[PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Reinette Chatre]

pci_msix_alloc_irq_at() and pci_msix_free_irq() are not
declared when CONFIG_PCI_MSI is disabled.

Users of these two calls do not yet exist but when users
do appear (shown below is an attempt to use the new API
in vfio-pci) the following errors will be encountered when
compiling with CONFIG_PCI_MSI disabled:
drivers/vfio/pci/vfio_pci_intrs.c:461:4: error: implicit declaration of\
        function 'pci_msix_free_irq' is invalid in C99\
        [-Werror,-Wimplicit-function-declaration]
                           pci_msix_free_irq(pdev, msix_map);
                           ^
   drivers/vfio/pci/vfio_pci_intrs.c:461:4: note: did you mean 'pci_ims_free_irq'?
   include/linux/pci.h:2516:6: note: 'pci_ims_free_irq' declared here
   void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
        ^
drivers/vfio/pci/vfio_pci_intrs.c:511:15: error: implicit declaration of\
        function 'pci_msix_alloc_irq_at' is invalid in C99\
        [-Werror,-Wimplicit-function-declaration]
                   msix_map = pci_msix_alloc_irq_at(pdev, vector, NULL);
                                      ^
   drivers/vfio/pci/vfio_pci_intrs.c:511:15: note: did you mean 'pci_ims_alloc_irq'?
   include/linux/pci.h:2514:16: note: 'pci_ims_alloc_irq' declared here
   struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev,\
                                    union msi_instance_cookie *icookie,

Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
preparation for users that need to compile when CONFIG_PCI_MSI is
disabled.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---

checkpatch.pl warns about the usage of -ENOSYS but it does appear
to be the custom.

 include/linux/pci.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/pci.h b/include/linux/pci.h
index adffd65e84b4..448482d1c4fe 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1621,6 +1621,19 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
 					      flags, NULL);
 }
 
+static inline struct msi_map
+pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
+		      const struct irq_affinity_desc *affdesc)
+{
+	struct msi_map map = { .index = -ENOSYS };
+
+	return map;
+}
+
+static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
+{
+}
+
 static inline void pci_free_irq_vectors(struct pci_dev *dev)
 {
 }
-- 
2.34.1

RE: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Tian, Kevin]

> From: Chatre, Reinette <reinette.chatre@intel.com>
> Sent: Friday, February 10, 2023 5:49 AM
> 
> pci_msix_alloc_irq_at() and pci_msix_free_irq() are not
> declared when CONFIG_PCI_MSI is disabled.
> 
> Users of these two calls do not yet exist but when users
> do appear (shown below is an attempt to use the new API
> in vfio-pci) the following errors will be encountered when
> compiling with CONFIG_PCI_MSI disabled:
> drivers/vfio/pci/vfio_pci_intrs.c:461:4: error: implicit declaration of\
>         function 'pci_msix_free_irq' is invalid in C99\
>         [-Werror,-Wimplicit-function-declaration]
>                            pci_msix_free_irq(pdev, msix_map);
>                            ^
>    drivers/vfio/pci/vfio_pci_intrs.c:461:4: note: did you mean
> 'pci_ims_free_irq'?
>    include/linux/pci.h:2516:6: note: 'pci_ims_free_irq' declared here
>    void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
>         ^
> drivers/vfio/pci/vfio_pci_intrs.c:511:15: error: implicit declaration of\
>         function 'pci_msix_alloc_irq_at' is invalid in C99\
>         [-Werror,-Wimplicit-function-declaration]
>                    msix_map = pci_msix_alloc_irq_at(pdev, vector, NULL);
>                                       ^
>    drivers/vfio/pci/vfio_pci_intrs.c:511:15: note: did you mean
> 'pci_ims_alloc_irq'?
>    include/linux/pci.h:2514:16: note: 'pci_ims_alloc_irq' declared here
>    struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev,\
>                                     union msi_instance_cookie *icookie,
> 
> Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
> preparation for users that need to compile when CONFIG_PCI_MSI is
> disabled.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[ALOK TIWARI]

shall we need to define this function under -> #ifndef CONFIG_PCI_MSI

#ifndef CONFIG_PCI_MSI

+static inline struct msi_map
+pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
+		      const struct irq_affinity_desc *affdesc)
+{
+	struct msi_map map = { .index = -ENOSYS };
+
+	return map;
+}
+
+static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
+{
+}
+#endif

