From: Edward Cree <ecree@solarflare.com>
Date: Tue, 24 Apr 2018 17:09:30 +0100
Subject: sfc: ARFS filter IDs
Patch-mainline: v4.17-rc3
Git-commit: f8d6203780b73c07dc49ee421fedae8edb76b6e4
References: bsc#1105555 FATE#326117
Associate an arbitrary ID with each ARFS filter, allowing to properly query
for expiry. The association is maintained in a hash table, which is
protected by a spinlock.
v3: fix build warnings when CONFIG_RFS_ACCEL is disabled (thanks lkp-robot).
v2: fixed uninitialised variable (thanks davem and lkp-robot).
Fixes: 3af0f34290f6 ("sfc: replace asynchronous filter operations")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/sfc/ef10.c | 80 ++++++++++---------
drivers/net/ethernet/sfc/efx.c | 143 ++++++++++++++++++++++++++++++++++
drivers/net/ethernet/sfc/efx.h | 21 ++++
drivers/net/ethernet/sfc/farch.c | 41 ++++++++-
drivers/net/ethernet/sfc/net_driver.h | 36 ++++++++
drivers/net/ethernet/sfc/rx.c | 62 +++++++++++++-
6 files changed, 337 insertions(+), 46 deletions(-)
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -3999,29 +3999,6 @@ static void efx_ef10_prepare_flr(struct
atomic_set(&efx->active_queues, 0);
}
-static bool efx_ef10_filter_equal(const struct efx_filter_spec *left,
- const struct efx_filter_spec *right)
-{
- if ((left->match_flags ^ right->match_flags) |
- ((left->flags ^ right->flags) &
- (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
- return false;
-
- return memcmp(&left->outer_vid, &right->outer_vid,
- sizeof(struct efx_filter_spec) -
- offsetof(struct efx_filter_spec, outer_vid)) == 0;
-}
-
-static unsigned int efx_ef10_filter_hash(const struct efx_filter_spec *spec)
-{
- BUILD_BUG_ON(offsetof(struct efx_filter_spec, outer_vid) & 3);
- return jhash2((const u32 *)&spec->outer_vid,
- (sizeof(struct efx_filter_spec) -
- offsetof(struct efx_filter_spec, outer_vid)) / 4,
- 0);
- /* XXX should we randomise the initval? */
-}
-
/* Decide whether a filter should be exclusive or else should allow
* delivery to additional recipients. Currently we decide that
* filters for specific local unicast MAC and IP addresses are
@@ -4346,7 +4323,7 @@ static s32 efx_ef10_filter_insert(struct
goto out_unlock;
match_pri = rc;
- hash = efx_ef10_filter_hash(spec);
+ hash = efx_filter_spec_hash(spec);
is_mc_recip = efx_filter_is_mc_recipient(spec);
if (is_mc_recip)
bitmap_zero(mc_rem_map, EFX_EF10_FILTER_SEARCH_LIMIT);
@@ -4378,7 +4355,7 @@ static s32 efx_ef10_filter_insert(struct
if (!saved_spec) {
if (ins_index < 0)
ins_index = i;
- } else if (efx_ef10_filter_equal(spec, saved_spec)) {
+ } else if (efx_filter_spec_equal(spec, saved_spec)) {
if (spec->priority < saved_spec->priority &&
spec->priority != EFX_FILTER_PRI_AUTO) {
rc = -EPERM;
@@ -4762,27 +4739,62 @@ static s32 efx_ef10_filter_get_rx_ids(st
static bool efx_ef10_filter_rfs_expire_one(struct efx_nic *efx, u32 flow_id,
unsigned int filter_idx)
{
+ struct efx_filter_spec *spec, saved_spec;
struct efx_ef10_filter_table *table;
- struct efx_filter_spec *spec;
- bool ret;
+ struct efx_arfs_rule *rule = NULL;
+ bool ret = true, force = false;
+ u16 arfs_id;
down_read(&efx->filter_sem);
table = efx->filter_state;
down_write(&table->lock);
spec = efx_ef10_filter_entry_spec(table, filter_idx);
- if (!spec || spec->priority != EFX_FILTER_PRI_HINT) {
- ret = true;
+ if (!spec || spec->priority != EFX_FILTER_PRI_HINT)
goto out_unlock;
- }
- if (!rps_may_expire_flow(efx->net_dev, spec->dmaq_id, flow_id, 0)) {
- ret = false;
