[patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Move port_setup() op to be called before devlink_port_register() and
port_teardown() after devlink_port_unregister().

RFC note: I don't see why this would not work, but I have no way to
test this does not break things. But I think it makes sense to move this
alongside the rest of the devlink port code, the reinit() function
also gets much nicer, as clearly the fact that
port_setup()->devlink_port_region_create() was called in dsa_port_setup
did not fit the flow.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/dsa/dsa2.c | 64 +++++++++++++++++---------------------------------
 1 file changed, 21 insertions(+), 43 deletions(-)

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index cac48a741f27..a8b6c6434df2 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -451,19 +451,12 @@ static int dsa_port_setup(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
 	bool dsa_port_link_registered = false;
-	struct dsa_switch *ds = dp->ds;
 	bool dsa_port_enabled = false;
 	int err = 0;
 
 	if (dp->setup)
 		return 0;
 
-	if (ds->ops->port_setup) {
-		err = ds->ops->port_setup(ds, dp->index);
-		if (err)
-			return err;
-	}
-
 	switch (dp->type) {
 	case DSA_PORT_TYPE_UNUSED:
 		dsa_port_disable(dp);
@@ -506,11 +499,6 @@ static int dsa_port_setup(struct dsa_port *dp)
 		dsa_port_disable(dp);
 	if (err && dsa_port_link_registered)
 		dsa_port_link_unregister_of(dp);
-	if (err) {
-		if (ds->ops->port_teardown)
-			ds->ops->port_teardown(ds, dp->index);
-		return err;
-	}
 
 	dp->setup = true;
 
@@ -523,10 +511,17 @@ static int dsa_port_devlink_setup(struct dsa_port *dp)
 	struct dsa_switch_tree *dst = dp->ds->dst;
 	struct devlink_port_attrs attrs = {};
 	struct devlink *dl = dp->ds->devlink;
+	struct dsa_switch *ds = dp->ds;
 	const unsigned char *id;
 	unsigned char len;
 	int err;
 
+	if (ds->ops->port_setup) {
+		err = ds->ops->port_setup(ds, dp->index);
+		if (err)
+			return err;
+	}
+
 	id = (const unsigned char *)&dst->index;
 	len = sizeof(dst->index);
 
@@ -552,24 +547,23 @@ static int dsa_port_devlink_setup(struct dsa_port *dp)
 
 	devlink_port_attrs_set(dlp, &attrs);
 	err = devlink_port_register(dl, dlp, dp->index);
+	if (err) {
+		if (ds->ops->port_teardown)
+			ds->ops->port_teardown(ds, dp->index);
+		return err;
+	}
+	dp->devlink_port_setup = true;
 
-	if (!err)
-		dp->devlink_port_setup = true;
-
-	return err;
+	return 0;
 }
 
 static void dsa_port_teardown(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
-	struct dsa_switch *ds = dp->ds;
 
 	if (!dp->setup)
 		return;
 
-	if (ds->ops->port_teardown)
-		ds->ops->port_teardown(ds, dp->index);
-
 	devlink_port_type_clear(dlp);
 
 	switch (dp->type) {
@@ -597,40 +591,24 @@ static void dsa_port_teardown(struct dsa_port *dp)
 static void dsa_port_devlink_teardown(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
+	struct dsa_switch *ds = dp->ds;
 
-	if (dp->devlink_port_setup)
+	if (dp->devlink_port_setup) {
 		devlink_port_unregister(dlp);
+		if (ds->ops->port_teardown)
+			ds->ops->port_teardown(ds, dp->index);
+	}
 	dp->devlink_port_setup = false;
 }
 
 /* Destroy the current devlink port, and create a new one which has the UNUSED
- * flavour. At this point, any call to ds->ops->port_setup has been already
- * balanced out by a call to ds->ops->port_teardown, so we know that any
- * devlink port regions the driver had are now unregistered. We then call its
- * ds->ops->port_setup again, in order for the driver to re-create them on the
- * new devlink port.
+ * flavour.
  */
 static int dsa_port_reinit_as_unused(struct dsa_port *dp)
 {
-	struct dsa_switch *ds = dp->ds;
-	int err;
-
 	dsa_port_devlink_teardown(dp);
 	dp->type = DSA_PORT_TYPE_UNUSED;
-	err = dsa_port_devlink_setup(dp);
-	if (err)
-		return err;
-
-	if (ds->ops->port_setup) {
-		/* On error, leave the devlink port registered,
-		 * dsa_switch_teardown will clean it up later.
-		 */
-		err = ds->ops->port_setup(ds, dp->index);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return dsa_port_devlink_setup(dp);
 }
 
 static int dsa_devlink_info_get(struct devlink *dl,
-- 
2.35.3

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Vladimir Oltean]

Hi Jiri,

On Tue, Jul 26, 2022 at 02:41:05PM +0200, Jiri Pirko wrote:
> From: Jiri Pirko <jiri@nvidia.com>
> 
> Move port_setup() op to be called before devlink_port_register() and
> port_teardown() after devlink_port_unregister().
> 
> RFC note: I don't see why this would not work, but I have no way to
> test this does not break things. But I think it makes sense to move this
> alongside the rest of the devlink port code, the reinit() function
> also gets much nicer, as clearly the fact that
> port_setup()->devlink_port_region_create() was called in dsa_port_setup
> did not fit the flow.
> 
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---

devlink_port->devlink isn't set (it's set in devl_port_register), so
when devlink_port_region_create() calls devl_lock(devlink), it blasts
right through that NULL pointer:

[    4.966960] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000320
[    5.009201] [0000000000000320] user address but active_mm is swapper
[    5.015616] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    5.024244] CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.19.0-rc7-07010-ga9b9500ffaac-dirty #3395
[    5.033281] Hardware name: CZ.NIC Turris Mox Board (DT)
[    5.038499] Workqueue: events_unbound deferred_probe_work_func
[    5.044342] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    5.051297] pc : __mutex_lock+0x5c/0x460
[    5.055220] lr : __mutex_lock+0x50/0x460
[    5.133818] Call trace:
[    5.136258]  __mutex_lock+0x5c/0x460
[    5.139831]  mutex_lock_nested+0x40/0x50
[    5.143750]  devlink_port_region_create+0x54/0x15c
[    5.148542]  dsa_devlink_port_region_create+0x64/0x90
[    5.153592]  mv88e6xxx_setup_devlink_regions_port+0x30/0x60
[    5.159165]  mv88e6xxx_port_setup+0x10/0x20
[    5.163345]  dsa_port_devlink_setup+0x60/0x150
[    5.167786]  dsa_register_switch+0x938/0x119c
[    5.172138]  mv88e6xxx_probe+0x714/0x770
[    5.176058]  mdio_probe+0x34/0x70
[    5.179370]  really_probe.part.0+0x9c/0x2ac
[    5.183550]  __driver_probe_device+0x98/0x144
[    5.187902]  driver_probe_device+0xac/0x14c

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Jiri Pirko]

Tue, Jul 26, 2022 at 03:43:09PM CEST, olteanv@gmail.com wrote:
>Hi Jiri,
>
>On Tue, Jul 26, 2022 at 02:41:05PM +0200, Jiri Pirko wrote:
>> From: Jiri Pirko <jiri@nvidia.com>
>> 
>> Move port_setup() op to be called before devlink_port_register() and
>> port_teardown() after devlink_port_unregister().
>> 
>> RFC note: I don't see why this would not work, but I have no way to
>> test this does not break things. But I think it makes sense to move this
>> alongside the rest of the devlink port code, the reinit() function
>> also gets much nicer, as clearly the fact that
>> port_setup()->devlink_port_region_create() was called in dsa_port_setup
>> did not fit the flow.
>> 
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> ---
>
>devlink_port->devlink isn't set (it's set in devl_port_register), so
>when devlink_port_region_create() calls devl_lock(devlink), it blasts
>right through that NULL pointer:
>
>[    4.966960] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000320
>[    5.009201] [0000000000000320] user address but active_mm is swapper
>[    5.015616] Internal error: Oops: 96000004 [#1] PREEMPT SMP
>[    5.024244] CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.19.0-rc7-07010-ga9b9500ffaac-dirty #3395
>[    5.033281] Hardware name: CZ.NIC Turris Mox Board (DT)
>[    5.038499] Workqueue: events_unbound deferred_probe_work_func
>[    5.044342] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>[    5.051297] pc : __mutex_lock+0x5c/0x460
>[    5.055220] lr : __mutex_lock+0x50/0x460
>[    5.133818] Call trace:
>[    5.136258]  __mutex_lock+0x5c/0x460
>[    5.139831]  mutex_lock_nested+0x40/0x50
>[    5.143750]  devlink_port_region_create+0x54/0x15c
>[    5.148542]  dsa_devlink_port_region_create+0x64/0x90
>[    5.153592]  mv88e6xxx_setup_devlink_regions_port+0x30/0x60
>[    5.159165]  mv88e6xxx_port_setup+0x10/0x20
>[    5.163345]  dsa_port_devlink_setup+0x60/0x150
>[    5.167786]  dsa_register_switch+0x938/0x119c
>[    5.172138]  mv88e6xxx_probe+0x714/0x770
>[    5.176058]  mdio_probe+0x34/0x70
>[    5.179370]  really_probe.part.0+0x9c/0x2ac
>[    5.183550]  __driver_probe_device+0x98/0x144
>[    5.187902]  driver_probe_device+0xac/0x14c

Oh yes, could you please try together with following patch? (nevermind
chicken-egg problem you may spot now)

Subject: [patch net-next RFC] net: devlink: convert region creation/destroy()
 to be forbidden on registered devlink/port

No need to create or destroy region when devlink or devlink ports are
registered. Limit the possibility to call the region create/destroy()
only for non-registered devlink or devlink port. Benefit from that and
avoid need to take devl_lock.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 drivers/net/netdevsim/dev.c |  8 ++--
 include/net/devlink.h       |  5 ---
 net/core/devlink.c          | 78 ++++++++-----------------------------
 3 files changed, 20 insertions(+), 71 deletions(-)

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 925dc8a5254d..3f0c19e30650 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -557,15 +557,15 @@ static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
 				      struct devlink *devlink)
 {
 	nsim_dev->dummy_region =
-		devl_region_create(devlink, &dummy_region_ops,
-				   NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
-				   NSIM_DEV_DUMMY_REGION_SIZE);
+		devlink_region_create(devlink, &dummy_region_ops,
+				      NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
+				      NSIM_DEV_DUMMY_REGION_SIZE);
 	return PTR_ERR_OR_ZERO(nsim_dev->dummy_region);
 }
 
 static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev)
 {
-	devl_region_destroy(nsim_dev->dummy_region);
+	devlink_region_destroy(nsim_dev->dummy_region);
 }
 
 static int
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 9edb4a28cf30..2416750e050d 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1666,10 +1666,6 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
 int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
 				       union devlink_param_value init_val);
 void devlink_param_value_changed(struct devlink *devlink, u32 param_id);
-struct devlink_region *devl_region_create(struct devlink *devlink,
-					  const struct devlink_region_ops *ops,
-					  u32 region_max_snapshots,
-					  u64 region_size);
 struct devlink_region *
 devlink_region_create(struct devlink *devlink,
 		      const struct devlink_region_ops *ops,
@@ -1678,7 +1674,6 @@ struct devlink_region *
 devlink_port_region_create(struct devlink_port *port,
 			   const struct devlink_port_region_ops *ops,
 			   u32 region_max_snapshots, u64 region_size);
-void devl_region_destroy(struct devlink_region *region);
 void devlink_region_destroy(struct devlink_region *region);
 void devlink_port_region_destroy(struct devlink_region *region);
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 4e0c4f9265e8..15d28aba69fc 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -5701,8 +5701,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
 	struct sk_buff *msg;
 
 	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
-		return;
+	ASSERT_DEVLINK_REGISTERED(devlink);
 
 	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
 	if (IS_ERR(msg))
@@ -11131,21 +11130,22 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
 EXPORT_SYMBOL_GPL(devlink_param_value_changed);
 
