[PATCH net-next] net: phy: link_topology: Don't stub-away the topology creation

[PATCH net-next] net: phy: link_topology: Don't stub-away the topology creation

[Maxime Chevallier]

Some of the phy_link_topology operations are protected by IS_REACHABLE,
which can lead to scenarios where the consumer, built as modules, sees the topology
unstubbed, whereas the initialization didn't occur.

Don't stub away the creation of the topology, it has no dependency on
any other parts like phylib, so we can make it always available.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Closes: https://lore.kernel.org/netdev/2e11b89d-100f-49e7-9c9a-834cc0b82f97@gmail.com/
Closes: https://lore.kernel.org/netdev/20240409201553.GA4124869@dev-arch.thelio-3990X/
---
Hi Nathan, Heiner,

I'm currently at EOSS, so I'm sending this patch without having been
able to properly test it (build-tested only), but as this addresses an
issue for people using -next, I'm sending this anyway, sorry about that.

Hopefully it can address the issue for now, I haven't given-up on your
idea to introduce a config option Heiner :)

Thanks,

Maxime

 include/linux/phy_link_topology_core.h | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/include/linux/phy_link_topology_core.h b/include/linux/phy_link_topology_core.h
index 0a6479055745..61e2592f24ac 100644
--- a/include/linux/phy_link_topology_core.h
+++ b/include/linux/phy_link_topology_core.h
@@ -4,22 +4,7 @@
 
 struct phy_link_topology;
 
-#if IS_REACHABLE(CONFIG_PHYLIB)
-
 struct phy_link_topology *phy_link_topo_create(struct net_device *dev);
 void phy_link_topo_destroy(struct phy_link_topology *topo);
 
-#else
-
-static inline struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
-{
-	return NULL;
-}
-
-static inline void phy_link_topo_destroy(struct phy_link_topology *topo)
-{
-}
-
-#endif
-
 #endif /* __PHY_LINK_TOPOLOGY_CORE_H */
-- 
2.44.0

Re: [PATCH net-next] net: phy: link_topology: Don't stub-away the topology creation

[Nathan Chancellor]

Hi Maxime,

On Wed, Apr 17, 2024 at 04:27:05PM +0200, Maxime Chevallier wrote:
> Some of the phy_link_topology operations are protected by IS_REACHABLE,
> which can lead to scenarios where the consumer, built as modules, sees the topology
> unstubbed, whereas the initialization didn't occur.
> 
> Don't stub away the creation of the topology, it has no dependency on
> any other parts like phylib, so we can make it always available.
> 
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> Closes: https://lore.kernel.org/netdev/2e11b89d-100f-49e7-9c9a-834cc0b82f97@gmail.com/
> Closes: https://lore.kernel.org/netdev/20240409201553.GA4124869@dev-arch.thelio-3990X/
> ---
> Hi Nathan, Heiner,
> 
> I'm currently at EOSS, so I'm sending this patch without having been
> able to properly test it (build-tested only), but as this addresses an
> issue for people using -next, I'm sending this anyway, sorry about that.

No worries, thanks for continuing to take a look. Unfortunately, this
patch fails to build during the linking stage for me with my
configuration:

x86_64-linux-ld: vmlinux.o: in function `free_netdev':
net/core/dev.c:11060:(.text+0xb14030): undefined reference to `phy_link_topo_destroy'
x86_64-linux-ld: vmlinux.o: in function `alloc_netdev_mqs':
net/core/dev.c:10966:(.text+0xb142d6): undefined reference to `phy_link_topo_create'

