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         /* 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         /* Use NAPI for guest TX */
 141         struct napi_struct napi;
 142         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 143         unsigned int tx_irq;
 144         /* Only used when feature-split-event-channels = 1 */
 145         char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
 146         struct xen_netif_tx_back_ring tx;
 147         struct sk_buff_head tx_queue;
 148         struct page *mmap_pages[MAX_PENDING_REQS];
 149         pending_ring_idx_t pending_prod;
 150         pending_ring_idx_t pending_cons;
 151         u16 pending_ring[MAX_PENDING_REQS];
 152         struct pending_tx_info pending_tx_info[MAX_PENDING_REQS];
 153         grant_handle_t grant_tx_handle[MAX_PENDING_REQS];
 154
 155         struct gnttab_copy tx_copy_ops[MAX_PENDING_REQS];
 156         struct gnttab_map_grant_ref tx_map_ops[MAX_PENDING_REQS];
 157         struct gnttab_unmap_grant_ref tx_unmap_ops[MAX_PENDING_REQS];
 158         /* passed to gnttab_[un]map_refs with pages under (un)mapping */
 159         struct page *pages_to_map[MAX_PENDING_REQS];
 160         struct page *pages_to_unmap[MAX_PENDING_REQS];
 161
 162         /* This prevents zerocopy callbacks  to race over dealloc_ring */
 163         spinlock_t callback_lock;
 164         /* This prevents dealloc thread and NAPI instance to race over response
 165          * creation and pending_ring in xenvif_idx_release. In xenvif_tx_err
 166          * it only protect response creation
 167          */
 168         spinlock_t response_lock;
 169         pending_ring_idx_t dealloc_prod;
 170         pending_ring_idx_t dealloc_cons;
 171         u16 dealloc_ring[MAX_PENDING_REQS];
 172         struct task_struct *dealloc_task;
 173         wait_queue_head_t dealloc_wq;
 174         atomic_t inflight_packets;
 175
 176         /* Use kthread for guest RX */
 177         struct task_struct *task;
 178         wait_queue_head_t wq;
 179         /* When feature-split-event-channels = 0, tx_irq = rx_irq. */
 180         unsigned int rx_irq;
 181         /* Only used when feature-split-event-channels = 1 */
 182         char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
 183         struct xen_netif_rx_back_ring rx;
 184         struct sk_buff_head rx_queue;
 185
 186         unsigned int rx_queue_max;
 187         unsigned int rx_queue_len;
 188         unsigned long last_rx_time;
 189         bool stalled;
 190
 191         struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS];
 192
 193         /* We create one meta structure per ring request we consume, so
 194          * the maximum number is the same as the ring size.
 195          */
 196         struct xenvif_rx_meta meta[XEN_NETIF_RX_RING_SIZE];
 197
 198         /* Transmit shaping: allow 'credit_bytes' every 'credit_usec'. */
 199         unsigned long   credit_bytes;
 200         unsigned long   credit_usec;
 201         unsigned long   remaining_credit;
 202         struct timer_list credit_timeout;
 203         u64 credit_window_start;
 204
 205         /* Statistics */
 206         struct xenvif_stats stats;
 207 };
 208
 209 enum state_bit_shift {
 210         /* This bit marks that the vif is connected */
 211         VIF_STATUS_CONNECTED,
 212 };
 213
 214 struct xenvif_mcast_addr {
 215         struct list_head entry;
 216         struct rcu_head rcu;
 217         u8 addr[6];
 218 };
 219
 220 #define XEN_NETBK_MCAST_MAX 64
 221
 222 struct xenvif {
 223         /* Unique identifier for this interface. */
 224         domid_t          domid;
 225         unsigned int     handle;
 226
 227         u8               fe_dev_addr[6];
 228         struct list_head fe_mcast_addr;
 229         unsigned int     fe_mcast_count;
 230
 231         /* Frontend feature information. */
 232         int gso_mask;
 233         int gso_prefix_mask;
 234
 235         u8 can_sg:1;
 236         u8 ip_csum:1;
 237         u8 ipv6_csum:1;
 238         u8 multicast_control:1;
 239
 240         /* Is this interface disabled? True when backend discovers
 241          * frontend is rogue.