- goto out_unlock;
+ spin_lock_bh(&efx->rps_hash_lock);
+ if (!efx->rps_hash_table) {
+ /* In the absence of the table, we always return 0 to ARFS. */
+ arfs_id = 0;
+ } else {
+ rule = efx_rps_hash_find(efx, spec);
+ if (!rule)
+ /* ARFS table doesn't know of this filter, so remove it */
+ goto expire;
+ arfs_id = rule->arfs_id;
+ ret = efx_rps_check_rule(rule, filter_idx, &force);
+ if (force)
+ goto expire;
+ if (!ret) {
+ spin_unlock_bh(&efx->rps_hash_lock);
+ goto out_unlock;
+ }
}
-
+ if (!rps_may_expire_flow(efx->net_dev, spec->dmaq_id, flow_id, arfs_id))
+ ret = false;
+ else if (rule)
+ rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
+expire:
+ saved_spec = *spec; /* remove operation will kfree spec */
+ spin_unlock_bh(&efx->rps_hash_lock);
+ /* At this point (since we dropped the lock), another thread might queue
+ * up a fresh insertion request (but the actual insertion will be held
+ * up by our possession of the filter table lock). In that case, it
+ * will set rule->filter_id to EFX_ARFS_FILTER_ID_PENDING, meaning that
+ * the rule is not removed by efx_rps_hash_del() below.
+ */
ret = efx_ef10_filter_remove_internal(efx, 1U << spec->priority,
filter_idx, true) == 0;
+ /* While we can't safely dereference rule (we dropped the lock), we can
+ * still test it for NULL.
+ */
+ if (ret && rule) {
+ /* Expiring, so remove entry from ARFS table */
+ spin_lock_bh(&efx->rps_hash_lock);
+ efx_rps_hash_del(efx, &saved_spec);
+ spin_unlock_bh(&efx->rps_hash_lock);
+ }
out_unlock:
up_write(&table->lock);
up_read(&efx->filter_sem);
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -3027,6 +3027,10 @@ static int efx_init_struct(struct efx_ni
mutex_init(&efx->mac_lock);
#ifdef CONFIG_RFS_ACCEL
mutex_init(&efx->rps_mutex);
+ spin_lock_init(&efx->rps_hash_lock);
+ /* Failure to allocate is not fatal, but may degrade ARFS performance */
+ efx->rps_hash_table = kcalloc(EFX_ARFS_HASH_TABLE_SIZE,
+ sizeof(*efx->rps_hash_table), GFP_KERNEL);
#endif
efx->phy_op = &efx_dummy_phy_operations;
efx->mdio.dev = net_dev;
@@ -3070,6 +3074,10 @@ static void efx_fini_struct(struct efx_n
{
int i;
+#ifdef CONFIG_RFS_ACCEL
+ kfree(efx->rps_hash_table);
+#endif
+
for (i = 0; i < EFX_MAX_CHANNELS; i++)
kfree(efx->channel[i]);
@@ -3092,6 +3100,141 @@ void efx_update_sw_stats(struct efx_nic
stats[GENERIC_STAT_rx_noskb_drops] = atomic_read(&efx->n_rx_noskb_drops);
}
+bool efx_filter_spec_equal(const struct efx_filter_spec *left,
+ const struct efx_filter_spec *right)
+{
+ if ((left->match_flags ^ right->match_flags) |
+ ((left->flags ^ right->flags) &
+ (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
+ return false;
+
+ return memcmp(&left->outer_vid, &right->outer_vid,
+ sizeof(struct efx_filter_spec) -
+ offsetof(struct efx_filter_spec, outer_vid)) == 0;
+}
+
+u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
+{
+ BUILD_BUG_ON(offsetof(struct efx_filter_spec, outer_vid) & 3);
+ return jhash2((const u32 *)&spec->outer_vid,
+ (sizeof(struct efx_filter_spec) -
+ offsetof(struct efx_filter_spec, outer_vid)) / 4,
+ 0);
+}
+
+#ifdef CONFIG_RFS_ACCEL
+bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
+ bool *force)
+{
+ if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
+ /* ARFS is currently updating this entry, leave it */
+ return false;
+ }
+ if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
+ /* ARFS tried and failed to update this, so it's probably out
+ * of date. Remove the filter and the ARFS rule entry.
