[PATCH net-next 0/6] devlink: expose instance locking and simplify port splitting

[PATCH net-next 0/6] devlink: expose instance locking and simplify port splitting

[Jakub Kicinski]

This series puts the devlink ports fully under the devlink instance
lock's protection. As discussed in the past it implements my preferred
solution of exposing the instance lock to the drivers. This way drivers
which want to support port splitting can lock the devlink instance
themselves on the probe path, and we can take that lock in the core
on the split/unsplit paths.

nfp and mlxsw are converted, with slightly deeper changes done in
nfp since I'm more familiar with that driver.

Now that the devlink port is protected we can pass a pointer to
the drivers, instead of passing a port index and forcing the drivers
to do their own lookups. Both nfp and mlxsw can container_of() to
their own structures.

v1:
 - redo the lockdep check (patch 1)
 - add a small section to the docs (patch 1)
 - build fix (patch 2)
 - keeping the devl_ prefix :X

Jakub Kicinski (6):
  devlink: expose instance locking and add locked port registering
  eth: nfp: wrap locking assertions in helpers
  eth: nfp: replace driver's "pf" lock with devlink instance lock
  eth: mlxsw: switch to explicit locking for port registration
  devlink: hold the instance lock in port_split / port_unsplit callbacks
  devlink: pass devlink_port to port_split / port_unsplit callbacks

 Documentation/networking/devlink/index.rst    |  16 ++
 drivers/net/ethernet/mellanox/mlxsw/core.c    |  36 ++---
 drivers/net/ethernet/mellanox/mlxsw/minimal.c |   6 +
 .../net/ethernet/mellanox/mlxsw/spectrum.c    |   7 +
 .../net/ethernet/netronome/nfp/flower/main.c  |   4 +-
 drivers/net/ethernet/netronome/nfp/nfp_app.c  |   2 +-
 drivers/net/ethernet/netronome/nfp/nfp_app.h  |  12 +-
 .../net/ethernet/netronome/nfp/nfp_devlink.c  |  55 +++----
 drivers/net/ethernet/netronome/nfp/nfp_main.c |  19 +--
 drivers/net/ethernet/netronome/nfp/nfp_main.h |   6 +-
 .../net/ethernet/netronome/nfp/nfp_net_main.c |  34 +++--
 .../net/ethernet/netronome/nfp/nfp_net_repr.c |   4 +-
 drivers/net/ethernet/netronome/nfp/nfp_port.c |  17 ---
 drivers/net/ethernet/netronome/nfp/nfp_port.h |   2 -
 include/net/devlink.h                         |  15 +-
 net/core/devlink.c                            | 144 ++++++++++--------
 16 files changed, 208 insertions(+), 171 deletions(-)

-- 
2.34.1

[PATCH net-next 1/6] devlink: expose instance locking and add locked port registering

[Jakub Kicinski]

It should be familiar and beneficial to expose devlink instance
lock to the drivers. This way drivers can block devlink from
calling them during critical sections without breakneck locking.

Add port helpers, port splitting callbacks will be the first
target.

Use 'devl_' prefix for "explicitly locked" API. Initial RFC used
'__devlink' but that's too much typing.

devl_lock_is_held() is not defined without lockdep, which is
the same behavior as lockdep_is_held() itself.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v1: - add a small section to the docs
    - redo the lockdep ifdef
---
 Documentation/networking/devlink/index.rst | 16 ++++
 include/net/devlink.h                      | 11 +++
 net/core/devlink.c                         | 95 ++++++++++++++++------
 3 files changed, 98 insertions(+), 24 deletions(-)

diff --git a/Documentation/networking/devlink/index.rst b/Documentation/networking/devlink/index.rst
index 443123772f44..c17cdb079611 100644
--- a/Documentation/networking/devlink/index.rst
+++ b/Documentation/networking/devlink/index.rst
@@ -4,6 +4,22 @@ Linux Devlink Documentation
 devlink is an API to expose device information and resources not directly
 related to any device class, such as chip-wide/switch-ASIC-wide configuration.
 
+Locking
+-------
+
+Driver facing APIs are currently transitioning to allow more explicit
+locking. Drivers can use the existing ``devlink_*`` set of APIs, or
+new APIs prefixed by ``devl_*``. The older APIs handle all the locking
+in devlink core, but don't allow registration of most sub-objects once
+the main devlink object is itself registered. The newer ``devl_*`` APIs assume
+the devlink instance lock is already held. Drivers can take the instance
+lock by calling ``devl_lock()``. It is also held in most of the callbacks.
+Eventually all callbacks will be invoked under the devlink instance lock,
+refer to the use of the ``DEVLINK_NL_FLAG_NO_LOCK`` flag in devlink core
+to find out which callbacks are not converted, yet.
+
+Drivers are encouraged to use the devlink instance lock for their own needs.
+
 Interface documentation
 -----------------------
 
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 8d5349d2fb68..9de0d091aee9 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1479,6 +1479,17 @@ void *devlink_priv(struct devlink *devlink);
 struct devlink *priv_to_devlink(void *priv);
 struct device *devlink_to_dev(const struct devlink *devlink);
 
+/* Devlink instance explicit locking */
+void devl_lock(struct devlink *devlink);
+void devl_unlock(struct devlink *devlink);
+void devl_assert_locked(struct devlink *devlink);
+bool devl_lock_is_held(struct devlink *devlink);
+
+int devl_port_register(struct devlink *devlink,
+		       struct devlink_port *devlink_port,
+		       unsigned int port_index);
+void devl_port_unregister(struct devlink_port *devlink_port);
+
 struct ib_device;
 
 struct net *devlink_net(const struct devlink *devlink);
diff --git a/net/core/devlink.c b/net/core/devlink.c
index fcd9f6d85cf1..769e5f7fa219 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -225,6 +225,33 @@ struct devlink *__must_check devlink_try_get(struct devlink *devlink)
 	return NULL;
 }
 
+void devl_assert_locked(struct devlink *devlink)
+{
+	lockdep_assert_held(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_assert_locked);
+
+#ifdef CONFIG_LOCKDEP
+/* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
+bool devl_lock_is_held(struct devlink *devlink)
+{
+	return lockdep_is_held(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_lock_is_held);
+#endif
+
+void devl_lock(struct devlink *devlink)
+{
+	mutex_lock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_lock);
+
+void devl_unlock(struct devlink *devlink)
+{
+	mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_unlock);
+
 static struct devlink *devlink_get_from_attrs(struct net *net,
 					      struct nlattr **attrs)
 {
@@ -9249,6 +9276,32 @@ static void devlink_port_type_warn_cancel(struct devlink_port *devlink_port)
 	cancel_delayed_work_sync(&devlink_port->type_warn_dw);
 }
 
+int devl_port_register(struct devlink *devlink,
+		       struct devlink_port *devlink_port,
+		       unsigned int port_index)
+{
+	lockdep_assert_held(&devlink->lock);
+
+	if (devlink_port_index_exists(devlink, port_index))
+		return -EEXIST;
+
+	WARN_ON(devlink_port->devlink);
+	devlink_port->devlink = devlink;
+	devlink_port->index = port_index;
+	spin_lock_init(&devlink_port->type_lock);
+	INIT_LIST_HEAD(&devlink_port->reporter_list);
+	mutex_init(&devlink_port->reporters_lock);
+	list_add_tail(&devlink_port->list, &devlink->port_list);
+	INIT_LIST_HEAD(&devlink_port->param_list);
+	INIT_LIST_HEAD(&devlink_port->region_list);
+
+	INIT_DELAYED_WORK(&devlink_port->type_warn_dw, &devlink_port_type_warn);
+	devlink_port_type_warn_schedule(devlink_port);
+	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devl_port_register);
+
 /**
  *	devlink_port_register - Register devlink port
  *
@@ -9266,29 +9319,28 @@ int devlink_port_register(struct devlink *devlink,
 			  struct devlink_port *devlink_port,
 			  unsigned int port_index)
 {
-	mutex_lock(&devlink->lock);
-	if (devlink_port_index_exists(devlink, port_index)) {
-		mutex_unlock(&devlink->lock);
-		return -EEXIST;
-	}
+	int err;
 