 242          */
 243         bool disabled;
 244         unsigned long status;
 245         unsigned long drain_timeout;
 246         unsigned long stall_timeout;
 247
 248         /* Queues */
 249         struct xenvif_queue *queues;
 250         unsigned int num_queues; /* active queues, resource allocated */
 251         unsigned int stalled_queues;
 252
 253         struct xenbus_watch credit_watch;
 254
 255         spinlock_t lock;
 256
 257 #ifdef CONFIG_DEBUG_FS
 258         struct dentry *xenvif_dbg_root;
 259 #endif
 260
 261         /* Miscellaneous private stuff. */
 262         struct net_device *dev;
 263 };
 264
 265 struct xenvif_rx_cb {
 266         unsigned long expires;
 267         int meta_slots_used;
 268 };
 269
 270 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
 271
 272 static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 273 {
 274         return to_xenbus_device(vif->dev->dev.parent);
 275 }
 276
 277 void xenvif_tx_credit_callback(unsigned long data);
 278
 279 struct xenvif *xenvif_alloc(struct device *parent,
 280                             domid_t domid,
 281                             unsigned int handle);
 282
 283 int xenvif_init_queue(struct xenvif_queue *queue);
 284 void xenvif_deinit_queue(struct xenvif_queue *queue);
 285
 286 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
 287                    unsigned long rx_ring_ref, unsigned int tx_evtchn,
 288                    unsigned int rx_evtchn);
 289 void xenvif_disconnect(struct xenvif *vif);
 290 void xenvif_free(struct xenvif *vif);
 291
 292 int xenvif_xenbus_init(void);
 293 void xenvif_xenbus_fini(void);
 294
 295 int xenvif_schedulable(struct xenvif *vif);
 296
 297 int xenvif_queue_stopped(struct xenvif_queue *queue);
 298 void xenvif_wake_queue(struct xenvif_queue *queue);
 299
 300 /* (Un)Map communication rings. */
 301 void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
 302 int xenvif_map_frontend_rings(struct xenvif_queue *queue,
 303                               grant_ref_t tx_ring_ref,
 304                               grant_ref_t rx_ring_ref);
 305
 306 /* Check for SKBs from frontend and schedule backend processing */
 307 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 308
 309 /* Prevent the device from generating any further traffic. */
 310 void xenvif_carrier_off(struct xenvif *vif);
 311
 312 int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 313
 314 int xenvif_kthread_guest_rx(void *data);
 315 void xenvif_kick_thread(struct xenvif_queue *queue);
 316
 317 int xenvif_dealloc_kthread(void *data);
 318
 319 void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 320
 321 void xenvif_carrier_on(struct xenvif *vif);
 322
 323 /* Callback from stack when TX packet can be released */
 324 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
 325
 326 /* Unmap a pending page and release it back to the guest */
 327 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 328
 329 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
 330 {
 331         return MAX_PENDING_REQS -
 332                 queue->pending_prod + queue->pending_cons;
 333 }
 334
 335 irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 336
 337 extern bool separate_tx_rx_irq;
 338
 339 extern unsigned int rx_drain_timeout_msecs;
 340 extern unsigned int rx_stall_timeout_msecs;
 341 extern unsigned int xenvif_max_queues;
 342
 343 #ifdef CONFIG_DEBUG_FS
 344 extern struct dentry *xen_netback_dbg_root;
 345 #endif
 346
 347 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 348                                  struct sk_buff *skb);
 349 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 350
 351 /* Multicast control */
 352 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 353 void xenvif_mcast_addr_list_free(struct xenvif *vif);
 354
 355 #endif /* __XEN_NETBACK__COMMON_H__ */