+ */
+ rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
+ *force = true;
+ return true;
+ } else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
+ /* ARFS has moved on, so old filter is not needed. Since we did
+ * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
+ * not be removed by efx_rps_hash_del() subsequently.
+ */
+ *force = true;
+ return true;
+ }
+ /* Remove it iff ARFS wants to. */
+ return true;
+}
+
+struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
+ const struct efx_filter_spec *spec)
+{
+ u32 hash = efx_filter_spec_hash(spec);
+
+ WARN_ON(!spin_is_locked(&efx->rps_hash_lock));
+ if (!efx->rps_hash_table)
+ return NULL;
+ return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
+}
+
+struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
+ const struct efx_filter_spec *spec)
+{
+ struct efx_arfs_rule *rule;
+ struct hlist_head *head;
+ struct hlist_node *node;
+
+ head = efx_rps_hash_bucket(efx, spec);
+ if (!head)
+ return NULL;
+ hlist_for_each(node, head) {
+ rule = container_of(node, struct efx_arfs_rule, node);
+ if (efx_filter_spec_equal(spec, &rule->spec))
+ return rule;
+ }
+ return NULL;
+}
+
+struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
+ const struct efx_filter_spec *spec,
+ bool *new)
+{
+ struct efx_arfs_rule *rule;
+ struct hlist_head *head;
+ struct hlist_node *node;
+
+ head = efx_rps_hash_bucket(efx, spec);
+ if (!head)
+ return NULL;
+ hlist_for_each(node, head) {
+ rule = container_of(node, struct efx_arfs_rule, node);
+ if (efx_filter_spec_equal(spec, &rule->spec)) {
+ *new = false;
+ return rule;
+ }
+ }
+ rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
+ *new = true;
+ if (rule) {
+ memcpy(&rule->spec, spec, sizeof(rule->spec));
+ hlist_add_head(&rule->node, head);
+ }
+ return rule;
+}
+
+void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
+{
+ struct efx_arfs_rule *rule;
+ struct hlist_head *head;
+ struct hlist_node *node;
+
+ head = efx_rps_hash_bucket(efx, spec);
+ if (WARN_ON(!head))
+ return;
+ hlist_for_each(node, head) {
+ rule = container_of(node, struct efx_arfs_rule, node);
+ if (efx_filter_spec_equal(spec, &rule->spec)) {
+ /* Someone already reused the entry. We know that if
+ * this check doesn't fire (i.e. filter_id == REMOVING)
+ * then the REMOVING mark was put there by our caller,
+ * because caller is holding a lock on filter table and
+ * only holders of that lock set REMOVING.
+ */
+ if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
+ return;
+ hlist_del(node);
+ kfree(rule);
+ return;
+ }
+ }
+ /* We didn't find it. */
+ WARN_ON(1);
+}
+#endif
+
/* RSS contexts. We're using linked lists and crappy O(n) algorithms, because
* (a) this is an infrequent control-plane operation and (b) n is small (max 64)
*/
--- a/drivers/net/ethernet/sfc/efx.h
+++ b/drivers/net/ethernet/sfc/efx.h
@@ -186,6 +186,27 @@ static inline void efx_filter_rfs_expire
#endif
bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec);
+bool efx_filter_spec_equal(const struct efx_filter_spec *left,
+ const struct efx_filter_spec *right);
+u32 efx_filter_spec_hash(const struct efx_filter_spec *spec);
+
+#ifdef CONFIG_RFS_ACCEL
+bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
+ bool *force);
+
+struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
+ const struct efx_filter_spec *spec);
+
+/* @new is written to indicate if entry was newly added (true) or if an old
+ * entry was found and returned (false).
