1223 lines
30 KiB
C
1223 lines
30 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (c) 2007-2014 Nicira, Inc.
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*/
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#include "flow.h"
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#include "datapath.h"
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#include "flow_netlink.h"
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#include <linux/uaccess.h>
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/if_ether.h>
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#include <linux/if_vlan.h>
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#include <net/llc_pdu.h>
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#include <linux/kernel.h>
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#include <linux/jhash.h>
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#include <linux/jiffies.h>
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#include <linux/llc.h>
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#include <linux/module.h>
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#include <linux/in.h>
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#include <linux/rcupdate.h>
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#include <linux/cpumask.h>
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#include <linux/if_arp.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/sctp.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/icmp.h>
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#include <linux/icmpv6.h>
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#include <linux/rculist.h>
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#include <linux/sort.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <net/ndisc.h>
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#define TBL_MIN_BUCKETS 1024
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#define MASK_ARRAY_SIZE_MIN 16
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#define REHASH_INTERVAL (10 * 60 * HZ)
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#define MC_DEFAULT_HASH_ENTRIES 256
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#define MC_HASH_SHIFT 8
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#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT)
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static struct kmem_cache *flow_cache;
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struct kmem_cache *flow_stats_cache __read_mostly;
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static u16 range_n_bytes(const struct sw_flow_key_range *range)
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{
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return range->end - range->start;
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}
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void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
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bool full, const struct sw_flow_mask *mask)
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{
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int start = full ? 0 : mask->range.start;
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int len = full ? sizeof *dst : range_n_bytes(&mask->range);
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const long *m = (const long *)((const u8 *)&mask->key + start);
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const long *s = (const long *)((const u8 *)src + start);
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long *d = (long *)((u8 *)dst + start);
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int i;
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/* If 'full' is true then all of 'dst' is fully initialized. Otherwise,
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* if 'full' is false the memory outside of the 'mask->range' is left
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* uninitialized. This can be used as an optimization when further
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* operations on 'dst' only use contents within 'mask->range'.
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*/
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for (i = 0; i < len; i += sizeof(long))
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*d++ = *s++ & *m++;
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}
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struct sw_flow *ovs_flow_alloc(void)
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{
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struct sw_flow *flow;
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struct sw_flow_stats *stats;
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flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
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if (!flow)
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return ERR_PTR(-ENOMEM);
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flow->stats_last_writer = -1;
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/* Initialize the default stat node. */
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stats = kmem_cache_alloc_node(flow_stats_cache,
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GFP_KERNEL | __GFP_ZERO,
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node_online(0) ? 0 : NUMA_NO_NODE);
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if (!stats)
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goto err;
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spin_lock_init(&stats->lock);
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RCU_INIT_POINTER(flow->stats[0], stats);
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cpumask_set_cpu(0, &flow->cpu_used_mask);
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return flow;
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err:
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kmem_cache_free(flow_cache, flow);
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return ERR_PTR(-ENOMEM);
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}
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int ovs_flow_tbl_count(const struct flow_table *table)
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{
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return table->count;
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}
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static void flow_free(struct sw_flow *flow)
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{
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int cpu;
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if (ovs_identifier_is_key(&flow->id))
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kfree(flow->id.unmasked_key);
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if (flow->sf_acts)
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ovs_nla_free_flow_actions((struct sw_flow_actions __force *)
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flow->sf_acts);
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/* We open code this to make sure cpu 0 is always considered */
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for (cpu = 0; cpu < nr_cpu_ids;
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cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
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if (flow->stats[cpu])
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kmem_cache_free(flow_stats_cache,
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(struct sw_flow_stats __force *)flow->stats[cpu]);
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}
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kmem_cache_free(flow_cache, flow);
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}
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static void rcu_free_flow_callback(struct rcu_head *rcu)
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{
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struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
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flow_free(flow);
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}
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void ovs_flow_free(struct sw_flow *flow, bool deferred)
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{
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if (!flow)
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return;
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if (deferred)
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call_rcu(&flow->rcu, rcu_free_flow_callback);
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else
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flow_free(flow);
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}
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static void __table_instance_destroy(struct table_instance *ti)
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{
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kvfree(ti->buckets);
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kfree(ti);
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}
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static struct table_instance *table_instance_alloc(int new_size)
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{
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struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
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int i;
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if (!ti)
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return NULL;
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ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
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GFP_KERNEL);
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if (!ti->buckets) {
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kfree(ti);
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return NULL;
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}
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for (i = 0; i < new_size; i++)
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INIT_HLIST_HEAD(&ti->buckets[i]);
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ti->n_buckets = new_size;
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ti->node_ver = 0;
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get_random_bytes(&ti->hash_seed, sizeof(u32));
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return ti;
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}
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static void __mask_array_destroy(struct mask_array *ma)
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{
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free_percpu(ma->masks_usage_stats);
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kfree(ma);
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}
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static void mask_array_rcu_cb(struct rcu_head *rcu)
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{
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struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
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__mask_array_destroy(ma);
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}
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static void tbl_mask_array_reset_counters(struct mask_array *ma)
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{
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int i, cpu;
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/* As the per CPU counters are not atomic we can not go ahead and
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* reset them from another CPU. To be able to still have an approximate
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* zero based counter we store the value at reset, and subtract it
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* later when processing.