-	WARN_ON(devlink_port->devlink);
-	devlink_port->devlink = devlink;
-	devlink_port->index = port_index;
-	spin_lock_init(&devlink_port->type_lock);
-	INIT_LIST_HEAD(&devlink_port->reporter_list);
-	mutex_init(&devlink_port->reporters_lock);
-	list_add_tail(&devlink_port->list, &devlink->port_list);
-	INIT_LIST_HEAD(&devlink_port->param_list);
-	INIT_LIST_HEAD(&devlink_port->region_list);
+	mutex_lock(&devlink->lock);
+	err = devl_port_register(devlink, devlink_port, port_index);
 	mutex_unlock(&devlink->lock);
-	INIT_DELAYED_WORK(&devlink_port->type_warn_dw, &devlink_port_type_warn);
-	devlink_port_type_warn_schedule(devlink_port);
-	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL_GPL(devlink_port_register);
 
+void devl_port_unregister(struct devlink_port *devlink_port)
+{
+	lockdep_assert_held(&devlink_port->devlink->lock);
+
+	devlink_port_type_warn_cancel(devlink_port);
+	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_DEL);
+	list_del(&devlink_port->list);
+	WARN_ON(!list_empty(&devlink_port->reporter_list));
+	WARN_ON(!list_empty(&devlink_port->region_list));
+	mutex_destroy(&devlink_port->reporters_lock);
+}
+EXPORT_SYMBOL_GPL(devl_port_unregister);
+
 /**
  *	devlink_port_unregister - Unregister devlink port
  *
@@ -9298,14 +9350,9 @@ void devlink_port_unregister(struct devlink_port *devlink_port)
 {
 	struct devlink *devlink = devlink_port->devlink;
 
-	devlink_port_type_warn_cancel(devlink_port);
-	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_DEL);
 	mutex_lock(&devlink->lock);
-	list_del(&devlink_port->list);
+	devl_port_unregister(devlink_port);
 	mutex_unlock(&devlink->lock);
-	WARN_ON(!list_empty(&devlink_port->reporter_list));
-	WARN_ON(!list_empty(&devlink_port->region_list));
-	mutex_destroy(&devlink_port->reporters_lock);
 }
 EXPORT_SYMBOL_GPL(devlink_port_unregister);
 
-- 
2.34.1

[PATCH net-next 2/6] eth: nfp: wrap locking assertions in helpers

[Jakub Kicinski]

We can replace the PF lock with devlink instance lock in subsequent
changes. To make the patches easier to comprehend and limit line
lengths - factor out the existing locking assertions.

No functional changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/netronome/nfp/flower/main.c  | 4 ++--
 drivers/net/ethernet/netronome/nfp/nfp_app.c      | 2 +-
 drivers/net/ethernet/netronome/nfp/nfp_app.h      | 9 +++++++++
 drivers/net/ethernet/netronome/nfp/nfp_net_repr.c | 4 ++--
 4 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/flower/main.c b/drivers/net/ethernet/netronome/nfp/flower/main.c
index ac1dcfa1d179..4d960a9641b3 100644
--- a/drivers/net/ethernet/netronome/nfp/flower/main.c
+++ b/drivers/net/ethernet/netronome/nfp/flower/main.c
@@ -266,7 +266,7 @@ nfp_flower_reprs_reify(struct nfp_app *app, enum nfp_repr_type type,
 	int i, err, count = 0;
 
 	reprs = rcu_dereference_protected(app->reprs[type],
-					  lockdep_is_held(&app->pf->lock));
+					  nfp_app_is_locked(app));
 	if (!reprs)
 		return 0;
 
@@ -295,7 +295,7 @@ nfp_flower_wait_repr_reify(struct nfp_app *app, atomic_t *replies, int tot_repl)
 	if (!tot_repl)
 		return 0;
 
-	lockdep_assert_held(&app->pf->lock);
+	assert_nfp_app_locked(app);
 	if (!wait_event_timeout(priv->reify_wait_queue,
 				atomic_read(replies) >= tot_repl,
 				NFP_FL_REPLY_TIMEOUT)) {
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.c b/drivers/net/ethernet/netronome/nfp/nfp_app.c
index 3a973282b2bb..09f250e74dfa 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.c
@@ -121,7 +121,7 @@ struct nfp_reprs *
 nfp_reprs_get_locked(struct nfp_app *app, enum nfp_repr_type type)
 {
 	return rcu_dereference_protected(app->reprs[type],
-					 lockdep_is_held(&app->pf->lock));
+					 nfp_app_is_locked(app));
 }
 
 struct nfp_reprs *
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.h b/drivers/net/ethernet/netronome/nfp/nfp_app.h
index 3e9baff07100..60cb8a71e02d 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.h
@@ -4,10 +4,12 @@
 #ifndef _NFP_APP_H
 #define _NFP_APP_H 1
 
+#include <linux/lockdep.h>
 #include <net/devlink.h>
 
 #include <trace/events/devlink.h>
 
+#include "nfp_main.h"
 #include "nfp_net_repr.h"
 
 #define NFP_APP_CTRL_MTU_MAX	U32_MAX
@@ -174,6 +176,13 @@ struct nfp_app {
 	void *priv;
 };
 
+static inline void assert_nfp_app_locked(struct nfp_app *app)
+{
+	lockdep_assert_held(&app->pf->lock);
+}
+
+#define nfp_app_is_locked(app)	lockdep_is_held(&(app)->pf->lock)
+
 void nfp_check_rhashtable_empty(void *ptr, void *arg);
 bool __nfp_ctrl_tx(struct nfp_net *nn, struct sk_buff *skb);
 bool nfp_ctrl_tx(struct nfp_net *nn, struct sk_buff *skb);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
index 181ac8e789a3..ba3fa7eac98d 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_repr.c
@@ -20,7 +20,7 @@ struct net_device *
 nfp_repr_get_locked(struct nfp_app *app, struct nfp_reprs *set, unsigned int id)
 {
 	return rcu_dereference_protected(set->reprs[id],
-					 lockdep_is_held(&app->pf->lock));
+					 nfp_app_is_locked(app));
 }
 
 static void
@@ -476,7 +476,7 @@ nfp_reprs_clean_and_free_by_type(struct nfp_app *app, enum nfp_repr_type type)
 	int i;
 
 	reprs = rcu_dereference_protected(app->reprs[type],
-					  lockdep_is_held(&app->pf->lock));
+					  nfp_app_is_locked(app));
 	if (!reprs)
 		return;
 
-- 
2.34.1

[PATCH net-next 3/6] eth: nfp: replace driver's "pf" lock with devlink instance lock

[Jakub Kicinski]

The whole reason for existence of the pf mutex is that we could
not lock the devlink instance around port splitting. There are
more types of reconfig which can make ports appear or disappear.
Now that the devlink instance lock is exposed to drivers and
"locked" helpers exist we can switch to using the devlink lock
directly.

