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 #include <xen/page.h>
48 #include <linux/debugfs.h>
49
50 typedef unsigned int pending_ring_idx_t;
51 #define INVALID_PENDING_RING_IDX (~0U)
52
53 struct pending_tx_info {
54 struct xen_netif_tx_request req; /* tx request */
55 /* Callback data for released SKBs. The callback is always
56 * xenvif_zerocopy_callback, desc contains the pending_idx, which is
57 * also an index in pending_tx_info array. It is initialized in
58 * xenvif_alloc and it never changes.
59 * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
60 * callback_struct in this array of struct pending_tx_info's, then ctx
61 * to the next, or NULL if there is no more slot for this skb.
62 * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
63 * to this field.
64 */
65 struct ubuf_info callback_struct;
66 };
67
68 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
69 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
70
71 struct xenvif_rx_meta {
72 int id;
73 int size;
74 int gso_type;
75 int gso_size;
76 };
77
78 #define GSO_BIT(type) \
79 (1 << XEN_NETIF_GSO_TYPE_ ## type)
80
81 /* Discriminate from any valid pending_idx value. */
82 #define INVALID_PENDING_IDX 0xFFFF
83
84 #define MAX_BUFFER_OFFSET XEN_PAGE_SIZE
85
86 #define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
87
88 /* The maximum number of frags is derived from the size of a grant (same
89 * as a Xen page size for now).
90 */
91 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
92
93 /* It's possible for an skb to have a maximal number of frags
94 * but still be less than MAX_BUFFER_OFFSET in size. Thus the
95 * worst-case number of copy operations is MAX_XEN_SKB_FRAGS per
96 * ring slot.
97 */
98 #define MAX_GRANT_COPY_OPS (MAX_XEN_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
99
100 #define NETBACK_INVALID_HANDLE -1
101
102 /* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
103 * the maximum slots a valid packet can use. Now this value is defined
104 * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
105 * all backend.
106 */
107 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
108
109 /* Queue name is interface name with "-qNNN" appended */
110 #define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
111
112 /* IRQ name is queue name with "-tx" or "-rx" appended */
113 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
114
115 struct xenvif;
116
117 struct xenvif_stats {
118 /* Stats fields to be updated per-queue.
119 * A subset of struct net_device_stats that contains only the
120 * fields that are updated in netback.c for each queue.
121 */
122 unsigned int rx_bytes;
123 unsigned int rx_packets;
124 unsigned int tx_bytes;
125 unsigned int tx_packets;
126
127 /* Additional stats used by xenvif */
128 unsigned long rx_gso_checksum_fixup;
129 unsigned long tx_zerocopy_sent;
130 unsigned long tx_zerocopy_success;
131 unsigned long tx_zerocopy_fail;
132 unsigned long tx_frag_overflow;
133 };
134
135 struct xenvif_queue { /* Per-queue data for xenvif */
136 unsigned int id; /* Queue ID, 0-based */
137 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
138 struct xenvif *vif; /* Parent VIF */
139
140 /*
141 * TX/RX common EOI handling.
142 * When feature-split-event-channels = 0, interrupt handler sets
143 * NETBK_COMMON_EOI, otherwise NETBK_RX_EOI and NETBK_TX_EOI are set
144 * by the RX and TX interrupt handlers.
145 * RX and TX handler threads will issue an EOI when either
146 * NETBK_COMMON_EOI or their specific bits (NETBK_RX_EOI or
147 * NETBK_TX_EOI) are set and they will reset those bits.
148 */
149 atomic_t eoi_pending;
150 #define NETBK_RX_EOI 0x01
151 #define NETBK_TX_EOI 0x02
152 #define NETBK_COMMON_EOI 0x04
153
154 /* Use NAPI for guest TX */
155 struct napi_struct napi;
156 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
157 unsigned int tx_irq;
158 /* Only used when feature-split-event-channels = 1 */
159 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
160 struct xen_netif_tx_back_ring tx;
161 struct sk_buff_head tx_queue;
162 struct page *mmap_pages[MAX_PENDING_REQS];
163 pending_ring_idx_t pending_prod;
164 pending_ring_idx_t pending_cons;
165 u16 pending_ring[MAX_PENDING_REQS];
166 struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
167 grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
168
169 struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
170 struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
171 struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
172 /* passed to gnttab_[un]map_refs with pages under (un)mapping */
173 struct page *pages_to_map[MAX_PENDING_REQS];
174 struct page *pages_to_unmap[MAX_PENDING_REQS];
175
176 /* This prevents zerocopy callbacks to race over dealloc_ring */
177 spinlock_t callback_lock;
178 /* This prevents dealloc thread and NAPI instance to race over response
179 * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
180 * it only protect response creation
181 */
182 spinlock_t response_lock;
183 pending_ring_idx_t dealloc_prod;
184 pending_ring_idx_t dealloc_cons;
185 u16 dealloc_ring[MAX_PENDING_REQS];
186 struct task_struct *dealloc_task;
187 wait_queue_head_t dealloc_wq;
188 atomic_t inflight_packets;
189
190 /* Use kthread for guest RX */
191 struct task_struct *task;
192 wait_queue_head_t wq;
193 /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
194 unsigned int rx_irq;
195 /* Only used when feature-split-event-channels = 1 */
196 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
197 struct xen_netif_rx_back_ring rx;
198 struct sk_buff_head rx_queue;
199
200 unsigned int rx_queue_max;
201 unsigned int rx_queue_len;
202 unsigned long last_rx_time;
203 bool stalled;
204
205 struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
206
207 /* We create one meta structure per ring request we consume, so
208 * the maximum number is the same as the ring size.