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*/
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for (i = 0; i < ma->max; i++) {
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ma->masks_usage_zero_cntr[i] = 0;
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for_each_possible_cpu(cpu) {
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struct mask_array_stats *stats;
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unsigned int start;
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u64 counter;
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stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
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do {
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start = u64_stats_fetch_begin_irq(&stats->syncp);
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counter = stats->usage_cntrs[i];
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} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
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ma->masks_usage_zero_cntr[i] += counter;
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}
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}
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}
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static struct mask_array *tbl_mask_array_alloc(int size)
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{
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struct mask_array *new;
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size = max(MASK_ARRAY_SIZE_MIN, size);
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new = kzalloc(sizeof(struct mask_array) +
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sizeof(struct sw_flow_mask *) * size +
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sizeof(u64) * size, GFP_KERNEL);
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if (!new)
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return NULL;
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new->masks_usage_zero_cntr = (u64 *)((u8 *)new +
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sizeof(struct mask_array) +
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sizeof(struct sw_flow_mask *) *
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size);
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new->masks_usage_stats = __alloc_percpu(sizeof(struct mask_array_stats) +
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sizeof(u64) * size,
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__alignof__(u64));
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if (!new->masks_usage_stats) {
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kfree(new);
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return NULL;
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}
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new->count = 0;
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new->max = size;
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return new;
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}
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static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
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{
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struct mask_array *old;
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struct mask_array *new;
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new = tbl_mask_array_alloc(size);
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if (!new)
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return -ENOMEM;
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old = ovsl_dereference(tbl->mask_array);
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if (old) {
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int i;
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for (i = 0; i < old->max; i++) {
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if (ovsl_dereference(old->masks[i]))
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new->masks[new->count++] = old->masks[i];
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}
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call_rcu(&old->rcu, mask_array_rcu_cb);
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}
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rcu_assign_pointer(tbl->mask_array, new);
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return 0;
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}
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static int tbl_mask_array_add_mask(struct flow_table *tbl,
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struct sw_flow_mask *new)
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{
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struct mask_array *ma = ovsl_dereference(tbl->mask_array);
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int err, ma_count = READ_ONCE(ma->count);
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if (ma_count >= ma->max) {
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err = tbl_mask_array_realloc(tbl, ma->max +
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MASK_ARRAY_SIZE_MIN);
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if (err)
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return err;
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ma = ovsl_dereference(tbl->mask_array);
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} else {
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/* On every add or delete we need to reset the counters so
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* every new mask gets a fair chance of being prioritized.
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*/
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tbl_mask_array_reset_counters(ma);
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}
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BUG_ON(ovsl_dereference(ma->masks[ma_count]));
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rcu_assign_pointer(ma->masks[ma_count], new);
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WRITE_ONCE(ma->count, ma_count + 1);
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return 0;
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}
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static void tbl_mask_array_del_mask(struct flow_table *tbl,
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struct sw_flow_mask *mask)
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{
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struct mask_array *ma = ovsl_dereference(tbl->mask_array);
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int i, ma_count = READ_ONCE(ma->count);
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/* Remove the deleted mask pointers from the array */
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for (i = 0; i < ma_count; i++) {
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if (mask == ovsl_dereference(ma->masks[i]))
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goto found;
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}
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BUG();
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return;
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found:
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WRITE_ONCE(ma->count, ma_count - 1);
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rcu_assign_pointer(ma->masks[i], ma->masks[ma_count - 1]);
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RCU_INIT_POINTER(ma->masks[ma_count - 1], NULL);
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kfree_rcu(mask, rcu);
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/* Shrink the mask array if necessary. */
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if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
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ma_count <= (ma->max / 3))
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tbl_mask_array_realloc(tbl, ma->max / 2);
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else
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tbl_mask_array_reset_counters(ma);
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}
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/* Remove 'mask' from the mask list, if it is not needed any more. */
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static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
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{
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if (mask) {
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/* ovs-lock is required to protect mask-refcount and
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* mask list.
