Re: [PATCH v2 01/56] PCI: Convert to_pci_dev() into an inline function

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Apr 30, 2026 at 11:19:31AM -0700, Bart Van Assche wrote:
> Clang's context analysis checker performs alias analysis on expressions
> passed to annotations like __acquires(). Clang's alias analysis does not
> support container_of(). Convert to_pci_dev() from a macro into an inline
> function such that Clang recognizes multiple to_pci_dev() expressions as
> identical if the 'dev' argument is the same.
> 
> It is on purpose that to_pci_dev() accepts a const pointer and returns a
> pointer that is not const. Any other choice, e.g. accepting a non-const
> pointer or returning a const pointer, triggers compiler errors.
> 
> While _Generic() could be used to support const and non-const struct
> device pointers in a more elegant way, Clang's alias analysis does not
> support _Generic().
> 
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  include/linux/pci.h | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 2c4454583c11..f5989267a537 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -606,7 +606,10 @@ static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
>  
>  struct pci_dev *pci_alloc_dev(struct pci_bus *bus);
>  
> -#define	to_pci_dev(n) container_of(n, struct pci_dev, dev)
> +static inline struct pci_dev *to_pci_dev(const struct device *dev)
> +{
> +	return container_of(dev, struct pci_dev, dev);
> +}
>  #define for_each_pci_dev(d) while ((d = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, d)) != NULL)
>  #define for_each_pci_dev_reverse(d) \
>  	while ((d = pci_get_device_reverse(PCI_ANY_ID, PCI_ANY_ID, d)) != NULL)