drivers/net/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 #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         unsigned int extra_count;
  56         /* Callback data for released SKBs. The callback is always
  57          * xenvif_zerocopy_callback, desc contains the pending_idx, which is
  58          * also an index in pending_tx_info array. It is initialized in
  59          * xenvif_alloc and it never changes.
  60          * skb_shinfo(skb)->destructor_arg points to the first mapped slot's
  61          * callback_struct in this array of struct pending_tx_info's, then ctx
  62          * to the next, or NULL if there is no more slot for this skb.
  63          * ubuf_to_vif is a helper which finds the struct xenvif from a pointer
  64          * to this field.
  65          */
  66         struct ubuf_info callback_struct;
  67 };
  68
  69 #define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
  70 #define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
  71
  72 struct xenvif_rx_meta {
  73         int id;
  74         int size;
  75         int gso_type;
  76         int gso_size;
  77 };
  78
  79 #define GSO_BIT(type) \
  80         (1 << XEN_NETIF_GSO_TYPE_ ## type)
  81
  82 /* Discriminate from any valid pending_idx value. */
  83 #define INVALID_PENDING_IDX 0xFFFF
  84
  85 #define MAX_BUFFER_OFFSET XEN_PAGE_SIZE
  86
  87 #define MAX_PENDING_REQS XEN_NETIF_TX_RING_SIZE
  88
  89 /* The maximum number of frags is derived from the size of a grant (same
  90  * as a Xen page size for now).
  91  */
  92 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
  93
  94 /* It's possible for an skb to have a maximal number of frags
  95  * but still be less than MAX_BUFFER_OFFSET in size. Thus the
  96  * worst-case number of copy operations is MAX_XEN_SKB_FRAGS per
  97  * ring slot.
  98  */
  99 #define MAX_GRANT_COPY_OPS (MAX_XEN_SKB_FRAGS * XEN_NETIF_RX_RING_SIZE)
 100
 101 #define NETBACK_INVALID_HANDLE -1
 102
 103 /* To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
 104  * the maximum slots a valid packet can use. Now this value is defined
 105  * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
 106  * all backend.
 107  */
 108 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
 109
 110 /* Queue name is interface name with "-qNNN" appended */
 111 #define QUEUE_NAME_SIZE (IFNAMSIZ + 5)
 112
 113 /* IRQ name is queue name with "-tx" or "-rx" appended */
 114 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
 115
 116 struct xenvif;
 117
 118 struct xenvif_stats {
 119         /* Stats fields to be updated per-queue.
 120          * A subset of struct net_device_stats that contains only the
 121          * fields that are updated in netback.c for each queue.
 122          */
 123         unsigned int rx_bytes;
 124         unsigned int rx_packets;
 125         unsigned int tx_bytes;
 126         unsigned int tx_packets;
 127
 128         /* Additional stats used by xenvif */
 129         unsigned long rx_gso_checksum_fixup;
 130         unsigned long tx_zerocopy_sent;
 131         unsigned long tx_zerocopy_success;
 132         unsigned long tx_zerocopy_fail;
 133         unsigned long tx_frag_overflow;
 134 };
 135
 136 struct xenvif_queue { /* Per-queue data for xenvif */
 137         unsigned int id; /* Queue ID, 0-based */
 138         char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
 139         struct xenvif *vif; /* Parent VIF */
 140
 141         /* Use NAPI for guest TX */
 142         struct napi_struct napi;
 143         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 144         unsigned int tx_irq;
 145         /* Only used when feature-split-event-channels = 1 */
 146         char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
 147         struct xen_netif_tx_back_ring tx;
 148         struct sk_buff_head tx_queue;
 149         struct page *mmap_pages[MAX_PENDING_REQS];
 150         pending_ring_idx_t pending_prod;
 151         pending_ring_idx_t pending_cons;
 152         u16 pending_ring[MAX_PENDING_REQS];
 153         struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
 154         grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
