mlx4: Replace the mlx4_interface.event callback with a notifier

Use a notifier to implement mlx4_dispatch_event() in preparation to
switch mlx4_en and mlx4_ib to be an auxiliary device.

A problem is that if the mlx4_interface.event callback was replaced with
something as mlx4_adrv.event then the implementation of
mlx4_dispatch_event() would need to acquire a lock on a given device
before executing this callback. That is necessary because otherwise
there is no guarantee that the associated driver cannot get unbound when
the callback is running. However, taking this lock is not possible
because mlx4_dispatch_event() can be invoked from the hardirq context.
Using an atomic notifier allows the driver to accurately record when it
wants to receive these events and solves this problem.

A handler registration is done by both mlx4_en and mlx4_ib at the end of
their mlx4_interface.add callback. This matches the current situation
when mlx4_add_device() would enable events for a given device
immediately after this callback, by adding the device on the
mlx4_priv.list.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 2c5fd8174b3ca9d3007dcb4f32d66b65178ea6a6..6debee494a16248c937031e116c76b3b57460699 100644 (file)
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -82,6 +82,8 @@ static const char mlx4_ib_version[] =
 static void do_slave_init(struct mlx4_ib_dev *ibdev, int slave, int do_init);
 static enum rdma_link_layer mlx4_ib_port_link_layer(struct ib_device *device,
                                                    u32 port_num);
+static int mlx4_ib_event(struct notifier_block *this, unsigned long event,
+                        void *param);
 
 static struct workqueue_struct *wq;
 
@@ -2836,6 +2838,12 @@ static void *mlx4_ib_add(struct mlx4_dev *dev)
                                do_slave_init(ibdev, j, 1);
                }
        }
+
+       /* register mlx4 core notifier */
+       ibdev->mlx_nb.notifier_call = mlx4_ib_event;
+       err = mlx4_register_event_notifier(dev, &ibdev->mlx_nb);
+       WARN(err, "failed to register mlx4 event notifier (%d)", err);
+
        return ibdev;
 
 err_notif:
@@ -2953,6 +2961,8 @@ static void mlx4_ib_remove(struct mlx4_dev *dev, void *ibdev_ptr)
        int p;
        int i;
 
+       mlx4_unregister_event_notifier(dev, &ibdev->mlx_nb);
+
        mlx4_foreach_port(i, dev, MLX4_PORT_TYPE_IB)
                devlink_port_type_clear(mlx4_get_devlink_port(dev, i));
        ibdev->ib_active = false;
@@ -3173,11 +3183,13 @@ void mlx4_sched_ib_sl2vl_update_work(struct mlx4_ib_dev *ibdev,
        }
 }
 
-static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
-                         enum mlx4_dev_event event, void *param)
+static int mlx4_ib_event(struct notifier_block *this, unsigned long event,
+                        void *param)
 {
+       struct mlx4_ib_dev *ibdev =
+               container_of(this, struct mlx4_ib_dev, mlx_nb);
+       struct mlx4_dev *dev = ibdev->dev;
        struct ib_event ibev;
-       struct mlx4_ib_dev *ibdev = to_mdev((struct ib_device *) ibdev_ptr);
        struct mlx4_eqe *eqe = NULL;
        struct ib_event_work *ew;
        int p = 0;
@@ -3187,11 +3199,11 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
            (event == MLX4_DEV_EVENT_PORT_DOWN))) {
                ew = kmalloc(sizeof(*ew), GFP_ATOMIC);
                if (!ew)
-                       return;
+                       return NOTIFY_DONE;
                INIT_WORK(&ew->work, handle_bonded_port_state_event);
                ew->ib_dev = ibdev;
                queue_work(wq, &ew->work);
-               return;
+               return NOTIFY_DONE;
        }
 
        switch (event) {
@@ -3208,7 +3220,7 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
        switch (event) {
        case MLX4_DEV_EVENT_PORT_UP:
                if (p > ibdev->num_ports)
-                       return;
+                       return NOTIFY_DONE;
                if (!mlx4_is_slave(dev) &&
                    rdma_port_get_link_layer(&ibdev->ib_dev, p) ==
                        IB_LINK_LAYER_INFINIBAND) {
@@ -3223,7 +3235,7 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
 
        case MLX4_DEV_EVENT_PORT_DOWN:
                if (p > ibdev->num_ports)
-                       return;
+                       return NOTIFY_DONE;
                ibev.event = IB_EVENT_PORT_ERR;
                break;
 
