Message-Id: <20230821131225.11290-9-petr.pavlu@suse.com>
Date: Mon, 21 Aug 2023 15:12:22 +0200
From: Petr Pavlu <petr.pavlu@...e.com>
To: tariqt@...dia.com,
	yishaih@...dia.com,
	leon@...nel.org
Cc: davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com,
	jgg@...pe.ca,
	netdev@...r.kernel.org,
	linux-rdma@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Petr Pavlu <petr.pavlu@...e.com>,
	Leon Romanovsky <leonro@...dia.com>
Subject: [PATCH net-next v3 08/11] mlx4: Register mlx4 devices to an auxiliary virtual bus

Add an auxiliary virtual bus to model the mlx4 driver structure. The
code is added along the current custom device management logic.
Subsequent patches switch mlx4_en and mlx4_ib to the auxiliary bus and
the old interface is then removed.

Structure mlx4_priv gains a new adev dynamic array to keep track of its
auxiliary devices. Access to the array is protected by the global
mlx4_intf mutex.

Functions mlx4_register_device() and mlx4_unregister_device() are
updated to expose auxiliary devices on the bus in order to load mlx4_en
and/or mlx4_ib. Functions mlx4_register_auxiliary_driver() and
mlx4_unregister_auxiliary_driver() are added to substitute
mlx4_register_interface() and mlx4_unregister_interface(), respectively.
Function mlx4_do_bond() is adjusted to walk over the adev array and
re-adds a specific auxiliary device if its driver sets the
MLX4_INTFF_BONDING flag.

Signed-off-by: Petr Pavlu <petr.pavlu@...e.com>
Tested-by: Leon Romanovsky <leonro@...dia.com>
Reviewed-by: Leon Romanovsky <leonro@...dia.com>
Acked-by: Tariq Toukan <tariqt@...dia.com>
---
 drivers/net/ethernet/mellanox/mlx4/Kconfig |   1 +
 drivers/net/ethernet/mellanox/mlx4/intf.c  | 230 ++++++++++++++++++++-
 drivers/net/ethernet/mellanox/mlx4/main.c  |  17 +-
 drivers/net/ethernet/mellanox/mlx4/mlx4.h  |   6 +
 include/linux/mlx4/device.h                |   7 +
 include/linux/mlx4/driver.h                |  11 +
 6 files changed, 268 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/Kconfig b/drivers/net/ethernet/mellanox/mlx4/Kconfig
index 1b4b1f642317..825e05fb8607 100644
--- a/drivers/net/ethernet/mellanox/mlx4/Kconfig
+++ b/drivers/net/ethernet/mellanox/mlx4/Kconfig
@@ -27,6 +27,7 @@ config MLX4_EN_DCB
 config MLX4_CORE
 	tristate
 	depends on PCI
+	select AUXILIARY_BUS
 	select NET_DEVLINK
 	default n
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/intf.c b/drivers/net/ethernet/mellanox/mlx4/intf.c
index d578f754d882..79b1eaa62ac2 100644
--- a/drivers/net/ethernet/mellanox/mlx4/intf.c
+++ b/drivers/net/ethernet/mellanox/mlx4/intf.c
@@ -48,6 +48,89 @@ struct mlx4_device_context {
 static LIST_HEAD(intf_list);
 static LIST_HEAD(dev_list);
 static DEFINE_MUTEX(intf_mutex);
+static DEFINE_IDA(mlx4_adev_ida);
+
+static const struct mlx4_adev_device {
+	const char *suffix;
+	bool (*is_supported)(struct mlx4_dev *dev);
+} mlx4_adev_devices[1] = {};
+
+int mlx4_adev_init(struct mlx4_dev *dev)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+
+	priv->adev_idx = ida_alloc(&mlx4_adev_ida, GFP_KERNEL);
+	if (priv->adev_idx < 0)
+		return priv->adev_idx;
+
+	priv->adev = kcalloc(ARRAY_SIZE(mlx4_adev_devices),
+			     sizeof(struct mlx4_adev *), GFP_KERNEL);
+	if (!priv->adev) {
+		ida_free(&mlx4_adev_ida, priv->adev_idx);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void mlx4_adev_cleanup(struct mlx4_dev *dev)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+
+	kfree(priv->adev);
+	ida_free(&mlx4_adev_ida, priv->adev_idx);
+}
+
+static void adev_release(struct device *dev)
+{
+	struct mlx4_adev *mlx4_adev =
+		container_of(dev, struct mlx4_adev, adev.dev);
+	struct mlx4_priv *priv = mlx4_priv(mlx4_adev->mdev);
+	int idx = mlx4_adev->idx;
+
+	kfree(mlx4_adev);
+	priv->adev[idx] = NULL;
+}
+
+static struct mlx4_adev *add_adev(struct mlx4_dev *dev, int idx)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+	const char *suffix = mlx4_adev_devices[idx].suffix;
+	struct auxiliary_device *adev;
+	struct mlx4_adev *madev;
+	int ret;
+
+	madev = kzalloc(sizeof(*madev), GFP_KERNEL);
+	if (!madev)
+		return ERR_PTR(-ENOMEM);
+
+	adev = &madev->adev;
+	adev->id = priv->adev_idx;
+	adev->name = suffix;
+	adev->dev.parent = &dev->persist->pdev->dev;
+	adev->dev.release = adev_release;
+	madev->mdev = dev;
+	madev->idx = idx;
+
+	ret = auxiliary_device_init(adev);
+	if (ret) {
+		kfree(madev);
+		return ERR_PTR(ret);
+	}
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ERR_PTR(ret);
+	}
+	return madev;
+}
+
+static void del_adev(struct auxiliary_device *adev)
+{
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
 
