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/* 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
 116struct xenvif;
 117
 118struct 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
 136struct 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
 210enum state_bit_shift {
 211        /* This bit marks that the vif is connected */
 212        VIF_STATUS_CONNECTED,
 213};
 214
 215struct 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
 227struct 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
 236struct xenvif_hash_cache {
 237        spinlock_t lock;
 238        struct list_head list;
 239        unsigned int count;
 240        atomic_t seq;
 241};
 242
 243struct 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
 252struct 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
 303struct 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
 310static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 311{
 312        return to_xenbus_device(vif->dev->dev.parent);
 313}
 314
 315void xenvif_tx_credit_callback(unsigned long data);
 316
 317struct xenvif *xenvif_alloc(struct device *parent,
 318                            domid_t domid,
 319                            unsigned int handle);
 320
 321int xenvif_init_queue(struct xenvif_queue *queue);
 322void xenvif_deinit_queue(struct xenvif_queue *queue);
 323
 324int 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);
 329void xenvif_disconnect_data(struct xenvif *vif);
 330int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
 331                        unsigned int evtchn);
 332void xenvif_disconnect_ctrl(struct xenvif *vif);
 333void xenvif_free(struct xenvif *vif);
 334
 335int xenvif_xenbus_init(void);
 336void xenvif_xenbus_fini(void);
 337
 338int xenvif_schedulable(struct xenvif *vif);
 339
 340int xenvif_queue_stopped(struct xenvif_queue *queue);
 341void xenvif_wake_queue(struct xenvif_queue *queue);
 342
 343/* (Un)Map communication rings. */
 344void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue);
 345int 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 */
 350void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 351
 352/* Prevent the device from generating any further traffic. */
 353void xenvif_carrier_off(struct xenvif *vif);
 354
 355int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 356
 357int xenvif_kthread_guest_rx(void *data);
 358void xenvif_kick_thread(struct xenvif_queue *queue);
 359
 360int xenvif_dealloc_kthread(void *data);
 361
 362int xenvif_ctrl_kthread(void *data);
 363
 364void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 365
 366void xenvif_carrier_on(struct xenvif *vif);
 367
 368/* Callback from stack when TX packet can be released */
 369void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
 370
 371/* Unmap a pending page and release it back to the guest */
 372void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 373
 374static 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
 380irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 381
 382extern bool separate_tx_rx_irq;
 383
 384extern unsigned int rx_drain_timeout_msecs;
 385extern unsigned int rx_stall_timeout_msecs;
 386extern unsigned int xenvif_max_queues;
 387extern unsigned int xenvif_hash_cache_size;
 388
 389#ifdef CONFIG_DEBUG_FS
 390extern struct dentry *xen_netback_dbg_root;
 391#endif
 392
 393void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 394                                 struct sk_buff *skb);
 395void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 396
 397/* Multicast control */
 398bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 399void xenvif_mcast_addr_list_free(struct xenvif *vif);
 400
 401/* Hash */
 402void xenvif_init_hash(struct xenvif *vif);
 403void xenvif_deinit_hash(struct xenvif *vif);
 404
 405u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg);
 406u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags);
 407u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags);
 408u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len);
 409u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size);
 410u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
 411                            u32 off);
 412
 413void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb);
 414
 415#endif /* __XEN_NETBACK__COMMON_H__ */
 416