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*/
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ASSERT_OVSL();
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BUG_ON(!mask->ref_count);
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mask->ref_count--;
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if (!mask->ref_count)
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tbl_mask_array_del_mask(tbl, mask);
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}
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}
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static void __mask_cache_destroy(struct mask_cache *mc)
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{
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free_percpu(mc->mask_cache);
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kfree(mc);
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}
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static void mask_cache_rcu_cb(struct rcu_head *rcu)
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{
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struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
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__mask_cache_destroy(mc);
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}
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static struct mask_cache *tbl_mask_cache_alloc(u32 size)
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{
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struct mask_cache_entry __percpu *cache = NULL;
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struct mask_cache *new;
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/* Only allow size to be 0, or a power of 2, and does not exceed
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* percpu allocation size.
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*/
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if ((!is_power_of_2(size) && size != 0) ||
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(size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
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return NULL;
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new = kzalloc(sizeof(*new), GFP_KERNEL);
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if (!new)
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return NULL;
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new->cache_size = size;
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if (new->cache_size > 0) {
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cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
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new->cache_size),
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__alignof__(struct mask_cache_entry));
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if (!cache) {
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kfree(new);
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return NULL;
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}
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}
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new->mask_cache = cache;
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return new;
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}
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int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
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{
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struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
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struct mask_cache *new;
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if (size == mc->cache_size)
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return 0;
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if ((!is_power_of_2(size) && size != 0) ||
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(size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
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return -EINVAL;
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new = tbl_mask_cache_alloc(size);
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if (!new)
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return -ENOMEM;
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rcu_assign_pointer(table->mask_cache, new);
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call_rcu(&mc->rcu, mask_cache_rcu_cb);
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return 0;
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}
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int ovs_flow_tbl_init(struct flow_table *table)
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{
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struct table_instance *ti, *ufid_ti;
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struct mask_cache *mc;
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struct mask_array *ma;
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mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
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if (!mc)
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return -ENOMEM;
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ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
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if (!ma)
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goto free_mask_cache;
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ti = table_instance_alloc(TBL_MIN_BUCKETS);
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if (!ti)
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goto free_mask_array;
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ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
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if (!ufid_ti)
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goto free_ti;
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rcu_assign_pointer(table->ti, ti);
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rcu_assign_pointer(table->ufid_ti, ufid_ti);
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rcu_assign_pointer(table->mask_array, ma);
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rcu_assign_pointer(table->mask_cache, mc);
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table->last_rehash = jiffies;
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table->count = 0;
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table->ufid_count = 0;
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return 0;
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free_ti:
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__table_instance_destroy(ti);
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free_mask_array:
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__mask_array_destroy(ma);
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free_mask_cache:
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__mask_cache_destroy(mc);
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return -ENOMEM;
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}
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static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
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{
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struct table_instance *ti;
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ti = container_of(rcu, struct table_instance, rcu);
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__table_instance_destroy(ti);
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}
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static void table_instance_flow_free(struct flow_table *table,
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struct table_instance *ti,
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struct table_instance *ufid_ti,
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struct sw_flow *flow)
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{
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hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
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table->count--;
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if (ovs_identifier_is_ufid(&flow->id)) {
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hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
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table->ufid_count--;
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}
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flow_mask_remove(table, flow->mask);
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}
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|
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/* Must be called with OVS mutex held. */
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void table_instance_flow_flush(struct flow_table *table,
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struct table_instance *ti,
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struct table_instance *ufid_ti)
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{
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int i;
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for (i = 0; i < ti->n_buckets; i++) {
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struct hlist_head *head = &ti->buckets[i];
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struct hlist_node *n;
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struct sw_flow *flow;
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hlist_for_each_entry_safe(flow, n, head,
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flow_table.node[ti->node_ver]) {
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table_instance_flow_free(table, ti, ufid_ti,
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flow);
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ovs_flow_free(flow, true);
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}
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}
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if (WARN_ON(table->count != 0 ||
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table->ufid_count != 0)) {
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table->count = 0;
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table->ufid_count = 0;
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}
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}
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static void table_instance_destroy(struct table_instance *ti,
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struct table_instance *ufid_ti)
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{
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call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
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call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
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}
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|
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/* No need for locking this function is called from RCU callback or
|
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* error path.