Next patches will move the locking inside .port_(un)split to
the core.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/netronome/nfp/nfp_app.h  | 11 +++---
 .../net/ethernet/netronome/nfp/nfp_devlink.c  | 16 ++++-----
 drivers/net/ethernet/netronome/nfp/nfp_main.c | 19 ++++++-----
 drivers/net/ethernet/netronome/nfp/nfp_main.h |  6 ++--
 .../net/ethernet/netronome/nfp/nfp_net_main.c | 34 +++++++++++--------
 drivers/net/ethernet/netronome/nfp/nfp_port.c |  3 +-
 6 files changed, 48 insertions(+), 41 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_app.h b/drivers/net/ethernet/netronome/nfp/nfp_app.h
index 60cb8a71e02d..dd56207df246 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_app.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_app.h
@@ -4,12 +4,10 @@
 #ifndef _NFP_APP_H
 #define _NFP_APP_H 1
 
-#include <linux/lockdep.h>
 #include <net/devlink.h>
 
 #include <trace/events/devlink.h>
 
-#include "nfp_main.h"
 #include "nfp_net_repr.h"
 
 #define NFP_APP_CTRL_MTU_MAX	U32_MAX
@@ -77,7 +75,7 @@ extern const struct nfp_app_type app_abm;
  * @bpf:	BPF ndo offload-related calls
  * @xdp_offload:    offload an XDP program
  * @eswitch_mode_get:    get SR-IOV eswitch mode
- * @eswitch_mode_set:    set SR-IOV eswitch mode (under pf->lock)
+ * @eswitch_mode_set:    set SR-IOV eswitch mode
  * @sriov_enable: app-specific sriov initialisation
  * @sriov_disable: app-specific sriov clean-up
  * @dev_get:	get representor or internal port representing netdev
@@ -178,10 +176,13 @@ struct nfp_app {
 
 static inline void assert_nfp_app_locked(struct nfp_app *app)
 {
-	lockdep_assert_held(&app->pf->lock);
+	devl_assert_locked(priv_to_devlink(app->pf));
 }
 
-#define nfp_app_is_locked(app)	lockdep_is_held(&(app)->pf->lock)
+static inline bool nfp_app_is_locked(struct nfp_app *app)
+{
+	return devl_lock_is_held(priv_to_devlink(app->pf));
+}
 
 void nfp_check_rhashtable_empty(void *ptr, void *arg);
 bool __nfp_ctrl_tx(struct nfp_net *nn, struct sk_buff *skb);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
index bea978df7713..865f62958a72 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
@@ -70,7 +70,7 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 	unsigned int lanes;
 	int ret;
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 
 	rtnl_lock();
 	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
@@ -90,7 +90,7 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 
 	ret = nfp_devlink_set_lanes(pf, eth_port.index, lanes);
 out:
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	return ret;
 }
@@ -104,7 +104,7 @@ nfp_devlink_port_unsplit(struct devlink *devlink, unsigned int port_index,
 	unsigned int lanes;
 	int ret;
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 
 	rtnl_lock();
 	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
@@ -124,7 +124,7 @@ nfp_devlink_port_unsplit(struct devlink *devlink, unsigned int port_index,
 
 	ret = nfp_devlink_set_lanes(pf, eth_port.index, lanes);
 out:
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	return ret;
 }
@@ -163,9 +163,9 @@ static int nfp_devlink_eswitch_mode_set(struct devlink *devlink, u16 mode,
 	struct nfp_pf *pf = devlink_priv(devlink);
 	int ret;
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	ret = nfp_app_eswitch_mode_set(pf->app, mode);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	return ret;
 }
@@ -375,12 +375,12 @@ int nfp_devlink_port_register(struct nfp_app *app, struct nfp_port *port)
 
 	devlink = priv_to_devlink(app->pf);
 
-	return devlink_port_register(devlink, &port->dl_port, port->eth_id);
+	return devl_port_register(devlink, &port->dl_port, port->eth_id);
 }
 
 void nfp_devlink_port_unregister(struct nfp_port *port)
 {
-	devlink_port_unregister(&port->dl_port);
+	devl_port_unregister(&port->dl_port);
 }
 
 void nfp_devlink_port_type_eth_set(struct nfp_port *port)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.c b/drivers/net/ethernet/netronome/nfp/nfp_main.c
index 8693f9905fbe..eeda39e34f84 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.c
@@ -227,6 +227,7 @@ static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs)
 {
 #ifdef CONFIG_PCI_IOV
 	struct nfp_pf *pf = pci_get_drvdata(pdev);
+	struct devlink *devlink;
 	int err;
 
 	if (num_vfs > pf->limit_vfs) {
@@ -241,7 +242,8 @@ static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs)
 		return err;
 	}
 
-	mutex_lock(&pf->lock);
+	devlink = priv_to_devlink(pf);
+	devl_lock(devlink);
 
 	err = nfp_app_sriov_enable(pf->app, num_vfs);
 	if (err) {
@@ -255,11 +257,11 @@ static int nfp_pcie_sriov_enable(struct pci_dev *pdev, int num_vfs)
 
 	dev_dbg(&pdev->dev, "Created %d VFs.\n", pf->num_vfs);
 
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 	return num_vfs;
 
 err_sriov_disable:
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 	pci_disable_sriov(pdev);
 	return err;
 #endif
@@ -270,8 +272,10 @@ static int nfp_pcie_sriov_disable(struct pci_dev *pdev)
 {
 #ifdef CONFIG_PCI_IOV
 	struct nfp_pf *pf = pci_get_drvdata(pdev);
+	struct devlink *devlink;
 
-	mutex_lock(&pf->lock);
+	devlink = priv_to_devlink(pf);
+	devl_lock(devlink);
 
 	/* If the VFs are assigned we cannot shut down SR-IOV without
 	 * causing issues, so just leave the hardware available but
@@ -279,7 +283,7 @@ static int nfp_pcie_sriov_disable(struct pci_dev *pdev)
 	 */
 	if (pci_vfs_assigned(pdev)) {
 		dev_warn(&pdev->dev, "Disabling while VFs assigned - VFs will not be deallocated\n");
-		mutex_unlock(&pf->lock);
+		devl_unlock(devlink);
 		return -EPERM;
 	}
 
@@ -287,7 +291,7 @@ static int nfp_pcie_sriov_disable(struct pci_dev *pdev)
 
 	pf->num_vfs = 0;
 
