Initial import

1 files changed, 347 insertions, 0 deletions

diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
new file mode 100644
index 000000000..8a495b318
--- /dev/null
+++ b/drivers/net/xen-netback/common.h
@@ -0,0 +1,347 @@
+/*
+ * 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.
+ */
+
+#ifndef __XEN_NETBACK__COMMON_H__
+#define __XEN_NETBACK__COMMON_H__
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/io.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include <xen/interface/io/netif.h>
+#include <xen/interface/grant_table.h>
+#include <xen/grant_table.h>
+#include <xen/xenbus.h>
+#include <linux/debugfs.h>
+
+typedef unsigned int pending_ring_idx_t;
+#define INVALID_PENDING_RING_IDX (~0U)
+
+struct pending_tx_info {
+	struct xen_netif_tx_request req; /* tx request */
+	/* Callback data for released SKBs. The callback is always
+	 * xenvif_zerocopy_callback, desc contains the pending_idx, which is
+	 * also an index in pending_tx_info array. It is initialized in
+	 * xenvif_alloc and it never changes.
+	 * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
+	 * callback_struct in this array of struct pending_tx_info's, then ctx
+	 * to the next, or NULL if there is no more slot for this skb.
+	 * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
+	 * to this field.
+	 */
+	struct ubuf_info callback_struct;
+};
+
+#define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
+#define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
+
+struct xenvif_rx_meta {
+	int id;
+	int size;
+	int gso_type;
+	int gso_size;
+};
+
+#define GSO_BIT(type) \
+	(1 << XEN_NETIF_GSO_TYPE_ ## type)
+
+/* Discriminate from any valid pending_idx value. */
+#define INVALID_PENDING_IDX 0xFFFF
+
+#define MAX_BUFFER_OFFSET PAGE_SIZE
+
+#define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
+
+/* It's possible for an skb to have a maximal number of frags
+ * but still be less than MAX_BUFFER_OFFSET in size. Thus the
+ * worst-case number of copy operations is MAX_SKB_FRAGS per
+ * ring slot.
+ */
+#define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
+
+#define NETBACK_INVALID_HANDLE -1
+
+/* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
+ * the maximum slots a valid packet can use. Now this value is defined
+ * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
+ * all backend.
+ */
+#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
+
+/* Queue name is interface name with "-qNNN" appended */
+#define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
+
+/* IRQ name is queue name with "-tx" or "-rx" appended */
+#define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
+
+struct xenvif;
+
+struct xenvif_stats {
+	/* Stats fields to be updated per-queue.
+	 * A subset of struct net_device_stats that contains only the
+	 * fields that are updated in netback.c for each queue.
+	 */
+	unsigned int rx_bytes;
+	unsigned int rx_packets;
+	unsigned int tx_bytes;
+	unsigned int tx_packets;
+
+	/* Additional stats used by xenvif */
+	unsigned long rx_gso_checksum_fixup;
+	unsigned long tx_zerocopy_sent;
+	unsigned long tx_zerocopy_success;
+	unsigned long tx_zerocopy_fail;
+	unsigned long tx_frag_overflow;
+};
+
+struct xenvif_queue { /* Per-queue data for xenvif */
+	unsigned int id; /* Queue ID, 0-based */
+	char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
+	struct xenvif *vif; /* Parent VIF */
+
+	/* Use NAPI for guest TX */
+	struct napi_struct napi;
+	/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
+	unsigned int tx_irq;
+	/* Only used when feature-split-event-channels = 1 */
+	char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
+	struct xen_netif_tx_back_ring tx;
+	struct sk_buff_head tx_queue;
+	struct page *mmap_pages[MAX_PENDING_REQS];
+	pending_ring_idx_t pending_prod;
+	pending_ring_idx_t pending_cons;
+	u16 pending_ring[MAX_PENDING_REQS];
+	struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
+	grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
+
+	struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
+	struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
+	struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
+	/* passed to gnttab_[un]map_refs with pages under (un)mapping */
+	struct page *pages_to_map[MAX_PENDING_REQS];
+	struct page *pages_to_unmap[MAX_PENDING_REQS];
+
+	/* This prevents zerocopy callbacks  to race over dealloc_ring */
+	spinlock_t callback_lock;
+	/* This prevents dealloc thread and NAPI instance to race over response
+	 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
+	 * it only protect response creation
+	 */
+	spinlock_t response_lock;
+	pending_ring_idx_t dealloc_prod;
+	pending_ring_idx_t dealloc_cons;
+	u16 dealloc_ring[MAX_PENDING_REQS];
+	struct task_struct *dealloc_task;
+	wait_queue_head_t dealloc_wq;
+	atomic_t inflight_packets;
+
+	/* Use kthread for guest RX */
+	struct task_struct *task;
+	wait_queue_head_t wq;
+	/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
+	unsigned int rx_irq;
+	/* Only used when feature-split-event-channels = 1 */
+	char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
+	struct xen_netif_rx_back_ring rx;
+	struct sk_buff_head rx_queue;
+
+	unsigned int rx_queue_max;
+	unsigned int rx_queue_len;
+	unsigned long last_rx_time;
+	bool stalled;
+
+	struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
+
+	/* We create one meta structure per ring request we consume, so
+	 * the maximum number is the same as the ring size.
