LXR linux/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
  50typedef unsigned int pending_ring_idx_t;
  51#define INVALID_PENDING_RING_IDX (~0U)
  52
  53struct 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
  72struct 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
 109struct xenvif;
 110
 111struct 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
 131struct 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
 138struct 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
 208enum state_bit_shift {
 209        /* This bit marks that the vif is connected */
 210        VIF_STATUS_CONNECTED,
 211};
 212
 213struct 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
 225struct 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
 234struct xenvif_hash_cache {
 235        spinlock_t lock;
 236        struct list_head list;
 237        unsigned int count;
 238        atomic_t seq;
 239};
 240
 241struct 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
 250struct 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
 298struct 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
 305static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 306{
 307        return to_xenbus_device(vif->dev->dev.parent);
 308}
 309
 310void xenvif_tx_credit_callback(struct timer_list *t);
 311
 312struct xenvif *xenvif_alloc(struct device *parent,
 313                            domid_t domid,
 314                            unsigned int handle);
 315
 316int xenvif_init_queue(struct xenvif_queue *queue);
 317void xenvif_deinit_queue(struct xenvif_queue *queue);
 318
 319int 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);
 324void xenvif_disconnect_data(struct xenvif *vif);
 325int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 326                        unsigned int evtchn);
 327void xenvif_disconnect_ctrl(struct xenvif *vif);
 328void xenvif_free(struct xenvif *vif);
 329
 330int xenvif_xenbus_init(void);
 331void xenvif_xenbus_fini(void);
 332
 333int xenvif_schedulable(struct xenvif *vif);
 334
 335int xenvif_queue_stopped(struct xenvif_queue *queue);
 336void xenvif_wake_queue(struct xenvif_queue *queue);
 337
 338/* (Un)Map communication rings. */
 339void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue);
 340int 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 */
 345void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 346
 347/* Prevent the device from generating any further traffic. */
 348void xenvif_carrier_off(struct xenvif *vif);
 349
 350int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 351
 352int xenvif_kthread_guest_rx(void *data);
 353void xenvif_kick_thread(struct xenvif_queue *queue);
 354
 355int xenvif_dealloc_kthread(void *data);
 356
 357irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data);
 358
 359void xenvif_rx_action(struct xenvif_queue *queue);
 360void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 361
 362void xenvif_carrier_on(struct xenvif *vif);
 363
 364/* Callback from stack when TX packet can be released */
 365void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
 366
 367/* Unmap a pending page and release it back to the guest */
 368void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 369
 370static 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
 376irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 377
 378extern bool separate_tx_rx_irq;
 379
 380extern unsigned int rx_drain_timeout_msecs;
 381extern unsigned int rx_stall_timeout_msecs;
 382extern unsigned int xenvif_max_queues;
 383extern unsigned int xenvif_hash_cache_size;
 384
 385#ifdef CONFIG_DEBUG_FS
 386extern struct dentry *xen_netback_dbg_root;
 387#endif
 388
 389void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 390                                 struct sk_buff *skb);
 391void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 392
 393/* Multicast control */
 394bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 395void xenvif_mcast_addr_list_free(struct xenvif *vif);
 396
 397/* Hash */
 398void xenvif_init_hash(struct xenvif *vif);
 399void xenvif_deinit_hash(struct xenvif *vif);
 400
 401u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg);
 402u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags);
 403u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags);
 404u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len);
 405u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size);
 406u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
 407                            u32 off);
 408
 409void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb);
 410
 411#ifdef CONFIG_DEBUG_FS
 412void xenvif_dump_hash_info(struct xenvif *vif, struct seq_file *m);
 413#endif
 414
 415#endif /* __XEN_NETBACK__COMMON_H__ */
 416