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	pci_disable_sriov(pdev);
 	dev_dbg(&pdev->dev, "Removed VFs.\n");
@@ -707,7 +711,6 @@ static int nfp_pci_probe(struct pci_dev *pdev,
 	pf = devlink_priv(devlink);
 	INIT_LIST_HEAD(&pf->vnics);
 	INIT_LIST_HEAD(&pf->ports);
-	mutex_init(&pf->lock);
 	pci_set_drvdata(pdev, pf);
 	pf->pdev = pdev;
 	pf->dev_info = dev_info;
@@ -798,7 +801,6 @@ static int nfp_pci_probe(struct pci_dev *pdev,
 	destroy_workqueue(pf->wq);
 err_pci_priv_unset:
 	pci_set_drvdata(pdev, NULL);
-	mutex_destroy(&pf->lock);
 	devlink_free(devlink);
 err_rel_regions:
 	pci_release_regions(pdev);
@@ -835,7 +837,6 @@ static void __nfp_pci_shutdown(struct pci_dev *pdev, bool unload_fw)
 
 	kfree(pf->eth_tbl);
 	kfree(pf->nspi);
-	mutex_destroy(&pf->lock);
 	devlink_free(priv_to_devlink(pf));
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_main.h b/drivers/net/ethernet/netronome/nfp/nfp_main.h
index 9c72a0ad18ea..f56ca11de134 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_main.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_main.h
@@ -13,7 +13,6 @@
 #include <linux/list.h>
 #include <linux/types.h>
 #include <linux/msi.h>
-#include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/workqueue.h>
 #include <net/devlink.h>
@@ -85,7 +84,8 @@ struct nfp_dumpspec {
  * @port_refresh_work:	Work entry for taking netdevs out
  * @shared_bufs:	Array of shared buffer structures if FW has any SBs
  * @num_shared_bufs:	Number of elements in @shared_bufs
- * @lock:		Protects all fields which may change after probe
+ *
+ * Fields which may change after proble are protected by devlink instance lock.
  */
 struct nfp_pf {
 	struct pci_dev *pdev;
@@ -141,8 +141,6 @@ struct nfp_pf {
 
 	struct nfp_shared_buf *shared_bufs;
 	unsigned int num_shared_bufs;
-
-	struct mutex lock;
 };
 
 extern struct pci_driver nfp_netvf_pci_driver;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_main.c b/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
index a18b99c93ab3..09a0a2076c6e 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_main.c
@@ -308,6 +308,7 @@ static int nfp_net_pf_init_vnics(struct nfp_pf *pf)
 static int
 nfp_net_pf_app_init(struct nfp_pf *pf, u8 __iomem *qc_bar, unsigned int stride)
 {
+	struct devlink *devlink = priv_to_devlink(pf);
 	u8 __iomem *ctrl_bar;
 	int err;
 
@@ -315,9 +316,9 @@ nfp_net_pf_app_init(struct nfp_pf *pf, u8 __iomem *qc_bar, unsigned int stride)
 	if (IS_ERR(pf->app))
 		return PTR_ERR(pf->app);
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	err = nfp_app_init(pf->app);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 	if (err)
 		goto err_free;
 
@@ -344,9 +345,9 @@ nfp_net_pf_app_init(struct nfp_pf *pf, u8 __iomem *qc_bar, unsigned int stride)
 err_unmap:
 	nfp_cpp_area_release_free(pf->ctrl_vnic_bar);
 err_app_clean:
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	nfp_app_clean(pf->app);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 err_free:
 	nfp_app_free(pf->app);
 	pf->app = NULL;
@@ -355,14 +356,16 @@ nfp_net_pf_app_init(struct nfp_pf *pf, u8 __iomem *qc_bar, unsigned int stride)
 
 static void nfp_net_pf_app_clean(struct nfp_pf *pf)
 {
+	struct devlink *devlink = priv_to_devlink(pf);
+
 	if (pf->ctrl_vnic) {
 		nfp_net_pf_free_vnic(pf, pf->ctrl_vnic);
 		nfp_cpp_area_release_free(pf->ctrl_vnic_bar);
 	}
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	nfp_app_clean(pf->app);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	nfp_app_free(pf->app);
 	pf->app = NULL;
@@ -548,12 +551,13 @@ nfp_net_eth_port_update(struct nfp_cpp *cpp, struct nfp_port *port,
 
 int nfp_net_refresh_port_table_sync(struct nfp_pf *pf)
 {
+	struct devlink *devlink = priv_to_devlink(pf);
 	struct nfp_eth_table *eth_table;
 	struct nfp_net *nn, *next;
 	struct nfp_port *port;
 	int err;
 
-	lockdep_assert_held(&pf->lock);
+	devl_assert_locked(devlink);
 
 	/* Check for nfp_net_pci_remove() racing against us */
 	if (list_empty(&pf->vnics))
@@ -602,10 +606,11 @@ static void nfp_net_refresh_vnics(struct work_struct *work)
 {
 	struct nfp_pf *pf = container_of(work, struct nfp_pf,
 					 port_refresh_work);
+	struct devlink *devlink = priv_to_devlink(pf);
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	nfp_net_refresh_port_table_sync(pf);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 }
 
 void nfp_net_refresh_port_table(struct nfp_port *port)
@@ -711,7 +716,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 	if (err)
 		goto err_shared_buf_unreg;
 
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	pf->ddir = nfp_net_debugfs_device_add(pf->pdev);
 
 	/* Allocate the vnics and do basic init */
@@ -731,7 +736,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 	if (err)
 		goto err_stop_app;
 
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 	devlink_register(devlink);
 
 	return 0;
@@ -744,7 +749,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 	nfp_net_pf_free_vnics(pf);
 err_clean_ddir:
 	nfp_net_debugfs_dir_clean(&pf->ddir);
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 	nfp_devlink_params_unregister(pf);
 err_shared_buf_unreg:
 	nfp_shared_buf_unregister(pf);
@@ -758,10 +763,11 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 
 void nfp_net_pci_remove(struct nfp_pf *pf)
 {
+	struct devlink *devlink = priv_to_devlink(pf);
 	struct nfp_net *nn, *next;
 
 	devlink_unregister(priv_to_devlink(pf));
-	mutex_lock(&pf->lock);
+	devl_lock(devlink);
 	list_for_each_entry_safe(nn, next, &pf->vnics, vnic_list) {
 		if (!nfp_net_is_data_vnic(nn))
 			continue;
@@ -773,7 +779,7 @@ void nfp_net_pci_remove(struct nfp_pf *pf)
 	/* stop app first, to avoid double free of ctrl vNIC's ddir */
 	nfp_net_debugfs_dir_clean(&pf->ddir);
 
-	mutex_unlock(&pf->lock);
+	devl_unlock(devlink);
 
 	nfp_devlink_params_unregister(pf);
 	nfp_shared_buf_unregister(pf);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_port.c b/drivers/net/ethernet/netronome/nfp/nfp_port.c
index 93c5bfc0510b..236cd3c1201f 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_port.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_port.c
@@ -78,9 +78,10 @@ int nfp_port_set_features(struct net_device *netdev, netdev_features_t features)
 struct nfp_port *
 nfp_port_from_id(struct nfp_pf *pf, enum nfp_port_type type, unsigned int id)
 {
+	struct devlink *devlink = priv_to_devlink(pf);
 	struct nfp_port *port;
 
-	lockdep_assert_held(&pf->lock);
+	devl_assert_locked(devlink);
 
 	if (type != NFP_PORT_PHYS_PORT)
 		return NULL;
-- 
2.34.1

[PATCH net-next 4/6] eth: mlxsw: switch to explicit locking for port registration

[Jakub Kicinski]

Explicitly lock the devlink instance and use devl_ API.

