->tx_queue, skb);
+
+ netbk->pending_cons++;
+
+ request_gop = xen_netbk_get_requests(netbk, vif,
+ skb, txfrags, gop);
+ if (request_gop == NULL) {
+ kfree_skb(skb);
+ netbk_tx_err(vif, &txreq, idx);
+ continue;
+ }
+ gop = request_gop;
+
+ vif->tx.req_cons = idx;
+ xen_netbk_check_rx_xenvif(vif);
+
+ if ((gop-netbk->tx_copy_ops) >= ARRAY_SIZE(netbk->tx_copy_ops))
+ break;
+ }
+
+ return gop - netbk->tx_copy_ops;
+}
+
+static void xen_netbk_tx_submit(struct xen_netbk *netbk)
+{
+ struct gnttab_copy *gop = netbk->tx_copy_ops;
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue(&netbk->tx_queue)) != NULL) {
+ struct xen_netif_tx_request *txp;
+ struct xenvif *vif;
+ u16 pending_idx;
+ unsigned data_len;
+
+ pending_idx = *((u16 *)skb->data);
+ vif = netbk->pending_tx_info[pending_idx].vif;
+ txp = &netbk->pending_tx_info[pending_idx].req;
+
+ /* Check the remap error code. */
+ if (unlikely(xen_netbk_tx_check_gop(netbk, skb, &gop))) {
+ netdev_dbg(vif->dev, "netback grant failed.\n");
+ skb_shinfo(skb)->nr_frags = 0;
+ kfree_skb(skb);
+ continue;
+ }
+
+ data_len = skb->len;
+ memcpy(skb->data,
+ (void *)(idx_to_kaddr(netbk, pending_idx)|txp->offset),
+ data_len);
+ if (data_len < txp->size) {
+ /* Append the packet payload as a fragment. */
+ txp->offset += data_len;
+ txp->size -= data_len;
+ } else {
+ /* Schedule a response immediately. */
+ xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
+ }
+
+ if (txp->flags & XEN_NETTXF_csum_blank)
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ else if (txp->flags & XEN_NETTXF_data_validated)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ xen_netbk_fill_frags(netbk, skb);
+
+ /*
+ * If the initial fragment was < PKT_PROT_LEN then
+ * pull through some bytes from the other fragments to
+ * increase the linear region to PKT_PROT_LEN bytes.
+ */
+ if (skb_headlen(skb) < PKT_PROT_LEN && skb_is_nonlinear(skb)) {
+ int target = min_t(int, skb->len, PKT_PROT_LEN);
+ __pskb_pull_tail(skb, target - skb_headlen(skb));
+ }
+
+ skb->dev = vif->dev;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+
+ if (checksum_setup(vif, skb)) {
+ netdev_dbg(vif->dev,
+ "Can't setup checksum in net_tx_action\n");
+ kfree_skb(skb);
+ continue;
+ }
+
+ vif->dev->stats.rx_bytes += skb->len;
+ vif->dev->stats.rx_packets++;
+
+ xenvif_receive_skb(vif, skb);
+ }
+}
+
+/* Called after netfront has transmitted */
+static void xen_netbk_tx_action(struct xen_netbk *netbk)
+{
+ unsigned nr_gops;
+ int ret;
+
+ nr_gops = xen_netbk_tx_build_gops(netbk);
+
+ if (nr_gops == 0)
+ return;
+ ret = HYPERVISOR_grant_table_op(GNTTABOP_copy,
+ netbk->tx_copy_ops, nr_gops);
+ BUG_ON(ret);
+
+ xen_netbk_tx_submit(netbk);
+
+}
+
+static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx,
+ u8 status)
+{
+ struct xenvif *vif;
+ struct pending_tx_info *pending_tx_info;
+ pending_ring_idx_t head;
+ u16 peek; /* peek into next tx request */
+
+ BUG_ON(netbk->mmap_pages[pending_idx] == (void *)(~0UL));
+
+ /* Already complete? */
+ if (netbk->mmap_pages[pending_idx] == NULL)
+ return;
+
+ pending_tx_info = &netbk->pending_tx_info[pending_idx];
+
+ vif = pending_tx_info->vif;
+ head = pending_tx_info->head;
+
+ BUG_ON(!pending_tx_is_head(netbk, head));
+ BUG_ON(netbk->pending_ring[pending_index(head)] != pending_idx);
+
+ do {
+ pending_ring_idx_t index;
+ pending_ring_idx_t idx = pending_index(head);
+ u16 info_idx = netbk->pending_ring[idx];
+
+ pending_tx_info = &netbk->pending_tx_info[info_idx];
+ make_tx_response(vif, &pending_tx_info->req, status);
+
+ /* Setting any number other than
+ * INVALID_PENDING_RING_IDX indicates this slot is
+ * starting a new packet / ending a previous packet.
