i40e/i40evf: Add support for writeback on ITR feature for X722

X722 fixes an issue from X710 where TX descriptor WB would not happen if
the interrupts were disabled. In order for the write backs to happen a
bit needs to be set in the dynamic interrupt control register called
WB_ON_ITR. With this feature, the SW driver need not arm SW interrupts to
work around the issue in X710.

Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 66d0780f12972e86818f8bca6729507eac0234c6..0f97883c149300fdfb30825cb4731a74cd85b553 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -560,6 +560,7 @@ struct i40e_q_vector {
        cpumask_t affinity_mask;
        struct rcu_head rcu;    /* to avoid race with update stats on free */
        char name[I40E_INT_NAME_STR_LEN];
+       bool arm_wb_state;
 } ____cacheline_internodealigned_in_smp;
 
 /* lan device */

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2e84165606328022c4e6fbaa45ec9ea0690cd6df..28f547ce4eb55c97028b629f61639a3ff55c1364 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -7071,6 +7071,8 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
                tx_ring->count = vsi->num_desc;
                tx_ring->size = 0;
                tx_ring->dcb_tc = 0;
+               if (vsi->back->flags & I40E_FLAG_WB_ON_ITR_CAPABLE)
+                       tx_ring->flags = I40E_TXR_FLAGS_WB_ON_ITR;
                vsi->tx_rings[i] = tx_ring;
 
                rx_ring = &tx_ring[1];

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 330e4ef43cd8fafc9a5a8985b0b713e9aec93e49..7d0a5ea086567fb03bfa2c024aaa04ac0921e4a6 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -853,15 +853,40 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
  **/
 static void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
 {
-       u32 val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
-                 I40E_PFINT_DYN_CTLN_ITR_INDX_MASK | /* set noitr */
-                 I40E_PFINT_DYN_CTLN_SWINT_TRIG_MASK |
-                 I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK;
-                 /* allow 00 to be written to the index */
-
-       wr32(&vsi->back->hw,
-            I40E_PFINT_DYN_CTLN(q_vector->v_idx + vsi->base_vector - 1),
-            val);
+       u16 flags = q_vector->tx.ring[0].flags;
+
+       if (flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+               u32 val;
+
+               if (q_vector->arm_wb_state)
+                       return;
+
+               val = I40E_PFINT_DYN_CTLN_WB_ON_ITR_MASK;
+
+               wr32(&vsi->back->hw,
+                    I40E_PFINT_DYN_CTLN(q_vector->v_idx +
+                                        vsi->base_vector - 1),
+                    val);
+               q_vector->arm_wb_state = true;
+       } else if (vsi->back->flags & I40E_FLAG_MSIX_ENABLED) {
+               u32 val = I40E_PFINT_DYN_CTLN_INTENA_MASK |
+                         I40E_PFINT_DYN_CTLN_ITR_INDX_MASK | /* set noitr */
+                         I40E_PFINT_DYN_CTLN_SWINT_TRIG_MASK |
+                         I40E_PFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK;
+                         /* allow 00 to be written to the index */
+
+               wr32(&vsi->back->hw,
+                    I40E_PFINT_DYN_CTLN(q_vector->v_idx +
+                                        vsi->base_vector - 1), val);
+       } else {
+               u32 val = I40E_PFINT_DYN_CTL0_INTENA_MASK |
+                         I40E_PFINT_DYN_CTL0_ITR_INDX_MASK | /* set noitr */
+                         I40E_PFINT_DYN_CTL0_SWINT_TRIG_MASK |
+                         I40E_PFINT_DYN_CTL0_SW_ITR_INDX_ENA_MASK;
+                       /* allow 00 to be written to the index */
+
+               wr32(&vsi->back->hw, I40E_PFINT_DYN_CTL0, val);
+       }
 }
 
 /**
@@ -1918,6 +1943,9 @@ int i40e_napi_poll(struct napi_struct *napi, int budget)
                return budget;
        }
 
+       if (vsi->back->flags & I40E_TXR_FLAGS_WB_ON_ITR)
+               q_vector->arm_wb_state = false;
+
        /* Work is done so exit the polling mode and re-enable the interrupt */
        napi_complete(napi);
        if (vsi->back->flags & I40E_FLAG_MSIX_ENABLED) {