This will be used by the subsequent patch to invoke
.port_split / .port_unsplit callbacks with devlink
instance lock held.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/mellanox/mlxsw/core.c     |  4 ++--
 drivers/net/ethernet/mellanox/mlxsw/minimal.c  |  6 ++++++
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 14 ++++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 0bf1d64644ba..e2a6a759eb6c 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -2983,7 +2983,7 @@ static int __mlxsw_core_port_init(struct mlxsw_core *mlxsw_core, u16 local_port,
 	attrs.switch_id.id_len = switch_id_len;
 	mlxsw_core_port->local_port = local_port;
 	devlink_port_attrs_set(devlink_port, &attrs);
-	err = devlink_port_register(devlink, devlink_port, local_port);
+	err = devl_port_register(devlink, devlink_port, local_port);
 	if (err)
 		memset(mlxsw_core_port, 0, sizeof(*mlxsw_core_port));
 	return err;
@@ -2995,7 +2995,7 @@ static void __mlxsw_core_port_fini(struct mlxsw_core *mlxsw_core, u16 local_port
 					&mlxsw_core->ports[local_port];
 	struct devlink_port *devlink_port = &mlxsw_core_port->devlink_port;
 
-	devlink_port_unregister(devlink_port);
+	devl_port_unregister(devlink_port);
 	memset(mlxsw_core_port, 0, sizeof(*mlxsw_core_port));
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlxsw/minimal.c b/drivers/net/ethernet/mellanox/mlxsw/minimal.c
index 060209983438..3bc012dafd08 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/minimal.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/minimal.c
@@ -422,6 +422,7 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 			struct netlink_ext_ack *extack)
 {
 	struct mlxsw_m *mlxsw_m = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	int err;
 
 	mlxsw_m->core = mlxsw_core;
@@ -437,7 +438,9 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 		return err;
 	}
 
+	devl_lock(devlink);
 	err = mlxsw_m_ports_create(mlxsw_m);
+	devl_unlock(devlink);
 	if (err) {
 		dev_err(mlxsw_m->bus_info->dev, "Failed to create ports\n");
 		return err;
@@ -449,8 +452,11 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 static void mlxsw_m_fini(struct mlxsw_core *mlxsw_core)
 {
 	struct mlxsw_m *mlxsw_m = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 
+	devl_lock(devlink);
 	mlxsw_m_ports_remove(mlxsw_m);
+	devl_unlock(devlink);
 }
 
 static const struct mlxsw_config_profile mlxsw_m_config_profile;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 7b7b17183d10..1e823b669d1c 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2025,6 +2025,7 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 			       struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	struct mlxsw_sp_port_mapping port_mapping;
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	enum mlxsw_reg_pmtdb_status status;
@@ -2062,6 +2063,7 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 
 	port_mapping = mlxsw_sp_port->mapping;
 
+	devl_lock(devlink);
 	for (i = 0; i < count; i++) {
 		u16 s_local_port = mlxsw_reg_pmtdb_port_num_get(pmtdb_pl, i);
 
@@ -2075,11 +2077,13 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to create split ports\n");
 		goto err_port_split_create;
 	}
+	devl_unlock(devlink);
 
 	return 0;
 
 err_port_split_create:
 	mlxsw_sp_port_unsplit_create(mlxsw_sp, count, pmtdb_pl);
+	devl_unlock(devlink);
 	return err;
 }
 
@@ -2087,6 +2091,7 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 				 struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	char pmtdb_pl[MLXSW_REG_PMTDB_LEN];
 	unsigned int count;
@@ -2118,6 +2123,7 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 		return err;
 	}
 
+	devl_lock(devlink);
 	for (i = 0; i < count; i++) {
 		u16 s_local_port = mlxsw_reg_pmtdb_port_num_get(pmtdb_pl, i);
 
@@ -2126,6 +2132,7 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 	}
 
 	mlxsw_sp_port_unsplit_create(mlxsw_sp, count, pmtdb_pl);
+	devl_unlock(devlink);
 
 	return 0;
 }
@@ -2818,6 +2825,7 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 			 struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	int err;
 
 	mlxsw_sp->core = mlxsw_core;
@@ -2978,7 +2986,9 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 		goto err_sample_trigger_init;
 	}
 
+	devl_lock(devlink);
 	err = mlxsw_sp_ports_create(mlxsw_sp);
+	devl_unlock(devlink);
 	if (err) {
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to create ports\n");
 		goto err_ports_create;
@@ -3159,8 +3169,12 @@ static int mlxsw_sp4_init(struct mlxsw_core *mlxsw_core,
 static void mlxsw_sp_fini(struct mlxsw_core *mlxsw_core)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 
+	devl_lock(devlink);
 	mlxsw_sp_ports_remove(mlxsw_sp);
+	devl_unlock(devlink);
+
 	rhashtable_destroy(&mlxsw_sp->sample_trigger_ht);
 	mlxsw_sp_port_module_info_fini(mlxsw_sp);
 	mlxsw_sp_dpipe_fini(mlxsw_sp);
-- 
2.34.1

[PATCH net-next 5/6] devlink: hold the instance lock in port_split / port_unsplit callbacks

[Jakub Kicinski]

Let the core take the devlink instance lock around port splitting
and remove the now redundant locking in the drivers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../net/ethernet/mellanox/mlxsw/spectrum.c    |  7 ----
 .../net/ethernet/netronome/nfp/nfp_devlink.c  | 32 +++++--------------
 net/core/devlink.c                            |  2 --
 3 files changed, 8 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 1e823b669d1c..8eb05090ffec 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -2025,7 +2025,6 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 			       struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	struct mlxsw_sp_port_mapping port_mapping;
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	enum mlxsw_reg_pmtdb_status status;
@@ -2063,7 +2062,6 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 
 	port_mapping = mlxsw_sp_port->mapping;
 
-	devl_lock(devlink);
 	for (i = 0; i < count; i++) {
 		u16 s_local_port = mlxsw_reg_pmtdb_port_num_get(pmtdb_pl, i);
 
@@ -2077,13 +2075,11 @@ static int mlxsw_sp_port_split(struct mlxsw_core *mlxsw_core, u16 local_port,
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to create split ports\n");
 		goto err_port_split_create;
 	}
-	devl_unlock(devlink);
 
 	return 0;
 
 err_port_split_create:
 	mlxsw_sp_port_unsplit_create(mlxsw_sp, count, pmtdb_pl);
-	devl_unlock(devlink);
 	return err;
 }
 
@@ -2091,7 +2087,6 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 				 struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	char pmtdb_pl[MLXSW_REG_PMTDB_LEN];
 	unsigned int count;
@@ -2123,7 +2118,6 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 		return err;
 	}
 
-	devl_lock(devlink);
 	for (i = 0; i < count; i++) {
 		u16 s_local_port = mlxsw_reg_pmtdb_port_num_get(pmtdb_pl, i);
 
@@ -2132,7 +2126,6 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u16 local_port,
 	}
 
 	mlxsw_sp_port_unsplit_create(mlxsw_sp, count, pmtdb_pl);
-	devl_unlock(devlink);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
index 865f62958a72..6bd6f4a67c30 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
@@ -70,29 +70,21 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 	unsigned int lanes;
 	int ret;
 
-	devl_lock(devlink);
-
 	rtnl_lock();
 	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
 	rtnl_unlock();
 	if (ret)
-		goto out;
+		return ret;
 
-	if (eth_port.port_lanes % count) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (eth_port.port_lanes % count)
+		return -EINVAL;
 
 	/* Special case the 100G CXP -> 2x40G split */
 	lanes = eth_port.port_lanes / count;
 	if (eth_port.lanes == 10 && count == 2)
 		lanes = 8 / count;
 
-	ret = nfp_devlink_set_lanes(pf, eth_port.index, lanes);
-out:
-	devl_unlock(devlink);
-
-	return ret;
+	return nfp_devlink_set_lanes(pf, eth_port.index, lanes);
 }
 
 static int
@@ -104,29 +96,21 @@ nfp_devlink_port_unsplit(struct devlink *devlink, unsigned int port_index,
 	unsigned int lanes;
 	int ret;
 
-	devl_lock(devlink);
-
 	rtnl_lock();
 	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
 	rtnl_unlock();
 	if (ret)
-		goto out;
+		return ret;
 
-	if (!eth_port.is_split) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (!eth_port.is_split)
+		return -EINVAL;
 
 	/* Special case the 100G CXP -> 2x40G unsplit */
 	lanes = eth_port.port_lanes;
 	if (eth_port.port_lanes == 8)
 		lanes = 10;
 
-	ret = nfp_devlink_set_lanes(pf, eth_port.index, lanes);
-out:
-	devl_unlock(devlink);
-
-	return ret;
+	return nfp_devlink_set_lanes(pf, eth_port.index, lanes);
 }
 
 static int
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 769e5f7fa219..545ae784e9d2 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -8672,14 +8672,12 @@ static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_port_split_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PORT_UNSPLIT,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_port_unsplit_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PORT_NEW,
-- 
2.34.1

[PATCH net-next 6/6] devlink: pass devlink_port to port_split / port_unsplit callbacks

[Jakub Kicinski]

Now that devlink ports are protected by the instance lock
it seems natural to pass devlink_port as an argument to
the port_split / port_unsplit callbacks.