+ */
+ pending_tx_info->head = 0;
+
+ index = pending_index(netbk->pending_prod++);
+ netbk->pending_ring[index] = netbk->pending_ring[info_idx];
+
+ xenvif_put(vif);
+
+ peek = netbk->pending_ring[pending_index(++head)];
+
+ } while (!pending_tx_is_head(netbk, peek));
+
+ netbk->mmap_pages[pending_idx]->mapping = 0;
+ put_page(netbk->mmap_pages[pending_idx]);
+ netbk->mmap_pages[pending_idx] = NULL;
+}
+
+
+static void make_tx_response(struct xenvif *vif,
+ struct xen_netif_tx_request *txp,
+ s8 st)
+{
+ RING_IDX i = vif->tx.rsp_prod_pvt;
+ struct xen_netif_tx_response *resp;
+ int notify;
+
+ resp = RING_GET_RESPONSE(&vif->tx, i);
+ resp->id = txp->id;
+ resp->status = st;
+
+ if (txp->flags & XEN_NETTXF_extra_info)
+ RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
+
+ vif->tx.rsp_prod_pvt = ++i;
+ RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
+ if (notify)
+ notify_remote_via_irq(vif->irq);
+}
+
+static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
+ u16 id,
+ s8 st,
+ u16 offset,
+ u16 size,
+ u16 flags)
+{
+ RING_IDX i = vif->rx.rsp_prod_pvt;
+ struct xen_netif_rx_response *resp;
+
+ resp = RING_GET_RESPONSE(&vif->rx, i);
+ resp->offset = offset;
+ resp->flags = flags;
+ resp->id = id;
+ resp->status = (s16)size;
+ if (st < 0)
+ resp->status = (s16)st;
+
+ vif->rx.rsp_prod_pvt = ++i;
+
+ return resp;
+}
+
+static inline int rx_work_todo(struct xen_netbk *netbk)
+{
+ return !skb_queue_empty(&netbk->rx_queue);
+}
+
+static inline int tx_work_todo(struct xen_netbk *netbk)
+{
+
+ if ((nr_pending_reqs(netbk) + XEN_NETIF_NR_SLOTS_MIN
+ < MAX_PENDING_REQS) &&
+ !list_empty(&netbk->net_schedule_list))
+ return 1;
+
+ return 0;
+}
+
+static int xen_netbk_kthread(void *data)
+{
+ struct xen_netbk *netbk = data;
+ while (!kthread_should_stop()) {
+ wait_event_interruptible(netbk->wq,
+ rx_work_todo(netbk) ||
+ tx_work_todo(netbk) ||
+ kthread_should_stop());
+ cond_resched();
+
+ if (kthread_should_stop())
+ break;
+
+ if (rx_work_todo(netbk))
+ xen_netbk_rx_action(netbk);
+
+ if (tx_work_todo(netbk))
+ xen_netbk_tx_action(netbk);
+ }
+
+ return 0;
+}
+
+void xen_netbk_unmap_frontend_rings(struct xenvif *vif)
+{
+ if (vif->tx.sring)
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
+ vif->tx.sring);
+ if (vif->rx.sring)
+ xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
+ vif->rx.sring);
+}
+
+int xen_netbk_map_frontend_rings(struct xenvif *vif,
+ grant_ref_t tx_ring_ref,
+ grant_ref_t rx_ring_ref)
+{
+ void *addr;
+ struct xen_netif_tx_sring *txs;
+ struct xen_netif_rx_sring *rxs;