|
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*/
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void ovs_flow_tbl_destroy(struct flow_table *table)
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{
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struct table_instance *ti = rcu_dereference_raw(table->ti);
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struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
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struct mask_cache *mc = rcu_dereference_raw(table->mask_cache);
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struct mask_array *ma = rcu_dereference_raw(table->mask_array);
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|
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call_rcu(&mc->rcu, mask_cache_rcu_cb);
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call_rcu(&ma->rcu, mask_array_rcu_cb);
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table_instance_destroy(ti, ufid_ti);
|
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}
|
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|
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struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
|
|
u32 *bucket, u32 *last)
|
|
{
|
|
struct sw_flow *flow;
|
|
struct hlist_head *head;
|
|
int ver;
|
|
int i;
|
|
|
|
ver = ti->node_ver;
|
|
while (*bucket < ti->n_buckets) {
|
|
i = 0;
|
|
head = &ti->buckets[*bucket];
|
|
hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
|
|
if (i < *last) {
|
|
i++;
|
|
continue;
|
|
}
|
|
*last = i + 1;
|
|
return flow;
|
|
}
|
|
(*bucket)++;
|
|
*last = 0;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
|
|
{
|
|
hash = jhash_1word(hash, ti->hash_seed);
|
|
return &ti->buckets[hash & (ti->n_buckets - 1)];
|
|
}
|
|
|
|
static void table_instance_insert(struct table_instance *ti,
|
|
struct sw_flow *flow)
|
|
{
|
|
struct hlist_head *head;
|
|
|
|
head = find_bucket(ti, flow->flow_table.hash);
|
|
hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
|
|
}
|
|
|
|
static void ufid_table_instance_insert(struct table_instance *ti,
|
|
struct sw_flow *flow)
|
|
{
|
|
struct hlist_head *head;
|
|
|
|
head = find_bucket(ti, flow->ufid_table.hash);
|
|
hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
|
|
}
|
|
|
|
static void flow_table_copy_flows(struct table_instance *old,
|
|
struct table_instance *new, bool ufid)
|
|
{
|
|
int old_ver;
|
|
int i;
|
|
|
|
old_ver = old->node_ver;
|
|
new->node_ver = !old_ver;
|
|
|
|
/* Insert in new table. */
|
|
for (i = 0; i < old->n_buckets; i++) {
|
|
struct sw_flow *flow;
|
|
struct hlist_head *head = &old->buckets[i];
|
|
|
|
if (ufid)
|
|
hlist_for_each_entry_rcu(flow, head,
|
|
ufid_table.node[old_ver],
|
|
lockdep_ovsl_is_held())
|
|
ufid_table_instance_insert(new, flow);
|
|
else
|
|
hlist_for_each_entry_rcu(flow, head,
|
|
flow_table.node[old_ver],
|
|
lockdep_ovsl_is_held())
|
|
table_instance_insert(new, flow);
|
|
}
|
|
}
|
|
|
|
static struct table_instance *table_instance_rehash(struct table_instance *ti,
|
|
int n_buckets, bool ufid)
|
|
{
|
|
struct table_instance *new_ti;
|
|
|
|
new_ti = table_instance_alloc(n_buckets);
|
|
if (!new_ti)
|
|
return NULL;
|
|
|
|
flow_table_copy_flows(ti, new_ti, ufid);
|
|
|
|
return new_ti;
|
|
}
|
|
|
|
int ovs_flow_tbl_flush(struct flow_table *flow_table)
|
|
{
|
|
struct table_instance *old_ti, *new_ti;
|
|
struct table_instance *old_ufid_ti, *new_ufid_ti;
|
|
|
|
new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
|
|
if (!new_ti)
|
|
return -ENOMEM;
|
|
new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
|
|
if (!new_ufid_ti)
|
|
goto err_free_ti;
|
|
|
|
old_ti = ovsl_dereference(flow_table->ti);
|
|
old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
|
|
|
|
rcu_assign_pointer(flow_table->ti, new_ti);
|
|
rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
|
|
flow_table->last_rehash = jiffies;
|
|
|
|
table_instance_flow_flush(flow_table, old_ti, old_ufid_ti);
|
|
table_instance_destroy(old_ti, old_ufid_ti);
|
|
return 0;
|
|