This should save the drivers from doing a lookup.

In theory drivers may have supported unsplitting ports
which were not registered prior to this change.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/mellanox/mlxsw/core.c    | 32 ++++++-------
 .../net/ethernet/netronome/nfp/nfp_devlink.c  | 15 +++---
 drivers/net/ethernet/netronome/nfp/nfp_port.c | 18 -------
 drivers/net/ethernet/netronome/nfp/nfp_port.h |  2 -
 include/net/devlink.h                         |  4 +-
 net/core/devlink.c                            | 47 +++++--------------
 6 files changed, 35 insertions(+), 83 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index e2a6a759eb6c..b13e0f8d232a 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -1217,36 +1217,37 @@ static void mlxsw_core_fw_params_unregister(struct mlxsw_core *mlxsw_core)
 				  ARRAY_SIZE(mlxsw_core_fw_devlink_params));
 }
 
+static void *__dl_port(struct devlink_port *devlink_port)
+{
+	return container_of(devlink_port, struct mlxsw_core_port, devlink_port);
+}
+
 static int mlxsw_devlink_port_split(struct devlink *devlink,
-				    unsigned int port_index,
+				    struct devlink_port *port,
 				    unsigned int count,
 				    struct netlink_ext_ack *extack)
 {
+	struct mlxsw_core_port *mlxsw_core_port = __dl_port(port);
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
 
-	if (port_index >= mlxsw_core->max_ports) {
-		NL_SET_ERR_MSG_MOD(extack, "Port index exceeds maximum number of ports");
-		return -EINVAL;
-	}
 	if (!mlxsw_core->driver->port_split)
 		return -EOPNOTSUPP;
-	return mlxsw_core->driver->port_split(mlxsw_core, port_index, count,
-					      extack);
+	return mlxsw_core->driver->port_split(mlxsw_core,
+					      mlxsw_core_port->local_port,
+					      count, extack);
 }
 
 static int mlxsw_devlink_port_unsplit(struct devlink *devlink,
-				      unsigned int port_index,
+				      struct devlink_port *port,
 				      struct netlink_ext_ack *extack)
 {
+	struct mlxsw_core_port *mlxsw_core_port = __dl_port(port);
 	struct mlxsw_core *mlxsw_core = devlink_priv(devlink);
 
-	if (port_index >= mlxsw_core->max_ports) {
-		NL_SET_ERR_MSG_MOD(extack, "Port index exceeds maximum number of ports");
-		return -EINVAL;
-	}
 	if (!mlxsw_core->driver->port_unsplit)
 		return -EOPNOTSUPP;
-	return mlxsw_core->driver->port_unsplit(mlxsw_core, port_index,
+	return mlxsw_core->driver->port_unsplit(mlxsw_core,
+						mlxsw_core_port->local_port,
 						extack);
 }
 
@@ -1280,11 +1281,6 @@ mlxsw_devlink_sb_pool_set(struct devlink *devlink,
 					 extack);
 }
 
-static void *__dl_port(struct devlink_port *devlink_port)
-{
-	return container_of(devlink_port, struct mlxsw_core_port, devlink_port);
-}
-
 static int mlxsw_devlink_port_type_set(struct devlink_port *devlink_port,
 				       enum devlink_port_type port_type)
 {
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
index 6bd6f4a67c30..48b95566b52b 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
@@ -26,12 +26,11 @@ nfp_devlink_fill_eth_port(struct nfp_port *port,
 }
 
 static int
-nfp_devlink_fill_eth_port_from_id(struct nfp_pf *pf, unsigned int port_index,
+nfp_devlink_fill_eth_port_from_id(struct nfp_pf *pf,
+				  struct devlink_port *dl_port,
 				  struct nfp_eth_table_port *copy)
 {
-	struct nfp_port *port;
-
-	port = nfp_port_from_id(pf, NFP_PORT_PHYS_PORT, port_index);
+	struct nfp_port *port = container_of(dl_port, struct nfp_port, dl_port);
 
 	return nfp_devlink_fill_eth_port(port, copy);
 }
@@ -62,7 +61,7 @@ nfp_devlink_set_lanes(struct nfp_pf *pf, unsigned int idx, unsigned int lanes)
 }
 
 static int
-nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
+nfp_devlink_port_split(struct devlink *devlink, struct devlink_port *port,
 		       unsigned int count, struct netlink_ext_ack *extack)
 {
 	struct nfp_pf *pf = devlink_priv(devlink);
@@ -71,7 +70,7 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 	int ret;
 
 	rtnl_lock();
-	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
+	ret = nfp_devlink_fill_eth_port_from_id(pf, port, &eth_port);
 	rtnl_unlock();
 	if (ret)
 		return ret;
@@ -88,7 +87,7 @@ nfp_devlink_port_split(struct devlink *devlink, unsigned int port_index,
 }
 
 static int
-nfp_devlink_port_unsplit(struct devlink *devlink, unsigned int port_index,
+nfp_devlink_port_unsplit(struct devlink *devlink, struct devlink_port *port,
 			 struct netlink_ext_ack *extack)
 {
 	struct nfp_pf *pf = devlink_priv(devlink);
@@ -97,7 +96,7 @@ nfp_devlink_port_unsplit(struct devlink *devlink, unsigned int port_index,
 	int ret;
 
 	rtnl_lock();
-	ret = nfp_devlink_fill_eth_port_from_id(pf, port_index, &eth_port);
+	ret = nfp_devlink_fill_eth_port_from_id(pf, port, &eth_port);
 	rtnl_unlock();
 	if (ret)
 		return ret;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_port.c b/drivers/net/ethernet/netronome/nfp/nfp_port.c
index 236cd3c1201f..4f2308570dcf 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_port.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_port.c
@@ -75,24 +75,6 @@ int nfp_port_set_features(struct net_device *netdev, netdev_features_t features)
 	return 0;
 }
 