Thanks,

Alok

On 2/10/2023 3:19 AM, Reinette Chatre wrote:
> pci_msix_alloc_irq_at() and pci_msix_free_irq() are not
> declared when CONFIG_PCI_MSI is disabled.
>
> Users of these two calls do not yet exist but when users
> do appear (shown below is an attempt to use the new API
> in vfio-pci) the following errors will be encountered when
> compiling with CONFIG_PCI_MSI disabled:
> drivers/vfio/pci/vfio_pci_intrs.c:461:4: error: implicit declaration of\
>          function 'pci_msix_free_irq' is invalid in C99\
>          [-Werror,-Wimplicit-function-declaration]
>                             pci_msix_free_irq(pdev, msix_map);
>                             ^
>     drivers/vfio/pci/vfio_pci_intrs.c:461:4: note: did you mean 'pci_ims_free_irq'?
>     include/linux/pci.h:2516:6: note: 'pci_ims_free_irq' declared here
>     void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
>          ^
> drivers/vfio/pci/vfio_pci_intrs.c:511:15: error: implicit declaration of\
>          function 'pci_msix_alloc_irq_at' is invalid in C99\
>          [-Werror,-Wimplicit-function-declaration]
>                     msix_map = pci_msix_alloc_irq_at(pdev, vector, NULL);
>                                        ^
>     drivers/vfio/pci/vfio_pci_intrs.c:511:15: note: did you mean 'pci_ims_alloc_irq'?
>     include/linux/pci.h:2514:16: note: 'pci_ims_alloc_irq' declared here
>     struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev,\
>                                      union msi_instance_cookie *icookie,
>
> Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
> preparation for users that need to compile when CONFIG_PCI_MSI is
> disabled.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
> ---
>
> checkpatch.pl warns about the usage of -ENOSYS but it does appear
> to be the custom.
>
>   include/linux/pci.h | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index adffd65e84b4..448482d1c4fe 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1621,6 +1621,19 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
>   					      flags, NULL);
>   }
>   
> +static inline struct msi_map
> +pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
> +		      const struct irq_affinity_desc *affdesc)
> +{
> +	struct msi_map map = { .index = -ENOSYS };
> +
> +	return map;
> +}
> +
> +static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
> +{
> +}
> +
>   static inline void pci_free_irq_vectors(struct pci_dev *dev)
>   {
>   }

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Reinette Chatre]

Hi Alok,

On 2/10/2023 12:45 PM, ALOK TIWARI wrote:
> shall we need to define this function under -> #ifndef CONFIG_PCI_MSI
> 
> #ifndef CONFIG_PCI_MSI
> 
> +static inline struct msi_map
> +pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
> +              const struct irq_affinity_desc *affdesc)
> +{
> +    struct msi_map map = { .index = -ENOSYS };
> +
> +    return map;
> +}
> +
> +static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
> +{
> +}
> +#endif

No need. include/linux/pci.h already has those definitions.

include/linux/pci.h already has:

#ifdef CONFIG_PCI_MSI

...

#else

... 
/*  new function definitions will be inserted here */
...

#endif


Reinette

Re: [External] : Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[ALOK TIWARI]

if, new function going to part of #else case . that is absolutely fine.

but that is not present in given PATCH.

Thanks,

Alok

On 2/11/2023 2:42 AM, Reinette Chatre wrote:
> Hi Alok,
>
> On 2/10/2023 12:45 PM, ALOK TIWARI wrote:
>> shall we need to define this function under -> #ifndef CONFIG_PCI_MSI
>>
>> #ifndef CONFIG_PCI_MSI
>>
>> +static inline struct msi_map
>> +pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
>> +              const struct irq_affinity_desc *affdesc)
>> +{
>> +    struct msi_map map = { .index = -ENOSYS };
>> +
>> +    return map;
>> +}
>> +
>> +static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
>> +{
>> +}
>> +#endif
> No need. include/linux/pci.h already has those definitions.
>
> include/linux/pci.h already has:
>
> #ifdef CONFIG_PCI_MSI
>
> ...
>
> #else
>
> ...
> /*  new function definitions will be inserted here */
> ...
>
> #endif
>
>
> Reinette

Re: [External] : Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Thomas Gleixner]

Alok!

On Sat, Feb 11 2023 at 10:35, ALOK TIWARI wrote:

Please do not top-post and trim your replies.

  https://people.kernel.org/tglx/notes-about-netiquette

> if, new function going to part of #else case . that is absolutely fine.
> but that is not present in given PATCH.

Care to apply the patch and look where the stub functions are placed
instead of making uninformed claims?

