undefined reference to pci_io_base

I'm trying to understand the intended design of the inb() and outb() macros in asm-powerpc/io.h. They are causing me some grief when I set CONFIG_PCI=n:

drivers/built-in.o: undefined reference to `pci_io_base'

This is coming from drivers/char/mem.c, which is always built in, and is referencing pci_io_base through inb() and outb().

Anyway, it seems asm-powerpc/io.h has two sets of io macros, one set for iSeries, and one generic set for everything else. The problem arises because the generic macros just use the eeh macros in eeh.h, which in turn, directly use pci_io_base.

I can think of three solutions to this that work for me, but I'm not sure which, if any, would be the most proper. One would be to just have this in io.h:

  #if defined(CONFI_PCI)
  extern unsigned long pci_io_base;
  #else
  #define pci_io_base 0
  #endif

Another would be to have this in some file that is always built in, like setup-common.c:

  #if !defined(CONFI_PCI)
  unsigned long pci_io_base;
  EXPORT_SYMBOL(pci_io_base);
  #endif

A third would be to have another set of io macros in io.h that are used when CONFIG_PCI=n.

Quoted 6 lines

  #if defined(CONFI_PCI)
  extern unsigned long pci_io_base;
  #else
  #define pci_io_base 0
  #endif

This makes the most sense to me; it compiles to something nice.

I'm trying to understand the intended design of the inb() and outb() macros in asm-powerpc/io.h. They are causing me some grief when I set CONFIG_PCI=n:

drivers/built-in.o: undefined reference to `pci_io_base'

This is coming from drivers/char/mem.c, which is always built in, and is referencing pci_io_base through inb() and outb().

Quoted 4 lines · Geoff Levand

I'm trying to understand the intended design of the inb() and outb() macros in asm-powerpc/io.h. They are causing me some grief when I set CONFIG_PCI=n:

Quoted 5 lines

drivers/built-in.o: undefined reference to `pci_io_base'

This is coming from drivers/char/mem.c, which is always built in, and is referencing pci_io_base through inb() and outb().

Hmmm. inb and outb are designed for accessing PCI I/O space. I guess we could turn them into BUG() when CONFIG_PCI=n.

Quoted 6 lines · Paul Mackerras

Quoted 4 lines · Geoff Levand

I'm trying to understand the intended design of the inb() and outb() macros in asm-powerpc/io.h. They are causing me some grief when I set CONFIG_PCI=n:

Quoted 8 lines

Quoted 5 lines

drivers/built-in.o: undefined reference to `pci_io_base'

This is coming from drivers/char/mem.c, which is always built in, and is referencing pci_io_base through inb() and outb().

Hmmm. inb and outb are designed for accessing PCI I/O space. I guess we could turn them into BUG() when CONFIG_PCI=n.

I just looked at drivers/char/mem.c and the code in question is surrounded by

#if defined(CONFIG_ISA) || !defined(__mc68000__)

which seems just plain wrong.

It should probably be changed to

#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__)

This code surrounds fileops to enale fileio on /dev/port which maps to inb/outb.

Do we want to enable /dev/port for pci space ??

I found the same, but was thinking

#if defined(CONFIG_ISA) && !defined(__mc68000__)

So it is only built when CONFIG_ISA=y. Is there any reason to always have it whit PCI?

Paul, can I send you that fix, or should I send it to someone else?

Quoted 6 lines · Geoff Levand

I found the same, but was thinking

#if defined(CONFIG_ISA) && !defined(__mc68000__)

So it is only built when CONFIG_ISA=y. Is there any reason to always have it whit PCI?

It's occasionally useful with PCI && !ISA. It's pretty useless with !PCI && !ISA.

Quoted 2 lines

Paul, can I send you that fix, or should I send it to someone else?

Send it to Andrew Morton.