|
|
err_free_ti:
|
|
__table_instance_destroy(new_ti);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static u32 flow_hash(const struct sw_flow_key *key,
|
|
const struct sw_flow_key_range *range)
|
|
{
|
|
const u32 *hash_key = (const u32 *)((const u8 *)key + range->start);
|
|
|
|
/* Make sure number of hash bytes are multiple of u32. */
|
|
int hash_u32s = range_n_bytes(range) >> 2;
|
|
|
|
return jhash2(hash_key, hash_u32s, 0);
|
|
}
|
|
|
|
static int flow_key_start(const struct sw_flow_key *key)
|
|
{
|
|
if (key->tun_proto)
|
|
return 0;
|
|
else
|
|
return rounddown(offsetof(struct sw_flow_key, phy),
|
|
sizeof(long));
|
|
}
|
|
|
|
static bool cmp_key(const struct sw_flow_key *key1,
|
|
const struct sw_flow_key *key2,
|
|
int key_start, int key_end)
|
|
{
|
|
const long *cp1 = (const long *)((const u8 *)key1 + key_start);
|
|
const long *cp2 = (const long *)((const u8 *)key2 + key_start);
|
|
int i;
|
|
|
|
for (i = key_start; i < key_end; i += sizeof(long))
|
|
if (*cp1++ ^ *cp2++)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool flow_cmp_masked_key(const struct sw_flow *flow,
|
|
const struct sw_flow_key *key,
|
|
const struct sw_flow_key_range *range)
|
|
{
|
|
return cmp_key(&flow->key, key, range->start, range->end);
|
|
}
|
|
|
|
static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
|
|
const struct sw_flow_match *match)
|
|
{
|
|
struct sw_flow_key *key = match->key;
|
|
int key_start = flow_key_start(key);
|
|
int key_end = match->range.end;
|
|
|
|
BUG_ON(ovs_identifier_is_ufid(&flow->id));
|
|
return cmp_key(flow->id.unmasked_key, key, key_start, key_end);
|
|
}
|
|
|
|
static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
|
|
const struct sw_flow_key *unmasked,
|
|
const struct sw_flow_mask *mask,
|
|
u32 *n_mask_hit)
|
|
{
|
|
struct sw_flow *flow;
|
|
struct hlist_head *head;
|
|
u32 hash;
|
|
struct sw_flow_key masked_key;
|
|
|
|
ovs_flow_mask_key(&masked_key, unmasked, false, mask);
|
|
hash = flow_hash(&masked_key, &mask->range);
|
|
head = find_bucket(ti, hash);
|
|
(*n_mask_hit)++;
|
|
|
|
hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver],
|
|
lockdep_ovsl_is_held()) {
|
|
if (flow->mask == mask && flow->flow_table.hash == hash &&
|
|
flow_cmp_masked_key(flow, &masked_key, &mask->range))
|
|
return flow;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Flow lookup does full lookup on flow table. It starts with
|
|
* mask from index passed in *index.
|
|
* This function MUST be called with BH disabled due to the use
|
|
* of CPU specific variables.
|
|
*/
|
|
static struct sw_flow *flow_lookup(struct flow_table *tbl,
|
|
struct table_instance *ti,
|
|
struct mask_array *ma,
|
|
const struct sw_flow_key *key,
|
|
u32 *n_mask_hit,
|
|
u32 *n_cache_hit,
|
|
u32 *index)
|
|
{
|
|
struct mask_array_stats *stats = this_cpu_ptr(ma->masks_usage_stats);
|
|
struct sw_flow *flow;
|
|
struct sw_flow_mask *mask;
|
|
int i;
|
|
|
|
if (likely(*index < ma->max)) {
|
|
mask = rcu_dereference_ovsl(ma->masks[*index]);
|
|
if (mask) {
|
|
flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
|
|
if (flow) {
|
|
u64_stats_update_begin(&stats->syncp);
|
|
stats->usage_cntrs[*index]++;
|
|
u64_stats_update_end(&stats->syncp);
|
|
(*n_cache_hit)++;
|
|
return flow;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < ma->max; i++) {
|
|
|
|
if (i == *index)
|
|
continue;
|
|
|
|
mask = rcu_dereference_ovsl(ma->masks[i]);
|
|
if (unlikely(!mask))
|
|
break;
|
|
|
|
flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
|
|
if (flow) { /* Found */
|
|
*index = i;
|
|
u64_stats_update_begin(&stats->syncp);
|
|
stats->usage_cntrs[*index]++;
|
|
u64_stats_update_end(&stats->syncp);
|
|
return flow;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mask_cache maps flow to probable mask. This cache is not tightly
|
|
* coupled cache, It means updates to mask list can result in inconsistent
|
|
* cache entry in mask cache.
|
|
* This is per cpu cache and is divided in MC_HASH_SEGS segments.
|
|
* In case of a hash collision the entry is hashed in next segment.
