i40evf: don't use more queues than CPUs

It's kind of silly to configure and attempt to use a bunch of queue
pairs when you're running on a single (virtual) CPU. Instead of
unconditionally configuring all of the queues that the PF gives us,
clamp the number of queue pairs to the number of CPUs.

Change-ID: I321714c9e15072ee76de8f95ab9a81f86ed347d1
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Patrick Lu <patrick.lu@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 29 insertions, 21 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index b2f01eb2f9e5..f0d07ad54198 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -397,8 +397,8 @@ static int i40evf_map_rings_to_vectors(struct i40evf_adapter *adapter)
         int q_vectors;
         int v_start = 0;
         int rxr_idx = 0, txr_idx = 0;
-        int rxr_remaining = adapter->vsi_res->num_queue_pairs;
-        int txr_remaining = adapter->vsi_res->num_queue_pairs;
+        int rxr_remaining = adapter->num_active_queues;
+        int txr_remaining = adapter->num_active_queues;
         int i, j;
         int rqpv, tqpv;
         int err = 0;
@@ -584,7 +584,7 @@ static void i40evf_configure_tx(struct i40evf_adapter *adapter)
 {
         struct i40e_hw *hw = &adapter->hw;
         int i;
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++)
+        for (i = 0; i < adapter->num_active_queues; i++)
                 adapter->tx_rings[i]->tail = hw->hw_addr + I40E_QTX_TAIL1(i);
 }
 
@@ -629,7 +629,7 @@ static void i40evf_configure_rx(struct i40evf_adapter *adapter)
                         rx_buf_len = ALIGN(max_frame, 1024);
         }
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 adapter->rx_rings[i]->tail = hw->hw_addr + I40E_QRX_TAIL1(i);
                 adapter->rx_rings[i]->rx_buf_len = rx_buf_len;
         }
@@ -918,7 +918,7 @@ static void i40evf_configure(struct i40evf_adapter *adapter)
         i40evf_configure_rx(adapter);
         adapter->aq_required |= I40EVF_FLAG_AQ_CONFIGURE_QUEUES;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 struct i40e_ring *ring = adapter->rx_rings[i];
                 i40evf_alloc_rx_buffers(ring, ring->count);
                 ring->next_to_use = ring->count - 1;
@@ -950,7 +950,7 @@ static void i40evf_clean_all_rx_rings(struct i40evf_adapter *adapter)
 {
         int i;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++)
+        for (i = 0; i < adapter->num_active_queues; i++)
                 i40evf_clean_rx_ring(adapter->rx_rings[i]);
 }
 
@@ -962,7 +962,7 @@ static void i40evf_clean_all_tx_rings(struct i40evf_adapter *adapter)
 {
         int i;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++)
+        for (i = 0; i < adapter->num_active_queues; i++)
                 i40evf_clean_tx_ring(adapter->tx_rings[i]);
 }
 
@@ -1064,7 +1064,7 @@ static void i40evf_free_queues(struct i40evf_adapter *adapter)
 
         if (!adapter->vsi_res)
                 return;
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 if (adapter->tx_rings[i])
                         kfree_rcu(adapter->tx_rings[i], rcu);
                 adapter->tx_rings[i] = NULL;
@@ -1084,7 +1084,7 @@ static int i40evf_alloc_queues(struct i40evf_adapter *adapter)
 {
         int i;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 struct i40e_ring *tx_ring;
                 struct i40e_ring *rx_ring;
 
@@ -1130,7 +1130,7 @@ static int i40evf_set_interrupt_capability(struct i40evf_adapter *adapter)
                 err = -EIO;
                 goto out;
         }
-        pairs = adapter->vsi_res->num_queue_pairs;
+        pairs = adapter->num_active_queues;
 
         /* It's easy to be greedy for MSI-X vectors, but it really
          * doesn't do us much good if we have a lot more vectors
@@ -1210,7 +1210,7 @@ static void i40evf_free_q_vectors(struct i40evf_adapter *adapter)
         int napi_vectors;
 
         num_q_vectors = adapter->num_msix_vectors - NONQ_VECS;
-        napi_vectors = adapter->vsi_res->num_queue_pairs;
+        napi_vectors = adapter->num_active_queues;
 
         for (q_idx = 0; q_idx < num_q_vectors; q_idx++) {
                 struct i40e_q_vector *q_vector = adapter->q_vector[q_idx];
@@ -1265,8 +1265,8 @@ int i40evf_init_interrupt_scheme(struct i40evf_adapter *adapter)
         }
 
