xref: /openbmc/linux/drivers/net/xen-netback/common.h (revision 5104d265)
1 /*
2  * This program is free software; you can redistribute it and/or
3  * modify it under the terms of the GNU General Public License version 2
4  * as published by the Free Software Foundation; or, when distributed
5  * separately from the Linux kernel or incorporated into other
6  * software packages, subject to the following license:
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this source file (the "Software"), to deal in the Software without
10  * restriction, including without limitation the rights to use, copy, modify,
11  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
12  * and to permit persons to whom the Software is furnished to do so, subject to
13  * the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24  * IN THE SOFTWARE.
25  */
26 
27 #ifndef __XEN_NETBACK__COMMON_H__
28 #define __XEN_NETBACK__COMMON_H__
29 
30 #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
31 
32 #include <linux/module.h>
33 #include <linux/interrupt.h>
34 #include <linux/slab.h>
35 #include <linux/ip.h>
36 #include <linux/in.h>
37 #include <linux/io.h>
38 #include <linux/netdevice.h>
39 #include <linux/etherdevice.h>
40 #include <linux/wait.h>
41 #include <linux/sched.h>
42 
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>
47 
48 struct xen_netbk;
49 
50 struct xenvif {
51 	/* Unique identifier for this interface. */
52 	domid_t          domid;
53 	unsigned int     handle;
54 
55 	/* Reference to netback processing backend. */
56 	struct xen_netbk *netbk;
57 
58 	u8               fe_dev_addr[6];
59 
60 	/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
61 	unsigned int tx_irq;
62 	unsigned int rx_irq;
63 	/* Only used when feature-split-event-channels = 1 */
64 	char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
65 	char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
66 
67 	/* List of frontends to notify after a batch of frames sent. */
68 	struct list_head notify_list;
69 
70 	/* The shared rings and indexes. */
71 	struct xen_netif_tx_back_ring tx;
72 	struct xen_netif_rx_back_ring rx;
73 
74 	/* Frontend feature information. */
75 	u8 can_sg:1;
76 	u8 gso:1;
77 	u8 gso_prefix:1;
78 	u8 csum:1;
79 
80 	/* Internal feature information. */
81 	u8 can_queue:1;	    /* can queue packets for receiver? */
82 
83 	/*
84 	 * Allow xenvif_start_xmit() to peek ahead in the rx request
85 	 * ring.  This is a prediction of what rx_req_cons will be
86 	 * once all queued skbs are put on the ring.
87 	 */
88 	RING_IDX rx_req_cons_peek;
89 
90 	/* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
91 	unsigned long   credit_bytes;
92 	unsigned long   credit_usec;
93 	unsigned long   remaining_credit;
94 	struct timer_list credit_timeout;
95 
96 	/* Statistics */
97 	unsigned long rx_gso_checksum_fixup;
98 
99 	/* Miscellaneous private stuff. */
100 	struct list_head schedule_list;
101 	atomic_t         refcnt;
102 	struct net_device *dev;
103 
104 	wait_queue_head_t waiting_to_free;
105 };
106 
107 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
108 {
109 	return to_xenbus_device(vif->dev->dev.parent);
110 }
111 
112 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
113 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
114 
115 struct xenvif *xenvif_alloc(struct device *parent,
116 			    domid_t domid,
117 			    unsigned int handle);
118 
119 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
120 		   unsigned long rx_ring_ref, unsigned int tx_evtchn,
121 		   unsigned int rx_evtchn);
122 void xenvif_disconnect(struct xenvif *vif);
123 
124 void xenvif_get(struct xenvif *vif);
125 void xenvif_put(struct xenvif *vif);
126 
127 int xenvif_xenbus_init(void);
128 void xenvif_xenbus_fini(void);
129 
130 int xenvif_schedulable(struct xenvif *vif);
131 
132 int xen_netbk_rx_ring_full(struct xenvif *vif);
133 
134 int xen_netbk_must_stop_queue(struct xenvif *vif);
135 
136 /* (Un)Map communication rings. */
137 void xen_netbk_unmap_frontend_rings(struct xenvif *vif);
138 int xen_netbk_map_frontend_rings(struct xenvif *vif,
139 				 grant_ref_t tx_ring_ref,
140 				 grant_ref_t rx_ring_ref);
141 
142 /* (De)Register a xenvif with the netback backend. */
143 void xen_netbk_add_xenvif(struct xenvif *vif);
144 void xen_netbk_remove_xenvif(struct xenvif *vif);
145 
146 /* (De)Schedule backend processing for a xenvif */
147 void xen_netbk_schedule_xenvif(struct xenvif *vif);
148 void xen_netbk_deschedule_xenvif(struct xenvif *vif);
149 
150 /* Check for SKBs from frontend and schedule backend processing */
151 void xen_netbk_check_rx_xenvif(struct xenvif *vif);
152 /* Receive an SKB from the frontend */
153 void xenvif_receive_skb(struct xenvif *vif, struct sk_buff *skb);
154 
155 /* Queue an SKB for transmission to the frontend */
156 void xen_netbk_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb);
157 /* Notify xenvif that ring now has space to send an skb to the frontend */
158 void xenvif_notify_tx_completion(struct xenvif *vif);
159 
160 /* Prevent the device from generating any further traffic. */
161 void xenvif_carrier_off(struct xenvif *vif);
162 
163 /* Returns number of ring slots required to send an skb to the frontend */
164 unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff *skb);
165 
166 extern bool separate_tx_rx_irq;
167 
168 #endif /* __XEN_NETBACK__COMMON_H__ */
169