net/mlx4_en: Don't use irq_affinity_notifier to track changes in IRQ affinity map

IRQ affinity notifier can only have a single notifier - cpu_rmap
notifier. Can't use it to track changes in IRQ affinity map.
Detect IRQ affinity changes by comparing CPU to current IRQ affinity map
during NAPI poll thread.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Hutchings <ben@decadent.org.uk>
Fixes: 2eacc23 ("net/mlx4_core: Enforce irq affinity changes immediatly")
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 28 insertions, 74 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c b/drivers/net/ethernet/mellanox/mlx4/cq.c
index 80f725228f5b..56022d647837 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cq.c
@@ -294,8 +294,6 @@ int mlx4_cq_alloc(struct mlx4_dev *dev, int nent,
         init_completion(&cq->free);
 
         cq->irq = priv->eq_table.eq[cq->vector].irq;
-        cq->irq_affinity_change = false;
-
         return 0;
 
 err_radix:
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
index 4b2130760eed..1213cc71348c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
@@ -128,6 +128,10 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
                                         mlx4_warn(mdev, "Failed assigning an EQ to %s, falling back to legacy EQ's\n",
                                                   name);
                                 }
+
+                                cq->irq_desc =
+                                        irq_to_desc(mlx4_eq_get_irq(mdev->dev,
+                                                                    cq->vector));
                         }
                 } else {
                         cq->vector = (cq->ring + 1 + priv->port) %
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index d2d415732d99..96724170308a 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -40,6 +40,7 @@
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>
 #include <linux/vmalloc.h>
+#include <linux/irq.h>
 
 #include "mlx4_en.h"
 
@@ -896,16 +897,25 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget)
 
         /* If we used up all the quota - we're probably not done yet... */
         if (done == budget) {
+                int cpu_curr;
+                const struct cpumask *aff;
+
                 INC_PERF_COUNTER(priv->pstats.napi_quota);
-                if (unlikely(cq->mcq.irq_affinity_change)) {
-                        cq->mcq.irq_affinity_change = false;
+
+                cpu_curr = smp_processor_id();
+                aff = irq_desc_get_irq_data(cq->irq_desc)->affinity;
+
+                if (unlikely(!cpumask_test_cpu(cpu_curr, aff))) {
+                        /* Current cpu is not according to smp_irq_affinity -
+                         * probably affinity changed. need to stop this NAPI
+                         * poll, and restart it on the right CPU
+                         */
                         napi_complete(napi);
                         mlx4_en_arm_cq(priv, cq);
                         return 0;
                 }
         } else {
                 /* Done for now */
-                cq->mcq.irq_affinity_change = false;
                 napi_complete(napi);
                 mlx4_en_arm_cq(priv, cq);
         }
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 8be7483f8236..ac3dead3792c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -474,15 +474,9 @@ int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
         /* If we used up all the quota - we're probably not done yet... */
         if (done < budget) {
                 /* Done for now */
-                cq->mcq.irq_affinity_change = false;
                 napi_complete(napi);
                 mlx4_en_arm_cq(priv, cq);
                 return done;
-        } else if (unlikely(cq->mcq.irq_affinity_change)) {
-                cq->mcq.irq_affinity_change = false;
-                napi_complete(napi);
-                mlx4_en_arm_cq(priv, cq);
-                return 0;
         }
         return budget;
 }
diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index d954ec1eac17..2a004b347e1d 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
@@ -53,11 +53,6 @@ enum {
         MLX4_EQ_ENTRY_SIZE      = 0x20
 };
 
-struct mlx4_irq_notify {
-        void *arg;
-        struct irq_affinity_notify notify;
-};
-
 #define MLX4_EQ_STATUS_OK          ( 0 << 28)
 #define MLX4_EQ_STATUS_WRITE_FAIL  (10 << 28)
 #define MLX4_EQ_OWNER_SW           ( 0 << 24)
@@ -1088,57 +1083,6 @@ static void mlx4_unmap_clr_int(struct mlx4_dev *dev)
         iounmap(priv->clr_base);
 }
 
