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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
48typedef unsigned int pending_ring_idx_t;
49#define INVALID_PENDING_RING_IDX (~0U)
50
51struct 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
61 * to this field.
62 */
63 struct ubuf_info callback_struct;
64};
65
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)
68
69struct xenvif_rx_meta {
70 int id;
71 int size;
72 int gso_type;
73 int gso_size;
74};
75
76#define GSO_BIT(type) \
77 (1 << XEN_NETIF_GSO_TYPE_ ## type)
78
79/* Discriminate from any valid pending_idx value. */
80#define INVALID_PENDING_IDX 0xFFFF
81
82#define MAX_BUFFER_OFFSET PAGE_SIZE
83
84#define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
85
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
89 * ring slot.
90 */
91#define MAX_GRANT_COPY_OPS (MAX_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
92
93#define NETBACK_INVALID_HANDLE -1
94
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
98 * all backend.
99 */
100#define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
101
102struct xenvif {
103 /* Unique identifier for this interface. */
104 domid_t domid;
105 unsigned int handle;
106
107 /* Is this interface disabled? True when backend discovers
108 * frontend is rogue.
109 */
110 bool disabled;
111
112 /* Use NAPI for guest TX */
113 struct napi_struct napi;
114 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
115 unsigned int tx_irq;
116 /* Only used when feature-split-event-channels = 1 */
117 char tx_irq_name[IFNAMSIZ+4]; /* DEVNAME-tx */
118 struct xen_netif_tx_back_ring tx;
119 struct sk_buff_head tx_queue;
120 struct page *mmap_pages[MAX_PENDING_REQS];
121 pending_ring_idx_t pending_prod;
122 pending_ring_idx_t pending_cons;
123 u16 pending_ring[MAX_PENDING_REQS];
124 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
125 grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
126
127 struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
128 struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
129 struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
130 /* passed to gnttab_[un]map_refs with pages under (un)mapping */
131 struct page *pages_to_map[MAX_PENDING_REQS];
132 struct page *pages_to_unmap[MAX_PENDING_REQS];
133
134 /* This prevents zerocopy callbacks to race over dealloc_ring */
135 spinlock_t callback_lock;
136 /* This prevents dealloc thread and NAPI instance to race over response
137 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
138 * it only protect response creation
139 */
140 spinlock_t response_lock;
141 pending_ring_idx_t dealloc_prod;
142 pending_ring_idx_t dealloc_cons;
143 u16 dealloc_ring[MAX_PENDING_REQS];
144 struct task_struct *dealloc_task;
145 wait_queue_head_t dealloc_wq;
146
147 /* Use kthread for guest RX */
148 struct task_struct *task;
149 wait_queue_head_t wq;
150 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
151 unsigned int rx_irq;
152 /* Only used when feature-split-event-channels = 1 */
153 char rx_irq_name[IFNAMSIZ+4]; /* DEVNAME-rx */
154 struct xen_netif_rx_back_ring rx;
155 struct sk_buff_head rx_queue;
156 RING_IDX rx_last_skb_slots;
157 bool rx_queue_purge;
158
159 struct timer_list wake_queue;
160
161 /* This array is allocated seperately as it is large */
162 struct gnttab_copy *grant_copy_op;
163
164 /* We create one meta structure per ring request we consume, so
165 * the maximum number is the same as the ring size.
166 */
167 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
168
169 u8 fe_dev_addr[6];
170
171 /* Frontend feature information. */
172 int gso_mask;
173 int gso_prefix_mask;
174
175 u8 can_sg:1;
176 u8 ip_csum:1;
177 u8 ipv6_csum:1;
178
179 /* Internal feature information. */
180 u8 can_queue:1; /* can queue packets for receiver? */
181
182 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
183 unsigned long credit_bytes;
184 unsigned long credit_usec;
185 unsigned long remaining_credit;
186 struct timer_list credit_timeout;
187 u64 credit_window_start;
188
189 /* Statistics */
190 unsigned long rx_gso_checksum_fixup;
191 unsigned long tx_zerocopy_sent;
192 unsigned long tx_zerocopy_success;
193 unsigned long tx_zerocopy_fail;
194 unsigned long tx_frag_overflow;
195
196 /* Miscellaneous private stuff. */
197 struct net_device *dev;
198};
199
200static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
201{
202 return to_xenbus_device(vif->dev->dev.parent);
203}
204
205struct xenvif *xenvif_alloc(struct device *parent,
206 domid_t domid,
207 unsigned int handle);
208
209int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
210 unsigned long rx_ring_ref, unsigned int tx_evtchn,
211 unsigned int rx_evtchn);
212void xenvif_disconnect(struct xenvif *vif);
213void xenvif_free(struct xenvif *vif);
214
215int xenvif_xenbus_init(void);
216void xenvif_xenbus_fini(void);
217
218int xenvif_schedulable(struct xenvif *vif);
219
220int xenvif_must_stop_queue(struct xenvif *vif);
221
222/* (Un)Map communication rings. */
223void xenvif_unmap_frontend_rings(struct xenvif *vif);
224int xenvif_map_frontend_rings(struct xenvif *vif,
225 grant_ref_t tx_ring_ref,
226 grant_ref_t rx_ring_ref);
227
228/* Check for SKBs from frontend and schedule backend processing */
229void xenvif_napi_schedule_or_enable_events(struct xenvif *vif);
230
231/* Prevent the device from generating any further traffic. */
232void xenvif_carrier_off(struct xenvif *vif);
233
234int xenvif_tx_action(struct xenvif *vif, int budget);
235
236int xenvif_kthread_guest_rx(void *data);
237void xenvif_kick_thread(struct xenvif *vif);
238
239int xenvif_dealloc_kthread(void *data);
240
241/* Determine whether the needed number of slots (req) are available,
242 * and set req_event if not.
