sfc: replace asynchronous filter operations

Instead of having an efx->type->filter_rfs_insert() method, just use
 workitems with a worker function that calls efx->type->filter_insert().
The only user of this is efx_filter_rfs(), which now queues a call to
 efx_filter_rfs_work().
Similarly, efx_filter_rfs_expire() is now a worker function called on a
 new channel->filter_work work_struct, so the method
 efx->type->filter_rfs_expire_one() is no longer called in atomic context.
 We also add a new mutex efx->rps_mutex to protect the RPS state (efx->
 rps_expire_channel, efx->rps_expire_index, and channel->rps_flow_id) so
 that the taking of efx->filter_lock can be moved to
 efx->type->filter_rfs_expire_one().
Thus, all filter table functions are now called in a sleepable context,
 allowing them to use sleeping locks in a future patch.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index ad001e77d554..6b5ca569db5e 100644
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/drivers/net/ethernet/sfc/farch.c
@@ -2901,28 +2901,25 @@ void efx_farch_filter_update_rx_scatter(struct efx_nic *efx)
 
 #ifdef CONFIG_RFS_ACCEL
 
-s32 efx_farch_filter_rfs_insert(struct efx_nic *efx,
-				struct efx_filter_spec *gen_spec)
-{
-	return efx_farch_filter_insert(efx, gen_spec, true);
-}
-
 bool efx_farch_filter_rfs_expire_one(struct efx_nic *efx, u32 flow_id,
 				     unsigned int index)
 {
 	struct efx_farch_filter_state *state = efx->filter_state;
-	struct efx_farch_filter_table *table =
-		&state->table[EFX_FARCH_FILTER_TABLE_RX_IP];
+	struct efx_farch_filter_table *table;
+	bool ret = false;
 
+	spin_lock_bh(&efx->filter_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, index)) {
 		efx_farch_filter_table_clear_entry(efx, table, index);
-		return true;
+		ret = true;
 	}
 
-	return false;
+	spin_unlock_bh(&efx->filter_lock);
+	return ret;
 }
 
 #endif /* CONFIG_RFS_ACCEL */