 static void mlx4_add_device(struct mlx4_interface *intf, struct mlx4_priv *priv)
 {
@@ -120,12 +203,24 @@ void mlx4_unregister_interface(struct mlx4_interface *intf)
 }
 EXPORT_SYMBOL_GPL(mlx4_unregister_interface);
 
+int mlx4_register_auxiliary_driver(struct mlx4_adrv *madrv)
+{
+	return auxiliary_driver_register(&madrv->adrv);
+}
+EXPORT_SYMBOL_GPL(mlx4_register_auxiliary_driver);
+
+void mlx4_unregister_auxiliary_driver(struct mlx4_adrv *madrv)
+{
+	auxiliary_driver_unregister(&madrv->adrv);
+}
+EXPORT_SYMBOL_GPL(mlx4_unregister_auxiliary_driver);
+
 int mlx4_do_bond(struct mlx4_dev *dev, bool enable)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_device_context *dev_ctx = NULL, *temp_dev_ctx;
 	unsigned long flags;
-	int ret;
+	int i, ret;
 	LIST_HEAD(bond_list);
 
 	if (!(dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_PORT_REMAP))
@@ -177,6 +272,57 @@ int mlx4_do_bond(struct mlx4_dev *dev, bool enable)
 			 dev_ctx->intf->protocol, enable ?
 			 "enabled" : "disabled");
 	}
+
+	mutex_lock(&intf_mutex);
+
+	for (i = 0; i < ARRAY_SIZE(mlx4_adev_devices); i++) {
+		struct mlx4_adev *madev = priv->adev[i];
+		struct mlx4_adrv *madrv;
+		enum mlx4_protocol protocol;
+
+		if (!madev)
+			continue;
+
+		device_lock(&madev->adev.dev);
+		if (!madev->adev.dev.driver) {
+			device_unlock(&madev->adev.dev);
+			continue;
+		}
+
+		madrv = container_of(madev->adev.dev.driver, struct mlx4_adrv,
+				     adrv.driver);
+		if (!(madrv->flags & MLX4_INTFF_BONDING)) {
+			device_unlock(&madev->adev.dev);
+			continue;
+		}
+
+		if (mlx4_is_mfunc(dev)) {
+			mlx4_dbg(dev,
+				 "SRIOV, disabled HA mode for intf proto %d\n",
+				 madrv->protocol);
+			device_unlock(&madev->adev.dev);
+			continue;
+		}
+
+		protocol = madrv->protocol;
+		device_unlock(&madev->adev.dev);
+
+		del_adev(&madev->adev);
+		priv->adev[i] = add_adev(dev, i);
+		if (IS_ERR(priv->adev[i])) {
+			mlx4_warn(dev, "Device[%d] (%s) failed to load\n", i,
+				  mlx4_adev_devices[i].suffix);
+			priv->adev[i] = NULL;
+			continue;
+		}
+
+		mlx4_dbg(dev,
+			 "Interface for protocol %d restarted with bonded mode %s\n",
+			 protocol, enable ? "enabled" : "disabled");
+	}
+
+	mutex_unlock(&intf_mutex);
+
 	return 0;
 }
 