|
|
* */
|
|
struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
|
|
const struct sw_flow_key *key,
|
|
u32 skb_hash,
|
|
u32 *n_mask_hit,
|
|
u32 *n_cache_hit)
|
|
{
|
|
struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
|
|
struct mask_array *ma = rcu_dereference(tbl->mask_array);
|
|
struct table_instance *ti = rcu_dereference(tbl->ti);
|
|
struct mask_cache_entry *entries, *ce;
|
|
struct sw_flow *flow;
|
|
u32 hash;
|
|
int seg;
|
|
|
|
*n_mask_hit = 0;
|
|
*n_cache_hit = 0;
|
|
if (unlikely(!skb_hash || mc->cache_size == 0)) {
|
|
u32 mask_index = 0;
|
|
u32 cache = 0;
|
|
|
|
return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
|
|
&mask_index);
|
|
}
|
|
|
|
/* Pre and post recirulation flows usually have the same skb_hash
|
|
* value. To avoid hash collisions, rehash the 'skb_hash' with
|
|
* 'recirc_id'. */
|
|
if (key->recirc_id)
|
|
skb_hash = jhash_1word(skb_hash, key->recirc_id);
|
|
|
|
ce = NULL;
|
|
hash = skb_hash;
|
|
entries = this_cpu_ptr(mc->mask_cache);
|
|
|
|
/* Find the cache entry 'ce' to operate on. */
|
|
for (seg = 0; seg < MC_HASH_SEGS; seg++) {
|
|
int index = hash & (mc->cache_size - 1);
|
|
struct mask_cache_entry *e;
|
|
|
|
e = &entries[index];
|
|
if (e->skb_hash == skb_hash) {
|
|
flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
|
|
n_cache_hit, &e->mask_index);
|
|
if (!flow)
|
|
e->skb_hash = 0;
|
|
return flow;
|
|
}
|
|
|
|
if (!ce || e->skb_hash < ce->skb_hash)
|
|
ce = e; /* A better replacement cache candidate. */
|
|
|
|
hash >>= MC_HASH_SHIFT;
|
|
}
|
|
|
|
/* Cache miss, do full lookup. */
|
|
flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
|
|
&ce->mask_index);
|
|
if (flow)
|
|
ce->skb_hash = skb_hash;
|
|
|
|
*n_cache_hit = 0;
|
|
return flow;
|
|
}
|
|
|
|
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
|
|
const struct sw_flow_key *key)
|
|
{
|
|
struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
|
|
struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
|
|
u32 __always_unused n_mask_hit;
|
|
u32 __always_unused n_cache_hit;
|
|
struct sw_flow *flow;
|
|
u32 index = 0;
|
|
|
|
/* This function gets called trough the netlink interface and therefore
|
|
* is preemptible. However, flow_lookup() function needs to be called
|
|
* with BH disabled due to CPU specific variables.
|
|
*/
|
|
local_bh_disable();
|
|
flow = flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
|
|
local_bh_enable();
|
|
return flow;
|
|
}
|
|
|
|
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
|
|
const struct sw_flow_match *match)
|
|
{
|
|
struct mask_array *ma = ovsl_dereference(tbl->mask_array);
|
|
int i;
|
|
|
|
/* Always called under ovs-mutex. */
|
|
for (i = 0; i < ma->max; i++) {
|
|
struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
|
|
u32 __always_unused n_mask_hit;
|
|
struct sw_flow_mask *mask;
|
|
struct sw_flow *flow;
|
|
|
|
mask = ovsl_dereference(ma->masks[i]);
|
|
if (!mask)
|
|
continue;
|
|
|
|
flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
|
|
if (flow && ovs_identifier_is_key(&flow->id) &&
|
|
ovs_flow_cmp_unmasked_key(flow, match)) {
|
|
return flow;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static u32 ufid_hash(const struct sw_flow_id *sfid)
|
|
{
|
|
return jhash(sfid->ufid, sfid->ufid_len, 0);
|
|
}
|
|
|
|
static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
|
|
const struct sw_flow_id *sfid)
|
|
{
|
|
if (flow->id.ufid_len != sfid->ufid_len)
|
|
return false;
|
|
|
|
return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
|
|
}
|
|
|
|
bool ovs_flow_cmp(const struct sw_flow *flow,
|
|
const struct sw_flow_match *match)
|
|
{
|
|
if (ovs_identifier_is_ufid(&flow->id))
|
|
return flow_cmp_masked_key(flow, match->key, &match->range);
|
|
|
|
return ovs_flow_cmp_unmasked_key(flow, match);
|
|
}
|
|
|
|
struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
|
|
const struct sw_flow_id *ufid)
|
|
{
|
|
struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
|
|
struct sw_flow *flow;
|
|
