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        /* 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
  71struct 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
 115struct xenvif;
 116
 117struct 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
 135struct 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
 209enum state_bit_shift {
 210        /* This bit marks that the vif is connected */
 211        VIF_STATUS_CONNECTED,
 212};
 213
 214struct 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
 222struct 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
 265struct 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
 272static inline struct xenbus_device *xenvif_to_xenbus_device(struct xenvif *vif)
 273{
 274        return to_xenbus_device(vif->dev->dev.parent);
 275}
 276
 277void xenvif_tx_credit_callback(unsigned long data);
 278
 279struct xenvif *xenvif_alloc(struct device *parent,
 280                            domid_t domid,
 281                            unsigned int handle);
 282
 283int xenvif_init_queue(struct xenvif_queue *queue);
 284void xenvif_deinit_queue(struct xenvif_queue *queue);
 285
 286int 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);
 289void xenvif_disconnect(struct xenvif *vif);
 290void xenvif_free(struct xenvif *vif);
 291
 292int xenvif_xenbus_init(void);
 293void xenvif_xenbus_fini(void);
 294
 295int xenvif_schedulable(struct xenvif *vif);
 296
 297int xenvif_queue_stopped(struct xenvif_queue *queue);
 298void xenvif_wake_queue(struct xenvif_queue *queue);
 299
 300/* (Un)Map communication rings. */
 301void xenvif_unmap_frontend_rings(struct xenvif_queue *queue);
 302int 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 */
 307void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue);
 308
 309/* Prevent the device from generating any further traffic. */
 310void xenvif_carrier_off(struct xenvif *vif);
 311
 312int xenvif_tx_action(struct xenvif_queue *queue, int budget);
 313
 314int xenvif_kthread_guest_rx(void *data);
 315void xenvif_kick_thread(struct xenvif_queue *queue);
 316
 317int xenvif_dealloc_kthread(void *data);
 318
 319void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 320
 321void xenvif_carrier_on(struct xenvif *vif);
 322
 323/* Callback from stack when TX packet can be released */
 324void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success);
 325
 326/* Unmap a pending page and release it back to the guest */
 327void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
 328
 329static 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
 335irqreturn_t xenvif_interrupt(int irq, void *dev_id);
 336
 337extern bool separate_tx_rx_irq;
 338
 339extern unsigned int rx_drain_timeout_msecs;
 340extern unsigned int rx_stall_timeout_msecs;
 341extern unsigned int xenvif_max_queues;
 342
 343#ifdef CONFIG_DEBUG_FS
 344extern struct dentry *xen_netback_dbg_root;
 345#endif
 346
 347void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 348                                 struct sk_buff *skb);
 349void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue);
 350
 351/* Multicast control */
 352bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr);
 353void xenvif_mcast_addr_list_free(struct xenvif *vif);
 354
 355#endif /* __XEN_NETBACK__COMMON_H__ */
 356