-struct nfp_port *
-nfp_port_from_id(struct nfp_pf *pf, enum nfp_port_type type, unsigned int id)
-{
-	struct devlink *devlink = priv_to_devlink(pf);
-	struct nfp_port *port;
-
-	devl_assert_locked(devlink);
-
-	if (type != NFP_PORT_PHYS_PORT)
-		return NULL;
-
-	list_for_each_entry(port, &pf->ports, port_list)
-		if (port->eth_id == id)
-			return port;
-
-	return NULL;
-}
-
 struct nfp_eth_table_port *__nfp_port_get_eth_port(struct nfp_port *port)
 {
 	if (!port)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_port.h b/drivers/net/ethernet/netronome/nfp/nfp_port.h
index df316b9e891d..d1ebe6c72f7f 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_port.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_port.h
@@ -106,8 +106,6 @@ nfp_port_set_features(struct net_device *netdev, netdev_features_t features);
 struct nfp_port *nfp_port_from_netdev(struct net_device *netdev);
 int nfp_port_get_port_parent_id(struct net_device *netdev,
 				struct netdev_phys_item_id *ppid);
-struct nfp_port *
-nfp_port_from_id(struct nfp_pf *pf, enum nfp_port_type type, unsigned int id);
 struct nfp_eth_table_port *__nfp_port_get_eth_port(struct nfp_port *port);
 struct nfp_eth_table_port *nfp_port_get_eth_port(struct nfp_port *port);
 
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 9de0d091aee9..fd89a17adea1 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1197,9 +1197,9 @@ struct devlink_ops {
 			 struct netlink_ext_ack *extack);
 	int (*port_type_set)(struct devlink_port *devlink_port,
 			     enum devlink_port_type port_type);
-	int (*port_split)(struct devlink *devlink, unsigned int port_index,
+	int (*port_split)(struct devlink *devlink, struct devlink_port *port,
 			  unsigned int count, struct netlink_ext_ack *extack);
-	int (*port_unsplit)(struct devlink *devlink, unsigned int port_index,
+	int (*port_unsplit)(struct devlink *devlink, struct devlink_port *port,
 			    struct netlink_ext_ack *extack);
 	int (*sb_pool_get)(struct devlink *devlink, unsigned int sb_index,
 			   u16 pool_index,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 545ae784e9d2..f2a277053ec6 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -1568,35 +1568,20 @@ static int devlink_nl_cmd_port_set_doit(struct sk_buff *skb,
 	return 0;
 }
 
-static int devlink_port_split(struct devlink *devlink, u32 port_index,
-			      u32 count, struct netlink_ext_ack *extack)
-
-{
-	if (devlink->ops->port_split)
-		return devlink->ops->port_split(devlink, port_index, count,
-						extack);
-	return -EOPNOTSUPP;
-}
-
 static int devlink_nl_cmd_port_split_doit(struct sk_buff *skb,
 					  struct genl_info *info)
 {
+	struct devlink_port *devlink_port = info->user_ptr[1];
 	struct devlink *devlink = info->user_ptr[0];
-	struct devlink_port *devlink_port;
-	u32 port_index;
 	u32 count;
 
-	if (!info->attrs[DEVLINK_ATTR_PORT_INDEX] ||
-	    !info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT])
+	if (!info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT])
 		return -EINVAL;
+	if (!devlink->ops->port_split)
+		return -EOPNOTSUPP;
 
-	devlink_port = devlink_port_get_from_info(devlink, info);
-	port_index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
 	count = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT]);
 
-	if (IS_ERR(devlink_port))
-		return -EINVAL;
-
 	if (!devlink_port->attrs.splittable) {
 		/* Split ports cannot be split. */
 		if (devlink_port->attrs.split)
@@ -1611,29 +1596,19 @@ static int devlink_nl_cmd_port_split_doit(struct sk_buff *skb,
 		return -EINVAL;
 	}
 
-	return devlink_port_split(devlink, port_index, count, info->extack);
-}
-
-static int devlink_port_unsplit(struct devlink *devlink, u32 port_index,
-				struct netlink_ext_ack *extack)
-
-{
-	if (devlink->ops->port_unsplit)
-		return devlink->ops->port_unsplit(devlink, port_index, extack);
-	return -EOPNOTSUPP;
+	return devlink->ops->port_split(devlink, devlink_port, count,
+					info->extack);
 }
 
 static int devlink_nl_cmd_port_unsplit_doit(struct sk_buff *skb,
 					    struct genl_info *info)
 {
+	struct devlink_port *devlink_port = info->user_ptr[1];
 	struct devlink *devlink = info->user_ptr[0];
-	u32 port_index;
 
-	if (!info->attrs[DEVLINK_ATTR_PORT_INDEX])
-		return -EINVAL;
-
-	port_index = nla_get_u32(info->attrs[DEVLINK_ATTR_PORT_INDEX]);
-	return devlink_port_unsplit(devlink, port_index, info->extack);
+	if (!devlink->ops->port_unsplit)
+		return -EOPNOTSUPP;
+	return devlink->ops->port_unsplit(devlink, devlink_port, info->extack);
 }
 
 static int devlink_port_new_notifiy(struct devlink *devlink,
@@ -8672,12 +8647,14 @@ static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_port_split_doit,
 		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_PORT,
 	},
 	{
 		.cmd = DEVLINK_CMD_PORT_UNSPLIT,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_port_unsplit_doit,
 		.flags = GENL_ADMIN_PERM,
+		.internal_flags = DEVLINK_NL_FLAG_NEED_PORT,
 	},
 	{
 		.cmd = DEVLINK_CMD_PORT_NEW,
-- 
2.34.1

Re: [PATCH net-next 4/6] eth: mlxsw: switch to explicit locking for port registration

[Ido Schimmel]

On Mon, Mar 14, 2022 at 11:00:07PM -0700, Jakub Kicinski wrote:
> Explicitly lock the devlink instance and use devl_ API.
> 
> This will be used by the subsequent patch to invoke
> .port_split / .port_unsplit callbacks with devlink
> instance lock held.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>

Re: [PATCH net-next 5/6] devlink: hold the instance lock in port_split / port_unsplit callbacks

[Ido Schimmel]

On Mon, Mar 14, 2022 at 11:00:08PM -0700, Jakub Kicinski wrote:
> Let the core take the devlink instance lock around port splitting
> and remove the now redundant locking in the drivers.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>

Re: [PATCH net-next 6/6] devlink: pass devlink_port to port_split / port_unsplit callbacks

[Ido Schimmel]

On Mon, Mar 14, 2022 at 11:00:09PM -0700, Jakub Kicinski wrote:
> Now that devlink ports are protected by the instance lock
> it seems natural to pass devlink_port as an argument to
> the port_split / port_unsplit callbacks.
> 
> This should save the drivers from doing a lookup.
> 
> In theory drivers may have supported unsplitting ports
> which were not registered prior to this change.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>

Re: [PATCH net-next 1/6] devlink: expose instance locking and add locked port registering

[Leon Romanovsky]

On Mon, Mar 14, 2022 at 11:00:04PM -0700, Jakub Kicinski wrote:
> It should be familiar and beneficial to expose devlink instance
> lock to the drivers. This way drivers can block devlink from
> calling them during critical sections without breakneck locking.
> 
> Add port helpers, port splitting callbacks will be the first
> target.
> 
> Use 'devl_' prefix for "explicitly locked" API. Initial RFC used
> '__devlink' but that's too much typing.
> 
> devl_lock_is_held() is not defined without lockdep, which is
> the same behavior as lockdep_is_held() itself.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> v1: - add a small section to the docs
>     - redo the lockdep ifdef
> ---
>  Documentation/networking/devlink/index.rst | 16 ++++
>  include/net/devlink.h                      | 11 +++
>  net/core/devlink.c                         | 95 ++++++++++++++++------
>  3 files changed, 98 insertions(+), 24 deletions(-)

<...>

> +void devl_assert_locked(struct devlink *devlink)
> +{
> +	lockdep_assert_held(&devlink->lock);
> +}
> +EXPORT_SYMBOL_GPL(devl_assert_locked);
> +
> +#ifdef CONFIG_LOCKDEP
> +/* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
> +bool devl_lock_is_held(struct devlink *devlink)
> +{
> +	return lockdep_is_held(&devlink->lock);
> +}
> +EXPORT_SYMBOL_GPL(devl_lock_is_held);
> +#endif

Sorry that I'm asking you again same question.
How will this devl_lock_is_held() be used in drivers?

