From mboxrd@z Thu Jan  1 00:00:00 1970
From: arnd@arndb.de (Arnd Bergmann)
Date: Tue, 24 Jul 2012 12:43:55 +0000
Subject: [GIT PULL] io.h clean-up for PCI
In-Reply-To: <500E962D.2080104@gmail.com>
References: <50049285.1060100@gmail.com> <201207191412.00540.arnd@arndb.de>
 <500E962D.2080104@gmail.com>
Message-ID: <201207241243.55640.arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tuesday 24 July 2012, Rob Herring wrote:
> > --- a/arch/arm/mach-iop13xx/include/mach/iop13xx.h
> > +++ b/arch/arm/mach-iop13xx/include/mach/iop13xx.h
> > @@ -95,7 +95,6 @@ extern unsigned long get_iop_tick_rate(void);
> >  /* PCI-E ranges */
> >  #define IOP13XX_PCIE_LOWER_IO_PA              0xfffd0000UL
> >  #define IOP13XX_PCIE_LOWER_IO_BA              0x0UL  /* OIOTVR */
> > -#define IOP13XX_PCIE_LOWER_IO_BA              0x10000UL
> 
> This means we have PCIE and PCIX buses both using i/o bus addresses
> starting at 0x0. We can't have that, right?
> 
> The requested resource won't match either as the resource start address
> is bus_nr * 64K.

Well, this is the number that gets written into the outbound
translation window register, which has to be zero AFAICT.

The PCI device you plug into the bus will always see its io
ports as being between zero and 65536 -- the part that
stays at 0x10000UL is the offset address that we use in Linux
to give it a unique address in the virtual address space
window we use to cover all the io port ranges.

The io_offset still gets set to 0x10000, so this number always
gets added and subtracted when converting between Linux port
numbers and bus-specific port numbers.

	Arnd