@@ -3236,7 +3248,7 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
        case MLX4_DEV_EVENT_PORT_MGMT_CHANGE:
                ew = kmalloc(sizeof *ew, GFP_ATOMIC);
                if (!ew)
-                       return;
+                       return NOTIFY_DONE;
 
                INIT_WORK(&ew->work, handle_port_mgmt_change_event);
                memcpy(&ew->ib_eqe, eqe, sizeof *eqe);
@@ -3246,7 +3258,7 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
                        queue_work(wq, &ew->work);
                else
                        handle_port_mgmt_change_event(&ew->work);
-               return;
+               return NOTIFY_DONE;
 
        case MLX4_DEV_EVENT_SLAVE_INIT:
                /* here, p is the slave id */
@@ -3262,7 +3274,7 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
                                                                       1);
                        }
                }
-               return;
+               return NOTIFY_DONE;
 
        case MLX4_DEV_EVENT_SLAVE_SHUTDOWN:
                if (mlx4_is_master(dev)) {
@@ -3278,22 +3290,22 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
                }
                /* here, p is the slave id */
                do_slave_init(ibdev, p, 0);
-               return;
+               return NOTIFY_DONE;
 
        default:
-               return;
+               return NOTIFY_DONE;
        }
 
-       ibev.device           = ibdev_ptr;
+       ibev.device           = &ibdev->ib_dev;
        ibev.element.port_num = mlx4_is_bonded(ibdev->dev) ? 1 : (u8)p;
 
        ib_dispatch_event(&ibev);
+       return NOTIFY_DONE;
 }
 
 static struct mlx4_interface mlx4_ib_interface = {
        .add            = mlx4_ib_add,
        .remove         = mlx4_ib_remove,
-       .event          = mlx4_ib_event,
        .protocol       = MLX4_PROT_IB_IPV6,
        .flags          = MLX4_INTFF_BONDING
 };

diff --git a/drivers/infiniband/hw/mlx4/mlx4_ib.h b/drivers/infiniband/hw/mlx4/mlx4_ib.h
index 17fee1e73a45ae2238fa775c48048cd6c32d2718..41ca1114a9958e2dd5e81eb28aca8c03c670234e 100644 (file)
--- a/drivers/infiniband/hw/mlx4/mlx4_ib.h
+++ b/drivers/infiniband/hw/mlx4/mlx4_ib.h
@@ -38,6 +38,7 @@
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/notifier.h>
 
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_umem.h>
@@ -644,6 +645,7 @@ struct mlx4_ib_dev {
        spinlock_t              reset_flow_resource_lock;
        struct list_head                qp_list;
        struct mlx4_ib_diag_counters diag_counters[MLX4_DIAG_COUNTERS_TYPES];
+       struct notifier_block   mlx_nb;
 };
 
 struct ib_event_work {

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_main.c b/drivers/net/ethernet/mellanox/mlx4/en_main.c
index 83dae886ade6e96f701151444f6f05f788b6355a..31bf625b8158e2e04d33b28684c97b6a3734f4fd 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c
@@ -183,10 +183,12 @@ static void mlx4_en_get_profile(struct mlx4_en_dev *mdev)
        }
 }
 
-static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
-                         enum mlx4_dev_event event, void *param)
+static int mlx4_en_event(struct notifier_block *this, unsigned long event,
+                        void *param)
 {
-       struct mlx4_en_dev *mdev = (struct mlx4_en_dev *) endev_ptr;
+       struct mlx4_en_dev *mdev =
+               container_of(this, struct mlx4_en_dev, mlx_nb);
+       struct mlx4_dev *dev = mdev->dev;
        struct mlx4_en_priv *priv;
        int port;
 
