Re: [PATCH 5/6] ARM: convert PCI defines to variables

[Arnd Bergmann <arnd@arndb.de>]

Hi Rob,

On Wednesday 29 June 2011 18:46:58 Rob Herring wrote:
> From: Rob Herring <rob.herring@calxeda.com>
> 
> Convert PCIBIOS_MIN_IO and PCIBIOS_MIN_MEM to variables to allow
> multi-platform builds. This also removes the requirement for a platform to
> have a mach/hardware.h.

Good idea.

> @@ -24,6 +23,12 @@ EXPORT_SYMBOL(ioport_unmap);
>  #endif
>  
>  #ifdef CONFIG_PCI
> +unsigned long pcibios_min_io;
> +EXPORT_SYMBOL(pcibios_min_io);
> +
> +unsigned long pcibios_min_mem;
> +EXPORT_SYMBOL(pcibios_min_mem);
> +

How about setting these to sensible defaults that will work on
most platforms, so that the majority won't have to set them at
all?

Basically, the defaults should clearly be 

unsigned long pcibios_min_io  = 0x1000;
unsigned long pcibios_min_mem = 0x01000000;

This just gets us out of the ISA bus range, so an ISA card behind
a bridge can use all cards correctly. Most of the ones that
currently set both to zero can probably just use those defaults
as well, but some architectures have multiple buses or don't start
the memory range at zero, so they might need higher values.

> --- a/arch/arm/mach-versatile/include/mach/hardware.h
> +++ b/arch/arm/mach-versatile/include/mach/hardware.h
> @@ -30,10 +30,6 @@
>  #define VERSATILE_PCI_VIRT_BASE		(void __iomem *)0xe8000000ul
>  #define VERSATILE_PCI_CFG_VIRT_BASE	(void __iomem *)0xe9000000ul
>  
> -/* CIK guesswork */
> -#define PCIBIOS_MIN_IO			0x44000000
> -#define PCIBIOS_MIN_MEM			0x50000000
> -
>  /* macro to get at IO space when running virtually */
>  #define IO_ADDRESS(x)		(((x) & 0x0fffffff) + (((x) >> 4) & 0x0f000000) + 0xf0000000)
>  

This PCIBIOS_MIN_IO setting is wrong, and PIO doesn't work on versatile
because of this. I have an older patch series that I should dig out again
to fix them and make versatile use the defaults. Don't worry about this
one.

	Arnd