243 */
244bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed);
245
246void xenvif_stop_queue(struct xenvif *vif);
247
248/* Callback from stack when TX packet can be released */
249void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
250
251/* Unmap a pending page and release it back to the guest */
252void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx);
253
254static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
255{
256 return MAX_PENDING_REQS -
257 vif->pending_prod + vif->pending_cons;
258}
259
260/* Callback from stack when TX packet can be released */
261void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
262
263extern bool separate_tx_rx_irq;
264
265extern unsigned int rx_drain_timeout_msecs;
266extern unsigned int rx_drain_timeout_jiffies;
267
268#endif /* __XEN_NETBACK__COMMON_H__ */
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
48struct xen_netbk;
49
50struct 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 /* Physical parameters of the comms window. */
61 unsigned int irq;
62
63 /* List of frontends to notify after a batch of frames sent. */
64 struct list_head notify_list;
65
66 /* The shared rings and indexes. */
67 struct xen_netif_tx_back_ring tx;
68 struct xen_netif_rx_back_ring rx;
69
70 /* Frontend feature information. */
71 u8 can_sg:1;
72 u8 gso:1;
73 u8 gso_prefix:1;
74 u8 csum:1;
75
76 /* Internal feature information. */
77 u8 can_queue:1; /* can queue packets for receiver? */
78
79 /*
80 * Allow xenvif_start_xmit() to peek ahead in the rx request
81 * ring. This is a prediction of what rx_req_cons will be
82 * once all queued skbs are put on the ring.
83 */
84 RING_IDX rx_req_cons_peek;
85
86 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
87 unsigned long credit_bytes;
88 unsigned long credit_usec;
89 unsigned long remaining_credit;
90 struct timer_list credit_timeout;
91
92 /* Statistics */
93 unsigned long rx_gso_checksum_fixup;
94
95 /* Miscellaneous private stuff. */
96 struct list_head schedule_list;
97 atomic_t refcnt;
98 struct net_device *dev;
99
100 wait_queue_head_t waiting_to_free;
101};
102
103static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
104{
105 return to_xenbus_device(vif->dev->dev.parent);
106}
107
108#define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
109#define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
110
111struct xenvif *xenvif_alloc(struct device *parent,
112 domid_t domid,
113 unsigned int handle);
114
115int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
116 unsigned long rx_ring_ref, unsigned int evtchn);
117void xenvif_disconnect(struct xenvif *vif);
118
119void xenvif_get(struct xenvif *vif);
120void xenvif_put(struct xenvif *vif);
121
122int xenvif_xenbus_init(void);
123
124int xenvif_schedulable(struct xenvif *vif);
125
126int xen_netbk_rx_ring_full(struct xenvif *vif);
127
128int xen_netbk_must_stop_queue(struct xenvif *vif);
129
130/* (Un)Map communication rings. */
131void xen_netbk_unmap_frontend_rings(struct xenvif *vif);
132int xen_netbk_map_frontend_rings(struct xenvif *vif,
133 grant_ref_t tx_ring_ref,
134 grant_ref_t rx_ring_ref);
135
136/* (De)Register a xenvif with the netback backend. */
137void xen_netbk_add_xenvif(struct xenvif *vif);
138void xen_netbk_remove_xenvif(struct xenvif *vif);
139
140/* (De)Schedule backend processing for a xenvif */
141void xen_netbk_schedule_xenvif(struct xenvif *vif);
142void xen_netbk_deschedule_xenvif(struct xenvif *vif);
143
144/* Check for SKBs from frontend and schedule backend processing */
145void xen_netbk_check_rx_xenvif(struct xenvif *vif);
146/* Receive an SKB from the frontend */
147void xenvif_receive_skb(struct xenvif *vif, struct sk_buff *skb);
148
149/* Queue an SKB for transmission to the frontend */
150void xen_netbk_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb);
151/* Notify xenvif that ring now has space to send an skb to the frontend */
152void xenvif_notify_tx_completion(struct xenvif *vif);
153
154/* Returns number of ring slots required to send an skb to the frontend */
155unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff *skb);
156
157#endif /* __XEN_NETBACK__COMMON_H__ */