On Fri, Mar 07, 2014 at 01:37:38AM +0100, Arnd Bergmann wrote:

On Thursday 06 March 2014, Russell King - ARM Linux wrote:

quoted

On Wed, Mar 05, 2014 at 11:49:08AM +0000, Liviu Dudau wrote:

quoted

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.

quoted

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

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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.

quoted

arch/openrisc/include/asm/io.h:#include <asm-generic/io.h>

No PCI support

quoted

arch/s390/include/asm/io.h:#include <asm-generic/io.h>

s390 supports PCI but no I/O space

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arch/score/include/asm/io.h:#include <asm-generic/io.h>

No PCI support

quoted

arch/unicore32/include/asm/io.h:#include <asm-generic/io.h>

unicore32 is broken currently, the patch fixes it.

quoted

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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