 /**
- * devl_region_create - create a new address region
+ * devlink_region_create - create a new address region
  *
  * @devlink: devlink
  * @ops: region operations and name
  * @region_max_snapshots: Maximum supported number of snapshots for region
  * @region_size: size of region
  */
-struct devlink_region *devl_region_create(struct devlink *devlink,
-					  const struct devlink_region_ops *ops,
-					  u32 region_max_snapshots,
-					  u64 region_size)
+struct devlink_region *
+devlink_region_create(struct devlink *devlink,
+		      const struct devlink_region_ops *ops,
+		      u32 region_max_snapshots,
+		      u64 region_size)
 {
 	struct devlink_region *region;
 
-	devl_assert_locked(devlink);
+	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
 
 	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
 		return ERR_PTR(-EINVAL);
@@ -11164,35 +11164,9 @@ struct devlink_region *devl_region_create(struct devlink *devlink,
 	INIT_LIST_HEAD(&region->snapshot_list);
 	mutex_init(&region->snapshot_lock);
 	list_add_tail(&region->list, &devlink->region_list);
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
 
 	return region;
 }
-EXPORT_SYMBOL_GPL(devl_region_create);
-
-/**
- *	devlink_region_create - create a new address region
- *
- *	@devlink: devlink
- *	@ops: region operations and name
- *	@region_max_snapshots: Maximum supported number of snapshots for region
- *	@region_size: size of region
- *
- *	Context: Takes and release devlink->lock <mutex>.
- */
-struct devlink_region *
-devlink_region_create(struct devlink *devlink,
-		      const struct devlink_region_ops *ops,
-		      u32 region_max_snapshots, u64 region_size)
-{
-	struct devlink_region *region;
-
-	devl_lock(devlink);
-	region = devl_region_create(devlink, ops, region_max_snapshots,
-				    region_size);
-	devl_unlock(devlink);
-	return region;
-}
 EXPORT_SYMBOL_GPL(devlink_region_create);
 
 /**
@@ -11202,8 +11176,6 @@ EXPORT_SYMBOL_GPL(devlink_region_create);
  *	@ops: region operations and name
  *	@region_max_snapshots: Maximum supported number of snapshots for region
  *	@region_size: size of region
- *
- *	Context: Takes and release devlink->lock <mutex>.
  */
 struct devlink_region *
 devlink_port_region_create(struct devlink_port *port,
@@ -11214,11 +11186,11 @@ devlink_port_region_create(struct devlink_port *port,
 	struct devlink_region *region;
 	int err = 0;
 
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(port);
+
 	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
 		return ERR_PTR(-EINVAL);
 
-	devl_lock(devlink);
-
 	if (devlink_port_region_get_by_name(port, ops->name)) {
 		err = -EEXIST;
 		goto unlock;
@@ -11238,9 +11210,7 @@ devlink_port_region_create(struct devlink_port *port,
 	INIT_LIST_HEAD(&region->snapshot_list);
 	mutex_init(&region->snapshot_lock);
 	list_add_tail(&region->list, &port->region_list);
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
 
-	devl_unlock(devlink);
 	return region;
 
 unlock:
@@ -11250,16 +11220,18 @@ devlink_port_region_create(struct devlink_port *port,
 EXPORT_SYMBOL_GPL(devlink_port_region_create);
 
 /**
- * devl_region_destroy - destroy address region
+ * devlink_region_destroy - destroy address region
  *
  * @region: devlink region to destroy
  */
-void devl_region_destroy(struct devlink_region *region)
+void devlink_region_destroy(struct devlink_region *region)
 {
-	struct devlink *devlink = region->devlink;
 	struct devlink_snapshot *snapshot, *ts;
 
-	devl_assert_locked(devlink);
+	if (region->port)
+		ASSERT_DEVLINK_PORT_NOT_REGISTERED(region->port);
+	else
+		ASSERT_DEVLINK_NOT_REGISTERED(region->devlink);
 
 	/* Free all snapshots of region */
 	list_for_each_entry_safe(snapshot, ts, &region->snapshot_list, list)
@@ -11268,26 +11240,8 @@ void devl_region_destroy(struct devlink_region *region)
 	list_del(&region->list);
 	mutex_destroy(&region->snapshot_lock);
 
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_DEL);
 	kfree(region);
 }
-EXPORT_SYMBOL_GPL(devl_region_destroy);
-
-/**
- *	devlink_region_destroy - destroy address region
- *
- *	@region: devlink region to destroy
- *
- *	Context: Takes and release devlink->lock <mutex>.
- */
-void devlink_region_destroy(struct devlink_region *region)
-{
-	struct devlink *devlink = region->devlink;
-
-	devl_lock(devlink);
-	devl_region_destroy(region);
-	devl_unlock(devlink);
-}
 EXPORT_SYMBOL_GPL(devlink_region_destroy);
 
 /**
-- 
2.35.3

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Vladimir Oltean]

On Tue, Jul 26, 2022 at 04:45:44PM +0200, Jiri Pirko wrote:
> Oh yes, could you please try together with following patch? (nevermind
> chicken-egg problem you may spot now)

Duly ignoring ;)

