2 * This program is free software; you can redistribute it and/or
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5 * separately from the Linux kernel or incorporated into other
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9 * of this source file (the "Software"), to deal in the Software without
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12 * and to permit persons to whom the Software is furnished to do so, subject to
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15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
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19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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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 /* Is this interface disabled? True when backend discovers
110 /* Use NAPI for guest TX */
111 struct napi_struct napi
;
112 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
114 /* Only used when feature-split-event-channels = 1 */
115 char tx_irq_name
[IFNAMSIZ
+4]; /* DEVNAME-tx */
116 struct xen_netif_tx_back_ring tx
;
117 struct sk_buff_head tx_queue
;
118 struct page
*mmap_pages
[MAX_PENDING_REQS
];
119 pending_ring_idx_t pending_prod
;
120 pending_ring_idx_t pending_cons
;
121 u16 pending_ring
[MAX_PENDING_REQS
];
122 struct pending_tx_info pending_tx_info
[MAX_PENDING_REQS
];
124 /* Coalescing tx requests before copying makes number of grant
125 * copy ops greater or equal to number of slots required. In
126 * worst case a tx request consumes 2 gnttab_copy.
128 struct gnttab_copy tx_copy_ops
[2*MAX_PENDING_REQS
];
131 /* Use kthread for guest RX */
132 struct task_struct
*task
;
133 wait_queue_head_t wq
;
134 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
136 /* Only used when feature-split-event-channels = 1 */
137 char rx_irq_name
[IFNAMSIZ
+4]; /* DEVNAME-rx */
138 struct xen_netif_rx_back_ring rx
;
139 struct sk_buff_head rx_queue
;
141 /* Allow xenvif_start_xmit() to peek ahead in the rx request
142 * ring. This is a prediction of what rx_req_cons will be
143 * once all queued skbs are put on the ring.
145 RING_IDX rx_req_cons_peek
;
147 /* Given MAX_BUFFER_OFFSET of 4096 the worst case is that each
148 * head/fragment page uses 2 copy operations because it
149 * straddles two buffers in the frontend.
151 struct gnttab_copy grant_copy_op
[2*XEN_NETIF_RX_RING_SIZE
];
152 struct xenvif_rx_meta meta
[2*XEN_NETIF_RX_RING_SIZE
];
157 /* Frontend feature information. */
163 /* Internal feature information. */
164 u8 can_queue
:1; /* can queue packets for receiver? */
166 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
167 unsigned long credit_bytes
;
168 unsigned long credit_usec
;
169 unsigned long remaining_credit
;
170 struct timer_list credit_timeout
;
171 u64 credit_window_start
;
174 unsigned long rx_gso_checksum_fixup
;
176 /* Miscellaneous private stuff. */
177 struct net_device
*dev
;
180 static inline struct xenbus_device
*xenvif_to_xenbus_device(struct xenvif
*vif
)
182 return to_xenbus_device(vif
->dev
->dev
.parent
);
185 struct xenvif
*xenvif_alloc(struct device
*parent
,
187 unsigned int handle
);
189 int xenvif_connect(struct xenvif
*vif
, unsigned long tx_ring_ref
,
190 unsigned long rx_ring_ref
, unsigned int tx_evtchn
,
191 unsigned int rx_evtchn
);
192 void xenvif_disconnect(struct xenvif
*vif
);
193 void xenvif_free(struct xenvif
*vif
);
195 int xenvif_xenbus_init(void);
196 void xenvif_xenbus_fini(void);
198 int xenvif_schedulable(struct xenvif
*vif
);
200 int xenvif_rx_ring_full(struct xenvif
*vif
);
202 int xenvif_must_stop_queue(struct xenvif
*vif
);
204 /* (Un)Map communication rings. */
205 void xenvif_unmap_frontend_rings(struct xenvif
*vif
);
206 int xenvif_map_frontend_rings(struct xenvif
*vif
,
207 grant_ref_t tx_ring_ref
,
208 grant_ref_t rx_ring_ref
);
210 /* Check for SKBs from frontend and schedule backend processing */
211 void xenvif_check_rx_xenvif(struct xenvif
*vif
);
213 /* Queue an SKB for transmission to the frontend */
214 void xenvif_queue_tx_skb(struct xenvif
*vif
, struct sk_buff
*skb
);
215 /* Notify xenvif that ring now has space to send an skb to the frontend */
216 void xenvif_notify_tx_completion(struct xenvif
*vif
);
218 /* Prevent the device from generating any further traffic. */
219 void xenvif_carrier_off(struct xenvif
*vif
);
221 /* Returns number of ring slots required to send an skb to the frontend */
222 unsigned int xenvif_count_skb_slots(struct xenvif
*vif
, struct sk_buff
*skb
);
224 int xenvif_tx_action(struct xenvif
*vif
, int budget
);
225 void xenvif_rx_action(struct xenvif
*vif
);
227 int xenvif_kthread(void *data
);
229 extern bool separate_tx_rx_irq
;
231 #endif /* __XEN_NETBACK__COMMON_H__ */