+ */
+struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
+ const struct efx_filter_spec *spec,
+ bool *new);
+
+void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec);
+#endif
+
/* RSS contexts */
struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx);
struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id);
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -2905,18 +2905,45 @@ bool efx_farch_filter_rfs_expire_one(str
{
struct efx_farch_filter_state *state = efx->filter_state;
struct efx_farch_filter_table *table;
- bool ret = false;
+ bool ret = false, force = false;
+ u16 arfs_id;
down_write(&state->lock);
+ spin_lock_bh(&efx->rps_hash_lock);
table = &state->table[EFX_FARCH_FILTER_TABLE_RX_IP];
if (test_bit(index, table->used_bitmap) &&
- table->spec[index].priority == EFX_FILTER_PRI_HINT &&
- rps_may_expire_flow(efx->net_dev, table->spec[index].dmaq_id,
- flow_id, 0)) {
- efx_farch_filter_table_clear_entry(efx, table, index);
- ret = true;
- }
+ table->spec[index].priority == EFX_FILTER_PRI_HINT) {
+ struct efx_arfs_rule *rule = NULL;
+ struct efx_filter_spec spec;
+ efx_farch_filter_to_gen_spec(&spec, &table->spec[index]);
+ if (!efx->rps_hash_table) {
+ /* In the absence of the table, we always returned 0 to
+ * ARFS, so use the same to query it.
+ */
+ arfs_id = 0;
+ } else {
+ rule = efx_rps_hash_find(efx, &spec);
+ if (!rule) {
+ /* ARFS table doesn't know of this filter, remove it */
+ force = true;
+ } else {
+ arfs_id = rule->arfs_id;
+ if (!efx_rps_check_rule(rule, index, &force))
+ goto out_unlock;
+ }
+ }
+ if (force || rps_may_expire_flow(efx->net_dev, spec.dmaq_id,
+ flow_id, arfs_id)) {
+ if (rule)
+ rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
+ efx_rps_hash_del(efx, &spec);
+ efx_farch_filter_table_clear_entry(efx, table, index);
+ ret = true;
+ }
+ }
+out_unlock:
+ spin_unlock_bh(&efx->rps_hash_lock);
up_write(&state->lock);
return ret;
}
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -734,6 +734,35 @@ struct efx_rss_context {
};
#ifdef CONFIG_RFS_ACCEL
+/* Order of these is important, since filter_id >= %EFX_ARFS_FILTER_ID_PENDING
+ * is used to test if filter does or will exist.
+ */
+#define EFX_ARFS_FILTER_ID_PENDING -1
+#define EFX_ARFS_FILTER_ID_ERROR -2
+#define EFX_ARFS_FILTER_ID_REMOVING -3
+/**
+ * struct efx_arfs_rule - record of an ARFS filter and its IDs
+ * @node: linkage into hash table
+ * @spec: details of the filter (used as key for hash table). Use efx->type to
+ * determine which member to use.
+ * @rxq_index: channel to which the filter will steer traffic.
+ * @arfs_id: filter ID which was returned to ARFS
+ * @filter_id: index in software filter table. May be
+ * %EFX_ARFS_FILTER_ID_PENDING if filter was not inserted yet,
+ * %EFX_ARFS_FILTER_ID_ERROR if filter insertion failed, or
+ * %EFX_ARFS_FILTER_ID_REMOVING if expiry is currently removing the filter.
+ */
+struct efx_arfs_rule {
+ struct hlist_node node;
+ struct efx_filter_spec spec;
+ u16 rxq_index;
+ u16 arfs_id;
+ s32 filter_id;
+};
+
+/* Size chosen so that the table is one page (4kB) */
+#define EFX_ARFS_HASH_TABLE_SIZE 512
+
/**
* struct efx_async_filter_insertion - Request to asynchronously insert a filter
* @net_dev: Reference to the netdevice
@@ -873,6 +902,10 @@ struct efx_async_filter_insertion {
* @rps_expire_channel's @rps_flow_id
* @rps_slot_map: bitmap of in-flight entries in @rps_slot
* @rps_slot: array of ARFS insertion requests for efx_filter_rfs_work()
+ * @rps_hash_lock: Protects ARFS filter mapping state (@rps_hash_table and
+ * @rps_next_id).
+ * @rps_hash_table: Mapping between ARFS filters and their various IDs
+ * @rps_next_id: next arfs_id for an ARFS filter
* @active_queues: Count of RX and TX queues that haven't been flushed and drained.
* @rxq_flush_pending: Count of number of receive queues that need to be flushed.
* Decremented when the efx_flush_rx_queue() is called.