Right now, if I decide to use this function in mlx5 (or in any other driver),
the code will be something like this:

void func(...)
{
   ....
   if (IS_ENABLED(CONFIG_LOCKDEP))
   	if (rcu_dereference_protected(a, devl_lock_is_held(devlink) == b) {
		....
}

The line "if (IS_ENABLED(CONFIG_LOCKDEP))" needs to be in every driver
or it won't compile in release mode.

Thanks

Re: [PATCH net-next 3/6] eth: nfp: replace driver's "pf" lock with devlink instance lock

[Leon Romanovsky]

On Mon, Mar 14, 2022 at 11:00:06PM -0700, Jakub Kicinski wrote:
> The whole reason for existence of the pf mutex is that we could
> not lock the devlink instance around port splitting. There are
> more types of reconfig which can make ports appear or disappear.
> Now that the devlink instance lock is exposed to drivers and
> "locked" helpers exist we can switch to using the devlink lock
> directly.
> 
> Next patches will move the locking inside .port_(un)split to
> the core.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>  drivers/net/ethernet/netronome/nfp/nfp_app.h  | 11 +++---
>  .../net/ethernet/netronome/nfp/nfp_devlink.c  | 16 ++++-----
>  drivers/net/ethernet/netronome/nfp/nfp_main.c | 19 ++++++-----
>  drivers/net/ethernet/netronome/nfp/nfp_main.h |  6 ++--
>  .../net/ethernet/netronome/nfp/nfp_net_main.c | 34 +++++++++++--------
>  drivers/net/ethernet/netronome/nfp/nfp_port.c |  3 +-
>  6 files changed, 48 insertions(+), 41 deletions(-)

<...>

> -#define nfp_app_is_locked(app)	lockdep_is_held(&(app)->pf->lock)
> +static inline bool nfp_app_is_locked(struct nfp_app *app)
> +{
> +	return devl_lock_is_held(priv_to_devlink(app->pf));
> +}

Does it compile if you set CONFIG_LOCKDEP=n?

Thanks

Re: [PATCH net-next 3/6] eth: nfp: replace driver's "pf" lock with devlink instance lock

[Jakub Kicinski]

On Wed, 16 Mar 2022 10:34:31 +0200 Leon Romanovsky wrote:
> > -#define nfp_app_is_locked(app)	lockdep_is_held(&(app)->pf->lock)
> > +static inline bool nfp_app_is_locked(struct nfp_app *app)
> > +{
> > +	return devl_lock_is_held(priv_to_devlink(app->pf));
> > +}  
> 
> Does it compile if you set CONFIG_LOCKDEP=n?

Yes, it's exactly the same as lockdep_is_held(). PTAL at lockdep.h, 
the extern int lockdep_is_held(const void *); is under LOCKDEP=n.
There is no definition for it.

Re: [PATCH net-next 1/6] devlink: expose instance locking and add locked port registering

[Jakub Kicinski]

On Wed, 16 Mar 2022 10:29:16 +0200 Leon Romanovsky wrote:
> Sorry that I'm asking you again same question.
> How will this devl_lock_is_held() be used in drivers?
> 
> Right now, if I decide to use this function in mlx5 (or in any other driver),
> the code will be something like this:
> 
> void func(...)
> {
>    ....
>    if (IS_ENABLED(CONFIG_LOCKDEP))
>    	if (rcu_dereference_protected(a, devl_lock_is_held(devlink) == b) {
> 		....
> }
> 
> The line "if (IS_ENABLED(CONFIG_LOCKDEP))" needs to be in every driver
> or it won't compile in release mode.

It follows the semantics of lockdep_is_held(), note that
rcu_dereference_protected() makes the last parameter dead 
code with LOCKDEP=n 

#define RCU_LOCKDEP_WARN(c, s) do { } while (0 && (c))

where (c) would be devl_lock_is_held()

so the call to devl_lock_is_held() is eliminated, and we 
won't get a linker error. There's no need for IS_ENABLED().

Re: [PATCH net-next 1/6] devlink: expose instance locking and add locked port registering

[Leon Romanovsky]

On Wed, Mar 16, 2022 at 09:48:59AM -0700, Jakub Kicinski wrote:
> On Wed, 16 Mar 2022 10:29:16 +0200 Leon Romanovsky wrote:
> > Sorry that I'm asking you again same question.
> > How will this devl_lock_is_held() be used in drivers?
> > 
> > Right now, if I decide to use this function in mlx5 (or in any other driver),
> > the code will be something like this:
> > 
> > void func(...)
> > {
> >    ....
> >    if (IS_ENABLED(CONFIG_LOCKDEP))
> >    	if (rcu_dereference_protected(a, devl_lock_is_held(devlink) == b) {
> > 		....
> > }
> > 
> > The line "if (IS_ENABLED(CONFIG_LOCKDEP))" needs to be in every driver
> > or it won't compile in release mode.
> 
> It follows the semantics of lockdep_is_held(), note that
> rcu_dereference_protected() makes the last parameter dead 
> code with LOCKDEP=n 
> 
> #define RCU_LOCKDEP_WARN(c, s) do { } while (0 && (c))

Ahhh, I see, thanks for an explanation.

> 
> where (c) would be devl_lock_is_held()
> 
> so the call to devl_lock_is_held() is eliminated, and we 
> won't get a linker error. There's no need for IS_ENABLED().

Re: [PATCH net-next 1/6] devlink: expose instance locking and add locked port registering

[Leon Romanovsky]

On Mon, Mar 14, 2022 at 11:00:04PM -0700, Jakub Kicinski wrote:
> It should be familiar and beneficial to expose devlink instance
> lock to the drivers. This way drivers can block devlink from
> calling them during critical sections without breakneck locking.
> 
> Add port helpers, port splitting callbacks will be the first
> target.
> 
> Use 'devl_' prefix for "explicitly locked" API. Initial RFC used
> '__devlink' but that's too much typing.
> 
> devl_lock_is_held() is not defined without lockdep, which is
> the same behavior as lockdep_is_held() itself.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> v1: - add a small section to the docs
>     - redo the lockdep ifdef
> ---
>  Documentation/networking/devlink/index.rst | 16 ++++
>  include/net/devlink.h                      | 11 +++
>  net/core/devlink.c                         | 95 ++++++++++++++++------
>  3 files changed, 98 insertions(+), 24 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net-next 0/6] devlink: expose instance locking and simplify port splitting

[Jakub Kicinski]

On Mon, 14 Mar 2022 23:00:03 -0700 Jakub Kicinski wrote:
> This series puts the devlink ports fully under the devlink instance
> lock's protection. As discussed in the past it implements my preferred
> solution of exposing the instance lock to the drivers. This way drivers
> which want to support port splitting can lock the devlink instance
> themselves on the probe path, and we can take that lock in the core
> on the split/unsplit paths.
> 
> nfp and mlxsw are converted, with slightly deeper changes done in
> nfp since I'm more familiar with that driver.
> 
> Now that the devlink port is protected we can pass a pointer to
> the drivers, instead of passing a port index and forcing the drivers
> to do their own lookups. Both nfp and mlxsw can container_of() to
> their own structures.

Applied now, thanks for reviews and testing!