Subject: Re: [PATCH net] net/smc: Fix dependency of SMC on ISM

From: Gerd Bayer <[email-masked]>
Date: Tue, 17 Oct 2023 16:15:20 +0200

On Mon, 2023-10-16 at 16:09 -0700, Randy Dunlap wrote:
> Hi Gerd,
> 
> On 10/6/23 05:58, Gerd Bayer wrote:
> > When the SMC protocol is built into the kernel proper while ISM is
> > configured to be built as module, linking the kernel fails due to
> > unresolved dependencies out of net/smc/smc_ism.o to
> > ism_get_smcd_ops, ism_register_client, and ism_unregister_client
> > as reported via the linux-next test automation (see link).
> > This however is a bug introduced a while ago.
> > 
> > Correct the dependency list in ISM's and SMC's Kconfig to reflect
> > the
> > dependencies that are actually inverted. With this you cannot build
> > a
> > kernel with CONFIG_SMC=y and CONFIG_ISM=m. Either ISM needs to be
> > 'y',
> > too - or a 'n'. That way, SMC can still be configured on non-s390
> > architectures that do not have (nor need) an ISM driver.
> > 
> > Fixes: 89e7d2ba61b7 ("net/ism: Add new API for client
> > registration")
> > 
> > Reported-by: Randy Dunlap <[email-masked]>
> > Closes:
> > https://lore.kernel.org/linux-next/[email-masked]/
> > Co-developed-by: Wenjia Zhang <[email-masked]>
> > Signed-off-by: Wenjia Zhang <[email-masked]>
> > Signed-off-by: Gerd Bayer <[email-masked]>
> 
> With this patch, ISM can be build without SMC being enabled.
> 
> This leads to some build warnings:
> 
> ../drivers/s390/net/ism_drv.c:572:12: warning: 'ism_get_local_gid'
> defined but not used [-Wunused-function]
>   572 | static u64 ism_get_local_gid(struct ism_dev *ism)
>       |            ^~~~~~~~~~~~~~~~~
> ../drivers/s390/net/ism_drv.c:506:12: warning: 'ism_get_chid' defined
> but not used [-Wunused-function]
>   506 | static u16 ism_get_chid(struct ism_dev *ism)
>       |            ^~~~~~~~~~~~
> ../drivers/s390/net/ism_drv.c:432:12: warning: 'ism_signal_ieq'
> defined but not used [-Wunused-function]
>   432 | static int ism_signal_ieq(struct ism_dev *ism, u64 rgid, u32
> trigger_irq,
>       |            ^~~~~~~~~~~~~~
> ../drivers/s390/net/ism_drv.c:292:12: warning: 'ism_query_rgid'
> defined but not used [-Wunused-function]
>   292 | static int ism_query_rgid(struct ism_dev *ism, u64 rgid, u32
> vid_valid,
>       |            ^~~~~~~~~~~~~~

Hi Randy,

I must have missed testing a config of ISM without SMC. I'm working on
a fix.

Thanks for reporting,
Gerd