> Subject: [patch net-next RFC] net: devlink: convert region creation/destroy()
>  to be forbidden on registered devlink/port
> 
> No need to create or destroy region when devlink or devlink ports are
> registered. Limit the possibility to call the region create/destroy()
> only for non-registered devlink or devlink port. Benefit from that and
> avoid need to take devl_lock.
> 
> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
> ---
>  drivers/net/netdevsim/dev.c |  8 ++--
>  include/net/devlink.h       |  5 ---
>  net/core/devlink.c          | 78 ++++++++-----------------------------
>  3 files changed, 20 insertions(+), 71 deletions(-)
> 
> diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
> index 925dc8a5254d..3f0c19e30650 100644
> --- a/drivers/net/netdevsim/dev.c
> +++ b/drivers/net/netdevsim/dev.c
> @@ -557,15 +557,15 @@ static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
>  				      struct devlink *devlink)
>  {
>  	nsim_dev->dummy_region =
> -		devl_region_create(devlink, &dummy_region_ops,
> -				   NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
> -				   NSIM_DEV_DUMMY_REGION_SIZE);
> +		devlink_region_create(devlink, &dummy_region_ops,
> +				      NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
> +				      NSIM_DEV_DUMMY_REGION_SIZE);
>  	return PTR_ERR_OR_ZERO(nsim_dev->dummy_region);
>  }
>  
>  static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev)
>  {
> -	devl_region_destroy(nsim_dev->dummy_region);
> +	devlink_region_destroy(nsim_dev->dummy_region);
>  }
>  
>  static int
> diff --git a/include/net/devlink.h b/include/net/devlink.h
> index 9edb4a28cf30..2416750e050d 100644
> --- a/include/net/devlink.h
> +++ b/include/net/devlink.h
> @@ -1666,10 +1666,6 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
>  int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
>  				       union devlink_param_value init_val);
>  void devlink_param_value_changed(struct devlink *devlink, u32 param_id);
> -struct devlink_region *devl_region_create(struct devlink *devlink,
> -					  const struct devlink_region_ops *ops,
> -					  u32 region_max_snapshots,
> -					  u64 region_size);
>  struct devlink_region *
>  devlink_region_create(struct devlink *devlink,
>  		      const struct devlink_region_ops *ops,
> @@ -1678,7 +1674,6 @@ struct devlink_region *
>  devlink_port_region_create(struct devlink_port *port,
>  			   const struct devlink_port_region_ops *ops,
>  			   u32 region_max_snapshots, u64 region_size);
> -void devl_region_destroy(struct devlink_region *region);
>  void devlink_region_destroy(struct devlink_region *region);
>  void devlink_port_region_destroy(struct devlink_region *region);
>  
> diff --git a/net/core/devlink.c b/net/core/devlink.c
> index 4e0c4f9265e8..15d28aba69fc 100644
> --- a/net/core/devlink.c
> +++ b/net/core/devlink.c
> @@ -5701,8 +5701,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
>  	struct sk_buff *msg;
>  
>  	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
> -	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
> -		return;
> +	ASSERT_DEVLINK_REGISTERED(devlink);
>  
>  	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
>  	if (IS_ERR(msg))
> @@ -11131,21 +11130,22 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
>  EXPORT_SYMBOL_GPL(devlink_param_value_changed);
>  
>  /**
> - * devl_region_create - create a new address region
> + * devlink_region_create - create a new address region
>   *
>   * @devlink: devlink
>   * @ops: region operations and name
>   * @region_max_snapshots: Maximum supported number of snapshots for region
>   * @region_size: size of region
>   */
> -struct devlink_region *devl_region_create(struct devlink *devlink,
> -					  const struct devlink_region_ops *ops,
> -					  u32 region_max_snapshots,
> -					  u64 region_size)
> +struct devlink_region *
> +devlink_region_create(struct devlink *devlink,
> +		      const struct devlink_region_ops *ops,
> +		      u32 region_max_snapshots,
> +		      u64 region_size)
>  {
>  	struct devlink_region *region;
>  
> -	devl_assert_locked(devlink);
> +	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
>  
>  	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
>  		return ERR_PTR(-EINVAL);
> @@ -11164,35 +11164,9 @@ struct devlink_region *devl_region_create(struct devlink *devlink,
>  	INIT_LIST_HEAD(&region->snapshot_list);
>  	mutex_init(&region->snapshot_lock);
>  	list_add_tail(&region->list, &devlink->region_list);
> -	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
>  
>  	return region;
>  }
> -EXPORT_SYMBOL_GPL(devl_region_create);
> -
> -/**
> - *	devlink_region_create - create a new address region
> - *
> - *	@devlink: devlink
> - *	@ops: region operations and name
> - *	@region_max_snapshots: Maximum supported number of snapshots for region
> - *	@region_size: size of region
> - *
> - *	Context: Takes and release devlink->lock <mutex>.
> - */
> -struct devlink_region *
> -devlink_region_create(struct devlink *devlink,
> -		      const struct devlink_region_ops *ops,
> -		      u32 region_max_snapshots, u64 region_size)
> -{
> -	struct devlink_region *region;
> -
> -	devl_lock(devlink);
> -	region = devl_region_create(devlink, ops, region_max_snapshots,
> -				    region_size);
> -	devl_unlock(devlink);
> -	return region;
> -}
>  EXPORT_SYMBOL_GPL(devlink_region_create);
>  
>  /**

Were you on net-next when you generated this patch? Here's what I have
at 11164:

devlink_port_region_create:
	if (devlink_port_region_get_by_name(port, ops->name)) {
		err = -EEXIST;
		goto unlock;
	}

	region = kzalloc(sizeof(*region), GFP_KERNEL);
	if (!region) {

My end of devl_region_create() and start of devlink_region_create() are
at 11106, but notice how I lack the mutex_init(&region->snapshot_lock)
that you have in your context:

	INIT_LIST_HEAD(&region->snapshot_list);
	list_add_tail(&region->list, &devlink->region_list);
	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);

	return region;
}
EXPORT_SYMBOL_GPL(devl_region_create);

Would you mind regenerating this patch rather than letting me bodge it?

