[PATCH] ARM: Add support for PCI domains

[Simon Horman]

On Tue, Mar 30, 2010 at 11:14:42PM +0400, Anton Vorontsov wrote:
> This patch adds support for PCI domains on ARM platforms.
> 
> Also, protect asm/mach/pci.h from multiple inclustions, otherwise
> build fails because of pci_domain_nr() and pci_proc_domain()
> redefinitions.
> 
> p.s.
> 
> Not sure if it makes sense to do PCI domains support optional.
> 
> With PCI domains:
>    text    data     bss     dec     hex filename
> 3407890  139808  102016 3649714  37b0b2 vmlinux
> 
> Without PCI domains:
>    text    data     bss     dec     hex filename
> 3407730  139808  102016 3649554  37b012 vmlinux
> 
> I.e. 160 bytes saved. Is it worth the amount of ifdefs? We can
> just make it always enabled (and it seems other architectures
> always enable it).
> 
> pp.s.
> I found that Richard Liu seem to have posted a similar patch[1],
> but it wasn't propely signed off... Heh.
> 
> [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2009-December/006244.html

Seeing as arm is targeted as embedded, I suspect that saving every last byte
is a good idea where possible.

> Signed-off-by: Anton Vorontsov <avorontsov at mvista.com>

Reviewed-by: Simon Horman <horms at verge.net.au>

> ---
>  arch/arm/Kconfig                |    4 ++++
>  arch/arm/include/asm/mach/pci.h |   11 +++++++++++
>  arch/arm/include/asm/pci.h      |   15 +++++++++++++++
>  arch/arm/kernel/bios32.c        |    3 +++
>  4 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index d779e25..2a1bc52 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1075,6 +1075,10 @@ config PCI
>  	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
>  	  VESA. If you have PCI, say Y, otherwise N.
>  
> +config PCI_DOMAINS
> +	bool
> +	depends on PCI
> +
>  config PCI_SYSCALL
>  	def_bool PCI
>  
> diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
> index a38bdc7..52f0da1 100644
> --- a/arch/arm/include/asm/mach/pci.h
> +++ b/arch/arm/include/asm/mach/pci.h
> @@ -8,10 +8,16 @@
>   * published by the Free Software Foundation.
>   */
>  
> +#ifndef __ASM_MACH_PCI_H
> +#define __ASM_MACH_PCI_H
> +
>  struct pci_sys_data;
>  struct pci_bus;
>  
>  struct hw_pci {
> +#ifdef CONFIG_PCI_DOMAINS
> +	int		domain;
> +#endif
>  	struct list_head buses;
>  	int		nr_controllers;
>  	int		(*setup)(int nr, struct pci_sys_data *);
> @@ -26,6 +32,9 @@ struct hw_pci {
>   * Per-controller structure
>   */
>  struct pci_sys_data {
> +#ifdef CONFIG_PCI_DOMAINS
> +	int		domain;
> +#endif
>  	struct list_head node;
>  	int		busnr;		/* primary bus number			*/
>  	u64		mem_offset;	/* bus->cpu memory mapping offset	*/
> @@ -70,3 +79,5 @@ extern int pci_v3_setup(int nr, struct pci_sys_data *);
>  extern struct pci_bus *pci_v3_scan_bus(int nr, struct pci_sys_data *);
>  extern void pci_v3_preinit(void);
>  extern void pci_v3_postinit(void);
> +
> +#endif /* __ASM_MACH_PCI_H */
> diff --git a/arch/arm/include/asm/pci.h b/arch/arm/include/asm/pci.h
> index 4798011..92e2a83 100644
> --- a/arch/arm/include/asm/pci.h
> +++ b/arch/arm/include/asm/pci.h
> @@ -4,8 +4,23 @@
>  #ifdef __KERNEL__
>  #include <asm-generic/pci-dma-compat.h>
>  
> +#include <asm/mach/pci.h> /* for pci_sys_data */
>  #include <mach/hardware.h> /* for PCIBIOS_MIN_* */
>  
> +#ifdef CONFIG_PCI_DOMAINS
> +static inline int pci_domain_nr(struct pci_bus *bus)
> +{
> +	struct pci_sys_data *root = bus->sysdata;
> +
> +	return root->domain;
> +}
> +
> +static inline int pci_proc_domain(struct pci_bus *bus)
> +{
> +	return pci_domain_nr(bus);
> +}
> +#endif /* CONFIG_PCI_DOMAINS */
> +
>  #ifdef CONFIG_PCI_HOST_ITE8152
>  /* ITE bridge requires setting latency timer to avoid early bus access
>     termination by PIC bus mater devices
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index bd397e0..c6273a3 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -527,6 +527,9 @@ static void __init pcibios_init_hw(struct hw_pci *hw)
>  		if (!sys)
>  			panic("PCI: unable to allocate sys data!");
>  
> +#ifdef CONFIG_PCI_DOMAINS
> +		sys->domain  = hw->domain;
> +#endif
>  		sys->hw      = hw;
>  		sys->busnr   = busnr;
>  		sys->swizzle = hw->swizzle;
> -- 
> 1.7.0.3
> 
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