209 */
210 struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
211
212 /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
213 unsigned long credit_bytes;
214 unsigned long credit_usec;
215 unsigned long remaining_credit;
216 struct timer_list credit_timeout;
217 u64 credit_window_start;
218 bool rate_limited;
219
220 /* Statistics */
221 struct xenvif_stats stats;
222 };
223
224 enum state_bit_shift {
225 /* This bit marks that the vif is connected */
226 VIF_STATUS_CONNECTED,
227 };
228
229 struct xenvif_mcast_addr {
230 struct list_head entry;
231 struct rcu_head rcu;
232 u8 addr[6];
233 };
234
235 #define XEN_NETBK_MCAST_MAX 64
236
237 struct xenvif {
238 /* Unique identifier for this interface. */
239 domid_t domid;
240 unsigned int handle;
241
242 u8 fe_dev_addr[6];
243 struct list_head fe_mcast_addr;
244 unsigned int fe_mcast_count;
245
246 /* Frontend feature information. */
247 int gso_mask;
248 int gso_prefix_mask;
249
250 u8 can_sg:1;
251 u8 ip_csum:1;
252 u8 ipv6_csum:1;
253 u8 multicast_control:1;
254
255 /* Is this interface disabled? True when backend discovers
256 * frontend is rogue.
257 */
258 bool disabled;
259 unsigned long status;
260 unsigned long drain_timeout;
261 unsigned long stall_timeout;
262
263 /* Queues */
264 struct xenvif_queue *queues;
265 unsigned int num_queues; /* active queues, resource allocated */
266 unsigned int stalled_queues;
267
268 struct xenbus_watch credit_watch;
269
270 spinlock_t lock;
271
272 #ifdef CONFIG_DEBUG_FS
273 struct dentry *xenvif_dbg_root;
274 #endif
275
276 /* Miscellaneous private stuff. */
277 struct net_device *dev;
278 };
279
280 struct xenvif_rx_cb {
281 unsigned long expires;
282 int meta_slots_used;
283 };
284
285 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
286
xenvif_to_xenbus_device(struct xenvif * vif)287 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
288 {
289 return to_xenbus_device(vif->dev->dev.parent);
290 }
291
292 void xenvif_tx_credit_callback(unsigned long data);
293
294 struct xenvif *xenvif_alloc(struct device *parent,
295 domid_t domid,
296 unsigned int handle);
297
298 int xenvif_init_queue(struct xenvif_queue *queue);
299 void xenvif_deinit_queue(struct xenvif_queue *queue);
300
301 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
302 unsigned long rx_ring_ref, unsigned int tx_evtchn,
303 unsigned int rx_evtchn);
304 void xenvif_disconnect(struct xenvif *vif);
305 void xenvif_free(struct xenvif *vif);
306
307 int xenvif_xenbus_init(void);
308 void xenvif_xenbus_fini(void);
309
310 int xenvif_schedulable(struct xenvif *vif);
311
312 int xenvif_queue_stopped(struct xenvif_queue *queue);
313 void xenvif_wake_queue(struct xenvif_queue *queue);
314
315 /* (Un)Map communication rings. */
316 void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
317 int xenvif_map_frontend_rings(struct xenvif_queue *queue,
318 grant_ref_t tx_ring_ref,
319 grant_ref_t rx_ring_ref);
320
321 /* Check for SKBs from frontend and schedule backend processing */
322 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
323
324 /* Prevent the device from generating any further traffic. */
325 void xenvif_carrier_off(struct xenvif *vif);
326
327 int xenvif_tx_action(struct xenvif_queue *queue, int budget);
328
329 int xenvif_kthread_guest_rx(void *data);
330 void xenvif_kick_thread(struct xenvif_queue *queue);
331
332 int xenvif_dealloc_kthread(void *data);
333
334 bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread);
335 void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
336
337 void xenvif_carrier_on(struct xenvif *vif);
338
339 /* Callback from stack when TX packet can be released */
340 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
341
342 /* Unmap a pending page and release it back to the guest */
343 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
344
nr_pending_reqs(struct xenvif_queue * queue)345 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
346 {
347 return MAX_PENDING_REQS -
348 queue->pending_prod + queue->pending_cons;
349 }
350
351 irqreturn_t xenvif_interrupt(int irq, void *dev_id);
352
353 extern bool separate_tx_rx_irq;
354
355 extern unsigned int rx_drain_timeout_msecs;
356 extern unsigned int rx_stall_timeout_msecs;
357 extern unsigned int xenvif_max_queues;
358
359 #ifdef CONFIG_DEBUG_FS
360 extern struct dentry *xen_netback_dbg_root;
361 #endif
362
363 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
364 struct sk_buff *skb);
365 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
366
367 /* Multicast control */
368 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
369 void xenvif_mcast_addr_list_free(struct xenvif *vif);
370
371 #include <linux/atomic.h>
372
xenvif_atomic_fetch_or(int i,atomic_t * v)373 static inline int xenvif_atomic_fetch_or(int i, atomic_t *v)
374 {
375 int c, old;
376
377 c = v->counter;
378 while ((old = cmpxchg(&v->counter, c, c | i)) != c)
379 c = old;
380
381 return c;
382 }
383
xenvif_atomic_fetch_andnot(int i,atomic_t * v)384 static inline int xenvif_atomic_fetch_andnot(int i, atomic_t *v)
385 {
386 int c, old;
387
388 c = v->counter;
389 while ((old = cmpxchg(&v->counter, c, c & ~i)) != c)
390 c = old;
391
392 return c;
393 }
394
395 #endif /* __XEN_NETBACK__COMMON_H__ */
396