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Jiri Pirko]

Tue, Jul 26, 2022 at 05:20:59PM CEST, olteanv@gmail.com wrote:
>On Tue, Jul 26, 2022 at 04:45:44PM +0200, Jiri Pirko wrote:
>> Oh yes, could you please try together with following patch? (nevermind
>> chicken-egg problem you may spot now)
>
>Duly ignoring ;)
>
>> Subject: [patch net-next RFC] net: devlink: convert region creation/destroy()
>>  to be forbidden on registered devlink/port
>> 
>> No need to create or destroy region when devlink or devlink ports are
>> registered. Limit the possibility to call the region create/destroy()
>> only for non-registered devlink or devlink port. Benefit from that and
>> avoid need to take devl_lock.
>> 
>> Signed-off-by: Jiri Pirko <jiri@nvidia.com>
>> ---
>>  drivers/net/netdevsim/dev.c |  8 ++--
>>  include/net/devlink.h       |  5 ---
>>  net/core/devlink.c          | 78 ++++++++-----------------------------
>>  3 files changed, 20 insertions(+), 71 deletions(-)
>> 
>> diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
>> index 925dc8a5254d..3f0c19e30650 100644
>> --- a/drivers/net/netdevsim/dev.c
>> +++ b/drivers/net/netdevsim/dev.c
>> @@ -557,15 +557,15 @@ static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
>>  				      struct devlink *devlink)
>>  {
>>  	nsim_dev->dummy_region =
>> -		devl_region_create(devlink, &dummy_region_ops,
>> -				   NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
>> -				   NSIM_DEV_DUMMY_REGION_SIZE);
>> +		devlink_region_create(devlink, &dummy_region_ops,
>> +				      NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
>> +				      NSIM_DEV_DUMMY_REGION_SIZE);
>>  	return PTR_ERR_OR_ZERO(nsim_dev->dummy_region);
>>  }
>>  
>>  static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev)
>>  {
>> -	devl_region_destroy(nsim_dev->dummy_region);
>> +	devlink_region_destroy(nsim_dev->dummy_region);
>>  }
>>  
>>  static int
>> diff --git a/include/net/devlink.h b/include/net/devlink.h
>> index 9edb4a28cf30..2416750e050d 100644
>> --- a/include/net/devlink.h
>> +++ b/include/net/devlink.h
>> @@ -1666,10 +1666,6 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
>>  int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
>>  				       union devlink_param_value init_val);
>>  void devlink_param_value_changed(struct devlink *devlink, u32 param_id);
>> -struct devlink_region *devl_region_create(struct devlink *devlink,
>> -					  const struct devlink_region_ops *ops,
>> -					  u32 region_max_snapshots,
>> -					  u64 region_size);
>>  struct devlink_region *
>>  devlink_region_create(struct devlink *devlink,
>>  		      const struct devlink_region_ops *ops,
>> @@ -1678,7 +1674,6 @@ struct devlink_region *
>>  devlink_port_region_create(struct devlink_port *port,
>>  			   const struct devlink_port_region_ops *ops,
>>  			   u32 region_max_snapshots, u64 region_size);
>> -void devl_region_destroy(struct devlink_region *region);
>>  void devlink_region_destroy(struct devlink_region *region);
>>  void devlink_port_region_destroy(struct devlink_region *region);
>>  
>> diff --git a/net/core/devlink.c b/net/core/devlink.c
>> index 4e0c4f9265e8..15d28aba69fc 100644
>> --- a/net/core/devlink.c
>> +++ b/net/core/devlink.c
>> @@ -5701,8 +5701,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
>>  	struct sk_buff *msg;
>>  
>>  	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
>> -	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
>> -		return;
>> +	ASSERT_DEVLINK_REGISTERED(devlink);
>>  
>>  	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
>>  	if (IS_ERR(msg))
>> @@ -11131,21 +11130,22 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
>>  EXPORT_SYMBOL_GPL(devlink_param_value_changed);
>>  
>>  /**
>> - * devl_region_create - create a new address region
>> + * devlink_region_create - create a new address region
>>   *
>>   * @devlink: devlink
>>   * @ops: region operations and name
>>   * @region_max_snapshots: Maximum supported number of snapshots for region
>>   * @region_size: size of region
>>   */
>> -struct devlink_region *devl_region_create(struct devlink *devlink,
>> -					  const struct devlink_region_ops *ops,
>> -					  u32 region_max_snapshots,
>> -					  u64 region_size)
>> +struct devlink_region *
>> +devlink_region_create(struct devlink *devlink,
>> +		      const struct devlink_region_ops *ops,
>> +		      u32 region_max_snapshots,
>> +		      u64 region_size)
>>  {
>>  	struct devlink_region *region;
>>  
>> -	devl_assert_locked(devlink);
>> +	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
>>  
>>  	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
>>  		return ERR_PTR(-EINVAL);
>> @@ -11164,35 +11164,9 @@ struct devlink_region *devl_region_create(struct devlink *devlink,
>>  	INIT_LIST_HEAD(&region->snapshot_list);
>>  	mutex_init(&region->snapshot_lock);
>>  	list_add_tail(&region->list, &devlink->region_list);
>> -	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
>>  
>>  	return region;
>>  }
>> -EXPORT_SYMBOL_GPL(devl_region_create);
>> -
>> -/**
>> - *	devlink_region_create - create a new address region
>> - *
>> - *	@devlink: devlink
>> - *	@ops: region operations and name
>> - *	@region_max_snapshots: Maximum supported number of snapshots for region
>> - *	@region_size: size of region
>> - *
>> - *	Context: Takes and release devlink->lock <mutex>.
>> - */
>> -struct devlink_region *
>> -devlink_region_create(struct devlink *devlink,
>> -		      const struct devlink_region_ops *ops,
>> -		      u32 region_max_snapshots, u64 region_size)
>> -{
>> -	struct devlink_region *region;
>> -
>> -	devl_lock(devlink);
>> -	region = devl_region_create(devlink, ops, region_max_snapshots,
>> -				    region_size);
>> -	devl_unlock(devlink);
>> -	return region;
>> -}
>>  EXPORT_SYMBOL_GPL(devlink_region_create);
>>  
>>  /**
>
>Were you on net-next when you generated this patch? Here's what I have
>at 11164:
>
>devlink_port_region_create:
>	if (devlink_port_region_get_by_name(port, ops->name)) {
>		err = -EEXIST;
>		goto unlock;
>	}
>
>	region = kzalloc(sizeof(*region), GFP_KERNEL);
>	if (!region) {
>
>My end of devl_region_create() and start of devlink_region_create() are
>at 11106, but notice how I lack the mutex_init(&region->snapshot_lock)
>that you have in your context:
>
>	INIT_LIST_HEAD(&region->snapshot_list);
>	list_add_tail(&region->list, &devlink->region_list);
>	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
>
>	return region;
>}
>EXPORT_SYMBOL_GPL(devl_region_create);
>
>Would you mind regenerating this patch rather than letting me bodge it?