@@ -205,7 +207,7 @@ static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
        case MLX4_DEV_EVENT_PORT_UP:
        case MLX4_DEV_EVENT_PORT_DOWN:
                if (!mdev->pndev[port])
-                       return;
+                       return NOTIFY_DONE;
                priv = netdev_priv(mdev->pndev[port]);
                /* To prevent races, we poll the link state in a separate
                  task rather than changing it here */
@@ -224,10 +226,12 @@ static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
        default:
                if (port < 1 || port > dev->caps.num_ports ||
                    !mdev->pndev[port])
-                       return;
-               mlx4_warn(mdev, "Unhandled event %d for port %d\n", event,
+                       return NOTIFY_DONE;
+               mlx4_warn(mdev, "Unhandled event %d for port %d\n", (int)event,
                          port);
        }
+
+       return NOTIFY_DONE;
 }
 
 static void mlx4_en_remove(struct mlx4_dev *dev, void *endev_ptr)
@@ -235,6 +239,8 @@ static void mlx4_en_remove(struct mlx4_dev *dev, void *endev_ptr)
        struct mlx4_en_dev *mdev = endev_ptr;
        int i;
 
+       mlx4_unregister_event_notifier(dev, &mdev->mlx_nb);
+
        mutex_lock(&mdev->state_lock);
        mdev->device_up = false;
        mutex_unlock(&mdev->state_lock);
@@ -276,7 +282,7 @@ static void mlx4_en_activate(struct mlx4_dev *dev, void *ctx)
 static void *mlx4_en_add(struct mlx4_dev *dev)
 {
        struct mlx4_en_dev *mdev;
-       int i;
+       int err, i;
 
        printk_once(KERN_INFO "%s", mlx4_en_version);
 
@@ -339,6 +345,11 @@ static void *mlx4_en_add(struct mlx4_dev *dev)
        mutex_init(&mdev->state_lock);
        mdev->device_up = true;
 
+       /* register mlx4 core notifier */
+       mdev->mlx_nb.notifier_call = mlx4_en_event;
+       err = mlx4_register_event_notifier(dev, &mdev->mlx_nb);
+       WARN(err, "failed to register mlx4 event notifier (%d)", err);
+
        return mdev;
 
 err_mr:
@@ -359,7 +370,6 @@ err_free_res:
 static struct mlx4_interface mlx4_en_interface = {
        .add            = mlx4_en_add,
        .remove         = mlx4_en_remove,
-       .event          = mlx4_en_event,
        .protocol       = MLX4_PROT_ETH,
        .activate       = mlx4_en_activate,
 };

diff --git a/drivers/net/ethernet/mellanox/mlx4/intf.c b/drivers/net/ethernet/mellanox/mlx4/intf.c
index a761971cd0c4c1508b570a83a9ee62f4c1f64ed1..fecb63e6960737ff8bb27dd788314c89d84b6c5c 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/intf.c
+++ b/drivers/net/ethernet/mellanox/mlx4/intf.c
@@ -183,17 +183,27 @@ void mlx4_dispatch_event(struct mlx4_dev *dev, enum mlx4_dev_event type,
                         void *param)
 {
        struct mlx4_priv *priv = mlx4_priv(dev);
-       struct mlx4_device_context *dev_ctx;
-       unsigned long flags;
 
-       spin_lock_irqsave(&priv->ctx_lock, flags);
+       atomic_notifier_call_chain(&priv->event_nh, type, param);
+}
 
-       list_for_each_entry(dev_ctx, &priv->ctx_list, list)
-               if (dev_ctx->intf->event)
-                       dev_ctx->intf->event(dev, dev_ctx->context, type, param);
+int mlx4_register_event_notifier(struct mlx4_dev *dev,
+                                struct notifier_block *nb)
+{
+       struct mlx4_priv *priv = mlx4_priv(dev);
 