         dev_info(&adapter->pdev->dev, "Multiqueue %s: Queue pair count = %u",
-                (adapter->vsi_res->num_queue_pairs > 1) ? "Enabled" :
-                "Disabled", adapter->vsi_res->num_queue_pairs);
+                (adapter->num_active_queues > 1) ? "Enabled" :
+                "Disabled", adapter->num_active_queues);
 
         return 0;
 err_alloc_queues:
@@ -1425,7 +1425,7 @@ static int next_queue(struct i40evf_adapter *adapter, int j)
 {
         j += 1;
 
-        return j >= adapter->vsi_res->num_queue_pairs ? 0 : j;
+        return j >= adapter->num_active_queues ? 0 : j;
 }
 
 /**
@@ -1446,9 +1446,14 @@ static void i40evf_configure_rss(struct i40evf_adapter *adapter)
                         0xc135cafa, 0x7a6f7e2d, 0xe7102d28, 0x163cd12e,
                         0x4954b126 };
 
-        /* Hash type is configured by the PF - we just supply the key */
+        /* No RSS for single queue. */
+        if (adapter->num_active_queues == 1) {
+                wr32(hw, I40E_VFQF_HENA(0), 0);
+                wr32(hw, I40E_VFQF_HENA(1), 0);
+                return;
+        }
 
-        /* Fill out hash function seed */
+        /* Hash type is configured by the PF - we just supply the key */
         for (i = 0; i <= I40E_VFQF_HKEY_MAX_INDEX; i++)
                 wr32(hw, I40E_VFQF_HKEY(i), seed[i]);
 
@@ -1458,7 +1463,7 @@ static void i40evf_configure_rss(struct i40evf_adapter *adapter)
         wr32(hw, I40E_VFQF_HENA(1), (u32)(hena >> 32));
 
         /* Populate the LUT with max no. of queues in round robin fashion */
-        j = adapter->vsi_res->num_queue_pairs;
+        j = adapter->num_active_queues;
         for (i = 0; i <= I40E_VFQF_HLUT_MAX_INDEX; i++) {
                 j = next_queue(adapter, j);
                 lut = j;
@@ -1703,7 +1708,7 @@ static void i40evf_free_all_tx_resources(struct i40evf_adapter *adapter)
 {
         int i;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++)
+        for (i = 0; i < adapter->num_active_queues; i++)
                 if (adapter->tx_rings[i]->desc)
                         i40evf_free_tx_resources(adapter->tx_rings[i]);
 
@@ -1723,7 +1728,7 @@ static int i40evf_setup_all_tx_resources(struct i40evf_adapter *adapter)
 {
         int i, err = 0;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 adapter->tx_rings[i]->count = adapter->tx_desc_count;
                 err = i40evf_setup_tx_descriptors(adapter->tx_rings[i]);
                 if (!err)
@@ -1751,7 +1756,7 @@ static int i40evf_setup_all_rx_resources(struct i40evf_adapter *adapter)
 {
         int i, err = 0;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++) {
+        for (i = 0; i < adapter->num_active_queues; i++) {
                 adapter->rx_rings[i]->count = adapter->rx_desc_count;
                 err = i40evf_setup_rx_descriptors(adapter->rx_rings[i]);
                 if (!err)
@@ -1774,7 +1779,7 @@ static void i40evf_free_all_rx_resources(struct i40evf_adapter *adapter)
 {
         int i;
 
-        for (i = 0; i < adapter->vsi_res->num_queue_pairs; i++)
+        for (i = 0; i < adapter->num_active_queues; i++)
                 if (adapter->rx_rings[i]->desc)
                         i40evf_free_rx_resources(adapter->rx_rings[i]);
 }
@@ -2150,6 +2155,9 @@ static void i40evf_init_task(struct work_struct *work)
         adapter->watchdog_timer.data = (unsigned long)adapter;
         mod_timer(&adapter->watchdog_timer, jiffies + 1);
 
+        adapter->num_active_queues = min_t(int,
+                                           adapter->vsi_res->num_queue_pairs,
+                                           (int)(num_online_cpus()));
         adapter->tx_desc_count = I40EVF_DEFAULT_TXD;
         adapter->rx_desc_count = I40EVF_DEFAULT_RXD;
         err = i40evf_init_interrupt_scheme(adapter);