Re: [PATCH] rust: pci: fix build failure when CONFIG_PCI_MSI is disabled

[Joel Fernandes <joelagnelf@nvidia.com>]

On 12/2/2025 4:01 PM, Danilo Krummrich wrote:
> When CONFIG_PCI_MSI is disabled pci_alloc_irq_vectors() and
> pci_free_irq_vectors() are defined as inline functions and hence require
> a Rust helper.
> 
> 	error[E0425]: cannot find function `pci_alloc_irq_vectors` in crate `bindings`
> 	    --> rust/kernel/pci/irq.rs:144:23
> 	     |
> 	 144 | ...s::pci_alloc_irq_vectors(dev.as_raw(), min_vecs, max_vecs, irq_types.as_raw())
> 	     |       ^^^^^^^^^^^^^^^^^^^^^ help: a function with a similar name exists: `pci_irq_vector`
> 	     |
> 	    ::: .../rust/bindings/bindings_helpers_generated.rs:1197:5
> 	     |
> 	1197 |     pub fn pci_irq_vector(pdev: *mut pci_dev, nvec: ffi::c_uint) -> ffi::c_int;
> 	     |     --------------------------------------------------------------------------- similarly named function `pci_irq_vector` defined here
> 
> 	error[E0425]: cannot find function `pci_free_irq_vectors` in crate `bindings`
> 	    --> rust/kernel/pci/irq.rs:170:28
> 	     |
> 	 170 |         unsafe { bindings::pci_free_irq_vectors(self.dev.as_raw()) };
> 	     |                            ^^^^^^^^^^^^^^^^^^^^ help: a function with a similar name exists: `pci_irq_vector`
> 	     |
> 	    ::: .../rust/bindings/bindings_helpers_generated.rs:1197:5
> 	     |
> 	1197 |     pub fn pci_irq_vector(pdev: *mut pci_dev, nvec: ffi::c_uint) -> ffi::c_int;
> 	     |     --------------------------------------------------------------------------- similarly named function `pci_irq_vector` defined here
> 
> 	error: aborting due to 2 previous errors
> 
> Fix this by adding the corresponding helpers.
> 

Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>

thanks,

 - Joel


> Fixes: 340ccc973544 ("rust: pci: Allocate and manage PCI interrupt vectors")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202512012238.YgVvRRUx-lkp@intel.com/
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
>  rust/helpers/pci.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/rust/helpers/pci.c b/rust/helpers/pci.c
> index fb814572b236..bf8173979c5e 100644
> --- a/rust/helpers/pci.c
> +++ b/rust/helpers/pci.c
> @@ -23,9 +23,21 @@ bool rust_helper_dev_is_pci(const struct device *dev)
>  }
>  
>  #ifndef CONFIG_PCI_MSI
> +int rust_helper_pci_alloc_irq_vectors(struct pci_dev *dev,
> +				      unsigned int min_vecs,
> +				      unsigned int max_vecs,
> +				      unsigned int flags)
> +{
> +	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
> +}
> +
> +void rust_helper_pci_free_irq_vectors(struct pci_dev *dev)
> +{
> +	pci_free_irq_vectors(dev);
> +}
> +
>  int rust_helper_pci_irq_vector(struct pci_dev *pdev, unsigned int nvec)
>  {
>  	return pci_irq_vector(pdev, nvec);
>  }
> -
>  #endif
> 
> base-commit: d3666c1f8a31b7ff6805effcfedfac22454c6517