-       spin_unlock_irqrestore(&priv->ctx_lock, flags);
+       return atomic_notifier_chain_register(&priv->event_nh, nb);
+}
+EXPORT_SYMBOL(mlx4_register_event_notifier);
+
+int mlx4_unregister_event_notifier(struct mlx4_dev *dev,
+                                  struct notifier_block *nb)
+{
+       struct mlx4_priv *priv = mlx4_priv(dev);
+
+       return atomic_notifier_chain_unregister(&priv->event_nh, nb);
 }
+EXPORT_SYMBOL(mlx4_unregister_event_notifier);
 
 int mlx4_register_device(struct mlx4_dev *dev)
 {

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 8a5409b00530ffc9cb3893191bb88114bf568710..5f3ba8385e230002a12a858b09f5e099ce822929 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3378,6 +3378,8 @@ static int mlx4_load_one(struct pci_dev *pdev, int pci_dev_data,
        INIT_LIST_HEAD(&priv->ctx_list);
        spin_lock_init(&priv->ctx_lock);
 
+       ATOMIC_INIT_NOTIFIER_HEAD(&priv->event_nh);
+
        mutex_init(&priv->port_mutex);
        mutex_init(&priv->bond_mutex);
 

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
index de5699a4ddaab97cdd0402ddb7d294ed023c5305..8dbea814a2f5e555c20f00b63537a4f3bca76a08 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
@@ -47,6 +47,7 @@
 #include <linux/spinlock.h>
 #include <net/devlink.h>
 #include <linux/rwsem.h>
+#include <linux/notifier.h>
 
 #include <linux/mlx4/device.h>
 #include <linux/mlx4/driver.h>
@@ -878,6 +879,7 @@ struct mlx4_priv {
        struct list_head        dev_list;
        struct list_head        ctx_list;
        spinlock_t              ctx_lock;
+       struct atomic_notifier_head event_nh;
 
        int                     pci_dev_data;
        int                     removed;

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index 72a3fea36702c1077987b067e2b00bbec76fb406..efe3f97b874fec780e40f64b52fbe27d73ff78f0 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -49,6 +49,7 @@
 #include <linux/ptp_clock_kernel.h>
 #include <linux/irq.h>
 #include <net/xdp.h>
+#include <linux/notifier.h>
 
 #include <linux/mlx4/device.h>
 #include <linux/mlx4/qp.h>
@@ -433,6 +434,7 @@ struct mlx4_en_dev {
        struct ptp_clock        *ptp_clock;
        struct ptp_clock_info   ptp_clock_info;
        struct notifier_block   netdev_nb;
+       struct notifier_block   mlx_nb;
 };
 
 

diff --git a/include/linux/mlx4/driver.h b/include/linux/mlx4/driver.h
index 032d7f5bfef67257f24550bb285d267ceae482c7..228da8ed7e7507e1ca5d4ee12dcc01d56ae66823 100644 (file)
--- a/include/linux/mlx4/driver.h
+++ b/include/linux/mlx4/driver.h
@@ -34,6 +34,7 @@
 #define MLX4_DRIVER_H
 
 #include <net/devlink.h>
+#include <linux/notifier.h>
 #include <linux/mlx4/device.h>
 
 struct mlx4_dev;
@@ -57,8 +58,6 @@ enum {
 struct mlx4_interface {
        void *                  (*add)   (struct mlx4_dev *dev);
        void                    (*remove)(struct mlx4_dev *dev, void *context);
-       void                    (*event) (struct mlx4_dev *dev, void *context,
-                                         enum mlx4_dev_event event, void *param);
        void                    (*activate)(struct mlx4_dev *dev, void *context);
        struct list_head        list;
        enum mlx4_protocol      protocol;
@@ -87,6 +86,11 @@ struct mlx4_port_map {
 
 int mlx4_port_map_set(struct mlx4_dev *dev, struct mlx4_port_map *v2p);
 
+int mlx4_register_event_notifier(struct mlx4_dev *dev,
+                                struct notifier_block *nb);
+int mlx4_unregister_event_notifier(struct mlx4_dev *dev,
+                                  struct notifier_block *nb);
+
 struct devlink_port *mlx4_get_devlink_port(struct mlx4_dev *dev, int port);
 
 #endif /* MLX4_DRIVER_H */