@@ -1029,6 +1062,9 @@ struct efx_nic {
unsigned int rps_expire_index;
unsigned long rps_slot_map;
struct efx_async_filter_insertion rps_slot[EFX_RPS_MAX_IN_FLIGHT];
+ spinlock_t rps_hash_lock;
+ struct hlist_head *rps_hash_table;
+ u32 rps_next_id;
#endif
atomic_t active_queues;
--- a/drivers/net/ethernet/sfc/rx.c
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -834,9 +834,29 @@ static void efx_filter_rfs_work(struct w
struct efx_nic *efx = netdev_priv(req->net_dev);
struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
int slot_idx = req - efx->rps_slot;
+ struct efx_arfs_rule *rule;
+ u16 arfs_id = 0;
int rc;
rc = efx->type->filter_insert(efx, &req->spec, true);
+ if (efx->rps_hash_table) {
+ spin_lock_bh(&efx->rps_hash_lock);
+ rule = efx_rps_hash_find(efx, &req->spec);
+ /* The rule might have already gone, if someone else's request
+ * for the same spec was already worked and then expired before
+ * we got around to our work. In that case we have nothing
+ * tying us to an arfs_id, meaning that as soon as the filter
+ * is considered for expiry it will be removed.
+ */
+ if (rule) {
+ if (rc < 0)
+ rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
+ else
+ rule->filter_id = rc;
+ arfs_id = rule->arfs_id;
+ }
+ spin_unlock_bh(&efx->rps_hash_lock);
+ }
if (rc >= 0) {
/* Remember this so we can check whether to expire the filter
* later.
@@ -848,18 +868,18 @@ static void efx_filter_rfs_work(struct w
if (req->spec.ether_type == htons(ETH_P_IP))
netif_info(efx, rx_status, efx->net_dev,
- "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
+ "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
(req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
req->spec.rem_host, ntohs(req->spec.rem_port),
req->spec.loc_host, ntohs(req->spec.loc_port),
- req->rxq_index, req->flow_id, rc);
+ req->rxq_index, req->flow_id, rc, arfs_id);
else
netif_info(efx, rx_status, efx->net_dev,
- "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
+ "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
(req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
req->spec.rem_host, ntohs(req->spec.rem_port),
req->spec.loc_host, ntohs(req->spec.loc_port),
- req->rxq_index, req->flow_id, rc);
+ req->rxq_index, req->flow_id, rc, arfs_id);
}
/* Release references */
@@ -872,8 +892,10 @@ int efx_filter_rfs(struct net_device *ne
{
struct efx_nic *efx = netdev_priv(net_dev);
struct efx_async_filter_insertion *req;
+ struct efx_arfs_rule *rule;
struct flow_keys fk;
int slot_idx;
+ bool new;
int rc;
/* find a free slot */
@@ -926,12 +948,42 @@ int efx_filter_rfs(struct net_device *ne
req->spec.rem_port = fk.ports.src;
req->spec.loc_port = fk.ports.dst;
+ if (efx->rps_hash_table) {
+ /* Add it to ARFS hash table */
+ spin_lock(&efx->rps_hash_lock);
+ rule = efx_rps_hash_add(efx, &req->spec, &new);
+ if (!rule) {
+ rc = -ENOMEM;
+ goto out_unlock;
+ }
+ if (new)
+ rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
+ rc = rule->arfs_id;
+ /* Skip if existing or pending filter already does the right thing */
+ if (!new && rule->rxq_index == rxq_index &&
+ rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
+ goto out_unlock;
+ rule->rxq_index = rxq_index;
+ rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
+ spin_unlock(&efx->rps_hash_lock);
+ } else {
+ /* Without an ARFS hash table, we just use arfs_id 0 for all
+ * filters. This means if multiple flows hash to the same
+ * flow_id, all but the most recently touched will be eligible
+ * for expiry.
+ */
+ rc = 0;
+ }
+
+ /* Queue the request */
dev_hold(req->net_dev = net_dev);
INIT_WORK(&req->work, efx_filter_rfs_work);
req->rxq_index = rxq_index;
req->flow_id = flow_id;
schedule_work(&req->work);
- return 0;
+ return rc;
+out_unlock:
+ spin_unlock(&efx->rps_hash_lock);
out_clear:
clear_bit(slot_idx, &efx->rps_slot_map);
return rc;