struct hlist_head *head;
|
|
u32 hash;
|
|
|
|
hash = ufid_hash(ufid);
|
|
head = find_bucket(ti, hash);
|
|
hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver],
|
|
lockdep_ovsl_is_held()) {
|
|
if (flow->ufid_table.hash == hash &&
|
|
ovs_flow_cmp_ufid(flow, ufid))
|
|
return flow;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int ovs_flow_tbl_num_masks(const struct flow_table *table)
|
|
{
|
|
struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
|
|
return READ_ONCE(ma->count);
|
|
}
|
|
|
|
u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
|
|
{
|
|
struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
|
|
|
|
return READ_ONCE(mc->cache_size);
|
|
}
|
|
|
|
static struct table_instance *table_instance_expand(struct table_instance *ti,
|
|
bool ufid)
|
|
{
|
|
return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
|
|
}
|
|
|
|
/* Must be called with OVS mutex held. */
|
|
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
|
|
{
|
|
struct table_instance *ti = ovsl_dereference(table->ti);
|
|
struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
|
|
|
|
BUG_ON(table->count == 0);
|
|
table_instance_flow_free(table, ti, ufid_ti, flow);
|
|
}
|
|
|
|
static struct sw_flow_mask *mask_alloc(void)
|
|
{
|
|
struct sw_flow_mask *mask;
|
|
|
|
mask = kmalloc(sizeof(*mask), GFP_KERNEL);
|
|
if (mask)
|
|
mask->ref_count = 1;
|
|
|
|
return mask;
|
|
}
|
|
|
|
static bool mask_equal(const struct sw_flow_mask *a,
|
|
const struct sw_flow_mask *b)
|
|
{
|
|
const u8 *a_ = (const u8 *)&a->key + a->range.start;
|
|
const u8 *b_ = (const u8 *)&b->key + b->range.start;
|
|
|
|
return (a->range.end == b->range.end)
|
|
&& (a->range.start == b->range.start)
|
|
&& (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
|
|
}
|
|
|
|
static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
|
|
const struct sw_flow_mask *mask)
|
|
{
|
|
struct mask_array *ma;
|
|
int i;
|
|
|
|
ma = ovsl_dereference(tbl->mask_array);
|
|
for (i = 0; i < ma->max; i++) {
|
|
struct sw_flow_mask *t;
|
|
t = ovsl_dereference(ma->masks[i]);
|
|
|
|
if (t && mask_equal(mask, t))
|
|
return t;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Add 'mask' into the mask list, if it is not already there. */
|
|
static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
|
|
const struct sw_flow_mask *new)
|
|
{
|
|
struct sw_flow_mask *mask;
|
|
|
|
mask = flow_mask_find(tbl, new);
|
|
if (!mask) {
|
|
/* Allocate a new mask if none exsits. */
|
|
mask = mask_alloc();
|
|
if (!mask)
|
|
return -ENOMEM;
|
|
mask->key = new->key;
|
|
mask->range = new->range;
|
|
|
|
/* Add mask to mask-list. */
|
|
if (tbl_mask_array_add_mask(tbl, mask)) {
|
|
kfree(mask);
|
|
return -ENOMEM;
|
|
}
|
|
} else {
|
|
BUG_ON(!mask->ref_count);
|
|
mask->ref_count++;
|
|
}
|
|
|
|
flow->mask = mask;
|
|
return 0;
|
|
}
|
|
|
|
/* Must be called with OVS mutex held. */
|
|
static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
|
|
{
|
|
struct table_instance *new_ti = NULL;
|
|
struct table_instance *ti;
|
|
|
|
flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
|
|
ti = ovsl_dereference(table->ti);
|
|
table_instance_insert(ti, flow);
|
|
table->count++;
|
|
|
|
/* Expand table, if necessary, to make room. */
|
|
if (table->count > ti->n_buckets)
|
|
new_ti = table_instance_expand(ti, false);
|
|
else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
|
|
new_ti = table_instance_rehash(ti, ti->n_buckets, false);
|
|
|
|
if (new_ti) {
|
|
rcu_assign_pointer(table->ti, new_ti);
|
|
call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
|
|
table->last_rehash = jiffies;
|
|
}
|
|
}
|
|
|
|
/* Must be called with OVS mutex held. */
|
|
static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
|
|
{
|
|
struct table_instance *ti;
|
|
|
|
flow->ufid_table.hash = ufid_hash(&flow->id);
|
|
ti = ovsl_dereference(table->ufid_ti);
|
|
ufid_table_instance_insert(ti, flow);
|
|
table->ufid_count++;
|
|
|
|
/* Expand table, if necessary, to make room. */
|
|
if (table->ufid_count > ti->n_buckets) {