Darn, wait. I will fixup a squash for you. Sorry.

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Jiri Pirko]

Tue, Jul 26, 2022 at 05:57:59PM CEST, jiri@resnulli.us wrote:
>Tue, Jul 26, 2022 at 05:20:59PM CEST, olteanv@gmail.com wrote:
>>On Tue, Jul 26, 2022 at 04:45:44PM +0200, Jiri Pirko wrote:

[..]

>
>Darn, wait. I will fixup a squash for you. Sorry.

Here it is:

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 5802e80e8fe1..ddfc03722ab5 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -557,15 +557,15 @@ static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
 				      struct devlink *devlink)
 {
 	nsim_dev->dummy_region =
-		devl_region_create(devlink, &dummy_region_ops,
-				   NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
-				   NSIM_DEV_DUMMY_REGION_SIZE);
+		devlink_region_create(devlink, &dummy_region_ops,
+				      NSIM_DEV_DUMMY_REGION_SNAPSHOT_MAX,
+				      NSIM_DEV_DUMMY_REGION_SIZE);
 	return PTR_ERR_OR_ZERO(nsim_dev->dummy_region);
 }
 
 static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev)
 {
-	devl_region_destroy(nsim_dev->dummy_region);
+	devlink_region_destroy(nsim_dev->dummy_region);
 }
 
 static int
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 780744b550b8..6885c8928327 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1665,10 +1665,6 @@ int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
 int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
 				       union devlink_param_value init_val);
 void devlink_param_value_changed(struct devlink *devlink, u32 param_id);
-struct devlink_region *devl_region_create(struct devlink *devlink,
-					  const struct devlink_region_ops *ops,
-					  u32 region_max_snapshots,
-					  u64 region_size);
 struct devlink_region *
 devlink_region_create(struct devlink *devlink,
 		      const struct devlink_region_ops *ops,
@@ -1677,7 +1673,6 @@ struct devlink_region *
 devlink_port_region_create(struct devlink_port *port,
 			   const struct devlink_port_region_ops *ops,
 			   u32 region_max_snapshots, u64 region_size);
-void devl_region_destroy(struct devlink_region *region);
 void devlink_region_destroy(struct devlink_region *region);
 void devlink_port_region_destroy(struct devlink_region *region);
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 98d79feeb3dc..71219f66da4e 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -310,6 +310,11 @@ static struct devlink *devlink_get_from_attrs(struct net *net,
 	return devlink;
 }
 
+#define ASSERT_DEVLINK_PORT_REGISTERED(devlink_port)				\
+	WARN_ON_ONCE(!devlink_port->devlink)
+#define ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port)			\
+	WARN_ON_ONCE(devlink_port->devlink)
+
 static struct devlink_port *devlink_port_get_by_index(struct devlink *devlink,
 						      unsigned int port_index)
 {
@@ -5646,8 +5651,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
 	struct sk_buff *msg;
 
 	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
-		return;
+	ASSERT_DEVLINK_REGISTERED(devlink);
 
 	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
 	if (IS_ERR(msg))
@@ -9704,7 +9708,8 @@ int devl_port_register(struct devlink *devlink,
 	if (devlink_port_index_exists(devlink, port_index))
 		return -EEXIST;
 
-	WARN_ON(devlink_port->devlink);
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	devlink_port->devlink = devlink;
 	devlink_port->index = port_index;
 	spin_lock_init(&devlink_port->type_lock);
@@ -9788,8 +9793,8 @@ static void __devlink_port_type_set(struct devlink_port *devlink_port,
 				    enum devlink_port_type type,
 				    void *type_dev)
 {
-	if (WARN_ON(!devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_REGISTERED(devlink_port);
+
 	devlink_port_type_warn_cancel(devlink_port);
 	spin_lock_bh(&devlink_port->type_lock);
 	devlink_port->type = type;
@@ -9908,8 +9913,8 @@ void devlink_port_attrs_set(struct devlink_port *devlink_port,
 {
 	int ret;
 
-	if (WARN_ON(devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	devlink_port->attrs = *attrs;
 	ret = __devlink_port_attrs_set(devlink_port, attrs->flavour);
 	if (ret)
@@ -9932,8 +9937,8 @@ void devlink_port_attrs_pci_pf_set(struct devlink_port *devlink_port, u32 contro
 	struct devlink_port_attrs *attrs = &devlink_port->attrs;
 	int ret;
 
-	if (WARN_ON(devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	ret = __devlink_port_attrs_set(devlink_port,
 				       DEVLINK_PORT_FLAVOUR_PCI_PF);
 	if (ret)
@@ -9959,8 +9964,8 @@ void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port, u32 contro
 	struct devlink_port_attrs *attrs = &devlink_port->attrs;
 	int ret;
 
-	if (WARN_ON(devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	ret = __devlink_port_attrs_set(devlink_port,
 				       DEVLINK_PORT_FLAVOUR_PCI_VF);
 	if (ret)
@@ -9987,8 +9992,8 @@ void devlink_port_attrs_pci_sf_set(struct devlink_port *devlink_port, u32 contro
 	struct devlink_port_attrs *attrs = &devlink_port->attrs;
 	int ret;
 
-	if (WARN_ON(devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	ret = __devlink_port_attrs_set(devlink_port,
 				       DEVLINK_PORT_FLAVOUR_PCI_SF);
 	if (ret)
@@ -10103,8 +10108,8 @@ EXPORT_SYMBOL_GPL(devl_rate_nodes_destroy);
 void devlink_port_linecard_set(struct devlink_port *devlink_port,
 			       struct devlink_linecard *linecard)
 {
-	if (WARN_ON(devlink_port->devlink))
-		return;
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(devlink_port);
+
 	devlink_port->linecard = linecard;
 }
 EXPORT_SYMBOL_GPL(devlink_port_linecard_set);
@@ -11073,21 +11078,22 @@ void devlink_param_value_changed(struct devlink *devlink, u32 param_id)
 EXPORT_SYMBOL_GPL(devlink_param_value_changed);
 