-static void mlx4_irq_notifier_notify(struct irq_affinity_notify *notify,
-                                     const cpumask_t *mask)
-{
-        struct mlx4_irq_notify *n = container_of(notify,
-                                                 struct mlx4_irq_notify,
-                                                 notify);
-        struct mlx4_priv *priv = (struct mlx4_priv *)n->arg;
-        struct radix_tree_iter iter;
-        void **slot;
-
-        radix_tree_for_each_slot(slot, &priv->cq_table.tree, &iter, 0) {
-                struct mlx4_cq *cq = (struct mlx4_cq *)(*slot);
-
-                if (cq->irq == notify->irq)
-                        cq->irq_affinity_change = true;
-        }
-}
-
-static void mlx4_release_irq_notifier(struct kref *ref)
-{
-        struct mlx4_irq_notify *n = container_of(ref, struct mlx4_irq_notify,
-                                                 notify.kref);
-        kfree(n);
-}
-
-static void mlx4_assign_irq_notifier(struct mlx4_priv *priv,
-                                     struct mlx4_dev *dev, int irq)
-{
-        struct mlx4_irq_notify *irq_notifier = NULL;
-        int err = 0;
-
-        irq_notifier = kzalloc(sizeof(*irq_notifier), GFP_KERNEL);
-        if (!irq_notifier) {
-                mlx4_warn(dev, "Failed to allocate irq notifier. irq %d\n",
-                          irq);
-                return;
-        }
-
-        irq_notifier->notify.irq = irq;
-        irq_notifier->notify.notify = mlx4_irq_notifier_notify;
-        irq_notifier->notify.release = mlx4_release_irq_notifier;
-        irq_notifier->arg = priv;
-        err = irq_set_affinity_notifier(irq, &irq_notifier->notify);
-        if (err) {
-                kfree(irq_notifier);
-                irq_notifier = NULL;
-                mlx4_warn(dev, "Failed to set irq notifier. irq %d\n", irq);
-        }
-}
-
-
 int mlx4_alloc_eq_table(struct mlx4_dev *dev)
 {
         struct mlx4_priv *priv = mlx4_priv(dev);
@@ -1409,8 +1353,6 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
                                 continue;
                                 /*we dont want to break here*/
                         }
-                        mlx4_assign_irq_notifier(priv, dev,
-                                                 priv->eq_table.eq[vec].irq);
 
                         eq_set_ci(&priv->eq_table.eq[vec], 1);
                 }
@@ -1427,6 +1369,14 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
 }
 EXPORT_SYMBOL(mlx4_assign_eq);
 
+int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec)
+{
+        struct mlx4_priv *priv = mlx4_priv(dev);
+
+        return priv->eq_table.eq[vec].irq;
+}
+EXPORT_SYMBOL(mlx4_eq_get_irq);
+
 void mlx4_release_eq(struct mlx4_dev *dev, int vec)
 {
         struct mlx4_priv *priv = mlx4_priv(dev);
@@ -1438,9 +1388,6 @@ void mlx4_release_eq(struct mlx4_dev *dev, int vec)
                   Belonging to a legacy EQ*/
                 mutex_lock(&priv->msix_ctl.pool_lock);
                 if (priv->msix_ctl.pool_bm & 1ULL << i) {
-                        irq_set_affinity_notifier(
-                                priv->eq_table.eq[vec].irq,
-                                NULL);
                         free_irq(priv->eq_table.eq[vec].irq,
                                  &priv->eq_table.eq[vec]);
                         priv->msix_ctl.pool_bm &= ~(1ULL << i);
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 0e15295bedd6..624e1939e9ee 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -343,6 +343,7 @@ struct mlx4_en_cq {
 #define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD)
         spinlock_t poll_lock; /* protects from LLS/napi conflicts */
 #endif  /* CONFIG_NET_RX_BUSY_POLL */
+        struct irq_desc *irq_desc;
 };
 
 struct mlx4_en_port_profile {
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index b12f4bbd064c..35b51e7af886 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -578,8 +578,6 @@ struct mlx4_cq {
         u32                     cons_index;
 
         u16                     irq;
-        bool                    irq_affinity_change;
-
         __be32                 *set_ci_db;
         __be32                 *arm_db;
         int                     arm_sn;
@@ -1167,6 +1165,8 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap,
                    int *vector);
 void mlx4_release_eq(struct mlx4_dev *dev, int vec);
 
+int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec);
+
 int mlx4_get_phys_port_id(struct mlx4_dev *dev);
 int mlx4_wol_read(struct mlx4_dev *dev, u64 *config, int port);
 int mlx4_wol_write(struct mlx4_dev *dev, u64 config, int port);