drivers/net/cxgb3/l2t.h

   1 /*
   2  * Copyright (c) 2006 Chelsio, Inc. All rights reserved.
   3  * Copyright (c) 2006 Open Grid Computing, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33 #ifndef _CHELSIO_L2T_H
  34 #define _CHELSIO_L2T_H
  35
  36 #include <linux/spinlock.h>
  37 #include "t3cdev.h"
  38 #include <asm/atomic.h>
  39
  40 enum {
  41         L2T_STATE_VALID,        /* entry is up to date */
  42         L2T_STATE_STALE,        /* entry may be used but needs revalidation */
  43         L2T_STATE_RESOLVING,    /* entry needs address resolution */
  44         L2T_STATE_UNUSED        /* entry not in use */
  45 };
  46
  47 struct neighbour;
  48 struct sk_buff;
  49
  50 /*
  51  * Each L2T entry plays multiple roles.  First of all, it keeps state for the
  52  * corresponding entry of the HW L2 table and maintains a queue of offload
  53  * packets awaiting address resolution.  Second, it is a node of a hash table
  54  * chain, where the nodes of the chain are linked together through their next
  55  * pointer.  Finally, each node is a bucket of a hash table, pointing to the
  56  * first element in its chain through its first pointer.
  57  */
  58 struct l2t_entry {
  59         u16 state;              /* entry state */
  60         u16 idx;                /* entry index */
  61         u32 addr;               /* dest IP address */
  62         int ifindex;            /* neighbor's net_device's ifindex */
  63         u16 smt_idx;            /* SMT index */
  64         u16 vlan;               /* VLAN TCI (id: bits 0-11, prio: 13-15 */
  65         struct neighbour *neigh;        /* associated neighbour */
  66         struct l2t_entry *first;        /* start of hash chain */
  67         struct l2t_entry *next; /* next l2t_entry on chain */
  68         struct sk_buff *arpq_head;      /* queue of packets awaiting resolution */
  69         struct sk_buff *arpq_tail;
  70         spinlock_t lock;
  71         atomic_t refcnt;        /* entry reference count */
  72         u8 dmac[6];             /* neighbour's MAC address */
  73 };
  74
  75 struct l2t_data {
  76         unsigned int nentries;  /* number of entries */
  77         struct l2t_entry *rover;        /* starting point for next allocation */
  78         atomic_t nfree;         /* number of free entries */
  79         rwlock_t lock;
  80         struct l2t_entry l2tab[0];
  81 };
  82
  83 typedef void (*arp_failure_handler_func)(struct t3cdev * dev,
  84                                          struct sk_buff * skb);
  85
  86 /*
  87  * Callback stored in an skb to handle address resolution failure.
  88  */
  89 struct l2t_skb_cb {
  90         arp_failure_handler_func arp_failure_handler;
  91 };
  92
  93 #define L2T_SKB_CB(skb) ((struct l2t_skb_cb *)(skb)->cb)
  94
  95 static inline void set_arp_failure_handler(struct sk_buff *skb,
  96                                            arp_failure_handler_func hnd)
  97 {
  98         L2T_SKB_CB(skb)->arp_failure_handler = hnd;
  99 }
 100
 101 /*
 102  * Getting to the L2 data from an offload device.
 103  */
 104 #define L2DATA(dev) ((dev)->l2opt)
 105
 106 #define W_TCB_L2T_IX    0
 107 #define S_TCB_L2T_IX    7
 108 #define M_TCB_L2T_IX    0x7ffULL
 109 #define V_TCB_L2T_IX(x) ((x) << S_TCB_L2T_IX)
 110
 111 void t3_l2e_free(struct l2t_data *d, struct l2t_entry *e);
 112 void t3_l2t_update(struct t3cdev *dev, struct neighbour *neigh);
 113 struct l2t_entry *t3_l2t_get(struct t3cdev *cdev, struct neighbour *neigh,
 114                              struct net_device *dev);
 115 int t3_l2t_send_slow(struct t3cdev *dev, struct sk_buff *skb,
 116                      struct l2t_entry *e);
 117 void t3_l2t_send_event(struct t3cdev *dev, struct l2t_entry *e);
 118 struct l2t_data *t3_init_l2t(unsigned int l2t_capacity);
 119 void t3_free_l2t(struct l2t_data *d);
 120
 121 int cxgb3_ofld_send(struct t3cdev *dev, struct sk_buff *skb);
 122
 123 static inline int l2t_send(struct t3cdev *dev, struct sk_buff *skb,
 124                            struct l2t_entry *e)
 125 {
 126         if (likely(e->state == L2T_STATE_VALID))
 127                 return cxgb3_ofld_send(dev, skb);
 128         return t3_l2t_send_slow(dev, skb, e);
 129 }
 130
 131 static inline void l2t_release(struct l2t_data *d, struct l2t_entry *e)
 132 {
 133         if (atomic_dec_and_test(&e->refcnt))
 134                 t3_l2e_free(d, e);
 135 }
 136
 137 static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
 138 {
 139         if (atomic_add_return(1, &e->refcnt) == 1)      /* 0 -> 1 transition */
 140                 atomic_dec(&d->nfree);
 141 }
 142
 143 #endif