 /**
- * devl_region_create - create a new address region
+ * devlink_region_create - create a new address region
  *
  * @devlink: devlink
  * @ops: region operations and name
  * @region_max_snapshots: Maximum supported number of snapshots for region
  * @region_size: size of region
  */
-struct devlink_region *devl_region_create(struct devlink *devlink,
-					  const struct devlink_region_ops *ops,
-					  u32 region_max_snapshots,
-					  u64 region_size)
+struct devlink_region *
+devlink_region_create(struct devlink *devlink,
+		      const struct devlink_region_ops *ops,
+		      u32 region_max_snapshots,
+		      u64 region_size)
 {
 	struct devlink_region *region;
 
-	devl_assert_locked(devlink);
+	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
 
 	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
 		return ERR_PTR(-EINVAL);
@@ -11105,35 +11111,9 @@ struct devlink_region *devl_region_create(struct devlink *devlink,
 	region->size = region_size;
 	INIT_LIST_HEAD(&region->snapshot_list);
 	list_add_tail(&region->list, &devlink->region_list);
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
 
 	return region;
 }
-EXPORT_SYMBOL_GPL(devl_region_create);
-
-/**
- *	devlink_region_create - create a new address region
- *
- *	@devlink: devlink
- *	@ops: region operations and name
- *	@region_max_snapshots: Maximum supported number of snapshots for region
- *	@region_size: size of region
- *
- *	Context: Takes and release devlink->lock <mutex>.
- */
-struct devlink_region *
-devlink_region_create(struct devlink *devlink,
-		      const struct devlink_region_ops *ops,
-		      u32 region_max_snapshots, u64 region_size)
-{
-	struct devlink_region *region;
-
-	devl_lock(devlink);
-	region = devl_region_create(devlink, ops, region_max_snapshots,
-				    region_size);
-	devl_unlock(devlink);
-	return region;
-}
 EXPORT_SYMBOL_GPL(devlink_region_create);
 
 /**
@@ -11143,8 +11123,6 @@ EXPORT_SYMBOL_GPL(devlink_region_create);
  *	@ops: region operations and name
  *	@region_max_snapshots: Maximum supported number of snapshots for region
  *	@region_size: size of region
- *
- *	Context: Takes and release devlink->lock <mutex>.
  */
 struct devlink_region *
 devlink_port_region_create(struct devlink_port *port,
@@ -11155,11 +11133,11 @@ devlink_port_region_create(struct devlink_port *port,
 	struct devlink_region *region;
 	int err = 0;
 
+	ASSERT_DEVLINK_PORT_NOT_REGISTERED(port);
+
 	if (WARN_ON(!ops) || WARN_ON(!ops->destructor))
 		return ERR_PTR(-EINVAL);
 
-	devl_lock(devlink);
-
 	if (devlink_port_region_get_by_name(port, ops->name)) {
 		err = -EEXIST;
 		goto unlock;
@@ -11178,9 +11156,7 @@ devlink_port_region_create(struct devlink_port *port,
 	region->size = region_size;
 	INIT_LIST_HEAD(&region->snapshot_list);
 	list_add_tail(&region->list, &port->region_list);
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
 
-	devl_unlock(devlink);
 	return region;
 
 unlock:
@@ -11190,16 +11166,18 @@ devlink_port_region_create(struct devlink_port *port,
 EXPORT_SYMBOL_GPL(devlink_port_region_create);
 
 /**
- * devl_region_destroy - destroy address region
+ * devlink_region_destroy - destroy address region
  *
  * @region: devlink region to destroy
  */
-void devl_region_destroy(struct devlink_region *region)
+void devlink_region_destroy(struct devlink_region *region)
 {
-	struct devlink *devlink = region->devlink;
 	struct devlink_snapshot *snapshot, *ts;
 
-	devl_assert_locked(devlink);
+	if (region->port)
+		ASSERT_DEVLINK_PORT_NOT_REGISTERED(region->port);
+	else
+		ASSERT_DEVLINK_NOT_REGISTERED(region->devlink);
 
 	/* Free all snapshots of region */
 	list_for_each_entry_safe(snapshot, ts, &region->snapshot_list, list)
@@ -11207,26 +11185,8 @@ void devl_region_destroy(struct devlink_region *region)
 
 	list_del(&region->list);
 
-	devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_DEL);
 	kfree(region);
 }
-EXPORT_SYMBOL_GPL(devl_region_destroy);
-
-/**
- *	devlink_region_destroy - destroy address region
- *
- *	@region: devlink region to destroy
- *
- *	Context: Takes and release devlink->lock <mutex>.
- */
-void devlink_region_destroy(struct devlink_region *region)
-{
-	struct devlink *devlink = region->devlink;
-
-	devl_lock(devlink);
-	devl_region_destroy(region);
-	devl_unlock(devlink);
-}
 EXPORT_SYMBOL_GPL(devlink_region_destroy);
 
 /**
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index cac48a741f27..a8b6c6434df2 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -451,19 +451,12 @@ static int dsa_port_setup(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
 	bool dsa_port_link_registered = false;
-	struct dsa_switch *ds = dp->ds;
 	bool dsa_port_enabled = false;
 	int err = 0;
 
 	if (dp->setup)
 		return 0;
 
-	if (ds->ops->port_setup) {
-		err = ds->ops->port_setup(ds, dp->index);
-		if (err)
-			return err;
-	}
-
 	switch (dp->type) {
 	case DSA_PORT_TYPE_UNUSED:
 		dsa_port_disable(dp);
@@ -506,11 +499,6 @@ static int dsa_port_setup(struct dsa_port *dp)
 		dsa_port_disable(dp);
 	if (err && dsa_port_link_registered)
 		dsa_port_link_unregister_of(dp);
-	if (err) {
-		if (ds->ops->port_teardown)
-			ds->ops->port_teardown(ds, dp->index);
-		return err;
-	}
 
 	dp->setup = true;
 