+
+ int err = -ENOMEM;
+
+ err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
+ tx_ring_ref, &addr);
+ if (err)
+ goto err;
+
+ txs = (struct xen_netif_tx_sring *)addr;
+ BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
+
+ err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
+ rx_ring_ref, &addr);
+ if (err)
+ goto err;
+
+ rxs = (struct xen_netif_rx_sring *)addr;
+ BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
+
+ vif->rx_req_cons_peek = 0;
+
+ return 0;
+
+err:
+ xen_netbk_unmap_frontend_rings(vif);
+ return err;
+}
+
+static int __init netback_init(void)
+{
+ int i;
+ int rc = 0;
+ int group;
+
+ if (!xen_domain())
+ return -ENODEV;
+
+ if (max_skb_slots < XEN_NETIF_NR_SLOTS_MIN) {
+ printk(KERN_INFO
+ "xen-netback: max_skb_slots too small (%d), bump it to XEN_NETIF_NR_SLOTS_MIN (%d)\n",
+ max_skb_slots, XEN_NETIF_NR_SLOTS_MIN);
+ max_skb_slots = XEN_NETIF_NR_SLOTS_MIN;
+ }
+
+ xen_netbk_group_nr = num_online_cpus();
+ xen_netbk = vzalloc(sizeof(struct xen_netbk) * xen_netbk_group_nr);
+ if (!xen_netbk)
+ return -ENOMEM;
+
+ for (group = 0; group < xen_netbk_group_nr; group++) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ skb_queue_head_init(&netbk->rx_queue);
+ skb_queue_head_init(&netbk->tx_queue);
+
+ init_timer(&netbk->net_timer);
+ netbk->net_timer.data = (unsigned long)netbk;
+ netbk->net_timer.function = xen_netbk_alarm;
+
+ netbk->pending_cons = 0;
+ netbk->pending_prod = MAX_PENDING_REQS;
+ for (i = 0; i < MAX_PENDING_REQS; i++)
+ netbk->pending_ring[i] = i;
+
+ init_waitqueue_head(&netbk->wq);
+ netbk->task = kthread_create(xen_netbk_kthread,
+ (void *)netbk,
+ "netback/%u", group);
+
+ if (IS_ERR(netbk->task)) {
+ printk(KERN_ALERT "kthread_create() fails at netback\n");
+ del_timer(&netbk->net_timer);
+ rc = PTR_ERR(netbk->task);
+ goto failed_init;
+ }
+
+ kthread_bind(netbk->task, group);
+
+ INIT_LIST_HEAD(&netbk->net_schedule_list);
+
+ spin_lock_init(&netbk->net_schedule_list_lock);
+
+ atomic_set(&netbk->netfront_count, 0);
+
+ wake_up_process(netbk->task);
+ }
+
+ rc = xenvif_xenbus_init();
+ if (rc)
+ goto failed_init;
+
+ return 0;
+
+failed_init:
+ while (--group >= 0) {
+ struct xen_netbk *netbk = &xen_netbk[group];
+ for (i = 0; i < MAX_PENDING_REQS; i++) {
+ if (netbk->mmap_pages[i])
+ __free_page(netbk->mmap_pages[i]);
+ }
+ del_timer(&netbk->net_timer);
+ kthread_stop(netbk->task);
+ }
+ vfree(xen_netbk);
+ return rc;
+
+}
+
+module_init(netback_init);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("xen-backend:vif");