[v3,1/5] x86/pci: Add a to_pci_sysdata helper

From: Christoph Hellwig <hch@lst.de>

Various helpers need the pci_sysdata just to dereference a single field
in it.  Add a little helper that returns the properly typed sysdata
pointer to require a little less boilerplate code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[jonathan.derrick: added un-const cast]
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
---
 arch/x86/include/asm/pci.h | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

On Fri, Jan 10, 2020 at 10:21:09AM -0700, Jon Derrick wrote:
> From: Christoph Hellwig <hch@lst.de>
> 
> Various helpers need the pci_sysdata just to dereference a single field
> in it.  Add a little helper that returns the properly typed sysdata
> pointer to require a little less boilerplate code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> [jonathan.derrick: added un-const cast]
> Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
> ---
>  arch/x86/include/asm/pci.h | 28 +++++++++++++---------------
>  1 file changed, 13 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
> index 90d0731..cf680c5 100644
> --- a/arch/x86/include/asm/pci.h
> +++ b/arch/x86/include/asm/pci.h
> @@ -35,12 +35,15 @@ struct pci_sysdata {
>  
>  #ifdef CONFIG_PCI
>  
> +static inline struct pci_sysdata *to_pci_sysdata(struct pci_bus *bus)
> +{
> +	return bus->sysdata;
> +}
> +
>  #ifdef CONFIG_PCI_DOMAINS
>  static inline int pci_domain_nr(struct pci_bus *bus)
>  {
> -	struct pci_sysdata *sd = bus->sysdata;
> -
> -	return sd->domain;
> +	return to_pci_sysdata(bus)->domain;
>  }
>  
>  static inline int pci_proc_domain(struct pci_bus *bus)
> @@ -52,23 +55,20 @@ static inline int pci_proc_domain(struct pci_bus *bus)
>  #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
>  static inline void *_pci_root_bus_fwnode(struct pci_bus *bus)
>  {
> -	struct pci_sysdata *sd = bus->sysdata;
> -
> -	return sd->fwnode;
> +	return to_pci_sysdata(bus)->fwnode;
>  }
>  
>  #define pci_root_bus_fwnode	_pci_root_bus_fwnode
>  #endif
>  
> +#if IS_ENABLED(CONFIG_VMD)
>  static inline bool is_vmd(struct pci_bus *bus)
>  {
> -#if IS_ENABLED(CONFIG_VMD)
> -	struct pci_sysdata *sd = bus->sysdata;
> -
> -	return sd->vmd_domain;
> +	return to_pci_sysdata(bus)->vmd_domain;
> +}
>  #else
> -	return false;
> -#endif
> +#define is_vmd(bus)		false
> +#endif /* CONFIG_VMD */
>  }

I think this patch leaves this stray close brace here (it's cleaned up
in the next patch, but looks like it will break bisection).

Also, when you fix this, can you update the subject lines?  There's a
mix of "x86/PCI" and "x86/pci" (the convention per "git log --oneline"
is "x86/PCI").

>  /* Can be used to override the logic in pci_scan_bus for skipping
> @@ -124,9 +124,7 @@ static inline void early_quirks(void) { }
>  /* Returns the node based on pci bus */
>  static inline int __pcibus_to_node(const struct pci_bus *bus)
>  {
> -	const struct pci_sysdata *sd = bus->sysdata;
> -
> -	return sd->node;
> +	return to_pci_sysdata((struct pci_bus *) bus)->node;
>  }
>  
>  static inline const struct cpumask *
> -- 
> 1.8.3.1
>

On Fri, Jan 10, 2020 at 10:21:09AM -0700, Jon Derrick wrote:
> From: Christoph Hellwig <hch@lst.de>
> 
> Various helpers need the pci_sysdata just to dereference a single field
> in it.  Add a little helper that returns the properly typed sysdata
> pointer to require a little less boilerplate code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> [jonathan.derrick: added un-const cast]

> +	return to_pci_sysdata((struct pci_bus *) bus)->node;

Instead of this case I think we'd be better off marking the bus
argument to to_pci_sysdata const.