@@ -523,10 +511,17 @@ static int dsa_port_devlink_setup(struct dsa_port *dp)
 	struct dsa_switch_tree *dst = dp->ds->dst;
 	struct devlink_port_attrs attrs = {};
 	struct devlink *dl = dp->ds->devlink;
+	struct dsa_switch *ds = dp->ds;
 	const unsigned char *id;
 	unsigned char len;
 	int err;
 
+	if (ds->ops->port_setup) {
+		err = ds->ops->port_setup(ds, dp->index);
+		if (err)
+			return err;
+	}
+
 	id = (const unsigned char *)&dst->index;
 	len = sizeof(dst->index);
 
@@ -552,24 +547,23 @@ static int dsa_port_devlink_setup(struct dsa_port *dp)
 
 	devlink_port_attrs_set(dlp, &attrs);
 	err = devlink_port_register(dl, dlp, dp->index);
+	if (err) {
+		if (ds->ops->port_teardown)
+			ds->ops->port_teardown(ds, dp->index);
+		return err;
+	}
+	dp->devlink_port_setup = true;
 
-	if (!err)
-		dp->devlink_port_setup = true;
-
-	return err;
+	return 0;
 }
 
 static void dsa_port_teardown(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
-	struct dsa_switch *ds = dp->ds;
 
 	if (!dp->setup)
 		return;
 
-	if (ds->ops->port_teardown)
-		ds->ops->port_teardown(ds, dp->index);
-
 	devlink_port_type_clear(dlp);
 
 	switch (dp->type) {
@@ -597,40 +591,24 @@ static void dsa_port_teardown(struct dsa_port *dp)
 static void dsa_port_devlink_teardown(struct dsa_port *dp)
 {
 	struct devlink_port *dlp = &dp->devlink_port;
+	struct dsa_switch *ds = dp->ds;
 
-	if (dp->devlink_port_setup)
+	if (dp->devlink_port_setup) {
 		devlink_port_unregister(dlp);
+		if (ds->ops->port_teardown)
+			ds->ops->port_teardown(ds, dp->index);
+	}
 	dp->devlink_port_setup = false;
 }
 
 /* Destroy the current devlink port, and create a new one which has the UNUSED
- * flavour. At this point, any call to ds->ops->port_setup has been already
- * balanced out by a call to ds->ops->port_teardown, so we know that any
- * devlink port regions the driver had are now unregistered. We then call its
- * ds->ops->port_setup again, in order for the driver to re-create them on the
- * new devlink port.
+ * flavour.
  */
 static int dsa_port_reinit_as_unused(struct dsa_port *dp)
 {
-	struct dsa_switch *ds = dp->ds;
-	int err;
-
 	dsa_port_devlink_teardown(dp);
 	dp->type = DSA_PORT_TYPE_UNUSED;
-	err = dsa_port_devlink_setup(dp);
-	if (err)
-		return err;
-
-	if (ds->ops->port_setup) {
-		/* On error, leave the devlink port registered,
-		 * dsa_switch_teardown will clean it up later.
-		 */
-		err = ds->ops->port_setup(ds, dp->index);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return dsa_port_devlink_setup(dp);
 }
 
 static int dsa_devlink_info_get(struct devlink *dl,

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Vladimir Oltean]

On Tue, Jul 26, 2022 at 06:13:11PM +0200, Jiri Pirko wrote:
> Here it is:

Thanks, this one does apply.

We have the same problem, except now it's with port->region_list
(region_create does list_add_tail, port_register does INIT_LIST_HEAD).

I don't think you need to see this anymore, but anyway, here it is.

[    4.949727] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
[    5.020395] CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.19.0-rc7-07010-ga9b9500ffaac-dirty #3397
[    5.047447] pc : devlink_port_region_create+0x6c/0x150
[    5.052587] lr : dsa_devlink_port_region_create+0x64/0x90
[    5.057983] sp : ffff80000c17b8b0
[    5.132669] Call trace:
[    5.135109]  devlink_port_region_create+0x6c/0x150
[    5.139899]  dsa_devlink_port_region_create+0x64/0x90
[    5.144946]  mv88e6xxx_setup_devlink_regions_port+0x30/0x60
[    5.150520]  mv88e6xxx_port_setup+0x10/0x20
[    5.154700]  dsa_port_devlink_setup+0x60/0x150
[    5.159141]  dsa_register_switch+0x938/0x119c
[    5.163496]  mv88e6xxx_probe+0x714/0x770
[    5.167416]  mdio_probe+0x34/0x70

Re: [patch net-next RFC] net: dsa: move port_setup/teardown to be called outside devlink port registered area

[Jiri Pirko]

Tue, Jul 26, 2022 at 06:55:20PM CEST, olteanv@gmail.com wrote:
>On Tue, Jul 26, 2022 at 06:13:11PM +0200, Jiri Pirko wrote:
>> Here it is:
>
>Thanks, this one does apply.
>
>We have the same problem, except now it's with port->region_list
>(region_create does list_add_tail, port_register does INIT_LIST_HEAD).
>
>I don't think you need to see this anymore, but anyway, here it is.

Thanks, will fix this and send it to you off-list, to avoid spamming
people, sorry.

Thanks!

>
>[    4.949727] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
>[    5.020395] CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.19.0-rc7-07010-ga9b9500ffaac-dirty #3397
>[    5.047447] pc : devlink_port_region_create+0x6c/0x150
>[    5.052587] lr : dsa_devlink_port_region_create+0x64/0x90
>[    5.057983] sp : ffff80000c17b8b0
>[    5.132669] Call trace:
>[    5.135109]  devlink_port_region_create+0x6c/0x150
>[    5.139899]  dsa_devlink_port_region_create+0x64/0x90
>[    5.144946]  mv88e6xxx_setup_devlink_regions_port+0x30/0x60
>[    5.150520]  mv88e6xxx_port_setup+0x10/0x20
>[    5.154700]  dsa_port_devlink_setup+0x60/0x150
>[    5.159141]  dsa_register_switch+0x938/0x119c
>[    5.163496]  mv88e6xxx_probe+0x714/0x770
>[    5.167416]  mdio_probe+0x34/0x70