@@ -206,10 +352,80 @@ int mlx4_unregister_event_notifier(struct mlx4_dev *dev,
 }
 EXPORT_SYMBOL(mlx4_unregister_event_notifier);
 
+static int add_drivers(struct mlx4_dev *dev)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+	int i, ret = 0;
+
+	for (i = 0; i < ARRAY_SIZE(mlx4_adev_devices); i++) {
+		bool is_supported = false;
+
+		if (priv->adev[i])
+			continue;
+
+		if (mlx4_adev_devices[i].is_supported)
+			is_supported = mlx4_adev_devices[i].is_supported(dev);
+
+		if (!is_supported)
+			continue;
+
+		priv->adev[i] = add_adev(dev, i);
+		if (IS_ERR(priv->adev[i])) {
+			mlx4_warn(dev, "Device[%d] (%s) failed to load\n", i,
+				  mlx4_adev_devices[i].suffix);
+			/* We continue to rescan drivers and leave to the caller
+			 * to make decision if to release everything or
+			 * continue. */
+			ret = PTR_ERR(priv->adev[i]);
+			priv->adev[i] = NULL;
+		}
+	}
+	return ret;
+}
+
+static void delete_drivers(struct mlx4_dev *dev)
+{
+	struct mlx4_priv *priv = mlx4_priv(dev);
+	bool delete_all;
+	int i;
+
+	delete_all = !(dev->persist->interface_state & MLX4_INTERFACE_STATE_UP);
+
+	for (i = ARRAY_SIZE(mlx4_adev_devices) - 1; i >= 0; i--) {
+		bool is_supported = false;
+
+		if (!priv->adev[i])
+			continue;
+
+		if (mlx4_adev_devices[i].is_supported && !delete_all)
+			is_supported = mlx4_adev_devices[i].is_supported(dev);
+
+		if (is_supported)
+			continue;
+
+		del_adev(&priv->adev[i]->adev);
+		priv->adev[i] = NULL;
+	}
+}
+
+/* This function is used after mlx4_dev is reconfigured.
+ */
+static int rescan_drivers_locked(struct mlx4_dev *dev)
+{
+	lockdep_assert_held(&intf_mutex);
+
+	delete_drivers(dev);
+	if (!(dev->persist->interface_state & MLX4_INTERFACE_STATE_UP))
+		return 0;
+
+	return add_drivers(dev);
+}
+
 int mlx4_register_device(struct mlx4_dev *dev)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	struct mlx4_interface *intf;
+	int ret;
 
 	mutex_lock(&intf_mutex);
 
@@ -218,10 +434,18 @@ int mlx4_register_device(struct mlx4_dev *dev)
 	list_for_each_entry(intf, &intf_list, list)
 		mlx4_add_device(intf, priv);
 
+	ret = rescan_drivers_locked(dev);
+
 	mutex_unlock(&intf_mutex);
+
+	if (ret) {
+		mlx4_unregister_device(dev);
+		return ret;
+	}
+
 	mlx4_start_catas_poll(dev);
 
-	return 0;
+	return ret;
 }
 
 void mlx4_unregister_device(struct mlx4_dev *dev)
@@ -253,6 +477,8 @@ void mlx4_unregister_device(struct mlx4_dev *dev)
 	list_del(&priv->dev_list);
 	dev->persist->interface_state &= ~MLX4_INTERFACE_STATE_UP;
 
+	rescan_drivers_locked(dev);
+
 	mutex_unlock(&intf_mutex);
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 0ed490b99163..c4ec7377aa71 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3429,6 +3429,10 @@ 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);
 
+	err = mlx4_adev_init(dev);
+	if (err)
+		return err;
+
 	ATOMIC_INIT_NOTIFIER_HEAD(&priv->event_nh);
 
 	mutex_init(&priv->port_mutex);
@@ -3455,10 +3459,11 @@ static int mlx4_load_one(struct pci_dev *pdev, int pci_dev_data,
 		err = mlx4_get_ownership(dev);
 		if (err) {
 			if (err < 0)
-				return err;
+				goto err_adev;
 			else {
 				mlx4_warn(dev, "Multiple PFs not yet supported - Skipping PF\n");
-				return -EINVAL;
+				err = -EINVAL;
+				goto err_adev;
 			}
 		}
 