 155
 156         struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
 157         struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
 158         struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
 159         /* passed to gnttab_[un]map_refs with pages under (un)mapping */
 160         struct page *pages_to_map[MAX_PENDING_REQS];
 161         struct page *pages_to_unmap[MAX_PENDING_REQS];
 162
 163         /* This prevents zerocopy callbacks  to race over dealloc_ring */
 164         spinlock_t callback_lock;
 165         /* This prevents dealloc thread and NAPI instance to race over response
 166          * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
 167          * it only protect response creation
 168          */
 169         spinlock_t response_lock;
 170         pending_ring_idx_t dealloc_prod;
 171         pending_ring_idx_t dealloc_cons;
 172         u16 dealloc_ring[MAX_PENDING_REQS];
 173         struct task_struct *dealloc_task;
 174         wait_queue_head_t dealloc_wq;
 175         atomic_t inflight_packets;
 176
 177         /* Use kthread for guest RX */
 178         struct task_struct *task;
 179         wait_queue_head_t wq;
 180         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 181         unsigned int rx_irq;
 182         /* Only used when feature-split-event-channels = 1 */
 183         char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
 184         struct xen_netif_rx_back_ring rx;
 185         struct sk_buff_head rx_queue;
 186
 187         unsigned int rx_queue_max;
 188         unsigned int rx_queue_len;
 189         unsigned long last_rx_time;
 190         bool stalled;
 191
 192         struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
 193
 194         /* We create one meta structure per ring request we consume, so
 195          * the maximum number is the same as the ring size.
 196          */
 197         struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
 198
 199         /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
 200         unsigned long   credit_bytes;
 201         unsigned long   credit_usec;
 202         unsigned long   remaining_credit;
 203         struct timer_list credit_timeout;
 204         u64 credit_window_start;
 205
 206         /* Statistics */
 207         struct xenvif_stats stats;
 208 };
 209
 210 enum state_bit_shift {
 211         /* This bit marks that the vif is connected */
 212         VIF_STATUS_CONNECTED,
 213 };
 214
 215 struct xenvif_mcast_addr {
 216         struct list_head entry;
 217         struct rcu_head rcu;
 218         u8 addr[6];
 219 };
 220
 221 #define XEN_NETBK_MCAST_MAX 64
 222
 223 #define XEN_NETBK_MAX_HASH_KEY_SIZE 40
 224 #define XEN_NETBK_MAX_HASH_MAPPING_SIZE 128
 225 #define XEN_NETBK_HASH_TAG_SIZE 40
 226
 227 struct xenvif_hash_cache_entry {
 228         struct list_head link;
 229         struct rcu_head rcu;
 230         u8 tag[XEN_NETBK_HASH_TAG_SIZE];
 231         unsigned int len;
 232         u32 val;
 233         int seq;
 234 };
 235
 236 struct xenvif_hash_cache {
 237         spinlock_t lock;
 238         struct list_head list;
 239         unsigned int count;
 240         atomic_t seq;
 241 };
 242
 243 struct xenvif_hash {
 244         unsigned int alg;
 245         u32 flags;
 246         u8 key[XEN_NETBK_MAX_HASH_KEY_SIZE];
 247         u32 mapping[XEN_NETBK_MAX_HASH_MAPPING_SIZE];
 248         unsigned int size;
 249         struct xenvif_hash_cache cache;
 250 };
 251
 252 struct xenvif {
 253         /* Unique identifier for this interface. */
 254         domid_t          domid;
 255         unsigned int     handle;
 256
 257         u8               fe_dev_addr[6];
 258         struct list_head fe_mcast_addr;
 259         unsigned int     fe_mcast_count;
 260
 261         /* Frontend feature information. */
 262         int gso_mask;
 263         int gso_prefix_mask;
 264
 265         u8 can_sg:1;
 266         u8 ip_csum:1;
 267         u8 ipv6_csum:1;
 268         u8 multicast_control:1;
 269
 270         /* Is this interface disabled? True when backend discovers
 271          * frontend is rogue.