Thanks,

        tglx

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Bjorn Helgaas]

On Thu, Feb 09, 2023 at 01:49:00PM -0800, Reinette Chatre wrote:
> pci_msix_alloc_irq_at() and pci_msix_free_irq() are not
> declared when CONFIG_PCI_MSI is disabled.
> 
> Users of these two calls do not yet exist but when users
> do appear (shown below is an attempt to use the new API
> in vfio-pci) the following errors will be encountered when
> compiling with CONFIG_PCI_MSI disabled:
> drivers/vfio/pci/vfio_pci_intrs.c:461:4: error: implicit declaration of\
>         function 'pci_msix_free_irq' is invalid in C99\
>         [-Werror,-Wimplicit-function-declaration]
>                            pci_msix_free_irq(pdev, msix_map);
>                            ^
>    drivers/vfio/pci/vfio_pci_intrs.c:461:4: note: did you mean 'pci_ims_free_irq'?
>    include/linux/pci.h:2516:6: note: 'pci_ims_free_irq' declared here
>    void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
>         ^
> drivers/vfio/pci/vfio_pci_intrs.c:511:15: error: implicit declaration of\
>         function 'pci_msix_alloc_irq_at' is invalid in C99\
>         [-Werror,-Wimplicit-function-declaration]
>                    msix_map = pci_msix_alloc_irq_at(pdev, vector, NULL);
>                                       ^
>    drivers/vfio/pci/vfio_pci_intrs.c:511:15: note: did you mean 'pci_ims_alloc_irq'?
>    include/linux/pci.h:2514:16: note: 'pci_ims_alloc_irq' declared here
>    struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev,\
>                                     union msi_instance_cookie *icookie,
> 
> Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
> preparation for users that need to compile when CONFIG_PCI_MSI is
> disabled.

I think this should have a "Fixes:" tag to connect it with the commit
that added pci_msix_alloc_irq_at() and pci_msix_free_irq().

Looks like 34026364df8e ("PCI/MSI: Provide post-enable dynamic
allocation interfaces for MSI-X").

Thomas merged 34026364df8e, so it would be best if he took the fixup
as well.

> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
> ---
> 
> checkpatch.pl warns about the usage of -ENOSYS but it does appear
> to be the custom.
> 
>  include/linux/pci.h | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index adffd65e84b4..448482d1c4fe 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1621,6 +1621,19 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
>  					      flags, NULL);
>  }
>  
> +static inline struct msi_map
> +pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
> +		      const struct irq_affinity_desc *affdesc)
> +{
> +	struct msi_map map = { .index = -ENOSYS };
> +
> +	return map;
> +}
> +
> +static inline void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map)
> +{
> +}
> +
>  static inline void pci_free_irq_vectors(struct pci_dev *dev)
>  {
>  }
> -- 
> 2.34.1
> 

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Reinette Chatre]

Hi Bjorn,

On 2/14/2023 2:24 PM, Bjorn Helgaas wrote:

> I think this should have a "Fixes:" tag to connect it with the commit
> that added pci_msix_alloc_irq_at() and pci_msix_free_irq().
> 

Thank you. I was not sure if a Fixes tag was needed since it does not
fix an existing issue but instead prevents a future issue.

> Looks like 34026364df8e ("PCI/MSI: Provide post-enable dynamic
> allocation interfaces for MSI-X").
> 

Correct.

> Thomas merged 34026364df8e, so it would be best if he took the fixup
> as well.

Thomas did pick this up in tip's irq/urgent branch. While doing so he
added the Fixes tag that you proposed and also improved the subject.

Thank you very much

Reinette

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Thomas Gleixner]

On Tue, Feb 14 2023 at 16:24, Bjorn Helgaas wrote:
>> Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
>> preparation for users that need to compile when CONFIG_PCI_MSI is
>> disabled.
>
> I think this should have a "Fixes:" tag to connect it with the commit
> that added pci_msix_alloc_irq_at() and pci_msix_free_irq().
>
> Looks like 34026364df8e ("PCI/MSI: Provide post-enable dynamic
> allocation interfaces for MSI-X").
>
> Thomas merged 34026364df8e, so it would be best if he took the fixup
> as well.

I did and miserably failed to Cc you on the notification. Sorry about that.

  https://lore.kernel.org/r/167628749774.4906.17069524905880641563.tip-bot2@tip-bot2

Thanks,

        tglx

Re: [PATCH] PCI: Fix build error when CONFIG_PCI_MSI disabled

[Bjorn Helgaas]

On Wed, Feb 15, 2023 at 12:02:17AM +0100, Thomas Gleixner wrote:
> On Tue, Feb 14 2023 at 16:24, Bjorn Helgaas wrote:
> >> Provide definitions for pci_msix_alloc_irq_at() and pci_msix_free_irq() in
> >> preparation for users that need to compile when CONFIG_PCI_MSI is
> >> disabled.
> >
> > I think this should have a "Fixes:" tag to connect it with the commit
> > that added pci_msix_alloc_irq_at() and pci_msix_free_irq().
> >
> > Looks like 34026364df8e ("PCI/MSI: Provide post-enable dynamic
> > allocation interfaces for MSI-X").
> >
> > Thomas merged 34026364df8e, so it would be best if he took the fixup
> > as well.
> 
> I did and miserably failed to Cc you on the notification. Sorry about that.
> 
>   https://lore.kernel.org/r/167628749774.4906.17069524905880641563.tip-bot2@tip-bot2

No worries, thank you!