> Hopefully it can address the issue for now, I haven't given-up on your
> idea to introduce a config option Heiner :)
> 
> Thanks,
> 
> Maxime
> 
>  include/linux/phy_link_topology_core.h | 15 ---------------
>  1 file changed, 15 deletions(-)
> 
> diff --git a/include/linux/phy_link_topology_core.h b/include/linux/phy_link_topology_core.h
> index 0a6479055745..61e2592f24ac 100644
> --- a/include/linux/phy_link_topology_core.h
> +++ b/include/linux/phy_link_topology_core.h
> @@ -4,22 +4,7 @@
>  
>  struct phy_link_topology;
>  
> -#if IS_REACHABLE(CONFIG_PHYLIB)
> -
>  struct phy_link_topology *phy_link_topo_create(struct net_device *dev);
>  void phy_link_topo_destroy(struct phy_link_topology *topo);
>  
> -#else
> -
> -static inline struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
> -{
> -	return NULL;
> -}
> -
> -static inline void phy_link_topo_destroy(struct phy_link_topology *topo)
> -{
> -}
> -
> -#endif
> -
>  #endif /* __PHY_LINK_TOPOLOGY_CORE_H */
> -- 
> 2.44.0
> 

Re: [PATCH net-next] net: phy: link_topology: Don't stub-away the topology creation

[Maxime Chevallier]

Hello Nathan,

On Wed, 17 Apr 2024 11:07:21 -0700
Nathan Chancellor <nathan@kernel.org> wrote:

> Hi Maxime,
> 
> On Wed, Apr 17, 2024 at 04:27:05PM +0200, Maxime Chevallier wrote:
> > Some of the phy_link_topology operations are protected by IS_REACHABLE,
> > which can lead to scenarios where the consumer, built as modules, sees the topology
> > unstubbed, whereas the initialization didn't occur.
> > 
> > Don't stub away the creation of the topology, it has no dependency on
> > any other parts like phylib, so we can make it always available.
> > 
> > Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> > Closes: https://lore.kernel.org/netdev/2e11b89d-100f-49e7-9c9a-834cc0b82f97@gmail.com/
> > Closes: https://lore.kernel.org/netdev/20240409201553.GA4124869@dev-arch.thelio-3990X/
> > ---
> > Hi Nathan, Heiner,
> > 
> > I'm currently at EOSS, so I'm sending this patch without having been
> > able to properly test it (build-tested only), but as this addresses an
> > issue for people using -next, I'm sending this anyway, sorry about that.  
> 
> No worries, thanks for continuing to take a look. Unfortunately, this
> patch fails to build during the linking stage for me with my
> configuration:
> 
> x86_64-linux-ld: vmlinux.o: in function `free_netdev':
> net/core/dev.c:11060:(.text+0xb14030): undefined reference to `phy_link_topo_destroy'
> x86_64-linux-ld: vmlinux.o: in function `alloc_netdev_mqs':
> net/core/dev.c:10966:(.text+0xb142d6): undefined reference to `phy_link_topo_create'

Heh serves me well for trying to go too fast :) phy_link_topo_create
then need to compile unconditionally, so I'm indeed missing some bits
here.

Thanks a lot for testing,

Maxime

> 
> > Hopefully it can address the issue for now, I haven't given-up on your
> > idea to introduce a config option Heiner :)
> > 
> > Thanks,
> > 
> > Maxime
> > 
> >  include/linux/phy_link_topology_core.h | 15 ---------------
> >  1 file changed, 15 deletions(-)
> > 
> > diff --git a/include/linux/phy_link_topology_core.h b/include/linux/phy_link_topology_core.h
> > index 0a6479055745..61e2592f24ac 100644
> > --- a/include/linux/phy_link_topology_core.h
> > +++ b/include/linux/phy_link_topology_core.h
> > @@ -4,22 +4,7 @@
> >  
> >  struct phy_link_topology;
> >  
> > -#if IS_REACHABLE(CONFIG_PHYLIB)
> > -
> >  struct phy_link_topology *phy_link_topo_create(struct net_device *dev);
> >  void phy_link_topo_destroy(struct phy_link_topology *topo);
> >  
> > -#else
> > -
> > -static inline struct phy_link_topology *phy_link_topo_create(struct net_device *dev)
> > -{
> > -	return NULL;
> > -}
> > -
> > -static inline void phy_link_topo_destroy(struct phy_link_topology *topo)
> > -{
> > -}
> > -
> > -#endif
> > -
> >  #endif /* __PHY_LINK_TOPOLOGY_CORE_H */
> > -- 
> > 2.44.0
> >