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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 /* For the head field in pending_tx_info: it is used to indicate
52 * whether this tx info is the head of one or more coalesced requests.
54 * When head != INVALID_PENDING_RING_IDX, it means the start of a new
55 * tx requests queue and the end of previous queue.
57 * An example sequence of head fields (I = INVALID_PENDING_RING_IDX):
59 * ...|0 I I I|5 I|9 I I I|...
60 * -->|<-INUSE----------------
62 * After consuming the first slot(s) we have:
64 * ...|V V V V|5 I|9 I I I|...
65 * -----FREE->|<-INUSE--------
67 * where V stands for "valid pending ring index". Any number other
68 * than INVALID_PENDING_RING_IDX is OK. These entries are considered
69 * free and can contain any number other than
70 * INVALID_PENDING_RING_IDX. In practice we use 0.
72 * The in use non-INVALID_PENDING_RING_IDX (say 0, 5 and 9 in the
73 * above example) number is the index into pending_tx_info and
76 struct pending_tx_info {
77 struct xen_netif_tx_request req; /* coalesced tx request */
78 pending_ring_idx_t head; /* head != INVALID_PENDING_RING_IDX
79 * if it is head of one or more tx
84 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
85 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
87 struct xenvif_rx_meta {
93 /* Discriminate from any valid pending_idx value. */
94 #define INVALID_PENDING_IDX 0xFFFF
96 #define MAX_BUFFER_OFFSET PAGE_SIZE
98 #define MAX_PENDING_REQS 256
101 /* Unique identifier for this interface. */
105 /* Use NAPI for guest TX */
106 struct napi_struct napi;
107 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
109 /* Only used when feature-split-event-channels = 1 */
110 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
111 struct xen_netif_tx_back_ring tx;
112 struct sk_buff_head tx_queue;
113 struct page *mmap_pages[MAX_PENDING_REQS];
114 pending_ring_idx_t pending_prod;
115 pending_ring_idx_t pending_cons;
116 u16 pending_ring[MAX_PENDING_REQS];
117 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
119 /* Coalescing tx requests before copying makes number of grant
120 * copy ops greater or equal to number of slots required. In
121 * worst case a tx request consumes 2 gnttab_copy.
123 struct gnttab_copy tx_copy_ops[2*MAX_PENDING_REQS];
126 /* Use kthread for guest RX */
127 struct task_struct *task;
128 wait_queue_head_t wq;
129 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
131 /* Only used when feature-split-event-channels = 1 */
132 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
133 struct xen_netif_rx_back_ring rx;
134 struct sk_buff_head rx_queue;
136 /* Allow xenvif_start_xmit() to peek ahead in the rx request
137 * ring. This is a prediction of what rx_req_cons will be
138 * once all queued skbs are put on the ring.
140 RING_IDX rx_req_cons_peek;
142 /* Given MAX_BUFFER_OFFSET of 4096 the worst case is that each
143 * head/fragment page uses 2 copy operations because it
144 * straddles two buffers in the frontend.
146 struct gnttab_copy grant_copy_op[2*XEN_NETIF_RX_RING_SIZE];
147 struct xenvif_rx_meta meta[2*XEN_NETIF_RX_RING_SIZE];
152 /* Frontend feature information. */
158 /* Internal feature information. */
159 u8 can_queue:1; /* can queue packets for receiver? */
161 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
162 unsigned long credit_bytes;
163 unsigned long credit_usec;
164 unsigned long remaining_credit;
165 struct timer_list credit_timeout;
168 unsigned long rx_gso_checksum_fixup;
170 /* Miscellaneous private stuff. */
171 struct net_device *dev;
174 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
176 return to_xenbus_device(vif->dev->dev.parent);
179 struct xenvif *xenvif_alloc(struct device *parent,
181 unsigned int handle);
183 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
184 unsigned long rx_ring_ref, unsigned int tx_evtchn,
185 unsigned int rx_evtchn);
186 void xenvif_disconnect(struct xenvif *vif);
187 void xenvif_free(struct xenvif *vif);
189 int xenvif_xenbus_init(void);
190 void xenvif_xenbus_fini(void);
192 int xenvif_schedulable(struct xenvif *vif);
194 int xenvif_rx_ring_full(struct xenvif *vif);
196 int xenvif_must_stop_queue(struct xenvif *vif);
198 /* (Un)Map communication rings. */
199 void xenvif_unmap_frontend_rings(struct xenvif *vif);
200 int xenvif_map_frontend_rings(struct xenvif *vif,
201 grant_ref_t tx_ring_ref,
202 grant_ref_t rx_ring_ref);
204 /* Check for SKBs from frontend and schedule backend processing */
205 void xenvif_check_rx_xenvif(struct xenvif *vif);
207 /* Queue an SKB for transmission to the frontend */
208 void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb);
209 /* Notify xenvif that ring now has space to send an skb to the frontend */
210 void xenvif_notify_tx_completion(struct xenvif *vif);
212 /* Prevent the device from generating any further traffic. */
213 void xenvif_carrier_off(struct xenvif *vif);
215 /* Returns number of ring slots required to send an skb to the frontend */
216 unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb);
218 int xenvif_tx_action(struct xenvif *vif, int budget);
219 void xenvif_rx_action(struct xenvif *vif);
221 int xenvif_kthread(void *data);
223 extern bool separate_tx_rx_irq;
225 #endif /* __XEN_NETBACK__COMMON_H__ */