|
|
struct table_instance *new_ti;
|
|
|
|
new_ti = table_instance_expand(ti, true);
|
|
if (new_ti) {
|
|
rcu_assign_pointer(table->ufid_ti, new_ti);
|
|
call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Must be called with OVS mutex held. */
|
|
int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
|
|
const struct sw_flow_mask *mask)
|
|
{
|
|
int err;
|
|
|
|
err = flow_mask_insert(table, flow, mask);
|
|
if (err)
|
|
return err;
|
|
flow_key_insert(table, flow);
|
|
if (ovs_identifier_is_ufid(&flow->id))
|
|
flow_ufid_insert(table, flow);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int compare_mask_and_count(const void *a, const void *b)
|
|
{
|
|
const struct mask_count *mc_a = a;
|
|
const struct mask_count *mc_b = b;
|
|
|
|
return (s64)mc_b->counter - (s64)mc_a->counter;
|
|
}
|
|
|
|
/* Must be called with OVS mutex held. */
|
|
void ovs_flow_masks_rebalance(struct flow_table *table)
|
|
{
|
|
struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
|
|
struct mask_count *masks_and_count;
|
|
struct mask_array *new;
|
|
int masks_entries = 0;
|
|
int i;
|
|
|
|
/* Build array of all current entries with use counters. */
|
|
masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count),
|
|
GFP_KERNEL);
|
|
if (!masks_and_count)
|
|
return;
|
|
|
|
for (i = 0; i < ma->max; i++) {
|
|
struct sw_flow_mask *mask;
|
|
int cpu;
|
|
|
|
mask = rcu_dereference_ovsl(ma->masks[i]);
|
|
if (unlikely(!mask))
|
|
break;
|
|
|
|
masks_and_count[i].index = i;
|
|
masks_and_count[i].counter = 0;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct mask_array_stats *stats;
|
|
unsigned int start;
|
|
u64 counter;
|
|
|
|
stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
|
|
do {
|
|
start = u64_stats_fetch_begin_irq(&stats->syncp);
|
|
counter = stats->usage_cntrs[i];
|
|
} while (u64_stats_fetch_retry_irq(&stats->syncp,
|
|
start));
|
|
|
|
masks_and_count[i].counter += counter;
|
|
}
|
|
|
|
/* Subtract the zero count value. */
|
|
masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i];
|
|
|
|
/* Rather than calling tbl_mask_array_reset_counters()
|
|
* below when no change is needed, do it inline here.
|
|
*/
|
|
ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter;
|
|
}
|
|
|
|
if (i == 0)
|
|
goto free_mask_entries;
|
|
|
|
/* Sort the entries */
|
|
masks_entries = i;
|
|
sort(masks_and_count, masks_entries, sizeof(*masks_and_count),
|
|
compare_mask_and_count, NULL);
|
|
|
|
/* If the order is the same, nothing to do... */
|
|
for (i = 0; i < masks_entries; i++) {
|
|
if (i != masks_and_count[i].index)
|
|
break;
|
|
}
|
|
if (i == masks_entries)
|
|
goto free_mask_entries;
|
|
|
|
/* Rebuilt the new list in order of usage. */
|
|
new = tbl_mask_array_alloc(ma->max);
|
|
if (!new)
|
|
goto free_mask_entries;
|
|
|
|
for (i = 0; i < masks_entries; i++) {
|
|
int index = masks_and_count[i].index;
|
|
|
|
if (ovsl_dereference(ma->masks[index]))
|
|
new->masks[new->count++] = ma->masks[index];
|
|
}
|
|
|
|
rcu_assign_pointer(table->mask_array, new);
|
|
call_rcu(&ma->rcu, mask_array_rcu_cb);
|
|
|
|
free_mask_entries:
|
|
kfree(masks_and_count);
|
|
}
|
|
|
|
/* Initializes the flow module.
|
|
* Returns zero if successful or a negative error code. */
|
|
int ovs_flow_init(void)
|
|
{
|
|
BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
|
|
BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
|
|
|
|
flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
|
|
+ (nr_cpu_ids
|
|
* sizeof(struct sw_flow_stats *)),
|
|
0, 0, NULL);
|
|
if (flow_cache == NULL)
|
|
return -ENOMEM;
|
|
|
|
flow_stats_cache
|
|
= kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats),
|
|
0, SLAB_HWCACHE_ALIGN, NULL);
|
|
if (flow_stats_cache == NULL) {
|
|
kmem_cache_destroy(flow_cache);
|
|
flow_cache = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Uninitializes the flow module. */
|
|
void ovs_flow_exit(void)
|
|
{
|
|
kmem_cache_destroy(flow_stats_cache);
|
|
kmem_cache_destroy(flow_cache);
|
|
}
|