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27 #ifndef __XEN_NETBACK__COMMON_H__
28 #define __XEN_NETBACK__COMMON_H__
30 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
32 #include <linux/module.h>
33 #include <linux/interrupt.h>
34 #include <linux/slab.h>
38 #include <linux/netdevice.h>
39 #include <linux/etherdevice.h>
40 #include <linux/wait.h>
41 #include <linux/sched.h>
43 #include <xen/interface/io/netif.h>
44 #include <xen/interface/grant_table.h>
45 #include <xen/grant_table.h>
46 #include <xen/xenbus.h>
48 typedef unsigned int pending_ring_idx_t;
49 #define INVALID_PENDING_RING_IDX (~0U)
51 struct pending_tx_info {
52 struct xen_netif_tx_request req; /* tx request */
53 /* Callback data for released SKBs. The callback is always
54 * xenvif_zerocopy_callback, desc contains the pending_idx, which is
55 * also an index in pending_tx_info array. It is initialized in
56 * xenvif_alloc and it never changes.
57 * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
58 * callback_struct in this array of struct pending_tx_info's, then ctx
59 * to the next, or NULL if there is no more slot for this skb.
60 * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
63 struct ubuf_info callback_struct;
66 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
67 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
69 struct xenvif_rx_meta {
76 #define GSO_BIT(type) \
77 (1 << XEN_NETIF_GSO_TYPE_ ## type)
79 /* Discriminate from any valid pending_idx value. */
80 #define INVALID_PENDING_IDX 0xFFFF
82 #define MAX_BUFFER_OFFSET PAGE_SIZE
84 #define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
86 /* It's possible for an skb to have a maximal number of frags
87 * but still be less than MAX_BUFFER_OFFSET in size. Thus the
88 * worst-case number of copy operations is MAX_SKB_FRAGS per
91 #define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
93 #define NETBACK_INVALID_HANDLE -1
95 /* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
96 * the maximum slots a valid packet can use. Now this value is defined
97 * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
100 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
102 /* Queue name is interface name with "-qNNN" appended */
103 #define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
105 /* IRQ name is queue name with "-tx" or "-rx" appended */
106 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
110 struct xenvif_stats {
111 /* Stats fields to be updated per-queue.
112 * A subset of struct net_device_stats that contains only the
113 * fields that are updated in netback.c for each queue.
115 unsigned int rx_bytes;
116 unsigned int rx_packets;
117 unsigned int tx_bytes;
118 unsigned int tx_packets;
120 /* Additional stats used by xenvif */
121 unsigned long rx_gso_checksum_fixup;
122 unsigned long tx_zerocopy_sent;
123 unsigned long tx_zerocopy_success;
124 unsigned long tx_zerocopy_fail;
125 unsigned long tx_frag_overflow;
128 struct xenvif_queue { /* Per-queue data for xenvif */
129 unsigned int id; /* Queue ID, 0-based */
130 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
131 struct xenvif *vif; /* Parent VIF */
133 /* Use NAPI for guest TX */
134 struct napi_struct napi;
135 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
137 /* Only used when feature-split-event-channels = 1 */
138 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
139 struct xen_netif_tx_back_ring tx;
140 struct sk_buff_head tx_queue;
141 struct page *mmap_pages[MAX_PENDING_REQS];
142 pending_ring_idx_t pending_prod;
143 pending_ring_idx_t pending_cons;
144 u16 pending_ring[MAX_PENDING_REQS];
145 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
146 grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
148 struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
149 struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
150 struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
151 /* passed to gnttab_[un]map_refs with pages under (un)mapping */
152 struct page *pages_to_map[MAX_PENDING_REQS];
153 struct page *pages_to_unmap[MAX_PENDING_REQS];
155 /* This prevents zerocopy callbacks to race over dealloc_ring */
156 spinlock_t callback_lock;
157 /* This prevents dealloc thread and NAPI instance to race over response
158 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
159 * it only protect response creation
161 spinlock_t response_lock;
162 pending_ring_idx_t dealloc_prod;
163 pending_ring_idx_t dealloc_cons;
164 u16 dealloc_ring[MAX_PENDING_REQS];
165 struct task_struct *dealloc_task;
166 wait_queue_head_t dealloc_wq;
168 /* Use kthread for guest RX */
169 struct task_struct *task;
170 wait_queue_head_t wq;
171 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
173 /* Only used when feature-split-event-channels = 1 */
174 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
175 struct xen_netif_rx_back_ring rx;
176 struct sk_buff_head rx_queue;
177 RING_IDX rx_last_skb_slots;
180 struct timer_list wake_queue;
182 struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
184 /* We create one meta structure per ring request we consume, so
185 * the maximum number is the same as the ring size.
187 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
189 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
190 unsigned long credit_bytes;
191 unsigned long credit_usec;
192 unsigned long remaining_credit;
193 struct timer_list credit_timeout;
194 u64 credit_window_start;
197 struct xenvif_stats stats;
201 /* Unique identifier for this interface. */
207 /* Frontend feature information. */
215 /* Internal feature information. */
216 u8 can_queue:1; /* can queue packets for receiver? */
218 /* Is this interface disabled? True when backend discovers
224 struct xenvif_queue *queues;
226 /* Miscellaneous private stuff. */
227 struct net_device *dev;
230 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
232 return to_xenbus_device(vif->dev->dev.parent);
235 struct xenvif *xenvif_alloc(struct device *parent,
237 unsigned int handle);
239 int xenvif_init_queue(struct xenvif_queue *queue);
240 void xenvif_deinit_queue(struct xenvif_queue *queue);
242 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
243 unsigned long rx_ring_ref, unsigned int tx_evtchn,
244 unsigned int rx_evtchn);
245 void xenvif_disconnect(struct xenvif *vif);
246 void xenvif_free(struct xenvif *vif);
248 int xenvif_xenbus_init(void);
249 void xenvif_xenbus_fini(void);
251 int xenvif_schedulable(struct xenvif *vif);
253 int xenvif_must_stop_queue(struct xenvif_queue *queue);
255 int xenvif_queue_stopped(struct xenvif_queue *queue);
256 void xenvif_wake_queue(struct xenvif_queue *queue);
258 /* (Un)Map communication rings. */
259 void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
260 int xenvif_map_frontend_rings(struct xenvif_queue *queue,
261 grant_ref_t tx_ring_ref,
262 grant_ref_t rx_ring_ref);
264 /* Check for SKBs from frontend and schedule backend processing */
265 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
267 /* Prevent the device from generating any further traffic. */
268 void xenvif_carrier_off(struct xenvif *vif);
270 int xenvif_tx_action(struct xenvif_queue *queue, int budget);
272 int xenvif_kthread_guest_rx(void *data);
273 void xenvif_kick_thread(struct xenvif_queue *queue);
275 int xenvif_dealloc_kthread(void *data);
277 /* Determine whether the needed number of slots (req) are available,
278 * and set req_event if not.
280 bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue, int needed);
282 void xenvif_carrier_on(struct xenvif *vif);
284 /* Callback from stack when TX packet can be released */
285 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
287 /* Unmap a pending page and release it back to the guest */
288 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
290 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
292 return MAX_PENDING_REQS -
293 queue->pending_prod + queue->pending_cons;
296 /* Callback from stack when TX packet can be released */
297 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
299 extern bool separate_tx_rx_irq;
301 extern unsigned int rx_drain_timeout_msecs;
302 extern unsigned int rx_drain_timeout_jiffies;
303 extern unsigned int xenvif_max_queues;
305 #endif /* __XEN_NETBACK__COMMON_H__ */