 272          */
 273         bool disabled;
 274         unsigned long status;
 275         unsigned long drain_timeout;
 276         unsigned long stall_timeout;
 277
 278         /* Queues */
 279         struct xenvif_queue *queues;
 280         unsigned int num_queues; /* active queues, resource allocated */
 281         unsigned int stalled_queues;
 282
 283         struct xenvif_hash hash;
 284
 285         struct xenbus_watch credit_watch;
 286         struct xenbus_watch mcast_ctrl_watch;
 287
 288         spinlock_t lock;
 289
 290 #ifdef CONFIG_DEBUG_FS
 291         struct dentry *xenvif_dbg_root;
 292 #endif
 293
 294         struct xen_netif_ctrl_back_ring ctrl;
 295         struct task_struct *ctrl_task;
 296         wait_queue_head_t ctrl_wq;
 297         unsigned int ctrl_irq;
 298
 299         /* Miscellaneous private stuff. */
 300         struct net_device *dev;
 301 };
 302
 303 struct xenvif_rx_cb {
 304         unsigned long expires;
 305         int meta_slots_used;
 306 };
 307
 308 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
 309
 310 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 311 {
 312         return to_xenbus_device(vif->dev->dev.parent);
 313 }
 314
 315 void xenvif_tx_credit_callback(unsigned long data);
 316
 317 struct xenvif *xenvif_alloc(struct device *parent,
 318                             domid_t domid,
 319                             unsigned int handle);
 320
 321 int xenvif_init_queue(struct xenvif_queue *queue);
 322 void xenvif_deinit_queue(struct xenvif_queue *queue);
 323
 324 int xenvif_connect_data(struct xenvif_queue *queue,
 325                         unsigned long tx_ring_ref,
 326                         unsigned long rx_ring_ref,
 327                         unsigned int tx_evtchn,
 328                         unsigned int rx_evtchn);
 329 void xenvif_disconnect_data(struct xenvif *vif);
 330 int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 331                         unsigned int evtchn);
 332 void xenvif_disconnect_ctrl(struct xenvif *vif);
 333 void xenvif_free(struct xenvif *vif);
 334
 335 int xenvif_xenbus_init(void);
 336 void xenvif_xenbus_fini(void);
 337
 338 int xenvif_schedulable(struct xenvif *vif);
 339
 340 int xenvif_queue_stopped(struct xenvif_queue *queue);
 341 void xenvif_wake_queue(struct xenvif_queue *queue);
 342
 343 /* (Un)Map communication rings. */
 344 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue);
 345 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
 346                                    grant_ref_t tx_ring_ref,
 347                                    grant_ref_t rx_ring_ref);
 348
 349 /* Check for SKBs from frontend and schedule backend processing */
 350 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 351
 352 /* Prevent the device from generating any further traffic. */
 353 void xenvif_carrier_off(struct xenvif *vif);
 354
 355 int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 356
 357 int xenvif_kthread_guest_rx(void *data);
 358 void xenvif_kick_thread(struct xenvif_queue *queue);
 359
 360 int xenvif_dealloc_kthread(void *data);
 361
 362 int xenvif_ctrl_kthread(void *data);
 363
 364 void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 365
 366 void xenvif_carrier_on(struct xenvif *vif);
 367
 368 /* Callback from stack when TX packet can be released */
 369 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
 370
 371 /* Unmap a pending page and release it back to the guest */
 372 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 373
 374 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
 375 {
 376         return MAX_PENDING_REQS -
 377                 queue->pending_prod + queue->pending_cons;
 378 }
 379
 380 irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 381
 382 extern bool separate_tx_rx_irq;
 383
 384 extern unsigned int rx_drain_timeout_msecs;
 385 extern unsigned int rx_stall_timeout_msecs;
 386 extern unsigned int xenvif_max_queues;
 387 extern unsigned int xenvif_hash_cache_size;
 388
 389 #ifdef CONFIG_DEBUG_FS
 390 extern struct dentry *xen_netback_dbg_root;
 391 #endif
 392
 393 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 394                                  struct sk_buff *skb);
 395 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 396
 397 /* Multicast control */
 398 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 399 void xenvif_mcast_addr_list_free(struct xenvif *vif);
 400
 401 /* Hash */
 402 void xenvif_init_hash(struct xenvif *vif);
 403 void xenvif_deinit_hash(struct xenvif *vif);
 404
 405 u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg);
 406 u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags);
 407 u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags);
 408 u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len);
 409 u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size);
 410 u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
 411                             u32 off);
 412
 413 void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb);
 414
 415 #endif /* __XEN_NETBACK__COMMON_H__ */