@@ -3806,6 +3811,9 @@ static int mlx4_load_one(struct pci_dev *pdev, int pci_dev_data,
 		mlx4_free_ownership(dev);
 
 	kfree(dev_cap);
+
+err_adev:
+	mlx4_adev_cleanup(dev);
 	return err;
 }
 
@@ -4186,6 +4194,8 @@ static void mlx4_unload_one(struct pci_dev *pdev)
 	mlx4_slave_destroy_special_qp_cap(dev);
 	kfree(dev->dev_vfs);
 
+	mlx4_adev_cleanup(dev);
+
 	mlx4_clean_dev(dev);
 	priv->pci_dev_data = pci_dev_data;
 	priv->removed = 1;
@@ -4573,6 +4583,9 @@ static int __init mlx4_init(void)
 {
 	int ret;
 
+	WARN_ONCE(strcmp(MLX4_ADEV_NAME, KBUILD_MODNAME),
+		  "mlx4_core name not in sync with kernel module name");
+
 	if (mlx4_verify_params())
 		return -EINVAL;
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h
index 73b4fdfd63f4..36de79c8d053 100644
--- 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/auxiliary_bus.h>
 #include <linux/notifier.h>
 
 #include <linux/mlx4/device.h>
@@ -884,6 +885,8 @@ struct mlx4_priv {
 	struct list_head	dev_list;
 	struct list_head	ctx_list;
 	spinlock_t		ctx_lock;
+	struct mlx4_adev	**adev;
+	int			adev_idx;
 	struct atomic_notifier_head event_nh;
 
 	int			pci_dev_data;
@@ -1052,6 +1055,9 @@ void mlx4_catas_end(struct mlx4_dev *dev);
 int mlx4_crdump_init(struct mlx4_dev *dev);
 void mlx4_crdump_end(struct mlx4_dev *dev);
 int mlx4_restart_one(struct pci_dev *pdev);
+
+int mlx4_adev_init(struct mlx4_dev *dev);
+void mlx4_adev_cleanup(struct mlx4_dev *dev);
 int mlx4_register_device(struct mlx4_dev *dev);
 void mlx4_unregister_device(struct mlx4_dev *dev);
 void mlx4_dispatch_event(struct mlx4_dev *dev, enum mlx4_dev_event type,
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index 049d8a4b044d..27f42f713c89 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -33,6 +33,7 @@
 #ifndef MLX4_DEVICE_H
 #define MLX4_DEVICE_H
 
+#include <linux/auxiliary_bus.h>
 #include <linux/if_ether.h>
 #include <linux/pci.h>
 #include <linux/completion.h>
@@ -889,6 +890,12 @@ struct mlx4_dev {
 	u8  uar_page_shift;
 };
 
+struct mlx4_adev {
+	struct auxiliary_device adev;
+	struct mlx4_dev *mdev;
+	int idx;
+};
+
 struct mlx4_clock_params {
 	u64 offset;
 	u8 bar;
diff --git a/include/linux/mlx4/driver.h b/include/linux/mlx4/driver.h
index 781d5a0c2faa..9cf157d381c6 100644
--- a/include/linux/mlx4/driver.h
+++ b/include/linux/mlx4/driver.h
@@ -34,9 +34,12 @@
 #define MLX4_DRIVER_H
 
 #include <net/devlink.h>
+#include <linux/auxiliary_bus.h>
 #include <linux/notifier.h>
 #include <linux/mlx4/device.h>
 
+#define MLX4_ADEV_NAME "mlx4_core"
+
 struct mlx4_dev;
 
 #define MLX4_MAC_MASK	   0xffffffffffffULL
@@ -63,8 +66,16 @@ struct mlx4_interface {
 	int			flags;
 };
 
+struct mlx4_adrv {
+	struct auxiliary_driver	adrv;
+	enum mlx4_protocol	protocol;
+	int			flags;
+};
+
 int mlx4_register_interface(struct mlx4_interface *intf);
 void mlx4_unregister_interface(struct mlx4_interface *intf);
+int mlx4_register_auxiliary_driver(struct mlx4_adrv *madrv);
+void mlx4_unregister_auxiliary_driver(struct mlx4_adrv *madrv);
 
 int mlx4_register_event_notifier(struct mlx4_dev *dev,
 				 struct notifier_block *nb);
-- 
2.35.3

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