On Fri, Mar 07, 2014 at 01:37:38AM +0100, Arnd Bergmann wrote:
> On Thursday 06 March 2014, Russell King - ARM Linux wrote:
> > On Wed, Mar 05, 2014 at 11:49:08AM +0000, Liviu Dudau wrote:
> > > The inline version of ioport_map() that gets used when !CONFIG_GENERIC_IOMAP
> > > is wrong. It returns a mapped (i.e. virtual) address that can start from
> > > zero and completely ignores the PCI_IOBASE and IO_SPACE_LIMIT that most
> > > architectures that use !CONFIG_GENERIC_MAP define.
> >
> > What value does PCI_IOBASE and IO_SPACE_LIMIT have on other architectures
> > who make use of asm-generic/io.h ?
> >
> > $ git grep asm-generic/io.h arch/
> > arch/arc/include/asm/io.h:#include <asm-generic/io.h>
>
> PCI support hasn't been upstreamed.
>
> > arch/blackfin/include/asm/io.h:#include <asm-generic/io.h>
> > arch/metag/include/asm/io.h:#include <asm-generic/io.h>
>
> No PCI support
>
> > arch/microblaze/include/asm/io.h:/* from asm-generic/io.h */
>
> PCI_IOBASE=0, IO_SPACE_LIMIT=0xffffffff, so no change.
Seems to define _IO_BASE not PCI_IOBASE.
> > arch/openrisc/include/asm/io.h:#include <asm-generic/io.h>
>
> No PCI support
>
> > arch/s390/include/asm/io.h:#include <asm-generic/io.h>
>
> s390 supports PCI but no I/O space
>
> > arch/score/include/asm/io.h:#include <asm-generic/io.h>
>
> No PCI support
>
> > arch/unicore32/include/asm/io.h:#include <asm-generic/io.h>
>
> unicore32 is broken currently, the patch fixes it.
>
> > arch/xtensa/include/asm/io.h:#include <asm-generic/io.h>
>
> PCI_IOBASE=0, IO_SPACE_LIMIT=0xffffffff, so no change.
Doesn't appear to define PCI_IOBASE.
Maybe there's other patches required for these?
> For most of these, I assume we actually want to remove support
> for inb/outb as they don't support I/O space accesses. The other
> ones look correct to me.
Right, so:
#ifdef CONFIG_HAS_IOPORT
#ifndef CONFIG_GENERIC_IOMAP
static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
{
return (void __iomem *) port;
}
changing that to include PCI_IOBASE in there will result in a build
failure if the C compiler sees that. In other words, when HAS_IOPORT=y
and GENERIC_IOMAP=n.
HAS_IOPORT is set when HAS_IOMEM is also set and NO_IOPORT unset.
It looks to me like blackfin doesn't set NO_IOPORT nor NO_IOMEM, so
this would have HAS_IOPORT set, and from what I can see doesn't set
GENERIC_IOMAP. So, this change probably breaks blackfin.
I haven't looked deeply at the others.
--
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