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