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 8b618d0151cd2fa4be4b573ca97b1792e63185a1..0e40994500c1febb3df298d45ea43ae4660c0452 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -265,6 +265,8 @@ struct i40e_ring {
        bool ring_active;               /* is ring online or not */
        bool arm_wb;            /* do something to arm write back */
 
+       u16 flags;
+#define I40E_TXR_FLAGS_WB_ON_ITR       BIT(0)
        /* stats structs */
        struct i40e_queue_stats stats;
        struct u64_stats_sync syncp;

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 60f88e4ad065ebdfe609e5e94cdce94e5a410d3c..6dbcbca77279ea7b5b1b1a5bbcac24a10813ddef 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -366,15 +366,32 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
  **/
 static void i40e_force_wb(struct i40e_vsi *vsi, struct i40e_q_vector *q_vector)
 {
-       u32 val = I40E_VFINT_DYN_CTLN_INTENA_MASK |
-                 I40E_VFINT_DYN_CTLN1_ITR_INDX_MASK | /* set noitr */
-                 I40E_VFINT_DYN_CTLN_SWINT_TRIG_MASK |
-                 I40E_VFINT_DYN_CTLN_SW_ITR_INDX_ENA_MASK;
-                 /* allow 00 to be written to the index */
-
-       wr32(&vsi->back->hw,
-            I40E_VFINT_DYN_CTLN1(q_vector->v_idx + vsi->base_vector - 1),
-            val);
+       u16 flags = q_vector->tx.ring[0].flags;
+
+       if (flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+               u32 val;
+
+               if (q_vector->arm_wb_state)
+                       return;
+
+               val = I40E_VFINT_DYN_CTLN1_WB_ON_ITR_MASK;
+
+               wr32(&vsi->back->hw,
+                    I40E_VFINT_DYN_CTLN1(q_vector->v_idx +
+                                         vsi->base_vector - 1),
+                    val);
+               q_vector->arm_wb_state = true;
+       } else {
+               u32 val = I40E_VFINT_DYN_CTLN1_INTENA_MASK |
+                         I40E_VFINT_DYN_CTLN1_ITR_INDX_MASK | /* set noitr */
+                         I40E_VFINT_DYN_CTLN1_SWINT_TRIG_MASK |
+                         I40E_VFINT_DYN_CTLN1_SW_ITR_INDX_ENA_MASK;
+                         /* allow 00 to be written to the index */
+
+               wr32(&vsi->back->hw,
+                    I40E_VFINT_DYN_CTLN1(q_vector->v_idx +
+                                         vsi->base_vector - 1), val);
+       }
 }
 
 /**
@@ -1372,6 +1389,9 @@ int i40evf_napi_poll(struct napi_struct *napi, int budget)
                return budget;
        }
 
+       if (vsi->back->flags & I40E_TXR_FLAGS_WB_ON_ITR)
+               q_vector->arm_wb_state = false;
+
        /* Work is done so exit the polling mode and re-enable the interrupt */
        napi_complete(napi);
        i40e_update_enable_itr(vsi, q_vector);

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
index b2f9b8203c673a0720c588771bf2714039063474..17bb59d3016cb0dcffc70d47f728f48e114a9f05 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.h
@@ -262,6 +262,8 @@ struct i40e_ring {
        bool ring_active;               /* is ring online or not */
        bool arm_wb;            /* do something to arm write back */
 
+       u16 flags;
+#define I40E_TXR_FLAGS_WB_ON_ITR       BIT(0)
        /* stats structs */
        struct i40e_queue_stats stats;
        struct u64_stats_sync syncp;

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf.h b/drivers/net/ethernet/intel/i40evf/i40evf.h
index fa421d6020bea329b0a31ce0ccb85c7852a475e8..3817cbbf45e6e753089b3d36e0c03daf7b5073d8 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40evf.h
+++ b/drivers/net/ethernet/intel/i40evf/i40evf.h
@@ -117,6 +117,7 @@ struct i40e_q_vector {
        u8 num_ringpairs;       /* total number of ring pairs in vector */
        int v_idx;        /* vector index in list */
        char name[IFNAMSIZ + 9];
+       bool arm_wb_state;
        cpumask_var_t affinity_mask;
 };