diff options
Diffstat (limited to 'pfinet/linux-src/net/core/dst.c')
-rw-r--r-- | pfinet/linux-src/net/core/dst.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/pfinet/linux-src/net/core/dst.c b/pfinet/linux-src/net/core/dst.c new file mode 100644 index 00000000..9007dde6 --- /dev/null +++ b/pfinet/linux-src/net/core/dst.c @@ -0,0 +1,145 @@ +/* + * net/dst.c Protocol independent destination cache. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + */ + +#include <asm/segment.h> +#include <asm/system.h> +#include <asm/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> + +#include <net/dst.h> + +struct dst_entry * dst_garbage_list; +atomic_t dst_total = ATOMIC_INIT(0); + +static unsigned long dst_gc_timer_expires; +static unsigned long dst_gc_timer_inc = DST_GC_MAX; +static void dst_run_gc(unsigned long); + +static struct timer_list dst_gc_timer = + { NULL, NULL, DST_GC_MIN, 0L, dst_run_gc }; + +#if RT_CACHE_DEBUG >= 2 +atomic_t hh_count; +#endif + +static void dst_run_gc(unsigned long dummy) +{ + int delayed = 0; + struct dst_entry * dst, **dstp; + + del_timer(&dst_gc_timer); + dstp = &dst_garbage_list; + while ((dst = *dstp) != NULL) { + if (atomic_read(&dst->use)) { + dstp = &dst->next; + delayed++; + continue; + } + *dstp = dst->next; + dst_destroy(dst); + } + if (!dst_garbage_list) { + dst_gc_timer_inc = DST_GC_MAX; + return; + } + if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX) + dst_gc_timer_expires = DST_GC_MAX; + dst_gc_timer_inc += DST_GC_INC; + dst_gc_timer.expires = jiffies + dst_gc_timer_expires; +#if RT_CACHE_DEBUG >= 2 + printk("dst_total: %d/%d %ld\n", + atomic_read(&dst_total), delayed, dst_gc_timer_expires); +#endif + add_timer(&dst_gc_timer); +} + +static int dst_discard(struct sk_buff *skb) +{ + kfree_skb(skb); + return 0; +} + +static int dst_blackhole(struct sk_buff *skb) +{ + kfree_skb(skb); + return 0; +} + +void * dst_alloc(int size, struct dst_ops * ops) +{ + struct dst_entry * dst; + + if (ops->gc && atomic_read(&ops->entries) > ops->gc_thresh) { + if (ops->gc()) + return NULL; + } + dst = kmalloc(size, GFP_ATOMIC); + if (!dst) + return NULL; + memset(dst, 0, size); + dst->ops = ops; + atomic_set(&dst->refcnt, 0); + dst->lastuse = jiffies; + dst->input = dst_discard; + dst->output = dst_blackhole; + atomic_inc(&dst_total); + atomic_inc(&ops->entries); + return dst; +} + +void __dst_free(struct dst_entry * dst) +{ + start_bh_atomic(); + /* The first case (dev==NULL) is required, when + protocol module is unloaded. + */ + if (dst->dev == NULL || !(dst->dev->flags&IFF_UP)) { + dst->input = dst_discard; + dst->output = dst_blackhole; + dst->dev = &loopback_dev; + } + dst->obsolete = 2; + dst->next = dst_garbage_list; + dst_garbage_list = dst; + if (dst_gc_timer_inc > DST_GC_INC) { + del_timer(&dst_gc_timer); + dst_gc_timer_inc = DST_GC_INC; + dst_gc_timer_expires = DST_GC_MIN; + dst_gc_timer.expires = jiffies + dst_gc_timer_expires; + add_timer(&dst_gc_timer); + } + end_bh_atomic(); +} + +void dst_destroy(struct dst_entry * dst) +{ + struct neighbour *neigh = dst->neighbour; + struct hh_cache *hh = dst->hh; + + dst->hh = NULL; + if (hh && atomic_dec_and_test(&hh->hh_refcnt)) + kfree(hh); + + if (neigh) { + dst->neighbour = NULL; + neigh_release(neigh); + } + + atomic_dec(&dst->ops->entries); + + if (dst->ops->destroy) + dst->ops->destroy(dst); + atomic_dec(&dst_total); + kfree(dst); +} |