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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 256
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
103 /* Unique identifier for this interface. */
107 /* Use NAPI for guest TX */
108 struct napi_struct napi;
109 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
111 /* Only used when feature-split-event-channels = 1 */
112 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
113 struct xen_netif_tx_back_ring tx;
114 struct sk_buff_head tx_queue;
115 struct page *mmap_pages[MAX_PENDING_REQS];
116 pending_ring_idx_t pending_prod;
117 pending_ring_idx_t pending_cons;
118 u16 pending_ring[MAX_PENDING_REQS];
119 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
120 grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
122 struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
123 struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
124 /* passed to gnttab_[un]map_refs with pages under (un)mapping */
125 struct page *pages_to_map[MAX_PENDING_REQS];
126 struct page *pages_to_unmap[MAX_PENDING_REQS];
128 /* This prevents zerocopy callbacks to race over dealloc_ring */
129 spinlock_t callback_lock;
130 /* This prevents dealloc thread and NAPI instance to race over response
131 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
132 * it only protect response creation
134 spinlock_t response_lock;
135 pending_ring_idx_t dealloc_prod;
136 pending_ring_idx_t dealloc_cons;
137 u16 dealloc_ring[MAX_PENDING_REQS];
138 struct task_struct *dealloc_task;
139 wait_queue_head_t dealloc_wq;
141 /* Use kthread for guest RX */
142 struct task_struct *task;
143 wait_queue_head_t wq;
144 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
146 /* Only used when feature-split-event-channels = 1 */
147 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
148 struct xen_netif_rx_back_ring rx;
149 struct sk_buff_head rx_queue;
150 RING_IDX rx_last_skb_slots;
152 /* This array is allocated seperately as it is large */
153 struct gnttab_copy *grant_copy_op;
155 /* We create one meta structure per ring request we consume, so
156 * the maximum number is the same as the ring size.
158 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
162 /* Frontend feature information. */
170 /* Internal feature information. */
171 u8 can_queue:1; /* can queue packets for receiver? */
173 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
174 unsigned long credit_bytes;
175 unsigned long credit_usec;
176 unsigned long remaining_credit;
177 struct timer_list credit_timeout;
178 u64 credit_window_start;
181 unsigned long rx_gso_checksum_fixup;
182 unsigned long tx_zerocopy_sent;
183 unsigned long tx_zerocopy_success;
184 unsigned long tx_zerocopy_fail;
185 unsigned long tx_frag_overflow;
187 /* Miscellaneous private stuff. */
188 struct net_device *dev;
191 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
193 return to_xenbus_device(vif->dev->dev.parent);
196 struct xenvif *xenvif_alloc(struct device *parent,
198 unsigned int handle);
200 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
201 unsigned long rx_ring_ref, unsigned int tx_evtchn,
202 unsigned int rx_evtchn);
203 void xenvif_disconnect(struct xenvif *vif);
204 void xenvif_free(struct xenvif *vif);
206 int xenvif_xenbus_init(void);
207 void xenvif_xenbus_fini(void);
209 int xenvif_schedulable(struct xenvif *vif);
211 int xenvif_must_stop_queue(struct xenvif *vif);
213 /* (Un)Map communication rings. */
214 void xenvif_unmap_frontend_rings(struct xenvif *vif);
215 int xenvif_map_frontend_rings(struct xenvif *vif,
216 grant_ref_t tx_ring_ref,
217 grant_ref_t rx_ring_ref);
219 /* Check for SKBs from frontend and schedule backend processing */
220 void xenvif_check_rx_xenvif(struct xenvif *vif);
222 /* Prevent the device from generating any further traffic. */
223 void xenvif_carrier_off(struct xenvif *vif);
225 int xenvif_tx_action(struct xenvif *vif, int budget);
227 int xenvif_kthread_guest_rx(void *data);
228 void xenvif_kick_thread(struct xenvif *vif);
230 int xenvif_dealloc_kthread(void *data);
232 /* Determine whether the needed number of slots (req) are available,
233 * and set req_event if not.
235 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed);
237 void xenvif_stop_queue(struct xenvif *vif);
239 /* Callback from stack when TX packet can be released */
240 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
242 /* Unmap a pending page and release it back to the guest */
243 void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx);
245 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
247 return MAX_PENDING_REQS -
248 vif->pending_prod + vif->pending_cons;
251 static inline bool xenvif_tx_pending_slots_available(struct xenvif *vif)
253 return nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
257 /* Callback from stack when TX packet can be released */
258 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
260 extern bool separate_tx_rx_irq;
262 #endif /* __XEN_NETBACK__COMMON_H__ */