+	 */
+	struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
+
+	/* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
+	unsigned long   credit_bytes;
+	unsigned long   credit_usec;
+	unsigned long   remaining_credit;
+	struct timer_list credit_timeout;
+	u64 credit_window_start;
+
+	/* Statistics */
+	struct xenvif_stats stats;
+};
+
+/* Maximum number of Rx slots a to-guest packet may use, including the
+ * slot needed for GSO meta-data.
+ */
+#define XEN_NETBK_RX_SLOTS_MAX (MAX_SKB_FRAGS + 1)
+
+enum state_bit_shift {
+	/* This bit marks that the vif is connected */
+	VIF_STATUS_CONNECTED,
+};
+
+struct xenvif {
+	/* Unique identifier for this interface. */
+	domid_t          domid;
+	unsigned int     handle;
+
+	u8               fe_dev_addr[6];
+
+	/* Frontend feature information. */
+	int gso_mask;
+	int gso_prefix_mask;
+
+	u8 can_sg:1;
+	u8 ip_csum:1;
+	u8 ipv6_csum:1;
+
+	/* Is this interface disabled? True when backend discovers
+	 * frontend is rogue.
+	 */
+	bool disabled;
+	unsigned long status;
+	unsigned long drain_timeout;
+	unsigned long stall_timeout;
+
+	/* Queues */
+	struct xenvif_queue *queues;
+	unsigned int num_queues; /* active queues, resource allocated */
+	unsigned int stalled_queues;
+
+	struct xenbus_watch credit_watch;
+
+	spinlock_t lock;
+
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *xenvif_dbg_root;
+#endif
+
+	/* Miscellaneous private stuff. */
+	struct net_device *dev;
+};
+
+struct xenvif_rx_cb {
+	unsigned long expires;
+	int meta_slots_used;
+};
+
+#define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
+
+static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
+{
+	return to_xenbus_device(vif->dev->dev.parent);
+}
+
+void xenvif_tx_credit_callback(unsigned long data);
+
+struct xenvif *xenvif_alloc(struct device *parent,
+			    domid_t domid,
+			    unsigned int handle);
+
+int xenvif_init_queue(struct xenvif_queue *queue);
+void xenvif_deinit_queue(struct xenvif_queue *queue);
+
+int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
+		   unsigned long rx_ring_ref, unsigned int tx_evtchn,
+		   unsigned int rx_evtchn);
+void xenvif_disconnect(struct xenvif *vif);
+void xenvif_free(struct xenvif *vif);
+
+int xenvif_xenbus_init(void);
+void xenvif_xenbus_fini(void);
+
+int xenvif_schedulable(struct xenvif *vif);
+
+int xenvif_queue_stopped(struct xenvif_queue *queue);
+void xenvif_wake_queue(struct xenvif_queue *queue);
+
+/* (Un)Map communication rings. */
+void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
+int xenvif_map_frontend_rings(struct xenvif_queue *queue,
+			      grant_ref_t tx_ring_ref,
+			      grant_ref_t rx_ring_ref);
+
+/* Check for SKBs from frontend and schedule backend processing */
+void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
+
+/* Prevent the device from generating any further traffic. */
+void xenvif_carrier_off(struct xenvif *vif);
+
+int xenvif_tx_action(struct xenvif_queue *queue, int budget);
+
+int xenvif_kthread_guest_rx(void *data);
+void xenvif_kick_thread(struct xenvif_queue *queue);
+
+int xenvif_dealloc_kthread(void *data);
+
+void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
+
+/* Determine whether the needed number of slots (req) are available,
+ * and set req_event if not.
+ */
+bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed);
+
+void xenvif_carrier_on(struct xenvif *vif);
+
+/* Callback from stack when TX packet can be released */
+void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
+
+/* Unmap a pending page and release it back to the guest */
+void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
+
+static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
+{
+	return MAX_PENDING_REQS -
+		queue->pending_prod + queue->pending_cons;
+}
+
+/* Callback from stack when TX packet can be released */
+void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
+
+irqreturn_t xenvif_interrupt(int irq, void *dev_id);
+
+extern bool separate_tx_rx_irq;
+
+extern unsigned int rx_drain_timeout_msecs;
+extern unsigned int rx_stall_timeout_msecs;
+extern unsigned int xenvif_max_queues;
+
+#ifdef CONFIG_DEBUG_FS
+extern struct dentry *xen_netback_dbg_root;
+#endif
+
+void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
+				 struct sk_buff *skb);
+void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
+
+#endif /* __XEN_NETBACK__COMMON_H__ */